Merge pull request #945 from telemt/bump/3.5.12

Bump -> 3.5.12

Cargo.lock

@@ -2780,7 +2780,7 @@ dependencies = [
 
 [[package]]
 name = "telemt"
-version = "3.5.9"
+version = "3.5.12"
 dependencies = [
  "aes",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "telemt"
-version = "3.5.9"
+version = "3.5.12"
 edition = "2024"
 rust-version = "1.88"
 

docs/WEB/WEB_PROXY.de.md

@@ -2,7 +2,7 @@
 
 [English](WEB_PROXY.en.md) | [Русский](WEB_PROXY.ru.md) | [Deutsch](WEB_PROXY.de.md)
 
-Der WEB-Modus transportiert gewöhnliche MTProxy-Streams über begrenzte HTTPS- oder WebSocket-Carrier, die mit dem Proxy-Typ `WEB` von Telegram Desktop kompatibel sind. Telemt terminiert TLS nicht selbst: NGINX oder HAProxy verwaltet das öffentliche Zertifikat und leitet unverschlüsseltes HTTP/1.1 an einen privaten Telemt-Listener weiter.
+Der WEB-Modus transportiert gewöhnliche MTProxy-Streams über begrenzte HTTPS- oder WebSocket-Carrier, die mit dem Proxy-Typ `WEB` von Telegram Desktop kompatibel sind. Telemt terminiert TLS nicht selbst: NGINX, HAProxy oder Caddy verwaltet das öffentliche Zertifikat und leitet unverschlüsseltes HTTP/1.1 an einen privaten Telemt-Listener weiter.
 
 > [!IMPORTANT]
 >
@@ -14,7 +14,7 @@ Der WEB-Modus transportiert gewöhnliche MTProxy-Streams über begrenzte HTTPS-
 Telegram Desktop
     | HTTPS oder WSS :443
     v
-NGINX oder HAProxy (TLS-Terminierung, kanonischer Host und eine X-Forwarded-For-Adresse)
+NGINX, HAProxy oder Caddy (TLS-Terminierung, kanonischer Host und eine X-Forwarded-For-Adresse)
     | unverschlüsseltes HTTP/1.1 in einem privaten Netz
     v
 Telemt-WEB-Listener
@@ -270,6 +270,66 @@ backend telemt_web
 
 Im Frontend oder im Abschnitt `defaults` muss für das standardmäßige WebSocket-Liveness-Intervall auch `timeout client 65s` oder länger gesetzt sein. Für `https-lanes` muss das öffentliche HAProxy-ALPN `h2`, für WebSocket-Upgrade außerdem `http/1.1` enthalten. Bewahren Sie `Connection`, `Upgrade` und `Sec-WebSocket-*` unverändert; Pfad, Raw Query, Body sowie die Carrier-Header `Authorization`, `Content-Type`, `X-Up-Seq`, `X-Down-Cursor` und `X-Lane-ID` dürfen nicht umgeschrieben werden. Fügen Sie für Prefix-only-Cohosting `acl telemt_web_path path_beg /telegram/web/` hinzu und verlangen Sie in `use_backend` sowohl Host- als auch Pfad-ACL; entfernen Sie das Präfix nicht.
 
+## TLS-Terminierung mit Caddy
+
+```caddyfile
+{
+	servers {
+		protocols h1 h2
+	}
+}
+
+proxy.example.com {
+	reverse_proxy 127.0.0.1:18080 {
+		header_up X-Forwarded-For {remote_host}
+		flush_interval -1
+		stream_close_delay 5m
+	}
+}
+```
+
+Caddy bezieht und erneuert das öffentliche Zertifikat für die Site-Adresse automatisch. Den ursprünglichen `Host` sowie die Header `Connection`, `Upgrade` und `Sec-WebSocket-*` leitet Caddy unverändert weiter, WebSocket-Upgrade wird ohne zusätzliche Direktiven proxied; fügen Sie kein `header_up Host` hinzu. Öffentliches HTTP/2 (für `https-lanes`) und HTTP/1.1 (für WebSocket-Upgrade) sind standardmäßig aktiv, der private Abschnitt Caddy → Telemt bleibt HTTP/1.1. Die globale Option `protocols h1 h2` hält HTTP/3 aus dem WEB-Pfad heraus, weil der WEB-Vertrag nur HTTP/1.1 und HTTP/2 abdeckt. Sie gilt für alle Sites dieses Caddy-Servers.
+
+`header_up X-Forwarded-For {remote_host}` überschreibt den Header mit genau einer Adresse. Ohne diese Zeile hängt Caddy bei Peers aus `trusted_proxies` an einen eingehenden `X-Forwarded-For` an, Telemt akzeptiert jedoch nur eine parsebare IP-Adresse. Steht Caddy selbst hinter einem L4-Balancer mit `listener_wrappers { proxy_protocol }`, ist `{remote_host}` die Client-Adresse aus dem PROXY-Header. `flush_interval -1` deaktiviert die Antwortpufferung für Long Polls und Downlinks. Request-Bodies streamt Caddy standardmäßig; aktivieren Sie kein `request_buffers`.
+
+`reverse_proxy` hat in Caddy standardmäßig weder Read-/Write-Timeouts noch ein Body-Limit, daher passieren der 25-Sekunden-Long-Poll und das WebSocket-Liveness-Intervall unverändert. Sind serverweite `timeouts` oder `request_body max_size` gesetzt, müssen sie über 65 Sekunden bzw. mindestens bei `web.limits.max_body_bytes` liegen. Mit einem einzigen Upstream wiederholt Caddy fehlgeschlagene Anfragen nicht; fügen Sie weder `lb_retries` noch `lb_try_duration` hinzu. Bei einem Konfigurations-Reload schließt Caddy upgegradete Verbindungen standardmäßig sofort. `stream_close_delay` hält bestehende WebSocket-Lanes nach einem Reload für die angegebene Zeit offen.
+
+Leiten Sie für Prefix-only-Cohosting mit `base_path = "telegram/web"` den Teilbaum über `handle` und nicht über `handle_path` weiter, denn `handle_path` entfernt das Präfix:
+
+```caddyfile
+proxy.example.com {
+	handle /telegram/web/* {
+		reverse_proxy 127.0.0.1:18080 {
+			header_up X-Forwarded-For {remote_host}
+			flush_interval -1
+			stream_close_delay 5m
+		}
+	}
+
+	handle {
+		# gewöhnliche Site
+	}
+}
+```
+
+Das Routing von Caddy fügt keine Weiterleitung mit angehängtem Slash hinzu: `/telegram/web` ohne abschließenden Slash landet im Handler der gewöhnlichen Site. Stellen Sie sicher, dass auch dieser Handler nicht weiterleitet; `file_server` leitet etwa eine Verzeichnisanfrage auf die Variante mit Slash um.
+
+Ohne `log`-Direktive schreibt Caddy kein Access-Log. Wird eines benötigt, schwärzen Sie Bridge-Capability und Bearer-Credentials:
+
+```caddyfile
+log {
+	format filter {
+		request>uri query {
+			replace bridge REDACTED
+		}
+		request>headers>Authorization delete
+		request>headers>Sec-Websocket-Protocol delete
+	}
+}
+```
+
+Tragen Sie in `web_trusted_proxy_cidrs` die Adresse ein, von der aus Caddy Telemt erreicht, für die obige Konfiguration also `["127.0.0.1/32"]`.
+
 ## Lebenszyklus und Reload-Verhalten
 
 | Konfiguration | Runtime-Verhalten |
@@ -431,7 +491,7 @@ Der vollständige Vertrag für Requests, Revisionen, Fehler und alle Benutzer-En
 | `/telegram/web` leitet auf `/telegram/web/` um | Fügen Sie für den Pfad ohne Schrägstrich einen exakten Non-WEB-Handler hinzu. Nur der mit Schrägstrich abgeschlossene konfigurierte Teilbaum gehört zum WEB-Vertrag von Telemt. |
 | Ein konkurrierender `https-lanes`-Downlink erreicht den Decoy mit `404` | Prüfen Sie, dass er mit `X-Down-Cursor: 0` beginnt, bewahren Sie `X-Lane-ID` und setzen Sie `lane_open_wait_secs` über den beobachteten Abstand zwischen Downlink und `OPEN`. Fortgeschrittene Cursor fehlender Lanes schlagen absichtlich fail-closed fehl. |
 | Auto-Negotiation wechselt weiter, nachdem Daten bereits akzeptiert wurden | Das ist ungültig. Prüfen Sie das authentifizierte `X-Carrier-State`-Replay und das Carrier-Commit-Lifecycle-Ereignis; `committed` oder `healthy` ist terminal und erfordert eine neue Sitzung. |
-| Long Polls werden nach einem festen Intervall getrennt | Setzen Sie Client-, Server-, Sende- und Lese-Timeouts von NGINX/HAProxy über `web.timeouts.long_poll_secs`. |
+| Long Polls werden nach einem festen Intervall getrennt | Setzen Sie Client-, Server-, Sende- und Lese-Timeouts von NGINX/HAProxy/Caddy über `web.timeouts.long_poll_secs`. |
 | WebSocket-Upgrade erreicht statt `101` den Decoy | Bewahren Sie HTTP/1.1 `Connection: Upgrade`, `Upgrade: websocket`, das einzelne exakte `Sec-WebSocket-Protocol` und den kanonischen bodylosen Request an der konfigurierten Basis plus `/api/v1/ws`. Prüfen Sie außerdem Carrier-/Session-Kompatibilität und die Prozess-Verbindungsreserve. |
 | Ein `websocket-lanes`-Stream wurde geschlossen, Geschwister bleiben aber verbunden | Dies ist die beabsichtigte Fehlergrenze. Prüfen Sie die Message-/Frame-Zeilen dieser Lane in `/web-status`; fehlerhafte oder lane-fremde Frames, Write-Timeouts und Backend-Close schließen nur die betroffene Lane. |
 | `/web-status` ist leer | Prüfen Sie, dass `[web.debug].enabled = true` gesetzt ist, wenden Sie die Konfiguration an, wählen Sie ein Fenster innerhalb von `max_window_secs` und erzeugen Sie nach der Policy-Änderung neuen WEB-Datenverkehr. |

docs/WEB/WEB_PROXY.en.md

@@ -2,7 +2,7 @@
 
 [English](WEB_PROXY.en.md) | [Русский](WEB_PROXY.ru.md) | [Deutsch](WEB_PROXY.de.md)
 
-WEB mode carries ordinary MTProxy streams through bounded HTTPS or WebSocket carriers compatible with Telegram Desktop's `WEB` proxy type. Telemt does not terminate TLS: NGINX or HAProxy owns the public certificate and forwards plain HTTP/1.1 to a private Telemt listener.
+WEB mode carries ordinary MTProxy streams through bounded HTTPS or WebSocket carriers compatible with Telegram Desktop's `WEB` proxy type. Telemt does not terminate TLS: NGINX, HAProxy, or Caddy owns the public certificate and forwards plain HTTP/1.1 to a private Telemt listener.
 
 > [!IMPORTANT]
 >
@@ -14,7 +14,7 @@ WEB mode carries ordinary MTProxy streams through bounded HTTPS or WebSocket car
 Telegram Desktop
     | HTTPS or WSS :443
     v
-NGINX or HAProxy (TLS termination, canonical Host and one X-Forwarded-For address)
+NGINX, HAProxy, or Caddy (TLS termination, canonical Host and one X-Forwarded-For address)
     | plain HTTP/1.1 on a private network
     v
 Telemt WEB listener
@@ -270,6 +270,66 @@ backend telemt_web
 
 The frontend or `defaults` section must also set `timeout client 65s` or longer for the default WebSocket liveness interval. HAProxy's public ALPN must include `h2` for `https-lanes` and `http/1.1` for WebSocket Upgrade. Preserve `Connection`, `Upgrade`, and `Sec-WebSocket-*`; do not rewrite the path, raw query, body, or the `Authorization`, `Content-Type`, `X-Up-Seq`, `X-Down-Cursor`, and `X-Lane-ID` carrier headers. For prefix-only cohosting, add `acl telemt_web_path path_beg /telegram/web/` and require both the host and path ACLs on `use_backend`; do not remove the prefix.
 
+## Caddy TLS termination
+
+```caddyfile
+{
+	servers {
+		protocols h1 h2
+	}
+}
+
+proxy.example.com {
+	reverse_proxy 127.0.0.1:18080 {
+		header_up X-Forwarded-For {remote_host}
+		flush_interval -1
+		stream_close_delay 5m
+	}
+}
+```
+
+Caddy obtains and renews the public certificate for the site address automatically. It forwards the original `Host` and the `Connection`, `Upgrade`, and `Sec-WebSocket-*` headers unchanged and proxies WebSocket Upgrade without extra directives; do not add `header_up Host`. Public HTTP/2 (needed for `https-lanes`) and HTTP/1.1 (needed for WebSocket Upgrade) are both enabled by default, while the private Caddy-to-Telemt hop stays HTTP/1.1. The global `protocols h1 h2` option keeps HTTP/3 out of the WEB path, because the WEB contract only covers HTTP/1.1 and HTTP/2. It applies to every site of that Caddy server.
+
+`header_up X-Forwarded-For {remote_host}` overwrites the header with one address. Without it, Caddy appends to an incoming `X-Forwarded-For` from peers listed in `trusted_proxies`, and Telemt accepts only one parseable IP address. If Caddy itself sits behind an L4 balancer with `listener_wrappers { proxy_protocol }`, `{remote_host}` is the client address taken from the PROXY header. `flush_interval -1` disables response buffering for long polls and downlinks. Request bodies are streamed by default; do not enable `request_buffers`.
+
+Caddy's `reverse_proxy` has no read or write timeout and no request-body limit by default, so the 25-second long poll and the WebSocket liveness interval pass unchanged. If server-wide `timeouts` or `request_body max_size` are configured, keep them above 65 seconds and at least `web.limits.max_body_bytes` respectively. With a single upstream Caddy does not retry failed requests; do not add `lb_retries` or `lb_try_duration`. On a configuration reload Caddy closes upgraded connections immediately by default. `stream_close_delay` keeps established WebSocket lanes open across a reload for the given time.
+
+For prefix-only cohosting with `base_path = "telegram/web"`, route the subtree with `handle`, not `handle_path`, because `handle_path` strips the prefix:
+
+```caddyfile
+proxy.example.com {
+	handle /telegram/web/* {
+		reverse_proxy 127.0.0.1:18080 {
+			header_up X-Forwarded-For {remote_host}
+			flush_interval -1
+			stream_close_delay 5m
+		}
+	}
+
+	handle {
+		# ordinary site
+	}
+}
+```
+
+Caddy's routing does not add a slash-appending redirect: `/telegram/web` without the trailing slash falls through to the ordinary site handler. Make sure that handler does not redirect it either; for example, `file_server` redirects a directory request to its slash-terminated form.
+
+Caddy writes no access log unless a `log` directive is present. If one is needed, redact the bridge capability and bearer credentials:
+
+```caddyfile
+log {
+	format filter {
+		request>uri query {
+			replace bridge REDACTED
+		}
+		request>headers>Authorization delete
+		request>headers>Sec-Websocket-Protocol delete
+	}
+}
+```
+
+Set `web_trusted_proxy_cidrs` to the address Caddy uses to connect to Telemt, for example `["127.0.0.1/32"]` for the configuration above.
+
 ## Lifecycle and reload behavior
 
 | Configuration | Runtime behavior |
@@ -431,7 +491,7 @@ See the complete [Control API contract](../Architecture/API/API.md) for request
 | `/telegram/web` redirects to `/telegram/web/` | Add an exact non-WEB handler for the no-slash path. Only the slash-terminated configured subtree belongs to Telemt's WEB contract. |
 | A racing `https-lanes` downlink reaches the decoy with `404` | Confirm it starts at `X-Down-Cursor: 0`, preserve `X-Lane-ID`, and set `lane_open_wait_secs` above the observed down-before-`OPEN` skew. Advanced cursors for missing lanes intentionally fail closed. |
 | Auto-negotiation advances after traffic was already accepted | This is not valid behavior. Inspect the authenticated `X-Carrier-State` replay and the carrier commit lifecycle row; a committed or healthy response is terminal and requires a new session. |
-| Long polls disconnect near a fixed interval | Raise NGINX/HAProxy client, server, send, and read timeouts above `web.timeouts.long_poll_secs`. |
+| Long polls disconnect near a fixed interval | Raise NGINX/HAProxy/Caddy client, server, send, and read timeouts above `web.timeouts.long_poll_secs`. |
 | WebSocket Upgrade reaches the decoy instead of returning `101` | Preserve HTTP/1.1 `Connection: Upgrade`, `Upgrade: websocket`, the single exact `Sec-WebSocket-Protocol`, and the canonical bodyless request at the configured base plus `/api/v1/ws`. Also check carrier/session compatibility and the process connection reserve. |
 | One `websocket-lanes` stream closes while siblings stay connected | This is the intended failure boundary. Inspect that lane's message/frame rows in `/web-status`; malformed, cross-lane, write-timeout, and backend-close paths terminate only the affected lane. |
 | `/web-status` is empty | Confirm `[web.debug].enabled = true`, apply the configuration, select a window within `max_window_secs`, and generate new WEB traffic after the policy change. |

docs/WEB/WEB_PROXY.ru.md

@@ -2,7 +2,7 @@
 
 [English](WEB_PROXY.en.md) | [Русский](WEB_PROXY.ru.md) | [Deutsch](WEB_PROXY.de.md)
 
-WEB-режим переносит обычные MTProxy-потоки через bounded HTTPS или WebSocket carriers, совместимые с типом прокси `WEB` в Telegram Desktop. Telemt не терминирует TLS: публичный сертификат обслуживает NGINX или HAProxy, который передаёт обычный HTTP/1.1 на приватный listener Telemt.
+WEB-режим переносит обычные MTProxy-потоки через bounded HTTPS или WebSocket carriers, совместимые с типом прокси `WEB` в Telegram Desktop. Telemt не терминирует TLS: публичный сертификат обслуживает NGINX, HAProxy или Caddy, который передаёт обычный HTTP/1.1 на приватный listener Telemt.
 
 > [!IMPORTANT]
 >
@@ -14,7 +14,7 @@ WEB-режим переносит обычные MTProxy-потоки через
 Telegram Desktop
     | HTTPS или WSS :443
     v
-NGINX или HAProxy (TLS termination, канонический Host и один адрес X-Forwarded-For)
+NGINX, HAProxy или Caddy (TLS termination, канонический Host и один адрес X-Forwarded-For)
     | обычный HTTP/1.1 в приватной сети
     v
 WEB-listener Telemt
@@ -270,6 +270,66 @@ backend telemt_web
 
 Во frontend или секции `defaults` также задайте `timeout client 65s` или больше для default WebSocket liveness interval. Для `https-lanes` публичный ALPN HAProxy должен содержать `h2`, а для WebSocket Upgrade — `http/1.1`. Сохраняйте `Connection`, `Upgrade` и `Sec-WebSocket-*`; не переписывайте path, raw query, body и carrier headers `Authorization`, `Content-Type`, `X-Up-Seq`, `X-Down-Cursor`, `X-Lane-ID`. Для prefix-only cohosting добавьте `acl telemt_web_path path_beg /telegram/web/` и потребуйте одновременно host- и path-ACL в `use_backend`; не удаляйте prefix.
 
+## Терминация TLS на Caddy
+
+```caddyfile
+{
+	servers {
+		protocols h1 h2
+	}
+}
+
+proxy.example.com {
+	reverse_proxy 127.0.0.1:18080 {
+		header_up X-Forwarded-For {remote_host}
+		flush_interval -1
+		stream_close_delay 5m
+	}
+}
+```
+
+Caddy сам получает и продлевает публичный сертификат для адреса сайта. Он передаёт исходный `Host` и заголовки `Connection`, `Upgrade` и `Sec-WebSocket-*` без изменений и проксирует WebSocket Upgrade без дополнительных директив; не добавляйте `header_up Host`. Публичные HTTP/2 (нужен для `https-lanes`) и HTTP/1.1 (нужен для WebSocket Upgrade) включены по умолчанию, а приватный участок Caddy → Telemt остаётся HTTP/1.1. Глобальная опция `protocols h1 h2` убирает HTTP/3 с пути WEB: контракт WEB описывает только HTTP/1.1 и HTTP/2. Она действует на все сайты этого сервера Caddy.
+
+`header_up X-Forwarded-For {remote_host}` перезаписывает заголовок одним адресом. Без неё Caddy дописывает адрес к входящему `X-Forwarded-For` от пиров из `trusted_proxies`, а Telemt принимает только один разбираемый IP-адрес. Если сам Caddy стоит за L4-балансировщиком с `listener_wrappers { proxy_protocol }`, `{remote_host}` — адрес клиента из заголовка PROXY. `flush_interval -1` отключает буферизацию ответа для long polls и downlink. Тела запросов Caddy по умолчанию передаёт потоком; не включайте `request_buffers`.
+
+У `reverse_proxy` в Caddy по умолчанию нет read/write timeout и лимита тела запроса, поэтому 25-секундный long poll и WebSocket liveness interval проходят без изменений. Если заданы серверные `timeouts` или `request_body max_size`, держите их выше 65 секунд и не меньше `web.limits.max_body_bytes` соответственно. С одним upstream Caddy не повторяет неудачные запросы; не добавляйте `lb_retries` и `lb_try_duration`. При reload конфигурации Caddy по умолчанию сразу закрывает upgraded-соединения. `stream_close_delay` держит установленные WebSocket lanes открытыми на заданное время после reload.
+
+Для prefix-only cohosting с `base_path = "telegram/web"` направляйте поддерево через `handle`, а не `handle_path`: `handle_path` срезает prefix.
+
+```caddyfile
+proxy.example.com {
+	handle /telegram/web/* {
+		reverse_proxy 127.0.0.1:18080 {
+			header_up X-Forwarded-For {remote_host}
+			flush_interval -1
+			stream_close_delay 5m
+		}
+	}
+
+	handle {
+		# обычный сайт
+	}
+}
+```
+
+Маршрутизация Caddy не добавляет редирект со слэшем: `/telegram/web` без завершающего слэша уходит в обработчик обычного сайта. Убедитесь, что и этот обработчик не редиректит его; например, `file_server` перенаправляет запрос каталога на вариант со слэшем.
+
+Caddy не пишет access log без директивы `log`. Если журнал нужен, скройте bridge capability и bearer credentials:
+
+```caddyfile
+log {
+	format filter {
+		request>uri query {
+			replace bridge REDACTED
+		}
+		request>headers>Authorization delete
+		request>headers>Sec-Websocket-Protocol delete
+	}
+}
+```
+
+В `web_trusted_proxy_cidrs` укажите адрес, с которого Caddy подключается к Telemt, например `["127.0.0.1/32"]` для конфигурации выше.
+
 ## Lifecycle и reload
 
 | Конфигурация | Поведение runtime |
@@ -431,7 +491,7 @@ curl -sS -X POST http://127.0.0.1:9091/v1/users/web-user/rotate-secret \
 | `/telegram/web` перенаправляет на `/telegram/web/` | Добавьте точный non-WEB handler для path без слеша. В WEB-контракт Telemt входит только настроенное поддерево с завершающим слешем. |
 | Downlink `https-lanes`, участвующий в гонке, попадает в decoy с `404` | Убедитесь, что он начинается с `X-Down-Cursor: 0`, сохраняйте `X-Lane-ID` и задайте `lane_open_wait_secs` выше наблюдаемого разрыва down-before-`OPEN`. Продвинутый cursor отсутствующей lane намеренно закрывается fail-closed. |
 | Auto-negotiation переходит дальше после уже принятого трафика | Такое поведение некорректно. Проверьте аутентифицированный replay `X-Carrier-State` и lifecycle row commit carrier; ответ `committed` или `healthy` terminal и требует новой сессии. |
-| Long polls разрываются через фиксированный интервал | Поднимите client, server, send и read timeouts NGINX/HAProxy выше `web.timeouts.long_poll_secs`. |
+| Long polls разрываются через фиксированный интервал | Поднимите client, server, send и read timeouts NGINX/HAProxy/Caddy выше `web.timeouts.long_poll_secs`. |
 | WebSocket Upgrade попадает в decoy вместо `101` | Сохраните HTTP/1.1 `Connection: Upgrade`, `Upgrade: websocket`, единственный точный `Sec-WebSocket-Protocol` и канонический bodyless request по настроенному base плюс `/api/v1/ws`. Также проверьте соответствие carrier/session и process connection reserve. |
 | Один stream `websocket-lanes` закрылся, а siblings остались подключены | Это штатная failure boundary. Проверьте message/frame rows этой lane в `/web-status`; malformed, cross-lane, write-timeout и backend-close закрывают только затронутую lane. |
 | `/web-status` пуст | Убедитесь, что `[web.debug].enabled = true`, примените конфигурацию, выберите окно в пределах `max_window_secs` и создайте новый WEB-трафик после изменения policy. |

src/api/config_edit/tests.rs

@@ -1,5 +1,54 @@
 use super::*;
 
+#[tokio::test]
+async fn carrier_method_api_defaults_and_patches_are_hot() {
+    let (path, _directory) = temp_config("[web]\nenabled = false\n");
+    let (value, _) = read_managed_config(&path).await.unwrap();
+    assert_eq!(value["web"]["carrier_method"].as_str(), Some("post"));
+    for token in ["put", "post"] {
+        let active = ProxyConfig::load(&path).unwrap();
+        let patch = serde_json::json!({"web": {"carrier_method": token}});
+        let mut response = apply_patch_to_path(&path, &patch, None).await.unwrap();
+        let desired = ProxyConfig::load(&path).unwrap();
+        reconcile_runtime_effect(&mut response, &active, &desired).unwrap();
+        assert!(!response.restart_required);
+        assert!(response.runtime_reload_required);
+        assert!(!response.process_restart_required);
+        assert!(response.deferred_process_fields.is_empty());
+        let (value, revision) = read_managed_config(&path).await.unwrap();
+        assert_eq!(value["web"]["carrier_method"].as_str(), Some(token));
+        assert_eq!(revision, response.revision);
+        let written = tokio::fs::read_to_string(&path).await.unwrap();
+        assert!(written.contains(&format!("carrier_method = \"{token}\"")));
+    }
+}
+
+#[tokio::test]
+async fn carrier_method_api_rejects_invalid_values_without_writing() {
+    let (path, _directory) = temp_config("[web]\ncarrier_method = \"put\"\n");
+    let original = tokio::fs::read(&path).await.unwrap();
+    let revision = crate::api::config_store::current_revision(&path)
+        .await
+        .unwrap();
+    for value in [
+        serde_json::json!("PUT"),
+        serde_json::json!("patch"),
+        serde_json::json!(true),
+        serde_json::json!(42),
+    ] {
+        let patch = serde_json::json!({"web": {"carrier_method": value}});
+        let error = apply_patch_to_path(&path, &patch, None).await.unwrap_err();
+        assert_eq!(error.status, hyper::StatusCode::BAD_REQUEST);
+        assert_eq!(tokio::fs::read(&path).await.unwrap(), original);
+        assert_eq!(
+            crate::api::config_store::current_revision(&path)
+                .await
+                .unwrap(),
+            revision
+        );
+    }
+}
+
 #[test]
 fn json_object_converts_to_toml_table() {
     let j: Json = serde_json::json!({"censorship": {"tls_domain": "a.com"}, "default_dc": 2});

src/cli.rs

@@ -2,9 +2,9 @@
 //!
 //! Subcommands:
 //! - `start [OPTIONS] [config.toml]` - Start the daemon
-//! - `stop [--pid-file PATH]` - Stop a running daemon
-//! - `reload [--pid-file PATH]` - Reload configuration (SIGHUP)
-//! - `status [--pid-file PATH]` - Check daemon status
+//! - `stop [--pid-file PATH] [--strict-runtime-paths]` - Stop a running daemon
+//! - `reload [--pid-file PATH] [--strict-runtime-paths]` - Reload configuration (SIGHUP)
+//! - `status [--pid-file PATH] [--strict-runtime-paths]` - Check daemon status
 //! - `run [OPTIONS] [config.toml]` - Run in foreground (default behavior)
 //! - `healthcheck [OPTIONS] [config.toml]` - Run control-plane health probe
 
@@ -137,6 +137,10 @@ pub fn parse_command(args: &[String]) -> ParsedCommand {
     while i < args.len() {
         match args[i].as_str() {
             "start" | "stop" | "reload" | "status" | "run" | "healthcheck" => {}
+            #[cfg(unix)]
+            "--strict-runtime-paths" => {
+                cmd.daemon_opts.strict_runtime_paths = true;
+            }
             "--mode" => {
                 i += 1;
                 if i < args.len() {
@@ -199,9 +203,18 @@ pub fn parse_command(args: &[String]) -> ParsedCommand {
 #[cfg(unix)]
 pub fn execute_subcommand(cmd: &ParsedCommand) -> Option<i32> {
     match cmd.subcommand {
-        Subcommand::Stop => Some(daemon_commands::stop(&cmd.pid_file)),
-        Subcommand::Reload => Some(daemon_commands::reload(&cmd.pid_file)),
-        Subcommand::Status => Some(daemon_commands::status(&cmd.pid_file)),
+        Subcommand::Stop => Some(daemon_commands::stop(
+            &cmd.pid_file,
+            cmd.daemon_opts.strict_runtime_paths,
+        )),
+        Subcommand::Reload => Some(daemon_commands::reload(
+            &cmd.pid_file,
+            cmd.daemon_opts.strict_runtime_paths,
+        )),
+        Subcommand::Status => Some(daemon_commands::status(
+            &cmd.pid_file,
+            cmd.daemon_opts.strict_runtime_paths,
+        )),
         Subcommand::Healthcheck => {
             if let Some(invalid_mode) = cmd.healthcheck_mode_invalid.as_ref() {
                 if invalid_mode.is_empty() {

src/cli/daemon_commands.rs

@@ -15,6 +15,9 @@ pub fn parse_daemon_args(args: &[String]) -> DaemonOptions {
             "--foreground" | "-f" => {
                 opts.foreground = true;
             }
+            "--strict-runtime-paths" => {
+                opts.strict_runtime_paths = true;
+            }
             "--pid-file" => {
                 i += 1;
                 if i < args.len() {
@@ -60,19 +63,21 @@ pub fn parse_daemon_args(args: &[String]) -> DaemonOptions {
 }
 
 /// Sends SIGTERM and waits briefly for graceful PID-file cleanup.
-pub(super) fn stop(pid_file: &Path) -> i32 {
+pub(super) fn stop(pid_file: &Path, strict_runtime_paths: bool) -> i32 {
     use nix::sys::signal::Signal;
 
     println!("Stopping telemt daemon...");
 
-    match daemon::signal_pid_file(pid_file, Signal::SIGTERM) {
+    match daemon::signal_pid_file(pid_file, Signal::SIGTERM, strict_runtime_paths) {
         Ok(()) => {
             println!("Stop signal sent successfully");
 
             // Wait for process to exit for up to ten seconds.
             for _ in 0..20 {
                 std::thread::sleep(std::time::Duration::from_millis(500));
-                if let daemon::DaemonStatus::NotRunning = daemon::check_status(pid_file) {
+                if let daemon::DaemonStatus::NotRunning =
+                    daemon::check_status(pid_file, strict_runtime_paths)
+                {
                     println!("Daemon stopped");
                     return 0;
                 }
@@ -88,12 +93,12 @@ pub(super) fn stop(pid_file: &Path) -> i32 {
 }
 
 /// Sends SIGHUP to trigger configuration reload.
-pub(super) fn reload(pid_file: &Path) -> i32 {
+pub(super) fn reload(pid_file: &Path, strict_runtime_paths: bool) -> i32 {
     use nix::sys::signal::Signal;
 
     println!("Reloading telemt configuration...");
 
-    match daemon::signal_pid_file(pid_file, Signal::SIGHUP) {
+    match daemon::signal_pid_file(pid_file, Signal::SIGHUP, strict_runtime_paths) {
         Ok(()) => {
             println!("Reload signal sent successfully");
             0
@@ -106,8 +111,8 @@ pub(super) fn reload(pid_file: &Path) -> i32 {
 }
 
 /// Reports daemon status without mutating PID lifecycle state.
-pub(super) fn status(pid_file: &Path) -> i32 {
-    match daemon::check_status(pid_file) {
+pub(super) fn status(pid_file: &Path, strict_runtime_paths: bool) -> i32 {
+    match daemon::check_status(pid_file, strict_runtime_paths) {
         daemon::DaemonStatus::Running(pid) => {
             println!("telemt is running (pid {})", pid);
             0
@@ -126,16 +131,168 @@ pub(super) fn status(pid_file: &Path) -> i32 {
 #[cfg(test)]
 mod tests {
     use std::fs;
+    use std::os::unix::fs::{PermissionsExt, symlink};
+    use std::process::{Child, Command, Stdio};
+    use std::time::{Duration, Instant};
 
     use super::*;
 
