netfilter: prefer extension check to pointer check

The pointer check usually results in a 'false positive': its likely
that the ctnetlink module is loaded but no event monitoring is enabled.

After

netfilter: prefer extension check to pointer check

The pointer check usually results in a 'false positive': its likely
that the ctnetlink module is loaded but no event monitoring is enabled.

After recent change to autodetect ctnetlink usage and only allocate
the ecache extension if a listener is active, check if the extension
is present on a given conntrack.

If its not there, there is nothing to report and calls to the
notification framework can be elided.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: un-inline nf_ct_ecache_ext_add

Only called when new ct is allocated or the extension isn't present.
This function will be extended, place this in the conntrack module
instead o

netfilter: conntrack: un-inline nf_ct_ecache_ext_add

Only called when new ct is allocated or the extension isn't present.
This function will be extended, place this in the conntrack module
instead of inlining.

The callers already depend on nf_conntrack module.
Return value is changed to bool, noone used the returned pointer.

Make sure that the core drops the newly allocated conntrack
if the extension is requested but can't be added.
This makes it necessary to ifdef the section, as the stub
always returns false we'd drop every new conntrack if the
the ecache extension is disabled in kconfig.

Add from data path (xt_CT, nft_ct) is unchanged.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: include ecache dying list in dumps

The new pernet dying list includes conntrack entries that await
delivery of the 'destroy' event via ctnetlink.

The old percpu dying list wil

netfilter: conntrack: include ecache dying list in dumps

The new pernet dying list includes conntrack entries that await
delivery of the 'destroy' event via ctnetlink.

The old percpu dying list will be removed soon.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: ecache: use dedicated list for event redelivery

This disentangles event redelivery and the percpu dying list.

Because entries are now stored on a dedicated list, all
entries are in NFCT_

netfilter: ecache: use dedicated list for event redelivery

This disentangles event redelivery and the percpu dying list.

Because entries are now stored on a dedicated list, all
entries are in NFCT_ECACHE_DESTROY_FAIL state and all entries
still have confirmed bit set -- the reference count is at least 1.

The 'struct net' back-pointer can be removed as well.

The pcpu dying list will be removed eventually, it has no functionality.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: ecache: don't use nf_conn spinlock

For updating eache missed value we can use cmpxchg.
This also avoids need to disable BH.

kernel robot reported build failure on v1 because not all arch

netfilter: ecache: don't use nf_conn spinlock

For updating eache missed value we can use cmpxchg.
This also avoids need to disable BH.

kernel robot reported build failure on v1 because not all arches support
cmpxchg for u16, so extend this to u32.

This doesn't increase struct size, existing padding is used.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: remove extension register api

These no longer register/unregister a meaningful structure so remove it.

Cc: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Florian Westphal <fw@s

netfilter: conntrack: remove extension register api

These no longer register/unregister a meaningful structure so remove it.

Cc: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: ecache: remove nf_exp_event_notifier structure

Reuse the conntrack event notofier struct, this allows to remove the
extra register/unregister functions and avoids a pointer in struct net.

netfilter: ecache: remove nf_exp_event_notifier structure

Reuse the conntrack event notofier struct, this allows to remove the
extra register/unregister functions and avoids a pointer in struct net.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: ecache: prepare for event notifier merge

This prepares for merge for ct and exp notifier structs.

The 'fcn' member is renamed to something unique.
Second, the register/unregister api is

netfilter: ecache: prepare for event notifier merge

This prepares for merge for ct and exp notifier structs.

The 'fcn' member is renamed to something unique.
Second, the register/unregister api is simplified. There is only
one implementation so there is no need to do any error checking.

Replace the EBUSY logic with WARN_ON_ONCE. This allows to remove
error unwinding.

The exp notifier register/unregister function is removed in
a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: ecache: remove one indent level

nf_conntrack_eventmask_report and nf_ct_deliver_cached_events shared
most of their code. This unifies the layout by changing

if (nf_ct_is_confirmed(ct))

netfilter: ecache: remove one indent level

nf_conntrack_eventmask_report and nf_ct_deliver_cached_events shared
most of their code. This unifies the layout by changing

if (nf_ct_is_confirmed(ct)) {
foo
}

to
if (!nf_ct_is_confirmed(ct)))
return
foo

This removes one level of indentation.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: move ecache dwork to net_generic infra

dwork struct is large (>128 byte) and not needed when conntrack module
is not loaded.

