blob: 6c2144ae39bb01dadda123064275cecaffca5c34 [file] [log] [blame]
// 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.
// Definitions and utility functions related to handling of QUIC versions.
//
// QUIC versions are encoded over the wire as an opaque 32bit field. The wire
// encoding is represented in memory as a QuicVersionLabel type (which is an
// alias to uint32_t). Conceptual versions are represented in memory as
// ParsedQuicVersion.
//
// We currently support two kinds of QUIC versions, GoogleQUIC and IETF QUIC.
//
// All GoogleQUIC versions use a wire encoding that matches the following regex
// when converted to ASCII: "[QT]0\d\d" (e.g. Q050). Q or T distinguishes the
// type of handshake used (Q for the QUIC_CRYPTO handshake, T for the QUIC+TLS
// handshake), and the two digits at the end contain the numeric value of
// the transport version used.
//
// All IETF QUIC versions use the wire encoding described in:
// https://tools.ietf.org/html/draft-ietf-quic-transport
#ifndef QUICHE_QUIC_CORE_QUIC_VERSIONS_H_
#define QUICHE_QUIC_CORE_QUIC_VERSIONS_H_
#include <string>
#include <vector>
#include "absl/base/macros.h"
#include "absl/strings/string_view.h"
#include "quic/core/quic_tag.h"
#include "quic/core/quic_types.h"
#include "quic/platform/api/quic_export.h"
namespace quic {
// The list of existing QUIC transport versions. Note that QUIC versions are
// sent over the wire as an encoding of ParsedQuicVersion, which requires a
// QUIC transport version and handshake protocol. For transport versions of the
// form QUIC_VERSION_XX where XX is decimal, the enum numeric value is
// guaranteed to match the name. Older deprecated transport versions are
// documented in comments below.
enum QuicTransportVersion {
// Special case to indicate unknown/unsupported QUIC version.
QUIC_VERSION_UNSUPPORTED = 0,
// Version 1 was the first version of QUIC that supported versioning.
// Version 2 decoupled versioning of non-cryptographic parameters from the
// SCFG.
// Version 3 moved public flags into the beginning of the packet.
// Version 4 added support for variable-length connection IDs.
// Version 5 made specifying FEC groups optional.
// Version 6 introduced variable-length packet numbers.
// Version 7 introduced a lower-overhead encoding for stream frames.
// Version 8 made salt length equal to digest length for the RSA-PSS
// signatures.
// Version 9 added stream priority.
// Version 10 redid the frame type numbering.
// Version 11 reduced the length of null encryption authentication tag
// from 16 to 12 bytes.
// Version 12 made the sequence numbers in the ACK frames variable-sized.
// Version 13 added the dedicated header stream.
// Version 14 added byte_offset to RST_STREAM frame.
// Version 15 added a list of packets recovered using FEC to the ACK frame.
// Version 16 added STOP_WAITING frame.
// Version 17 added per-stream flow control.
// Version 18 added PING frame.
// Version 19 added connection-level flow control
// Version 20 allowed to set stream- and connection-level flow control windows
// to different values.
// Version 21 made header and crypto streams flow-controlled.
// Version 22 added support for SCUP (server config update) messages.
// Version 23 added timestamps into the ACK frame.
// Version 24 added SPDY/4 header compression.
// Version 25 added support for SPDY/4 header keys and removed error_details
// from RST_STREAM frame.
// Version 26 added XLCT (expected leaf certificate) tag into CHLO.
// Version 27 added a nonce into SHLO.
// Version 28 allowed receiver to refuse creating a requested stream.
// Version 29 added support for QUIC_STREAM_NO_ERROR.
// Version 30 added server-side support for certificate transparency.
// Version 31 incorporated the hash of CHLO into the crypto proof supplied by
// the server.
// Version 32 removed FEC-related fields from wire format.
// Version 33 added diversification nonces.