+    const CONTROL_PID: &str = "TELEMT_RUNTIME_PATH_TEST_PID";
+    const CONTROL_READY: &str = "TELEMT_RUNTIME_PATH_TEST_READY";
+    const CONTROL_RELOADED: &str = "TELEMT_RUNTIME_PATH_TEST_RELOADED";
+
+    struct ControlChild(Child);
+
+    impl Drop for ControlChild {
+        fn drop(&mut self) {
+            let _ = self.0.kill();
+            let _ = self.0.wait();
+        }
+    }
+
+    fn wait_for_file(path: &Path) -> bool {
+        let deadline = Instant::now() + Duration::from_secs(5);
+        while Instant::now() < deadline {
+            if path.exists() {
+                return true;
+            }
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        false
+    }
+
+    #[test]
+    fn runtime_path_policy_defaults_to_compatibility_for_all_commands() {
+        for command in ["run", "start", "stop", "reload", "status"] {
+            let args = vec![command.to_string(), "config.toml".to_string()];
+            assert!(
+                !crate::cli::parse_command(&args)
+                    .daemon_opts
+                    .strict_runtime_paths
+            );
+            assert!(!parse_daemon_args(&args).strict_runtime_paths);
+
+            for position in [1, args.len()] {
+                let mut strict_args = args.clone();
+                strict_args.insert(position, "--strict-runtime-paths".to_string());
+                let parsed = crate::cli::parse_command(&strict_args);
+                assert!(parsed.daemon_opts.strict_runtime_paths);
+                assert!(parse_daemon_args(&strict_args).strict_runtime_paths);
+                assert_eq!(parsed.config_path, "config.toml");
+            }
+        }
+        let args = vec![
+            "--strict-runtime-paths".to_string(),
+            "config.toml".to_string(),
+        ];
+        let parsed = crate::cli::parse_command(&args);
+        assert_eq!(parsed.subcommand, crate::cli::Subcommand::Run);
+        assert!(parsed.daemon_opts.strict_runtime_paths);
+        assert_eq!(parsed.config_path, "config.toml");
+    }
+
+    #[tokio::test(flavor = "current_thread")]
+    async fn daemon_control_subprocess() {
+        let Some(pid_path) = std::env::var_os(CONTROL_PID) else {
+            return;
+        };
+        let ready = PathBuf::from(std::env::var_os(CONTROL_READY).unwrap());
+        let reloaded = PathBuf::from(std::env::var_os(CONTROL_RELOADED).unwrap());
+        let mut terminate =
+            tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate()).unwrap();
+        let mut reload =
+            tokio::signal::unix::signal(tokio::signal::unix::SignalKind::hangup()).unwrap();
+        let mut owner = daemon::PidFile::new(PathBuf::from(pid_path), false);
+        owner.acquire().unwrap();
+        fs::write(&ready, b"ready").unwrap();
+        let deadline = tokio::time::sleep(Duration::from_secs(15));
+        tokio::pin!(deadline);
+        loop {
+            tokio::select! {
+                _ = terminate.recv() => break,
+                _ = reload.recv() => fs::write(&reloaded, b"reloaded").unwrap(),
+                _ = &mut deadline => panic!("daemon control subprocess timed out"),
+            }
+        }
+        owner.release().unwrap();
+    }
+
+    #[test]
+    fn control_commands_follow_runtime_path_policy() {
+        for (mode, linked_parent, trusted_parent) in [
+            (0o777, false, false),
+            (0o777, true, false),
+            (0o755, false, true),
+        ] {
+            let root = tempfile::tempdir().unwrap();
+            let real = root.path().join("run");
+            let linked = root.path().join("linked");
+            fs::create_dir(&real).unwrap();
+            fs::set_permissions(&real, fs::Permissions::from_mode(mode)).unwrap();
+            symlink(&real, &linked).unwrap();
+            let pid_path = if linked_parent { &linked } else { &real }.join("telemt.pid");
+            let ready = root.path().join("ready");
+            let reloaded = root.path().join("reloaded");
+            let mut child = ControlChild(
+                Command::new(std::env::current_exe().unwrap())
+                    .args([
+                        "--exact",
+                        "cli::daemon_commands::tests::daemon_control_subprocess",
+                        "--nocapture",
+                    ])
+                    .env(CONTROL_PID, &pid_path)
+                    .env(CONTROL_READY, &ready)
+                    .env(CONTROL_RELOADED, &reloaded)
+                    .stdout(Stdio::null())
+                    .stderr(Stdio::null())
+                    .spawn()
+                    .unwrap(),
+            );
+            assert!(
+                wait_for_file(&ready),
+                "daemon control subprocess did not become ready"
+            );
+            let command = |name: &str, strict: bool| {
+                let mut args = vec![
+                    name.to_string(),
+                    "--pid-file".to_string(),
+                    pid_path.to_str().unwrap().to_string(),
+                ];
+                if strict {
+                    args.push("--strict-runtime-paths".to_string());
+                }
+                crate::cli::execute_subcommand(&crate::cli::parse_command(&args))
+            };
+
+            assert_eq!(command("status", false), Some(0));
+            if trusted_parent {
+                assert_eq!(command("status", true), Some(0));
+                assert_eq!(command("reload", true), Some(0));
+                assert!(wait_for_file(&reloaded));
+                assert_eq!(command("stop", true), Some(0));
+            } else {
+                assert_eq!(command("status", true), Some(1));
+                assert_eq!(command("reload", true), Some(1));
+                assert!(!reloaded.exists());
+                assert_eq!(command("stop", true), Some(1));
+                assert_eq!(command("status", false), Some(0));
+                assert_eq!(command("reload", false), Some(0));
+                assert!(wait_for_file(&reloaded));
+                assert_eq!(command("stop", false), Some(0));
+            }
+            assert!(child.0.wait().unwrap().success());
+            assert!(!pid_path.exists());
+            assert_eq!(command("status", false), Some(1));
+        }
+    }
+
     #[test]
     fn status_does_not_remove_stale_pid_file() {
         let directory = tempfile::tempdir().unwrap();
         let pid_file = directory.path().join("telemt.pid");
         fs::write(&pid_file, b"2000000000\n").unwrap();
 
-        assert_eq!(status(&pid_file), 1);
+        assert_eq!(status(&pid_file, false), 1);
         assert!(pid_file.exists());
     }
 }

src/config/defaults.rs

@@ -59,7 +59,7 @@ const DEFAULT_ME_POOL_DRAIN_SOFT_EVICT_BUDGET_PER_CORE: u16 = 16;
 const DEFAULT_ME_POOL_DRAIN_SOFT_EVICT_COOLDOWN_MS: u64 = 1000;
 const DEFAULT_USER_MAX_UNIQUE_IPS_WINDOW_SECS: u64 = 30;
 const DEFAULT_ACCEPT_PERMIT_TIMEOUT_MS: u64 = 250;
-const DEFAULT_CONNTRACK_CONTROL_ENABLED: bool = true;
+const DEFAULT_CONNTRACK_CONTROL_ENABLED: bool = false;
 const DEFAULT_CONNTRACK_PRESSURE_HIGH_WATERMARK_PCT: u8 = 85;
 const DEFAULT_CONNTRACK_PRESSURE_LOW_WATERMARK_PCT: u8 = 70;
 const DEFAULT_CONNTRACK_DELETE_BUDGET_PER_SEC: u64 = 4096;
@@ -244,6 +244,7 @@ pub(crate) fn default_accept_permit_timeout_ms() -> u64 {
     DEFAULT_ACCEPT_PERMIT_TIMEOUT_MS
 }
 
+/// Keeps privileged conntrack control disabled unless explicitly requested.
 pub(crate) fn default_conntrack_control_enabled() -> bool {
     DEFAULT_CONNTRACK_CONTROL_ENABLED
 }

src/config/hot_reload.rs

@@ -17,6 +17,7 @@
 //! | `network` | `dns_overrides`                | Applied immediately                            |
 //! | `access`  | All user/quota fields          | Effective immediately                          |
 //! | `web`     | Carrier, timing, and debug policy | Applied to newly issued sessions             |
+//! | `web`     | `carrier_method`               | Applied to newly rendered bridge pages        |
 //! Fields that require re-binding sockets (`server.listeners`, legacy
 //! `server.port`, `censorship.*`, `network.*`, `use_middle_proxy`) are **not**
 //! applied; a warning is emitted. SYN limiter rules are process-owned and are
@@ -67,3 +68,7 @@ use watcher::{ReloadState, reload_config};
 mod base_path_tests;
 #[cfg(test)]
 mod tests;
+// Carrier method reloads preserve page-owned requests and process-owned limits.
+#[cfg(test)]
+#[path = "hot_reload/carrier_method_tests.rs"]
+mod carrier_method_tests;

src/config/hot_reload/carrier_method_tests.rs

@@ -0,0 +1,50 @@
+use super::*;
+
+use crate::config::WebCarrierMethod;
+
+#[test]
+fn carrier_method_reload_is_hot_and_preserves_process_limits() {
+    let mut active = ProxyConfig::default();
+    for method in [WebCarrierMethod::Put, WebCarrierMethod::Post] {
+        let mut desired = active.clone();
+        desired.web.carrier_method = method;
+        assert_eq!(classify_config_changes(&active, &desired).changed, ["web"]);
+        assert!(!classify_config_changes(&active, &desired).restart_required);
+        desired.web.limits.max_http_connections += 1;
+        let applied = overlay_hot_fields(&active, &desired);
+        assert_eq!(applied.web.carrier_method, method);
+        assert_eq!(
+            applied.web.limits.max_http_connections,
+            active.web.limits.max_http_connections
+        );
+        active = applied;
+    }
+}
+
+#[test]
+fn carrier_method_reload_publishes_both_directions_and_keeps_last_good_value() {
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("config.toml");
+    let source = |method| format!("[web]\ncarrier_method = \"{method}\"\n");
+    std::fs::write(&path, source("post")).unwrap();
+    let initial = Arc::new(ProxyConfig::load(&path).unwrap());
+    let initial_hash = ProxyConfig::load_with_metadata(&path)
+        .unwrap()
+        .rendered_hash;
+    let (config_tx, _config_rx) = watch::channel(Arc::clone(&initial));
+    let (log_tx, _log_rx) = watch::channel(initial.general.log_level.clone());
+    let mut reload_state = ReloadState::new(Some(initial_hash));
+    for (token, method) in [
+        ("put", WebCarrierMethod::Put),
+        ("post", WebCarrierMethod::Post),
+    ] {
+        std::fs::write(&path, source(token)).unwrap();
+        reload_config(&path, &config_tx, &log_tx, None, None, &mut reload_state).unwrap();
+        let applied = config_tx.borrow().clone();
+        assert_eq!(applied.web.carrier_method, method);
+        std::fs::write(&path, source("PATCH")).unwrap();
+        reload_config(&path, &config_tx, &log_tx, None, None, &mut reload_state);
+        let unchanged = config_tx.borrow().clone();
+        assert!(Arc::ptr_eq(&unchanged, &applied));
+    }
+}

src/config/load/strict_keys.rs

@@ -263,6 +263,7 @@ const LISTENER_CONFIG_KEYS: &[&str] = &[
 const WEB_CONFIG_KEYS: &[&str] = &[
     "enabled",
     "carrier",
+    "carrier_method",
     "carriers",
     "carrier_learning",
     "carrier_negotiation_aggressiveness",

src/config/tests/load_basic_tests/conntrack_tests.rs

@@ -1,5 +1,71 @@
 use super::*;
 
+#[test]
+fn conntrack_control_is_opt_in_by_default() {
+    assert!(!default_conntrack_control_enabled());
+    assert!(
+        !ProxyConfig::default()
+            .server
+            .conntrack_control
+            .inline_conntrack_control
+    );
+    let cfg = load_config_from_temp_toml(
+        r#"
+        [censorship]
+        tls_domain = "example.com"
+
+        [access.users]
+        user = "00000000000000000000000000000000"
+        "#,
+    );
+    assert!(!cfg.server.conntrack_control.inline_conntrack_control);
+    assert!(
+        !cfg.server
+            .conntrack_control
+            .inline_conntrack_control_explicit
+    );
+    assert_eq!(
+        serde_json::to_value(&cfg.server.conntrack_control).unwrap()["inline_conntrack_control"],
+        false,
+    );
+}
+
+#[test]
+fn conntrack_control_preserves_explicit_enablement() {
+    for enabled in [false, true] {
+        let cfg = load_config_from_temp_toml(&format!(
+            r#"
+            [server.conntrack_control]
+            inline_conntrack_control = {enabled}
+            backend = "nftables"
+
+            [censorship]
+            tls_domain = "example.com"
+
+            [access.users]
+            user = "00000000000000000000000000000000"
+            "#,
+        ));
+        assert_eq!(
+            cfg.server.conntrack_control.inline_conntrack_control,
+            enabled
+        );
+        assert!(
+            cfg.server
+                .conntrack_control
+                .inline_conntrack_control_explicit
+        );
+        assert_eq!(
+            cfg.server.conntrack_control.backend,
+            ConntrackBackend::Nftables
+        );
+        assert_eq!(
+            serde_json::to_value(&cfg.server.conntrack_control).unwrap()["inline_conntrack_control"],
+            enabled,
+        );
+    }
+}
+
 #[test]
 fn conntrack_pressure_high_watermark_out_of_range_is_rejected() {
     let toml = r#"

src/config/tests/load_basic_tests/web_tests.rs

@@ -3,6 +3,10 @@ use super::*;
 #[path = "web_tests/base_path_tests.rs"]
 mod base_path_tests;
 
+// Method selection must not alter capability identity or accepted config literals.
+#[path = "web_tests/carrier_method_tests.rs"]
+mod carrier_method_tests;
+
 const WEB_CONFIG: &str = r#"
 [access.users]
 alice = "000102030405060708090a0b0c0d0e0f"

src/config/tests/load_basic_tests/web_tests/carrier_method_tests.rs

@@ -0,0 +1,48 @@
+use super::*;
+
+#[test]
+fn carrier_method_defaults_and_roundtrips_without_changing_capabilities() {
+    let default = load_config_from_temp_toml(WEB_CONFIG);
+    assert_eq!(default.web.carrier_method, WebCarrierMethod::Post);
+    let capabilities = default.web.runtime.as_ref().unwrap().capabilities.clone();
+    for (token, method) in [
+        ("post", WebCarrierMethod::Post),
+        ("put", WebCarrierMethod::Put),
+    ] {
+        let configured = WEB_CONFIG.replace(
+            "carrier = \"https-lanes\"",
+            &format!("carrier = \"https-lanes\"\ncarrier_method = \"{token}\""),
+        );
+        let source = format!("[general]\nconfig_strict = true\n{configured}");
+        let config = load_config_from_temp_toml(&source);
+        assert_eq!(config.web.carrier_method, method);
+        assert_eq!(
+            config.web.runtime.as_ref().unwrap().capabilities,
+            capabilities
+        );
+        let json = serde_json::to_value(&config.web).unwrap();
+        assert_eq!(json["carrier_method"], token);
+        let decoded: WebConfig = serde_json::from_value(json).unwrap();
+        assert_eq!(decoded.carrier_method, method);
+        let serialized = toml::to_string(&config.web).unwrap();
+        let decoded: WebConfig = toml::from_str(&serialized).unwrap();
+        assert_eq!(decoded.carrier_method, method);
+    }
+}
+
+#[test]
+fn carrier_method_rejects_unknown_tokens_types_and_aliases() {
+    for value in ["\"POST\"", "\"PUT\"", "\"patch\"", "true", "42", "[]"] {
+        let source = WEB_CONFIG.replace(
+            "carrier = \"https-lanes\"",
+            &format!("carrier = \"https-lanes\"\ncarrier_method = {value}"),
+        );
+        assert!(load_config_error_from_temp_toml(&source).contains("carrier_method"));
+    }
+    let configured = WEB_CONFIG.replace(
+        "carrier = \"https-lanes\"",
+        "carrier = \"https-lanes\"\nhttp_method = \"put\"",
+    );
+    let source = format!("[general]\nconfig_strict = true\n{configured}");
+    assert!(load_config_error_from_temp_toml(&source).contains("http_method"));
+}

src/config/types.rs

@@ -63,7 +63,7 @@ pub(crate) use web::{
 };
 pub(crate) use web_carrier::WEB_CARRIER_LEARNING_MIN_ENTRIES;
 #[allow(unused_imports)]
-pub use web_carrier::{WebCarrier, WebCarriers};
+pub use web_carrier::{WebCarrier, WebCarrierMethod, WebCarriers};
 pub(crate) use web_debug::web_debug_fits_limits;
 pub use web_debug::{WebDebugBodyCapture, WebDebugConfig};
 

src/config/types/web.rs

@@ -6,7 +6,7 @@ use std::sync::Arc;
 use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 
-use super::web_carrier::{WebCarrier, WebCarriers};
+use super::web_carrier::{WebCarrier, WebCarrierMethod, WebCarriers};
 use super::web_debug::WebDebugConfig;
 
 // Serialized WEB defaults remain separate from the runtime data model.
@@ -413,6 +413,9 @@ pub struct WebConfig {
     /// Sole carrier when negotiation is disabled and final fallback when enabled.
     #[serde(default)]
     pub carrier: WebCarrier,
+    /// Page-owned HTTP method for HTTPS uplink and downlink, including retries.
+    #[serde(default)]
+    pub carrier_method: WebCarrierMethod,
     /// Ordered carriers considered by server-side negotiation before the fallback carrier.
     #[serde(default)]
     pub carriers: WebCarriers,
@@ -471,6 +474,7 @@ impl Default for WebConfig {
         Self {
             enabled: false,
             carrier: WebCarrier::default(),
+            carrier_method: WebCarrierMethod::default(),
             carriers: WebCarriers::default(),
             carrier_learning: default_web_carrier_learning(),
             carrier_negotiation_aggressiveness: WebCarrierNegotiationAggressiveness::default(),

src/config/types/web_carrier.rs

@@ -3,6 +3,27 @@ use serde::{Deserialize, Serialize};
 /// Minimum restart-owned entries required for one complete learning sample.
 pub(crate) const WEB_CARRIER_LEARNING_MIN_ENTRIES: usize = 3;
 
+/// HTTP method emitted by newly rendered HTTPS carrier bridges.
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum WebCarrierMethod {
+    /// Preserve the original bridge request method.
+    #[default]
+    Post,
+    /// Allow idempotent-method connection reuse in Linux WebKitGTK.
+    Put,
+}
+
+impl WebCarrierMethod {
+    /// Returns the HTTP token embedded in the page-owned carrier policy.
+    pub(crate) const fn as_str(self) -> &'static str {
+        match self {
+            Self::Post => "POST",
+            Self::Put => "PUT",
+        }
+    }
+}
+
 /// Carrier selected for one newly issued WEB relay session.
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]

src/conntrack_control/firewall/actor.rs

@@ -26,15 +26,21 @@ const RETRY_DELAYS: [Duration; 6] = [
     Duration::from_secs(30),
 ];
 
+/// Reports whether a generation's desired firewall policy was confirmed.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(super) enum ReconcileOutcome {
+    /// The applied policy matches the accepted generation's desired policy.
     Applied,
+    /// The attempt failed without confirming the desired policy.
     Failed,
 }
 
+/// Associates a reconciliation result with its accepted runtime generation.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(super) struct ReconcileStatus {
+    /// Runtime generation whose desired policy was attempted.
     pub(super) generation: u64,
+    /// Result of the latest completed attempt for this generation.
     pub(super) outcome: ReconcileOutcome,
 }
 
@@ -51,25 +57,14 @@ pub(crate) struct FirewallAuthority {
 }
 
 impl FirewallAuthority {
-    /// Starts the single process-owned firewall reconciler.
-    pub(crate) fn spawn(control_plane: &ProcessControlPlane) -> Result<Self, String> {
-        let (desired_tx, desired_rx) = watch::channel(None);
-        let (status_tx, status_rx) = watch::channel(None);
-        let terminal = CancellationToken::new();
-        let closed = Arc::new(AtomicBool::new(false));
-        let completed_flag = Arc::new(AtomicBool::new(false));
-        let cleanup_succeeded = Arc::new(AtomicBool::new(false));
-        let completed = Arc::new(Notify::new());
-        let actor = FirewallReconciler::new(
-            SystemCommandRunner,
-            desired_rx,
-            status_tx,
-            terminal.clone(),
-            Arc::clone(&closed),
-            Arc::clone(&completed_flag),
-            Arc::clone(&cleanup_succeeded),
-            Arc::clone(&completed),
-        );
+    /// Starts reconciliation only when enabled and CAP_NET_ADMIN is available.
+    pub(crate) fn spawn(
+        control_plane: &ProcessControlPlane,
+        config: &ProxyConfig,
+    ) -> Result<Option<Self>, String> {
+        let Some((authority, actor)) = Self::prepare(config, SystemCommandRunner) else {
+            return Ok(None);
+        };
         control_plane
             .spawn_cooperative(move |process_cancellation| async move {
                 actor.run(process_cancellation).await;
@@ -78,7 +73,37 @@ impl FirewallAuthority {
                 "process control-plane admission closed before conntrack firewall startup"
                     .to_string()
             })?;
-        Ok(Self {
+        Ok(Some(authority))
+    }
+
+    // Admission precedes allocation so an opted-out process never owns firewall cleanup.
+    // Keeping construction separate permits fake runners without changing async Send bounds.
+    fn prepare<R>(config: &ProxyConfig, runner: R) -> Option<(Self, FirewallReconciler<R>)>
+    where
+        R: FirewallCommandRunner + 'static,
+    {
+        if !config.server.conntrack_control.inline_conntrack_control || !runner.has_cap_net_admin()
+        {
+            return None;
+        }
+        let (desired_tx, desired_rx) = watch::channel(None);
+        let (status_tx, status_rx) = watch::channel(None);
+        let terminal = CancellationToken::new();
+        let closed = Arc::new(AtomicBool::new(false));
+        let completed_flag = Arc::new(AtomicBool::new(false));
+        let cleanup_succeeded = Arc::new(AtomicBool::new(false));
+        let completed = Arc::new(Notify::new());
+        let actor = FirewallReconciler::new(
+            runner,
+            desired_rx,
+            status_tx,
+            terminal.clone(),
+            Arc::clone(&closed),
+            Arc::clone(&completed_flag),
+            Arc::clone(&cleanup_succeeded),
+            Arc::clone(&completed),
+        );
+        let authority = Self {
             desired_tx,
             status_rx,
             terminal,
@@ -86,7 +111,8 @@ impl FirewallAuthority {
             completed_flag,
             cleanup_succeeded,
             completed,
-        })
+        };
+        Some((authority, actor))
     }
 
     /// Publishes policy only after its runtime generation becomes active.
@@ -169,6 +195,7 @@ impl Drop for CompletionGuard {
     }
 }
 
+/// Serializes confirmed-state transitions and retains cleanup ownership until shutdown.
 pub(super) struct FirewallReconciler<R> {
     runner: R,
     desired_rx: watch::Receiver<Option<DesiredState>>,
@@ -186,6 +213,7 @@ impl<R> FirewallReconciler<R>
 where
     R: FirewallCommandRunner + 'static,
 {
+    /// Constructs an admitted actor with unknown state pending startup recovery.
     pub(super) fn new(
         runner: R,
         desired_rx: watch::Receiver<Option<DesiredState>>,
@@ -214,6 +242,7 @@ where
         }
     }
 
+    /// Reconciles accepted generations and completes bounded cleanup on cancellation.
     pub(super) async fn run(mut self, process_cancellation: CancellationToken) {
         let mut current = None;
         let mut retry_index = 0usize;
@@ -337,6 +366,7 @@ where
         let _completion = &self.completion;
     }
 
+    /// Accepts fenced publications without replacing telemetry with stale desired state.
     pub(super) fn take_latest_desired(&mut self) -> Option<DesiredState> {
         let next = self.desired_rx.borrow_and_update().clone()?;
         if next.generation < self.last_generation {
@@ -369,3 +399,8 @@ where
         Some(next)
     }
 }
+
+// Exercises startup admission and cleanup ownership with fake helper processes.
+#[cfg(test)]
+#[path = "tests/startup_admission.rs"]
+mod startup_admission_tests;

src/conntrack_control/firewall/command.rs

@@ -10,14 +10,19 @@ use crate::util::trusted_command::{resolve_trusted_helper, trusted_helper_comman
 
 const COMMAND_TIMEOUT: Duration = Duration::from_secs(30);
 
+/// A privileged helper invocation with arguments kept separate from shell syntax.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(super) struct CommandSpec {
+    /// Logical helper name resolved by the trusted executable policy.
     pub(super) binary: &'static str,
+    /// Arguments passed directly to the helper process.
     pub(super) args: Vec<String>,
+    /// Optional restore script supplied on standard input.
     pub(super) stdin: Option<String>,
 }
 
 impl CommandSpec {
+    /// Creates a helper invocation without an input script.
     pub(super) fn new(binary: &'static str, args: impl IntoIterator<Item = &'static str>) -> Self {
         Self {
             binary,
@@ -26,6 +31,7 @@ impl CommandSpec {
         }
     }
 
+    /// Creates a helper invocation that receives a restore script.
     pub(super) fn with_stdin(
         binary: &'static str,
         args: impl IntoIterator<Item = &'static str>,
@@ -39,22 +45,32 @@ impl CommandSpec {
     }
 }
 
+/// Distinguishes idempotent absence from transaction and execution failures.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(super) enum CommandErrorKind {
+    /// The trusted helper executable is unavailable.
     Missing,
+    /// The requested firewall object or rule is absent.
     NotFound,
+    /// A terminal or process cancellation interrupted the invocation.
     Cancelled,
+    /// The helper exceeded its execution deadline.
     Timeout,
+    /// A failure that must not be treated as successful cleanup.
     Failed,
 }
 
+/// A classified helper failure retaining its diagnostic for reconciliation.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(super) struct CommandError {
+    /// Recovery semantics associated with the failure.
     pub(super) kind: CommandErrorKind,
+    /// Original helper diagnostic or an execution failure description.
     pub(super) message: String,
 }
 
 impl CommandError {
+    /// Creates the cancellation failure used by interruptible transactions.
     pub(super) fn cancelled() -> Self {
         Self {
             kind: CommandErrorKind::Cancelled,
@@ -62,6 +78,7 @@ impl CommandError {
         }
     }
 
+    /// Creates a failure that prevents idempotent cleanup from claiming success.
     pub(super) fn failed(message: impl Into<String>) -> Self {
         Self {
             kind: CommandErrorKind::Failed,
@@ -76,14 +93,19 @@ impl std::fmt::Display for CommandError {
     }
 }
 
+/// Executes firewall commands through a production or deterministic test runner.
 pub(super) trait FirewallCommandRunner: Send + Sync {
+    /// Reports whether a helper can be resolved under the runner's trust policy.
     fn available(&self, binary: &str) -> bool;
 
+    /// Reports whether the process has the capability required to alter firewall rules.
     fn has_cap_net_admin(&self) -> bool;
 
+    /// Executes one invocation while preserving classified failure semantics.
     async fn run(&self, spec: CommandSpec) -> Result<(), CommandError>;
 }
 
+/// Runs trusted system helpers with bounded execution and captured diagnostics.
 #[derive(Clone, Copy, Default)]
 pub(super) struct SystemCommandRunner;
 
@@ -187,18 +209,95 @@ impl FirewallCommandRunner for SystemCommandRunner {
             } else {
                 stderr
             };
-            let kind = if is_not_found_error(&message) {
-                CommandErrorKind::NotFound
-            } else {
-                CommandErrorKind::Failed
-            };
+            let kind = classify_command_error(binary, &spec.args, &message);
             Err(CommandError { kind, message })
         }
     }
 }
 
+/// Recognizes the existing legacy iptables and native nftables absence formats.
 pub(super) fn is_not_found_error(message: &str) -> bool {
     message.contains("No chain/target/match by that name")
         || message.contains("Bad rule (does a matching rule exist in that chain?)")
         || message.contains("Could not process rule: No such file or directory")
 }
+
+/// Bounds additional iptables-nft absence diagnostics to owned cleanup and checks.
+pub(super) fn classify_command_error(
+    binary: &str,
+    args: &[String],
+    message: &str,
+) -> CommandErrorKind {
+    if is_not_found_error(message) || is_missing_owned_iptables_chain(binary, args, message) {
+        CommandErrorKind::NotFound
+    } else {
+        CommandErrorKind::Failed
+    }
+}
+
+fn is_missing_owned_iptables_chain(binary: &str, args: &[String], message: &str) -> bool {
+    if !matches!(binary, "iptables" | "ip6tables") {
+        return false;
+    }
+    // An absent jump target is harmless for deletion, but not for installation.
+    let chain = match args {
+        [flag, table, operation, source, jump, target]
+            if flag == "-t"
+                && table == "raw"
+                && matches!(operation.as_str(), "-C" | "-D")
+                && source == "PREROUTING"
+                && jump == "-j"
+                && target == "TELEMT_NOTRACK" =>
+        {
+            target.as_str()
+        }
+        [flag, table, operation, target]
+            if flag == "-t"
+                && table == "raw"
+                && matches!(operation.as_str(), "-F" | "-X")
+                && matches!(
+                    target.as_str(),
+                    "TELEMT_NOTRACK" | "TELEMT_NT_A" | "TELEMT_NT_B"
+                ) =>
+        {
+            target.as_str()
+        }
+        _ => return false,
+    };
+    let mut lines = message.lines();
+    let Some(first) = lines.next() else {
+        return false;
+    };
+    let diagnostic = if first.starts_with("Chain '") {
+        first
+    } else {
+        let Some((version, diagnostic)) = first
+            .strip_prefix(binary)
+            .and_then(|line| line.strip_prefix(" v"))
+            .and_then(|line| line.split_once(" (nf_tables): "))
+        else {
+            return false;
+        };
+        if version.is_empty() || version.bytes().any(|byte| byte.is_ascii_whitespace()) {
+            return false;
+        }
+        diagnostic
+    };
+    if diagnostic
+        .strip_prefix("Chain '")
+        .and_then(|line| line.strip_suffix("' does not exist"))
+        != Some(chain)
+    {
+        return false;
+    }
+    // Reject mixed diagnostics instead of hiding another failure after an absence message.
+    let Some(help) = lines.next() else {
+        return true;
+    };
+    help.strip_prefix("Try `")
+        .and_then(|line| line.strip_prefix(binary))
+        .and_then(|line| line.strip_prefix(" -h' or '"))
+        .and_then(|line| line.strip_prefix(binary))
+        == Some(" --help' for more information.")
+        && lines.next().is_none()
+}

src/conntrack_control/firewall/tests.rs

@@ -20,6 +20,10 @@ use super::transaction::{InterruptibleRunner, reconcile_once};
 #[path = "tests/model_tests.rs"]
 mod model_tests;
 
