79 lines
2.7 KiB
C++
79 lines
2.7 KiB
C++
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/*
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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>(*initiate_tag_);
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buffer.Store32<12>(*initial_tsn_);
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buffer.Store32<16>(a_rwnd_);
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buffer.Store32<20>(static_cast<uint32_t>(*tie_tag_ >> 32));
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buffer.Store32<24>(static_cast<uint32_t>(*tie_tag_));
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buffer.Store8<28>(capabilities_.partial_reliability);
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buffer.Store8<29>(capabilities_.message_interleaving);
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buffer.Store8<30>(capabilities_.reconfig);
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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 verification_tag(buffer.Load32<8>());
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TSN initial_tsn(buffer.Load32<12>());
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uint32_t a_rwnd = buffer.Load32<16>();
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uint32_t tie_tag_upper = buffer.Load32<20>();
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uint32_t tie_tag_lower = buffer.Load32<24>();
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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<28>() != 0;
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capabilities.message_interleaving = buffer.Load8<29>() != 0;
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capabilities.reconfig = buffer.Load8<30>() != 0;
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return StateCookie(verification_tag, initial_tsn, a_rwnd, tie_tag,
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capabilities);
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}
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} // namespace dcsctp
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