History log of /linux-master/net/netfilter/ipset/ip_set_hash_netnet.c
Revision Date Author Comments
# 5e29dc36 30-Dec-2022 Jozsef Kadlecsik <kadlec@netfilter.org>

netfilter: ipset: Rework long task execution when adding/deleting entries

When adding/deleting large number of elements in one step in ipset, it can
take a reasonable amount of time and can result in soft lockup errors. The
patch 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of
consecutive elements to add/delete") tried to fix it by limiting the max
elements to process at all. However it was not enough, it is still possible
that we get hung tasks. Lowering the limit is not reasonable, so the
approach in this patch is as follows: rely on the method used at resizing
sets and save the state when we reach a smaller internal batch limit,
unlock/lock and proceed from the saved state. Thus we can avoid long
continuous tasks and at the same time removed the limit to add/delete large
number of elements in one step.

The nfnl mutex is held during the whole operation which prevents one to
issue other ipset commands in parallel.

Fixes: 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete")
Reported-by: syzbot+9204e7399656300bf271@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# e9374524 22-Nov-2022 Vishwanath Pai <vpai@akamai.com>

netfilter: ipset: Add support for new bitmask parameter

Add a new parameter to complement the existing 'netmask' option. The
main difference between netmask and bitmask is that bitmask takes any
arbitrary ip address as input, it does not have to be a valid netmask.

The name of the new parameter is 'bitmask'. This lets us mask out
arbitrary bits in the ip address, for example:
ipset create set1 hash:ip bitmask 255.128.255.0
ipset create set2 hash:ip,port family inet6 bitmask ffff::ff80

Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Joshua Hunt <johunt@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 5f7b51bf 28-Jul-2021 Jozsef Kadlecsik <kadlec@netfilter.org>

netfilter: ipset: Limit the maximal range of consecutive elements to add/delete

The range size of consecutive elements were not limited. Thus one could
define a huge range which may result soft lockup errors due to the long
execution time. Now the range size is limited to 2^20 entries.

Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 3976ca10 29-Oct-2020 Jozsef Kadlecsik <kadlec@netfilter.org>

netfilter: ipset: Expose the initval hash parameter to userspace

It makes possible to reproduce exactly the same set after a save/restore.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# ccf0a4b7 29-Oct-2020 Jozsef Kadlecsik <kadlec@netfilter.org>

netfilter: ipset: Add bucketsize parameter to all hash types

The parameter defines the upper limit in any hash bucket at adding new entries
from userspace - if the limit would be exceeded, ipset doubles the hash size
and rehashes. It means the set may consume more memory but gives faster
evaluation at matching in the set.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 12899756 01-Nov-2019 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Fix nla_policies to fully support NL_VALIDATE_STRICT

Since v5.2 (commit "netlink: re-add parse/validate functions in strict
mode") NL_VALIDATE_STRICT is enabled. Fix the ipset nla_policies which did
not support strict mode and convert from deprecated parsings to verified ones.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>


# 8dea982a 03-Oct-2019 Jeremy Sowden <jeremy@azazel.net>

netfilter: ipset: remove inline from static functions in .c files.

The inline function-specifier should not be used for static functions
defined in .c files since it bloats the kernel. Instead leave the
compiler to decide which functions to inline.

While a couple of the files affected (ip_set_*_gen.h) are technically
headers, they contain templates for generating the common parts of
particular set-types and so we treat them like .c files.

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


# d2912cb1 04-Jun-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# fe03d474 10-Jun-2019 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

Update my email address

It's better to use my kadlec@netfilter.org email address in
the source code. I might not be able to use
kadlec@blackhole.kfki.hu in the future.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 0b8d9073 12-Jan-2018 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Fix wraparound in hash:*net* types

Fix wraparound bug which could lead to memory exhaustion when adding an
x.x.x.x-255.255.255.255 range to any hash:*net* types.

Fixes Netfilter's bugzilla id #1212, reported by Thomas Schwark.

Fixes: 48596a8ddc46 ("netfilter: ipset: Fix adding an IPv4 range containing more than 2^31 addresses")
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 48596a8d 23-Sep-2017 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Fix adding an IPv4 range containing more than 2^31 addresses

Wrong comparison prevented the hash types to add a range with more than
2^31 addresses but reported as a success.

Fixes Netfilter's bugzilla id #1005, reported by Oleg Serditov and
Oliver Ford.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 21956ab2 26-Jun-2015 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Make struct htype per ipset family

Before this patch struct htype created at the first source
of ip_set_hash_gen.h and it is common for both IPv4 and IPv6
set variants.

