| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "quic/core/quic_utils.h" |
| |
| #include <algorithm> |
| #include <cstdint> |
| #include <cstring> |
| #include <limits> |
| #include <string> |
| |
| #include "absl/base/macros.h" |
| #include "absl/base/optimization.h" |
| #include "absl/numeric/int128.h" |
| #include "absl/strings/string_view.h" |
| #include "quic/core/quic_connection_id.h" |
| #include "quic/core/quic_constants.h" |
| #include "quic/core/quic_types.h" |
| #include "quic/core/quic_versions.h" |
| #include "quic/platform/api/quic_bug_tracker.h" |
| #include "quic/platform/api/quic_flag_utils.h" |
| #include "quic/platform/api/quic_flags.h" |
| #include "quic/platform/api/quic_mem_slice.h" |
| #include "common/platform/api/quiche_logging.h" |
| #include "common/platform/api/quiche_prefetch.h" |
| #include "common/quiche_endian.h" |
| |
| namespace quic { |
| namespace { |
| |
| // We know that >= GCC 4.8 and Clang have a __uint128_t intrinsic. Other |
| // compilers don't necessarily, notably MSVC. |
| #if defined(__x86_64__) && \ |
| ((defined(__GNUC__) && \ |
| (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) || \ |
| defined(__clang__)) |
| #define QUIC_UTIL_HAS_UINT128 1 |
| #endif |
| |
| #ifdef QUIC_UTIL_HAS_UINT128 |
| absl::uint128 IncrementalHashFast(absl::uint128 uhash, absl::string_view data) { |
| // This code ends up faster than the naive implementation for 2 reasons: |
| // 1. absl::uint128 is sufficiently complicated that the compiler |
| // cannot transform the multiplication by kPrime into a shift-multiply-add; |
| // it has go through all of the instructions for a 128-bit multiply. |
| // 2. Because there are so fewer instructions (around 13), the hot loop fits |
| // nicely in the instruction queue of many Intel CPUs. |
| // kPrime = 309485009821345068724781371 |
| static const absl::uint128 kPrime = |
| (static_cast<absl::uint128>(16777216) << 64) + 315; |
| auto hi = absl::Uint128High64(uhash); |
| auto lo = absl::Uint128Low64(uhash); |
| absl::uint128 xhash = (static_cast<absl::uint128>(hi) << 64) + lo; |
| const uint8_t* octets = reinterpret_cast<const uint8_t*>(data.data()); |
| for (size_t i = 0; i < data.length(); ++i) { |
| xhash = (xhash ^ static_cast<uint32_t>(octets[i])) * kPrime; |
| } |
| return absl::MakeUint128(absl::Uint128High64(xhash), |
| absl::Uint128Low64(xhash)); |
| } |
| #endif |
| |
| #ifndef QUIC_UTIL_HAS_UINT128 |
| // Slow implementation of IncrementalHash. In practice, only used by Chromium. |
| absl::uint128 IncrementalHashSlow(absl::uint128 hash, absl::string_view data) { |
| // kPrime = 309485009821345068724781371 |
| static const absl::uint128 kPrime = absl::MakeUint128(16777216, 315); |
| const uint8_t* octets = reinterpret_cast<const uint8_t*>(data.data()); |
| for (size_t i = 0; i < data.length(); ++i) { |
| hash = hash ^ absl::MakeUint128(0, octets[i]); |
| hash = hash * kPrime; |
| } |
| return hash; |
| } |
| #endif |
| |
| absl::uint128 IncrementalHash(absl::uint128 hash, absl::string_view data) { |
| #ifdef QUIC_UTIL_HAS_UINT128 |
| return IncrementalHashFast(hash, data); |
| #else |
| return IncrementalHashSlow(hash, data); |
| #endif |
| } |
| |
| } // namespace |
| |
| // static |
| uint64_t QuicUtils::FNV1a_64_Hash(absl::string_view data) { |
| static const uint64_t kOffset = UINT64_C(14695981039346656037); |
| static const uint64_t kPrime = UINT64_C(1099511628211); |
| |
| const uint8_t* octets = reinterpret_cast<const uint8_t*>(data.data()); |