+// Replays helper diagnostics through command classification and recovery.
+#[path = "tests/recovery_errors.rs"]
+mod recovery_errors;
+
 #[derive(Clone)]
 struct FailureRule {
     binary: &'static str,

src/conntrack_control/firewall/tests/recovery_errors.rs

@@ -0,0 +1,512 @@
+use super::super::command::classify_command_error;
+use super::super::transaction::recover_to_empty;
+use super::*;
+
+const OWNED_CHAINS: [&str; 3] = ["TELEMT_NOTRACK", "TELEMT_NT_A", "TELEMT_NT_B"];
+type ChainKey = (&'static str, String, String);
+type ChainRules = BTreeMap<ChainKey, BTreeSet<String>>;
+
+fn missing_chain(binary: &str, chain: &str) -> String {
+    format!(
+        "{binary} v1.8.10 (nf_tables): Chain '{chain}' does not exist\n\
+         Try `{binary} -h' or '{binary} --help' for more information."
+    )
+}
+
+fn classified_error(spec: &CommandSpec, message: &str) -> CommandError {
+    CommandError {
+        kind: classify_command_error(spec.binary, &spec.args, message),
+        message: message.to_string(),
+    }
+}
+
+#[derive(Default)]
+struct FixtureState {
+    calls: Vec<CommandSpec>,
+    chains: ChainRules,
+    nft_tables: BTreeSet<String>,
+    failure: Option<&'static str>,
+}
+
+#[derive(Clone)]
+struct FixtureRunner {
+    state: Arc<Mutex<FixtureState>>,
+}
+
+impl FixtureRunner {
+    fn new(failure: Option<&'static str>) -> Self {
+        let mut state = FixtureState {
+            failure,
+            ..FixtureState::default()
+        };
+        for binary in ["iptables", "ip6tables"] {
+            for (table, chain, rules) in [
+                ("raw", "PREROUTING", vec!["-j FOREIGN_RAW"]),
+                ("raw", "FOREIGN_RAW", vec!["-j ACCEPT"]),
+                ("filter", "INPUT", vec!["-j MTPR_SYNFIX", "-j TMT_SYN_TEST"]),
+                ("filter", "MTPR_SYNFIX", vec!["-p tcp --syn -j DROP"]),
+                ("filter", "TMT_SYN_TEST", vec!["-p tcp --syn -j DROP"]),
+            ] {
+                state.chains.insert(
+                    (binary, table.to_string(), chain.to_string()),
+                    rules.into_iter().map(str::to_string).collect(),
+                );
+            }
+        }
+        state.nft_tables.extend([
+            "mtpr_synfix".to_string(),
+            "telemt_synlimit_test".to_string(),
+            "foreign_table".to_string(),
+        ]);
+        Self {
+            state: Arc::new(Mutex::new(state)),
+        }
+    }
+
+    fn calls(&self) -> Vec<CommandSpec> {
+        self.state.lock().unwrap().calls.clone()
+    }
+
+    fn foreign_snapshot(&self) -> (ChainRules, BTreeSet<String>) {
+        let state = self.state.lock().unwrap();
+        let mut chains = state.chains.clone();
+        chains.retain(|(_, table, chain), _| {
+            table != "raw" || !OWNED_CHAINS.contains(&chain.as_str())
+        });
+        for ((_, table, chain), rules) in &mut chains {
+            if table == "raw" && chain == "PREROUTING" {
+                rules.remove("-j TELEMT_NOTRACK");
+            }
+        }
+        (chains, state.nft_tables.clone())
+    }
+
+    fn assert_owned_policy(&self, enabled: bool) {
+        let state = self.state.lock().unwrap();
+        for (binary, ip) in [("iptables", "192.0.2.10"), ("ip6tables", "2001:db8::10")] {
+            for chain in OWNED_CHAINS {
+                let key = (binary, "raw".to_string(), chain.to_string());
+                if !enabled {
+                    assert!(!state.chains.contains_key(&key));
+                    continue;
+                }
+                let expected = match chain {
+                    "TELEMT_NOTRACK" => BTreeSet::from(["-j TELEMT_NT_A".to_string()]),
+                    "TELEMT_NT_A" => {
+                        BTreeSet::from([format!("-p tcp --dport 443 -d {ip} -j CT --notrack")])
+                    }
+                    "TELEMT_NT_B" => BTreeSet::new(),
+                    _ => unreachable!(),
+                };
+                assert_eq!(state.chains.get(&key), Some(&expected));
+            }
+            let prerouting = (binary, "raw".to_string(), "PREROUTING".to_string());
+            assert_eq!(
+                state.chains[&prerouting].contains("-j TELEMT_NOTRACK"),
+                enabled
+            );
+        }
+    }
+}
+
+impl FirewallCommandRunner for FixtureRunner {
+    fn available(&self, _binary: &str) -> bool {
+        true
+    }
+
+    fn has_cap_net_admin(&self) -> bool {
+        true
+    }
+
+    async fn run(&self, spec: CommandSpec) -> Result<(), CommandError> {
+        let mut state = self.state.lock().unwrap();
+        state.calls.push(spec.clone());
+        if spec.binary == "nft" {
+            assert_eq!(&spec.args[..3], ["delete", "table", "inet"]);
+            return if state.nft_tables.remove(&spec.args[3]) {
+                Ok(())
+            } else {
+                Err(classified_error(
+                    &spec,
+                    "Error: Could not process rule: No such file or directory",
+                ))
+            };
+        }
+        if let Some(script) = &spec.stdin {
+            let binary = match spec.binary {
+                "iptables-restore" => "iptables",
+                "ip6tables-restore" => "ip6tables",
+                _ => panic!("unexpected restore helper"),
+            };
+            assert_eq!(spec.args, ["--noflush"]);
+            for line in script.lines().filter(|line| line.starts_with('-')) {
+                let fields = line.split_whitespace().collect::<Vec<_>>();
+                let key = (binary, "raw".to_string(), fields[1].to_string());
+                let rules = state.chains.get_mut(&key).expect("restore target exists");
+                match fields[0] {
+                    "-F" => rules.clear(),
+                    "-A" => {
+                        rules.insert(fields[2..].join(" "));
+                    }
+                    _ => panic!("unexpected restore operation"),
+                }
+            }
+            return Ok(());
+        }
+        assert!(matches!(spec.binary, "iptables" | "ip6tables"));
+        assert_eq!(spec.args[0], "-t");
+        let operation = spec.args[2].as_str();
+        let key = (spec.binary, spec.args[1].clone(), spec.args[3].clone());
+        match operation {
+            "-N" => {
+                if state.chains.contains_key(&key) {
+                    Err(classified_error(&spec, "iptables: Chain already exists."))
+                } else {
+                    state.chains.insert(key, BTreeSet::new());
+                    Ok(())
+                }
+            }
+            "-C" | "-D" => {
+                if operation == "-D"
+                    && let Some(message) = state.failure.take()
+                {
+                    return Err(classified_error(&spec, message));
+                }
+                let target = (spec.binary, spec.args[1].clone(), spec.args[5].clone());
+                if !state.chains.contains_key(&target) {
+                    return Err(classified_error(
+                        &spec,
+                        &missing_chain(spec.binary, &spec.args[5]),
+                    ));
+                }
+                let rules = state.chains.get_mut(&key).expect("builtin chain exists");
+                let rule = spec.args[4..].join(" ");
+                if !rules.contains(&rule) {
+                    return Err(classified_error(
+                        &spec,
+                        "Bad rule (does a matching rule exist in that chain?).",
+                    ));
+                }
+                if operation == "-D" {
+                    rules.remove(&rule);
+                }
+                Ok(())
+            }
+            "-I" => {
+                let target = (spec.binary, spec.args[1].clone(), spec.args[6].clone());
+                if !state.chains.contains_key(&target) {
+                    return Err(classified_error(
+                        &spec,
+                        &missing_chain(spec.binary, &spec.args[6]),
+                    ));
+                }
+                state
+                    .chains
+                    .get_mut(&key)
+                    .unwrap()
+                    .insert(spec.args[5..].join(" "));
+                Ok(())
+            }
+            "-F" | "-X" => {
+                let Some(rules) = state.chains.get_mut(&key) else {
+                    return Err(classified_error(
+                        &spec,
+                        "iptables: No chain/target/match by that name.",
+                    ));
+                };
+                if operation == "-F" {
+                    rules.clear();
+                } else {
+                    assert!(rules.is_empty());
+                    state.chains.remove(&key);
+                }
+                Ok(())
+            }
+            _ => panic!("unexpected iptables operation"),
+        }
+    }
+}
+
+#[test]
+fn quoted_missing_chains_are_scoped_to_owned_commands() {
+    for binary in ["iptables", "ip6tables"] {
+        for operation in ["-C", "-D"] {
+            let spec = CommandSpec::new(
+                binary,
+                ["-t", "raw", operation, "PREROUTING", "-j", "TELEMT_NOTRACK"],
+            );
+            let message = missing_chain(binary, "TELEMT_NOTRACK");
+            let error = classified_error(&spec, &message);
+            assert_eq!(error.kind, CommandErrorKind::NotFound, "{spec:?}");
+            assert_eq!(error.message, message);
+        }
+        for operation in ["-F", "-X"] {
+            for chain in OWNED_CHAINS {
+                let spec = CommandSpec::new(binary, ["-t", "raw", operation, chain]);
+                assert_eq!(
+                    classified_error(&spec, &missing_chain(binary, chain)).kind,
+                    CommandErrorKind::NotFound,
+                );
+            }
+        }
+        let spec = CommandSpec::new(binary, ["-t", "raw", "-F", "TELEMT_NOTRACK"]);
+        for message in [
+            "Chain 'TELEMT_NOTRACK' does not exist".to_string(),
+            format!("{binary} v1.8.11 (nf_tables): Chain 'TELEMT_NOTRACK' does not exist"),
+        ] {
+            assert_eq!(
+                classified_error(&spec, &message).kind,
+                CommandErrorKind::NotFound
+            );
+        }
+    }
+}
+
+#[test]
+fn unrelated_commands_and_diagnostics_remain_failures() {
+    let message = missing_chain("iptables", "TELEMT_NOTRACK");
+    for spec in [
+        CommandSpec::new("iptables", ["-t", "raw", "-N", "TELEMT_NOTRACK"]),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-A", "PREROUTING", "-j", "TELEMT_NOTRACK"],
+        ),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-I", "PREROUTING", "1", "-j", "TELEMT_NOTRACK"],
+        ),
+        CommandSpec::new("iptables", ["-t", "filter", "-F", "TELEMT_NOTRACK"]),
+        CommandSpec::new("iptables", ["-t", "raw", "-F", "TELEMT_NT_A"]),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-D", "PREROUTING", "-j", "TELEMT_NT_A"],
+        ),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-D", "INPUT", "-j", "TELEMT_NOTRACK"],
+        ),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-D", "PREROUTING", "-g", "TELEMT_NOTRACK"],
+        ),
+        CommandSpec::new("iptables", ["-F", "TELEMT_NOTRACK"]),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-F", "TELEMT_NOTRACK", "--invalid"],
+        ),
+        CommandSpec::new("iptables-restore", ["--noflush"]),
+        CommandSpec::new("ip6tables-restore", ["--noflush"]),
+        CommandSpec::new("nft", ["delete", "table", "inet", "telemt_conntrack"]),
+        CommandSpec::new("conntrack", ["-D"]),
+    ] {
+        assert_eq!(
+            classified_error(&spec, &message).kind,
+            CommandErrorKind::Failed,
+            "{spec:?}",
+        );
+    }
+    for chain in [
+        "TELEMT_NT_C",
+        "TELEMT_NOTRACK_EXTRA",
+        "MTPR_SYNFIX",
+        "PREROUTING",
+    ] {
+        let spec = CommandSpec::new("iptables", ["-t", "raw", "-F", chain]);
+        assert_eq!(
+            classified_error(&spec, &missing_chain("iptables", chain)).kind,
+            CommandErrorKind::Failed,
+        );
+    }
+    let spec = CommandSpec::new(
+        "iptables",
+        ["-t", "raw", "-D", "PREROUTING", "-j", "TELEMT_NOTRACK"],
+    );
+    for message in [
+        "Permission denied",
+        "can't initialize iptables table `raw': Table does not exist",
+        "Another app is currently holding the xtables lock",
+        "Chain is not empty",
+        "Directory not empty",
+        "Can't delete chain with references left",
+        "unknown option --invalid",
+        "command timed out",
+    ] {
+        assert_eq!(
+            classified_error(&spec, message).kind,
+            CommandErrorKind::Failed
+        );
+    }
+    for message in [
+        format!("{message}\nPermission denied"),
+        format!("Permission denied\n{message}"),
+        "Chain 'TELEMT_NOTRACK' does not exist\nPermission denied".to_string(),
+        "Chain 'TELEMT_NOTRACK' does not exist\n\
+         Try `ip6tables -h' or 'ip6tables --help' for more information."
+            .to_string(),
+        "iptables v1.8.10 (legacy): Chain 'TELEMT_NOTRACK' does not exist".to_string(),
+        "iptables v (nf_tables): Chain 'TELEMT_NOTRACK' does not exist".to_string(),
+        missing_chain("ip6tables", "TELEMT_NOTRACK"),
+        missing_chain("iptables", "TELEMT_NT_A"),
+    ] {
+        assert_eq!(
+            classified_error(&spec, &message).kind,
+            CommandErrorKind::Failed
+        );
+    }
+    for binary in ["nft", "conntrack", "iptables-restore", "ip6tables-restore"] {
+        let spec = CommandSpec::new(binary, ["-t", "raw", "-F", "TELEMT_NOTRACK"]);
+        assert_eq!(
+            classified_error(&spec, "Chain 'TELEMT_NOTRACK' does not exist").kind,
+            CommandErrorKind::Failed,
+        );
+    }
+}
+
+#[tokio::test]
+async fn unknown_recovery_converges_without_touching_foreign_rules() {
+    for policy in [DesiredPolicy::Empty, dual_stack_policy(443)] {
+        let runner = FixtureRunner::new(None);
+        let foreign = runner.foreign_snapshot();
+        let mut applied = AppliedState::Unknown;
+        let requested = desired(1, policy);
+        reconcile_once(&runner, &runner, &mut applied, &requested)
+            .await
+            .unwrap();
+        assert!(matches!(
+            &applied,
+            AppliedState::Known(plan) if plan.matches_policy(&requested.policy)
+        ));
+        runner.assert_owned_policy(matches!(requested.policy, DesiredPolicy::Rules { .. }));
+        assert_eq!(runner.foreign_snapshot(), foreign);
+        for binary in ["iptables", "ip6tables"] {
+            let calls = runner.calls();
+            assert_eq!(
+                calls
+                    .iter()
+                    .filter(|call| call.binary == binary && call.args[2] == "-D")
+                    .count(),
+                1,
+            );
+            assert_eq!(
+                calls
+                    .iter()
+                    .filter(|call| {
+                        call.binary == binary && matches!(call.args[2].as_str(), "-F" | "-X")
+                    })
+                    .count(),
+                6,
+            );
+        }
+        let calls = runner.calls().len();
+        reconcile_once(
+            &runner,
+            &runner,
+            &mut applied,
+            &desired(2, requested.policy.clone()),
+        )
+        .await
+        .unwrap();
+        assert_eq!(runner.calls().len(), calls);
+        recover_to_empty(&runner).await.unwrap();
+        recover_to_empty(&runner).await.unwrap();
+        runner.assert_owned_policy(false);
+        assert_eq!(runner.foreign_snapshot(), foreign);
+    }
+}
+
+#[tokio::test]
+async fn genuine_recovery_failures_leave_state_unknown_and_do_not_install() {
+    for message in [
+        "Permission denied",
+        "can't initialize iptables table `raw': Table does not exist",
+        "Another app is currently holding the xtables lock",
+        "unknown firewall failure",
+    ] {
+        let runner = FixtureRunner::new(Some(message));
+        let mut applied = AppliedState::Unknown;
+        let error = reconcile_once(
+            &runner,
+            &runner,
+            &mut applied,
+            &desired(1, dual_stack_policy(443)),
+        )
+        .await
+        .unwrap_err();
+        assert!(error.message.contains(message));
+        assert_eq!(applied, AppliedState::Unknown);
+        assert!(runner.calls().iter().all(|call| call.stdin.is_none()));
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn actor_converges_then_idles_and_preserves_foreign_rules_on_shutdown() {
+    for failure in [None, Some("Permission denied")] {
+        let runner = FixtureRunner::new(failure);
+        let observed = runner.clone();
+        let foreign = observed.foreign_snapshot();
+        let (desired_tx, desired_rx) = watch::channel(None);
+        let (status_tx, mut status_rx) = watch::channel(None);
+        let terminal = CancellationToken::new();
+        let closed = Arc::new(std::sync::atomic::AtomicBool::new(false));
+        let completed = Arc::new(std::sync::atomic::AtomicBool::new(false));
+        let cleanup = Arc::new(std::sync::atomic::AtomicBool::new(false));
+        let reconciler = FirewallReconciler::new(
+            runner,
+            desired_rx,
+            status_tx,
+            terminal.clone(),
+            closed.clone(),
+            completed.clone(),
+            cleanup.clone(),
+            Arc::new(Notify::new()),
+        );
+        let task = tokio::spawn(reconciler.run(CancellationToken::new()));
+        let requested = desired(1, dual_stack_policy(443));
+        let stats = requested.stats.clone();
+        desired_tx.send_replace(Some(requested));
+        status_rx.changed().await.unwrap();
+        if failure.is_some() {
+            assert_eq!(
+                status_rx.borrow().as_ref().unwrap().outcome,
+                ReconcileOutcome::Failed,
+            );
+            assert!(!stats.get_conntrack_rule_apply_ok());
+            assert_eq!(stats.get_conntrack_rule_reconcile_error_total(), 1);
+            let calls = observed.calls().len();
+            tokio::time::advance(Duration::from_millis(999)).await;
+            tokio::task::yield_now().await;
+            assert_eq!(observed.calls().len(), calls);
+            tokio::time::advance(Duration::from_millis(1)).await;
+            status_rx.changed().await.unwrap();
+        }
+        assert_eq!(
+            status_rx.borrow().as_ref().unwrap().outcome,
+            ReconcileOutcome::Applied,
+        );
+        assert_eq!(status_rx.borrow().as_ref().unwrap().generation, 1);
+        assert!(stats.get_conntrack_rule_apply_ok());
+        assert_eq!(stats.get_conntrack_rule_reconcile_success_total(), 1);
+        assert_eq!(
+            stats.get_conntrack_rule_reconcile_error_total(),
+            u64::from(failure.is_some()),
+        );
+        let calls = observed.calls().len();
+        tokio::time::advance(Duration::from_secs(90)).await;
+        tokio::task::yield_now().await;
+        assert_eq!(observed.calls().len(), calls);
+        assert!(!status_rx.has_changed().unwrap());
+        observed.assert_owned_policy(true);
+        assert_eq!(observed.foreign_snapshot(), foreign);
+        terminal.cancel();
+        tokio::time::timeout(Duration::from_secs(1), task)
+            .await
+            .unwrap()
+            .unwrap();
+        assert!(closed.load(Ordering::Acquire));
+        assert!(completed.load(Ordering::Acquire));
+        assert!(cleanup.load(Ordering::Acquire));
+        assert!(!stats.get_conntrack_rule_apply_ok());
+        observed.assert_owned_policy(false);
+        assert_eq!(observed.foreign_snapshot(), foreign);
+    }
+}

src/conntrack_control/firewall/tests/startup_admission.rs

@@ -0,0 +1,267 @@
+use std::sync::Mutex;
+use std::sync::atomic::AtomicUsize;
+
+use crate::config::{ConntrackBackend, ConntrackMode};
+
+use super::super::command::{CommandErrorKind, CommandSpec, classify_command_error};
+use super::super::transaction::reconcile_once;
+use super::*;
+
+const NETLINK_ERROR: &str =
+    "src/mnl.c:68: Unable to initialize Netlink socket: Address family not supported by protocol";
+const PERMISSION_ERROR: &str = "iptables v1.8.11 (nf_tables): Could not fetch rule set generation id: Permission denied (you must be root)";
+
+#[derive(Clone)]
+struct StartupRunner {
+    has_cap_net_admin: bool,
+    cap_probes: Arc<AtomicUsize>,
+    calls: Arc<Mutex<Vec<CommandSpec>>>,
+    failure: Option<&'static str>,
+}
+
+impl StartupRunner {
+    fn new(has_cap_net_admin: bool, failure: Option<&'static str>) -> Self {
+        Self {
+            has_cap_net_admin,
+            cap_probes: Arc::new(AtomicUsize::new(0)),
+            calls: Arc::new(Mutex::new(Vec::new())),
+            failure,
+        }
+    }
+
+    fn calls(&self) -> Vec<CommandSpec> {
+        self.calls.lock().unwrap().clone()
+    }
+}
+
+impl FirewallCommandRunner for StartupRunner {
+    fn available(&self, _binary: &str) -> bool {
+        true
+    }
+
+    fn has_cap_net_admin(&self) -> bool {
+        self.cap_probes.fetch_add(1, Ordering::Relaxed);
+        self.has_cap_net_admin
+    }
+
+    async fn run(&self, spec: CommandSpec) -> Result<(), CommandError> {
+        self.calls.lock().unwrap().push(spec.clone());
+        if let Some(message) = self.failure {
+            return Err(CommandError {
+                kind: classify_command_error(spec.binary, &spec.args, message),
+                message: message.to_string(),
+            });
+        }
+        if (spec.binary == "nft" && spec.args.first().map(String::as_str) == Some("delete"))
+            || (matches!(spec.binary, "iptables" | "ip6tables")
+                && matches!(
+                    spec.args.get(2).map(String::as_str),
+                    Some("-C" | "-D" | "-F" | "-X")
+                ))
+        {
+            return Err(CommandError {
+                kind: CommandErrorKind::NotFound,
+                message: "injected absent owned object".to_string(),
+            });
+        }
+        Ok(())
+    }
+}
+
+fn start_with_runner(
+    config: &ProxyConfig,
+    runner: StartupRunner,
+    scope: &ProcessControlPlane,
+) -> Option<FirewallAuthority> {
+    let (authority, actor) = FirewallAuthority::prepare(config, runner)?;
+    assert!(
+        scope
+            .spawn_cooperative(move |cancellation| actor.run(cancellation))
+            .is_ok()
+    );
+    Some(authority)
+}
+
+#[tokio::test(start_paused = true)]
+async fn disabled_startup_never_acquires_cleanup_ownership() {
+    for explicit in [false, true] {
+        for has_cap in [true, false] {
+            for backend in [
+                ConntrackBackend::Auto,
+                ConntrackBackend::Nftables,
+                ConntrackBackend::Iptables,
+            ] {
+                for mode in [
+                    ConntrackMode::Tracked,
+                    ConntrackMode::Notrack,
+                    ConntrackMode::Hybrid,
+                ] {
+                    for message in [NETLINK_ERROR, PERMISSION_ERROR] {
+                        let mut config = ProxyConfig::default();
+                        if explicit {
+                            config.server.conntrack_control.inline_conntrack_control = false;
+                            config
+                                .server
+                                .conntrack_control
+                                .inline_conntrack_control_explicit = true;
+                        }
+                        config.server.conntrack_control.backend = backend;
+                        config.server.conntrack_control.mode = mode;
+                        let runner = StartupRunner::new(has_cap, Some(message));
+                        let scope = ProcessControlPlane::new();
+                        let authority = start_with_runner(&config, runner.clone(), &scope);
+                        assert!(
+                            authority.is_none(),
+                            "{explicit} {has_cap} {backend:?} {mode:?}"
+                        );
+                        assert_eq!(runner.cap_probes.load(Ordering::Relaxed), 0);
+                        tokio::time::advance(Duration::from_secs(90)).await;
+                        assert!(scope.shutdown(Duration::from_secs(1)).await);
+                        assert!(runner.calls().is_empty());
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn enabled_startup_without_capability_creates_no_firewall_work() {
+    let mut config = ProxyConfig::default();
+    config.server.conntrack_control.inline_conntrack_control = true;
+    for mode in [ConntrackMode::Tracked, ConntrackMode::Notrack] {
+        config.server.conntrack_control.mode = mode;
+        let runner = StartupRunner::new(false, Some(PERMISSION_ERROR));
+        let scope = ProcessControlPlane::new();
+        assert!(start_with_runner(&config, runner.clone(), &scope).is_none());
+        assert_eq!(runner.cap_probes.load(Ordering::Relaxed), 1);
+        tokio::time::advance(Duration::from_secs(90)).await;
+        assert!(scope.shutdown(Duration::from_secs(1)).await);
+        assert!(runner.calls().is_empty());
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn admitted_startup_preserves_recovery_idle_and_shutdown_cleanup() {
+    for mode in [ConntrackMode::Tracked, ConntrackMode::Notrack] {
+        let mut config = ProxyConfig::default();
+        config.server.conntrack_control.inline_conntrack_control = true;
+        config.server.conntrack_control.mode = mode;
+        config.server.conntrack_control.backend = ConntrackBackend::Nftables;
+        let runner = StartupRunner::new(true, None);
+        let scope = ProcessControlPlane::new();
+        let authority = start_with_runner(&config, runner.clone(), &scope).unwrap();
+        let stats = Arc::new(Stats::new());
+        assert!(
+            authority
+                .publish_initial(1, Arc::new(config), stats.clone())
+                .await
+        );
+        assert!(stats.get_conntrack_rule_apply_ok());
+        for binary in ["nft", "iptables", "ip6tables"] {
+            assert!(runner.calls().iter().any(|call| call.binary == binary));
+        }
+        let calls = runner.calls().len();
+        tokio::time::advance(Duration::from_secs(90)).await;
+        tokio::task::yield_now().await;
+        assert_eq!(runner.calls().len(), calls);
+        assert!(authority.shutdown_and_clear().await);
+        assert!(!stats.get_conntrack_rule_apply_ok());
+        assert!(runner.calls().len() > calls);
+        assert!(scope.shutdown(Duration::from_secs(1)).await);
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn admitted_process_cancellation_preserves_cleanup() {
+    let mut config = ProxyConfig::default();
+    config.server.conntrack_control.inline_conntrack_control = true;
+    let runner = StartupRunner::new(true, None);
+    let scope = ProcessControlPlane::new();
+    let authority = start_with_runner(&config, runner.clone(), &scope).unwrap();
+    assert!(scope.shutdown(Duration::from_secs(1)).await);
+    assert!(authority.shutdown_and_clear().await);
+    assert!(!runner.calls().is_empty());
+}
+
+#[test]
+fn netlink_and_permission_errors_are_not_classified_as_absence() {
+    for spec in [
+        CommandSpec::new("nft", ["delete", "table", "inet", "telemt_conntrack"]),
+        CommandSpec::new("nft", ["-f", "-"]),
+        CommandSpec::new(
+            "iptables",
+            ["-t", "raw", "-D", "PREROUTING", "-j", "TELEMT_NOTRACK"],
+        ),
+        CommandSpec::new("iptables", ["-t", "raw", "-F", "TELEMT_NT_A"]),
+        CommandSpec::new("ip6tables", ["-t", "raw", "-X", "TELEMT_NT_B"]),
+        CommandSpec::new("iptables-restore", ["--noflush"]),
+        CommandSpec::new("ip6tables-restore", ["--noflush"]),
+    ] {
+        for message in [
+            NETLINK_ERROR,
+            PERMISSION_ERROR,
+            "iptables: Failed to initialize nft: Address family not supported by protocol",
+        ] {
+            assert_eq!(
+                classify_command_error(spec.binary, &spec.args, message),
+                CommandErrorKind::Failed,
+                "{spec:?} {message}",
+            );
+        }
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn admitted_genuine_failures_remain_unknown_and_retry() {
+    for message in [NETLINK_ERROR, PERMISSION_ERROR] {
+        let mut config = ProxyConfig::default();
+        config.server.conntrack_control.inline_conntrack_control = true;
+        config.server.conntrack_control.mode = ConntrackMode::Notrack;
+        config.server.conntrack_control.backend = ConntrackBackend::Nftables;
+        let runner = StartupRunner::new(true, Some(message));
+        let mut applied = AppliedState::Unknown;
+        let requested = DesiredState {
+            generation: 1,
+            policy: DesiredPolicy::from_config(&config),
+            stats: Arc::new(Stats::new()),
+        };
+        let error = reconcile_once(&runner, &runner, &mut applied, &requested)
+            .await
+            .unwrap_err();
+        assert!(error.message.contains(message));
+        assert_eq!(applied, AppliedState::Unknown);
+        assert!(runner.calls().iter().all(|call| call.stdin.is_none()));
+
+        let scope = ProcessControlPlane::new();
+        let authority = start_with_runner(&config, runner.clone(), &scope).unwrap();
+        let stats = Arc::new(Stats::new());
+        assert!(
+            !authority
+                .publish_initial(1, Arc::new(config), stats.clone())
+                .await
+        );
+        assert!(!stats.get_conntrack_rule_apply_ok());
+        assert_eq!(stats.get_conntrack_rule_reconcile_error_total(), 1);
+        let mut status = authority.status_rx.clone();
+        assert_eq!(
+            status.borrow_and_update().as_ref().unwrap().outcome,
+            ReconcileOutcome::Failed,
+        );
+        let calls = runner.calls().len();
+        tokio::time::advance(Duration::from_millis(999)).await;
+        tokio::task::yield_now().await;
+        assert_eq!(runner.calls().len(), calls);
+        tokio::time::advance(Duration::from_millis(1)).await;
+        status.changed().await.unwrap();
+        assert_eq!(
+            status.borrow().as_ref().unwrap().outcome,
+            ReconcileOutcome::Failed,
+        );
+        assert_eq!(stats.get_conntrack_rule_reconcile_error_total(), 2);
+        assert!(!authority.shutdown_and_clear().await);
+        assert!(authority.completed_flag.load(Ordering::Acquire));
+        assert!(scope.shutdown(Duration::from_secs(1)).await);
+        assert!(runner.calls().iter().all(|call| call.stdin.is_none()));
+    }
+}

src/daemon/mod.rs

@@ -9,7 +9,7 @@ use std::os::unix::fs::OpenOptionsExt;
 use std::path::{Path, PathBuf};
 
 use nix::errno::Errno;
-use nix::unistd::{self, ForkResult, Gid, Uid, chdir, close, fork, getpid, setsid};
+use nix::unistd::{self, ForkResult, Gid, Uid, chdir, fork, getpid, setsid};
 use tracing::info;
 
 // PID file ownership and process-control helpers.
@@ -29,6 +29,8 @@ pub struct DaemonOptions {
     pub daemonize: bool,
     /// Path to PID file.
     pub pid_file: Option<PathBuf>,
+    /// Require trusted, symlink-free PID and log parents. Disabled by default for compatibility.
+    pub strict_runtime_paths: bool,
     /// User to run as after binding sockets.
     pub user: Option<String>,
     /// Group to run as after binding sockets.
@@ -174,8 +176,10 @@ fn redirect_stdio_to_devnull() -> Result<(), DaemonError> {
         }
     }
 
-    if devnull_fd > 2 {
-        let _ = close(devnull_fd);
+    // Keep stdio descriptors open; other source descriptors are closed once by File's Drop.
+    // Transfer ownership only after all dup2 calls succeed so errors retain RAII cleanup.
+    if devnull_fd <= 2 {
+        let _ = std::os::unix::io::IntoRawFd::into_raw_fd(devnull);
     }
 
     Ok(())
@@ -332,6 +336,7 @@ mod tests {
     fn test_daemon_options_default() {
         let opts = DaemonOptions::default();
         assert!(!opts.daemonize);
+        assert!(!opts.strict_runtime_paths);
         assert!(!opts.should_daemonize());
         assert_eq!(opts.pid_file_path(), Path::new(DEFAULT_PID_FILE));
     }

src/daemon/pid_file.rs

@@ -17,6 +17,7 @@ use crate::util::secure_fs::AnchoredPath;
 /// PID file manager backed by a persistent sibling lock file.
 pub struct PidFile {
     path: PathBuf,
+    strict_runtime_paths: bool,
     lock_path: PathBuf,
     pid_file: Option<File>,
     pid_identity: Option<FileIdentity>,
@@ -40,12 +41,13 @@ impl FileIdentity {
 }
 
 impl PidFile {
-    /// Creates a new PID file manager for the given path.
-    pub fn new<P: AsRef<Path>>(path: P) -> Self {
+    /// Creates a PID manager with explicit parent-path policy; `false` allows legacy parents.
+    pub fn new<P: AsRef<Path>>(path: P, strict_runtime_paths: bool) -> Self {
         let path = normalize_pid_path(path.as_ref());
         let lock_path = sibling_lock_path(&path);
         Self {
             path,
+            strict_runtime_paths,
             lock_path,
             pid_file: None,
             pid_identity: None,
@@ -56,7 +58,7 @@ impl PidFile {
 
     /// Checks whether the PID file names a running process without modifying either file.
     pub fn check_running(&self) -> Result<Option<i32>, DaemonError> {
-        let Some(pid) = read_pid_file_if_exists(&self.path)? else {
+        let Some(pid) = read_pid_file_if_exists(&self.path, self.strict_runtime_paths)? else {
             return Ok(None);
         };
         Ok(is_process_running(pid).then_some(pid))
@@ -67,9 +69,10 @@ impl PidFile {
     /// Fails if another owner holds the lock or the existing PID names a running process.
     pub fn acquire(&mut self) -> Result<(), DaemonError> {
         let anchor =
-            AnchoredPath::open_trusted_parent_or_create(&self.path, 0o755).map_err(|error| {
+            AnchoredPath::open_runtime_parent(&self.path, Some(0o755), self.strict_runtime_paths)
+                .map_err(|error| {
                 DaemonError::PidFile(format!(
-                    "cannot open trusted parent for {}: {}",
+                    "cannot open PID parent for {}: {}",
                     self.path.display(),
                     error
                 ))
@@ -245,13 +248,16 @@ fn open_file_at(anchor: &AnchoredPath, name: &OsStr, flags: OFlag, mode: u32) ->
     Ok(File::from(descriptor))
 }
 
-fn read_pid_file_if_exists(path: &Path) -> Result<Option<i32>, DaemonError> {
-    let anchor = match AnchoredPath::open_trusted_parent(path) {
+fn read_pid_file_if_exists(
+    path: &Path,
+    strict_runtime_paths: bool,
+) -> Result<Option<i32>, DaemonError> {
+    let anchor = match AnchoredPath::open_runtime_parent(path, None, strict_runtime_paths) {
         Ok(anchor) => anchor,
         Err(error) if error.kind() == ErrorKind::NotFound => return Ok(None),
         Err(error) => {
             return Err(DaemonError::PidFile(format!(
-                "cannot open trusted parent for {}: {}",
+                "cannot open PID parent for {}: {}",
                 path.display(),
                 error
             )));
@@ -352,11 +358,14 @@ fn validate_regular_single_link(file: &File, path: &Path) -> Result<fs::Metadata
     Ok(metadata)
 }
 
-/// Reads a PID from a PID file.
+/// Reads a PID using the selected parent-path policy; `false` allows legacy parents.
 #[allow(dead_code)]
-pub fn read_pid_file<P: AsRef<Path>>(path: P) -> Result<i32, DaemonError> {
+pub fn read_pid_file<P: AsRef<Path>>(
+    path: P,
+    strict_runtime_paths: bool,
+) -> Result<i32, DaemonError> {
     let path = normalize_pid_path(path.as_ref());
-    read_pid_file_if_exists(&path)?.ok_or_else(|| {
+    read_pid_file_if_exists(&path, strict_runtime_paths)?.ok_or_else(|| {
         DaemonError::PidFile(format!(
             "cannot read {}: file does not exist",
             path.display()
@@ -364,17 +373,18 @@ pub fn read_pid_file<P: AsRef<Path>>(path: P) -> Result<i32, DaemonError> {
     })
 }
 
-/// Sends a signal to the process specified in a PID file.
+/// Signals a lock-owning process using the same parent-path policy for PID and lock files.
 #[allow(dead_code)]
 pub fn signal_pid_file<P: AsRef<Path>>(
     path: P,
     signal: nix::sys::signal::Signal,
+    strict_runtime_paths: bool,
 ) -> Result<(), DaemonError> {
     let path = normalize_pid_path(path.as_ref());
-    let pid = read_pid_file(&path)?;
+    let pid = read_pid_file(&path, strict_runtime_paths)?;
     #[cfg(target_os = "linux")]
     let pidfd = open_pidfd(pid)?;
-    if !daemon_lock_is_held(&path)? {
+    if !daemon_lock_is_held(&path, strict_runtime_paths)? {
         return Err(DaemonError::PidFile(format!(
             "refusing to signal unlocked or stale PID file {}",
             path.display()
@@ -399,12 +409,15 @@ pub enum DaemonStatus {
     NotRunning,
 }
 
-/// Checks daemon status without modifying the PID or lock file.
+/// Checks daemon status read-only, applying the selected policy to both parent lookups.
 #[allow(dead_code)]
-pub fn check_status<P: AsRef<Path>>(path: P) -> DaemonStatus {
+pub fn check_status<P: AsRef<Path>>(path: P, strict_runtime_paths: bool) -> DaemonStatus {
     let path = normalize_pid_path(path.as_ref());
-    match read_pid_file_if_exists(&path) {
-        Ok(Some(pid)) if daemon_lock_is_held(&path).unwrap_or(false) && is_process_running(pid) => {
+    match read_pid_file_if_exists(&path, strict_runtime_paths) {
+        Ok(Some(pid))
+            if daemon_lock_is_held(&path, strict_runtime_paths).unwrap_or(false)
+                && is_process_running(pid) =>
+        {
             DaemonStatus::Running(pid)
         }
         Ok(Some(pid)) => DaemonStatus::Stale(pid),
@@ -412,14 +425,14 @@ pub fn check_status<P: AsRef<Path>>(path: P) -> DaemonStatus {
     }
 }
 