// Version 34 removed entropy bits from packets and ACK frames, removed
// private flag from packet header and changed the ACK format to
// specify ranges of packets acknowledged rather than missing
// ranges.
// Version 35 allows endpoints to independently set stream limit.
// Version 36 added support for forced head-of-line blocking experiments.
// Version 37 added perspective into null encryption.
// Version 38 switched to IETF padding frame format and support for NSTP (no
// stop waiting frame) connection option.
// Version 39 writes integers and floating numbers in big endian, stops acking
// acks, sends a connection level WINDOW_UPDATE every 20 sent packets which do
// not contain retransmittable frames.
// Version 40 was an attempt to convert QUIC to IETF frame format; it was
// never shipped due to a bug.
// Version 41 was a bugfix for version 40. The working group changed the wire
// format before it shipped, which caused it to be never shipped
// and all the changes from it to be reverted. No changes from v40
// or v41 are present in subsequent versions.
// Version 42 allowed receiving overlapping stream data.
QUIC_VERSION_43 = 43, // PRIORITY frames are sent by client and accepted by
// server.
// Version 44 used IETF header format from draft-ietf-quic-invariants-05.
// Version 45 added MESSAGE frame.
QUIC_VERSION_46 = 46, // Use IETF draft-17 header format with demultiplexing
// bit.
// Version 47 added variable-length QUIC server connection IDs.
// Version 48 added CRYPTO frames for the handshake.
// Version 49 added client connection IDs, long header lengths, and the IETF
// header format from draft-ietf-quic-invariants-06
QUIC_VERSION_50 = 50, // Header protection and initial obfuscators.
// Number 51 was T051 which used draft-29 features but with GoogleQUIC frames.
// Number 70 used to represent draft-ietf-quic-transport-25.
// Number 71 used to represent draft-ietf-quic-transport-27.
// Number 72 used to represent draft-ietf-quic-transport-28.
QUIC_VERSION_IETF_DRAFT_29 = 73, // draft-ietf-quic-transport-29.
QUIC_VERSION_IETF_RFC_V1 = 80, // RFC 9000.
QUIC_VERSION_IETF_2_DRAFT_01 = 81, // draft-ietf-quic-v2-01.
// Version 99 was a dumping ground for IETF QUIC changes which were not yet
// ready for production between 2018-02 and 2020-02.
// QUIC_VERSION_RESERVED_FOR_NEGOTIATION is sent over the wire as ?a?a?a?a
// which is part of a range reserved by the IETF for version negotiation
// testing (see the "Versions" section of draft-ietf-quic-transport).
// This version is intentionally meant to never be supported to trigger
// version negotiation when proposed by clients and to prevent client
// ossification when sent by servers.
QUIC_VERSION_RESERVED_FOR_NEGOTIATION = 999,
};
// Helper function which translates from a QuicTransportVersion to a string.
// Returns strings corresponding to enum names (e.g. QUIC_VERSION_6).
QUIC_EXPORT_PRIVATE std::string QuicVersionToString(
QuicTransportVersion transport_version);
// The crypto handshake protocols that can be used with QUIC.
// We are planning on eventually deprecating PROTOCOL_QUIC_CRYPTO in favor of
// PROTOCOL_TLS1_3.
enum HandshakeProtocol {
PROTOCOL_UNSUPPORTED,
PROTOCOL_QUIC_CRYPTO,
PROTOCOL_TLS1_3,
};
// Helper function which translates from a HandshakeProtocol to a string.
QUIC_EXPORT_PRIVATE std::string HandshakeProtocolToString(
HandshakeProtocol handshake_protocol);
// Returns whether |transport_version| uses CRYPTO frames for the handshake
// instead of stream 1.
QUIC_EXPORT_PRIVATE constexpr bool QuicVersionUsesCryptoFrames(
QuicTransportVersion transport_version) {
// CRYPTO frames were added in version 48.
return transport_version > QUIC_VERSION_46;
}
// Returns whether this combination of handshake protocol and transport
// version is allowed. For example, {PROTOCOL_TLS1_3, QUIC_VERSION_43} is NOT
// allowed as TLS requires crypto frames which v43 does not support. Note that
// UnsupportedQuicVersion is a valid version.
