Support socketpairs in proc_open()

Closes GH-5777.

UPGRADING

@@ -631,6 +631,14 @@ PHP 8.0 UPGRADE NOTES
 
         $proc = proc_open($command, [['pty'], ['pty'], ['pty']], $pipes);
 
+  . proc_open() now supports socket pair descriptors. The following attaches
+    a distinct socket pair to stdin, stdout and stderr:
+
+        $proc = proc_open(
+            $command, [['socket'], ['socket'], ['socket']], $pipes);
+
+    Unlike pipes, sockets do not suffer from blocking I/O issues on Windows.
+    However, not all programs may work correctly with stdio sockets.
   . Sorting functions are now stable, which means that equal-comparing elements
     will retain their original order.
     RFC: https://wiki.php.net/rfc/stable_sorting

ext/standard/proc_open.c

@@ -444,11 +444,18 @@ static inline HANDLE dup_fd_as_handle(int fd)
 # define close_descriptor(fd)	close(fd)
 #endif
 
+/* Determines the type of a descriptor item. */
+typedef enum _descriptor_type {
+	DESCRIPTOR_TYPE_STD,
+	DESCRIPTOR_TYPE_PIPE,
+	DESCRIPTOR_TYPE_SOCKET
+} descriptor_type;
+
 /* One instance of this struct is created for each item in `$descriptorspec` argument to `proc_open`
  * They are used within `proc_open` and freed before it returns */
 typedef struct _descriptorspec_item {
 	int index;                       /* desired FD # in child process */
-	int is_pipe;
+	descriptor_type type;
 	php_file_descriptor_t childend;  /* FD # opened for use in child
 	                                  * (will be copied to `index` in child) */
 	php_file_descriptor_t parentend; /* FD # opened for use in parent
@@ -679,7 +686,7 @@ static int set_proc_descriptor_to_pty(descriptorspec_item *desc, int *master_fd,
 		}
 	}
 
-	desc->is_pipe    = 1;
+	desc->type       = DESCRIPTOR_TYPE_PIPE;
 	desc->childend   = dup(*slave_fd);
 	desc->parentend  = dup(*master_fd);
 	desc->mode_flags = O_RDWR;
@@ -690,6 +697,19 @@ static int set_proc_descriptor_to_pty(descriptorspec_item *desc, int *master_fd,
 #endif
 }
 
+/* Mark the descriptor close-on-exec, so it won't be inherited by children */
+static php_file_descriptor_t make_descriptor_cloexec(php_file_descriptor_t fd)
+{
+#ifdef PHP_WIN32
+	return dup_handle(fd, FALSE, TRUE);
+#else
+#if defined(F_SETFD) && defined(FD_CLOEXEC)
+	fcntl(fd, F_SETFD, FD_CLOEXEC);
+#endif
+	return fd;
+#endif
+}
+
 static int set_proc_descriptor_to_pipe(descriptorspec_item *desc, zend_string *zmode)
 {
 	php_file_descriptor_t newpipe[2];
@@ -699,7 +719,7 @@ static int set_proc_descriptor_to_pipe(descriptorspec_item *desc, zend_string *z
 		return FAILURE;
 	}
 
-	desc->is_pipe = 1;
+	desc->type = DESCRIPTOR_TYPE_PIPE;
 
 	if (strncmp(ZSTR_VAL(zmode), "w", 1) != 0) {
 		desc->parentend = newpipe[1];
@@ -711,10 +731,9 @@ static int set_proc_descriptor_to_pipe(descriptorspec_item *desc, zend_string *z
 		desc->mode_flags = O_RDONLY;
 	}
 
-#ifdef PHP_WIN32
-	/* don't let the child inherit the parent side of the pipe */
-	desc->parentend = dup_handle(desc->parentend, FALSE, TRUE);
+	desc->parentend = make_descriptor_cloexec(desc->parentend);
 
+#ifdef PHP_WIN32
 	if (ZSTR_LEN(zmode) >= 2 && ZSTR_VAL(zmode)[1] == 'b')
 		desc->mode_flags |= O_BINARY;
 #endif
@@ -722,6 +741,32 @@ static int set_proc_descriptor_to_pipe(descriptorspec_item *desc, zend_string *z
 	return SUCCESS;
 }
 
