// HandleChannel handles one SSH channel
func (c *Client) HandleChannel(newChannel ssh.NewChannel) error {
if newChannel.ChannelType() != "session" {
log.Debugf("Unknown channel type: %s", newChannel.ChannelType())
newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
return nil
}
channel, requests, err := newChannel.Accept()
if err != nil {
log.Errorf("newChannel.Accept failed: %v", err)
return err
}
c.ChannelIdx++
log.Debugf("HandleChannel.channel (client=%d channel=%d)", c.Idx, c.ChannelIdx)
log.Debug("Creating pty...")
c.Pty, c.Tty, err = pty.Open()
if err != nil {
log.Errorf("pty.Open failed: %v", err)
return nil
}
c.HandleChannelRequests(channel, requests)
return nil
}
// Handle is the SSH client entrypoint, it takes a net.Conn
// instance and handle all the ssh and ssh2docker stuff
func (s *Server) Handle(netConn net.Conn) error {
if err := s.Init(); err != nil {
return err
}
log.Debugf("Server.Handle netConn=%v", netConn)
// Initialize a Client object
conn, chans, reqs, err := ssh.NewServerConn(netConn, s.SshConfig)
if err != nil {
log.Infof("Received disconnect from %s: 11: Bye Bye [preauth]", netConn.RemoteAddr().String())
return err
}
client := NewClient(conn, chans, reqs, s)
// Handle requests
if err = client.HandleRequests(); err != nil {
return err
}
// Handle channels
if err = client.HandleChannels(); err != nil {
return err
}
return nil
}
// functionVars returns the function ARN's as terraform -var arguments.
func (p *Proxy) functionVars() (args []string) {
args = append(args, "-var")
args = append(args, fmt.Sprintf("aws_region=%s", p.Region))
args = append(args, "-var")
args = append(args, fmt.Sprintf("apex_environment=%s", p.Environment))
if p.Role != "" {
args = append(args, "-var")
args = append(args, fmt.Sprintf("apex_function_role=%s", p.Role))
}
for _, fn := range p.Functions {
config, err := fn.GetConfig()
if err != nil {
log.Debugf("can't fetch function config: %s", err.Error())
continue
}
args = append(args, "-var")
args = append(args, fmt.Sprintf("apex_function_%s=%s", fn.Name, *config.Configuration.FunctionArn))
}
return args
}
// DockerKill kills a container
func DockerKill(containerID string) error {
cmd := exec.Command("docker", "kill", "-s", "9", containerID)
_, err := cmd.CombinedOutput()
if err != nil {
return err
}
log.Debugf("Killed container: %q", containerID)
return nil
}
// DockerRemove removes a container
func DockerRemove(containerID string) error {
cmd := exec.Command("docker", "rm", "-f", containerID)
_, err := cmd.CombinedOutput()
if err != nil {
return err
}
log.Debugf("Deleted container: %q", containerID)
return nil
}
// HandleRequests handles SSH requests
func (c *Client) HandleRequests() error {
go func(in <-chan *ssh.Request) {
for req := range in {
log.Debugf("HandleRequest: %v", req)
if req.WantReply {
req.Reply(false, nil)
}
}
}(c.Reqs)
return nil
}
// outputTFvars format.
func outputTFvars() {
for _, fn := range root.Project.Functions {
config, err := fn.GetConfig()
if err != nil {
log.Debugf("can't fetch function config: %s", err.Error())
continue
}
fmt.Printf("apex_function_%s=%q\n", fn.Name, *config.Configuration.FunctionArn)
}
}
// functionVars returns the function ARN's as terraform -var arguments.
