xref: /aosp_15_r20/external/webrtc/net/dcsctp/packet/chunk/shutdown_chunk.cc (revision d9f758449e529ab9291ac668be2861e7a55c2422)
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 #include "net/dcsctp/packet/chunk/shutdown_chunk.h"
11 
12 #include <stdint.h>
13 
14 #include <type_traits>
15 #include <vector>
16 
17 #include "absl/types/optional.h"
18 #include "api/array_view.h"
19 #include "net/dcsctp/packet/bounded_byte_reader.h"
20 #include "net/dcsctp/packet/bounded_byte_writer.h"
21 #include "net/dcsctp/packet/tlv_trait.h"
22 
23 namespace dcsctp {
24 
25 // https://tools.ietf.org/html/rfc4960#section-3.3.8
26 
27 //   0                   1                   2                   3
28 //   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
29 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
30 //  |   Type = 7    | Chunk  Flags  |      Length = 8               |
31 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
32 //  |                      Cumulative TSN Ack                       |
33 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
34 constexpr int ShutdownChunk::kType;
35 
Parse(rtc::ArrayView<const uint8_t> data)36 absl::optional<ShutdownChunk> ShutdownChunk::Parse(
37     rtc::ArrayView<const uint8_t> data) {
38   absl::optional<BoundedByteReader<kHeaderSize>> reader = ParseTLV(data);
39   if (!reader.has_value()) {
40     return absl::nullopt;
41   }
42 
43   TSN cumulative_tsn_ack(reader->Load32<4>());
44   return ShutdownChunk(cumulative_tsn_ack);
45 }
46 
SerializeTo(std::vector<uint8_t> & out) const47 void ShutdownChunk::SerializeTo(std::vector<uint8_t>& out) const {
48   BoundedByteWriter<kHeaderSize> writer = AllocateTLV(out);
49   writer.Store32<4>(*cumulative_tsn_ack_);
50 }
51 
ToString() const52 std::string ShutdownChunk::ToString() const {
53   return "SHUTDOWN";
54 }
55 }  // namespace dcsctp
56