gecko-dev/netwerk/protocol/http/Http2Session.h

450 lines
18 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_net_Http2Session_h
#define mozilla_net_Http2Session_h
// HTTP/2
#include "ASpdySession.h"
#include "mozilla/Attributes.h"
#include "nsAHttpConnection.h"
#include "nsClassHashtable.h"
#include "nsDataHashtable.h"
#include "nsDeque.h"
#include "nsHashKeys.h"
#include "Http2Compression.h"
class nsISocketTransport;
namespace mozilla {
namespace net {
class Http2PushedStream;
class Http2Stream;
class Http2Session MOZ_FINAL : public ASpdySession
, public nsAHttpConnection
, public nsAHttpSegmentReader
, public nsAHttpSegmentWriter
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSAHTTPTRANSACTION
NS_DECL_NSAHTTPCONNECTION(mConnection)
NS_DECL_NSAHTTPSEGMENTREADER
NS_DECL_NSAHTTPSEGMENTWRITER
Http2Session(nsAHttpTransaction *, nsISocketTransport *, int32_t);
~Http2Session();
bool AddStream(nsAHttpTransaction *, int32_t);
bool CanReuse() { return !mShouldGoAway && !mClosed; }
bool RoomForMoreStreams();
// When the connection is active this is called up to once every 1 second
// return the interval (in seconds) that the connection next wants to
// have this invoked. It might happen sooner depending on the needs of
// other connections.
uint32_t ReadTimeoutTick(PRIntervalTime now);
// Idle time represents time since "goodput".. e.g. a data or header frame
PRIntervalTime IdleTime();
// Registering with a newID of 0 means pick the next available odd ID
uint32_t RegisterStreamID(Http2Stream *, uint32_t aNewID = 0);
/*
HTTP/2 framing
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length (16) | Type (8) | Flags (8) |
+-+-------------+---------------+-------------------------------+
|R| Stream Identifier (31) |
+-+-------------------------------------------------------------+
| Frame Data (0...) ...
+---------------------------------------------------------------+
*/
enum frameType {
FRAME_TYPE_DATA = 0,
FRAME_TYPE_HEADERS = 1,
FRAME_TYPE_PRIORITY = 2,
FRAME_TYPE_RST_STREAM = 3,
FRAME_TYPE_SETTINGS = 4,
FRAME_TYPE_PUSH_PROMISE = 5,
FRAME_TYPE_PING = 6,
FRAME_TYPE_GOAWAY = 7,
FRAME_TYPE_UNUSED1 = 8,
FRAME_TYPE_WINDOW_UPDATE = 9,
FRAME_TYPE_CONTINUATION = 10,
FRAME_TYPE_LAST = 11
};
// NO_ERROR is a macro defined on windows, so we'll name the HTTP2 goaway
// code NO_ERROR to be NO_HTTP_ERROR
enum errorType {
NO_HTTP_ERROR = 0,
PROTOCOL_ERROR = 1,
INTERNAL_ERROR = 2,
FLOW_CONTROL_ERROR = 3,
SETTINGS_TIMEOUT_ERROR = 4,
STREAM_CLOSED_ERROR = 5,
FRAME_SIZE_ERROR = 6,
REFUSED_STREAM_ERROR = 7,
CANCEL_ERROR = 8,
COMPRESSION_ERROR = 9,
CONNECT_ERROR = 10,
ENHANCE_YOUR_CALM = 420
};
// These are frame flags. If they, or other undefined flags, are
// used on frames other than the comments indicate they MUST be ignored.
const static uint8_t kFlag_END_STREAM = 0x01; // data, headers
const static uint8_t kFlag_END_HEADERS = 0x04; // headers, continuation
const static uint8_t kFlag_PRIORITY = 0x08; //headers
const static uint8_t kFlag_END_PUSH_PROMISE = 0x04; // push promise
const static uint8_t kFlag_ACK = 0x01; // ping and settings
enum {
SETTINGS_TYPE_HEADER_TABLE_SIZE = 1, // compression table size
SETTINGS_TYPE_ENABLE_PUSH = 2, // can be used to disable push
SETTINGS_TYPE_MAX_CONCURRENT = 4, // streams recvr allowed to initiate
SETTINGS_TYPE_INITIAL_WINDOW = 7, // bytes for flow control default
SETTINGS_TYPE_FLOW_CONTROL = 10 // flow control details
};
// This should be big enough to hold all of your control packets,
// but if it needs to grow for huge headers it can do so dynamically.
