dbus: verify object path of incoming signals

dbus/object_proxy.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "dbus/bus.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
@@ skipping 286 matching lines @@
     // We should add the filter only once. Otherwise, HandleMessage() will
     // be called more than once.
     if (!filter_added_) {
       if (bus_->AddFilterFunction(&ObjectProxy::HandleMessageThunk, this)) {
         filter_added_ = true;
       } else {
         LOG(ERROR) << "Failed to add filter function";
       }
     }
     // Add a match rule so the signal goes through HandleMessage().
-    //
-    // We don't restrict the sender object path to be |object_path_| here,
-    // to make it easy to test D-Bus signal handling with dbus-send, that
-    // uses "/" as the sender object path. We can make the object path
-    // restriction customizable when it becomes necessary.
     const std::string match_rule =
-        base::StringPrintf("type='signal', interface='%s'",
-                           interface_name.c_str());
+        base::StringPrintf("type='signal', interface='%s', path='%s'",
+                           interface_name.c_str(),
+                           object_path_.value().c_str());
 
     // Add the match rule if we don't have it.
     if (match_rules_.find(match_rule) == match_rules_.end()) {
       ScopedDBusError error;
       bus_->AddMatch(match_rule, error.get());;
       if (error.is_set()) {
         LOG(ERROR) << "Failed to add match rule: " << match_rule;
       } else {
         // Store the match rule, so that we can remove this in Detach().
         match_rules_.insert(match_rule);
@@ skipping 34 matching lines @@
   bus_->AssertOnDBusThread();
   if (dbus_message_get_type(raw_message) != DBUS_MESSAGE_TYPE_SIGNAL)
     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 
   // raw_message will be unrefed on exit of the function. Increment the
   // reference so we can use it in Signal.
   dbus_message_ref(raw_message);
   scoped_ptr<Signal> signal(
       Signal::FromRawMessage(raw_message));
 
+  // Verify the signal comes from the object we're proxying for, this is
+  // our last chance to return DBUS_HANDLER_RESULT_NOT_YET_HANDLED and
+  // allow other object proxies to handle instead.
+  const dbus::ObjectPath path = signal->GetPath();
+  if (path != object_path_) {
+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+  }
+
   const std::string interface = signal->GetInterface();
   const std::string member = signal->GetMember();
 
   // Check if we know about the signal.
   const std::string absolute_signal_name = GetAbsoluteSignalName(
       interface, member);
   MethodTable::const_iterator iter = method_table_.find(absolute_signal_name);
   if (iter == method_table_.end()) {
     // Don't know about the signal.
     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
@@ skipping 46 matching lines @@
 void ObjectProxy::LogMethodCallFailure(
     const base::StringPiece& error_name,
     const base::StringPiece& error_message) const {
   if (ignore_service_unknown_errors_ && error_name == kErrorServiceUnknown)
     return;
   LOG(ERROR) << "Failed to call method: " << error_name
              << ": " << error_message;
 }
 
 }  // namespace dbus