| |
| uint64_t hash = kOffset; |
| |
| for (size_t i = 0; i < data.length(); ++i) { |
| hash = hash ^ octets[i]; |
| hash = hash * kPrime; |
| } |
| |
| return hash; |
| } |
| |
| // static |
| absl::uint128 QuicUtils::FNV1a_128_Hash(absl::string_view data) { |
| return FNV1a_128_Hash_Three(data, absl::string_view(), absl::string_view()); |
| } |
| |
| // static |
| absl::uint128 QuicUtils::FNV1a_128_Hash_Two(absl::string_view data1, |
| absl::string_view data2) { |
| return FNV1a_128_Hash_Three(data1, data2, absl::string_view()); |
| } |
| |
| // static |
| absl::uint128 QuicUtils::FNV1a_128_Hash_Three(absl::string_view data1, |
| absl::string_view data2, |
| absl::string_view data3) { |
| // The two constants are defined as part of the hash algorithm. |
| // see http://www.isthe.com/chongo/tech/comp/fnv/ |
| // kOffset = 144066263297769815596495629667062367629 |
| const absl::uint128 kOffset = absl::MakeUint128( |
| UINT64_C(7809847782465536322), UINT64_C(7113472399480571277)); |
| |
| absl::uint128 hash = IncrementalHash(kOffset, data1); |
| if (data2.empty()) { |
| return hash; |
| } |
| |
| hash = IncrementalHash(hash, data2); |
| if (data3.empty()) { |
| return hash; |
| } |
| return IncrementalHash(hash, data3); |
| } |
| |
| // static |
| void QuicUtils::SerializeUint128Short(absl::uint128 v, uint8_t* out) { |
| const uint64_t lo = absl::Uint128Low64(v); |
| const uint64_t hi = absl::Uint128High64(v); |
| // This assumes that the system is little-endian. |
| memcpy(out, &lo, sizeof(lo)); |
| memcpy(out + sizeof(lo), &hi, sizeof(hi) / 2); |
| } |
| |
| #define RETURN_STRING_LITERAL(x) \ |
| case x: \ |
| return #x; |
| |
| std::string QuicUtils::AddressChangeTypeToString(AddressChangeType type) { |
| switch (type) { |
| RETURN_STRING_LITERAL(NO_CHANGE); |
| RETURN_STRING_LITERAL(PORT_CHANGE); |
| RETURN_STRING_LITERAL(IPV4_SUBNET_CHANGE); |
| RETURN_STRING_LITERAL(IPV4_TO_IPV6_CHANGE); |
| RETURN_STRING_LITERAL(IPV6_TO_IPV4_CHANGE); |
| RETURN_STRING_LITERAL(IPV6_TO_IPV6_CHANGE); |
| RETURN_STRING_LITERAL(IPV4_TO_IPV4_CHANGE); |
| } |
| return "INVALID_ADDRESS_CHANGE_TYPE"; |
| } |
| |
| const char* QuicUtils::SentPacketStateToString(SentPacketState state) { |
| switch (state) { |
| RETURN_STRING_LITERAL(OUTSTANDING); |
| RETURN_STRING_LITERAL(NEVER_SENT); |
| RETURN_STRING_LITERAL(ACKED); |
| RETURN_STRING_LITERAL(UNACKABLE); |
| RETURN_STRING_LITERAL(NEUTERED); |
| RETURN_STRING_LITERAL(HANDSHAKE_RETRANSMITTED); |
| RETURN_STRING_LITERAL(LOST); |
| RETURN_STRING_LITERAL(TLP_RETRANSMITTED); |
| RETURN_STRING_LITERAL(RTO_RETRANSMITTED); |
| RETURN_STRING_LITERAL(PTO_RETRANSMITTED); |
| RETURN_STRING_LITERAL(PROBE_RETRANSMITTED); |
| RETURN_STRING_LITERAL(NOT_CONTRIBUTING_RTT); |
| } |
| return "INVALID_SENT_PACKET_STATE"; |
| } |
| |
| // static |
| const char* QuicUtils::QuicLongHeaderTypetoString(QuicLongHeaderType type) { |
| switch (type) { |
| RETURN_STRING_LITERAL(VERSION_NEGOTIATION); |
| RETURN_STRING_LITERAL(INITIAL); |
| RETURN_STRING_LITERAL(RETRY); |
| RETURN_STRING_LITERAL(HANDSHAKE); |
| RETURN_STRING_LITERAL(ZERO_RTT_PROTECTED); |
| default: |
| return "INVALID_PACKET_TYPE"; |
| } |
| } |
| |
| // static |
| const char* QuicUtils::AckResultToString(AckResult result) { |
| switch (result) { |
| RETURN_STRING_LITERAL(PACKETS_NEWLY_ACKED); |
| RETURN_STRING_LITERAL(NO_PACKETS_NEWLY_ACKED); |
| RETURN_STRING_LITERAL(UNSENT_PACKETS_ACKED); |
| RETURN_STRING_LITERAL(UNACKABLE_PACKETS_ACKED); |
