Xwayland: first draft, just start server for now

1 files changed, 170 insertions, 0 deletions

diff --git a/xwayland/xwayland.c b/xwayland/xwayland.c
new file mode 100644
index 00000000..49173ace
--- /dev/null
+++ b/xwayland/xwayland.c
@@ -0,0 +1,170 @@
+#define _XOPEN_SOURCE 700
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/socket.h>
+#include <time.h>
+#include <errno.h>
+#include <wayland-server.h>
+#include "wlr/util/log.h"
+#include "wlr/xwayland.h"
+#include "xwayland/internals.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 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);
+	}
+
+	char *argv[11] = { 0 };
+	argv[0] = "Xwayland";
+	if (asprintf(&argv[1], ":%d", wlr_xwayland->display) < 0) {
+		wlr_log_errno(L_ERROR, "asprintf failed");
+		exit(EXIT_FAILURE);
+	}
+	argv[2] = "-rootless";
+	argv[3] = "-terminate";
+	argv[4] = "-listen";
+	if (asprintf(&argv[5], "%d", wlr_xwayland->x_fd[0]) < 0) {
+		wlr_log_errno(L_ERROR, "asprintf failed");
+		exit(EXIT_FAILURE);
+	}
+	argv[6] = "-listen";
+	if (asprintf(&argv[7], "%d", wlr_xwayland->x_fd[1]) < 0) {
+		wlr_log_errno(L_ERROR, "asprintf failed");
+		exit(EXIT_FAILURE);
+	}
+	argv[8] = "-wm";
+	if (asprintf(&argv[9], "%d", wlr_xwayland->wm_fd[1]) < 0) {
+		wlr_log_errno(L_ERROR, "asprintf failed");
+		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);
+	}
+
+	char *envp[3] = { 0 };
+	if (asprintf(&envp[0], "XDG_RUNTIME_DIR=%s", xdg_runtime) < 0 ||
+			asprintf(&envp[1], "WAYLAND_SOCKET=%d", wlr_xwayland->wl_fd[1]) < 0) {
+		wlr_log_errno(L_ERROR, "asprintf failed");
+		exit(EXIT_FAILURE);
+	}
+
+	wlr_log(L_INFO, "Xwayland :%d -rootless -terminate -listen %d -listen %d -wm %d",
+			wlr_xwayland->display, wlr_xwayland->x_fd[0], wlr_xwayland->x_fd[1],
+			wlr_xwayland->wm_fd[1]);
+
+	execvpe("Xwayland", argv, envp);
+}
+
+static void xwayland_destroy_event(struct wl_listener *listener, void *data) {
+	struct wl_client *client = data;
+	struct wlr_xwayland *wlr_xwayland = wl_container_of(client, wlr_xwayland, client);
+
+	/* don't call client destroy */
+	wlr_xwayland->client = NULL;
+	wlr_xwayland_finish(wlr_xwayland);
+
+	if (wlr_xwayland->server_start - time(NULL) > 5) {
+		wlr_xwayland_init(wlr_xwayland, wlr_xwayland->wl_display);
+	}
+}
+
+static struct wl_listener xwayland_destroy_listener = {
+	.notify = xwayland_destroy_event,
+};
+
+void wlr_xwayland_finish(struct wlr_xwayland *wlr_xwayland) {
+
+	if (wlr_xwayland->client) {
+		wl_list_remove(&xwayland_destroy_listener.link);
+		wl_client_destroy(wlr_xwayland->client);
+	}
+
+	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_sockets(wlr_xwayland->display);	
+	unsetenv("DISPLAY");
+	/* kill Xwayland process? */
+}
+
+bool wlr_xwayland_init(struct wlr_xwayland *wlr_xwayland,
+		struct wl_display *wl_display) {
+	wlr_xwayland->wl_display = wl_display;
+	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;
+
+	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;
+
+	char display_name[16];
+	snprintf(display_name, sizeof(display_name), ":%d", wlr_xwayland->display);
+	setenv("DISPLAY", display_name, true);
+	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);
+	}
+
+	wl_client_add_destroy_listener(wlr_xwayland->client, &xwayland_destroy_listener);
+
+	return true;
+}