/
tcpproxy.go
55 lines (48 loc) · 1.01 KB
/
tcpproxy.go
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package main
import (
"fmt"
"io"
"net"
"os"
"github.com/golang/glog"
)
type tcpproxy struct {
config *Config
backends *backends
}
func NewTCPProxy(c *Config, backends *backends) *tcpproxy {
return &tcpproxy{c, backends}
}
func (p *tcpproxy) start() {
local, err := net.Listen("tcp", p.config.acceptAddr)
glog.Infof("Listening on %s : ", p.config.acceptAddr)
if local == nil {
fatal("cannot listen: %v", err)
}
for {
conn, err := local.Accept()
if conn == nil {
fatal("accept failed: %v", err)
}
remoteAddr := p.backends.Next()
if "" != remoteAddr {
go forward(conn, remoteAddr)
} else {
glog.Errorf("No host found for service")
conn.Close()
}
}
}
func forward(local net.Conn, remoteAddr string) {
remote, err := net.Dial("tcp", remoteAddr)
if remote == nil {
glog.Fatalf("remote dial failed: %v\n", err)
return
}
go io.Copy(local, remote)
go io.Copy(remote, local)
}
func fatal(s string, a ...interface{}) {
glog.Fatalf("netfwd: %s\n", fmt.Sprintf(s, a))
os.Exit(2)
}