diff options
Diffstat (limited to 'third_party/libwebrtc/net/dcsctp/packet/chunk/data_chunk.cc')
| -rw-r--r-- | third_party/libwebrtc/net/dcsctp/packet/chunk/data_chunk.cc | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/third_party/libwebrtc/net/dcsctp/packet/chunk/data_chunk.cc b/third_party/libwebrtc/net/dcsctp/packet/chunk/data_chunk.cc new file mode 100644 index 0000000000..769be2db91 --- /dev/null +++ b/third_party/libwebrtc/net/dcsctp/packet/chunk/data_chunk.cc @@ -0,0 +1,101 @@ +/* + * 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/data_chunk.h" + +#include <stdint.h> + +#include <string> +#include <type_traits> +#include <vector> + +#include "absl/types/optional.h" +#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/chunk/data_common.h" +#include "rtc_base/strings/string_builder.h" + +namespace dcsctp { + +// https://tools.ietf.org/html/rfc4960#section-3.3.1 + +// 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 = 0 | Reserved|U|B|E| Length | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | TSN | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | Stream Identifier S | Stream Sequence Number n | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | Payload Protocol Identifier | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// \ \ +// / User Data (seq n of Stream S) / +// \ \ +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +constexpr int DataChunk::kType; + +absl::optional<DataChunk> DataChunk::Parse(rtc::ArrayView<const uint8_t> data) { + absl::optional<BoundedByteReader<kHeaderSize>> reader = ParseTLV(data); + if (!reader.has_value()) { + return absl::nullopt; + } + + uint8_t flags = reader->Load8<1>(); + TSN tsn(reader->Load32<4>()); + StreamID stream_identifier(reader->Load16<8>()); + SSN ssn(reader->Load16<10>()); + PPID ppid(reader->Load32<12>()); + + Options options; + options.is_end = Data::IsEnd((flags & (1 << kFlagsBitEnd)) != 0); + options.is_beginning = + Data::IsBeginning((flags & (1 << kFlagsBitBeginning)) != 0); + options.is_unordered = IsUnordered((flags & (1 << kFlagsBitUnordered)) != 0); + options.immediate_ack = + ImmediateAckFlag((flags & (1 << kFlagsBitImmediateAck)) != 0); + + return DataChunk(tsn, stream_identifier, ssn, ppid, + std::vector<uint8_t>(reader->variable_data().begin(), + reader->variable_data().end()), + options); +} + +void DataChunk::SerializeTo(std::vector<uint8_t>& out) const { + BoundedByteWriter<kHeaderSize> writer = AllocateTLV(out, payload().size()); + + writer.Store8<1>( + (*options().is_end ? (1 << kFlagsBitEnd) : 0) | + (*options().is_beginning ? (1 << kFlagsBitBeginning) : 0) | + (*options().is_unordered ? (1 << kFlagsBitUnordered) : 0) | + (*options().immediate_ack ? (1 << kFlagsBitImmediateAck) : 0)); + writer.Store32<4>(*tsn()); + writer.Store16<8>(*stream_id()); + writer.Store16<10>(*ssn()); + writer.Store32<12>(*ppid()); + + writer.CopyToVariableData(payload()); +} + +std::string DataChunk::ToString() const { + rtc::StringBuilder sb; + sb << "DATA, type=" << (options().is_unordered ? "unordered" : "ordered") + << "::" + << (*options().is_beginning && *options().is_end + ? "complete" + : *options().is_beginning ? "first" + : *options().is_end ? "last" : "middle") + << ", tsn=" << *tsn() << ", sid=" << *stream_id() << ", ssn=" << *ssn() + << ", ppid=" << *ppid() << ", length=" << payload().size(); + return sb.Release(); +} + +} // namespace dcsctp |