streams: apply so_linger, so_rcvbuf and so_sndbuf to unix sockets

UPGRADING

@@ -483,16 +483,16 @@ PHP 8.6 UPGRADE NOTES
     tcp_keepintvl and tcp_keepcnt that allow setting socket keepalive
     options.
   . Added stream socket context option so_linger that sets SO_LINGER on TCP
-    sockets. A positive value enables lingering for that many seconds, zero
-    or a negative value disables it. Values above 65535 are clamped as the
+    and unix sockets. A positive value enables lingering for that many seconds,
+    zero or a negative value disables it. Values above 65535 are clamped as the
     linger time is limited to an unsigned short on some platforms.
   . Added stream socket context options so_rcvbuf and so_sndbuf that set the
     socket receive and send buffer sizes in bytes (SO_RCVBUF and SO_SNDBUF) on
-    TCP and UDP sockets. The value must be an integer between 1 and 2147483647,
-    any other value makes the stream creation fail. The operating system may
-    round, cap or otherwise adjust the requested size, and may stop sizing that
-    buffer automatically, so the size read back can differ from the one
-    requested.
+    TCP, UDP, unix and unix datagram sockets. The value must be an integer
+    between 1 and 2147483647, any other value makes the stream creation fail.
+    The operating system may round, cap or otherwise adjust the requested size,
+    and may stop sizing that buffer automatically, so the size read back can
+    differ from the one requested.
   . Allowed casting filtered streams as file descriptors for select.
   . Added the "write_seek_mode" filter parameter for the bz2, iconv,
     zlib, and string stream filters. This parameter must be set via an

ext/standard/tests/network/so_linger_unix.phpt

@@ -0,0 +1,85 @@
+--TEST--
+stream_socket_server() and stream_socket_client() SO_LINGER context option test with unix sockets
+--EXTENSIONS--
+sockets
+--SKIPIF--
+<?php
+if (array_search("unix", stream_get_transports()) === false) {
+    die('skip No support for UNIX domain sockets.');
+}
+?>
+--FILE--
+<?php
+// macOS expresses SO_LINGER in ticks, SO_LINGER_SEC in seconds.
+$so_linger = defined('SO_LINGER_SEC') ? SO_LINGER_SEC : SO_LINGER;
+
+function linger($stream): array {
+    global $so_linger;
+
+    return socket_get_option(socket_import_stream($stream), SOL_SOCKET, $so_linger);
+}
+
+$server_path = sys_get_temp_dir() . '/' . uniqid('so_linger_server_') . '.sock';
+$dgram_path = sys_get_temp_dir() . '/' . uniqid('so_linger_dgram_') . '.sock';
+
+$server = stream_socket_server("unix://$server_path", $errno, $errstr,
+    STREAM_SERVER_BIND | STREAM_SERVER_LISTEN,
+    stream_context_create(['socket' => ['so_linger' => 10]]));
+
+if (!$server) {
+    die('Unable to create server');
+}
+
+$client = stream_socket_client("unix://$server_path", $errno, $errstr, 30,
+    STREAM_CLIENT_CONNECT,
+    stream_context_create(['socket' => ['so_linger' => 8]]));
+
+if (!$client) {
+    die('Unable to create client');
+}
+
+$accepted = stream_socket_accept($server, 1);
+
+if (!$accepted) {
+    die('Unable to accept connection');
+}
+
+$listen_linger = linger($server);
+echo "Listen SO_LINGER", PHP_EOL;
+var_dump($listen_linger['l_onoff'] > 0);
+var_dump($listen_linger['l_linger']);
+
+$client_linger = linger($client);
+echo "Client SO_LINGER", PHP_EOL;
+var_dump($client_linger['l_onoff'] > 0);
+var_dump($client_linger['l_linger']);
+
+// The option is meaningless on datagram sockets and is not applied there.
+$dgram = stream_socket_server("udg://$dgram_path", $errno, $errstr, STREAM_SERVER_BIND,
+    stream_context_create(['socket' => ['so_linger' => 10]]));
+
+if (!$dgram) {
+    die('Unable to create server');
+}
+
+$dgram_linger = linger($dgram);
+echo "Datagram SO_LINGER", PHP_EOL;
+var_dump($dgram_linger['l_onoff'] > 0);
+
+fclose($accepted);
+fclose($client);
+fclose($server);
+fclose($dgram);
+unlink($server_path);
+unlink($dgram_path);
+
+?>
+--EXPECT--
+Listen SO_LINGER
+bool(true)
+int(10)
+Client SO_LINGER
+bool(true)
+int(8)
+Datagram SO_LINGER
+bool(false)

