| // 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 "remoting/host/native_messaging/native_messaging_writer.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <string> |
| #include <utility> |
| |
| #include "base/json/json_writer.h" |
| |
| namespace { |
| |
| // 4-byte type used for the message header. |
| typedef uint32_t MessageLengthType; |
| |
| // Defined as an int, for passing to APIs that take an int, to avoid |
| // signed/unsigned warnings about implicit cast. |
| const int kMessageHeaderSize = sizeof(MessageLengthType); |
| |
| // Limit the size of sent messages, since Chrome will not accept messages |
| // larger than 1MB, and this helps deal with the problem of integer overflow |
| // when passing sizes to net::FileStream APIs that take |int| parameters. |
| // This is defined as size_t (unsigned type) so it can be compared with the |
| // result of std::string::length() without compiler warnings. |
| const size_t kMaximumMessageSize = 1024 * 1024; |
| |
| } // namespace |
| |
| namespace remoting { |
| |
| NativeMessagingWriter::NativeMessagingWriter(base::File file) |
| : write_stream_(std::move(file)), fail_(false) {} |
| |
| NativeMessagingWriter::~NativeMessagingWriter() = default; |
| |
| bool NativeMessagingWriter::WriteMessage(const base::Value& message) { |
| if (fail_) { |
| LOG(ERROR) << "Stream marked as corrupt."; |
| return false; |
| } |
| |
| std::string message_json; |
| base::JSONWriter::Write(message, &message_json); |
| |
| CHECK_LE(message_json.length(), kMaximumMessageSize); |
| |
| // Cast from size_t to the proper header type. The check above ensures this |
| // won't overflow. |
| MessageLengthType message_length = |
| static_cast<MessageLengthType>(message_json.length()); |
| |
| int result = write_stream_.WriteAtCurrentPos( |
| reinterpret_cast<char*>(&message_length), kMessageHeaderSize); |
| if (result != kMessageHeaderSize) { |
| LOG(ERROR) << "Failed to send message header, write returned " << result; |
| fail_ = true; |
| return false; |
| } |
| |
| // The length check above ensures that the cast won't overflow a signed |
| // 32-bit int. |
| int message_length_as_int = message_length; |
| |
| // CHECK needed since data() is undefined on an empty std::string. |
| CHECK(!message_json.empty()); |
| result = write_stream_.WriteAtCurrentPos(message_json.data(), |
| message_length_as_int); |
| if (result != message_length_as_int) { |
| LOG(ERROR) << "Failed to send message body, write returned " << result; |
| fail_ = true; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| } // namespace remoting |