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

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

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

Approved by: re (implicit)

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

Adapt OpenBSD pf's "sloopy" TCP state machine which is useful for Direct
Server Return mode, where not all packets would be visible to the load
balancer or gateway.

This commit should be reverted when we merge future pf versions. The
benefit it would provide is that this version does not break any existing
public interface and thus won't be a problem if we want to MFC it to
earlier FreeBSD releases.

Discussed with: mlaier
Obtained from: OpenBSD
Sponsored by: iXsystems, Inc.
MFC after: 1 month

Commit resolved import of OpenBSD 4.1 pf from perforce.

Approved by: re (kensmith)

Teach pfsync(4) that its member interfaces may go away.

This change partially resolves the issue in the PR. Further architectural
fixes, in the form of reference counting, are needed.

PR: 86848
Reviewed by: yar
MFC after: 1 month

Defer ip_output of pfsync updates to an independent callout thread instead
of just dropping the lock around the ip_output call. This used to cause
corrupted state tree walks for some call-paths.

In a second stage all callouts will be marked MPSAFE according to the
setting of mpsafenet.

Reported and tested by: Matthew Grooms <mgrooms at seton dot org>
MFC after: 3 days
X-MFC after: Marking callouts MPSAFE + 1 week

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

Resolve conflicts created during the import of pf 3.7 Some features are
missing and will be implemented in a second step. This is functional as is.

Tested by: freebsd-pf, pfsense.org
Obtained from: OpenBSD
X-MFC after: never (breaks API/ABI)

Commit pf version 3.5 and link additional files to the kernel build.

Version 3.5 brings:
- Atomic commits of ruleset changes (reduce the chance of ending up in an
inconsistent state).
- A 30% reduction in the size of state table entries.
- Source-tracking (limit number of clients and states per client).
- Sticky-address (the flexibility of round-robin with the benefits of
source-hash).
- Significant improvements to interface handling.
- and many more ...

Style(9) round for the pf kernel parts. Mostly #if defined() -> #ifdef

Also set HOOK_HACK to true (remove the related #ifdef's) as we have the
hooks in the kernel this was missed during the merge from the port.

Noticed by: Amir S. (for the HOOK_HACK part)
Approved by: bms(mentor)

Bring diff from the security/pf port. This has code been tested as a port
for a long time and is run in production use. This is the code present in
portversion 2.03 with some additional tweaks.

The rather extensive diff accounts for:
- locking (to enable pf to work with a giant-free netstack)
- byte order difference between OpenBSD and FreeBSD for ip_len/ip_off
- conversion from pool(9) to zone(9)
- api differences etc.

Approved by: bms(mentor) (in general)

This commit was generated by cvs2svn to compensate for changes in r126258,
which included commits to RCS files with non-trunk default branches.

Vendor import of OpenBSD's packet filter (pf) as of OpenBSD 3.4

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