ext/curl: Add CURLOPT_PREREQFUNCTION

Curl >= 7.80.0 supports declaring a function for `CURLOPT_PREREQFUNCTION` option
that gets called after Curl establishes a connection (including the TLS handshake
for HTTPS connections), but before the actual request is made.

The callable must return either `CURL_PREREQFUNC_OK` or `CURL_PREREQFUNC_ABORT` to
allow or abort the request.

This adds support for it to PHP with required ifdef.

 - libc: https://curl.se/libcurl/c/CURLOPT_PREREQFUNCTION.html

Author: Ayesh

ext/curl/curl.stub.php

@@ -3497,6 +3497,21 @@
  * @cvalue CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256
  */
 const CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 = UNKNOWN;
+/**
+ * @var int
+ * @cvalue CURLOPT_PREREQFUNCTION
+ */
+const CURLOPT_PREREQFUNCTION = UNKNOWN;
+/**
+ * @var int
+ * @cvalue CURL_PREREQFUNC_OK
+ */
+const CURL_PREREQFUNC_OK = UNKNOWN;
+/**
+ * @var int
+ * @cvalue CURL_PREREQFUNC_ABORT
+ */
+const CURL_PREREQFUNC_ABORT = UNKNOWN;
 #endif
 
 #if LIBCURL_VERSION_NUM >= 0x075100 /* Available since 7.81.0 */

ext/curl/curl_arginfo.h

@@ -68,6 +68,9 @@ typedef struct {
 	zend_fcall_info_cache progress;
 	zend_fcall_info_cache xferinfo;
 	zend_fcall_info_cache fnmatch;
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	zend_fcall_info_cache prereq;
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	zend_fcall_info_cache sshhostkey;
 #endif

ext/curl/curl_private.h

@@ -504,6 +504,11 @@ static HashTable *curl_get_gc(zend_object *object, zval **table, int *n)
 		zend_get_gc_buffer_add_fcc(gc_buffer, &curl->handlers.fnmatch);
 	}
 
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	if (ZEND_FCC_INITIALIZED(curl->handlers.prereq)) {
+		zend_get_gc_buffer_add_fcc(gc_buffer, &curl->handlers.prereq);
+	}
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	if (ZEND_FCC_INITIALIZED(curl->handlers.sshhostkey)) {
 		zend_get_gc_buffer_add_fcc(gc_buffer, &curl->handlers.sshhostkey);
@@ -709,6 +714,53 @@ static size_t curl_xferinfo(void *clientp, curl_off_t dltotal, curl_off_t dlnow,
 }
 /* }}} */
 
