Date: Tue, 22 Jan 2002 15:30:04 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: Lajos Zaccomer <Lajos.Zaccomer@eth.ericsson.se> Cc: freebsd-hackers@FreeBSD.org Subject: Re: Telnet option negotiation Message-ID: <3C4DF5FC.211B3B3E@mindspring.com> References: <200201221416.PAA18961@lt.eth.ericsson.se>
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Lajos Zaccomer wrote: > Thanx for the impressive welcome, Terry. Yes, I might be wrong; > however, in this case, please interpret the following quotation > from RFC854, page 4: [ ... ] > Might be you who don't understand? If I was wrong, how is that > all other platforms supported the way I used, except FreeBSD? > Fuzzy, isn't it? > > So, the question is still not answered. I have the advantage on you, having written my first telnet protocol based modem pool server and client in 1986, and ported it to around 60 different UNIX platforms. You will find that your code also does not work against NeXTStep, Ultrix 4.2, and SunOS 4.0.2 through SunOS 4.1.3u2. I rather suspect you will also find (if you can find one), that it won't work against an NCR Tower XP, and NCR Tower 32, a Heurikon, a Sanyo ICON (old one, not new one), SCO Xenix with Lachman TCP/IP, and the Ungerman Bass TCP/IP, as well as the NRC Fusion TCP/IP on DOS and VMS. 8-). The problem is that the order of negotiation is used as a hint by the operating system to know whether out of band data is handled correctly or not, and the server behaves differently. Any server software that can interoperate correctly with older versions of telnet clients running over version of TCP/IP that got the OOB data header length reporting wrong will not work with your client. You don't have problems with the servers you can talk to because they are non-interoperable with older implementations. Since the telnet code itself is extremely complicated and hard to easily cut down or implement from scratch, the best place to look is the FTP client code, since it uses telnet protocol over the command channel. You may also want to look at some of the Kermit network driver source code for the terminal client, which should be available for download from Columbia University. PS: Your clock on your mail client machine is way off. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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