| RETURN_STRING_LITERAL(PACKETS_ACKED_IN_WRONG_PACKET_NUMBER_SPACE); |
| } |
| return "INVALID_ACK_RESULT"; |
| } |
| |
| // static |
| AddressChangeType QuicUtils::DetermineAddressChangeType( |
| const QuicSocketAddress& old_address, |
| const QuicSocketAddress& new_address) { |
| if (!old_address.IsInitialized() || !new_address.IsInitialized() || |
| old_address == new_address) { |
| return NO_CHANGE; |
| } |
| |
| if (old_address.host() == new_address.host()) { |
| return PORT_CHANGE; |
| } |
| |
| bool old_ip_is_ipv4 = old_address.host().IsIPv4() ? true : false; |
| bool migrating_ip_is_ipv4 = new_address.host().IsIPv4() ? true : false; |
| if (old_ip_is_ipv4 && !migrating_ip_is_ipv4) { |
| return IPV4_TO_IPV6_CHANGE; |
| } |
| |
| if (!old_ip_is_ipv4) { |
| return migrating_ip_is_ipv4 ? IPV6_TO_IPV4_CHANGE : IPV6_TO_IPV6_CHANGE; |
| } |
| |
| const int kSubnetMaskLength = 24; |
| if (old_address.host().InSameSubnet(new_address.host(), kSubnetMaskLength)) { |
| // Subnet part does not change (here, we use /24), which is considered to be |
| // caused by NATs. |
| return IPV4_SUBNET_CHANGE; |
| } |
| |
| return IPV4_TO_IPV4_CHANGE; |
| } |
| |
| // static |
| void QuicUtils::CopyToBuffer(const struct iovec* iov, |
| int iov_count, |
| size_t iov_offset, |
| size_t buffer_length, |
| char* buffer) { |
| int iovnum = 0; |
| while (iovnum < iov_count && iov_offset >= iov[iovnum].iov_len) { |
| iov_offset -= iov[iovnum].iov_len; |
| ++iovnum; |
| } |
| QUICHE_DCHECK_LE(iovnum, iov_count); |
| QUICHE_DCHECK_LE(iov_offset, iov[iovnum].iov_len); |
| if (iovnum >= iov_count || buffer_length == 0) { |
| return; |
| } |
| |
| // Unroll the first iteration that handles iov_offset. |
| const size_t iov_available = iov[iovnum].iov_len - iov_offset; |
| size_t copy_len = std::min(buffer_length, iov_available); |
| |
| // Try to prefetch the next iov if there is at least one more after the |
| // current. Otherwise, it looks like an irregular access that the hardware |
| // prefetcher won't speculatively prefetch. Only prefetch one iov because |
| // generally, the iov_offset is not 0, input iov consists of 2K buffers and |
| // the output buffer is ~1.4K. |
| if (copy_len == iov_available && iovnum + 1 < iov_count) { |
| char* next_base = static_cast<char*>(iov[iovnum + 1].iov_base); |
| // Prefetch 2 cachelines worth of data to get the prefetcher started; leave |
| // it to the hardware prefetcher after that. |
| quiche::QuichePrefetchT0(next_base); |
| if (iov[iovnum + 1].iov_len >= 64) { |
| quiche::QuichePrefetchT0(next_base + ABSL_CACHELINE_SIZE); |
| } |
| } |
| |
| const char* src = static_cast<char*>(iov[iovnum].iov_base) + iov_offset; |
| while (true) { |
| memcpy(buffer, src, copy_len); |
| buffer_length -= copy_len; |
| buffer += copy_len; |
| if (buffer_length == 0 || ++iovnum >= iov_count) { |
| break; |
| } |
| src = static_cast<char*>(iov[iovnum].iov_base); |
| copy_len = std::min(buffer_length, iov[iovnum].iov_len); |
| } |
| QUIC_BUG_IF(quic_bug_10839_1, buffer_length > 0) |
| << "Failed to copy entire length to buffer."; |
| } |
| |
| // static |
| struct iovec QuicUtils::MakeIovec(absl::string_view data) { |
| struct iovec iov = {const_cast<char*>(data.data()), |
| static_cast<size_t>(data.size())}; |
| return iov; |
| } |
| |
| // static |
| bool QuicUtils::IsAckable(SentPacketState state) { |
| return state != NEVER_SENT && state != ACKED && state != UNACKABLE; |
| } |
| |
| // static |
| bool QuicUtils::IsRetransmittableFrame(QuicFrameType type) { |
