| /* |
| * 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/idata_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/rfc8260#section-2.1 |
| |
| // 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 = 64 | Res |I|U|B|E| Length = Variable | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | TSN | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | Stream Identifier | Reserved | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | Message Identifier | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | Payload Protocol Identifier / Fragment Sequence Number | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // \ \ |
| // / User Data / |
| // \ \ |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr int IDataChunk::kType; |
| |
| absl::optional<IDataChunk> IDataChunk::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>()); |
| MID message_id(reader->Load32<12>()); |
| uint32_t ppid_or_fsn = reader->Load32<16>(); |
| |
| 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 IDataChunk(tsn, stream_identifier, message_id, |
| PPID(options.is_beginning ? ppid_or_fsn : 0), |
| FSN(options.is_beginning ? 0 : ppid_or_fsn), |
| std::vector<uint8_t>(reader->variable_data().begin(), |
| reader->variable_data().end()), |
| options); |
| } |
| |
| void IDataChunk::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.Store32<12>(*message_id()); |
| writer.Store32<16>(options().is_beginning ? *ppid() : *fsn()); |
| writer.CopyToVariableData(payload()); |
| } |
| |
| std::string IDataChunk::ToString() const { |
| rtc::StringBuilder sb; |
| sb << "I-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() << ", stream_id=" << *stream_id() |
| << ", message_id=" << *message_id(); |
| |
| if (*options().is_beginning) { |
| sb << ", ppid=" << *ppid(); |
| } else { |
| sb << ", fsn=" << *fsn(); |
| } |
| sb << ", length=" << payload().size(); |
| return sb.Release(); |
| } |
| |
| } // namespace dcsctp |