QUIC - Some sketching of the crypto handshake.

net/quic/crypto/crypto_framer.cc

 // Copyright (c) 2012 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 "net/quic/crypto/crypto_framer.h"
 
 #include "net/quic/quic_data_reader.h"
 #include "net/quic/quic_data_writer.h"
 #include "net/quic/quic_protocol.h"
 
 using base::StringPiece;
 
 namespace net {
 
 namespace {
 
 const size_t kCryptoTagSize = sizeof(uint32);
 const size_t kNumEntriesSize = sizeof(uint16);
 const size_t kValueLenSize = sizeof(uint16);
 
+// OneShotVisitor is a framer visitor that records a single handshake message.
+class OneShotVisitor : public CryptoFramerVisitorInterface {
+ public:
+  explicit OneShotVisitor(CryptoHandshakeMessage* out)
+      : out_(out),
+        error_(false) {
+  }
+
+  void OnError(CryptoFramer* framer) {
+    error_ = true;
+  }
+
+  void OnHandshakeMessage(const CryptoHandshakeMessage& message) {
+    *out_ = message;
+  }
+
+  bool error() const {
+    return error_;
+  }
+
+ private:
+  CryptoHandshakeMessage* const out_;
+  bool error_;
+};
+
 }  // namespace
 
 CryptoFramer::CryptoFramer()
     : visitor_(NULL),
       message_tag_(0),
       num_entries_(0),
       values_len_(0) {
   Clear();
 }
 
 CryptoFramer::~CryptoFramer() {}
 
+// static
+CryptoHandshakeMessage* CryptoFramer::ParseMessage(StringPiece in) {
+  scoped_ptr<CryptoHandshakeMessage> msg(new CryptoHandshakeMessage);
+  OneShotVisitor visitor(msg.get());
+  CryptoFramer framer;
+
+  framer.set_visitor(&visitor);
+  if (!framer.ProcessInput(in) ||
+      visitor.error() ||
+      framer.InputBytesRemaining()) {
+    return NULL;
+  }
+
+  return msg.release();
+}
+
 bool CryptoFramer::ProcessInput(StringPiece input) {
   DCHECK_EQ(QUIC_NO_ERROR, error_);
   if (error_ != QUIC_NO_ERROR) {
     return false;
   }
   // Add this data to the buffer.
   buffer_.append(input.data(), input.length());
   QuicDataReader reader(buffer_.data(), buffer_.length());
 
   switch (state_) {
@@ skipping 69 matching lines @@
       visitor_->OnHandshakeMessage(message);
       Clear();
       state_ = STATE_READING_TAG;
       break;
   }
   // Save any remaining data.
   buffer_ = reader.PeekRemainingPayload().as_string();
   return true;
 }
 
+// static
 QuicData* CryptoFramer::ConstructHandshakeMessage(
     const CryptoHandshakeMessage& message) {
   if (message.tag_value_map.size() > kMaxEntries) {
     return NULL;
   }
   size_t len = sizeof(uint32);  // message tag
   len += sizeof(uint16);  // number of map entries
   CryptoTagValueMap::const_iterator it = message.tag_value_map.begin();
   while (it != message.tag_value_map.end()) {
     len += sizeof(uint32);  // tag
@@ skipping 50 matching lines @@
 
 void CryptoFramer::Clear() {
   tag_value_map_.clear();
   tag_length_map_.clear();
   tags_.clear();
   error_ = QUIC_NO_ERROR;
   state_ = STATE_READING_TAG;
 }
 
 }  // namespace net