commit d6d3f08b0f
(netfilter: xtables: conntrack match revision 2) does break the
v1 conntrack match iptables-save output in a subtle way.
Problem is as follows:
up = kmalloc(sizeof(*up), GFP_KERNEL);
[..]
/*
* The strategy here is to minimize the overhead of v1 matching,
* by prebuilding a v2 struct and putting the pointer into the
* v1 dataspace.
*/
memcpy(up, info, offsetof(typeof(*info), state_mask));
[..]
*(void **)info = up;
As the v2 struct pointer is saved in the match data space,
it clobbers the first structure member (->origsrc_addr).
Because the _v1 match function grabs this pointer and does not actually
look at the v1 origsrc, run time functionality does not break.
But iptables -nvL (or iptables-save) cannot know that v1 origsrc_addr
has been overloaded in this way:
$ iptables -p tcp -A OUTPUT -m conntrack --ctorigsrc 10.0.0.1 -j ACCEPT
$ iptables-save
-A OUTPUT -p tcp -m conntrack --ctorigsrc 128.173.134.206 -j ACCEPT
(128.173... is the address to the v2 match structure).
To fix this, we take advantage of the fact that the v1 and v2 structures
are identical with exception of the last two structure members (u8 in v1,
u16 in v2).
We extract them as early as possible and prevent the v2 matching function
from looking at those two members directly.
Previously reported by Michel Messerschmidt via Ben Hutchings, also
see Debian Bug tracker #556587.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Without this patch, if we receive a SYN packet from the client while
the firewall is out-of-sync, we let it go through. Then, if we see
the SYN/ACK reply coming from the server, we destroy the conntrack
entry and drop the packet to trigger a new retransmission. Then,
the retransmision from the client is used to start a new clean
session.
This patch improves the current handling. Basically, if we see an
unexpected SYN packet, we annotate the TCP options. Then, if we
see the reply SYN/ACK, this means that the firewall was indeed
out-of-sync. Therefore, we set a clean new session from the existing
entry based on the annotated values.
This patch adds two new 8-bits fields that fit in a 16-bits gap of
the ip_ct_tcp structure.
This patch is particularly useful for conntrackd since the
asynchronous nature of the state-synchronization allows to have
backup nodes that are not perfect copies of the master. This helps
to improve the recovery under some worst-case scenarios.
I have tested this by creating lots of conntrack entries in wrong
state:
for ((i=1024;i<65535;i++)); do conntrack -I -p tcp -s 192.168.2.101 -d 192.168.2.2 --sport $i --dport 80 -t 800 --state ESTABLISHED -u ASSURED,SEEN_REPLY; done
Then, I make some TCP connections:
$ echo GET / | nc 192.168.2.2 80
The events show the result:
[UPDATE] tcp 6 60 SYN_RECV src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED]
[UPDATE] tcp 6 432000 ESTABLISHED src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED]
[UPDATE] tcp 6 120 FIN_WAIT src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED]
[UPDATE] tcp 6 30 LAST_ACK src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED]
[UPDATE] tcp 6 120 TIME_WAIT src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED]
and tcpdump shows no retransmissions:
20:47:57.271951 IP 192.168.2.101.33221 > 192.168.2.2.www: S 435402517:435402517(0) win 5840 <mss 1460,sackOK,timestamp 4294961827 0,nop,wscale 6>
20:47:57.273538 IP 192.168.2.2.www > 192.168.2.101.33221: S 3509927945:3509927945(0) ack 435402518 win 5792 <mss 1460,sackOK,timestamp 235681024 4294961827,nop,wscale 4>
20:47:57.273608 IP 192.168.2.101.33221 > 192.168.2.2.www: . ack 3509927946 win 92 <nop,nop,timestamp 4294961827 235681024>
20:47:57.273693 IP 192.168.2.101.33221 > 192.168.2.2.www: P 435402518:435402524(6) ack 3509927946 win 92 <nop,nop,timestamp 4294961827 235681024>
20:47:57.275492 IP 192.168.2.2.www > 192.168.2.101.33221: . ack 435402524 win 362 <nop,nop,timestamp 235681024 4294961827>
20:47:57.276492 IP 192.168.2.2.www > 192.168.2.101.33221: P 3509927946:3509928082(136) ack 435402524 win 362 <nop,nop,timestamp 235681025 4294961827>
20:47:57.276515 IP 192.168.2.101.33221 > 192.168.2.2.www: . ack 3509928082 win 108 <nop,nop,timestamp 4294961828 235681025>
20:47:57.276521 IP 192.168.2.2.www > 192.168.2.101.33221: F 3509928082:3509928082(0) ack 435402524 win 362 <nop,nop,timestamp 235681025 4294961827>
20:47:57.277369 IP 192.168.2.101.33221 > 192.168.2.2.www: F 435402524:435402524(0) ack 3509928083 win 108 <nop,nop,timestamp 4294961828 235681025>
20:47:57.279491 IP 192.168.2.2.www > 192.168.2.101.33221: . ack 435402525 win 362 <nop,nop,timestamp 235681025 4294961828>
I also added a rule to log invalid packets, with no occurrences :-) .
