Commit Graph

3424 Commits

Author SHA1 Message Date
Liping Zhang 8fff1722f7 netfilter: nf_tables: fix a wrong check to skip the inactive rules
nft_genmask_cur has already done left-shift operator on the gencursor,
so there's no need to do left-shift operator on it again.

Fixes: ea4bd995b0 ("netfilter: nf_tables: add transaction helper functions")
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-15 12:17:24 +02:00
Liping Zhang a02f424863 netfilter: nf_tables: fix wrong destroy anonymous sets if binding fails
When we add a nft rule like follows:
  # nft add rule filter test tcp dport vmap {1: jump test}
-ELOOP error will be returned, and the anonymous set will be
destroyed.

But after that, nf_tables_abort will also try to remove the
element and destroy the set, which was already destroyed and
freed.

If we add a nft wrong rule, nft_tables_abort will do the cleanup
work rightly, so nf_tables_set_destroy call here is redundant and
wrong, remove it.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-15 12:17:23 +02:00
Pablo Neira Ayuso 8588ac097b netfilter: nf_tables: reject loops from set element jump to chain
Liping Zhang says:

"Users may add such a wrong nft rules successfully, which will cause an
endless jump loop:

  # nft add rule filter test tcp dport vmap {1: jump test}

This is because before we commit, the element in the current anonymous
set is inactive, so osp->walk will skip this element and miss the
validate check."

To resolve this problem, this patch passes the generation mask to the
walk function through the iter container structure depending on the code
path:

1) If we're dumping the elements, then we have to check if the element
   is active in the current generation. Thus, we check for the current
   bit in the genmask.

2) If we're checking for loops, then we have to check if the element is
   active in the next generation, as we're in the middle of a
   transaction. Thus, we check for the next bit in the genmask.

Based on original patch from Liping Zhang.

Reported-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Liping Zhang <liping.zhang@spreadtrum.com>
2016-06-15 12:17:23 +02:00
Liping Zhang a46844021f netfilter: nf_tables: fix wrong check of NFT_SET_MAP in nf_tables_bind_set
We should check "i" is used as a dictionary or not, "binding" is already
checked before.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-15 12:17:23 +02:00
Florian Westphal 7757114972 netfilter: conntrack: destroy kmemcache on module removal
I forgot to move the kmem_cache_destroy into the exit path.

Fixes: 0c5366b3a8 ("netfilter: conntrack: use single slab cache)
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-15 12:17:22 +02:00
Marco Angaroni 3ec10d3a2b ipvs: update real-server binding of outgoing connections in SIP-pe
Previous patch that introduced handling of outgoing packets in SIP
persistent-engine did not call ip_vs_check_template() in case packet was
matching a connection template. Assumption was that real-server was
healthy, since it was sending a packet just in that moment.

There are however real-server fault conditions requiring that association
between call-id and real-server (represented by connection template)
gets updated. Here is an example of the sequence of events:
  1) RS1 is a back2back user agent that handled call-id1 and call-id2
  2) RS1 is down and was marked as unavailable
  3) new message from outside comes to IPVS with call-id1
  4) IPVS reschedules the message to RS2, which becomes new call handler
  5) RS2 forwards the message outside, translating call-id1 to call-id2
  6) inside pe->conn_out() IPVS matches call-id2 with existing template
  7) IPVS does not change association call-id2 <-> RS1
  8) new message comes from client with call-id2
  9) IPVS reschedules the message to a real-server potentially different
     from RS2, which is now the correct destination

This patch introduces ip_vs_check_template() call in the handling of
outgoing packets for SIP-pe. And also introduces a second optional
argument for ip_vs_check_template() that allows to check if dest
associated to a connection template is the same dest that was identified
as the source of the packet. This is to change the real-server bound to a
particular call-id independently from its availability status: the idea
is that it's more reliable, for in->out direction (where internal
network can be considered trusted), to always associate a call-id with
the last real-server that used it in one of its messages. Think about
above sequence of events where, just after step 5, RS1 returns instead
to be available.

