Commit graph

88 commits

Author SHA1 Message Date
Xavier Beaudouin 80044c785c Add UDP encapsulation of ESP in IPv6
This patch provides UDP encapsulation of ESP packets over IPv6.
Ports the IPv4 code to IPv6 and adds support for IPv6 in udpencap.c
As required by the RFC and unlike in IPv4 encapsulation,
UDP checksums are calculated.

Co-authored-by:	Aurelien Cazuc <aurelien.cazuc.external@stormshield.eu>
Sponsored-by:	Stormshield
Sponsored-by:	Wiktel
Sponsored-by:	Klara, Inc.
2024-01-16 20:44:34 +00:00
Warner Losh 95ee2897e9 sys: Remove $FreeBSD$: two-line .h pattern
Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/
2023-08-16 11:54:11 -06:00
Warner Losh 4d846d260e spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with:		pfg
MFC After:		3 days
Sponsored by:		Netflix
2023-05-12 10:44:03 -06:00
Gleb Smirnoff e68b379244 tcp: embed inpcb into tcpcb
For the TCP protocol inpcb storage specify allocation size that would
provide space to most of the data a TCP connection needs, embedding
into struct tcpcb several structures, that previously were allocated
separately.

The most import one is the inpcb itself.  With embedding we can provide
strong guarantee that with a valid TCP inpcb the tcpcb is always valid
and vice versa.  Also we reduce number of allocs/frees per connection.
The embedded inpcb is placed in the beginning of the struct tcpcb,
since in_pcballoc() requires that.  However, later we may want to move
it around for cache line efficiency, and this can be done with a little
effort.  The new intotcpcb() macro is ready for such move.

The congestion algorithm data, the TCP timers and osd(9) data are
also embedded into tcpcb, and temprorary struct tcpcb_mem goes away.
There was no extra allocation here, but we went through extra pointer
every time we accessed this data.

One interesting side effect is that now TCP data is allocated from
SMR-protected zone.  Potentially this allows the TCP stacks or other
TCP related modules to utilize that for their own synchronization.

Large part of the change was done with sed script:

s/tp->ccv->/tp->t_ccv./g
s/tp->ccv/\&tp->t_ccv/g
s/tp->cc_algo/tp->t_cc/g
s/tp->t_timers->tt_/tp->tt_/g
s/CCV\(ccv, osd\)/\&CCV(ccv, t_osd)/g

Dependency side effect is that code that needs to know struct tcpcb
should also know struct inpcb, that added several <netinet/in_pcb.h>.

Differential revision:	https://reviews.freebsd.org/D37127
2022-12-07 09:00:48 -08:00
Gleb Smirnoff 809fef2913 netipsec: move specific ipsecmethods declarations to ipsec_support.h
where struct ipsec_methods is defined.  Not a functional change.
Allows further modification of method prototypes without breaking
compilation of other ipsec compilation units.

Differential revision:	https://reviews.freebsd.org/D36730
2022-10-03 20:53:04 -07:00
John Baldwin 4046178557 ipsec_encap: setdf is only used for INET. 2022-04-13 16:08:21 -07:00
Mark Johnston 44775b163b netinet: Remove unneeded mb_unmapped_to_ext() calls
in_cksum_skip() now handles unmapped mbufs on platforms where they're
permitted.

Reviewed by:	glebius, jhb
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33097
2021-11-24 13:31:16 -05:00
Mark Johnston 756bb50b6a sctp: Remove now-unneeded mb_unmapped_to_ext() calls
sctp_delayed_checksum() now handles unmapped mbufs, thanks to m_apply().

No functional change intended.

