1 files changed, 488 insertions, 0 deletions
diff --git a/xwayland/xwayland.c b/xwayland/xwayland.c
new file mode 100644
index 00000000..e6f15735
--- /dev/null
+++ b/xwayland/xwayland.c
@@ -0,0 +1,488 @@
+#define _POSIX_C_SOURCE 200112L
+#ifdef __FreeBSD__
+// for SOCK_CLOEXEC
+#define __BSD_VISIBLE 1
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <wayland-server.h>
+#include <wlr/util/log.h>
+#include <wlr/xwayland.h>
+#include "sockets.h"
+#include "util/signal.h"
+#include "xwayland/xwm.h"
+
+struct wlr_xwayland_cursor {
+	uint8_t *pixels;
+	uint32_t stride;
+	uint32_t width;
+	uint32_t height;
+	int32_t hotspot_x;
+	int32_t hotspot_y;
+};
+
+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(WLR_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;
+}
+
+_Noreturn
+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(WLR_ERROR, "alloc/print failure");
+		_exit(EXIT_FAILURE);
+	}
+
+	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(WLR_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]);
+
+	// Closes stdout/stderr depending on log verbosity
+	enum wlr_log_importance verbosity = wlr_log_get_verbosity();
+	int devnull = open("/dev/null", O_WRONLY | O_CREAT, 0666);
+	if (devnull < 0) {
+		wlr_log_errno(WLR_ERROR, "XWayland: failed to open /dev/null");
+		_exit(EXIT_FAILURE);
+	}
+	if (verbosity < WLR_INFO) {
+		dup2(devnull, STDOUT_FILENO);
+	}
+	if (verbosity < WLR_ERROR) {
+		dup2(devnull, STDERR_FILENO);
+	}
+
+	// This returns if and only if the call fails
+	execvp("Xwayland", argv);
+
+	wlr_log_errno(WLR_ERROR, "failed to exec Xwayland");
+	close(devnull);
+	_exit(EXIT_FAILURE);
+}
+
+static void xwayland_finish_server(struct wlr_xwayland *wlr_xwayland) {
+	if (!wlr_xwayland || wlr_xwayland->display == -1) {
+		return;
+	}
+
+	if (wlr_xwayland->x_fd_read_event[0]) {
+		wl_event_source_remove(wlr_xwayland->x_fd_read_event[0]);
+		wl_event_source_remove(wlr_xwayland->x_fd_read_event[1]);
+
+		wlr_xwayland->x_fd_read_event[0] = wlr_xwayland->x_fd_read_event[1] = NULL;
+	}
+
+	if (wlr_xwayland->cursor != NULL) {
+		free(wlr_xwayland->cursor);
+	}
+
+	xwm_destroy(wlr_xwayland->xwm);
+
+	if (wlr_xwayland->client) {
+		wl_list_remove(&wlr_xwayland->client_destroy.link);
+		wl_client_destroy(wlr_xwayland->client);
+	}
+	if (wlr_xwayland->sigusr1_source) {
+		wl_event_source_remove(wlr_xwayland->sigusr1_source);
+	}
+
+	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]);
+	memset(wlr_xwayland, 0, offsetof(struct wlr_xwayland, display));
+	wlr_xwayland->wl_fd[0] = wlr_xwayland->wl_fd[1] = -1;
+	wlr_xwayland->wm_fd[0] = wlr_xwayland->wm_fd[1] = -1;
+
+	/* 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.
