mirror of https://github.com/v2ray/v2ray-core
433 lines
11 KiB
Go
433 lines
11 KiB
Go
package socks
|
|
|
|
import (
|
|
"io"
|
|
|
|
"v2ray.com/core/common"
|
|
"v2ray.com/core/common/buf"
|
|
"v2ray.com/core/common/net"
|
|
"v2ray.com/core/common/protocol"
|
|
"v2ray.com/core/common/serial"
|
|
)
|
|
|
|
const (
|
|
socks5Version = 0x05
|
|
socks4Version = 0x04
|
|
|
|
cmdTCPConnect = 0x01
|
|
cmdTCPBind = 0x02
|
|
cmdUDPPort = 0x03
|
|
cmdTorResolve = 0xF0
|
|
cmdTorResolvePTR = 0xF1
|
|
|
|
socks4RequestGranted = 90
|
|
socks4RequestRejected = 91
|
|
|
|
authNotRequired = 0x00
|
|
//authGssAPI = 0x01
|
|
authPassword = 0x02
|
|
authNoMatchingMethod = 0xFF
|
|
|
|
statusSuccess = 0x00
|
|
statusCmdNotSupport = 0x07
|
|
)
|
|
|
|
var addrParser = protocol.NewAddressParser(
|
|
protocol.AddressFamilyByte(0x01, net.AddressFamilyIPv4),
|
|
protocol.AddressFamilyByte(0x04, net.AddressFamilyIPv6),
|
|
protocol.AddressFamilyByte(0x03, net.AddressFamilyDomain),
|
|
)
|
|
|
|
type ServerSession struct {
|
|
config *ServerConfig
|
|
port net.Port
|
|
}
|
|
|
|
func (s *ServerSession) Handshake(reader io.Reader, writer io.Writer) (*protocol.RequestHeader, error) {
|
|
buffer := buf.New()
|
|
defer buffer.Release()
|
|
|
|
request := new(protocol.RequestHeader)
|
|
|
|
if err := buffer.AppendSupplier(buf.ReadFullFrom(reader, 2)); err != nil {
|
|
return nil, newError("insufficient header").Base(err)
|
|
}
|
|
|
|
version := buffer.Byte(0)
|
|
if version == socks4Version {
|
|
if s.config.AuthType == AuthType_PASSWORD {
|
|
writeSocks4Response(writer, socks4RequestRejected, net.AnyIP, net.Port(0)) // nolint: errcheck
|
|
return nil, newError("socks 4 is not allowed when auth is required.")
|
|
}
|
|
|
|
if err := buffer.AppendSupplier(buf.ReadFullFrom(reader, 6)); err != nil {
|
|
return nil, newError("insufficient header").Base(err)
|
|
}
|
|
port := net.PortFromBytes(buffer.BytesRange(2, 4))
|
|
address := net.IPAddress(buffer.BytesRange(4, 8))
|
|
if _, err := readUntilNull(reader); /* user id */ err != nil {
|
|
return nil, err
|
|
}
|
|
if address.IP()[0] == 0x00 {
|
|
domain, err := readUntilNull(reader)
|
|
if err != nil {
|
|
return nil, newError("failed to read domain for socks 4a").Base(err)
|
|
}
|
|
address = net.DomainAddress(domain)
|
|
}
|
|
|
|
switch buffer.Byte(1) {
|
|
case cmdTCPConnect:
|
|
request.Command = protocol.RequestCommandTCP
|
|
request.Address = address
|
|
request.Port = port
|
|
request.Version = socks4Version
|
|
if err := writeSocks4Response(writer, socks4RequestGranted, net.AnyIP, net.Port(0)); err != nil {
|
|
return nil, err
|
|
}
|
|
return request, nil
|
|
default:
|
|
writeSocks4Response(writer, socks4RequestRejected, net.AnyIP, net.Port(0)) // nolint: errcheck
|
|
return nil, newError("unsupported command: ", buffer.Byte(1))
|
|
}
|
|
}
|
|
|
|
if version == socks5Version {
|
|
nMethod := int32(buffer.Byte(1))
|
|
if err := buffer.AppendSupplier(buf.ReadFullFrom(reader, nMethod)); err != nil {
|
|
return nil, newError("failed to read auth methods").Base(err)
|
|
}
|
|
|
|
var expectedAuth byte = authNotRequired
|
|
if s.config.AuthType == AuthType_PASSWORD {
|
|
expectedAuth = authPassword
|
|
}
|
|
|
|
if !hasAuthMethod(expectedAuth, buffer.BytesRange(2, 2+nMethod)) {
|
|
writeSocks5AuthenticationResponse(writer, socks5Version, authNoMatchingMethod) // nolint: errcheck
