1 files changed, 250 insertions, 0 deletions
diff --git a/xwayland/xwayland.c b/xwayland/xwayland.c
new file mode 100644
index 00000000..211e2a04
--- /dev/null
+++ b/xwayland/xwayland.c
@@ -0,0 +1,250 @@
+#define _XOPEN_SOURCE 700
+#define _DEFAULT_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <wayland-server.h>
+#include "wlr/util/log.h"
+#include "wlr/xwayland.h"
+#include "sockets.h"
+#include "xwm.h"
+
+static void safe_close(int fd) {
+	if (fd >= 0) {
+		close(fd);
+	}
+}
+
+static int unset_cloexec(int fd) {
+	if (fcntl(fd, F_SETFD, 0) != 0) {
+		wlr_log_errno(L_ERROR, "fcntl() failed on fd %d", fd);
+		return -1;
+	}
+	return 0;
+}
+
+static int fill_arg(char ***argv, const char *fmt, ...) {
+	int len;
+	char **cur_arg = *argv;
+	va_list args;
+	va_start(args, fmt);
+	len = vsnprintf(NULL, 0, fmt, args) + 1;
+	va_end(args);
+	while (*cur_arg) {
+		cur_arg++;
+	}
+	*cur_arg = malloc(len);
+	if (!*cur_arg) {
+		return -1;
+	}
+	*argv = cur_arg;
+	va_start(args, fmt);
+	len = vsnprintf(*cur_arg, len, fmt, args);
+	va_end(args);
+	return len;
+}
+
+static void exec_xwayland(struct wlr_xwayland *wlr_xwayland) {
+	if (unset_cloexec(wlr_xwayland->x_fd[0]) ||
+			unset_cloexec(wlr_xwayland->x_fd[1]) ||
+			unset_cloexec(wlr_xwayland->wm_fd[1]) ||
+			unset_cloexec(wlr_xwayland->wl_fd[1])) {
+		exit(EXIT_FAILURE);
+	}
+
+	/* Make Xwayland signal us when it's ready */
+	signal(SIGUSR1, SIG_IGN);
+
+	char *argv[] = {
+		"Xwayland", NULL /* display, e.g. :1 */,
+		"-rootless", "-terminate",
+		"-listen", NULL /* x_fd[0] */,
+		"-listen", NULL /* x_fd[1] */,
+		"-wm", NULL /* wm_fd[1] */,
+		NULL };
+	char **cur_arg = argv;
+
+	if (fill_arg(&cur_arg, ":%d", wlr_xwayland->display) < 0 ||
+			fill_arg(&cur_arg, "%d", wlr_xwayland->x_fd[0]) < 0 ||
+			fill_arg(&cur_arg, "%d", wlr_xwayland->x_fd[1]) < 0 ||
+			fill_arg(&cur_arg, "%d", wlr_xwayland->wm_fd[1]) < 0) {
+		wlr_log_errno(L_ERROR, "alloc/print failure");
+		exit(EXIT_FAILURE);
+	}
+
+	const char *xdg_runtime = getenv("XDG_RUNTIME_DIR");
+	if (!xdg_runtime) {
+		wlr_log(L_ERROR, "XDG_RUNTIME_DIR is not set");
+		exit(EXIT_FAILURE);
+	}
+
+	if (clearenv()) {	    
+		wlr_log_errno(L_ERROR, "clearenv failed");
+		exit(EXIT_FAILURE);
+	}
+	setenv("XDG_RUNTIME_DIR", xdg_runtime, true);
+	char wayland_socket_str[16];
+	snprintf(wayland_socket_str, sizeof(wayland_socket_str), "%d", wlr_xwayland->wl_fd[1]);
+	setenv("WAYLAND_SOCKET", wayland_socket_str, true);
+
+	wlr_log(L_INFO, "WAYLAND_SOCKET=%d Xwayland :%d -rootless -terminate -listen %d -listen %d -wm %d",
+		wlr_xwayland->wl_fd[1], wlr_xwayland->display, wlr_xwayland->x_fd[0],
+		wlr_xwayland->x_fd[1], wlr_xwayland->wm_fd[1]);
+
+	// TODO: close stdout/err depending on log level
+
+	execvp("Xwayland", argv);
+}
+
+static bool wlr_xwayland_init(struct wlr_xwayland *wlr_xwayland,
+		struct wl_display *wl_display, struct wlr_compositor *compositor);
+static void wlr_xwayland_finish(struct wlr_xwayland *wlr_xwayland);
+
+static void xwayland_destroy_event(struct wl_listener *listener, void *data) {
+	struct wlr_xwayland *wlr_xwayland = wl_container_of(listener, wlr_xwayland, destroy_listener);
+
+	/* don't call client destroy */
+	wlr_xwayland->client = NULL;
+	wl_list_remove(&wlr_xwayland->destroy_listener.link);
+	wlr_xwayland_finish(wlr_xwayland);
+
+	if (time(NULL) - wlr_xwayland->server_start > 5) {
+		wlr_xwayland_init(wlr_xwayland, wlr_xwayland->wl_display,
+			wlr_xwayland->compositor);
+	}
+}
+
+static void wlr_xwayland_finish(struct wlr_xwayland *wlr_xwayland) {
+	if (!wlr_xwayland || wlr_xwayland->display == -1) {
+		return;
+	}
+	if (wlr_xwayland->client) {
+		wl_list_remove(&wlr_xwayland->destroy_listener.link);
+		wl_client_destroy(wlr_xwayland->client);
+	}
+	if (wlr_xwayland->sigusr1_source) {
+		wl_event_source_remove(wlr_xwayland->sigusr1_source);
+	}
+
+	xwm_destroy(wlr_xwayland->xwm);
+
+	safe_close(wlr_xwayland->x_fd[0]);
+	safe_close(wlr_xwayland->x_fd[1]);
+	safe_close(wlr_xwayland->wl_fd[0]);
+	safe_close(wlr_xwayland->wl_fd[1]);
+	safe_close(wlr_xwayland->wm_fd[0]);
+	safe_close(wlr_xwayland->wm_fd[1]);
+
+	unlink_display_sockets(wlr_xwayland->display);
+	wlr_xwayland->display = -1;
+	unsetenv("DISPLAY");
+	/* We do not kill the Xwayland process, it dies to broken pipe
+	 * after we close our side of the wm/wl fds. This is more reliable
+	 * than trying to kill something that might no longer be Xwayland.
