From 0fb626ef53c5d2e5138092d2388587f6b907b6f7 Mon Sep 17 00:00:00 2001
From: Cosimo Alfarano <cosimo.alfarano@collabora.co.uk>
Date: Tue, 12 Jul 2011 17:40:34 +0100
Subject: [PATCH 1/3] Add eavesdrop=true when supported

Bug https://bugs.freedesktop.org/show_bug.cgi?id=39140
---
 bustle-dbus-monitor.c |   91 +++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 80 insertions(+), 11 deletions(-)

diff --git a/bustle-dbus-monitor.c b/bustle-dbus-monitor.c
index 0ebaded..3b9326d 100644
--- a/bustle-dbus-monitor.c
+++ b/bustle-dbus-monitor.c
@@ -67,6 +67,15 @@ gettimeofday (struct timeval *__p,
 #define PROFILE_TIMED_FORMAT "%s\t%lu\t%lu"
 #define TRAP_NULL_STRING(str) ((str) ? (str) : "<none>")
 
+#define EAVESDROPPING_RULE "eavesdrop=true"
+
+inline static void
+oom (const char *doing)
+{
+    fprintf (stderr, "OOM while %s\n", doing);
+      exit (1);
+}
+
 static void
 print_name_owner_changed (struct timeval *t,
     const char *name,
@@ -315,6 +324,7 @@ main (int argc, char *argv[])
   DBusError error = DBUS_ERROR_INIT;
   DBusBusType type = DBUS_BUS_SESSION;
   DBusHandleMessageFunction filter_func = profile_filter_func;
+  dbus_bool_t supports_eavesdrop_keyword = TRUE;
 
   int i = 0, j = 0, numFilters = 0;
   char **filters = NULL;
@@ -357,41 +367,100 @@ main (int argc, char *argv[])
 
   get_well_known_names (connection);
 
+  /* check support for eavesdrop=true in filter */
+  dbus_bus_add_match (connection, EAVESDROPPING_RULE, &error);
+  if (dbus_error_is_set (&error) &&
+      strcmp (error.name, DBUS_ERROR_MATCH_RULE_INVALID) == 0)
+    {
+      /* make it re-usable */
+      dbus_error_free (&error);
+      dbus_error_init (&error);
+
+      /* using a dbus version witout this feature, too bad, but still OK */
+      supports_eavesdrop_keyword = FALSE;
+    }
+  else if (dbus_error_is_set (&error)) /* but not RULE_INVALID */
+    {
+      fprintf (stderr, "Failed to set rule \"%s\": %s\n",
+          EAVESDROPPING_RULE, error.message);
+      dbus_error_free (&error);
+      exit (1);
+    }
+  else /* we support it! cleanup and go! */
+    {
+      dbus_bus_remove_match (connection, EAVESDROPPING_RULE, &error);
+      if (dbus_error_is_set (&error))
+        {
+          fprintf (stderr, "Failed to removed rule \"%s\": %s\n",
+              EAVESDROPPING_RULE, error.message);
+          dbus_error_free (&error);
+          exit (1);
+        }
+    }
+
   if (numFilters)
     {
       for (i = 0; i < j; i++)
         {
-          dbus_bus_add_match (connection, filters[i], &error);
+          char *filter = filters[i]; /* by default we use the user supplied
+                                       filter */
+
+          if (supports_eavesdrop_keyword)
+            {
+              /* prepend eavesdrop=true to the filter rule, amending the user
+               * supplied rule. User can disable it using "eavesdrop=false" */
+              unsigned int eavesdrop_filter_len;
+
+              eavesdrop_filter_len = strlen (EAVESDROPPING_RULE) + 1 + \
+                                     strlen (filters[i]) + 1;
+
+              filter = malloc (eavesdrop_filter_len * sizeof(char *));
+              if (filter == NULL)
+                oom ("creating rule with eavesdrop=true");
+
+              snprintf(filter, eavesdrop_filter_len, "%s,%s",
+                  EAVESDROPPING_RULE, filters[i]);
+            }
+
+          dbus_bus_add_match (connection, filter, &error);
           if (dbus_error_is_set (&error))
             {
               fprintf (stderr, "Failed to setup match \"%s\": %s\n",
-                       filters[i], error.message);
+                  filter, error.message);
               dbus_error_free (&error);
               exit (1);
             }
-	  free(filters[i]);
+
+          free (filters[i]);
+          if (supports_eavesdrop_keyword)
+            free (filter);
         }
     }
   else
     {
       dbus_bus_add_match (connection,
-		          "type='signal'",
-		          &error);
+          supports_eavesdrop_keyword ?
+          EAVESDROPPING_RULE ",type='signal'" : "type='signal'",
+          &error);
       if (dbus_error_is_set (&error))
         goto lose;
       dbus_bus_add_match (connection,
-		          "type='method_call'",
-		          &error);
+          supports_eavesdrop_keyword ?
+          EAVESDROPPING_RULE ",type='method_call'" : "type='method_call'",
+          &error);
       if (dbus_error_is_set (&error))
         goto lose;
       dbus_bus_add_match (connection,
-		          "type='method_return'",
-		          &error);
+          supports_eavesdrop_keyword ?
+          EAVESDROPPING_RULE ",type='method_return'" :
+          "type='method_return'",
+          &error);
       if (dbus_error_is_set (&error))
         goto lose;
       dbus_bus_add_match (connection,
-		          "type='error'",
-		          &error);
+          supports_eavesdrop_keyword ?
+          EAVESDROPPING_RULE ",type='error'" : "type='error'",
+          &error);
       if (dbus_error_is_set (&error))
         goto lose;
     }
-- 
1.7.5.4