richardopenai
e8bb1b6641
## Why QPACK can expand compact response headers into large decoded field sections. Bound their size before `h3` constructs its capacity-limited `HeaderMap`. ## What changed Set the HTTP/3 client's maximum field section size to 64 KiB so oversized responses are rejected with `HeaderTooBig`. ## Testing Add a regression test that sends QPACK static references around the size limit and a much larger expansion. Verify that oversized responses are rejected and a subsequent valid response succeeds on the same connection. GitOrigin-RevId: d7c83a7a755dfafae05919ec52542ffce40a1ef4
HTTP/3 TCP tunnel
The ordinary Codex binary includes the hidden codex tcp-tunnel command. It forwards a loopback TCP listener to an explicitly selected host and port through a TLS-verified HTTP/3 CONNECT proxy. The proxy URL must be an exact HTTPS origin in the supplied policy file; the target is provided separately as host:port or [IPv6]:port.
The initial bearer must be provided as a single line on standard input (--auth-token-stdin). With --auth-token-updates-stdin, later lines replace the bearer for new connections, emit AUTH_UPDATED, and closure of the controlling pipe stops the tunnel. With --connect-headers-stdin, the first line is instead a JSON list of ["x-name","value"] pairs; token lines follow. Only non-forwarding x- extension headers are accepted. No header values or credentials belong in the command arguments.
The process emits LISTENING 127.0.0.1:<port> after connecting to the proxy. A proxy handshake does not authorize the target; each local connection makes its own authenticated CONNECT. The listener survives transport reconnects, but TCP streams are never replayed.
--diagnostics-json opts into newline-delimited JSON on stderr. Version 1 contains
v, phase (startup, connect, transport, or control), code (failed,
timeout, rejected, closed, draining, or invalid_input), and terminal.
A rejected CONNECT may also include a numeric http_status (100–599, excluding
2xx). Records contain no credentials, addresses, headers, or raw error messages
and are less than 256 bytes. Stdout readiness and credential acknowledgments are
unchanged. A terminal record is flushed before an unsuccessful return; closing
the controlling pipe normally emits no failure. The CLI may append a generic
error line after the terminal record. Nonterminal events may concern
one TCP stream or a reconnecting shared transport and do not identify the cause
of a later child-process failure. Consumers must ignore records with unknown versions or fields and keep a generic
fallback for helpers without this flag.
Version 1 terminal combinations are startup/{failed,timeout},
control/{failed,invalid_input}, and transport/failed. Nonterminal combinations
are connect/{failed,rejected} and transport/{failed,timeout,closed,draining}.
Other combinations are unknown records and must use the generic fallback.