+
+#ifdef HAVE_XHPDISABLERESET
+/* This function enables and disables the C-Sh-Reset hot-key, which
+ normally resets the X server (logging out the logged-in user.)
+ We don't want random people to be able to do that while the
+ screen is locked.
+ */
+static void
+hp_lock_reset (saver_info *si, Bool lock_p)
+{
+ static Bool hp_locked_p = False;
+
+ /* Calls to XHPDisableReset and XHPEnableReset must be balanced,
+ or BadAccess errors occur. (It's ok for this to be global,
+ since it affects the whole machine, not just the current screen.)
+ */
+ if (hp_locked_p == lock_p)
+ return;
+
+ if (lock_p)
+ XHPDisableReset (si->dpy);
+ else
+ XHPEnableReset (si->dpy);
+ hp_locked_p = lock_p;
+}
+#endif /* HAVE_XHPDISABLERESET */
+
+
+\f
+/* This function enables and disables the C-Sh-F1 ... F12 hot-keys,
+ which, on Linux systems, switches to another virtual console.
+ We'd like the whole screen/keyboard to be locked, not just one
+ virtual console, so this function disables that while the X
+ screen is locked.
+
+ Unfortunately, this doesn't work -- this ioctl only works when
+ called by root, and we have disavowed our privileges long ago.
+ */
+#ifdef HAVE_VT_LOCKSWITCH
+static void
+linux_lock_vt_switch (saver_info *si, Bool lock_p)
+{
+ saver_preferences *p = &si->prefs;
+ static Bool vt_locked_p = False;
+ const char *dev_console = "/dev/console";
+ int fd;
+
+ if (lock_p == vt_locked_p)
+ return;
+
+ if (lock_p && !p->lock_vt_p)
+ return;
+
+ fd = open (dev_console, O_RDWR);
+ if (fd < 0)
+ {
+ char buf [255];
+ sprintf (buf, "%s: couldn't %s VTs: %s", blurb(),
+ (lock_p ? "lock" : "unlock"),
+ dev_console);
+#if 1 /* #### doesn't work yet, so don't bother complaining */
+ perror (buf);
+#endif
+ return;
+ }
+
+ if (ioctl (fd, (lock_p ? VT_LOCKSWITCH : VT_UNLOCKSWITCH)) == 0)
+ {
+ vt_locked_p = lock_p;
+
+ if (p->verbose_p)
+ fprintf (stderr, "%s: %s VTs\n", blurb(),
+ (lock_p ? "locked" : "unlocked"));
+ }
+ else
+ {
+ char buf [255];
+ sprintf (buf, "%s: couldn't %s VTs: ioctl", blurb(),
+ (lock_p ? "lock" : "unlock"));
+#if 0 /* #### doesn't work yet, so don't bother complaining */
+ perror (buf);
+#endif
+ }
+
+ close (fd);
+}
+#endif /* HAVE_VT_LOCKSWITCH */
+
+\f
+/* This function enables and disables the C-Alt-Plus and C-Alt-Minus
+ hot-keys, which normally change the resolution of the X server.
+ We don't want people to be able to switch the server resolution
+ while the screen is locked, because if they switch to a higher
+ resolution, it could cause part of the underlying desktop to become
+ exposed.
+ */
+#ifdef HAVE_XF86VMODE
+
+static int ignore_all_errors_ehandler (Display *dpy, XErrorEvent *error);
+static Bool vp_got_error = False;
+
+static void
+xfree_lock_mode_switch (saver_info *si, Bool lock_p)
+{
+ static Bool any_mode_locked_p = False;
+ saver_preferences *p = &si->prefs;
+ int screen;
+ int event, error;
+ Bool status;
+ XErrorHandler old_handler;
+
+ if (any_mode_locked_p == lock_p)
+ return;
+ if (!XF86VidModeQueryExtension (si->dpy, &event, &error))
+ return;
+
+ for (screen = 0; screen < si->nscreens; screen++)
+ {
+ XSync (si->dpy, False);
+ old_handler = XSetErrorHandler (ignore_all_errors_ehandler);
+ status = XF86VidModeLockModeSwitch (si->dpy, screen, lock_p);
+ XSync (si->dpy, False);
+ XSetErrorHandler (old_handler);
+ if (vp_got_error) status = False;
+
+ if (status)
+ any_mode_locked_p = lock_p;
+
+ if (!status && (p->verbose_p || !lock_p))
+ /* Only print this when verbose, or when we locked but can't unlock.
+ I tried printing this message whenever it comes up, but
+ mode-locking always fails if DontZoom is set in XF86Config. */
+ fprintf (stderr, "%s: %d: unable to %s mode switching!\n",
+ blurb(), screen, (lock_p ? "lock" : "unlock"));
+ else if (p->verbose_p)
+ fprintf (stderr, "%s: %d: %s mode switching.\n",
+ blurb(), screen, (lock_p ? "locked" : "unlocked"));
+ }
+}
+
+static int
+ignore_all_errors_ehandler (Display *dpy, XErrorEvent *error)
+{
+ vp_got_error = True;
+ return 0;
+}
+
+#endif /* HAVE_XF86VMODE */
+
+\f
+/* If the viewport has been scrolled since the screen was blanked,
+ then scroll it back to where it belongs. This function only exists
+ to patch over a very brief race condition.
+ */
+static void
+undo_vp_motion (saver_info *si)
+{
+#ifdef HAVE_XF86VMODE
+ saver_preferences *p = &si->prefs;
+ int screen;
+ int event, error;
+
+ if (!XF86VidModeQueryExtension (si->dpy, &event, &error))
+ return;
+
+ for (screen = 0; screen < si->nscreens; screen++)
+ {
+ saver_screen_info *ssi = &si->screens[screen];
+ int x, y;
+ Bool status;
+
+ if (ssi->blank_vp_x == -1 && ssi->blank_vp_y == -1)
+ break;
+ if (!XF86VidModeGetViewPort (si->dpy, screen, &x, &y))
+ return;
+ if (ssi->blank_vp_x == x && ssi->blank_vp_y == y)
+ return;
+
+ /* We're going to move the viewport. The mouse has just been grabbed on
+ (and constrained to, thus warped to) the password window, so it is no
+ longer near the edge of the screen. However, wait a bit anyway, just
+ to make sure the server drains its last motion event, so that the
+ screen doesn't continue to scroll after we've reset the viewport.
+ */
+ XSync (si->dpy, False);
+ usleep (250000); /* 1/4 second */
+ XSync (si->dpy, False);
+
+ status = XF86VidModeSetViewPort (si->dpy, screen,
+ ssi->blank_vp_x, ssi->blank_vp_y);
+
+ if (!status)
+ fprintf (stderr,
+ "%s: %d: unable to move vp from (%d,%d) back to (%d,%d)!\n",
+ blurb(), screen, x, y, ssi->blank_vp_x, ssi->blank_vp_y);
+ else if (p->verbose_p)
+ fprintf (stderr,
+ "%s: %d: vp moved to (%d,%d); moved it back to (%d,%d).\n",
+ blurb(), screen, x, y, ssi->blank_vp_x, ssi->blank_vp_y);
+ }
+#endif /* HAVE_XF86VMODE */
+}
+
+