Merge pull request #29 from ascent12/session

Moved session into backend/session and changed ownership

1 files changed, 244 insertions, 0 deletions

diff --git a/backend/session/direct.c b/backend/session/direct.c
new file mode 100644
index 00000000..82aa8e00
--- /dev/null
+++ b/backend/session/direct.c
@@ -0,0 +1,244 @@
+#define _POSIX_C_SOURCE 200809L
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <linux/kd.h>
+#include <linux/major.h>
+#include <linux/input.h>
+#include <linux/vt.h>
+#include <wayland-server.h>
+#include <wlr/backend/session/interface.h>
+#include <wlr/util/log.h>
+#include "backend/session/direct-ipc.h"
+
+enum { DRM_MAJOR = 226 };
+
+const struct session_impl session_direct;
+
+struct direct_session {
+	struct wlr_session base;
+	int tty_fd;
+	int old_kbmode;
+	int sock;
+	pid_t child;
+
+	struct wl_event_source *vt_source;
+};
+
+static int direct_session_open(struct wlr_session *base, const char *path) {
+	struct direct_session *session = wl_container_of(base, session, base);
+
+	int fd = direct_ipc_open(session->sock, path);
+	if (fd < 0) {
+		wlr_log(L_ERROR, "Failed to open %s: %s%s", path, strerror(-fd),
+			fd == -EINVAL ? "; is another display server running?" : "");
+		return fd;
+	}
+
+	struct stat st;
+	if (fstat(fd, &st) < 0) {
+		close(fd);
+		return -errno;
+	}
+
+	if (major(st.st_rdev) == DRM_MAJOR) {
+		session->base.drm_fd = fd;
+	}
+
+	return fd;
+}
+
+static void direct_session_close(struct wlr_session *base, int fd) {
+	struct direct_session *session = wl_container_of(base, session, base);
+
+	struct stat st;
+	if (fstat(fd, &st) < 0) {
+		wlr_log_errno(L_ERROR, "Stat failed");
+		close(fd);
+		return;
+	}
+
+	if (major(st.st_rdev) == DRM_MAJOR) {
+		direct_ipc_dropmaster(session->sock, session->base.drm_fd);
+		session->base.drm_fd = -1;
+	} else if (major(st.st_rdev) == INPUT_MAJOR) {
+		ioctl(fd, EVIOCREVOKE, 0);
+	}
+
+	close(fd);
+}
+
+static bool direct_change_vt(struct wlr_session *base, unsigned vt) {
+	struct direct_session *session = wl_container_of(base, session, base);
+	return ioctl(session->tty_fd, VT_ACTIVATE, (int)vt) == 0;
+}
+
+static void direct_session_finish(struct wlr_session *base) {
+	struct direct_session *session = wl_container_of(base, session, base);
+	struct vt_mode mode = {
+		.mode = VT_AUTO,
+	};
+
+	errno = 0;
+
+	ioctl(session->tty_fd, KDSKBMODE, session->old_kbmode);
+	ioctl(session->tty_fd, KDSETMODE, KD_TEXT);
+	ioctl(session->tty_fd, VT_SETMODE, &mode);
+
+	if (errno) {
+		wlr_log(L_ERROR, "Failed to restore tty");
+	}
+
+	direct_ipc_finish(session->sock, session->child);
+	close(session->sock);
+
+	wl_event_source_remove(session->vt_source);
+	close(session->tty_fd);
+	free(session);
+}
+
+static int vt_handler(int signo, void *data) {
+	struct direct_session *session = data;
+
+	if (session->base.active) {
+		session->base.active = false;
+		wl_signal_emit(&session->base.session_signal, session);
+		direct_ipc_dropmaster(session->sock, session->base.drm_fd);
+		ioctl(session->tty_fd, VT_RELDISP, 1);
+	} else {
+		ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ);
