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

sys: Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

netinet[6]: make in[6]_control use ucred instead of td.

Reviewed by: markj, zlei
Differential Revision: https://reviews.freebsd.org/D40793
MFC after: 2 weeks

IfAPI: Hide the in6m_lookup_locked() implementation.

Summary:
in6m_lookup_locked() iterates over the ifnet's multiaddrs list. Keep
this implementation detail private, by moving the implementation to the
netstack source from the header.

Sponsored by: Juniper Networks, Inc.
Reviewed by: glebius, melifaro
Differential Revision: https://reviews.freebsd.org/D38201

netinet*: remove PRC_ constants and streamline ICMP processing

In the original design of the network stack from the protocol control
input method pr_ctlinput was used notify the protocols about two very
different kinds of events: internal system events and receival of an
ICMP messages from outside. These events were coded with PRC_ codes.
Today these methods are removed from the protosw(9) and are isolated
to IPv4 and IPv6 stacks and are called only from icmp*_input(). The
PRC_ codes now just create a shim layer between ICMP codes and errors
or actions taken by protocols.

- Change ipproto_ctlinput_t to pass just pointer to ICMP header. This
allows protocols to not deduct it from the internal IP header.
- Change ip6proto_ctlinput_t to pass just struct ip6ctlparam pointer.
It has all the information needed to the protocols. In the structure,
change ip6c_finaldst fields to sockaddr_in6. The reason is that
icmp6_input() already has this address wrapped in sockaddr, and the
protocols want this address as sockaddr.
- For UDP tunneling control input, as well as for IPSEC control input,
change the prototypes to accept a transparent union of either ICMP
header pointer or struct ip6ctlparam pointer.
- In icmp_input() and icmp6_input() do only validation of ICMP header and
count bad packets. The translation of ICMP codes to errors/actions is
done by protocols.
- Provide icmp_errmap() and icmp6_errmap() as substitute to inetctlerrmap,
inet6ctlerrmap arrays.
- In protocol ctlinput methods either trust what icmp_errmap() recommend,
or do our own logic based on the ICMP header.

Differential revision: https://reviews.freebsd.org/D36731

netinet6: factor interface addition code to the dedicated function

Summary:
Move SIOCAIFADDR_IN6 (current "primary" ioctl to add an IPv6
interface address) handling code to the dedicated in6_addifaddr()
function and make it a part of KPI. This allows in-kernel users to
add/delete interfaces addresses without relying on ioctl interface.

Subscribers: imp, ae, glebius

Differential Revision: https://reviews.freebsd.org/D36713

netinet6: fix SIOCSPFXFLUSH_IN6 by skipping manually-configured prefixes

Summary:
Currently netinet6/ code allocates IPv6 prefixes (nd_prefix) for
both manually-assigned addresses and advertised prefixes. As a result,
prefixes from manually-assigned prefixes can be seen in `ndp -p` list
and be cleared via `ndp -P`. The latter relies on the SIOCSPFXFLUSH_IN6
ioctl to clear to prefix list.
The original intent of the SIOCSPFXFLUSH_IN6 was to clear prefixes
originated from the advertising routers:

```
1998-09-02 JINMEI, Tatuya <jinmei@isl.rdc.toshiba.co.jp>
* nd6.c (nd6_ioctl): added 2 new ioctls; SIOCSRTRFLUSH_IN6 and
SIOCSPFXFLUSH_IN6. The former is to flush all default routers
in the default router list, and the latter is to flush all the
prefixes and the addresses derived from them in the prefix list.
```

Restore the intent by marking prefixes derived from the RA messages
with newly-added ndpr_flags.ra_derived flag and skip prefixes not marked
with such flag during deletion and listing.

Differential Revision: https://reviews.freebsd.org/D36312
MFC after: 2 weeks

protosw: change prototype for pr_control

For some reason protosw.h is used during world complation and userland
is not aware of caddr_t, a relic from the first version of C. Broken
buildworld is good reason to get rid of yet another caddr_t in kernel.

Fixes: 886fc1e80490fb03e72e306774766cbb2c733ac6

netinet6: fix ndp proxying

We could insert proxy NDP entries by the ndp command, but the host
with proxy ndp entries had not responded to Neighbor Solicitations.
Change the following points for proxy NDP to work as expected:
* join solicited-node multicast addresses for proxy NDP entries
in order to receive Neighbor Solicitations.
* look up proxy NDP entries not on the routing table but on the
link-level address table when receiving Neighbor Solicitations.

Reviewed By: melifaro
Differential Revision: https://reviews.freebsd.org/D35307
MFC after: 2 weeks

if_stf: add 6rd support

Implement IPv6 Rapid Deployment (RFC5969) on top of the existing 6to4
(RFC3056) if_stf code.

PR: 253328
Reviewed by: hrs
Obtained from: pfSense
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D33037

Remove per-packet ifa refcounting from IPv6 fast path.

Currently ip6_input() calls in6ifa_ifwithaddr() for
every local packet, in order to check if the target ip
belongs to the local ifa in proper state and increase
its counters.

in6ifa_ifwithaddr() references found ifa.
With epoch changes, both `ip6_input()` and all other current callers
of `in6ifa_ifwithaddr()` do not need this reference
anymore, as epoch provides stability guarantee.

