Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 02:59:54PM -0800, Nathan Kinkade wrote: > On Thu, Feb 06, 2003 at 10:34:53PM +, Matthew Seaman wrote: > > On Thu, Feb 06, 2003 at 01:55:12PM -0800, Nathan Kinkade wrote: > > > On Thu, Feb 06, 2003 at 07:47:16PM +, Matthew Seaman wrote: > > > > > > Interesting. The source code seems pretty clear in that it only looks > > > > at the 'im' property: > > > > > > Looks like it's time to send-pr. > > > > > Thanks Matthew. I did a bit of searching and couldn't find this problem > > > mentioned anywhere else. I have submitted a PR with id "docs/48018". > > > > Ah. Beat me to it. I'm just working up a patch to telnetd to make it > > work the way the manual says. Just testing now before I submit it. > > > > Oh no, I didn't submit a patch! I just pointed to issue out, suggesting > that someone may like to remove the incorrect text from the telnetd(8) > manpage, or possibly update the telnetd sources to match the manpage. > By all means, please do submit a patch! I do a good bit of work with > PHP, but I've never programmed with C, so I didn't even think about > trying to patch. Thanks for all of your help on this issue. This was > the first PR that I have ever submitted, maybe I shouldn't have > submitted the PR at all if I didn't have the capability to fix the > problem. Is there any way that you can send in a patch relating to the > PR that I already submitted. Hmmm... Having spent some time looking at this over the weekend, I've come to the conclusion that adding support for having telnetd display the /etc/issue file before prompting for a login is impractical when combined with the SRA encryption used in FreeBSDs standard telnet setup. It's certainly beyond my extremely rusty C programming skills. Furthermore, the display of the IM gettytab property is somewhat dubious as well: Consider this entry in the standard /etc/gettytab: default:\ :cb:ce:ck:lc:fd#1000:im=\r\n%s/%m (%h) (%t)\r\n\r\n:sp#1200:\ ^^ :if=/etc/issue: which means you should see a banner like: FreeBSD/i386 (hostname.example.com) (ttyp0) when you attempt to log in either via telnet or on the console. However, it's conspicuously absent *before* the login prompt in a FreeBSD to FreeBSD telnet sesssion: % telnet localhost Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Trying SRA secure login: User (matthew): Password: [ SRA accepts you ] FreeBSD/i386 (happy-idiot-talk.infracaninophi) (ttyp4) Those 'User' and 'Password' prompts originate from the client machine, and occur as a necessary pre-requisite before the encrypted channel between the client and server can be set up. So you've got to log in before you can see any pre-login messages. I'm not sure what would appear given an older telnet client that doesn't support encryption, not having any older telnet clients around to test with. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message
Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 10:34:53PM +, Matthew Seaman wrote: > On Thu, Feb 06, 2003 at 01:55:12PM -0800, Nathan Kinkade wrote: > > On Thu, Feb 06, 2003 at 07:47:16PM +, Matthew Seaman wrote: > > > > Interesting. The source code seems pretty clear in that it only looks > > > at the 'im' property: > > > > Looks like it's time to send-pr. > > > Thanks Matthew. I did a bit of searching and couldn't find this problem > > mentioned anywhere else. I have submitted a PR with id "docs/48018". > > Ah. Beat me to it. I'm just working up a patch to telnetd to make it > work the way the manual says. Just testing now before I submit it. > > Cheers, > > Matthew Oh no, I didn't submit a patch! I just pointed to issue out, suggesting that someone may like to remove the incorrect text from the telnetd(8) manpage, or possibly update the telnetd sources to match the manpage. By all means, please do submit a patch! I do a good bit of work with PHP, but I've never programmed with C, so I didn't even think about trying to patch. Thanks for all of your help on this issue. This was the first PR that I have ever submitted, maybe I shouldn't have submitted the PR at all if I didn't have the capability to fix the problem. Is there any way that you can send in a patch relating to the PR that I already submitted. Thanks, Nathan -- GPG Public Key ID: 0x4250A04C gpg --keyserver pgp.mit.edu --recv-keys 4250A04C http://63.105.21.156/gpg_nkinkade_4250A04C.asc msg18319/pgp0.pgp Description: PGP signature
Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 01:55:12PM -0800, Nathan Kinkade wrote: > On Thu, Feb 06, 2003 at 07:47:16PM +, Matthew Seaman wrote: > > Interesting. The source code seems pretty clear in that it only looks > > at the 'im' property: > > Looks like it's time to send-pr. > Thanks Matthew. I did a bit of searching and couldn't find this problem > mentioned anywhere else. I have submitted a PR with id "docs/48018". Ah. Beat me to it. I'm just working up a patch to telnetd to make it work the way the manual says. Just testing now before I submit it. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message
Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 07:47:16PM +, Matthew Seaman wrote:
> On Thu, Feb 06, 2003 at 11:23:21AM -0800, Nathan Kinkade wrote:
> > I guess I wasn't paying close enough attention to the original posters
> > question. I somehow missed the "pre". In any case, all this has
> > prompted me to play around with pre-login messages. Using gettytab I
> > can alter the pre-login message for telnet sessions by changing the 'im'
> > capability in gettytab, but for the life of me I can't seem to get
> > telnetd to recognize the 'if' capability. The console responds to both,
> > but telnetd seems to ignore 'if'. The perms on /etc/issue are 644. I
> > don't run inetd, but just for experiment I uncommented telnetd and
> > launched and inetd for testing. Can anyone explain why telnetd might
> > ignore the 'if' capability specified in the 'default' heading of
> > gettytab? The telnetd man page clearly states that if 'if' is present
> > it will override 'im'.