+#ifdef PHP_WIN32
+#define create_socketpair(socks) socketpair_win32(AF_INET, SOCK_STREAM, 0, (socks), 0)
+#else
+#define create_socketpair(socks) socketpair(AF_UNIX, SOCK_STREAM, 0, (socks))
+#endif
+
+static int set_proc_descriptor_to_socket(descriptorspec_item *desc)
+{
+	php_socket_t sock[2];
+
+	if (create_socketpair(sock)) {
+		zend_string *err = php_socket_error_str(php_socket_errno());
+		php_error_docref(NULL, E_WARNING, "Unable to create socket pair: %s", ZSTR_VAL(err));
+		zend_string_release(err);
+		return FAILURE;
+	}
+
+	desc->type = DESCRIPTOR_TYPE_SOCKET;
+	desc->parentend = make_descriptor_cloexec((php_file_descriptor_t) sock[0]);
+
+	/* Pass sock[1] to child because it will never use overlapped IO on Windows. */
+	desc->childend = (php_file_descriptor_t) sock[1];
+
+	return SUCCESS;
+}
+
 static int set_proc_descriptor_to_file(descriptorspec_item *desc, zend_string *file_path,
 	zend_string *file_mode)
 {
@@ -827,6 +872,9 @@ static int set_proc_descriptor_from_array(zval *descitem, descriptorspec_item *d
 			goto finish;
 		}
 		retval = set_proc_descriptor_to_pipe(&descriptors[ndesc], zmode);
+	} else if (zend_string_equals_literal(ztype, "socket")) {
+		/* Set descriptor to socketpair */
+		retval = set_proc_descriptor_to_socket(&descriptors[ndesc]);
 	} else if (zend_string_equals_literal(ztype, "file")) {
 		/* Set descriptor to file */
 		if ((zfile = get_string_parameter(descitem, 1, "file name parameter for 'file'")) == NULL) {
@@ -903,7 +951,7 @@ static int close_parentends_of_pipes(descriptorspec_item *descriptors, int ndesc
 	 * Also, dup() the child end of all pipes as necessary so they will use the FD
 	 * number which the user requested */
 	for (int i = 0; i < ndesc; i++) {
-		if (descriptors[i].is_pipe) {
+		if (descriptors[i].type != DESCRIPTOR_TYPE_STD) {
 			close(descriptors[i].parentend);
 		}
 		if (descriptors[i].childend != descriptors[i].index) {
@@ -1194,12 +1242,13 @@ PHP_FUNCTION(proc_open)
 	/* Clean up all the child ends and then open streams on the parent
 	 *   ends, where appropriate */
 	for (i = 0; i < ndesc; i++) {
-		char *mode_string = NULL;
 		php_stream *stream = NULL;
 
 		close_descriptor(descriptors[i].childend);
 
-		if (descriptors[i].is_pipe) {
+		if (descriptors[i].type == DESCRIPTOR_TYPE_PIPE) {
+			char *mode_string = NULL;
+
 			switch (descriptors[i].mode_flags) {
 #ifdef PHP_WIN32
 				case O_WRONLY|O_BINARY:
@@ -1219,18 +1268,20 @@ PHP_FUNCTION(proc_open)
 					mode_string = "r+";
 					break;
 			}
+
 #ifdef PHP_WIN32
 			stream = php_stream_fopen_from_fd(_open_osfhandle((zend_intptr_t)descriptors[i].parentend,
 						descriptors[i].mode_flags), mode_string, NULL);
 			php_stream_set_option(stream, PHP_STREAM_OPTION_PIPE_BLOCKING, blocking_pipes, NULL);
 #else
 			stream = php_stream_fopen_from_fd(descriptors[i].parentend, mode_string, NULL);
-# if defined(F_SETFD) && defined(FD_CLOEXEC)
-			/* Mark the descriptor close-on-exec, so it won't be inherited by
-			 * potential other children */
-			fcntl(descriptors[i].parentend, F_SETFD, FD_CLOEXEC);
-# endif
 #endif
+		} else if (descriptors[i].type == DESCRIPTOR_TYPE_SOCKET) {
+			stream = php_stream_sock_open_from_socket((php_socket_t) descriptors[i].parentend, NULL);
+		} else {
+			proc->pipes[i] = NULL;
+		}
+
 		if (stream) {
 			zval retfp;
 