Reviewed by:	tuexen
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32942
2021-11-16 13:38:09 -05:00
Wojciech Macek 8deba29c0a ipsec: fix typo part2 2021-09-27 07:46:56 +02:00
Wojciech Macek c27214f0af ipsec: fix typo in comment 2021-09-27 07:45:33 +02:00
Bartlomiej Grzesik 9dfc8606eb ipsec: Add support for PMTUD for IPv6 tunnels
Discard and send ICMPv6 Packet Too Big to sender when we try to encapsulate
and forward a packet which total length exceeds the PMTU.
Logic is based on the IPv4 implementation.
Common code was moved to a separate function.

Differential revision:	https://reviews.freebsd.org/D31771
Obtained from:		Semihalf
Sponsored by:		Stormshield
2021-09-24 10:27:21 +02:00
Bartlomiej Grzesik b4220bf387 ipsec: If no PMTU in hostcache assume it's equal to link's MTU
If we fail to find to PMTU in hostcache, we assume it's equal
to link's MTU.

This patch prevents packets larger then link's MTU to be dropped
silently if there is no PMTU in hostcache.

Differential revision:	https://reviews.freebsd.org/D31770
Obtained from:		Semihalf
Sponsored by:		Stormshield
2021-09-24 10:25:53 +02:00
Bartlomiej Grzesik 4f3376951d ipsec: Add PMTUD support for IPsec IPv4 over IPv6 tunnel
Add support for checking PMTU for IPv4 packets encapsulated in IPv6 tunnels.

Differential revision:	https://reviews.freebsd.org/D31769
Sponsored by:		Stormshield
Obtained from:		Semihalf
2021-09-24 10:17:11 +02:00
Kornel Duleba a16771de4c ipsec: Return error code if no matching SA was found
If we matched SP to a packet, but no associated SA was found
ipsec4_allocsa will return NULL while setting error=0.
This resulted in use after free and potential kernel panic.
Return EINPROGRESS if the case described above instead.

Obtained from:		Semihalf
Sponsored by:		Stormshield
Differential revision:	https://reviews.freebsd.org/D30994
2021-08-13 09:35:08 +02:00
Kornel Duleba 6b66194bcb ipsec: Check PMTU before sending a frame.
If an encapsulated frame is going to have DF bit set check its desitnitions'
PMTU and if it won't fit drop it and:

Generate ICMP 3/4 message if the packet was to be forwarded.
Return EMSGSIZE error otherwise.

Obtained from:		Semihalf
Sponsored by:		Stormshield
Differential revision:	https://reviews.freebsd.org/D30993
2021-08-13 09:22:24 +02:00
John Baldwin 8e9313caa6 Convert unmapped mbufs before computing checksums in IPsec.
This is similar to the logic used in ip_output() to convert mbufs
prior to computing checksums.  Unmapped mbufs can be sent when using
sendfile() over IPsec or using KTLS over IPsec.

Reported by:	Sony Arpita Das @ Chelsio QA
Reviewed by:	np
Sponsored by:	Chelsio
Differential Revision:	https://reviews.freebsd.org/D28187
2021-01-19 11:52:00 -08:00
Mateusz Guzik 662c13053f net: clean up empty lines in .c and .h files 2020-09-01 21:19:14 +00:00
John Baldwin f82eb2a6f0 Enter and exit the network epoch for async IPsec callbacks.
When an IPsec packet has been encrypted or decrypted, the next step in
the packet's traversal through the network stack is invoked from a
crypto worker thread, not from the original calling thread.  These
threads need to enter the network epoch before passing packets down to
IP output routines or up to transport protocols.

Reviewed by:	ae
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D25444
2020-06-25 23:57:30 +00:00
Mark Johnston 95033af923 Add the SCTP_SUPPORT kernel option.
This is in preparation for enabling a loadable SCTP stack.  Analogous to
IPSEC/IPSEC_SUPPORT, the SCTP_SUPPORT kernel option must be configured
in order to support a loadable SCTP implementation.