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The NETLINK_URELEASE notifier is only invoked for bound sockets, so
there is no need to check ->pid again.
Signed-off-by: Patrick McHardy <kaber@trash.net>
This should make it possible to test for the existence of local
sockets in the INPUT path.
References: http://marc.info/?l=netfilter-devel&m=125380481517129&w=2
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
In order to have better cache layouts of struct sock (separate zones
for rx/tx paths), we need this preliminary patch.
Goal is to transfert fields used at lookup time in the first
read-mostly cache line (inside struct sock_common) and move sk_refcnt
to a separate cache line (only written by rx path)
This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr,
sport and id fields. This allows a future patch to define these
fields as macros, like sk_refcnt, without name clashes.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.
Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.
Signed-off-by: David S. Miller <davem@davemloft.net>
It's unused.
It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.
It _was_ used in two places at arch/frv for some reason.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages. The amount of what actually is usable as storage
should instead be used as a basis here.
Some of the calculations (i.e. those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add handling of incoming ICMPv6 messages.
This follows the handling of IPv4 ICMP messages.
Amongst ther things this problem allows IPVS to behave sensibly
when an ICMPV6_PKT_TOOBIG message is received:
This message is received when a realserver sends a packet >PMTU to the
client. The hop on this path with insufficient MTU will generate an
ICMPv6 Packet Too Big message back to the VIP. The LVS server receives
this message, but the call to the function handling this has been
missing. Thus, IPVS fails to forward the message to the real server,
which then does not adjust the path MTU. This patch adds the missing
call to ip_vs_in_icmp_v6() in ip_vs_in() to handle this situation.
Thanks to Rob Gallagher from HEAnet for reporting this issue and for
testing this patch in production (with direct routing mode).
[horms@verge.net.au: tweaked changelog]
Signed-off-by: Julius Volz <julius.volz@gmail.com>
Tested-by: Rob Gallagher <robert.gallagher@heanet.ie>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Conntracks in netns other than init_net dying list were never killed.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
A pointed out by Shin Hong, IPVS doesn't always use atomic operations
in an atomic manner. While this seems unlikely to be manifest in
strange behaviour, it seems appropriate to clean this up.
Cc: shin hong <hongshin@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The inputted table is never modified, so should be considered const.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Success was indicated on a memory allocation failure, thereby causing
a crash due to a later NULL deref.
(Affects v2.6.30-rc1 up to here.)
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In 5e140dfc1f "net: reorder struct Qdisc
for better SMP performance" the definition of struct gnet_stats_basic
changed incompatibly, as copies of this struct are shipped to
userland via netlink.
Restoring old behavior is not welcome, for performance reason.
Fix is to use a private structure for kernel, and
teach gnet_stats_copy_basic() to convert from kernel to user land,
using legacy structure (struct gnet_stats_basic)
Based on a report and initial patch from Michael Spang.
Reported-by: Michael Spang <mspang@csclub.uwaterloo.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
String literals are constant, and usually, we can also tag the array
of pointers const too, moving it to the .rodata section.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since pr_err and friends are used instead of printk there is no point
in keeping IP_VS_ERR and friends. Furthermore make use of '__func__'
instead of hard coded function names.
Signed-off-by: Hannes Eder <heder@google.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a slab cache uses SLAB_DESTROY_BY_RCU, we must be careful when allocating
objects, since slab allocator could give a freed object still used by lockless
readers.
In particular, nf_conntrack RCU lookups rely on ct->tuplehash[xxx].hnnode.next
being always valid (ie containing a valid 'nulls' value, or a valid pointer to next
object in hash chain.)
kmem_cache_zalloc() setups object with NULL values, but a NULL value is not valid
for ct->tuplehash[xxx].hnnode.next.
Fix is to call kmem_cache_alloc() and do the zeroing ourself.
