Index: net/http2/decoder/http2_frame_decoder.h |
diff --git a/net/http2/decoder/http2_frame_decoder.h b/net/http2/decoder/http2_frame_decoder.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f440993a3b6765b99591f4aa4b949de4877706b2 |
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+++ b/net/http2/decoder/http2_frame_decoder.h |
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+// 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 NET_HTTP2_DECODER_HTTP2_FRAME_DECODER_H_ |
+#define NET_HTTP2_DECODER_HTTP2_FRAME_DECODER_H_ |
+ |
+// Http2FrameDecoder decodes the available input until it reaches the end of |
+// the input or it reaches the end of the first frame in the input. |
+// Note that Http2FrameDecoder does only minimal validation; for example, |
+// stream ids are not checked, nor is the sequence of frames such as |
+// CONTINUATION frame placement. |
+// |
+// Http2FrameDecoder enters state kError once it has called the listener's |
+// OnFrameSizeError or OnPaddingTooLong methods, and at this time has no |
+// provision for leaving that state. While the HTTP/2 spec (RFC7540) allows |
+// for some such errors to be considered as just stream errors in some cases, |
+// this implementation treats them all as connection errors. |
+ |
+#include <stddef.h> |
+ |
+#include "base/logging.h" |
+#include "base/macros.h" |
+#include "net/base/net_export.h" |
+#include "net/http2/decoder/decode_buffer.h" |
+#include "net/http2/decoder/decode_status.h" |
+#include "net/http2/decoder/frame_decoder_state.h" |
+#include "net/http2/decoder/http2_frame_decoder_listener.h" |
+#include "net/http2/decoder/payload_decoders/altsvc_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/continuation_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/data_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/goaway_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/headers_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/ping_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/priority_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/push_promise_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/rst_stream_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/settings_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/unknown_payload_decoder.h" |
+#include "net/http2/decoder/payload_decoders/window_update_payload_decoder.h" |
+#include "net/http2/http2_structures.h" |
+ |
+namespace net { |
+namespace test { |
+class Http2FrameDecoderPeer; |
+} // namespace test |
+ |
+class NET_EXPORT_PRIVATE Http2FrameDecoder { |
+ public: |
+ explicit Http2FrameDecoder(Http2FrameDecoderListener* listener); |
+ Http2FrameDecoder() : Http2FrameDecoder(nullptr) {} |
+ |
+ // The decoder will call the listener's methods as it decodes a frame. |
+ void set_listener(Http2FrameDecoderListener* listener); |
+ Http2FrameDecoderListener* listener() const; |
+ |
+ // The decoder will reject frame's whose payload |
+ // length field exceeds the maximum payload size. |
+ void set_maximum_payload_size(size_t v) { maximum_payload_size_ = v; } |
+ size_t maximum_payload_size() const { return maximum_payload_size_; } |
+ |
+ // Decodes the input up to the next frame boundary (i.e. at most one frame). |
+ // |
+ // Returns kDecodeDone if it decodes the final byte of a frame, OR if there |
+ // is no input and it is awaiting the start of a new frame (e.g. if this |
+ // is the first call to DecodeFrame, or if the previous call returned |
+ // kDecodeDone). |
+ // |
+ // Returns kDecodeInProgress if it decodes all of the decode buffer, but has |
+ // not reached the end of the frame. |
+ // |
+ // Returns kDecodeError if the frame's padding or length wasn't valid (i.e. if |
+ // the decoder called either the listener's OnPaddingTooLong or |
+ // OnFrameSizeError method). |
+ DecodeStatus DecodeFrame(DecodeBuffer* db); |
+ |
+ ////////////////////////////////////////////////////////////////////////////// |
+ // Methods that support Http2FrameDecoderAdapter. |
+ |
+ // Is the remainder of the frame's payload being discarded? |
+ bool IsDiscardingPayload() const { return state_ == State::kDiscardPayload; } |
+ |
+ // Returns the number of bytes of the frame's payload that remain to be |
+ // decoded, excluding any trailing padding. This method must only be called |
+ // after the frame header has been decoded AND DecodeFrame has returned |
+ // kDecodeInProgress. |
+ size_t remaining_payload() const; |
+ |
+ // Returns the number of bytes of trailing padding after the payload that |
+ // remain to be decoded. This method must only be called if the frame type |
+ // allows padding, and after the frame header has been decoded AND |
+ // DecodeFrame has returned. Will return 0 if the Pad Length field has not |
+ // yet been decoded. |
+ uint32_t remaining_padding() const; |
+ |
+ private: |
+ enum class State { |
+ // Ready to start decoding a new frame's header. |
+ kStartDecodingHeader, |
+ // Was in state kStartDecodingHeader, but unable to read the entire frame |
