Warn when fpm socket was not registered on the expected path

This might happen if the UDS length limit is exceeded.

Co-authored-by: Jakub Zelenka <bukka@php.net>

Closes GH-11066

Author: JoshuaBehrens

NEWS

@@ -22,6 +22,10 @@ PHP                                                                        NEWS
   . Added DOMElement::className and DOMElement::id. (nielsdos)
   . Added DOMParentNode::replaceChildren(). (nielsdos)
 
+- FPM:
+  . Added warning to log when fpm socket was not registered on the expected
+    path. (Joshua Behrens, Jakub Zelenka)
+
 - Intl:
   . Fix memory leak in MessageFormatter::format() on failure. (Girgias)
 

UPGRADING

@@ -429,6 +429,9 @@ PHP 8.3 UPGRADE NOTES
     current system user. Previously, calling FFI::load() was not possible during
     preloading if the opcache.preload_user directive was set.
 
+- FPM:
+  . FPM CLI test now fails if the socket path is longer than supported by OS.
+
 - Opcache:
   . In the cli and phpdbg SAPIs, preloading does not require the
     opcache.preload_user directive to be set anymore when running as root. In

sapi/fpm/fpm/fpm_sockets.c

@@ -396,9 +396,25 @@ static int fpm_socket_af_inet_listening_socket(struct fpm_worker_pool_s *wp) /*
 static int fpm_socket_af_unix_listening_socket(struct fpm_worker_pool_s *wp) /* {{{ */
 {
 	struct sockaddr_un sa_un;
+    size_t socket_length = sizeof(sa_un.sun_path);
+    size_t address_length = strlen(wp->config->listen_address);
 
 	memset(&sa_un, 0, sizeof(sa_un));
-	strlcpy(sa_un.sun_path, wp->config->listen_address, sizeof(sa_un.sun_path));
+	strlcpy(sa_un.sun_path, wp->config->listen_address, socket_length);
+
+    if (address_length >= socket_length) {
+        zlog(
+            ZLOG_WARNING,
+            "[pool %s] cannot bind to UNIX socket '%s' as path is too long (found length: %zu, "
+				"maximal length: %zu), trying cut socket path instead '%s'",
+            wp->config->name,
+			wp->config->listen_address,
+			address_length,
+			socket_length,
+			sa_un.sun_path
+        );
+    }
+
 	sa_un.sun_family = AF_UNIX;
 	return fpm_sockets_get_listening_socket(wp, (struct sockaddr *) &sa_un, sizeof(struct sockaddr_un));
 }

sapi/fpm/fpm/fpm_unix.c

@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <sys/un.h>
 #include <pwd.h>
 #include <grp.h>
 
@@ -63,6 +64,33 @@ static struct passwd *fpm_unix_get_passwd(struct fpm_worker_pool_s *wp, const ch
 	return pwd;
 }
 
