blob: 7ce2c850e50eac3e087ddf76ba182e00e7fb1372 [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.
#include <list>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "base/basictypes.h"
#include "base/gtest_prod_util.h"
#include "base/memory/scoped_ptr.h"
#include "base/strings/string_piece.h"
#include "base/sys_byteorder.h"
#include "net/base/net_export.h"
#include "net/spdy/hpack_decoder.h"
#include "net/spdy/hpack_encoder.h"
#include "net/spdy/spdy_header_block.h"
#include "net/spdy/spdy_protocol.h"
// TODO(akalin): Remove support for CREDENTIAL frames.
typedef struct z_stream_s z_stream; // Forward declaration for zlib.
namespace net {
class HttpProxyClientSocketPoolTest;
class HttpNetworkLayer;
class HttpNetworkTransactionTest;
class SpdyHttpStreamTest;
class SpdyNetworkTransactionTest;
class SpdyProxyClientSocketTest;
class SpdySessionTest;
class SpdyStreamTest;
class SpdyFramer;
class SpdyFrameBuilder;
class SpdyFramerTest;
namespace test {
class TestSpdyVisitor;
} // namespace test
// A datastructure for holding a set of headers from a HEADERS, PUSH_PROMISE,
// SYN_STREAM, or SYN_REPLY frame.
typedef std::map<std::string, std::string> SpdyHeaderBlock;
// A datastructure for holding the ID and flag fields for SETTINGS.
// Conveniently handles converstion to/from wire format.
class NET_EXPORT_PRIVATE SettingsFlagsAndId {
static SettingsFlagsAndId FromWireFormat(SpdyMajorVersion version,
uint32 wire);
SettingsFlagsAndId() : flags_(0), id_(0) {}
// TODO(hkhalil): restrict to enums instead of free-form ints.
SettingsFlagsAndId(uint8 flags, uint32 id);
uint32 GetWireFormat(SpdyMajorVersion version) const;
uint32 id() const { return id_; }
uint8 flags() const { return flags_; }
static void ConvertFlagsAndIdForSpdy2(uint32* val);
uint8 flags_;
uint32 id_;
// SettingsMap has unique (flags, value) pair for given SpdySettingsIds ID.
typedef std::pair<SpdySettingsFlags, uint32> SettingsFlagsAndValue;
typedef std::map<SpdySettingsIds, SettingsFlagsAndValue> SettingsMap;
// Scratch space necessary for processing SETTINGS frames.
struct NET_EXPORT_PRIVATE SpdySettingsScratch {
SpdySettingsScratch() { Reset(); }
void Reset() {
setting_buf_len = 0;
last_setting_id = -1;
// Buffer contains up to one complete key/value pair.
char setting_buf[8];
// The amount of the buffer that is filled with valid data.
size_t setting_buf_len;
// The ID of the last setting that was processed in the current SETTINGS
// frame. Used for detecting out-of-order or duplicate keys within a settings
// frame. Set to -1 before first key/value pair is processed.
int last_setting_id;
// Scratch space necessary for processing ALTSVC frames.
struct NET_EXPORT_PRIVATE SpdyAltSvcScratch {
void Reset() {
max_age = 0;
port = 0;
pid_len = 0;
host_len = 0;
origin_len = 0;
pid_buf_len = 0;
host_buf_len = 0;
origin_buf_len = 0;
uint32 max_age;
uint16 port;
uint8 pid_len;
uint8 host_len;
size_t origin_len;
size_t pid_buf_len;
size_t host_buf_len;
size_t origin_buf_len;
scoped_ptr<char[]> protocol_id;
scoped_ptr<char[]> host;
scoped_ptr<char[]> origin;
// SpdyFramerVisitorInterface is a set of callbacks for the SpdyFramer.
// Implement this interface to receive event callbacks as frames are
// decoded from the framer.
// Control frames that contain SPDY header blocks (SYN_STREAM, SYN_REPLY,
// HEADER, and PUSH_PROMISE) are processed in fashion that allows the
// decompressed header block to be delivered in chunks to the visitor.
// The following steps are followed:
// 1. OnSynStream, OnSynReply, OnHeaders, or OnPushPromise is called.
// 2. Repeated: OnControlFrameHeaderData is called with chunks of the
// decompressed header block. In each call the len parameter is greater
// than zero.
