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

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

After r193232 rt_tables in vnet.h are no longer indirectly dependent on
the ROUTETABLES kernel option thus there is no need to include opt_route.h
anymore in all consumers of vnet.h and no longer depend on it for module
builds.

Remove the hidden include in flowtable.h as well and leave the two
explicit #includes in ip_input.c and ip_output.c.

Remove opt_mac.h generation for various kernel modules that no longer
require it.

Submitted by: pjd

Introduce a number of changes to the MROUTING code.
This is purely a forwarding plane cleanup; no control plane
code is involved.

Summary:
* Split IPv4 and IPv6 MROUTING support. The static compile-time
kernel option remains the same, however, the modules may now
be built for IPv4 and IPv6 separately as ip_mroute_mod and
ip6_mroute_mod.
* Clean up the IPv4 multicast forwarding code to use BSD queue
and hash table constructs. Don't build our own timer abstractions
when ratecheck() and timevalclear() etc will do.
* Expose the multicast forwarding cache (MFC) and virtual interface
table (VIF) as sysctls, to reduce netstat's dependence on libkvm
for this information for running kernels.
* bandwidth meters however still require libkvm.
* Make the MFC hash table size a boot/load-time tunable ULONG,
net.inet.ip.mfchashsize (defaults to 256).
* Remove unused members from struct vif and struct mfc.
* Kill RSVP support, as no current RSVP implementation uses it.
These stubs could be moved to raw_ip.c.
* Don't share locks or initialization between IPv4 and IPv6.
* Don't use a static struct route_in6 in ip6_mroute.c.
The v6 code is still using a cached struct route_in6, this is
moved to mif6 for the time being.
* More cleanup remains to be merged from ip_mroute.c to ip6_mroute.c.

v4 path tested using ports/net/mcast-tools.
v6 changes are mostly mechanical locking and *have not* been tested.
As these changes partially break some kernel ABIs, they will not
be MFCed. There is a lot more work to be done here.

Reviewed by: Pavlin Radoslavov

Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by: brooks, gnn, des, zec, imp
Sponsored by: The FreeBSD Foundation

Options spring cleanup:
- Add and document the KVM and KVM_SUPPORT options that
are needed for the ifmcstats(3) makefile
- Garbage collect unused variables
- Add missing inclusion of bsd.own.mk where needed

Approved by: kan (mentor)
Reviewed by: ru

Make IPv6 multicast forwarding dynamically loadable from a GENERIC kernel.
It is built in the same module as IPv4 multicast forwarding, i.e. ip_mroute.ko,
if and only if IPv6 support is enabled for loadable modules.
Export IPv6 forwarding structs to userland netstat(1) via sysctl(9).

Remove an unneeded define.

Let modules use the kernel's opt_*.h files if built along with
the kernel by wrapping all targets for fake opt_*.h files in
.if defined(KERNBUILDDIR). Thus, such fake files won't be
created at all if modules are built with the kernel.

Some modules undergo cleanup like removing unused or unneeded
options or .h files, without which they wouldn't build this way
or the other.

Reviewed by: ru
Tested by: no binary changes in modules built alone
Tested on: i386 sparc64 amd64

Get rid of the RANDOM_IP_ID option and make it a sysctl. NetBSD
have already done this, so I have styled the patch on their work:

1) introduce a ip_newid() static inline function that checks
the sysctl and then decides if it should return a sequential
or random IP ID.

2) named the sysctl net.inet.ip.random_id

3) IPv6 flow IDs and fragment IDs are now always random.
Flow IDs and frag IDs are significantly less common in the
IPv6 world (ie. rarely generated per-packet), so there should
be smaller performance concerns.

The sysctl defaults to 0 (sequential IP IDs).

Reviewed by: andre, silby, mlaier, ume
Based on: NetBSD
MFC after: 2 months

Hook up opt_mac.h to the build dependencies. The way we currently
handle this stuff is dangerous. :-)

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Drop <bsd.man.mk> support from <bsd.kmod.mk>.

Not objected to by: -current

Unbreak ip_mroute_mod

Use a consistent style and one much closer to the rest of /usr/src

Use .include <bsd.kmod.mk> to get to ../../*/conf/kmod.mk instead of
encoding the relative path.

Pull in sys/conf/kmod.mk, rather than /usr/share/mk/bsd.kmod.mk.
This means that the kernel can be totally self contained now and is not
dependent on the last buildworld to update /usr/share/mk. This might
also make it easier to build 5.x kernels on 4.0 boxes etc, assuming
gensetdefs and config(8) are updated.

$Id$ -> $FreeBSD$

Sample initial set of kld-ified modules. Not all have been completely
converted yet. These are more of a starting point. This is NOT connected
to the parent Makefile.

OK'ed by jkh (who is ever so patiently waiting)

Revert $FreeBSD$ back to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Per discussion on the mailing-lists, move LKMs from /sbin to /lkm, and
arrange for that directory to get created by mtree. Also, process secure
directory after all the others, because the programs there may overlay
ones installed from the main part of the tree.