124 lines
2.5 KiB
Go
124 lines
2.5 KiB
Go
package v4
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import (
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"context"
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"errors"
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"fmt"
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"net"
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"strconv"
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"time"
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"github.com/go-gost/core/connector"
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md "github.com/go-gost/core/metadata"
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"github.com/go-gost/gosocks4"
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"github.com/go-gost/x/registry"
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)
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func init() {
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registry.ConnectorRegistry().Register("socks4", NewConnector)
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registry.ConnectorRegistry().Register("socks4a", NewConnector)
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}
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type socks4Connector struct {
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md metadata
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options connector.Options
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}
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func NewConnector(opts ...connector.Option) connector.Connector {
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options := connector.Options{}
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for _, opt := range opts {
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opt(&options)
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}
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return &socks4Connector{
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options: options,
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}
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}
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func (c *socks4Connector) Init(md md.Metadata) (err error) {
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return c.parseMetadata(md)
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}
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func (c *socks4Connector) Connect(ctx context.Context, conn net.Conn, network, address string, opts ...connector.ConnectOption) (net.Conn, error) {
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log := c.options.Logger.WithFields(map[string]any{
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"remote": conn.RemoteAddr().String(),
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"local": conn.LocalAddr().String(),
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"network": network,
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"address": address,
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})
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log.Debugf("connect %s/%s", address, network)
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switch network {
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case "tcp", "tcp4", "tcp6":
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if _, ok := conn.(net.PacketConn); ok {
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err := fmt.Errorf("tcp over udp is unsupported")
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log.Error(err)
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return nil, err
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}
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default:
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err := fmt.Errorf("network %s is unsupported", network)
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log.Error(err)
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return nil, err
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}
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var addr *gosocks4.Addr
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if c.md.disable4a {
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taddr, err := net.ResolveTCPAddr("tcp4", address)
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if err != nil {
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log.Error("resolve: ", err)
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return nil, err
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}
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if len(taddr.IP) == 0 {
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taddr.IP = net.IPv4zero
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}
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addr = &gosocks4.Addr{
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Type: gosocks4.AddrIPv4,
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Host: taddr.IP.String(),
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Port: uint16(taddr.Port),
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}
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} else {
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host, port, err := net.SplitHostPort(address)
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if err != nil {
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return nil, err
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}
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p, _ := strconv.Atoi(port)
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addr = &gosocks4.Addr{
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Type: gosocks4.AddrDomain,
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Host: host,
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Port: uint16(p),
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}
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}
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if c.md.connectTimeout > 0 {
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conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
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defer conn.SetDeadline(time.Time{})
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}
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var userid []byte
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if c.options.Auth != nil {
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userid = []byte(c.options.Auth.Username())
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}
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req := gosocks4.NewRequest(gosocks4.CmdConnect, addr, userid)
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log.Trace(req)
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if err := req.Write(conn); err != nil {
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log.Error(err)
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return nil, err
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}
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reply, err := gosocks4.ReadReply(conn)
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if err != nil {
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log.Error(err)
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return nil, err
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}
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log.Trace(reply)
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if reply.Code != gosocks4.Granted {
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err = errors.New("host unreachable")
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log.Error(err)
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return nil, err
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}
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return conn, nil
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}
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