Discussed with:	tuexen
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2020-06-18 19:32:34 +00:00
Pedro F. Giffuni fe267a5590 sys: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.
2017-11-27 15:23:17 +00:00
Andrey V. Elsukov 22bbefb2c9 Fix the regression introduced in r275710.
When a security policy should match TCP connection with specific ports,
the SYN+ACK segment send by syncache_respond() is considered as forwarded
packet, because at this moment TCP connection does not have PCB structure,
and ip_output() is called without inpcb pointer. In this case SPIDX filled
for SP lookup will not contain TCP ports and security policy will not
be found. This can lead to unencrypted SYN+ACK on the wire.

This patch restores the old behavior, when ports will not be filled only
for forwarded packets.

Reported by:	Dewayne Geraghty <dewayne.geraghty at heuristicsystems.com.au>
MFC after:	1 week
2017-08-21 13:52:21 +00:00
Andrey V. Elsukov 1a01e0e7ac Add inpcb pointer to struct ipsec_ctx_data and pass it to the pfil hook
from enc_hhook().

This should solve the problem when pf is used with if_enc(4) interface,
and outbound packet with existing PCB checked by pf, and this leads to
deadlock due to pf does its own PCB lookup and tries to take rlock when
wlock is already held.

Now we pass PCB pointer if it is known to the pfil hook, this helps to
avoid extra PCB lookup and thus rlock acquiring is not needed.
For inbound packets it is safe to pass NULL, because we do not held any
PCB locks yet.

PR:		220217
MFC after:	3 weeks
Sponsored by:	Yandex LLC
2017-07-31 11:04:35 +00:00
Andrey V. Elsukov 7f1f65918b Disable IPsec debugging code by default when IPSEC_DEBUG kernel option
is not specified.

Due to the long call chain IPsec code can produce the kernel stack
exhaustion on the i386 architecture. The debugging code usually is not
used, but it requires a lot of stack space to keep buffers for strings
formatting. This patch conditionally defines macros to disable building
of IPsec debugging code.

IPsec currently has two sysctl variables to configure debug output:
 * net.key.debug variable is used to enable debug output for PF_KEY
   protocol. Such debug messages are produced by KEYDBG() macro and
   usually they can be interesting for developers.
 * net.inet.ipsec.debug variable is used to enable debug output for
   DPRINTF() macro and ipseclog() function. DPRINTF() macro usually
   is used for development debugging. ipseclog() function is used for
   debugging by administrator.

The patch disables KEYDBG() and DPRINTF() macros, and formatting buffers
declarations when IPSEC_DEBUG is not present in kernel config. This reduces
stack requirement for up to several hundreds of bytes.
The net.inet.ipsec.debug variable still can be used to enable ipseclog()
messages by administrator.

PR:		219476
Reported by:	eugen
No objection from:	#network
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D10869
2017-05-29 09:30:38 +00:00
Andrey V. Elsukov 3aee70991d Fix possible double releasing for SA and SP references.
There are two possible ways how crypto callback are called: directly from
caller and deffered from crypto thread.

For outbound packets the direct call chain is the following:
 IPSEC_OUTPUT() method -> ipsec[46]_common_output() ->
 -> ipsec[46]_perform_request() -> xform_output() ->
 -> crypto_dispatch() -> crypto_invoke() -> crypto_done() ->
 -> xform_output_cb() -> ipsec_process_done() -> ip[6]_output().

The SA and SP references are held while crypto processing is not finished.
The error handling code wrongly expected that crypto callback always called
from the crypto thread context, and it did references releasing in
xform_output_cb(). But when the crypto callback called directly, in case of
error the error handling code in ipsec[46]_perform_request() also did
references releasing.

To fix this, remove error handling from ipsec[46]_perform_request() and do it
in xform_output() before crypto_dispatch().

