| // 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 "net/third_party/quic/core/quic_utils.h" |
| |
| #include <algorithm> |
| #include <cstdint> |
| |
| #include "net/third_party/quic/core/quic_constants.h" |
| #include "net/third_party/quic/core/quic_types.h" |
| #include "net/third_party/quic/platform/api/quic_aligned.h" |
| #include "net/third_party/quic/platform/api/quic_arraysize.h" |
| #include "net/third_party/quic/platform/api/quic_bug_tracker.h" |
| #include "net/third_party/quic/platform/api/quic_endian.h" |
| #include "net/third_party/quic/platform/api/quic_flags.h" |
| #include "net/third_party/quic/platform/api/quic_prefetch.h" |
| #include "net/third_party/quic/platform/api/quic_string.h" |
| #include "net/third_party/quic/platform/api/quic_uint128.h" |
| #include "starboard/memory.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 |
| QuicUint128 IncrementalHashFast(QuicUint128 uhash, QuicStringPiece data) { |
| // This code ends up faster than the naive implementation for 2 reasons: |
| // 1. QuicUint128 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 QuicUint128 kPrime = |
| (static_cast<QuicUint128>(16777216) << 64) + 315; |
| auto hi = QuicUint128High64(uhash); |
| auto lo = QuicUint128Low64(uhash); |
| QuicUint128 xhash = (static_cast<QuicUint128>(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 MakeQuicUint128(QuicUint128High64(xhash), QuicUint128Low64(xhash)); |
| } |
| #endif |
| |
| #ifndef QUIC_UTIL_HAS_UINT128 |
| // Slow implementation of IncrementalHash. In practice, only used by Chromium. |
| QuicUint128 IncrementalHashSlow(QuicUint128 hash, QuicStringPiece data) { |
| // kPrime = 309485009821345068724781371 |
| static const QuicUint128 kPrime = MakeQuicUint128(16777216, 315); |
| const uint8_t* octets = reinterpret_cast<const uint8_t*>(data.data()); |
| for (size_t i = 0; i < data.length(); ++i) { |
| hash = hash ^ MakeQuicUint128(0, octets[i]); |
| hash = hash * kPrime; |
| } |
| return hash; |
| } |
| #endif |
| |
| QuicUint128 IncrementalHash(QuicUint128 hash, QuicStringPiece data) { |
| #ifdef QUIC_UTIL_HAS_UINT128 |
| return IncrementalHashFast(hash, data); |
| #else |
| return IncrementalHashSlow(hash, data); |
| #endif |
| } |
| |
| } // namespace |
| |
| // static |
| uint64_t QuicUtils::FNV1a_64_Hash(QuicStringPiece 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 |
| QuicUint128 QuicUtils::FNV1a_128_Hash(QuicStringPiece data) { |
| return FNV1a_128_Hash_Three(data, QuicStringPiece(), QuicStringPiece()); |
| } |
| |
| // static |
| QuicUint128 QuicUtils::FNV1a_128_Hash_Two(QuicStringPiece data1, |
| QuicStringPiece data2) { |
| return FNV1a_128_Hash_Three(data1, data2, QuicStringPiece()); |
| } |
| |
| // static |
| QuicUint128 QuicUtils::FNV1a_128_Hash_Three(QuicStringPiece data1, |
| QuicStringPiece data2, |
| QuicStringPiece data3) { |
| // The two constants are defined as part of the hash algorithm. |
| // see http://www.isthe.com/chongo/tech/comp/fnv/ |
| // kOffset = 144066263297769815596495629667062367629 |
| const QuicUint128 kOffset = MakeQuicUint128(UINT64_C(7809847782465536322), |
| UINT64_C(7113472399480571277)); |
| |
| QuicUint128 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(QuicUint128 v, uint8_t* out) { |
| const uint64_t lo = QuicUint128Low64(v); |
| const uint64_t hi = QuicUint128High64(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; |
| |
| // static |
| const char* QuicUtils::EncryptionLevelToString(EncryptionLevel level) { |
| switch (level) { |
| RETURN_STRING_LITERAL(ENCRYPTION_NONE); |
| RETURN_STRING_LITERAL(ENCRYPTION_ZERO_RTT); |
