135f781b94
The elements in it can be packet better. This saves one byte. The state cookie is only used from one peer to itself, so there is no considerations around backwards or forwards compatibility. Bug: None Change-Id: I4f9a44f4c825626c7ed84bff52ed3155f5025a69 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/353142 Reviewed-by: Florent Castelli <orphis@webrtc.org> Commit-Queue: Florent Castelli <orphis@webrtc.org> Auto-Submit: Victor Boivie <boivie@webrtc.org> Cr-Commit-Position: refs/heads/main@{#42421}
89 lines
3.3 KiB
C++
89 lines
3.3 KiB
C++
/*
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* Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "net/dcsctp/socket/state_cookie.h"
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#include <cstdint>
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#include <vector>
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#include "absl/types/optional.h"
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#include "api/array_view.h"
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#include "net/dcsctp/packet/bounded_byte_reader.h"
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#include "net/dcsctp/packet/bounded_byte_writer.h"
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#include "net/dcsctp/socket/capabilities.h"
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#include "rtc_base/logging.h"
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namespace dcsctp {
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// Magic values, which the state cookie is prefixed with.
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constexpr uint32_t kMagic1 = 1684230979;
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constexpr uint32_t kMagic2 = 1414541360;
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constexpr size_t StateCookie::kCookieSize;
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std::vector<uint8_t> StateCookie::Serialize() {
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std::vector<uint8_t> cookie;
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cookie.resize(kCookieSize);
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BoundedByteWriter<kCookieSize> buffer(cookie);
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buffer.Store32<0>(kMagic1);
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buffer.Store32<4>(kMagic2);
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buffer.Store32<8>(*peer_tag_);
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buffer.Store32<12>(*my_tag_);
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buffer.Store32<16>(*peer_initial_tsn_);
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buffer.Store32<20>(*my_initial_tsn_);
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buffer.Store32<24>(a_rwnd_);
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buffer.Store32<28>(static_cast<uint32_t>(*tie_tag_ >> 32));
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buffer.Store32<32>(static_cast<uint32_t>(*tie_tag_));
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buffer.Store8<36>(capabilities_.partial_reliability);
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buffer.Store8<37>(capabilities_.message_interleaving);
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buffer.Store8<38>(capabilities_.reconfig);
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buffer.Store8<39>(capabilities_.zero_checksum);
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buffer.Store16<40>(capabilities_.negotiated_maximum_incoming_streams);
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buffer.Store16<42>(capabilities_.negotiated_maximum_outgoing_streams);
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return cookie;
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}
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absl::optional<StateCookie> StateCookie::Deserialize(
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rtc::ArrayView<const uint8_t> cookie) {
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if (cookie.size() != kCookieSize) {
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RTC_DLOG(LS_WARNING) << "Invalid state cookie: " << cookie.size()
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<< " bytes";
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return absl::nullopt;
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}
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BoundedByteReader<kCookieSize> buffer(cookie);
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uint32_t magic1 = buffer.Load32<0>();
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uint32_t magic2 = buffer.Load32<4>();
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if (magic1 != kMagic1 || magic2 != kMagic2) {
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RTC_DLOG(LS_WARNING) << "Invalid state cookie; wrong magic";
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return absl::nullopt;
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}
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VerificationTag peer_tag(buffer.Load32<8>());
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VerificationTag my_tag(buffer.Load32<12>());
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TSN peer_initial_tsn(buffer.Load32<16>());
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TSN my_initial_tsn(buffer.Load32<20>());
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uint32_t a_rwnd = buffer.Load32<24>();
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uint32_t tie_tag_upper = buffer.Load32<28>();
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uint32_t tie_tag_lower = buffer.Load32<32>();
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TieTag tie_tag(static_cast<uint64_t>(tie_tag_upper) << 32 |
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static_cast<uint64_t>(tie_tag_lower));
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Capabilities capabilities;
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capabilities.partial_reliability = buffer.Load8<36>() != 0;
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capabilities.message_interleaving = buffer.Load8<37>() != 0;
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capabilities.reconfig = buffer.Load8<38>() != 0;
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capabilities.zero_checksum = buffer.Load8<39>() != 0;
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capabilities.negotiated_maximum_incoming_streams = buffer.Load16<40>();
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capabilities.negotiated_maximum_outgoing_streams = buffer.Load16<42>();
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return StateCookie(peer_tag, my_tag, peer_initial_tsn, my_initial_tsn, a_rwnd,
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tie_tag, capabilities);
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}
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} // namespace dcsctp
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