徒手撸socks5和http代理服务器

由于平时有些服务器木有外网权限，所以需要代理，网上找了一些代理工具，但都功能太多，很多用不上。因此决定自己写一个，参考了这个github项目[FQ利器](https://github.com/shadowsocks/shadowsocks-go)，完成了如下代码，够用就好。但是要想实现翻墙，还得自己写服务器实现加密才行额，加密的放出来就不保密了，哈哈。一般用那个开源项目就够用了额，只是用的人多了可能会特征识别封IP或端口，大家且翻且珍惜吧。 ```c package main import ( "bytes" "errors" "flag" "io" "log" "net" "net/url" "strconv" "strings" "sync" "time" ) func main() { socks5 := flag.String("s", ":1081", "socks5 server addr") http := flag.String("h", ":1082", "http server addr") flag.DurationVar(&readTimeout, "t", time.Minute, "read timeout") flag.Parse() go func() { err := handleProxyBase(proxySocks5, *socks5) if err != nil { log.Fatal(err) } }() err := handleProxyBase(proxyHttp, *http) if err != nil { log.Fatal(err) } } const ( socksVer5 = 5 socksCmdConnect = 1 cliIdVer = 0 cliIdNMethod = 1 cliIdCmd = 1 cliIdType = 3 cliIdIP0 = 4 cliIdDmLen = 4 cliIdDm0 = 5 cliTypeIPv4 = 1 cliTypeDm = 3 cliTypeIPv6 = 4 cliLenIPv4 = 3 + 1 + net.IPv4len + 2 cliLenIPv6 = 3 + 1 + net.IPv6len + 2 cliLenDmBase = 3 + 1 + 1 + 2 proxySocks5 = "socks5" proxyHttp = "http" ) var ( readTimeout time.Duration bytePool = &sync.Pool{New: func() interface{} { return make([]byte, 4108) }} errMode = errors.New("must socks5 or http") errVer = errors.New("socks5 version not supported") errAuthExtraData = errors.New("socks5 authentication get extra data") errCmd = errors.New("socks5 command not supported") errAddrType = errors.New("socks5 addr type not supported") errReqExtraData = errors.New("socks5 request get extra data") established = []byte("HTTP/1.1 200 Connection Established\r\n\r\n") httpConnect = []byte("CONNECT") socksVer5Established = []byte{socksVer5, 0, 0, 1, 0, 0, 0, 0, 8, 0x43} ) func handleProxyBase(mode, addr string) error { ser, err := net.Listen("tcp", addr) if err != nil { return err } for { conn, err := ser.Accept() if err != nil { return err } go func() { if err := handleProxy(mode, conn); err != nil { conn.Close() if err != io.EOF { log.Println("handle socks client:", err) } } }() } } func handleProxy(mode string, conn net.Conn) error { var ( n = 0 err error notConnect = true rawAddr string buf0 = bytePool.Get().([]byte) ) defer bytePool.Put(buf0) switch mode { case proxySocks5: notConnect = false // socks5后面不需要发送 err = handleCliShake(conn, buf0[:258]) if err != nil { return err } rawAddr, err = getCliRequest(conn, buf0[:269]) if err != nil { return err } if _, err = conn.Write(socksVer5Established); err != nil { return err } case proxyHttp: SetReadTimeout(conn) n, err = conn.Read(buf0) if err != nil { return err } var httpUrl *url.URL // 从第一行中得到有用信息 for s, i := 0, 0; buf0[i] != '\n'; i++ { if buf0[i] == 0x20 { if s == 0 { if bytes.Compare(httpConnect, buf0[:i]) == 0 { conn.Write(established) // CONNECT模式,返回代理成功 notConnect = false } s = i + 1 } else { if httpUrl, err = url.Parse(string(buf0[s:i])); err != nil { return err } break } } } if httpUrl.Opaque == "" { rawAddr = httpUrl.Host if strings.LastIndex(httpUrl.Host, ":") < 0 { rawAddr += ":80" // 没有端口则默认80 } } else { rawAddr = httpUrl.Scheme + ":" + httpUrl.Opaque } default: return errMode } log.Println("handle proxy:", mode, ",addr:", rawAddr) // 如果想FQ,可以自定义[remote net.Conn]接口的对象,并编写服务器 // 自定义Read和Write方法,在里面实现加密传输,即可达到FQ需求 // 参考https://github.com/shadowsocks/shadowsocks-go remote, err := net.DialTimeout("tcp", rawAddr, time.Minute) if err != nil { return err } if notConnect { // 只有http代理,非CONNECT模式 remote.Write(buf0[:n]) } go CopyBufferThenClose(conn, remote, buf0) buf := bytePool.Get().([]byte) CopyBufferThenClose(remote, conn, buf) bytePool.Put(buf) return nil } /*---------------------------socks5 handle------------------------------------*/ func handleCliShake(conn net.Conn, buf []byte) error { SetReadTimeout(conn) n, err := io.ReadFull(conn, buf[:cliIdNMethod+1]) if err != nil { return err } if buf[cliIdVer] != socksVer5 { return errVer } msgLen := int(buf[cliIdNMethod]) + 2 if n == msgLen { } else if n < msgLen { if _, err = io.ReadFull(conn, buf[n:msgLen]); err != nil { return err } } else { return errAuthExtraData } _, err = conn.Write(socksVer5Established[:2]) return err } func getCliRequest(conn net.Conn, buf []byte) (string, error) { SetReadTimeout(conn) n, err := io.ReadFull(conn, buf[:cliIdDmLen+1]) if err != nil { return "", err } if buf[cliIdVer] != socksVer5 { return "", errVer } if buf[cliIdCmd] != socksCmdConnect { return "", errCmd } reqLen := -1 switch buf[cliIdType] { case cliTypeDm: reqLen = int(buf[cliIdDmLen]) + cliLenDmBase case cliTypeIPv4: reqLen = cliLenIPv4 case cliTypeIPv6: reqLen = cliLenIPv6 default: return "", errAddrType } if n == reqLen { } else if n < reqLen { if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil { return "", err } } else { return "", errReqExtraData } var host string switch buf[cliIdType] { case cliTypeDm: host = string(buf[cliIdDm0 : cliIdDm0+int(buf[cliIdDmLen])]) case cliTypeIPv4: host = net.IP(buf[cliIdIP0 : cliIdIP0+net.IPv4len]).String() case cliTypeIPv6: host = net.IP(buf[cliIdIP0 : cliIdIP0+net.IPv6len]).String() } port := int64(uint16(buf[reqLen-1]) | uint16(buf[reqLen-2])<<8) host = net.JoinHostPort(host, strconv.FormatInt(port, 10)) return host, nil } /*---------------------------------tools--------------------------------------*/ func SetReadTimeout(conn net.Conn) { conn.SetReadDeadline(time.Now().Add(readTimeout)) } func CopyBufferThenClose(dst, src net.Conn, buf []byte) { var ( n int er, ew error ) defer dst.Close() for { SetReadTimeout(src) n, er = src.Read(buf) if n > 0 { if _, ew = dst.Write(buf[:n]); ew != nil { break } } if er != nil { break } } } ```