Merge in changes to support the new rpc.yppasswdd(8) and fix a few bugs.

In passwd(1):

- Gut most of yp_passwd.c and leave only a few things that aren't common
  to pw_yp.c.

- Add support for -d and -h flags to select domains and NIS server hosts
  to use when updating NIS passwords. This allows passwd(1) to be used
  for changing NIS passwords from machines that aren't configured as
  NIS clients. (This is mostly to allow passwd(1) to work on NIS master
  servers that aren't configured as clients -- an NIS server need not
  necessarily be configured as a client itself.)

  NOTE: Realize that having the ability to specify a domain and hostname
  lets you use passwd(1) (and chpass(1) too) to submit update requests
  to yppasswd daemons running on remote servers in remote domains which
  you may not even be bound to. For example, my machine at home is not
  an NIS client of the servers on the network that I manage, yet I can
  easily change my password at work using my FreeBSD box at home by doing:
  'passwd -d work.net.domain -h any.nis.server.on.my.net wpaul'. (Yes,
  I do use securenets at work; temporarily modified my securenets file
  to give my home system access.) Some people may not be too thrilled
  with this idea. Those who don't like this feature can recompile passwd(1)
  and chpass(1) with -DPARANOID to restrict the use of these flags to
  the superuser.

  (Oh, I should be adding proper securenets support to ypserv(8) and
  rpc.yppasswdd(8) over the weekend.)

- Merge in changes to allow root on the NIS master server to bypass
  authentication and change any user's NIS password. (The super-user
  on the NIS master already has privileges to do this, but doing it
  through passwd(1) is much easier than updating the maps by hand.)
  Note that passwd(1) communicates with rpc.yppasswdd(8) via a UNIX
  domain socket instead of via standard RPC/IP in this case.

- Update man page.

In chpass(1):

- Fix pw_yp.c to work properly in environments where NIS client
  services aren't available.

- Use realloc() instead of malloc() in copy_yp_pass() and copy_local_pass().

- Fix silly bug in copy_yp_pass(); some of the members of the passwd
  structure weren't being filled in correctly. (This went unnoticed
  for a while since the old yppasswdd didn't allow changes to the
  fields that were being botched.)

- chpass(1) now also allows the superuser on the NIS master server to
  make unrestricted changes to any user's NIS password information.

- Use UNIX domain comm channel to rpc.yppasswdd(8) when run by the
  superuser on the NIS master. This allows several new things:

   o superuser can update an entire master.passwd.{byname,byuid} entry
   o superuser can update records in arbitrary domains using -d flag to
     select a domain (before you could only change the default domain)
   o superuser can _add_ records to the NIS master.passwd maps, provided
     rpc.yppasswdd(8) has been started with the -a flag (to do this,
     the superuser must force NIS operation by specifying the -y flag
     to chpass(1) along with -a, i.e. 'chpass -y -a 'foo:::::::::')

- Back out the 'chpass -a <new password entry> breaks with NIS' fix
  from the last revision and fix it properly this time. The previous
  revision fixed the immediate problem but broke NIS operation in
  some cases.

- In edit.c, be a little more reasonable about deciding when to
  prevent the shell field from being changed.

  Submitted by Charles Owens <owensc@enc.edu>, who said:

  "I made a minor (one-line) modification to chpass, with regards
   to whether or not it allows the changing of shells.  In the 2.0.5 code,
   field changing follows the settings specified in the "list" structure
   defined in table.c .  For the shell, though, this is ignored.  A quick
   look in edit.c showed me why, but I don't understand why it was written as
   such.  The logic was

        if shell is standard shell, allow changing

   I changed it to

        if shell changing is allowed (per table.c) and it is a standard shell
             OR if uid=0, then allow changing."

   Makes sense to me.

- Update man page.

