All other error handling paths in this function go through the 'error'
label. This one should do the same.
Fixes: 9cc9a5cb17 ("datapath: Avoid using stack larger than 1024.")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree. Basically, updates to the conntrack core, enhancements for
nf_tables, conversion of netfilter hooks from linked list to array to
improve memory locality and asorted improvements for the Netfilter
codebase. More specifically, they are:
1) Add expection to hashes after timer initialization to prevent
access from another CPU that walks on the hashes and calls
del_timer(), from Florian Westphal.
2) Don't update nf_tables chain counters from hot path, this is only
used by the x_tables compatibility layer.
3) Get rid of nested rcu_read_lock() calls from netfilter hook path.
Hooks are always guaranteed to run from rcu read side, so remove
nested rcu_read_lock() where possible. Patch from Taehee Yoo.
4) nf_tables new ruleset generation notifications include PID and name
of the process that has updated the ruleset, from Phil Sutter.
5) Use skb_header_pointer() from nft_fib, so we can reuse this code from
the nf_family netdev family. Patch from Pablo M. Bermudo.
6) Add support for nft_fib in nf_tables netdev family, also from Pablo.
7) Use deferrable workqueue for conntrack garbage collection, to reduce
power consumption, from Patch from Subash Abhinov Kasiviswanathan.
8) Add nf_ct_expect_iterate_net() helper and use it. From Florian
Westphal.
9) Call nf_ct_unconfirmed_destroy only from cttimeout, from Florian.
10) Drop references on conntrack removal path when skbuffs has escaped via
nfqueue, from Florian.
11) Don't queue packets to nfqueue with dying conntrack, from Florian.
12) Constify nf_hook_ops structure, from Florian.
13) Remove neededlessly branch in nf_tables trace code, from Phil Sutter.
14) Add nla_strdup(), from Phil Sutter.
15) Rise nf_tables objects name size up to 255 chars, people want to use
DNS names, so increase this according to what RFC 1035 specifies.
Patch series from Phil Sutter.
16) Kill nf_conntrack_default_on, it's broken. Default on conntrack hook
registration on demand, suggested by Eric Dumazet, patch from Florian.
17) Remove unused variables in compat_copy_entry_from_user both in
ip_tables and arp_tables code. Patch from Taehee Yoo.
18) Constify struct nf_conntrack_l4proto, from Julia Lawall.
19) Constify nf_loginfo structure, also from Julia.
20) Use a single rb root in connlimit, from Taehee Yoo.
21) Remove unused netfilter_queue_init() prototype, from Taehee Yoo.
22) Use audit_log() instead of open-coding it, from Geliang Tang.
23) Allow to mangle tcp options via nft_exthdr, from Florian.
24) Allow to fetch TCP MSS from nft_rt, from Florian. This includes
a fix for a miscalculation of the minimal length.
25) Simplify branch logic in h323 helper, from Nick Desaulniers.
26) Calculate netlink attribute size for conntrack tuple at compile
time, from Florian.
27) Remove protocol name field from nf_conntrack_{l3,l4}proto structure.
From Florian.
28) Remove holes in nf_conntrack_l4proto structure, so it becomes
smaller. From Florian.
29) Get rid of print_tuple() indirection for /proc conntrack listing.
Place all the code in net/netfilter/nf_conntrack_standalone.c.
Patch from Florian.
30) Do not built in print_conntrack() if CONFIG_NF_CONNTRACK_PROCFS is
off. From Florian.
31) Constify most nf_conntrack_{l3,l4}proto helper functions, from
Florian.
32) Fix broken indentation in ebtables extensions, from Colin Ian King.
33) Fix several harmless sparse warning, from Florian.
34) Convert netfilter hook infrastructure to use array for better memory
locality, joint work done by Florian and Aaron Conole. Moreover, add
some instrumentation to debug this.
35) Batch nf_unregister_net_hooks() calls, to call synchronize_net once
per batch, from Florian.