|
|
return nil, newError("no matching auth method")
|
|
}
|
|
|
|
if err := writeSocks5AuthenticationResponse(writer, socks5Version, expectedAuth); err != nil {
|
|
return nil, newError("failed to write auth response").Base(err)
|
|
}
|
|
|
|
if expectedAuth == authPassword {
|
|
username, password, err := readUsernamePassword(reader)
|
|
if err != nil {
|
|
return nil, newError("failed to read username and password for authentication").Base(err)
|
|
}
|
|
|
|
if !s.config.HasAccount(username, password) {
|
|
writeSocks5AuthenticationResponse(writer, 0x01, 0xFF) // nolint: errcheck
|
|
return nil, newError("invalid username or password")
|
|
}
|
|
|
|
if err := writeSocks5AuthenticationResponse(writer, 0x01, 0x00); err != nil {
|
|
return nil, newError("failed to write auth response").Base(err)
|
|
}
|
|
}
|
|
if err := buffer.Reset(buf.ReadFullFrom(reader, 3)); err != nil {
|
|
return nil, newError("failed to read request").Base(err)
|
|
}
|
|
|
|
cmd := buffer.Byte(1)
|
|
switch cmd {
|
|
case cmdTCPConnect, cmdTorResolve, cmdTorResolvePTR:
|
|
// We don't have a solution for Tor case now. Simply treat it as connect command.
|
|
request.Command = protocol.RequestCommandTCP
|
|
case cmdUDPPort:
|
|
if !s.config.UdpEnabled {
|
|
writeSocks5Response(writer, statusCmdNotSupport, net.AnyIP, net.Port(0)) // nolint: errcheck
|
|
return nil, newError("UDP is not enabled.")
|
|
}
|
|
request.Command = protocol.RequestCommandUDP
|
|
case cmdTCPBind:
|
|
writeSocks5Response(writer, statusCmdNotSupport, net.AnyIP, net.Port(0)) // nolint: errcheck
|
|
return nil, newError("TCP bind is not supported.")
|
|
default:
|
|
writeSocks5Response(writer, statusCmdNotSupport, net.AnyIP, net.Port(0)) // nolint: errcheck
|
|
return nil, newError("unknown command ", cmd)
|
|
}
|
|
|
|
buffer.Clear()
|
|
|
|
request.Version = socks5Version
|
|
|
|
addr, port, err := addrParser.ReadAddressPort(buffer, reader)
|
|
if err != nil {
|
|
return nil, newError("failed to read address").Base(err)
|
|
}
|
|
request.Address = addr
|
|
request.Port = port
|
|
|
|
responseAddress := net.AnyIP
|
|
responsePort := net.Port(1717)
|
|
if request.Command == protocol.RequestCommandUDP {
|
|
addr := s.config.Address.AsAddress()
|
|
if addr == nil {
|
|
addr = net.LocalHostIP
|
|
}
|
|
responseAddress = addr
|
|
responsePort = s.port
|
|
}
|
|
if err := writeSocks5Response(writer, statusSuccess, responseAddress, responsePort); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return request, nil
|
|
}
|
|
|
|
return nil, newError("unknown Socks version: ", version)
|
|
}
|
|
|
|
func readUsernamePassword(reader io.Reader) (string, string, error) {
|
|
buffer := buf.New()
|
|
defer buffer.Release()
|
|
|
|
if err := buffer.Reset(buf.ReadFullFrom(reader, 2)); err != nil {
|
|
return "", "", err
|
|
}
|
|
nUsername := int32(buffer.Byte(1))
|
|
|
|
if err := buffer.Reset(buf.ReadFullFrom(reader, nUsername)); err != nil {
|
|
return "", "", err
|
|
}
|
|
username := buffer.String()
|
|
|
|
if err := buffer.Reset(buf.ReadFullFrom(reader, 1)); err != nil {
|
|
return "", "", err
|
|
}
|
|
nPassword := int32(buffer.Byte(0))
|
|
if err := buffer.Reset(buf.ReadFullFrom(reader, nPassword)); err != nil {
|
|
return "", "", err
|
|
}
|
|
password := buffer.String()
|
|
return username, password, nil
|
|
}
|
|
|
|