>
> Interesting. The source code seems pretty clear in that it only looks
> at the 'im' property:
>
> .../src/libexec/telnetd/telnetd.c at about line 770
>
> /*
> * Show banner that getty never gave.
> *
> * We put the banner in the pty input buffer. This way, it
> * gets carriage return null processing, etc., just like all
> * other pty --> client data.
> */
>
> if (getent(defent, "default") == 1) {
> char *cp=defstrs;
>
> HE = Getstr("he", &cp);
> HN = Getstr("hn", &cp);
> IM = Getstr("im", &cp);
> if (HN && *HN)
> (void) strlcpy(host_name, HN, sizeof(host_name));
> if (IM == 0)
> IM = strdup("");
> } else {
> IM = strdup(DEFAULT_IM);
> HE = 0;
> }
>
> Looks like it's time to send-pr.
>
> Cheers,
>
> Matthew
Thanks Matthew. I did a bit of searching and couldn't find this problem
mentioned anywhere else. I have submitted a PR with id "docs/48018".
Nathan
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Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 11:23:21AM -0800, Nathan Kinkade wrote:
> I guess I wasn't paying close enough attention to the original posters
> question. I somehow missed the "pre". In any case, all this has
> prompted me to play around with pre-login messages. Using gettytab I
> can alter the pre-login message for telnet sessions by changing the 'im'
> capability in gettytab, but for the life of me I can't seem to get
> telnetd to recognize the 'if' capability. The console responds to both,
> but telnetd seems to ignore 'if'. The perms on /etc/issue are 644. I
> don't run inetd, but just for experiment I uncommented telnetd and
> launched and inetd for testing. Can anyone explain why telnetd might
> ignore the 'if' capability specified in the 'default' heading of
> gettytab? The telnetd man page clearly states that if 'if' is present
> it will override 'im'.
Interesting. The source code seems pretty clear in that it only looks
at the 'im' property:
.../src/libexec/telnetd/telnetd.c at about line 770
/*
* Show banner that getty never gave.
*
* We put the banner in the pty input buffer. This way, it
* gets carriage return null processing, etc., just like all
* other pty --> client data.
*/
if (getent(defent, "default") == 1) {
char *cp=defstrs;
HE = Getstr("he", &cp);
HN = Getstr("hn", &cp);
IM = Getstr("im", &cp);
if (HN && *HN)
(void) strlcpy(host_name, HN, sizeof(host_name));
if (IM == 0)
IM = strdup("");
} else {
IM = strdup(DEFAULT_IM);
HE = 0;
}
Looks like it's time to send-pr.
Cheers,
Matthew
--
Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks
Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey Marlow
Tel: +44 1628 476614 Bucks., SL7 1TH UK
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-questions" in the body of the message
Re: How to change Telnet Prelogin message?