36) Get rid of noisy logging in ICMPv6 conntrack helper, from Florian.
37) Get rid of obsolete NFDEBUG() instrumentation, from Varsha Rao.
38) Remove unused code in the generic protocol tracker, from Davide
Caratti.
I think I will have material for a second Netfilter batch in my queue if
time allow to make it fit in this merge window.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Doesn't change generated code, but will make it easier to eventually
make the actual trackers themselvers const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For sw_flow_actions, the actions_len only represents the kernel part's
size, and when we dump the actions to the userspace, we will do the
convertions, so it's true size may become bigger than the actions_len.
But unfortunately, for OVS_PACKET_ATTR_ACTIONS, we use the actions_len
to alloc the skbuff, so the user_skb's size may become insufficient and
oops will happen like this:
skbuff: skb_over_panic: text:ffffffff8148fabf len:1749 put:157 head:
ffff881300f39000 data:ffff881300f39000 tail:0x6d5 end:0x6c0 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:129!
[...]
Call Trace:
<IRQ>
[<ffffffff8148be82>] skb_put+0x43/0x44
[<ffffffff8148fabf>] skb_zerocopy+0x6c/0x1f4
[<ffffffffa0290d36>] queue_userspace_packet+0x3a3/0x448 [openvswitch]
[<ffffffffa0292023>] ovs_dp_upcall+0x30/0x5c [openvswitch]
[<ffffffffa028d435>] output_userspace+0x132/0x158 [openvswitch]
[<ffffffffa01e6890>] ? ip6_rcv_finish+0x74/0x77 [ipv6]
[<ffffffffa028e277>] do_execute_actions+0xcc1/0xdc8 [openvswitch]
[<ffffffffa028e3f2>] ovs_execute_actions+0x74/0x106 [openvswitch]
[<ffffffffa0292130>] ovs_dp_process_packet+0xe1/0xfd [openvswitch]
[<ffffffffa0292b77>] ? key_extract+0x63c/0x8d5 [openvswitch]
[<ffffffffa029848b>] ovs_vport_receive+0xa1/0xc3 [openvswitch]
[...]
Also we can find that the actions_len is much little than the orig_len:
crash> struct sw_flow_actions 0xffff8812f539d000
struct sw_flow_actions {
rcu = {
next = 0xffff8812f5398800,
func = 0xffffe3b00035db32
},
orig_len = 1384,
actions_len = 592,
actions = 0xffff8812f539d01c
}
So as a quick fix, use the orig_len instead of the actions_len to alloc
the user_skb.
Last, this oops happened on our system running a relative old kernel, but
the same risk still exists on the mainline, since we use the wrong
actions_len from the beginning.
Fixes: ccea74457b ("openvswitch: include datapath actions with sampled-packet upcall to userspace")
Cc: Neil McKee <neil.mckee@inmon.com>
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
OVS_NLERR already adds a newline so these just add blank
lines to the logging.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Joe Stringer <joe@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Two minor conflicts in virtio_net driver (bug fix overlapping addition
of a helper) and MAINTAINERS (new driver edit overlapping revamp of
PHY entry).
Signed-off-by: David S. Miller <davem@davemloft.net>
Before the 'type' is validated, we shouldn't use it to fetch the
ovs_ct_attr_lens's minlen and maxlen, else, out of bound access
may happen.
Fixes: 7f8a436eaa ("openvswitch: Add conntrack action")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When calling the flow_free() to free the flow, we call many times
(cpu_possible_mask, eg. 128 as default) cpumask_next(). That will
take up our CPU usage if we call the flow_free() frequently.
When we put all packets to userspace via upcall, and OvS will send
them back via netlink to ovs_packet_cmd_execute(will call flow_free).
The test topo is shown as below. VM01 sends TCP packets to VM02,
and OvS forward packtets. When testing, we use perf to report the
system performance.
