Console user security policy

* bus/config-parser.c:
(struct PolicyType): Add POLICY_CONSOLE
(struct Element.d.policy): s/gid_or_uid/gid_uid_or_at_console
(start_busconfig_child): Sets up console element when
<policy at_console=""> is encountered in a policy file
(append_rule_from_element): Convert console elements to console
rules.

* bus/policy.c:
(bus_policy_create_client_policy): Add console rules to the client
policy based on if the client is at the console
(bus_policy_append_console_rule): New function for adding a
console rule to a policy
(bus_policy_merge): Handle console rule merging

* dbus/dbus-sysdeps.h: Added the DBUS_CONSOLE_DIR constant
where we check for console user files

* dbus/dbus-sysdeps.c:
(_dbus_file_exists): New function which checks if the given
file exists
(_dbus_user_at_console): New function which does the system
specific process of checking if the user is at the console

* dbus/dbus-userdb.c:
(_dbus_is_console_user): New function converts a UID to user name
and then calls the system specific _dbus_user_at_console to
see if the user is at the console and therefor a console user

1 files changed, 49 insertions, 0 deletions

diff --git a/dbus/dbus-sysdeps.c b/dbus/dbus-sysdeps.c
index e5d4bdba..4af70931 100644
--- a/dbus/dbus-sysdeps.c
+++ b/dbus/dbus-sysdeps.c
@@ -3332,6 +3332,55 @@ _dbus_set_signal_handler (int               sig,
   sigaction (sig,  &act, 0);
 }
 
+/** Checks if a file exists
+*
+* @param file full path to the file
+* @returns #TRUE if file exists
+*/
+dbus_bool_t 
+_dbus_file_exists (const char *file)
+{
+  return (access (file, F_OK) == 0);
+}
+
+/** Checks if user is at the console
+*
+* @param username user to check
+* @param error return location for errors
+* @returns #TRUE is the user is at the consolei and there are no errors
+*/
+dbus_bool_t 
+_dbus_user_at_console (const char *username,
+                       DBusError  *error)
+{
+
+  DBusString f;
+  dbus_bool_t result;
+
+  if (!_dbus_string_init (&f))
+    {
+      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+      return FALSE;
+    }
+
+  if (!_dbus_string_append (&f, DBUS_CONSOLE_DIR))
+    {
+      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+      return FALSE;
+    }
+
+
+  if (!_dbus_string_append (&f, username))
+    {
+      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+      return FALSE;
+    }
+
+  result = _dbus_file_exists (_dbus_string_get_const_data (&f));
+  _dbus_string_free (&f);
+
+  return result;
+}
 
 #ifdef DBUS_BUILD_TESTS
 #include <stdlib.h>