/
proxy.go
74 lines (70 loc) · 1.32 KB
/
proxy.go
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package main
import (
"flag"
"io"
"log"
"net"
"os"
"sync"
"time"
)
var (
listenAddr = flag.String("l", ":8080", "local listen port")
dstAddr = flag.String("d", "localhost:7070", "proxy to dest addr")
bufferPool = sync.Pool{
New: func() interface{} {
return make([]byte, 256*1024)
},
}
dialer = net.Dialer{
KeepAlive: time.Minute * 5,
Timeout: time.Second * 5,
}
)
func handleConn(conn net.Conn) {
defer conn.Close()
log.Println("connected from:", conn.RemoteAddr())
dst, err := dialer.Dial("tcp", *dstAddr)
if err != nil {
log.Println(err)
return
}
defer dst.Close()
wg := &sync.WaitGroup{}
wg.Add(2)
go func(wg *sync.WaitGroup) {
buf := bufferPool.Get()
_, err = io.CopyBuffer(conn, dst, buf.([]byte))
if err != nil {
log.Println(err)
}
bufferPool.Put(buf)
wg.Done()
}(wg)
go func(wg *sync.WaitGroup) {
buf := bufferPool.Get()
_, err = io.CopyBuffer(dst, conn, buf.([]byte))
if err != nil {
log.Println(err)
}
bufferPool.Put(buf)
wg.Done()
}(wg)
wg.Wait()
}
func main() {
flag.Parse()
log.Printf("%s listen at :%s and proxy to %s\n", os.Args[0], *listenAddr, *dstAddr)
ln, err := net.Listen("tcp", *listenAddr)
if err != nil {
log.Fatal(err)
}
for {
conn, err := ln.Accept()
if err != nil {
log.Println(err)
continue
}
go handleConn(conn)
}
}