QUIC_EXPORT_PRIVATE constexpr bool ParsedQuicVersionIsValid(
HandshakeProtocol handshake_protocol,
QuicTransportVersion transport_version) {
bool transport_version_is_valid = false;
constexpr QuicTransportVersion valid_transport_versions[] = {
QUIC_VERSION_IETF_2_DRAFT_01,
QUIC_VERSION_IETF_RFC_V1,
QUIC_VERSION_IETF_DRAFT_29,
QUIC_VERSION_50,
QUIC_VERSION_46,
QUIC_VERSION_43,
QUIC_VERSION_RESERVED_FOR_NEGOTIATION,
QUIC_VERSION_UNSUPPORTED,
};
for (size_t i = 0; i < ABSL_ARRAYSIZE(valid_transport_versions); ++i) {
if (transport_version == valid_transport_versions[i]) {
transport_version_is_valid = true;
break;
}
}
if (!transport_version_is_valid) {
return false;
}
switch (handshake_protocol) {
case PROTOCOL_UNSUPPORTED:
return transport_version == QUIC_VERSION_UNSUPPORTED;
case PROTOCOL_QUIC_CRYPTO:
return transport_version != QUIC_VERSION_UNSUPPORTED &&
transport_version != QUIC_VERSION_RESERVED_FOR_NEGOTIATION &&
transport_version != QUIC_VERSION_IETF_DRAFT_29 &&
transport_version != QUIC_VERSION_IETF_RFC_V1 &&
transport_version != QUIC_VERSION_IETF_2_DRAFT_01;
case PROTOCOL_TLS1_3:
return transport_version != QUIC_VERSION_UNSUPPORTED &&
transport_version != QUIC_VERSION_50 &&
QuicVersionUsesCryptoFrames(transport_version);
}
return false;
}
// A parsed QUIC version label which determines that handshake protocol
// and the transport version.
struct QUIC_EXPORT_PRIVATE ParsedQuicVersion {
HandshakeProtocol handshake_protocol;
QuicTransportVersion transport_version;
constexpr ParsedQuicVersion(HandshakeProtocol handshake_protocol,
QuicTransportVersion transport_version)
: handshake_protocol(handshake_protocol),
transport_version(transport_version) {
QUICHE_DCHECK(
ParsedQuicVersionIsValid(handshake_protocol, transport_version))
<< QuicVersionToString(transport_version) << " "
<< HandshakeProtocolToString(handshake_protocol);
}
constexpr ParsedQuicVersion(const ParsedQuicVersion& other)
: ParsedQuicVersion(other.handshake_protocol, other.transport_version) {}
ParsedQuicVersion& operator=(const ParsedQuicVersion& other) {
QUICHE_DCHECK(ParsedQuicVersionIsValid(other.handshake_protocol,
other.transport_version))
<< QuicVersionToString(other.transport_version) << " "
<< HandshakeProtocolToString(other.handshake_protocol);
if (this != &other) {
handshake_protocol = other.handshake_protocol;
transport_version = other.transport_version;
}
return *this;
}
bool operator==(const ParsedQuicVersion& other) const {
return handshake_protocol == other.handshake_protocol &&
transport_version == other.transport_version;
}
bool operator!=(const ParsedQuicVersion& other) const {
return handshake_protocol != other.handshake_protocol ||
transport_version != other.transport_version;
}
static constexpr ParsedQuicVersion V2Draft01() {
return ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_IETF_2_DRAFT_01);
}
static constexpr ParsedQuicVersion RFCv1() {
return ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_IETF_RFC_V1);
}
static constexpr ParsedQuicVersion Draft29() {
return ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_IETF_DRAFT_29);
}
static constexpr ParsedQuicVersion Q050() {
return ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50);
}
static constexpr ParsedQuicVersion Q046() {
return ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_46);
}
static constexpr ParsedQuicVersion Q043() {
return ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_43);
}
static constexpr ParsedQuicVersion Unsupported() {
return ParsedQuicVersion(PROTOCOL_UNSUPPORTED, QUIC_VERSION_UNSUPPORTED);
}
static constexpr ParsedQuicVersion ReservedForNegotiation() {
return ParsedQuicVersion(PROTOCOL_TLS1_3,
QUIC_VERSION_RESERVED_FOR_NEGOTIATION);
}
// Returns whether our codebase understands this version. This should only be
// called on valid versions, see ParsedQuicVersionIsValid. Assuming the
// version is valid, IsKnown returns whether the version is not
// UnsupportedQuicVersion.
