+ sprintf(path, "/dev/tty%u", s->vtnr);
+ s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
+ if (s->vtfd < 0) {
+ log_error("cannot open VT %s of session %s: %m", path, s->id);
+ return -1;
+ }
+
+ return s->vtfd;
+}
+
+static int session_vt_fn(sd_event_source *source, const struct signalfd_siginfo *si, void *data) {
+ Session *s = data;
+
+ if (s->vtfd >= 0)
+ ioctl(s->vtfd, VT_RELDISP, 1);
+
+ return 0;
+}
+
+void session_mute_vt(Session *s) {
+ int vt, r;
+ struct vt_mode mode = { 0 };
+ sigset_t mask;
+
+ vt = session_open_vt(s);
+ if (vt < 0)
+ return;
+
+ r = ioctl(vt, KDSKBMODE, K_OFF);
+ if (r < 0)
+ goto error;
+
+ r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
+ if (r < 0)
+ goto error;
+
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGUSR1);
+ sigprocmask(SIG_BLOCK, &mask, NULL);
+
+ r = sd_event_add_signal(s->manager->event, &s->vt_source, SIGUSR1, session_vt_fn, s);
+ if (r < 0)
+ goto error;
+
+ /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
+ * So we need a dummy handler here which just acknowledges *all* VT
+ * switch requests. */
+ mode.mode = VT_PROCESS;
+ mode.relsig = SIGUSR1;
+ mode.acqsig = SIGUSR1;
+ r = ioctl(vt, VT_SETMODE, &mode);
+ if (r < 0)
+ goto error;
+
+ return;
+
+error:
+ log_error("cannot mute VT %u for session %s (%d/%d)", s->vtnr, s->id, r, errno);
+ session_restore_vt(s);
+}
+
+void session_restore_vt(Session *s) {
+ _cleanup_free_ char *utf8 = NULL;
+ int vt, kb = K_XLATE;
+ struct vt_mode mode = { 0 };
+
+ vt = session_open_vt(s);
+ if (vt < 0)
+ return;
+
+ s->vt_source = sd_event_source_unref(s->vt_source);
+
+ ioctl(vt, KDSETMODE, KD_TEXT);