OLD | NEW |
| (Empty) |
1 // Copyright 2014 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef NET_SPDY_HPACK_HPACK_DECODER_H_ | |
6 #define NET_SPDY_HPACK_HPACK_DECODER_H_ | |
7 | |
8 #include <stddef.h> | |
9 #include <stdint.h> | |
10 | |
11 #include <map> | |
12 #include <memory> | |
13 #include <vector> | |
14 | |
15 #include "base/macros.h" | |
16 #include "net/base/net_export.h" | |
17 #include "net/spdy/hpack/hpack_decoder_interface.h" | |
18 #include "net/spdy/hpack/hpack_header_table.h" | |
19 #include "net/spdy/hpack/hpack_input_stream.h" | |
20 #include "net/spdy/platform/api/spdy_string.h" | |
21 #include "net/spdy/platform/api/spdy_string_piece.h" | |
22 #include "net/spdy/spdy_headers_handler_interface.h" | |
23 #include "net/spdy/spdy_protocol.h" | |
24 | |
25 // An HpackDecoder decodes header sets as outlined in | |
26 // http://tools.ietf.org/html/rfc7541. | |
27 | |
28 namespace net { | |
29 | |
30 namespace test { | |
31 class HpackDecoderPeer; | |
32 } // namespace test | |
33 | |
34 class NET_EXPORT_PRIVATE HpackDecoder : public HpackDecoderInterface { | |
35 public: | |
36 friend class test::HpackDecoderPeer; | |
37 | |
38 HpackDecoder(); | |
39 ~HpackDecoder() override; | |
40 | |
41 // Called upon sending a SETTINGS_HEADER_TABLE_SIZE value. | |
42 void ApplyHeaderTableSizeSetting(size_t size_setting) override; | |
43 | |
44 // If a SpdyHeadersHandlerInterface is provided, HpackDecoder will emit | |
45 // headers to it rather than accumulating them in a SpdyHeaderBlock. | |
46 void HandleControlFrameHeadersStart( | |
47 SpdyHeadersHandlerInterface* handler) override; | |
48 | |
49 // Called as headers data arrives. Returns false if an error occurred. | |
50 // TODO(jgraettinger): A future version of this method will incrementally | |
51 // parse and deliver headers via SpdyHeadersHandlerInterface. For now, | |
52 // header data is buffered until HandleControlFrameHeadersComplete(). | |
53 bool HandleControlFrameHeadersData(const char* headers_data, | |
54 size_t headers_data_length) override; | |
55 | |
56 // Called after a headers block has been completely delivered via | |
57 // HandleControlFrameHeadersData(). Returns false if an error | |
58 // occurred. |compressed_len| if non-null will be set to the size | |
59 // of the encoded buffered block that was accumulated in | |
60 // HandleControlFrameHeadersData(), to support subsequent | |
61 // calculation of compression percentage. Clears |handler_|. | |
62 // TODO(jgraettinger): A | |
63 // future version of this method will simply deliver the Cookie | |
64 // header (which has been incrementally reconstructed) and notify | |
65 // the visitor that the block is finished. | |
66 bool HandleControlFrameHeadersComplete(size_t* compressed_len) override; | |
67 | |
68 // Accessor for the most recently decoded headers block. Valid until the next | |
69 // call to HandleControlFrameHeadersData(). | |
70 // TODO(birenroy): Remove this method when all users of HpackDecoder specify | |
71 // a SpdyHeadersHandlerInterface. | |
72 const SpdyHeaderBlock& decoded_block() const override; | |
73 | |
74 void SetHeaderTableDebugVisitor( | |
75 std::unique_ptr<HpackHeaderTable::DebugVisitorInterface> visitor) | |
76 override; | |
77 | |
78 void set_max_decode_buffer_size_bytes( | |
79 size_t max_decode_buffer_size_bytes) override; | |
80 | |
81 size_t EstimateMemoryUsage() const override; | |
82 | |
83 private: | |
84 // Adds the header representation to |decoded_block_|, applying the | |
85 // following rules: | |
86 // - Multiple values of the Cookie header are joined, delmited by '; '. | |
87 // This reconstruction is required to properly handle Cookie crumbling | |
88 // (as per section 8.1.2.5 in RFC 7540). | |
89 // - Multiple values of other headers are joined and delimited by '\0'. | |
90 // Note that this may be too accomodating, as the sender's HTTP2 layer | |
91 // should have already joined and delimited these values. | |
92 // | |
93 // Returns false if a pseudo-header field follows a regular header one, which | |
94 // MUST be treated as malformed, as per sections 8.1.2.3. of the HTTP2 | |
95 // specification (RFC 7540). | |
96 // | |
97 bool HandleHeaderRepresentation(SpdyStringPiece name, SpdyStringPiece value); | |
98 | |
99 // Handlers for decoding HPACK opcodes and header representations | |
100 // (or parts thereof). These methods return true on success and | |
101 // false on error. | |
102 bool DecodeNextOpcodeWrapper(HpackInputStream* input_stream); | |
103 bool DecodeNextOpcode(HpackInputStream* input_stream); | |
104 bool DecodeNextHeaderTableSizeUpdate(HpackInputStream* input_stream); | |
105 bool DecodeNextIndexedHeader(HpackInputStream* input_stream); | |
106 bool DecodeNextLiteralHeader(HpackInputStream* input_stream, | |
107 bool should_index); | |
108 bool DecodeNextName(HpackInputStream* input_stream, | |
109 SpdyStringPiece* next_name); | |
110 bool DecodeNextStringLiteral(HpackInputStream* input_stream, | |
111 bool is_header_key, // As distinct from a value. | |
112 SpdyStringPiece* output); | |
113 | |
114 HpackHeaderTable header_table_; | |
115 | |
116 // TODO(jgraettinger): Buffer for headers data, and storage for the last- | |
117 // processed headers block. Both will be removed with the switch to | |
118 // SpdyHeadersHandlerInterface. | |
119 SpdyString headers_block_buffer_; | |
120 SpdyHeaderBlock decoded_block_; | |
121 | |
122 // Scratch space for storing decoded literals. | |
123 SpdyString key_buffer_, value_buffer_; | |
124 | |
125 // If non-NULL, handles decoded headers. | |
126 SpdyHeadersHandlerInterface* handler_; | |
127 size_t total_header_bytes_; | |
128 | |
129 // How much encoded data this decoder is willing to buffer. | |
130 size_t max_decode_buffer_size_bytes_ = 32 * 1024; // 32 KB | |
131 | |
132 // Total bytes have been removed from headers_block_buffer_. | |
133 // Its value is updated during incremental decoding. | |
134 uint32_t total_parsed_bytes_; | |
135 | |
136 // Flag to keep track of having seen the header block start. | |
137 bool header_block_started_; | |
138 | |
139 // Number of dynamic table size updates seen at the start; a max of two | |
140 // are permitted. | |
141 uint8_t size_updates_seen_; | |
142 | |
143 // Are dynamic table size updates allowed at this point in decoding? True | |
144 // at the start, but not once we've seen a header entry. | |
145 bool size_updates_allowed_; | |
146 | |
147 // Saved value of --chromium_http2_flag_add_hpack_incremental_decode. | |
148 bool incremental_decode_; | |
149 | |
150 DISALLOW_COPY_AND_ASSIGN(HpackDecoder); | |
151 }; | |
152 | |
153 } // namespace net | |
154 | |
155 #endif // NET_SPDY_HPACK_HPACK_DECODER_H_ | |
OLD | NEW |