func (p *Proxy) functionVars() (args []string) {
for _, fn := range p.Functions {
config, err := fn.GetConfig()
if err != nil {
log.Debugf("can't fetch function config: %s", err.Error())
continue
}
args = append(args, "-var")
args = append(args, fmt.Sprintf("apex_function_%s=%s", fn.Name, *config.Configuration.FunctionArn))
}
return args
}
// CheckConfig checks if the ClientConfig has access
func (s *Server) CheckConfig(config *ClientConfig) error {
if !config.Allowed && (s.PasswordAuthScript != "" || s.PublicKeyAuthScript != "") {
log.Debugf("config.Allowed = false")
return fmt.Errorf("Access not allowed")
}
if s.AllowedImages != nil {
allowed := false
for _, image := range s.AllowedImages {
if image == config.ImageName {
allowed = true
break
}
}
if !allowed {
log.Warnf("Image is not allowed: %q", config.ImageName)
return fmt.Errorf("Image not allowed")
}
}
return nil
}
// PublicKeyCallback is called when the user tries to authenticate using an SSH public key
func (s *Server) PublicKeyCallback(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
username := conn.User()
clientID := conn.RemoteAddr().String()
keyText := strings.TrimSpace(string(ssh.MarshalAuthorizedKey(key)))
log.Debugf("PublicKeyCallback: %q %q", username, keyText)
// sessionID := conn.SessionID()
config := s.ClientConfigs[clientID]
if config == nil {
s.ClientConfigs[clientID] = &ClientConfig{
RemoteUser: username,
ImageName: username,
Keys: []string{},
AuthenticationMethod: "noauth",
AuthenticationAttempts: 0,
AuthenticationComment: "",
Env: make(envhelper.Environment, 0),
}
}
config = s.ClientConfigs[clientID]
config.Keys = append(config.Keys, keyText)
return nil, s.CheckConfig(config)
}
// Debugf level formatted message.
func Debugf(msg string, v ...interface{}) {
apexlog.Debugf(msg, v...)
}
func SetWinsize(fd uintptr, w, h uint32) {
log.Debugf("Window resize '%dx%d'", w, h)
ws := &Winsize{Width: uint16(w), Height: uint16(h)}
syscall.Syscall(syscall.SYS_IOCTL, fd, uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(ws)))
}
// PasswordCallback is called when the user tries to authenticate using a password
func (s *Server) PasswordCallback(conn ssh.ConnMetadata, password []byte) (*ssh.Permissions, error) {
username := conn.User()
clientID := conn.RemoteAddr().String()
log.Debugf("PasswordCallback: %q %q", username, password)
// map config in the memory
config := s.ClientConfigs[clientID]
if config == nil {
s.ClientConfigs[clientID] = &ClientConfig{
//Allowed: true,
RemoteUser: username,
ImageName: username,
Keys: []string{},
AuthenticationMethod: "noauth",
AuthenticationAttempts: 0,
AuthenticationComment: "",
Env: make(envhelper.Environment, 0),
}
config = s.ClientConfigs[clientID]
}
// if there is a password callback
if s.PasswordAuthScript == "" {
return nil, s.CheckConfig(config)
}
config.AuthenticationAttempts++
var output []byte
switch {
case strings.HasPrefix(s.PasswordAuthScript, "http://"),
strings.HasPrefix(s.PasswordAuthScript, "https://"):
input := struct {
Username string `json:"username"`
Password string `json:"password"`
}{
Username: username,
Password: string(password),
}
resp, body, errs := gorequest.New().Type("json").Post(s.PasswordAuthScript).Send(input).End()
if len(errs) > 0 {
return nil, fmt.Errorf("gorequest errs: %v", errs)
}
if resp.StatusCode != 200 {
return nil, fmt.Errorf("invalid status code: %d", resp.StatusCode)
}
output = []byte(body)
default:
script, err := homedir.Expand(s.PasswordAuthScript)
if err != nil {
log.Warnf("Failed to expandUser: %v", err)
return nil, err
}
cmd := exec.Command(script, username, string(password))
cmd.Env = config.Env.List()
// FIXME: redirect stderr to log
cmd.Stderr = os.Stderr
output, err = cmd.Output()
if err != nil {
log.Warnf("Failed to execute password-auth-script: %v", err)
return nil, err
}
}
if err := json.Unmarshal(output, &config); err != nil {
log.Warnf("Failed to unmarshal json %q: %v", string(output), err)
return nil, err
}
if err := s.CheckConfig(config); err != nil {
return nil, err
}
// success
