woe/server/setuptelnet.go

package server

import "gitlab.com/beoran/woe/monolog"
import t "gitlab.com/beoran/woe/telnet"
import "gitlab.com/beoran/woe/telnet"
import "strings"
import "strconv"

/* This file contains telnet setup helpers for the client. */

// generic negotiation

func (me *Client) SetupNegotiate(millis int, command byte, option byte, yes_event telnet.EventType, no_event telnet.EventType) (bool, telnet.Event) {
	me.telnet.TelnetSendNegotiate(command, option)
	tev, timeout, close := me.TryReadEvent(millis)

	if tev == nil || timeout || close {
		monolog.Info("Timeout or close in TryReadEvent")
		return false, nil
	}

	evtype := telnet.EventTypeOf(tev)

	if evtype == no_event {
		monolog.Info("Negative event no_event %v %v %v", tev, evtype, no_event)
		return false, tev
	}

	if evtype != yes_event {
		monolog.Info("Unexpected event yes_event %v %v %v", tev, evtype, yes_event)
		return false, tev
	}

	if tev == nil {
		return false, tev
	}

	return true, tev
}

// Negotiate BINARY support, for sending UTF-8. This is largely a courtesy to the cliennt,
// since woe will send UTF-8 anyway.
func (me *Client) SetupBinary() telnet.Event {
	ok, tev := me.SetupNegotiate(1000, t.TELNET_WILL, t.TELNET_TELOPT_BINARY, t.TELNET_DO_EVENT, t.TELNET_DONT_EVENT)
	if !ok {
		me.info.binary = false
		return tev
	}

	monolog.Info("Client #{@id} accepts BINARY")
	me.info.binary = true
	return tev
}

// negotiate suppress go ahead
func (me *Client) SetupSupressGA() telnet.Event {
	ok, tev := me.SetupNegotiate(1000, t.TELNET_WILL, t.TELNET_TELOPT_SGA, t.TELNET_DO_EVENT, t.TELNET_DONT_EVENT)
	if !ok {
		me.info.binary = false
		return tev
	}

	monolog.Info("Client #{@id} will suppress GA")
	me.info.sga = true
	return tev

}

// Negotiate COMPRESS2 support
func (me *Client) SetupCompress2() telnet.Event {
	ok, tev := me.SetupNegotiate(1000, t.TELNET_WILL, t.TELNET_TELOPT_COMPRESS2, t.TELNET_DO_EVENT, t.TELNET_DONT_EVENT)
	if !ok {
		return tev
	}

	me.telnet.TelnetBeginCompress2()
	monolog.Info("Client #{@id} started COMPRESS2 compression")
	me.info.compress2 = true
	return tev
}

// Negotiate NAWS (window size) support
func (me *Client) SetupNAWS() telnet.Event {
	ok, tev := me.SetupNegotiate(1000, t.TELNET_DO, t.TELNET_TELOPT_NAWS, t.TELNET_WILL_EVENT, t.TELNET_WONT_EVENT)
	if !ok {
		return tev
	}

	tev2, _, _ := me.TryReadEvent(1000)
	if (tev2 == nil) || (!telnet.IsEventType(tev2, t.TELNET_NAWS_EVENT)) {
		return tev2
	}

	nawsevent, ok := tev2.(*telnet.NAWSEvent)
	if ok {
		me.info.w = nawsevent.W
		me.info.h = nawsevent.H
		monolog.Info("Client %d window size #{%d}x#{%d}", me.id, me.info.w, me.info.h)
		me.info.naws = true
	}
	return nil
}

func (me *Client) SetupMSSP() telnet.Event {
	ok, tev := me.SetupNegotiate(1000, t.TELNET_WILL, t.TELNET_TELOPT_MSSP, t.TELNET_DO_EVENT, t.TELNET_DONT_EVENT)
	if !ok {
		return tev
	}
	me.telnet.TelnetSendMSSP(MSSP)
	monolog.Info("Client %d accepts MSSP", me.id)
	me.info.mssp = true
	return nil
}

// Check for MXP (html-like) support (but don't implement it yet)
func (me *Client) SetupMXP() telnet.Event {

	ok, tev := me.SetupNegotiate(1000, t.TELNET_DO, t.TELNET_TELOPT_MXP, t.TELNET_WILL_EVENT, t.TELNET_WONT_EVENT)
	if !ok {
		return tev
	}
	monolog.Info("Client %d accepts MXP", me.id)
	me.info.mxp = true
	return nil
}

// Check for MSP (sound) support (but don't implement it yet)
func (me *Client) SetupMSP() telnet.Event {

	ok, tev := me.SetupNegotiate(1000, t.TELNET_DO, t.TELNET_TELOPT_MSP, t.TELNET_WILL_EVENT, t.TELNET_WONT_EVENT)
	if !ok {
		return tev
	}
	monolog.Info("Client %d accepts MSP", me.id)
	me.info.msp = true
	return nil
}