-fn daemon_lock_is_held(path: &Path) -> Result<bool, DaemonError> {
+fn daemon_lock_is_held(path: &Path, strict_runtime_paths: bool) -> Result<bool, DaemonError> {
     let lock_path = sibling_lock_path(path);
-    let anchor = match AnchoredPath::open_trusted_parent(path) {
+    let anchor = match AnchoredPath::open_runtime_parent(path, None, strict_runtime_paths) {
         Ok(anchor) => anchor,
         Err(error) if error.kind() == ErrorKind::NotFound => return Ok(false),
         Err(error) => {
             return Err(DaemonError::PidFile(format!(
-                "cannot open trusted parent for {}: {}",
+                "cannot open PID parent for {}: {}",
                 path.display(),
                 error
             )));

src/daemon/pid_file/tests.rs

@@ -38,6 +38,107 @@ fn pid_file_remains_send_and_sync() {
     assert_send_sync::<PidFile>();
 }
 
+#[test]
+fn compatibility_pid_lifecycle_accepts_writable_parent_directories() {
+    use std::os::unix::fs::PermissionsExt;
+
+    for mode in [0o770, 0o777, 0o1777] {
+        let directory = tempfile::tempdir().unwrap();
+        fs::set_permissions(directory.path(), fs::Permissions::from_mode(mode)).unwrap();
+        let pid_path = directory.path().join("telemt.pid");
+        let mut strict_owner = PidFile::new(&pid_path, true);
+        assert!(strict_owner.acquire().is_err());
+        assert!(!pid_path.exists());
+        assert!(!sibling_lock_path(&pid_path).exists());
+        let mut owner = PidFile::new(&pid_path, false);
+        owner.acquire().unwrap();
+
+        assert_eq!(
+            read_pid_file(&pid_path, false).unwrap(),
+            std::process::id() as i32
+        );
+        assert_eq!(
+            owner.check_running().unwrap(),
+            Some(std::process::id() as i32)
+        );
+        assert_eq!(
+            check_status(&pid_path, false),
+            DaemonStatus::Running(std::process::id() as i32)
+        );
+        assert!(read_pid_file(&pid_path, true).is_err());
+        assert!(strict_owner.check_running().is_err());
+        assert_eq!(check_status(&pid_path, true), DaemonStatus::NotRunning);
+
+        owner.release().unwrap();
+        assert!(!pid_path.exists());
+        assert!(sibling_lock_path(&pid_path).exists());
+        assert_eq!(check_status(&pid_path, false), DaemonStatus::NotRunning);
+    }
+}
+
+#[test]
+fn compatibility_pid_lifecycle_follows_symlinked_parents() {
+    let directory = tempfile::tempdir().unwrap();
+    let real = directory.path().join("tmp");
+    let linked = directory.path().join("var");
+    fs::create_dir(&real).unwrap();
+    symlink("tmp", &linked).unwrap();
+    let pid_path = linked.join("run/telemt.pid");
+    let mut strict_owner = PidFile::new(&pid_path, true);
+    assert!(strict_owner.acquire().is_err());
+    assert!(!real.join("run").exists());
+    let mut owner = PidFile::new(&pid_path, false);
+    owner.acquire().unwrap();
+
+    assert_eq!(
+        read_pid_file(&pid_path, false).unwrap(),
+        std::process::id() as i32
+    );
+    assert_eq!(
+        check_status(&pid_path, false),
+        DaemonStatus::Running(std::process::id() as i32)
+    );
+    assert!(real.join("run/telemt.pid.lock").exists());
+    assert!(read_pid_file(&pid_path, true).is_err());
+    assert_eq!(check_status(&pid_path, true), DaemonStatus::NotRunning);
+
+    owner.release().unwrap();
+    assert!(!real.join("run/telemt.pid").exists());
+}
+
+#[test]
+fn private_pid_parent_supports_both_policies() {
+    for strict_runtime_paths in [false, true] {
+        let directory = tempfile::tempdir().unwrap();
+        let pid_path = directory.path().join("nested/run/telemt.pid");
+        let mut owner = PidFile::new(&pid_path, strict_runtime_paths);
+        owner.acquire().unwrap();
+
+        for read_strict in [false, true] {
+            assert_eq!(
+                read_pid_file(&pid_path, read_strict).unwrap(),
+                std::process::id() as i32
+            );
+            assert_eq!(
+                check_status(&pid_path, read_strict),
+                DaemonStatus::Running(std::process::id() as i32)
+            );
+        }
+        assert_eq!(
+            fs::metadata(pid_path.parent().unwrap()).unwrap().mode() & 0o777,
+            0o755
+        );
+        let mut contender = PidFile::new(&pid_path, strict_runtime_paths);
+        assert!(matches!(
+            contender.acquire(),
+            Err(DaemonError::AlreadyRunning(_))
+        ));
+        owner.release().unwrap();
+        contender.acquire().unwrap();
+        contender.release().unwrap();
+    }
+}
+
 #[test]
 fn system_var_run_alias_keeps_the_default_pid_path_usable() {
     let Ok(metadata) = fs::symlink_metadata("/var/run") else {
@@ -52,7 +153,7 @@ fn system_var_run_alias_keeps_the_default_pid_path_usable() {
         return;
     }
 
-    let pid_file = PidFile::new("/var/run/telemt.pid");
+    let pid_file = PidFile::new("/var/run/telemt.pid", false);
 
     assert_eq!(pid_file.path(), Path::new("/run/telemt.pid"));
 }
@@ -64,7 +165,7 @@ fn lock_holder_subprocess() {
     };
     let ready_path = PathBuf::from(std::env::var_os(HELPER_READY_PATH).unwrap());
     let stop_path = PathBuf::from(std::env::var_os(HELPER_STOP_PATH).unwrap());
-    let mut pid_file = PidFile::new(PathBuf::from(pid_path));
+    let mut pid_file = PidFile::new(PathBuf::from(pid_path), false);
     pid_file.acquire().unwrap();
     fs::write(&ready_path, b"ready").unwrap();
     assert!(wait_for_path(&stop_path, Duration::from_secs(10)));
@@ -100,7 +201,7 @@ fn persistent_sibling_lock_serializes_processes_after_pid_unlink() {
     let lock_inode = fs::metadata(&lock_path).unwrap().ino();
     fs::remove_file(&pid_path).unwrap();
 
-    let mut contender = PidFile::new(&pid_path);
+    let mut contender = PidFile::new(&pid_path, false);
     assert!(contender.acquire().is_err());
 
     fs::write(&stop_path, b"stop").unwrap();
@@ -123,10 +224,13 @@ fn stale_pid_checks_are_read_only() {
     let directory = tempfile::tempdir().unwrap();
     let pid_path = directory.path().join("telemt.pid");
     fs::write(&pid_path, b"2000000000\n").unwrap();
-    let pid_file = PidFile::new(&pid_path);
+    let pid_file = PidFile::new(&pid_path, false);
 
     assert_eq!(pid_file.check_running().unwrap(), None);
-    assert_eq!(check_status(&pid_path), DaemonStatus::Stale(2_000_000_000));
+    assert_eq!(
+        check_status(&pid_path, false),
+        DaemonStatus::Stale(2_000_000_000)
+    );
     assert!(pid_path.exists());
 }
 
@@ -136,15 +240,15 @@ fn status_requires_live_lock_ownership() {
     let pid_path = directory.path().join("telemt.pid");
     fs::write(&pid_path, format!("{}\n", std::process::id())).unwrap();
     assert_eq!(
-        check_status(&pid_path),
+        check_status(&pid_path, false),
         DaemonStatus::Stale(std::process::id() as i32)
     );
 
     fs::remove_file(&pid_path).unwrap();
-    let mut owner = PidFile::new(&pid_path);
+    let mut owner = PidFile::new(&pid_path, false);
     owner.acquire().unwrap();
     assert_eq!(
-        check_status(&pid_path),
+        check_status(&pid_path, false),
         DaemonStatus::Running(std::process::id() as i32)
     );
     owner.release().unwrap();
@@ -155,7 +259,7 @@ fn unowned_release_does_not_remove_pid_file() {
     let directory = tempfile::tempdir().unwrap();
     let pid_path = directory.path().join("telemt.pid");
     fs::write(&pid_path, b"2000000000\n").unwrap();
-    let mut pid_file = PidFile::new(&pid_path);
+    let mut pid_file = PidFile::new(&pid_path, false);
 
     pid_file.release().unwrap();
 
@@ -169,10 +273,11 @@ fn acquire_rejects_pid_symlink_without_truncating_target() {
     let target_path = directory.path().join("target");
     fs::write(&target_path, b"preserve\n").unwrap();
     symlink(&target_path, &pid_path).unwrap();
-    let mut pid_file = PidFile::new(&pid_path);
-
-    assert!(pid_file.acquire().is_err());
-    assert_eq!(fs::read(&target_path).unwrap(), b"preserve\n");
+    for strict_runtime_paths in [false, true] {
+        let mut pid_file = PidFile::new(&pid_path, strict_runtime_paths);
+        assert!(pid_file.acquire().is_err());
+        assert_eq!(fs::read(&target_path).unwrap(), b"preserve\n");
+    }
 }
 
 #[test]
@@ -182,10 +287,11 @@ fn acquire_rejects_pid_hard_link_without_truncating_target() {
     let target_path = directory.path().join("target");
     fs::write(&target_path, b"preserve\n").unwrap();
     fs::hard_link(&target_path, &pid_path).unwrap();
-    let mut pid_file = PidFile::new(&pid_path);
-
-    assert!(pid_file.acquire().is_err());
-    assert_eq!(fs::read(&target_path).unwrap(), b"preserve\n");
+    for strict_runtime_paths in [false, true] {
+        let mut pid_file = PidFile::new(&pid_path, strict_runtime_paths);
+        assert!(pid_file.acquire().is_err());
+        assert_eq!(fs::read(&target_path).unwrap(), b"preserve\n");
+    }
 }
 
 #[test]
@@ -196,7 +302,7 @@ fn acquire_rejects_symlinked_parent_without_publishing_outside() {
     fs::create_dir(&real_parent).unwrap();
     symlink(&real_parent, &linked_parent).unwrap();
     let pid_path = linked_parent.join("telemt.pid");
-    let mut pid_file = PidFile::new(&pid_path);
+    let mut pid_file = PidFile::new(&pid_path, true);
 
     assert!(pid_file.acquire().is_err());
     assert!(!real_parent.join("telemt.pid").exists());
@@ -210,7 +316,7 @@ fn release_remains_anchored_after_parent_path_replacement() {
     let moved_parent = directory.path().join("moved");
     fs::create_dir(&active_parent).unwrap();
     let pid_path = active_parent.join("telemt.pid");
-    let mut pid_file = PidFile::new(&pid_path);
+    let mut pid_file = PidFile::new(&pid_path, false);
     pid_file.acquire().unwrap();
 
     fs::rename(&active_parent, &moved_parent).unwrap();
@@ -231,7 +337,7 @@ fn release_does_not_remove_replacement_path() {
     let directory = tempfile::tempdir().unwrap();
     let pid_path = directory.path().join("telemt.pid");
     let owned_path = directory.path().join("owned.pid");
-    let mut pid_file = PidFile::new(&pid_path);
+    let mut pid_file = PidFile::new(&pid_path, false);
     pid_file.acquire().unwrap();
     fs::rename(&pid_path, &owned_path).unwrap();
     fs::write(&pid_path, b"replacement\n").unwrap();
@@ -253,7 +359,7 @@ fn pid_parser_rejects_process_group_values() {
 
     for value in ["-1\n", "0\n", "1\n"] {
         fs::write(&pid_path, value).unwrap();
-        assert!(read_pid_file(&pid_path).is_err());
+        assert!(read_pid_file(&pid_path, false).is_err());
     }
 }
 
@@ -262,7 +368,7 @@ fn pid_file_release_keeps_lock_inode() {
     let directory = tempfile::tempdir().unwrap();
     let pid_path = directory.path().join("telemt.pid");
     let lock_path = sibling_lock_path(&pid_path);
-    let mut pid_file = PidFile::new(&pid_path);
+    let mut pid_file = PidFile::new(&pid_path, false);
 
     pid_file.acquire().unwrap();
     assert!(
@@ -271,7 +377,10 @@ fn pid_file_release_keeps_lock_inode() {
             .into_iter()
             .all(|file| file.is_some())
     );
-    assert_eq!(read_pid_file(&pid_path).unwrap(), std::process::id() as i32);
+    assert_eq!(
+        read_pid_file(&pid_path, false).unwrap(),
+        std::process::id() as i32
+    );
     let lock_inode = fs::metadata(&lock_path).unwrap().ino();
     pid_file.release().unwrap();
 

src/logging.rs

@@ -77,6 +77,8 @@ pub struct LoggingOptions {
     pub destination: LogDestination,
     /// Disable ANSI colors.
     pub disable_colors: bool,
+    /// Require trusted, symlink-free log parents on Unix. Disabled by default for compatibility.
+    pub strict_runtime_paths: bool,
 }
 
 /// Guard that must be held to keep file logging active.
@@ -125,7 +127,6 @@ pub fn init_logging(
 
         #[cfg(unix)]
         LogDestination::Syslog => {
-            // Use a custom fmt layer that writes to syslog
             let fmt_layer = fmt::Layer::default()
                 .with_ansi(false)
                 .with_target(false)
@@ -143,7 +144,8 @@ pub fn init_logging(
 
         LogDestination::File { options } => {
             let file_appender =
-                file::BoundedFileAppender::new(options.clone()).expect("Failed to open log file");
+                file::BoundedFileAppender::new(options.clone(), opts.strict_runtime_paths)
+                    .expect("Failed to open log file");
             let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);
 
             let fmt_layer = fmt::Layer::default()
@@ -175,14 +177,10 @@ struct SyslogWriter {
 #[cfg(unix)]
 impl SyslogMakeWriter {
     fn new() -> Self {
-        // Open syslog connection on first use
         static INIT: std::sync::Once = std::sync::Once::new();
-        INIT.call_once(|| {
-            unsafe {
-                // Open syslog with ident "telemt", LOG_PID, LOG_DAEMON facility
-                let ident = b"telemt\0".as_ptr() as *const libc::c_char;
-                libc::openlog(ident, libc::LOG_PID | libc::LOG_NDELAY, libc::LOG_DAEMON);
-            }
+        INIT.call_once(|| unsafe {
+            let ident = b"telemt\0".as_ptr() as *const libc::c_char;
+            libc::openlog(ident, libc::LOG_PID | libc::LOG_NDELAY, libc::LOG_DAEMON);
         });
         Self
     }
@@ -202,7 +200,6 @@ fn syslog_priority_for_level(level: &tracing::Level) -> libc::c_int {
 #[cfg(unix)]
 impl std::io::Write for SyslogWriter {
     fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
-        // Convert to C string, stripping newlines
         let msg = String::from_utf8_lossy(buf);
         let msg = msg.trim_end();
 
@@ -210,7 +207,6 @@ impl std::io::Write for SyslogWriter {
             return Ok(buf.len());
         }
 
-        // Write to syslog
         let c_msg = std::ffi::CString::new(msg.as_bytes())
             .unwrap_or_else(|_| std::ffi::CString::new("(invalid utf8)").unwrap());
 

src/logging/file.rs

@@ -44,13 +44,15 @@ pub(crate) struct BoundedFileAppender {
 }
 
 impl BoundedFileAppender {
-    pub(crate) fn new(options: FileLogOptions) -> io::Result<Self> {
-        Self::with_now(options, Box::new(Utc::now))
+    /// Opens the appender using the process-level Unix parent-path policy.
+    pub(crate) fn new(options: FileLogOptions, strict_runtime_paths: bool) -> io::Result<Self> {
+        Self::with_now(options, Box::new(Utc::now), strict_runtime_paths)
     }
 
     fn with_now(
         options: FileLogOptions,
         now: Box<dyn Fn() -> DateTime<Utc> + Send + Sync>,
+        strict_runtime_paths: bool,
     ) -> io::Result<Self> {
         let path = Path::new(&options.path);
         let dir = path
@@ -67,7 +69,13 @@ impl BoundedFileAppender {
         let start = now();
         let current_path = active_path_for(&dir, &base_name, options.rotation, &start);
         #[cfg(unix)]
-        let dir_fd = crate::util::secure_fs::open_trusted_dir_nofollow_or_create(&dir, 0o750)?;
+        let dir_fd = if strict_runtime_paths {
+            crate::util::secure_fs::open_trusted_dir_nofollow_or_create(&dir, 0o750)?
+        } else {
+            crate::util::secure_fs::open_compatible_dir(&dir, Some(0o750))?
+        };
+        #[cfg(not(unix))]
+        let _ = strict_runtime_paths;
         #[cfg(unix)]
         let (file, current_size) = open_append_file(&dir_fd, &current_path)?;
         #[cfg(not(unix))]

src/logging/file/tests.rs

@@ -34,6 +34,115 @@ fn matching_logs(dir: &Path) -> Vec<PathBuf> {
     files
 }
 
+#[cfg(unix)]
+#[test]
+fn compatibility_appender_accepts_writable_log_directories() {
+    use std::os::unix::fs::PermissionsExt;
+
+    for mode in [0o770, 0o777, 0o1777] {
+        let dir = tempdir().unwrap();
+        fs::set_permissions(dir.path(), fs::Permissions::from_mode(mode)).unwrap();
+        let path = dir.path().join("telemt.log");
+        assert!(
+            BoundedFileAppender::with_now(options(path.clone()), Box::new(fixed_now), true)
+                .is_err()
+        );
+        assert!(!path.exists());
+        let mut appender =
+            BoundedFileAppender::with_now(options(path.clone()), Box::new(fixed_now), false)
+                .unwrap();
+        appender.write_all(b"compatibility\n").unwrap();
+        appender.flush().unwrap();
+
+        assert_eq!(fs::read(&path).unwrap(), b"compatibility\n");
+        assert_eq!(
+            fs::metadata(&path).unwrap().permissions().mode() & 0o777,
+            0o640
+        );
+    }
+}
+
+#[cfg(unix)]
+#[test]
+fn compatibility_appender_follows_symlinked_parents() {
+    use std::os::unix::fs::symlink;
+
+    let dir = tempdir().unwrap();
+    let real = dir.path().join("real");
+    let linked = dir.path().join("linked");
+    fs::create_dir(&real).unwrap();
+    symlink(&real, &linked).unwrap();
+    let path = linked.join("nested/telemt.log");
+    assert!(
+        BoundedFileAppender::with_now(options(path.clone()), Box::new(fixed_now), true).is_err()
+    );
+    assert!(!real.join("nested").exists());
+    let mut appender =
+        BoundedFileAppender::with_now(options(path), Box::new(fixed_now), false).unwrap();
+    appender.write_all(b"compatibility\n").unwrap();
+    appender.flush().unwrap();
+
+    assert_eq!(
+        fs::read(real.join("nested/telemt.log")).unwrap(),
+        b"compatibility\n"
+    );
+}
+
+#[cfg(unix)]
+#[test]
+fn appender_rejects_final_symlinks_and_hard_links_in_both_modes() {
+    use std::os::unix::fs::symlink;
+
+    for strict_runtime_paths in [false, true] {
+        for hard_link in [false, true] {
+            let dir = tempdir().unwrap();
+            let target = dir.path().join("sentinel");
+            let path = dir.path().join("telemt.log");
+            fs::write(&target, b"preserve\n").unwrap();
+            if hard_link {
+                fs::hard_link(&target, &path).unwrap();
+            } else {
+                symlink(&target, &path).unwrap();
+            }
+
+            assert!(
+                BoundedFileAppender::with_now(
+                    options(path),
+                    Box::new(fixed_now),
+                    strict_runtime_paths
+                )
+                .is_err()
+            );
+            assert_eq!(fs::read(&target).unwrap(), b"preserve\n");
+        }
+    }
+}
+
+#[cfg(unix)]
+#[test]
+fn time_rotation_and_retention_work_through_compatible_parent_alias() {
+    use std::os::unix::fs::{PermissionsExt, symlink};
+
+    let root = tempdir().unwrap();
+    let real = root.path().join("logs");
+    let linked = root.path().join("linked");
+    fs::create_dir(&real).unwrap();
+    fs::set_permissions(&real, fs::Permissions::from_mode(0o777)).unwrap();
+    symlink(&real, &linked).unwrap();
+    let mut options = options(linked.join("telemt.log"));
+    options.rotation = LogRotation::Daily;
+    options.max_files = 1;
+    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now), false).unwrap();
+    appender.write_all(b"first\n").unwrap();
+    appender.now = Box::new(|| fixed_now() + ChronoDuration::days(1));
+    appender.write_all(b"second\n").unwrap();
+    appender.flush().unwrap();
+
+    let remaining = matching_logs(&real);
+    assert_eq!(remaining.len(), 1);
+    assert_eq!(fs::read(&remaining[0]).unwrap(), b"second\n");
+}
+
 #[test]
 fn size_rotation_keeps_latest_write_in_active_file() {
     let dir = tempdir().unwrap();
@@ -41,7 +150,7 @@ fn size_rotation_keeps_latest_write_in_active_file() {
     let mut options = options(path.clone());
     options.max_size_bytes = 6;
 
-    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now)).unwrap();
+    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now), false).unwrap();
     appender.write_all(b"abc\n").unwrap();
     appender.write_all(b"def\n").unwrap();
     appender.flush().unwrap();
@@ -58,7 +167,7 @@ fn max_files_retention_removes_oldest_archives() {
     options.max_size_bytes = 4;
     options.max_files = 2;
 
-    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now)).unwrap();
+    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now), false).unwrap();
     for line in [b"aa\n", b"bb\n", b"cc\n", b"dd\n"] {
         appender.write_all(line).unwrap();
     }
@@ -94,7 +203,7 @@ fn max_age_retention_removes_old_archives() {
 
     let mut options = options(path);
     options.max_age_secs = 1;
-    let _appender = BoundedFileAppender::with_now(options, Box::new(fixed_now)).unwrap();
+    let _appender = BoundedFileAppender::with_now(options, Box::new(fixed_now), false).unwrap();
 
     assert!(!old_archive.exists());
 }
@@ -112,7 +221,7 @@ fn rotation_stays_bound_to_opened_directory_after_path_replacement() {
     fs::create_dir(&redirect).unwrap();
     let mut options = options(original.join("telemt.log"));
     options.max_size_bytes = 4;
-    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now)).unwrap();
+    let mut appender = BoundedFileAppender::with_now(options, Box::new(fixed_now), false).unwrap();
     appender.write_all(b"aa\n").unwrap();
     fs::rename(&original, &moved).unwrap();
     symlink(&redirect, &original).unwrap();
@@ -137,7 +246,11 @@ fn appender_rejects_group_writable_log_directory() {
     fs::set_permissions(dir.path(), fs::Permissions::from_mode(0o770)).unwrap();
 
     assert!(
-        BoundedFileAppender::with_now(options(dir.path().join("telemt.log")), Box::new(fixed_now),)
-            .is_err()
+        BoundedFileAppender::with_now(
+            options(dir.path().join("telemt.log")),
+            Box::new(fixed_now),
+            true
+        )
+        .is_err()
     );
 }

src/logging/tests.rs

@@ -4,6 +4,7 @@ use super::*;
 fn test_parse_log_cli_options_default() {
     let args: Vec<String> = vec![];
     let options = parse_log_cli_options(&args).unwrap();
+    assert!(!LoggingOptions::default().strict_runtime_paths);
     assert_eq!(
         resolve_log_destination(&LoggingConfig::default(), &options).unwrap(),
         LogDestination::Stderr

src/maestro/admission.rs

@@ -13,6 +13,11 @@ use super::generation::RuntimeTaskScope;
 const STARTUP_FALLBACK_AFTER: Duration = Duration::from_secs(80);
 const RUNTIME_FALLBACK_AFTER: Duration = Duration::from_secs(6);
 
+// Admission regressions cover notification loss without network startup.
+#[cfg(test)]
+mod tests;
+
+/// Keeps generation admission and routing synchronized with periodic ME readiness.
 pub(crate) async fn configure_admission_gate(
     config: &Arc<ProxyConfig>,
     me_pool: Option<Arc<MePool>>,
@@ -76,11 +81,18 @@ pub(crate) async fn configure_admission_gate(
                 } else {
                     Some(Instant::now())
                 };
+                let mut config_watch_open = true;
+                let mut me_ready_watch_open = true;
                 loop {
                     tokio::select! {
-                        changed = config_rx_gate.changed() => {
+                        changed = config_rx_gate.changed(), if config_watch_open => {
                             if changed.is_err() {
-                                break;
+                                config_watch_open = false;
+                                warn!(
+                                    watch_channel = "config",
+                                    "Admission config watch closed; continuing readiness polling with last configuration"
+                                );
+                                continue;
                             }
                             let cfg = config_rx_gate.borrow_and_update().clone();
                             admission_poll_ms = cfg.general.me_admission_poll_ms.max(1);
@@ -88,9 +100,13 @@ pub(crate) async fn configure_admission_gate(
                             fast_fallback_enabled = cfg.general.me2dc_fallback && cfg.general.me2dc_fast;
                             continue;
                         }
-                        changed = me_ready_rx_gate.changed() => {
+                        changed = me_ready_rx_gate.changed(), if me_ready_watch_open => {
                             if changed.is_err() {
-                                break;
+                                me_ready_watch_open = false;
+                                warn!(
+                                    watch_channel = "me_ready",
+                                    "Admission ME readiness watch closed; continuing periodic polling"
+                                );
                             }
                         }
                         _ = tokio::time::sleep(Duration::from_millis(admission_poll_ms)) => {}

src/maestro/admission/tests.rs

@@ -0,0 +1,210 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use tracing::{Event, Subscriber};
+use tracing_subscriber::Layer;
+use tracing_subscriber::layer::{Context, SubscriberExt};
+
+use super::*;
+use crate::transport::middle_proxy::admission_test_support::IdlePoolFixture;
+
+const POLL_MS: u64 = 20;
+
+struct ClosureWarnings(Arc<AtomicUsize>);
+
+impl<S: Subscriber> Layer<S> for ClosureWarnings {
+    fn on_event(&self, event: &Event<'_>, _ctx: Context<'_, S>) {
+        struct ChannelField(bool);
+        impl tracing::field::Visit for ChannelField {
+            fn record_debug(
+                &mut self,
+                field: &tracing::field::Field,
+                _value: &dyn std::fmt::Debug,
+            ) {
+                self.0 |= field.name() == "watch_channel";
+            }
+        }
+        if event.metadata().level() == &tracing::Level::WARN {
+            let mut visitor = ChannelField(false);
+            event.record(&mut visitor);
+            if visitor.0 {
+                self.0.fetch_add(1, Ordering::Relaxed);
+            }
+        }
+    }
+}
+
+struct GateFixture {
+    pool: IdlePoolFixture,
+    route: Arc<RouteRuntimeController>,
+    admission: watch::Receiver<bool>,
+    config_tx: Option<watch::Sender<Arc<ProxyConfig>>>,
+    ready_tx: Option<watch::Sender<u64>>,
+    config: Arc<ProxyConfig>,
+    scope: RuntimeTaskScope,
+}
+
+impl GateFixture {
+    async fn new() -> Self {
+        let pool = IdlePoolFixture::new(false).await;
+        let mut cfg = ProxyConfig::default();
+        cfg.general.use_middle_proxy = true;
+        cfg.general.me2dc_fallback = true;
+        cfg.general.me2dc_fast = true;
+        cfg.general.me_admission_poll_ms = POLL_MS;
+        let config = Arc::new(cfg);
+        let (config_tx, config_rx) = watch::channel(config.clone());
+        let (ready_tx, ready_rx) = watch::channel(0);
+        let (admission_tx, mut admission) = watch::channel(false);
+        let route = Arc::new(RouteRuntimeController::new(RelayRouteMode::Direct));
+        let scope = RuntimeTaskScope::new();
+        configure_admission_gate(
+            &config,
+            Some(pool.pool()),
+            Arc::new(RwLock::new(Some(pool.pool()))),
+            route.clone(),
+            &admission_tx,
+            config_rx,
+            ready_rx,
+            scope.clone(),
+        )
+        .await;
+        drop(admission_tx);
+        admission.borrow_and_update();
+        tokio::task::yield_now().await;
+        Self {
+            pool,
+            route,
+            admission,
+            config_tx: Some(config_tx),
+            ready_tx: Some(ready_tx),
+            config,
+            scope,
+        }
+    }
+
+    async fn poll(&self) {
+        tokio::task::yield_now().await;
+        tokio::time::advance(Duration::from_millis(POLL_MS)).await;
+        tokio::task::yield_now().await;
+    }
+
+    async fn expect_route(&self, mode: RelayRouteMode) {
+        let mut rx = self.route.subscribe();
+        tokio::time::timeout(Duration::from_secs(1), async {
+            loop {
+                if rx.borrow_and_update().mode == mode {
+                    return;
+                }
+                rx.changed().await.unwrap();
+            }
+        })
+        .await
+        .expect("the generation must keep sampling readiness without client traffic");
+    }
+}
+
+async fn recovery_after_watch_closure(close_config: bool, close_ready: bool) {
+    let warnings = Arc::new(AtomicUsize::new(0));
+    let subscriber = tracing_subscriber::registry().with(ClosureWarnings(warnings.clone()));
+    let _default = tracing::subscriber::set_default(subscriber);
+    let mut fixture = GateFixture::new().await;
+    assert!(*fixture.admission.borrow());
+    if close_config {
+        fixture.config_tx.take();
+    }
+    if close_ready {
+        fixture.ready_tx.take();
+    }
+    for _ in 0..4 {
+        tokio::task::yield_now().await;
+    }
+    let expected_warnings = usize::from(close_config) + usize::from(close_ready);
+    fixture.pool.set_ready(true);
+    for _ in 0..4 {
+        tokio::task::yield_now().await;
+    }
+    assert_eq!(fixture.route.snapshot().mode, RelayRouteMode::Direct);
+    fixture.poll().await;
+    fixture.expect_route(RelayRouteMode::Middle).await;
+    fixture.pool.set_ready(false);
+    fixture.poll().await;
+    fixture.expect_route(RelayRouteMode::Direct).await;
+    fixture.pool.set_ready(true);
+    fixture.poll().await;
+    fixture.expect_route(RelayRouteMode::Middle).await;
+    for _ in 0..5 {
+        fixture.poll().await;
+    }
+    assert_eq!(warnings.load(Ordering::Relaxed), expected_warnings);
+    fixture.scope.stop().await;
+    assert!(fixture.admission.has_changed().is_err());
+}
+
+#[tokio::test(start_paused = true)]
+async fn idle_gate_recovers_after_readiness_watch_closes() {
+    recovery_after_watch_closure(false, true).await;
+}
+
+#[tokio::test(start_paused = true)]
+async fn idle_gate_recovers_after_config_watch_closes() {
+    recovery_after_watch_closure(true, false).await;
+}
+
+#[tokio::test(start_paused = true)]
+async fn idle_gate_recovers_after_both_watches_close_without_spinning() {
+    recovery_after_watch_closure(true, true).await;
+}
+
+#[tokio::test(start_paused = true)]
+async fn closed_config_watch_preserves_last_effective_fallback_policy() {
+    let mut fixture = GateFixture::new().await;
+    let mut cfg = fixture.config.as_ref().clone();
+    cfg.general.me2dc_fallback = false;
+    fixture
+        .config_tx
+        .as_ref()
+        .unwrap()
+        .send_replace(Arc::new(cfg));
+    fixture.poll().await;
+    fixture.expect_route(RelayRouteMode::Middle).await;
+    assert!(!*fixture.admission.borrow_and_update());
+    fixture.config_tx.take();
+    fixture.ready_tx.take();
+    fixture.poll().await;
+    fixture.pool.set_ready(true);
+    fixture.poll().await;
+    tokio::time::timeout(Duration::from_secs(1), fixture.admission.changed())
+        .await
+        .expect("restored readiness must open admission after notification loss")
+        .unwrap();
+    assert!(*fixture.admission.borrow_and_update());
+    fixture.pool.set_ready(false);
+    fixture.poll().await;
+    tokio::time::timeout(Duration::from_secs(1), fixture.admission.changed())
+        .await
+        .unwrap()
+        .unwrap();
+    assert!(!*fixture.admission.borrow_and_update());
+    assert_eq!(fixture.route.snapshot().mode, RelayRouteMode::Middle);
+    fixture.scope.stop().await;
+}
+
+#[tokio::test(start_paused = true)]
+async fn generation_cancellation_stops_gate_after_notification_loss() {
+    let mut fixture = GateFixture::new().await;
+    fixture.config_tx.take();
+    fixture.ready_tx.take();
+    fixture.poll().await;
+    fixture.pool.set_ready(true);
+    fixture.poll().await;
+    fixture.expect_route(RelayRouteMode::Middle).await;
+    fixture.scope.stop().await;
+    assert!(fixture.admission.has_changed().is_err());
+    let state = fixture.route.snapshot();
+    fixture.pool.set_ready(false);
+    for _ in 0..3 {
+        fixture.poll().await;
+    }
+    assert_eq!(fixture.route.snapshot(), state);
+    assert!(*fixture.admission.borrow());
+}

src/maestro/bootstrap.rs

@@ -15,20 +15,32 @@ use super::helpers::{
 use super::runtime_tasks;
 use super::validate_synlimit_privilege_drop;
 
+/// Process-level configuration and logging resources retained across runtime generations.
 pub(super) struct BootstrapState {
+    /// Monotonic process startup time.
     pub(super) process_started_at: Instant,
+    /// Process startup time as Unix epoch seconds.
     pub(super) process_started_at_epoch_secs: u64,
+    /// Startup component progress shared with the control plane.
     pub(super) startup_tracker: Arc<StartupTracker>,
+    /// Validated initial runtime configuration.
     pub(super) config: ProxyConfig,
+    /// Resolved source path used by reload operations.
     pub(super) config_path: PathBuf,
+    /// Whether the environment owns the log filter policy.
     pub(super) has_rust_log: bool,
+    /// Initial verbosity after CLI overrides.
     pub(super) effective_log_level: LogLevel,
+    /// Process-owned dynamic tracing filter.
     pub(super) runtime_log_filter: runtime_tasks::RuntimeLogFilter,
+    /// Keeps the file logging worker alive until process shutdown.
     pub(super) logging_guard: Option<crate::logging::LoggingGuard>,
 }
 
