重构代理解析流程，引入端口混合协议转发
This commit is contained in:
@@ -1,87 +0,0 @@
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package socks
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import (
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"context"
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"io"
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"log/slog"
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"proxy-server/pkg/utils"
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"slices"
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"github.com/pkg/errors"
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)
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type AuthMethod byte
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const (
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AuthVersion = byte(1)
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AuthSuccess = byte(0)
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AuthFailure = byte(1)
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NoAuth = AuthMethod(0)
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UserPassAuth = AuthMethod(2)
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NoAcceptable = byte(0xFF)
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)
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type Authenticator interface {
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Method() AuthMethod
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Authenticate(ctx context.Context, reader io.Reader, writer io.Writer) (*Authentication, error)
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}
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// authenticate 执行认证流程
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func (s *Server) authenticate(reader io.Reader, writer io.Writer) (*Authentication, error) {
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// 版本检查
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err := checkVersion(reader)
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if err != nil {
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return nil, err
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}
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// 获取客户端认证方式
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nAuth, err := utils.ReadByte(reader)
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if err != nil {
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return nil, err
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}
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methods, err := utils.ReadBuffer(reader, int(nAuth))
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if err != nil {
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return nil, err
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}
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// 认证客户端连接
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for _, authenticator := range s.config.AuthMethods {
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method := authenticator.Method()
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if slices.Contains(methods, byte(method)) {
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slog.Debug("使用的认证方式", method)
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_, err := writer.Write([]byte{Version, byte(method)})
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if err != nil {
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slog.Error("响应认证方式失败", err)
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return nil, err
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}
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ctx := context.WithValue(context.Background(), "service", s)
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authContext, err := authenticator.Authenticate(ctx, reader, writer)
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if err != nil {
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return nil, err
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}
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return authContext, nil
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}
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}
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// 无适用的认证方式
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_, err = writer.Write([]byte{Version, NoAcceptable})
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if err != nil {
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return nil, err
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}
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return nil, errors.New("没有适用的认证方式")
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}
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type Authentication struct {
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Method AuthMethod
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Timeout uint
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Payload Payload
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Data map[string]any
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}
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type Payload struct {
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ID uint
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}
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@@ -1,7 +0,0 @@
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package socks
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type ConfigError string
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func (c ConfigError) Error() string {
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return string(c)
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}
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@@ -1,353 +0,0 @@
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package socks
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import (
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"context"
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"fmt"
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"io"
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"log/slog"
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"net"
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"proxy-server/pkg/utils"
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"strconv"
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"github.com/pkg/errors"
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)
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const (
