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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
