Stdlib: socket_atmark() — TCP urgent-data OOB probe missing (ext/sockets/sockets.c) #6544

Category

stdlib

Problem

socket_atmark() (PHP 8.0+) reports whether the next received byte is out-of-band / at the TCP urgent mark. It is registered in php-src ext/sockets but missing here — function_exists('socket_atmark') is false on bin/vm.php.

Distinct from ancillary-data helpers tracked in #6333 (socket_sendmsg / socket_recvmsg / socket_cmsg_space).

php-src reference

• php/php-src ext/sockets/sockets.c — PHP_FUNCTION(socket_atmark)
• php/php-src ext/sockets/sockets.stub.php

Repro (failure today)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php -r "var_export(function_exists(\"socket_atmark\"));"'

Observed: false.

Zend PHP 8.4: true when ext/sockets is loaded.

Scope (this repo)

Implement in ext/ + VM lowering; avoid new logic in runtime/*.c except unavoidable socket ABI.

Verification

• test/compliance/cases/stdlib/socket_atmark.phpt (Unix stream socket pair + send(..., MSG_OOB) when stream_socket_pair lands — Stdlib: stream_socket_pair() — connected socket pair (ext/standard/streams.c parity) #3437; until then skip with @requires function stream_socket_pair)
• ./script/docker-exec.sh -- bash -lc 'vendor/bin/phpunit test/compliance/VMTest.php --filter socket_atmark'

Related

• Stdlib: socket_select() — ext/sockets multiplexing API missing (ext/sockets/sockets.c) #6395 / Stdlib: socket_listen()/socket_accept()/socket_set_option()/socket_get_option() — ext/sockets server API (ext/sockets/sockets.c) #6176 ext/sockets server API
• Stdlib: socket_sendmsg()/socket_recvmsg()/socket_cmsg_space() — ext/sockets ancillary data API missing (ext/sockets/sockets.c) #6333 ancillary data (separate API)
• Stdlib: stream_socket_pair() — connected socket pair (ext/standard/streams.c parity) #3437 stream_socket_pair() for IPC test harness

Done when

• function_exists('socket_atmark') is true on bin/vm.php
• socket_atmark($stream) returns bool per SIOCATMARK / platform equivalent (document unsupported platforms)
• test/compliance/cases/stdlib/socket_atmark.phpt passes when stream_socket_pair available (Stdlib: stream_socket_pair() — connected socket pair (ext/standard/streams.c parity) #3437), skips otherwise
• ./script/ci-fast.sh --filter socket_atmark green
• Capability matrix notes VM/JIT/AOT status

Strictness

php-src-strict — match PHP_FUNCTION(socket_atmark) in php-src ext/sockets/sockets.c.