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ConnectCommand = byte(1)
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BindCommand = byte(2)
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AssociateCommand = byte(3)
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ipv4Address = byte(1)
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fqdnAddress = byte(3)
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ipv6Address = byte(4)
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)
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const (
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successReply byte = iota
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serverFailure
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ruleFailure
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networkUnreachable
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hostUnreachable
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connectionRefused
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ttlExpired
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commandNotSupported
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addrTypeNotSupported
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)
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var (
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unrecognizedAddrType = fmt.Errorf("unrecognized address type")
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)
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// AddressRewriter is used to rewrite a destination transparently
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type AddressRewriter interface {
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Rewrite(ctx context.Context, request *Request) (context.Context, *AddrSpec)
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}
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// AddrSpec 地址
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type AddrSpec struct {
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FQDN string
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IP net.IP
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Port int
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}
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func (a AddrSpec) String() string {
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if a.FQDN != "" {
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return fmt.Sprintf("%s (%s):%d", a.FQDN, a.IP, a.Port)
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}
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return fmt.Sprintf("%s:%d", a.IP, a.Port)
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}
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// Address returns a string suitable to dial; prefer returning IP-based
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// address, fallback to FQDN
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func (a AddrSpec) Address() string {
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if 0 != len(a.IP) {
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return net.JoinHostPort(a.IP.String(), strconv.Itoa(a.Port))
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}
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return net.JoinHostPort(a.FQDN, strconv.Itoa(a.Port))
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}
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func (s *Server) request(reader io.Reader, writer io.Writer) (*Request, error) {
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// 检查版本
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err := checkVersion(reader)
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if err != nil {
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return nil, err
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}
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// 检查连接命令
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command, err := utils.ReadByte(reader)
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if err != nil {
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return nil, err
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}
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slog.Debug("客户端使用的连接指令：%v", command)
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if command != ConnectCommand && command != BindCommand && command != AssociateCommand {
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err = sendReply(writer, commandNotSupported, nil)
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if err != nil {
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return nil, err
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}
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return nil, errors.New("不支持该连接指令")
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}
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// 跳过保留字段 rsv
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_, err = utils.ReadByte(reader)
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if err != nil {
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return nil, err
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}
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// 获取目标地址
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dest, err := s.parseTarget(reader, writer)
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if err != nil {
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return nil, err
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}
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request := &Request{
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Version: Version,
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Command: command,
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DestAddr: dest,
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bufConn: reader,
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}
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return request, nil
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}
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func (s *Server) parseTarget(reader io.Reader, writer io.Writer) (*AddrSpec, error) {
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dest := &AddrSpec{}
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aTypeBuf := make([]byte, 1)
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_, err := reader.Read(aTypeBuf)
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if err != nil {
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return nil, err
