package outbound import ( "context" "crypto/tls" "errors" "fmt" "io" "io/ioutil" "net" "strconv" "github.com/Dreamacro/clash/component/dialer" C "github.com/Dreamacro/clash/constant" "github.com/Dreamacro/clash/transport/socks5" ) type Socks5 struct { *Base user string pass string tls bool skipCertVerify bool tlsConfig *tls.Config } type Socks5Option struct { Name string `proxy:"name"` Server string `proxy:"server"` Port int `proxy:"port"` UserName string `proxy:"username,omitempty"` Password string `proxy:"password,omitempty"` TLS bool `proxy:"tls,omitempty"` UDP bool `proxy:"udp,omitempty"` SkipCertVerify bool `proxy:"skip-cert-verify,omitempty"` } // StreamConn implements C.ProxyAdapter func (ss *Socks5) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) { if ss.tls { cc := tls.Client(c, ss.tlsConfig) err := cc.Handshake() c = cc if err != nil { return nil, fmt.Errorf("%s connect error: %w", ss.addr, err) } } var user *socks5.User if ss.user != "" { user = &socks5.User{ Username: ss.user, Password: ss.pass, } } if _, err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdConnect, user); err != nil { return nil, err } return c, nil } // DialContext implements C.ProxyAdapter func (ss *Socks5) DialContext(ctx context.Context, metadata *C.Metadata) (_ C.Conn, err error) { c, err := dialer.DialContext(ctx, "tcp", ss.addr) if err != nil { return nil, fmt.Errorf("%s connect error: %w", ss.addr, err) } tcpKeepAlive(c) defer safeConnClose(c, err) c, err = ss.StreamConn(c, metadata) if err != nil { return nil, err } return NewConn(c, ss), nil } // DialUDP implements C.ProxyAdapter func (ss *Socks5) DialUDP(metadata *C.Metadata) (_ C.PacketConn, err error) { ctx, cancel := context.WithTimeout(context.Background(), C.DefaultTCPTimeout) defer cancel() c, err := dialer.DialContext(ctx, "tcp", ss.addr) if err != nil { err = fmt.Errorf("%s connect error: %w", ss.addr, err) return } if ss.tls { cc := tls.Client(c, ss.tlsConfig) err = cc.Handshake() c = cc } defer safeConnClose(c, err) tcpKeepAlive(c) var user *socks5.User if ss.user != "" { user = &socks5.User{ Username: ss.user, Password: ss.pass, } } bindAddr, err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdUDPAssociate, user) if err != nil { err = fmt.Errorf("client hanshake error: %w", err) return } pc, err := dialer.ListenPacket(context.Background(), "udp", "") if err != nil { return } go func() { io.Copy(ioutil.Discard, c) c.Close() // A UDP association terminates when the TCP connection that the UDP // ASSOCIATE request arrived on terminates. RFC1928 pc.Close() }() // Support unspecified UDP bind address. bindUDPAddr := bindAddr.UDPAddr() if bindUDPAddr == nil { err = errors.New("invalid UDP bind address") return } else if bindUDPAddr.IP.IsUnspecified() { serverAddr, err := resolveUDPAddr("udp", ss.Addr()) if err != nil { return nil, err } bindUDPAddr.IP = serverAddr.IP } return newPacketConn(&socksPacketConn{PacketConn: pc, rAddr: bindUDPAddr, tcpConn: c}, ss), nil } func NewSocks5(option Socks5Option) *Socks5 { var tlsConfig *tls.Config if option.TLS { tlsConfig = &tls.Config{ InsecureSkipVerify: option.SkipCertVerify, ServerName: option.Server, } } return &Socks5{ Base: &Base{ name: option.Name, addr: net.JoinHostPort(option.Server, strconv.Itoa(option.Port)), tp: C.Socks5, udp: option.UDP, }, user: option.UserName, pass: option.Password, tls: option.TLS, skipCertVerify: option.SkipCertVerify, tlsConfig: tlsConfig, } } type socksPacketConn struct { net.PacketConn rAddr net.Addr tcpConn net.Conn } func (uc *socksPacketConn) WriteTo(b []byte, addr net.Addr) (n int, err error) { packet, err := socks5.EncodeUDPPacket(socks5.ParseAddrToSocksAddr(addr), b) if err != nil { return } return uc.PacketConn.WriteTo(packet, uc.rAddr) } func (uc *socksPacketConn) ReadFrom(b []byte) (int, net.Addr, error) { n, _, e := uc.PacketConn.ReadFrom(b) if e != nil { return 0, nil, e } addr, payload, err := socks5.DecodeUDPPacket(b) if err != nil { return 0, nil, err } udpAddr := addr.UDPAddr() if udpAddr == nil { return 0, nil, errors.New("parse udp addr error") } // due to DecodeUDPPacket is mutable, record addr length copy(b, payload) return n - len(addr) - 3, udpAddr, nil } func (uc *socksPacketConn) Close() error { uc.tcpConn.Close() return uc.PacketConn.Close() }