Commit Graph

189 Commits

Author SHA1 Message Date
Michael Tuexen
3e1465754f Make ICMPv6 hard error handling for TCP consistent with the ICMPv4
handling. Ensure that:
* Protocol unreachable errors are handled by indicating ECONNREFUSED
  to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Communication prohibited errors are handled by indicating ECONNREFUSED
  to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Hop Limited exceeded errors are handled by indicating EHOSTUNREACH
  to the TCP user for both IPv4 and IPv6.
  For IPv6 the TCP connected was dropped but errno wasn't set.

Reviewed by: gallatin, rrs
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: 7904
2016-10-21 10:32:57 +00:00
Andrey V. Elsukov
7aeccebc0d Add net.inet6.ip6.intr_queue_maxlen sysctl. It can be used to
change netisr queue limit for IPv6 at runtime.

Obtained from:	Yandex LLC
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2016-07-15 17:09:30 +00:00
Bjoern A. Zeeb
89856f7e2d Get closer to a VIMAGE network stack teardown from top to bottom rather
than removing the network interfaces first. This change is rather larger
and convoluted as the ordering requirements cannot be separated.

Move the pfil(9) framework to SI_SUB_PROTO_PFIL, move Firewalls and
related modules to their own SI_SUB_PROTO_FIREWALL.
Move initialization of "physical" interfaces to SI_SUB_DRIVERS,
move virtual (cloned) interfaces to SI_SUB_PSEUDO.
Move Multicast to SI_SUB_PROTO_MC.

Re-work parts of multicast initialisation and teardown, not taking the
huge amount of memory into account if used as a module yet.

For interface teardown we try to do as many of them as we can on
SI_SUB_INIT_IF, but for some this makes no sense, e.g., when tunnelling
over a higher layer protocol such as IP. In that case the interface
has to go along (or before) the higher layer protocol is shutdown.

Kernel hhooks need to go last on teardown as they may be used at various
higher layers and we cannot remove them before we cleaned up the higher
layers.

For interface teardown there are multiple paths:
(a) a cloned interface is destroyed (inside a VIMAGE or in the base system),
(b) any interface is moved from a virtual network stack to a different
network stack ("vmove"), or (c) a virtual network stack is being shut down.
All code paths go through if_detach_internal() where we, depending on the
vmove flag or the vnet state, make a decision on how much to shut down;
in case we are destroying a VNET the individual protocol layers will
cleanup their own parts thus we cannot do so again for each interface as
we end up with, e.g., double-frees, destroying locks twice or acquiring
already destroyed locks.
When calling into protocol cleanups we equally have to tell them
whether they need to detach upper layer protocols ("ulp") or not
(e.g., in6_ifdetach()).

Provide or enahnce helper functions to do proper cleanup at a protocol
rather than at an interface level.

Approved by:		re (hrs)
Obtained from:		projects/vnet
Reviewed by:		gnn, jhb
Sponsored by:		The FreeBSD Foundation
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D6747
2016-06-21 13:48:49 +00:00
Andrey V. Elsukov
4c10540274 Cleanup unneded include "opt_ipfw.h".
It was used for conditional build IPFIREWALL_FORWARD support.
But IPFIREWALL_FORWARD option was removed a long time ago.
2016-06-09 05:48:34 +00:00
Bjoern A. Zeeb
484149def8 Introduce a per-VNET flag to enable/disable netisr prcessing on that VNET.
Add accessor functions to toggle the state per VNET.
The base system (vnet0) will always enable itself with the normal
registration. We will share the registered protocol handlers in all
VNETs minimising duplication and management.
Upon disabling netisr processing for a VNET drain the netisr queue from
packets for that VNET.

Update netisr consumers to (de)register on a per-VNET start/teardown using
VNET_SYS(UN)INIT functionality.

The change should be transparent for non-VIMAGE kernels.

Reviewed by:	gnn (, hiren)
Obtained from:	projects/vnet
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D6691
2016-06-03 13:57:10 +00:00
Bjoern A. Zeeb
3f58662dd9 The pr_destroy field does not allow us to run the teardown code in a
specific order.  VNET_SYSUNINITs however are doing exactly that.
Thus remove the VIMAGE conditional field from the domain(9) protosw
structure and replace it with VNET_SYSUNINITs.
This also allows us to change some order and to make the teardown functions
file local static.
Also convert divert(4) as it uses the same mechanism ip(4) and ip6(4) use
internally.

Slightly reshuffle the SI_SUB_* fields in kernel.h and add a new ones, e.g.,
for pfil consumers (firewalls), partially for this commit and for others
to come.