bool IsKnown() const;
bool KnowsWhichDecrypterToUse() const;
// Returns whether this version uses keys derived from the Connection ID for
// ENCRYPTION_INITIAL keys (instead of NullEncrypter/NullDecrypter).
bool UsesInitialObfuscators() const;
// Indicates that this QUIC version does not have an enforced minimum value
// for flow control values negotiated during the handshake.
bool AllowsLowFlowControlLimits() const;
// Returns whether header protection is used in this version of QUIC.
bool HasHeaderProtection() const;
// Returns whether this version supports IETF RETRY packets.
bool SupportsRetry() const;
// Returns true if this version sends variable length packet number in long
// header.
bool SendsVariableLengthPacketNumberInLongHeader() const;
// Returns whether this version allows server connection ID lengths
// that are not 64 bits.
bool AllowsVariableLengthConnectionIds() const;
// Returns whether this version supports client connection ID.
bool SupportsClientConnectionIds() const;
// Returns whether this version supports long header 8-bit encoded
// connection ID lengths as described in draft-ietf-quic-invariants-06 and
// draft-ietf-quic-transport-22.
bool HasLengthPrefixedConnectionIds() const;
// Returns whether this version supports IETF style anti-amplification limit,
// i.e., server will send no more than FLAGS_quic_anti_amplification_factor
// times received bytes until address can be validated.
bool SupportsAntiAmplificationLimit() const;
// Returns true if this version can send coalesced packets.
bool CanSendCoalescedPackets() const;
// Returns true if this version supports the old Google-style Alt-Svc
// advertisement format.
bool SupportsGoogleAltSvcFormat() const;
// Returns true if |transport_version| uses IETF invariant headers.
bool HasIetfInvariantHeader() const;
// Returns true if |transport_version| supports MESSAGE frames.
bool SupportsMessageFrames() const;
// If true, HTTP/3 instead of gQUIC will be used at the HTTP layer.
// Notable changes are:
// * Headers stream no longer exists.
// * PRIORITY, HEADERS are moved from headers stream to HTTP/3 control stream.
// * PUSH_PROMISE is moved to request stream.
// * Unidirectional streams will have their first byte as a stream type.
// * HEADERS frames are compressed using QPACK.
// * DATA frame has frame headers.
// * GOAWAY is moved to HTTP layer.
bool UsesHttp3() const;
// Returns whether the transport_version supports the variable length integer
// length field as defined by IETF QUIC draft-13 and later.
bool HasLongHeaderLengths() const;
// Returns whether |transport_version| uses CRYPTO frames for the handshake
// instead of stream 1.
bool UsesCryptoFrames() const;
// Returns whether |transport_version| makes use of IETF QUIC
// frames or not.
bool HasIetfQuicFrames() const;
// Returns whether this version uses the legacy TLS extension codepoint.
bool UsesLegacyTlsExtension() const;
// Returns whether this version uses PROTOCOL_TLS1_3.
bool UsesTls() const;
// Returns whether this version uses PROTOCOL_QUIC_CRYPTO.
bool UsesQuicCrypto() const;
// Returns whether this version uses the QUICv2 Long Header Packet Types.
bool UsesV2PacketTypes() const;
};
QUIC_EXPORT_PRIVATE ParsedQuicVersion UnsupportedQuicVersion();
QUIC_EXPORT_PRIVATE ParsedQuicVersion QuicVersionReservedForNegotiation();
// Outer version used when encapsulating other packets using the Legacy Version
// Encapsulation feature.
