Support interactive D-Bus authorization

When invoking D-Bus methods, let the user enable interactive
authorization by passing an :authorizable t parameter.  This makes
it possible to D-Bus methods that require polkit authorization.

* configure.ac (HAVE_DBUS_MESSAGE_SET_ALLOW_INTERACTIVE_AUTHORIZATION):
Set a new variable if `dbus_message_set_allow_interactive_authorization'
is available.

* src/dbusbind.c (dbus-message-internal): Allow interactive
authorization by passing :authorizable t.

* doc/misc/dbus.texi (Synchronous Methods, Asynchronous Methods):
* etc/NEWS:
* lisp/net/dbus.el (dbus-call-method-asynchronously): Document the
new parameter.

1 files changed, 35 insertions, 6 deletions

diff --git a/src/dbusbind.c b/src/dbusbind.c
index 35ce03c7911..27b9c190793 100644
--- a/src/dbusbind.c
+++ b/src/dbusbind.c
@@ -1314,7 +1314,7 @@ The following usages are expected:
 `dbus-call-method', `dbus-call-method-asynchronously':
   (dbus-message-internal
     dbus-message-type-method-call BUS SERVICE PATH INTERFACE METHOD HANDLER
-    &optional :timeout TIMEOUT &rest ARGS)
+    &optional :timeout TIMEOUT :authorizable AUTH &rest ARGS)
 
 `dbus-send-signal':
   (dbus-message-internal
@@ -1512,12 +1512,38 @@ usage: (dbus-message-internal &rest REST)  */)
         XD_SIGNAL1 (build_string ("Unable to create an error message"));
     }
 
-  /* Check for timeout parameter.  */
-  if ((count + 2 <= nargs) && EQ (args[count], QCtimeout))
+  while ((count + 2 <= nargs))
     {
-      CHECK_FIXNAT (args[count+1]);
-      timeout = min (XFIXNAT (args[count+1]), INT_MAX);
-      count = count+2;
+      /* Check for timeout parameter.  */
+      if (EQ (args[count], QCtimeout))
+        {
+          if (mtype != DBUS_MESSAGE_TYPE_METHOD_CALL)
+            XD_SIGNAL1
+              (build_string (":timeout is only supported on method calls"));
+
+          CHECK_FIXNAT (args[count+1]);
+          timeout = min (XFIXNAT (args[count+1]), INT_MAX);
+          count = count+2;
+        }
+      /* Check for authorizable parameter.  */
+      else if (EQ (args[count], QCauthorizable))
+        {
+          if (mtype != DBUS_MESSAGE_TYPE_METHOD_CALL)
+            XD_SIGNAL1
+              (build_string (":authorizable is only supported on method calls"));
+
+          /* Ignore this keyword if unsupported.  */
+#ifdef HAVE_DBUS_MESSAGE_SET_ALLOW_INTERACTIVE_AUTHORIZATION
+          dbus_message_set_allow_interactive_authorization
+            (dmessage, NILP (args[count+1]) ? FALSE : TRUE);
+#else
+          XD_DEBUG_MESSAGE (":authorizable not supported");
+#endif
+
+          count = count+2;
+        }
+      else break;
+
     }
 
   /* Initialize parameter list of message.  */
@@ -1895,6 +1921,9 @@ syms_of_dbusbind (void)
   /* Lisp symbol for method call timeout.  */
   DEFSYM (QCtimeout, ":timeout");
 
+  /* Lisp symbol for method interactive authorization.  */
+  DEFSYM (QCauthorizable, ":authorizable");
+
   /* Lisp symbols of D-Bus types.  */
   DEFSYM (QCbyte, ":byte");
   DEFSYM (QCboolean, ":boolean");