1 files changed, 99 insertions, 14 deletions

diff --git a/chpass/chpass.1 b/chpass/chpass.1
index 83cddb8..2ba9be0 100644
--- a/chpass/chpass.1
+++ b/chpass/chpass.1
@@ -212,39 +212,64 @@ apply.
 Currently,
 .Nm chpass
 can only make changes to the NIS passwd maps through
-.Xr yppasswdd 8 ,
-which only permits changes to a user's password, shell and gecos
-fields. It can not be used to change other user information or to
-add new records to the NIS passwd maps. (Doing that would require
-something such as ypupdated, which is not yet supported.)
+.Xr rpc.yppasswdd 8 ,
+which normally only permits changes to a user's password, shell and GECOS
+fields. Except when invoked by the super-user on the NIS master server,
+.Nm chpass
+(and, similarly,
+.Xr passwd 1 )
+can not use the
+.Xr rpc.yppasswdd 8
+server to change other user information or
+add new records to the NIS passwd maps.
 Furthermore,
-.Xr yppasswdd 8
+.Xr rpc.yppasswdd 8
 requires password authentication before it will make any
-changes, even if it receives a request from the super-user.
+changes. The only user allowed to submit changes without supplying
+a password is the super-user on the NIS master server; all other users,
+including those with root privileges on NIS clients (and NIS slave
+servers) must enter a password.
+(The super-user on the NIS master is allowed to bypass these restrictions
+largely for convenience: a user with root access
+to the NIS master server already has the privileges required to make
+updates to the NIS maps, but editing the map source files by hand can
+be cumbersome.
+.Pp
+Note: these exceptions only apply when the NIS master server is a
+FreeBSD system.)
 .Pp
-As a result, the following restrictions apply when
+Consequently, except where noted, the following restrictions apply when
 .Nm chpass
 is used with NIS:
 .Bl -enum -offset indent
 .It
-.Pa Only the shell and gecos information may be changed.
+.Pa Only the shell and GECOS information may be changed.
 All other
 fields are restricted, even when
 .Nm chpass
-is invoked by the super-user, because the
-.Xr yppasswdd 8
-daemon has no support for updating them. While support for
+is invoked by the super-user.
+While support for
 changing other fields could be added, this would lead to
 compatibility problems with other NIS-capable systems.
 Even though the super-user may supply data for other fields
 while editing an entry, the extra information (other than the
 password -- see below) will be silently discarded.
+.Pp
+Exception: the super-user on the NIS master server is permitted to
+change any field.
+.Pp
 .It
 .Pa Password authentication is required.
 .Nm Chpass
 will prompt for the user's NIS password before effecting
 any changes. If the password is invalid, all changes will be
 discarded.
+.Pp
+Exception: the super-user on the NIS master server is allowed to
+submit changes without supplying a password. (The super-user may
+choose to turn off this feature using the
+.Fl o
+flag, described below.)
 .It
 .Pa Adding new records to the local
 .Pa password database is discouraged.
@@ -257,6 +282,18 @@ The administrator should use
 .Xr vipw 8
 to modify the local password
 file when NIS is running.
+.Pp
+The super-user on the NIS master server is permitted to add new records
+to the NIS password maps, provided the
+.Xr rpc.yppasswdd 8
+server has been started with the
+.Fl a
+flag to permitted additions (it refuses them by default).
+.Nm Chpass
+tries to update the local password database by default; to update the
+NIS maps instead, invoke chpass with the
+.Fl y
+flag.
 .It
 .Pa Password changes are not permitted.
 Users should use
@@ -268,11 +305,15 @@ a new password (even though the ``Password:'' field does not show
 up in the editor template, the super-user may add it back by hand),
 but even the super-user must supply the user's original password
 otherwise
-.Xr yppasswdd 8
+.Xr rpc.yppasswdd 8
 will refuse to update the NIS maps.
+.Pp
+Exception: the super-user on the NIS master server is permitted to
+change a user's NIS password with
+.Nm chpass .
 .El
 .Pp
-There are also two extra option flags that are available when
+There are also a few extra option flags that are available when
 .Nm chpass
 is compiled with NIS support:
 .Bl -tag -width flag
@@ -290,6 +331,50 @@ This flag has the opposite effect of
 This flag is largely redundant since
 .Nm chpass
 operates on NIS entries by default if NIS is enabled.
+.It Fl d Ar domain
+Specify a particular NIS domain.
+.Nm Chpass
+uses the system domain name by default, as set by the
+.Xr domainname 1
+command. The
+.Fl d
+option can be used to override a default, or to specify a domain
+when the system domain name is not set.
+.It Fl h Ar host
+Specify the name or address of an NIS server to query. Normally,
+.Nm chpass
+will communicate with the NIS master host specified in the
+.Pa master.passwd
+or
+.Pa passwd
+maps. On hosts that have not been configured as NIS clients, there is
+no way for the program to determine this information unless the user
+provides the hostname of a server. Note that the specified hostname need
+not be that of the NIS master server; the name of any server, master or
+slave, in a given NIS domain will do.
+.Pp
+When using the
+.Fl d
+option, the hostname defaults to ``localhost.'' The
+.Fl h
+option can be used in conjunction with the
+.Fl d
+option, in which case the user-specified hostname will override
+the default.
+.Pp
+.It Fl o
+Force the use of RPC-based updates when communicating with
+.Xr rpc.yppasswdd 8
+(``old-mode'').
+When invoked by the super-user on the NIS master server,
+.Nm chpass
+allows unrestricted changes to the NIS passwd maps using dedicated,
+non-RPC-based mechanism (in this case, a UNIX domain socket). The
+.Fl o
+flag can be used to force
+.Nm chpass
+to use the standard update mechanism instead. This option is provided
+mainly for testing purposes.
 .El
 .Pp
 .Sh FILES