QUIC_EXPORT_PRIVATE ParsedQuicVersion LegacyVersionForEncapsulation();
QUIC_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
const ParsedQuicVersion& version);
using ParsedQuicVersionVector = std::vector<ParsedQuicVersion>;
QUIC_EXPORT_PRIVATE std::ostream& operator<<(
std::ostream& os, const ParsedQuicVersionVector& versions);
// Representation of the on-the-wire QUIC version number. Will be written/read
// to the wire in network-byte-order.
using QuicVersionLabel = uint32_t;
using QuicVersionLabelVector = std::vector<QuicVersionLabel>;
QUIC_EXPORT_PRIVATE std::ostream& operator<<(
std::ostream& os, const QuicVersionLabelVector& version_labels);
// This vector contains all crypto handshake protocols that are supported.
constexpr std::array<HandshakeProtocol, 2> SupportedHandshakeProtocols() {
return {PROTOCOL_TLS1_3, PROTOCOL_QUIC_CRYPTO};
}
constexpr std::array<ParsedQuicVersion, 6> SupportedVersions() {
return {
ParsedQuicVersion::V2Draft01(), ParsedQuicVersion::RFCv1(),
ParsedQuicVersion::Draft29(), ParsedQuicVersion::Q050(),
ParsedQuicVersion::Q046(), ParsedQuicVersion::Q043(),
};
}
using QuicTransportVersionVector = std::vector<QuicTransportVersion>;
QUIC_EXPORT_PRIVATE std::ostream& operator<<(
std::ostream& os, const QuicTransportVersionVector& transport_versions);
// Returns a vector of supported QUIC versions.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector AllSupportedVersions();
// Returns a vector of supported QUIC versions, with any versions disabled by
// flags excluded.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector CurrentSupportedVersions();
// Returns a vector of QUIC versions from |versions| which exclude any versions
// which are disabled by flags.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
FilterSupportedVersions(ParsedQuicVersionVector versions);
// Returns a subset of AllSupportedVersions() with
// handshake_protocol == PROTOCOL_QUIC_CRYPTO, in the same order.
// Deprecated; only to be used in components that do not yet support
// PROTOCOL_TLS1_3.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
AllSupportedVersionsWithQuicCrypto();
// Returns a subset of CurrentSupportedVersions() with
// handshake_protocol == PROTOCOL_QUIC_CRYPTO, in the same order.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
CurrentSupportedVersionsWithQuicCrypto();
// Returns a subset of AllSupportedVersions() with
// handshake_protocol == PROTOCOL_TLS1_3, in the same order.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector AllSupportedVersionsWithTls();
// Returns a subset of CurrentSupportedVersions() with handshake_protocol ==
// PROTOCOL_TLS1_3.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector CurrentSupportedVersionsWithTls();
// Returns a subset of CurrentSupportedVersions() using HTTP/3 at the HTTP
// layer.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector CurrentSupportedHttp3Versions();
// Returns QUIC version of |index| in result of |versions|. Returns
// UnsupportedQuicVersion() if |index| is out of bounds.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
ParsedVersionOfIndex(const ParsedQuicVersionVector& versions, int index);
// QuicVersionLabel is written to and read from the wire, but we prefer to use
// the more readable ParsedQuicVersion at other levels.
// Helper function which translates from a QuicVersionLabel to a
// ParsedQuicVersion.
QUIC_EXPORT_PRIVATE ParsedQuicVersion
ParseQuicVersionLabel(QuicVersionLabel version_label);
// Helper function that translates from a QuicVersionLabelVector to a
// ParsedQuicVersionVector.
