Add QuicFramer and friends.

net/quic/quic_protocol.h

+// 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.
+
+#ifndef NET_QUIC_QUIC_PROTOCOL_H_
+#define NET_QUIC_QUIC_PROTOCOL_H_
+
+#include <limits>
+#include <utility>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/hash_tables.h"
+#include "base/logging.h"
+#include "base/string_piece.h"
+#include "net/base/net_export.h"
+#include "net/quic/uint128.h"
+
+namespace net {
+
+class QuicPacket;
+
+typedef uint64 QuicGuid;
+typedef uint32 QuicStreamId;
+typedef uint64 QuicStreamOffset;
+typedef uint64 QuicPacketSequenceNumber;
+typedef uint64 QuicTransmissionTime;
+typedef uint8 QuicFecGroupNumber;
+
+// TODO(rch): Consider Quic specific names for these constants.
+const size_t kMaxPacketSize = 1200;  // Maximum size in bytes of a QUIC packet.
+
+// Maximum number of open streams per connection.
+const size_t kDefaultMaxStreamsPerConnection = 100;
+
+// Size in bytes of the packet header common across all packets.
+const size_t kPacketHeaderSize = 25;
+// Index of the first byte in a QUIC packet of FEC protected data.
+const size_t kStartOfFecProtectedData = kPacketHeaderSize;
+// Index of the first byte in a QUIC packet of encrypted data.
+const size_t kStartOfEncryptedData = kPacketHeaderSize - 1;
+// Index of the first byte in a QUIC packet which is hashed.
+const size_t kStartOfHashData = 0;
+// Index into the retransmission offset in the header.
+// (After GUID and sequence number.)
+const int kRetransmissionOffset = 14;
+// Index into the transmission time offset in the header.
+const int kTransmissionTimeOffset = 15;
+
+// Size in bytes of all stream fragment fields.
+const size_t kMinStreamFragmentLength = 15;
+
+// Limit on the delta between stream IDs.
+const QuicStreamId kMaxStreamIdDelta = 100;
+
+// Reserved ID for the crypto stream.
+// TODO(rch): ensure that this is not usable by any other streams.
+const QuicStreamId kCryptoStreamId = 1;
+
+typedef std::pair<QuicPacketSequenceNumber, QuicPacket*> PacketPair;
+
+const int64 kDefaultTimeout = 600000000;  // 10 minutes
+
+enum QuicFragmentType {
+  STREAM_FRAGMENT = 0,
+  PDU_FRAGMENT,
+  ACK_FRAGMENT,
+  RST_STREAM_FRAGMENT,
+  CONNECTION_CLOSE_FRAGMENT,
+  NUM_FRAGMENT_TYPES
+};
+
+enum QuicPacketFlags {
+  PACKET_FLAGS_NONE = 0,
+  PACKET_FLAGS_FEC = 1,  // Payload is FEC as opposed to fragments.
+
+  PACKET_FLAGS_MAX = PACKET_FLAGS_FEC
+};
+
+enum QuicErrorCode {
+  // Stream errors.
+  QUIC_NO_ERROR = 0,
+
+  // There were data fragments after the a fin or reset.
+  QUIC_STREAM_DATA_AFTER_TERMINATION,
+  // There was some server error which halted stream processing.
+  QUIC_SERVER_ERROR_PROCESSING_STREAM,
+  // We got two fin or reset offsets which did not match.
+  QUIC_MULTIPLE_TERMINATION_OFFSETS,
+  // We got bad payload and can not respond to it at the protocol level.
+  QUIC_BAD_APPLICATION_PAYLOAD,
+
+  // Connection errors.
+
+  // Control frame is malformed.
+  QUIC_INVALID_PACKET_HEADER,
+  // Fragment data is malformed.
+  QUIC_INVALID_FRAGMENT_DATA,
+  // FEC data is malformed.
+  QUIC_INVALID_FEC_DATA,
+  // Stream rst data is malformed
+  QUIC_INVALID_RST_STREAM_DATA,
+  // Connection close data is malformed.
+  QUIC_INVALID_CONNECTION_CLOSE_DATA,
+  // Ack data is malformed.
+  QUIC_INVALID_ACK_DATA,
+  // There was an error decrypting.
+  QUIC_DECRYPTION_FAILURE,
+  // There was an error encrypting.
+  QUIC_ENCRYPTION_FAILURE,
+  // The packet exceeded kMaxPacketSize.
+  QUIC_PACKET_TOO_LARGE,
+  // Data was sent for a stream which did not exist.
+  QUIC_PACKET_FOR_NONEXISTENT_STREAM,
+  // The client is going away (browser close, etc.)
+  QUIC_CLIENT_GOING_AWAY,
+  // The server is going away (restart etc.)
+  QUIC_SERVER_GOING_AWAY,
+  // A stream ID was invalid.
+  QUIC_INVALID_STREAM_ID,
+  // Too many streams already open.
+  QUIC_TOO_MANY_OPEN_STREAMS,
+
+  // We hit our prenegotiated (or default) timeout
+  QUIC_CONNECTION_TIMED_OUT,
+
+  // Crypto errors.
+
+  // Handshake message contained out of order tags.
+  QUIC_CRYPTO_TAGS_OUT_OF_ORDER,
+  // Handshake message contained too many entires.
+  QUIC_CRYPTO_TOO_MANY_ENTRIES,
+  // Handshake message contained an invalid value length.
+  QUIC_CRYPTO_INVALID_VALUE_LENGTH,
+  // A crypto message was received after the handshake was complete.
+  QUIC_CRYPTO_MESSAGE_AFTER_HANDSHAKE_COMPLETE,
+  // A crypto message was receieved with an illegal message tag.
+  QUIC_INVALID_CRYPTO_MESSAGE_TYPE,
+
+};
+
+struct NET_EXPORT_PRIVATE QuicPacketHeader {
+  // Includes the ConnectionHeader and CongestionMonitoredHeader
+  // from the design docs, as well as some elements of DecryptedData.
+  QuicGuid guid;
+  QuicPacketSequenceNumber packet_sequence_number;
+  uint8 retransmission_count;
+  QuicTransmissionTime transmission_time;
+  QuicPacketFlags flags;
+  QuicFecGroupNumber fec_group;
+};
+
+struct NET_EXPORT_PRIVATE QuicStreamFragment {
+  QuicStreamFragment();
+  QuicStreamFragment(QuicStreamId stream_id,
+                     bool fin,
+                     uint64 offset,
+                     base::StringPiece data);
+
+  QuicStreamId stream_id;
+  bool fin;
+  uint64 offset;
+  base::StringPiece data;
+};
+
+struct NET_EXPORT_PRIVATE ReceivedPacketInfo {
+  ReceivedPacketInfo();
+  ~ReceivedPacketInfo();
+  // The highest packet sequence number we've received from the peer.
+  QuicPacketSequenceNumber largest_received;
+  // The time at which we received the above packet.
+  QuicTransmissionTime time_received;
+  // The set of packets which we're expecting and have not received.
+  // This includes any packets between the lowest and largest_received
+  // which we have neither seen nor been informed are non-retransmitting.
+  base::hash_set<QuicPacketSequenceNumber> missing_packets;