func readUntilNull(reader io.Reader) (string, error) {
|
|
var b [256]byte
|
|
size := 0
|
|
for {
|
|
_, err := reader.Read(b[size : size+1])
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if b[size] == 0x00 {
|
|
return string(b[:size]), nil
|
|
}
|
|
size++
|
|
if size == 256 {
|
|
return "", newError("buffer overrun")
|
|
}
|
|
}
|
|
}
|
|
|
|
func hasAuthMethod(expectedAuth byte, authCandidates []byte) bool {
|
|
for _, a := range authCandidates {
|
|
if a == expectedAuth {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func writeSocks5AuthenticationResponse(writer io.Writer, version byte, auth byte) error {
|
|
return buf.WriteAllBytes(writer, []byte{version, auth})
|
|
}
|
|
|
|
func writeSocks5Response(writer io.Writer, errCode byte, address net.Address, port net.Port) error {
|
|
buffer := buf.New()
|
|
defer buffer.Release()
|
|
|
|
common.Must2(buffer.WriteBytes(socks5Version, errCode, 0x00 /* reserved */))
|
|
if err := addrParser.WriteAddressPort(buffer, address, port); err != nil {
|
|
return err
|
|
}
|
|
|
|
return buf.WriteAllBytes(writer, buffer.Bytes())
|
|
}
|
|
|
|
func writeSocks4Response(writer io.Writer, errCode byte, address net.Address, port net.Port) error {
|
|
buffer := buf.New()
|
|
defer buffer.Release()
|
|
|
|
common.Must2(buffer.WriteBytes(0x00, errCode))
|
|
common.Must(buffer.AppendSupplier(serial.WriteUint16(port.Value())))
|
|
common.Must2(buffer.Write(address.IP()))
|
|
return buf.WriteAllBytes(writer, buffer.Bytes())
|
|
}
|
|
|
|
func DecodeUDPPacket(packet *buf.Buffer) (*protocol.RequestHeader, error) {
|
|
if packet.Len() < 5 {
|
|
return nil, newError("insufficient length of packet.")
|
|
}
|
|
request := &protocol.RequestHeader{
|
|
Version: socks5Version,
|
|
Command: protocol.RequestCommandUDP,
|
|
}
|
|
|
|
// packet[0] and packet[1] are reserved
|
|
if packet.Byte(2) != 0 /* fragments */ {
|
|
return nil, newError("discarding fragmented payload.")
|
|
}
|
|
|
|
packet.Advance(3)
|
|
|
|
addr, port, err := addrParser.ReadAddressPort(nil, packet)
|
|
if err != nil {
|
|
return nil, newError("failed to read UDP header").Base(err)
|
|
}
|
|
request.Address = addr
|
|
request.Port = port
|
|
return request, nil
|
|
}
|
|
|
|
func EncodeUDPPacket(request *protocol.RequestHeader, data []byte) (*buf.Buffer, error) {
|
|
b := buf.New()
|
|
common.Must2(b.WriteBytes(0, 0, 0 /* Fragment */))
|
|
if err := addrParser.WriteAddressPort(b, request.Address, request.Port); err != nil {
|
|
b.Release()
|
|
return nil, err
|
|
}
|
|
common.Must2(b.Write(data))
|
|
return b, nil
|
|
}
|
|
|
|
type UDPReader struct {
|
|
reader io.Reader
|
|
}
|
|
|
|
func NewUDPReader(reader io.Reader) *UDPReader {
|
|
return &UDPReader{reader: reader}
|
|
}
|
|
|
|
func (r *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
|
|
b := buf.New()
|
|
if err := b.AppendSupplier(buf.ReadFrom(r.reader)); err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := DecodeUDPPacket(b); err != nil {
|
|
return nil, err
|
|
}
|
|
return buf.NewMultiBufferValue(b), nil
|
|
}
|
|
|
|
type UDPWriter struct {
|
|
request *protocol.RequestHeader
|
|
writer io.Writer
|
|
}
|
|
|
|
func NewUDPWriter(request *protocol.RequestHeader, writer io.Writer) *UDPWriter {
|
|
return &UDPWriter{
|
|
request: request,
|
|
writer: writer,
|
|
}
|
|
}
|
|
|
|
// Write implements io.Writer.
