Add the multicast DNS message format.
This CL adds the utilities to generate and parse mDNS messages (RFC 1035
and RFC 6762).
TBR=phoglund@webrtc.org
Bug: webrtc:9605
Change-Id: Id6121c17926887cd3a41a2dfc829462fd15f3a4c
Reviewed-on: https://webrtc-review.googlesource.com/93241
Commit-Queue: Qingsi Wang <qingsi@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Qingsi Wang <qingsi@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Alex Loiko <aleloi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24505}diff --git a/rtc_base/message_buffer_reader.h b/rtc_base/message_buffer_reader.h
new file mode 100644
index 0000000..baba89e
--- /dev/null
+++ b/rtc_base/message_buffer_reader.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef RTC_BASE_MESSAGE_BUFFER_READER_H_
+#define RTC_BASE_MESSAGE_BUFFER_READER_H_
+
+#include "rtc_base/bytebuffer.h"
+
+namespace webrtc {
+
+// A simple subclass of the ByteBufferReader that exposes the starting address
+// of the message and its length, so that we can recall previously parsed data.
+class MessageBufferReader : public rtc::ByteBufferReader {
+ public:
+ MessageBufferReader(const char* bytes, size_t len)
+ : rtc::ByteBufferReader(bytes, len) {}
+ ~MessageBufferReader() = default;
+
+ // Starting address of the message.
+ const char* MessageData() const { return bytes_; }
+ // Total length of the message. Note that this is different from Length(),
+ // which is the length of the remaining message from the current offset.
+ size_t MessageLength() const { return size_; }
+ // Current offset in the message.
+ size_t CurrentOffset() const { return start_; }
+};
+
+} // namespace webrtc
+
+#endif // RTC_BASE_MESSAGE_BUFFER_READER_H_