mirror of
https://gitlab.freedesktop.org/wayland/weston
synced 2024-09-06 18:05:39 +00:00
![Daniel Stone](/assets/img/avatar_default.png)
The X11 lock file was somewhat opaque. Into a sized array of 16
characters, we previously read 11 bytes. 61beda653b
fixed the parsing of
this input to ensure that we only considered the first 10 bytes: this
has the effect of culling a LF byte at the end of the string.
This commit more explicitly NULLs the entire string before reading, and
trims trailing LF characters only.
It also adds some documentation by way of resizing pid, an explicit size
check on snprintf's return, and comments.
Verified manually that it emits lock files with a trailing \n, as Xorg
does. Also verified manually that it ignores misformatted lock files,
but accepts either \n or \0 in the trailing position.
Related Mutter issue: https://bugzilla.gnome.org/show_bug.cgi?id=774613
Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
397 lines
9.7 KiB
C
397 lines
9.7 KiB
C
/*
|
|
* Copyright © 2011 Intel Corporation
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files (the
|
|
* "Software"), to deal in the Software without restriction, including
|
|
* without limitation the rights to use, copy, modify, merge, publish,
|
|
* distribute, sublicense, and/or sell copies of the Software, and to
|
|
* permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice (including the
|
|
* next paragraph) shall be included in all copies or substantial
|
|
* portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
|
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/un.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <signal.h>
|
|
|
|
#include "xwayland.h"
|
|
#include "xwayland-api.h"
|
|
#include "shared/helpers.h"
|
|
#include "shared/string-helpers.h"
|
|
#include "compositor/weston.h"
|
|
|
|
static int
|
|
weston_xserver_handle_event(int listen_fd, uint32_t mask, void *data)
|
|
{
|
|
struct weston_xserver *wxs = data;
|
|
char display[8];
|
|
|
|
snprintf(display, sizeof display, ":%d", wxs->display);
|
|
|
|
wxs->pid = wxs->spawn_func(wxs->user_data, display, wxs->abstract_fd, wxs->unix_fd);
|
|
if (wxs->pid == -1) {
|
|
weston_log("Failed to spawn the Xwayland server\n");
|
|
return 1;
|
|
}
|
|
|
|
weston_log("Spawned Xwayland server, pid %d\n", wxs->pid);
|
|
wl_event_source_remove(wxs->abstract_source);
|
|
wl_event_source_remove(wxs->unix_source);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
weston_xserver_shutdown(struct weston_xserver *wxs)
|
|
{
|
|
char path[256];
|
|
|
|
snprintf(path, sizeof path, "/tmp/.X%d-lock", wxs->display);
|
|
unlink(path);
|
|
snprintf(path, sizeof path, "/tmp/.X11-unix/X%d", wxs->display);
|
|
unlink(path);
|
|
if (wxs->pid == 0) {
|
|
wl_event_source_remove(wxs->abstract_source);
|
|
wl_event_source_remove(wxs->unix_source);
|
|
}
|
|
close(wxs->abstract_fd);
|
|
close(wxs->unix_fd);
|
|
if (wxs->wm) {
|
|
weston_wm_destroy(wxs->wm);
|
|
wxs->wm = NULL;
|
|
}
|
|
wxs->loop = NULL;
|
|
}
|
|
|
|
static int
|
|
bind_to_abstract_socket(int display)
|
|
{
|
|
struct sockaddr_un addr;
|
|
socklen_t size, name_size;
|
|
int fd;
|
|
|
|
fd = socket(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
|
|
if (fd < 0)
|
|
return -1;
|
|
|
|
addr.sun_family = AF_LOCAL;
|
|
name_size = snprintf(addr.sun_path, sizeof addr.sun_path,
|
|
"%c/tmp/.X11-unix/X%d", 0, display);
|
|
size = offsetof(struct sockaddr_un, sun_path) + name_size;
|
|
if (bind(fd, (struct sockaddr *) &addr, size) < 0) {
|
|
weston_log("failed to bind to @%s: %m\n", addr.sun_path + 1);
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
if (listen(fd, 1) < 0) {
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
static int
|