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+static int curl_prereqfunction(void *clientp, char *conn_primary_ip, char *conn_local_ip, int conn_primary_port, int conn_local_port)
+{
+	php_curl *ch = (php_curl *)clientp;
+	int rval = CURL_PREREQFUNC_ABORT;
+
+#if PHP_CURL_DEBUG
+	fprintf(stderr, "curl_prereqfunction() called\n");
+	fprintf(stderr, "conn_primary_ip = %s, conn_local_ip = %s, conn_primary_port = %d, conn_local_port = %d\n", conn_primary_ip, conn_local_ip, conn_primary_port, conn_local_port);
+#endif
+
+	zval args[5];
+	zval retval;
+
+	GC_ADDREF(&ch->std);
+	ZVAL_OBJ(&args[0], &ch->std);
+	ZVAL_STRING(&args[1], conn_primary_ip);
+	ZVAL_STRING(&args[2], conn_local_ip);
+	ZVAL_LONG(&args[3], conn_primary_port);
+	ZVAL_LONG(&args[4], conn_local_port);
+
+	ch->in_callback = true;
+	zend_call_known_fcc(&ch->handlers.prereq, &retval, /* param_count */ 5, args, /* named_params */ NULL);
+	ch->in_callback = false;
+
+	if (!Z_ISUNDEF(retval)) {
+		_php_curl_verify_handlers(ch, /* reporterror */ true);
+		if (Z_TYPE(retval) == IS_LONG) {
+			zend_long retval_long = Z_LVAL(retval);
+			if (retval_long == CURL_PREREQFUNC_OK || retval_long == CURL_PREREQFUNC_ABORT) {
+				rval = retval_long;
+			} else {
+				zend_value_error("The CURLOPT_PREREQFUNCTION callback must return either CURL_PREREQFUNC_OK or CURL_PREREQFUNC_ABORT");
+			}
+		} else {
+			zend_type_error("The CURLOPT_PREREQFUNCTION callback must return either CURL_PREREQFUNC_OK or CURL_PREREQFUNC_ABORT");
+		}
+	}
+
+	zval_ptr_dtor(&args[0]);
+	zval_ptr_dtor(&args[1]);
+	zval_ptr_dtor(&args[2]);
+
+	return rval;
+}
+#endif
+
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 static int curl_ssh_hostkeyfunction(void *clientp, int keytype, const char *key, size_t keylen)
 {
@@ -1037,6 +1089,9 @@ void init_curl_handle(php_curl *ch)
 	ch->handlers.progress = empty_fcall_info_cache;
 	ch->handlers.xferinfo = empty_fcall_info_cache;
 	ch->handlers.fnmatch = empty_fcall_info_cache;
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	ch->handlers.prereq = empty_fcall_info_cache;
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	ch->handlers.sshhostkey = empty_fcall_info_cache;
 #endif
@@ -1210,6 +1265,9 @@ void _php_setup_easy_copy_handlers(php_curl *ch, php_curl *source)
 	php_curl_copy_fcc_with_option(ch, CURLOPT_PROGRESSDATA, &ch->handlers.progress, &source->handlers.progress);
 	php_curl_copy_fcc_with_option(ch, CURLOPT_XFERINFODATA, &ch->handlers.xferinfo, &source->handlers.xferinfo);
 	php_curl_copy_fcc_with_option(ch, CURLOPT_FNMATCH_DATA, &ch->handlers.fnmatch, &source->handlers.fnmatch);
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	php_curl_copy_fcc_with_option(ch, CURLOPT_PREREQDATA, &ch->handlers.prereq, &source->handlers.prereq);
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	php_curl_copy_fcc_with_option(ch, CURLOPT_SSH_HOSTKEYDATA, &ch->handlers.sshhostkey, &source->handlers.sshhostkey);
 #endif
@@ -1570,6 +1628,9 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 		HANDLE_CURL_OPTION_CALLABLE(ch, CURLOPT_PROGRESS, handlers.progress, curl_progress);
 		HANDLE_CURL_OPTION_CALLABLE(ch, CURLOPT_XFERINFO, handlers.xferinfo, curl_xferinfo);
 		HANDLE_CURL_OPTION_CALLABLE(ch, CURLOPT_FNMATCH_, handlers.fnmatch, curl_fnmatch);
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+		HANDLE_CURL_OPTION_CALLABLE(ch, CURLOPT_PREREQ, handlers.prereq, curl_prereqfunction);
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 		HANDLE_CURL_OPTION_CALLABLE(ch, CURLOPT_SSH_HOSTKEY, handlers.sshhostkey, curl_ssh_hostkeyfunction);
 #endif
@@ -2736,6 +2797,11 @@ static void curl_free_obj(zend_object *object)
 	if (ZEND_FCC_INITIALIZED(ch->handlers.fnmatch)) {
 		zend_fcc_dtor(&ch->handlers.fnmatch);
 	}
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	if (ZEND_FCC_INITIALIZED(ch->handlers.prereq)) {
+		zend_fcc_dtor(&ch->handlers.prereq);
+	}
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	if (ZEND_FCC_INITIALIZED(ch->handlers.sshhostkey)) {
 		zend_fcc_dtor(&ch->handlers.sshhostkey);
@@ -2814,7 +2880,11 @@ static void _php_curl_reset_handlers(php_curl *ch)
 	if (ZEND_FCC_INITIALIZED(ch->handlers.fnmatch)) {
 		zend_fcc_dtor(&ch->handlers.fnmatch);
 	}
-
+#if LIBCURL_VERSION_NUM >= 0x075000 /* Available since 7.80.0 */
+	if (ZEND_FCC_INITIALIZED(ch->handlers.prereq)) {
+		zend_fcc_dtor(&ch->handlers.prereq);
+	}
+#endif
 #if LIBCURL_VERSION_NUM >= 0x075400 /* Available since 7.84.0 */
 	if (ZEND_FCC_INITIALIZED(ch->handlers.sshhostkey)) {
 		zend_fcc_dtor(&ch->handlers.sshhostkey);

ext/curl/interface.c

@@ -17,6 +17,7 @@
 const IGNORED_CURL_CONSTANTS = [
     'CURLOPT_PROGRESSDATA',
     'CURLOPT_XFERINFODATA',
+    'CURLOPT_PREREQDATA',
 ];
 