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}
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switch aTypeBuf[0] {
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case ipv4Address:
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addr := make([]byte, 4)
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_, err := io.ReadFull(reader, addr)
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if err != nil {
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return nil, err
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}
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dest.IP = addr
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case ipv6Address:
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addr := make([]byte, 16)
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_, err := io.ReadFull(reader, addr)
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if err != nil {
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return nil, err
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}
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dest.IP = addr
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case fqdnAddress:
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aLenBuf := make([]byte, 1)
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_, err := reader.Read(aLenBuf)
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if err != nil {
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return nil, err
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}
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fqdnBuff := make([]byte, int(aLenBuf[0]))
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_, err = io.ReadFull(reader, fqdnBuff)
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if err != nil {
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return nil, err
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}
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dest.FQDN = string(fqdnBuff)
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// 域名解析
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addr, err := s.config.Resolver.Resolve(dest.FQDN)
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if err != nil {
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err := sendReply(writer, hostUnreachable, nil)
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if err != nil {
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return nil, fmt.Errorf("failed to send reply: %v", err)
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}
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return nil, fmt.Errorf("failed to resolve destination '%v': %v", dest.FQDN, err)
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}
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dest.IP = addr
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default:
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err := sendReply(writer, addrTypeNotSupported, nil)
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if err != nil {
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return nil, err
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}
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return nil, unrecognizedAddrType
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}
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portBuf := make([]byte, 2)
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_, err = io.ReadFull(reader, portBuf)
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if err != nil {
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return nil, err
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}
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dest.Port = (int(portBuf[0]) << 8) | int(portBuf[1])
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return dest, nil
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}
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// A Request represents request received by a server
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type Request struct {
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// Protocol version
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Version uint8
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// Requested command
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Command uint8
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// Authentication provided during negotiation
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Authentication *Authentication
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// AddrSpec of the network that sent the request
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RemoteAddr *AddrSpec
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// AddrSpec of the desired destination
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DestAddr *AddrSpec
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// AddrSpec of the actual destination (might be affected by rewrite)
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realDestAddr *AddrSpec
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bufConn io.Reader
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}
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func (s *Server) handle(req *Request, conn net.Conn) error {
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ctx := context.Background()
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// 目标地址重写
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req.realDestAddr = req.DestAddr
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if s.config.Rewriter != nil {
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ctx, req.realDestAddr = s.config.Rewriter.Rewrite(ctx, req)
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}
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// 根据协商方法建立连接
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switch req.Command {
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case ConnectCommand:
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return s.handleConnect(ctx, conn, req)
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case BindCommand:
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return s.handleBind(ctx, conn, req)
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case AssociateCommand:
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return s.handleAssociate(ctx, conn, req)
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default:
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return fmt.Errorf("unsupported command: %v", req.Command)
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}
