ssh-chat/client.go

512 lines
13 KiB
Go

package main
import (
"fmt"
"strings"
"sync"
"time"
"golang.org/x/crypto/ssh"
"golang.org/x/crypto/ssh/terminal"
)
const (
// MsgBuffer is the length of the message buffer
MsgBuffer int = 50
// MaxMsgLength is the maximum length of a message
MaxMsgLength int = 1024
// HelpText is the text returned by /help
HelpText string = `Available commands:
/about - About this chat.
/exit - Exit the chat.
/help - Show this help text.
/list - List the users that are currently connected.
/beep - Enable BEL notifications on mention.
/me $ACTION - Show yourself doing an action.
/nick $NAME - Rename yourself to a new name.
/whois $NAME - Display information about another connected user.
/msg $NAME $MESSAGE - Sends a private message to a user.
/motd - Prints the Message of the Day.
/theme [color|mono] - Set client theme.`
// OpHelpText is the additional text returned by /help if the client is an Op
OpHelpText string = `Available operator commands:
/ban $NAME - Banish a user from the chat
/kick $NAME - Kick em' out.
/op $NAME - Promote a user to server operator.
/silence $NAME - Revoke a user's ability to speak.
/shutdown $MESSAGE - Broadcast message and shutdown server.
/motd $MESSAGE - Set message shown whenever somebody joins.
/whitelist $FINGERPRINT - Add fingerprint to whitelist, prevent anyone else from joining.
/whitelist github.com/$USER - Add github user's pubkeys to whitelist.`
// AboutText is the text returned by /about
AboutText string = `ssh-chat is made by @shazow.
It is a custom ssh server built in Go to serve a chat experience
instead of a shell.
Source: https://github.com/shazow/ssh-chat
For more, visit shazow.net or follow at twitter.com/shazow`
// RequiredWait is the time a client is required to wait between messages
RequiredWait time.Duration = time.Second / 2
)
// Client holds all the fields used by the client
type Client struct {
Server *Server
Conn *ssh.ServerConn
Msg chan string
Name string
Color string
Op bool
ready chan struct{}
term *terminal.Terminal
termWidth int
termHeight int
silencedUntil time.Time
lastTX time.Time
beepMe bool
colorMe bool
closed bool
sync.RWMutex
}
// NewClient constructs a new client
func NewClient(server *Server, conn *ssh.ServerConn) *Client {
return &Client{
Server: server,
Conn: conn,
Name: conn.User(),
Color: RandomColor256(),
Msg: make(chan string, MsgBuffer),
ready: make(chan struct{}, 1),
lastTX: time.Now(),
colorMe: true,
}
}
// ColoredName returns the client name in its color
func (c *Client) ColoredName() string {
return ColorString(c.Color, c.Name)
}
// SysMsg sends a message in continuous format over the message channel
func (c *Client) SysMsg(msg string, args ...interface{}) {
c.Send(ContinuousFormat(systemMessageFormat, "-> "+fmt.Sprintf(msg, args...)))
}
// Write writes the given message
func (c *Client) Write(msg string) {
if !c.colorMe {
msg = DeColorString(msg)
}
c.term.Write([]byte(msg + "\r\n"))
}
// WriteLines writes multiple messages
func (c *Client) WriteLines(msg []string) {
for _, line := range msg {
c.Write(line)
}
}
// Send sends the given message
func (c *Client) Send(msg string) {
if len(msg) > MaxMsgLength || c.closed {
return
}
select {
case c.Msg <- msg:
default:
logger.Errorf("Msg buffer full, dropping: %s (%s)", c.Name, c.Conn.RemoteAddr())
c.Conn.Close()
}
}
// SendLines sends multiple messages
func (c *Client) SendLines(msg []string) {
for _, line := range msg {
c.Send(line)
}
}
// IsSilenced checks if the client is silenced
func (c *Client) IsSilenced() bool {
return c.silencedUntil.After(time.Now())
}
// Silence silences a client for the given duration
func (c *Client) Silence(d time.Duration) {
c.silencedUntil = time.Now().Add(d)
}
// Resize resizes the client to the given width and height
func (c *Client) Resize(width, height int) error {
width = 1000000 // TODO: Remove this dirty workaround for text overflow once ssh/terminal is fixed
err := c.term.SetSize(width, height)
if err != nil {
logger.Errorf("Resize failed: %dx%d", width, height)
return err
}
c.termWidth, c.termHeight = width, height
return nil
}
// Rename renames the client to the given name
func (c *Client) Rename(name string) {
c.Name = name
var prompt string
if c.colorMe {
prompt = c.ColoredName()
} else {
prompt = c.Name
}
c.term.SetPrompt(fmt.Sprintf("[%s] ", prompt))
}
// Fingerprint returns the fingerprint
func (c *Client) Fingerprint() string {
if c.Conn.Permissions == nil {
return ""
}
return c.Conn.Permissions.Extensions["fingerprint"]
}
// Emote formats and sends an emote
func (c *Client) Emote(message string) {
formatted := fmt.Sprintf("** %s%s", c.ColoredName(), message)
if c.IsSilenced() || len(message) > 1000 {
c.SysMsg("Message rejected")
}
c.Server.Broadcast(formatted, nil)
}
func (c *Client) handleShell(channel ssh.Channel) {
defer channel.Close()
defer c.Conn.Close()
// FIXME: This shouldn't live here, need to restructure the call chaining.