@@ -1243,9 +1294,6 @@ PHP_FUNCTION(proc_open)
 			proc->pipes[i] = Z_RES(retfp);
 			Z_ADDREF(retfp);
 		}
-		} else {
-			proc->pipes[i] = NULL;
-		}
 	}
 
 	if (1) {

ext/standard/tests/general_functions/proc_open_sockets1.inc

@@ -0,0 +1,7 @@
+<?php
+
+echo "hello";
+sleep(1);
+fwrite(STDERR, "SOME ERROR");
+sleep(1);
+echo "world";

ext/standard/tests/general_functions/proc_open_sockets1.phpt

@@ -0,0 +1,56 @@
+--TEST--
+proc_open() with output socketpairs
+--FILE--
+<?php
+
+$cmd = [
+	getenv("TEST_PHP_EXECUTABLE"),
+	__DIR__ . '/proc_open_sockets1.inc'
+];
+
+$spec = [
+	['null'],
+	['socket'],
+	['socket']
+];
+
+$proc = proc_open($cmd, $spec, $pipes);
+
+foreach ($pipes as $pipe) {
+	var_dump(stream_set_blocking($pipe, false));
+}
+
+while ($pipes) {
+	$r = $pipes;
+	$w = null;
+	$e = null;
+	
+	if (!stream_select($r, $w, $e, null, 0)) {
+		throw new Error("Select failed");
+	}
+	
+	foreach ($r as $i => $pipe) {
+		if (!is_resource($pipe) || feof($pipe)) {
+			unset($pipes[$i]);
+			continue;
+		}
+		
+		$chunk = @fread($pipe, 8192);
+		
+		if ($chunk === false) {
+			throw new Error("Failed to read: " . (error_get_last()['message'] ?? 'N/A'));
+		}
+		
+		if ($chunk !== '') {
+			echo "PIPE {$i} << {$chunk}\n";
+		}
+	}
+}
+
+?>
+--EXPECTF--
+bool(true)
+bool(true)
+PIPE 1 << hello
+PIPE 2 << SOME ERROR
+PIPE 1 << world

ext/standard/tests/general_functions/proc_open_sockets2.inc

@@ -0,0 +1,7 @@
+<?php
+
+echo "hello";
+sleep(1);
+echo "world";
+
+echo strtoupper(trim(fgets(STDIN)));

ext/standard/tests/general_functions/proc_open_sockets2.phpt

@@ -0,0 +1,67 @@
+--TEST--
+proc_open() with IO socketpairs
+--FILE--
+<?php
+
+function poll($pipe, $read = true)
+{
+	$r = ($read == true) ? [$pipe] : null;
+	$w = ($read == false) ? [$pipe] : null;
+	$e = null;
+	
+	if (!stream_select($r, $w, $e, null, 0)) {
+		throw new \Error("Select failed");
+	}
+}
+
+function read_pipe($pipe): string
+{
+	poll($pipe);
+	
+	if (false === ($chunk = @fread($pipe, 8192))) {
+		throw new Error("Failed to read: " . (error_get_last()['message'] ?? 'N/A'));
+	}
+	
+	return $chunk;
+}
+
+function write_pipe($pipe, $data)
+{
+	poll($pipe, false);
+	
+	if (false == @fwrite($pipe, $data)) {
+		throw new Error("Failed to write: " . (error_get_last()['message'] ?? 'N/A'));
+	}
+}
+
+$cmd = [
+	getenv("TEST_PHP_EXECUTABLE"),
+	__DIR__ . '/proc_open_sockets2.inc'
+];
+
+$spec = [
+	['socket'],
+	['socket']
+];
+
+$proc = proc_open($cmd, $spec, $pipes);
+
+foreach ($pipes as $pipe) {
+	var_dump(stream_set_blocking($pipe, false));
+}
+
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+
+write_pipe($pipes[0], 'done');
+fclose($pipes[0]);
+
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+
+?>
+--EXPECTF--
+bool(true)
+bool(true)
+STDOUT << hello
+STDOUT << world
+STDOUT << DONE

