8 files changed, 32 insertions(+), 1 deletions(-)

M examples/simpletest/main.c
M include/backend.h
M include/libseat.h
M include/protocol.h
M libseat/backend/logind.c
M libseat/backend/seatd.c
M libseat/libseat.c
M seatd/client.c

@@ 45,7 45,8 @@ int main(int argc, char *argv[]) {
 		fprintf(stderr, "waiting for activation...\n");
 		libseat_dispatch(backend, -1);
 	}
-	fprintf(stderr, "active!\n");
+	fprintf(stderr, "active! seat name: %s, session id: %d\n", libseat_seat_name(backend),
+		libseat_session(backend));
 
 	int fd, device;
 	device = libseat_open_device(backend, file, &fd);

@@ 20,6 20,7 @@ struct seat_impl {
 	int (*disable_seat)(struct libseat *seat);
 	int (*close_seat)(struct libseat *seat);
 	const char *(*seat_name)(struct libseat *seat);
+	int (*session)(struct libseat *seat);
 
 	int (*open_device)(struct libseat *seat, const char *path, int *fd);
 	int (*close_device)(struct libseat *seat, int device_id);

@@ 103,6 103,12 @@ int libseat_close_device(struct libseat *seat, int device_id);
 const char *libseat_seat_name(struct libseat *seat);
 
 /*
+ * Retrieves the session ID of the seat that is currently made available
+ * through the provided libseat instance.
+ */
+int libseat_session(struct libseat *seat);
+
+/*
  * Requests that the seat switches session to the specified session number.
  * For seats that are VT-bound, the session number matches the VT number, and
  * switching session results in a VT switch.

@@ 50,6 50,7 @@ struct proto_client_switch_session {
 };
 
 struct proto_server_seat_opened {
+	int session;
 	uint16_t seat_name_len;
 	// NULL-terminated byte-sequence seat_name_len long follows
 };

@@ 245,6 245,12 @@ static const char *seat_name(struct libseat *base) {
 	return backend->seat;
 }
 
+static int session(struct libseat *base) {
+	(void)base;
+	errno = ENOSYS;
+	return -1;
+}
+
 static struct backend_logind *backend_logind_from_libseat_backend(struct libseat *base) {
 	assert(base->impl == &logind_impl);
 	return (struct backend_logind *)base;


@@ 682,6 688,7 @@ const struct seat_impl logind_impl = {
 	.open_seat = logind_open_seat,
 	.disable_seat = disable_seat,
 	.close_seat = close_seat,
+	.session = session,
 	.seat_name = seat_name,
 	.open_device = open_device,
 	.close_device = close_device,

@@ 38,6 38,7 @@ struct backend_seatd {
 	struct linked_list pending_events;
 	bool error;
 
+	int session;
 	char seat_name[MAX_SEAT_LEN];
 };
 


@@ 386,6 387,7 @@ static struct libseat *_open_seat(struct libseat_seat_listener *listener, void *
 	if (size == SIZE_MAX || conn_get(backend, &rmsg, sizeof rmsg) == -1) {
 		goto backend_error;
 	}
+	backend->session = rmsg.session;
 	if (rmsg.seat_name_len != size - sizeof rmsg) {
 		log_errorf("Invalid message: seat_name_len does not match remaining message size (%d != %zd)",
 			   rmsg.seat_name_len, size);


@@ 445,6 447,11 @@ static const char *seat_name(struct libseat *base) {
 	return backend->seat_name;
 }
 
+static int session(struct libseat *base) {
+	struct backend_seatd *backend = backend_seatd_from_libseat_backend(base);
+	return backend->session;
+}
+
 static int open_device(struct libseat *base, const char *path, int *fd) {
 	struct backend_seatd *backend = backend_seatd_from_libseat_backend(base);
 	if (backend->error) {


@@ 565,6 572,7 @@ const struct seat_impl seatd_impl = {
 	.open_seat = open_seat,
 	.disable_seat = disable_seat,
 	.close_seat = close_seat,
+	.session = session,
 	.seat_name = seat_name,
 	.open_device = open_device,
 	.close_device = close_device,


@@ 650,6 658,7 @@ const struct seat_impl builtin_impl = {
 	.open_seat = builtin_open_seat,
 	.disable_seat = disable_seat,
 	.close_seat = close_seat,
+	.session = session,
 	.seat_name = seat_name,
 	.open_device = open_device,
 	.close_device = close_device,

@@ 90,6 90,11 @@ const char *libseat_seat_name(struct libseat *seat) {
 	return seat->impl->seat_name(seat);
 }
 
+int libseat_session(struct libseat *seat) {
+	assert(seat && seat->impl);
+	return seat->impl->session(seat);
+}
+
 int libseat_open_device(struct libseat *seat, const char *path, int *fd) {
 	assert(seat && seat->impl);
 	return seat->impl->open_device(seat, path, fd);

@@ 142,6 142,7 @@ static int handle_open_seat(struct client *client, char *seat_name) {
 	size_t seat_name_len = strlen(seat_name);
 
 	struct proto_server_seat_opened rmsg = {
+		.session = client->session,
 		.seat_name_len = (uint16_t)seat_name_len,
 	};
 	struct proto_header header = {