Given that, update `in6ifa_ifwithaddr()` to allow
it to return ifa without referencing it, while preserving
option for getting referenced ifa if so desired.

MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28648

Create new in6_purgeifaddr() which purges bound ifa prefix if
it gets unused.

Currently if_purgeifaddrs() uses in6_purgeaddr() to remove IPv6
ifaddrs. in6_purgeaddr() does not trrigger prefix removal if
number of linked ifas goes to 0, as this is a low-level function.
As a result, if_purgeifaddrs() purges all IPv4/IPv6 addresses but
keeps corresponding IPv6 prefixes.

Fix this by creating higher-level wrapper which handles unused
prefix usecase and use it in if_purgeifaddrs().

Differential revision: https://reviews.freebsd.org/D28128

Simplify dom_<rtattach|rtdetach>.

Remove unused arguments from dom_rtattach/dom_rtdetach functions and make
them return/accept 'struct rib_head' instead of 'void **'.
Declare inet/inet6 implementations in the relevant _var.h headers similar
to domifattach / domifdetach.
Add rib_subscribe_internal() function to accept subscriptions to the rnh
directly.

Differential Revision: https://reviews.freebsd.org/D26053

Make sure the multicast release tasks are properly drained when
destroying a VNET or a network interface.

Else the inm release tasks, both IPv4 and IPv6 may cause a panic
accessing a freed VNET or network interface.

Reviewed by: jmg@
Discussed with: bz@
Differential Revision: https://reviews.freebsd.org/D24914
MFC after: 1 week
Sponsored by: Mellanox Technologies

Transition from rtrequest1_fib() to rib_action().

Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.

Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546

Temporarly revert r363319 to unbreak the build.

Reported by: CI
Pointy hat to: melifaro

Transition from rtrequest1_fib() to rib_action().

Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.

Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546

Eliminate now-unused parts of old routing KPI.

r360292 switched most of the remaining routing customers to a new KPI,
leaving a bunch of wrappers for old routing lookup functions unused.

Remove them from the tree as a part of routing cleanup.

Differential Revision: https://reviews.freebsd.org/D24569

Bring back redirect route expiration.

Redirect (and temporal) route expiration was broken a while ago.
This change brings route expiration back, with unified IPv4/IPv6 handling code.

It introduces net.inet.icmp.redirtimeout sysctl, allowing to set
an expiration time for redirected routes. It defaults to 10 minutes,
analogues with net.inet6.icmp6.redirtimeout.

Implementation uses separate file, route_temporal.c, as route.c is already
bloated with tons of different functions.
Internally, expiration is implemented as an per-rnh callout scheduled when
route with non-zero rt_expire time is added or rt_expire is changed.
It does not add any overhead when no temporal routes are present.

Callout traverses entire routing tree under wlock, scheduling expired routes
for deletion and calculating the next time it needs to be run. The rationale
for such implemention is the following: typically workloads requiring large
amount of routes have redirects turned off already, while the systems with
small amount of routes will not inhibit large overhead during tree traversal.

This changes also fixes netstat -rn display of route expiration time, which
has been broken since the conversion from kread() to sysctl.

Reviewed by: bz
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D23075

in6_mcast: make in6_joingroup_locked() static

in6_joingroup_locked() is only used file-local. No need to export it
hance make it static.

Widen NET_EPOCH coverage.

When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.

However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.

Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.

On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().

This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.

Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.

This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.

Reviewed by: gallatin, hselasky, cy, adrian, kristof
Differential Revision: https://reviews.freebsd.org/D19111

Convert all IPv4 and IPv6 multicast memberships into using a STAILQ
instead of a linear array.

The multicast memberships for the inpcb structure are protected by a
non-sleepable lock, INP_WLOCK(), which needs to be dropped when
calling the underlying possibly sleeping if_ioctl() method. When using
a linear array to keep track of multicast memberships, the computed
memory location of the multicast filter may suddenly change, due to
concurrent insertion or removal of elements in the linear array. This
in turn leads to various invalid memory access issues and kernel
panics.

To avoid this problem, put all multicast memberships on a STAILQ based
list. Then the memory location of the IPv4 and IPv6 multicast filters
become fixed during their lifetime and use after free and memory leak
issues are easier to track, for example by: vmstat -m | grep multi

All list manipulation has been factored into inline functions
including some macros, to easily allow for a future hash-list
implementation, if needed.

This patch has been tested by pho@ .

Differential Revision: https://reviews.freebsd.org/D20080
Reviewed by: markj @
MFC after: 1 week
Sponsored by: Mellanox Technologies

Fix refcounting leaks in IPv6 MLD code leading to loss of IPv6
connectivity.

Looking at past changes in this area like r337866, some refcounting
bugs have been introduced, one by one. For example like calling
in6m_disconnect() and in6m_rele_locked() in mld_v1_process_group_timer()
where previously no disconnect nor refcount decrement was done.
Calling in6m_disconnect() when it shouldn't causes IPv6 solitation to no
longer work, because all the multicast addresses receiving the solitation
messages are now deleted from the network interface.

This patch reverts some recent changes while improving the MLD
refcounting and concurrency model after the MLD code was converted
to using EPOCH(9).

