socket: support unix paths in the abstract namespace

Those starting with '\0'.

Author: cataphract

ext/sockets/conversions.c

@@ -98,8 +98,8 @@ typedef struct {
 } field_descriptor;
 
 #define KEY_FILL_SOCKADDR "fill_sockaddr"
-#define KEY_RECVMSG_RET "recvmsg_ret"
-#define KEY_CMSG_LEN	"cmsg_len"
+#define KEY_RECVMSG_RET   "recvmsg_ret"
+#define KEY_CMSG_LEN	  "cmsg_len"
 
 const struct key_value empty_key_value_list[] = {{0}};
 
@@ -667,6 +667,13 @@ static void from_zval_write_sun_path(const zval *path, char *sockaddr_un_c, ser_
 		path = &lzval;
 	}
 
+	/* code in this file relies on the path being nul terminated, even though
+	 * this is not required, at least on linux for abstract paths. It also
+	 * assumes that the path is not empty */
+	if (Z_STRLEN_P(path) == 0) {
+		do_from_zval_err(ctx, "%s", "the path is cannot be empty");
+		return;
+	}
 	if (Z_STRLEN_P(path) >= sizeof(saddr->sun_path)) {
 		do_from_zval_err(ctx, "the path is too long, the maximum permitted "
 				"length is %ld", sizeof(saddr->sun_path) - 1);
@@ -768,10 +775,22 @@ static void from_zval_write_sockaddr_aux(const zval *container,
 			return;
 		}
 		*sockaddr_ptr = accounted_ecalloc(1, sizeof(struct sockaddr_un), ctx);
-		*sockaddr_len = sizeof(struct sockaddr_un);
 		if (fill_sockaddr) {
+			struct sockaddr_un *sock_un = (struct sockaddr_un*)*sockaddr_ptr;
+
 			from_zval_write_sockaddr_un(container, (char*)*sockaddr_ptr, ctx);
 			(*sockaddr_ptr)->sa_family = AF_UNIX;
+
+			/* calculating length is more complicated here. Giving the size of
+			 * struct sockaddr_un here and relying on the nul termination of
+			 * sun_path does not work for paths in the abstract namespace. Note
+			 * that we always assume the path is not empty and nul terminated */
+			*sockaddr_len = offsetof(struct sockaddr_un, sun_path) +
+					(sock_un->sun_path[0] == '\0'
+					? (1 + strlen(&sock_un->sun_path[1]))
+					: strlen(sock_un->sun_path));
+		} else {
+			*sockaddr_len = sizeof(struct sockaddr_un);
 		}
 		break;
 

ext/sockets/sockets.c

@@ -1479,7 +1479,7 @@ PHP_FUNCTION(socket_strerror)
 PHP_FUNCTION(socket_bind)
 {
 	zval					*arg1;
-	php_sockaddr_storage	sa_storage;
+	php_sockaddr_storage	sa_storage = {0};
 	struct sockaddr			*sock_type = (struct sockaddr*) &sa_storage;
 	php_socket				*php_sock;
 	char					*addr;
@@ -1497,19 +1497,26 @@ PHP_FUNCTION(socket_bind)
 		case AF_UNIX:
 			{
 				struct sockaddr_un *sa = (struct sockaddr_un *) sock_type;
-				memset(sa, 0, sizeof(sa_storage));
+
 				sa->sun_family = AF_UNIX;
-				snprintf(sa->sun_path, 108, "%s", addr);
-				retval = bind(php_sock->bsd_socket, (struct sockaddr *) sa, SUN_LEN(sa));
+
+				if (addr_len >= sizeof(sa->sun_path)) {
+					php_error_docref(NULL TSRMLS_CC, E_WARNING,
+							"Invalid path: too long (maximum size is %d)",
+							(int)sizeof(sa->sun_path) - 1);
+					RETURN_FALSE;
+				}
+				memcpy(&sa->sun_path, addr, addr_len);
+
+				retval = bind(php_sock->bsd_socket, (struct sockaddr *) sa,
+						offsetof(struct sockaddr_un, sun_path) + addr_len);
 				break;
 			}
 
 		case AF_INET:
 			{
 				struct sockaddr_in *sa = (struct sockaddr_in *) sock_type;
 