// Check for MSDP (two way MSSP) support (but don't implement it yet)
func (me *Client) SetupMSDP() telnet.Event {

	ok, tev := me.SetupNegotiate(1000, t.TELNET_WILL, t.TELNET_TELOPT_MSDP, t.TELNET_DO_EVENT, t.TELNET_DONT_EVENT)
	if !ok {
		return tev
	}
	monolog.Info("Client %d accepts MSDP", me.id)
	me.info.msdp = true
	return nil
}

func (me *Client) HasTerminal(name string) bool {
	monolog.Debug("Client %d supports terminals? %s %v", me.id, name, me.info.terminals)
	for index := range me.info.terminals {
		if me.info.terminals[index] == name {
			return true
		}
	}
	return false
}

// Negotiate MTTS/TTYPE (TERMINAL TYPE) support
func (me *Client) SetupTType() telnet.Event {
	me.info.terminals = nil
	ok, tev := me.SetupNegotiate(1000, t.TELNET_DO, t.TELNET_TELOPT_TTYPE, t.TELNET_WILL_EVENT, t.TELNET_WONT_EVENT)
	if !ok {
		return tev
	}

	var last string = "none"
	var now string = ""

	for last != now {
		last = now
		me.telnet.TelnetTTypeSend()
		var tev2 telnet.Event = nil
		// Some clients (like KildClient, but not TinTin or telnet),
		// insist on spamming useless NUL characters
		// here... So we have to retry a few times to get a ttype_is
		// throwing away any undesirable junk in between.
	GET_TTYPE:
		for index := 0; index < 3; index++ {
			tev2, _, _ = me.TryReadEvent(1000)
			if tev2 != nil {
				etyp := telnet.EventTypeOf(tev2)
				monolog.Info("Waiting for TTYPE: %T %v %d", tev2, tev2, etyp)
				if telnet.IsEventType(tev2, t.TELNET_TTYPE_EVENT) {
					monolog.Info("TTYPE received: %T %v %d", tev2, tev2, etyp)
					break GET_TTYPE
				}
			} else { // and some clients don't respond, even
				monolog.Info("Waiting for TTYPE: %T", tev2)
			}
		}

		if tev2 == nil || !telnet.IsEventType(tev2, t.TELNET_TTYPE_EVENT) {
			etyp := telnet.EventTypeOf(tev2)
			monolog.Warning("Received no TTYPE: %T %v %d", tev2, tev2, etyp)
			return tev2
		}

		ttypeevent := tev2.(*telnet.TTypeEvent)
		now = ttypeevent.Name
		if !me.HasTerminal(now) {
			me.info.terminals = append(me.info.terminals, now)
		}
		me.info.terminal = now
	}

	monolog.Info("Client %d supports terminals %v", me.id, me.info.terminals)
	monolog.Info("Client %d active terminal %v", me.id, me.info.terminal)

	//  MTTS support
	for i := range me.info.terminals {
		term := me.info.terminals[i]
		monolog.Info("Checking MTTS support: %s", term)
		if strings.HasPrefix(term, "MTTS ") {
			// it's an mtts terminal
			strnum := strings.TrimPrefix(term, "MTTS ")
			num, err := strconv.Atoi(strnum)
			if err == nil {
				me.info.mtts = num
				monolog.Info("Client %d supports mtts %d", me.id, me.info.mtts)
			} else {
				monolog.Warning("Client %d could not parse mtts %s %v", me.id, strnum, err)
			}
		}
	}
	me.info.ttype = true
	return nil
}

/*
Although most clients don't do this, some clients, like tinyfuge actively initiate telnet setup.
Deal with that first, then do our own setup. It seems like tinyfuge is "waiting" for something
before performing the setup, which messes up TryReadEvent...
*/

func (me *Client) ReadTelnetSetup() {
	/* First send a NOP to prod the client into activity. This shouldn't be neccesary,
	but some clients, in particular Tinyfugue waits for server activity before it sends it's own
	telnet setup messages. If the NOP is not sent, those setup messages will then end up messing up the
	telnet setup the WOE server is trying to do. Arguably this should perhaps be an AYT, but a NOP will
	hopefully do the least damage.
	*/
	msg := []byte{telnet.TELNET_IAC, telnet.TELNET_NOP}
	me.telnet.SendRaw(msg)

	for {
		// wait for incoming events.
		event, _, _ := me.TryReadEvent(500)
		if event == nil {
			monolog.Info("Client %d no telnet setup received", me.id)
			return
		}

		monolog.Info("Client %d telnet setup received: %v", me.id, event)

		switch event := event.(type) {
		case *telnet.DataEvent:
			monolog.Info("Unexpected DATA event %T : %d.", event, len(event.Data))
			// should do something with the data, maybe?
			return
		case *telnet.NAWSEvent:
			monolog.Info("Received Telnet NAWS event %T.", event)
			me.HandleNAWSEvent(event)

		case *telnet.WillEvent:
			monolog.Info("Received Telnet WILL event %T.", event)
			// XXX do something with it!

		default:
			monolog.Info("Unexpected event in setup phase %T : %v. Ignored for now.", event, event)
		}
	}
}

func (me *Client) SetupTelnet() {
	me.ReadTelnetSetup()
	me.SetupSupressGA()
	// me.SetupBinary()
	me.SetupMSSP()
	// me.SetupCompress2
	me.SetupNAWS()
	me.SetupTType()
	me.SetupMXP()
	me.SetupMSP()
	me.SetupMSDP()
	// me.ColorTest()
}