MFC r306614:
Note the version PF first appeared in FreeBSD & from which version it was ported from.
Address the contractions raised by igor.

PR: 212574
Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D8105

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Minor mdoc fix.

o Create directory sys/netpfil, where all packet filters should
reside, and move there ipfw(4) and pf(4).

o Move most modified parts of pf out of contrib.

Actual movements:

sys/contrib/pf/net/*.c -> sys/netpfil/pf/
sys/contrib/pf/net/*.h -> sys/net/
contrib/pf/pfctl/*.c -> sbin/pfctl
contrib/pf/pfctl/*.h -> sbin/pfctl
contrib/pf/pfctl/pfctl.8 -> sbin/pfctl
contrib/pf/pfctl/*.4 -> share/man/man4
contrib/pf/pfctl/*.5 -> share/man/man5

sys/netinet/ipfw -> sys/netpfil/ipfw

The arguable movement is pf/net/*.h -> sys/net. There are
future plans to refactor pf includes, so I decided not to
break things twice.

Not modified bits of pf left in contrib: authpf, ftp-proxy,
tftp-proxy, pflogd.

The ipfw(4) movement is planned to be merged to stable/9,
to make head and stable match.

Discussed with: bz, luigi

Replace an OpenBSDism with a FreeBSDism in the pfctl(8) man page: we put
configuration file man pages in section 5, and we prefer rc.conf to
rc.conf.local.

MFC after: 3 days

Update packet filter (pf) code to OpenBSD 4.5.

You need to update userland (world and ports) tools
to be in sync with the kernel.

Submitted by: mlaier
Submitted by: eri

Add a new option -P to suppress getservbyport(3) calls when printing rules.
This allows one to force consistent printing of numeric port numbers like
we do with -n for other tools like netstat (just that -n was already taken)
rather than the service names.

-P is currently unused in OpenBSD so the change is eligible for upstreaming.

PR: misc/151015
Submitted by: Matt Koivisto (mkoivisto sandvine.com)
Sponsored by: Sandvine Incorporated
MFC after: 1 week

Commit resolved import of OpenBSD 4.1 pf userland from perforce.

Approved by: re (kensmith)

- Remove MLINKS to nonexistant manpages
- Change some section numbers to match reality
- For MLINKS to manpages from ports, mention which port installs them

MFC after: 3 days

This commit was generated by cvs2svn to compensate for changes in r145837,
which included commits to RCS files with non-trunk default branches.

Import pf userland from OpenBSD 3.7 (OPENBSD_3_7 as of today)

Import userland of pf 3.5 from OpenBSD (OPENBSD_3_5_BASE).

Vendor import of OpenBSD's pf userland as of OpenBSD 3.4

Approved by: bms(mentor), core(in general)