v2ray-core/app/proxyman/mux/frame.go

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2017-02-07 20:11:47 +00:00
package mux
import (
"errors"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/net"
"v2ray.com/core/common/serial"
)
type SessionStatus byte
const (
SessionStatusNew SessionStatus = 0x01
SessionStatusKeep SessionStatus = 0x02
SessionStatusEnd SessionStatus = 0x03
)
type TargetNetwork byte
const (
TargetNetworkTCP TargetNetwork = 0x01
TargetnetworkUDP TargetNetwork = 0x02
)
type AddressType byte
const (
AddressTypeIPv4 AddressType = 0x01
AddressTypeDomain AddressType = 0x02
AddressTypeIPv6 AddressType = 0x03
)
type FrameMetadata struct {
SessionId uint16
SessionStatus SessionStatus
Target net.Destination
}
func (f FrameMetadata) AsSupplier() buf.Supplier {
return func(b []byte) (int, error) {
b = serial.Uint16ToBytes(uint16(0), b) // place holder for length
b = serial.Uint16ToBytes(f.SessionId, b)
b = append(b, byte(f.SessionStatus), 0 /* reserved */)
length := 4
if f.SessionStatus == SessionStatusNew {
switch f.Target.Network {
case net.Network_TCP:
b = append(b, byte(TargetNetworkTCP))
case net.Network_UDP:
b = append(b, byte(TargetnetworkUDP))
}
length++
b = serial.Uint16ToBytes(f.Target.Port.Value(), b)
length += 2
addr := f.Target.Address
switch addr.Family() {
case net.AddressFamilyIPv4:
b = append(b, byte(AddressTypeIPv4))
b = append(b, addr.IP()...)
length += 5
case net.AddressFamilyIPv6:
b = append(b, byte(AddressTypeIPv6))
b = append(b, addr.IP()...)
length += 17
case net.AddressFamilyDomain:
nDomain := len(addr.Domain())
b = append(b, byte(nDomain))
b = append(b, addr.Domain()...)
length += nDomain + 1
}
}
return length + 2, nil
}
}
func ReadFrameFrom(b []byte) (*FrameMetadata, error) {
if len(b) < 4 {
return nil, errors.New("Proxyman|Mux: Insufficient buffer.")
}
f := &FrameMetadata{
SessionId: serial.BytesToUint16(b[:2]),
SessionStatus: SessionStatus(b[2]),
}
b = b[4:]
if f.SessionStatus == SessionStatusNew {
network := TargetNetwork(b[0])
port := net.PortFromBytes(b[1:3])
addrType := AddressType(b[3])
b = b[4:]
var addr net.Address
switch addrType {
case AddressTypeIPv4:
addr = net.IPAddress(b[0:4])
b = b[4:]
case AddressTypeIPv6:
addr = net.IPAddress(b[0:16])
b = b[16:]
case AddressTypeDomain:
nDomain := int(b[0])
addr = net.DomainAddress(string(b[1 : 1+nDomain]))
b = b[nDomain+1:]
}
switch network {
case TargetNetworkTCP:
f.Target = net.TCPDestination(addr, port)
case TargetnetworkUDP:
f.Target = net.UDPDestination(addr, port)
}
}
return f, nil
}