+	 */
+}
+
+static void xwayland_finish_display(struct wlr_xwayland *wlr_xwayland) {
+	if (!wlr_xwayland || wlr_xwayland->display == -1) {
+		return;
+	}
+
+	safe_close(wlr_xwayland->x_fd[0]);
+	safe_close(wlr_xwayland->x_fd[1]);
+	wlr_xwayland->x_fd[0] = wlr_xwayland->x_fd[1] = -1;
+
+	wl_list_remove(&wlr_xwayland->display_destroy.link);
+
+	unlink_display_sockets(wlr_xwayland->display);
+	wlr_xwayland->display = -1;
+	unsetenv("DISPLAY");
+}
+
+static bool xwayland_start_display(struct wlr_xwayland *wlr_xwayland,
+	struct wl_display *wl_display);
+
+static bool xwayland_start_server(struct wlr_xwayland *wlr_xwayland);
+static bool xwayland_start_server_lazy(struct wlr_xwayland *wlr_xwayland);
+
+static void handle_client_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_xwayland *wlr_xwayland =
+		wl_container_of(listener, wlr_xwayland, client_destroy);
+
+	if (wlr_xwayland->sigusr1_source) {
+		// Xwayland failed to start, let the sigusr1 handler deal with it
+		return;
+	}
+
+	// Don't call client destroy: it's being destroyed already
+	wlr_xwayland->client = NULL;
+	wl_list_remove(&wlr_xwayland->client_destroy.link);
+
+	xwayland_finish_server(wlr_xwayland);
+
+	if (time(NULL) - wlr_xwayland->server_start > 5) {
+		if (wlr_xwayland->lazy) {
+			wlr_log(WLR_INFO, "Restarting Xwayland (lazy)");
+			xwayland_start_server_lazy(wlr_xwayland);
+		} else  {
+			wlr_log(WLR_INFO, "Restarting Xwayland");
+			xwayland_start_server(wlr_xwayland);
+		}
+	}
+}
+
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_xwayland *wlr_xwayland =
+		wl_container_of(listener, wlr_xwayland, display_destroy);
+
+	// Don't call client destroy: the display is being destroyed, it's too late
+	if (wlr_xwayland->client) {
+		wlr_xwayland->client = NULL;
+		wl_list_remove(&wlr_xwayland->client_destroy.link);
+	}
+
+	wlr_xwayland_destroy(wlr_xwayland);
+}
+
+static int xserver_handle_ready(int signal_number, void *data) {
+	struct wlr_xwayland *wlr_xwayland = data;
+
+	int stat_val = -1;
+	while (waitpid(wlr_xwayland->pid, &stat_val, 0) < 0) {
+		if (errno == EINTR) {
+			continue;
+		}
+		wlr_log_errno(WLR_ERROR, "waitpid for Xwayland fork failed");
+		return 1;
+	}
+	if (stat_val) {
+		wlr_log(WLR_ERROR, "Xwayland startup failed, not setting up xwm");
+		return 1;
+	}
+	wlr_log(WLR_DEBUG, "Xserver is ready");
+
+	wlr_xwayland->xwm = xwm_create(wlr_xwayland);
+	if (!wlr_xwayland->xwm) {
+		xwayland_finish_server(wlr_xwayland);
+		return 1;
+	}
+
+	if (wlr_xwayland->seat) {
+		xwm_set_seat(wlr_xwayland->xwm, wlr_xwayland->seat);
+	}
+
+	wl_event_source_remove(wlr_xwayland->sigusr1_source);
+	wlr_xwayland->sigusr1_source = NULL;
+
+	if (wlr_xwayland->cursor != NULL) {
+		struct wlr_xwayland_cursor *cur = wlr_xwayland->cursor;
+		xwm_set_cursor(wlr_xwayland->xwm, cur->pixels, cur->stride, cur->width,
+			cur->height, cur->hotspot_x, cur->hotspot_y);
+		free(cur);
+		wlr_xwayland->cursor = NULL;
+	}
+
+
+	wlr_signal_emit_safe(&wlr_xwayland->events.ready, wlr_xwayland);
+	/* ready is a one-shot signal, fire and forget */