// 3. OnControlFrameHeaderData is called with len set to zero, indicating
// that the full header block has been delivered for the control frame.
// During step 2 the visitor may return false, indicating that the chunk of
// header data could not be handled by the visitor (typically this indicates
// resource exhaustion). If this occurs the framer will discontinue
// delivering chunks to the visitor, set a SPDY_CONTROL_PAYLOAD_TOO_LARGE
// error, and clean up appropriately. Note that this will cause the header
// decompressor to lose synchronization with the sender's header compressor,
// making the SPDY session unusable for future work. The visitor's OnError
// function should deal with this condition by closing the SPDY connection.
class NET_EXPORT_PRIVATE SpdyFramerVisitorInterface {
virtual ~SpdyFramerVisitorInterface() {}
// Called if an error is detected in the SpdyFrame protocol.
virtual void OnError(SpdyFramer* framer) = 0;
// Called when a data frame header is received. The frame's data
// payload will be provided via subsequent calls to
// OnStreamFrameData().
virtual void OnDataFrameHeader(SpdyStreamId stream_id,
size_t length,
bool fin) = 0;
// Called when data is received.
// |stream_id| The stream receiving data.
// |data| A buffer containing the data received.
// |len| The length of the data buffer.
// When the other side has finished sending data on this stream,
// this method will be called with a zero-length buffer.
virtual void OnStreamFrameData(SpdyStreamId stream_id,
const char* data,
size_t len,
bool fin) = 0;
// Called when a chunk of header data is available. This is called
// after OnSynStream, OnSynReply, OnHeaders(), or OnPushPromise.
// |stream_id| The stream receiving the header data.
// |header_data| A buffer containing the header data chunk received.
// |len| The length of the header data buffer. A length of zero indicates
// that the header data block has been completely sent.
// When this function returns true the visitor indicates that it accepted
// all of the data. Returning false indicates that that an unrecoverable
// error has occurred, such as bad header data or resource exhaustion.
virtual bool OnControlFrameHeaderData(SpdyStreamId stream_id,
const char* header_data,
size_t len) = 0;
// Called when a SYN_STREAM frame is received.
// Note that header block data is not included. See
// OnControlFrameHeaderData().
virtual void OnSynStream(SpdyStreamId stream_id,
SpdyStreamId associated_stream_id,
SpdyPriority priority,
bool fin,
bool unidirectional) = 0;
// Called when a SYN_REPLY frame is received.
// Note that header block data is not included. See
// OnControlFrameHeaderData().
virtual void OnSynReply(SpdyStreamId stream_id, bool fin) = 0;
// Called when a RST_STREAM frame has been parsed.
virtual void OnRstStream(SpdyStreamId stream_id,
SpdyRstStreamStatus status) = 0;
// Called when a SETTINGS frame is received.
// |clear_persisted| True if the respective flag is set on the SETTINGS frame.
virtual void OnSettings(bool clear_persisted) {}
// Called when a complete setting within a SETTINGS frame has been parsed and
// validated.
virtual void OnSetting(SpdySettingsIds id, uint8 flags, uint32 value) = 0;
// Called when a SETTINGS frame is received with the ACK flag set.
virtual void OnSettingsAck() {}
// Called before and after parsing SETTINGS id and value tuples.
virtual void OnSettingsEnd() = 0;
// Called when a PING frame has been parsed.
virtual void OnPing(SpdyPingId unique_id, bool is_ack) = 0;
// Called when a GOAWAY frame has been parsed.
virtual void OnGoAway(SpdyStreamId last_accepted_stream_id,
SpdyGoAwayStatus status) = 0;
// Called when a HEADERS frame is received.
// Note that header block data is not included. See
// OnControlFrameHeaderData().
virtual void OnHeaders(SpdyStreamId stream_id,
bool has_priority,
SpdyPriority priority,
bool fin,
bool end) = 0;
// Called when a WINDOW_UPDATE frame has been parsed.
virtual void OnWindowUpdate(SpdyStreamId stream_id,
uint32 delta_window_size) = 0;
// Called when a goaway frame opaque data is available.
// |goaway_data| A buffer containing the opaque GOAWAY data chunk received.
// |len| The length of the header data buffer. A length of zero indicates
// that the header data block has been completely sent.
