ChildPortHandshake: allow receive rights to be received

util/mach/mach_message.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "util/mach/mach_message.h"
 
 #include <AvailabilityMacros.h>
 #include <bsm/libbsm.h>
 
 #include <limits>
 
 #include "base/logging.h"
+#include "base/mac/mach_logging.h"
 #include "util/misc/clock.h"
 #include "util/misc/implicit_cast.h"
 
 namespace crashpad {
 
 namespace {
 
 const int kNanosecondsPerMillisecond = 1E6;
 
 // TimerRunning() determines whether |deadline| has passed. If |deadline| is
@@ skipping 209 matching lines @@
                       &audit_pid,
                       nullptr,
                       nullptr);
 #else
   pid_t audit_pid = audit_token_to_pid(audit_trailer->msgh_audit);
 #endif
 
   return audit_pid;
 }
 
+bool MachMessageDestroyReceivedPort(mach_port_t port,
+                                    mach_msg_type_name_t port_right_type) {
+  // This implements a subset of 10.10.5
+  // xnu-2782.40.9/libsyscall/mach/mach_msg.c mach_msg_destroy_port() that deals
+  // only with port rights that can be received in Mach messages.
+  switch (port_right_type) {
+    case MACH_MSG_TYPE_PORT_RECEIVE: {
+      kern_return_t kr = mach_port_mod_refs(
+          mach_task_self(), port, MACH_PORT_RIGHT_RECEIVE, -1);
+      if (kr != KERN_SUCCESS) {
+        MACH_LOG(ERROR, kr) << "mach_port_mod_refs";
+        return false;
+      }
+      return true;
+    }
+
+    case MACH_MSG_TYPE_PORT_SEND:
+    case MACH_MSG_TYPE_PORT_SEND_ONCE: {
+      kern_return_t kr = mach_port_deallocate(mach_task_self(), port);
+      if (kr != KERN_SUCCESS) {
+        MACH_LOG(ERROR, kr) << "mach_port_deallocate";
+        return false;
+      }
+      return true;
+    }
+
+    default: {
+      LOG(ERROR) << "unexpected port right type " << port_right_type;
+      return false;
+    }
+  }
+}
+
 }  // namespace crashpad