commit 558b93b3e9a176a737ffea9de069eaa3184e5d2f
author Qingsi Wang <qingsi@google.com> Thu Aug 30 17:38:44 2018
committer Commit Bot <commit-bot@chromium.org> Fri Aug 31 00:02:44 2018
tree 0bb79c2a34c38c9e148fcc778562b83c69a09b7d
parent cc22f51988e293d44b3f43dcbfca6b613c180631

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}

rtc_base/BUILD.gn

diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 7a03b3b..2ef79fa 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -413,6 +413,7 @@
     "ignore_wundef.h",
     "location.cc",
     "location.h",
+    "message_buffer_reader.h",
     "numerics/histogram_percentile_counter.cc",
     "numerics/histogram_percentile_counter.h",
     "numerics/mod_ops.h",

rtc_base/bytebuffer.h

diff --git a/rtc_base/bytebuffer.h b/rtc_base/bytebuffer.h
index 9036bcd..9e08f02 100644
--- a/rtc_base/bytebuffer.h
+++ b/rtc_base/bytebuffer.h
@@ -185,7 +185,7 @@
   // after this call.
   bool Consume(size_t size);
 
- private:
+ protected:
   void Construct(const char* bytes, size_t size);
 
   const char* bytes_;
@@ -193,6 +193,7 @@
   size_t start_;
   size_t end_;
 
+ private:
   RTC_DISALLOW_COPY_AND_ASSIGN(ByteBufferReader);
 };
 

rtc_base/message_buffer_reader.h

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_