common.proxy.client.go Maven / Gradle / Ivy
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package proxy
import (
"context"
"errors"
"log"
"net"
"net/url"
"strconv"
"time"
"github.com/miekg/dns"
"github.com/pion/transport/v2"
"github.com/txthinking/socks5"
)
func NewSocks5UDPClient(addr *url.URL) SocksClient {
return SocksClient{addr: addr}
}
type SocksClient struct {
addr *url.URL
}
type SocksConn struct {
net.Conn
socks5Client *socks5.Client
}
func (s SocksConn) SetReadBuffer(bytes int) error {
return nil
}
func (s SocksConn) SetWriteBuffer(bytes int) error {
return nil
}
func (s SocksConn) ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error) {
var buf [2000]byte
n, err = s.Conn.Read(buf[:])
if err != nil {
return 0, nil, err
}
Datagram, err := socks5.NewDatagramFromBytes(buf[:n])
if err != nil {
return 0, nil, err
}
addr, err = net.ResolveUDPAddr("udp", Datagram.Address())
if err != nil {
return 0, nil, err
}
n = copy(b, Datagram.Data)
if n < len(Datagram.Data) {
return 0, nil, errors.New("short buffer")
}
return len(Datagram.Data), addr, nil
}
func (s SocksConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *net.UDPAddr, err error) {
panic("unimplemented")
}
func (s SocksConn) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
a, addrb, portb, err := socks5.ParseAddress(addr.String())
if err != nil {
return 0, err
}
packet := socks5.NewDatagram(a, addrb, portb, b)
_, err = s.Conn.Write(packet.Bytes())
if err != nil {
return 0, err
}
return len(b), nil
}
func (s SocksConn) WriteMsgUDP(b, oob []byte, addr *net.UDPAddr) (n, oobn int, err error) {
panic("unimplemented")
}
func (sc *SocksClient) ListenPacket(network string, locAddr *net.UDPAddr) (transport.UDPConn, error) {
conn, err := sc.listenPacket()
if err != nil {
log.Println("[SOCKS5 Client Error] cannot listen packet", err)
}
return conn, err
}
func (sc *SocksClient) listenPacket() (transport.UDPConn, error) {
var username, password string
if sc.addr.User != nil {
username = sc.addr.User.Username()
password, _ = sc.addr.User.Password()
}
client, err := socks5.NewClient(
sc.addr.Host,
username, password, 300, 300)
if err != nil {
return nil, err
}
err = client.Negotiate(nil)
if err != nil {
return nil, err
}
udpRequest := socks5.NewRequest(socks5.CmdUDP, socks5.ATYPIPv4, []byte{0x00, 0x00, 0x00, 0x00}, []byte{0x00, 0x00})
reply, err := client.Request(udpRequest)
if err != nil {
return nil, err
}
udpServerAddr := socks5.ToAddress(reply.Atyp, reply.BndAddr, reply.BndPort)
conn, err := net.Dial("udp", udpServerAddr)
if err != nil {
return nil, err
}
return &SocksConn{conn, client}, nil
}
func (s SocksConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
return s.WriteToUDP(p, addr.(*net.UDPAddr))
}
func (s SocksConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
return s.ReadFromUDP(p)
}
func (s SocksConn) Read(b []byte) (int, error) {
panic("implement me")
}
func (s SocksConn) RemoteAddr() net.Addr {
panic("implement me")
}
func (s SocksConn) Write(b []byte) (int, error) {
panic("implement me")
}
func (sc *SocksClient) ResolveUDPAddr(network string, address string) (*net.UDPAddr, error) {
dnsServer, err := net.ResolveUDPAddr("udp", "1.1.1.1:53")
if err != nil {
return nil, err
}
proxiedResolver := newDnsResolver(sc, dnsServer)
ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
defer cancel()
host, port, err := net.SplitHostPort(address)
if err != nil {
return nil, err
}
ip, err := proxiedResolver.lookupIPAddr(ctx, host, network == "udp6")
if err != nil {
return nil, err
}
if len(ip) <= 0 {
return nil, errors.New("cannot resolve hostname: NXDOMAIN")
}
switch network {
case "udp4":
var v4IPAddr []net.IPAddr
for _, v := range ip {
if v.IP.To4() != nil {
v4IPAddr = append(v4IPAddr, v)
}
}
ip = v4IPAddr
case "udp6":
var v6IPAddr []net.IPAddr
for _, v := range ip {
if v.IP.To4() == nil {
v6IPAddr = append(v6IPAddr, v)
}
}
ip = v6IPAddr
case "udp":
default:
return nil, errors.New("unknown network")
}
if len(ip) <= 0 {
return nil, errors.New("cannot resolve hostname: so suitable address")
}
portInInt, err := strconv.ParseInt(port, 10, 32)
return &net.UDPAddr{
IP: ip[0].IP,
Port: int(portInInt),
Zone: "",
}, nil
}
func newDnsResolver(sc *SocksClient,
serverAddress net.Addr) *dnsResolver {
return &dnsResolver{sc: sc, serverAddress: serverAddress}
}
type dnsResolver struct {
sc *SocksClient
serverAddress net.Addr
}
func (r *dnsResolver) lookupIPAddr(ctx context.Context, host string, ipv6 bool) ([]net.IPAddr, error) {
packetConn, err := r.sc.listenPacket()
if err != nil {
return nil, err
}
msg := new(dns.Msg)
if !ipv6 {
msg.SetQuestion(dns.Fqdn(host), dns.TypeA)
} else {
msg.SetQuestion(dns.Fqdn(host), dns.TypeAAAA)
}
encodedMsg, err := msg.Pack()
if err != nil {
log.Println(err.Error())
}
for i := 2; i >= 0; i-- {
_, err := packetConn.WriteTo(encodedMsg, r.serverAddress)
if err != nil {
log.Println(err.Error())
}
}
ctx, cancel := context.WithTimeout(ctx, time.Second)
defer cancel()
go func() {
<-ctx.Done()
packetConn.Close()
}()
var dataBuf [1600]byte
n, _, err := packetConn.ReadFrom(dataBuf[:])
if err != nil {
return nil, err
}
err = msg.Unpack(dataBuf[:n])
if err != nil {
return nil, err
}
var returnedIPs []net.IPAddr
for _, resp := range msg.Answer {
switch respTyped := resp.(type) {
case *dns.A:
returnedIPs = append(returnedIPs, net.IPAddr{IP: respTyped.A})
case *dns.AAAA:
returnedIPs = append(returnedIPs, net.IPAddr{IP: respTyped.AAAA})
}
}
return returnedIPs, nil
}
func NewTransportWrapper(sc *SocksClient, innerNet transport.Net) transport.Net {
return &transportWrapper{sc: sc, Net: innerNet}
}
type transportWrapper struct {
transport.Net
sc *SocksClient
}
func (t *transportWrapper) ListenUDP(network string, locAddr *net.UDPAddr) (transport.UDPConn, error) {
return t.sc.ListenPacket(network, nil)
}
func (t *transportWrapper) ListenPacket(network string, address string) (net.PacketConn, error) {
return t.sc.ListenPacket(network, nil)
}
func (t *transportWrapper) ResolveUDPAddr(network string, address string) (*net.UDPAddr, error) {
return t.sc.ResolveUDPAddr(network, address)
}