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
ParseQuicVersionLabelVector(const QuicVersionLabelVector& version_labels);
// Parses a QUIC version string such as "Q043" or "T051". Also supports parsing
// ALPN such as "h3-29" or "h3-Q050". For PROTOCOL_QUIC_CRYPTO versions, also
// supports parsing numbers such as "46".
QUIC_EXPORT_PRIVATE ParsedQuicVersion
ParseQuicVersionString(absl::string_view version_string);
// Parses a comma-separated list of QUIC version strings. Supports parsing by
// label, ALPN and numbers for PROTOCOL_QUIC_CRYPTO. Skips unknown versions.
// For example: "h3-29,Q050,46".
QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
ParseQuicVersionVectorString(absl::string_view versions_string);
// Constructs a QuicVersionLabel from the provided ParsedQuicVersion.
// QuicVersionLabel is written to and read from the wire, but we prefer to use
// the more readable ParsedQuicVersion at other levels.
// Helper function which translates from a ParsedQuicVersion to a
// QuicVersionLabel. Returns 0 if |parsed_version| is unsupported.
QUIC_EXPORT_PRIVATE QuicVersionLabel
CreateQuicVersionLabel(ParsedQuicVersion parsed_version);
// Constructs a QuicVersionLabelVector from the provided
// ParsedQuicVersionVector.
QUIC_EXPORT_PRIVATE QuicVersionLabelVector
CreateQuicVersionLabelVector(const ParsedQuicVersionVector& versions);
// Helper function which translates from a QuicVersionLabel to a string.
QUIC_EXPORT_PRIVATE std::string QuicVersionLabelToString(
QuicVersionLabel version_label);
// Returns |separator|-separated list of string representations of
// QuicVersionLabel values in the supplied |version_labels| vector. The values
// after the (0-based) |skip_after_nth_version|'th are skipped.
QUIC_EXPORT_PRIVATE std::string QuicVersionLabelVectorToString(
const QuicVersionLabelVector& version_labels, const std::string& separator,
size_t skip_after_nth_version);
// Returns comma separated list of string representations of QuicVersionLabel
// values in the supplied |version_labels| vector.
QUIC_EXPORT_PRIVATE inline std::string QuicVersionLabelVectorToString(
const QuicVersionLabelVector& version_labels) {
return QuicVersionLabelVectorToString(version_labels, ",",
std::numeric_limits<size_t>::max());
}
// Helper function which translates from a ParsedQuicVersion to a string.
// Returns strings corresponding to the on-the-wire tag.
QUIC_EXPORT_PRIVATE std::string ParsedQuicVersionToString(
ParsedQuicVersion version);
// Returns a vector of supported QUIC transport versions. DEPRECATED, use
// AllSupportedVersions instead.
QUIC_EXPORT_PRIVATE QuicTransportVersionVector AllSupportedTransportVersions();
// Returns comma separated list of string representations of
// QuicTransportVersion enum values in the supplied |versions| vector.
QUIC_EXPORT_PRIVATE std::string QuicTransportVersionVectorToString(
const QuicTransportVersionVector& versions);
// Returns comma separated list of string representations of ParsedQuicVersion
// values in the supplied |versions| vector.
QUIC_EXPORT_PRIVATE std::string ParsedQuicVersionVectorToString(
const ParsedQuicVersionVector& versions);
// Returns |separator|-separated list of string representations of
// ParsedQuicVersion values in the supplied |versions| vector. The values after
// the (0-based) |skip_after_nth_version|'th are skipped.
QUIC_EXPORT_PRIVATE std::string ParsedQuicVersionVectorToString(
const ParsedQuicVersionVector& versions, const std::string& separator,
size_t skip_after_nth_version);
// Returns comma separated list of string representations of ParsedQuicVersion
// values in the supplied |versions| vector.
QUIC_EXPORT_PRIVATE inline std::string ParsedQuicVersionVectorToString(
const ParsedQuicVersionVector& versions) {
return ParsedQuicVersionVectorToString(versions, ",",
std::numeric_limits<size_t>::max());
}
// Returns true if |transport_version| uses IETF invariant headers.
