getgrouplist: If YP is #defined and enabled in /etc/group(5) and /etc/netid(5)

  contains a matching entry, use that and refrain from accessing YP.
getpwnam/getpwuid: If YP is #defined and /etc/master.passwd(5) contains
  a matching entry before the first YP entry, use that and stay away from YP.

Taken together, this allows a solution to the following problem pointed
out by deraadt@: When YP was configured but temporarily unavailable, even
root login would block, hindering you when trying to do repairs.
To avoid this, you can now provide a static entry for root in /etc/netid.

Using suggestions from miod@ otto@ blambert@ jmc@.
"commit" deraadt@, "cool" ajacoutot@, "looks fine" jmc@.

2 files changed, 16 insertions, 4 deletions

diff --git a/share/man/man5/group.5 b/share/man/man5/group.5
index b828451b74e..302b80d88ac 100644
--- a/share/man/man5/group.5
+++ b/share/man/man5/group.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: group.5,v 1.12 2008/07/28 16:27:39 deraadt Exp $
+.\"	$OpenBSD: group.5,v 1.13 2009/03/27 12:31:31 schwarze Exp $
 .\"	$NetBSD: group.5,v 1.4 1995/07/28 06:41:39 phil Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)group.5	8.3 (Berkeley) 4/19/94
 .\"
-.Dd $Mdocdate: July 28 2008 $
+.Dd $Mdocdate: March 27 2009 $
 .Dt GROUP 5
 .Os
 .Sh NAME
@@ -130,6 +130,11 @@ See
 and
 .Xr getgrouplist 3
 for details.
+.Pp
+When YP is enabled but temporarily unavailable, login becomes impossible
+for all users except those having an entry in the
+.Xr netid 5
+file.
 .Sh FILES
 .Bl -tag -width /etc/group -compact
 .It Pa /etc/group
@@ -139,6 +144,7 @@ for details.
 .Xr setgroups 2 ,
 .Xr crypt 3 ,
 .Xr initgroups 3 ,
+.Xr netid 5 ,
 .Xr passwd 5 ,
 .Xr yp 8
 .Sh HISTORY
diff --git a/share/man/man5/passwd.5 b/share/man/man5/passwd.5
index 21b45e1ad33..d9faf023476 100644
--- a/share/man/man5/passwd.5
+++ b/share/man/man5/passwd.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: passwd.5,v 1.34 2008/10/22 20:31:20 jmc Exp $
+.\"	$OpenBSD: passwd.5,v 1.35 2009/03/27 12:31:31 schwarze Exp $
 .\"	$NetBSD: passwd.5,v 1.4 1995/07/28 06:46:05 phil Exp $
 .\"
 .\" Copyright (c) 1988, 1991, 1993
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)passwd.5	8.1 (Berkeley) 6/5/93
 .\"
-.Dd $Mdocdate: October 22 2008 $
+.Dd $Mdocdate: March 27 2009 $
 .Dt PASSWD 5
 .Os
 .Sh NAME
@@ -278,6 +278,11 @@ will result in
 containing:
 .Pp
 +:*:0:0:::
+.Pp
+When YP is enabled but temporarily unavailable, login becomes impossible
+for all users except those having an entry in the
+.Xr netid 5
+file.
 .Sh SEE ALSO
 .Xr chpass 1 ,
 .Xr login 1 ,
@@ -286,6 +291,7 @@ containing:
 .Xr getpwent 3 ,
 .Xr login.conf 5 ,
 .Xr netgroup 5 ,
+.Xr netid 5 ,
 .Xr adduser 8 ,
 .Xr Makefile.yp 8 ,
 .Xr pwd_mkdb 8 ,