List changes:
- All CK_STAILQ_FOREACH() macros are now properly enclosed into
EPOCH(9) sections. This simplifies assertion of locking inside
in6m_ifmultiaddr_get_inm().
- Corrected bad use of in6m_disconnect() leading to loss of IPv6
connectivity for MLD v1.
- Factored out checks for valid inm structure into
in6m_ifmultiaddr_get_inm().

PR: 233535
Differential Revision: https://reviews.freebsd.org/D18887
Reviewed by: bz (net)
Tested by: ae
MFC after: 1 week
Sponsored by: Mellanox Technologies

When detaching a network interface drain the workqueue freeing the inm's
because the destructor will access the if_ioctl() callback in the ifnet
pointer which is about to be freed. This prevents use-after-free.

PR: 233535
Differential Revision: https://reviews.freebsd.org/D18887
Reviewed by: bz (net)
Tested by: ae
MFC after: 1 week
Sponsored by: Mellanox Technologies

Mechanical cleanup of epoch(9) usage in network stack.

- Remove macros that covertly create epoch_tracker on thread stack. Such
macros a quite unsafe, e.g. will produce a buggy code if same macro is
used in embedded scopes. Explicitly declare epoch_tracker always.

- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
locking macros to what they actually are - the net_epoch.
Keeping them as is is very misleading. They all are named FOO_RLOCK(),
while they no longer have lock semantics. Now they allow recursion and
what's more important they now no longer guarantee protection against
their companion WLOCK macros.
Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.

This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.

Discussed with: jtl, gallatin

Fix in6_multi double free

This is actually several different bugs:
- The code is not designed to handle inpcb deletion after interface deletion
- add reference for inpcb membership
- The multicast address has to be removed from interface lists when the refcount
goes to zero OR when the interface goes away
- decouple list disconnect from refcount (v6 only for now)
- ifmultiaddr can exist past being on interface lists
- add flag for tracking whether or not it's enqueued
- deferring freeing moptions makes the incpb cleanup code simpler but opens the
door wider still to races
- call inp_gcmoptions synchronously after dropping the the inpcb lock

Fundamentally multicast needs a rewrite - but keep applying band-aids for now.

Tested by: kp
Reported by: novel, kp, lwhsu

CK: update consumers to use CK macros across the board

r334189 changed the fields to have names distinct from those in queue.h
in order to expose the oversights as compile time errors

ip(6)_freemoptions: defer imo destruction to epoch callback task

Avoid the ugly unlock / lock of the inpcbinfo where we need to
figure out what kind of lock we hold by simply deferring the
operation to another context. (Also a small dependency for
converting the pcbinfo read lock to epoch)

ifnet: Replace if_addr_lock rwlock with epoch + mutex

Run on LLNW canaries and tested by pho@

gallatin:
Using a 14-core, 28-HTT single socket E5-2697 v3 with a 40GbE MLX5
based ConnectX 4-LX NIC, I see an almost 12% improvement in received
packet rate, and a larger improvement in bytes delivered all the way
to userspace.

When the host receiving 64 streams of netperf -H $DUT -t UDP_STREAM -- -m 1,
I see, using nstat -I mce0 1 before the patch:

InMpps OMpps InGbs OGbs err TCP Est %CPU syscalls csw irq GBfree
4.98 0.00 4.42 0.00 4235592 33 83.80 4720653 2149771 1235 247.32
4.73 0.00 4.20 0.00 4025260 33 82.99 4724900 2139833 1204 247.32
4.72 0.00 4.20 0.00 4035252 33 82.14 4719162 2132023 1264 247.32
4.71 0.00 4.21 0.00 4073206 33 83.68 4744973 2123317 1347 247.32
4.72 0.00 4.21 0.00 4061118 33 80.82 4713615 2188091 1490 247.32
4.72 0.00 4.21 0.00 4051675 33 85.29 4727399 2109011 1205 247.32
4.73 0.00 4.21 0.00 4039056 33 84.65 4724735 2102603 1053 247.32

After the patch

InMpps OMpps InGbs OGbs err TCP Est %CPU syscalls csw irq GBfree
5.43 0.00 4.20 0.00 3313143 33 84.96 5434214 1900162 2656 245.51
5.43 0.00 4.20 0.00 3308527 33 85.24 5439695 1809382 2521 245.51
5.42 0.00 4.19 0.00 3316778 33 87.54 5416028 1805835 2256 245.51
5.42 0.00 4.19 0.00 3317673 33 90.44 5426044 1763056 2332 245.51
5.42 0.00 4.19 0.00 3314839 33 88.11 5435732 1792218 2499 245.52
5.44 0.00 4.19 0.00 3293228 33 91.84 5426301 1668597 2121 245.52

Similarly, netperf reports 230Mb/s before the patch, and 270Mb/s after the patch

Reviewed by: gallatin
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15366

r333175 introduced deferred deletion of multicast addresses in order to permit the driver ioctl
to sleep on commands to the NIC when updating multicast filters. More generally this permitted
driver's to use an sx as a softc lock. Unfortunately this change introduced a race whereby a
a multicast update would still be queued for deletion when ifconfig deleted the interface
thus calling down in to _purgemaddrs and synchronously deleting _all_ of the multicast addresses
on the interface.

Synchronously remove all external references to a multicast address before enqueueing for delete.

