Reject cross-origin websocket connections (#24714)

* reject cross-origin websocket handshakes

Neither /ws nor the jsmpeg websockets checked Origin, and the internal port grants admin to everyone, so any page a LAN user visited could open ws://frigate:5000/ws and send commands or read streams. Both servers now reject a browser handshake whose Origin host matches neither Host nor X-Forwarded-Host, and allow handshakes without an Origin for non-browser clients. nginx now forwards an outer proxy's X-Forwarded-Host instead of overwriting it, so proxies that rewrite Host and the Home Assistant integration's proxy still match.

* apply runtime role changes to jsmpeg streams

The output process never subscribed to config/auth, so role edits from the Roles UI (requires_restart 0) did not reach it and jsmpeg kept streaming cameras that had been removed from a role until restart. The output process now replaces its auth config on config/auth updates, which the camera and birdseye broadcast threads read through the shared config.

* tidy origin check docstring and auth update comment

* reject cross-origin go2rtc stream requests in /auth

The go2rtc websockets and the webrtc offer POST still accepted any Origin, since go2rtc runs with origin "*" and /auth grants admin on the internal port, so a page on another site could pull live video through a LAN user's browser. nginx now passes Origin, Host, X-Forwarded-Host and Upgrade to /auth, which rejects a websocket upgrade or go2rtc stream request with a foreign Origin before the internal-port early return. The hostname rule moves to frigate/util/origin.py so /auth and the ws4py servers share it.

* set Host in the nginx proxy doc examples

* drain all queued auth updates in the output process

* note that cards must stream through the integration proxy

* strip the query before matching go2rtc paths in the origin check

docker/main/rootfs/usr/local/nginx/conf/auth_location.conf

@@ -20,6 +20,11 @@ location /auth {
     proxy_set_header X-Go2rtc-Stream-Proxy $go2rtc_stream_proxy;
     proxy_set_header X-Server-Port $server_port;
     proxy_set_header X-Forwarded-Proto $scheme;
+    # inputs for the cross-origin check on websocket and go2rtc stream requests
+    proxy_set_header Origin $http_origin;
+    proxy_set_header X-Original-Host $http_host;
+    proxy_set_header X-Forwarded-Host $forwarded_host;
+    proxy_set_header X-Original-Upgrade $http_upgrade;
     proxy_set_header Content-Length "";
     # Pass along auth related info
     proxy_set_header Authorization $http_authorization;

docker/main/rootfs/usr/local/nginx/conf/nginx.conf

@@ -54,6 +54,13 @@ http {
         default 1;
     }
 
+    # keep an outer proxy's X-Forwarded-Host so the websocket servers can
+    # match a browser's Origin when that proxy rewrites Host
+    map $http_x_forwarded_host $forwarded_host {
+        "" $http_host;
+        default $http_x_forwarded_host;
+    }
+
     upstream frigate_api {
         server 127.0.0.1:5001;
         keepalive 1024;

docker/main/rootfs/usr/local/nginx/conf/proxy.conf

@@ -4,7 +4,7 @@ proxy_set_header Upgrade $http_upgrade;
 proxy_set_header Connection "Upgrade";
 proxy_set_header X-Original-URL $request_uri;
 proxy_set_header X-Forwarded-Proto $scheme;
-proxy_set_header X-Forwarded-Host $http_host;
+proxy_set_header X-Forwarded-Host $forwarded_host;
 proxy_set_header X-Forwarded-URI $request_uri;
 proxy_set_header X-Forwarded-Ssl on;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;