blob: c6902e0ad9bf6fdb547d54e9e44d1570c0cc35f1 [file] [log] [blame]
// 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.
// Responsible for generating packets on behalf of a QuicConnection.
// Packets are serialized just-in-time.
// Ack and Feedback frames will be requested from the Connection
// just-in-time. When a packet needs to be sent, the Generator
// will serialize a packet and pass it to QuicConnection::SendOrQueuePacket()
// The Generator's mode of operation is controlled by two conditions:
// 1) Is the Delegate writable?
// If the Delegate is not writable, then no operations will cause
// a packet to be serialized. In particular:
// * SetShouldSendAck will simply record that an ack is to be sent.
// * AddControlFrame will enqueue the control frame.
// * ConsumeData will do nothing.
// If the Delegate is writable, then the behavior depends on the second
// condition:
// 2) Is the Generator in batch mode?
// If the Generator is NOT in batch mode, then each call to a write
// operation will serialize one or more packets. The contents will
// include any previous queued frames. If an ack should be sent
// but has not been sent, then the Delegate will be asked to create
// an Ack frame which will then be included in the packet. When
// the write call completes, the current packet will be serialized
// and sent to the Delegate, even if it is not full.
// If the Generator is in batch mode, then each write operation will
// add data to the "current" packet. When the current packet becomes
// full, it will be serialized and sent to the packet. When batch
// mode is ended via |FinishBatchOperations|, the current packet
// will be serialzied, even if it is not full.
#include <cstddef>
#include <cstdint>
#include <list>
#include "net/third_party/quiche/src/quic/core/quic_packet_creator.h"
#include "net/third_party/quiche/src/quic/core/quic_pending_retransmission.h"
#include "net/third_party/quiche/src/quic/core/quic_sent_packet_manager.h"
#include "net/third_party/quiche/src/quic/core/quic_types.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_export.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_mem_slice_span.h"
namespace quic {
namespace test {
class QuicPacketGeneratorPeer;
} // namespace test
class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
class QUIC_EXPORT_PRIVATE DelegateInterface
: public QuicPacketCreator::DelegateInterface {
~DelegateInterface() override {}
// Consults delegate whether a packet should be generated.
virtual bool ShouldGeneratePacket(HasRetransmittableData retransmittable,
IsHandshake handshake) = 0;
// Called when there is data to be sent. Retrieves updated ACK frame from
// the delegate.
virtual const QuicFrames MaybeBundleAckOpportunistically() = 0;
QuicPacketGenerator(QuicConnectionId server_connection_id,
QuicFramer* framer,
QuicRandom* random_generator,
DelegateInterface* delegate);
QuicPacketGenerator(const QuicPacketGenerator&) = delete;
QuicPacketGenerator& operator=(const QuicPacketGenerator&) = delete;
// Consumes retransmittable control |frame|. Returns true if the frame is
// successfully consumed. Returns false otherwise.
bool ConsumeRetransmittableControlFrame(const QuicFrame& frame);
// Given some data, may consume part or all of it and pass it to the
// packet creator to be serialized into packets. If not in batch
// mode, these packets will also be sent during this call.
// When |state| is FIN_AND_PADDING, random padding of size [1, 256] will be
// added after stream frames. If current constructed packet cannot
// accommodate, the padding will overflow to the next packet(s).
QuicConsumedData ConsumeData(QuicStreamId id,
size_t write_length,
QuicStreamOffset offset,
StreamSendingState state);
// Consumes data for CRYPTO frames sent at |level| starting at |offset| for a
// total of |write_length| bytes, and returns the number of bytes consumed.
// The data is passed into the packet creator and serialized into one or more
// packets.
size_t ConsumeCryptoData(EncryptionLevel level,
size_t write_length,
QuicStreamOffset offset);
// Sends as many data only packets as allowed by the send algorithm and the
// available iov.
// This path does not support padding, or bundling pending frames.
// In case we access this method from ConsumeData, total_bytes_consumed
// keeps track of how many bytes have already been consumed.
QuicConsumedData ConsumeDataFastPath(QuicStreamId id,
size_t write_length,
QuicStreamOffset offset,
bool fin,
size_t total_bytes_consumed);
// Generates an MTU discovery packet of specified size.
void GenerateMtuDiscoveryPacket(QuicByteCount target_mtu);
// Indicates whether packet flusher is currently attached.
bool PacketFlusherAttached() const;
// Attaches packet flusher.
void AttachPacketFlusher();
// Flushes everything, including current open packet and pending padding.
void Flush();
// Flushes current open packet.
void FlushAllQueuedFrames();
// Returns true if there are frames pending to be serialized.
bool HasPendingFrames() const;
// Makes the framer not serialize the protocol version in sent packets.
void StopSendingVersion();
// SetDiversificationNonce sets the nonce that will be sent in each public
// header of packets encrypted at the initial encryption level. Should only
// be called by servers.
void SetDiversificationNonce(const DiversificationNonce& nonce);
// Creates a version negotiation packet which supports |supported_versions|.
std::unique_ptr<QuicEncryptedPacket> SerializeVersionNegotiationPacket(
bool ietf_quic,
bool use_length_prefix,
const ParsedQuicVersionVector& supported_versions);
// Creates a connectivity probing packet.
