Add DBus method to return the AA context of a connection

This is not intended for upstream inclusion. It implements a bus method
(GetConnectionAppArmorSecurityContext) to get a connection's AppArmor
security context but upstream D-Bus has recently added a generic way of
getting a connection's security credentials (GetConnectionCredentials).
Ubuntu should carry this patch until packages in the archive are moved
over to the new, generic method of getting a connection's credentials.

[Altered by Simon McVittie: survive non-UTF-8 contexts which
would otherwise be a local denial of service, except that Ubuntu
inherits a non-fatal warnings patch from Debian; new commit message
taken from the Ubuntu changelog; do not emit unreachable code if
AppArmor is disabled.]

1 files changed, 15 insertions, 0 deletions

diff --git a/bus/apparmor.c b/bus/apparmor.c
index 072e2edf..af76ca27 100644
--- a/bus/apparmor.c
+++ b/bus/apparmor.c
@@ -105,6 +105,21 @@ bus_apparmor_confinement_new (char       *label,
   return confinement;
 }
 
+const char*
+bus_apparmor_confinement_get_label (BusAppArmorConfinement *confinement)
+{
+#ifdef HAVE_APPARMOR
+  if (!apparmor_enabled)
+    return NULL;
+
+  _dbus_assert (confinement != NULL);
+
+  return confinement->label;
+#else
+  return NULL;
+#endif
+}
+
 void
 bus_apparmor_confinement_unref (BusAppArmorConfinement *confinement)
 {