/
tunnel.go
85 lines (78 loc) · 1.83 KB
/
tunnel.go
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package ssh
import (
"fmt"
"golang.org/x/crypto/ssh"
"io"
"log"
"net"
"sync"
"sync/atomic"
)
//Tunnel represents a SSH forwarding link
type Tunnel struct {
RemoteAddress string
client *ssh.Client
Local net.Listener
Connections []net.Conn
mutex *sync.Mutex
closed int32
}
func (f *Tunnel) tunnelTraffic(local, remote net.Conn) {
defer local.Close()
defer remote.Close()
completionChannel := make(chan bool)
go func() {
_, err := io.Copy(local, remote)
if err != nil {
log.Printf("failed to copy remote to local: %v", err)
}
completionChannel <- true
}()
go func() {
_, _ = io.Copy(remote, local)
//if err != nil {
// log.Printf("failed to copy local to remote: %v", err)
//}
completionChannel <- true
}()
<-completionChannel
}
//Handle listen on local client to create tunnel with remote address.
func (f *Tunnel) Handle() error {
for {
if atomic.LoadInt32(&f.closed) == 1 {
return nil
}
localclient, err := f.Local.Accept()
if err != nil {
return err
}
remote, err := f.client.Dial("tcp", f.RemoteAddress)
if err != nil {
return fmt.Errorf("failed to connect to remote: %v %v", f.RemoteAddress, err)
}
f.Connections = append(f.Connections, remote)
f.Connections = append(f.Connections, localclient)
go f.tunnelTraffic(localclient, remote)
}
return nil
}
//Close closes forwarding link
func (f *Tunnel) Close() error {
atomic.StoreInt32(&f.closed, 1)
_ = f.Local.Close()
for _, remote := range f.Connections {
_ = remote.Close()
}
return nil
}
//NewForwarding creates a new ssh forwarding link
func NewForwarding(client *ssh.Client, remoteAddress string, local net.Listener) *Tunnel {
return &Tunnel{
client: client,
RemoteAddress: remoteAddress,
Connections: make([]net.Conn, 0),
Local: local,
mutex: &sync.Mutex{},
}
}