forked from dqminh/ssh-gateway-docker
/
main.go
161 lines (144 loc) · 3.35 KB
/
main.go
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package main
import (
"bufio"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"os"
"os/exec"
"strings"
"sync"
"syscall"
"github.com/kr/pty"
"code.google.com/p/go.crypto/ssh"
)
func serverConfig() *ssh.ServerConfig {
privateBytes, err := ioutil.ReadFile("./nopass_rsa")
if err != nil {
log.Fatalf("[FATAL] Failed to load private key %q", err)
}
private, err := ssh.ParsePrivateKey(privateBytes)
if err != nil {
log.Fatalf("[FATAL] Failed to parse private key %q", err)
}
// FIXME: do not accepts any keys here
conf := &ssh.ServerConfig{
PublicKeyCallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
return nil, nil
},
}
conf.AddHostKey(private)
return conf
}
func main() {
conf := serverConfig()
// start the server
addr := fmt.Sprintf("0.0.0.0:%s", os.Args[1])
listener, err := net.Listen("tcp", addr)
if err != nil {
log.Fatalf("[FATAL] failed to listen to %q, err %q", addr, err)
}
log.Printf("[INFO] listening to %q", addr)
for {
conn, err := listener.Accept()
if err != nil {
log.Fatalf("[FATAL] failed to accept tcp conn %q", err)
}
_, chs, reqs, err := ssh.NewServerConn(conn, conf)
if err != nil {
log.Printf("[ERROR] failed to open new ssh server conn %q", err)
continue
}
// discard all requests sent outside of normal data
go ssh.DiscardRequests(reqs)
for ch := range chs {
handleChannel(ch)
}
}
}
func handleChannel(ch ssh.NewChannel) {
if ch.ChannelType() != "session" {
log.Printf("[ERROR] unknown channel type %q", ch.ChannelType())
ch.Reject(ssh.UnknownChannelType, "unknown channel type")
return
}
channel, requests, err := ch.Accept()
if err != nil {
log.Printf("[ERROR] could not accept channel %q", err)
}
defer channel.Close()
var master, slave *os.File
defer func() {
if master != nil {
master.Close()
}
if slave != nil {
slave.Close()
}
}()
var wg sync.WaitGroup
wg.Add(1)
go func(in <-chan *ssh.Request) {
for req := range in {
log.Printf("[INFO] got request %q", req.Type)
switch req.Type {
case "shell":
if len(req.Payload) > 0 {
// do not accept any extra commands for shell
req.Reply(false, nil)
return
}
req.Reply(true, nil)
case "pty-req":
pty, tty, err := pty.Open()
if err != nil {
log.Printf("[ERROR] failed to open a pty %q", err)
return
}
master, slave = pty, tty
wg.Done()
// FIXME handle pty request
req.Reply(true, nil)
case "window-change":
// FIXME handle window resize
req.Reply(true, nil)
}
}
}(requests)
wg.Wait()
go io.Copy(channel, master)
go io.Copy(master, channel)
s := bufio.NewScanner(slave)
for {
prompt(slave)
if !s.Scan() {
break
}
line := s.Text()
// clear the terminal and continue
if line == "cls" {
fmt.Fprintf(slave, "\033[2J")
fmt.Fprintf(slave, "\033[1;1H")
continue
}
tokens := strings.Split(line, " ")
cmd := exec.Command("docker", tokens...)
cmd.Stdin = slave
cmd.Stdout = slave
cmd.Stderr = slave
cmd.SysProcAttr = &syscall.SysProcAttr{Setctty: true, Setsid: true}
log.Println("command: %#v", cmd)
if err := cmd.Start(); err != nil {
fmt.Fprintf(master, "invalid docker cmd %q\n", line)
}
if err := cmd.Wait(); err != nil {
fmt.Fprintf(master, "cmd %q failed\n", line)
}
fmt.Fprint(slave, "\r\n")
}
}
func prompt(w io.Writer) {
fmt.Fprint(w, "docker > ")
}