| // 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 <cstdint> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/quic/core/http/http_frames.h" |
| #include "quiche/quic/core/quic_error_codes.h" |
| #include "quiche/quic/core/quic_types.h" |
| #include "quiche/quic/platform/api/quic_export.h" |
| |
| namespace quic { |
| |
| namespace test { |
| |
| class HttpDecoderPeer; |
| |
| } // namespace test |
| |
| class QuicDataReader; |
| |
| // A class for decoding the HTTP frames that are exchanged in an HTTP over QUIC |
| // session. |
| class QUIC_EXPORT_PRIVATE HttpDecoder { |
| public: |
| struct QUIC_EXPORT_PRIVATE Options { |
| // Indicates that WEBTRANSPORT_STREAM should be parsed. |
| bool allow_web_transport_stream = false; |
| }; |
| |
| 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. |
| // On*FrameStart() methods are called after the frame header is completely |
| // processed. At that point it is safe to consume |header_length| bytes. |
| |
| // Called when a MAX_PUSH_ID frame has been successfully parsed. |
| virtual bool OnMaxPushIdFrame() = 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(QuicByteCount header_length) = 0; |
| |
| // Called when a SETTINGS frame has been successfully parsed. |
| virtual bool OnSettingsFrame(const SettingsFrame& frame) = 0; |
| |
| // Called when a DATA frame has been received. |
| // |header_length| and |payload_length| are the length of DATA frame header |
| // and payload, respectively. |
| virtual bool OnDataFrameStart(QuicByteCount header_length, |
| QuicByteCount payload_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(absl::string_view payload) = 0; |
| // Called when a DATA frame has been completely processed. |
| virtual bool OnDataFrameEnd() = 0; |
| |
| // Called when a HEADERS frame has been received. |
| // |header_length| and |payload_length| are the length of HEADERS frame |
| // header and payload, respectively. |
| virtual bool OnHeadersFrameStart(QuicByteCount header_length, |
| QuicByteCount payload_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(absl::string_view payload) = 0; |
| // Called when a HEADERS frame has been completely processed. |
| virtual bool OnHeadersFrameEnd() = 0; |
| |
| // Called when a PRIORITY_UPDATE frame has been received. |
| // |header_length| contains PRIORITY_UPDATE frame length and payload length. |
| virtual bool OnPriorityUpdateFrameStart(QuicByteCount header_length) = 0; |
| |
| // Called when a PRIORITY_UPDATE frame has been successfully parsed. |
| virtual bool OnPriorityUpdateFrame(const PriorityUpdateFrame& frame) = 0; |
| |
| // Called when an ACCEPT_CH frame has been received. |
| // |header_length| contains ACCEPT_CH frame length and payload length. |
| virtual bool OnAcceptChFrameStart(QuicByteCount header_length) = 0; |
| |
| // Called when an ACCEPT_CH frame has been successfully parsed. |
| virtual bool OnAcceptChFrame(const AcceptChFrame& frame) = 0; |
| |
| // Called when a WEBTRANSPORT_STREAM frame type and the session ID varint |
| // immediately following it has been received. Any further parsing should |
| // be done by the stream itself, and not the parser. Note that this does not |
| // return bool, because WEBTRANSPORT_STREAM always causes the parsing |
| // process to cease. |
| virtual void OnWebTransportStreamFrameType( |
| QuicByteCount header_length, WebTransportSessionId session_id) = 0; |
| |
| // Called when a frame of unknown type |frame_type| has been received. |
| // Frame type might be reserved, Visitor must make sure to ignore. |
| // |header_length| and |payload_length| are the length of the frame header |
| // and payload, respectively. |
| virtual bool OnUnknownFrameStart(uint64_t frame_type, |
| QuicByteCount header_length, |
| QuicByteCount payload_length) = 0; |
| // Called when part of the payload of the unknown frame has been read. May |
| // be called multiple times for a single frame. |payload| is guaranteed to |
| // be non-empty. |
| virtual bool OnUnknownFramePayload(absl::string_view payload) = 0; |
| // Called when the unknown frame has been completely processed. |
| virtual bool OnUnknownFrameEnd() = 0; |
| }; |
| |
| // |visitor| must be non-null, and must outlive HttpDecoder. |
| explicit HttpDecoder(Visitor* visitor); |
