rpc.ypxfrd: Remove return statement at the end of void functions

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

yp*: fix -fno-common build

This is mostly two problems spread out far and wide:
- ypldap_process should be declared properly
- debug is defined differently in many programs

For the latter, just extern it and define it everywhere that actually needs
it. This mostly works out nicely for ^/libexec/ypxfr, which can remove the
assignment at the beginning of main in favor of defining it properly.

-fno-common will become the default in GCC10/LLVM11.

MFC after: 3 days

spdx: initial adoption of licensing ID tags.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Include <rpc/rpc_com.h> for a _rpc_dtablesize() prototype.

Approved by: das (mentor)

Use __FBSDID over rcsid[]. Protect copyright[] where needed.

ANSIfy and remove some dead code.

Sponsored by: DARPA, NAI Labs

Apply the following mechanical transformations in preparation for
ansification and constification:

s{\s+__P\((\(.*?\))\)}{$1}g;
s{\(\s+}{\(}g;
s{\s+\)}{\)}g;
s{\s+,}{,}g;
s{(\s+)(for|if|switch|while)\(}{$1$2 \(}g;
s{return ([^\(].*?);}{return ($1);}g;
s{([\w\)])([!=+/\*-]?=)([\w\(+-])}{$1 $2 $3}g;
s{\s+$}{\n};g

Also add $FreeBSD$ where needed.

MFC after: 1 week

Add `_PATH_DEVZERO'.
Use _PATH_* where where possible.

Don't call syslog() without a format string.

$Id$ -> $FreeBSD$

Darnit, that last commit was only supposed to change files in the
-current branch. I mistakenly checked out the 2.2.x rpc.ypxfrd into my
-current working directory. No harm done, but I got really confused
when I went to check out rpc.ypxfrd again and found the changes I
wanted to make were already there. (I'm going to fix the other 2.2.x
versions of the other programs in a minute.)

Anyway: protect errno in the signal handler, in the -current version
of rpc.ypxfrd this time.

Use err(3). Remove multiply defined Id string.

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

Update to work under Lite2 includes

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Import rpc.ypxfrd.

This server impliments an RPC-based file transfer protocol that allows
an NIS slave server to copy a raw map database file from an NIS master.

The goal here is to speed up the transfer of very large maps. If you
have, for example, an NIS password database with 30,000 records in it,
it can take around 8 to 10 minutes to regenerate it (four hash databases
are created). As it stands now, ypxfr(8) transfers a map by sucking all
the records from ypserv(8) on the master using yp_all() and writing them
to a new database using the db(3) library. This adds up to another 8 to 10
minutes, per slave. With as the number of slaves increases, this latency
becomes prohibitive.

With rpc.ypxfrd, all the slave has to do is copy the already-built
hash database file from the master and move it into place. Even with a
multi-megabyte file, this reduces the master to slave transfer time
to well under a minute. (This is using TCP.)

Access restrictions are applied using the same mechanism as in ypserv:
you can control access using /var/yp/securenets, and the server will
not transmit the master.passwd.* maps unless the transfer request originates
on a reserved port.

Note: this server is based on my hastily contrived protocol and is _NOT_
compatible with Sun's protocol of the same name. It can't be compatible
for a couple of reasons. For one thing, Sun's protocol has not been published
anywhere that I know of. It is not included in any of the SunRPC source
distributions that I've been able to find. Second, Sun's NIS v2 code
uses old style ndbm maps while FreeBSD uses Berkeley DB. The file formats
are incompatible, so being able to transfer maps between FreeBSD and SunOS
hosts wouldn't do any good anyway. (You could always port the FreeBSD NIS
code to SunOS if you really wanted to do it. :)

(There's also the little fact that SunOS/SPARC is big-endian and FreeBSD/i386
is little-endian. Berkeley DB can handle byte ordering differences; ndbm
probably can't.)