const static uint32_t kDefaultBufferSize = 2048;
// kDefaultQueueSize must be >= other queue size constants
const static uint32_t kDefaultQueueSize = 32768;
const static uint32_t kQueueMinimumCleanup = 24576;
const static uint32_t kQueueTailRoom = 4096;
const static uint32_t kQueueReserved = 1024;
const static uint32_t kDefaultMaxConcurrent = 100;
const static uint32_t kMaxStreamID = 0x7800000;
// This is a sentinel for a deleted stream. It is not a valid
// 31 bit stream ID.
const static uint32_t kDeadStreamID = 0xffffdead;
// below the emergency threshold of local window we ack every received
// byte. Above that we coalesce bytes into the MinimumToAck size.
const static int32_t kEmergencyWindowThreshold = 256 * 1024;
const static uint32_t kMinimumToAck = 4 * 1024 * 1024;
// The default rwin is 64KB - 1 unless updated by a settings frame
const static uint32_t kDefaultRwin = 65535;
// Frames with HTTP semantics are limited to 2^14 - 1 bytes of length in
// order to preserve responsiveness
const static uint32_t kMaxFrameData = 16383;
static nsresult RecvHeaders(Http2Session *);
static nsresult RecvPriority(Http2Session *);
static nsresult RecvRstStream(Http2Session *);
static nsresult RecvSettings(Http2Session *);
static nsresult RecvPushPromise(Http2Session *);
static nsresult RecvPing(Http2Session *);
static nsresult RecvGoAway(Http2Session *);
static nsresult RecvUnused1(Http2Session *);
static nsresult RecvWindowUpdate(Http2Session *);
static nsresult RecvContinuation(Http2Session *);
template<typename T>
static void EnsureBuffer(nsAutoArrayPtr<T> &,
uint32_t, uint32_t, uint32_t &);
char *EnsureOutputBuffer(uint32_t needed);
template<typename charType>
void CreateFrameHeader(charType dest, uint16_t frameLength,
uint8_t frameType, uint8_t frameFlags,
uint32_t streamID);
// For writing the data stream to LOG4
static void LogIO(Http2Session *, Http2Stream *, const char *,
const char *, uint32_t);
// an overload of nsAHttpConnection
void TransactionHasDataToWrite(nsAHttpTransaction *);
// a similar version for Http2Stream
void TransactionHasDataToWrite(Http2Stream *);
// an overload of nsAHttpSegementReader
virtual nsresult CommitToSegmentSize(uint32_t size, bool forceCommitment);
nsresult BufferOutput(const char *, uint32_t, uint32_t *);
void FlushOutputQueue();
uint32_t AmountOfOutputBuffered() { return mOutputQueueUsed - mOutputQueueSent; }
uint32_t GetServerInitialStreamWindow() { return mServerInitialStreamWindow; }
void ConnectPushedStream(Http2Stream *stream);
nsresult ConfirmTLSProfile();
uint64_t Serial() { return mSerial; }
void PrintDiagnostics (nsCString &log);
// Streams need access to these
uint32_t SendingChunkSize() { return mSendingChunkSize; }
uint32_t PushAllowance() { return mPushAllowance; }
Http2Compressor *Compressor() { return &mCompressor; }
nsISocketTransport *SocketTransport() { return mSocketTransport; }
int64_t ServerSessionWindow() { return mServerSessionWindow; }
bool ServerUsesFlowControl() { return mServerUsesFlowControl; }
void DecrementServerSessionWindow (uint32_t bytes) { mServerSessionWindow -= bytes; }
private:
// These internal states do not correspond to the states of the HTTP/2 specification
enum internalStateType {
BUFFERING_OPENING_SETTINGS,
BUFFERING_FRAME_HEADER,
BUFFERING_CONTROL_FRAME,
PROCESSING_DATA_FRAME,
DISCARDING_DATA_FRAME,
PROCESSING_COMPLETE_HEADERS,
PROCESSING_CONTROL_RST_STREAM
};
static const uint8_t kMagicHello[24];
nsresult ResponseHeadersComplete();
uint32_t GetWriteQueueSize();
void ChangeDownstreamState(enum internalStateType);
void ResetDownstreamState();
nsresult UncompressAndDiscard();
void MaybeDecrementConcurrent(Http2Stream *);
void GeneratePing(bool);
void GenerateSettingsAck();
void GeneratePriority(uint32_t, uint32_t);
void GenerateRstStream(uint32_t, uint32_t);
void GenerateGoAway(uint32_t);
void CleanupStream(Http2Stream *, nsresult, errorType);
void CloseStream(Http2Stream *, nsresult);
void SendHello();
void RemoveStreamFromQueues(Http2Stream *);