OwningSerializedPacketPointer SerializeConnectivityProbingPacket();
// Create connectivity probing request and response packets using PATH
// CHALLENGE and PATH RESPONSE frames, respectively.
// SerializePathChallengeConnectivityProbingPacket will pad the packet to be
// MTU bytes long.
OwningSerializedPacketPointer SerializePathChallengeConnectivityProbingPacket(
QuicPathFrameBuffer* payload);
// If |is_padded| is true then SerializePathResponseConnectivityProbingPacket
// will pad the packet to be MTU bytes long, else it will not pad the packet.
// |payloads| is cleared.
OwningSerializedPacketPointer SerializePathResponseConnectivityProbingPacket(
const QuicDeque<QuicPathFrameBuffer>& payloads,
const bool is_padded);
// Re-serializes frames with the original packet's packet number length.
// Used for retransmitting packets to ensure they aren't too long.
void ReserializeAllFrames(const QuicPendingRetransmission& retransmission,
char* buffer,
size_t buffer_len);
// Update the packet number length to use in future packets as soon as it
// can be safely changed.
void UpdatePacketNumberLength(QuicPacketNumber least_packet_awaited_by_peer,
QuicPacketCount max_packets_in_flight);
// Set the minimum number of bytes for the server connection id length;
void SetServerConnectionIdLength(uint32_t length);
// Sets the encrypter to use for the encryption level.
void SetEncrypter(EncryptionLevel level,
std::unique_ptr<QuicEncrypter> encrypter);
// Returns true if there are control frames or current constructed packet has
// pending retransmittable frames.
bool HasRetransmittableFrames() const;
// Returns true if current constructed packet has pending stream frames for
// stream |id|.
bool HasPendingStreamFramesOfStream(QuicStreamId id) const;
// Sets the encryption level that will be applied to new packets.
void set_encryption_level(EncryptionLevel level);
// packet number of the last created packet, or 0 if no packets have been
// created.
QuicPacketNumber packet_number() const;
// Returns the maximum length a current packet can actually have.
QuicByteCount GetCurrentMaxPacketLength() const;
// Set maximum packet length in the creator immediately. May not be called
// when there are frames queued in the creator.
void SetMaxPacketLength(QuicByteCount length);
// Set transmission type of next constructed packets.
void SetTransmissionType(TransmissionType type);
// Sets the retry token to be sent over the wire in IETF Initial packets.
void SetRetryToken(QuicStringPiece retry_token);
// Allow/Disallow setting transmission type of next constructed packets.
void SetCanSetTransmissionType(bool can_set_transmission_type);
// Tries to add a message frame containing |message| and returns the status.
MessageStatus AddMessageFrame(QuicMessageId message_id,
QuicMemSliceSpan message);
// Called to flush ACK and STOP_WAITING frames, returns false if the flush
// fails.
bool FlushAckFrame(const QuicFrames& frames);
// Returns the largest payload that will fit into a single MESSAGE frame.
QuicPacketLength GetCurrentLargestMessagePayload() const;
QuicPacketLength GetGuaranteedLargestMessagePayload() const;
// Update the server connection ID used in outgoing packets.
void SetServerConnectionId(QuicConnectionId server_connection_id);
// Update the client connection ID used in outgoing packets.
void SetClientConnectionId(QuicConnectionId client_connection_id);
void set_debug_delegate(QuicPacketCreator::DebugDelegate* debug_delegate) {
void set_fully_pad_crypto_hadshake_packets(bool new_value) {
fully_pad_crypto_handshake_packets_ = new_value;
bool fully_pad_crypto_handshake_packets() const {
return fully_pad_crypto_handshake_packets_;
friend class test::QuicPacketGeneratorPeer;
// Adds a random amount of padding (between 1 to 256 bytes).
void AddRandomPadding();
// Sends remaining pending padding.
// Pending paddings should only be sent when there is nothing else to send.
void SendRemainingPendingPadding();
// Called when there is data to be sent, Retrieves updated ACK frame from
// delegate_ and flushes it.
void MaybeBundleAckOpportunistically();
DelegateInterface* delegate_;
QuicPacketCreator packet_creator_;
// Transmission type of the next serialized packet.
TransmissionType next_transmission_type_;
// True if packet flusher is currently attached.
bool flusher_attached_;
QuicRandom* random_generator_;
// Whether crypto handshake packets should be fully padded.
bool fully_pad_crypto_handshake_packets_;
// Packet number of the first packet of a write operation. This gets set
// when the out-most flusher attaches and gets cleared when the out-most
// flusher detaches.
QuicPacketNumber write_start_packet_number_;
} // namespace quic