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protocol.go
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protocol.go
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package shadowsocks
import (
"bytes"
"io"
"github.com/v2ray/v2ray-core/common/alloc"
"github.com/v2ray/v2ray-core/common/log"
v2net "github.com/v2ray/v2ray-core/common/net"
"github.com/v2ray/v2ray-core/proxy"
"github.com/v2ray/v2ray-core/transport"
)
const (
AddrTypeIPv4 = 1
AddrTypeIPv6 = 4
AddrTypeDomain = 3
)
type Request struct {
Address v2net.Address
Port v2net.Port
OTA bool
UDPPayload *alloc.Buffer
}
func (this *Request) Release() {
this.Address = nil
if this.UDPPayload != nil {
this.UDPPayload.Release()
}
}
func (this *Request) DetachUDPPayload() *alloc.Buffer {
payload := this.UDPPayload
this.UDPPayload = nil
return payload
}
func ReadRequest(reader io.Reader, auth *Authenticator, udp bool) (*Request, error) {
buffer := alloc.NewSmallBuffer()
defer buffer.Release()
_, err := io.ReadFull(reader, buffer.Value[:1])
if err != nil {
if err != io.EOF {
log.Warning("Shadowsocks: Failed to read address type: ", err)
return nil, transport.ErrCorruptedPacket
}
return nil, err
}
lenBuffer := 1
request := new(Request)
addrType := (buffer.Value[0] & 0x0F)
if (buffer.Value[0] & 0x10) == 0x10 {
request.OTA = true
}
switch addrType {
case AddrTypeIPv4:
_, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+4])
if err != nil {
log.Warning("Shadowsocks: Failed to read IPv4 address: ", err)
return nil, transport.ErrCorruptedPacket
}
request.Address = v2net.IPAddress(buffer.Value[lenBuffer : lenBuffer+4])
lenBuffer += 4
case AddrTypeIPv6:
_, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+16])
if err != nil {
log.Warning("Shadowsocks: Failed to read IPv6 address: ", err)
return nil, transport.ErrCorruptedPacket
}
request.Address = v2net.IPAddress(buffer.Value[lenBuffer : lenBuffer+16])
lenBuffer += 16
case AddrTypeDomain:
_, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+1])
if err != nil {
log.Warning("Shadowsocks: Failed to read domain lenth: ", err)
return nil, transport.ErrCorruptedPacket
}
domainLength := int(buffer.Value[lenBuffer])
lenBuffer++
_, err = io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+domainLength])
if err != nil {
log.Warning("Shadowsocks: Failed to read domain: ", err)
return nil, transport.ErrCorruptedPacket
}
request.Address = v2net.DomainAddress(string(buffer.Value[lenBuffer : lenBuffer+domainLength]))
lenBuffer += domainLength
default:
log.Warning("Shadowsocks: Unknown address type: ", addrType)
return nil, transport.ErrCorruptedPacket
}
_, err = io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+2])
if err != nil {
log.Warning("Shadowsocks: Failed to read port: ", err)
return nil, transport.ErrCorruptedPacket
}
request.Port = v2net.PortFromBytes(buffer.Value[lenBuffer : lenBuffer+2])
lenBuffer += 2
var authBytes []byte
if udp {
nBytes, err := reader.Read(buffer.Value[lenBuffer:])
if err != nil {
log.Warning("Shadowsocks: Failed to read UDP payload: ", err)
return nil, transport.ErrCorruptedPacket
}
buffer.Slice(0, lenBuffer+nBytes)
if request.OTA {
authBytes = buffer.Value[lenBuffer+nBytes-AuthSize:]
request.UDPPayload = alloc.NewSmallBuffer().Clear().Append(buffer.Value[lenBuffer : lenBuffer+nBytes-AuthSize])
lenBuffer = lenBuffer + nBytes - AuthSize
} else {
request.UDPPayload = alloc.NewSmallBuffer().Clear().Append(buffer.Value[lenBuffer:])
}
} else {
if request.OTA {
authBytes = buffer.Value[lenBuffer : lenBuffer+AuthSize]
_, err = io.ReadFull(reader, authBytes)
if err != nil {
log.Warning("Shadowsocks: Failed to read OTA: ", err)
return nil, transport.ErrCorruptedPacket
}
}
}
if request.OTA {
actualAuth := auth.Authenticate(nil, buffer.Value[0:lenBuffer])
if !bytes.Equal(actualAuth, authBytes) {
log.Warning("Shadowsocks: Invalid OTA.")
return nil, proxy.ErrInvalidAuthentication
}
}
return request, nil
}