ext/standard/tests/network/so_rcvbuf_sndbuf_udg.phpt

@@ -0,0 +1,58 @@
+--TEST--
+stream_socket_server() SO_RCVBUF and SO_SNDBUF context options test with unix datagram sockets
+--EXTENSIONS--
+sockets
+--SKIPIF--
+<?php
+if (array_search("udg", stream_get_transports()) === false) {
+    die('skip No support for UNIX domain sockets.');
+}
+?>
+--FILE--
+<?php
+function buffers($stream): array {
+    $sock = socket_import_stream($stream);
+    return [
+        socket_get_option($sock, SOL_SOCKET, SO_RCVBUF),
+        socket_get_option($sock, SOL_SOCKET, SO_SNDBUF),
+    ];
+}
+
+$control_path = sys_get_temp_dir() . '/' . uniqid('so_buf_control_') . '.sock';
+$server_path = sys_get_temp_dir() . '/' . uniqid('so_buf_server_') . '.sock';
+
+$control = stream_socket_server("udg://$control_path", $errno, $errstr, STREAM_SERVER_BIND);
+
+if (!$control) {
+    die('Unable to create server');
+}
+
+[$rcvbuf, $sndbuf] = buffers($control);
+
+// Shrinking is always honoured, while growing may be capped by the system maximum.
+$context = stream_context_create(['socket' => [
+    'so_rcvbuf' => intdiv($rcvbuf, 4),
+    'so_sndbuf' => intdiv($sndbuf, 4),
+]]);
+
+$server = stream_socket_server("udg://$server_path", $errno, $errstr, STREAM_SERVER_BIND, $context);
+
+if (!$server) {
+    die('Unable to create server');
+}
+
+[$server_rcvbuf, $server_sndbuf] = buffers($server);
+echo "Server buffers", PHP_EOL;
+var_dump($server_rcvbuf < $rcvbuf);
+var_dump($server_sndbuf < $sndbuf);
+
+fclose($server);
+fclose($control);
+unlink($server_path);
+unlink($control_path);
+
+?>
+--EXPECT--
+Server buffers
+bool(true)
+bool(true)

ext/standard/tests/network/so_rcvbuf_sndbuf_unix.phpt

@@ -0,0 +1,108 @@
+--TEST--
+stream_socket_server() and stream_socket_client() SO_RCVBUF and SO_SNDBUF context options test with unix sockets
+--EXTENSIONS--
+sockets
+--SKIPIF--
+<?php
+if (array_search("unix", stream_get_transports()) === false) {
+    die('skip No support for UNIX domain sockets.');
+}
+?>
+--FILE--
+<?php
+function buffers($stream): array {
+    $sock = socket_import_stream($stream);
+    return [
+        socket_get_option($sock, SOL_SOCKET, SO_RCVBUF),
+        socket_get_option($sock, SOL_SOCKET, SO_SNDBUF),
+    ];
+}
+
+$control_path = sys_get_temp_dir() . '/' . uniqid('so_buf_control_') . '.sock';
+$server_path = sys_get_temp_dir() . '/' . uniqid('so_buf_server_') . '.sock';
+
+$control = stream_socket_server("unix://$control_path", $errno, $errstr,
+    STREAM_SERVER_BIND | STREAM_SERVER_LISTEN);
+
+if (!$control) {
+    die('Unable to create server');
+}
+
+$control_client = stream_socket_client("unix://$control_path", $errno, $errstr, 30);
+
+if (!$control_client) {
+    die('Unable to create client');
+}
+
+[$rcvbuf, $sndbuf] = buffers($control);
+[$client_rcvbuf, $client_sndbuf] = buffers($control_client);
+
+// Shrinking is always honoured, while growing may be capped by the system maximum.
+function context(int $rcvbuf, int $sndbuf) {
+    return stream_context_create(['socket' => [
+        'so_rcvbuf' => intdiv($rcvbuf, 4),
+        'so_sndbuf' => intdiv($sndbuf, 4),
+    ]]);
+}
+
+$server = stream_socket_server("unix://$server_path", $errno, $errstr,
+    STREAM_SERVER_BIND | STREAM_SERVER_LISTEN, context($rcvbuf, $sndbuf));
+
+if (!$server) {
+    die('Unable to create server');
+}
+
+echo "Listen buffers", PHP_EOL;
+[$listen_rcvbuf, $listen_sndbuf] = buffers($server);
+var_dump($listen_rcvbuf < $rcvbuf);
+var_dump($listen_sndbuf < $sndbuf);
+
+$client = stream_socket_client("unix://$server_path", $errno, $errstr, 30,
+    STREAM_CLIENT_CONNECT, context($client_rcvbuf, $client_sndbuf));
+
+if (!$client) {
+    die('Unable to create client');
+}
+
+$accepted = stream_socket_accept($server, 1);
+
+if (!$accepted) {
+    die('Unable to accept connection');
+}
+
+echo "Client buffers", PHP_EOL;
+[$rcvbuf2, $sndbuf2] = buffers($client);
+var_dump($rcvbuf2 < $client_rcvbuf);
+var_dump($sndbuf2 < $client_sndbuf);
+
+$invalid = stream_context_create(['socket' => ['so_rcvbuf' => 0]]);
+
+echo "Invalid buffer size", PHP_EOL;
+var_dump(@stream_socket_server("unix://$server_path.invalid", $errno, $errstr,
+    STREAM_SERVER_BIND | STREAM_SERVER_LISTEN, $invalid));
+echo $errstr, PHP_EOL;
+var_dump(@stream_socket_client("unix://$server_path", $errno, $errstr, 30,
+    STREAM_CLIENT_CONNECT, $invalid));
+echo $errstr, PHP_EOL;
+
+fclose($accepted);
+fclose($client);
+fclose($server);
+fclose($control_client);
+fclose($control);
+unlink($server_path);
+unlink($control_path);
+
+?>
+--EXPECT--
+Listen buffers
+bool(true)
+bool(true)
+Client buffers
+bool(true)
+bool(true)
+Invalid buffer size
+bool(false)
+so_rcvbuf context option must be between 1 and 2147483647
+bool(false)
+so_rcvbuf context option must be between 1 and 2147483647