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}
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func (s *Server) handleConnect(ctx context.Context, conn net.Conn, req *Request) error {
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// 检查规则集约束
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s.config.Logger.Printf("检查约束规则\n")
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if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
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if err := sendReply(conn, ruleFailure, nil); err != nil {
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return fmt.Errorf("failed to send reply: %v", err)
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}
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return fmt.Errorf("request to %v blocked by rules", req.DestAddr)
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} else {
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ctx = ctx_
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}
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slog.Info("需要向 " + req.DestAddr.Address() + " 建立连接")
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select {
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case <-s.ctx.Done():
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if conn != nil {
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utils.Close(conn)
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}
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case s.Conn <- ProxyConn{
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req.Authentication.Payload.ID,
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conn,
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req.realDestAddr.Address(),
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}:
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}
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return nil
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}
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func (s *Server) handleBind(ctx context.Context, conn net.Conn, req *Request) error {
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// Check if this is allowed
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if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
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if err := sendReply(conn, ruleFailure, nil); err != nil {
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return fmt.Errorf("failed to send reply: %v", err)
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}
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return fmt.Errorf("bind to %v blocked by rules", req.DestAddr)
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} else {
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ctx = ctx_
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}
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// TODO: Support bind
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if err := sendReply(conn, commandNotSupported, nil); err != nil {
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return fmt.Errorf("failed to send reply: %v", err)
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}
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return nil
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}
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func (s *Server) handleAssociate(ctx context.Context, conn net.Conn, req *Request) error {
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// Check if this is allowed
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if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
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if err := sendReply(conn, ruleFailure, nil); err != nil {
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return fmt.Errorf("failed to send reply: %v", err)
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}
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return fmt.Errorf("associate to %v blocked by rules", req.DestAddr)
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} else {
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ctx = ctx_
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}
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// TODO: Support associate
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if err := sendReply(conn, commandNotSupported, nil); err != nil {
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return fmt.Errorf("failed to send reply: %v", err)
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}
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return nil
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}
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func sendReply(w io.Writer, resp uint8, addr *AddrSpec) error {
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var addrType uint8
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var addrBody []byte
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var addrPort uint16
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switch {
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case addr == nil:
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addrType = ipv4Address
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addrBody = []byte{0, 0, 0, 0}
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addrPort = 0
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case addr.FQDN != "":
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addrType = fqdnAddress
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addrBody = append([]byte{byte(len(addr.FQDN))}, addr.FQDN...)
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addrPort = uint16(addr.Port)
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case addr.IP.To4() != nil:
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addrType = ipv4Address
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addrBody = addr.IP.To4()
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addrPort = uint16(addr.Port)
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case addr.IP.To16() != nil:
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addrType = ipv6Address
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addrBody = addr.IP.To16()
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addrPort = uint16(addr.Port)
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default:
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return fmt.Errorf("failed to format address: %v", addr)
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}
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msg := make([]byte, 6+len(addrBody))
