Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

A set of MFCs allowing stable/9 to be built again on head after r250881:

r250227:
Improve compatibility with recent flex from flex.sourceforge.net.

r250914:
Improve compatibility with old flex and fix build with GCC.

r250926 (partial):
Work around build breakages with GCC 4.2.

MFC r228552:

Define YY_NO_INPUT in lib/libipsec/policy_token.l, so lex's input()
function does not get defined needlessly.

MFC r228555:

In lib/libipsec/policy_token.l, use lex's standard "%option noinput"
instead of hand-defining the YY_NO_INPUT macro.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Commit IPv6 support for FAST_IPSEC to the tree.
This commit includes all remaining changes for the time being including
user space updates.

Submitted by: bz
Approved by: re

Initial import of RFC 2385 (TCP-MD5) digest support.

This is the second of two commits; bring in the userland support to finish.

Teach libipsec and setkey about the tcp-md5 class of security associations,
thus allowing administrators to add per-host keys to the SADB for use by
the tcpsignature_compute() function.

Document that a single SPI must be used until such time as the code which
adds support to the SPD to specify flows for tcp-md5 treatment is suitable
for production.

Sponsored by: sentex.net

- plug memory leak.
- fixed a length of the sadb extension in the case of pfkey_send_x5().
- used getprotobynumber() for printing a upper layer protocol name.
- modified the output format against the change of the setkey syntax
about a icmp6 type/code.
- don't enumerate reserved fields. use memset.

Obtained from: KAME

Remove __P() usage.

Sync with recent KAME.
This work was based on kame-20010528-freebsd43-snap.tgz and some
critical problem after the snap was out were fixed.
There are many many changes since last KAME merge.

TODO:
- The definitions of SADB_* in sys/net/pfkeyv2.h are still different
from RFC2407/IANA assignment because of binary compatibility
issue. It should be fixed under 5-CURRENT.
- ip6po_m member of struct ip6_pktopts is no longer used. But, it
is still there because of binary compatibility issue. It should
be removed under 5-CURRENT.

Reviewed by: itojun
Obtained from: KAME
MFC after: 3 weeks

synchronize with latest kame tree.

behavior change: policy syntax was changed. you may need to update your
setkey(8) configuration files.

Replace the prefix for yylval to less confusing one.
(Sorry, this should be committed with previous commit to Makefile.)

Change IPv6 scoped addr format again based on recent standard discussion.
Sorry for the flapping, but no change will be done for 4.0 anymore.
Official standard will be published around April or later.
If different format would be adopted at that time, then support for
the new format will be added to the succeeding FreeBSD 4.x.

Approved by: jkh

libipsec and IPsec related apps. (and some KAME related man pages)

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