[Ryan Sleevi, 2012/10/17 04:27:13]

nit: Reading this without a colorized terminal (eg: in Codereview), the lack of
vertical whitespace throughout this file makes it much harder to separate out
comments, methods, and members. While
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Vertic...
discourages excessive use, typical Chromium style has been to include whitespace
between methods and (less commonly but still dominant) between members, when
members include supporting commentary.

+};
+
+struct NET_EXPORT_PRIVATE SentPacketInfo {
+  SentPacketInfo();
+  ~SentPacketInfo();
+  // The lowest packet we've sent which is unacked, and we expect an ack for.
+  QuicPacketSequenceNumber least_unacked;
+  // The set of packets between least_unacked and the last packet we have sent
+  // which we will not resend.
+  base::hash_set<QuicPacketSequenceNumber> non_retransmiting;
+};
+
+// Defines for all types of congestion feedback that will be negotiated in QUIC,
+// kTCP MUST be supported by all QUIC implementations to guarentee 100%
+// compatibility.
+enum CongestionFeedbackType {
+  kNone = 0,  // No feedback provided
+  kTCP,  // Used to mimic TCP.
+  kInterArrival,  // Use additional inter arrival information.
+  kFixRate,  // Provided for testing.
+};
+
+struct NET_EXPORT_PRIVATE CongestionFeedbackMessageTCP {
+  uint16 accumulated_number_of_lost_packets;
+  uint16 receive_window;  // Number of bytes >> 4.
+};
+
+struct NET_EXPORT_PRIVATE CongestionFeedbackMessageInterArrival {
+  uint16 accumulated_number_of_lost_packets;
+  int16 offset_time;
+  uint16 delta_time;  // delta time is described below.