+	 */
+	// TODO: figure how to wait for dying process though. Probably handle SIGCHILD
+}
+
+static int xserver_handle_ready(int signal_number, void *data) {
+	struct wlr_xwayland *wlr_xwayland = data;
+
+	wlr_log(L_DEBUG, "Xserver is ready");
+
+	wlr_xwayland->xwm = xwm_create(wlr_xwayland);
+	if (!wlr_xwayland->xwm) {
+		wlr_xwayland_finish(wlr_xwayland);
+		return 1;
+	}
+
+	wl_event_source_remove(wlr_xwayland->sigusr1_source);
+	wlr_xwayland->sigusr1_source = NULL;
+
+	char display_name[16];
+	snprintf(display_name, sizeof(display_name), ":%d", wlr_xwayland->display);
+	setenv("DISPLAY", display_name, true);
+
+	return 1; /* wayland event loop dispatcher's count */
+}
+
+static bool wlr_xwayland_init(struct wlr_xwayland *wlr_xwayland,
+		struct wl_display *wl_display, struct wlr_compositor *compositor) {
+	memset(wlr_xwayland, 0, sizeof(struct wlr_xwayland));
+	wlr_xwayland->wl_display = wl_display;
+	wlr_xwayland->compositor = compositor;
+	wlr_xwayland->x_fd[0] = wlr_xwayland->x_fd[1] = -1;
+	wlr_xwayland->wl_fd[0] = wlr_xwayland->wl_fd[1] = -1;
+	wlr_xwayland->wm_fd[0] = wlr_xwayland->wm_fd[1] = -1;
+	wl_list_init(&wlr_xwayland->displayable_windows);
+
+	wlr_xwayland->display = open_display_sockets(wlr_xwayland->x_fd);
+	if (wlr_xwayland->display < 0) {
+		wlr_xwayland_finish(wlr_xwayland);
+		return false;
+	}
+	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wlr_xwayland->wl_fd) != 0 ||
+			socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wlr_xwayland->wm_fd) != 0) {
+		wlr_log_errno(L_ERROR, "failed to create socketpair");
+		wlr_xwayland_finish(wlr_xwayland);
+		return false;
+	}
+
+	if ((wlr_xwayland->pid = fork()) == 0) {
+		exec_xwayland(wlr_xwayland);
+		wlr_log_errno(L_ERROR, "execvpe failed");
+		exit(EXIT_FAILURE);
+	}
+
+	if (wlr_xwayland->pid < 0) {
+		wlr_log_errno(L_ERROR, "fork failed");
+		wlr_xwayland_finish(wlr_xwayland);
+		return false;
+	}
+
+	/* close child fds */
+	close(wlr_xwayland->x_fd[0]);
+	close(wlr_xwayland->x_fd[1]);
+	close(wlr_xwayland->wl_fd[1]);
+	close(wlr_xwayland->wm_fd[1]);
+	wlr_xwayland->x_fd[0] = wlr_xwayland->x_fd[1] = -1;
+	wlr_xwayland->wl_fd[1] = wlr_xwayland->wm_fd[1] = -1;
+
+	wlr_xwayland->server_start = time(NULL);
+
+	if (!(wlr_xwayland->client = wl_client_create(wl_display, wlr_xwayland->wl_fd[0]))) {
+		wlr_log_errno(L_ERROR, "wl_client_create failed");
+		wlr_xwayland_finish(wlr_xwayland);
+		return false;
+	}
+	wlr_xwayland->wl_fd[0] = -1; /* not ours anymore */
+
+	wlr_xwayland->destroy_listener.notify = xwayland_destroy_event;
+	wl_client_add_destroy_listener(wlr_xwayland->client, &wlr_xwayland->destroy_listener);
+
+	struct wl_event_loop *loop = wl_display_get_event_loop(wl_display);
+	wlr_xwayland->sigusr1_source = wl_event_loop_add_signal(loop, SIGUSR1, xserver_handle_ready, wlr_xwayland);
+
+	return true;
+}
+
+void wlr_xwayland_destroy(struct wlr_xwayland *wlr_xwayland) {
+	wlr_xwayland_finish(wlr_xwayland);
+	free(wlr_xwayland);
+}
+
+struct wlr_xwayland *wlr_xwayland_create(struct wl_display *wl_display,
+		struct wlr_compositor *compositor) {
+	struct wlr_xwayland *wlr_xwayland = calloc(1, sizeof(struct wlr_xwayland));
+	if (wlr_xwayland_init(wlr_xwayland, wl_display, compositor)) {
+		return wlr_xwayland;
+	}
+	free(wlr_xwayland);
+	return NULL;
+}