c.Server.Add(c)
go func() {
// Block until done, then remove.
c.Conn.Wait()
c.closed = true
c.Server.Remove(c)
close(c.Msg)
}()
go func() {
for msg := range c.Msg {
c.Write(msg)
}
}()
for {
line, err := c.term.ReadLine()
if err != nil {
break
}
parts := strings.SplitN(line, " ", 3)
isCmd := strings.HasPrefix(parts[0], "/")
if isCmd {
// TODO: Factor this out.
switch parts[0] {
case "/test-colors": // Shh, this command is a secret!
c.Write(ColorString("32", "Lorem ipsum dolor sit amet,"))
c.Write("consectetur " + ColorString("31;1", "adipiscing") + " elit.")
case "/exit":
channel.Close()
case "/help":
c.SysMsg(strings.Replace(HelpText, "\n", "\r\n", -1))
if c.Server.IsOp(c) {
c.SysMsg(strings.Replace(OpHelpText, "\n", "\r\n", -1))
}
case "/about":
c.SysMsg(strings.Replace(AboutText, "\n", "\r\n", -1))
case "/uptime":
c.SysMsg(c.Server.Uptime())
case "/beep":
c.beepMe = !c.beepMe
if c.beepMe {
c.SysMsg("I'll beep you good.")
} else {
c.SysMsg("No more beeps. :(")
}
case "/me":
me := strings.TrimLeft(line, "/me")
if me == "" {
me = " is at a loss for words."
}
c.Emote(me)
case "/slap":
slappee := "themself"
if len(parts) > 1 {
slappee = parts[1]
if len(parts[1]) > 100 {
slappee = "some long-named jerk"
}
}
c.Emote(fmt.Sprintf(" slaps %s around a bit with a large trout.", slappee))
case "/nick":
if len(parts) == 2 {
c.Server.Rename(c, parts[1])
} else {
c.SysMsg("Missing $NAME from: /nick $NAME")
}
case "/whois":
if len(parts) >= 2 {
client := c.Server.Who(parts[1])
if client != nil {
version := reStripText.ReplaceAllString(string(client.Conn.ClientVersion()), "")
if len(version) > 100 {
version = "Evil Jerk with a superlong string"
}
c.SysMsg("%s is %s via %s", client.ColoredName(), client.Fingerprint(), version)
} else {
c.SysMsg("No such name: %s", parts[1])
}
} else {
c.SysMsg("Missing $NAME from: /whois $NAME")
}
case "/names", "/list":
names := ""
nameList := c.Server.List(nil)
for _, name := range nameList {
names += c.Server.Who(name).ColoredName() + systemMessageFormat + ", "
}
if len(names) > 2 {
names = names[:len(names)-2]
}
c.SysMsg("%d connected: %s", len(nameList), names)
case "/ban":
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else if len(parts) != 2 {
c.SysMsg("Missing $NAME from: /ban $NAME")
} else {
client := c.Server.Who(parts[1])
if client == nil {
c.SysMsg("No such name: %s", parts[1])
} else {
fingerprint := client.Fingerprint()
client.SysMsg("Banned by %s.", c.ColoredName())
c.Server.Ban(fingerprint, nil)
client.Conn.Close()
c.Server.Broadcast(fmt.Sprintf("* %s was banned by %s", parts[1], c.ColoredName()), nil)
}
}
case "/op":
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else if len(parts) != 2 {
c.SysMsg("Missing $NAME from: /op $NAME")
} else {
client := c.Server.Who(parts[1])
if client == nil {
c.SysMsg("No such name: %s", parts[1])
} else {
fingerprint := client.Fingerprint()
client.SysMsg("Made op by %s.", c.ColoredName())
c.Server.Op(fingerprint)
}
}
case "/kick":
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else if len(parts) != 2 {
c.SysMsg("Missing $NAME from: /kick $NAME")
} else {
client := c.Server.Who(parts[1])
if client == nil {
c.SysMsg("No such name: %s", parts[1])
} else {
client.SysMsg("Kicked by %s.", c.ColoredName())
client.Conn.Close()
c.Server.Broadcast(fmt.Sprintf("* %s was kicked by %s", parts[1], c.ColoredName()), nil)
}
}
case "/silence":
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else if len(parts) < 2 {
c.SysMsg("Missing $NAME from: /silence $NAME")
} else {
duration := time.Duration(5) * time.Minute