// When this function returns true the visitor indicates that it accepted
// all of the data. Returning false indicates that that an error has
// occurred while processing the data. Default implementation returns true.
virtual bool OnGoAwayFrameData(const char* goaway_data, size_t len);
// Called when rst_stream frame opaque data is available.
// |rst_stream_data| A buffer containing the opaque RST_STREAM
// data chunk received.
// |len| The length of the header data buffer. A length of zero indicates
// that the opaque data has been completely sent.
// When this function returns true the visitor indicates that it accepted
// all of the data. Returning false indicates that that an error has
// occurred while processing the data. Default implementation returns true.
virtual bool OnRstStreamFrameData(const char* rst_stream_data, size_t len);
// Called when a BLOCKED frame has been parsed.
virtual void OnBlocked(SpdyStreamId stream_id) {}
// Called when a PUSH_PROMISE frame is received.
// Note that header block data is not included. See
// OnControlFrameHeaderData().
virtual void OnPushPromise(SpdyStreamId stream_id,
SpdyStreamId promised_stream_id,
bool end) = 0;
// Called when a CONTINUATION frame is received.
// Note that header block data is not included. See
// OnControlFrameHeaderData().
virtual void OnContinuation(SpdyStreamId stream_id, bool end) = 0;
// Called when an ALTSVC frame has been parsed.
virtual void OnAltSvc(SpdyStreamId stream_id,
uint32 max_age,
uint16 port,
base::StringPiece protocol_id,
base::StringPiece host,
base::StringPiece origin) {}
// Called when a PRIORITY frame is received.
virtual void OnPriority(SpdyStreamId stream_id,
SpdyStreamId parent_stream_id,
uint8 weight,
bool exclusive) {}
// Called when a frame type we don't recognize is received.
// Return true if this appears to be a valid extension frame, false otherwise.
// We distinguish between extension frames and nonsense by checking
// whether the stream id is valid.
virtual bool OnUnknownFrame(SpdyStreamId stream_id, int frame_type) = 0;
// Optionally, and in addition to SpdyFramerVisitorInterface, a class supporting
// SpdyFramerDebugVisitorInterface may be used in conjunction with SpdyFramer in
// order to extract debug/internal information about the SpdyFramer as it
// operates.
// Most SPDY implementations need not bother with this interface at all.
class NET_EXPORT_PRIVATE SpdyFramerDebugVisitorInterface {
virtual ~SpdyFramerDebugVisitorInterface() {}
// Called after compressing a frame with a payload of
// a list of name-value pairs.
// |payload_len| is the uncompressed payload size.
// |frame_len| is the compressed frame size.
virtual void OnSendCompressedFrame(SpdyStreamId stream_id,
SpdyFrameType type,
size_t payload_len,
size_t frame_len) {}
// Called when a frame containing a compressed payload of
// name-value pairs is received.
// |frame_len| is the compressed frame size.
virtual void OnReceiveCompressedFrame(SpdyStreamId stream_id,
SpdyFrameType type,
size_t frame_len) {}
class NET_EXPORT_PRIVATE SpdyFramer {
// SPDY states.
// TODO(mbelshe): Can we move these into the implementation
// and avoid exposing through the header. (Needed for test)
enum SpdyState {
// SPDY error codes.
enum SpdyError {
SPDY_INVALID_CONTROL_FRAME, // Control frame is mal-formatted.
SPDY_CONTROL_PAYLOAD_TOO_LARGE, // Control frame payload was too large.
SPDY_ZLIB_INIT_FAILURE, // The Zlib library could not initialize.
SPDY_UNSUPPORTED_VERSION, // Control frame has unsupported version.
SPDY_DECOMPRESS_FAILURE, // There was an error decompressing.
SPDY_COMPRESS_FAILURE, // There was an error compressing.
SPDY_GOAWAY_FRAME_CORRUPT, // GOAWAY frame could not be parsed.
SPDY_RST_STREAM_FRAME_CORRUPT, // RST_STREAM frame could not be parsed.
SPDY_INVALID_DATA_FRAME_FLAGS, // Data frame has invalid flags.
SPDY_INVALID_CONTROL_FRAME_FLAGS, // Control frame has invalid flags.
SPDY_UNEXPECTED_FRAME, // Frame received out of order.
LAST_ERROR, // Must be the last entry in the enum.
