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/*
* Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "net/dcsctp/packet/chunk/init_ack_chunk.h"
#include <stdint.h>
#include <optional>
#include <string>
#include <utility>
#include <vector>
#include "api/array_view.h"
#include "net/dcsctp/packet/bounded_byte_reader.h"
#include "net/dcsctp/packet/bounded_byte_writer.h"
#include "net/dcsctp/packet/parameter/parameter.h"
#include "net/dcsctp/packet/tlv_trait.h"
#include "rtc_base/strings/string_format.h"
namespace dcsctp {
// https://tools.ietf.org/html/rfc4960#section-3.3.3
// 0 1 2 3
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Type = 2 | Chunk Flags | Chunk Length |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Initiate Tag |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Advertised Receiver Window Credit |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Number of Outbound Streams | Number of Inbound Streams |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Initial TSN |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// \ \
// / Optional/Variable-Length Parameters /
// \ \
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
constexpr int InitAckChunk::kType;
std::optional<InitAckChunk> InitAckChunk::Parse(
webrtc::ArrayView<const uint8_t> data) {
std::optional<BoundedByteReader<kHeaderSize>> reader = ParseTLV(data);
if (!reader.has_value()) {
return std::nullopt;
}
VerificationTag initiate_tag(reader->Load32<4>());
uint32_t a_rwnd = reader->Load32<8>();
uint16_t nbr_outbound_streams = reader->Load16<12>();
uint16_t nbr_inbound_streams = reader->Load16<14>();
TSN initial_tsn(reader->Load32<16>());
std::optional<Parameters> parameters =
Parameters::Parse(reader->variable_data());
if (!parameters.has_value()) {
return std::nullopt;
}
return InitAckChunk(initiate_tag, a_rwnd, nbr_outbound_streams,
nbr_inbound_streams, initial_tsn, *std::move(parameters));
}
void InitAckChunk::SerializeTo(std::vector<uint8_t>& out) const {
webrtc::ArrayView<const uint8_t> parameters = parameters_.data();
BoundedByteWriter<kHeaderSize> writer = AllocateTLV(out, parameters.size());
writer.Store32<4>(*initiate_tag_);
writer.Store32<8>(a_rwnd_);
writer.Store16<12>(nbr_outbound_streams_);
writer.Store16<14>(nbr_inbound_streams_);
writer.Store32<16>(*initial_tsn_);
writer.CopyToVariableData(parameters);
}
std::string InitAckChunk::ToString() const {
return webrtc::StringFormat("INIT_ACK, initiate_tag=0x%0x, initial_tsn=%u",
*initiate_tag(), *initial_tsn());
}
} // namespace dcsctp
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