Comparison of dests is done by simply comparing pointers to struct
ip_vs_dest; there should be no cases where struct ip_vs_dest keeps its
memory address, but represent a different real-server in terms of
ip-address / port.

Fixes: 39b9722315 ("ipvs: handle connections started by real-servers")
Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
2016-06-06 09:47:25 +09:00
Florian Westphal 7b7eba0f35 netfilter: x_tables: don't reject valid target size on some architectures
Quoting John Stultz:
  In updating a 32bit arm device from 4.6 to Linus' current HEAD, I
  noticed I was having some trouble with networking, and realized that
  /proc/net/ip_tables_names was suddenly empty.
  Digging through the registration process, it seems we're catching on the:

   if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
       target_offset + sizeof(struct xt_standard_target) != next_offset)
         return -EINVAL;

  Where next_offset seems to be 4 bytes larger then the
  offset + standard_target struct size.

next_offset needs to be aligned via XT_ALIGN (so we can access all members
of ip(6)t_entry struct).

This problem didn't show up on i686 as it only needs 4-byte alignment for
u64, but iptables userspace on other 32bit arches does insert extra padding.

Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Fixes: 7ed2abddd2 ("netfilter: x_tables: check standard target size too")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-02 14:09:33 +02:00
David S. Miller fc14963f24 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix incorrect timestamp in nfnetlink_queue introduced when addressing
   y2038 safe timestamp, from Florian Westphal.

2) Get rid of leftover conntrack definition from the previous merge
   window, oneliner from Florian.

3) Make nf_queue handler pernet to resolve race on dereferencing the
   hook state structure with netns removal, from Eric Biederman.

4) Ensure clean exit on unregistered helper ports, from Taehee Yoo.

5) Restore FLOWI_FLAG_KNOWN_NH in nf_dup_ipv6. This got lost while
   generalizing xt_TEE to add packet duplication support in nf_tables,
   from Paolo Abeni.

6) Insufficient netlink NFTA_SET_TABLE attribute check in
   nf_tables_getset(), from Phil Turnbull.

7) Reject helper registration on duplicated ports via modparams.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-01 17:54:19 -07:00
Pablo Neira Ayuso 893e093c78 netfilter: nf_ct_helper: bail out on duplicated helpers
Don't allow registration of helpers using the same tuple:

	{ l3proto, l4proto, src-port }

We lookup for the helper from the packet path using this tuple through
__nf_ct_helper_find(). Therefore, we have to avoid having two helpers
with the same tuple to ensure predictible behaviour.

Don't compare the helper string names anymore since it is valid to
register two helpers with the same name, but using different tuples.
This is also implicitly fixing up duplicated helper registration via
ports= modparam since the name comparison was defeating the tuple
duplication validation.

Reported-by: Feng Gao <gfree.wind@gmail.com>
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-31 11:57:18 +02:00
Phil Turnbull eaa2bcd6d1 netfilter: nf_tables: validate NFTA_SET_TABLE parameter
If the NFTA_SET_TABLE parameter is missing and the NLM_F_DUMP flag is
not set, then a NULL pointer dereference is triggered in
nf_tables_set_lookup because ctx.table is NULL.

Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-30 12:21:23 +02:00
Taehee Yoo b7a8daa9f3 netfilter: nf_ct_helper: Fix helper unregister count.
helpers should unregister the only registered ports.
but, helper cannot have correct registered ports value when
failed to register.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-30 12:21:22 +02:00
Eric W. Biederman dc3ee32e96 netfilter: nf_queue: Make the queue_handler pernet
Florian Weber reported:
> Under full load (unshare() in loop -> OOM conditions) we can
> get kernel panic:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> IP: [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> [..]
> task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000
> RIP: 0010:[<ffffffff81476c85>]  [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> RSP: 0000:ffff88012dfffd80  EFLAGS: 00010206
> RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000
> [..]
> Call Trace:
>  [<ffffffff81474d98>] nf_queue_nf_hook_drop+0x18/0x20
>  [<ffffffff814738eb>] nf_unregister_net_hook+0xdb/0x150
>  [<ffffffff8147398f>] netfilter_net_exit+0x2f/0x60
>  [<ffffffff8141b088>] ops_exit_list.isra.4+0x38/0x60
>  [<ffffffff8141b652>] setup_net+0xc2/0x120
>  [<ffffffff8141bd09>] copy_net_ns+0x79/0x120
>  [<ffffffff8106965b>] create_new_namespaces+0x11b/0x1e0
>  [<ffffffff810698a7>] unshare_nsproxy_namespaces+0x57/0xa0
>  [<ffffffff8104baa2>] SyS_unshare+0x1b2/0x340
>  [<ffffffff81608276>] entry_SYSCALL_64_fastpath+0x1e/0xa8
> Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47
>

The simple fix for this requires a new pernet variable for struct
nf_queue that indicates when it is safe to use the dynamically
allocated nf_queue state.

As we need a variable anyway make nf_register_queue_handler and
nf_unregister_queue_handler pernet.  This allows the existing logic of
when it is safe to use the state from the nfnetlink_queue module to be
reused with no changes except for making it per net.

The syncrhonize_rcu from nf_unregister_queue_handler is moved to a new
function nfnl_queue_net_exit_batch so that the worst case of having a
syncrhonize_rcu in the pernet exit path is not experienced in batch
mode.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-25 11:54:22 +02:00
Florian Westphal 720b287d83 netfilter: conntrack: remove leftover binary sysctl define
Users got removed in f8572d8f2a ("sysctl net: Remove unused binary
sysctl code").

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-25 11:54:14 +02:00
Tom Herbert 7e13318daa net: define gso types for IPx over IPv4 and IPv6
This patch defines two new GSO definitions SKB_GSO_IPXIP4 and
SKB_GSO_IPXIP6 along with corresponding NETIF_F_GSO_IPXIP4 and
NETIF_F_GSO_IPXIP6. These are used to described IP in IP
tunnel and what the outer protocol is. The inner protocol
can be deduced from other GSO types (e.g. SKB_GSO_TCPV4 and
SKB_GSO_TCPV6). The GSO types of SKB_GSO_IPIP and SKB_GSO_SIT
are removed (these are both instances of SKB_GSO_IPXIP4).
SKB_GSO_IPXIP6 will be used when support for GSO with IP
encapsulation over IPv6 is added.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 18:03:15 -04:00
David S. Miller 909b27f706 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The nf_conntrack_core.c fix in 'net' is not relevant in 'net-next'
because we no longer have a per-netns conntrack hash.

The ip_gre.c conflict as well as the iwlwifi ones were cases of
overlapping changes.

Conflicts:
	drivers/net/wireless/intel/iwlwifi/mvm/tx.c
	net/ipv4/ip_gre.c
	net/netfilter/nf_conntrack_core.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-15 13:32:48 -04:00
Linus Torvalds 31b0b385f6 nf_conntrack: avoid kernel pointer value leak in slab name
The slab name ends up being visible in the directory structure under
/sys, and even if you don't have access rights to the file you can see
the filenames.

Just use a 64-bit counter instead of the pointer to the 'net' structure
to generate a unique name.

This code will go away in 4.7 when the conntrack code moves to a single
kmemcache, but this is the backportable simple solution to avoiding
leaking kernel pointers to user space.

Fixes: 5b3501faa8 ("netfilter: nf_conntrack: per netns nf_conntrack_cachep")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-14 15:04:43 -04:00
Florian Westphal a7f1884554 netfilter: nfnetlink_queue: fix timestamp attribute
Since 4.4 we erronously use timestamp of the netlink skb (which is zero).

