ipc: Update Message::FindNext to parse brokered attachments.

tools/ipc_fuzzer/message_lib/message_file_reader.cc

 // Copyright 2013 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 <limits.h>
 
 #include "base/files/file_path.h"
 #include "base/files/memory_mapped_file.h"
 #include "base/logging.h"
 #include "base/strings/string_piece.h"
@@ skipping 90 matching lines @@
   }
   const char* data = reinterpret_cast<const char*>(mapped_file_.data());
   file_data_.set(data, mapped_file_.length());
   return true;
 }
 
 bool Reader::ReadMessages() {
   for (size_t i = 0; i < header_->message_count; ++i) {
     const char* begin = file_data_.begin();
     const char* end = file_data_.end();
-    const char* message_tail = IPC::Message::FindNext(begin, end);
-    if (!message_tail) {
+    IPC::Message::NextMessageInfo info = IPC::Message::FindNext(begin, end);

[Tom Sepez, 2015/09/01 18:01:54]

nit: the assignment may not be cheap; a copy of the entire attachment vector
will take place.

[erikchen, 2015/09/04 02:13:39]

I changed the signature of FindNext to take a NextMessageInfo* as an output
parameter.

+    if (!info.message_found) {
       LOG(ERROR) << "Failed to parse message.";
       return false;
     }
 
-    size_t msglen = message_tail - begin;
+    CHECK_EQ(info.message_end, info.pickle_end);
+    size_t msglen = info.message_end - begin;
     if (msglen > INT_MAX) {
       LOG(ERROR) << "Message too large.";
       return false;
     }
 
     // Copy is necessary to fix message type later.
     IPC::Message const_message(begin, msglen);
     IPC::Message* message = new IPC::Message(const_message);
     messages_->push_back(message);
     file_data_.remove_prefix(msglen);
@@ skipping 93 matching lines @@
 }
 
 }  // namespace
 
 bool MessageFile::Read(const base::FilePath& path, MessageVector* messages) {
   Reader reader(path);
   return reader.Read(messages);
 }
 
 }  // namespace ipc_fuzzer