void SetWriteCallbacks();
void RealignOutputQueue();
bool RoomForMoreConcurrent();
void ActivateStream(Http2Stream *);
void ProcessPending();
nsresult SetInputFrameDataStream(uint32_t);
bool VerifyStream(Http2Stream *, uint32_t);
void SetNeedsCleanup();
void UpdateLocalRwin(Http2Stream *stream, uint32_t bytes);
void UpdateLocalStreamWindow(Http2Stream *stream, uint32_t bytes);
void UpdateLocalSessionWindow(uint32_t bytes);
// a wrapper for all calls to the nshttpconnection level segment writer. Used
// to track network I/O for timeout purposes
nsresult NetworkRead(nsAHttpSegmentWriter *, char *, uint32_t, uint32_t *);
static PLDHashOperator ShutdownEnumerator(nsAHttpTransaction *,
nsAutoPtr<Http2Stream> &,
void *);
static PLDHashOperator GoAwayEnumerator(nsAHttpTransaction *,
nsAutoPtr<Http2Stream> &,
void *);
static PLDHashOperator UpdateServerRwinEnumerator(nsAHttpTransaction *,
nsAutoPtr<Http2Stream> &,
void *);
static PLDHashOperator RestartBlockedOnRwinEnumerator(nsAHttpTransaction *,
nsAutoPtr<Http2Stream> &,
void *);
// This is intended to be nsHttpConnectionMgr:nsConnectionHandle taken
// from the first transaction on this session. That object contains the
// pointer to the real network-level nsHttpConnection object.
nsRefPtr<nsAHttpConnection> mConnection;
// The underlying socket transport object is needed to propogate some events
nsISocketTransport *mSocketTransport;
// These are temporary state variables to hold the argument to
// Read/WriteSegments so it can be accessed by On(read/write)segment
// further up the stack.
nsAHttpSegmentReader *mSegmentReader;
nsAHttpSegmentWriter *mSegmentWriter;
uint32_t mSendingChunkSize; /* the transmission chunk size */
uint32_t mNextStreamID; /* 24 bits */
uint32_t mConcurrentHighWater; /* max parallelism on session */
uint32_t mPushAllowance; /* rwin for unmatched pushes */
internalStateType mDownstreamState; /* in frame, between frames, etc.. */
// Maintain 2 indexes - one by stream ID, one by transaction pointer.
// There are also several lists of streams: ready to write, queued due to
// max parallelism, streams that need to force a read for push, and the full
// set of pushed streams.
// The objects are not ref counted - they get destroyed
// by the nsClassHashtable implementation when they are removed from
// the transaction hash.
nsDataHashtable<nsUint32HashKey, Http2Stream *> mStreamIDHash;
nsClassHashtable<nsPtrHashKey<nsAHttpTransaction>,
Http2Stream> mStreamTransactionHash;
nsDeque mReadyForWrite;
nsDeque mQueuedStreams;
nsDeque mReadyForRead;
nsTArray<Http2PushedStream *> mPushedStreams;
// Compression contexts for header transport.
// HTTP/2 compresses only HTTP headers and does not reset the context in between
// frames. Even data that is not associated with a stream (e.g invalid
// stream ID) is passed through these contexts to keep the compression
// context correct.
Http2Compressor mCompressor;
Http2Decompressor mDecompressor;
nsCString mDecompressBuffer;
// mInputFrameBuffer is used to store received control packets and the 8 bytes
// of header on data packets
uint32_t mInputFrameBufferSize; // buffer allocation
uint32_t mInputFrameBufferUsed; // amt of allocation used
nsAutoArrayPtr<char> mInputFrameBuffer;
// mInputFrameDataSize/Read are used for tracking the amount of data consumed
// in a frame after the 8 byte header. Control frames are always fully buffered
// and the fixed 8 byte leading header is at mInputFrameBuffer + 0, the first
// data byte (i.e. the first settings/goaway/etc.. specific byte) is at
// mInputFrameBuffer + 8
// The frame size is mInputFrameDataSize + the constant 8 byte header
uint32_t mInputFrameDataSize;
uint32_t mInputFrameDataRead;
bool mInputFrameFinal; // This frame was marked FIN
uint8_t mInputFrameType;
uint8_t mInputFrameFlags;
uint32_t mInputFrameID;
// When a frame has been received that is addressed to a particular stream
// (e.g. a data frame after the stream-id has been decoded), this points
// to the stream.