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msg[0] = Version
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msg[1] = resp
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msg[2] = 0 // Reserved
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msg[3] = addrType
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copy(msg[4:], addrBody)
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msg[4+len(addrBody)] = byte(addrPort >> 8)
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msg[4+len(addrBody)+1] = byte(addrPort & 0xff)
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_, err := w.Write(msg)
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return err
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}
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func SendSuccess(user net.Conn, target net.Conn) error {
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local := target.LocalAddr().(*net.TCPAddr)
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bind := AddrSpec{IP: local.IP, Port: local.Port}
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err := sendReply(user, successReply, &bind)
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if err != nil {
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return err
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}
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return nil
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}
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type ProxyConn struct {
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Uid uint
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// 用户连入的连接
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Conn net.Conn
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// 用户目标地址
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Dest string
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}
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func (d ProxyConn) Tag() string {
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local := d.Conn.LocalAddr()
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remote := d.Conn.RemoteAddr()
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return fmt.Sprintf("%s-%s", remote, local)
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}
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func (d ProxyConn) Close() error {
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return d.Conn.Close()
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}
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@@ -1,21 +0,0 @@
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package socks
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import (
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"net"
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)
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// NameResolver 域名解析器
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type NameResolver interface {
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Resolve(name string) (net.IP, error)
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}
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// DNSResolver 使用系统 dns 服务解析域名
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type DNSResolver struct{}
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func (d DNSResolver) Resolve(name string) (net.IP, error) {
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addr, err := net.ResolveIPAddr("ip", name)
|
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if err != nil {
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return nil, err
|
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}
|
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return addr.IP, err
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}
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@@ -1,41 +0,0 @@
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package socks
|
||||
|
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import (
|
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"context"
|
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)
|
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|
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// RuleSet is used to provide custom rules to allow or prohibit actions
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type RuleSet interface {
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Allow(ctx context.Context, req *Request) (context.Context, bool)
|
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}
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// PermitAll returns a RuleSet which allows all types of connections
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func PermitAll() RuleSet {
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return &PermitCommand{true, true, true}
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}
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// PermitNone returns a RuleSet which disallows all types of connections
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func PermitNone() RuleSet {
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return &PermitCommand{false, false, false}
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}
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|
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// PermitCommand is an implementation of the RuleSet which
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// enables filtering supported commands
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type PermitCommand struct {
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EnableConnect bool
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EnableBind bool
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EnableAssociate bool
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}
|
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func (p *PermitCommand) Allow(ctx context.Context, req *Request) (context.Context, bool) {
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switch req.Command {
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case ConnectCommand:
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return ctx, p.EnableConnect
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case BindCommand:
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return ctx, p.EnableBind
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case AssociateCommand:
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return ctx, p.EnableAssociate
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}
