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// Copyright (c) 2018 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 QUICHE_QUIC_CORE_HTTP_HTTP_DECODER_H_
#define QUICHE_QUIC_CORE_HTTP_HTTP_DECODER_H_
#include "net/third_party/quiche/src/quic/core/http/http_frames.h"
#include "net/third_party/quiche/src/quic/core/quic_error_codes.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_export.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_string_piece.h"
namespace quic {
namespace test {
class HttpDecoderPeer;
} // namespace test
class QuicDataReader;
// Struct that stores meta data of an HTTP/3 frame.
// |header_length| is frame header length in bytes.
// |payload_length| is frame payload length in bytes.
struct QUIC_EXPORT_PRIVATE Http3FrameLengths {
Http3FrameLengths(QuicByteCount header, QuicByteCount payload)
: header_length(header), payload_length(payload) {}
bool operator==(const Http3FrameLengths& other) const {
return (header_length == other.header_length) &&
(payload_length == other.payload_length);
}
QuicByteCount header_length;
QuicByteCount payload_length;
};
// A class for decoding the HTTP frames that are exchanged in an HTTP over QUIC
// session.
class QUIC_EXPORT_PRIVATE HttpDecoder {
public:
class QUIC_EXPORT_PRIVATE Visitor {
public:
virtual ~Visitor() {}
// Called if an error is detected.
virtual void OnError(HttpDecoder* decoder) = 0;
// All the following methods return true to continue decoding,
// and false to pause it.
// Called when a PRIORITY frame has been received.
// |frame_length| contains PRIORITY frame length and payload length.
virtual bool OnPriorityFrameStart(Http3FrameLengths frame_length) = 0;
// Called when a PRIORITY frame has been successfully parsed.
virtual bool OnPriorityFrame(const PriorityFrame& frame) = 0;
// Called when a CANCEL_PUSH frame has been successfully parsed.
virtual bool OnCancelPushFrame(const CancelPushFrame& frame) = 0;
// Called when a MAX_PUSH_ID frame has been successfully parsed.
virtual bool OnMaxPushIdFrame(const MaxPushIdFrame& frame) = 0;
// Called when a GOAWAY frame has been successfully parsed.
virtual bool OnGoAwayFrame(const GoAwayFrame& frame) = 0;
// Called when a SETTINGS frame has been received.
virtual bool OnSettingsFrameStart(Http3FrameLengths frame_length) = 0;
// Called when a SETTINGS frame has been successfully parsed.
virtual bool OnSettingsFrame(const SettingsFrame& frame) = 0;
// Called when a DUPLICATE_PUSH frame has been successfully parsed.
virtual bool OnDuplicatePushFrame(const DuplicatePushFrame& frame) = 0;
// Called when a DATA frame has been received.
// |frame_length| contains DATA frame length and payload length.
virtual bool OnDataFrameStart(Http3FrameLengths frame_length) = 0;
// Called when part of the payload of a DATA frame has been read. May be
// called multiple times for a single frame. |payload| is guaranteed to be
// non-empty.
virtual bool OnDataFramePayload(QuicStringPiece payload) = 0;
// Called when a DATA frame has been completely processed.
virtual bool OnDataFrameEnd() = 0;
// Called when a HEADERS frame has been received.
// |frame_length| contains HEADERS frame length and payload length.
virtual bool OnHeadersFrameStart(Http3FrameLengths frame_length) = 0;
// Called when part of the payload of a HEADERS frame has been read. May be
// called multiple times for a single frame. |payload| is guaranteed to be
// non-empty.
virtual bool OnHeadersFramePayload(QuicStringPiece payload) = 0;
// Called when a HEADERS frame has been completely processed.
// |frame_len| is the length of the HEADERS frame payload.
virtual bool OnHeadersFrameEnd() = 0;
// Called when a PUSH_PROMISE frame has been received for |push_id|.
virtual bool OnPushPromiseFrameStart(PushId push_id) = 0;
// Called when part of the payload of a PUSH_PROMISE frame has been read.
// May be called multiple times for a single frame. |payload| is guaranteed
// to be non-empty.
virtual bool OnPushPromiseFramePayload(QuicStringPiece payload) = 0;
// Called when a PUSH_PROMISE frame has been completely processed.
virtual bool OnPushPromiseFrameEnd() = 0;
// TODO(rch): Consider adding methods like:
// OnUnknownFrame{Start,Payload,End}()
// to allow callers to handle unknown frames.