| switch (type) { |
| case ACK_FRAME: |
| case PADDING_FRAME: |
| case STOP_WAITING_FRAME: |
| case MTU_DISCOVERY_FRAME: |
| case PATH_CHALLENGE_FRAME: |
| case PATH_RESPONSE_FRAME: |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| // static |
| bool QuicUtils::IsHandshakeFrame(const QuicFrame& frame, |
| QuicTransportVersion transport_version) { |
| if (!QuicVersionUsesCryptoFrames(transport_version)) { |
| return frame.type == STREAM_FRAME && |
| frame.stream_frame.stream_id == GetCryptoStreamId(transport_version); |
| } else { |
| return frame.type == CRYPTO_FRAME; |
| } |
| } |
| |
| // static |
| bool QuicUtils::ContainsFrameType(const QuicFrames& frames, |
| QuicFrameType type) { |
| for (const QuicFrame& frame : frames) { |
| if (frame.type == type) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // static |
| SentPacketState QuicUtils::RetransmissionTypeToPacketState( |
| TransmissionType retransmission_type) { |
| switch (retransmission_type) { |
| case ALL_ZERO_RTT_RETRANSMISSION: |
| return UNACKABLE; |
| case HANDSHAKE_RETRANSMISSION: |
| return HANDSHAKE_RETRANSMITTED; |
| case LOSS_RETRANSMISSION: |
| return LOST; |
| case TLP_RETRANSMISSION: |
| return TLP_RETRANSMITTED; |
| case RTO_RETRANSMISSION: |
| return RTO_RETRANSMITTED; |
| case PTO_RETRANSMISSION: |
| return PTO_RETRANSMITTED; |
| case PROBING_RETRANSMISSION: |
| return PROBE_RETRANSMITTED; |
| case PATH_RETRANSMISSION: |
| return NOT_CONTRIBUTING_RTT; |
| case ALL_INITIAL_RETRANSMISSION: |
| return UNACKABLE; |
| default: |
| QUIC_BUG(quic_bug_10839_2) |
| << retransmission_type << " is not a retransmission_type"; |
| return UNACKABLE; |
| } |
| } |
| |
| // static |
| bool QuicUtils::IsIetfPacketHeader(uint8_t first_byte) { |
| return (first_byte & FLAGS_LONG_HEADER) || (first_byte & FLAGS_FIXED_BIT) || |
| !(first_byte & FLAGS_DEMULTIPLEXING_BIT); |
| } |
| |
| // static |
| bool QuicUtils::IsIetfPacketShortHeader(uint8_t first_byte) { |
| return IsIetfPacketHeader(first_byte) && !(first_byte & FLAGS_LONG_HEADER); |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetInvalidStreamId(QuicTransportVersion version) { |
| return VersionHasIetfQuicFrames(version) |
| ? std::numeric_limits<QuicStreamId>::max() |
| : 0; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetCryptoStreamId(QuicTransportVersion version) { |
| QUIC_BUG_IF(quic_bug_12982_1, QuicVersionUsesCryptoFrames(version)) |
| << "CRYPTO data aren't in stream frames; they have no stream ID."; |
| return QuicVersionUsesCryptoFrames(version) ? GetInvalidStreamId(version) : 1; |
| } |
| |
| // static |
| bool QuicUtils::IsCryptoStreamId(QuicTransportVersion version, |
| QuicStreamId stream_id) { |
| if (QuicVersionUsesCryptoFrames(version)) { |
| return false; |
| } |
| return stream_id == GetCryptoStreamId(version); |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetHeadersStreamId(QuicTransportVersion version) { |
| QUICHE_DCHECK(!VersionUsesHttp3(version)); |
| return GetFirstBidirectionalStreamId(version, Perspective::IS_CLIENT); |
| } |
| |
| // static |
| bool QuicUtils::IsClientInitiatedStreamId(QuicTransportVersion version, |
| QuicStreamId id) { |
| if (id == GetInvalidStreamId(version)) { |
| return false; |
| } |
| return VersionHasIetfQuicFrames(version) ? id % 2 == 0 : id % 2 != 0; |
| } |
| |
| // static |
| bool QuicUtils::IsServerInitiatedStreamId(QuicTransportVersion version, |
| QuicStreamId id) { |
| if (id == GetInvalidStreamId(version)) { |