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return ctx, false
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}
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@@ -3,212 +3,90 @@ package socks
|
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import (
|
||||
"bufio"
|
||||
"context"
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
"io"
|
||||
"log"
|
||||
"log/slog"
|
||||
"net"
|
||||
"os"
|
||||
"proxy-server/pkg/utils"
|
||||
"strconv"
|
||||
"time"
|
||||
"proxy-server/server/fwd/core"
|
||||
"slices"
|
||||
|
||||
"github.com/pkg/errors"
|
||||
)
|
||||
|
||||
const (
|
||||
Version = byte(5)
|
||||
Version = byte(5)
|
||||
AuthVersion = byte(1)
|
||||
)
|
||||
|
||||
type Config struct {
|
||||
Name string
|
||||
const (
|
||||
NoAuth = byte(0)
|
||||
UserPassAuth = byte(2)
|
||||
NoAcceptable = byte(0xFF)
|
||||
)
|
||||
|
||||
Host string
|
||||
Port uint16
|
||||
const (
|
||||
AuthSuccess = byte(0)
|
||||
AuthFailure = byte(1)
|
||||
)
|
||||
|
||||
// 认证方法
|
||||
AuthMethods []Authenticator
|
||||
const (
|
||||
ConnectCommand = byte(1)
|
||||
BindCommand = byte(2)
|
||||
AssociateCommand = byte(3)
|
||||
)
|
||||
|
||||
// 域名解析
|
||||
Resolver NameResolver
|
||||
const (
|
||||
ipv4Address = byte(1)
|
||||
fqdnAddress = byte(3)
|
||||
ipv6Address = byte(4)
|
||||
)
|
||||
|
||||
// 自定义认证规则
|
||||
Rules RuleSet
|
||||
|
||||
// 地址重写
|
||||
Rewriter AddressRewriter
|
||||
|
||||
// 用于 bind 和 associate
|
||||
BindIP net.IP
|
||||
|
||||
// Logger
|
||||
Logger *log.Logger
|
||||
|
||||
// 自定义连接流程
|
||||
Dial func(network, addr string) (net.Conn, error)
|
||||
}
|
||||
|
||||
type Server struct {
|
||||
config *Config
|
||||
ctx context.Context
|
||||
cancel context.CancelFunc
|
||||
wg utils.CountWaitGroup
|
||||
Name string
|
||||
Port uint16
|
||||
Conn chan ProxyConn
|
||||
}
|
||||
|
||||
// New 创建服务器
|
||||
func New(conf *Config) (*Server, error) {
|
||||
if conf == nil {
|
||||
conf = &Config{}
|
||||
}
|
||||
|
||||
if len(conf.AuthMethods) == 0 {
|
||||
return nil, ConfigError("认证方法不能为空")
|
||||
}
|
||||
|
||||
if conf.Resolver == nil {
|
||||
conf.Resolver = DNSResolver{}
|
||||
}
|
||||
|
||||
if conf.Rules == nil {
|
||||
conf.Rules = PermitAll()
|
||||
}
|
||||
|
||||
if conf.Logger == nil {
|
||||
conf.Logger = log.New(os.Stdout, "", log.LstdFlags)
|
||||
}
|
||||
|
||||
if conf.Dial == nil {
|
||||
conf.Dial = func(network, addr string) (net.Conn, error) {
|
||||
return net.Dial(network, addr)
|
||||
}
|
||||
}
|
||||
|
||||
ctx, cancel := context.WithCancel(context.Background())
|
||||
return &Server{
|
||||
config: conf,
|
||||
ctx: ctx,
|
||||
cancel: cancel,
|
||||
wg: utils.CountWaitGroup{},
|
||||
Name: conf.Name,
|
||||
Port: conf.Port,
|
||||
Conn: make(chan ProxyConn),
|
||||
}, nil
|
||||
}
|
||||
|
||||
// Run 监听端口
|
||||
func (s *Server) Run() error {
|
||||
slog.Debug("启动 socks5 代理服务")
|
||||
|
||||
// 监听端口
|
||||
host := s.config.Host
|
||||
port := s.config.Port
|
||||
addr := net.JoinHostPort(host, strconv.Itoa(int(port)))
|
||||
ls, err := net.Listen("tcp", addr)
|
||||
if err != nil {
|
||||
return errors.Wrap(err, "监听端口失败")
|
||||
}
|
||||
defer utils.Close(ls)
|
||||
slog.Debug("正在监听端口", slog.Uint64("port", uint64(port)))
|
||||
|
||||
// 处理连接
|
||||
connCh := utils.ChanConnAccept(s.ctx, ls)
|
||||
defer close(connCh)
|
||||
|
||||
err = nil
|
||||
for loop := true; loop; {
|
||||
select {
|
||||
case <-s.ctx.Done():
|
||||
slog.Debug("socks 服务主动停止")
|
||||
loop = false
|
||||
case conn, ok := <-connCh:
|
||||
if !ok {
|
||||
err = errors.New("意外错误，无法获取连接")
|
||||
loop = false
|
||||
s.Close()
|
||||
break
|
||||
}
|
||||
s.wg.Add(1)
|
||||
go func() {
|
||||
defer s.wg.Done()
|
||||
// 连接要传出，不能在这里关闭连接
|
||||
err := s.process(conn)
|
||||
if err != nil {
|
||||
slog.Error("处理连接失败", err)
|
||||
}
|
||||
}()
|
||||
}
|
||||
}
|
||||
|
||||
// 关闭服务
|
||||
timeout, cancel := context.WithTimeout(context.Background(), 5*time.Second)
|
||||
defer cancel()
|
||||
wgCh := utils.ChanWgWait(timeout, &s.wg)
|
||||
|
||||
err = nil
|
||||
select {
|
||||
case <-timeout.Done():
|
||||
err = errors.New("关闭超时（强制关闭）")
|
||||
case <-wgCh:
|
||||
}
|
||||
|
||||
close(s.Conn)
|
||||
return err
|
||||
}
|
||||
|
||||
// Close 关闭服务
|
||||
func (s *Server) Close() {
|
||||
s.cancel()
|
||||
}
|
||||
|
||||
// process 建立连接
|
||||
func (s *Server) process(conn net.Conn) error {
|
||||
slog.Info("收到来自" + conn.RemoteAddr().String() + "的连接")
|
||||
const (
|
||||
successReply byte = iota
|
||||
serverFailure
|
||||
ruleFailure
|
||||
networkUnreachable
|
||||
hostUnreachable
|
||||
connectionRefused
|
||||
ttlExpired
|
||||
commandNotSupported
|
||||
addrTypeNotSupported
|
||||
)
|
||||
|
||||
// Process 处理连接
|
||||
func Process(ctx context.Context, conn net.Conn) (*core.Conn, error) {
|
||||
reader := bufio.NewReader(conn)
|
||||
|
||||
// 认证
|
||||
slog.Debug("开始认证流程")
|
||||
authContext, err := s.authenticate(reader, conn)
|
||||
auth, err := authenticate(ctx, reader, conn)
|
||||
if err != nil {
|
||||
utils.Close(conn)
|
||||
slog.Error("认证失败", err)
|
||||
return err
|
||||
} else {
|
||||
slog.Debug("认证完成")
|
||||
return nil, errors.Wrap(err, "认证失败")
|
||||
}
|
||||
|
||||
// 处理连接请求
|
||||
slog.Debug("处理连接请求")
|
||||
request, err := s.request(reader, conn)
|
||||
request, err := request(ctx, reader, conn)
|
||||
if err != nil {
|
||||
slog.Error("连接请求处理失败", err)
|
||||
return err
|
||||
} else {
|
||||
slog.Debug("连接请求处理完成")
|
||||
return nil, errors.Wrap(err, "处理连接请求失败")
|
||||
}
|
||||
|
||||
request.Authentication = authContext
|
||||
user, ok := conn.RemoteAddr().(*net.TCPAddr)
|
||||
if !ok {
|
||||
return fmt.Errorf("获取用户地址失败")
|
||||
// 代理连接
|
||||
if request.Command != ConnectCommand {
|
||||
return nil, errors.New("不支持的连接指令")
|
||||
}
|
||||
|
||||
request.RemoteAddr = &AddrSpec{
|
||||
IP: user.IP,
|
||||
Port: user.Port,
|
||||
}
|
||||
// 响应成功
|
||||
err = sendReply(conn, successReply, request.DestAddr)
|
||||
|
||||
// 处理请求
|
||||
slog.Debug("开始代理流量")
|
||||
err = s.handle(request, conn)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
return nil
|
||||
return &core.Conn{
|
||||
Conn: conn,
|
||||
Reader: reader,
|
||||
Protocol: "socks5",
|
||||
Tag: conn.RemoteAddr().String() + "_" + conn.LocalAddr().String(),
|
||||
Dest: request.DestAddr,
|
||||
Auth: auth,
|
||||
}, nil
|
||||
}
|
||||
|
||||
// checkVersion 检查客户端版本
|
||||
@@ -218,11 +96,280 @@ func checkVersion(reader io.Reader) error {
|
||||
return err
|
||||
}
|
||||
|
||||
slog.Debug("客户端请求版本", "version", version)
|
||||
|
||||
if version != Version {
|
||||
return errors.New("客户端版本不兼容")
