xwayland: make the plugin usable by libweston compositors
This patch follows a similar approach taken to detach the backends from
weston. But instead of passing a configuration struct when loading the
plugin, we use the plugin API registry to register an API, and to get it
in the compositor side. This API allows to spawn the Xwayland process
in the compositor side, and to deal with signal handling. A new
function is added in compositor.c to load and init the xwayland.so
plugin.
Also make sure to re-arm the SIGUSR1 when the X server quits.
Signed-off-by: Giulio Camuffo <giuliocamuffo@gmail.com>
[Pekka: moved xwayland/weston-xwayland.c -> compositor/xwayland.c]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/compositor/xwayland.c b/compositor/xwayland.c
new file mode 100644
index 0000000..26eda20
--- /dev/null
+++ b/compositor/xwayland.c
@@ -0,0 +1,207 @@
+/*
+ * 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 <signal.h>
+#include <sys/socket.h>
+
+#include "compositor.h"
+#include "compositor/weston.h"
+#include "xwayland/xwayland-api.h"
+#include "shared/helpers.h"
+
+struct wet_xwayland {
+ struct weston_compositor *compositor;
+ const struct weston_xwayland_api *api;
+ struct weston_xwayland *xwayland;
+ struct wl_event_source *sigusr1_source;
+ struct wl_client *client;
+ int wm_fd;
+ struct weston_process process;
+};
+
+static int
+handle_sigusr1(int signal_number, void *data)
+{
+ struct wet_xwayland *wxw = data;
+
+ /* We'd be safer if we actually had the struct
+ * signalfd_siginfo from the signalfd data and could verify
+ * this came from Xwayland.*/
+ wxw->api->xserver_loaded(wxw->xwayland, wxw->client, wxw->wm_fd);
+ wl_event_source_remove(wxw->sigusr1_source);
+
+ return 1;
+}
+
+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;
+ char s[8], abstract_fd_str[8], unix_fd_str[8], wm_fd_str[8];
+ int sv[2], wm[2], fd;
+ char *xserver = NULL;
+ struct weston_config *config = wet_get_config(wxw->compositor);
+ struct weston_config_section *section;
+
+ if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, sv) < 0) {
+ weston_log("wl connection socketpair failed\n");
+ return 1;
+ }
+
+ if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wm) < 0) {
+ weston_log("X wm connection socketpair failed\n");
+ return 1;
+ }
+
+ pid = fork();
+ switch (pid) {
+ case 0:
+ /* SOCK_CLOEXEC closes both ends, so we need to unset
+ * the flag on the client fd. */
+ fd = dup(sv[1]);
+ if (fd < 0)
+ goto fail;
+ snprintf(s, sizeof s, "%d", fd);
+ setenv("WAYLAND_SOCKET", s, 1);
+
+ fd = dup(abstract_fd);
+ if (fd < 0)
+ goto fail;
+ snprintf(abstract_fd_str, sizeof abstract_fd_str, "%d", fd);
+ fd = dup(unix_fd);
+ if (fd < 0)
+ goto fail;
+ snprintf(unix_fd_str, sizeof unix_fd_str, "%d", fd);
+ fd = dup(wm[1]);
+ if (fd < 0)
+ goto fail;
+ snprintf(wm_fd_str, sizeof wm_fd_str, "%d", fd);
+
+ section = weston_config_get_section(config,
+ "xwayland", NULL, NULL);
+ weston_config_section_get_string(section, "path",
+ &xserver, XSERVER_PATH);
+
+ /* Ignore SIGUSR1 in the child, which will make the X
+ * server send SIGUSR1 to the parent (weston) when
+ * it's done with initialization. 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. */
+ signal(SIGUSR1, SIG_IGN);
+
+ if (execl(xserver,
+ xserver,
+ display,
+ "-rootless",
+ "-listen", abstract_fd_str,
+ "-listen", unix_fd_str,
+ "-wm", wm_fd_str,
+ "-terminate",
+ NULL) < 0)
+ weston_log("exec of '%s %s -rootless "
+ "-listen %s -listen %s -wm %s "
+ "-terminate' failed: %m\n",
+ xserver, display,
+ abstract_fd_str, unix_fd_str, wm_fd_str);
+ fail:
+ _exit(EXIT_FAILURE);
+
+ default:
+ close(sv[1]);
+ wxw->client = wl_client_create(wxw->compositor->wl_display, sv[0]);
+
+ close(wm[1]);
+ wxw->wm_fd = wm[0];
+
+ wxw->process.pid = pid;
+ weston_watch_process(&wxw->process);
+ break;
+
+ case -1:
+ weston_log( "failed to fork\n");
+ break;
+ }
+
+ return pid;
+}
+
+static void
+xserver_cleanup(struct weston_process *process, int status)
+{
+ struct wet_xwayland *wxw =
+ container_of(process, struct wet_xwayland, process);
+ struct wl_event_loop *loop =
+ wl_display_get_event_loop(wxw->compositor->wl_display);
+
+ wxw->api->xserver_exited(wxw->xwayland, status);
+ wxw->sigusr1_source = wl_event_loop_add_signal(loop, SIGUSR1,
+ handle_sigusr1, wxw);
+ wxw->client = NULL;
+}
+
+int
+wet_load_xwayland(struct weston_compositor *comp)
+{
+ const struct weston_xwayland_api *api;
+ struct weston_xwayland *xwayland;
+ struct wet_xwayland *wxw;
+ struct wl_event_loop *loop;
+
+ 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;
+ wxw->process.cleanup = xserver_cleanup;
+ if (api->listen(xwayland, wxw, spawn_xserver) < 0)
+ return -1;
+
+ loop = wl_display_get_event_loop(comp->wl_display);
+ wxw->sigusr1_source = wl_event_loop_add_signal(loop, SIGUSR1,
+ handle_sigusr1, wxw);
+
+ return 0;
+}