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ledudu/nvpproxy.go

Forked from jannson/nvpproxy.go
Created October 19, 2016 15:11
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Revisions

  1. @jannson jannson created this gist Jun 9, 2016.
    114 changes: 114 additions & 0 deletions nvpproxy.go
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,114 @@
    package main

    import (
    "bufio"
    "flag"
    "io"
    "log"
    "net"
    "net/http"
    "os"
    "strconv"
    )

    func checkError(err error) {
    if err != nil {
    log.Println(err)
    os.Exit(-1)
    }
    }

    func handleClient(p1, p2 net.Conn) {
    //log.Println("stream opened")
    //defer log.Println("stream closed")
    defer p1.Close()
    defer p2.Close()

    // start tunnel
    p1die := make(chan struct{})
    go func() {
    io.Copy(p1, p2)
    close(p1die)
    }()

    p2die := make(chan struct{})
    go func() {
    io.Copy(p2, p1)
    close(p2die)
    }()

    // wait for tunnel termination
    select {
    case <-p1die:
    case <-p2die:
    }
    }

    func handleHttpProxy(conn net.Conn, proxy string) (err error) {
    defer conn.Close()

    req, err := http.ReadRequest(bufio.NewReader(conn))
    if req == nil || req.Host == "" {
    //log.Println("req is nil or empty, ignore it")
    return
    }

    log.Println("new conn from", conn.RemoteAddr(), "host=", req.Host)

    req.Host = proxy

    remote, err := net.Dial("tcp", proxy)
    if err != nil {
    log.Println("dial vpn error")
    return err
    }
    defer remote.Close()

    if req.Method == "CONNECT" {
    //log.Println("conn, host=", req.Host)
    b := []byte("HTTP/1.1 200 Connection established\r\n" +
    "Proxy-Agent: KcpTun\r\n\r\n")

    if _, err := conn.Write(b); err != nil {
    log.Println("method == CONNECT and err=", err)
    return err
    }
    } else {
    //log.Println("why write, host=", req.Host)
    err = req.Write(remote)
    if err != nil {
    log.Println("method != CONNECT and err=", err)
    return
    }
    }

    //log.Println("CONNECT", req.Host, "OK")
    handleClient(conn, remote)
    return
    }

    func main() {
    var proxy string
    var port int

    flag.StringVar(&proxy, "proxy", "127.0.0.1:1194", "server of open-v-p-n")
    flag.IntVar(&port, "port", 18888, "local port of proxy")
    flag.Parse()

    addr, err := net.ResolveTCPAddr("tcp", ":"+strconv.Itoa(port))
    checkError(err)
    listener, err := net.ListenTCP("tcp", addr)
    checkError(err)
    log.Println("proxy listening on:", listener.Addr())

    for {
    conn, err := listener.AcceptTCP()
    if err != nil {
    log.Println(err)
    continue
    }

    conn.SetNoDelay(false)
    go handleHttpProxy(conn, proxy)
    }
    }