| RETURN_STRING_LITERAL(ENCRYPTION_FORWARD_SECURE); |
| RETURN_STRING_LITERAL(NUM_ENCRYPTION_LEVELS); |
| } |
| return "INVALID_ENCRYPTION_LEVEL"; |
| } |
| |
| // static |
| const char* QuicUtils::TransmissionTypeToString(TransmissionType type) { |
| switch (type) { |
| RETURN_STRING_LITERAL(NOT_RETRANSMISSION); |
| RETURN_STRING_LITERAL(HANDSHAKE_RETRANSMISSION); |
| RETURN_STRING_LITERAL(LOSS_RETRANSMISSION); |
| RETURN_STRING_LITERAL(ALL_UNACKED_RETRANSMISSION); |
| RETURN_STRING_LITERAL(ALL_INITIAL_RETRANSMISSION); |
| RETURN_STRING_LITERAL(RTO_RETRANSMISSION); |
| RETURN_STRING_LITERAL(TLP_RETRANSMISSION); |
| RETURN_STRING_LITERAL(PROBING_RETRANSMISSION); |
| } |
| return "INVALID_TRANSMISSION_TYPE"; |
| } |
| |
| QuicString 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(HANDSHAKE_RETRANSMITTED); |
| RETURN_STRING_LITERAL(LOST); |
| RETURN_STRING_LITERAL(TLP_RETRANSMITTED); |
| RETURN_STRING_LITERAL(RTO_RETRANSMITTED); |
| RETURN_STRING_LITERAL(PROBE_RETRANSMITTED); |
| } |
| 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 |
| 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; |
| } |
| DCHECK_LE(iovnum, iov_count); |
| 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. |
| QuicPrefetchT0(next_base); |
| if (iov[iovnum + 1].iov_len >= 64) { |
| QuicPrefetchT0(next_base + QUIC_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(buffer_length > 0) << "Failed to copy entire length to buffer."; |
| } |
| |
| // static |
| struct IOVEC QuicUtils::MakeIovec(QuicStringPiece 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: |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| // static |
| bool QuicUtils::IsHandshakeFrame(const QuicFrame& frame, |
| QuicTransportVersion transport_version) { |
| if (transport_version < QUIC_VERSION_47) { |
| return frame.type == STREAM_FRAME && |
| frame.stream_frame.stream_id == GetCryptoStreamId(transport_version); |
| } else { |
| return frame.type == CRYPTO_FRAME; |
| } |
| } |
| |
| // static |
| SentPacketState QuicUtils::RetransmissionTypeToPacketState( |
| TransmissionType retransmission_type) { |
| switch (retransmission_type) { |
| case ALL_UNACKED_RETRANSMISSION: |
| case ALL_INITIAL_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 PROBING_RETRANSMISSION: |
| return PROBE_RETRANSMITTED; |
| default: |
| QUIC_BUG << QuicUtils::TransmissionTypeToString(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 version == QUIC_VERSION_99 ? std::numeric_limits<QuicStreamId>::max() |
| : 0; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetCryptoStreamId(QuicTransportVersion version) { |
| // TODO(nharper): Change this to return GetInvalidStreamId for version 47 or |
| // greater. Currently, too many things break with that change. |
| return version == QUIC_VERSION_99 ? 0 : 1; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetHeadersStreamId(QuicTransportVersion version) { |
| return version == QUIC_VERSION_99 ? 4 : 3; |
| } |
| |
| // static |
| bool QuicUtils::IsClientInitiatedStreamId(QuicTransportVersion version, |
| QuicStreamId id) { |
| if (id == GetInvalidStreamId(version)) { |
| return false; |
| } |
| return version == QUIC_VERSION_99 ? id % 2 == 0 : id % 2 != 0; |
| } |
| |
| // static |
| bool QuicUtils::IsServerInitiatedStreamId(QuicTransportVersion version, |
| QuicStreamId id) { |
| if (id == GetInvalidStreamId(version)) { |
| return false; |
| } |
| return version == QUIC_VERSION_99 ? id % 2 != 0 : id % 2 == 0; |
| } |
| |
| // static |
| bool QuicUtils::IsBidirectionalStreamId(QuicStreamId id) { |
| return id % 4 < 2; |
| } |
