Occasionally I sent this in private, although I wanted to send it to the
psst list, so here it is.
----- Forwarded message from Balazs Scheidler <[EMAIL PROTECTED]> -----
Date: Wed, 5 Jan 2000 13:03:37 +0100
From: Balazs Scheidler <[EMAIL PROTECTED]>
To: "Eric J. Schwertfeger" <[EMAIL PROTECTED]>
Subject: Re: lsh-0.1.20 startup sequence
> > It seems the client requested a pty, and crashed when it couldn't get
> > one. In this case, it is supposed to just go on, but not bother trying
> > to do things like setting the tty into raw mode.
>
> When I edited config.h to fix PTY_BSD_SCHEME_FIRST_CHARS and
> PTY_BSD_SCHEME_SECOND_CHARS by hand, it worked. So the previously
> mentioned problems are all that have to be overcome before FreeBSD has an
> unencumbered encrypted login method :-) (I know, I've seen the warnings,
> but lsh can't be worse than telnet throwing unencrypted passwords around,
> as long as there's no buffer overflows or other serious problems of that
> nature).
I've checked out FreeBSD, and as it seems this is a bug in its default
/bin/sh. Running configure with bash fixes the problem, or alternatively you
can apply this patch, and rerun autoconf.
--- configure.in~ Fri Dec 31 01:17:45 1999
+++ configure.in Wed Jan 5 12:50:24 2000
@@ -544,8 +544,10 @@
AC_MSG_CHECKING(for BSD pty names)
dnl FIXME: What is most portable, tr -d '\n' or tr -d '\012' ?
-AC_DEFINE_UNQUOTED(PTY_BSD_SCHEME_FIRST_CHARS, "`ls /dev/pty* | cut -c 9-9 | uniq |
tr -d '\n'`")
-AC_DEFINE_UNQUOTED(PTY_BSD_SCHEME_SECOND_CHARS, "`ls /dev/pty* | cut -c 10-10 | sort
| uniq | tr -d '\n'`")
+first=`ls /dev/pty* | cut -c 9-9 | uniq | tr -d '\n'`
+second=`ls /dev/pty* | cut -c 10-10 | sort | uniq | tr -d '\n'`
+AC_DEFINE_UNQUOTED(PTY_BSD_SCHEME_FIRST_CHARS, "$first")
+AC_DEFINE_UNQUOTED(PTY_BSD_SCHEME_SECOND_CHARS, "$second")
dnl FIXME: How can we test if the bsd scheme is likely to work?
AC_DEFINE(PTY_BSD_SCHEME)
>
> I'll look into POLLIN vs POLLRDNORM.
As it seems under Linux, POLLIN roughly equals to POLLRDNORM, checking out
man pages under Solaris:
POLLIN Data other than high priority data may
be read without blocking. For STREAMS,
this flag is set in revents even if the
message is of zero length.
POLLRDNORM Normal data (priority band equals 0) may
be read without blocking. For STREAMS,
this flag is set in revents even if the
message is of zero length.
POLLRDBAND Data from a non-zero priority band may
be read without blocking. For STREAMS,
this flag is set in revents even if the
message is of zero length.
POLLPRI High priority data may be received
without blocking. For STREAMS, this
flag is set in revents even if the
message is of zero length.
POLLOUT Normal data (priority band equals 0) may
be written without blocking.
POLLWRNORM The same as POLLOUT.
POLLWRBAND Priority data (priority band > 0) may be
written. This event only examines bands
that have been written to at least once.
POLLERR An error has occurred on the device or
stream. This flag is only valid in the
revents bitmask; it is not used in the
events member.
POLLHUP A hangup has occurred on the stream.
This event and POLLOUT are mutually
exclusive; a stream can never be writ-
able if a hangup has occurred. However,
this event and POLLIN, POLLRDNORM,
POLLRDBAND, or POLLPRI are not mutually
exclusive. This flag is only valid in
the revents bitmask; it is not used in
the events member.
POLLNVAL The specified fd value does not belong
to an open file. This flag is only
valid in the revents member; it is not
used in the events member.
I think the best solution would be to set both POLLIN and POLLRDNORM when
trying to read, and also accept any of those received events.
> The PTY_BSD_SCHEME_FIRST_CHARS can be fixed either by figuring out what
> the problem is in the configure script, or by making openpty work, and
> tweaking things so that it uses openpty before the traditional method that
> uses PTY_BSD_SCHEME_(FIRST|SECOND)_CHARS.
This was the intended behaviour, however as it seems openpty() support is
currently broken.
--
Bazsi
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url: http://www.balabit.hu/pgpkey.txt
----- End forwarded message -----
--
Bazsi
PGP info: KeyID 9AF8D0A9 Fingerprint CD27 CFB0 802C 0944 9CFD 804E C82C 8EB1
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