Place it in net_generic data instead. The struct

netfilter: conntrack: move ecache dwork to net_generic infra

dwork struct is large (>128 byte) and not needed when conntrack module
is not loaded.

Place it in net_generic data instead. The struct net dwork member is now
obsolete and will be removed in a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: use consistent style when defining inline functions

The header contains some inline functions defined as:

static inline f (...)
{
#ifdef CONFIG_NF_CONNTRACK_EVENTS
.

netfilter: conntrack: use consistent style when defining inline functions

The header contains some inline functions defined as:

static inline f (...)
{
#ifdef CONFIG_NF_CONNTRACK_EVENTS
...
#else
...
#endif
}

and a few others as:

#ifdef CONFIG_NF_CONNTRACK_EVENTS
static inline f (...)
{
...
}
#else
static inline f (...)
{
...
}
#endif

Prefer the former style, which is more numerous.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: fix coding-style errors.

Several header-files, Kconfig files and Makefiles have trailing
white-space. Remove it.

In netfilter/Kconfig, indent the type of CONFIG_NETFILTER_NETLINK_ACCT
c

netfilter: fix coding-style errors.

Several header-files, Kconfig files and Makefiles have trailing
white-space. Remove it.

In netfilter/Kconfig, indent the type of CONFIG_NETFILTER_NETLINK_ACCT
correctly.

There are semicolons at the end of two function definitions in
include/net/netfilter/nf_conntrack_acct.h and
include/net/netfilter/nf_conntrack_ecache.h. Remove them.

Fix indentation in nf_conntrack_l4proto.h.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: remove empty pernet fini stubs

after moving sysctl handling into single place, the init functions
can't fail anymore and some of the fini functions are empty.

Remove them and

netfilter: conntrack: remove empty pernet fini stubs

after moving sysctl handling into single place, the init functions
can't fail anymore and some of the fini functions are empty.

Remove them and change return type to void.
This also simplifies error unwinding in conntrack module init path.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

nefilter: eache: reduce struct size from 32 to 24 byte

Only "cache" needs to use ulong (its used with set_bit()), missed can use
u16. Also add build-time assertion to ensure event bits fit.

Signed

nefilter: eache: reduce struct size from 32 to 24 byte

Only "cache" needs to use ulong (its used with set_bit()), missed can use
u16. Also add build-time assertion to ensure event bits fit.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: don't rely on DYING bit to detect when destroy event was sent

The reliable event delivery mode currently (ab)uses the DYING bit to
detect which entries on the dying list have to be skippe

netfilter: don't rely on DYING bit to detect when destroy event was sent

The reliable event delivery mode currently (ab)uses the DYING bit to
detect which entries on the dying list have to be skipped when
re-delivering events from the eache worker in reliable event mode.

Currently when we delete the conntrack from main table we only set this
bit if we could also deliver the netlink destroy event to userspace.

If we fail we move it to the dying list, the ecache worker will
reattempt event delivery for all confirmed conntracks on the dying list
that do not have the DYING bit set.

Once timer is gone, we can no longer use if (del_timer()) to detect
when we 'stole' the reference count owned by the timer/hash entry, so
we need some other way to avoid racing with other cpu.

Pablo suggested to add a marker in the ecache extension that skips
entries that have been unhashed from main table but are still waiting
for the last reference count to be dropped (e.g. because one skb waiting
on nfqueue verdict still holds a reference).

We do this by adding a tristate.
If we fail to deliver the destroy event, make a note of this in the
eache extension. The worker can then skip all entries that are in
a different state. Either they never delivered a destroy event,
e.g. because the netlink backend was not loaded, or redelivery took
place already.

Once the conntrack timer is removed we will now be able to replace
del_timer() test with test_and_set_bit(DYING, &ct->status) to avoid
racing with other cpu that tries to evict the same conntrack.

Because DYING will then be set right before we report the destroy event
we can no longer skip event reporting when dying bit is set.