MFC after:	10 days
2017-05-23 09:32:26 +00:00
Andrey V. Elsukov fcf596178b Merge projects/ipsec into head/.
Small summary
 -------------

o Almost all IPsec releated code was moved into sys/netipsec.
o New kernel modules added: ipsec.ko and tcpmd5.ko. New kernel
  option IPSEC_SUPPORT added. It enables support for loading
  and unloading of ipsec.ko and tcpmd5.ko kernel modules.
o IPSEC_NAT_T option was removed. Now NAT-T support is enabled by
  default. The UDP_ENCAP_ESPINUDP_NON_IKE encapsulation type
  support was removed. Added TCP/UDP checksum handling for
  inbound packets that were decapsulated by transport mode SAs.
  setkey(8) modified to show run-time NAT-T configuration of SA.
o New network pseudo interface if_ipsec(4) added. For now it is
  build as part of ipsec.ko module (or with IPSEC kernel).
  It implements IPsec virtual tunnels to create route-based VPNs.
o The network stack now invokes IPsec functions using special
  methods. The only one header file <netipsec/ipsec_support.h>
  should be included to declare all the needed things to work
  with IPsec.
o All IPsec protocols handlers (ESP/AH/IPCOMP protosw) were removed.
  Now these protocols are handled directly via IPsec methods.
o TCP_SIGNATURE support was reworked to be more close to RFC.
o PF_KEY SADB was reworked:
  - now all security associations stored in the single SPI namespace,
    and all SAs MUST have unique SPI.
  - several hash tables added to speed up lookups in SADB.
  - SADB now uses rmlock to protect access, and concurrent threads
    can do SA lookups in the same time.
  - many PF_KEY message handlers were reworked to reflect changes
    in SADB.
  - SADB_UPDATE message was extended to support new PF_KEY headers:
    SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST. They
    can be used by IKE daemon to change SA addresses.
o ipsecrequest and secpolicy structures were cardinally changed to
  avoid locking protection for ipsecrequest. Now we support
  only limited number (4) of bundled SAs, but they are supported
  for both INET and INET6.
o INPCB security policy cache was introduced. Each PCB now caches
  used security policies to avoid SP lookup for each packet.
o For inbound security policies added the mode, when the kernel does
  check for full history of applied IPsec transforms.
o References counting rules for security policies and security
  associations were changed. The proper SA locking added into xform
  code.
o xform code was also changed. Now it is possible to unregister xforms.
  tdb_xxx structures were changed and renamed to reflect changes in
  SADB/SPDB, and changed rules for locking and refcounting.

Reviewed by:	gnn, wblock
Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D9352
2017-02-06 08:49:57 +00:00
Pedro F. Giffuni a4641f4eaa sys/net*: minor spelling fixes.
No functional change.
2016-05-03 18:05:43 +00:00
Andrey V. Elsukov 6f814d0ec1 Fix handling of net.inet.ipsec.dfbit=2 variable.
IP_DF macro is in host bytes order, but ip_off field is in network bytes
order. So, use htons() for correct check.
2016-03-18 09:03:00 +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
Andrey V. Elsukov f367798498 Take extra reference to security policy before calling crypto_dispatch().
Currently we perform crypto requests for IPSEC synchronous for most of
crypto providers (software, aesni) and only VIA padlock calls crypto
callback asynchronous. In synchronous mode it is possible, that security
policy will be removed during the processing crypto request. And crypto
callback will release the last reference to SP. Then upon return into
ipsec[46]_process_packet() IPSECREQUEST_UNLOCK() will be called to already
freed request. To prevent this we will take extra reference to SP.

PR:		201876
Sponsored by:	Yandex LLC
2015-09-30 08:16:33 +00:00
Ermal Luçi 59959de526 Correct IPSec SA statistic keeping
The IPsec SA statistic keeping is used even for decision making on expiry/rekeying SAs.
When there are multiple transformations being done the statistic keeping might be wrong.

This mostly impacts multiple encapsulations on IPsec since the usual scenario it is not noticed due to the code path not taken.

