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Author SHA1 Message Date
Alexey 94f4f7d540 Merge pull request #939 from telemt/conntrack
Сonntrack recovery on absent iptables-nft chains fixes
2026-10-01 23:03:27 +03:00
Alexey c10677ed97 Bump -> 3.5.11 2026-10-01 22:54:07 +03:00
Alexey 86912e34b2 Сonntrack recovery on absent iptables-nft chains fixes
Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>
2026-10-01 22:50:50 +03:00
5 changed files with 622 additions and 7 deletions
Generated
+1 -1
View File
@@ -2780,7 +2780,7 @@ dependencies = [
[[package]]
name = "telemt"
version = "3.5.10"
version = "3.5.11"
dependencies = [
"aes",
"anyhow",
+1 -1
View File
@@ -1,6 +1,6 @@
[package]
name = "telemt"
version = "3.5.10"
version = "3.5.11"
edition = "2024"
rust-version = "1.88"
+104 -5
View File
@@ -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()
}
+4
View File
@@ -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,
@@ -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);
}
}