lib: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

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

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

lib: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

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.

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.

Fixing !INET6 builds.

Like many other functions that handle sockaddrs, realhostname_sa() takes a
struct sockaddr * that it casts internally to the appropriate type based on
sa_family. However, struct sockaddr has very lax alignment requirements,
which causes the compiler to complain when you cast a struct sockaddr * to,
say, a struct sockaddr_in6 *.

I find it reasonable to assume that the pointer we received is in fact
correctly aligned. Therefore, we can work around the compiler warnings by
casting to void * before casting to the desired type. For readability's
sake, this is done with macros.

The same technique should prove useful in other parts of the tree that
deal with socket addresses.

MFC after: 3 weeks

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

Use strlcpy() when we mean it.

NI_WITHSCOPEID cleanup. Neither RFC 2553 nor RFC 3493 defines
NI_WITHSCOPEID, and our getaddrinfo(3) does nothing special
for it, now.

ANSIfy, WARNSify, CONSTify. Bit of style(9)-ify.

Tidy up. Sort headers.

Return HOSTNAME_INVALIDADDR when reverse lookup is fail.

Submitted by: Sergey Zorin <sergey@cc.tpu.edu.ru>

Add __FBSDID()s to libutil

Simplify IPv4 mapped IPv6 address handling.

Reviewed by: brian
MFC after: 5 days

Hint getaddrinfo() correctly if we're looking up a name that we got from
an AF_INET6 address.

MFC after: 1 week

MAXHOSTNAMELEN includes space for the NUL
Don't read past the end of the host passed to realhostname()

Not objected to by: freebsd-audit
Interface disliked by: imp

Call trimdomain properly for ip4 addresses.

PR: 24659
realhostname_sa() stuff submitted by: Jim.Pirzyk@disney.com

Sshd writes connected host into utmp directly. If the connection is
via IPv6, the hostname is trimed due to the length of IPv6 address.
This change saves it as possible.
I have a grudge against the shortage of UT_HOSTSIZE.

We should see the ai_canonname menber of the first addrinfo
structure in the linked list. RFC2553 mentions only first.

Reviewed by: shin

Return IPv4 native address for IPv4 mapped IPv6 address, even if
A RR is not found.

Reviewed by: shin

Since crypto/openssh/login.c was changed to use realhostname_sa(),
when connecting via IPv6, hostname was not recorded to utmp anymore.
Because, if hostname is longer than buffer size, getnameinfo() returns
with ENI_MEMORY.

Reviewed by: shin
Approved by: jkh

Avoid core dump when ai_canonname is NULL.
(Now this happens for numeric addrs, as getaddrinfo() 1.3 -> 1.4 change)

Reviewed by: Mark Huizer <xaa@timewasters.nl>

several tcp apps IPv6 update
-inetd
-rshd
-rlogind
-telnetd
-rsh
-rlogin

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project

$Id$ -> $FreeBSD$

Put parenthesis around sizeof args.
Allow for host names up to MAXHOSTNAMELEN - 1 in length.

Prompted by: bde

Add realhostname() - a function to correctly lookup
a name by address and ensure that the name resolves
back to the original address.