+/// Loads configuration and initializes process logging with the startup parent-path policy.
 pub(super) async fn bootstrap(
     privilege_drop_requested: bool,
+    strict_runtime_paths: bool,
 ) -> std::result::Result<BootstrapState, Box<dyn std::error::Error>> {
     let process_started_at = Instant::now();
     let process_started_at_epoch_secs = SystemTime::now()
@@ -268,6 +280,7 @@ pub(super) async fn bootstrap(
             let logging_opts = crate::logging::LoggingOptions {
                 destination: log_destination,
                 disable_colors: true,
+                strict_runtime_paths,
             };
             let (_, guard) = crate::logging::init_logging(&logging_opts, &initial_filter_spec);
             logging_guard = Some(guard);
@@ -276,6 +289,7 @@ pub(super) async fn bootstrap(
             let logging_opts = crate::logging::LoggingOptions {
                 destination: log_destination,
                 disable_colors: true,
+                strict_runtime_paths,
             };
             let (_, guard) = crate::logging::init_logging(&logging_opts, &initial_filter_spec);
             logging_guard = Some(guard);

src/maestro/helpers.rs

@@ -30,6 +30,7 @@ pub(crate) fn print_maestro_line(message: impl AsRef<str>) {
     );
 }
 
+/// Resolves the config source against startup cwd while retaining symlink components.
 pub(crate) fn resolve_runtime_config_path(
     config_path_cli: &str,
     startup_cwd: &Path,
@@ -75,6 +76,7 @@ pub(crate) fn resolve_runtime_config_path(
     startup_cwd.join("config.toml")
 }
 
+/// Selects the runtime directory from CLI, startup cwd, and explicit config location.
 pub(crate) fn resolve_runtime_base_dir(
     config_path: &Path,
     startup_cwd: &Path,
@@ -120,14 +122,21 @@ fn normalize_runtime_dir(path: &Path, startup_cwd: &Path) -> PathBuf {
 
 /// Parsed CLI arguments.
 pub(crate) struct CliArgs {
+    /// Config source selected by positional arguments.
     pub config_path: String,
+    /// Whether the config source was explicitly provided.
     pub config_path_explicit: bool,
+    /// Runtime directory override from CLI.
     pub data_path: Option<PathBuf>,
+    /// Whether CLI requests minimal logging output.
     pub silent: bool,
+    /// Verbosity override from CLI.
     pub log_level: Option<String>,
+    /// Logging destination, rotation, and retention overrides.
     pub log_cli_options: LogCliOptions,
 }
 
+/// Parses runtime arguments after early daemon and control-command handling.
 pub(crate) fn parse_cli() -> CliArgs {
     let mut config_path = "config.toml".to_string();
     let mut config_path_explicit = false;
@@ -222,6 +231,8 @@ pub(crate) fn parse_cli() -> CliArgs {
             }
             // Skip daemon-related flags (already parsed)
             "--daemon" | "-d" | "--foreground" | "-f" => {}
+            #[cfg(unix)]
+            "--strict-runtime-paths" => {}
             s if s.starts_with("--pid-file") => {
                 if !s.contains('=') {
                     // Skip the pid-file value consumed by daemon argument parsing.
@@ -300,6 +311,15 @@ fn print_help() {
         eprintln!("  --daemon, -d            Fork to background (daemonize)");
         eprintln!("  --foreground, -f        Explicit foreground mode (for systemd)");
         eprintln!("  --pid-file <PATH>       PID file path (default: /var/run/telemt.pid)");
+        eprintln!(
+            "  --strict-runtime-paths  Require trusted, symlink-free PID/log parents (default: off)"
+        );
+        eprintln!(
+            "                          Applies to run/start/stop/reload/status; parent symlinks and"
+        );
+        eprintln!(
+            "                          writable directories are allowed when this flag is absent"
+        );
         eprintln!("  --run-as-user <USER>    Drop privileges to this user after binding");
         eprintln!("  --run-as-group <GROUP>  Drop privileges to this group after binding");
         eprintln!("  --working-dir <DIR>     Working directory for daemon mode");

src/maestro/mod.rs

@@ -96,7 +96,10 @@ async fn run_inner(
     // Acquire PID file if daemonizing or if explicitly requested.
     // Keep it alive until shutdown for RAII cleanup.
     let _pid_file = if daemon_opts.daemonize || daemon_opts.pid_file.is_some() {
-        let mut pf = PidFile::new(daemon_opts.pid_file_path());
+        let mut pf = PidFile::new(
+            daemon_opts.pid_file_path(),
+            daemon_opts.strict_runtime_paths,
+        );
         if let Err(e) = pf.acquire() {
             eprintln!("[telemt] {}", e);
             std::process::exit(1);
@@ -109,20 +112,25 @@ async fn run_inner(
     let user = daemon_opts.user.clone();
     let group = daemon_opts.group.clone();
 
-    orchestrator::run_telemt_core(user.is_some() || group.is_some(), || {
-        if (user.is_some() || group.is_some())
-            && let Err(e) = drop_privileges(user.as_deref(), group.as_deref(), _pid_file.as_ref())
-        {
-            error!(error = %e, "Failed to drop privileges");
-            std::process::exit(1);
-        }
-    })
+    orchestrator::run_telemt_core(
+        user.is_some() || group.is_some(),
+        daemon_opts.strict_runtime_paths,
+        || {
+            if (user.is_some() || group.is_some())
+                && let Err(e) =
+                    drop_privileges(user.as_deref(), group.as_deref(), _pid_file.as_ref())
+            {
+                error!(error = %e, "Failed to drop privileges");
+                std::process::exit(1);
+            }
+        },
+    )
     .await
 }
 
 #[cfg(not(unix))]
 async fn run_inner() -> std::result::Result<(), Box<dyn std::error::Error>> {
-    orchestrator::run_telemt_core(false, || {}).await
+    orchestrator::run_telemt_core(false, false, || {}).await
 }
 
 #[cfg(test)]

src/maestro/orchestrator.rs

@@ -30,10 +30,11 @@ use super::{
     runtime_tasks, shutdown, tls_bootstrap,
 };
 
-// Shared maestro startup and main loop. `drop_after_bind` runs on Unix after listeners are bound
-// and privileged firewall setup completes; it is a no-op on other platforms.
+/// Runs startup and the main loop with explicit runtime-path policy.
+/// `drop_after_bind` runs after listeners and privileged firewall setup are ready.
 pub(super) async fn run_telemt_core(
     privilege_drop_requested: bool,
+    strict_runtime_paths: bool,
     drop_after_bind: impl FnOnce(),
 ) -> std::result::Result<(), Box<dyn std::error::Error>> {
     let bootstrap::BootstrapState {
@@ -46,7 +47,7 @@ pub(super) async fn run_telemt_core(
         effective_log_level,
         runtime_log_filter,
         logging_guard: _logging_guard,
-    } = bootstrap::bootstrap(privilege_drop_requested).await?;
+    } = bootstrap::bootstrap(privilege_drop_requested, strict_runtime_paths).await?;
 
     if privilege_drop_requested && config.server.conntrack_control.inline_conntrack_control {
         warn!("Inline conntrack control is disabled when process privileges are dropped");
@@ -374,17 +375,21 @@ pub(super) async fn run_telemt_core(
 
     #[cfg(target_os = "linux")]
     let conntrack_firewall = {
-        let authority = crate::conntrack_control::FirewallAuthority::spawn(&process_control_plane)
-            .map_err(std::io::Error::other)?;
-        if !authority
-            .publish_initial(1, runtime.config.clone(), stats.clone())
-            .await
+        let authority = crate::conntrack_control::FirewallAuthority::spawn(
+            &process_control_plane,
+            &runtime.config,
+        )
+        .map_err(std::io::Error::other)?;
+        if let Some(authority) = &authority
+            && !authority
+                .publish_initial(1, runtime.config.clone(), stats.clone())
+                .await
         {
             warn!(
                 "Initial conntrack firewall reconciliation failed; background retries remain active"
             );
         }
-        Some(authority)
+        authority
     };
     #[cfg(not(target_os = "linux"))]
     let conntrack_firewall = None::<crate::conntrack_control::FirewallAuthority>;

src/service/mod.rs

@@ -104,11 +104,12 @@ pub fn generate_service_file(init_system: InitSystem, opts: &ServiceOptions) ->
         InitSystem::Systemd => generate_systemd_unit(opts),
         InitSystem::OpenRC => generate_openrc_script(opts),
         InitSystem::FreeBSDRc => generate_freebsd_rc_script(opts),
-        InitSystem::Unknown => generate_systemd_unit(opts), // Default to systemd format
+        // Preserve systemd generation when init detection is unavailable.
+        InitSystem::Unknown => generate_systemd_unit(opts),
     }
 }
 
-/// Generates an enhanced systemd unit file.
+/// Generates a hardened systemd unit with Netlink access for optional firewall helpers.
 fn generate_systemd_unit(opts: &ServiceOptions) -> String {
     let user_line = opts.user.map(|u| format!("User={}", u)).unwrap_or_default();
     let group_line = opts
@@ -151,14 +152,14 @@ PrivateDevices=true
 ProtectKernelTunables=true
 ProtectKernelModules=true
 ProtectControlGroups=true
-RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
+RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX AF_NETLINK
 RestrictNamespaces=true
 RestrictRealtime=true
 RestrictSUIDSGID=true
 MemoryDenyWriteExecute=true
 LockPersonality=true
 
-# Allow binding to privileged ports and writing to specific paths
+# Allow privileged port binding, optional firewall helpers, and runtime state writes
 AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_NET_ADMIN
 CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_ADMIN
 ReadWritePaths=/etc/telemt /var/run /var/lib/telemt
@@ -233,9 +234,11 @@ fn generate_freebsd_rc_script(opts: &ServiceOptions) -> String {
 # Add the following lines to /etc/rc.conf to enable telemt:
 #
 # telemt_enable="YES"
-# telemt_config="/etc/telemt/config.toml"  # optional
-# telemt_user="telemt"                      # optional
-# telemt_group="telemt"                     # optional
+# The configuration path can be overridden in rc.conf.
+# telemt_config="/etc/telemt/config.toml"
+# The service user and group can be overridden in rc.conf.
+# telemt_user="telemt"
+# telemt_group="telemt"
 #
 
 . /etc/rc.subr
@@ -355,6 +358,28 @@ mod tests {
         assert!(unit.contains("PIDFile="));
     }
 
+    #[test]
+    fn systemd_unit_allows_netlink_without_removing_hardening() {
+        let unit = generate_systemd_unit(&ServiceOptions::default());
+        let families = unit
+            .lines()
+            .find_map(|line| line.strip_prefix("RestrictAddressFamilies="))
+            .unwrap();
+        assert_eq!(
+            families.split_whitespace().collect::<Vec<_>>(),
+            ["AF_INET", "AF_INET6", "AF_UNIX", "AF_NETLINK"],
+        );
+        for directive in [
+            "NoNewPrivileges=true",
+            "ProtectSystem=strict",
+            "RestrictNamespaces=true",
+            "AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_NET_ADMIN",
+            "CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_ADMIN",
+        ] {
+            assert!(unit.lines().any(|line| line == directive), "{directive}");
+        }
+    }
+
     #[test]
     fn test_openrc_script_generation() {
         let opts = ServiceOptions::default();

src/transport/middle_proxy/handshake.rs

@@ -8,6 +8,7 @@ use std::net::{IpAddr, SocketAddr};
 use std::os::fd::{AsRawFd, RawFd};
 #[cfg(target_os = "linux")]
 use std::os::raw::c_int;
+use std::sync::Arc;
 use std::sync::atomic::Ordering;
 use std::time::{Duration, Instant};
 
@@ -252,7 +253,7 @@ impl MePool {
     /// Perform full ME RPC handshake on an established TCP stream.
     /// Returns cipher keys/ivs and split halves; does not register writer.
     pub(crate) async fn handshake_only(
-        &self,
+        self: &Arc<Self>,
         stream: TcpStream,
         addr: SocketAddr,
         upstream_egress: Option<UpstreamEgressInfo>,

src/transport/middle_proxy/health/recovery.rs

@@ -1,5 +1,10 @@
 use super::*;
 
+// Outage regressions use loopback sockets and explicit family-state snapshots.
+#[cfg(test)]
+mod tests;
+
+/// Reports whether replacing an endpoint could disrupt a bound client.
 pub(super) fn has_bound_clients_on_endpoint(
     writer_ids: &[u64],
     bound_clients_by_writer: &HashMap<u64, usize>,
@@ -9,6 +14,7 @@ pub(super) fn has_bound_clients_on_endpoint(
         .any(|writer_id| bound_clients_by_writer.get(writer_id).copied().unwrap_or(0) > 0)
 }
 
+/// Restores missing single-endpoint coverage under the bounded outage retry policy.
 pub(super) async fn recover_single_endpoint_outage(
     pool: &Arc<MePool>,
     rng: &Arc<SecureRandom>,
@@ -53,13 +59,21 @@ pub(super) async fn recover_single_endpoint_outage(
     pool.stats
         .increment_me_single_endpoint_outage_reconnect_attempt_total();
 
+    let generation = pool.current_generation();
     let bypass_quarantine = pool.single_endpoint_outage_disable_quarantine();
     let attempt_ok = if bypass_quarantine {
         pool.stats
             .increment_me_single_endpoint_quarantine_bypass_total();
         match tokio::time::timeout(
             pool.reconnect_runtime.me_one_timeout,
-            pool.connect_one_for_dc(endpoint, key.0, rng.as_ref()),
+            pool.connect_one_with_generation_contour_for_dc_with_intent(
+                endpoint,
+                rng.as_ref(),
+                generation,
+                WriterContour::Active,
+                key.0,
+                WriterOpenIntent::Coverage,
+            ),
         )
         .await
         {
@@ -88,7 +102,14 @@ pub(super) async fn recover_single_endpoint_outage(
         let one_endpoint = [endpoint];
         match tokio::time::timeout(
             pool.reconnect_runtime.me_one_timeout,
-            pool.connect_endpoints_round_robin(key.0, &one_endpoint, rng.as_ref()),
+            pool.connect_endpoints_round_robin_with_generation_contour(
+                key.0,
+                &one_endpoint,
+                rng.as_ref(),
+                generation,
+                WriterContour::Active,
+                WriterOpenIntent::Coverage,
+            ),
         )
         .await
         {
@@ -142,6 +163,7 @@ pub(super) async fn recover_single_endpoint_outage(
     );
 }
 
+/// Rotates an idle single-endpoint shadow without removing the existing coverage first.
 pub(super) async fn maybe_rotate_single_endpoint_shadow(
     pool: &Arc<MePool>,
     rng: &Arc<SecureRandom>,

src/transport/middle_proxy/health/recovery/tests.rs

@@ -0,0 +1,148 @@
+use std::sync::atomic::Ordering;
+
+use super::*;
+use crate::transport::middle_proxy::admission_test_support::unregistered_writer;
+use crate::transport::middle_proxy::pool_writer_security_tests::make_pool;
+
+async fn single_endpoint_reaches_tcp_with_a_full_cap(bypass_quarantine: bool) {
+    let pool = make_pool().await;
+    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let endpoint = listener.local_addr().unwrap();
+    let donor = SocketAddr::new(endpoint.ip(), 1);
+    pool.update_proxy_maps(
+        HashMap::from([
+            (2, vec![(endpoint.ip(), endpoint.port())]),
+            (3, vec![(donor.ip(), donor.port())]),
+        ]),
+        None,
+    )
+    .await;
+    pool.floor_runtime
+        .me_adaptive_floor_cpu_cores_override
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_per_core
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_global
+        .store(1, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_outage_disable_quarantine
+        .store(bypass_quarantine, Ordering::Relaxed);
+    let (writer, _receiver) = unregistered_writer(
+        &pool,
+        1,
+        3,
+        donor,
+        pool.current_generation(),
+        WriterContour::Active,
+    );
+    pool.writers.write().await.push(writer);
+    if bypass_quarantine {
+        pool.endpoint_quarantine
+            .lock()
+            .await
+            .insert(endpoint, Instant::now() + Duration::from_secs(60));
+    }
+    let rng = Arc::new(SecureRandom::new());
+    let key = (2, IpFamily::V4);
+    let mut backoff = HashMap::new();
+    let mut next_attempt = HashMap::new();
+    let semaphore = Arc::new(Semaphore::new(1));
+    let required = pool.required_writers_for_dc(1);
+    // TCP acceptance proves capacity admission; closing the peer deliberately rejects the handshake.
+    tokio::time::timeout(Duration::from_secs(1), async {
+        tokio::join!(
+            recover_single_endpoint_outage(
+                &pool,
+                &rng,
+                key,
+                endpoint,
+                required,
+                &mut backoff,
+                &mut next_attempt,
+                &semaphore,
+            ),
+            async {
+                let (stream, _) = listener.accept().await.unwrap();
+                drop(stream);
+            },
+        );
+    })
+    .await
+    .expect("missing-DC recovery must reach TCP even when another DC fills the cap");
+    assert_eq!(
+        pool.stats
+            .get_me_single_endpoint_outage_reconnect_attempt_total(),
+        1
+    );
+    assert_eq!(
+        pool.stats
+            .get_me_single_endpoint_outage_reconnect_success_total(),
+        0
+    );
+    assert_eq!(
+        pool.stats.get_me_single_endpoint_quarantine_bypass_total(),
+        u64::from(bypass_quarantine)
+    );
+    assert!(next_attempt.contains_key(&key));
+    assert!(backoff.contains_key(&key));
+    assert_eq!(semaphore.available_permits(), 1);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test]
+async fn single_endpoint_quarantine_bypass_recovers_coverage_at_cap() {
+    single_endpoint_reaches_tcp_with_a_full_cap(true).await;
+}
+
+#[tokio::test]
+async fn single_endpoint_round_robin_recovers_coverage_at_cap() {
+    single_endpoint_reaches_tcp_with_a_full_cap(false).await;
+}
+
+#[tokio::test]
+async fn restored_coverage_preserves_family_suppression_hysteresis() {
+    let pool = make_pool().await;
+    let now = MePool::now_epoch_secs();
+    let until = now + 3600;
+    pool.set_family_runtime_state(
+        IpFamily::V4,
+        MeFamilyRuntimeState::Suppressed,
+        now,
+        until,
+        5,
+        0,
+    );
+    super::super::update_family_runtime_state(&pool, IpFamily::V4, false);
+    assert_eq!(
+        pool.family_runtime_state(IpFamily::V4),
+        MeFamilyRuntimeState::Suppressed
+    );
+    assert_eq!(pool.family_suppressed_until_epoch_secs(IpFamily::V4), until);
+    assert_eq!(pool.family_recover_success_streak(IpFamily::V4), 0);
+
+    pool.set_family_runtime_state(
+        IpFamily::V4,
+        MeFamilyRuntimeState::Suppressed,
+        now,
+        now - 1,
+        5,
+        0,
+    );
+    super::super::update_family_runtime_state(&pool, IpFamily::V4, false);
+    assert_eq!(
+        pool.family_runtime_state(IpFamily::V4),
+        MeFamilyRuntimeState::Recovering
+    );
+    assert_eq!(pool.family_recover_success_streak(IpFamily::V4), 1);
+    super::super::update_family_runtime_state(&pool, IpFamily::V4, false);
+    assert_eq!(
+        pool.family_runtime_state(IpFamily::V4),
+        MeFamilyRuntimeState::Healthy
+    );
+    assert_eq!(pool.family_fail_streak(IpFamily::V4), 0);
+}

src/transport/middle_proxy/mod.rs

@@ -49,6 +49,11 @@ mod send;
 mod send_adversarial_tests;
 mod wire;
 
+/// Network-free writer fixtures shared by admission and recovery regressions.
+#[cfg(test)]
+#[path = "tests/admission_test_support.rs"]
+pub(crate) mod admission_test_support;
+
 use bytes::Bytes;
 use tokio::sync::OwnedSemaphorePermit;
 

src/transport/middle_proxy/pool.rs

@@ -407,6 +407,7 @@ pub(super) struct BindingPolicyCore {
 }
 
 pub(super) struct NatRuntimeCore {
+    pub(super) discovery: super::pool_nat::NatDiscovery,
     pub(super) nat_ip_cfg: Option<IpAddr>,
     pub(super) nat_ip_detected: Arc<RwLock<Option<IpAddr>>>,
     pub(super) nat_probe: bool,

src/transport/middle_proxy/pool/construction.rs

@@ -279,6 +279,7 @@ impl MePool {
                 me_bind_stale_ttl_secs: AtomicU64::new(me_bind_stale_ttl_secs),
             }),
             nat_runtime: Arc::new(NatRuntimeCore {
+                discovery: super::super::pool_nat::NatDiscovery::default(),
                 nat_ip_cfg: nat_ip,
                 nat_ip_detected: Arc::new(RwLock::new(None)),
                 nat_probe,

src/transport/middle_proxy/pool/writer_admission.rs

@@ -61,13 +61,13 @@ impl Drop for WriterOpenReservation<'_> {
 }
 
 impl MePool {
-    /// Computes the authoritative active-writer floor across enabled families and DCs.
+    /// Computes reservation coverage across configured families, including suppressed ones.
     pub(in crate::transport::middle_proxy) async fn active_coverage_required_total(&self) -> usize {
-        let now_epoch_secs = Self::now_epoch_secs();
         let mut required_total = 0usize;
         let endpoint_snapshot = self.endpoint_snapshot.load_full();
 
-        if self.family_enabled_for_drain_coverage(IpFamily::V4, now_epoch_secs) {
+        // Suppression must not remove the capacity needed to recover active coverage.
+        if self.decision.ipv4_me {
             for addrs in endpoint_snapshot.map_v4.values() {
                 let mut endpoints = HashSet::<SocketAddr>::new();
                 for (ip, port) in addrs.iter().copied() {
@@ -79,7 +79,7 @@ impl MePool {
             }
         }
 
-        if self.family_enabled_for_drain_coverage(IpFamily::V6, now_epoch_secs) {
+        if self.decision.ipv6_me {
             for addrs in endpoint_snapshot.map_v6.values() {
                 let mut endpoints = HashSet::<SocketAddr>::new();
                 for (ip, port) in addrs.iter().copied() {

src/transport/middle_proxy/pool_nat.rs

@@ -1,7 +1,9 @@
 use std::collections::HashMap;
 use std::net::IpAddr;
+use std::sync::Arc;
 use std::time::Duration;
 
+use tokio::sync::oneshot;
 use tokio::task::JoinSet;
 use tokio::time::timeout;
 use tracing::{debug, info};
@@ -18,7 +20,18 @@ use std::time::Instant;
 
 const STUN_BATCH_TIMEOUT: Duration = Duration::from_secs(5);
 const STUN_BATCH_TCP_FALLBACK_TIMEOUT: Duration = Duration::from_secs(12);
+const STUN_CACHE_TTL: Duration = Duration::from_secs(600);
+const HTTP_FAILURE_TTL: Duration = Duration::from_secs(60);
 
+// Discovery ownership and source-bound cache admission for this pool generation.
+mod state;
+pub(super) use state::NatDiscovery;
+
+// Local network regressions exercise cancellation before discovery publication.
+#[cfg(test)]
+mod tests;
+
+/// Probes the configured or default STUN endpoint with both address families.
 #[allow(dead_code)]
 pub async fn stun_probe(stun_addr: Option<String>) -> Result<crate::network::stun::DualStunResult> {
     let stun_addr = stun_addr.unwrap_or_else(|| {
@@ -35,6 +48,7 @@ pub async fn stun_probe(stun_addr: Option<String>) -> Result<crate::network::stu
     stun_probe_dual_with_tcp_fallback(&stun_addr, false).await
 }
 
+/// Detects a public IPv4 address using the default HTTP endpoints.
 #[allow(dead_code)]
 pub async fn detect_public_ip() -> Option<IpAddr> {
     let urls = crate::config::defaults::default_http_ip_detect_urls();
@@ -151,6 +165,7 @@ impl MePool {
         (live_servers, best_reflected)
     }
 
+    /// Applies the configured or HTTP-detected NAT IP to non-public addresses.
     pub(super) fn translate_ip_for_nat(&self, ip: IpAddr) -> IpAddr {
         let nat_ip = self.nat_runtime.nat_ip_cfg.or_else(|| {
             self.nat_runtime
@@ -177,6 +192,7 @@ impl MePool {
         }
     }
 
+    /// Selects the NAT source IP without replacing the actual TCP source port.
     pub(super) fn translate_our_addr_with_reflection(
         &self,
         addr: std::net::SocketAddr,
@@ -203,7 +219,8 @@ impl MePool {
         std::net::SocketAddr::new(ip, addr.port())
     }
 
-    pub(super) async fn maybe_detect_nat_ip(&self, local_ip: IpAddr) -> Option<IpAddr> {
+    /// Waits for pool-owned HTTP discovery without owning its cancellation.
+    pub(super) async fn maybe_detect_nat_ip(self: &Arc<Self>, local_ip: IpAddr) -> Option<IpAddr> {
         if self.nat_runtime.nat_ip_cfg.is_some() {
             return self.nat_runtime.nat_ip_cfg;
         }
@@ -220,103 +237,117 @@ impl MePool {
             return Some(ip);
         }
 
-        let Some(ip) = detect_public_ipv4_http(&self.nat_runtime.http_ip_detect_urls).await else {
-            return None;
-        };
-        {
-            let mut guard = self.nat_runtime.nat_ip_detected.write().await;
-            *guard = Some(IpAddr::V4(ip));
+        let mut flight = self.nat_runtime.discovery.http.clone().lock_owned().await;
+        if let Some(ip) = *self.nat_runtime.nat_ip_detected.read().await {
+            return Some(ip);
         }
-        info!(public_ip = %ip, "Auto-detected public IP for NAT translation");
-        Some(IpAddr::V4(ip))
+        if flight.is_some_and(|until| Instant::now() < until) {
+            return None;
+        }
+
+        let pool = self.clone();
+        let (send, receive) = oneshot::channel();
+        // Transfer singleflight ownership before the producer can be cancelled or polled.
+        self.lifecycle
+            .spawn_producer(async move {
+                let detected = detect_public_ipv4_http(&pool.nat_runtime.http_ip_detect_urls)
+                    .await
+                    .map(IpAddr::V4);
+                if let Some(ip) = detected {
+                    *pool.nat_runtime.nat_ip_detected.write().await = Some(ip);
+                    *flight = None;
+                    info!(public_ip = %ip, "Auto-detected public IP for NAT translation");
+                } else {
+                    *flight = Some(Instant::now() + HTTP_FAILURE_TTL);
+                }
+                let _ = send.send(detected);
+            })
+            .ok()?;
+        receive.await.ok().flatten()
     }
 
+    /// Waits for a pool-owned STUN refresh in the exact source-address context.
     pub(super) async fn maybe_reflect_public_addr(
-        &self,
+        self: &Arc<Self>,
         family: IpFamily,
         bind_ip: Option<IpAddr>,
     ) -> Option<std::net::SocketAddr> {
-        const STUN_CACHE_TTL: Duration = Duration::from_secs(600);
-        let use_shared_cache = bind_ip.is_none();
-        if !use_shared_cache {
-            match (family, bind_ip) {
-                (IpFamily::V4, Some(IpAddr::V4(_)))
-                | (IpFamily::V6, Some(IpAddr::V6(_)))
-                | (_, None) => {}
-                _ => return None,
-            }
+        if let Some(bind_ip) = bind_ip {
+            return self.reflect_bound_addr(family, bind_ip).await;
         }
-        // Backoff window
-        if use_shared_cache
-            && let Some(until) = *self.nat_runtime.stun_backoff_until.read().await
-            && Instant::now() < until
-        {
-            if let Ok(cache) = self.nat_runtime.nat_reflection_cache.try_lock() {
-                let slot = match family {
-                    IpFamily::V4 => cache.v4,
-                    IpFamily::V6 => cache.v6,
-                };
-                return slot.map(|(_, addr)| addr);
-            }
-            return None;
+        if let Some(cached) = self.cached_shared_reflection(family).await {
+            return cached;
+        }
+        let singleflight = match family {
+            IpFamily::V4 => self.nat_runtime.nat_reflection_singleflight_v4.clone(),
+            IpFamily::V6 => self.nat_runtime.nat_reflection_singleflight_v6.clone(),
+        };
+        let flight = singleflight.lock_owned().await;
+        if let Some(cached) = self.cached_shared_reflection(family).await {
+            return cached;
         }
 
-        if use_shared_cache && let Ok(mut cache) = self.nat_runtime.nat_reflection_cache.try_lock()
-        {
-            let slot = match family {
-                IpFamily::V4 => &mut cache.v4,
-                IpFamily::V6 => &mut cache.v6,
-            };
-            if let Some((ts, addr)) = slot
-                && ts.elapsed() < STUN_CACHE_TTL
-            {
-                return Some(*addr);
-            }
-        }
-
-        let _singleflight_guard = if use_shared_cache {
-            Some(match family {
-                IpFamily::V4 => self.nat_runtime.nat_reflection_singleflight_v4.lock().await,
-                IpFamily::V6 => self.nat_runtime.nat_reflection_singleflight_v6.lock().await,
+        let pool = self.clone();
+        let (send, receive) = oneshot::channel();
+        self.lifecycle
+            .spawn_producer(async move {
+                let _flight = flight;
+                let attempt = pool
+                    .nat_runtime
+                    .nat_probe_attempts
+                    .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+                let reflected = pool.refresh_stun(family, None, attempt).await;
+                if let Some(addr) = reflected {
+                    // Cache readers must never cause a completed refresh to be discarded.
+                    let mut cache = pool.nat_runtime.nat_reflection_cache.lock().await;
+                    let slot = match family {
+                        IpFamily::V4 => &mut cache.v4,
+                        IpFamily::V6 => &mut cache.v6,
+                    };
+                    *slot = Some((Instant::now(), addr));
+                    pool.nat_runtime
+                        .nat_probe_attempts
+                        .store(0, std::sync::atomic::Ordering::Relaxed);
+                } else {
+                    let backoff = Duration::from_secs(60 * 2u64.pow((attempt as u32).min(6)));
+                    *pool.nat_runtime.stun_backoff_until.write().await =
+                        Some(Instant::now() + backoff);
+                }
+                let _ = send.send(reflected);
             })
-        } else {
-            None
+            .ok()?;
+        receive.await.ok().flatten()
+    }
+
+    async fn cached_shared_reflection(
+        &self,
+        family: IpFamily,
+    ) -> Option<Option<std::net::SocketAddr>> {
+        let backoff = self
+            .nat_runtime
+            .stun_backoff_until
+            .read()
+            .await
+            .is_some_and(|until| Instant::now() < until);
+        let cache = self.nat_runtime.nat_reflection_cache.lock().await;
+        let slot = match family {
+            IpFamily::V4 => cache.v4,
+            IpFamily::V6 => cache.v6,
         };
-
-        if use_shared_cache
-            && let Some(until) = *self.nat_runtime.stun_backoff_until.read().await
-            && Instant::now() < until
-        {
-            if let Ok(cache) = self.nat_runtime.nat_reflection_cache.try_lock() {
-                let slot = match family {
-                    IpFamily::V4 => cache.v4,
-                    IpFamily::V6 => cache.v6,
-                };
-                return slot.map(|(_, addr)| addr);
-            }
-            return None;
+        // Preserve the existing stale-result fallback during shared failure backoff.
+        if backoff {
+            return Some(slot.map(|(_, addr)| addr));
         }
+        slot.filter(|(created, _)| created.elapsed() < STUN_CACHE_TTL)
+            .map(|(_, addr)| Some(addr))
+    }
 