On Thu, Feb 06, 2003 at 09:27:21AM +, Matthew Seaman wrote: > On Wed, Feb 05, 2003 at 08:45:12PM -0800, Nathan Kinkade wrote: > > On Wed, Feb 05, 2003 at 11:17:30PM -0500, Michael wrote: > > > Hey friends, > > > I got a BBS up as you may know from my previous post, and i need to allow > > > telnet access. I want a pre login message telling users to please only use > > > telnet for BBS and to use SSH2 for shell access. FreeBSDdiary.org is down, > > > and FreeBSD cheat sheets example has a much older GETTYTAB. Im almost > > > positive you guys can have me hacking this in moments. Pour some knowledge > > > on me. Thanks. > > > > motd(5) > > Close, but motd is definitely post login. /etc/issue can be used to > display a message on the console before the login prompt. All you > need do is write some content into the file. This file should work > using the standard gettytab(5) file under FreeBSD with both getty(8) > and telnetd(8), although I haven't tried using it with telnet recently > myself. You want to look for use of the 'if' or the 'im' properties > in gettytab(5). > > The equivalent for sshd(8) is to set the Banner property in > /etc/ssh/sshd_config, although this only works if you use the SSH2 > protocol. > > Cheers, > > Matthew I guess I wasn't paying close enough attention to the original posters question. I somehow missed the "pre". In any case, all this has prompted me to play around with pre-login messages. Using gettytab I can alter the pre-login message for telnet sessions by changing the 'im' capability in gettytab, but for the life of me I can't seem to get telnetd to recognize the 'if' capability. The console responds to both, but telnetd seems to ignore 'if'. The perms on /etc/issue are 644. I don't run inetd, but just for experiment I uncommented telnetd and launched and inetd for testing. Can anyone explain why telnetd might ignore the 'if' capability specified in the 'default' heading of gettytab? The telnetd man page clearly states that if 'if' is present it will override 'im'. Thanks, Nathan -- GPG Public Key ID: 0x4250A04C gpg --keyserver pgp.mit.edu --recv-keys 4250A04C http://63.105.21.156/gpg_nkinkade_4250A04C.asc msg18282/pgp0.pgp Description: PGP signature
Re: How to change Telnet Prelogin message?
On Wed, Feb 05, 2003 at 08:45:12PM -0800, Nathan Kinkade wrote: > On Wed, Feb 05, 2003 at 11:17:30PM -0500, Michael wrote: > > Hey friends, > > I got a BBS up as you may know from my previous post, and i need to allow > > telnet access. I want a pre login message telling users to please only use > > telnet for BBS and to use SSH2 for shell access. FreeBSDdiary.org is down, > > and FreeBSD cheat sheets example has a much older GETTYTAB. Im almost > > positive you guys can have me hacking this in moments. Pour some knowledge > > on me. Thanks. > > motd(5) Close, but motd is definitely post login. /etc/issue can be used to display a message on the console before the login prompt. All you need do is write some content into the file. This file should work using the standard gettytab(5) file under FreeBSD with both getty(8) and telnetd(8), although I haven't tried using it with telnet recently myself. You want to look for use of the 'if' or the 'im' properties in gettytab(5). The equivalent for sshd(8) is to set the Banner property in /etc/ssh/sshd_config, although this only works if you use the SSH2 protocol. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message
Re: How to change Telnet Prelogin message?
On Wed, Feb 05, 2003 at 11:17:30PM -0500, Michael wrote: > Hey friends, > I got a BBS up as you may know from my previous post, and i need to allow > telnet access. I want a pre login message telling users to please only use > telnet for BBS and to use SSH2 for shell access. FreeBSDdiary.org is down, > and FreeBSD cheat sheets example has a much older GETTYTAB. Im almost > positive you guys can have me hacking this in moments. Pour some knowledge > on me. Thanks. motd(5) Nathan -- GPG Public Key ID: 0x4250A04C gpg --keyserver pgp.mit.edu --recv-keys 4250A04C http://63.105.21.156/gpg_nkinkade_4250A04C.asc msg18198/pgp0.pgp Description: PGP signature
How to change Telnet Prelogin message?
Hey friends, I got a BBS up as you may know from my previous post, and i need to allow telnet access. I want a pre login message telling users to please only use telnet for BBS and to use SSH2 for shell access. FreeBSDdiary.org is down, and FreeBSD cheat sheets example has a much older GETTYTAB. Im almost positive you guys can have me hacking this in moments. Pour some knowledge on me. Thanks. -- Independent WWW/FreeBSD/Linux/Unix consultant, email me for more information. Founder/WebMaster/ The unixhideout network http://www.unixhideout.com [EMAIL PROTECTED] - Free, secure and stable email from UnixHideout "The UnixHideout network" http://www.unixhideout.com/ To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message