| |
| // static |
| StreamType QuicUtils::GetStreamType(QuicStreamId id, |
| Perspective perspective, |
| bool peer_initiated) { |
| if (IsBidirectionalStreamId(id)) { |
| return BIDIRECTIONAL; |
| } |
| |
| if (peer_initiated) { |
| if (perspective == Perspective::IS_SERVER) { |
| DCHECK_EQ(2u, id % 4); |
| } else { |
| DCHECK_EQ(Perspective::IS_CLIENT, perspective); |
| DCHECK_EQ(3u, id % 4); |
| } |
| return READ_UNIDIRECTIONAL; |
| } |
| |
| if (perspective == Perspective::IS_SERVER) { |
| DCHECK_EQ(3u, id % 4); |
| } else { |
| DCHECK_EQ(Perspective::IS_CLIENT, perspective); |
| DCHECK_EQ(2u, id % 4); |
| } |
| return WRITE_UNIDIRECTIONAL; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::StreamIdDelta(QuicTransportVersion version) { |
| return version == QUIC_VERSION_99 ? 4 : 2; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetFirstBidirectionalStreamId( |
| QuicTransportVersion version, |
| Perspective perspective) { |
| if (perspective == Perspective::IS_CLIENT) { |
| return version == QUIC_VERSION_99 ? 4 : 3; |
| } |
| return version == QUIC_VERSION_99 ? 1 : 2; |
| } |
| |
| // static |
| QuicStreamId QuicUtils::GetFirstUnidirectionalStreamId( |
| QuicTransportVersion version, |
| Perspective perspective) { |
| if (perspective == Perspective::IS_CLIENT) { |
| return version == QUIC_VERSION_99 ? 2 : 3; |
| } |
| return version == QUIC_VERSION_99 ? 3 : 2; |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId() { |
| return CreateRandomConnectionId(QuicRandom::GetInstance()); |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateRandomConnectionId(QuicRandom* random) { |
| char connection_id_bytes[kQuicDefaultConnectionIdLength]; |
| random->RandBytes(connection_id_bytes, QUIC_ARRAYSIZE(connection_id_bytes)); |
| return QuicConnectionId(static_cast<char*>(connection_id_bytes), |
| QUIC_ARRAYSIZE(connection_id_bytes)); |
| } |
| |
| // static |
| bool QuicUtils::VariableLengthConnectionIdAllowedForVersion( |
| QuicTransportVersion version) { |
| // TODO(dschinazi): Allow in appropriate version when supported. |
| return false; |
| } |
| |
| // static |
| QuicConnectionId QuicUtils::CreateZeroConnectionId( |
| QuicTransportVersion version) { |
| if (!VariableLengthConnectionIdAllowedForVersion(version)) { |
| char connection_id_bytes[8] = {0, 0, 0, 0, 0, 0, 0, 0}; |
| return QuicConnectionId(static_cast<char*>(connection_id_bytes), |
| QUIC_ARRAYSIZE(connection_id_bytes)); |
| } |
| return EmptyQuicConnectionId(); |
| } |
| |
| // static |
| bool QuicUtils::IsConnectionIdValidForVersion(QuicConnectionId connection_id, |
| QuicTransportVersion version) { |
| if (VariableLengthConnectionIdAllowedForVersion(version)) { |
| return true; |
| } |
| return connection_id.length() == kQuicDefaultConnectionIdLength; |
| } |
| |
| QuicUint128 QuicUtils::GenerateStatelessResetToken( |
| QuicConnectionId connection_id) { |
| uint64_t data_bytes[3] = {0, 0, 0}; |
| static_assert(sizeof(data_bytes) >= kQuicMaxConnectionIdLength, |
| "kQuicMaxConnectionIdLength changed"); |
| memcpy(data_bytes, connection_id.data(), connection_id.length()); |
| // This is designed so that the common case of 64bit connection IDs |
| // produces a stateless reset token that is equal to the connection ID |
| // interpreted as a 64bit unsigned integer, to facilitate debugging. |
| return MakeQuicUint128( |
| QuicEndian::NetToHost64(sizeof(uint64_t) ^ connection_id.length() ^ |
| data_bytes[1] ^ data_bytes[2]), |
| QuicEndian::NetToHost64(data_bytes[0])); |
| } |
| |
| #undef RETURN_STRING_LITERAL // undef for jumbo builds |
| } // namespace quic |