-        if use_shared_cache && let Ok(mut cache) = self.nat_runtime.nat_reflection_cache.try_lock()
-        {
-            let slot = match family {
-                IpFamily::V4 => &mut cache.v4,
-                IpFamily::V6 => &mut cache.v6,
-            };
-            if let Some((ts, addr)) = slot
-                && ts.elapsed() < STUN_CACHE_TTL
-            {
-                return Some(*addr);
-            }
-        }
-
-        let attempt = if use_shared_cache {
-            self.nat_runtime
-                .nat_probe_attempts
-                .fetch_add(1, std::sync::atomic::Ordering::Relaxed)
-        } else {
-            0
-        };
+    async fn refresh_stun(
+        &self,
+        family: IpFamily,
+        bind_ip: Option<IpAddr>,
+        attempt: u8,
+    ) -> Option<std::net::SocketAddr> {
         let configured_servers = self.configured_stun_servers();
         let live_snapshot = self.nat_runtime.nat_stun_live_servers.read().await.clone();
         let primary_servers = if live_snapshot.is_empty() {
@@ -348,33 +379,14 @@ impl MePool {
         }
 
         if let Some(reflected_addr) = selected_reflected {
-            if use_shared_cache {
-                self.nat_runtime
-                    .nat_probe_attempts
-                    .store(0, std::sync::atomic::Ordering::Relaxed);
-            }
             info!(
                 family = ?family,
                 live_servers = live_server_count,
                 "STUN-Quorum reached, IP: {}",
                 reflected_addr.ip()
             );
-            if use_shared_cache
-                && let Ok(mut cache) = self.nat_runtime.nat_reflection_cache.try_lock()
-            {
-                let slot = match family {
-                    IpFamily::V4 => &mut cache.v4,
-                    IpFamily::V6 => &mut cache.v6,
-                };
-                *slot = Some((Instant::now(), reflected_addr));
-            }
             return Some(reflected_addr);
         }
-
-        if use_shared_cache {
-            let backoff = Duration::from_secs(60 * 2u64.pow((attempt as u32).min(6)));
-            *self.nat_runtime.stun_backoff_until.write().await = Some(Instant::now() + backoff);
-        }
         None
     }
 }

src/transport/middle_proxy/pool_nat/state.rs

@@ -0,0 +1,119 @@
+use std::collections::{BTreeSet, HashMap};
+use std::net::{IpAddr, SocketAddr};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use tokio::sync::{Mutex, oneshot};
+use tokio_util::sync::CancellationToken;
+
+use super::{IpFamily, MePool, STUN_CACHE_TTL};
+
+// Context retirement and TTL tests use the same gates as production discovery.
+#[cfg(test)]
+mod tests;
+
+/// Pool-local discovery gates; bound entries are limited to configured egress addresses.
+#[derive(Default)]
+pub(in crate::transport::middle_proxy) struct NatDiscovery {
+    pub(super) http: Arc<Mutex<Option<Instant>>>,
+    bound: Mutex<HashMap<(IpFamily, IpAddr), Arc<BoundDiscovery>>>,
+}
+
+#[derive(Default)]
+struct BoundDiscovery {
+    state: Arc<Mutex<BoundDiscoveryState>>,
+    cancel: CancellationToken,
+}
+
+#[derive(Default)]
+struct BoundDiscoveryState {
+    reflection: Option<(Instant, SocketAddr)>,
+    retry_after: Option<Instant>,
+    attempt: u8,
+}
+
+impl NatDiscovery {
+    async fn bound_context(
+        &self,
+        family: IpFamily,
+        bind_ip: IpAddr,
+        allowed: &BTreeSet<IpAddr>,
+    ) -> Option<Arc<BoundDiscovery>> {
+        let mut contexts = self.bound.lock().await;
+        // Retired producers cannot republish into the map or a replacement context.
+        contexts.retain(|(entry_family, ip), context| {
+            let keep = *entry_family != family || allowed.contains(ip);
+            if !keep {
+                context.cancel.cancel();
+            }
+            keep
+        });
+        if !allowed.contains(&bind_ip) {
+            return None;
+        }
+        Some(contexts.entry((family, bind_ip)).or_default().clone())
+    }
+}
+
+impl MePool {
+    /// Refreshes one configured source without borrowing another source's cached reflection.
+    pub(super) async fn reflect_bound_addr(
+        self: &Arc<Self>,
+        family: IpFamily,
+        bind_ip: IpAddr,
+    ) -> Option<SocketAddr> {
+        if bind_ip.is_ipv6() != matches!(family, IpFamily::V6) {
+            return None;
+        }
+        let allowed = self
+            .upstream
+            .as_ref()?
+            .direct_bind_ips_for_family(bind_ip.is_ipv6())
+            .await;
+        let context = self
+            .nat_runtime
+            .discovery
+            .bound_context(family, bind_ip, &allowed)
+            .await?;
+        let mut flight = tokio::select! {
+            biased;
+            _ = context.cancel.cancelled() => return None,
+            guard = context.state.clone().lock_owned() => guard,
+        };
+        if let Some((created, addr)) = flight.reflection
+            && created.elapsed() < STUN_CACHE_TTL
+        {
+            return Some(addr);
+        }
+        if flight
+            .retry_after
+            .is_some_and(|until| Instant::now() < until)
+        {
+            return None;
+        }
+
+        let pool = self.clone();
+        let (send, receive) = oneshot::channel();
+        self.lifecycle.spawn_producer(async move {
+            tokio::select! {
+                biased;
+                _ = context.cancel.cancelled() => {}
+                _ = async {
+                    let reflected = pool.refresh_stun(family, Some(bind_ip), flight.attempt).await;
+                    if let Some(addr) = reflected {
+                        flight.reflection = Some((Instant::now(), addr));
+                        flight.retry_after = None;
+                        flight.attempt = 0;
+                    } else {
+                        // Completed failures must also survive a short reconnect deadline.
+                        let backoff = Duration::from_secs(60 * 2u64.pow(flight.attempt as u32));
+                        flight.retry_after = Some(Instant::now() + backoff);
+                        flight.attempt = flight.attempt.saturating_add(1).min(6);
+                    }
+                    let _ = send.send(reflected);
+                } => {}
+            }
+        }).ok()?;
+        receive.await.ok().flatten()
+    }
+}

src/transport/middle_proxy/pool_nat/state/tests.rs

@@ -0,0 +1,146 @@
+use super::*;
+use crate::transport::middle_proxy::pool_nat::tests::lifecycle::set_bind_addresses;
+use crate::transport::middle_proxy::pool_nat::tests::{
+    PUBLIC_IP, TEST_DEADLINE, nat_pool, stun_server,
+};
+use std::net::Ipv4Addr;
+use std::sync::atomic::Ordering;
+use tokio::time::timeout;
+
+#[tokio::test]
+async fn bound_positive_ttl_refreshes_without_publishing_to_default_cache() {
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    stun.release.add_permits(16);
+    let mut pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    set_bind_addresses(&mut pool, &["127.0.0.1"]);
+    let ip = IpAddr::V4(Ipv4Addr::LOCALHOST);
+    let allowed = BTreeSet::from([ip]);
+    let context = pool
+        .nat_runtime
+        .discovery
+        .bound_context(IpFamily::V4, ip, &allowed)
+        .await
+        .unwrap();
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+            .is_some()
+    );
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+            .is_some()
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    context.state.lock().await.reflection.as_mut().unwrap().0 = Instant::now() - STUN_CACHE_TTL;
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+            .is_some()
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 2);
+    assert_eq!(pool.nat_runtime.nat_reflection_cache.lock().await.v4, None);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn context_churn_is_bounded_and_retirement_does_not_mix_families() {
+    let discovery = NatDiscovery::default();
+    let v6: IpAddr = "::1".parse().unwrap();
+    let v6_context = discovery
+        .bound_context(IpFamily::V6, v6, &BTreeSet::from([v6]))
+        .await
+        .unwrap();
+    let mut previous: Option<Arc<BoundDiscovery>> = None;
+    for suffix in 1..=1000u32 {
+        let ip = IpAddr::V4(Ipv4Addr::from(0x7f000000 + suffix));
+        let context = discovery
+            .bound_context(IpFamily::V4, ip, &BTreeSet::from([ip]))
+            .await
+            .unwrap();
+        if let Some(old) = previous.replace(context.clone()) {
+            assert!(old.cancel.is_cancelled());
+        }
+        assert!(!context.cancel.is_cancelled());
+        assert!(!v6_context.cancel.is_cancelled());
+        assert_eq!(discovery.bound.lock().await.len(), 2);
+    }
+    let denied = IpAddr::V4(Ipv4Addr::LOCALHOST);
+    assert!(
+        discovery
+            .bound_context(IpFamily::V4, denied, &BTreeSet::new())
+            .await
+            .is_none()
+    );
+    assert!(previous.unwrap().cancel.is_cancelled());
+    assert_eq!(discovery.bound.lock().await.len(), 1);
+}
+
+#[tokio::test]
+async fn retiring_bound_context_cancels_its_producer_and_prevents_late_publication() {
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let mut pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    set_bind_addresses(&mut pool, &["127.0.0.1"]);
+    let ip = IpAddr::V4(Ipv4Addr::LOCALHOST);
+    let context = pool
+        .nat_runtime
+        .discovery
+        .bound_context(IpFamily::V4, ip, &BTreeSet::from([ip]))
+        .await
+        .unwrap();
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        waiter_pool
+            .maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+    });
+    stun.received().await;
+    assert!(
+        pool.nat_runtime
+            .discovery
+            .bound_context(IpFamily::V4, ip, &BTreeSet::new())
+            .await
+            .is_none()
+    );
+    assert_eq!(timeout(TEST_DEADLINE, waiter).await.unwrap().unwrap(), None);
+    stun.release.add_permits(16);
+    assert_eq!(context.state.lock().await.reflection, None);
+    assert!(pool.nat_runtime.discovery.bound.lock().await.is_empty());
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn bound_failure_retry_deadline_expires_and_success_resets_backoff() {
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    stun.release.add_permits(16);
+    let mut pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    set_bind_addresses(&mut pool, &["127.0.0.1"]);
+    let ip = IpAddr::V4(Ipv4Addr::LOCALHOST);
+    let context = pool
+        .nat_runtime
+        .discovery
+        .bound_context(IpFamily::V4, ip, &BTreeSet::from([ip]))
+        .await
+        .unwrap();
+    {
+        let mut state = context.state.lock().await;
+        state.retry_after = Some(Instant::now() + Duration::from_secs(60));
+        state.attempt = 3;
+    }
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+            .is_none()
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 0);
+    context.state.lock().await.retry_after = Some(Instant::now() - Duration::from_secs(1));
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some(ip))
+            .await
+            .is_some()
+    );
+    assert_eq!(context.state.lock().await.attempt, 0);
+    assert_eq!(context.state.lock().await.retry_after, None);
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}

src/transport/middle_proxy/pool_nat/tests.rs

@@ -0,0 +1,294 @@
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::time::{Duration, Instant};
+
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpListener, UdpSocket};
+use tokio::sync::Semaphore;
+use tokio::task::JoinHandle;
+
+use super::*;
+use crate::network::probe::NetworkDecision;
+use crate::transport::middle_proxy::pool_writer_security_tests::make_pool_with_decision;
+
+/// Public IPv4 used as source material by local discovery and encrypted ME fixtures.
+pub(super) const PUBLIC_IP: Ipv4Addr = Ipv4Addr::new(91, 108, 56, 1);
+/// Bounds asynchronous fixture assertions without relying on external services.
+pub(super) const TEST_DEADLINE: Duration = Duration::from_secs(2);
+
+// Concurrency and end-to-end regressions share gated local discovery servers.
+pub(super) mod lifecycle;
+mod recovery;
+
+/// Gated local discovery service with observable request counts.
+pub(super) struct DiscoveryServer {
+    /// Listening address selected by the kernel.
+    pub(super) addr: SocketAddr,
+    /// Number of requests actually received from clients.
+    pub(super) requests: Arc<AtomicUsize>,
+    arrived: Arc<Semaphore>,
+    /// One permit releases one discovery response.
+    pub(super) release: Arc<Semaphore>,
+    task: JoinHandle<()>,
+}
+
+impl Drop for DiscoveryServer {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}
+
+impl DiscoveryServer {
+    /// Waits until a real discovery request reaches the server.
+    pub(super) async fn received(&self) {
+        tokio::time::timeout(TEST_DEADLINE, self.arrived.acquire())
+            .await
+            .expect("discovery request must reach the local server")
+            .unwrap()
+            .forget();
+    }
+}
+
+/// Serves valid STUN responses with a deliberately different reflected port.
+pub(super) async fn stun_server(bind: SocketAddr, reflected: IpAddr) -> DiscoveryServer {
+    stun_server_response(bind, Some(reflected), Duration::ZERO).await
+}
+
+async fn stun_server_response(
+    bind: SocketAddr,
+    reflected: Option<IpAddr>,
+    delay: Duration,
+) -> DiscoveryServer {
+    let socket = UdpSocket::bind(bind).await.unwrap();
+    let addr = socket.local_addr().unwrap();
+    let requests = Arc::new(AtomicUsize::new(0));
+    let arrived = Arc::new(Semaphore::new(0));
+    let release = Arc::new(Semaphore::new(0));
+    let count = requests.clone();
+    let signal = arrived.clone();
+    let gate = release.clone();
+    let task = tokio::spawn(async move {
+        let mut request = [0u8; 512];
+        loop {
+            let (len, peer) = socket.recv_from(&mut request).await.unwrap();
+            assert!(len >= 20);
+            count.fetch_add(1, Ordering::Relaxed);
+            signal.add_permits(1);
+            gate.acquire().await.unwrap().forget();
+            tokio::time::sleep(delay).await;
+            let Some(reflected) = reflected else {
+                socket.send_to(&[0u8], peer).await.unwrap();
+                continue;
+            };
+            let (family, ip) = match reflected {
+                IpAddr::V4(ip) => (1u8, ip.octets().to_vec()),
+                IpAddr::V6(ip) => (2u8, ip.octets().to_vec()),
+            };
+            let attribute_len = 4 + ip.len();
+            let mut response = vec![0u8; 24 + attribute_len];
+            response[..2].copy_from_slice(&0x0101u16.to_be_bytes());
+            response[2..4].copy_from_slice(&((4 + attribute_len) as u16).to_be_bytes());
+            response[4..20].copy_from_slice(&request[4..20]);
+            response[20..22].copy_from_slice(&1u16.to_be_bytes());
+            response[22..24].copy_from_slice(&(attribute_len as u16).to_be_bytes());
+            response[25] = family;
+            response[26..28].copy_from_slice(&45678u16.to_be_bytes());
+            response[28..].copy_from_slice(&ip);
+            socket.send_to(&response, peer).await.unwrap();
+        }
+    });
+    DiscoveryServer {
+        addr,
+        requests,
+        arrived,
+        release,
+        task,
+    }
+}
+
+async fn http_server(body: &'static str) -> DiscoveryServer {
+    http_server_with_delay(body, Duration::ZERO).await
+}
+
+async fn http_server_with_delay(body: &'static str, delay: Duration) -> DiscoveryServer {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    let requests = Arc::new(AtomicUsize::new(0));
+    let arrived = Arc::new(Semaphore::new(0));
+    let release = Arc::new(Semaphore::new(0));
+    let count = requests.clone();
+    let signal = arrived.clone();
+    let gate = release.clone();
+    let task = tokio::spawn(async move {
+        loop {
+            let (mut stream, _) = listener.accept().await.unwrap();
+            let mut request = [0u8; 4096];
+            let _ = stream.read(&mut request).await.unwrap();
+            count.fetch_add(1, Ordering::Relaxed);
+            signal.add_permits(1);
+            gate.acquire().await.unwrap().forget();
+            tokio::time::sleep(delay).await;
+            let response = format!(
+                "HTTP/1.1 200 OK\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{}",
+                body.len(),
+                body
+            );
+            let _ = stream.write_all(response.as_bytes()).await;
+        }
+    });
+    DiscoveryServer {
+        addr,
+        requests,
+        arrived,
+        release,
+        task,
+    }
+}
+
+/// Builds an isolated dual-stack pool using only caller-supplied discovery services.
+pub(super) async fn nat_pool(servers: Vec<String>, urls: Vec<String>) -> Arc<MePool> {
+    let mut pool = make_pool_with_decision(NetworkDecision {
+        ipv4_me: true,
+        ipv6_me: true,
+        ..NetworkDecision::default()
+    })
+    .await;
+    let pool_mut = Arc::get_mut(&mut pool).unwrap();
+    let nat = Arc::get_mut(&mut pool_mut.nat_runtime).unwrap();
+    nat.nat_probe = true;
+    nat.nat_stun_servers = servers;
+    nat.http_ip_detect_urls = urls;
+    nat.nat_probe_concurrency = 2;
+    pool
+}
+
+async fn wait_for_reflection(pool: &MePool, family: IpFamily) -> SocketAddr {
+    tokio::time::timeout(TEST_DEADLINE, async {
+        loop {
+            let cached = {
+                let cache = pool.nat_runtime.nat_reflection_cache.lock().await;
+                match family {
+                    IpFamily::V4 => cache.v4,
+                    IpFamily::V6 => cache.v6,
+                }
+            };
+            if let Some((created, addr)) = cached
+                && created.elapsed() < Duration::from_secs(600)
+            {
+                return addr;
+            }
+            tokio::time::sleep(Duration::from_millis(5)).await;
+        }
+    })
+    .await
+    .expect("pool-owned STUN refresh must publish after its caller is cancelled")
+}
+
+#[tokio::test]
+async fn expired_stun_refresh_survives_reconnect_timeout() {
+    let fast = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let slow = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    fast.release.add_permits(16);
+    let pool = nat_pool(vec![fast.addr.to_string(), slow.addr.to_string()], vec![]).await;
+    pool.nat_runtime.nat_reflection_cache.lock().await.v4 = Some((
+        Instant::now() - Duration::from_secs(601),
+        SocketAddr::new(PUBLIC_IP.into(), 1),
+    ));
+    let caller_pool = pool.clone();
+    let caller = tokio::spawn(async move {
+        tokio::time::timeout(
+            Duration::from_millis(100),
+            caller_pool.maybe_reflect_public_addr(IpFamily::V4, None),
+        )
+        .await
+    });
+    fast.received().await;
+    slow.received().await;
+    assert!(caller.await.unwrap().is_err());
+    slow.release.add_permits(16);
+    assert_eq!(
+        wait_for_reflection(&pool, IpFamily::V4).await.ip(),
+        PUBLIC_IP
+    );
+    assert_eq!(fast.requests.load(Ordering::Relaxed), 1);
+    assert_eq!(slow.requests.load(Ordering::Relaxed), 1);
+    assert_eq!(
+        pool.nat_runtime.nat_probe_attempts.load(Ordering::Relaxed),
+        0
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn http_discovery_survives_reconnect_timeout() {
+    let http = http_server("91.108.56.1").await;
+    let pool = nat_pool(vec![], vec![format!("http://{}/", http.addr)]).await;
+    let caller_pool = pool.clone();
+    let caller = tokio::spawn(async move {
+        tokio::time::timeout(
+            Duration::from_millis(100),
+            caller_pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()),
+        )
+        .await
+    });
+    http.received().await;
+    assert!(caller.await.unwrap().is_err());
+    http.release.add_permits(16);
+    tokio::time::timeout(TEST_DEADLINE, async {
+        while pool.nat_runtime.nat_ip_detected.read().await.is_none() {
+            tokio::time::sleep(Duration::from_millis(5)).await;
+        }
+    })
+    .await
+    .expect("pool-owned HTTP discovery must publish after caller cancellation");
+    assert_eq!(
+        *pool.nat_runtime.nat_ip_detected.read().await,
+        Some(PUBLIC_IP.into())
+    );
+    assert_eq!(http.requests.load(Ordering::Relaxed), 1);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn failed_http_discovery_is_reused_during_negative_cache_window() {
+    let http = http_server("not an IP address").await;
+    http.release.add_permits(16);
+    let pool = nat_pool(vec![], vec![format!("http://{}/", http.addr)]).await;
+    for _ in 0..2 {
+        assert!(
+            pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into())
+                .await
+                .is_none()
+        );
+    }
+    assert_eq!(
+        http.requests.load(Ordering::Relaxed),
+        1,
+        "a failed HTTP lookup must not restart ahead of every STUN/handshake attempt"
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn successful_stun_publication_waits_for_cache_reader() {
+    let server = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let pool = nat_pool(vec![server.addr.to_string()], vec![]).await;
+    let caller_pool = pool.clone();
+    let caller = tokio::spawn(async move {
+        caller_pool
+            .maybe_reflect_public_addr(IpFamily::V4, None)
+            .await
+    });
+    server.received().await;
+    let cache_reader = pool.nat_runtime.nat_reflection_cache.lock().await;
+    server.release.add_permits(16);
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    drop(cache_reader);
+    assert_eq!(caller.await.unwrap().unwrap().ip(), PUBLIC_IP);
+    assert_eq!(
+        wait_for_reflection(&pool, IpFamily::V4).await.ip(),
+        PUBLIC_IP
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}

src/transport/middle_proxy/pool_nat/tests/lifecycle.rs

@@ -0,0 +1,342 @@
+use super::*;
+use crate::config::{UpstreamConfig, UpstreamType};
+use crate::transport::UpstreamManager;
+
+/// Gives an isolated pool the same finite bind-address authority as production egress.
+pub(in crate::transport::middle_proxy::pool_nat) fn set_bind_addresses(
+    pool: &mut Arc<MePool>,
+    addresses: &[&str],
+) {
+    let manager = UpstreamManager::new(
+        vec![UpstreamConfig {
+            upstream_type: UpstreamType::Direct {
+                interface: None,
+                bind_addresses: Some(addresses.iter().map(|value| value.to_string()).collect()),
+                bindtodevice: None,
+            },
+            weight: 1,
+            enabled: true,
+            scopes: String::new(),
+            selected_scope: String::new(),
+            ipv4: None,
+            ipv6: None,
+            prefer: None,
+        }],
+        1,
+        0,
+        1000,
+        1,
+        1,
+        true,
+        pool.stats.clone(),
+    );
+    Arc::get_mut(pool).unwrap().upstream = Some(Arc::new(manager));
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn cancelled_waiter_storm_shares_one_http_and_stun_producer() {
+    let http = http_server("91.108.56.1").await;
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let pool = nat_pool(
+        vec![stun.addr.to_string()],
+        vec![format!("http://{}/", http.addr)],
+    )
+    .await;
+    let mut waiters = JoinSet::new();
+    for _ in 0..32 {
+        let pool = pool.clone();
+        waiters.spawn(async move {
+            tokio::join!(
+                pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()),
+                pool.maybe_reflect_public_addr(IpFamily::V4, None),
+            );
+        });
+    }
+    http.received().await;
+    stun.received().await;
+    waiters.abort_all();
+    while waiters.join_next().await.is_some() {}
+    http.release.add_permits(64);
+    stun.release.add_permits(64);
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        Some(PUBLIC_IP.into())
+    );
+    assert_eq!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, None)
+            .await
+            .unwrap()
+            .ip(),
+        PUBLIC_IP
+    );
+    assert_eq!(http.requests.load(Ordering::Relaxed), 1);
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn shutdown_cancels_discovery_and_releases_all_waiters() {
+    let http = http_server("91.108.56.1").await;
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let pool = nat_pool(
+        vec![stun.addr.to_string()],
+        vec![format!("http://{}/", http.addr)],
+    )
+    .await;
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        tokio::join!(
+            waiter_pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()),
+            waiter_pool.maybe_reflect_public_addr(IpFamily::V4, None),
+        )
+    });
+    http.received().await;
+    stun.received().await;
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+    assert_eq!(
+        timeout(TEST_DEADLINE, waiter).await.unwrap().unwrap(),
+        (None, None)
+    );
+    http.release.add_permits(64);
+    stun.release.add_permits(64);
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        None
+    );
+    assert_eq!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, None).await,
+        None
+    );
+    assert_eq!(*pool.nat_runtime.nat_ip_detected.read().await, None);
+    assert_eq!(pool.nat_runtime.nat_reflection_cache.lock().await.v4, None);
+    assert_eq!(http.requests.load(Ordering::Relaxed), 1);
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert!(
+        pool.nat_runtime
+            .nat_reflection_singleflight_v4
+            .try_lock()
+            .is_ok()
+    );
+    assert!(pool.nat_runtime.discovery.http.try_lock().is_ok());
+}
+
+#[tokio::test]
+async fn bound_refresh_survives_cancellation_and_reuses_only_its_source() {
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let mut pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    set_bind_addresses(&mut pool, &["127.0.0.1", "127.0.0.2"]);
+    let bind = Some(Ipv4Addr::LOCALHOST.into());
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        waiter_pool
+            .maybe_reflect_public_addr(IpFamily::V4, bind)
+            .await
+    });
+    stun.received().await;
+    waiter.abort();
+    assert!(waiter.await.unwrap_err().is_cancelled());
+    stun.release.add_permits(64);
+    assert_eq!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, bind)
+            .await
+            .unwrap()
+            .ip(),
+        PUBLIC_IP
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert_eq!(pool.nat_runtime.nat_reflection_cache.lock().await.v4, None);
+    let other = Some("127.0.0.2".parse().unwrap());
+    assert_eq!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, other)
+            .await
+            .unwrap()
+            .ip(),
+        PUBLIC_IP
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 2);
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, Some("127.0.0.3".parse().unwrap()))
+            .await
+            .is_none()
+    );
+    assert!(
+        pool.maybe_reflect_public_addr(IpFamily::V6, bind)
+            .await
+            .is_none()
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 2);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn failed_bound_refresh_is_observable_after_caller_cancellation() {
+    let stun = stun_server_response("127.0.0.1:0".parse().unwrap(), None, Duration::ZERO).await;
+    let mut pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    set_bind_addresses(&mut pool, &["127.0.0.1"]);
+    let bind = Some(Ipv4Addr::LOCALHOST.into());
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        waiter_pool
+            .maybe_reflect_public_addr(IpFamily::V4, bind)
+            .await
+    });
+    stun.received().await;
+    waiter.abort();
+    let _ = waiter.await;
+    // One response completes the original probe; a restarted probe would block forever here.
+    stun.release.add_permits(1);
+    assert_eq!(
+        timeout(
+            TEST_DEADLINE,
+            pool.maybe_reflect_public_addr(IpFamily::V4, bind)
+        )
+        .await
+        .unwrap(),
+        None
+    );
+    assert_eq!(
+        timeout(
+            TEST_DEADLINE,
+            pool.maybe_reflect_public_addr(IpFamily::V4, bind)
+        )
+        .await
+        .unwrap(),
+        None
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn http_negative_cache_expires_without_waiting_a_minute() {
+    let http = http_server("invalid").await;
+    http.release.add_permits(64);
+    let pool = nat_pool(vec![], vec![format!("http://{}/", http.addr)]).await;
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        None
+    );
+    *pool.nat_runtime.discovery.http.lock().await = Some(Instant::now() - Duration::from_secs(1));
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        None
+    );
+    assert_eq!(http.requests.load(Ordering::Relaxed), 2);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn ipv6_refresh_is_independent_of_blocked_ipv4_refresh() {
+    let v4 = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let public_v6: IpAddr = "2001:4860:4860::8888".parse().unwrap();
+    let v6 = stun_server("[::1]:0".parse().unwrap(), public_v6).await;
+    v6.release.add_permits(16);
+    let pool = nat_pool(vec![v4.addr.to_string(), v6.addr.to_string()], vec![]).await;
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        waiter_pool
+            .maybe_reflect_public_addr(IpFamily::V4, None)
+            .await
+    });
+    v4.received().await;
+    assert_eq!(
+        timeout(
+            TEST_DEADLINE,
+            pool.maybe_reflect_public_addr(IpFamily::V6, None)
+        )
+        .await
+        .unwrap()
+        .unwrap()
+        .ip(),
+        public_v6
+    );
+    assert!(!waiter.is_finished());
+    v4.release.add_permits(16);
+    assert_eq!(waiter.await.unwrap().unwrap().ip(), PUBLIC_IP);
+    assert_eq!(
+        pool.nat_runtime
+            .nat_reflection_cache
+            .lock()
+            .await
+            .v4
+            .unwrap()
+            .1
+            .ip(),
+        PUBLIC_IP
+    );
+    assert_eq!(
+        pool.nat_runtime
+            .nat_reflection_cache
+            .lock()
+            .await
+            .v6
+            .unwrap()
+            .1
+            .ip(),
+        public_v6
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn failed_shared_refresh_publishes_backoff_after_caller_cancellation() {
+    let stun = stun_server_response("127.0.0.1:0".parse().unwrap(), None, Duration::ZERO).await;
+    let pool = nat_pool(vec![stun.addr.to_string()], vec![]).await;
+    let waiter_pool = pool.clone();
+    let waiter = tokio::spawn(async move {
+        waiter_pool
+            .maybe_reflect_public_addr(IpFamily::V4, None)
+            .await
+    });
+    stun.received().await;
+    waiter.abort();
+    let _ = waiter.await;
+    stun.release.add_permits(1);
+    assert_eq!(
+        timeout(
+            TEST_DEADLINE,
+            pool.maybe_reflect_public_addr(IpFamily::V4, None)
+        )
+        .await
+        .unwrap(),
+        None
+    );
+    assert!(pool.nat_runtime.stun_backoff_until.read().await.unwrap() > Instant::now());
+    assert_eq!(
+        pool.maybe_reflect_public_addr(IpFamily::V4, None).await,
+        None
+    );
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 1);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn shutdown_before_producer_first_poll_releases_owned_gates() {
+    let http = http_server("91.108.56.1").await;
+    let stun = stun_server("127.0.0.1:0".parse().unwrap(), PUBLIC_IP.into()).await;
+    let pool = nat_pool(
+        vec![stun.addr.to_string()],
+        vec![format!("http://{}/", http.addr)],
+    )
+    .await;
+    let mut http_waiter =
+        tokio_test::task::spawn(pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()));
+    let mut stun_waiter =
+        tokio_test::task::spawn(pool.maybe_reflect_public_addr(IpFamily::V4, None));
+    assert!(http_waiter.poll().is_pending());
+    assert!(stun_waiter.poll().is_pending());
+    // On this current-thread runtime neither producer can run before shutdown admission closes.
+    pool.begin_shutdown();
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+    assert_eq!(http_waiter.poll(), std::task::Poll::Ready(None));
+    assert_eq!(stun_waiter.poll(), std::task::Poll::Ready(None));
+    assert_eq!(http.requests.load(Ordering::Relaxed), 0);
+    assert_eq!(stun.requests.load(Ordering::Relaxed), 0);
+    assert!(pool.nat_runtime.discovery.http.try_lock().is_ok());
+    assert!(
+        pool.nat_runtime
+            .nat_reflection_singleflight_v4
+            .try_lock()
+            .is_ok()
+    );
+}

src/transport/middle_proxy/pool_nat/tests/recovery.rs

@@ -0,0 +1,266 @@
+use super::*;
+use crate::crypto::{SecureRandom, derive_middleproxy_keys};
+use crate::transport::middle_proxy::codec::{
+    RpcChecksumMode, build_handshake_payload, build_nonce_payload, build_rpc_frame,
+    cbc_decrypt_inplace, cbc_encrypt_padded, parse_handshake_flags, parse_nonce_payload,
+    read_rpc_frame_plaintext, rpc_crc,
+};
+use crate::transport::middle_proxy::me_health_monitor;
+use crate::transport::middle_proxy::pool::MeFamilyRuntimeState;
+use tokio::net::TcpStream;
+
+struct MiddlePeer {
+    addr: SocketAddr,
+    handshakes: Arc<AtomicUsize>,
+    cancelled: Arc<AtomicUsize>,
+    task: JoinHandle<()>,
+}
+
+impl Drop for MiddlePeer {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}
+
+impl MiddlePeer {
+    async fn new(server_ip: Ipv4Addr) -> Self {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+        let handshakes = Arc::new(AtomicUsize::new(0));
+        let cancelled = Arc::new(AtomicUsize::new(0));
+        let succeeded = handshakes.clone();
+        let closed = cancelled.clone();
+        let task = tokio::spawn(async move {
+            let mut pending = JoinSet::new();
+            let mut established = Vec::new();
+            loop {
+                tokio::select! {
+                    accepted = listener.accept() => {
+                        let (stream, _) = accepted.unwrap();
+                        pending.spawn(accept_handshake(stream, server_ip));
+                    }
+                    completed = pending.join_next(), if !pending.is_empty() => {
+                        match completed.unwrap().expect("fake ME handshake task must not panic") {
+                            Some(stream) => {
+                                established.push(stream);
+                                succeeded.fetch_add(1, Ordering::Release);
+                            }
+                            None => { closed.fetch_add(1, Ordering::Release); }
+                        }
+                    }
+                }
+            }
+        });
+        Self {
+            addr,
+            handshakes,
+            cancelled,
+            task,
+        }
+    }
+}
+
+async fn accept_handshake(mut stream: TcpStream, server_ip: Ipv4Addr) -> Option<TcpStream> {
+    let client_port = stream.peer_addr().unwrap().port();
+    let server_port = stream.local_addr().unwrap().port();
+    let (seq, payload) = match read_rpc_frame_plaintext(&mut stream).await {
+        Ok(frame) => frame,
+        // Reconnect may time out during NAT discovery, before sending any nonce.
+        Err(ProxyError::Io(error)) if error.kind() == std::io::ErrorKind::UnexpectedEof => {
+            return None;
+        }
+        Err(error) => panic!("invalid client nonce: {error}"),
+    };
+    assert_eq!(seq, -2);
+    let (selector, _, timestamp, client_nonce) = parse_nonce_payload(&payload).unwrap();
+    let server_nonce = [0x42u8; 16];
+    let nonce = build_nonce_payload(selector, timestamp, &server_nonce);
+    stream
+        .write_all(&build_rpc_frame(-2, &nonce, RpcChecksumMode::Crc32))
+        .await
+        .unwrap();
+    let mut client_ip = PUBLIC_IP.octets();
+    client_ip.reverse();
+    let mut server_ip = server_ip.octets();
+    server_ip.reverse();
+    let (read_key, read_iv) = derive_middleproxy_keys(
+        &server_nonce,
+        &client_nonce,
+        &timestamp.to_le_bytes(),
+        Some(&server_ip),
+        &client_port.to_le_bytes(),
+        b"CLIENT",
+        Some(&client_ip),
+        &server_port.to_le_bytes(),
+        &[1u8; 32],
+        None,
+        None,
+    );
+    let (write_key, write_iv) = derive_middleproxy_keys(
+        &server_nonce,
+        &client_nonce,
+        &timestamp.to_le_bytes(),
+        Some(&server_ip),
+        &client_port.to_le_bytes(),
+        b"SERVER",
+        Some(&client_ip),
+        &server_port.to_le_bytes(),
+        &[1u8; 32],
+        None,
+        None,
+    );
+    let mut encrypted = [0u8; 48];
+    stream.read_exact(&mut encrypted).await.unwrap();
+    cbc_decrypt_inplace(&read_key, &read_iv, &mut encrypted).unwrap();
+    assert_eq!(u32::from_le_bytes(encrypted[..4].try_into().unwrap()), 44);
+    assert_eq!(i32::from_le_bytes(encrypted[4..8].try_into().unwrap()), -1);
+    assert_eq!(
+        u32::from_le_bytes(encrypted[40..44].try_into().unwrap()),
+        rpc_crc(RpcChecksumMode::Crc32, &encrypted[..40])
+    );
+    parse_handshake_flags(&encrypted[8..40]).unwrap();
+    assert_eq!(&encrypted[16..20], &client_ip);
+    assert_eq!(
+        u16::from_le_bytes(encrypted[20..22].try_into().unwrap()),
+        client_port
+    );
+    assert_eq!(
+        u16::from_le_bytes(encrypted[32..34].try_into().unwrap()),
+        server_port
+    );
+    let reply = build_handshake_payload(server_ip, server_port, client_ip, client_port, 0);
+    let (encrypted, _) = cbc_encrypt_padded(
+        &write_key,
+        &write_iv,
+        &build_rpc_frame(-1, &reply, RpcChecksumMode::Crc32),
+    )
+    .unwrap();
+    stream.write_all(&encrypted).await.unwrap();
+    Some(stream)
+}
+
+async fn suppressed_pool_recovers_after_delayed_discovery(http_slow: bool) {
+    // Every lookup exceeds me_one_timeout_ms, not just the first request of the outage.
+    let delay = Duration::from_millis(1500);
+    let stun = stun_server_response(
+        "127.0.0.1:0".parse().unwrap(),
+        Some(PUBLIC_IP.into()),
+        delay,
+    )
+    .await;
+    let http = http_server_with_delay("91.108.56.1", delay).await;
+    stun.release.add_permits(64);
+    http.release.add_permits(64);
+    let peer = MiddlePeer::new(if http_slow {
+        PUBLIC_IP
+    } else {
+        Ipv4Addr::LOCALHOST
+    })
+    .await;
+    let urls = if http_slow {
+        vec![format!("http://{}/", http.addr)]
+    } else {
+        vec![]
+    };
+    let pool = nat_pool(vec![stun.addr.to_string()], urls).await;
+    pool.health_runtime
+        .me_health_interval_ms_unhealthy
+        .store(10, Ordering::Relaxed);
+    pool.health_runtime
+        .me_health_interval_ms_healthy
+        .store(10, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_outage_backoff_min_ms
+        .store(100, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_outage_backoff_max_ms
+        .store(100, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_shadow_writers
+        .store(0, Ordering::Relaxed);
+    pool.update_proxy_maps(
+        HashMap::from([(2, vec![(peer.addr.ip(), peer.addr.port())])]),
+        None,
+    )
+    .await;
+    let generation = pool.current_generation();
+    let now = MePool::now_epoch_secs();
+    pool.set_family_runtime_state(
+        IpFamily::V4,
+        MeFamilyRuntimeState::Suppressed,
+        now,
+        now + 3600,
+        5,
+        0,
+    );
+    pool.nat_runtime.nat_reflection_cache.lock().await.v4 = Some((
+        if http_slow {
+            Instant::now()
+        } else {
+            Instant::now() - Duration::from_secs(601)
+        },
+        SocketAddr::new(PUBLIC_IP.into(), 45678),
+    ));
+    let monitor = tokio::spawn(me_health_monitor(
+        pool.clone(),
+        Arc::new(SecureRandom::new()),
+        0,
+    ));
+    if http_slow {
+        http.received().await;
+    } else {
+        stun.received().await;
+    }
+    timeout(Duration::from_secs(5), async {
+        while peer.cancelled.load(Ordering::Acquire) == 0 {
+            assert!(!peer.task.is_finished());
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .expect("the actual 1200ms reconnect must cancel at least one pre-KDF TCP connection");
+    assert_eq!(peer.handshakes.load(Ordering::Acquire), 0);
+    let expected = 2 * pool.required_writers_for_dc(1);
+    timeout(Duration::from_secs(10), async {
+        while !pool.admission_ready_full_floor().await
+            || peer.handshakes.load(Ordering::Acquire) < expected
+        {
+            assert!(
+                !peer.task.is_finished(),
+                "fake ME must validate every encrypted handshake"
+            );
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .expect("suppressed pool must autonomously regain its full floor without restart");
+    monitor.abort();
+    let _ = monitor.await;
+    assert_eq!(pool.current_generation(), generation);
+    assert_eq!(pool.reinit.status.load().pending_hardswap_generation, 0);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+    assert_eq!(pool.writers.read().await.len(), expected);
+    assert!(peer.handshakes.load(Ordering::Acquire) >= expected);
+    assert_eq!(
+        http.requests.load(Ordering::Relaxed),
+        usize::from(http_slow)
+    );
+    assert_eq!(
+        stun.requests.load(Ordering::Relaxed),
+        usize::from(!http_slow)
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn suppressed_pool_recovers_full_floor_after_expired_stun_refresh() {
+    suppressed_pool_recovers_after_delayed_discovery(false).await;
+}
+
+#[tokio::test]
+async fn suppressed_pool_recovers_full_floor_after_slow_http_with_fresh_stun() {
+    suppressed_pool_recovers_after_delayed_discovery(true).await;
+}

src/transport/middle_proxy/pool_writer.rs

@@ -33,6 +33,10 @@ mod publication;
 mod replacement;
 mod runtime;
 
