forked from quic-go/quic-go
/
protocol.go
152 lines (125 loc) · 3.96 KB
/
protocol.go
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package protocol
import (
"fmt"
"time"
)
// The PacketType is the Long Header Type
type PacketType uint8
const (
// PacketTypeInitial is the packet type of an Initial packet
PacketTypeInitial PacketType = 1 + iota
// PacketTypeRetry is the packet type of a Retry packet
PacketTypeRetry
// PacketTypeHandshake is the packet type of a Handshake packet
PacketTypeHandshake
// PacketType0RTT is the packet type of a 0-RTT packet
PacketType0RTT
)
func (t PacketType) String() string {
switch t {
case PacketTypeInitial:
return "Initial"
case PacketTypeRetry:
return "Retry"
case PacketTypeHandshake:
return "Handshake"
case PacketType0RTT:
return "0-RTT Protected"
default:
return fmt.Sprintf("unknown packet type: %d", t)
}
}
type ECN uint8
const (
ECNUnsupported ECN = iota
ECNNon // 00
ECT1 // 01
ECT0 // 10
ECNCE // 11
)
func ParseECNHeaderBits(bits byte) ECN {
switch bits {
case 0:
return ECNNon
case 0b00000010:
return ECT0
case 0b00000001:
return ECT1
case 0b00000011:
return ECNCE
default:
panic("invalid ECN bits")
}
}
func (e ECN) ToHeaderBits() byte {
//nolint:exhaustive // There are only 4 values.
switch e {
case ECNNon:
return 0
case ECT0:
return 0b00000010
case ECT1:
return 0b00000001
case ECNCE:
return 0b00000011
default:
panic("ECN unsupported")
}
}
func (e ECN) String() string {
switch e {
case ECNUnsupported:
return "ECN unsupported"
case ECNNon:
return "Not-ECT"
case ECT1:
return "ECT(1)"
case ECT0:
return "ECT(0)"
case ECNCE:
return "CE"
default:
return fmt.Sprintf("invalid ECN value: %d", e)
}
}
// A ByteCount in QUIC
type ByteCount int64
// MaxByteCount is the maximum value of a ByteCount
const MaxByteCount = ByteCount(1<<62 - 1)
// InvalidByteCount is an invalid byte count
const InvalidByteCount ByteCount = -1
// A StatelessResetToken is a stateless reset token.
type StatelessResetToken [16]byte
// MaxPacketBufferSize maximum packet size of any QUIC packet, based on
// ethernet's max size, minus the IP and UDP headers. IPv6 has a 40 byte header,
// UDP adds an additional 8 bytes. This is a total overhead of 48 bytes.
// Ethernet's max packet size is 1500 bytes, 1500 - 48 = 1452.
const MaxPacketBufferSize = 1452
// MaxLargePacketBufferSize is used when using GSO
const MaxLargePacketBufferSize = 20 * 1024
// MinInitialPacketSize is the minimum size an Initial packet is required to have.
const MinInitialPacketSize = 1200
// MinUnknownVersionPacketSize is the minimum size a packet with an unknown version
// needs to have in order to trigger a Version Negotiation packet.
const MinUnknownVersionPacketSize = MinInitialPacketSize
// MinStatelessResetSize is the minimum size of a stateless reset packet that we send
const MinStatelessResetSize = 1 /* first byte */ + 20 /* max. conn ID length */ + 4 /* max. packet number length */ + 1 /* min. payload length */ + 16 /* token */
// MinConnectionIDLenInitial is the minimum length of the destination connection ID on an Initial packet.
const MinConnectionIDLenInitial = 8
// DefaultAckDelayExponent is the default ack delay exponent
const DefaultAckDelayExponent = 3
// DefaultActiveConnectionIDLimit is the default active connection ID limit
const DefaultActiveConnectionIDLimit = 2
// MaxAckDelayExponent is the maximum ack delay exponent
const MaxAckDelayExponent = 20
// DefaultMaxAckDelay is the default max_ack_delay
const DefaultMaxAckDelay = 25 * time.Millisecond
// MaxMaxAckDelay is the maximum max_ack_delay
const MaxMaxAckDelay = (1<<14 - 1) * time.Millisecond
// MaxConnIDLen is the maximum length of the connection ID
const MaxConnIDLen = 20
// InvalidPacketLimitAES is the maximum number of packets that we can fail to decrypt when using
// AEAD_AES_128_GCM or AEAD_AES_265_GCM.
const InvalidPacketLimitAES = 1 << 52
// InvalidPacketLimitChaCha is the maximum number of packets that we can fail to decrypt when using AEAD_CHACHA20_POLY1305.
const InvalidPacketLimitChaCha = 1 << 36