| return false; |
| } |
| return VersionHasIetfQuicFrames(version) ? id % 2 != 0 : id % 2 == 0; |
| } |
| |
| // static |
| bool QuicUtils::IsOutgoingStreamId(ParsedQuicVersion version, |
| QuicStreamId id, |
| Perspective perspective) { |
| // Streams are outgoing streams, iff: |
| // - we are the server and the stream is server-initiated |
| // - we are the client and the stream is client-initiated. |
| const bool perspective_is_server = perspective == Perspective::IS_SERVER; |
| const bool stream_is_server = |
| QuicUtils::IsServerInitiatedStreamId(version.transport_version, id); |
| return perspective_is_server == stream_is_server; |
| } |
| |
| // static |
| bool QuicUtils::IsBidirectionalStreamId(QuicStreamId id, |
| ParsedQuicVersion version) { |
| QUICHE_DCHECK(version.HasIetfQuicFrames()); |
| return id % 4 < 2; |
| } |
| |
| // static |
| StreamType QuicUtils::GetStreamType(QuicStreamId id, |
| Perspective perspective, |
| bool peer_initiated, |
| ParsedQuicVersion version) { |
| QUICHE_DCHECK(version.HasIetfQuicFrames()); |
| if (IsBidirectionalStreamId(id, version)) { |
| return BIDIRECTIONAL; |
| } |
| |
| if (peer_initiated) { |
| if (perspective == Perspective::IS_SERVER) { |
| QUICHE_DCHECK_EQ(2u, id % 4); |
| } else { |
| QUICHE_DCHECK_EQ(Perspective::IS_CLIENT, perspective); |
| QUICHE_DCHECK_EQ(3u, id % 4); |
| } |
| return READ_UNIDIRECTIONAL; |
| } |
| |
| if (perspective == Perspective::IS_SERVER) { |
| QUICHE_DCHECK_EQ(3u, id % 4); |
| } else { |
| QUICHE_DCHECK_EQ(Perspective::IS_CLIENT, perspective); |
| QUICHE_DCHECK_EQ(2u, id % 4); |
| } |
| return WRITE_UNIDIRECTIONAL; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::StreamIdDelta(QuicTransportVersion version) { |
| return VersionHasIetfQuicFrames(version) ? 4 : 2; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetFirstBidirectionalStreamId( |
| QuicTransportVersion version, |
| Perspective perspective) { |
| if (VersionHasIetfQuicFrames(version)) { |
| return perspective == Perspective::IS_CLIENT ? 0 : 1; |
| } else if (QuicVersionUsesCryptoFrames(version)) { |
| return perspective == Perspective::IS_CLIENT ? 1 : 2; |
| } |
| return perspective == Perspective::IS_CLIENT ? 3 : 2; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetFirstUnidirectionalStreamId( |
| QuicTransportVersion version, |
| Perspective perspective) { |
| if (VersionHasIetfQuicFrames(version)) { |
| return perspective == Perspective::IS_CLIENT ? 2 : 3; |
| } else if (QuicVersionUsesCryptoFrames(version)) { |
| return perspective == Perspective::IS_CLIENT ? 1 : 2; |
| } |
| return perspective == Perspective::IS_CLIENT ? 3 : 2; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetMaxClientInitiatedBidirectionalStreamId( |
| QuicTransportVersion version) { |
| if (VersionHasIetfQuicFrames(version)) { |
| // Client initiated bidirectional streams have stream IDs divisible by 4. |
| return std::numeric_limits<QuicStreamId>::max() - 3; |
| } |
| |
| // Client initiated bidirectional streams have odd stream IDs. |
| return std::numeric_limits<QuicStreamId>::max(); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateReplacementConnectionId( |
| const QuicConnectionId& connection_id) { |
| return CreateReplacementConnectionId(connection_id, |
| kQuicDefaultConnectionIdLength); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateReplacementConnectionId( |
| const QuicConnectionId& connection_id, |
| uint8_t expected_connection_id_length) { |