VM01 --- OvS-VM --- VM02
Without this patch, perf-top show as below: The flow_free() is
3.02% CPU usage.
4.23% [kernel] [k] _raw_spin_unlock_irqrestore
3.62% [kernel] [k] __do_softirq
3.16% [kernel] [k] __memcpy
3.02% [kernel] [k] flow_free
2.42% libc-2.17.so [.] __memcpy_ssse3_back
2.18% [kernel] [k] copy_user_generic_unrolled
2.17% [kernel] [k] find_next_bit
When applied this patch, perf-top show as below: Not shown on
the list anymore.
4.11% [kernel] [k] _raw_spin_unlock_irqrestore
3.79% [kernel] [k] __do_softirq
3.46% [kernel] [k] __memcpy
2.73% libc-2.17.so [.] __memcpy_ssse3_back
2.25% [kernel] [k] copy_user_generic_unrolled
1.89% libc-2.17.so [.] _int_malloc
1.53% ovs-vswitchd [.] xlate_actions
With this patch, the TCP throughput(we dont use Megaflow Cache
+ Microflow Cache) between VMs is 1.18Gbs/sec up to 1.30Gbs/sec
(maybe ~10% performance imporve).
This patch adds cpumask struct, the cpu_used_mask stores the cpu_id
that the flow used. And we only check the flow_stats on the cpu we
used, and it is unncessary to check all possible cpu when getting,
cleaning, and updating the flow_stats. Adding the cpu_used_mask to
sw_flow struct does’t increase the cacheline number.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the ovs_flow_stats_update(), we only use the node
var to alloc flow_stats struct. But this is not a
common case, it is unnecessary to call the numa_node_id()
everytime. This patch is not a bugfix, but there maybe
a small increase.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When there is an established connection in direction A->B, it is
possible to receive a packet on port B which then executes
ct(commit,force) without first performing ct() - ie, a lookup.
In this case, we would expect that this packet can delete the existing
entry so that we can commit a connection with direction B->A. However,
currently we only perform a check in skb_nfct_cached() for whether
OVS_CS_F_TRACKED is set and OVS_CS_F_INVALID is not set, ie that a
lookup previously occurred. In the above scenario, a lookup has not
occurred but we should still be able to statelessly look up the
existing entry and potentially delete the entry if it is in the
opposite direction.
This patch extends the check to also hint that if the action has the
force flag set, then we will lookup the existing entry so that the
force check at the end of skb_nfct_cached has the ability to delete
the connection.
Fixes: dd41d330b03 ("openvswitch: Add force commit.")
CC: Pravin Shelar <pshelar@nicira.com>
CC: dev@openvswitch.org
Signed-off-by: Joe Stringer <joe@ovn.org>
Signed-off-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I was trying to wrap my head around meaning of mru, and realised
that the second line of the comment defining it had somehow
ended up after the line defining cutlen, leading to much confusion.
Reorder the lines to make sense.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
When compiling OvS-master on 4.4.0-81 kernel,
there is a warning:
CC [M] /root/ovs/datapath/linux/datapath.o
/root/ovs/datapath/linux/datapath.c: In function
'ovs_flow_cmd_set':
/root/ovs/datapath/linux/datapath.c:1221:1: warning:
the frame size of 1040 bytes is larger than 1024 bytes
[-Wframe-larger-than=]
This patch factors out match-init and action-copy to avoid
"Wframe-larger-than=1024" warning. Because mask is only
used to get actions, we new a function to save some
stack space.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Switches and modern SR-IOV enabled NICs may multiplex traffic from Port
representators and control messages over single set of hardware queues.
Control messages and muxed traffic may need ordered delivery.
Those requirements make it hard to comfortably use TC infrastructure today
unless we have a way of attaching metadata to skbs at the upper device.
Because single set of queues is used for many netdevs stopping TC/sched
queues of all of them reliably is impossible and lower device has to
retreat to returning NETDEV_TX_BUSY and usually has to take extra locks on
the fastpath.
