We gonna hurt (Was: PAM breakage)

On Sat, 14 May 2005, 15:25+0800, Tai-hwa Liang wrote:

> On Sat, 14 May 2005, Daniel Eriksson wrote:
> >
> > Somewhere between 2005.05.12.19.00.00 and 2005.05.13.18.10.00 PAM (or
> > something PAM relies on) got messed up. Installing a system with the later
> > date will prevent you from logging in, both via ssh and on the console.
> > Using ssh results in the following console output:
> >
> > sshd[530]: fatal: openpty returns device for which ttyname fails.
> > sshd[530]: error: chown  0 0 failed: No such file or directory
> > sshd[530]: error: chmod  0666 failed: No such file or directory
>
>   Does backing out ttyname related changes work for you?
>
> 	http://lists.freebsd.org/pipermail/cvs-src/2005-May/046254.html

Yes, it helps me.  Xin LI, could you please take a loot at this?

For those who already broke their sshd:

o apply the patch below
o rebuild and reinstall libc
o restart sshd

Index: include/unistd.h
===================================================================
RCS file: /home/ncvs/src/include/unistd.h,v
retrieving revision 1.78
diff -u -r1.78 unistd.h
--- include/unistd.h	13 May 2005 16:27:30 -0000	1.78
+++ include/unistd.h	14 May 2005 12:26:25 -0000
_at__at_ -31,7 +31,7 _at__at_
  * SUCH DAMAGE.
  *
  *	_at_(#)unistd.h	8.12 (Berkeley) 4/27/95
- * $FreeBSD: src/include/unistd.h,v 1.78 2005/05/13 16:27:30 delphij Exp $
+ * $FreeBSD: src/include/unistd.h,v 1.77 2005/05/11 14:07:25 delphij Exp $
  */

 #ifndef _UNISTD_H_
_at__at_ -365,7 +365,7 _at__at_
 pid_t	 tcgetpgrp(int);
 int	 tcsetpgrp(int, pid_t);
 char	*ttyname(int);
-int	ttyname_r(int, char *, size_t);
+char	*ttyname_r(int, char *, size_t);
 int	 unlink(const char *);
 ssize_t	 write(int, const void *, size_t);

Index: lib/libc/gen/ttyname.3
===================================================================
RCS file: /home/ncvs/src/lib/libc/gen/ttyname.3,v
retrieving revision 1.12
diff -u -r1.12 ttyname.3
--- lib/libc/gen/ttyname.3	13 May 2005 16:27:30 -0000	1.12
+++ lib/libc/gen/ttyname.3	14 May 2005 12:26:25 -0000
_at__at_ -30,14 +30,13 _at__at_
 .\" SUCH DAMAGE.
 .\"
 .\"     _at_(#)ttyname.3	8.1 (Berkeley) 6/4/93
-.\" $FreeBSD: src/lib/libc/gen/ttyname.3,v 1.12 2005/05/13 16:27:30 delphij Exp $
+.\" $FreeBSD: src/lib/libc/gen/ttyname.3,v 1.11 2005/03/08 21:35:52 phk Exp $
 .\"
-.Dd May 14, 2005
+.Dd June 4, 1993
 .Dt TTYNAME 3
 .Os
 .Sh NAME
 .Nm ttyname ,
-.Nm ttyname_r ,
 .Nm isatty ,
 .Nm ttyslot
 .Nd get name of associated terminal (tty) from file descriptor
_at__at_ -47,7 +46,7 _at__at_
 .In unistd.h
 .Ft char *
 .Fn ttyname "int fd"
-.Ft int
+.Ft char *
 .Fn ttyname_r "int fd" "char *buf" "size_t len"
 .Ft int
 .Fn isatty "int fd"
_at__at_ -83,13 +82,7 _at__at_
 gets the related device name of
 a file descriptor for which
 .Fn isatty
-is true.
-.Pp
-.Fn ttyname
-returns the name stored in a static buffer which will be overwritten
-on subsequent calls.
-.Fn ttyname_r
-takes a buffer and length as arguments to avoid this problem.
+is true
 .Pp
 The
 .Fn ttyslot
_at__at_ -107,25 +100,12 _at__at_
 a
 .Dv NULL
 pointer is returned.
-The
-.Fn ttyname_r
-function returns 0 if successful.  Otherwise an error number is returned.
 .Pp
 The
 .Fn ttyslot
 function
 returns the unit number of the device file if found; otherwise
 the value zero is returned.
-.Sh ERRORS
-.Fn ttyname_r
-may return the following error codes:
-.Bl -tag -width Er
-.It Bq Er ENOTTY
-.Fa fd
-is not a valid file descriptor.
-.It Bq Er ERANGE
-.Fa bufsize
-is smaller than the length of the string to be returned.
 .Sh FILES
 .Bl -tag -width /etc/ttys -compact
 .It Pa /dev/\(**
_at__at_ -143,6 +123,11 _at__at_
 function
 appeared in
 .At v7 .
-.Fn ttyname_r
-appeared in
-.Fx 6.0 .
+.Sh BUGS
+The
+.Fn ttyname
+function leaves its result in an internal static object and returns
+a pointer to that object.
+Subsequent calls to
+.Fn ttyname
+will modify the same object.
Index: lib/libc/gen/ttyname.c
===================================================================
RCS file: /home/ncvs/src/lib/libc/gen/ttyname.c,v
retrieving revision 1.18
diff -u -r1.18 ttyname.c
--- lib/libc/gen/ttyname.c	13 May 2005 16:27:30 -0000	1.18
+++ lib/libc/gen/ttyname.c	14 May 2005 12:26:25 -0000
_at__at_ -35,7 +35,7 _at__at_
 static char sccsid[] = "_at_(#)ttyname.c	8.2 (Berkeley) 1/27/94";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/gen/ttyname.c,v 1.18 2005/05/13 16:27:30 delphij Exp $");
+__FBSDID("$FreeBSD: src/lib/libc/gen/ttyname.c,v 1.17 2005/03/08 21:35:52 phk Exp $");