+	wl_signal_init(&wlr_xwayland->events.ready);
+
+	return 1; /* wayland event loop dispatcher's count */
+}
+
+static int xwayland_socket_connected(int fd, uint32_t mask, void* data){
+	struct wlr_xwayland *wlr_xwayland = data;
+
+	wl_event_source_remove(wlr_xwayland->x_fd_read_event[0]);
+	wl_event_source_remove(wlr_xwayland->x_fd_read_event[1]);
+
+	wlr_xwayland->x_fd_read_event[0] = wlr_xwayland->x_fd_read_event[1] = NULL;
+
+	xwayland_start_server(wlr_xwayland);
+
+	return 0;
+}
+
+static bool xwayland_start_display(struct wlr_xwayland *wlr_xwayland,
+		struct wl_display *wl_display) {
+
+	wlr_xwayland->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(wl_display, &wlr_xwayland->display_destroy);
+
+	wlr_xwayland->display = open_display_sockets(wlr_xwayland->x_fd);
+	if (wlr_xwayland->display < 0) {
+		xwayland_finish_display(wlr_xwayland);
+		return false;
+	}
+
+	char display_name[16];
+	snprintf(display_name, sizeof(display_name), ":%d", wlr_xwayland->display);
+	setenv("DISPLAY", display_name, true);
+
+	return true;
+}
+
+static bool xwayland_start_server(struct wlr_xwayland *wlr_xwayland) {
+
+	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(WLR_ERROR, "failed to create socketpair");
+		xwayland_finish_server(wlr_xwayland);
+		return false;
+	}
+	wlr_xwayland->server_start = time(NULL);
+
+	if (!(wlr_xwayland->client = wl_client_create(wlr_xwayland->wl_display, wlr_xwayland->wl_fd[0]))) {
+		wlr_log_errno(WLR_ERROR, "wl_client_create failed");
+		xwayland_finish_server(wlr_xwayland);
+		return false;
+	}
+
+	wlr_xwayland->wl_fd[0] = -1; /* not ours anymore */
+
+	wlr_xwayland->client_destroy.notify = handle_client_destroy;
+	wl_client_add_destroy_listener(wlr_xwayland->client,
+		&wlr_xwayland->client_destroy);
+
+	struct wl_event_loop *loop = wl_display_get_event_loop(wlr_xwayland->wl_display);
+	wlr_xwayland->sigusr1_source = wl_event_loop_add_signal(loop, SIGUSR1,
+		xserver_handle_ready, wlr_xwayland);
+
+	if ((wlr_xwayland->pid = fork()) == 0) {
+		/* Double-fork, but we need to forward SIGUSR1 once Xserver(1)
+		 * is ready, or error if there was one. */
+		pid_t pid, ppid;
+		sigset_t sigset;
+		int sig;
+		ppid = getppid();
+		sigemptyset(&sigset);
+		sigaddset(&sigset, SIGUSR1);
+		sigaddset(&sigset, SIGCHLD);
+		sigprocmask(SIG_BLOCK, &sigset, NULL);
+		if ((pid = fork()) == 0) {
+			exec_xwayland(wlr_xwayland);
+		}
+		if (pid < 0) {
+			wlr_log_errno(WLR_ERROR, "second fork failed");
+			_exit(EXIT_FAILURE);
+		}
+		sigwait(&sigset, &sig);
+		kill(ppid, SIGUSR1);
+		wlr_log(WLR_DEBUG, "sent SIGUSR1 to process %d", ppid);
+		if (sig == SIGCHLD) {
+			waitpid(pid, NULL, 0);
+			_exit(EXIT_FAILURE);
+		}
+		_exit(EXIT_SUCCESS);
+	}
+	if (wlr_xwayland->pid < 0) {
+		wlr_log_errno(WLR_ERROR, "fork failed");
+		xwayland_finish_server(wlr_xwayland);
+		return false;
+	}
+
+	/* close child fds */
+	/* remain managing x sockets for lazy start */
+	close(wlr_xwayland->wl_fd[1]);
+	close(wlr_xwayland->wm_fd[1]);
+	wlr_xwayland->wl_fd[1] = wlr_xwayland->wm_fd[1] = -1;
+
+	return true;
+}
+