// Constant for invalid (or unknown) stream IDs.
static const SpdyStreamId kInvalidStream;
// The maximum size of header data chunks delivered to the framer visitor
// through OnControlFrameHeaderData. (It is exposed here for unit test
// purposes.)
static const size_t kHeaderDataChunkMaxSize;
// Serializes a SpdyHeaderBlock.
static void WriteHeaderBlock(SpdyFrameBuilder* frame,
const SpdyMajorVersion spdy_version,
const SpdyHeaderBlock* headers);
// Retrieve serialized length of SpdyHeaderBlock.
// TODO(hkhalil): Remove, or move to quic code.
static size_t GetSerializedLength(
const SpdyMajorVersion spdy_version,
const SpdyHeaderBlock* headers);
// Create a new Framer, provided a SPDY version.
explicit SpdyFramer(SpdyMajorVersion version);
virtual ~SpdyFramer();
// Set callbacks to be called from the framer. A visitor must be set, or
// else the framer will likely crash. It is acceptable for the visitor
// to do nothing. If this is called multiple times, only the last visitor
// will be used.
void set_visitor(SpdyFramerVisitorInterface* visitor) {
visitor_ = visitor;
// Set debug callbacks to be called from the framer. The debug visitor is
// completely optional and need not be set in order for normal operation.
// If this is called multiple times, only the last visitor will be used.
void set_debug_visitor(SpdyFramerDebugVisitorInterface* debug_visitor) {
debug_visitor_ = debug_visitor;
// Pass data into the framer for parsing.
// Returns the number of bytes consumed. It is safe to pass more bytes in
// than may be consumed.
size_t ProcessInput(const char* data, size_t len);
// Resets the framer state after a frame has been successfully decoded.
// TODO(mbelshe): can we make this private?
void Reset();
// Check the state of the framer.
SpdyError error_code() const { return error_code_; }
SpdyState state() const { return state_; }
bool HasError() const { return state_ == SPDY_ERROR; }
// Given a buffer containing a decompressed header block in SPDY
// serialized format, parse out a SpdyHeaderBlock, putting the results
// in the given header block.
// Returns number of bytes consumed if successfully parsed, 0 otherwise.
size_t ParseHeaderBlockInBuffer(const char* header_data,
size_t header_length,
SpdyHeaderBlock* block) const;
// Serialize a data frame.
SpdySerializedFrame* SerializeData(const SpdyDataIR& data) const;
// Serializes the data frame header and optionally padding length fields,
// excluding actual data payload and padding.
SpdySerializedFrame* SerializeDataFrameHeaderWithPaddingLengthField(
const SpdyDataIR& data) const;
// Serializes a SYN_STREAM frame.
SpdySerializedFrame* SerializeSynStream(const SpdySynStreamIR& syn_stream);
// Serialize a SYN_REPLY SpdyFrame.
SpdySerializedFrame* SerializeSynReply(const SpdySynReplyIR& syn_reply);
SpdySerializedFrame* SerializeRstStream(
const SpdyRstStreamIR& rst_stream) const;
// Serializes a SETTINGS frame. The SETTINGS frame is
// used to communicate name/value pairs relevant to the communication channel.
SpdySerializedFrame* SerializeSettings(const SpdySettingsIR& settings) const;
// Serializes a PING frame. The unique_id is used to
// identify the ping request/response.
SpdySerializedFrame* SerializePing(const SpdyPingIR& ping) const;
// Serializes a GOAWAY frame. The GOAWAY frame is used
// prior to the shutting down of the TCP connection, and includes the
// stream_id of the last stream the sender of the frame is willing to process
// to completion.
SpdySerializedFrame* SerializeGoAway(const SpdyGoAwayIR& goaway) const;
// Serializes a HEADERS frame. The HEADERS frame is used
// for sending additional headers outside of a SYN_STREAM/SYN_REPLY.
SpdySerializedFrame* SerializeHeaders(const SpdyHeadersIR& headers);
// Serializes a WINDOW_UPDATE frame. The WINDOW_UPDATE
// frame is used to implement per stream flow control in SPDY.
SpdySerializedFrame* SerializeWindowUpdate(
const SpdyWindowUpdateIR& window_update) const;
// Serializes a BLOCKED frame. The BLOCKED frame is used to
// indicate to the remote endpoint that this endpoint believes itself to be
// flow-control blocked but otherwise ready to send data. The BLOCKED frame
// is purely advisory and optional.