-				memset(sa, 0, sizeof(sa_storage)); /* Apparently, Mac OSX needs this */
-
 				sa->sin_family = AF_INET;
 				sa->sin_port = htons((unsigned short) port);
 
@@ -1525,8 +1532,6 @@ PHP_FUNCTION(socket_bind)
 			{
 				struct sockaddr_in6 *sa = (struct sockaddr_in6 *) sock_type;
 
-				memset(sa, 0, sizeof(sa_storage)); /* Apparently, Mac OSX needs this */
-
 				sa->sin6_family = AF_INET6;
 				sa->sin6_port = htons((unsigned short) port);
 

ext/sockets/tests/socket_abstract_path.phpt

@@ -0,0 +1,44 @@
+--TEST--
+Support for paths in the abstract namespace (bind, connect)
+--SKIPIF--
+<?php
+if (!extension_loaded('sockets'))
+	die('skip sockets extension not available.');
+
+if (PHP_OS != 'Linux') {
+	die('skip For Linux only');
+}
+?>
+--FILE--
+<?php
+include __DIR__."/mcast_helpers.php.inc";
+
+$path = "\x00/foo_bar";
+
+echo "creating server socket\n";
+$servers = socket_create(AF_UNIX, SOCK_STREAM, 0) or die("err");
+socket_bind($servers, $path) or die("Could not bind");
+socket_listen($servers) or die("Could not listen");
+socket_set_nonblock($servers) or die("Could not put in non-blocking mode");
+
+echo "creating client socket\n";
+$clients = socket_create(AF_UNIX, SOCK_STREAM, 0) or die("err");
+socket_connect($clients, $path) or die("Error connecting");
+
+$conns = socket_accept($servers) or die("Could not accept connection");
+
+$r = socket_sendmsg($clients, [
+	//"name" => [ "addr" => $path, ],
+	"iov" => ["test ", "thing", "\n"],
+], 0);
+var_dump($r);
+checktimeout($conns, 500);
+
+if (!socket_recv($conns, $buf, 20, 0)) die("recv");
+print_r($buf);
+?>
+--EXPECTF--
+creating server socket
+creating client socket
+int(11)
+test thing

ext/sockets/tests/socket_abstract_path_sendmsg.phpt

@@ -0,0 +1,40 @@
+--TEST--
+Support for paths in the abstract namespace (bind, sendmsg, recvmsg)
+--SKIPIF--
+<?php
+if (!extension_loaded('sockets'))
+	die('skip sockets extension not available.');
+
+if (PHP_OS != 'Linux') {
+	die('skip For Linux only');
+}
+?>
+--FILE--
+<?php
+include __DIR__."/mcast_helpers.php.inc";
+
+$path = "\x00/bar_foo";
+
+echo "creating send socket\n";
+$sends1 = socket_create(AF_UNIX, SOCK_DGRAM, 0) or die("err");
+socket_set_nonblock($sends1) or die("Could not put in non-blocking mode");
+
+echo "creating receive socket\n";
+$s = socket_create(AF_UNIX, SOCK_DGRAM, 0) or die("err");
+socket_bind($s, $path) or die("err");
+
+$r = socket_sendmsg($sends1, [
+	"name" => [ "path" => $path],
+	"iov" => ["test ", "thing", "\n"],
+], 0);
+var_dump($r);
+checktimeout($s, 500);
+
+if (!socket_recv($s, $buf, 20, 0)) die("recv");
+print_r($buf);
+?>
+--EXPECTF--
+creating send socket
+creating receive socket
+int(11)
+test thing