+		direct_ipc_setmaster(session->sock, session->base.drm_fd);
+		session->base.active = true;
+		wl_signal_emit(&session->base.session_signal, session);
+	}
+
+	return 1;
+}
+
+static bool setup_tty(struct direct_session *session, struct wl_display *display) {
+	int fd = dup(STDIN_FILENO);
+	if (fd == -1) {
+		wlr_log_errno(L_ERROR, "Cannot open tty");
+		return false;
+	}
+
+	struct stat st;
+	if (fstat(fd, &st) == -1 || major(st.st_rdev) != TTY_MAJOR || minor(st.st_rdev) == 0) {
+		wlr_log(L_ERROR, "Not running from a virtual terminal");
+		goto error;
+	}
+
+	int tty = minor(st.st_rdev);
+	int ret, kd_mode, old_kbmode;
+
+	ret = ioctl(fd, KDGETMODE, &kd_mode);
+	if (ret) {
+		wlr_log_errno(L_ERROR, "Failed to get tty mode");
+		goto error;
+	}
+
+	if (kd_mode != KD_TEXT) {
+		wlr_log(L_ERROR,
+			"tty already in graphics mode; is another display server running?");
+		goto error;
+	}
+
+	ioctl(fd, VT_ACTIVATE, tty);
+	ioctl(fd, VT_WAITACTIVE, tty);
+
+	if (ioctl(fd, KDGKBMODE, &old_kbmode)) {
+		wlr_log_errno(L_ERROR, "Failed to read keyboard mode");
+		goto error;
+	}
+
+	if (ioctl(fd, KDSKBMODE, K_OFF)) {
+		wlr_log_errno(L_ERROR, "Failed to set keyboard mode");
+		goto error;
+	}
+
+	if (ioctl(fd, KDSETMODE, KD_GRAPHICS)) {
+		wlr_log_errno(L_ERROR, "Failed to set graphics mode on tty");
+		goto error;
+	}
+
+	struct vt_mode mode = {
+		.mode = VT_PROCESS,
+		.relsig = SIGUSR1,
+		.acqsig = SIGUSR1,
+	};
+
+	if (ioctl(fd, VT_SETMODE, &mode) < 0) {
+		wlr_log(L_ERROR, "Failed to take control of tty");
+		goto error;
+	}
+
+	struct wl_event_loop *loop = wl_display_get_event_loop(display);
+	session->vt_source = wl_event_loop_add_signal(loop, SIGUSR1,
+		vt_handler, session);
+	if (!session->vt_source) {
+		goto error;
+	}
+
+	session->base.vtnr = tty;
+	session->tty_fd = fd;
+	session->old_kbmode = old_kbmode;
+
+	return true;
+
+error:
+	close(fd);
+	return false;
+}
+
+static struct wlr_session *direct_session_start(struct wl_display *disp) {
+	struct direct_session *session = calloc(1, sizeof(*session));
+	if (!session) {
+		wlr_log_errno(L_ERROR, "Allocation failed");
+		return NULL;
+	}
+
+	session->sock = direct_ipc_start(&session->child);
+	if (session->sock == -1) {
+		goto error_session;
+	}
+
+	if (!setup_tty(session, disp)) {
+		goto error_ipc;
+	}
+
+	// XXX: Is it okay to trust the environment like this?
+	const char *seat = getenv("XDG_SEAT");
+	if (!seat) {
+		seat = "seat0";
+	}
+
+	wlr_log(L_INFO, "Successfully loaded direct session");
+
+	snprintf(session->base.seat, sizeof(session->base.seat), "%s", seat);
+	session->base.drm_fd = -1;
+	session->base.impl = &session_direct;
+	session->base.active = true;
+	wl_signal_init(&session->base.session_signal);
+	return &session->base;
+
+error_ipc:
+	direct_ipc_finish(session->sock, session->child);
+	close(session->sock);
+error_session:
+	free(session);
+	return NULL;
+}
+
+const struct session_impl session_direct = {
+	.start = direct_session_start,
+	.finish = direct_session_finish,
+	.open = direct_session_open,
+	.close = direct_session_close,
+	.change_vt = direct_change_vt,
+};