Add support for CURLINFO_CONN_ID in curl_getinfo() (#18984)

This patch adds support for the CURLINFO_CONN_ID constant in the curl_getinfo() function when compiled with libcurl >= 8.2.0.

CURLINFO_CONN_ID allows retrieving the unique identifier of the underlying connection used in the most recent transfer. This is useful for advanced features like connection reuse tracking, diagnostics, or connection pooling implementations at the PHP level.

UPGRADING

@@ -188,6 +188,11 @@ PHP 8.5 UPGRADE NOTES
     first redirect thus if there is any follow up redirect, it won't go
     any further. CURLFOLLOW_ALL is equivalent to setting CURLOPT_FOLLOWLOCATION
     to true.
+  . Added support for CURLINFO_CONN_ID (libcurl >= 8.2.0) to the curl_getinfo()
+    function. This constant allows retrieving the unique ID of the connection
+    used by a cURL transfer. It is primarily useful when connection reuse or
+    connection pooling logic is needed in PHP-level applications. When
+    curl_getinfo() returns an array, this value is available as the "conn_id" key.
 
 - DOM:
   . Added Dom\Element::$outerHTML.
@@ -517,6 +522,7 @@ PHP 8.5 UPGRADE NOTES
   . CURLINFO_USED_PROXY.
   . CURLINFO_HTTPAUTH_USED.
   . CURLINFO_PROXYAUTH_USED.
+  . CURLINFO_CONN_ID.
   . CURLOPT_INFILESIZE_LARGE.
   . CURLFOLLOW_ALL.
   . CURLFOLLOW_OBEYCODE.

ext/curl/curl.stub.php

@@ -3103,6 +3103,13 @@ const CURLINFO_USED_PROXY = UNKNOWN;
  */
 const CURLINFO_POSTTRANSFER_TIME_T = UNKNOWN;
 #endif
+#if LIBCURL_VERSION_NUM >= 0x080200 /* Available since 8.2.0 */
+/**
+ * @var int
+ * @cvalue CURLINFO_CONN_ID
+ */
+const CURLINFO_CONN_ID = UNKNOWN;
+#endif
 /**
  * @var int
  * @cvalue CURLOPT_DISALLOW_USERNAME_IN_URL

ext/curl/curl_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: c087ac501d0abe14ed87968023d837f358e6fee8 */
+ * Stub hash: 533884c442ca1146a61c0824a4f8c9628c31aae3 */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_curl_close, 0, 1, IS_VOID, 0)
 	ZEND_ARG_OBJ_INFO(0, handle, CurlHandle, 0)
@@ -824,6 +824,9 @@ static void register_curl_symbols(int module_number)
 #endif
 #if LIBCURL_VERSION_NUM >= 0x080a00 /* Available since 8.10.0 */
 	REGISTER_LONG_CONSTANT("CURLINFO_POSTTRANSFER_TIME_T", CURLINFO_POSTTRANSFER_TIME_T, CONST_PERSISTENT);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x080200 /* Available since 8.2.0 */
+	REGISTER_LONG_CONSTANT("CURLINFO_CONN_ID", CURLINFO_CONN_ID, CONST_PERSISTENT);
 #endif
 	REGISTER_LONG_CONSTANT("CURLOPT_DISALLOW_USERNAME_IN_URL", CURLOPT_DISALLOW_USERNAME_IN_URL, CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("CURLOPT_PROXY_TLS13_CIPHERS", CURLOPT_PROXY_TLS13_CIPHERS, CONST_PERSISTENT);

ext/curl/interface.c

@@ -2622,6 +2622,11 @@ PHP_FUNCTION(curl_getinfo)
 		if (curl_easy_getinfo(ch->cp, CURLINFO_PROXYAUTH_USED, &l_code) == CURLE_OK) {
 			CAAL("proxyauth_used", l_code);
 		}
+#endif
+#if LIBCURL_VERSION_NUM >= 0x080200 /* Available since 8.2.0 */
+		if (curl_easy_getinfo(ch->cp, CURLINFO_CONN_ID , &co) == CURLE_OK) {
+			CAAL("conn_id", co);
+		}
 #endif
 	} else {
 		switch (option) {

