Add internal SSH server as a replacement for ctl.

ssh.go

@@ -0,0 +1,211 @@
+package main
+
+import (
+	"bytes"
+	"crypto/rand"
+	"errors"
+	"exp/ssh"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"path/filepath"
+	"strings"
+)
+
+func passwordAuth(username, password string) bool {
+	if username == "admin" && password == "admin" {
+		return true
+	}
+	return false
+}
+
+type SshCmdReply interface {
+	WriteString(s string) (int, error)
+}
+
+type SshCmdFunc func(reply SshCmdReply, args []string) error
+
+type SshCmd struct {
+	CmdFunc      SshCmdFunc
+	Args         string
+	Description  string
+}
+
+func (c SshCmd) Call(reply SshCmdReply, args []string) error {
+	return c.CmdFunc(reply, args)
+}
+
+var cmdMap = map[string]SshCmd{}
+
+func RegisterSSHCmd(name string, cmdFunc SshCmdFunc, args string, desc string) {
+	cmdMap[name] = SshCmd{
+		CmdFunc: cmdFunc,
+		Args: args,
+		Description: desc,
+	}
+}
+
+func RunSSH() {
+	RegisterSSHCmd("help",
+		HelpCmd,
+		"[cmd]",
+		"Shows this help (or help for a given command)")
+	RegisterSSHCmd("start",
+		StartServerCmd,
+		"<id>",
+		"Starts the server with the given id")
+	RegisterSSHCmd("stop",
+		StopServerCmd,
+		"<id>",
+		"Stops the server with the given id")
+	RegisterSSHCmd("supw",
+		SetSuperUserPasswordCmd,
+		"<id> <password>",
+		"Set the SuperUser password for server with the given id")
+	RegisterSSHCmd("setconf",
+		SetConfCmd,
+		"<id> <key> <value>",
+		"Set a config value for the server with the given id")
+	RegisterSSHCmd("getconf",
+		GetConfCmd,
+		"<id> <key> <value>",
+		"Get a config value for the server with the given id")
+
+	pemBytes, err := ioutil.ReadFile(filepath.Join(Args.DataDir, "key"))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	cfg := new(ssh.ServerConfig)
+	cfg.Rand = rand.Reader
+	cfg.PasswordCallback = passwordAuth
+	cfg.SetRSAPrivateKey(pemBytes)
+
+	listener, err := ssh.Listen("tcp", Args.SshAddr, cfg)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Printf("Listening for SSH connections on '%v'", Args.SshAddr)
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			log.Fatalf("ssh: unable to accept incoming connection: %v", err)
+		}
+
+		err = conn.Handshake()
+		if err == io.EOF {
+			continue
+		} else if err != nil {
+			log.Fatalf("ssh: unable to perform handshake: %v", err)
+		}
+
+		go func() {
+			for {
+				channel, err := conn.Accept()
+				if err == io.EOF {
+					return
+				} else if err != nil {
+					log.Fatalf("ssh: unable to accept channel: %v", err)
+				}
+
+				go handleChannel(channel)
+			}
+		}()
+	}
+}
+
+func handleChannel(channel ssh.Channel) {
+	if channel.ChannelType() == "session" {
+		channel.Accept()
+		shell := ssh.NewServerShell(channel, "G> ")
+		go func() {
+			defer channel.Close()
+			for {
+				line, err := shell.ReadLine()
+				if err == io.EOF {
+					break
+				} else if err != nil {
+					log.Printf("ssh: error in reading from channel: %v", err)
+					break
+				}
+
+				line = strings.TrimSpace(line)
+				args := strings.Split(line, " ")
+
+				if len(args) < 1 {
+					continue
+				}
+
+				if args[0] == "exit" {
+					return
+				}
+
+				if cmd, ok := cmdMap[args[0]]; ok {
+					buf := new(bytes.Buffer)
+					err = cmd.Call(buf, args)
+					if err != nil {
+						_, err = shell.Write([]byte(fmt.Sprintf("error: %v\r\n", err.Error())))
+						if err != nil {
+							return
+						}
+						continue
+					}
+
+					_, err = shell.Write(buf.Bytes())
+					if err != nil {
+						return						
+					}
+				} else {
+					_, err = shell.Write([]byte("error: unknown command\r\n"))
+				}
+			}
+		}()
+		return
+	}
+
+	channel.Reject(ssh.UnknownChannelType, "unknown channel type")
+}
+
+func HelpCmd(reply SshCmdReply, args []string) error {
+	if len(args) == 1 {
+		for cmdName, cmd := range cmdMap {
+			reply.WriteString("\r\n")
+			reply.WriteString(" " + cmdName + " " + cmd.Args + "\r\n")
+			reply.WriteString("    " + cmd.Description + "\r\n")
+		}
+	} else if len(args) > 1 {
+		cmdName := args[1]
+		if cmd, ok := cmdMap[cmdName]; ok {
+			reply.WriteString("\r\n")
+			reply.WriteString(" " + cmdName + " " + cmd.Args + "\r\n")
+			reply.WriteString("    " + cmd.Description + "\r\n")
+		} else {
+			return errors.New("no such command name")
+		}
+	}
+	reply.WriteString("\r\n")
+	return nil
+}
+
+func StartServerCmd(reply SshCmdReply, args []string) error {
+	return errors.New("not implemented")
+}
+
+func StopServerCmd(reply SshCmdReply, args []string) error {
+	return errors.New("not implemented")
+}
+
+func SetSuperUserPasswordCmd(reply SshCmdReply, args []string) error {
+	return errors.New("not implemented")
+}
+
+func SetConfCmd(reply SshCmdReply, args []string) error {
+	return errors.New("not implemented")
+}
+
+func GetConfCmd(reply SshCmdReply, args []string) error {
+	return errors.New("not implemented")
+}