Reported by: lwhsu
Approved by: sbruno

Currently in_pcbfree will unconditionally wunlock the pcbinfo lock
to avoid a LOR on the multicast list lock in the freemoptions routines.
As it turns out, tcp_usr_detach can acquire the tcbinfo lock readonly.
Trying to wunlock the pcbinfo lock in that context has caused a number
of reported crashes.

This change unclutters in_pcbfree and moves the handling of wunlock vs
runlock of pcbinfo to the freemoptions routine.

Reported by: mjg@, bde@, o.hartmann at walstatt.org
Approved by: sbruno

Separate list manipulation locking from state change in multicast

Multicast incorrectly calls in to drivers with a mutex held causing drivers
to have to go through all manner of contortions to use a non sleepable lock.
Serialize multicast updates instead.

Submitted by: mmacy <mmacy@mattmacy.io>
Reviewed by: shurd, sbruno
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D14969

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Add ip6_tryforward() - a run to completion forwarding implementation
for IPv6.

It gets performance benefits from reduced number of checks. It doesn't
copy mbuf to be able send ICMPv6 error message, because it keeps mbuf
unchanged until the moment, when the route decision has been made.
It doesn't do IPsec checks, and when some IPsec security policies present,
ip6_input() uses normal slow path.

Reviewed by: bz, gnn
Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D8527

Remove the SIOCSIFALIFETIME_IN6 ioctl.

The SIOCSIFALIFETIME_IN6 provided by the kame project is unused,
it can't really be used safely and has been completely removed from
NetBSD and OpenBSD.

Obtained from: NetBSD (kern/35897)
PR: 210148 (exp-run)
Reviewed by: ae, hrs
Relnotes: yes
Approved by: re (glebius)
Differential Revision: https://reviews.freebsd.org/D5491

Revert r292275 & r292379

glebius has concerns about these changes so reverting those can be discussed
and addressed.

Sponsored by: Multiplay

Fix lagg failover due to missing notifications

When using lagg failover mode neither Gratuitous ARP (IPv4) or Unsolicited
Neighbour Advertisements (IPv6) are sent to notify other nodes that the
address may have moved.

This results is slow failover, dropped packets and network outages for the
lagg interface when the primary link goes down.

We now use the new if_link_state_change_cond with the force param set to
allow lagg to force through link state changes and hence fire a
ifnet_link_event which are now monitored by rip and nd6.

Upon receiving these events each protocol trigger the relevant
notifications:
* inet4 => Gratuitous ARP
* inet6 => Unsolicited Neighbour Announce

This also fixes the carp IPv6 NA's that stopped working after r251584 which
added the ipv6_route__llma route.

The new behavour can be controlled using the sysctls:
* net.link.ether.inet.arp_on_link
* net.inet6.icmp6.nd6_on_link

Also removed unused param from lagg_port_state and added descriptions for the
sysctls while here.

PR: 156226
MFC after: 1 month
Sponsored by: Multiplay
Differential Revision: https://reviews.freebsd.org/D4111

- Remove SIOCGDRLST_IN6 and SIOCGPRLST_IN6. These are quite old APIs and
there is no consumer now.

MFC after: 3 days

Remove IN6_IFF_NOPFX. This flag was no longer used.

MFC after: 3 days

Make in6ifa_ifpwithaddr() take const param.
Remove unneded DECONST from in6_lltable_rtcheck().

- Deprecate IN6_IFF_NODAD. It was used to prevent DAD on a loopback
interface but in6if_do_dad() already had a check for IFF_LOOPBACK.

- Remove in6if_do_dad() check in in6_broadcast_ifa(). An address
which needs DAD always has IN6_IFF_TENTATIVE there.

- in6if_do_dad() now returns EAGAIN when the interface is not ready
since DAD callout handler ignores such an interface.

- In DAD callout handler, mark an address as IN6_IFF_TENTATIVE
when the interface has ND6_IFF_IFDISABLED. And Do IFF_UP and
IFF_DRV_RUNNING check consistently when DAD is required.

- draft-ietf-6man-enhanced-dad is now published as RFC 7527.

- Fix some typos.

Convert in_ifaddr_lock and in6_ifaddr_lock to rmlock.

Both are used to protect access to IP addresses lists and they can be
acquired for reading several times per packet. To reduce lock contention
it is better to use rmlock here.

Reviewed by: gnn (previous version)
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D3149

Move ip6_sprintf() declaration from in6_var.h to in6.h. This is a simple
function that works with in6_addr and it is not related to the INET6
stack implementation.

Sponsored by: Nginx, Inc.

Now that all users of _WANT_IFADDR are fixed, remove this crutch and
hide ifaddr, in_ifaddr and in6_ifaddr under _KERNEL.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

- Rename 'struct mld_ifinfo' into 'struct mld_ifsoftc', since it really
represents a context.
- Preserve name 'struct mld_ifinfo' for a new structure, that will be stable
API between userland and kernel.
- Make sysctl_mld_ifinfo() return the new 'struct mld_ifinfo', instead of
old one, which had a bunch of internal kernel structures in it.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Widen _KERNEL ifdef to hide more kernel network stack structures from userland.

Use new struct mbufq instead of struct ifqueue to manage packet queues in
IPv6 multicast code.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Simplify lle lookup/create api by using addresses instead of sockaddrs.