[Ryan Sleevi, 2012/10/17 04:27:13]

nit; describe above?

+};
+
+/*
+ * Description of delta time.
+ *
+ * 0                   1
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |D|S|       offset_time         |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Where:
+ *   D is the time domain. If set time domain is in milliseconds, else in
+ *    microseconds.
+ *   S is the sign bit.
+ *   offset_time is the time offset where the relative packet size is equal to
+ *    0.
+ */
+
+struct NET_EXPORT_PRIVATE CongestionFeedbackMessageFixRate {
+  uint32 bitrate_in_bytes_per_second;
+};
+
+struct NET_EXPORT_PRIVATE CongestionInfo {
+  CongestionFeedbackType type;
+  union {
+    CongestionFeedbackMessageTCP tcp;
+    CongestionFeedbackMessageInterArrival inter_arrival;
+    CongestionFeedbackMessageFixRate fix_rate;
+  };
+};
+
+struct NET_EXPORT_PRIVATE QuicAckFragment {
+  QuicAckFragment() {}
+  QuicAckFragment(QuicPacketSequenceNumber largest_received,
+                  QuicTransmissionTime time_received,
+                  QuicPacketSequenceNumber least_unacked) {
+    received_info.largest_received = largest_received;
+    received_info.time_received = time_received;
+    sent_info.least_unacked = least_unacked;
+    congestion_info.type = kNone;
+  }
+
+  SentPacketInfo sent_info;
+  ReceivedPacketInfo received_info;
+  CongestionInfo congestion_info;
+
+  friend std::ostream& operator<<(std::ostream& os, const QuicAckFragment& s) {

[Ryan Sleevi, 2012/10/17 04:27:13]

style nit: methods before members
style nit: When possible, do not put this in the header, because this forces
<ostream> to be included, which brings in static initializers
style nit: IWYU: Missing <ostream>
style nit: If done for purposes of GTest, consider overloading PrintTo
privately/in a test file, as per
http://code.google.com/p/googletest/wiki/AdvancedGuide#Teaching_Google_Test_H...

+    os << "largest_received: " << s.received_info.largest_received
+       << " time: " << s.received_info.time_received
+       << " missing: ";
+    for (base::hash_set<QuicPacketSequenceNumber>::const_iterator it =
+           s.received_info.missing_packets.begin();
+           it != s.received_info.missing_packets.end(); ++it) {
+      os << *it << " ";
+    }
+
+    os << " least_waiting: " << s.sent_info.least_unacked
+       << " no_retransmit: ";
+    for (base::hash_set<QuicPacketSequenceNumber>::const_iterator it =
+           s.sent_info.non_retransmiting.begin();
+         it != s.sent_info.non_retransmiting.end(); ++it) {
+      os << *it << " ";
+    }
+    os << "\n";
+    return os;
+  }
+};
+
+struct NET_EXPORT_PRIVATE QuicRstStreamFragment {
+  QuicRstStreamFragment() {}
+  QuicRstStreamFragment(QuicStreamId stream_id, uint64 offset,
+                        QuicErrorCode details)
+      : stream_id(stream_id), offset(offset), details(details) {
+    DCHECK_LE(details, std::numeric_limits<uint8>::max());
+  }
+
+  QuicStreamId stream_id;
+  uint64 offset;
+  QuicErrorCode details;
+};
+
+struct NET_EXPORT_PRIVATE QuicConnectionCloseFragment {
+  QuicErrorCode details;
+  QuicAckFragment ack_fragment;
+};
+
+struct NET_EXPORT_PRIVATE QuicFragment {
+  QuicFragment() {}
+  explicit QuicFragment(QuicStreamFragment* stream_fragment)
+      : type(STREAM_FRAGMENT), stream_fragment(stream_fragment) {
+  }
+  explicit QuicFragment(QuicAckFragment* fragment)
+      : type(ACK_FRAGMENT), ack_fragment(fragment) {
+  }
+  explicit QuicFragment(QuicRstStreamFragment* fragment)
+      : type(RST_STREAM_FRAGMENT),
+        rst_stream_fragment(fragment) {
+  }
+  explicit QuicFragment(QuicConnectionCloseFragment* fragment)
+      : type(CONNECTION_CLOSE_FRAGMENT),
+        connection_close_fragment(fragment) {
+  }
+
+  QuicFragmentType type;
+  union {
+    QuicStreamFragment* stream_fragment;
+    QuicAckFragment* ack_fragment;
+    QuicRstStreamFragment* rst_stream_fragment;
+    QuicConnectionCloseFragment* connection_close_fragment;
+  };
+};
+
+typedef std::vector<QuicFragment> QuicFragments;
+
+struct NET_EXPORT_PRIVATE QuicFecData {
+  QuicFecData();
+  QuicFecGroupNumber fec_group;
+  QuicPacketSequenceNumber first_protected_packet_sequence_number;
+  // The last protected packet's sequence number will be one
+  // less than the sequence number of the FEC packet.
+  base::StringPiece redundancy;
+  bool operator==(const QuicFecData& other) const {