Bugzilla: https://bugzilla.netfilter.org/show_bug.cgi?id=1066
Fixes: b28b1e826f ("netfilter: nfnetlink_queue: use y2038 safe timestamp")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-12 17:06:59 +02:00
Arnd Bergmann c047c3b1af netfilter: conntrack: remove uninitialized shadow variable
A recent commit introduced an unconditional use of an uninitialized
variable, as reported in this gcc warning:

net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_confirm':
net/netfilter/nf_conntrack_core.c:632:33: error: 'ctinfo' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
                                 ^
net/netfilter/nf_conntrack_core.c:628:26: note: 'ctinfo' was declared here
   enum ip_conntrack_info ctinfo;

The problem is that a local variable shadows the function parameter.
This removes the local variable, which looks like what Pablo originally
intended.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 71d8c47fc6 ("netfilter: conntrack: introduce clash resolution on insertion race")
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-10 01:04:04 -04:00
David S. Miller e8ed77dfa9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following large patchset contains Netfilter updates for your
net-next tree. My initial intention was to send you this in two goes but
when I looked back twice I already had this burden on top of me.

Several updates for IPVS from Marco Angaroni:

1) Allow SIP connections originating from real-servers to be load
   balanced by the SIP persistence engine as is already implemented
   in the other direction.

2) Release connections immediately for One-packet-scheduling (OPS)
   in IPVS, instead of making it via timer and rcu callback.

3) Skip deleting conntracks for each one packet in OPS, and don't call
   nf_conntrack_alter_reply() since no reply is expected.

4) Enable drop on exhaustion for OPS + SIP persistence.

Miscelaneous conntrack updates from Florian Westphal, including fix for
hash resize:

5) Move conntrack generation counter out of conntrack pernet structure
   since this is only used by the init_ns to allow hash resizing.

6) Use get_random_once() from packet path to collect hash random seed
    instead of our compound.

7) Don't disable BH from ____nf_conntrack_find() for statistics,
   use NF_CT_STAT_INC_ATOMIC() instead.

8) Fix lookup race during conntrack hash resizing.

9) Introduce clash resolution on conntrack insertion for connectionless
   protocol.

Then, Florian's netns rework to get rid of per-netns conntrack table,
thus we use one single table for them all. There was consensus on this
change during the NFWS 2015 and, on top of that, it has recently been
pointed as a source of multiple problems from unpriviledged netns:

11) Use a single conntrack hashtable for all namespaces. Include netns
    in object comparisons and make it part of the hash calculation.
    Adapt early_drop() to consider netns.

12) Use single expectation and NAT hashtable for all namespaces.

13) Use a single slab cache for all namespaces for conntrack objects.

14) Skip full table scanning from nf_ct_iterate_cleanup() if the pernet
    conntrack counter tells us the table is empty (ie. equals zero).

Fixes for nf_tables interval set element handling, support to set
conntrack connlabels and allow set names up to 32 bytes.

15) Parse element flags from element deletion path and pass it up to the
    backend set implementation.

16) Allow adjacent intervals in the rbtree set type for dynamic interval
    updates.

17) Add support to set connlabel from nf_tables, from Florian Westphal.

18) Allow set names up to 32 bytes in nf_tables.

Several x_tables fixes and updates:

19) Fix incorrect use of IS_ERR_VALUE() in x_tables, original patch
    from Andrzej Hajda.

And finally, miscelaneous netfilter updates such as:

20) Disable automatic helper assignment by default. Note this proc knob
    was introduced by a900689264 ("netfilter: nf_ct_helper: allow to
    disable automatic helper assignment") 4 years ago to start moving
    towards explicit conntrack helper configuration via iptables CT
    target.

21) Get rid of obsolete and inconsistent debugging instrumentation
    in x_tables.

