weston/compositor/xwayland.c
Daniel Stone fafe5f0fc2 custom-env: Prepare for handling args as well as environment
Rename the bits handling environment variables (currently, all of it),
so we have room to handle args as well.

No functional changes.

Signed-off-by: Daniel Stone <daniels@collabora.com>
2022-07-19 14:12:37 +00:00

280 lines
7.7 KiB
C

/*
* 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;
bool ret;
if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wayland_socket.fds) < 0) {
weston_log("wl connection socketpair failed\n");
return 1;
}
fdstr_update_str1(&wayland_socket);
if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 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);
envp = custom_env_get_envp(&child_env);
const char *const argv[] = {
xserver,
display,
"-rootless",
LISTEN_STR, x11_abstract_socket.str1,
LISTEN_STR, x11_unix_socket.str1,
"-displayfd", display_pipe.str1,
"-wm", x11_wm_socket.str1,
"-terminate",
NULL
};
pid = fork();
switch (pid) {
case 0:
/* 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, (char *const *)argv, envp);
/* execve does not return on success, so it failed */
if (exec_failure_msg) {
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);
/* 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;
}