MFC r314659,r314676:

r314659:

usr.sbin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

r314676:

Fix build after r314656

Some of the changes I introduced to use .ALLSRC were correct in spirit,
but incorrect in reality -- in particular, ../Makefile.inc hadn't been
pulled in via bsd.init.mk (via bsd.lib.mk, bsd.prog.mk), so the value
of .ALLSRC (evaluated immediately) was empty. .include bsd.init.mk
explicitly so we can be certain that the values used as dependencies in
the targets are defined when the target recipe has been evaluated.

Reminder: thou shalt separate out separate functional changes before
committing them.

(YUGE) Pointyhat to: ngie
In collaboration with: bdrewery

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

use WARNS?= instead of WARNS=

MFC after: 3 days

Make usr.sbin/cron/crontab and usr.sbin/cron/lib WARNS=3 clean

Tested with: make universe

MFC after: 3 days

Add PAM support to cron(8). Now cron(8) will skip commands scheduled
by unavailable accounts, e.g., those locked, expired, not allowed in at
the moment by nologin(5), or whatever, depending on cron's pam.conf(5).
This applies to personal crontabs only, /etc/crontab is unaffected.

In other words, now the account management policy will apply to
commands scheduled by users via crontab(1) so that a user can no
longer use cron(8) to set up a delayed backdoor and run commands
during periods when the admin doesn't want him to.

The PAM check is done just before running a command, not when loading
a crontab, because accounts can get locked, expired, and re-enabled
any time with no changes to their crontabs. E.g., imagine that you
provide a system with payed access, or better a cluster of such
systems with centralized account management via PAM. When a user
pays for some days of access, you set his expire field respectively.
If the account expires before its owner pays more, its crontab
commands won't run until the next payment is made. Then it'll be
enough to set the expire field in future for the commands to run
again. And so on.

Document this change in the cron(8) manpage, which includes adding
a FILES section and touching the document date.

X-Security: should benefit as users have access to cron(8) by default

For variables that are only checked with defined(), don't provide
any fake value.

Mark all internal libraries with INTERNALLIB.

Perform a major cleanup of the usr.sbin Makefiles.
These are not perfectly in agreement with each other style-wise, but they
are orders of orders of magnitude more consistent style-wise than before.

Log run-time parsing errors now

Use getpwnam before getpwuid since two users with same uids can exists
(affects new login classes code only)

The same fixes as in inetd: by default run `system crontab things' with
daemon login class now, not restrict them to user class breaking
compatibility with old way (so-called nobody limits problem)

Implement user[:group][/login-class] syntax in system crontab
for more flexible control (the same as in inetd)

NOSHARED takes a yes/YES no/NO value, not "true, false, hey mon!".
NOPIC is used to not generate a shared library, not NOSHARED.
Make NOSHARED advisory where appropriate.
Remove bogus NOSHARED (kbdio).

Prevent installation.
Submitted by: jkh

This commit was generated by cvs2svn to compensate for changes in r2311,
which included commits to RCS files with non-trunk default branches.

Paul Vixie's cron, version 3.0. Munged into bmake format. If this goes
well, expect our two seperate directories for cron and crontab to go away
shortly.
Submitted by: jkh