config.AuthenticationMethod = "password"
return nil, nil
}
// HandleChannelRequests handles channel requests
func (c *Client) HandleChannelRequests(channel ssh.Channel, requests <-chan *ssh.Request) {
go func(in <-chan *ssh.Request) {
defer c.Tty.Close()
for req := range in {
ok := false
switch req.Type {
case "shell":
log.Debugf("HandleChannelRequests.req shell")
if len(req.Payload) != 0 {
break
}
ok = true
entrypoint := ""
if c.Config.EntryPoint != "" {
entrypoint = c.Config.EntryPoint
}
var args []string
if c.Config.Command != nil {
args = c.Config.Command
}
if entrypoint == "" && len(args) == 0 {
args = []string{c.Server.DefaultShell}
}
c.runCommand(channel, entrypoint, args)
case "exec":
command := string(req.Payload[4:])
log.Debugf("HandleChannelRequests.req exec: %q", command)
ok = true
args, err := shlex.Split(command)
if err != nil {
log.Errorf("Failed to parse command %q: %v", command, args)
}
c.runCommand(channel, c.Config.EntryPoint, args)
case "pty-req":
ok = true
c.Config.UseTTY = true
termLen := req.Payload[3]
c.Config.Env["TERM"] = string(req.Payload[4 : termLen+4])
c.Config.Env["USE_TTY"] = "1"
w, h := ttyhelper.ParseDims(req.Payload[termLen+4:])
ttyhelper.SetWinsize(c.Pty.Fd(), w, h)
log.Debugf("HandleChannelRequests.req pty-req: TERM=%q w=%q h=%q", c.Config.Env["TERM"], int(w), int(h))
case "window-change":
w, h := ttyhelper.ParseDims(req.Payload)
ttyhelper.SetWinsize(c.Pty.Fd(), w, h)
continue
case "env":
keyLen := req.Payload[3]
key := string(req.Payload[4 : keyLen+4])
valueLen := req.Payload[keyLen+7]
value := string(req.Payload[keyLen+8 : keyLen+8+valueLen])
log.Debugf("HandleChannelRequets.req 'env': %s=%q", key, value)
c.Config.Env[key] = value
default:
log.Debugf("Unhandled request type: %q: %v", req.Type, req)
}
if req.WantReply {
if !ok {
log.Debugf("Declining %s request...", req.Type)
}
req.Reply(ok, nil)
}
}
}(requests)
}
func (c *Client) runCommand(channel ssh.Channel, entrypoint string, command []string) {
var cmd *exec.Cmd
var err error
if c.Config.IsLocal {
cmd = exec.Command(entrypoint, command...)
} else {
// checking if a container already exists for this user
existingContainer := ""
if !c.Server.NoJoin {
cmd = exec.Command("docker", "ps", "--filter=label=ssh2docker", fmt.Sprintf("--filter=label=image=%s", c.Config.ImageName), fmt.Sprintf("--filter=label=user=%s", c.Config.RemoteUser), "--quiet", "--no-trunc")
cmd.Env = c.Config.Env.List()
buf, err := cmd.CombinedOutput()
if err != nil {
log.Warnf("docker ps ... failed: %v", err)
channel.Close()
return
}
existingContainer = strings.TrimSpace(string(buf))
}
// Opening Docker process
if existingContainer != "" {
// Attaching to an existing container
args := []string{"exec"}
if len(c.Config.DockerExecArgs) > 0 {
args = append(args, c.Config.DockerExecArgs...)
if err := c.alterArgs(args); err != nil {
log.Errorf("Failed to execute template on args: %v", err)
return
}
} else {
inlineExec, err := c.alterArg(c.Server.DockerExecArgsInline)
if err != nil {
log.Errorf("Failed to execute template on arg: %v", err)
return
}
execArgs, err := shlex.Split(inlineExec)
if err != nil {
log.Errorf("Failed to split arg %q: %v", inlineExec, err)
return
}
args = append(args, execArgs...)
}
args = append(args, existingContainer)
if entrypoint != "" {
args = append(args, entrypoint)
}
args = append(args, command...)
log.Debugf("Executing 'docker %s'", strings.Join(args, " "))
cmd = exec.Command("docker", args...)
cmd.Env = c.Config.Env.List()
} else {
// Creating and attaching to a new container
args := []string{"run"}
if len(c.Config.DockerRunArgs) > 0 {
args = append(args, c.Config.DockerRunArgs...)
if err := c.alterArgs(args); err != nil {
log.Errorf("Failed to execute template on args: %v", err)
return
}
} else {
inlineRun, err := c.alterArg(c.Server.DockerRunArgsInline)
if err != nil {
log.Errorf("Failed to execute template on arg: %v", err)
return
}
runArgs, err := shlex.Split(inlineRun)
if err != nil {
log.Errorf("Failed to split arg %q: %v", inlineRun, err)
return
}
args = append(args, runArgs...)