+// Recovery regressions exercise the serialized production publication boundary.
+#[cfg(test)]
+mod recovery_tests;
+
 struct PreparedWriter<'a> {
     writer: MeWriter,
     tx: mpsc::Sender<WriterCommand>,

src/transport/middle_proxy/pool_writer/publication.rs

@@ -84,7 +84,17 @@ impl MePool {
             crate::network::IpFamily::V6
         };
         let now_epoch_secs = Self::now_epoch_secs();
-        if !self.family_enabled_for_drain_coverage(family, now_epoch_secs) {
+        let configured = match family {
+            crate::network::IpFamily::V4 => self.decision.ipv4_me,
+            crate::network::IpFamily::V6 => self.decision.ipv6_me,
+        };
+        // Recovery coverage must remain publishable during suppression; the serialized
+        // per-group floor check below still bounds it and generation authority is unchanged.
+        let recovery_coverage =
+            contour == WriterContour::Active && intent == WriterOpenIntent::Coverage;
+        if !configured
+            || (self.is_family_temporarily_suppressed(family, now_epoch_secs) && !recovery_coverage)
+        {
             return Err(ProxyError::Proxy(
                 "ME writer family lost publication authority".into(),
             ));

src/transport/middle_proxy/pool_writer/recovery_tests.rs

@@ -0,0 +1,466 @@
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+
+use super::*;
+use crate::network::{IpFamily, probe::NetworkDecision};
+use crate::transport::middle_proxy::admission_test_support::unregistered_writer;
+use crate::transport::middle_proxy::pool::MeFamilyRuntimeState;
+use crate::transport::middle_proxy::pool_writer_security_tests::{
+    make_pool, make_pool_with_decision,
+};
+
+fn cap_at_one(pool: &MePool) {
+    pool.floor_runtime
+        .me_adaptive_floor_cpu_cores_override
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_per_core
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_global
+        .store(1, Ordering::Relaxed);
+}
+
+fn suppress(pool: &MePool, family: IpFamily) {
+    let now = MePool::now_epoch_secs();
+    pool.set_family_runtime_state(
+        family,
+        MeFamilyRuntimeState::Suppressed,
+        now,
+        now + 3600,
+        5,
+        0,
+    );
+}
+
+fn prepared<'a>(
+    pool: &'a Arc<MePool>,
+    writer: MeWriter,
+    intent: WriterOpenIntent,
+    reservation: WriterOpenReservation<'a>,
+    task_started: Arc<AtomicBool>,
+) -> PreparedWriter<'a> {
+    let cancel = writer.cancel.clone();
+    PreparedWriter {
+        tx: writer.tx.clone(),
+        byte_budget: writer.byte_budget.clone(),
+        writer,
+        task_registration: pool.lifecycle.try_register().unwrap(),
+        writer_task: Box::pin(async move {
+            task_started.store(true, Ordering::Release);
+            cancel.cancelled().await;
+        }),
+        intent,
+        _open_reservation: reservation,
+    }
+}
+
+#[tokio::test]
+async fn suppressed_active_coverage_publishes_only_the_missing_floor() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    cap_at_one(&pool);
+    suppress(&pool, IpFamily::V4);
+    let required = pool.required_writers_for_dc(1);
+    let mut receivers = Vec::new();
+    for id in 1..=required as u64 {
+        let reservation = pool
+            .reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+            .await
+            .expect("missing coverage must have a reservation despite suppression");
+        let (writer, receiver) = unregistered_writer(
+            &pool,
+            id,
+            2,
+            addr,
+            pool.current_generation(),
+            WriterContour::Active,
+        );
+        receivers.push(receiver);
+        pool.publish_connected_writer(prepared(
+            &pool,
+            writer,
+            WriterOpenIntent::Coverage,
+            reservation,
+            Arc::new(AtomicBool::new(false)),
+        ))
+        .await
+        .expect("authenticated coverage must publish without waiting for suppression expiry");
+        assert_eq!(pool.conn_count.load(Ordering::Relaxed), id as usize);
+        assert_eq!(
+            pool.writer_connect_active_reserved.load(Ordering::Acquire),
+            0
+        );
+    }
+    assert!(
+        pool.reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+            .await
+            .is_none()
+    );
+    let (extra, _receiver) = unregistered_writer(
+        &pool,
+        99,
+        2,
+        addr,
+        pool.current_generation(),
+        WriterContour::Active,
+    );
+    assert!(
+        pool.authorize_writer_publication_capacity(
+            &extra,
+            WriterContour::Active,
+            WriterOpenIntent::Coverage,
+            &pool.writers.read().await,
+        )
+        .is_err()
+    );
+    assert_eq!(
+        pool.family_runtime_state(IpFamily::V4),
+        MeFamilyRuntimeState::Suppressed
+    );
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+}
+
+#[tokio::test]
+async fn concurrent_suppressed_coverage_publications_cannot_overfill_a_group() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    cap_at_one(&pool);
+    suppress(&pool, IpFamily::V4);
+    let required = pool.required_writers_for_dc(1);
+    let mut receivers = Vec::new();
+    let mut publications = Vec::new();
+    for id in 1..=(required + 1) as u64 {
+        let reservation = pool
+            .reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+            .await
+            .unwrap();
+        let (writer, receiver) = unregistered_writer(
+            &pool,
+            id,
+            2,
+            addr,
+            pool.current_generation(),
+            WriterContour::Active,
+        );
+        receivers.push(receiver);
+        publications.push(pool.publish_connected_writer(prepared(
+            &pool,
+            writer,
+            WriterOpenIntent::Coverage,
+            reservation,
+            Arc::new(AtomicBool::new(false)),
+        )));
+    }
+    let guard = pool.writers.write().await;
+    let results = futures::future::join_all(publications);
+    tokio::pin!(results);
+    tokio::select! {
+        biased;
+        results = &mut results => panic!("publication bypassed the writer barrier: {results:?}"),
+        _ = tokio::task::yield_now() => {}
+    }
+    drop(guard);
+    let results = results.await;
+    assert_eq!(
+        results.iter().filter(|result| result.is_ok()).count(),
+        required
+    );
+    assert_eq!(results.iter().filter(|result| result.is_err()).count(), 1);
+    assert_eq!(pool.writers.read().await.len(), required);
+    assert_eq!(pool.conn_count.load(Ordering::Relaxed), required);
+    assert_eq!(
+        pool.registry.writer_idle_since_snapshot().await.len(),
+        required
+    );
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+}
+
+#[tokio::test]
+async fn committed_warm_writer_uses_resolved_active_coverage_authority() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    suppress(&pool, IpFamily::V4);
+    let reservation = pool
+        .reserve_writer_open(WriterContour::Warm, WriterOpenIntent::Coverage, 2, addr)
+        .await
+        .unwrap();
+    let (writer, _receiver) = unregistered_writer(
+        &pool,
+        1,
+        2,
+        addr,
+        pool.current_generation(),
+        WriterContour::Warm,
+    );
+    pool.publish_connected_writer(prepared(
+        &pool,
+        writer,
+        WriterOpenIntent::Coverage,
+        reservation,
+        Arc::new(AtomicBool::new(false)),
+    ))
+    .await
+    .expect("a committed generation must resolve warm coverage to its active role");
+    assert_eq!(
+        pool.writers.read().await[0].contour.load(Ordering::Acquire),
+        WriterContour::Active.as_u8()
+    );
+    assert_eq!(pool.writer_connect_warm_reserved.load(Ordering::Acquire), 0);
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+}
+
+#[tokio::test]
+async fn suppressed_families_keep_their_full_coverage_reservation_budget() {
+    let pool = make_pool_with_decision(NetworkDecision {
+        ipv4_me: true,
+        ipv6_me: true,
+        ..NetworkDecision::default()
+    })
+    .await;
+    let v4 = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    let v6 = SocketAddr::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(
+        HashMap::from([(2, vec![(v4.ip(), v4.port())])]),
+        Some(HashMap::from([(2, vec![(v6.ip(), v6.port())])])),
+    )
+    .await;
+    cap_at_one(&pool);
+    suppress(&pool, IpFamily::V4);
+    suppress(&pool, IpFamily::V6);
+    let required = pool.required_writers_for_dc(1);
+    assert_eq!(pool.active_coverage_required_total().await, required * 4);
+
+    let mut receivers = Vec::new();
+    let mut writers = pool.writers.write().await;
+    for (index, (dc, addr)) in [(2, v4), (-2, v4), (-2, v6)].into_iter().enumerate() {
+        for offset in 0..required {
+            let (writer, receiver) = unregistered_writer(
+                &pool,
+                (index * required + offset + 1) as u64,
+                dc,
+                addr,
+                pool.current_generation(),
+                WriterContour::Active,
+            );
+            writers.push(writer);
+            receivers.push(receiver);
+        }
+    }
+    drop(writers);
+    let reservation = pool
+        .reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, v6)
+        .await
+        .expect("other covered groups must not consume the suppressed family's floor budget");
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        1
+    );
+    drop(reservation);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test]
+async fn coverage_reservations_remain_bounded_and_release_on_drop() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    cap_at_one(&pool);
+    suppress(&pool, IpFamily::V4);
+    let limit = pool.required_writers_for_dc(1) * 2
+        + pool
+            .reconnect_runtime
+            .me_reconnect_max_concurrent_per_dc
+            .max(1) as usize;
+    let mut reservations = Vec::new();
+    for _ in 0..limit {
+        reservations.push(
+            pool.reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+                .await
+                .expect("the configured coverage budget must remain available"),
+        );
+    }
+    assert!(
+        pool.reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr,)
+            .await
+            .is_none()
+    );
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        limit
+    );
+    drop(reservations);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test]
+async fn suppression_exception_does_not_admit_growth_replacement_or_pending_warm() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    suppress(&pool, IpFamily::V4);
+    for (contour, intent) in [
+        (WriterContour::Active, WriterOpenIntent::Normal),
+        (WriterContour::Active, WriterOpenIntent::Replacement),
+        (WriterContour::Warm, WriterOpenIntent::Coverage),
+        (WriterContour::Warm, WriterOpenIntent::Normal),
+    ] {
+        let (writer, _receiver) =
+            unregistered_writer(&pool, 1, 2, addr, pool.current_generation(), contour);
+        assert!(
+            pool.authorize_writer_publication_capacity(&writer, contour, intent, &[])
+                .is_err()
+        );
+    }
+}
+
+#[tokio::test]
+async fn coverage_exception_never_enables_a_disabled_family() {
+    let pool = make_pool().await;
+    let v4 = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    let v6 = SocketAddr::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(
+        HashMap::from([(2, vec![(v4.ip(), v4.port())])]),
+        Some(HashMap::from([(2, vec![(v6.ip(), v6.port())])])),
+    )
+    .await;
+    suppress(&pool, IpFamily::V6);
+    assert_eq!(
+        pool.active_coverage_required_total().await,
+        pool.required_writers_for_dc(1) * 2
+    );
+    let (writer, _receiver) = unregistered_writer(
+        &pool,
+        1,
+        2,
+        v6,
+        pool.current_generation(),
+        WriterContour::Active,
+    );
+    assert!(
+        pool.authorize_writer_publication_capacity(
+            &writer,
+            WriterContour::Active,
+            WriterOpenIntent::Coverage,
+            &[],
+        )
+        .is_err()
+    );
+}
+
+#[tokio::test]
+async fn suppressed_coverage_cannot_publish_a_stale_generation() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    suppress(&pool, IpFamily::V4);
+    let reservation = pool
+        .reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+        .await
+        .unwrap();
+    let (writer, _receiver) = unregistered_writer(
+        &pool,
+        1,
+        2,
+        addr,
+        pool.current_generation().saturating_sub(1),
+        WriterContour::Active,
+    );
+    let task_started = Arc::new(AtomicBool::new(false));
+    let error = pool
+        .publish_connected_writer(prepared(
+            &pool,
+            writer,
+            WriterOpenIntent::Coverage,
+            reservation,
+            task_started.clone(),
+        ))
+        .await
+        .unwrap_err();
+    assert!(
+        error
+            .to_string()
+            .contains("generation lost publication authority")
+    );
+    assert!(pool.writers.read().await.is_empty());
+    assert!(pool.registry.writer_idle_since_snapshot().await.is_empty());
+    assert_eq!(pool.conn_count.load(Ordering::Relaxed), 0);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+    assert!(!task_started.load(Ordering::Acquire));
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+}
+
+#[tokio::test]
+async fn suppressed_coverage_rechecks_endpoints_after_publication_waits() {
+    let pool = make_pool().await;
+    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    suppress(&pool, IpFamily::V4);
+    let reservation = pool
+        .reserve_writer_open(WriterContour::Active, WriterOpenIntent::Coverage, 2, addr)
+        .await
+        .unwrap();
+    let (writer, _receiver) = unregistered_writer(
+        &pool,
+        1,
+        2,
+        addr,
+        pool.current_generation(),
+        WriterContour::Active,
+    );
+    let task_started = Arc::new(AtomicBool::new(false));
+    let publication = pool.publish_connected_writer(prepared(
+        &pool,
+        writer,
+        WriterOpenIntent::Coverage,
+        reservation,
+        task_started.clone(),
+    ));
+    tokio::pin!(publication);
+    let guard = pool.writers.write().await;
+    tokio::select! {
+        biased;
+        result = &mut publication => panic!("publication bypassed the writer barrier: {result:?}"),
+        _ = tokio::task::yield_now() => {}
+    }
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), 444)])]), None)
+        .await;
+    drop(guard);
+    let error = publication.await.unwrap_err();
+    assert!(
+        error
+            .to_string()
+            .contains("target changed before publication")
+    );
+    assert!(pool.writers.read().await.is_empty());
+    assert!(pool.registry.writer_idle_since_snapshot().await.is_empty());
+    assert_eq!(pool.conn_count.load(Ordering::Relaxed), 0);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+    assert!(!task_started.load(Ordering::Acquire));
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+}

src/transport/middle_proxy/tests/admission_test_support.rs

@@ -0,0 +1,98 @@
+use std::collections::HashMap;
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, AtomicU8, AtomicU32, AtomicU64, Ordering};
+use std::time::Instant;
+
+use tokio::sync::mpsc;
+use tokio_util::sync::CancellationToken;
+
+use super::codec::WriterCommand;
+use super::pool::{MePool, MeWriter, WriterContour};
+use super::pool_writer_security_tests::make_pool;
+
+/// Owns idle writer visibility without spawning ME transports or client sessions.
+pub(crate) struct IdlePoolFixture {
+    pool: Arc<MePool>,
+    draining: Vec<Arc<AtomicBool>>,
+    _receivers: Vec<mpsc::Receiver<WriterCommand>>,
+}
+
+impl IdlePoolFixture {
+    /// Builds both signed DC groups with a controllable readiness quorum.
+    pub(crate) async fn new(ready: bool) -> Self {
+        let pool = make_pool().await;
+        let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 443);
+        pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+            .await;
+        let mut draining = Vec::new();
+        let mut receivers = Vec::new();
+        {
+            let mut writers = pool.writers.write().await;
+            for (id, dc) in [(1, 2), (2, -2)] {
+                let (writer, receiver) = unregistered_writer(
+                    &pool,
+                    id,
+                    dc,
+                    addr,
+                    pool.current_generation(),
+                    WriterContour::Active,
+                );
+                writer.draining.store(!ready, Ordering::Release);
+                draining.push(writer.draining.clone());
+                receivers.push(receiver);
+                writers.push(writer);
+            }
+        }
+        Self {
+            pool,
+            draining,
+            _receivers: receivers,
+        }
+    }
+
+    /// Returns the pool sampled by the production admission gate.
+    pub(crate) fn pool(&self) -> Arc<MePool> {
+        self.pool.clone()
+    }
+
+    /// Changes the fixture quorum without notifying the admission gate.
+    pub(crate) fn set_ready(&self, ready: bool) {
+        for draining in &self.draining {
+            draining.store(!ready, Ordering::Release);
+        }
+    }
+}
+
+/// Builds a writer whose command receiver remains owned by the test.
+pub(super) fn unregistered_writer(
+    pool: &Arc<MePool>,
+    id: u64,
+    dc: i32,
+    addr: SocketAddr,
+    generation: u64,
+    contour: WriterContour,
+) -> (MeWriter, mpsc::Receiver<WriterCommand>) {
+    let (tx, rx) = mpsc::channel(8);
+    (
+        MeWriter {
+            id,
+            addr,
+            source_ip: addr.ip(),
+            writer_dc: dc,
+            generation,
+            contour: Arc::new(AtomicU8::new(contour.as_u8())),
+            created_at: Instant::now(),
+            tx,
+            byte_budget: pool.new_writer_byte_budget(),
+            cancel: CancellationToken::new(),
+            degraded: Arc::new(AtomicBool::new(false)),
+            rtt_ema_ms_x10: Arc::new(AtomicU32::new(0)),
+            draining: Arc::new(AtomicBool::new(false)),
+            draining_started_at_epoch_secs: Arc::new(AtomicU64::new(0)),
+            drain_deadline_epoch_secs: Arc::new(AtomicU64::new(0)),
+            allow_drain_fallback: Arc::new(AtomicBool::new(false)),
+        },
+        rx,
+    )
+}

src/transport/upstream.rs

@@ -339,6 +339,8 @@ pub struct UpstreamManager {
 
 // Upstream manager configuration, DNS resolution, and API snapshots.
 mod manager_config;
+// Current direct egress addresses eligible for source-bound NAT discovery.
+mod nat_contexts;
 // Latency- and scope-aware upstream selection.
 mod selection;
 // Direct and proxied connection establishment.

src/transport/upstream/nat_contexts.rs

@@ -0,0 +1,122 @@
+use super::*;
+
+impl UpstreamManager {
+    /// Resolves this generation's direct bind candidates without advancing round-robin state.
+    pub(crate) async fn direct_bind_ips_for_family(&self, ipv6: bool) -> BTreeSet<IpAddr> {
+        let guard = self.upstreams.read().await;
+        let target = SocketAddr::new(
+            if ipv6 {
+                std::net::Ipv6Addr::UNSPECIFIED.into()
+            } else {
+                std::net::Ipv4Addr::UNSPECIFIED.into()
+            },
+            0,
+        );
+        let mut allowed = BTreeSet::new();
+        for state in guard.iter() {
+            let config = &state.config;
+            let UpstreamType::Direct {
+                interface,
+                bind_addresses,
+                ..
+            } = &config.upstream_type
+            else {
+                continue;
+            };
+            if (if ipv6 { config.ipv6 } else { config.ipv4 }) == Some(false) {
+                continue;
+            }
+            if let Some(addresses) = bind_addresses.as_ref().filter(|v| !v.is_empty()) {
+                for address in addresses {
+                    if !address
+                        .parse::<IpAddr>()
+                        .is_ok_and(|ip| ip.is_ipv6() == ipv6)
+                    {
+                        continue;
+                    }
+                    if let Some(ip) = Self::resolve_bind_address(
+                        interface,
+                        &Some(vec![address.clone()]),
+                        target,
+                        None,
+                        true,
+                    ) {
+                        allowed.insert(ip);
+                    }
+                }
+            } else if let Some(ip) =
+                Self::resolve_bind_address(interface, bind_addresses, target, None, true)
+            {
+                allowed.insert(ip);
+            }
+        }
+        allowed
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn config(source: &str) -> UpstreamConfig {
+        toml::from_str(source).unwrap()
+    }
+
+    #[tokio::test]
+    async fn candidates_follow_generation_policy_without_advancing_round_robin() {
+        let manager = UpstreamManager::new(
+            vec![
+                config("type = 'direct'\nbind_addresses = ['127.0.0.1', '127.0.0.2', '::1']"),
+                config("type = 'direct'\ninterface = '127.0.0.3'"),
+                config("type = 'direct'\ninterface = '127.0.0.4'\nenabled = false"),
+                config("type = 'direct'\ninterface = '127.0.0.5'\nipv4 = false"),
+                config("type = 'socks5'\naddress = '127.0.0.1:1080'\ninterface = '127.0.0.6'"),
+            ],
+            1,
+            0,
+            1000,
+            1,
+            1,
+            true,
+            Arc::new(Stats::new()),
+        );
+        manager.upstreams.write().await[0].healthy = false;
+        let expected = ["127.0.0.1", "127.0.0.2", "127.0.0.3"]
+            .into_iter()
+            .map(|value| value.parse().unwrap())
+            .collect();
+        assert_eq!(manager.direct_bind_ips_for_family(false).await, expected);
+        assert_eq!(
+            manager.direct_bind_ips_for_family(true).await,
+            BTreeSet::from(["::1".parse().unwrap()])
+        );
+        for state in manager.upstreams.read().await.iter() {
+            assert_eq!(state.bind_rr.load(Ordering::Relaxed), 0);
+        }
+    }
+
+    #[cfg(target_os = "linux")]
+    #[tokio::test]
+    async fn named_interface_candidates_match_direct_socket_binding() {
+        let manager = UpstreamManager::new(
+            vec![config(
+                "type = 'direct'\ninterface = 'lo'\nbind_addresses = ['127.0.0.1', '::1']",
+            )],
+            1,
+            0,
+            1000,
+            1,
+            1,
+            true,
+            Arc::new(Stats::new()),
+        );
+        assert_eq!(
+            manager.direct_bind_ips_for_family(false).await,
+            BTreeSet::from(["127.0.0.1".parse().unwrap()])
+        );
+        assert_eq!(
+            manager.direct_bind_ips_for_family(true).await,
+            BTreeSet::from(["::1".parse().unwrap()])
+        );
+    }
+}

src/util/secure_fs/mod.rs

@@ -1,14 +1,15 @@
 //! Descriptor-anchored filesystem operations for privileged runtime paths.
 //!
 //! Submodules:
-//! - `path`: symlink-free directory traversal and anchored path ownership
+//! - `path`: strict or compatible directory traversal and anchored path ownership
 //! - `write`: regular-file opening and durable atomic replacement
 
 mod path;
 mod write;
 
 pub(crate) use path::{
-    AnchoredPath, chdir_nofollow_or_create, open_dir_nofollow, open_trusted_dir_nofollow_or_create,
+    AnchoredPath, chdir_nofollow_or_create, open_compatible_dir, open_dir_nofollow,
+    open_trusted_dir_nofollow_or_create,
 };
 pub(crate) use write::{
     atomic_replace, atomic_replace_async, open_append_regular, open_append_regular_at,

src/util/secure_fs/path.rs

@@ -1,7 +1,7 @@
 use std::ffi::{OsStr, OsString};
 use std::io;
 use std::os::fd::OwnedFd;
-use std::os::unix::fs::{MetadataExt, PermissionsExt};
+use std::os::unix::fs::{DirBuilderExt, MetadataExt, PermissionsExt};
 use std::path::{Component, Path};
 
 use nix::fcntl::{OFlag, open, openat};
@@ -53,6 +53,28 @@ impl AnchoredPath {
         Ok(Self { parent, name })
     }
 
+    /// Anchors a runtime parent, applying trusted traversal only when explicitly requested.
+    pub(crate) fn open_runtime_parent(
+        path: &Path,
+        create_mode: Option<u32>,
+        strict_runtime_paths: bool,
+    ) -> io::Result<Self> {
+        if strict_runtime_paths {
+            return match create_mode {
+                Some(mode) => Self::open_trusted_parent_or_create(path, mode),
+                None => Self::open_trusted_parent(path),
+            };
+        }
+        let name = path
+            .file_name()
+            .filter(|name| !name.is_empty())
+            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidInput, "path has no file name"))?
+            .to_os_string();
+        let parent =
+            open_compatible_dir(path.parent().unwrap_or_else(|| Path::new(".")), create_mode)?;
+        Ok(Self { parent, name })
+    }
+
     fn open_with_parent_creation(path: &Path, create_mode: Option<u32>) -> io::Result<Self> {
         let name = path
             .file_name()
@@ -97,6 +119,23 @@ pub(crate) fn open_trusted_dir_nofollow_or_create(path: &Path, mode: u32) -> io:
     open_dir_components(path, Some(mode), true)
 }
 
+/// Follows parent-directory symlinks without imposing ownership or permission policy.
+pub(crate) fn open_compatible_dir(path: &Path, create_mode: Option<u32>) -> io::Result<OwnedFd> {
+    let path = if path.as_os_str().is_empty() {
+        Path::new(".")
+    } else {
+        path
+    };
+    if let Some(mode) = create_mode {
+        std::fs::DirBuilder::new()
+            .recursive(true)
+            .mode(mode)
+            .create(path)?;
+    }
+    // Retain the resolved directory inode so subsequent file operations do not rewalk the path.
+    open(path, DIRECTORY_FLAGS & !OFlag::O_NOFOLLOW, Mode::empty()).map_err(errno_to_io)
+}
+
 /// Opens a directory only when its entire path is owned by root or the effective user.
 fn open_trusted_dir_nofollow(path: &Path) -> io::Result<OwnedFd> {
     open_dir_components(path, None, true)

src/util/secure_fs/tests.rs

@@ -1,4 +1,5 @@
 use std::os::unix::fs::{PermissionsExt, symlink};
+use std::path::Path;
 
 use super::path::AnchoredPath;
 use super::write::atomic_replace_after_anchor;
@@ -15,6 +16,50 @@ fn directory_walk_rejects_intermediate_symlink() {
     assert!(open_dir_nofollow(&link).is_err());
 }
 
+#[test]
+fn runtime_parent_policy_creates_and_reads_relative_paths() {
+    use std::os::unix::fs::MetadataExt;
+
+    let current = std::env::current_dir().unwrap();
+    let directory = tempfile::tempdir_in(&current).unwrap();
+    let relative = directory.path().strip_prefix(&current).unwrap();
+    for strict_runtime_paths in [false, true] {
+        let mode = if strict_runtime_paths {
+            "strict"
+        } else {
+            "compatible"
+        };
+        let path = relative.join(mode).join("nested/telemt.pid");
+        let created =
+            AnchoredPath::open_runtime_parent(&path, Some(0o750), strict_runtime_paths).unwrap();
+        let opened = AnchoredPath::open_runtime_parent(&path, None, strict_runtime_paths).unwrap();
+        let created = std::fs::File::from(created.parent().try_clone().unwrap())
+            .metadata()
+            .unwrap();
+        let opened = std::fs::File::from(opened.parent().try_clone().unwrap())
+            .metadata()
+            .unwrap();
+        assert_eq!((created.dev(), created.ino()), (opened.dev(), opened.ino()));
+        assert_eq!(created.permissions().mode() & 0o777, 0o750);
+    }
+    assert!(AnchoredPath::open_runtime_parent(Path::new("telemt.pid"), None, false).is_ok());
+}
+
+#[test]
+fn runtime_parent_policy_only_requires_trusted_ownership_when_strict() {
+    if !nix::unistd::Uid::effective().is_root() {
+        return;
+    }
+    let directory = tempfile::tempdir().unwrap();
+    let parent = directory.path().join("foreign-owner");
+    std::fs::create_dir(&parent).unwrap();
+    nix::unistd::chown(&parent, Some(nix::unistd::Uid::from_raw(65534)), None).unwrap();
+    let path = parent.join("telemt.pid");
+
+    assert!(AnchoredPath::open_runtime_parent(&path, None, false).is_ok());
+    assert!(AnchoredPath::open_runtime_parent(&path, None, true).is_err());
+}
+
 #[test]
 fn atomic_replace_does_not_follow_final_symlink() {
     let directory = tempfile::tempdir().unwrap();

src/web/bridge.rs

@@ -1,5 +1,6 @@
 use base64::Engine as _;
 
+use crate::config::WebCarrierMethod;
 use crate::crypto::SecureRandom;
 
