1 /* 2 * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 #ifndef NET_DCSCTP_PACKET_CHUNK_SACK_CHUNK_H_ 11 #define NET_DCSCTP_PACKET_CHUNK_SACK_CHUNK_H_ 12 #include <stddef.h> 13 14 #include <cstdint> 15 #include <set> 16 #include <string> 17 #include <utility> 18 #include <vector> 19 20 #include "absl/strings/string_view.h" 21 #include "api/array_view.h" 22 #include "net/dcsctp/packet/chunk/chunk.h" 23 #include "net/dcsctp/packet/tlv_trait.h" 24 25 namespace dcsctp { 26 27 // https://tools.ietf.org/html/rfc4960#section-3.3.4 28 struct SackChunkConfig : ChunkConfig { 29 static constexpr int kType = 3; 30 static constexpr size_t kHeaderSize = 16; 31 static constexpr size_t kVariableLengthAlignment = 4; 32 }; 33 34 class SackChunk : public Chunk, public TLVTrait<SackChunkConfig> { 35 public: 36 static constexpr int kType = SackChunkConfig::kType; 37 38 struct GapAckBlock { GapAckBlockGapAckBlock39 GapAckBlock(uint16_t start, uint16_t end) : start(start), end(end) {} 40 41 uint16_t start; 42 uint16_t end; 43 44 bool operator==(const GapAckBlock& other) const { 45 return start == other.start && end == other.end; 46 } 47 }; 48 SackChunk(TSN cumulative_tsn_ack,uint32_t a_rwnd,std::vector<GapAckBlock> gap_ack_blocks,std::set<TSN> duplicate_tsns)49 SackChunk(TSN cumulative_tsn_ack, 50 uint32_t a_rwnd, 51 std::vector<GapAckBlock> gap_ack_blocks, 52 std::set<TSN> duplicate_tsns) 53 : cumulative_tsn_ack_(cumulative_tsn_ack), 54 a_rwnd_(a_rwnd), 55 gap_ack_blocks_(std::move(gap_ack_blocks)), 56 duplicate_tsns_(std::move(duplicate_tsns)) {} 57 static absl::optional<SackChunk> Parse(rtc::ArrayView<const uint8_t> data); 58 59 void SerializeTo(std::vector<uint8_t>& out) const override; 60 std::string ToString() const override; 61 cumulative_tsn_ack()62 TSN cumulative_tsn_ack() const { return cumulative_tsn_ack_; } a_rwnd()63 uint32_t a_rwnd() const { return a_rwnd_; } gap_ack_blocks()64 rtc::ArrayView<const GapAckBlock> gap_ack_blocks() const { 65 return gap_ack_blocks_; 66 } duplicate_tsns()67 const std::set<TSN>& duplicate_tsns() const { return duplicate_tsns_; } 68 69 private: 70 static constexpr size_t kGapAckBlockSize = 4; 71 static constexpr size_t kDupTsnBlockSize = 4; 72 73 const TSN cumulative_tsn_ack_; 74 const uint32_t a_rwnd_; 75 std::vector<GapAckBlock> gap_ack_blocks_; 76 std::set<TSN> duplicate_tsns_; 77 }; 78 } // namespace dcsctp 79 80 #endif // NET_DCSCTP_PACKET_CHUNK_SACK_CHUNK_H_ 81