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

show more ...

netfilter: conntrack: move expectation event helper to ecache.c

Not performance critical, it is only invoked when an expectation is
added/destroyed.

While at it, kill unused nf_ct_expect_event() wr

netfilter: conntrack: move expectation event helper to ecache.c

Not performance critical, it is only invoked when an expectation is
added/destroyed.

While at it, kill unused nf_ct_expect_event() wrapper.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: de-inline nf_conntrack_eventmask_report

Way too large; move it to nf_conntrack_ecache.c.
Reduces total object size by 1216 byte on my machine.

Signed-off-by: Florian Westphal

netfilter: conntrack: de-inline nf_conntrack_eventmask_report

Way too large; move it to nf_conntrack_ecache.c.
Reduces total object size by 1216 byte on my machine.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: conntrack: remove timer from ecache extension

This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).

When event delivery fail

netfilter: conntrack: remove timer from ecache extension

This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).

When event delivery fails, re-delivery is attempted via work queue.

Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.

The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.

Joint work with Pablo Neira Ayuso.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.

Fun

netfilter: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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netfilter: nf_ct_ecache: move initialization out of pernet_operations

Move the global initial codes to the module_init/exit context.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by:

netfilter: nf_ct_ecache: move initialization out of pernet_operations

Move the global initial codes to the module_init/exit context.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netlink: Rename pid to portid to avoid confusion

It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold

netlink: Rename pid to portid to avoid confusion

It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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netfilter: nf_conntrack: fix racy timer handling with reliable events

Existing code assumes that del_timer returns true for alive conntrack
entries. However, this is not true if reliable events are

netfilter: nf_conntrack: fix racy timer handling with reliable events

Existing code assumes that del_timer returns true for alive conntrack
entries. However, this is not true if reliable events are enabled.
In that case, del_timer may return true for entries that were
just inserted in the dying list. Note that packets / ctnetlink may
hold references to conntrack entries that were just inserted to such
list.

This patch fixes the issue by adding an independent timer for
event delivery. This increases the size of the ecache extension.
Still we can revisit this later and use variable size extensions
to allocate this area on demand.

Tested-by: Oliver Smith <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: nf_ct_ecache: fix crash with multiple containers, one shutting down

Hans reports that he's still hitting:

BUG: unable to handle kernel NULL pointer dereference at 000000000000027c
IP: [<

netfilter: nf_ct_ecache: fix crash with multiple containers, one shutting down

Hans reports that he's still hitting:

BUG: unable to handle kernel NULL pointer dereference at 000000000000027c
IP: [<ffffffff813615db>] netlink_has_listeners+0xb/0x60
PGD 0
Oops: 0000 [#3] PREEMPT SMP
CPU 0

It happens when adding a number of containers with do:

nfct_query(h, NFCT_Q_CREATE, ct);

and most likely one namespace shuts down.

this problem was supposed to be fixed by:
70e9942 netfilter: nf_conntrack: make event callback registration per-netns

Still, it was missing one rcu_access_pointer to check if the callback
is set or not.

Reported-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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netfilter: nf_conntrack: make event callback registration per-netns

This patch fixes an oops that can be triggered following this recipe:

0) make sure nf_conntrack_netlink and nf_conntrack_ipv4 are

netfilter: nf_conntrack: make event callback registration per-netns

This patch fixes an oops that can be triggered following this recipe:

0) make sure nf_conntrack_netlink and nf_conntrack_ipv4 are loaded.
1) container is started.
2) connect to it via lxc-console.
3) generate some traffic with the container to create some conntrack
entries in its table.
4) stop the container: you hit one oops because the conntrack table
cleanup tries to report the destroy event to user-space but the
per-netns nfnetlink socket has already gone (as the nfnetlink
socket is per-netns but event callback registration is global).

To fix this situation, we make the ctnl_notifier per-netns so the
callback is registered/unregistered if the container is
created/destroyed.

Alex Bligh and Alexey Dobriyan originally proposed one small patch to
check if the nfnetlink socket is gone in nfnetlink_has_listeners,
but this is a very visited path for events, thus, it may reduce
performance and it looks a bit hackish to check for the nfnetlink
socket only to workaround this situation. As a result, I decided
to follow the bigger path choice, which seems to look nicer to me.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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