重构代理解析流程,引入端口混合协议转发

This commit is contained in:
2025-03-01 17:08:56 +08:00
parent b8a3dd93dc
commit 76139d28c4
24 changed files with 841 additions and 1042 deletions

View File

@@ -3,212 +3,90 @@ package socks
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
}