Make struct htype per ipset family and use NLEN to make
nets array fixed size to simplify struct htype allocation.

Ported from a patch proposed by Sergey Popovich <popovich_sergei@mail.ua>.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 96be5f28 21-Aug-2015 Elad Raz <eladr@mellanox.com>

netfilter: ipset: Fixing unnamed union init

In continue to proposed Vinson Lee's post [1], this patch fixes compilation
issues founded at gcc 4.4.7. The initialization of .cidr field of unnamed
unions causes compilation error in gcc 4.4.x.

References

Visible links
[1] https://lkml.org/lkml/2015/7/5/74

Signed-off-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# ca0f6a5c 13-Jun-2015 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Fix coding styles reported by checkpatch.pl

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 18f84d41 13-Jun-2015 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Introduce RCU locking in hash:* types

Three types of data need to be protected in the case of the hash types:

a. The hash buckets: standard rcu pointer operations are used.
b. The element blobs in the hash buckets are stored in an array and
a bitmap is used for book-keeping to tell which elements in the array
are used or free.
c. Networks per cidr values and the cidr values themselves are stored
in fix sized arrays and need no protection. The values are modified
in such an order that in the worst case an element testing is repeated
once with the same cidr value.

The ipset hash approach uses arrays instead of lists and therefore is
incompatible with rhashtable.

Performance is tested by Jesper Dangaard Brouer:

Simple drop in FORWARD
~~~~~~~~~~~~~~~~~~~~~~

Dropping via simple iptables net-mask match::

iptables -t raw -N simple || iptables -t raw -F simple
iptables -t raw -I simple -s 198.18.0.0/15 -j DROP
iptables -t raw -D PREROUTING -j simple
iptables -t raw -I PREROUTING -j simple

Drop performance in "raw": 11.3Mpps

Generator: sending 12.2Mpps (tx:12264083 pps)

Drop via original ipset in RAW table
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Create a set with lots of elements::

sudo ./ipset destroy test
echo "create test hash:ip hashsize 65536" > test.set
for x in `seq 0 255`; do
for y in `seq 0 255`; do
echo "add test 198.18.$x.$y" >> test.set
done
done
sudo ./ipset restore < test.set

Dropping via ipset::

iptables -t raw -F
iptables -t raw -N net198 || iptables -t raw -F net198
iptables -t raw -I net198 -m set --match-set test src -j DROP
iptables -t raw -I PREROUTING -j net198

Drop performance in "raw" with ipset: 8Mpps

Perf report numbers ipset drop in "raw"::

+ 24.65% ksoftirqd/1 [ip_set] [k] ip_set_test
- 21.42% ksoftirqd/1 [kernel.kallsyms] [k] _raw_read_lock_bh
- _raw_read_lock_bh
+ 99.88% ip_set_test
- 19.42% ksoftirqd/1 [kernel.kallsyms] [k] _raw_read_unlock_bh
- _raw_read_unlock_bh
+ 99.72% ip_set_test
+ 4.31% ksoftirqd/1 [ip_set_hash_ip] [k] hash_ip4_kadt
+ 2.27% ksoftirqd/1 [ixgbe] [k] ixgbe_fetch_rx_buffer
+ 2.18% ksoftirqd/1 [ip_tables] [k] ipt_do_table
+ 1.81% ksoftirqd/1 [ip_set_hash_ip] [k] hash_ip4_test
+ 1.61% ksoftirqd/1 [kernel.kallsyms] [k] __netif_receive_skb_core
+ 1.44% ksoftirqd/1 [kernel.kallsyms] [k] build_skb
+ 1.42% ksoftirqd/1 [kernel.kallsyms] [k] ip_rcv
+ 1.36% ksoftirqd/1 [kernel.kallsyms] [k] __local_bh_enable_ip
+ 1.16% ksoftirqd/1 [kernel.kallsyms] [k] dev_gro_receive
+ 1.09% ksoftirqd/1 [kernel.kallsyms] [k] __rcu_read_unlock
+ 0.96% ksoftirqd/1 [ixgbe] [k] ixgbe_clean_rx_irq
+ 0.95% ksoftirqd/1 [kernel.kallsyms] [k] __netdev_alloc_frag
+ 0.88% ksoftirqd/1 [kernel.kallsyms] [k] kmem_cache_alloc
+ 0.87% ksoftirqd/1 [xt_set] [k] set_match_v3
+ 0.85% ksoftirqd/1 [kernel.kallsyms] [k] inet_gro_receive
+ 0.83% ksoftirqd/1 [kernel.kallsyms] [k] nf_iterate
+ 0.76% ksoftirqd/1 [kernel.kallsyms] [k] put_compound_page
+ 0.75% ksoftirqd/1 [kernel.kallsyms] [k] __rcu_read_lock

Drop via ipset in RAW table with RCU-locking
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

With RCU locking, the RW-lock is gone.

Drop performance in "raw" with ipset with RCU-locking: 11.3Mpps

Performance-tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# f690cbae 12-Jun-2015 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Fix cidr handling for hash:*net* types

Commit "Simplify cidr handling for hash:*net* types" broke the cidr
handling for the hash:*net* types when the sets were used by the SET
target: entries with invalid cidr values were added to the sets.
Reported by Jonathan Johnson.

Testsuite entry is added to verify the fix.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# aff22758 12-Jun-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Check CIDR value only when attribute is given

There is no reason to check CIDR value regardless attribute
specifying CIDR is given.

Initialize cidr array in element structure on element structure
declaration to let more freedom to the compiler to optimize
initialization right before element structure is used.

Remove local variables cidr and cidr2 for netnet and netportnet
hashes as we do not use packed cidr value for such set types and
can store value directly in e.cidr[].

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# a212e08e 12-Jun-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Make sure we always return line number on batch

Even if we return with generic IPSET_ERR_PROTOCOL it is good idea
to return line number if we called in batch mode.

Moreover we are not always exiting with IPSET_ERR_PROTOCOL. For
example hash:ip,port,net may return IPSET_ERR_HASH_RANGE_UNSUPPORTED
or IPSET_ERR_INVALID_CIDR.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 7dd37bc8 12-Jun-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Check extensions attributes before getting extensions.

Make all extensions attributes checks within ip_set_get_extensions()
and reduce number of duplicated code.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 03726186 02-May-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Check for comment netlink attribute length

Ensure userspace supplies string not longer than
IPSET_MAX_COMMENT_SIZE.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 8e55d2e5 02-May-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Return ipset error instead of bool

Statement ret = func1() || func2() returns 0 when both func1()
and func2() return 0, or 1 if func1() or func2() returns non-zero.

However in our case func1() and func2() returns error code on
failure, so it seems good to propagate such error codes, rather
than returning 1 in case of failure.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 43ef29c9 02-May-2015 Sergey Popovich <popovich_sergei@mail.ua>

netfilter: ipset: Preprocessor directices cleanup

* Undefine mtype_data_reset_elem before defining.

* Remove duplicated mtype_gc_init undefine, move
mtype_gc_init define closer to mtype_gc define.

* Use htype instead of HTYPE in IPSET_TOKEN(HTYPE, _create)().

* Remove PF definition from sets: no more used.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# cac37639 30-Nov-2014 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: Explicitly add padding elements to hash:net, net and hash:net, port, net

The elements must be u32 sized for the used hash function.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# af331419 28-Aug-2014 Anton Danilov <littlesmilingcloud@gmail.com>

