94 lines
2.5 KiB
Go
94 lines
2.5 KiB
Go
![]() |
package proxy
|
||
|
|
||
|
import (
|
||
|
"github.com/dotcloud/docker/utils"
|
||
|
"io"
|
||
|
"log"
|
||
|
"net"
|
||
|
"syscall"
|
||
|
)
|
||
|
|
||
|
type TCPProxy struct {
|
||
|
listener *net.TCPListener
|
||
|
frontendAddr *net.TCPAddr
|
||
|
backendAddr *net.TCPAddr
|
||
|
}
|
||
|
|
||
|
func NewTCPProxy(frontendAddr, backendAddr *net.TCPAddr) (*TCPProxy, error) {
|
||
|
listener, err := net.ListenTCP("tcp", frontendAddr)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
// If the port in frontendAddr was 0 then ListenTCP will have a picked
|
||
|
// a port to listen on, hence the call to Addr to get that actual port:
|
||
|
return &TCPProxy{
|
||
|
listener: listener,
|
||
|
frontendAddr: listener.Addr().(*net.TCPAddr),
|
||
|
backendAddr: backendAddr,
|
||
|
}, nil
|
||
|
}
|
||
|
|
||
|
func (proxy *TCPProxy) clientLoop(client *net.TCPConn, quit chan bool) {
|
||
|
backend, err := net.DialTCP("tcp", nil, proxy.backendAddr)
|
||
|
if err != nil {
|
||
|
log.Printf("Can't forward traffic to backend tcp/%v: %v\n", proxy.backendAddr, err.Error())
|
||
|
client.Close()
|
||
|
return
|
||
|
}
|
||
|
|
||
|
event := make(chan int64)
|
||
|
var broker = func(to, from *net.TCPConn) {
|
||
|
written, err := io.Copy(to, from)
|
||
|
if err != nil {
|
||
|
// If the socket we are writing to is shutdown with
|
||
|
// SHUT_WR, forward it to the other end of the pipe:
|
||
|
if err, ok := err.(*net.OpError); ok && err.Err == syscall.EPIPE {
|
||
|
from.CloseWrite()
|
||
|
}
|
||
|
}
|
||
|
to.CloseRead()
|
||
|
event <- written
|
||
|
}
|
||
|
utils.Debugf("Forwarding traffic between tcp/%v and tcp/%v", client.RemoteAddr(), backend.RemoteAddr())
|
||
|
go broker(client, backend)
|
||
|
go broker(backend, client)
|
||
|
|
||
|
var transferred int64 = 0
|
||
|
for i := 0; i < 2; i++ {
|
||
|
select {
|
||
|
case written := <-event:
|
||
|
transferred += written
|
||
|
case <-quit:
|
||
|
// Interrupt the two brokers and "join" them.
|
||
|
client.Close()
|
||
|
backend.Close()
|
||
|
for ; i < 2; i++ {
|
||
|
transferred += <-event
|
||
|
}
|
||
|
goto done
|
||
|
}
|
||
|
}
|
||
|
client.Close()
|
||
|
backend.Close()
|
||
|
done:
|
||
|
utils.Debugf("%v bytes transferred between tcp/%v and tcp/%v", transferred, client.RemoteAddr(), backend.RemoteAddr())
|
||
|
}
|
||
|
|
||
|
func (proxy *TCPProxy) Run() {
|
||
|
quit := make(chan bool)
|
||
|
defer close(quit)
|
||
|
utils.Debugf("Starting proxy on tcp/%v for tcp/%v", proxy.frontendAddr, proxy.backendAddr)
|
||
|
for {
|
||
|
client, err := proxy.listener.Accept()
|
||
|
if err != nil {
|
||
|
utils.Debugf("Stopping proxy on tcp/%v for tcp/%v (%v)", proxy.frontendAddr, proxy.backendAddr, err.Error())
|
||
|
return
|
||
|
}
|
||
|
go proxy.clientLoop(client.(*net.TCPConn), quit)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func (proxy *TCPProxy) Close() { proxy.listener.Close() }
|
||
|
func (proxy *TCPProxy) FrontendAddr() net.Addr { return proxy.frontendAddr }
|
||
|
func (proxy *TCPProxy) BackendAddr() net.Addr { return proxy.backendAddr }
|