Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

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

libc: do not include <sys/types.h> where <sys/param.h> was already included

According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).

Use ANSI C prototypes. Eliminates -Wold-style-definition warnings.

Make inet6_rth_* family of functions more compliant with RFC3542:
1. CMSG_NXTHDR(mhdr, cmsg) is supposed to dereference cmsg and return
the next header in the chain. If cmsg is NULL it should return
the first header, behaving essentially like CMSG_FIRSTHDR().
2. inet6_rth_(space|init|add) should do basic checking on their input
to verify that the number of headers (segments) is
between 0 and 127 inclusive.

MFC-After: 1 month

refer RFC 3542 rather than RFC 2292bis.

Submitted by: Keiichi SHIMA <keiichi__at__iijlab.net>
Obtained from: KAME

fixed the validation code of routing header length in inet6_rth_getaddr().
reported by Delia Kecskemeti <delia.kecskemeti__at__windriver.com>

Submitted by: Keiichi SHIMA <keiichi__at__iijlab.net>
Obtained from: KAME

Switch Advanced Sockets API for IPv6 from RFC2292 to RFC3542
(aka RFC2292bis). Though I believe this commit doesn't break
backward compatibility againt existing binaries, it breaks
backward compatibility of API.
Now, the applications which use Advanced Sockets API such as
telnet, ping6, mld6query and traceroute6 use RFC3542 API.

Obtained from: KAME

just merged cosmetic changes from KAME to ease sync between KAME and FreeBSD.
(based on freebsd4-snap-20020128)

Reviewed by: ume
MFC after: 1 week

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove 'register' keyword.

CMSG_XXX macros alignment fixes to follow RFC2292.

Approved by: jkh

Submitted by: Partly from tech@openbsd
Reviewed by: itojun

KAME 4th patch
IPv6 specific library functions addition.
(getnameinfo(), getaddrinfo(), and IPv6 transport support is not yet)

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