}
args = append(args, "--label=ssh2docker", fmt.Sprintf("--label=user=%s", c.Config.RemoteUser), fmt.Sprintf("--label=image=%s", c.Config.ImageName))
if c.Config.User != "" {
args = append(args, "-u", c.Config.User)
}
if entrypoint != "" {
args = append(args, "--entrypoint", entrypoint)
}
args = append(args, c.Config.ImageName)
args = append(args, command...)
log.Debugf("Executing 'docker %s'", strings.Join(args, " "))
cmd = exec.Command("docker", args...)
cmd.Env = c.Config.Env.List()
}
}
if c.Server.Banner != "" {
banner := c.Server.Banner
banner = strings.Replace(banner, "\r", "", -1)
banner = strings.Replace(banner, "\n", "\n\r", -1)
fmt.Fprintf(channel, "%s\n\r", banner)
}
cmd.Stdout = channel
cmd.Stdin = channel
cmd.Stderr = channel
var wg sync.WaitGroup
if c.Config.UseTTY {
cmd.Stdout = c.Tty
cmd.Stdin = c.Tty
cmd.Stderr = c.Tty
wg.Add(1)
go func() {
io.Copy(channel, c.Pty)
wg.Done()
}()
wg.Add(1)
go func() {
io.Copy(c.Pty, channel)
wg.Done()
}()
defer wg.Wait()
}
cmd.SysProcAttr = &syscall.SysProcAttr{
Setctty: c.Config.UseTTY,
Setsid: true,
}
err = cmd.Start()
if err != nil {
log.Warnf("cmd.Start failed: %v", err)
channel.Close()
return
}
if err := cmd.Wait(); err != nil {
log.Warnf("cmd.Wait failed: %v", err)
}
channel.Close()
log.Debugf("cmd.Wait done")
}
// KeyboardInteractiveCallback is called after PublicKeyCallback
func (s *Server) KeyboardInteractiveCallback(conn ssh.ConnMetadata, challenge ssh.KeyboardInteractiveChallenge) (*ssh.Permissions, error) {
username := conn.User()
clientID := conn.RemoteAddr().String()
log.Debugf("KeyboardInteractiveCallback: %q", username)
config := s.ClientConfigs[clientID]
if config == nil {
s.ClientConfigs[clientID] = &ClientConfig{
RemoteUser: username,
ImageName: username,
Keys: []string{},
AuthenticationMethod: "noauth",
AuthenticationAttempts: 0,
AuthenticationComment: "",
Env: make(envhelper.Environment, 0),
}
}
config = s.ClientConfigs[clientID]
if len(config.Keys) == 0 {
log.Warnf("No user keys, continuing with password authentication")
return nil, s.CheckConfig(config)
}
if s.PublicKeyAuthScript == "" {
log.Debugf("%d keys received, but no hook script, continuing", len(config.Keys))
return nil, s.CheckConfig(config)
}
config.AuthenticationAttempts++
log.Debugf("%d keys received, trying to authenticate using publickey hook", len(config.Keys))
var output []byte
switch {
case strings.HasPrefix(s.PublicKeyAuthScript, "http://"),
strings.HasPrefix(s.PublicKeyAuthScript, "https://"):
input := struct {
Username string `json:"username"`
Publickeys []string `json:"publickeys"`
}{
Username: username,
Publickeys: config.Keys,
}
resp, body, errs := gorequest.New().Type("json").Post(s.PublicKeyAuthScript).Send(input).End()
if len(errs) > 0 {
return nil, fmt.Errorf("gorequest errs: %v", errs)
}
if resp.StatusCode != 200 {
return nil, fmt.Errorf("invalid status code: %d", resp.StatusCode)
}
output = []byte(body)
default:
script, err := homedir.Expand(s.PublicKeyAuthScript)
if err != nil {
log.Warnf("Failed to expandUser: %v", err)
return nil, err
}
cmd := exec.Command(script, append([]string{username}, config.Keys...)...)
cmd.Env = config.Env.List()
// FIXME: redirect stderr to log
cmd.Stderr = os.Stderr
output, err = cmd.Output()
if err != nil {
log.Warnf("Failed to execute publickey-auth-script: %v", err)
return nil, err
}
}
if err := json.Unmarshal(output, &config); err != nil {
log.Warnf("Failed to unmarshal json %q: %v", string(output), err)
return nil, err
}
if err := s.CheckConfig(config); err != nil {
return nil, err
}
// success
config.AuthenticationMethod = "publickey"
return nil, nil
}
if len(args) == 0 && !followAll {
cmd.Help()
return
}
// Set up MQTT Client
setupMQTT()
// Subscribe to device topics
switch {
case followAll:
devices = []string{"+"}
log.Debug("Will subscribe to all devices")
case len(args) == 1:
devices = args
log.Debugf("Will subscribe to device %s", devices[0])
default:
devices = args
log.Debugf("Will subscribe to %d devices", len(devices))
}
// Connect
connectMQTT()
// Keep running...
for {
time.Sleep(60 * time.Second)
}
},
}