|
|
func (w *UDPWriter) Write(b []byte) (int, error) {
|
|
eb, err := EncodeUDPPacket(w.request, b)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
defer eb.Release()
|
|
if _, err := w.writer.Write(eb.Bytes()); err != nil {
|
|
return 0, err
|
|
}
|
|
return len(b), nil
|
|
}
|
|
|
|
func ClientHandshake(request *protocol.RequestHeader, reader io.Reader, writer io.Writer) (*protocol.RequestHeader, error) {
|
|
authByte := byte(authNotRequired)
|
|
if request.User != nil {
|
|
authByte = byte(authPassword)
|
|
}
|
|
|
|
b := buf.New()
|
|
defer b.Release()
|
|
|
|
common.Must2(b.WriteBytes(socks5Version, 0x01, authByte))
|
|
if authByte == authPassword {
|
|
rawAccount, err := request.User.GetTypedAccount()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
account := rawAccount.(*Account)
|
|
|
|
common.Must2(b.WriteBytes(0x01, byte(len(account.Username))))
|
|
common.Must2(b.Write([]byte(account.Username)))
|
|
common.Must2(b.WriteBytes(byte(len(account.Password))))
|
|
common.Must2(b.Write([]byte(account.Password)))
|
|
}
|
|
|
|
if err := buf.WriteAllBytes(writer, b.Bytes()); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err := b.Reset(buf.ReadFullFrom(reader, 2)); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if b.Byte(0) != socks5Version {
|
|
return nil, newError("unexpected server version: ", b.Byte(0)).AtWarning()
|
|
}
|
|
if b.Byte(1) != authByte {
|
|
return nil, newError("auth method not supported.").AtWarning()
|
|
}
|
|
|
|
if authByte == authPassword {
|
|
if err := b.Reset(buf.ReadFullFrom(reader, 2)); err != nil {
|
|
return nil, err
|
|
}
|
|
if b.Byte(1) != 0x00 {
|
|
return nil, newError("server rejects account: ", b.Byte(1))
|
|
}
|
|
}
|
|
|
|
b.Clear()
|
|
|
|
command := byte(cmdTCPConnect)
|
|
if request.Command == protocol.RequestCommandUDP {
|
|
command = byte(cmdUDPPort)
|
|
}
|
|
common.Must2(b.WriteBytes(socks5Version, command, 0x00 /* reserved */))
|
|
if err := addrParser.WriteAddressPort(b, request.Address, request.Port); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err := buf.WriteAllBytes(writer, b.Bytes()); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
b.Clear()
|
|
if err := b.AppendSupplier(buf.ReadFullFrom(reader, 3)); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
resp := b.Byte(1)
|
|
if resp != 0x00 {
|
|
return nil, newError("server rejects request: ", resp)
|
|
}
|
|
|
|
b.Clear()
|
|
|
|
address, port, err := addrParser.ReadAddressPort(b, reader)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if request.Command == protocol.RequestCommandUDP {
|
|
udpRequest := &protocol.RequestHeader{
|
|
Version: socks5Version,
|
|
Command: protocol.RequestCommandUDP,
|
|
Address: address,
|
|
Port: port,
|
|
}
|
|
return udpRequest, nil
|
|
}
|
|
|
|
return nil, nil
|
|
}
|