|
bind_to_unix_socket(int display)
|
|
{
|
|
struct sockaddr_un addr;
|
|
socklen_t size, name_size;
|
|
int fd;
|
|
|
|
fd = socket(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
|
|
if (fd < 0)
|
|
return -1;
|
|
|
|
addr.sun_family = AF_LOCAL;
|
|
name_size = snprintf(addr.sun_path, sizeof addr.sun_path,
|
|
"/tmp/.X11-unix/X%d", display) + 1;
|
|
size = offsetof(struct sockaddr_un, sun_path) + name_size;
|
|
unlink(addr.sun_path);
|
|
if (bind(fd, (struct sockaddr *) &addr, size) < 0) {
|
|
weston_log("failed to bind to %s: %m\n", addr.sun_path);
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
if (listen(fd, 1) < 0) {
|
|
unlink(addr.sun_path);
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
static int
|
|
create_lockfile(int display, char *lockfile, size_t lsize)
|
|
{
|
|
/* 10 decimal characters, trailing LF and NUL byte; see comment
|
|
* at end of function. */
|
|
char pid[11];
|
|
int fd, size;
|
|
pid_t other;
|
|
|
|
snprintf(lockfile, lsize, "/tmp/.X%d-lock", display);
|
|
fd = open(lockfile, O_WRONLY | O_CLOEXEC | O_CREAT | O_EXCL, 0444);
|
|
if (fd < 0 && errno == EEXIST) {
|
|
fd = open(lockfile, O_CLOEXEC | O_RDONLY);
|
|
if (fd < 0 || read(fd, pid, 11) != 11) {
|
|
weston_log("can't read lock file %s: %s\n",
|
|
lockfile, strerror(errno));
|
|
if (fd >= 0)
|
|
close (fd);
|
|
|
|
errno = EEXIST;
|
|
return -1;
|
|
}
|
|
|
|
/* Trim the trailing LF, or at least ensure it's NULL. */
|
|
pid[10] = '\0';
|
|
|
|
if (!safe_strtoint(pid, &other)) {
|
|
weston_log("can't parse lock file %s\n",
|
|
lockfile);
|
|
close(fd);
|
|
errno = EEXIST;
|
|
return -1;
|
|
}
|
|
|
|
if (kill(other, 0) < 0 && errno == ESRCH) {
|
|
/* stale lock file; unlink and try again */
|
|
weston_log("unlinking stale lock file %s\n", lockfile);
|
|
close(fd);
|
|
if (unlink(lockfile))
|
|
/* If we fail to unlink, return EEXIST
|
|
so we try the next display number.*/
|
|
errno = EEXIST;
|
|
else
|
|
errno = EAGAIN;
|
|
return -1;
|
|
}
|
|
|
|
close(fd);
|
|
errno = EEXIST;
|
|
return -1;
|
|
} else if (fd < 0) {
|
|
weston_log("failed to create lock file %s: %s\n",
|
|
lockfile, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
/* Subtle detail: we use the pid of the wayland compositor, not the
|
|
* xserver in the lock file.
|
|
* Also subtle is that we don't emit a trailing NUL to the file, so
|
|
* our size here is 11 rather than 12. */
|
|
size = dprintf(fd, "%10d\n", getpid());
|
|
if (size != 11) {
|
|
unlink(lockfile);
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
close(fd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
weston_xserver_destroy(struct wl_listener *l, void *data)
|
|
{
|
|
struct weston_xserver *wxs =
|
|
container_of(l, struct weston_xserver, destroy_listener);
|
|
|
|
if (!wxs)
|
|
return;
|
|
|
|
if (wxs->loop)
|
|
weston_xserver_shutdown(wxs);
|
|
|
|
free(wxs);
|
|
}
|
|
|
|
static struct weston_xwayland *
|
|
weston_xwayland_get(struct weston_compositor *compositor)
|
|
{
|
|
struct wl_listener *listener;
|
|
struct weston_xserver *wxs;
|
|
|
|
listener = wl_signal_get(&compositor->destroy_signal,
|
|
weston_xserver_destroy);
|
|
if (!listener)
|
|
return NULL;
|
|
|
|
wxs = wl_container_of(listener, wxs, destroy_listener);
|
|
return (struct weston_xwayland *)wxs;
|
|
}
|
|
|
|
static int
|
|
weston_xwayland_listen(struct weston_xwayland *xwayland, void *user_data,
|
|
weston_xwayland_spawn_xserver_func_t spawn_func)
|
|
{
|
|
struct weston_xserver *wxs = (struct weston_xserver *)xwayland;
|
|
char lockfile[256], display_name[8];
|
|
|
|
wxs->user_data = user_data;
|
|
wxs->spawn_func = spawn_func;
|
|
|
|
retry:
|
|
if (create_lockfile(wxs->display, lockfile, sizeof lockfile) < 0) {
|
|
