socks5-forward

gistfile1.txt

//simple tool can forward a 'listen:port' to 'forward:port' though a 'socks5://server:port'
//usage socks5-forward listen:port forward:port socksurl
package main

import (
    "io"
    "log"
    "net"
    "os"
    "net/url"
    "golang.org/x/net/proxy"
)

func forward(conn net.Conn, proxyURL* url.URL) {
    //client, err := net.Dial("tcp", os.Args[2])

    proxy, err := proxy.FromURL(proxyURL, proxy.Direct)
    if err != nil {
        log.Fatalf("Proxy failed: %v", err)
    }
    client, err := proxy.Dial("tcp", os.Args[2])
    if err != nil {
        log.Fatalf("Dial failed: %v", err)
    }
    log.Printf("Connected to localhost %v\n", conn)
    go func() {
        defer client.Close()
        defer conn.Close()
        io.Copy(client, conn)
    }()
    go func() {
        defer client.Close()
        defer conn.Close()
        io.Copy(conn, client)
    }()
}

func main() {
    if len(os.Args) != 4 {
        log.Fatalf("Usage %s listen:port forward:port socksurl\n", os.Args[0]);
        return
    }    

    listener, err := net.Listen("tcp", os.Args[1])
    if err != nil {
        log.Fatalf("Failed to setup listener: %v", err)
    }
    proxyURL, err := url.Parse(os.Args[3])
    if err != nil {
        log.Fatalf("Proxy url invalid: %v", err)
    }
    for {
        conn, err := listener.Accept()
	log.Printf("new income")
        if err != nil {
            log.Fatalf("ERROR: failed to accept listener: %v", err)
        }
        log.Printf("Accepted connection %v\n", conn)
        go forward(conn, proxyURL)
    }
}