Differential Revision:	https://reviews.freebsd.org/D3239
Reviewed by:		ae, gnn
Approved by:		gnn(mentor)
2015-07-30 20:56:27 +00:00
Andrey V. Elsukov 6508929bc2 Fix the comment. We will not do SPD lookup again, because
ip[6]_ipsec_output() will find PACKET_TAG_IPSEC_OUT_DONE mbuf tag.

Sponsored by:	Yandex LLC
2015-04-28 11:03:47 +00:00
Andrey V. Elsukov 574fde00be Since PFIL can change mbuf pointer, we should update pointers after
calling ipsec_filter().

Sponsored by:	Yandex LLC
2015-04-28 09:29:28 +00:00
Andrey V. Elsukov 3d80e82d60 Fix possible use after free due to security policy deletion.
When we are passing mbuf to IPSec processing via ipsec[46]_process_packet(),
we hold one reference to security policy and release it just after return
from this function. But IPSec processing can be deffered and when we release
reference to security policy after ipsec[46]_process_packet(), user can
delete this security policy from SPDB. And when IPSec processing will be
done, xform's callback function will do access to already freed memory.

To fix this move KEY_FREESP() into callback function. Now IPSec code will
release reference to SP after processing will be finished.

Differential Revision:	https://reviews.freebsd.org/D2324
No objections from:	#network
Sponsored by:	Yandex LLC
2015-04-27 00:55:56 +00:00
Andrey V. Elsukov 962ac6c727 Change ipsec_address() and ipsec_logsastr() functions to take two
additional arguments - buffer and size of this buffer.

ipsec_address() is used to convert sockaddr structure to presentation
format. The IPv6 part of this function returns pointer to the on-stack
buffer and at the moment when it will be used by caller, it becames
invalid. IPv4 version uses 4 static buffers and returns pointer to
new buffer each time when it called. But anyway it is still possible
to get corrupted data when several threads will use this function.

ipsec_logsastr() is used to format string about SA entry. It also
uses static buffer and has the same problem with concurrent threads.

To fix these problems add the buffer pointer and size of this
buffer to arguments. Now each caller will pass buffer and its size
to these functions. Also convert all places where these functions
are used (except disabled code).

And now ipsec_address() uses inet_ntop() function from libkern.

PR:		185996
Differential Revision:	https://reviews.freebsd.org/D2321
Reviewed by:	gnn
Sponsored by:	Yandex LLC
2015-04-18 16:58:33 +00:00
Andrey V. Elsukov 1ae800e7a6 Fix handling of scoped IPv6 addresses in IPSec code.
* in ipsec_encap() embed scope zone ids into link-local addresses
  in the new IPv6 header, this helps ip6_output() disambiguate the
  scope;
* teach key_ismyaddr6() use in6_localip(). in6_localip() is less
  strict than key_sockaddrcmp(). It doesn't compare all fileds of
  struct sockaddr_in6, but it is faster and it should be safe,
  because all SA's data was checked for correctness. Also, since
  IPv6 link-local addresses in the &V_in6_ifaddrhead are stored in
  kernel-internal form, we need to embed scope zone id from SA into
  the address before calling in6_localip.
* in ipsec_common_input() take scope zone id embedded in the address
  and use it to initialize sin6_scope_id, then use this sockaddr
  structure to lookup SA, because we keep addresses in the SADB without
  embedded scope zone id.

Differential Revision:	https://reviews.freebsd.org/D2304
Reviewed by:	gnn
Sponsored by:	Yandex LLC
2015-04-18 16:46:31 +00:00
Andrey V. Elsukov 61f376155d Remove xform_ipip.c and code related to XF_IP4.
The only thing is used from this code is ipip_output() function, that does
IPIP encapsulation. Other parts of XF_IP4 code were removed in r275133.
Also it isn't possible to configure the use of XF_IP4, nor from userland
via setkey(8), nor from the kernel.