if (errno == EAGAIN) {
|
|
goto retry;
|
|
} else if (errno == EEXIST) {
|
|
wxs->display++;
|
|
goto retry;
|
|
} else {
|
|
free(wxs);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
wxs->abstract_fd = bind_to_abstract_socket(wxs->display);
|
|
if (wxs->abstract_fd < 0 && errno == EADDRINUSE) {
|
|
wxs->display++;
|
|
unlink(lockfile);
|
|
goto retry;
|
|
}
|
|
|
|
wxs->unix_fd = bind_to_unix_socket(wxs->display);
|
|
if (wxs->unix_fd < 0) {
|
|
unlink(lockfile);
|
|
close(wxs->abstract_fd);
|
|
free(wxs);
|
|
return -1;
|
|
}
|
|
|
|
snprintf(display_name, sizeof display_name, ":%d", wxs->display);
|
|
weston_log("xserver listening on display %s\n", display_name);
|
|
setenv("DISPLAY", display_name, 1);
|
|
|
|
wxs->loop = wl_display_get_event_loop(wxs->wl_display);
|
|
wxs->abstract_source =
|
|
wl_event_loop_add_fd(wxs->loop, wxs->abstract_fd,
|
|
WL_EVENT_READABLE,
|
|
weston_xserver_handle_event, wxs);
|
|
wxs->unix_source =
|
|
wl_event_loop_add_fd(wxs->loop, wxs->unix_fd,
|
|
WL_EVENT_READABLE,
|
|
weston_xserver_handle_event, wxs);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
weston_xwayland_xserver_loaded(struct weston_xwayland *xwayland,
|
|
struct wl_client *client, int wm_fd)
|
|
{
|
|
struct weston_xserver *wxs = (struct weston_xserver *)xwayland;
|
|
wxs->wm = weston_wm_create(wxs, wm_fd);
|
|
wxs->client = client;
|
|
}
|
|
|
|
static void
|
|
weston_xwayland_xserver_exited(struct weston_xwayland *xwayland,
|
|
int exit_status)
|
|
{
|
|
struct weston_xserver *wxs = (struct weston_xserver *)xwayland;
|
|
|
|
wxs->pid = 0;
|
|
wxs->client = NULL;
|
|
|
|
wxs->abstract_source =
|
|
wl_event_loop_add_fd(wxs->loop, wxs->abstract_fd,
|
|
WL_EVENT_READABLE,
|
|
weston_xserver_handle_event, wxs);
|
|
wxs->unix_source =
|
|
wl_event_loop_add_fd(wxs->loop, wxs->unix_fd,
|
|
WL_EVENT_READABLE,
|
|
weston_xserver_handle_event, wxs);
|
|
|
|
if (wxs->wm) {
|
|
weston_log("xserver exited, code %d\n", exit_status);
|
|
weston_wm_destroy(wxs->wm);
|
|
wxs->wm = NULL;
|
|
} else {
|
|
/* If the X server crashes before it binds to the
|
|
* xserver interface, shut down and don't try
|
|
* again. */
|
|
weston_log("xserver crashing too fast: %d\n", exit_status);
|
|
weston_xserver_shutdown(wxs);
|
|
}
|
|
}
|
|
|
|
const struct weston_xwayland_api api = {
|
|
weston_xwayland_get,
|
|
weston_xwayland_listen,
|
|
weston_xwayland_xserver_loaded,
|
|
weston_xwayland_xserver_exited,
|
|
};
|
|
extern const struct weston_xwayland_surface_api surface_api;
|
|
|
|
WL_EXPORT int
|
|
module_init(struct weston_compositor *compositor,
|
|
int *argc, char *argv[])
|
|
|
|
{
|
|
struct wl_display *display = compositor->wl_display;
|
|
struct weston_xserver *wxs;
|
|
int ret;
|
|
|
|
wxs = zalloc(sizeof *wxs);
|
|
if (wxs == NULL)
|
|
return -1;
|
|
wxs->wl_display = display;
|
|
wxs->compositor = compositor;
|
|
|
|
if (weston_xwayland_get_api(compositor) != NULL ||
|
|
weston_xwayland_surface_get_api(compositor) != NULL) {
|
|
weston_log("The xwayland module APIs are already loaded.\n");
|
|
free(wxs);
|
|
return -1;
|
|
}
|
|
|
|
ret = weston_plugin_api_register(compositor, WESTON_XWAYLAND_API_NAME,
|
|
&api, sizeof(api));
|
|
if (ret < 0) {
|
|
weston_log("Failed to register the xwayland module API.\n");
|
|
free(wxs);
|
|
return -1;
|
|
}
|
|
|
|
ret = weston_plugin_api_register(compositor,
|
|
WESTON_XWAYLAND_SURFACE_API_NAME,
|
|
&surface_api, sizeof(surface_api));
|
|
if (ret < 0) {
|
|
weston_log("Failed to register the xwayland surface API.\n");
|
|
free(wxs);
|
|
return -1;
|
|
}
|
|
|
|
wxs->destroy_listener.notify = weston_xserver_destroy;
|
|
wl_signal_add(&compositor->destroy_signal, &wxs->destroy_listener);
|
|
|
|
return 0;
|
|
}
|