+static bool xwayland_start_server_lazy(struct wlr_xwayland *wlr_xwayland) {
+	struct wl_event_loop *loop = wl_display_get_event_loop(wlr_xwayland->wl_display);
+	wlr_xwayland->x_fd_read_event[0] =
+		wl_event_loop_add_fd(loop, wlr_xwayland->x_fd[0], WL_EVENT_READABLE,
+				xwayland_socket_connected, wlr_xwayland);
+	wlr_xwayland->x_fd_read_event[1] =
+		wl_event_loop_add_fd(loop, wlr_xwayland->x_fd[1], WL_EVENT_READABLE,
+				xwayland_socket_connected, wlr_xwayland);
+
+	return true;
+}
+
+void wlr_xwayland_destroy(struct wlr_xwayland *wlr_xwayland) {
+	if (!wlr_xwayland) {
+		return;
+	}
+
+	wlr_xwayland_set_seat(wlr_xwayland, NULL);
+	xwayland_finish_server(wlr_xwayland);
+	xwayland_finish_display(wlr_xwayland);
+	free(wlr_xwayland);
+}
+
+struct wlr_xwayland *wlr_xwayland_create(struct wl_display *wl_display,
+		struct wlr_compositor *compositor, bool lazy) {
+	struct wlr_xwayland *wlr_xwayland = calloc(1, sizeof(struct wlr_xwayland));
+	if (!wlr_xwayland) {
+		return NULL;
+	}
+
+	wlr_xwayland->wl_display = wl_display;
+	wlr_xwayland->compositor = compositor;
+	wlr_xwayland->lazy = lazy;
+
+	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_signal_init(&wlr_xwayland->events.new_surface);
+	wl_signal_init(&wlr_xwayland->events.ready);
+
+	if (!xwayland_start_display(wlr_xwayland, wl_display)) {
+		goto error_alloc;
+	}
+
+	if (wlr_xwayland->lazy) {
+		if (!xwayland_start_server_lazy(wlr_xwayland)) {
+			goto error_display;
+		}
+	} else {
+		if (!xwayland_start_server(wlr_xwayland)) {
+			goto error_display;
+		}
+	}
+
+	return wlr_xwayland;
+
+error_display:
+	xwayland_finish_display(wlr_xwayland);
+
+error_alloc:
+	free(wlr_xwayland);
+	return NULL;
+}
+
+void wlr_xwayland_set_cursor(struct wlr_xwayland *wlr_xwayland,
+		uint8_t *pixels, uint32_t stride, uint32_t width, uint32_t height,
+		int32_t hotspot_x, int32_t hotspot_y) {
+	if (wlr_xwayland->xwm != NULL) {
+		xwm_set_cursor(wlr_xwayland->xwm, pixels, stride, width, height,
+			hotspot_x, hotspot_y);
+		return;
+	}
+
+	free(wlr_xwayland->cursor);
+
+	wlr_xwayland->cursor = calloc(1, sizeof(struct wlr_xwayland_cursor));
+	if (wlr_xwayland->cursor == NULL) {
+		return;
+	}
+	wlr_xwayland->cursor->pixels = pixels;
+	wlr_xwayland->cursor->stride = stride;
+	wlr_xwayland->cursor->width = width;
+	wlr_xwayland->cursor->height = height;
+	wlr_xwayland->cursor->hotspot_x = hotspot_x;
+	wlr_xwayland->cursor->hotspot_y = hotspot_y;
+}
+
+static void xwayland_handle_seat_destroy(struct wl_listener *listener,
+		void *data) {
+	struct wlr_xwayland *xwayland =
+		wl_container_of(listener, xwayland, seat_destroy);
+
+	wlr_xwayland_set_seat(xwayland, NULL);
+}
+
+void wlr_xwayland_set_seat(struct wlr_xwayland *xwayland,
+		struct wlr_seat *seat) {
+	if (xwayland->seat) {
+		wl_list_remove(&xwayland->seat_destroy.link);
+	}
+
+	xwayland->seat = seat;
+
+	if (xwayland->xwm) {
+		xwm_set_seat(xwayland->xwm, seat);
+	}
+
+	if (seat == NULL) {
+		return;
+	}
+
+	xwayland->seat_destroy.notify = xwayland_handle_seat_destroy;
+	wl_signal_add(&seat->events.destroy, &xwayland->seat_destroy);
+}