+ // header, so needs more input to complete decoding the header. |
+ kResumeDecodingHeader, |
+ |
+ // Have decoded the frame header, and started decoding the available bytes |
+ // of the frame's payload, but need more bytes to finish the job. |
+ kResumeDecodingPayload, |
+ |
+ // Decoding of the most recently started frame resulted in an error: |
+ // OnPaddingTooLong or OnFrameSizeError was called to indicate that the |
+ // decoder detected a problem, or OnFrameHeader returned false, indicating |
+ // that the listener detected a problem. Regardless of which, the decoder |
+ // will stay in state kDiscardPayload until it has been passed the rest |
+ // of the bytes of the frame's payload that it hasn't yet seen, after |
+ // which it will be ready to decode another frame. |
+ kDiscardPayload, |
+ }; |
+ |
+ friend class test::Http2FrameDecoderPeer; |
+ friend std::ostream& operator<<(std::ostream& out, State v); |
+ |
+ DecodeStatus StartDecodingPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingPayload(DecodeBuffer* db); |
+ DecodeStatus DiscardPayload(DecodeBuffer* db); |
+ |
+ const Http2FrameHeader& frame_header() const { |
+ return frame_decoder_state_.frame_header(); |
+ } |
+ |
+ // Clear any of the flags in the frame header that aren't set in valid_flags. |
+ void RetainFlags(uint8_t valid_flags); |
+ |
+ // Clear all of the flags in the frame header; for use with frame types that |
+ // don't define any flags, such as WINDOW_UPDATE. |
+ void ClearFlags(); |
+ |
+ // These methods call the StartDecodingPayload() method of the frame type's |
+ // payload decoder, after first clearing invalid flags in the header. The |
+ // caller must ensure that the decode buffer does not extend beyond the |
+ // end of the payload (handled by Http2FrameDecoder::StartDecodingPayload). |
+ DecodeStatus StartDecodingAltSvcPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingContinuationPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingDataPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingGoAwayPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingHeadersPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingPingPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingPriorityPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingPushPromisePayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingRstStreamPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingSettingsPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingUnknownPayload(DecodeBuffer* db); |
+ DecodeStatus StartDecodingWindowUpdatePayload(DecodeBuffer* db); |
+ |
+ // These methods call the ResumeDecodingPayload() method of the frame type's |
+ // payload decoder; they are called only if the preceding call to the |
+ // corresponding Start method (above) returned kDecodeInProgress, as did any |
+ // subsequent calls to the resume method. |
+ // Unlike the Start methods, the decode buffer may extend beyond the |
+ // end of the payload, so the method will create a DecodeBufferSubset |
+ // before calling the ResumeDecodingPayload method of the frame type's |
+ // payload decoder. |
+ DecodeStatus ResumeDecodingAltSvcPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingContinuationPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingDataPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingGoAwayPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingHeadersPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingPingPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingPriorityPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingPushPromisePayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingRstStreamPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingSettingsPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingUnknownPayload(DecodeBuffer* db); |
+ DecodeStatus ResumeDecodingWindowUpdatePayload(DecodeBuffer* db); |
+ |
+ FrameDecoderState frame_decoder_state_; |
+ |
+ // We only need one payload decoder at a time, so they share the same storage. |
+ union { |
+ AltSvcPayloadDecoder altsvc_payload_decoder_; |
+ ContinuationPayloadDecoder continuation_payload_decoder_; |
+ DataPayloadDecoder data_payload_decoder_; |
+ GoAwayPayloadDecoder goaway_payload_decoder_; |
+ HeadersPayloadDecoder headers_payload_decoder_; |
+ PingPayloadDecoder ping_payload_decoder_; |
+ PriorityPayloadDecoder priority_payload_decoder_; |
+ PushPromisePayloadDecoder push_promise_payload_decoder_; |
+ RstStreamPayloadDecoder rst_stream_payload_decoder_; |
+ SettingsPayloadDecoder settings_payload_decoder_; |
+ UnknownPayloadDecoder unknown_payload_decoder_; |
+ WindowUpdatePayloadDecoder window_update_payload_decoder_; |
+ }; |
+ |
+ State state_; |
+ size_t maximum_payload_size_; |
+ |
+ // Listener used whenever caller passes nullptr to set_listener. |
+ Http2FrameDecoderNoOpListener no_op_listener_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(Http2FrameDecoder); |
+}; |
+ |
+} // namespace net |
+ |
+#endif // NET_HTTP2_DECODER_HTTP2_FRAME_DECODER_H_ |