This patch attempts to enable port/representative devs to attach metadata
to skbs which carry port id. This way representatives can be queueless and
all queuing can be performed at the lower netdev in the usual way.
Traffic arriving on the port/representative interfaces will be have
metadata attached and will subsequently be queued to the lower device for
transmission. The lower device should recognize the metadata and translate
it to HW specific format which is most likely either a special header
inserted before the network headers or descriptor/metadata fields.
Metadata is associated with the lower device by storing the netdev pointer
along with port id so that if TC decides to redirect or mirror the new
netdev will not try to interpret it.
This is mostly for SR-IOV devices since switches don't have lower netdevs
today.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no good reason to keep the flags twice in vxlan_dev and
vxlan_config.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.
The following spatch found many more and also removes the
now unnecessary casts:
@@
identifier p, p2;
expression len;
expression skb;
type t, t2;
@@
(
-p = skb_put(skb, len);
+p = skb_put_zero(skb, len);
|
-p = (t)skb_put(skb, len);
+p = skb_put_zero(skb, len);
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, len);
|
-memset(p, 0, len);
)
@@
type t, t2;
identifier p, p2;
expression skb;
@@
t *p;
...
(
-p = skb_put(skb, sizeof(t));
+p = skb_put_zero(skb, sizeof(t));
|
-p = (t *)skb_put(skb, sizeof(t));
+p = skb_put_zero(skb, sizeof(t));
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, sizeof(*p));
|
-memset(p, 0, sizeof(*p));
)
@@
expression skb, len;
@@
-memset(skb_put(skb, len), 0, len);
+skb_put_zero(skb, len);
Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Network devices can allocate reasources and private memory using
netdev_ops->ndo_init(). However, the release of these resources
can occur in one of two different places.
Either netdev_ops->ndo_uninit() or netdev->destructor().
The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.
netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.
netdev->destructor(), on the other hand, does not run until the
netdev references all go away.
Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().
This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.
If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit(). But
it is not able to invoke netdev->destructor().
This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.
However, this means that the resources that would normally be released
by netdev->destructor() will not be.
Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.
Many drivers do not try to deal with this, and instead we have leaks.
Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().
netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().
netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().
Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().
And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().
Signed-off-by: David S. Miller <davem@davemloft.net>
if skb carries an SCTP packet and ip_summed is CHECKSUM_PARTIAL, it needs
CRC32c in place of Internet Checksum: use skb_csum_hwoffload_help to avoid
corrupting such packets while queueing them towards userspace.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
And convert module_put invocation to nf_conntrack_helper_put, this is
prepared for the followup patch, which will add a refcnt for cthelper,
so we can reject the deleting request when cthelper is in use.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS/OVS fixes for net
The following patchset contains a rather large batch of Netfilter, IPVS
and OVS fixes for your net tree. This includes fixes for ctnetlink, the
userspace conntrack helper infrastructure, conntrack OVS support,
ebtables DNAT target, several leaks in error path among other. More
specifically, they are:
1) Fix reference count leak in the CT target error path, from Gao Feng.
2) Remove conntrack entry clashing with a matching expectation, patch
from Jarno Rajahalme.
3) Fix bogus EEXIST when registering two different userspace helpers,
from Liping Zhang.
4) Don't leak dummy elements in the new bitmap set type in nf_tables,
from Liping Zhang.
5) Get rid of module autoload from conntrack update path in ctnetlink,
we don't need autoload at this late stage and it is happening with
rcu read lock held which is not good. From Liping Zhang.
6) Fix deadlock due to double-acquire of the expect_lock from conntrack
update path, this fixes a bug that was introduced when the central
spinlock got removed. Again from Liping Zhang.
7) Safe ct->status update from ctnetlink path, from Liping. The expect_lock
protection that was selected when the central spinlock was removed was
not really protecting anything at all.
8) Protect sequence adjustment under ct->lock.
9) Missing socket match with IPv6, from Peter Tirsek.
