| /* |
| * 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/socket/state_cookie.h" |
| |
| #include <cstdint> |
| #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/socket/capabilities.h" |
| #include "rtc_base/logging.h" |
| |
| namespace dcsctp { |
| |
| // Magic values, which the state cookie is prefixed with. |
| constexpr uint32_t kMagic1 = 1684230979; |
| constexpr uint32_t kMagic2 = 1414541360; |
| constexpr size_t StateCookie::kCookieSize; |
| |
| std::vector<uint8_t> StateCookie::Serialize() { |
| std::vector<uint8_t> cookie; |
| cookie.resize(kCookieSize); |
| BoundedByteWriter<kCookieSize> buffer(cookie); |
| buffer.Store32<0>(kMagic1); |
| buffer.Store32<4>(kMagic2); |
| buffer.Store32<8>(*peer_tag_); |
| buffer.Store32<12>(*my_tag_); |
| buffer.Store32<16>(*peer_initial_tsn_); |
| buffer.Store32<20>(*my_initial_tsn_); |
| buffer.Store32<24>(a_rwnd_); |
| buffer.Store32<28>(static_cast<uint32_t>(*tie_tag_ >> 32)); |
| buffer.Store32<32>(static_cast<uint32_t>(*tie_tag_)); |
| buffer.Store8<36>(capabilities_.partial_reliability); |
| buffer.Store8<37>(capabilities_.message_interleaving); |
| buffer.Store8<38>(capabilities_.reconfig); |
| buffer.Store8<39>(capabilities_.zero_checksum); |
| buffer.Store16<40>(capabilities_.negotiated_maximum_incoming_streams); |
| buffer.Store16<42>(capabilities_.negotiated_maximum_outgoing_streams); |
| return cookie; |
| } |
| |
| absl::optional<StateCookie> StateCookie::Deserialize( |
| rtc::ArrayView<const uint8_t> cookie) { |
| if (cookie.size() != kCookieSize) { |
| RTC_DLOG(LS_WARNING) << "Invalid state cookie: " << cookie.size() |
| << " bytes"; |
| return absl::nullopt; |
| } |
| |
| BoundedByteReader<kCookieSize> buffer(cookie); |
| uint32_t magic1 = buffer.Load32<0>(); |
| uint32_t magic2 = buffer.Load32<4>(); |
| if (magic1 != kMagic1 || magic2 != kMagic2) { |
| RTC_DLOG(LS_WARNING) << "Invalid state cookie; wrong magic"; |
| return absl::nullopt; |
| } |
| |
| VerificationTag peer_tag(buffer.Load32<8>()); |
| VerificationTag my_tag(buffer.Load32<12>()); |
| TSN peer_initial_tsn(buffer.Load32<16>()); |
| TSN my_initial_tsn(buffer.Load32<20>()); |
| uint32_t a_rwnd = buffer.Load32<24>(); |
| uint32_t tie_tag_upper = buffer.Load32<28>(); |
| uint32_t tie_tag_lower = buffer.Load32<32>(); |
| TieTag tie_tag(static_cast<uint64_t>(tie_tag_upper) << 32 | |
| static_cast<uint64_t>(tie_tag_lower)); |
| Capabilities capabilities; |
| capabilities.partial_reliability = buffer.Load8<36>() != 0; |
| capabilities.message_interleaving = buffer.Load8<37>() != 0; |
| capabilities.reconfig = buffer.Load8<38>() != 0; |
| capabilities.zero_checksum = buffer.Load8<39>() != 0; |
| capabilities.negotiated_maximum_incoming_streams = buffer.Load16<40>(); |
| capabilities.negotiated_maximum_outgoing_streams = buffer.Load16<42>(); |
| |
| return StateCookie(peer_tag, my_tag, peer_initial_tsn, my_initial_tsn, a_rwnd, |
| tie_tag, capabilities); |
| } |
| |
| } // namespace dcsctp |