uterm: vt: handle VT switches without kernel input

We now set KBMODE to K_OFF so we are totally independent of kernel input.
Instead, we handle VT switches with uterm-input now. This also allows us
to have full control of which keyboard input is parsed by us and which is
parsed by the kernel.

We still need to set a flag for uterm-input events that they were handled
to avoid having the TSM layer handle these events again.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/uterm_vt.c b/src/uterm_vt.c
index 6509578..9f31e31 100644 (file)
--- a/src/uterm_vt.c
+++ b/src/uterm_vt.c
@@ -66,6 +66,7 @@ struct uterm_vt {
        int real_fd;
        int real_num;
        int real_saved_num;
+       int real_kbmode;
        struct termios real_saved_attribs;
        struct ev_fd *real_efd;
 };
@@ -322,6 +323,20 @@ static int real_open(struct uterm_vt *vt, const char *vt_for_seat0)
                goto err_text;
        }
 
+       ret = ioctl(vt->real_fd, KDGKBMODE, &vt->real_kbmode);
+       if (ret) {
+               log_error("cannot retrieve VT KBMODE (%d): %m", errno);
+               ret = -EFAULT;
+               goto err_setmode;
+       }
+
+       ret = ioctl(vt->real_fd, KDSKBMODE, K_OFF);
+       if (ret) {
+               log_error("cannot set VT KBMODE to K_OFF (%d): %m", errno);
+               ret = -EFAULT;
+               goto err_setmode;
+       }
+
        sigemptyset(&mask);
        sigaddset(&mask, SIGUSR1);
        sigaddset(&mask, SIGUSR2);
@@ -331,6 +346,13 @@ static int real_open(struct uterm_vt *vt, const char *vt_for_seat0)
 
        return 0;
 
+err_setmode:
+       memset(&mode, 0, sizeof(mode));
+       mode.mode = VT_AUTO;
+       ret = ioctl(vt->real_fd, VT_SETMODE, &mode);
+       if (ret)
+               log_warning("cannot reset VT %d to VT_AUTO mode (%d): %m",
+                           vt->real_num, errno);
 err_text:
        ret = ioctl(vt->real_fd, KDSETMODE, KD_TEXT);
        if (ret)
@@ -356,6 +378,11 @@ static void real_close(struct uterm_vt *vt)
 
        log_debug("closing VT %d", vt->real_num);
 
+       ret = ioctl(vt->real_fd, KDSKBMODE, vt->real_kbmode);
+       if (ret)
+               log_error("cannot reset VT KBMODE to %d (%d): %m",
+                         vt->real_kbmode, errno);
+
        memset(&mode, 0, sizeof(mode));
        mode.mode = VT_AUTO;
        ret = ioctl(vt->real_fd, VT_SETMODE, &mode);
@@ -456,6 +483,52 @@ static int real_deactivate(struct uterm_vt *vt)
        return -EINPROGRESS;
 }
 
+static void real_input(struct uterm_vt *vt, struct uterm_input_event *ev)
+{
+       int id;
+       struct vt_stat vts;
+       int ret;
+
+       ret = ioctl(vt->real_fd, VT_GETSTATE, &vts);
+       if (ret) {
+               log_warn("cannot find current VT (%d): %m", errno);
+               return;
+       }
+
+       if (vts.v_active != vt->real_num)
+               return;
+
+       id = 0;
+       if (SHL_HAS_BITS(ev->mods, SHL_CONTROL_MASK | SHL_ALT_MASK) &&
+           ev->keysym >= XKB_KEY_F1 && ev->keysym <= XKB_KEY_F12) {
+               id = ev->keysym - XKB_KEY_F1 + 1;
+               if (id == vt->real_num)
+                       return;
+       } else if (ev->keysym >= XKB_KEY_XF86Switch_VT_1 &&
+                  ev->keysym <= XKB_KEY_XF86Switch_VT_12) {
+               id = ev->keysym - XKB_KEY_XF86Switch_VT_1 + 1;
+               if (id == vt->real_num)
+                       return;
+       }
+
+       if (!id)
+               return;
+
+       if (!vt->active)
+               log_warning("leaving VT %d even though it's not active",
+                           vt->real_num);
+
+       log_debug("deactivating VT %d to %d due to user input", vt->real_num,
+                 id);
+
+       ret = ioctl(vt->real_fd, VT_ACTIVATE, id);
+       if (ret) {
+               log_warn("cannot leave VT %d to %d (%d): %m", vt->real_num,
+                        id, errno);
+               return;
+       }
+}
+
 /*
  * Fake VT:
  * For systems without CONFIG_VT or for all seats that have no real VTs (which
@@ -535,7 +608,9 @@ static void vt_input(struct uterm_input *input,
 {
        struct uterm_vt *vt = data;
 
-       if (vt->mode == UTERM_VT_FAKE)
+       if (vt->mode == UTERM_VT_REAL)
+               real_input(vt, ev);
+       else if (vt->mode == UTERM_VT_FAKE)
                fake_input(vt, ev);
 }