22) Remove unnecessary check for null after ip6_route_output().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-09 15:02:58 -04:00
Florian Westphal 0c5366b3a8 netfilter: conntrack: use single slab cache
An earlier patch changed lookup side to also net_eq() namespaces after
obtaining a reference on the conntrack, so a single kmemcache can be used.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-09 16:45:50 +02:00
Florian Westphal a76ae1c855 netfilter: conntrack: use a single nat bysource table for all namespaces
We already include netns address in the hash, so we only need to use
net_eq in find_appropriate_src and can then put all entries into
same table.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-09 16:45:49 +02:00
Florian Westphal 464c38556e netfilter: conntrack: make netns address part of nat bysrc hash
Will be needed soon when we place all in the same hash table.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-09 16:45:49 +02:00
Pablo Neira Ayuso bbe848ec1a Merge tag 'ipvs2-for-v4.7' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs-next
Simon Horman says:

====================
Second Round of IPVS Updates for v4.7

please consider these enhancements to the IPVS. They allow its DoS
mitigation strategy effective in conjunction with the SIP persistence
engine.
====================

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:52 +02:00
Florian Westphal 0a93aaedc4 netfilter: conntrack: use a single expectation table for all namespaces
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the expectation table.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:01 +02:00
Florian Westphal a9a083c387 netfilter: conntrack: make netns address part of expect hash
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:01 +02:00
Florian Westphal 03d7dc5cdf netfilter: conntrack: check netns when walking expect hash
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:01 +02:00
Marco Angaroni 698e2a8dca ipvs: make drop_entry protection effective for SIP-pe
DoS protection policy that deletes connections to avoid out of memory is
currently not effective for SIP-pe plus OPS-mode for two reasons:
  1) connection templates (holding SIP call-id) are always skipped in
     ip_vs_random_dropentry()
  2) in_pkts counter (used by drop_entry algorithm) is not incremented
     for connection templates

This patch addresses such problems with the following changes:
  a) connection templates associated (via their dest) to virtual-services
     configured in OPS mode are included in ip_vs_random_dropentry()
     monitoring. This applies to SIP-pe over UDP (which requires OPS mode),
     but is more general principle: when OPS is controlled by templates
     memory can be used only by templates themselves, since OPS conns are
     deleted after packet is forwarded.
  b) OPS connections, if controlled by a template, cause increment of
     in_pkts counter of their template. This is already happening but only
     in case director is in master-slave mode (see ip_vs_sync_conn()).

Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
2016-05-06 16:26:23 +09:00
Phil Turnbull eda3fc50da netfilter: nfnetlink_acct: validate NFACCT_QUOTA parameter
If a quota bit is set in NFACCT_FLAGS but the NFACCT_QUOTA parameter is
missing then a NULL pointer dereference is triggered. CAP_NET_ADMIN is
required to trigger the bug.

Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:47:08 +02:00
Pablo Neira Ayuso cb39ad8b8e netfilter: nf_tables: allow set names up to 32 bytes
Currently, we support set names of up to 16 bytes, get this aligned
with the maximum length we can use in ipset to make it easier when
considering migration to nf_tables.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:51 +02:00
Pablo Neira Ayuso 71d8c47fc6 netfilter: conntrack: introduce clash resolution on insertion race
This patch introduces nf_ct_resolve_clash() to resolve race condition on
conntrack insertions.

This is particularly a problem for connection-less protocols such as
UDP, with no initial handshake. Two or more packets may race to insert
the entry resulting in packet drops.

Another problematic scenario are packets enqueued to userspace via
NFQUEUE after the raw table, that make it easier to trigger this
race.

To resolve this, the idea is to reset the conntrack entry to the one
that won race. Packet and bytes counters are also merged.

The 'insert_failed' stats still accounts for this situation, after
this patch, the drop counter is bumped whenever we drop packets, so we
can watch for unresolved clashes.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:50 +02:00
Pablo Neira Ayuso ba76738c03 netfilter: conntrack: introduce nf_ct_acct_update()
Introduce a helper function to update conntrack counters.
__nf_ct_kill_acct() was unnecessarily subtracting skb_network_offset()
that is expected to be zero from the ipv4/ipv6 hooks.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:49 +02:00
Pablo Neira Ayuso 4b4ceb9dbf netfilter: conntrack: __nf_ct_l4proto_find() always returns valid pointer
Remove unnecessary check for non-nul pointer in destroy_conntrack()
given that __nf_ct_l4proto_find() returns the generic protocol tracker
if the protocol is not supported.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:48 +02:00
Florian Westphal 3e86638e9a netfilter: conntrack: consider ct netns in early_drop logic
When iterating, skip conntrack entries living in a different netns.

