rudp/proxy/proxy.go

   1 /*
   2 Proxy is a Minetest RUDP proxy server
   3 supporting multiple concurrent connections.
   4
   5 Usage:
   6         proxy dial:port listen:port
   7 where dial:port is the server address
   8 and listen:port is the address to listen on.
   9 */
  10 package main
  11
  12 import (
  13         "fmt"
  14         "log"
  15         "net"
  16         "os"
  17
  18         "github.com/anon55555/mt/rudp"
  19 )
  20
  21 func main() {
  22         if len(os.Args) != 3 {
  23                 fmt.Fprintln(os.Stderr, "usage: proxy dial:port listen:port")
  24                 os.Exit(1)
  25         }
  26
  27         srvaddr, err := net.ResolveUDPAddr("udp", os.Args[1])
  28         if err != nil {
  29                 log.Fatal(err)
  30         }
  31
  32         lc, err := net.ListenPacket("udp", os.Args[2])
  33         if err != nil {
  34                 log.Fatal(err)
  35         }
  36         defer lc.Close()
  37
  38         l := rudp.Listen(lc)
  39         for {
  40                 clt, err := l.Accept()
  41                 if err != nil {
  42                         log.Print(err)
  43                         continue
  44                 }
  45
  46                 log.Print(clt.Addr(), " connected")
  47
  48                 conn, err := net.DialUDP("udp", nil, srvaddr)
  49                 if err != nil {
  50                         log.Print(err)
  51                         continue
  52                 }
  53                 srv := rudp.Connect(conn, conn.RemoteAddr())
  54
  55                 go proxy(clt, srv)
  56                 go proxy(srv, clt)
  57         }
  58 }
  59
  60 func proxy(src, dest *rudp.Peer) {
  61         for {
  62                 pkt, err := src.Recv()
  63                 if err != nil {
  64                         if err == rudp.ErrClosed {
  65                                 msg := src.Addr().String() + " disconnected"
  66                                 if src.TimedOut() {
  67                                         msg += " (timed out)"
  68                                 }
  69                                 log.Print(msg)
  70
  71                                 break
  72                         }
  73
  74                         log.Print(err)
  75                         continue
  76                 }
  77
  78                 if _, err := dest.Send(pkt); err != nil {
  79                         log.Print(err)
  80                 }
  81         }
  82
  83         dest.SendDisco(0, true)
  84         dest.Close()
  85 }