netfilter: ipset: Add skbinfo extension kernel support for the hash set types.

Add skbinfo extension kernel support for the hash set types.
Inroduce the new revisions of all hash set types.

Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 6e41ee68 05-May-2014 Sergey Popovich <popovich_sergei@mail.ru>

netfilter: ipset: netnet,netportnet: Fix value range support for IPv4

Ranges of values are broken with hash:net,net and hash:net,port,net.

hash:net,net
============

# ipset create test-nn hash:net,net
# ipset add test-nn 10.0.10.1-10.0.10.127,10.0.0.0/8

# ipset list test-nn
Name: test-nn
Type: hash:net,net
Revision: 0
Header: family inet hashsize 1024 maxelem 65536
Size in memory: 16960
References: 0
Members:
10.0.10.1,10.0.0.0/8

# ipset test test-nn 10.0.10.65,10.0.0.1
10.0.10.65,10.0.0.1 is NOT in set test-nn.
# ipset test test-nn 10.0.10.1,10.0.0.1
10.0.10.1,10.0.0.1 is in set test-nn.

hash:net,port,net
=================

# ipset create test-npn hash:net,port,net
# ipset add test-npn 10.0.10.1-10.0.10.127,tcp:80,10.0.0.0/8
# ipset list test-npn
Name: test-npn
Type: hash:net,port,net
Revision: 0
Header: family inet hashsize 1024 maxelem 65536
Size in memory: 17344
References: 0
Members:
10.0.10.8/29,tcp:80,10.0.0.0
10.0.10.16/28,tcp:80,10.0.0.0
10.0.10.2/31,tcp:80,10.0.0.0
10.0.10.64/26,tcp:80,10.0.0.0
10.0.10.32/27,tcp:80,10.0.0.0
10.0.10.4/30,tcp:80,10.0.0.0
10.0.10.1,tcp:80,10.0.0.0
# ipset list test-npn
# ipset test test-npn 10.0.10.126,tcp:80,10.0.0.2
10.0.10.126,tcp:80,10.0.0.2 is NOT in set test-npn.
# ipset test test-npn 10.0.10.126,tcp:80,10.0.0.0
10.0.10.126,tcp:80,10.0.0.0 is in set test-npn.

# ipset create test-npn hash:net,port,net
# ipset add test-npn 10.0.10.0/24,tcp:80-81,10.0.0.0/8
# ipset list test-npn
Name: test-npn
Type: hash:net,port,net
Revision: 0
Header: family inet hashsize 1024 maxelem 65536
Size in memory: 17024
References: 0
Members:
10.0.10.0,tcp:80,10.0.0.0
10.0.10.0,tcp:81,10.0.0.0
# ipset test test-npn 10.0.10.126,tcp:80,10.0.0.0
10.0.10.126,tcp:80,10.0.0.0 is NOT in set test-npn.
# ipset test test-npn 10.0.10.0,tcp:80,10.0.0.0
10.0.10.0,tcp:80,10.0.0.0 is in set test-npn.

Correctly setup from..to variables where no IPSET_ATTR_IP_TO{,2}
attribute is given, so in range processing loop we construct proper
cidr value. Check whenever we have no ranges and can short cut in
hash:net,net properly. Use unlikely() where appropriate, to comply
with other modules.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 07cf8f5a 28-Feb-2014 Josh Hunt <johunt@akamai.com>

netfilter: ipset: add forceadd kernel support for hash set types

Adds a new property for hash set types, where if a set is created
with the 'forceadd' option and the set becomes full the next addition
to the set may succeed and evict a random entry from the set.

To keep overhead low eviction is done very simply. It checks to see
which bucket the new entry would be added. If the bucket's pos value
is non-zero (meaning there's at least one entry in the bucket) it
replaces the first entry in the bucket. If pos is zero, then it continues
down the normal add process.

This property is useful if you have a set for 'ban' lists where it may
not matter if you release some entries from the set early.

Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# 9562cf28 27-Dec-2013 Fengguang Wu <fengguang.wu@intel.com>

netfilter: ipset: Add hash: fix coccinelle warnings

net/netfilter/ipset/ip_set_hash_netnet.c:115:8-9: WARNING: return of 0/1 in function 'hash_netnet4_data_list' with return type bool
/c/kernel-tests/src/cocci/net/netfilter/ipset/ip_set_hash_netnet.c:338:8-9: WARNING: return of 0/1 in function 'hash_netnet6_data_list' with return type bool

Return statements in functions returning bool should use
true/false instead of 1/0.
Generated by: coccinelle/misc/boolreturn.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# b49faea7 14-Nov-2013 Dave Jones <davej@redhat.com>

netfilter: ipset: fix incorret comparison in hash_netnet4_data_equal()

Both sides of the comparison are the same, looks like a cut-and-paste error.

Spotted by Coverity.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 1a869205 18-Oct-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

netfilter: ipset: The unnamed union initialization may lead to compilation error

The unnamed union should be possible to be initialized directly, but
unfortunately it's not so:

/usr/src/ipset/kernel/net/netfilter/ipset/ip_set_hash_netnet.c: In
function ?hash_netnet4_kadt?:
/usr/src/ipset/kernel/net/netfilter/ipset/ip_set_hash_netnet.c:141:
error: unknown field ?cidr? specified in initializer

Reported-by: Husnu Demir <hdemir@metu.edu.tr>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# fda75c6d 22-Sep-2013 Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>

netfilter: ipset: Support comments in hash-type ipsets.

This provides kernel support for creating ipsets with comment support.

This does incur a penalty to flushing/destroying an ipset since all
entries are walked in order to free the allocated strings, this penalty
is of course less expensive than the operation of listing an ipset to
userspace, so for general-purpose usage the overall impact is expected
to be little to none.

Signed-off-by: Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>


# ea53ac5b 20-Sep-2013 Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>

netfilter: ipset: Add hash:net,net module to kernel.

This adds a new set that provides the ability to configure pairs of
subnets. A small amount of additional handling code has been added to
the generic hash header file - this code is conditionally activated by a
preprocessor definition.

Signed-off-by: Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>