ext/curl/tests/curl_getinfo_CURLINFO_CONN_ID.phpt

@@ -0,0 +1,146 @@
+--TEST--
+Curlinfo CURLINFO_CONN_ID
+--EXTENSIONS--
+curl
+--SKIPIF--
+<?php
+$curl_version = curl_version();
+if ($curl_version['version_number'] < 0x080200) die("skip: test works only with curl >= 8.2.0");
+?>
+--FILE--
+<?php
+include 'server.inc';
+
+$host = curl_cli_server_start();
+$port = (int) (explode(':', $host))[1];
+
+$ch = curl_init();
+curl_setopt($ch, CURLOPT_URL, "{$host}/get.inc?test=get");
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+
+$info = curl_getinfo($ch);
+var_dump(isset($info['conn_id']));
+var_dump($info['conn_id'] === -1);
+
+$result = curl_exec($ch);
+
+$info = curl_getinfo($ch);
+var_dump(isset($info['conn_id']));
+var_dump(is_int($info['conn_id']));
+var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === $info['conn_id']);
+var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === 0);
+
+curl_setopt($ch, CURLOPT_URL, "{$host}/get.inc?test=get");
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+$result = curl_exec($ch);
+
+$info = curl_getinfo($ch);
+var_dump(isset($info['conn_id']));
+var_dump(is_int($info['conn_id']));
+var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === $info['conn_id']);
+var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === 1);
+
+$ch1=curl_init();
+$ch2=curl_init();
+$cmh=curl_multi_init();
+
+foreach([$ch1, $ch2] as $ch) {
+    curl_setopt($ch, CURLOPT_URL, "{$host}/get.inc?test=getpost&get_param=Curl%20Handle");
+    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+    $info = curl_getinfo($ch);
+    var_dump(isset($info['conn_id']));
+    var_dump($info['conn_id'] === -1);
+    curl_multi_add_handle($cmh,$ch);
+}
+
+$running=0;
+do {
+    curl_multi_exec($cmh,$running);
+} while ($running>0);
+
+foreach([$ch1, $ch2] as $key => $ch) {
+    $result = curl_multi_getcontent($ch);
+    $info = curl_getinfo($ch);
+    var_dump(isset($info['conn_id']));
+    var_dump(is_int($info['conn_id']));
+    var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === $info['conn_id']);
+    var_dump(curl_getinfo($ch, CURLINFO_CONN_ID) === $key);
+}
+
+$csh = curl_share_init();
+
+curl_share_setopt($csh, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);
+curl_share_setopt($csh, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
+curl_share_setopt($csh, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS);
+curl_share_setopt($csh, CURLSHOPT_SHARE, CURL_LOCK_DATA_SSL_SESSION);
+
+
+$ch1=curl_init();
+$ch2=curl_init();
+
+foreach([$ch1, $ch2] as $ch) {
+    curl_setopt($ch, CURLOPT_URL, "{$host}/get.inc?test=getpost&get_param=Curl%20Handle");
+    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+    $info = curl_getinfo($ch);
+    var_dump(isset($info['conn_id']));
+    var_dump($info['conn_id'] === -1);
+}
+
+
+curl_setopt($ch1, CURLOPT_SHARE, $csh);
+
+$result = curl_exec($ch1);
+
+$info = curl_getinfo($ch1);
+var_dump(isset($info['conn_id']));
+var_dump(is_int($info['conn_id']));
+var_dump(curl_getinfo($ch1, CURLINFO_CONN_ID) === $info['conn_id']);
+var_dump(curl_getinfo($ch1, CURLINFO_CONN_ID) === 0);
+
+curl_setopt($ch2, CURLOPT_SHARE, $csh);
+
+$result = curl_exec($ch2);
+
+$info = curl_getinfo($ch2);
+var_dump(isset($info['conn_id']));
+var_dump(is_int($info['conn_id']));
+var_dump(curl_getinfo($ch2, CURLINFO_CONN_ID) === $info['conn_id']);
+var_dump(curl_getinfo($ch2, CURLINFO_CONN_ID) === 1);
+
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+