add pkgs from core

connector/socks/v4/connector.go

@@ -0,0 +1,123 @@
+package v4
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"strconv"
+	"time"
+
+	"github.com/go-gost/core/connector"
+	md "github.com/go-gost/core/metadata"
+	"github.com/go-gost/gosocks4"
+	"github.com/go-gost/x/registry"
+)
+
+func init() {
+	registry.ConnectorRegistry().Register("socks4", NewConnector)
+	registry.ConnectorRegistry().Register("socks4a", NewConnector)
+}
+
+type socks4Connector struct {
+	md      metadata
+	options connector.Options
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := connector.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &socks4Connector{
+		options: options,
+	}
+}
+
+func (c *socks4Connector) Init(md md.Metadata) (err error) {
+	return c.parseMetadata(md)
+}
+
+func (c *socks4Connector) Connect(ctx context.Context, conn net.Conn, network, address string, opts ...connector.ConnectOption) (net.Conn, error) {
+	log := c.options.Logger.WithFields(map[string]any{
+		"remote":  conn.RemoteAddr().String(),
+		"local":   conn.LocalAddr().String(),
+		"network": network,
+		"address": address,
+	})
+	log.Infof("connect %s/%s", address, network)
+
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		if _, ok := conn.(net.PacketConn); ok {
+			err := fmt.Errorf("tcp over udp is unsupported")
+			log.Error(err)
+			return nil, err
+		}
+	default:
+		err := fmt.Errorf("network %s is unsupported", network)
+		log.Error(err)
+		return nil, err
+	}
+
+	var addr *gosocks4.Addr
+
+	if c.md.disable4a {
+		taddr, err := net.ResolveTCPAddr("tcp4", address)
+		if err != nil {
+			log.Error("resolve: ", err)
+			return nil, err
+		}
+		if len(taddr.IP) == 0 {
+			taddr.IP = net.IPv4zero
+		}
+		addr = &gosocks4.Addr{
+			Type: gosocks4.AddrIPv4,
+			Host: taddr.IP.String(),
+			Port: uint16(taddr.Port),
+		}
+	} else {
+		host, port, err := net.SplitHostPort(address)
+		if err != nil {
+			return nil, err
+		}
+		p, _ := strconv.Atoi(port)
+		addr = &gosocks4.Addr{
+			Type: gosocks4.AddrDomain,
+			Host: host,
+			Port: uint16(p),
+		}
+	}
+
+	if c.md.connectTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	var userid []byte
+	if c.options.Auth != nil {
+		userid = []byte(c.options.Auth.Username())
+	}
+	req := gosocks4.NewRequest(gosocks4.CmdConnect, addr, userid)
+	if err := req.Write(conn); err != nil {
+		log.Error(err)
+		return nil, err
+	}
+	log.Debug(req)
+
+	reply, err := gosocks4.ReadReply(conn)
+	if err != nil {
+		log.Error(err)
+		return nil, err
+	}
+	log.Debug(reply)
+
+	if reply.Code != gosocks4.Granted {
+		err = errors.New("host unreachable")
+		log.Error(err)
+		return nil, err
+	}
+
+	return conn, nil
+}

connector/socks/v4/metadata.go

@@ -0,0 +1,25 @@
+package v4
+
+import (
+	"time"
+
+	mdata "github.com/go-gost/core/metadata"
+	mdx "github.com/go-gost/x/metadata"
+)
+
+type metadata struct {
+	connectTimeout time.Duration
+	disable4a      bool
+}
+
+func (c *socks4Connector) parseMetadata(md mdata.Metadata) (err error) {
+	const (
+		connectTimeout = "timeout"
+		disable4a      = "disable4a"
+	)
+
+	c.md.connectTimeout = mdx.GetDuration(md, connectTimeout)
+	c.md.disable4a = mdx.GetBool(md, disable4a)
+
+	return
+}