Adding details to most quic connection close calls.

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 "base/strings/stringprintf.h"
 #include "net/quic/crypto/crypto_protocol.h"
 #include "net/quic/quic_data_reader.h"
 #include "net/quic/quic_data_writer.h"
 
 using base::StringPiece;
 using std::pair;
 using std::vector;
 
 namespace net {
 
@@ skipping 19 matching lines @@
   CryptoHandshakeMessage* release() { return out_.release(); }
 
  private:
   scoped_ptr<CryptoHandshakeMessage> out_;
   bool error_;
 };
 
 }  // namespace
 
 CryptoFramer::CryptoFramer()
-    : visitor_(nullptr),
-      num_entries_(0),
-      values_len_(0) {
+    : visitor_(nullptr), error_detail_(""), num_entries_(0), values_len_(0) {
   Clear();
 }
 
 CryptoFramer::~CryptoFramer() {}
 
 // static
 CryptoHandshakeMessage* CryptoFramer::ParseMessage(StringPiece in) {
   OneShotVisitor visitor;
   CryptoFramer framer;
 
   framer.set_visitor(&visitor);
   if (!framer.ProcessInput(in) || visitor.error() ||
       framer.InputBytesRemaining()) {
     return nullptr;
   }
 
   return visitor.release();
 }
 
 bool CryptoFramer::ProcessInput(StringPiece input) {
   DCHECK_EQ(QUIC_NO_ERROR, error_);
   if (error_ != QUIC_NO_ERROR) {
     return false;
   }
   error_ = Process(input);
   if (error_ != QUIC_NO_ERROR) {
+    DCHECK(!error_detail_.empty());
     visitor_->OnError(this);
     return false;
   }
 
   return true;
 }
 
 // static
 QuicData* CryptoFramer::ConstructHandshakeMessage(
     const CryptoHandshakeMessage& message) {
@@ skipping 95 matching lines @@
     }
   }
 
   return new QuicData(buffer.release(), len, true);
 }
 
 void CryptoFramer::Clear() {
   message_.Clear();
   tags_and_lengths_.clear();
   error_ = QUIC_NO_ERROR;
+  error_detail_ = "";
   state_ = STATE_READING_TAG;
 }
 
 QuicErrorCode CryptoFramer::Process(StringPiece input) {
   // Add this data to the buffer.
   buffer_.append(input.data(), input.length());
   QuicDataReader reader(buffer_.data(), buffer_.length());
 
   switch (state_) {
     case STATE_READING_TAG:
       if (reader.BytesRemaining() < kQuicTagSize) {
         break;
       }
       QuicTag message_tag;
       reader.ReadUInt32(&message_tag);
       message_.set_tag(message_tag);
       state_ = STATE_READING_NUM_ENTRIES;
     case STATE_READING_NUM_ENTRIES:
       if (reader.BytesRemaining() < kNumEntriesSize + sizeof(uint16)) {
         break;
       }
       reader.ReadUInt16(&num_entries_);
       if (num_entries_ > kMaxEntries) {
+        error_detail_ = base::StringPrintf("%u entries", num_entries_);
         return QUIC_CRYPTO_TOO_MANY_ENTRIES;
       }
       uint16 padding;
       reader.ReadUInt16(&padding);
 
       tags_and_lengths_.reserve(num_entries_);
       state_ = STATE_READING_TAGS_AND_LENGTHS;
       values_len_ = 0;
     case STATE_READING_TAGS_AND_LENGTHS: {
       if (reader.BytesRemaining() <
               num_entries_ * (kQuicTagSize + kCryptoEndOffsetSize)) {
         break;
       }
 
       uint32 last_end_offset = 0;
       for (unsigned i = 0; i < num_entries_; ++i) {
         QuicTag tag;
         reader.ReadUInt32(&tag);
         if (i > 0 && tag <= tags_and_lengths_[i-1].first) {
           if (tag == tags_and_lengths_[i-1].first) {
+            error_detail_ = base::StringPrintf("Duplicate tag:%u", tag);
             return QUIC_CRYPTO_DUPLICATE_TAG;
           }
+          error_detail_ = base::StringPrintf("Tag %u out of order", tag);
           return QUIC_CRYPTO_TAGS_OUT_OF_ORDER;
         }
 
         uint32 end_offset;
         reader.ReadUInt32(&end_offset);
 
         if (end_offset < last_end_offset) {
+          error_detail_ = base::StringPrintf("End offset: %u vs %u", end_offset,
+                                             last_end_offset);
           return QUIC_CRYPTO_TAGS_OUT_OF_ORDER;
         }
         tags_and_lengths_.push_back(std::make_pair(
             tag, static_cast<size_t>(end_offset - last_end_offset)));
         last_end_offset = end_offset;
       }
       values_len_ = last_end_offset;
       state_ = STATE_READING_VALUES;
     }
     case STATE_READING_VALUES:
@@ skipping 25 matching lines @@
   }
   *end_offset += pad_length;
   if (!writer->WriteUInt32(*end_offset)) {
     DCHECK(false) << "Failed to write end offset.";
     return false;
   }
   return true;
 }
 
 }  // namespace net