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weston/compositor/xwayland.c

288 lines
8.2 KiB

/*
* Copyright © 2011 Intel Corporation
* Copyright © 2016 Giulio Camuffo
*
* 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 <signal.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <libweston/libweston.h>
#include "compositor/weston.h"
#include <libweston/xwayland-api.h>
#include "shared/helpers.h"
#include "shared/os-compatibility.h"
#include "shared/process-util.h"
#include "shared/string-helpers.h"
#ifdef HAVE_XWAYLAND_LISTENFD
# define LISTEN_STR "-listenfd"
#else
# define LISTEN_STR "-listen"
#endif
struct wet_xwayland {
struct weston_compositor *compositor;
struct wl_listener compositor_destroy_listener;
const struct weston_xwayland_api *api;
struct weston_xwayland *xwayland;
struct wl_event_source *display_fd_source;
struct wl_client *client;
int wm_fd;
struct weston_process process;
};
static int
handle_display_fd(int fd, uint32_t mask, void *data)
{
struct wet_xwayland *wxw = data;
char buf[64];
ssize_t n;
/* xwayland exited before being ready, don't finish initialization,
* the process watcher will cleanup */
if (!(mask & WL_EVENT_READABLE))
goto out;
/* Xwayland writes to the pipe twice, so if we close it too early
* it's possible the second write will fail and Xwayland shuts down.
* Make sure we read until end of line marker to avoid this. */
n = read(fd, buf, sizeof buf);
if (n < 0 && errno != EAGAIN) {
weston_log("read from Xwayland display_fd failed: %s\n",
strerror(errno));
goto out;
}
/* Returning 1 here means recheck and call us again if required. */
if (n <= 0 || (n > 0 && buf[n - 1] != '\n'))
return 1;
wxw->api->xserver_loaded(wxw->xwayland, wxw->client, wxw->wm_fd);
out:
wl_event_source_remove(wxw->display_fd_source);
close(fd);
return 0;
}
static pid_t
spawn_xserver(void *user_data, const char *display, int abstract_fd, int unix_fd)
{
struct wet_xwayland *wxw = user_data;
pid_t pid;
struct fdstr wayland_socket;
struct fdstr x11_abstract_socket;
struct fdstr x11_unix_socket;
struct fdstr x11_wm_socket;
struct fdstr display_pipe;
char *xserver = NULL;
struct weston_config *config = wet_get_config(wxw->compositor);
struct weston_config_section *section;
struct wl_event_loop *loop;
char *exec_failure_msg;
struct custom_env child_env;
char *const *envp;
char *const *argp;
bool ret;
size_t written __attribute__ ((unused));
if (os_socketpair_cloexec(AF_UNIX, SOCK_STREAM, 0, wayland_socket.fds) < 0) {
weston_log("wl connection socketpair failed\n");
return 1;
}
fdstr_update_str1(&wayland_socket);
if (os_socketpair_cloexec(AF_UNIX, SOCK_STREAM, 0, x11_wm_socket.fds) < 0) {
weston_log("X wm connection socketpair failed\n");
return 1;
}
fdstr_update_str1(&x11_wm_socket);
if (pipe2(display_pipe.fds, O_CLOEXEC) < 0) {
weston_log("pipe creation for displayfd failed\n");
return 1;
}
fdstr_update_str1(&display_pipe);
fdstr_set_fd1(&x11_abstract_socket, abstract_fd);
fdstr_set_fd1(&x11_unix_socket, unix_fd);
section = weston_config_get_section(config, "xwayland", NULL, NULL);
weston_config_section_get_string(section, "path",
&xserver, XSERVER_PATH);
str_printf(&exec_failure_msg,
"Error: executing Xwayland as '%s' failed.\n", xserver);
custom_env_init_from_environ(&child_env);
custom_env_set_env_var(&child_env, "WAYLAND_SOCKET", wayland_socket.str1);
custom_env_add_arg(&child_env, xserver);
custom_env_add_arg(&child_env, display);
custom_env_add_arg(&child_env, "-rootless");
custom_env_add_arg(&child_env, LISTEN_STR);