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// authenticate 执行认证流程
|
||||
func authenticate(ctx context.Context, reader *bufio.Reader, conn net.Conn) (*core.AuthContext, error) {
|
||||
|
||||
// 版本检查
|
||||
err := checkVersion(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// 获取客户端认证方式
|
||||
nAuth, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
methods, err := utils.ReadBuffer(reader, int(nAuth))
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// 密码模式
|
||||
if slices.Contains(methods, UserPassAuth) {
|
||||
_, err := conn.Write([]byte{Version, byte(UserPassAuth)})
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "响应认证方式失败")
|
||||
}
|
||||
|
||||
// 检查认证版本
|
||||
slog.Debug("验证认证版本")
|
||||
v, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "读取版本号失败")
|
||||
}
|
||||
if v != AuthVersion {
|
||||
_, err := conn.Write([]byte{Version, AuthFailure})
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "响应认证失败")
|
||||
}
|
||||
return nil, errors.New("认证版本参数不正确")
|
||||
}
|
||||
|
||||
// 读取账号
|
||||
slog.Debug("验证用户账号")
|
||||
uLen, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "读取用户名长度失败")
|
||||
}
|
||||
usernameBuf, err := utils.ReadBuffer(reader, int(uLen))
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "读取用户名失败")
|
||||
}
|
||||
username := string(usernameBuf)
|
||||
|
||||
// 读取密码
|
||||
pLen, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "读取密码长度失败")
|
||||
}
|
||||
passwordBuf, err := utils.ReadBuffer(reader, int(pLen))
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "读取密码失败")
|
||||
}
|
||||
password := string(passwordBuf)
|
||||
|
||||
// 检查权限
|
||||
authContext, err := core.CheckPass(conn, username, password)
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "权限检查失败")
|
||||
}
|
||||
|
||||
// 响应认证成功
|
||||
_, err = conn.Write([]byte{AuthVersion, AuthSuccess})
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "响应认证成功失败")
|
||||
}
|
||||
|
||||
return authContext, nil
|
||||
}
|
||||
|
||||
// 无认证
|
||||
if slices.Contains(methods, NoAuth) {
|
||||
_, err = conn.Write([]byte{Version, NoAuth})
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "响应认证方式失败")
|
||||
}
|
||||
|
||||
authContext, err := core.CheckIp(conn)
|
||||
if err != nil {
|
||||
return nil, errors.Wrap(err, "权限检查失败")
|
||||
}
|
||||
|
||||
return authContext, nil
|
||||
}
|
||||
|
||||
// 无适用的认证方式
|
||||
_, err = conn.Write([]byte{Version, NoAcceptable})
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
return nil, errors.New("没有适用的认证方式")
|
||||
}
|
||||
|
||||
type Request struct {
|
||||
Command uint8
|
||||
DestAddr *core.FwdAddr
|
||||
}
|
||||
|
||||
// request 处理连接请求
|
||||
func request(ctx context.Context, reader io.Reader, writer io.Writer) (*Request, error) {
|
||||
|
||||
// 检查版本
|
||||
err := checkVersion(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// 检查连接命令
|
||||
command, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
if command != ConnectCommand && command != BindCommand && command != AssociateCommand {
|
||||
err = sendReply(writer, commandNotSupported, nil)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return nil, errors.New("不支持该连接指令")
|
||||
}
|
||||
|
||||
// 跳过保留字段 rsv
|
||||
_, err = utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// 获取目标地址
|
||||
dest, err := parseTarget(reader, writer)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
request := &Request{
|
||||
Command: command,
|
||||
DestAddr: dest,
|
||||
}
|
||||
|
||||
return request, nil
|
||||
}
|
||||
|
||||
func parseTarget(reader io.Reader, writer io.Writer) (*core.FwdAddr, error) {
|
||||
dest := &core.FwdAddr{}
|
||||
|
||||
aTypeBuf, err := utils.ReadByte(reader)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
switch aTypeBuf {
|
||||
|
||||
case ipv4Address:
|
||||
addr := make([]byte, 4)
|
||||
_, err := io.ReadFull(reader, addr)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
dest.IP = addr
|
||||
|
||||
case ipv6Address:
|
||||
addr := make([]byte, 16)
|
||||
_, err := io.ReadFull(reader, addr)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
dest.IP = addr
|
||||
|
||||
case fqdnAddress:
|
||||
aLenBuf := make([]byte, 1)
|
||||
_, err := reader.Read(aLenBuf)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
fqdnBuff := make([]byte, int(aLenBuf[0]))
|
||||
_, err = io.ReadFull(reader, fqdnBuff)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
dest.Domain = string(fqdnBuff)
|
||||
|
||||
// 域名解析
|
||||
addr, err := net.ResolveIPAddr("ip", dest.Domain)
|
||||
if err != nil {
|
||||
err := sendReply(writer, hostUnreachable, nil)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("failed to send reply: %v", err)
|
||||
}
|
||||
return nil, fmt.Errorf("failed to resolve destination '%v': %v", dest.Domain, err)
|
||||
}
|
||||
dest.IP = addr.IP
|
||||
|
||||
default:
|
||||
err := sendReply(writer, addrTypeNotSupported, nil)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return nil, fmt.Errorf("unrecognized address type")
|
||||
}
|
||||
|
||||
portBuf := make([]byte, 2)
|
||||
_, err = io.ReadFull(reader, portBuf)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
dest.Port = int(binary.BigEndian.Uint16(portBuf))
|
||||
|
||||
return dest, nil
|
||||
}
|
||||
|
||||
func sendReply(w io.Writer, resp uint8, addr *core.FwdAddr) error {
|
||||
var addrType uint8
|
||||
var addrBody []byte
|
||||
var addrPort uint16
|
||||
switch {
|
||||
case addr == nil:
|
||||
addrType = ipv4Address
|
||||
addrBody = []byte{0, 0, 0, 0}
|
||||
addrPort = 0
|
||||
|
||||
case addr.Domain != "":
|
||||
addrType = fqdnAddress
|
||||
addrBody = append([]byte{byte(len(addr.Domain))}, addr.Domain...)
|
||||
addrPort = uint16(addr.Port)
|
||||
|
||||
case addr.IP.To4() != nil:
|
||||
addrType = ipv4Address
|
||||
addrBody = addr.IP.To4()
|
||||
addrPort = uint16(addr.Port)
|
||||
|
||||
case addr.IP.To16() != nil:
|
||||
addrType = ipv6Address
|
||||
addrBody = addr.IP.To16()
|
||||
addrPort = uint16(addr.Port)
|
||||
|
||||
default:
|
||||
return fmt.Errorf("failed to format address: %v", addr)
|
||||
}
|
||||
|
||||
msg := make([]byte, 6+len(addrBody))
|
||||
msg[0] = Version
|
||||
msg[1] = resp
|
||||
msg[2] = 0 // Reserved
|
||||
msg[3] = addrType
|
||||
copy(msg[4:], addrBody)
|
||||
msg[4+len(addrBody)] = byte(addrPort >> 8)
|
||||
msg[4+len(addrBody)+1] = byte(addrPort & 0xff)
|
||||
|
||||
_, err := w.Write(msg)
|
||||
return err
|
||||
}
|
||||
|
||||
func SendSuccess(user net.Conn, target net.Conn) error {
|
||||
local := target.LocalAddr().(*net.TCPAddr)
|
||||
bind := core.FwdAddr{IP: local.IP, Port: local.Port}
|
||||
err := sendReply(user, successReply, &bind)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user