 /// Browser security policy for the transient Telegram Desktop bridge page.
@@ -34,6 +35,7 @@ pub(crate) fn render(
     reconnect_grace_secs: u64,
     carrier_probe_coalesce_ms: u64,
     bridge_diagnostics_enabled: bool,
+    carrier_method: WebCarrierMethod,
     rng: &SecureRandom,
 ) -> BridgePage {
     let mut nonce = [0u8; 18];
@@ -124,6 +126,7 @@ pub(crate) fn render(
         .replace("__HOST__", host)
         .replace("__BASE_PREFIX__", base_prefix)
         .replace("__BOOTSTRAP__", bootstrap)
+        .replace("__CARRIER_METHOD__", carrier_method.as_str())
         .replace("__BATCH_LIMIT__", &batch_limit.to_string())
         .replace("__QUEUE_LIMIT__", &queue_limit.to_string())
         .replace("__QUEUE_ITEMS__", &queue_items.to_string())

src/web/bridge/runtime.js

@@ -7,6 +7,8 @@ const responseBody=globalThis.TelemtBridgeResponse;if(!responseBody)throw new Er
 const requestSupport=globalThis.TelemtBridgeRequest;if(!requestSupport)throw new Error('missing request runtime');
 const bufferSupport=globalThis.TelemtBridgeBuffers;if(!bufferSupport)throw new Error('missing buffer runtime');
 const recoverySupport=globalThis.TelemtBridgeRecovery;if(!recoverySupport)throw new Error('missing recovery runtime');
+// Keep the method page-owned so recovery and config rollback cannot change frozen retries.
+const carrierMethod='__CARRIER_METHOD__';
 let negotiationEnabled=__NEGOTIATION_ENABLED__,candidateCount=__CANDIDATE_COUNT__,candidateDeadlines=[__CARRIER_DEADLINES__];
 let longPollMs=__LONG_POLL_SECS__*1000,bridgeRequestMs=__BRIDGE_REQUEST_SECS__*1000,bridgeRetryMs=__BRIDGE_RETRY_SECS__*1000;
 let bridgeRecoveryMs=__BRIDGE_RECOVERY_SECS__*1000,websocketOpenMs=__WEBSOCKET_OPEN_SECS__*1000,reconnectGraceMs=__RECONNECT_GRACE_SECS__*1000;
@@ -226,7 +228,7 @@ async function createSession(epoch){
 async function probeHttp(probe,laneID,epoch){
  try{
   const headers={'X-Up-Seq':'1'},token=sessionToken,controller=attemptController,body=probe.data;if(laneID!==null)headers['X-Lane-ID']=String(laneID);
-  const response=await request('/api/v1/up',options('POST',token,body,headers,controller.signal));
+  const response=await request('/api/v1/up',options(carrierMethod,token,body,headers,controller.signal));
   if(closed||epoch!==attemptEpoch)return
   if(response.status!==204){advanceCarrier('http',epoch);return}
   if(response.headers.get('X-Up-Ack')!=='1'){advanceCarrier('protocol',epoch);return}
@@ -263,14 +265,14 @@ async function runUp(){
    lease=takeBatch(upPending,null);upLease=lease;lease.controller=new AbortController();const sequence=String(upSequence),token=sessionToken;
    for(;;){
     try{
-     const response=await request('/api/v1/up',options('POST',token,lease.body,{'X-Up-Seq':sequence},lease.controller.signal),null,1);
+     const response=await request('/api/v1/up',options(carrierMethod,token,lease.body,{'X-Up-Seq':sequence},lease.controller.signal),null,1);
      if(response.status!==204)throw failure('http','uplink rejected');
      if(response.headers.get('X-Up-Ack')!==sequence)throw failure('protocol','uplink acknowledgement rejected');
      break;
     }catch(error){
      let replayed=false;
      const recovered=await recoverTransport(error,async(signal,remaining)=>{
-      const response=await request('/api/v1/up',options('POST',token,lease.body,{'X-Up-Seq':sequence},signal),remaining,2);
+      const response=await request('/api/v1/up',options(carrierMethod,token,lease.body,{'X-Up-Seq':sequence},signal),remaining,2);
       if(response.status!==204)throw failure('http','uplink replay rejected');
       if(response.headers.get('X-Up-Ack')!==sequence)throw failure('protocol','uplink replay acknowledgement rejected');
       replayed=true;
@@ -343,7 +345,7 @@ async function poll(){
   const token=sessionToken,cursor=downCursor;
   try{
    pollController=new AbortController();
-   const response=await request('/api/v1/down',options('POST',token,null,{'X-Down-Cursor':cursor},pollController.signal),null,1);
+   const response=await request('/api/v1/down',options(carrierMethod,token,null,{'X-Down-Cursor':cursor},pollController.signal),null,1);
    if(closed||sessionToken!==token)return;
    if(response.status===204){status('connected');continue}
    if(response.status!==200)throw failure('http','downlink rejected');
@@ -354,7 +356,7 @@ async function poll(){
   }catch(error){
    if(closed)return;
    const recovered=await recoverTransport(error,async(signal,remaining)=>{
-    const response=await request('/api/v1/down',options('POST',token,null,{'X-Down-Cursor':cursor},signal),remaining,2);
+    const response=await request('/api/v1/down',options(carrierMethod,token,null,{'X-Down-Cursor':cursor},signal),remaining,2);
     if(response.status===204)return;
     if(response.status!==200||!response.body.byteLength||!response.headers.get('X-Down-Cursor'))throw failure('http','downlink replay rejected');
    });
@@ -422,14 +424,14 @@ async function runLaneUp(lane){
    const sequence=String(lane.sequence),laneID=String(lane.id),token=sessionToken;
    for(;;){
     try{
-     const response=await request('/api/v1/up',options('POST',token,lease.body,{'X-Up-Seq':sequence,'X-Lane-ID':laneID},lease.controller.signal),null,1);
+     const response=await request('/api/v1/up',options(carrierMethod,token,lease.body,{'X-Up-Seq':sequence,'X-Lane-ID':laneID},lease.controller.signal),null,1);
      if(response.status!==204)throw failure('http','lane uplink rejected');
      if(response.headers.get('X-Up-Ack')!==sequence)throw failure('protocol','lane uplink acknowledgement rejected');
      break;
     }catch(error){
      let replayed=false;
      const recovered=await recoverTransport(error,async(signal,remaining)=>{
-      const response=await request('/api/v1/up',options('POST',token,lease.body,{'X-Up-Seq':sequence,'X-Lane-ID':laneID},signal),remaining,2);
+      const response=await request('/api/v1/up',options(carrierMethod,token,lease.body,{'X-Up-Seq':sequence,'X-Lane-ID':laneID},signal),remaining,2);
       if(response.status!==204)throw failure('http','lane uplink replay rejected');
       if(response.headers.get('X-Up-Ack')!==sequence)throw failure('protocol','lane uplink replay acknowledgement rejected');
       replayed=true;
@@ -451,7 +453,7 @@ async function pollLane(lane){
   while(!closed&&sessionToken&&lanes.get(lane.id)===lane){
    const controller=new AbortController(),laneID=String(lane.id),token=sessionToken,cursor=lane.cursor;lane.controller=controller;
    failedToken=token;failedCursor=cursor;failedLaneID=laneID;
-   const response=await request('/api/v1/down',options('POST',token,null,{'X-Down-Cursor':cursor,'X-Lane-ID':laneID},controller.signal),null,1);
+   const response=await request('/api/v1/down',options(carrierMethod,token,null,{'X-Down-Cursor':cursor,'X-Lane-ID':laneID},controller.signal),null,1);
    if(closed||sessionToken!==token||lanes.get(lane.id)!==lane)return;
    if(response.status===204){
     if(response.headers.get('X-Lane-Closed')==='1'){finishLane(lane,false);return}
@@ -467,7 +469,7 @@ async function pollLane(lane){
   }catch(error){
    if(!closed&&lanes.get(lane.id)===lane){
     const recovered=await recoverTransport(error,async(signal,remaining)=>{
-     const response=await request('/api/v1/down',options('POST',failedToken,null,{'X-Down-Cursor':failedCursor,'X-Lane-ID':failedLaneID},signal),remaining,2);
+     const response=await request('/api/v1/down',options(carrierMethod,failedToken,null,{'X-Down-Cursor':failedCursor,'X-Lane-ID':failedLaneID},signal),remaining,2);
      if(response.status===204)return;
      if(response.status!==200||!response.body.byteLength||!response.headers.get('X-Down-Cursor'))throw failure('http','lane downlink replay rejected');
     });

src/web/bridge/tests.rs

@@ -1,5 +1,73 @@
 use super::*;
 
+#[test]
+fn carrier_method_is_page_owned_and_used_by_every_https_request() {
+    for method in [WebCarrierMethod::Post, WebCarrierMethod::Put] {
+        let page = render(
+            "proxy.example.com",
+            "/telegram/web/",
+            "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+            2 * 1024 * 1024,
+            32 * 1024 * 1024,
+            16 * 1024,
+            1024,
+            true,
+            4,
+            [3, 5, 8, 12],
+            25,
+            10,
+            90,
+            15,
+            15,
+            120,
+            0,
+            true,
+            method,
+            &SecureRandom::new(),
+        );
+        assert!(!page.body.contains("__"));
+        assert!(
+            page.body
+                .contains(&format!("const carrierMethod='{}';", method.as_str()))
+        );
+        assert_eq!(page.body.matches("carrierMethod=").count(), 1);
+        assert_eq!(page.body.matches("options(carrierMethod,").count(), 9);
+        let requests: Vec<_> = page
+            .body
+            .lines()
+            .filter(|line| {
+                line.contains("request('/api/v1/up'") || line.contains("request('/api/v1/down'")
+            })
+            .collect();
+        assert_eq!(requests.len(), 9);
+        assert!(
+            requests
+                .iter()
+                .all(|line| line.contains("options(carrierMethod,"))
+        );
+        assert_eq!(page.body.matches("options('POST',bootstrap,").count(), 2);
+        assert!(
+            page.body
+                .contains("fetch(relayBase+'/api/v1/diagnostic',{method:'POST'")
+        );
+        assert!(
+            page.body
+                .contains("options('DELETE',token,null,headers,undefined,true)")
+        );
+        assert!(
+            page.body
+                .contains("method:'GET',signal:requestController.signal")
+        );
+        assert!(
+            page.body
+                .contains("exactKeys(value,['v','bootstrap','limits','timeouts','negotiation'])")
+        );
+        assert!(!page.body.contains("policy.carrier_method"));
+        assert!(page.body.contains("port.postMessage({t:'status',state})"));
+        assert!(!page.body.contains("port.postMessage({t:'status',state,"));
+    }
+}
+
 fn render_page(bootstrap: &str, candidate_count: usize) -> BridgePage {
     render(
         "proxy.example.com",
@@ -20,6 +88,7 @@ fn render_page(bootstrap: &str, candidate_count: usize) -> BridgePage {
         120,
         0,
         false,
+        WebCarrierMethod::Post,
         &SecureRandom::new(),
     )
 }
@@ -44,6 +113,7 @@ fn render_diagnostic_page(bootstrap: &str) -> BridgePage {
         120,
         0,
         true,
+        WebCarrierMethod::Post,
         &SecureRandom::new(),
     )
 }
@@ -95,6 +165,7 @@ fn rendered_page_resolves_carriers_against_the_exact_base_path() {
         120,
         0,
         true,
+        WebCarrierMethod::Post,
         &SecureRandom::new(),
     );
 
@@ -148,6 +219,7 @@ fn rendered_page_embeds_the_configured_bridge_timing_policy() {
         119,
         4,
         false,
+        WebCarrierMethod::Post,
         &SecureRandom::new(),
     );
 
@@ -201,6 +273,7 @@ fn disabled_negotiation_does_not_arm_a_carrier_deadline() {
         120,
         0,
         false,
+        WebCarrierMethod::Post,
         &SecureRandom::new(),
     );
     assert!(page.body.contains(

src/web/http.rs

@@ -44,9 +44,9 @@ mod recovery;
 mod response;
 // Session creation and replacement negotiation remain separate from request routing.
 mod session;
-// RFC 6455 upgrade validation and carrier drivers remain isolated from HTTP routing.
 #[cfg(test)]
 mod tests;
+// RFC 6455 upgrade validation and carrier drivers remain isolated from HTTP routing.
 mod websocket;
 // Enabled-debug integration coverage remains separate from carrier behavior tests.
 #[cfg(test)]
@@ -389,6 +389,7 @@ async fn handle_root(
         config.web.timeouts.reconnect_grace_secs,
         config.web.timeouts.carrier_probe_coalesce_ms,
         config.web.debug.bridge_diagnostics_enabled(),
+        config.web.carrier_method,
         &generation.rng,
     );
     let mut response = full_response(StatusCode::OK, Bytes::from(page.body));
@@ -456,14 +457,13 @@ async fn handle_api(
         _ => serve_decoy(request, vhost, true, &runtime).await,
     }
 }
-
 async fn handle_up(
     request: Request<RequestBody>,
     runtime: Arc<WebProcessRuntime>,
     vhost: Arc<WebRuntimeVhost>,
     token_hash: crate::web::manager::TokenHash,
 ) -> HttpResponse {
-    if request.method() != Method::POST || !binary_content_type(&request) {
+    if !matches!(*request.method(), Method::POST | Method::PUT) || !binary_content_type(&request) {
         return serve_decoy(request, vhost, true, &runtime).await;
     }
     let Some(sequence) = canonical_u64_header(&request, "x-up-seq").filter(|value| *value != 0)

src/web/http/carrier_method_tests.rs

@@ -0,0 +1,480 @@
+use super::super::session_policy_tests::{open_keepalive, read_http_response};
+use super::super::*;
+use crate::config::WebCarrierMethod;
+
+fn carrier_request(method: &str, path: &str, token: &str, headers: &str, body: &[u8]) -> Vec<u8> {
+    let mut bytes = format!(
+        "{method} {path} HTTP/1.1\r\nHost: proxy.example.com\r\nX-Forwarded-For: 192.0.2.60\r\nAuthorization: Bearer {token}\r\n{headers}Content-Length: {}\r\nConnection: close\r\n\r\n",
+        body.len()
+    )
+    .into_bytes();
+    bytes.extend_from_slice(body);
+    bytes
+}
+
+async fn bridge_page(
+    listener: &TcpListener,
+    runtime: &Arc<WebProcessRuntime>,
+    capability: [u8; 32],
+    base: &str,
+) -> Vec<u8> {
+    let encoded = base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(capability);
+    request(
+        listener,
+        runtime,
+        format!(
+            "GET {base}?bridge={encoded} HTTP/1.1\r\nHost: proxy.example.com\r\nX-Forwarded-For: 192.0.2.60\r\nConnection: close\r\n\r\n"
+        )
+        .into_bytes(),
+    )
+    .await
+}
+
+fn bootstrap_from(page: &[u8]) -> &str {
+    let (headers, body) = split_response(page);
+    assert!(headers.starts_with(b"HTTP/1.1 200"));
+    std::str::from_utf8(body)
+        .unwrap()
+        .split_once("bootstrap=\"")
+        .unwrap()
+        .1
+        .split_once('"')
+        .unwrap()
+        .0
+}
+
+async fn create_session(
+    listener: &TcpListener,
+    runtime: &Arc<WebProcessRuntime>,
+    bootstrap: &str,
+    base: &str,
+) -> String {
+    let hello = frame::encode(FrameType::Hello, 0, &[1]);
+    let bytes = carrier_request(
+        "POST",
+        &format!("{base}api/v1/session"),
+        bootstrap,
+        "Content-Type: application/octet-stream\r\n",
+        &hello,
+    );
+    let response = request(listener, runtime, bytes).await;
+    let (headers, _) = split_response(&response);
+    assert!(headers.starts_with(b"HTTP/1.1 200"));
+    response_header(headers, "x-session-token").to_string()
+}
+
+async fn session_token(
+    listener: &TcpListener,
+    runtime: &Arc<WebProcessRuntime>,
+    capability: [u8; 32],
+    base: &str,
+) -> String {
+    let page = bridge_page(listener, runtime, capability, base).await;
+    create_session(listener, runtime, bootstrap_from(&page), base).await
+}
+
+async fn assert_put_accepted(path: &str) {
+    for (carrier, base, method) in [WebCarrier::Https, WebCarrier::HttpsLanes]
+        .into_iter()
+        .flat_map(|carrier| {
+            ["/", "/telegram/web/"].into_iter().flat_map(move |base| {
+                [WebCarrierMethod::Post, WebCarrierMethod::Put]
+                    .map(|method| (carrier, base, method))
+            })
+        })
+    {
+        let capability = [60; 32];
+        let mut config = runtime_config_with_base(capability, carrier, base);
+        config.web.carrier_method = method;
+        config.web.timeouts.long_poll_secs = 0;
+        let generation = test_runtime_generation(1, config);
+        let runtime = WebProcessRuntime::start(Arc::new(ArcSwap::from(Arc::clone(&generation))));
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let token = session_token(&listener, &runtime, capability, base).await;
+        let lane = if carrier.uses_lanes() {
+            "X-Lane-ID: 0\r\n"
+        } else {
+            ""
+        };
+        let pong = frame::encode(FrameType::Pong, 0, &[]);
+        let (headers, body) = if path.ends_with("/up") {
+            (
+                format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{lane}"),
+                pong.as_ref(),
+            )
+        } else {
+            (format!("X-Down-Cursor: 0\r\n{lane}"), &[][..])
+        };
+        let path = format!("{base}{}", path.trim_start_matches('/'));
+        let bytes = carrier_request("PUT", &path, &token, &headers, body);
+        let response = request(&listener, &runtime, bytes).await;
+        assert!(
+            response.starts_with(b"HTTP/1.1 204"),
+            "{carrier:?}: {}",
+            String::from_utf8_lossy(&response)
+        );
+        runtime.shutdown().await;
+        generation.stop_sessions().await;
+        generation.stop_background_tasks().await;
+    }
+}
+
+#[tokio::test]
+async fn put_uplink_is_accepted_for_both_https_carriers() {
+    assert_put_accepted("/api/v1/up").await;
+}
+
+#[tokio::test]
+async fn put_downlink_is_accepted_for_both_https_carriers() {
+    assert_put_accepted("/api/v1/down").await;
+}
+
+#[tokio::test]
+async fn carrier_method_mixed_retries_share_sequence_and_cursor_state() {
+    for carrier in [WebCarrier::Https, WebCarrier::HttpsLanes] {
+        for method in [WebCarrierMethod::Post, WebCarrierMethod::Put] {
+            let capability = [61; 32];
+            let mut config = runtime_config(capability, carrier);
+            config.web.carrier_method = method;
+            config.web.timeouts.long_poll_secs = 0;
+            // Exhausted admission queues a deterministic CLOSE without starting a relay task.
+            config.web.limits.max_streams_global = 0;
+            let generation = test_runtime_generation(1, config);
+            let runtime =
+                WebProcessRuntime::start(Arc::new(ArcSwap::from(Arc::clone(&generation))));
+            let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+            let token = session_token(&listener, &runtime, capability, "/").await;
+            for (index, stream_id) in [7, 8].into_iter().enumerate() {
+                let lane = if carrier.uses_lanes() {
+                    format!("X-Lane-ID: {stream_id}\r\n")
+                } else {
+                    String::new()
+                };
+                let sequence = if carrier.uses_lanes() { 1 } else { index + 1 };
+                let cursor = if carrier.uses_lanes() { 0 } else { index };
+                let open = frame::encode(FrameType::Open, stream_id, &[]);
+                let up_headers = format!(
+                    "Content-Type: application/octet-stream\r\nX-Up-Seq: {sequence}\r\n{lane}"
+                );
+                let methods = if index == 0 {
+                    ["POST", "PUT"]
+                } else {
+                    ["PUT", "POST"]
+                };
+                for verb in methods {
+                    let bytes = carrier_request(verb, "/api/v1/up", &token, &up_headers, &open);
+                    let response = request(&listener, &runtime, bytes).await;
+                    let (headers, body) = split_response(&response);
+                    assert!(headers.starts_with(b"HTTP/1.1 204"));
+                    assert_eq!(response_header(headers, "x-up-ack"), sequence.to_string());
+                    assert!(body.is_empty());
+                }
+                for verb in methods {
+                    let headers = format!("X-Down-Cursor: {cursor}\r\n{lane}");
+                    let bytes = carrier_request(verb, "/api/v1/down", &token, &headers, &[]);
+                    let response = request(&listener, &runtime, bytes).await;
+                    let (headers, body) = split_response(&response);
+                    assert!(headers.starts_with(b"HTTP/1.1 200"));
+                    assert_eq!(
+                        response_header(headers, "x-down-cursor"),
+                        (cursor + 1).to_string()
+                    );
+                    assert_eq!(body, frame::encode(FrameType::Close, stream_id, &[]));
+                }
+                let headers = format!("X-Down-Cursor: {}\r\n{lane}", cursor + 1);
+                let bytes = carrier_request("PUT", "/api/v1/down", &token, &headers, &[]);
+                let response = request(&listener, &runtime, bytes).await;
+                assert!(response.starts_with(b"HTTP/1.1 204"));
+            }
+            runtime.shutdown().await;
+            generation.stop_sessions().await;
+            generation.stop_background_tasks().await;
+        }
+    }
+}
+
+#[tokio::test]
+async fn carrier_method_changed_body_retry_keeps_protocol_failure() {
+    for carrier in [WebCarrier::Https, WebCarrier::HttpsLanes] {
+        let capability = [62; 32];
+        let generation = test_runtime_generation(1, runtime_config(capability, carrier));
+        let runtime = WebProcessRuntime::start(Arc::new(ArcSwap::from(Arc::clone(&generation))));
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let token = session_token(&listener, &runtime, capability, "/").await;
+        let lane = if carrier.uses_lanes() {
+            "X-Lane-ID: 0\r\n"
+        } else {
+            ""
+        };
+        let headers = format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{lane}");
+        let pong = frame::encode(FrameType::Pong, 0, &[]);
+        let bytes = carrier_request("POST", "/api/v1/up", &token, &headers, &pong);
+        let response = request(&listener, &runtime, bytes).await;
+        assert!(response.starts_with(b"HTTP/1.1 204"));
+        let mut changed = pong.to_vec();
+        changed.extend_from_slice(&pong);
+        let bytes = carrier_request("PUT", "/api/v1/up", &token, &headers, &changed);
+        let response = request(&listener, &runtime, bytes).await;
+        assert_private_decoy(&response);
+        runtime.shutdown().await;
+        generation.stop_sessions().await;
+        generation.stop_background_tasks().await;
+    }
+}
+
+fn assert_private_decoy(response: &[u8]) {
+    let (headers, body) = split_response(response);
+    assert!(headers.starts_with(b"HTTP/1.1 404"));
+    assert_eq!(response_header(headers, "cache-control"), "no-store");
+    assert_eq!(body, b"not found\n");
+    let headers = std::str::from_utf8(headers).unwrap().to_ascii_lowercase();
+    for name in ["x-up-ack:", "x-down-cursor:", "x-session-token:", "allow:"] {
+        assert!(!headers.contains(name));
+    }
+}
+
+#[tokio::test]
+async fn carrier_method_put_preserves_authenticated_request_shape_checks() {
+    for carrier in [WebCarrier::Https, WebCarrier::HttpsLanes] {
+        let capability = [63; 32];
+        let base = "/telegram/web/";
+        let generation =
+            test_runtime_generation(1, runtime_config_with_base(capability, carrier, base));
+        let runtime = WebProcessRuntime::start(Arc::new(ArcSwap::from(Arc::clone(&generation))));
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let token = session_token(&listener, &runtime, capability, base).await;
+        let pong = frame::encode(FrameType::Pong, 0, &[]);
+        let lane = if carrier.uses_lanes() {
+            "X-Lane-ID: 0\r\n"
+        } else {
+            ""
+        };
+        let up = format!("{base}api/v1/up");
+        let down = format!("{base}api/v1/down");
+        let up_headers = format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{lane}");
+        let down_headers = format!("X-Down-Cursor: 0\r\n{lane}");
+        let mut invalid = Vec::new();
+        for media in [
+            "",
+            "Content-Type: text/plain\r\n",
+            "Content-Type: application/octet-stream\r\nContent-Type: application/octet-stream\r\n",
+        ] {
+            let headers = format!("{media}X-Up-Seq: 1\r\n{lane}");
+            invalid.push(carrier_request("PUT", &up, &token, &headers, &pong));
+        }
+        for sequence in ["0", "01", ""] {
+            let sequence = if sequence.is_empty() {
+                String::new()
+            } else {
+                format!("X-Up-Seq: {sequence}\r\n")
+            };
+            let headers = format!("Content-Type: application/octet-stream\r\n{sequence}{lane}");
+            invalid.push(carrier_request("PUT", &up, &token, &headers, &pong));
+        }
+        let invalid_lane = if carrier.uses_lanes() {
+            ""
+        } else {
+            "X-Lane-ID: 0\r\n"
+        };
+        let headers =
+            format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{invalid_lane}");
+        invalid.push(carrier_request("PUT", &up, &token, &headers, &pong));
+        let headers = format!("{down_headers}Content-Type: application/octet-stream\r\n");
+        invalid.push(carrier_request("PUT", &down, &token, &headers, &[]));
+        invalid.push(carrier_request("PUT", &down, &token, &down_headers, &[0]));
+        let headers = format!("X-Down-Cursor: 01\r\n{lane}");
+        invalid.push(carrier_request("PUT", &down, &token, &headers, &[]));
+        for verb in ["GET", "PATCH"] {
+            invalid.push(carrier_request(verb, &up, &token, &up_headers, &pong));
+            invalid.push(carrier_request(verb, &down, &token, &down_headers, &[]));
+        }
+        for path in [
+            "/api/v1/up",
+            "/telegram/web/api/v1/up/",
+            "/telegram/web/api/v1/up?q=1",
+            "/telegram/web/api/v1//up",
+            "/telegram/web/api/v1/%75p",
+        ] {
+            invalid.push(carrier_request("PUT", path, &token, &up_headers, &pong));
+        }
+        let wrong_host = String::from_utf8(carrier_request("PUT", &up, &token, &up_headers, &pong))
+            .unwrap()
+            .replace("Host: proxy.example.com", "Host: other.example.com")
+            .into_bytes();
+        invalid.push(wrong_host);
+        let path = format!("{base}api/v1/session");
+        invalid.push(carrier_request("PUT", &path, &token, &up_headers, &pong));
+        for bytes in invalid {
+            let response = request(&listener, &runtime, bytes).await;
+            assert_private_decoy(&response);
+        }
+        // Rejected shapes must not consume the first sequence or close the valid session.
+        let bytes = carrier_request("PUT", &up, &token, &up_headers, &pong);
+        let response = request(&listener, &runtime, bytes).await;
+        assert!(response.starts_with(b"HTTP/1.1 204"));
+        runtime.shutdown().await;
+        generation.stop_sessions().await;
+        generation.stop_background_tasks().await;
+    }
+}
+
+#[tokio::test]
+async fn carrier_method_post_and_put_reuse_one_private_http_connection() {
+    for carrier in [WebCarrier::Https, WebCarrier::HttpsLanes] {
+        let capability = [64; 32];
+        let mut config = runtime_config(capability, carrier);
+        config.web.timeouts.long_poll_secs = 0;
+        config.web.limits.max_streams_global = 0;
+        let generation = test_runtime_generation(1, config);
+        let runtime = WebProcessRuntime::start(Arc::new(ArcSwap::from(Arc::clone(&generation))));
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let token = session_token(&listener, &runtime, capability, "/").await;
+        let (mut client, cancellation, task) = open_keepalive(&listener, &runtime).await;
+        let lane = if carrier.uses_lanes() {
+            "X-Lane-ID: 7\r\n"
+        } else {
+            ""
+        };
+        let open = frame::encode(FrameType::Open, 7, &[]);
+        let close = frame::encode(FrameType::Close, 7, &[]);
+        for verb in ["POST", "PUT", "PUT", "POST"] {
+            for (path, headers, body, ack_header) in [
+                (
+                    "/api/v1/up",
+                    format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{lane}"),
+                    open.as_ref(),
+                    "x-up-ack",
+                ),
+                (
+                    "/api/v1/down",
+                    format!("X-Down-Cursor: 0\r\n{lane}"),
+                    &[][..],
+                    "x-down-cursor",
+                ),
+            ] {
+                let bytes = carrier_request(verb, path, &token, &headers, body);
+                let bytes = String::from_utf8(bytes)
+                    .unwrap()
+                    .replace("Connection: close\r\n", "Connection: keep-alive\r\n")
+                    .into_bytes();
+                client.write_all(&bytes).await.unwrap();
+                let response = tokio::time::timeout(
+                    std::time::Duration::from_secs(5),
+                    read_http_response(&mut client),
+                )
+                .await
+                .unwrap();
+                let (headers, body) = split_response(&response);
+                assert_eq!(response_header(headers, ack_header), "1");
+                assert!(
+                    !std::str::from_utf8(headers)
+                        .unwrap()
+                        .to_ascii_lowercase()
+                        .contains("connection: close")
+                );
+                if path.ends_with("/up") {
+                    assert!(headers.starts_with(b"HTTP/1.1 204"));
+                    assert!(body.is_empty());
+                } else {
+                    assert!(headers.starts_with(b"HTTP/1.1 200"));
+                    assert_eq!(
+                        response_header(headers, "content-length"),
+                        close.len().to_string()
+                    );
+                    assert_eq!(body, close);
+                }
+            }
+        }
+        cancellation.cancel();
+        task.await.unwrap();
+        runtime.shutdown().await;
+        generation.stop_sessions().await;
+        generation.stop_background_tasks().await;
+    }
+}
+
+#[tokio::test]
+async fn carrier_method_reload_preserves_old_pages_bootstraps_sessions_and_recovery() {
+    for carrier in [WebCarrier::Https, WebCarrier::HttpsLanes] {
+        let capability = [65; 32];
+        let mut config = runtime_config(capability, carrier);
+        config.web.limits.max_bootstraps_per_ip = 6;
+        let generation = test_runtime_generation(1, config.clone());
+        let active_runtime = Arc::new(ArcSwap::from(Arc::clone(&generation)));
+        let runtime = WebProcessRuntime::start(Arc::clone(&active_runtime));
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let post_page = bridge_page(&listener, &runtime, capability, "/").await;
+        let old_session =
+            create_session(&listener, &runtime, bootstrap_from(&post_page), "/").await;
+        let unused_post_page = bridge_page(&listener, &runtime, capability, "/").await;
+        config.web.carrier_method = WebCarrierMethod::Put;
+        let put_generation = test_runtime_generation(2, config.clone());
+        active_runtime.store(Arc::clone(&put_generation));
+        let post_session =
+            create_session(&listener, &runtime, bootstrap_from(&unused_post_page), "/").await;
+        let put_page = bridge_page(&listener, &runtime, capability, "/").await;
+        assert!(String::from_utf8_lossy(&put_page).contains("const carrierMethod='PUT';"));
+        config.web.carrier_method = WebCarrierMethod::Post;
+        let rollback_generation = test_runtime_generation(3, config);
+        active_runtime.store(Arc::clone(&rollback_generation));
+        let put_session = create_session(&listener, &runtime, bootstrap_from(&put_page), "/").await;
+        let rollback_page = bridge_page(&listener, &runtime, capability, "/").await;
+        assert!(String::from_utf8_lossy(&rollback_page).contains("const carrierMethod='POST';"));
+        assert!(String::from_utf8_lossy(&post_page).contains("const carrierMethod='POST';"));
+        let lane = if carrier.uses_lanes() {
+            "X-Lane-ID: 0\r\n"
+        } else {
+            ""
+        };
+        let headers = format!("Content-Type: application/octet-stream\r\nX-Up-Seq: 1\r\n{lane}");
+        let pong = frame::encode(FrameType::Pong, 0, &[]);
+        for token in [&old_session, &post_session, &put_session] {
+            for verb in ["PUT", "POST"] {
+                let bytes = carrier_request(verb, "/api/v1/up", token, &headers, &pong);
+                let response = request(&listener, &runtime, bytes).await;
+                assert!(response.starts_with(b"HTTP/1.1 204"));
+            }
+        }
+        let encoded = base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(capability);
+        let bytes = carrier_request(
+            "GET",
+            &format!("/?bridge={encoded}"),
+            &put_session,
+            "Accept: application/vnd.telemt.web-recovery+json\r\n",
+            &[],
+        );
+        let recovery = request(&listener, &runtime, bytes).await;
+        let (recovery_headers, body) = split_response(&recovery);
+        assert!(recovery_headers.starts_with(b"HTTP/1.1 200"));
+        assert_eq!(
+            response_header(recovery_headers, "content-type"),
+            "application/vnd.telemt.web-recovery+json"
+        );
+        let document: serde_json::Value = serde_json::from_slice(body).unwrap();
+        let keys: std::collections::BTreeSet<_> = document
+            .as_object()
+            .unwrap()
+            .keys()
+            .map(String::as_str)
+            .collect();
+        assert_eq!(
+            keys,
+            ["v", "bootstrap", "limits", "timeouts", "negotiation"]
+                .into_iter()
+                .collect()
+        );
+        let bootstrap = document["bootstrap"].as_str().unwrap();
+        let recovered = create_session(&listener, &runtime, bootstrap, "/").await;
+        let bytes = carrier_request("PUT", "/api/v1/up", &recovered, &headers, &pong);
+        let response = request(&listener, &runtime, bytes).await;
+        assert!(response.starts_with(b"HTTP/1.1 204"));
+        let bytes = carrier_request("PUT", "/api/v1/up", &put_session, &headers, &pong);
+        let retired = request(&listener, &runtime, bytes).await;
+        assert_private_decoy(&retired);
+        runtime.shutdown().await;
+        for generation in [generation, put_generation, rollback_generation] {
+            generation.stop_sessions().await;
+            generation.stop_background_tasks().await;
+        }
+    }
+}

src/web/http/down.rs

@@ -22,7 +22,7 @@ pub(super) async fn handle_down(
     vhost: Arc<WebRuntimeVhost>,
     token_hash: TokenHash,
 ) -> HttpResponse {
-    if request.method() != hyper::Method::POST
+    if !matches!(*request.method(), hyper::Method::POST | hyper::Method::PUT)
         || request.headers().contains_key(header::CONTENT_TYPE)
     {
         return serve_decoy(request, vhost, true, &runtime).await;

src/web/http/legacy_tests.rs

@@ -1,5 +1,9 @@
 use super::*;
 
+// HTTP method compatibility keeps platform workarounds outside session state.
+#[path = "carrier_method_tests.rs"]
+mod carrier_method_tests;
+
 #[tokio::test]
 async fn windows_restricted_webview_empty_cookie_preserves_the_carrier_flow() {
     for (index, carrier) in [WebCarrier::Https, WebCarrier::HttpsLanes]

src/web/http/session_policy_tests.rs

@@ -1,6 +1,7 @@
 use super::*;
 
-async fn open_keepalive(
+/// Opens one reusable private HTTP connection for integration scenarios.
+pub(super) async fn open_keepalive(
     listener: &TcpListener,
     runtime: &Arc<WebProcessRuntime>,
 ) -> (TcpStream, CancellationToken, tokio::task::JoinHandle<()>) {
@@ -21,7 +22,8 @@ async fn open_keepalive(
     (client.unwrap(), cancellation, task)
 }
 
-async fn read_http_response(client: &mut TcpStream) -> Vec<u8> {
+/// Reads one length-delimited response without waiting for connection closure.
+pub(super) async fn read_http_response(client: &mut TcpStream) -> Vec<u8> {
     let mut response = Vec::new();
     while !response.ends_with(b"\r\n\r\n") {
         assert!(response.len() < 16 * 1024);