SpdySerializedFrame* SerializeBlocked(const SpdyBlockedIR& blocked) const;
// Serializes a PUSH_PROMISE frame. The PUSH_PROMISE frame is used
// to inform the client that it will be receiving an additional stream
// in response to the original request. The frame includes synthesized
// headers to explain the upcoming data.
SpdySerializedFrame* SerializePushPromise(
const SpdyPushPromiseIR& push_promise);
// Serializes a CONTINUATION frame. The CONTINUATION frame is used
// to continue a sequence of header block fragments.
// TODO(jgraettinger): This implementation is incorrect. The continuation
// frame continues a previously-begun HPACK encoding; it doesn't begin a
// new one. Figure out whether it makes sense to keep SerializeContinuation().
SpdySerializedFrame* SerializeContinuation(
const SpdyContinuationIR& continuation);
// Serializes an ALTSVC frame. The ALTSVC frame advertises the
// availability of an alternative service to the client.
SpdySerializedFrame* SerializeAltSvc(const SpdyAltSvcIR& altsvc);
// Serializes a PRIORITY frame. The PRIORITY frame advises a change in
// the relative priority of the given stream.
SpdySerializedFrame* SerializePriority(const SpdyPriorityIR& priority) const;
// Serialize a frame of unknown type.
SpdySerializedFrame* SerializeFrame(const SpdyFrameIR& frame);
// NOTES about frame compression.
// We want spdy to compress headers across the entire session. As long as
// the session is over TCP, frames are sent serially. The client & server
// can each compress frames in the same order and then compress them in that
// order, and the remote can do the reverse. However, we ultimately want
// the creation of frames to be less sensitive to order so that they can be
// placed over a UDP based protocol and yet still benefit from some
// compression. We don't know of any good compression protocol which does
// not build its state in a serial (stream based) manner.... For now, we're
// using zlib anyway.
// Compresses a SpdyFrame.
// On success, returns a new SpdyFrame with the payload compressed.
// Compression state is maintained as part of the SpdyFramer.
// Returned frame must be freed with "delete".
// On failure, returns NULL.
SpdyFrame* CompressFrame(const SpdyFrame& frame);
// For ease of testing and experimentation we can tweak compression on/off.
void set_enable_compression(bool value) {
enable_compression_ = value;
// Used only in log messages.
void set_display_protocol(const std::string& protocol) {
display_protocol_ = protocol;
// Returns the (minimum) size of frames (sans variable-length portions).
size_t GetDataFrameMinimumSize() const;
size_t GetControlFrameHeaderSize() const;
size_t GetSynStreamMinimumSize() const;
size_t GetSynReplyMinimumSize() const;
size_t GetRstStreamMinimumSize() const;
size_t GetSettingsMinimumSize() const;
size_t GetPingSize() const;
size_t GetGoAwayMinimumSize() const;
size_t GetHeadersMinimumSize() const;
size_t GetWindowUpdateSize() const;
size_t GetBlockedSize() const;
size_t GetPushPromiseMinimumSize() const;
size_t GetContinuationMinimumSize() const;
size_t GetAltSvcMinimumSize() const;
size_t GetPrioritySize() const;
// Returns the minimum size a frame can be (data or control).
size_t GetFrameMinimumSize() const;
// Returns the maximum size a frame can be (data or control).
size_t GetFrameMaximumSize() const;
// Returns the maximum size that a control frame can be.
size_t GetControlFrameMaximumSize() const;
// Returns the maximum payload size of a DATA frame.
size_t GetDataFrameMaximumPayload() const;
// Returns the prefix length for the given frame type.
size_t GetPrefixLength(SpdyFrameType type) const;
// For debugging.
static const char* StateToString(int state);
static const char* ErrorCodeToString(int error_code);
static const char* StatusCodeToString(int status_code);
static const char* FrameTypeToString(SpdyFrameType type);
SpdyMajorVersion protocol_version() const { return protocol_version_; }
bool probable_http_response() const { return probable_http_response_; }
SpdyStreamId expect_continuation() const { return expect_continuation_; }
SpdyPriority GetLowestPriority() const {
return protocol_version_ < SPDY3 ? 3 : 7;
SpdyPriority GetHighestPriority() const { return 0; }
// Interpolates SpdyPriority values into SPDY4/HTTP2 priority weights,
// and vice versa.
static uint8 MapPriorityToWeight(SpdyPriority priority);
static SpdyPriority MapWeightToPriority(uint8 weight);
// Deliver the given control frame's compressed headers block to the visitor
// in decompressed form, in chunks. Returns true if the visitor has
// accepted all of the chunks.
bool IncrementallyDecompressControlFrameHeaderData(
SpdyStreamId stream_id,
const char* data,
size_t len);
// TODO(jgraettinger): Switch to test peer pattern.