Replace 'struct route *' if_output() argument with 'struct nhop_info *'.
Leave 'struct route' as is for legacy routing api users.
Remove most of rtalloc_ign*-derived functions.

Make checks for rt_mtu generic:

Some virtual if drivers has (ab)used ifa ifa_rtrequest hook to enforce
route MTU to be not bigger that interface MTU. While ifa_rtrequest hooking
might be an option in some situation, it is not feasible to do MTU checks
there: generic (or per-domain) routing code is perfectly capable of doing
this.

We currrently have 3 places where MTU is altered:

1) route addition.
In this case domain overrides radix _addroute callback (in[6]_addroute)
and all necessary checks/fixes are/can be done there.

2) route change (especially, GW change).
In this case, there are no explicit per-domain calls, but one can
override rte by setting ifa_rtrequest hook to domain handler
(inet6 does this).

3) ifconfig ifaceX mtu YYYY
In this case, we have no callbacks, but ip[6]_output performes runtime
checks and decreases rt_mtu if necessary.

Generally, the goals are to be able to handle all MTU changes in
control plane, not in runtime part, and properly deal with increased
interface MTU.

This commit changes the following:
* removes hooks setting MTU from drivers side
* adds proper per-doman MTU checks for case 1)
* adds generic MTU check for case 2)

* The latter is done by using new dom_ifmtu callback since
if_mtu denotes L3 interface MTU, e.g. maximum trasmitted _packet_ size.
However, IPv6 mtu might be different from if_mtu one (e.g. default 1280)
for some cases, so we need an abstract way to know maximum MTU size
for given interface and domain.
* moves rt_setmetrics() before MTU/ifa_rtrequest hooks since it copies
user-supplied data which must be checked.
* removes RT_LOCK_ASSERT() from other ifa_rtrequest hooks to be able to
use this functions on new non-inserted rte.

More changes will follow soon.

MFC after: 1 month
Sponsored by: Yandex LLC

Remove unused function.

Sponsored by: Yandex LLC

Add const qualifier to in6_addrhash() function.
Add in6ifa_ifwithaddr() function. It is similar to ifa_ifwithaddr,
but does fast lookup in the hash of inet6 addresses.

Obtained from: Yandex LLC
Sponsored by: Yandex LLC

Add the ability to set `prefer_source' flag to an IPv6 address.
It affects the IPv6 source address selection algorithm (RFC 6724)
and allows override the last rule ("longest matching prefix") for
choosing among equivalent addresses. The address with `prefer_source'
will be preferred source address.

Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC

Further rework netinet6 address handling code:
* Set ia address/mask values BEFORE attaching to address lists.
Inet6 address assignment is not atomic, so the simplest way to
do this atomically is to fill in ia before attach.
* Validate irfa->ia_addr field before use (we permit ANY sockaddr in old code).
* Do some renamings:
in6_ifinit -> in6_notify_ifa (interaction with other subsystems is here)
in6_setup_ifa -> in6_broadcast_ifa (LLE/Multicast/DaD code)
in6_ifaddloop -> nd6_add_ifa_lle
in6_ifremloop -> nd6_rem_ifa_lle
* Split working with LLE and route announce code for last two.
Add temporary in6_newaddrmsg() function to mimic current rtsock behaviour.
* Call device SIOCSIFADDR handler IFF we're adding first address.
In IPv4 we have to call it on every address change since ARP record
is installed by arp_ifinit() which is called by given handler.
IPv6 stack, on the opposite is responsible to call nd6_add_ifa_lle() so
there is no reason to call SIOCSIFADDR often.

Add in6_prepare_ifra() function to ease preparing in-kernel IPv6
address requests.

MFC after: 2 weeks

Introduce IN6_MASK_ADDR() macro to unify various hand-rolled code
to do IPv6 addr & mask in different places.

MFC after: 2 weeks

Hide 'struct ifaddr' definition from userland. Two tools left that use it,
namely ipftest(1) and ifmcstat(1). These sniff structure definition using
_WANT_IFADDR define.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Now counter_u64_t is known to userland, thus remove hack from r253086.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Migrate structs in6_ifstat and icmp6_ifstat to PCPU counters.

Migrate structs ip6stat, icmp6stat and rip6stat to PCPU counters.

Prepare network statistics structures for migration to PCPU counters.
Use uint64_t as type for all fields of structures.

Changed structures: ahstat, arpstat, espstat, icmp6_ifstat, icmp6stat,
in6_ifstat, ip6stat, ipcompstat, ipipstat, ipsecstat, mrt6stat, mrtstat,
pfkeystat, pim6stat, pimstat, rip6stat, udpstat.

Discussed with: arch@

- Allow ND6_IFF_AUTO_LINKLOCAL for IFT_BRIDGE. An interface with IFT_BRIDGE
is initialized with !ND6_IFF_AUTO_LINKLOCAL && !ND6_IFF_ACCEPT_RTADV
regardless of net.inet6.ip6.accept_rtadv and net.inet6.ip6.auto_linklocal.
To configure an autoconfigured link-local address (RFC 4862), the
following rc.conf(5) configuration can be used:

ifconfig_bridge0_ipv6="inet6 auto_linklocal"

- if_bridge(4) now removes IPv6 addresses on a member interface to be
added when the parent interface or one of the existing member
interfaces has an IPv6 address. if_bridge(4) merges each link-local
scope zone which the member interfaces form respectively, so it causes
address scope violation. Removal of the IPv6 addresses prevents it.

