V10.420 guard 111 Ollama LAN access

scripts/ops/ollama111_allow_proxy.py

@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+"""
+User-space allowlist TCP proxy for the 111 Ollama fallback.
+
+Purpose:
+  - Keep the real Ollama server bound to 127.0.0.1:11434.
+  - Expose 192.168.0.111:11434 only to approved momo-pro clients.
+  - Reject noisy LAN / VM clients without requiring sudo/pfctl.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import ipaddress
+import logging
+import os
+import signal
+from typing import Iterable
+
+
+LISTEN_HOST = os.getenv("OLLAMA111_PROXY_LISTEN_HOST", "192.168.0.111")
+LISTEN_PORT = int(os.getenv("OLLAMA111_PROXY_LISTEN_PORT", "11434"))
+TARGET_HOST = os.getenv("OLLAMA111_PROXY_TARGET_HOST", "127.0.0.1")
+TARGET_PORT = int(os.getenv("OLLAMA111_PROXY_TARGET_PORT", "11434"))
+ALLOWED_CIDRS = tuple(
+    item.strip()
+    for item in os.getenv(
+        "OLLAMA111_PROXY_ALLOWED_CIDRS",
+        "127.0.0.1/32,192.168.0.80/32,192.168.0.111/32,192.168.0.188/32",
+    ).split(",")
+    if item.strip()
+)
+
+
+def _allowed_networks() -> tuple[ipaddress._BaseNetwork, ...]:
+    return tuple(ipaddress.ip_network(item, strict=False) for item in ALLOWED_CIDRS)
+
+
+ALLOWED_NETWORKS = _allowed_networks()
+
+
+def _is_allowed(peer_ip: str) -> bool:
+    try:
+        ip = ipaddress.ip_address(peer_ip)
+    except ValueError:
+        return False
+    return any(ip in network for network in ALLOWED_NETWORKS)
+
+
+async def _pipe(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
+    try:
+        while True:
+            data = await reader.read(65536)
+            if not data:
+                break
+            writer.write(data)
+            await writer.drain()
+    except (ConnectionError, asyncio.CancelledError):
+        pass
+    finally:
+        try:
+            writer.close()
+            await writer.wait_closed()
+        except Exception:
+            pass
+
+
+async def _handle_client(reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
+    peer = writer.get_extra_info("peername")
+    peer_ip = peer[0] if peer else "unknown"
+    if not _is_allowed(peer_ip):
+        logging.warning("reject peer=%s allowed=%s", peer_ip, ",".join(ALLOWED_CIDRS))
+        writer.close()
+        await writer.wait_closed()
+        return
+
+    try:
+        target_reader, target_writer = await asyncio.open_connection(TARGET_HOST, TARGET_PORT)
+    except Exception as exc:
+        logging.error("target connect failed peer=%s target=%s:%s err=%r", peer_ip, TARGET_HOST, TARGET_PORT, exc)
+        writer.close()
+        await writer.wait_closed()
+        return
+
+    logging.info("proxy peer=%s -> %s:%s", peer_ip, TARGET_HOST, TARGET_PORT)
+    await asyncio.gather(
+        _pipe(reader, target_writer),
+        _pipe(target_reader, writer),
+    )
+
+
+async def _main() -> None:
+    logging.basicConfig(
+        level=os.getenv("OLLAMA111_PROXY_LOG_LEVEL", "INFO"),
+        format="%(asctime)s %(levelname)s %(message)s",
+    )
+    server = await asyncio.start_server(_handle_client, LISTEN_HOST, LISTEN_PORT)
+    sockets = ", ".join(str(sock.getsockname()) for sock in (server.sockets or []))
+    logging.info(
+        "ollama111 allow proxy listening=%s target=%s:%s allowed=%s",
+        sockets,
+        TARGET_HOST,
+        TARGET_PORT,
+        ",".join(ALLOWED_CIDRS),
+    )
+
+    stop = asyncio.Event()
+    loop = asyncio.get_running_loop()
+    for sig in (signal.SIGINT, signal.SIGTERM):
+        loop.add_signal_handler(sig, stop.set)
+
+    async with server:
+        await stop.wait()
+        server.close()
+        await server.wait_closed()
+
+
+if __name__ == "__main__":
+    asyncio.run(_main())