10) Adjust skb->pkt_type of DNAT'ed frames from ebtables, from
Linus Luessing.
11) Don't give up on evaluating the expression on new entries added via
dynset expression in nf_tables, from Liping Zhang.
12) Use skb_checksum() when mangling icmpv6 in IPv6 NAT as this deals
with non-linear skbuffs.
13) Don't allow IPv6 service in IPVS if no IPv6 support is available,
from Paolo Abeni.
14) Missing mutex release in error path of xt_find_table_lock(), from
Dan Carpenter.
15) Update maintainers files, Netfilter section. Add Florian to the
file, refer to nftables.org and change project status from Supported
to Maintained.
16) Bail out on mismatching extensions in element updates in nf_tables.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:
1) Check for ct->status bit instead of using nfct_nat() from IPVS and
Netfilter codebase, patch from Florian Westphal.
2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.
3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.
4) Introduce nft_is_base_chain() helper function.
5) Enforce expectation limit from userspace conntrack helper,
from Gao Feng.
6) Add nf_ct_remove_expect() helper function, from Gao Feng.
7) NAT mangle helper function return boolean, from Gao Feng.
8) ctnetlink_alloc_expect() should only work for conntrack with
helpers, from Gao Feng.
9) Add nfnl_msg_type() helper function to nfnetlink to build the
netlink message type.
10) Get rid of unnecessary cast on void, from simran singhal.
11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
also from simran singhal.
12) Use list_prev_entry() from nf_tables, from simran signhal.
13) Remove unnecessary & on pointer function in the Netfilter and IPVS
code.
14) Remove obsolete comment on set of rules per CPU in ip6_tables,
no longer true. From Arushi Singhal.
15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.
16) Remove unnecessary nested rcu_read_lock() in
__nf_nat_decode_session(). Code running from hooks are already
guaranteed to run under RCU read side.
17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.
18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
also from Aaron.
19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.
20) Don't propagate NF_DROP error to userspace via ctnetlink in
__nf_nat_alloc_null_binding() function, from Gao Feng.
21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
from Gao Feng.
22) Kill the fake untracked conntrack objects, use ctinfo instead to
annotate a conntrack object is untracked, from Florian Westphal.
23) Remove nf_ct_is_untracked(), now obsolete since we have no
conntrack template anymore, from Florian.
24) Add event mask support to nft_ct, also from Florian.
25) Move nf_conn_help structure to
include/net/netfilter/nf_conntrack_helper.h.
26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
Thus, we don't deal with variable conntrack extensions anymore.
Make sure userspace conntrack helper doesn't go over that size.
Remove variable size ct extension infrastructure now this code
got no more clients. From Florian Westphal.
27) Restore offset and length of nf_ct_ext structure to 8 bytes now
that wraparound is not possible any longer, also from Florian.
28) Allow to get rid of unassured flows under stress in conntrack,
this applies to DCCP, SCTP and TCP protocols, from Florian.
29) Shrink size of nf_conntrack_ecache structure, from Florian.
30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
from Gao Feng.
31) Register SYNPROXY hooks on demand, from Florian Westphal.
32) Use pernet hook whenever possible, instead of global hook
registration, from Florian Westphal.
33) Pass hook structure to ebt_register_table() to consolidate some
infrastructure code, from Florian Westphal.
34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
SYNPROXY code, to make sure device stats are not fooled, patch
from Gao Feng.
35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
don't need anymore if we just select a fixed size instead of
expensive runtime time calculation of this. From Florian.
36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
from Florian.
37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
Florian.
38) Attach NAT extension on-demand from masquerade and pptp helper
path, from Florian.
39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.
40) Speed up netns by selective calls of synchronize_net(), from
Florian Westphal.
41) Silence stack size warning gcc in 32-bit arch in snmp helper,
from Florian.
42) Inconditionally call nf_ct_ext_destroy(), even if we have no
extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
Liping Zhang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