- if_lagg(4) now removes IPv6 addresses on a member interfaces
unconditionally.

- Set reasonable flags to non-IPv6-capable interfaces. [*]

Submitted by: rpaulo [*]
MFC after: 1 week

Remove unused variable.

MFC after: 1 week

In additional to the tailq of IPv6 addresses add the hash table.
For now use 256 buckets and fnv_hash function. Use xor'ed 32-bit
s6_addr32 parts of in6_addr structure as a hash key. Update
in6_localip and in6_is_addr_deprecated to use hash table for fastest
lookup.

Sponsored by: Yandex LLC
Discussed with: dwmalone, glebius, bz

Remove __P.

Submitted by: kevlo
Reviewed by: md5(1)
MFC after: 2 months

Provide the IPv6 counterpart to the extended IPv4 rtalloc(9) KPI.

Sponsored by: Cisco Systems, Inc.

Convert all users of IF_ADDR_LOCK to use new locking macros that specify
either a read lock or write lock.

Reviewed by: bz
MFC after: 2 weeks

Remove an uneeded inpcb forward declaration and align the function
declaration following to match the style in the rest of the file.

MFC after: 3 days

Provide ABI compatibility shim to enable configuring of addresses
with ifconfig(8) prior to r228571.

Requested by: brooks

A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.

The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.

ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.

To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]

The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.

Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!

PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

MFC r207369:
MFP4: @176978-176982, 176984, 176990-176994, 177441

"Whitspace" churn after the VIMAGE/VNET whirls.

Remove the need for some "init" functions within the network
stack, like pim6_init(), icmp_init() or significantly shorten
others like ip6_init() and nd6_init(), using static initialization
again where possible and formerly missed.

Move (most) variables back to the place they used to be before the
container structs and VIMAGE_GLOABLS (before r185088) and try to
reduce the diff to stable/7 and earlier as good as possible,
to help out-of-tree consumers to update from 6.x or 7.x to 8 or 9.

This also removes some header file pollution for putatively
static global variables.

Revert VIMAGE specific changes in ipfilter::ip_auth.c, that are
no longer needed.

Reviewed by: jhb
Discussed with: rwatson
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH

MFP4: @176978-176982, 176984, 176990-176994, 177441

"Whitspace" churn after the VIMAGE/VNET whirls.

Remove the need for some "init" functions within the network
stack, like pim6_init(), icmp_init() or significantly shorten
others like ip6_init() and nd6_init(), using static initialization
again where possible and formerly missed.

Move (most) variables back to the place they used to be before the
container structs and VIMAGE_GLOABLS (before r185088) and try to
reduce the diff to stable/7 and earlier as good as possible,
to help out-of-tree consumers to update from 6.x or 7.x to 8 or 9.

This also removes some header file pollution for putatively
static global variables.

Revert VIMAGE specific changes in ipfilter::ip_auth.c, that are
no longer needed.

Reviewed by: jhb
Discussed with: rwatson
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH
MFC after: 6 days

Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used. Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with: bz, julian
Reviewed by: bz
Approved by: re (kensmith, kib)

Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)

Fix "options VIMAGE_GLOBALS" build following introduction of
in6_ifaddrhead.

Approved by: re (kib)

Add address list locking for in6_ifaddrhead/ia_link: as with locking
for in_ifaddrhead, we stick with an rwlock for the time being, which
we will revisit in the future with a possible move to rmlocks.

Some pieces of code require significant further reworking to be
safe from all classes of writer-writer races.

Reviewed by: bz
MFC after: 6 weeks

Convert netinet6 to using queue(9) rather than hand-crafted linked lists
for the global IPv6 address list (in6_ifaddr -> in6_ifaddrhead). Adopt
the code styles and conventions present in netinet where possible.

Reviewed by: gnn, bz
MFC after: 6 weeks (possibly not MFCable?)

Modify most routines returning 'struct ifaddr *' to return references
rather than pointers, requiring callers to properly dispose of those
references. The following routines now return references:

ifaddr_byindex
ifa_ifwithaddr
ifa_ifwithbroadaddr
ifa_ifwithdstaddr
ifa_ifwithnet
ifaof_ifpforaddr
ifa_ifwithroute
ifa_ifwithroute_fib
rt_getifa
rt_getifa_fib
IFP_TO_IA
ip_rtaddr
in6_ifawithifp
in6ifa_ifpforlinklocal
in6ifa_ifpwithaddr
in6_ifadd
carp_iamatch6
ip6_getdstifaddr

Remove unused macro which didn't have required referencing:

IFP_TO_IA6

This closes many small races in which changes to interface
or address lists while an ifaddr was in use could lead to use of freed
memory (etc). In a few cases, add missing if_addr_list locking
required to safely acquire references.

Because of a lack of deep copying support, we accept a race in which
an in6_ifaddr pointed to by mbuf tags and extracted with
ip6_getdstifaddr() doesn't hold a reference while in transmit. Once
we have mbuf tag deep copy support, this can be fixed.