QUIC_EXPORT_PRIVATE constexpr bool VersionHasIetfInvariantHeader(
QuicTransportVersion transport_version) {
return transport_version > QUIC_VERSION_43;
}
// Returns true if |transport_version| supports MESSAGE frames.
QUIC_EXPORT_PRIVATE constexpr bool VersionSupportsMessageFrames(
QuicTransportVersion transport_version) {
// MESSAGE frames were added in version 45.
return transport_version > QUIC_VERSION_43;
}
// If true, HTTP/3 instead of gQUIC will be used at the HTTP layer.
// Notable changes are:
// * Headers stream no longer exists.
// * PRIORITY, HEADERS are moved from headers stream to HTTP/3 control stream.
// * PUSH_PROMISE is moved to request stream.
// * Unidirectional streams will have their first byte as a stream type.
// * HEADERS frames are compressed using QPACK.
// * DATA frame has frame headers.
// * GOAWAY is moved to HTTP layer.
QUIC_EXPORT_PRIVATE constexpr bool VersionUsesHttp3(
QuicTransportVersion transport_version) {
return transport_version >= QUIC_VERSION_IETF_DRAFT_29;
}
// Returns whether the transport_version supports the variable length integer
// length field as defined by IETF QUIC draft-13 and later.
QUIC_EXPORT_PRIVATE constexpr bool QuicVersionHasLongHeaderLengths(
QuicTransportVersion transport_version) {
// Long header lengths were added in version 49.
return transport_version > QUIC_VERSION_46;
}
// Returns whether |transport_version| makes use of IETF QUIC
// frames or not.
QUIC_EXPORT_PRIVATE constexpr bool VersionHasIetfQuicFrames(
QuicTransportVersion transport_version) {
return VersionUsesHttp3(transport_version);
}
// Returns whether this version supports long header 8-bit encoded
// connection ID lengths as described in draft-ietf-quic-invariants-06 and
// draft-ietf-quic-transport-22.
QUIC_EXPORT_PRIVATE bool VersionHasLengthPrefixedConnectionIds(
QuicTransportVersion transport_version);
// Returns true if this version supports the old Google-style Alt-Svc
// advertisement format.
QUIC_EXPORT_PRIVATE bool VersionSupportsGoogleAltSvcFormat(
QuicTransportVersion transport_version);
// Returns whether this version allows server connection ID lengths that are
// not 64 bits.
QUIC_EXPORT_PRIVATE bool VersionAllowsVariableLengthConnectionIds(
QuicTransportVersion transport_version);
// Returns whether this version label supports long header 4-bit encoded
// connection ID lengths as described in draft-ietf-quic-invariants-05 and
// draft-ietf-quic-transport-21.
QUIC_EXPORT_PRIVATE bool QuicVersionLabelUses4BitConnectionIdLength(
QuicVersionLabel version_label);
// Returns the ALPN string to use in TLS for this version of QUIC.
QUIC_EXPORT_PRIVATE std::string AlpnForVersion(
ParsedQuicVersion parsed_version);
// Initializes support for the provided IETF draft version by setting the
// correct flags.
QUIC_EXPORT_PRIVATE void QuicVersionInitializeSupportForIetfDraft();
// Configures the flags required to enable support for this version of QUIC.
QUIC_EXPORT_PRIVATE void QuicEnableVersion(const ParsedQuicVersion& version);
// Configures the flags required to disable support for this version of QUIC.
QUIC_EXPORT_PRIVATE void QuicDisableVersion(const ParsedQuicVersion& version);
// Returns whether support for this version of QUIC is currently enabled.
QUIC_EXPORT_PRIVATE bool QuicVersionIsEnabled(const ParsedQuicVersion& version);
} // namespace quic
#endif // QUICHE_QUIC_CORE_QUIC_VERSIONS_H_