+static inline bool fpm_unix_check_listen_address(struct fpm_worker_pool_s *wp, const char *address, int flags)
+{
+	if (wp->listen_address_domain != FPM_AF_UNIX) {
+		return true;
+	}
+
+	struct sockaddr_un test_socket;
+	size_t address_length = strlen(address);
+	size_t socket_length = sizeof(test_socket.sun_path);
+
+	if (address_length < socket_length) {
+		return true;
+	}
+
+	zlog(
+		flags,
+		"[pool %s] cannot bind to UNIX socket '%s' as path is too long (found length: %zu, "
+			"maximal length: %zu)",
+		wp->config->name,
+		address,
+		address_length,
+		socket_length
+	);
+
+	return false;
+}
+
 static inline bool fpm_unix_check_passwd(struct fpm_worker_pool_s *wp, const char *name, int flags)
 {
 	return !name || fpm_unix_is_id(name) || fpm_unix_get_passwd(wp, name, flags);
@@ -90,6 +118,7 @@ bool fpm_unix_test_config(struct fpm_worker_pool_s *wp)
 	return (
 		fpm_unix_check_passwd(wp, config->user, ZLOG_ERROR) &&
 		fpm_unix_check_group(wp, config->group, ZLOG_ERROR) &&
+		fpm_unix_check_listen_address(wp, config->listen_address, ZLOG_SYSERROR) &&
 		fpm_unix_check_passwd(wp, config->listen_owner, ZLOG_SYSERROR) &&
 		fpm_unix_check_group(wp, config->listen_group, ZLOG_SYSERROR)
 	);
@@ -273,7 +302,7 @@ int fpm_unix_set_socket_permissions(struct fpm_worker_pool_s *wp, const char *pa
 		/* Copy the new ACL entry from config */
 		for (i=ACL_FIRST_ENTRY ; acl_get_entry(aclconf, i, &entryconf) ; i=ACL_NEXT_ENTRY) {
 			if (0 > acl_create_entry (&aclfile, &entryfile) ||
-			    0 > acl_copy_entry(entryfile, entryconf)) {
+				0 > acl_copy_entry(entryfile, entryconf)) {
 				zlog(ZLOG_SYSERROR, "[pool %s] failed to add entry to the ACL of the socket '%s'", wp->config->name, path);
 				acl_free(aclfile);
 				return -1;

sapi/fpm/tests/logreader.inc

@@ -16,7 +16,7 @@ class LogReader
      *
      * @var string|null
      */
-    private ?string $currentSourceName;
+    private ?string $currentSourceName = null;
 
     /**
      * Log descriptors.

sapi/fpm/tests/socket-uds-too-long-filename-start.phpt

@@ -0,0 +1,74 @@
+--TEST--
+FPM: UNIX socket filename is too for start
+--SKIPIF--
+<?php
+include "skipif.inc"; ?>
+--FILE--
+<?php
+
+require_once "tester.inc";
+$socketFilePrefix = __DIR__ . '/socket-file';
+$socketFile = sprintf(
+    "%s-fpm-unix-socket-too-long-filename-but-starts-anyway%s.sock",
+    $socketFilePrefix,
+    str_repeat('-0000', 11)
+);
+
+$cfg = <<<EOT
+[global]
+error_log = {{FILE:LOG}}
+
+[fpm_pool]
+listen = $socketFile
+pm = static
+pm.max_children = 1
+catch_workers_output = yes
+EOT;
+
+$tester = new FPM\Tester($cfg);
+$tester->start();
+$tester->expectLogStartNotices();
+$tester->expectLogPattern(
+    sprintf(
+        '/\[pool fpm_pool\] cannot bind to UNIX socket \'%s\' as path is too long '
+            . '\(found length: %d, maximal length: \d+\), trying cut socket path instead \'.+\'/',
+        preg_quote($socketFile, '/'),
+        strlen($socketFile)
+    ),
+    true
+);
+
+$files = glob($socketFilePrefix . '*');
+
+if ($files === []) {
+    echo 'Socket files were not found.' . PHP_EOL;
+}
+
+if ($socketFile === $files[0]) {
+    // this means the socket file path length is not an issue (anymore). Might be not long enough
+    echo 'Socket file is the same as configured.' . PHP_EOL;
+}
+
+$tester->terminate();
+$tester->expectLogTerminatingNotices();
+$tester->close();
+?>
+Done
+--EXPECT--
+Done
+--CLEAN--
+<?php
+require_once "tester.inc";
+FPM\Tester::clean();
+
+// cleanup socket file if php-fpm was not killed
+$socketFile = sprintf(
+    "/socket-file-fpm-unix-socket-too-long-filename-but-starts-anyway%s.sock",
+    __DIR__,
+    str_repeat('-0000', 11)
+);
+
+if (is_file($socketFile)) {
+    unlink($socketFile);
+}
+?>