Reviewed by:		gnn, tuexen (sctp), jhb (kernel.h)
Obtained from:		projects/vnet
MFC after:		2 weeks
X-MFC:			do not remove pr_destroy
Sponsored by:		The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D6652
2016-06-01 10:14:04 +00:00
Bjoern A. Zeeb
9901091eba Mfp4 @180378:
Factor out nd6 and in6_attach initialization to their own files.
  Also move destruction into those files though still called from
  the central initialization.

  Sponsored by:	CK Software GmbH
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Reviewed by:	gnn
Differential Revision:	https://reviews.freebsd.org/D5033
2016-03-22 15:43:47 +00:00
Andrey V. Elsukov
ef91a9765d Overhaul if_enc(4) and make it loadable in run-time.
Use hhook(9) framework to achieve ability of loading and unloading
if_enc(4) kernel module. INET and INET6 code on initialization registers
two helper hooks points in the kernel. if_enc(4) module uses these helper
hook points and registers its hooks. IPSEC code uses these hhook points
to call helper hooks implemented in if_enc(4).
2015-11-25 07:31:59 +00:00
Adrian Chadd
aaa46574b0 [netinet6]: Create a new IPv6 netisr which expects the frames to have been verified.
This is required for fragments and encapsulated data (eg tunneling) to be redistributed
to the RSS bucket based on the eventual IPv6 header and protocol (TCP, UDP, etc) header.

* Add an mbuf tag with the state of IPv6 options parsing before the frame is queued
  into the direct dispatch handler;
* Continue processing and complete the frame reception in the correct RSS bucket /
  netisr context.

Testing results are in the phabricator review.

Differential Revision:	https://reviews.freebsd.org/D3563
Submitted by:	Tiwei Bie <btw@mail.ustc.edu.cn>
2015-11-06 23:07:43 +00:00
Adrian Chadd
68bb8d6249 Add support for receiving flowtype, flowid and RSS bucket information as part of recvmsg().
Submitted by:	Tiwei Bie <btw@mail.ustc.edu.cn>
Differential Revision:	https://reviews.freebsd.org/D3562
2015-09-06 20:57:57 +00:00
Adrian Chadd
0be189151f Implement RSS hashing/re-hashing for IPv6 ingress packets.
This mirrors the basic IPv4 implementation - IPv6 packets under RSS
now are checked for a correct RSS hash and if one isn't provided,
it's done in software.

This only handles the initial receive - it doesn't yet handle
reinjecting / rehashing packets after being decapsulated from
various tunneling setups.  That'll come in some follow-up work.

For non-RSS users, this is almost a giant no-op.

It does change a couple of ipv6 methods to use const mbuf * instead of
mbuf * but it doesn't have any functional changes.

So, the following now occurs:

* If the NIC doesn't do any RSS hashing, it's all done in software.
  Single-queue, non-RSS NICs will now have the RX path distributed
  into multiple receive netisr queues.

* If the NIC provides the wrong hash (eg only IPv6 hash when we needed
  an IPv6 TCP hash, or IPv6 UDP hash when we expected IPv6 hash)
  then the hash is recalculated.

* .. if the hash is recalculated, it'll end up being injected into
  the correct netisr queue for v6 processing.

Submitted by:	Tiwei Bie <btw@mail.ustc.edu.cn>
Differential Revision:	https://reviews.freebsd.org/D3504
2015-08-29 07:14:29 +00:00
Andrey V. Elsukov
cc0a3c8ca4 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
2015-07-29 08:12:05 +00:00
Andrey V. Elsukov
8f1beb889e Fix deadlock in IPv6 PCB code.
When several threads are trying to send datagram to the same destination,
but fragmentation is disabled and datagram size exceeds link MTU,
ip6_output() calls pfctlinput2(PRC_MSGSIZE). It does notify all
sockets wanted to know MTU to this destination. And since all threads
hold PCB lock while sending, taking the lock for each PCB in the
in6_pcbnotify() leads to deadlock.

RFC 3542 p.11.3 suggests notify all application wanted to receive
IPV6_PATHMTU ancillary data for each ICMPv6 packet too big message.
But it doesn't require this, when we don't receive ICMPv6 message.

Change ip6_notify_pmtu() function to be able use it directly from
ip6_output() to notify only one socket, and to notify all sockets
when ICMPv6 packet too big message received.