ext/standard/tests/general_functions/proc_open_sockets3.phpt

@@ -0,0 +1,55 @@
+--TEST--
+proc_open() with socket and pipe
+--FILE--
+<?php
+
+function poll($pipe, $read = true)
+{
+	$r = ($read == true) ? [$pipe] : null;
+	$w = ($read == false) ? [$pipe] : null;
+	$e = null;
+	
+	if (!stream_select($r, $w, $e, null, 0)) {
+		throw new \Error("Select failed");
+	}
+}
+
+function read_pipe($pipe): string
+{
+	poll($pipe);
+	
+	if (false === ($chunk = @fread($pipe, 8192))) {
+		throw new Error("Failed to read: " . (error_get_last()['message'] ?? 'N/A'));
+	}
+	
+	return $chunk;
+}
+
+$cmd = [
+	getenv("TEST_PHP_EXECUTABLE"),
+	__DIR__ . '/proc_open_sockets2.inc'
+];
+
+$spec = [
+	['pipe', 'r'],
+	['socket']
+];
+
+$proc = proc_open($cmd, $spec, $pipes);
+
+var_dump(stream_set_blocking($pipes[1], false));
+
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+
+fwrite($pipes[0], 'done');
+fclose($pipes[0]);
+
+printf("STDOUT << %s\n", read_pipe($pipes[1]));
+
+?>
+--EXPECTF--
+bool(true)
+STDOUT << hello
+STDOUT << world
+STDOUT << DONE

main/streams/plain_wrapper.c

@@ -257,6 +257,11 @@ static void detect_is_seekable(php_stdio_stream_data *self) {
 
 		self->is_seekable = !(file_type == FILE_TYPE_PIPE || file_type == FILE_TYPE_CHAR);
 		self->is_pipe = file_type == FILE_TYPE_PIPE;
+
+		/* Additional check needed to distinguish between pipes and sockets. */
+		if (self->is_pipe && !GetNamedPipeInfo((HANDLE) handle, NULL, NULL, NULL, NULL)) {
+			self->is_pipe = 0;
+		}
 	}
 #endif
 }

win32/sockets.c

@@ -24,19 +24,18 @@
 
 #include "php.h"
 
-PHPAPI int socketpair(int domain, int type, int protocol, SOCKET sock[2])
+PHPAPI int socketpair_win32(int domain, int type, int protocol, SOCKET sock[2], int overlapped)
 {
 	struct sockaddr_in address;
 	SOCKET redirect;
 	int size = sizeof(address);
 
-	if(domain != AF_INET) {
+	if (domain != AF_INET) {
 		WSASetLastError(WSAENOPROTOOPT);
 		return -1;
 	}
 
-	sock[0] = sock[1] = redirect = INVALID_SOCKET;
-
+	sock[1] = redirect = INVALID_SOCKET;
 
 	sock[0] = socket(domain, type, protocol);
 	if (INVALID_SOCKET == sock[0]) {
@@ -47,11 +46,11 @@ PHPAPI int socketpair(int domain, int type, int protocol, SOCKET sock[2])
 	address.sin_family = AF_INET;
 	address.sin_port = 0;
 
-	if (bind(sock[0], (struct sockaddr*)&address, sizeof(address)) != 0) {
+	if (bind(sock[0], (struct sockaddr *) &address, sizeof(address)) != 0) {
 		goto error;
 	}
 
-	if(getsockname(sock[0], (struct sockaddr *)&address, &size) != 0) {
+	if (getsockname(sock[0], (struct sockaddr *) &address, &size) != 0) {
 		goto error;
 	}
 
@@ -59,17 +58,22 @@ PHPAPI int socketpair(int domain, int type, int protocol, SOCKET sock[2])
 		goto error;
 	}
 
+	if (overlapped) {
 		sock[1] = socket(domain, type, protocol);
+	} else {
+		sock[1] = WSASocket(domain, type, protocol, NULL, 0, 0);
+	}
+
 	if (INVALID_SOCKET == sock[1]) {
 		goto error;
 	}
 
 	address.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-	if(connect(sock[1], (struct sockaddr*)&address, sizeof(address)) != 0) {
+	if (connect(sock[1], (struct sockaddr *) &address, sizeof(address)) != 0) {
 		goto error;
 	}
 
-	redirect = accept(sock[0],(struct sockaddr*)&address, &size);
+	redirect = accept(sock[0], (struct sockaddr *) &address, &size);
 	if (INVALID_SOCKET == redirect) {
 		goto error;
 	}
@@ -86,3 +90,8 @@ error:
 	WSASetLastError(WSAECONNABORTED);
 	return -1;
 }
+
+PHPAPI int socketpair(int domain, int type, int protocol, SOCKET sock[2])
+{
+	return socketpair_win32(domain, type, protocol, sock, 1);
+}

win32/sockets.h

@@ -22,6 +22,7 @@
 #ifndef PHP_WIN32_SOCKETS_H
 #define PHP_WIN32_SOCKETS_H
 
+PHPAPI int socketpair_win32(int domain, int type, int protocol, SOCKET sock[2], int overlapped);
 PHPAPI int socketpair(int domain, int type, int protocol, SOCKET sock[2]);
 
 #endif