Reviewed by: bz
Obtained from: Apple, Inc. (portions)
MFC after: 6 weeks (portions)

Bite the bullet, and make the IPv6 SSM and MLDv2 mega-commit:
import from p4 bms_netdev. Summary of changes:

* Connect netinet6/in6_mcast.c to build.
The legacy KAME KPIs are mostly preserved.
* Eliminate now dead code from ip6_output.c.
Don't do mbuf bingo, we are not going to do RFC 2292 style
CMSG tricks for multicast options as they are not required
by any current IPv6 normative reference.
* Refactor transports (UDP, raw_ip6) to do own mcast filtering.
SCTP, TCP unaffected by this change.
* Add ip6_msource, in6_msource structs to in6_var.h.
* Hookup mld_ifinfo state to in6_ifextra, allocate from
domifattach path.
* Eliminate IN6_LOOKUP_MULTI(), it is no longer referenced.
Kernel consumers which need this should use in6m_lookup().
* Refactor IPv6 socket group memberships to use a vector (like IPv4).
* Update ifmcstat(8) for IPv6 SSM.
* Add witness lock order for IN6_MULTI_LOCK.
* Move IN6_MULTI_LOCK out of lower ip6_output()/ip6_input() paths.
* Introduce IP6STAT_ADD/SUB/INC/DEC as per rwatson's IPv4 cleanup.
* Update carp(4) for new IPv6 SSM KPIs.
* Virtualize ip6_mrouter socket.
Changes mostly localized to IPv6 MROUTING.
* Don't do a local group lookup in MROUTING.
* Kill unused KAME prototypes in6_purgemkludge(), in6_restoremkludge().
* Preserve KAME DAD timer jitter behaviour in MLDv1 compatibility mode.
* Bump __FreeBSD_version to 800084.
* Update UPDATING.

NOTE WELL:
* This code hasn't been tested against real MLDv2 queriers
(yet), although the on-wire protocol has been verified in Wireshark.
* There are a few unresolved issues in the socket layer APIs to
do with scope ID propagation.
* There is a LOR present in ip6_output()'s use of
in6_setscope() which needs to be resolved. See comments in mld6.c.
This is believed to be benign and can't be avoided for the moment
without re-introducing an indirect netisr.

This work was mostly derived from the IGMPv3 implementation, and
has been sponsored by a third party.

Assert the interface address list lock in IFP_TO_IA6(), as it will
iterate the interface address list. Marginally expand IF_ADDR_LOCK()
coverage in mld6.c to make sure it's held when IFP_TO_IA6() is called.

MFC after: 2 weeks

Prefer structure fields (ifa_link) to macro aliases for them
(ifa_list).

MFC after: 2 weeks

Use TAILQ_FOREACH() and TAILQ_FOREACH_SAFE() rather than manually
accessing queue(9) structure fields for if_addrhead.

Prefer FreeBSD field name if_addrhead to compatibility macro
if_addrlist.

MFC after: 2 weeks

This main goals of this project are:
1. separating L2 tables (ARP, NDP) from the L3 routing tables
2. removing as much locking dependencies among these layers as
possible to allow for some parallelism in the search operations
3. simplify the logic in the routing code,

The most notable end result is the obsolescent of the route
cloning (RTF_CLONING) concept, which translated into code reduction
in both IPv4 ARP and IPv6 NDP related modules, and size reduction in
struct rtentry{}. The change in design obsoletes the semantics of
RTF_CLONING, RTF_WASCLONE and RTF_LLINFO routing flags. The userland
applications such as "arp" and "ndp" have been modified to reflect
those changes. The output from "netstat -r" shows only the routing
entries.

Quite a few developers have contributed to this project in the
past: Glebius Smirnoff, Luigi Rizzo, Alessandro Cerri, and
Andre Oppermann. And most recently:

- Kip Macy revised the locking code completely, thus completing
the last piece of the puzzle, Kip has also been conducting
active functional testing
- Sam Leffler has helped me improving/refactoring the code, and
provided valuable reviews
- Julian Elischer setup the perforce tree for me and has helped
me maintaining that branch before the svn conversion

Second round of putting global variables, which were virtualized
but formerly missed under VIMAGE_GLOBAL.

Put the extern declarations of the virtualized globals
under VIMAGE_GLOBAL as the globals themsevles are already.
This will help by the time when we are going to remove the globals
entirely.

Sponsored by: The FreeBSD Foundation

Put a global variables, which were virtualized but formerly
missed under VIMAGE_GLOBAL.

Start putting the extern declarations of the virtualized globals
under VIMAGE_GLOBAL as the globals themsevles are already.
This will help by the time when we are going to remove the globals
entirely.

While there garbage collect a few dead externs from ip6_var.h.

Sponsored by: The FreeBSD Foundation

- Import the HEAD csup code which is the basis for the cvsmode work.

Clean up VCS Ids.

fixed memory leak for IPv6 multicast membership information associated
with interface addresses.

Approved by: gnn (mentor)
MFC after: 1 week

MFp4: 92972, 98913 + one more change

In ip6_sprintf no longer use and return one of eight static buffers
for printing/logging ipv6 addresses.
The caller now has to hand in a sufficiently large buffer as first
argument.

There is a consensus that ifaddr.ifa_addr should never be NULL,
except in places dealing with ifaddr creation or destruction; and
in such special places incomplete ifaddrs should never be linked
to system-wide data structures. Therefore we can eliminate all the
superfluous checks for "ifa->ifa_addr != NULL" and get ready
to the system crashing honestly instead of masking possible bugs.

