fix: harden tcp bridge reconnect handling

2026-04-03 05:57:52 +08:00
parent fd1fae8ad7
commit 9fd748c512
5 changed files with 247 additions and 10 deletions
@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+"""Simple TCP debug server for validating raw payload forwarding.
+
+Usage examples:
+    python tools/tcp_debug_server.py --host 0.0.0.0 --port 8081
+    python tools/tcp_debug_server.py --port 8081 --echo
+
+Features:
+    - Listen as a plain TCP server
+    - Print connect/disconnect events
+    - Print received payload as text and hex
+    - Optional echo mode
+    - Optional stdin -> socket sender for manual testing
+"""
+
+from __future__ import annotations
+
+import argparse
+import select
+import socket
+import sys
+import threading
+from datetime import datetime
+
+
+def ts() -> str:
+    return datetime.now().strftime("%H:%M:%S.%f")[:-3]
+
+
+def hex_bytes(data: bytes) -> str:
+    return " ".join(f"{b:02X}" for b in data)
+
+
+def text_view(data: bytes) -> str:
+    return "".join(chr(b) if 32 <= b < 127 else "." for b in data)
+
+
+def sender_loop(conn: socket.socket, stop_event: threading.Event) -> None:
+    print(f"[{ts()}] stdin sender ready. Type text and press Enter to send.")
+    while not stop_event.is_set():
+        line = sys.stdin.readline()
+        if line == "":
+            stop_event.set()
+            break
+        payload = line.encode("utf-8", errors="replace")
+        try:
+            conn.sendall(payload)
+            print(
+                f"[{ts()}] TX {len(payload)} bytes | text={payload!r} | hex={hex_bytes(payload)}"
+            )
+        except OSError as exc:
+            print(f"[{ts()}] TX failed: {exc}")
+            stop_event.set()
+            break
+
+
+def serve(host: str, port: int, echo: bool, no_stdin: bool) -> int:
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server:
+        server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        server.bind((host, port))
+        server.listen(1)
+        print(f"[{ts()}] Listening on {host}:{port}")
+
+        conn, addr = server.accept()
+        with conn:
+            print(f"[{ts()}] Client connected from {addr[0]}:{addr[1]}")
+            stop_event = threading.Event()
+            sender_thread = None
+
+            if not no_stdin:
+                sender_thread = threading.Thread(
+                    target=sender_loop, args=(conn, stop_event), daemon=True
+                )
+                sender_thread.start()
+
+            conn.setblocking(False)
+
+            while not stop_event.is_set():
+                ready, _, _ = select.select([conn], [], [], 0.2)
+                if not ready:
+                    continue
+
+                try:
+                    data = conn.recv(4096)
+                except BlockingIOError:
+                    continue
+                except OSError as exc:
+                    print(f"[{ts()}] RX failed: {exc}")
+                    break
+
+                if not data:
+                    print(f"[{ts()}] Client disconnected")
+                    break
+
+                print(
+                    f"[{ts()}] RX {len(data)} bytes | text={text_view(data)} | hex={hex_bytes(data)}"
+                )
+
+                if echo:
+                    try:
+                        conn.sendall(data)
+                        print(f"[{ts()}] ECHO {len(data)} bytes")
+                    except OSError as exc:
+                        print(f"[{ts()}] Echo failed: {exc}")
+                        break
+
+            stop_event.set()
+            if sender_thread is not None:
+                sender_thread.join(timeout=0.5)
+
+    return 0
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="Minimal raw TCP debug server")
+    parser.add_argument(
+        "--host", default="0.0.0.0", help="Listen host, default: 0.0.0.0"
+    )
+    parser.add_argument(
+        "--port", type=int, default=8081, help="Listen port, default: 8081"
+    )
+    parser.add_argument(
+        "--echo", action="store_true", help="Echo received payload back to client"
+    )
+    parser.add_argument(
+        "--no-stdin",
+        action="store_true",
+        help="Disable stdin sender thread (receive-only mode)",
+    )
+    return parser.parse_args()
+
+
+def main() -> int:
+    args = parse_args()
+    try:
+        return serve(args.host, args.port, args.echo, args.no_stdin)
+    except KeyboardInterrupt:
+        print(f"\n[{ts()}] Stopped by user")
+        return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())