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147 lines
3.0 KiB
Go

package ssh
import (
"fmt"
"io"
"io/ioutil"
"net"
"os"
"strconv"
"strings"
"golang.org/x/crypto/ssh"
log "github.com/sirupsen/logrus"
)
type Endpoint struct {
Host string
Port int
User string
}
func NewEndpoint(s string) *Endpoint {
endpoint := &Endpoint{
Host: s,
}
if parts := strings.Split(endpoint.Host, "@"); len(parts) > 1 {
endpoint.User = parts[0]
endpoint.Host = parts[1]
}
if parts := strings.Split(endpoint.Host, ":"); len(parts) > 1 {
endpoint.Host = parts[0]
endpoint.Port, _ = strconv.Atoi(parts[1])
}
return endpoint
}
func (endpoint *Endpoint) String() string {
return fmt.Sprintf("%s", endpoint.Host)
}
type Tunnel struct {
Local *Endpoint
Server *Endpoint
Remote *Endpoint
Config *ssh.ClientConfig
log *log.Logger
Closer io.Closer
}
func (tunnel *Tunnel) logf(fmt string, args ...interface{}) {
if tunnel.log != nil {
fmt = "SSH Tunnel: " + fmt
tunnel.log.Debugf(fmt, args...)
}
}
func (tunnel *Tunnel) SetLogger(logger *log.Logger) {
tunnel.log = logger
}
func (tunnel *Tunnel) Start() error {
tunnel.logf("Starting")
listener, err := net.Listen("unix", tunnel.Local.String())
if err := os.Chmod(tunnel.Local.String(), 0700); err != nil {
return err
}
if err != nil {
return err
}
tunnel.Closer = listener
for {
conn, err := listener.Accept()
if err != nil {
return err
}
tunnel.logf("accepted connection")
go tunnel.forward(conn)
}
}
// Close closes the tunnel
func (tunnel *Tunnel) Close() {
if tunnel.Closer == nil {
return
}
tunnel.Closer.Close()
os.Remove(tunnel.Local.String())
}
func (tunnel *Tunnel) forward(localConn net.Conn) {
serverConn, err := ssh.Dial("tcp", fmt.Sprintf("%s:%d", tunnel.Server.Host, tunnel.Server.Port), tunnel.Config)
if err != nil {
tunnel.logf("server dial error: %s", err)
return
}
tunnel.logf("connected to %s (1 of 2)\n", tunnel.Server.String())
remoteConn, err := serverConn.Dial("unix", tunnel.Remote.String())
if err != nil {
tunnel.logf("remote dial error: %s", err)
return
}
tunnel.logf("connected to %s (2 of 2)\n", tunnel.Remote.String())
copyConn := func(writer, reader net.Conn) {
_, err := io.Copy(writer, reader)
if err != nil {
tunnel.logf("io.Copy error: %s", err)
}
}
go copyConn(localConn, remoteConn)
go copyConn(remoteConn, localConn)
}
func PrivateKeyFile(file string) ssh.AuthMethod {
buffer, err := ioutil.ReadFile(file)
if err != nil {
return nil
}
key, err := ssh.ParsePrivateKey(buffer)
if err != nil {
return nil
}
return ssh.PublicKeys(key)
}
func NewTunnel(tunnel string, auth []ssh.AuthMethod, localSocket string, destinationSocket string) *Tunnel {
// A random port will be chosen for us.
server := NewEndpoint(tunnel)
if server.Port == 0 {
server.Port = 22
}
Tunnel := &Tunnel{
Config: &ssh.ClientConfig{
User: server.User,
Auth: auth,
HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
// Always accept key.
return nil
},
},
Local: NewEndpoint(localSocket),
Server: server,
Remote: NewEndpoint(destinationSocket),
}
return Tunnel
}