| // Copyright 2016 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_HTTP2_HPACK_DECODER_HPACK_WHOLE_ENTRY_BUFFER_H_ |
| #define QUICHE_HTTP2_HPACK_DECODER_HPACK_WHOLE_ENTRY_BUFFER_H_ |
| |
| // HpackWholeEntryBuffer isolates a listener from the fact that an entry may |
| // be split across multiple input buffers, providing one callback per entry. |
| // HpackWholeEntryBuffer requires that the HpackEntryDecoderListener be made in |
| // the correct order, which is tested by hpack_entry_decoder_test.cc. |
| |
| #include <stddef.h> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoder_string_buffer.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoding_error.h" |
| #include "quiche/http2/hpack/decoder/hpack_entry_decoder_listener.h" |
| #include "quiche/http2/hpack/decoder/hpack_whole_entry_listener.h" |
| #include "quiche/http2/hpack/http2_hpack_constants.h" |
| #include "quiche/common/platform/api/quiche_export.h" |
| |
| namespace http2 { |
| |
| // TODO(jamessynge): Consider renaming HpackEntryDecoderListener to |
| // HpackEntryPartsListener or HpackEntryFragmentsListener. |
| class QUICHE_EXPORT HpackWholeEntryBuffer : public HpackEntryDecoderListener { |
| public: |
| // max_string_size specifies the maximum size of an on-the-wire string (name |
| // or value, plain or Huffman encoded) that will be accepted. See sections |
| // 5.1 and 5.2 of RFC 7541. This is a defense against OOM attacks; HTTP/2 |
| // allows a decoder to enforce any limit of the size of the header lists |
| // that it is willing decode, including less than the MAX_HEADER_LIST_SIZE |
| // setting, a setting that is initially unlimited. For example, we might |
| // choose to send a MAX_HEADER_LIST_SIZE of 64KB, and to use that same value |
| // as the upper bound for individual strings. |
| HpackWholeEntryBuffer(HpackWholeEntryListener* listener, |
| size_t max_string_size); |
| ~HpackWholeEntryBuffer() override; |
| |
| HpackWholeEntryBuffer(const HpackWholeEntryBuffer&) = delete; |
| HpackWholeEntryBuffer& operator=(const HpackWholeEntryBuffer&) = delete; |
| |
| // Set the listener to be notified when a whole entry has been decoded. |
| // The listener may be changed at any time. |
| void set_listener(HpackWholeEntryListener* listener); |
| |
| // Set how much encoded data this decoder is willing to buffer. |
| // TODO(jamessynge): Come up with consistent semantics for this protection |
| // across the various decoders; e.g. should it be for a single string or |
| // a single header entry? |
| void set_max_string_size_bytes(size_t max_string_size_bytes); |
| |
| // Ensure that decoded strings pointed to by the HpackDecoderStringBuffer |
| // instances name_ and value_ are buffered, which allows any underlying |
| // transport buffer to be freed or reused without overwriting the decoded |
| // strings. This is needed only when an HPACK entry is split across transport |
| // buffers. See HpackDecoder::DecodeFragment. |
| void BufferStringsIfUnbuffered(); |
| |
| // Was an error detected? After an error has been detected and reported, |
| // no further callbacks will be made to the listener. |
| bool error_detected() const { return error_detected_; } |
| |
| // Implement the HpackEntryDecoderListener methods. |
| |
| void OnIndexedHeader(size_t index) override; |
| void OnStartLiteralHeader(HpackEntryType entry_type, |
| size_t maybe_name_index) override; |
| void OnNameStart(bool huffman_encoded, size_t len) override; |
| void OnNameData(const char* data, size_t len) override; |
| void OnNameEnd() override; |
| void OnValueStart(bool huffman_encoded, size_t len) override; |
| void OnValueData(const char* data, size_t len) override; |
| void OnValueEnd() override; |
| void OnDynamicTableSizeUpdate(size_t size) override; |
| |
| private: |
| void ReportError(HpackDecodingError error, std::string detailed_error); |
| |
| HpackWholeEntryListener* listener_; |
| HpackDecoderStringBuffer name_, value_; |
| |
| // max_string_size_bytes_ specifies the maximum allowed size of an on-the-wire |
| // string. Larger strings will be reported as errors to the listener; the |
| // endpoint should treat these as COMPRESSION errors, which are CONNECTION |
| // level errors. |
| size_t max_string_size_bytes_; |
| |
| // The name index (or zero) of the current header entry with a literal value. |
| size_t maybe_name_index_; |
| |
| // The type of the current header entry (with literals) that is being decoded. |
| HpackEntryType entry_type_; |
| |
| bool error_detected_ = false; |
| }; |
| |
| } // namespace http2 |
| |
| #endif // QUICHE_HTTP2_HPACK_DECODER_HPACK_WHOLE_ENTRY_BUFFER_H_ |