custom_env_add_arg(&child_env, x11_abstract_socket.str1);
custom_env_add_arg(&child_env, LISTEN_STR);
custom_env_add_arg(&child_env, x11_unix_socket.str1);
custom_env_add_arg(&child_env, "-displayfd");
custom_env_add_arg(&child_env, display_pipe.str1);
custom_env_add_arg(&child_env, "-wm");
custom_env_add_arg(&child_env, x11_wm_socket.str1);
custom_env_add_arg(&child_env, "-terminate");
envp = custom_env_get_envp(&child_env);
argp = custom_env_get_argp(&child_env);
pid = fork();
switch (pid) {
case 0:
setsid();
/* SOCK_CLOEXEC closes both ends, so we need to unset
* the flag on the client fd. */
ret = fdstr_clear_cloexec_fd1(&wayland_socket);
ret &= fdstr_clear_cloexec_fd1(&x11_abstract_socket);
ret &= fdstr_clear_cloexec_fd1(&x11_unix_socket);
ret &= fdstr_clear_cloexec_fd1(&x11_wm_socket);
ret &= fdstr_clear_cloexec_fd1(&display_pipe);
if (!ret)
_exit(EXIT_FAILURE);
execve(xserver, argp, envp);
/* execve does not return on success, so it failed */
if (exec_failure_msg) {
written = write(STDERR_FILENO, exec_failure_msg,
strlen(exec_failure_msg));
}
_exit(EXIT_FAILURE);
default:
close(wayland_socket.fds[1]);
wxw->client = wl_client_create(wxw->compositor->wl_display,
wayland_socket.fds[0]);
close(x11_wm_socket.fds[1]);
wxw->wm_fd = x11_wm_socket.fds[0];
/* During initialization the X server will round trip
* and block on the wayland compositor, so avoid making
* blocking requests (like xcb_connect_to_fd) until
* it's done with that. */
close(display_pipe.fds[1]);
loop = wl_display_get_event_loop(wxw->compositor->wl_display);
wxw->display_fd_source =
wl_event_loop_add_fd(loop, display_pipe.fds[0],
WL_EVENT_READABLE,
handle_display_fd, wxw);
wxw->process.pid = pid;
wet_watch_process(wxw->compositor, &wxw->process);
break;
case -1:
weston_log("Failed to fork to spawn xserver process\n");
fdstr_close_all(&wayland_socket);
fdstr_close_all(&x11_wm_socket);
fdstr_close_all(&display_pipe);
break;
}
custom_env_fini(&child_env);
free(exec_failure_msg);
free(xserver);
return pid;
}
static void
xserver_cleanup(struct weston_process *process, int status)
{
struct wet_xwayland *wxw =
container_of(process, struct wet_xwayland, process);
wxw->api->xserver_exited(wxw->xwayland, status);
wxw->client = NULL;
}
static void
wxw_compositor_destroy(struct wl_listener *listener, void *data)
{
struct wet_xwayland *wxw =
wl_container_of(listener, wxw, compositor_destroy_listener);
wl_list_remove(&wxw->compositor_destroy_listener.link);
/* Don't call xserver_exited because Xwayland's own destroy handler
* already does this for us ... */
if (wxw->client)
kill(wxw->process.pid, SIGTERM);
wl_list_remove(&wxw->process.link);
free(wxw);
}
int
wet_load_xwayland(struct weston_compositor *comp)
{
const struct weston_xwayland_api *api;
struct weston_xwayland *xwayland;
struct wet_xwayland *wxw;
if (weston_compositor_load_xwayland(comp) < 0)
return -1;
api = weston_xwayland_get_api(comp);
if (!api) {
weston_log("Failed to get the xwayland module API.\n");
return -1;
}
xwayland = api->get(comp);
if (!xwayland) {
weston_log("Failed to get the xwayland object.\n");
return -1;
}
wxw = zalloc(sizeof *wxw);
if (!wxw)
return -1;
wxw->compositor = comp;
wxw->api = api;
wxw->xwayland = xwayland;
wl_list_init(&wxw->process.link);
wxw->process.cleanup = xserver_cleanup;
wxw->compositor_destroy_listener.notify = wxw_compositor_destroy;
if (api->listen(xwayland, wxw, spawn_xserver) < 0)
return -1;
wl_signal_add(&comp->destroy_signal, &wxw->compositor_destroy_listener);
return 0;
}