refactoring

proxy/utils.py

@@ -0,0 +1,48 @@
+import socket as _socket
+
+from typing import Optional
+
+
+ZERO_64 = b'\x00' * 64
+HANDSHAKE_LEN = 64
+SKIP_LEN = 8
+PREKEY_LEN = 32
+KEY_LEN = 32
+IV_LEN = 16
+PROTO_TAG_POS = 56
+DC_IDX_POS = 60
+
+PROTO_TAG_ABRIDGED = b'\xef\xef\xef\xef'
+PROTO_TAG_INTERMEDIATE = b'\xee\xee\xee\xee'
+PROTO_TAG_SECURE = b'\xdd\xdd\xdd\xdd'
+
+PROTO_ABRIDGED_INT = 0xEFEFEFEF
+PROTO_INTERMEDIATE_INT = 0xEEEEEEEE
+PROTO_PADDED_INTERMEDIATE_INT = 0xDDDDDDDD
+
+RESERVED_FIRST_BYTES = {0xEF}
+RESERVED_STARTS = {b'\x48\x45\x41\x44', b'\x50\x4F\x53\x54',
+                    b'\x47\x45\x54\x20', b'\xee\xee\xee\xee',
+                    b'\xdd\xdd\xdd\xdd', b'\x16\x03\x01\x02'}
+RESERVED_CONTINUE = b'\x00\x00\x00\x00'
+
+
+def human_bytes(n: int) -> str:
+    for unit in ('B', 'KB', 'MB', 'GB'):
+        if abs(n) < 1024:
+            return f"{n:.1f}{unit}"
+        n /= 1024
+    return f"{n:.1f}TB"
+
+
+def get_link_host(host: str) -> Optional[str]:
+    if host == '0.0.0.0':
+        try:
+            with _socket.socket(_socket.AF_INET, _socket.SOCK_DGRAM) as _s:
+                _s.connect(('8.8.8.8', 80))
+                link_host = _s.getsockname()[0]
+        except OSError:
+            link_host = '127.0.0.1'
+        return link_host
+    else:
+        return host