[Ryan Sleevi, 2012/10/17 04:27:13]

style nit: Do not overload operator==, as per
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Operat...
, or document why needed (only a few, specific algorithms require this, and I
haven't seen them being used.)

+    if (fec_group != other.fec_group) {
+      return false;
+    }
+    if (first_protected_packet_sequence_number !=
+        other.first_protected_packet_sequence_number) {
+      return false;
+    }
+    if (redundancy != other.redundancy) {
+      return false;
+    }
+    return true;
+  }
+};
+
+struct NET_EXPORT_PRIVATE QuicPacketData {
+  std::string data;
+};
+
+class NET_EXPORT_PRIVATE QuicData {
+ public:
+  QuicData(const char* buffer, size_t length)
+      : buffer_(buffer),
+        length_(length),
+        owns_buffer_(false) { }

[Ryan Sleevi, 2012/10/17 04:27:13]

nit: You inconsistently have constructors using { } or {
} form (eg: compare with lines 296-310)

The canonical example of the two acceptable formats,
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Constr...
, shows the use of multi-line braces when using multi-line initializer lists,
and that is the dominant pattern in Chromium in my experience.

You also inconsistently include whitespace between the braces for the one-liners
(the canonical example includes no whitespace, your implementation files include
no whitespace, but you occassionally include whitespace, such as here)

+
+  QuicData(char* buffer, size_t length, bool owns_buffer)
+      : buffer_(buffer),
+        length_(length),
+        owns_buffer_(owns_buffer) { }
+
+  virtual ~QuicData();
+
+  base::StringPiece AsStringPiece() const {
+    return base::StringPiece(data(), length());
+  }
+
+  const char* data() const { return buffer_; }
+  size_t length() const { return length_; }
+
+ private:
+  const char* buffer_;
+  size_t length_;
+  bool owns_buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(QuicData);
+};
+
+class NET_EXPORT_PRIVATE QuicPacket : public QuicData {
+ public:
+  QuicPacket(char* buffer, size_t length, bool owns_buffer)
+      : QuicData(buffer, length, owns_buffer),
+        buffer_(buffer) { }
+
+  base::StringPiece FecProtectedData() const {
+    return base::StringPiece(data() + kStartOfFecProtectedData,
+                             length() - kStartOfFecProtectedData);

[Ryan Sleevi, 2012/10/17 04:27:13]

DESIGN: There's no checking here in QuicPacket that |length| (line 380) is
either > kStartOfFecProtectedData, > kStartOfHashData (line 390), or >
kStartOfEncryptedData (line 394).

It would be a safer API to provide some checks at construction, perhaps through
making the constructor private and using a factory method that can return NULL
on bad input.

+  }
+
+  base::StringPiece AssociatedData() const {
+    return base::StringPiece(data() + kStartOfHashData, kStartOfEncryptedData);
+  }
+
+  base::StringPiece Plaintext() const {
+    return base::StringPiece(data() + kStartOfEncryptedData,
+                             length() - kStartOfEncryptedData);
+  }
+  char* mutable_data() { return buffer_; }
+
+ private:
+  char* buffer_;
+
+  // TODO(rch): DISALLOW_COPY_AND_ASSIGN
+};
+
+class NET_EXPORT_PRIVATE QuicEncryptedPacket : public QuicData {
+ public:
+  QuicEncryptedPacket(const char* buffer, size_t length)
+      : QuicData(buffer, length) { }
+
+  QuicEncryptedPacket(char* buffer, size_t length, bool owns_buffer)
+      : QuicData(buffer, length, owns_buffer) { }
+
+  base::StringPiece AssociatedData() const {
+    return base::StringPiece(data() + kStartOfHashData, kStartOfEncryptedData);
+  }
+
+  // TODO(rch): DISALLOW_COPY_AND_ASSIGN
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_QUIC_PROTOCOL_H_