Http2Stream *mInputFrameDataStream;
// mNeedsCleanup is a state variable to defer cleanup of a closed stream
// If needed, It is set in session::OnWriteSegments() and acted on and
// cleared when the stack returns to session::WriteSegments(). The stream
// cannot be destroyed directly out of OnWriteSegments because
// stream::writeSegments() is on the stack at that time.
Http2Stream *mNeedsCleanup;
// This reason code in the last processed RESET frame
uint32_t mDownstreamRstReason;
// When HEADERS/PROMISE are chained together, this is the expected ID of the next
// recvd frame which must be the same type
uint32_t mExpectedHeaderID;
uint32_t mExpectedPushPromiseID;
uint32_t mContinuedPromiseStream;
// for the conversion of downstream http headers into http/2 formatted headers
// The data here does not persist between frames
nsCString mFlatHTTPResponseHeaders;
uint32_t mFlatHTTPResponseHeadersOut;
// when set, the session will go away when it reaches 0 streams. This flag
// is set when: the stream IDs are running out (at either the client or the
// server), when DontReuse() is called, a RST that is not specific to a
// particular stream is received, a GOAWAY frame has been received from
// the server.
bool mShouldGoAway;
// the session has received a nsAHttpTransaction::Close() call
bool mClosed;
// the session received a GoAway frame with a valid GoAwayID
bool mCleanShutdown;
// if server has enabled flow control for all streams in this session.
// If disabled it does not generate window updates and does not expect
// the client to ever block on sending data frames
bool mServerUsesFlowControl;
// The TLS comlpiance checks are not done in the ctor beacuse of bad
// exception handling - so we do them at IO time and cache the result
bool mTLSProfileConfirmed;
// A specifc reason code for the eventual GoAway frame. If set to NO_HTTP_ERROR
// only NO_HTTP_ERROR, PROTOCOL_ERROR, or INTERNAL_ERROR will be sent.
errorType mGoAwayReason;
// If a GoAway message was received this is the ID of the last valid
// stream. 0 otherwise. (0 is never a valid stream id.)
uint32_t mGoAwayID;
// The last stream processed ID we will send in our GoAway frame.
uint32_t mOutgoingGoAwayID;
// The limit on number of concurrent streams for this session. Normally it
// is basically unlimited, but the SETTINGS control message from the
// server might bring it down.
uint32_t mMaxConcurrent;
// The actual number of concurrent streams at this moment. Generally below
// mMaxConcurrent, but the max can be lowered in real time to a value
// below the current value
uint32_t mConcurrent;
// The number of server initiated promises, tracked for telemetry
uint32_t mServerPushedResources;
// The server rwin for new streams as determined from a SETTINGS frame
uint32_t mServerInitialStreamWindow;
// The Local Session window is how much data the server is allowed to send
// (across all streams) without getting a window update to stream 0. It is
// signed because asynchronous changes via SETTINGS can drive it negative.
int64_t mLocalSessionWindow;
// The Remote Session Window is how much data the client is allowed to send
// (across all streams) without receiving a window update to stream 0. It is
// signed because asynchronous changes via SETTINGS can drive it negative.
int64_t mServerSessionWindow;
// This is a output queue of bytes ready to be written to the SSL stream.
// When that streams returns WOULD_BLOCK on direct write the bytes get
// coalesced together here. This results in larger writes to the SSL layer.
// The buffer is not dynamically grown to accomodate stream writes, but
// does expand to accept infallible session wide frames like GoAway and RST.
uint32_t mOutputQueueSize;
uint32_t mOutputQueueUsed;
uint32_t mOutputQueueSent;
nsAutoArrayPtr<char> mOutputQueueBuffer;
PRIntervalTime mPingThreshold;
PRIntervalTime mLastReadEpoch; // used for ping timeouts
PRIntervalTime mLastDataReadEpoch; // used for IdleTime()
PRIntervalTime mPingSentEpoch;
// used as a temporary buffer while enumerating the stream hash during GoAway
nsDeque mGoAwayStreamsToRestart;
// Each session gets a unique serial number because the push cache is correlated
// by the load group and the serial number can be used as part of the cache key
// to make sure streams aren't shared across sessions.
uint64_t mSerial;
};
} // namespace mozilla::net
} // namespace mozilla
#endif // mozilla_net_Http2Session_h