telnet and OOB data

[Charles Hannum]

In article <21071.Jun3021.48.4291 at kramden.acf.nyu.edu> brnstnd at kramden.acf.nyu.edu (Dan Bernstein) writes:

> telnet implements the TELNET protocol. If you want to talk to telnet,
> you have to speak TELNET too. Anything else is an invitation to
> disaster. Can you guarantee that telnet won't receive keyboard signals?
> Do you know what you have to do with an \0xff over a TELNET connection?
>
> The echo you're seeing is the normal echo from your tty. You can turn
> that off with stty, ioctl(), or from the telnet command line, but unless
> your server groks TELNET you should expect a continuing series of
> interoperability problems.

Good so far.  RFCs 854 and 856 (which I mentioned in my *last* article
about two minutes ago) would come in handy here.

> For a straight TCP connector without any weird protocols in the middle,
> you can use tcpclient and tcpserver in my clientserver package, just
> posted to alt.sources. One advantage of this is that you'll be able to
> use exactly the same code on top of undomclient and undomserver, or
> npipeclient and npipeserver for System V, or the forthcoming krb5client
> and krb5server, or any other set written to the same interface. In any
> case, you can set up a server like this:

(More product announcement than information...)

Not so good.  Some times we need to stop pushing our product, step
back, and take a good look at the situation.

My impression was that he wants J. Random Luser to be able to connect
via telnet, not some random client that they have to compile
themselves.  To do this, his only option is to teach his server
telnet, a very messy and unpleasant business, but one that more people
should start thinking about.