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, BasicCompression);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, ControlFrameSizesAreValidated);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, HeaderCompression);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, DecompressUncompressedFrame);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, ExpandBuffer_HeapSmash);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, HugeHeaderBlock);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, UnclosedStreamDataCompressors);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, ReadLargeSettingsFrame);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, ControlFrameAtMaxSizeLimit);
FRIEND_TEST_ALL_PREFIXES(SpdyFramerTest, ControlFrameTooLarge);
friend class HttpNetworkLayer; // This is temporary for the server.
friend class HttpNetworkTransactionTest;
friend class HttpProxyClientSocketPoolTest;
friend class SpdyHttpStreamTest;
friend class SpdyNetworkTransactionTest;
friend class SpdyProxyClientSocketTest;
friend class SpdySessionTest;
friend class SpdyStreamTest;
friend class test::TestSpdyVisitor;
// Internal breakouts from ProcessInput. Each returns the number of bytes
// consumed from the data.
size_t ProcessCommonHeader(const char* data, size_t len);
size_t ProcessControlFramePayload(const char* data, size_t len);
size_t ProcessControlFrameBeforeHeaderBlock(const char* data, size_t len);
// HPACK data is re-encoded as SPDY3 and re-entrantly delivered through
// |ProcessControlFrameHeaderBlock()|. |is_hpack_header_block| controls
// whether data is treated as HPACK- vs SPDY3-encoded.
size_t ProcessControlFrameHeaderBlock(const char* data,
size_t len,
bool is_hpack_header_block);
size_t ProcessDataFramePaddingLength(const char* data, size_t len);
size_t ProcessFramePadding(const char* data, size_t len);
size_t ProcessDataFramePayload(const char* data, size_t len);
size_t ProcessGoAwayFramePayload(const char* data, size_t len);
size_t ProcessRstStreamFramePayload(const char* data, size_t len);
size_t ProcessSettingsFramePayload(const char* data, size_t len);
size_t ProcessAltSvcFramePayload(const char* data, size_t len);
size_t ProcessIgnoredControlFramePayload(/*const char* data,*/ size_t len);
// TODO(jgraettinger): To be removed with migration to
// SpdyHeadersHandlerInterface.
// Serializes the last-processed header block of |hpack_decoder_| as
// a SPDY3 format block, and delivers it to the visitor via reentrant
// call to ProcessControlFrameHeaderBlock().
void DeliverHpackBlockAsSpdy3Block();
// Helpers for above internal breakouts from ProcessInput.
void ProcessControlFrameHeader(int control_frame_type_field);
// Always passed exactly 1 setting's worth of data.
bool ProcessSetting(const char* data);
// Retrieve serialized length of SpdyHeaderBlock. If compression is enabled, a
// maximum estimate is returned.
size_t GetSerializedLength(const SpdyHeaderBlock& headers);
// Get (and lazily initialize) the ZLib state.
z_stream* GetHeaderCompressor();
z_stream* GetHeaderDecompressor();
// Get (and lazily initialize) the HPACK state.
HpackEncoder* GetHpackEncoder();
HpackDecoder* GetHpackDecoder();
size_t GetNumberRequiredContinuationFrames(size_t size);
void WritePayloadWithContinuation(SpdyFrameBuilder* builder,
const std::string& hpack_encoding,
SpdyStreamId stream_id,
SpdyFrameType type,
int padding_payload_len);
// Deliver the given control frame's uncompressed headers block to the
// visitor in chunks. Returns true if the visitor has accepted all of the
// chunks.
bool IncrementallyDeliverControlFrameHeaderData(SpdyStreamId stream_id,
const char* data,
size_t len);
// Utility to copy the given data block to the current frame buffer, up
// to the given maximum number of bytes, and update the buffer
// data (pointer and length). Returns the number of bytes
// read, and:
// *data is advanced the number of bytes read.
