coroipcc: use malloc for path in service_connect

Coroipcc appropriately uses PATH_MAX sized variables for various data
structures handling files in the initialization of the client.  Due to
the use of 12 of these structures declared as stack variables, the
application stack balloons to over 12*4k. This is especially problematic
if threads are used by long running daemons to restart the connection
to corosync so as to be resilient in the face of system services
restarting (service corosync restart).

A simple alternative is to allocate temporary memory to avoid
requirements of large thread stacks.

Original patch by Dan Clark <2clarkd@gmail.com>

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Steven Dake <sdake@redhat.com>

lib/coroipcc.c

@@ -86,6 +86,15 @@ struct ipc_instance {
 	pthread_mutex_t mutex;
 };
 
+struct ipc_path_data {
+	mar_req_setup_t req_setup;
+	mar_res_setup_t res_setup;
+	char control_map_path[PATH_MAX];
+	char request_map_path[PATH_MAX];
+	char response_map_path[PATH_MAX];
+	char dispatch_map_path[PATH_MAX];
+};
+
 void ipc_hdb_destructor (void *context);
 
 DECLARE_HDB_DATABASE(ipc_hdb,ipc_hdb_destructor);
@@ -581,12 +590,7 @@ coroipcc_service_connect (
 	union semun semun;
 #endif
 	int sys_res;
-	mar_req_setup_t req_setup;
-	mar_res_setup_t res_setup;
-	char control_map_path[PATH_MAX];
-	char request_map_path[PATH_MAX];
-	char response_map_path[PATH_MAX];
-	char dispatch_map_path[PATH_MAX];
+	struct ipc_path_data *path_data;
 
 	res = hdb_error_to_cs (hdb_handle_create (&ipc_hdb,
 		sizeof (struct ipc_instance), handle));
@@ -599,8 +603,6 @@ coroipcc_service_connect (
 		return (res);
 	}
 
-	res_setup.error = CS_ERR_LIBRARY;
-
 #if defined(COROSYNC_SOLARIS)
 	request_fd = socket (PF_UNIX, SOCK_STREAM, 0);
 #else
@@ -613,6 +615,14 @@ coroipcc_service_connect (
 	socket_nosigpipe (request_fd);
 #endif
 
+	path_data = malloc (sizeof(*path_data));
+	if (path_data == NULL) {
+		goto error_connect;
+	}
+	memset(path_data, 0, sizeof(*path_data));
+
+	path_data->res_setup.error = CS_ERR_LIBRARY;
+
 	memset (&address, 0, sizeof (struct sockaddr_un));
 	address.sun_family = AF_UNIX;
 #if defined(COROSYNC_BSD) || defined(COROSYNC_DARWIN)
@@ -632,7 +642,7 @@ coroipcc_service_connect (
 	}
 
 	sys_res = memory_map (
-		control_map_path,
+		path_data->control_map_path,
 		"control_buffer-XXXXXX",
 		(void *)&ipc_instance->control_buffer,
 		8192);
@@ -642,7 +652,7 @@ coroipcc_service_connect (
 	}
 
 	sys_res = memory_map (
-		request_map_path,
+		path_data->request_map_path,
 		"request_buffer-XXXXXX",
 		(void *)&ipc_instance->request_buffer,
 		request_size);
@@ -652,7 +662,7 @@ coroipcc_service_connect (
 	}
 
 	sys_res = memory_map (
-		response_map_path,
+		path_data->response_map_path,
 		"response_buffer-XXXXXX",
 		(void *)&ipc_instance->response_buffer,
 		response_size);
@@ -662,7 +672,7 @@ coroipcc_service_connect (
 	}
 
 	sys_res = circular_memory_map (
-		dispatch_map_path,
+		path_data->dispatch_map_path,
 		"dispatch_buffer-XXXXXX",
 		(void *)&ipc_instance->dispatch_buffer,
 		dispatch_size);
@@ -717,33 +727,33 @@ coroipcc_service_connect (
 	/*
 	 * Initialize IPC setup message
 	 */
-	req_setup.service = service;
-	strcpy (req_setup.control_file, control_map_path);
-	strcpy (req_setup.request_file, request_map_path);
-	strcpy (req_setup.response_file, response_map_path);
-	strcpy (req_setup.dispatch_file, dispatch_map_path);
-	req_setup.control_size = 8192;
-	req_setup.request_size = request_size;
-	req_setup.response_size = response_size;
-	req_setup.dispatch_size = dispatch_size;
+	path_data->req_setup.service = service;
+	strcpy (path_data->req_setup.control_file, path_data->control_map_path);
+	strcpy (path_data->req_setup.request_file, path_data->request_map_path);
+	strcpy (path_data->req_setup.response_file, path_data->response_map_path);
+	strcpy (path_data->req_setup.dispatch_file, path_data->dispatch_map_path);
+	path_data->req_setup.control_size = 8192;
+	path_data->req_setup.request_size = request_size;
+	path_data->req_setup.response_size = response_size;
+	path_data->req_setup.dispatch_size = dispatch_size;
 
 #if _POSIX_THREAD_PROCESS_SHARED < 1
-	req_setup.semkey = semkey;
+	path_data->req_setup.semkey = semkey;
 #endif
 
-	res = socket_send (request_fd, &req_setup, sizeof (mar_req_setup_t));
+	res = socket_send (request_fd, &path_data->req_setup, sizeof (mar_req_setup_t));
 	if (res != CS_OK) {
 		goto error_exit;
 	}
-	res = socket_recv (request_fd, &res_setup, sizeof (mar_res_setup_t));
+	res = socket_recv (request_fd, &path_data->res_setup, sizeof (mar_res_setup_t));
 	if (res != CS_OK) {
 		goto error_exit;
 	}
 
 	ipc_instance->fd = request_fd;
 
-	if (res_setup.error == CS_ERR_TRY_AGAIN) {
-		res = res_setup.error;
+	if (path_data->res_setup.error == CS_ERR_TRY_AGAIN) {
+		res = path_data->res_setup.error;
 		goto error_exit;
 	}
 
@@ -756,7 +766,9 @@ coroipcc_service_connect (
 
 	hdb_handle_put (&ipc_hdb, *handle);
 
-	return (res_setup.error);
+	res = path_data->res_setup.error;
+	free(path_data);
+	return (res);
 
 error_exit:
 #if _POSIX_THREAD_PROCESS_SHARED < 1
@@ -775,6 +787,7 @@ error_connect:
 
 	hdb_handle_destroy (&ipc_hdb, *handle);
 	hdb_handle_put (&ipc_hdb, *handle);
+	free(path_data);
 
 	return (res);
 }