 const IGNORED_PHP_CONSTANTS = [

ext/curl/sync-constants.php

@@ -0,0 +1,151 @@
+--TEST--
+Curl option CURLOPT_PREREQFUNCTION
+--EXTENSIONS--
+curl
+--SKIPIF--
+<?php
+$curl_version = curl_version();
+if ($curl_version['version_number'] < 0x075000) die("skip: test works only with curl >= 7.80.0");
+?>
+--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=file");
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+
+$result = curl_exec($ch);
+
+var_dump(CURLOPT_PREREQFUNCTION);
+var_dump(CURL_PREREQFUNC_OK);
+var_dump(CURL_PREREQFUNC_ABORT);
+
+$returnValue = CURL_PREREQFUNC_ABORT;
+
+echo "\nTesting with CURL_PREREQFUNC_ABORT\n";
+$callback = function() use ($port, &$returnValue) {
+	var_dump('callback');
+	var_dump(func_num_args());
+	$args = func_get_args();
+	var_dump(get_class($args[0]));
+	var_dump(filter_var($args[1], FILTER_VALIDATE_IP) !== false);
+	var_dump(filter_var($args[2], FILTER_VALIDATE_IP) !== false);
+	var_dump($port === $args[3]);
+	var_dump(is_int($args[4]));
+
+	return $returnValue;
+};
+
+curl_setopt($ch, CURLOPT_PREREQFUNCTION, $callback);
+
+$result = curl_exec($ch);
+
+var_dump($result);
+var_dump(curl_error($ch));
+var_dump(curl_errno($ch));
+
+$returnValue = CURL_PREREQFUNC_OK;
+
+echo "\nTesting with CURL_PREREQFUNC_OK\n";
+$result = curl_exec($ch);
+
+var_dump($result);
+var_dump(curl_error($ch));
+var_dump(curl_errno($ch));
+
+
+echo "\nTesting with no return type\n";
+curl_setopt($ch, CURLOPT_PREREQFUNCTION, function() use ($port) {
+	// returns nothing
+});
+try {
+    curl_exec($ch);
+} catch (\TypeError $e) {
+    echo $e->getMessage() . \PHP_EOL;
+}
+
+echo "\nTesting with invalid type\n";
+curl_setopt($ch, CURLOPT_PREREQFUNCTION, function() use ($port) {
+	return 'this should be an integer';
+});
+try {
+    curl_exec($ch);
+} catch (\TypeError $e) {
+    echo $e->getMessage() . \PHP_EOL;
+}
+
+echo "\nTesting with invalid value\n";
+curl_setopt($ch, CURLOPT_PREREQFUNCTION, function() use ($port) {
+	return 42;
+});
+try {
+    curl_exec($ch);
+} catch (\ValueError $e) {
+    echo $e->getMessage() . \PHP_EOL;
+}
+
+echo "\nTesting with invalid option value\n";
+try {
+    curl_setopt($ch, CURLOPT_PREREQFUNCTION, 42);
+} catch (\TypeError $e) {
+    echo $e->getMessage() . \PHP_EOL;
+}
+
+echo "\nTesting with invalid option callback\n";
+try {
+    curl_setopt($ch, CURLOPT_PREREQFUNCTION, 'function_does_not_exist');
+} catch (\TypeError $e) {
+    echo $e->getMessage() . \PHP_EOL;
+}
+
+echo "\nDone";
+?>
+--EXPECT--
+int(20312)
+int(0)
+int(1)
+
+Testing with CURL_PREREQFUNC_ABORT
+string(8) "callback"
+int(5)
+string(10) "CurlHandle"
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(false)
+string(41) "operation aborted by pre-request callback"
+int(42)
+
+Testing with CURL_PREREQFUNC_OK
+string(8) "callback"
+int(5)
+string(10) "CurlHandle"
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+string(0) ""
+string(0) ""
+int(0)
+
+Testing with no return type
+The CURLOPT_PREREQFUNCTION callback must return either CURL_PREREQFUNC_OK or CURL_PREREQFUNC_ABORT
+
+Testing with invalid type
+The CURLOPT_PREREQFUNCTION callback must return either CURL_PREREQFUNC_OK or CURL_PREREQFUNC_ABORT
+
+Testing with invalid value
+The CURLOPT_PREREQFUNCTION callback must return either CURL_PREREQFUNC_OK or CURL_PREREQFUNC_ABORT
+
+Testing with invalid option value
+curl_setopt(): Argument #3 ($value) must be a valid callback for option CURLOPT_PREREQFUNCTION, no array or string given
+
+Testing with invalid option callback
+curl_setopt(): Argument #3 ($value) must be a valid callback for option CURLOPT_PREREQFUNCTION, function "function_does_not_exist" not found or invalid function name
+
+Done