We could ignore netns and kill some other non-assured one, but it
has two problems:

- a netns can kill non-assured conntracks in other namespace
- we would start to 'over-subscribe' the affected/overlimit netns.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:48 +02:00
Florian Westphal 56d52d4892 netfilter: conntrack: use a single hashtable for all namespaces
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the table.

Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a
64bit system.

NAT bysrc and expectation hash is still per namespace, those will
changed too soon.

Future patch will also make conntrack object slab cache global again.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:47 +02:00
Florian Westphal 1b8c8a9f64 netfilter: conntrack: make netns address part of hash
Once we place all conntracks into a global hash table we want them to be
spread across entire hash table, even if namespaces have overlapping ip
addresses.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:46 +02:00
Florian Westphal e0c7d47221 netfilter: conntrack: check netns when comparing conntrack objects
Once we place all conntracks in the same hash table we must also compare
the netns pointer to skip conntracks that belong to a different namespace.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:46 +02:00
Florian Westphal 868043485e netfilter: conntrack: use nf_ct_key_equal() in more places
This prepares for upcoming change that places all conntracks into a
single, global table.  For this to work we will need to also compare
net pointer during lookup.  To avoid open-coding such check use the
nf_ct_key_equal helper and then later extend it to also consider net_eq.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:44 +02:00
Florian Westphal 88b68bc523 netfilter: conntrack: don't attempt to iterate over empty table
Once we place all conntracks into same table iteration becomes more
costly because the table contains conntracks that we are not interested
in (belonging to other netns).

So don't bother scanning if the current namespace has no entries.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:44 +02:00
Florian Westphal 5e3c61f981 netfilter: conntrack: fix lookup race during hash resize
When resizing the conntrack hash table at runtime via
echo 42 > /sys/module/nf_conntrack/parameters/hashsize, we are racing with
the conntrack lookup path -- reads can happen in parallel and nothing
prevents readers from observing a the newly allocated hash but the old
size (or vice versa).

So access to hash[bucket] can trigger OOB read access in case the table got
expanded and we saw the new size but the old hash pointer (or it got shrunk
and we got new hash ptr but the size of the old and larger table):

kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.6.0-rc2+ #107
[..]
Call Trace:
[<ffffffff822c3d6a>] ? nf_conntrack_tuple_taken+0x12a/0xe90
[<ffffffff822c3ac1>] ? nf_ct_invert_tuplepr+0x221/0x3a0
[<ffffffff8230e703>] get_unique_tuple+0xfb3/0x2760

Use generation counter to obtain the address/length of the same table.

Also add a synchronize_net before freeing the old hash.
AFAICS, without it we might access ct_hash[bucket] after ct_hash has been
freed, provided that lockless reader got delayed by another event:

CPU1			CPU2
seq_begin
seq_retry
<delay>			resize occurs
			free oldhash
for_each(oldhash[size])

Note that resize is only supported in init_netns, it took over 2 minutes
of constant resizing+flooding to produce the warning, so this isn't a
big problem in practice.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:43 +02:00
Florian Westphal 2cf1234807 netfilter: conntrack: keep BH enabled during lookup
No need to disable BH here anymore:

stats are switched to _ATOMIC variant (== this_cpu_inc()), which
nowadays generates same code as the non _ATOMIC NF_STAT, at least on x86.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:43 +02:00
Florian Westphal 1ad8f48df6 netfilter: nftables: add connlabel set support
Conntrack labels are currently sized depending on the iptables
ruleset, i.e. if we're asked to test or set bits 1, 2, and 65 then we
would allocate enough room to store at least bit 65.