 #include "namespace.h"
 #include <sys/types.h>
_at__at_ -50,7 +50,6 _at__at_
 #include <string.h>
 #include <paths.h>
 #include <pthread.h>
-#include <errno.h>
 #include "un-namespace.h"

 #include "libc_private.h"
_at__at_ -61,32 +60,34 _at__at_
 static pthread_key_t	ttyname_key;
 static int		ttyname_init = 0;

-int
+char *
 ttyname_r(int fd, char *buf, size_t len)
 {
 	struct stat	sb;
+	char		*rval;
 	struct fiodgname_arg fgn;

+	rval = NULL;
 	*buf = '\0';

 	/* Must be a terminal. */
 	if (!isatty(fd))
-		return (ENOTTY);
+		return (rval);
 	/* Must be a character device. */
 	if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
-		return (ENOTTY);
+		return (rval);
 	/* Must have enough room */
 	if (len <= sizeof(_PATH_DEV))
-		return (ERANGE);
+		return (rval);

 	strcpy(buf, _PATH_DEV);
 	fgn.len = len - strlen(buf);
 	fgn.buf = buf + strlen(buf);
 	if (!_ioctl(fd, FIODGNAME, &fgn))
-		return (EINVAL);
+		return(buf);
 	devname_r(sb.st_rdev, S_IFCHR,
 	    buf + strlen(buf), sizeof(buf) - strlen(buf));
-	return (0);
+	return (buf);
 }

 char *
_at__at_ -94,12 +95,8 _at__at_
 {
 	char	*buf;

-	if (__isthreaded == 0) {
-		if (ttyname_r(fd, ttyname_buf, sizeof ttyname_buf) != 0)
-			return (NULL);
-		else
-			return (ttyname_buf);
-	}
+	if (__isthreaded == 0)
+		return (ttyname_r(fd, ttyname_buf, sizeof ttyname_buf));

 	if (ttyname_init == 0) {
 		_pthread_mutex_lock(&ttyname_lock);
_at__at_ -124,7 +121,6 _at__at_
 			return (NULL);
 		}
 	}
-	ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN);
-	return (buf);
+	return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN));
 }

Index: lib/libc_r/uthread/pthread_private.h
===================================================================
RCS file: /home/ncvs/src/lib/libc_r/uthread/pthread_private.h,v
retrieving revision 1.86
diff -u -r1.86 pthread_private.h
--- lib/libc_r/uthread/pthread_private.h	13 May 2005 16:27:30 -0000	1.86
+++ lib/libc_r/uthread/pthread_private.h	14 May 2005 12:26:25 -0000
_at__at_ -31,7 +31,7 _at__at_
  *
  * Private thread definitions for the uthread kernel.
  *
- * $FreeBSD: src/lib/libc_r/uthread/pthread_private.h,v 1.86 2005/05/13 16:27:30 delphij Exp $
+ * $FreeBSD: src/lib/libc_r/uthread/pthread_private.h,v 1.85 2005/02/28 17:15:31 marcus Exp $
  */

 #ifndef _PTHREAD_PRIVATE_H
_at__at_ -1212,6 +1212,8 _at__at_
  */
 __BEGIN_DECLS
 char    *__ttyname_basic(int);
+char    *__ttyname_r_basic(int, char *, size_t);
+char    *ttyname_r(int, char *, size_t);
 void	_cond_wait_backout(pthread_t);
 void	_fd_lock_backout(pthread_t);
 int     _find_thread(pthread_t);
%%%

-- 
Maxim Konovalov