// *len is reduced by the number of bytes read.
size_t UpdateCurrentFrameBuffer(const char** data, size_t* len,
size_t max_bytes);
void WriteHeaderBlockToZ(const SpdyHeaderBlock* headers,
z_stream* out) const;
void SerializeNameValueBlockWithoutCompression(
SpdyFrameBuilder* builder,
const SpdyNameValueBlock& name_value_block) const;
// Compresses automatically according to enable_compression_.
void SerializeNameValueBlock(
SpdyFrameBuilder* builder,
const SpdyFrameWithNameValueBlockIR& frame);
// Set the error code and moves the framer into the error state.
void set_error(SpdyError error);
// The size of the control frame buffer.
// Since this is only used for control frame headers, the maximum control
// frame header size (SYN_STREAM) is sufficient; all remaining control
// frame data is streamed to the visitor.
static const size_t kControlFrameBufferSize;
// The maximum size of the control frames that we support.
// This limit is arbitrary. We can enforce it here or at the application
// layer. We chose the framing layer, but this can be changed (or removed)
// if necessary later down the line.
static const size_t kMaxControlFrameSize;
SpdyState state_;
SpdyState previous_state_;
SpdyError error_code_;
// Note that for DATA frame, remaining_data_length_ is sum of lengths of
// frame header, padding length field (optional), data payload (optional) and
// padding payload (optional).
size_t remaining_data_length_;
// The length (in bytes) of the padding payload to be processed.
size_t remaining_padding_payload_length_;
// The number of bytes remaining to read from the current control frame's
// headers. Note that header data blocks (for control types that have them)
// are part of the frame's payload, and not the frame's headers.
size_t remaining_control_header_;
scoped_ptr<char[]> current_frame_buffer_;
// Number of bytes read into the current_frame_buffer_.
size_t current_frame_buffer_length_;
// The type of the frame currently being read.
SpdyFrameType current_frame_type_;
// The flags field of the frame currently being read.
uint8 current_frame_flags_;
// The total length of the frame currently being read, including frame header.
uint32 current_frame_length_;
// The stream ID field of the frame currently being read, if applicable.
SpdyStreamId current_frame_stream_id_;
// Scratch space for handling SETTINGS frames.
// TODO(hkhalil): Unify memory for this scratch space with
// current_frame_buffer_.
SpdySettingsScratch settings_scratch_;
SpdyAltSvcScratch altsvc_scratch_;
bool enable_compression_; // Controls all compression
// SPDY header compressors.
scoped_ptr<z_stream> header_compressor_;
scoped_ptr<z_stream> header_decompressor_;
scoped_ptr<HpackEncoder> hpack_encoder_;
scoped_ptr<HpackDecoder> hpack_decoder_;
SpdyFramerVisitorInterface* visitor_;
SpdyFramerDebugVisitorInterface* debug_visitor_;
std::string display_protocol_;
// The protocol version to be spoken/understood by this framer.
const SpdyMajorVersion protocol_version_;
// Tracks if we've ever gotten far enough in framing to see a control frame of
// If we ever get something which looks like a data frame before we've had a
// SYN, we explicitly check to see if it looks like we got an HTTP response
// to a SPDY request. This boolean lets us do that.
bool syn_frame_processed_;
// If we ever get a data frame before a SYN frame, we check to see if it
// starts with HTTP. If it does, we likely have an HTTP response. This
// isn't guaranteed though: we could have gotten a settings frame and then
// corrupt data that just looks like HTTP, but deterministic checking requires
// a lot more state.
bool probable_http_response_;
// Set this to the current stream when we receive a HEADERS, PUSH_PROMISE, or
// CONTINUATION frame without the END_HEADERS(0x4) bit set. These frames must
// be followed by a CONTINUATION frame, or else we throw a PROTOCOL_ERROR.
// A value of 0 indicates that we are not expecting a CONTINUATION frame.
SpdyStreamId expect_continuation_;
// If a HEADERS frame is followed by a CONTINUATION frame, the FIN/END_STREAM
// flag is still carried in the HEADERS frame. If it's set, flip this so that
// we know to terminate the stream when the entire header block has been
// processed.
bool end_stream_when_done_;
} // namespace net