However, with nft, the input is just a register with arbitrary runtime
content.

We therefore ask for the upper ceiling we currently have, which is
enough room to store 128 bits.

Alternatively, we could alter nf_connlabel_replace to increase
net->ct.label_words at run time, but since 128 bits is not that
big we'd only save sizeof(long) so it doesn't seem worth it for now.

This follows a similar approach that xtables 'connlabel'
match uses, so when user inputs

    ct label set bar

then we will set the bit used by the 'bar' label and leave the rest alone.

This is done by passing the sreg content to nf_connlabels_replace
as both value and mask argument.
Labels (bits) already set thus cannot be re-set to zero, but
this is not supported by xtables connlabel match either.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:27:59 +02:00
Liping Zhang cec5913c15 netfilter: IDLETIMER: fix race condition when destroy the target
Workqueue maybe still in running while we destroy the IDLETIMER target,
thus cause a use after free error, add cancel_work_sync() to avoid such
situation.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-29 14:28:48 +02:00
Florian Westphal 70d72b7e06 netfilter: conntrack: init all_locks to avoid debug warning
Else we get 'BUG: spinlock bad magic on CPU#' on resize when
spin lock debugging is enabled.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-29 11:27:10 +02:00
Nicolas Dichtel cbdeafd7e1 netfilter/ipvs: use nla_put_u64_64bit()
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-25 15:09:11 -04:00
Pablo Neira Ayuso 6cd54fc60c Merge tag 'ipvs-for-v4.7' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs-next
Simon Horman says:

====================
IPVS Updates for v4.7

please consider these enhancements to the IPVS. They allow SIP connections
originating from real-servers to be load balanced by the SIP psersitence
engine as is already implemented in the other direction. And for better one
packet scheduling (OPS) performance.
====================

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 15:35:53 +02:00
Pablo Neira Ayuso 3bb398d925 netfilter: nf_ct_helper: disable automatic helper assignment
Four years ago we introduced a new sysctl knob to disable automatic
helper assignment in 72110dfaa907 ("netfilter: nf_ct_helper: disable
automatic helper assignment"). This knob kept this behaviour enabled by
default to remain conservative.

This measure was introduced to provide a secure way to configure
iptables and connection tracking helpers through explicit rules.

Give the time we have waited for this, let's turn off this by default
now, worse case users still have a chance to recover the former
behaviour by explicitly enabling this back through sysctl.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 15:34:30 +02:00
Pablo Neira Ayuso e701001e7c netfilter: nft_rbtree: allow adjacent intervals with dynamic updates
This patch fixes dynamic element updates for adjacent intervals in the
rb-tree representation.

Since elements are sorted in the rb-tree, in case of adjacent nodes with
the same key, the assumption is that an interval end node must be placed
before an interval opening.

In tree lookup operations, the idea is to search for the closer element
that is smaller than the one we're searching for. Given that we'll have
two possible matchings, we have to take the opening interval in case of
adjacent nodes.

Range merges are not trivial with the current representation,
specifically we have to check if node extensions are equal and make sure
we keep the existing internal states around.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 15:32:41 +02:00
Pablo Neira Ayuso ef1d20e0f8 netfilter: nft_rbtree: introduce nft_rbtree_interval_end() helper
Add this new nft_rbtree_interval_end() helper function to check in the
end interval is set.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 14:52:12 +02:00
Pablo Neira Ayuso 3971ca1435 netfilter: nf_tables: parse element flags from nft_del_setelem()
Parse flags and pass them to the set via ->deactivate() to check if we
remove the right element from the intervals.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 14:52:12 +02:00
Pablo Neira Ayuso 0e9091d686 netfilter: nf_tables: introduce nft_setelem_parse_flags() helper
This function parses the set element flags, thus, we can reuse the same
handling when deleting elements.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 14:52:12 +02:00