PR:		197059
Differential Revision:	https://reviews.freebsd.org/D1949
Reviewed by:	no objection from #network
Obtained from:	Yandex LLC
MFC after:	1 week
Sponsored by:	Yandex LLC
2015-03-04 11:20:01 +00:00
Andrey V. Elsukov
3e88eb903b Remove ip6_getdstifaddr() and all functions to work with auxiliary data.
It isn't safe to keep unreferenced ifaddrs. Use in6ifa_ifwithaddr() to
determine ifaddr corresponding to destination address. Since currently
we keep addresses with embedded scope zone, in6ifa_ifwithaddr is called
with zero zoneid and marked with XXX.

Also remove route and lle lookups from ip6_input. Use in6ifa_ifwithaddr()
instead.

Sponsored by:	Yandex LLC
2014-11-08 19:38:34 +00:00
Kevin Lo
8f5a8818f5 Merge 'struct ip6protosw' and 'struct protosw' into one. Now we have
only one protocol switch structure that is shared between ipv4 and ipv6.

Phabric:	D476
Reviewed by:	jhb
2014-08-08 01:57:15 +00:00
Alexander V. Chernikov
36d55f0f9d Unify sa_equal() macro usage.
MFC after:	2 weeks
2014-04-26 14:52:03 +00:00
Andrey V. Elsukov
52c57247d3 Remove unused variable.
PR:		173521
MFC after:	1 week
Sponsored by:	Yandex LLC
2014-04-17 06:40:11 +00:00
Andrey V. Elsukov
e4c77ca0c0 Drop packets to multicast address whose scop field contains the
reserved value 0.

MFC after:	1 week
Sponsored by:	Yandex LLC
2014-02-13 14:10:44 +00:00
Gleb Smirnoff
5d6d7e756b o Revamp API between flowtable and netinet, netinet6.
- ip_output() and ip_output6() simply call flowtable_lookup(),
    passing mbuf and address family. That's the only code under
    #ifdef FLOWTABLE in the protocols code now.
o Revamp statistics gathering and export.
  - Remove hand made pcpu stats, and utilize counter(9).
  - Snapshot of statistics is available via 'netstat -rs'.
  - All sysctls are moved into net.flowtable namespace, since
    spreading them over net.inet isn't correct.
o Properly separate at compile time INET and INET6 parts.
o General cleanup.
  - Remove chain of multiple flowtables. We simply have one for
    IPv4 and one for IPv6.
  - Flowtables are allocated in flowtable.c, symbols are static.
  - With proper argument to SYSINIT() we no longer need flowtable_ready.
  - Hash salt doesn't need to be per-VNET.
  - Removed rudimentary debugging, which use quite useless in dtrace era.

The runtime behavior of flowtable shouldn't be changed by this commit.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-02-07 15:18:23 +00:00
Attilio Rao
54366c0bd7 - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
Gleb Smirnoff
76039bc84f The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-26 17:58:36 +00:00
Gleb Smirnoff
7caf4ab7ac - Utilize counter(9) to accumulate statistics on interface addresses. Add
four counters to struct ifaddr. This kills '+=' on a variables shared
  between processors for every packet.
- Nuke struct if_data from struct ifaddr.
- In ip_input() do not put a reference on ifaddr, instead update statistics
  right now in place and do IN_IFADDR_RUNLOCK(). These removes atomic(9)
  for every packet. [1]
- To properly support NET_RT_IFLISTL sysctl used by getifaddrs(3), in
  rtsock.c fill if_data fields using counter_u64_fetch().
- Accidentially fix bug in COMPAT_32 version of NET_RT_IFLISTL, which
  took if_data not from the ifaddr, but from ifaddr's ifnet. [2]

Submitted by:	melifaro [1], pluknet[2]
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-15 11:37:57 +00:00
Gleb Smirnoff
ca695e0807 Remove useless check of ia6 against NULL, right after dereferencing it. 2013-10-15 10:11:23 +00:00
Mikolaj Golub
4d3dfd450a Unregister inet/inet6 pfil hooks on vnet destroy.
Discussed with:	andre
Approved by:	re (rodrigc)
2013-09-13 18:45:10 +00:00
Mark Johnston
57f6086735 Implement the ip, tcp, and udp DTrace providers. The probe definitions use
dynamic translation so that their arguments match the definitions for
these providers in Solaris and illumos. Thus, existing scripts for these
providers should work unmodified on FreeBSD.