| if (expected_connection_id_length == 0) { |
| return EmptyQuicConnectionId(); |
| } |
| const uint64_t connection_id_hash64 = FNV1a_64_Hash( |
| absl::string_view(connection_id.data(), connection_id.length())); |
| if (expected_connection_id_length <= sizeof(uint64_t)) { |
| return QuicConnectionId( |
| reinterpret_cast<const char*>(&connection_id_hash64), |
| expected_connection_id_length); |
| } |
| char new_connection_id_data[255] = {}; |
| const absl::uint128 connection_id_hash128 = FNV1a_128_Hash( |
| absl::string_view(connection_id.data(), connection_id.length())); |
| static_assert(sizeof(connection_id_hash64) + sizeof(connection_id_hash128) <= |
| sizeof(new_connection_id_data), |
| "bad size"); |
| memcpy(new_connection_id_data, &connection_id_hash64, |
| sizeof(connection_id_hash64)); |
| memcpy(new_connection_id_data + sizeof(connection_id_hash64), |
| &connection_id_hash128, sizeof(connection_id_hash128)); |
| return QuicConnectionId(new_connection_id_data, |
| expected_connection_id_length); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId() { |
| return CreateRandomConnectionId(kQuicDefaultConnectionIdLength, |
| QuicRandom::GetInstance()); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId(QuicRandom* random) { |
| return CreateRandomConnectionId(kQuicDefaultConnectionIdLength, random); |
| } |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId( |
| uint8_t connection_id_length) { |
| return CreateRandomConnectionId(connection_id_length, |
| QuicRandom::GetInstance()); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId( |
| uint8_t connection_id_length, |
| QuicRandom* random) { |
| QuicConnectionId connection_id; |
| connection_id.set_length(connection_id_length); |
| if (connection_id.length() > 0) { |
| random->RandBytes(connection_id.mutable_data(), connection_id.length()); |
| } |
| return connection_id; |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateZeroConnectionId( |
| QuicTransportVersion version) { |
| if (!VersionAllowsVariableLengthConnectionIds(version)) { |
| char connection_id_bytes[8] = {0, 0, 0, 0, 0, 0, 0, 0}; |
| return QuicConnectionId(static_cast<char*>(connection_id_bytes), |
| ABSL_ARRAYSIZE(connection_id_bytes)); |
| } |
| return EmptyQuicConnectionId(); |
| } |
| |
| // static |
| bool QuicUtils::IsConnectionIdLengthValidForVersion( |
| size_t connection_id_length, |
| QuicTransportVersion transport_version) { |
| // No version of QUIC can support lengths that do not fit in an uint8_t. |
| if (connection_id_length > |
| static_cast<size_t>(std::numeric_limits<uint8_t>::max())) { |
| return false; |
| } |
| |
| if (transport_version == QUIC_VERSION_UNSUPPORTED || |
| transport_version == QUIC_VERSION_RESERVED_FOR_NEGOTIATION) { |
| // Unknown versions could allow connection ID lengths up to 255. |
| return true; |
| } |
| |
| const uint8_t connection_id_length8 = |
| static_cast<uint8_t>(connection_id_length); |
| // Versions that do not support variable lengths only support length 8. |
| if (!VersionAllowsVariableLengthConnectionIds(transport_version)) { |
| return connection_id_length8 == kQuicDefaultConnectionIdLength; |
| } |
| // Versions that do support variable length but do not have length-prefixed |
| // connection IDs use the 4-bit connection ID length encoding which can |
| // only encode values 0 and 4-18. |
| if (!VersionHasLengthPrefixedConnectionIds(transport_version)) { |
| return connection_id_length8 == 0 || |
| (connection_id_length8 >= 4 && |