if len(parts) >= 3 {
parsedDuration, err := time.ParseDuration(parts[2])
if err == nil {
duration = parsedDuration
}
}
client := c.Server.Who(parts[1])
if client == nil {
c.SysMsg("No such name: %s", parts[1])
} else {
client.Silence(duration)
client.SysMsg("Silenced for %s by %s.", duration, c.ColoredName())
}
}
case "/shutdown":
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else {
var split = strings.SplitN(line, " ", 2)
var msg string
if len(split) > 1 {
msg = split[1]
} else {
msg = ""
}
// Shutdown after 5 seconds
go func() {
c.Server.Broadcast(ColorString("31", msg), nil)
time.Sleep(time.Second * 5)
c.Server.Stop()
}()
}
case "/msg": /* Send a PM */
/* Make sure we have a recipient and a message */
if len(parts) < 2 {
c.SysMsg("Missing $NAME from: /msg $NAME $MESSAGE")
break
} else if len(parts) < 3 {
c.SysMsg("Missing $MESSAGE from: /msg $NAME $MESSAGE")
break
}
/* Ask the server to send the message */
if err := c.Server.Privmsg(parts[1], parts[2], c); nil != err {
c.SysMsg("Unable to send message to %v: %v", parts[1], err)
}
case "/motd": /* print motd */
if !c.Server.IsOp(c) {
c.Server.MotdUnicast(c)
} else if len(parts) < 2 {
c.Server.MotdUnicast(c)
} else {
var newmotd string
if len(parts) == 2 {
newmotd = parts[1]
} else {
newmotd = parts[1] + " " + parts[2]
}
c.Server.SetMotd(newmotd)
c.Server.MotdBroadcast(c)
}
case "/theme":
if len(parts) < 2 {
c.SysMsg("Missing $THEME from: /theme $THEME")
c.SysMsg("Choose either color or mono")
} else {
// Sets colorMe attribute of client
if parts[1] == "mono" {
c.colorMe = false
} else if parts[1] == "color" {
c.colorMe = true
}
// Rename to reset prompt
c.Rename(c.Name)
}
case "/whitelist": /* whitelist a fingerprint */
if !c.Server.IsOp(c) {
c.SysMsg("You're not an admin.")
} else if len(parts) != 2 {
c.SysMsg("Missing $FINGERPRINT from: /whitelist $FINGERPRINT")
} else {
fingerprint := parts[1]
go func() {
err = c.Server.Whitelist(fingerprint)
if err != nil {
c.SysMsg("Error adding to whitelist: %s", err)
} else {
c.SysMsg("Added %s to the whitelist", fingerprint)
}
}()
}
case "/version":
c.SysMsg("Version " + buildCommit)
default:
c.SysMsg("Invalid command: %s", line)
}
continue
}
msg := fmt.Sprintf("%s: %s", c.ColoredName(), line)
/* Rate limit */
if time.Now().Sub(c.lastTX) < RequiredWait {
c.SysMsg("Rate limiting in effect.")
continue
}
if c.IsSilenced() || len(msg) > 1000 || len(line) < 1 {
c.SysMsg("Message rejected.")
continue
}
c.Server.Broadcast(msg, c)
c.lastTX = time.Now()
}
}
func (c *Client) handleChannels(channels <-chan ssh.NewChannel) {
prompt := fmt.Sprintf("[%s] ", c.ColoredName())
hasShell := false
for ch := range channels {
if t := ch.ChannelType(); t != "session" {
ch.Reject(ssh.UnknownChannelType, fmt.Sprintf("unknown channel type: %s", t))
continue
}
channel, requests, err := ch.Accept()
if err != nil {
logger.Errorf("Could not accept channel: %v", err)
continue
}
defer channel.Close()
c.term = terminal.NewTerminal(channel, prompt)
c.term.AutoCompleteCallback = c.Server.AutoCompleteFunction
for req := range requests {
var width, height int
var ok bool
switch req.Type {
case "shell":
if c.term != nil && !hasShell {
go c.handleShell(channel)
ok = true
hasShell = true
}
case "pty-req":
width, height, ok = parsePtyRequest(req.Payload)
if ok {
err := c.Resize(width, height)
ok = err == nil
}
case "window-change":
width, height, ok = parseWinchRequest(req.Payload)
if ok {
err := c.Resize(width, height)
ok = err == nil
}
}
if req.WantReply {
req.Reply(ok, nil)
}
}
}
}