| // Copyright 2014 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 NET_SPDY_HPACK_HPACK_DECODER_H_ |
| #define NET_SPDY_HPACK_HPACK_DECODER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <map> |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "net/base/net_export.h" |
| #include "net/spdy/hpack/hpack_decoder_interface.h" |
| #include "net/spdy/hpack/hpack_header_table.h" |
| #include "net/spdy/hpack/hpack_input_stream.h" |
| #include "net/spdy/platform/api/spdy_string_piece.h" |
| #include "net/spdy/spdy_headers_handler_interface.h" |
| #include "net/spdy/spdy_protocol.h" |
| |
| // An HpackDecoder decodes header sets as outlined in |
| // http://tools.ietf.org/html/rfc7541. |
| |
| namespace net { |
| |
| namespace test { |
| class HpackDecoderPeer; |
| } // namespace test |
| |
| class NET_EXPORT_PRIVATE HpackDecoder : public HpackDecoderInterface { |
| public: |
| friend class test::HpackDecoderPeer; |
| |
| HpackDecoder(); |
| ~HpackDecoder() override; |
| |
| // Called upon sending a SETTINGS_HEADER_TABLE_SIZE value. |
| void ApplyHeaderTableSizeSetting(size_t size_setting) override; |
| |
| // If a SpdyHeadersHandlerInterface is provided, HpackDecoder will emit |
| // headers to it rather than accumulating them in a SpdyHeaderBlock. |
| void HandleControlFrameHeadersStart( |
| SpdyHeadersHandlerInterface* handler) override; |
| |
| // Called as headers data arrives. Returns false if an error occurred. |
| // TODO(jgraettinger): A future version of this method will incrementally |
| // parse and deliver headers via SpdyHeadersHandlerInterface. For now, |
| // header data is buffered until HandleControlFrameHeadersComplete(). |
| bool HandleControlFrameHeadersData(const char* headers_data, |
| size_t headers_data_length) override; |
| |
| // Called after a headers block has been completely delivered via |
| // HandleControlFrameHeadersData(). Returns false if an error |
| // occurred. |compressed_len| if non-null will be set to the size |
| // of the encoded buffered block that was accumulated in |
| // HandleControlFrameHeadersData(), to support subsequent |
| // calculation of compression percentage. Clears |handler_|. |
| // TODO(jgraettinger): A |
| // future version of this method will simply deliver the Cookie |
| // header (which has been incrementally reconstructed) and notify |
| // the visitor that the block is finished. |
| bool HandleControlFrameHeadersComplete(size_t* compressed_len) override; |
| |
| // Accessor for the most recently decoded headers block. Valid until the next |
| // call to HandleControlFrameHeadersData(). |
| // TODO(birenroy): Remove this method when all users of HpackDecoder specify |
| // a SpdyHeadersHandlerInterface. |
| const SpdyHeaderBlock& decoded_block() const override; |
| |
| void SetHeaderTableDebugVisitor( |
| std::unique_ptr<HpackHeaderTable::DebugVisitorInterface> visitor) |
| override; |
| |
| void set_max_decode_buffer_size_bytes( |
| size_t max_decode_buffer_size_bytes) override; |
| |
| size_t EstimateMemoryUsage() const override; |
| |
| private: |
| // Adds the header representation to |decoded_block_|, applying the |
| // following rules: |
| // - Multiple values of the Cookie header are joined, delmited by '; '. |
| // This reconstruction is required to properly handle Cookie crumbling |
| // (as per section 8.1.2.5 in RFC 7540). |
| // - Multiple values of other headers are joined and delimited by '\0'. |
| // Note that this may be too accomodating, as the sender's HTTP2 layer |
| // should have already joined and delimited these values. |
| // |
| // Returns false if a pseudo-header field follows a regular header one, which |
| // MUST be treated as malformed, as per sections 8.1.2.3. of the HTTP2 |
| // specification (RFC 7540). |
| // |
| bool HandleHeaderRepresentation(SpdyStringPiece name, SpdyStringPiece value); |
| |
| // Handlers for decoding HPACK opcodes and header representations |
| // (or parts thereof). These methods return true on success and |
| // false on error. |
| bool DecodeNextOpcodeWrapper(HpackInputStream* input_stream); |
| bool DecodeNextOpcode(HpackInputStream* input_stream); |
| bool DecodeNextHeaderTableSizeUpdate(HpackInputStream* input_stream); |
| bool DecodeNextIndexedHeader(HpackInputStream* input_stream); |
| bool DecodeNextLiteralHeader(HpackInputStream* input_stream, |
| bool should_index); |
| bool DecodeNextName(HpackInputStream* input_stream, |
| SpdyStringPiece* next_name); |
| bool DecodeNextStringLiteral(HpackInputStream* input_stream, |
| bool is_header_key, // As distinct from a value. |
| SpdyStringPiece* output); |
| |
| HpackHeaderTable header_table_; |
| |
| // TODO(jgraettinger): Buffer for headers data, and storage for the last- |
| // processed headers block. Both will be removed with the switch to |
| // SpdyHeadersHandlerInterface. |
| std::string headers_block_buffer_; |
| SpdyHeaderBlock decoded_block_; |
| |
| // Scratch space for storing decoded literals. |
| std::string key_buffer_, value_buffer_; |
| |
| // If non-NULL, handles decoded headers. |
| SpdyHeadersHandlerInterface* handler_; |
| size_t total_header_bytes_; |
| |
| // How much encoded data this decoder is willing to buffer. |
| size_t max_decode_buffer_size_bytes_ = 32 * 1024; // 32 KB |
| |
| // Total bytes have been removed from headers_block_buffer_. |
| // Its value is updated during incremental decoding. |
| uint32_t total_parsed_bytes_; |
| |
| // Flag to keep track of having seen the header block start. |
| bool header_block_started_; |
| |
| // Number of dynamic table size updates seen at the start; a max of two |
| // are permitted. |
| uint8_t size_updates_seen_; |
| |
| // Are dynamic table size updates allowed at this point in decoding? True |
| // at the start, but not once we've seen a header entry. |
| bool size_updates_allowed_; |
| |
| // Saved value of --chromium_http2_flag_add_hpack_incremental_decode. |
| bool incremental_decode_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HpackDecoder); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_SPDY_HPACK_HPACK_DECODER_H_ |