Simplify the ipip_output() function and rename it to ipsec_encap().
* move IP_DF handling from ipsec4_process_packet() into ipsec_encap();
* since ipsec_encap() called from ipsec[64]_process_packet(), it
  is safe to assume that mbuf is contiguous at least to IP header
  for used IP version. Remove all unneeded m_pullup(), m_copydata
  and related checks.
* use V_ip_defttl and V_ip6_defhlim for outer headers;
* use V_ip4_ipsec_ecn and V_ip6_ipsec_ecn for outer headers;
* move all diagnostic messages to the ipsec_encap() callers;
* simplify handling of ipsec_encap() results: if it returns non zero
  value, print diagnostic message and free mbuf.
* some style(9) fixes.

Differential Revision:	https://reviews.freebsd.org/D2303
Reviewed by:	glebius
Sponsored by:	Yandex LLC
2015-04-18 16:38:45 +00:00
Andrey V. Elsukov 619764beab Remove flags and tunalready arguments from ipsec4_process_packet()
and make its prototype similar to ipsec6_process_packet.
The flags argument isn't used here, tunalready is always zero.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
2014-12-11 17:34:49 +00:00
Andrey V. Elsukov 2d957916ef Remove route chaching support from ipsec code. It isn't used for some time.
* remove sa_route_union declaration and route_cache member from struct secashead;
* remove key_sa_routechange() call from ICMP and ICMPv6 code;
* simplify ip_ipsec_mtu();
* remove #include <net/route.h>;

Sponsored by:	Yandex LLC
2014-12-02 04:20:50 +00:00
Andrey V. Elsukov f9d8f66552 Count statistics for the specific address family.
MFC after:	1 week
Sponsored by:	Yandex LLC
2014-11-13 12:58:33 +00:00
Andrey V. Elsukov 67fd172767 ipsec6_process_packet is called before ip6_output fixes ip6_plen.
Update ip6_plen before bpf processing to be able see correct value.

MFC after:	1 week
Sponsored by:	Yandex LLC
2014-11-12 22:51:30 +00:00
Andrey V. Elsukov f3c93842bf Fix ips_out_nosa errors accounting.
MFC after:	1 week
Sponsored by:	Yandex LLC
2014-11-12 14:00:49 +00:00
Gleb Smirnoff 6ff8af1ca5 Mechanically convert to if_inc_counter(). 2014-09-19 10:18:14 +00:00
Marko Zec b01e3d0802 The assumption in ipsec4_process_packet() that the payload may be
only IPv4 is wrong, so check the IP version before mangling the
payload header.
2014-07-01 08:02:25 +00:00
Bjoern A. Zeeb 6d120f909c Use IPv4 statistics in ipsec4_process_packet() rather than the IPv6
version.  This also unbreaks the NOINET6 builds after r266800.
2014-05-28 23:01:20 +00:00
VANHULLEBUS Yvan aaf2cfc0d6 Fixed IPv4-in-IPv6 and IPv6-in-IPv4 IPsec tunnels.
For IPv6-in-IPv4, you may need to do the following command
on the tunnel interface if it is configured as IPv4 only:
ifconfig <interface> inet6 -ifdisabled

Code logic inspired from NetBSD.

PR: kern/169438
Submitted by: emeric.poupon@netasq.com
Reviewed by: fabient, ae
Obtained from: NETASQ
2014-05-28 12:45:27 +00:00
Andrey V. Elsukov cd92c2e1ec Remove _IP_VHL* macros and related ifdefs.
MFC after:	1 week
2014-04-16 05:31:54 +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
Andrey V. Elsukov a04d64d875 Use corresponding macros to update statistics for AH, ESP, IPIP, IPCOMP,
PFKEY.

MFC after:	2 weeks
2013-06-20 11:44:16 +00:00
Andrey V. Elsukov 6659296cb0 Use IPSECSTAT_INC() and IPSEC6STAT_INC() macros for ipsec statistics
accounting.

MFC after:	2 weeks
2013-06-20 09:55:53 +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