| explicit HttpDecoder(Visitor* visitor, Options options); |
| |
| ~HttpDecoder(); |
| |
| // 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); |
| |
| // Decode settings frame from |data|. |
| // Upon successful decoding, |frame| will be populated, and returns true. |
| // This method is not used for regular processing of incoming data. |
| static bool DecodeSettings(const char* data, QuicByteCount len, |
| SettingsFrame* frame); |
| |
| // 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_; } |
| |
| // Returns true if input data processed so far ends on a frame boundary. |
| bool AtFrameBoundary() const { return state_ == STATE_READING_FRAME_TYPE; } |
| |
| private: |
| friend test::HttpDecoderPeer; |
| |
| // Represents the current state of the parsing state machine. |
| enum HttpDecoderState { |
| STATE_READING_FRAME_LENGTH, |
| STATE_READING_FRAME_TYPE, |
| |
| // States used for buffered frame types |
| STATE_BUFFER_OR_PARSE_PAYLOAD, |
| |
| // States used for non-buffered frame types |
| STATE_READING_FRAME_PAYLOAD, |
| STATE_FINISH_PARSING, |
| |
| STATE_PARSING_NO_LONGER_POSSIBLE, |
| 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. Returns whether the |
| // processing should continue. |
| bool 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); |
| |
| // Returns whether the current frame is of a buffered type. |
| // The payload of buffered frames is buffered by HttpDecoder, and parsed by |
| // HttpDecoder after the entire frame has been received. (Copying to the |
| // buffer is skipped if the ProcessInput() call covers the entire payload.) |
| // Frames that are not buffered have every payload fragment synchronously |
| // passed to the Visitor without buffering. |
| bool IsFrameBuffered(); |
| |
| // For buffered frame types, calls BufferOrParsePayload(). For other frame |
| // types, reads the payload of the current frame from |reader| and calls |
| // visitor methods. Returns whether processing should continue. |
| bool ReadFramePayload(QuicDataReader* reader); |
| |
| // For buffered frame types, this method is only called if frame payload is |
| // empty, and it calls BufferOrParsePayload(). For other frame types, this |
| // method directly calls visitor methods to signal that frame had been |
| // received completely. Returns whether processing should continue. |
| bool FinishParsing(); |
| |
| // Reset internal fields to prepare for reading next frame. |
| void ResetForNextFrame(); |
| |
| // Read payload of unknown frame from |reader| and call |
| // Visitor::OnUnknownFramePayload(). Returns true decoding should continue, |
| // false if it should be paused. |
| bool HandleUnknownFramePayload(QuicDataReader* reader); |
| |
| // Buffers any remaining frame payload from |*reader| into |buffer_| if |
| // necessary. Parses the frame payload if complete. Parses out of |*reader| |
| // without unnecessary copy if |*reader| contains entire payload. |
| // Returns whether processing should continue. |
| // Must only be called when current frame type is buffered. |
| bool BufferOrParsePayload(QuicDataReader* reader); |
| |
| // Parses the entire payload of certain kinds of frames that are parsed in a |
| // single pass. |reader| must have at least |current_frame_length_| bytes. |
| // Returns whether processing should continue. |
| // Must only be called when current frame type is buffered. |
| bool ParseEntirePayload(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 SETTINGS frame from |reader| into |frame|. |
| bool ParseSettingsFrame(QuicDataReader* reader, SettingsFrame* frame); |
| |
| // Parses the payload of a PRIORITY_UPDATE frame (draft-02, type 0xf0700) |
| // from |reader| into |frame|. |
| bool ParsePriorityUpdateFrame(QuicDataReader* reader, |
| PriorityUpdateFrame* frame); |
| |
| // Parses the payload of an ACCEPT_CH frame from |reader| into |frame|. |
| bool ParseAcceptChFrame(QuicDataReader* reader, AcceptChFrame* frame); |
| |
| // Returns the max frame size of a given |frame_type|. |
| QuicByteCount MaxFrameLength(uint64_t frame_type); |
| |
| // Visitor to invoke when messages are parsed. |
| Visitor* const visitor_; // Unowned. |
| // Whether WEBTRANSPORT_STREAM should be parsed. |
| bool allow_web_transport_stream_; |
| // 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_ |