| // 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. Control frames are queued. |
| // 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. |
| |
| #ifndef NET_QUIC_QUIC_PACKET_GENERATOR_H_ |
| #define NET_QUIC_QUIC_PACKET_GENERATOR_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <list> |
| |
| #include "base/macros.h" |
| #include "net/quic/quic_packet_creator.h" |
| #include "net/quic/quic_sent_packet_manager.h" |
| #include "net/quic/quic_types.h" |
| |
| namespace net { |
| |
| namespace test { |
| class QuicPacketGeneratorPeer; |
| } // namespace test |
| |
| class NET_EXPORT_PRIVATE QuicPacketGenerator { |
| public: |
| class NET_EXPORT_PRIVATE DelegateInterface |
| : public QuicPacketCreator::DelegateInterface { |
| public: |
| ~DelegateInterface() override {} |
| // Consults delegate whether a packet should be generated. |
| virtual bool ShouldGeneratePacket(HasRetransmittableData retransmittable, |
| IsHandshake handshake) = 0; |
| virtual const QuicFrame GetUpdatedAckFrame() = 0; |
| virtual void PopulateStopWaitingFrame( |
| QuicStopWaitingFrame* stop_waiting) = 0; |
| }; |
| |
| QuicPacketGenerator(QuicConnectionId connection_id, |
| QuicFramer* framer, |
| QuicRandom* random_generator, |
| QuicBufferAllocator* buffer_allocator, |
| DelegateInterface* delegate); |
| |
| ~QuicPacketGenerator(); |
| |
| // Indicates that an ACK frame should be sent. |
| // If |also_send_stop_waiting| is true, then it also indicates that a |
| // STOP_WAITING frame should be sent as well. |
| // The contents of the frame(s) will be generated via a call to the delegate |
| // CreateAckFrame() when the packet is serialized. |
| void SetShouldSendAck(bool also_send_stop_waiting); |
| |
| void AddControlFrame(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. |
| // |delegate| (if not nullptr) will be informed once all packets sent as a |
| // result of this call are ACKed by the peer. |
| QuicConsumedData ConsumeData(QuicStreamId id, |
| QuicIOVector iov, |
| QuicStreamOffset offset, |
| bool fin, |
| QuicAckListenerInterface* listener); |
| |
| // Sends as many data only packets as allowed by the send algorithm and the |
| // available iov. |
| // This path does not support FEC, padding, or bundling pending frames. |
| QuicConsumedData ConsumeDataFastPath(QuicStreamId id, |
| const QuicIOVector& iov, |
| QuicStreamOffset offset, |
| bool fin, |
| QuicAckListenerInterface* listener); |
| |
| // Generates an MTU discovery packet of specified size. |
| void GenerateMtuDiscoveryPacket(QuicByteCount target_mtu, |
| QuicAckListenerInterface* listener); |
| |
| // Indicates whether batch mode is currently enabled. |
| bool InBatchMode(); |
| // Disables flushing. |
| void StartBatchOperations(); |
| // Enables flushing and flushes queued data which can be sent. |
| void FinishBatchOperations(); |
| |
| // Flushes all queued frames, even frames which are not sendable. |
| void FlushAllQueuedFrames(); |
| |
| bool HasQueuedFrames() const; |
| |
| // Whether the pending packet has no frames in it at the moment. |
| bool IsPendingPacketEmpty() 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|. |
| // Caller owns the created packet. Also, sets the entropy hash of the |
| // serialized packet to a random bool and returns that value as a member of |
| // SerializedPacket. |
| QuicEncryptedPacket* SerializeVersionNegotiationPacket( |
| const QuicVersionVector& supported_versions); |
| |
| // 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 PendingRetransmission& 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 UpdateSequenceNumberLength(QuicPacketNumber least_packet_awaited_by_peer, |
| QuicPacketCount max_packets_in_flight); |
| |
| // Set the minimum number of bytes for the connection id length; |
| void SetConnectionIdLength(uint32_t length); |
| |
| // Sets the encrypter to use for the encryption level. |
| void SetEncrypter(EncryptionLevel level, QuicEncrypter* encrypter); |
| |
| // 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); |
| |
| // Sets |path_id| to be the path on which next packet is generated. |
| void SetCurrentPath(QuicPathId path_id, |
| QuicPacketNumber least_packet_awaited_by_peer, |
| QuicPacketCount max_packets_in_flight); |
| |
| void set_debug_delegate(QuicPacketCreator::DebugDelegate* debug_delegate) { |
| packet_creator_.set_debug_delegate(debug_delegate); |
| } |
| |
| const QuicAckFrame& pending_ack_frame() const { return pending_ack_frame_; } |
| |
| private: |
| friend class test::QuicPacketGeneratorPeer; |
| |
| void SendQueuedFrames(bool flush); |
| |
| // Test to see if we have pending ack, or control frames. |
| bool HasPendingFrames() const; |
| // Returns true if addition of a pending frame (which might be |
| // retransmittable) would still allow the resulting packet to be sent now. |
| bool CanSendWithNextPendingFrameAddition() const; |
| // Add exactly one pending frame, preferring ack frames over control frames. |
| // Returns true if a pending frame is successfully added. |
| // Returns false and flushes current open packet if the pending frame cannot |
| // fit into current open packet. |
| bool AddNextPendingFrame(); |
| |
| DelegateInterface* delegate_; |
| |
| QuicPacketCreator packet_creator_; |
| QuicFrames queued_control_frames_; |
| |
| // True if batch mode is currently enabled. |
| bool batch_mode_; |
| |
| // Flags to indicate the need for just-in-time construction of a frame. |
| bool should_send_ack_; |
| bool should_send_stop_waiting_; |
| // If we put a non-retransmittable frame in this packet, then we have to hold |
| // a reference to it until we flush (and serialize it). Retransmittable frames |
| // are referenced elsewhere so that they can later be (optionally) |
| // retransmitted. |
| QuicAckFrame pending_ack_frame_; |
| QuicStopWaitingFrame pending_stop_waiting_frame_; |
| |
| DISALLOW_COPY_AND_ASSIGN(QuicPacketGenerator); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_QUIC_PACKET_GENERATOR_H_ |