netpfil: Fix typo (triple S)

While here, align the comment box.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/955

sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

ipfilter: Support only jails in VNET

Jails without VNET have complete access to the ipfilter rules, NAT,
pools and logs. This is insecure. Only allow jails to manipulate
ipfilter rules, NAT tables and ippools if the jail has its own VNET.
Otherwise a jail can affect the global system.

This patch brings ipfilter in line with ipfw's support of VNET jails and
non-support of non-VNET jails.

MFC after: 1 week

ipfilter: Correct a typo in a comment

MFC after: 3 days

ipfilter: Fixup comment

Fix comment documenting checksum block in ip_nat.c. Fastforward doesn't
perform checksum.

MFC after: 1 week

ipfilter: Fix whitespace errors

MFC after: 3 days

ipfilter: Correct function description

Correct the parameters descriptions for ipf_fix_outcksum and
ipf_fix_incksum.

MFC after: 3 days

ipfilter module: Style(9) requires a space after return

Reported by: jrtc27
Fixes: 8c82b37461fa4e60276639df214100fbf559ea6e
MFC after: 1 month

ipfilter: Unconditionally expose SDT probe frb_natv4in

SDT probe frb_natv4in is only available when an error is encountered.
Make it also available when no error is encountered, i.e. NATed and
not translated.

MFC after: 1 week

ipfilter: Adjust kernel module returns to conform to style(9)

Adjust ipfilter's kernel module return statements to conform to style(9).

MFC after: 1 month

ipflter: ANSIfy kernel function declarations

Convert ipfilter kernel function declarations from K&R to ANSI. This
syncs our function declarations with NetBSD hg commit 75edcd7552a0
(apply our changes). Though not copied from NetBSD, this change was
partially inspired by NetBSD's work and inspired by style(9).

Reviewed by: glebius (for #network)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D33595

ipfilter: Move kernel bits to netpfil

Through fixes and improvements our ipfilter sources have diverged
enough to warrant move from contrib into sys/netpil. Now that I'm
planning on implementing MSS clamping as in iptables it makes more
sense to move ipfilter to netpfil.

This is the first of three commits the ipfilter move.

Suggested by glebius on two occaions.

Suggested by and discussed with: glebius
Reviewed by: glebius, kp (for #network)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D33510