sapi/fpm/tests/socket-uds-too-long-filename-test.phpt

@@ -0,0 +1,47 @@
+--TEST--
+FPM: UNIX socket filename is too for test
+--SKIPIF--
+<?php
+include "skipif.inc"; ?>
+--FILE--
+<?php
+
+require_once "tester.inc";
+
+$socketFilePrefix = __DIR__ . '/socket-file';
+$socketFile = sprintf(
+    "/socket-file-fpm-unix-socket-too-long-filename-but-starts-anyway%s.sock",
+    __DIR__,
+    str_repeat('-0000', 11)
+);
+
+$cfg = <<<EOT
+[global]
+error_log = {{FILE:LOG}}
+
+[fpm_pool]
+listen = $socketFile
+pm = static
+pm.max_children = 1
+catch_workers_output = yes
+EOT;
+
+$tester = new FPM\Tester($cfg);
+$tester->testConfig(true, [
+    sprintf(
+        '/cannot bind to UNIX socket \'%s\' as path is too long '
+            . '\(found length: %d, maximal length: \d+\)/',
+        preg_quote($socketFile, '/'),
+        strlen($socketFile)
+    ),
+    '/FPM initialization failed/',
+]);
+?>
+Done
+--EXPECT--
+Done
+--CLEAN--
+<?php
+require_once "tester.inc";
+FPM\Tester::clean();
+?>

sapi/fpm/tests/tester.inc

@@ -382,26 +382,50 @@ class Tester
      * @return null|array
      * @throws \Exception
      */
-    public function testConfig($silent = false)
+    public function testConfig($silent = false, array|string|null $expectedPattern = null): ?array
     {
         $configFile = $this->createConfig();
         $cmd        = self::findExecutable() . ' -n -tt -y ' . $configFile . ' 2>&1';
         $this->trace('Testing config using command', $cmd, true);
         exec($cmd, $output, $code);
+        $found = 0;
+        if ($expectedPattern !== null) {
+            $expectedPatterns = is_array($expectedPattern) ? $expectedPattern : [$expectedPattern];
+        }
         if ($code) {
             $messages = [];
             foreach ($output as $outputLine) {
                 $message    = preg_replace("/\[.+?\]/", "", $outputLine, 1);
+                if ($expectedPattern !== null) {
+                    for ($i = 0; $i < count($expectedPatterns); $i++) {
+                        $pattern = $expectedPatterns[$i];
+                        if ($pattern !== null && preg_match($pattern, $message)) {
+                            $found++;
+                            $expectedPatterns[$i] = null;
+                        }
+                    }
+                }
                 $messages[] = $message;
                 if ( ! $silent) {
                     $this->error($message, null, false);
                 }
             }
+        } else {
+            $messages = null;
+        }
 
-            return $messages;
+        if ($expectedPattern !== null && $found < count($expectedPatterns)) {
+            $missingPatterns = array_filter($expectedPatterns);
+            $errorMessage = sprintf(
+                "The expected config %s %s %s not been found",
+                count($missingPatterns) > 1 ? 'patterns' : 'pattern',
+                implode(', ', $missingPatterns),
+                count($missingPatterns) > 1 ? 'have' : 'has',
+            );
+            $this->error($errorMessage);
         }
 
-        return null;
+        return $messages;
     }
 
     /**
@@ -1155,9 +1179,19 @@ class Tester
                 return $address;
             }
 
-            return sys_get_temp_dir() . '/' .
-                   hash('crc32', dirname($address)) . '-' .
-                   basename($address);
+            $addressPart = hash('crc32', dirname($address)) . '-' . basename($address);
+
+            // is longer on Mac, than on Linux
+            $tmpDirAddress = sys_get_temp_dir() . '/' . $addressPart;
+                   ;
+
+            if (strlen($tmpDirAddress) <= 104) {
+                return $tmpDirAddress;
+            }
+
+            $srcRootAddress = dirname(__DIR__, 3) . '/' . $addressPart;
+
+            return $srcRootAddress;
         }
 
         return $this->getHost($type) . ':' . $port;