Tested by:	gnn, hiren
MFC after:	1 month
2013-08-25 21:54:41 +00:00
Andrey V. Elsukov
a786f67981 Migrate structs ip6stat, icmp6stat and rip6stat to PCPU counters. 2013-07-09 09:54:54 +00:00
Andrey V. Elsukov
eca4d72003 Use IP6S_M2MMAX macro. 2013-04-16 11:19:13 +00:00
Andrey V. Elsukov
9cb8d207af Use IP6STAT_INC/IP6STAT_DEC macros to update ip6 stats.
MFC after:	1 week
2013-04-09 07:11:22 +00:00
Gleb Smirnoff
10e5acc3c6 - Use m_getcl() instead of hand allocating.
- Do not calculate constant length values at run time,
  CTASSERT() their sanity.
- Remove superfluous cleaning of mbuf fields after allocation.
- Replace compat macros with function calls.

Sponsored by:	Nginx, Inc.
2013-03-15 13:48:53 +00:00
Gleb Smirnoff
aa48181169 Use m_getcl() instead of hand made allocation.
Sponsored by:	Nginx, Inc.
2013-03-15 12:33:23 +00:00
Andrey V. Elsukov
68eba526b9 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
2012-12-15 20:04:24 +00:00
Gleb Smirnoff
eb1b1807af Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually
2012-12-05 08:04:20 +00:00
Andrey V. Elsukov
73cb2f38f2 Reduce the overhead of locking, use IF_AFDATA_RLOCK() when we are doing
simple lookups.

Sponsored by:	Yandex LLC
MFC after:	1 week
2012-11-16 12:12:02 +00:00
Andrey V. Elsukov
ffdbf9da3b Remove the recently added sysctl variable net.pfil.forward.
Instead, add protocol specific mbuf flags M_IP_NEXTHOP and
M_IP6_NEXTHOP. Use them to indicate that the mbuf's chain
contains the PACKET_TAG_IPFORWARD tag. And do a tag lookup
only when this flag is set.

Suggested by:	andre
2012-11-02 01:20:55 +00:00
Andrey V. Elsukov
c1de64a495 Remove the IPFIREWALL_FORWARD kernel option and make possible to turn
on the related functionality in the runtime via the sysctl variable
net.pfil.forward. It is turned off by default.

Sponsored by:	Yandex LLC
Discussed with:	net@
MFC after:	2 weeks
2012-10-25 09:39:14 +00:00
Michael Tuexen
b36dcb9a39 Deliver IPV6_TCLASS, IPV6_HOPLIMIT and IPV6_PKTINFO cmsgs (if
requested) on IPV6 sockets, which have been marked to be not IPV6_V6ONLY,
for each received IPV4 packet.

MFC after: 3 days
2012-06-12 13:57:56 +00:00
Maksim Yevmenkin
3df0e439b0 Plug reference leak.
Interface routes are refcounted as packets move through the stack,
and there's garbage collection tied to it so that route changes can
safely propagate while traffic is flowing. In our setup, we weren't
changing or deleting any routes, but the refcounting logic in
ip6_input() was wrong and caused a reference leak on every inbound
V6 packet. This eventually caused a 32bit overflow, and the resulting
0 value caused the garbage collection to run on the active route.
That then snowballed into the panic.

Reviewed by:	scottl
MFC after:	3 days
2012-06-03 07:36:59 +00:00
Bjoern A. Zeeb
ae14505058 MFp4 bz_ipv6_fast:
Factor out Hop-By-Hop option processing.  It's still not heavily used,
  it reduces the footprint of ip6_input() and makes ip6_input() more
  readable.

  Sponsored by:	The FreeBSD Foundation
  Sponsored by:	iXsystems

Reviewed by:	gnn (as part of the whole)
MFC After:	3 days
2012-05-25 02:58:21 +00:00
Bjoern A. Zeeb
d3443481dc MFp4 bz_ipv6_fast:
Hide the ip6aux functions.  The only one referenced outside ip6_input.c
  is not compiled in yet (__notyet__) in route6.c (r235954).  We do have
  accessor functions that should be used.

  Sponsored by:	The FreeBSD Foundation
  Sponsored by:	iXsystems

Reviewed by:	gnn (as part of the whole)
MFC After:	3 days
X-MFC:		KPI?
2012-05-25 01:48:15 +00:00
Hiroki Sato
dead19563c Allow to configure net.inet6.ip6.{accept_rtadv,no_radr} by the loader tunables
as well because they have to be configured before interface initialization for
AF_INET6.
2012-03-02 07:23:28 +00:00
Bjoern A. Zeeb
81d5d46b3c Add multi-FIB IPv6 support to the core network stack supplementing
the original IPv4 implementation from r178888:

- Use RT_DEFAULT_FIB in the IPv4 implementation where noticed.
- Use rt*fib() KPI with explicit RT_DEFAULT_FIB where applicable in
  the NFS code.
- Use the new in6_rt* KPI in TCP, gif(4), and the IPv6 network stack
  where applicable.
- Split in6_rtqtimo() and in6_mtutimo() as done in IPv4 and equally
  prevent multiple initializations of callouts in in6_inithead().
- Use wrapper functions where needed to preserve the current KPI to
  ease MFCs.  Use BURN_BRIDGES to indicate expected future cleanup.
- Fix (related) comments (both technical or style).
- Convert to rtinit() where applicable and only use custom loops where
  currently not possible otherwise.
- Multicast group, most neighbor discovery address actions and faith(4)
  are locked to the default FIB.  Individual IPv6 addresses will only
  appear in the default FIB, however redirect information and prefixes
  of connected subnets are automatically propagated to all FIBs by
  default (mimicking IPv4 behavior as closely as possible).

Sponsored by:	Cisco Systems, Inc.
2012-02-03 13:08:44 +00:00
John Baldwin
137f91e80f 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
2012-01-05 19:00:36 +00:00
Bjoern A. Zeeb
8a006adb24 Add support for IPv6 to ipfw fwd:
Distinguish IPv4 and IPv6 addresses and optional port numbers in
user space to set the option for the correct protocol family.
Add support in the kernel for carrying the new IPv6 destination
address and port.
Add support to TCP and UDP for IPv6 and fix UDP IPv4 to not change
the address in the IP header.
Add support for IPv6 forwarding to a non-local destination.
Add a regession test uitilizing VIMAGE to check all 20 possible
combinations I could think of.

Obtained from:	David Dolson at Sandvine Incorporated
		(original version for ipfw fwd IPv6 support)
Sponsored by:	Sandvine Incorporated
PR:		bin/117214
MFC after:	4 weeks
Approved by:	re (kib)
2011-08-20 17:05:11 +00:00
Bjoern A. Zeeb
869052041d Add the missing call to ip6_ipsec_filtertunnel() to be able to control
whether decapsulated IPsec packets will be passed to pfil again depending
on the setting of the net.ip6.ipsec6.filtertunnel sysctl.

PR:		kern/157670
Submitted by:	Manuel Kasper (mk neon1.net)
MFC after:	2 weeks
2011-06-08 10:59:36 +00:00
Rebecca Cran
6d79f3f6ae Fix more continuous/contiguous typos (cf. r215955) 2010-11-27 21:51:39 +00:00
Bjoern A. Zeeb
1b48d24533 MFp4 CH=183052 183053 183258:
In protosw we define pr_protocol as short, while on the wire
  it is an uint8_t.  That way we can have "internal" protocols
  like DIVERT, SEND or gaps for modules (PROTO_SPACER).
  Switch ipproto_{un,}register to accept a short protocol number(*)
  and do an upfront check for valid boundries. With this we
  also consistently report EPROTONOSUPPORT for out of bounds
  protocols, as we did for proto == 0.  This allows a caller
  to not error for this case, which is especially important
  if we want to automatically call these from domain handling.

  (*) the functions have been without any in-tree consumer
  since the initial introducation, so this is considered save.

  Implement ip6proto_{un,}register() similarly to their legacy IP
  counter parts to allow modules to hook up dynamically.

Reviewed by:	philip, will
MFC after:	1 week
2010-09-02 17:43:44 +00:00
Bjoern A. Zeeb
101235dcb3 Since r186119 IP6 input counters for octets and packets were not
working anymore.  In addition more checks and operations were missing.

In case lla_lookup results in a match, get the ifaddr to update the
statistics counters, and check that the address is neither tentative,
duplicate or otherwise invalid before accepting the packet.  If ok,
record the address information in the mbuf.  [ as is done in case
lla_lookup does not return a result and we go through the FIB ].

Reported by:	remko
Tested by:	remko
MFC after:	2 weeks
2010-07-21 13:01:21 +00:00
Kip Macy
83e711ec14 allocate ipv6 flows from the ipv6 flow zone
reported by: rrs@

MFC after:	3 days
2010-05-16 21:48:39 +00:00
Kip Macy
94162961c6 do a proper fix
Pointed out by: np@

MFC after:	3 days
2010-05-13 19:47:36 +00:00
Kip Macy
fc21c49a0f fix compile error on some builds by doing the equivalent of
an "extern VNET_DEFINE" without "__used"

MFC after:	3 days
2010-05-13 19:36:13 +00:00