Fix for: Bug 15155994 - SUNBT4849641 xscreensaver won't run as root

Let root lock the screen, but don't launch the hacks for root.

Rejected by upstream because upstream author argues instead that users should

not login as root, which is correct, but not something we can force all of

our customers to stop doing.

See http://www.jwz.org/xscreensaver/faq.html#root-lock for his side.

---

diff --git a/driver/demo-Gtk.c b/driver/demo-Gtk.c

--- a/driver/demo-Gtk.c

+++ b/driver/demo-Gtk.c

   char *err = 0;

   int status;

+  if (getuid () == 0)

+    {

+      char buf [255];

+      strlcpy (buf, _("Can not run hacks if logged in as root!"), sizeof(buf));

+      warning_dialog (s->toplevel_widget, buf, False, 100);

+      return;

+    }

+

   if (list_elt < 0) return;

   hack_number = s->list_elt_to_hack_number[list_elt];

     GtkMenu *menu = GTK_MENU (gtk_option_menu_get_menu (opt));

     GList *kids = gtk_container_children (GTK_CONTAINER (menu));

     int i;

+

+    if (getuid () == 0)

+      {

+        /* If logged in as root disable menu so user can't activate a hack. */

+        gtk_widget_set_sensitive (GTK_WIDGET (opt), False);

+        gtk_widget_set_sensitive (GTK_WIDGET (menu), False);

+      }

+    else

+    {

     for (i = 0; kids; kids = kids->next, i++)

       {

         gtk_signal_connect (GTK_OBJECT (kids->data), "activate",

             mode_menu_order[i] == RANDOM_HACKS_SAME)

           gtk_widget_hide (GTK_WIDGET (kids->data));

       }

+    }

     if (s->nscreens <= 1)   /* recompute option-menu size */

       {

diff --git a/driver/exec.c b/driver/exec.c

--- a/driver/exec.c

+++ b/driver/exec.c

@@ -186,6 +186,7 @@ exec_command (const char *shell, const char *command, int nice_level)

   hairy_p = !!strpbrk (command, "*?$&!<>[];`'\\\"=");

   /* note: = is in the above because of the sh syntax "FOO=bar cmd". */

+#ifdef DONT_ALLOW_ROOT_LOGIN

   if (getuid() == (uid_t) 0 || geteuid() == (uid_t) 0)

     {

       /* If you're thinking of commenting this out, think again.

@@ -196,6 +197,7 @@ exec_command (const char *shell, const char *command, int nice_level)

                blurb());

       exit (-1);

     }

+#endif /*DONT_ALLOW_ROOT_LOGIN*/

   if (hairy_p)

     /* If it contains any shell metacharacters, do it the hard way,

diff --git a/driver/setuid.c b/driver/setuid.c

--- a/driver/setuid.c

+++ b/driver/setuid.c

@@ -121,6 +121,10 @@ set_ids_by_number (uid_t uid, gid_t gid, char **message_ret)

   struct passwd *p = getpwuid (uid);

   struct group  *g = getgrgid (gid);

+  /* if we are logged in as root i.e. uid==0 then dont do anything*/

+  if (getuid () == (uid_t) 0)

+   return 0;

+

   if (message_ret)

     *message_ret = 0;

@@ -278,11 +282,13 @@ hack_uid (saver_info *si)

          of the xscreensaver manual titled "LOCKING AND ROOT LOGINS",

          and "USING XDM".

    */

+#ifdef DONT_ALLOW_ROOT_LOGIN

   if (getuid() == (uid_t) 0)

     {

       si->locking_disabled_p = True;

       si->nolock_reason = "running as root";

     }

+#endif /*DONT_ALLOW_ROOT_LOGIN*/

   /* If we're running as root, switch to a safer user.  This is above and

@@ -297,6 +303,8 @@ hack_uid (saver_info *si)

          of the xscreensaver manual titled "LOCKING AND ROOT LOGINS", 

          and "USING XDM".

    */

+/* We are letting root login to fix a P1 bug, i.e. root should lock screen*/

+#ifdef DONT_ALLOW_ROOT_LOGIN

   if (getuid() == (uid_t) 0)

     {

       struct passwd *p;

@@ -315,6 +323,7 @@ hack_uid (saver_info *si)

       if (set_ids_by_number (p->pw_uid, p->pw_gid, &si->uid_message) != 0)

 	saver_exit (si, -1, 0);

     }

+#endif /*DONT_ALLOW_ROOT_LOGIN*/

   /* If there's anything even remotely funny looking about the passwd struct,

@@ -357,7 +366,10 @@ hack_uid (saver_info *si)

 		 (p && p->pw_name && *p->pw_name

 		  ? p->pw_name : "<unknown>"));

 	si->nolock_reason = buf;

+

+#ifdef DONT_ALLOW_ROOT_LOGIN

 	si->locking_disabled_p = True;

+#endif

 	si->dangerous_uid_p = True;

       }

   }

diff --git a/driver/subprocs.c b/driver/subprocs.c

--- a/driver/subprocs.c

+++ b/driver/subprocs.c

   saver_preferences *p = &si->prefs;

   char* complete_hack_command;

+  if (getuid () == 0)

+    return;  /* Dont let hacks run if logged in as root*/

+

   if (si->prefs.verbose_p)

    fprintf(stderr, "--> spawn_screenhack()\n");

diff --git a/driver/timers.c b/driver/timers.c

--- a/driver/timers.c

+++ b/driver/timers.c

       raise_window (si, True, True, False);

-      if (!si->throttled_p)

+      if (!si->throttled_p && getuid () != 0)

         for (i = 0; i < si->nscreens; i++)

           spawn_screenhack (&si->screens[i]);

       else

diff --git a/driver/xscreensaver.c b/driver/xscreensaver.c

--- a/driver/xscreensaver.c

+++ b/driver/xscreensaver.c

   describe_uids (si, stderr);

+#ifdef DONT_ALLOW_ROOT_LOGIN

   if (si->orig_uid && !strncmp (si->orig_uid, "root/", 5))

     {

       fprintf (stderr, "\n"

                blurb());

     }

   else

+#endif /*DONT_ALLOW_ROOT_LOGIN*/

     {

       fprintf (stderr, "\n"

           "%s: Errors at startup are usually authorization problems.\n"

-"              But you're not logging in as root (good!) so something\n"

-"              else must be wrong.  Did you read the manual and the FAQ?\n",

+"              Did you read the manual and the FAQ?\n",

            blurb());

     }

         kill_screenhack (&si->screens[i]);

       raise_window (si, True, True, False);

-      if (si->throttled_p)

+      if (si->throttled_p || getuid () == 0)

         fprintf (stderr, "%s: not launching hack (throttled.)\n", blurb());

       else

         for (i = 0; i < si->nscreens; i++)