};
HttpDecoder();
~HttpDecoder();
// Set callbacks to be called from the decoder. A visitor must be set, or
// else the decoder will crash. It is acceptable for the visitor to do
// nothing. If this is called multiple times, only the last visitor
// will be used. |visitor| will be owned by the caller.
void set_visitor(Visitor* visitor) { visitor_ = visitor; }
// Processes the input and invokes the appropriate visitor methods, until a
// visitor method returns false or an error occurs. Returns the number of
// bytes processed. Does not process any input if called after an error.
// Paused processing can be resumed by calling ProcessInput() again with the
// unprocessed portion of data. Must not be called after an error has
// occurred.
QuicByteCount ProcessInput(const char* data, QuicByteCount len);
// Returns an error code other than QUIC_NO_ERROR if and only if
// Visitor::OnError() has been called.
QuicErrorCode error() const { return error_; }
const std::string& error_detail() const { return error_detail_; }
private:
friend test::HttpDecoderPeer;
// Represents the current state of the parsing state machine.
enum HttpDecoderState {
STATE_READING_FRAME_LENGTH,
STATE_READING_FRAME_TYPE,
STATE_READING_FRAME_PAYLOAD,
STATE_FINISH_PARSING,
STATE_ERROR
};
// Reads the type of a frame from |reader|. Sets error_ and error_detail_
// if there are any errors. Also calls OnDataFrameStart() or
// OnHeadersFrameStart() for appropriate frame types.
void ReadFrameType(QuicDataReader* reader);
// Reads the length of a frame from |reader|. Sets error_ and error_detail_
// if there are any errors. Returns whether processing should continue.
bool ReadFrameLength(QuicDataReader* reader);
// Reads the payload of the current frame from |reader| and processes it,
// possibly buffering the data or invoking the visitor. Returns whether
// processing should continue.
bool ReadFramePayload(QuicDataReader* reader);
// Optionally parses buffered data; calls visitor method to signal that frame
// had been parsed completely. Returns whether processing should continue.
bool FinishParsing();
// Discards any remaining frame payload from |reader|.
void DiscardFramePayload(QuicDataReader* reader);
// Buffers any remaining frame payload from |reader| into |buffer_|.
void BufferFramePayload(QuicDataReader* reader);
// Buffers any remaining frame length field from |reader| into
// |length_buffer_|.
void BufferFrameLength(QuicDataReader* reader);
// Buffers any remaining frame type field from |reader| into |type_buffer_|.
void BufferFrameType(QuicDataReader* reader);
// Sets |error_| and |error_detail_| accordingly.
void RaiseError(QuicErrorCode error, std::string error_detail);
// Parses the payload of a PRIORITY frame from |reader| into |frame|.
bool ParsePriorityFrame(QuicDataReader* reader, PriorityFrame* frame);
// Parses the payload of a SETTINGS frame from |reader| into |frame|.
bool ParseSettingsFrame(QuicDataReader* reader, SettingsFrame* frame);
// Returns the max frame size of a given |frame_type|.
QuicByteCount MaxFrameLength(uint8_t frame_type);
// Visitor to invoke when messages are parsed.
Visitor* visitor_; // Unowned.
// Current state of the parsing.
HttpDecoderState state_;
// Type of the frame currently being parsed.
uint64_t current_frame_type_;
// Size of the frame's length field.
QuicByteCount current_length_field_length_;
// Remaining length that's needed for the frame's length field.
QuicByteCount remaining_length_field_length_;
// Length of the payload of the frame currently being parsed.
QuicByteCount current_frame_length_;
// Remaining payload bytes to be parsed.
QuicByteCount remaining_frame_length_;
// Length of the frame's type field.
QuicByteCount current_type_field_length_;
// Remaining length that's needed for the frame's type field.
QuicByteCount remaining_type_field_length_;
// Last error.
QuicErrorCode error_;
// The issue which caused |error_|
std::string error_detail_;
// Remaining unparsed data.
std::string buffer_;
// Remaining unparsed length field data.
std::array<char, sizeof(uint64_t)> length_buffer_;
// Remaining unparsed type field data.
std::array<char, sizeof(uint64_t)> type_buffer_;
};
} // namespace quic
#endif // QUICHE_QUIC_CORE_HTTP_HTTP_DECODER_H_