Files
gstack/browse
Garry Tan 50d07eb234 fix(browse): apply codex adversarial findings on the new lifecycle
Codex outside-voice review caught five real production-failure modes in
the v1.28.0.0 proxy/headed lifecycle. Fixed:

1) `browse disconnect` skip-graceful for proxy-only daemons
   (browse/src/cli.ts). The graceful /command POST went out with stray
   `domains,` shorthand and (even fixed) the server's disconnect handler
   only tears down headed mode — proxy-only daemons returned 200 "Not
   in headed mode" while leaving the bridge running. Now disconnect
   short-circuits to force-cleanup for non-headed daemons, which kicks
   process.on('exit') in server.ts to close the bridge + Xvfb.

2) sendCommand crash retry preserves --proxy / --headed
   (browse/src/cli.ts). The ECONNRESET retry path called startServer()
   with no extraEnv, silently dropping the proxied flags. A daemon that
   died mid-command would silently restart in default direct/headless
   mode and bypass the SOCKS bridge. Now reapplies BROWSE_PROXY_URL,
   BROWSE_HEADED, and BROWSE_CONFIG_HASH from the resolved global flags.

3) `connect` honors --proxy (browse/src/cli.ts). The headed-mode
   `connect` command built its own serverEnv that didn't include
   BROWSE_PROXY_URL, so `browse --proxy <url> connect` launched headed
   Chromium without the proxy. Now threads proxyUrl + configHash into
   the connect serverEnv.

4) SOCKS5 bridge handles fragmented TCP frames
   (browse/src/socks-bridge.ts). Previously used once('data') and
   parsed each chunk as a complete SOCKS5 frame — TCP doesn't preserve
   message boundaries and split greetings/CONNECT requests caused
   intermittent handshake failures. Replaced with a single state
   machine that buffers chunks and uses size predicates on the SOCKS5
   header to know when a complete frame has arrived. Pauses the client
   socket during upstream connect and replays any remainder bytes
   into the upstream on success.

5) Xvfb cleanup-then-state-delete ordering
   (browse/src/server.ts). emergencyCleanup() previously deleted the
   state file BEFORE any Xvfb cleanup could read it, orphaning Xvfb
   on uncaughtException / unhandledRejection. Now reads the state
   file first, calls cleanupXvfb() (which validates cmdline +
   start-time before kill), then deletes the state file.

Adds a regression test for #4: writes the SOCKS5 greeting + CONNECT
one byte at a time with 5ms ticks, asserts a clean round trip after
the fragmented handshake.

Codex's sixth finding (bridge advertises NO_AUTH on 127.0.0.1, so any
co-located process can use the authenticated upstream) is documented
as a known limitation — gstack's threat model assumes single-user
hosts. Adding bridge-side auth is a separate change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 14:54:15 -07:00
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