| connection_id_length8 <= kQuicMaxConnectionId4BitLength); |
| } |
| return connection_id_length8 <= kQuicMaxConnectionIdWithLengthPrefixLength; |
| } |
| |
| // static |
| bool QuicUtils::IsConnectionIdValidForVersion( |
| QuicConnectionId connection_id, |
| QuicTransportVersion transport_version) { |
| return IsConnectionIdLengthValidForVersion(connection_id.length(), |
| transport_version); |
| } |
| |
| StatelessResetToken QuicUtils::GenerateStatelessResetToken( |
| QuicConnectionId connection_id) { |
| static_assert(sizeof(absl::uint128) == sizeof(StatelessResetToken), |
| "bad size"); |
| static_assert(alignof(absl::uint128) >= alignof(StatelessResetToken), |
| "bad alignment"); |
| absl::uint128 hash = FNV1a_128_Hash( |
| absl::string_view(connection_id.data(), connection_id.length())); |
| return *reinterpret_cast<StatelessResetToken*>(&hash); |
| } |
| |
| // static |
| QuicStreamCount QuicUtils::GetMaxStreamCount() { |
| return (kMaxQuicStreamCount >> 2) + 1; |
| } |
| |
| // static |
| PacketNumberSpace QuicUtils::GetPacketNumberSpace( |
| EncryptionLevel encryption_level) { |
| switch (encryption_level) { |
| case ENCRYPTION_INITIAL: |
| return INITIAL_DATA; |
| case ENCRYPTION_HANDSHAKE: |
| return HANDSHAKE_DATA; |
| case ENCRYPTION_ZERO_RTT: |
| case ENCRYPTION_FORWARD_SECURE: |
| return APPLICATION_DATA; |
| default: |
| QUIC_BUG(quic_bug_10839_3) |
| << "Try to get packet number space of encryption level: " |
| << encryption_level; |
| return NUM_PACKET_NUMBER_SPACES; |
| } |
| } |
| |
| // static |
| EncryptionLevel QuicUtils::GetEncryptionLevel( |
| PacketNumberSpace packet_number_space) { |
| switch (packet_number_space) { |
| case INITIAL_DATA: |
| return ENCRYPTION_INITIAL; |
| case HANDSHAKE_DATA: |
| return ENCRYPTION_HANDSHAKE; |
| case APPLICATION_DATA: |
| return ENCRYPTION_FORWARD_SECURE; |
| default: |
| QUICHE_DCHECK(false); |
| return NUM_ENCRYPTION_LEVELS; |
| } |
| } |
| |
| // static |
| bool QuicUtils::IsProbingFrame(QuicFrameType type) { |
| switch (type) { |
| case PATH_CHALLENGE_FRAME: |
| case PATH_RESPONSE_FRAME: |
| case NEW_CONNECTION_ID_FRAME: |
| case PADDING_FRAME: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| // static |
| bool QuicUtils::IsAckElicitingFrame(QuicFrameType type) { |
| switch (type) { |
| case PADDING_FRAME: |
| case STOP_WAITING_FRAME: |
| case ACK_FRAME: |
| case CONNECTION_CLOSE_FRAME: |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| // static |
| bool QuicUtils::AreStatelessResetTokensEqual( |
| const StatelessResetToken& token1, |
| const StatelessResetToken& token2) { |
| char byte = 0; |
| for (size_t i = 0; i < kStatelessResetTokenLength; i++) { |
| // This avoids compiler optimizations that could make us stop comparing |
| // after we find a byte that doesn't match. |
| byte |= (token1[i] ^ token2[i]); |
| } |
| return byte == 0; |
| } |
| |
| bool IsValidWebTransportSessionId(WebTransportSessionId id, |
| ParsedQuicVersion version) { |
| QUICHE_DCHECK(version.UsesHttp3()); |
| return (id <= std::numeric_limits<QuicStreamId>::max()) && |
| QuicUtils::IsBidirectionalStreamId(id, version) && |
| QuicUtils::IsClientInitiatedStreamId(version.transport_version, id); |
| } |
| |
| QuicByteCount MemSliceSpanTotalSize(absl::Span<QuicMemSlice> span) { |
| QuicByteCount total = 0; |
| for (const QuicMemSlice& slice : span) { |
| total += slice.length(); |
| } |
| return total; |
| } |
| |
| #undef RETURN_STRING_LITERAL // undef for jumbo builds |
| } // namespace quic |