Suggested by: glebius, jhb, ru

Use queue(3) macros instead of accessing list/queue internals directly.

sync with KAME regarding NDP

- introduced fine-grain-timer to manage ND-caches and IPv6 Multicast-Listeners
- supports Router-Preference <draft-ietf-ipv6-router-selection-07.txt>
- better prefix lifetime management
- more spec-comformant DAD advertisement
- updated RFC/internet-draft revisions

Obtained from: KAME
Reviewed by: ume, gnn
MFC after: 2 month

added an ioctl option in kernel so that ndp/rtadvd can change some NDP-related kernel variables based on their configurations (RFC2461 p.43 6.2.1 mandates this for IPv6 routers)

Obtained from: KAME
Reviewd by: ume, gnn
MFC after: 2 weeks

IPv6 was improperly defining its malloc type the same as IPv4 (M_IPMADDR,
M_IPMOPTS, M_MRTABLE). Thus we had conflicting instantiations.
Create an IPv6-specific type to overcome this.

- fix typo in comment.
- nuke unused code.

Submitted by: suz
Obtained from: KAME

Modify network protocol consumers of the ifnet multicast address lists
to lock if_addr_mtx.

Problem reported by: Ed Maste <emaste at phaedrus dot sandvine dot ca>
MFC after: 1 week

scope cleanup. with this change
- most of the kernel code will not care about the actual encoding of
scope zone IDs and won't touch "s6_addr16[1]" directly.
- similarly, most of the kernel code will not care about link-local
scoped addresses as a special case.
- scope boundary check will be stricter. For example, the current
*BSD code allows a packet with src=::1 and dst=(some global IPv6
address) to be sent outside of the node, if the application do:
s = socket(AF_INET6);
bind(s, "::1");
sendto(s, some_global_IPv6_addr);
This is clearly wrong, since ::1 is only meaningful within a single
node, but the current implementation of the *BSD kernel cannot
reject this attempt.

Submitted by: JINMEI Tatuya <jinmei__at__isl.rdc.toshiba.co.jp>
Obtained from: KAME

Add CARP (Common Address Redundancy Protocol), which allows multiple
hosts to share an IP address, providing high availability and load
balancing.

Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.

FreeBSD port done solely by Max Laier.

Patch by: mlaier
Obtained from: OpenBSD (mickey, mcbride)

/* -> /*- for license, minor formatting changes, separate for KAME

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

add management part of address selection policy described in
RFC3484.

Obtained from: KAME

Switch Advanced Sockets API for IPv6 from RFC2292 to RFC3542
(aka RFC2292bis). Though I believe this commit doesn't break
backward compatibility againt existing binaries, it breaks
backward compatibility of API.
Now, the applications which use Advanced Sockets API such as
telnet, ping6, mld6query and traceroute6 use RFC3542 API.

Obtained from: KAME

- change scope to zone.
- change node-local to interface-local.
- better error handling of address-to-scope mapping.
- use in6_clearscope().

Obtained from: KAME

nuke duplicate function and unused function.

Obtained from: KAME

- add dom_if{attach,detach} framework.
- transition to use ifp->if_afdata.

Obtained from: KAME

- fix typo in comments.
- style.
- NULL is not 0.
- some variables were renamed.
- nuke unused logic.
(there is no functional change.)

Obtained from: KAME

Update netisr handling; Each SWI now registers its queue, and all queue
drain routines are done by swi_net, which allows for better queue control
at some future point. Packets may also be directly dispatched to a netisr
instead of queued, this may be of interest at some installations, but
currently defaults to off.

Reviewed by: hsu, silby, jayanth, sam
Sponsored by: DARPA, NAI Labs

Increase size of ifnet.if_flags from 16 bits (short) to 32 bits (int). To avoid
breaking application ABI use unused ifreq.ifru_flags[1] for upper 16 bits in
SIOCSIFFLAGS and SIOCGIFFLAGS ioctl's.

Reviewed by: -hackers, -net

just merged cosmetic changes from KAME to ease sync between KAME and FreeBSD.
(based on freebsd4-snap-20020128)

Reviewed by: ume
MFC after: 1 week

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

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

Convert if_multiaddrs from LIST to TAILQ so that it can be traversed
backwards in the three drivers which want to do that.

Reviewed by: mikeh

sync with kame tree as of july00. tons of bug fixes/improvements.

API changes:
- additional IPv6 ioctls
- IPsec PF_KEY API was changed, it is mandatory to upgrade setkey(8).
(also syntax change)

Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by: msmith and others

Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by: phk
Reviewed by: phk
Approved by: mdodd

udp IPv6 support, IPv6/IPv4 tunneling support in kernel,
packet divert at kernel for IPv6/IPv4 translater daemon

This includes queue related patch submitted by jburkhol@home.com.

Submitted by: queue related patch from jburkhol@home.com
Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project

KAME netinet6 basic part(no IPsec,no V6 Multicast Forwarding, no UDP/TCP
for IPv6 yet)

With this patch, you can assigne IPv6 addr automatically, and can reply to
IPv6 ping.

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

KAME related header files additions and merges.
(only those which don't affect c source files so much)

Reviewed by: cvs-committers
Obtained from: KAME project