As spotted by Patrick, we also need to make sure lookup keys are committed to
memory before setting refcount to 1, or a lockless reader could get a reference
on the old version of the object. Its key re-check could then pass the barrier.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This makes generic netlink network namespace aware. No
generic netlink families except for the controller family
are made namespace aware, they need to be checked one by
one and then set the family->netnsok member to true.
A new function genlmsg_multicast_netns() is introduced to
allow sending a multicast message in a given namespace,
for example when it applies to an object that lives in
that namespace, a new function genlmsg_multicast_allns()
to send a message to all network namespaces (for objects
that do not have an associated netns).
The function genlmsg_multicast() is changed to multicast
the message in just init_net, which is currently correct
for all generic netlink families since they only work in
init_net right now. Some will later want to work in all
net namespaces because they do not care about the netns
at all -- those will have to be converted to use one of
the new functions genlmsg_multicast_allns() or
genlmsg_multicast_netns() whenever they are made netns
aware in some way.
After this patch families can easily decide whether or
not they should be available in all net namespaces. Many
genl families us it for objects not related to networking
and should therefore be available in all namespaces, but
that will have to be done on a per family basis.
Note that this doesn't touch on the checkpoint/restart
problem where network namespaces could be used, genl
families and multicast groups are numbered globally and
I see no easy way of changing that, especially since it
must be possible to multicast to all network namespaces
for those families that do not care about netns.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
As reported by Philip, the UNTRACKED state bit does not fit within
the 8-bit state_mask member. Enlarge state_mask and give status_mask
a few more bits too.
Reported-by: Philip Craig <philipc@snapgear.com>
References: http://markmail.org/thread/b7eg6aovfh4agyz7
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
When NAT helpers change the TCP packet size, the highest seen sequence
number needs to be corrected. This is currently only done upwards, when
the packet size is reduced the sequence number is unchanged. This causes
TCP conntrack to falsely detect unacknowledged data and decrease the
timeout.
Fix by updating the highest seen sequence number in both directions after
packet mangling.
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
RCU barriers, rcu_barrier(), is inserted two places.
In nf_conntrack_expect.c nf_conntrack_expect_fini() before the
kmem_cache_destroy(). Firstly to make sure the callback to the
nf_ct_expect_free_rcu() code is still around. Secondly because I'm
unsure about the consequence of having in flight
nf_ct_expect_free_rcu/kmem_cache_free() calls while doing a
kmem_cache_destroy() slab destroy.
And in nf_conntrack_extend.c nf_ct_extend_unregister(), inorder to
wait for completion of callbacks to __nf_ct_ext_free_rcu(), which is
invoked by __nf_ct_ext_add(). It might be more efficient to call
rcu_barrier() in nf_conntrack_core.c nf_conntrack_cleanup_net(), but
thats make it more difficult to read the code (as the callback code
in located in nf_conntrack_extend.c).
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Patrick McHardy <kaber@trash.net>
As noticed by Török Edwin <edwintorok@gmail.com>:
Compiling the kernel with clang has shown this warning:
net/netfilter/xt_rateest.c:69:16: warning: self-comparison always results in a
constant value
ret &= pps2 == pps2;
^
Looking at the code:
if (info->flags & XT_RATEEST_MATCH_BPS)
ret &= bps1 == bps2;
if (info->flags & XT_RATEEST_MATCH_PPS)
ret &= pps2 == pps2;
Judging from the MATCH_BPS case it seems to be a typo, with the intention of
comparing pps1 with pps2.
http://bugzilla.kernel.org/show_bug.cgi?id=13535
Signed-off-by: Patrick McHardy <kaber@trash.net>
Commit v2.6.29-rc5-872-gacc738f ("xtables: avoid pointer to self")
forgot to copy the initial quota value supplied by iptables into the
private structure, thus counting from whatever was in the memory
kmalloc returned.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
net/netfilter/xt_NFQUEUE.c:46:9: warning: incorrect type in assignment (different base types)
net/netfilter/xt_NFQUEUE.c:46:9: expected unsigned int [unsigned] [usertype] ipaddr
net/netfilter/xt_NFQUEUE.c:46:9: got restricted unsigned int
net/netfilter/xt_NFQUEUE.c:68:10: warning: incorrect type in assignment (different base types)
net/netfilter/xt_NFQUEUE.c:68:10: expected unsigned int [unsigned] <noident>
net/netfilter/xt_NFQUEUE.c:68:10: got restricted unsigned int
net/netfilter/xt_NFQUEUE.c:69:10: warning: incorrect type in assignment (different base types)
net/netfilter/xt_NFQUEUE.c:69:10: expected unsigned int [unsigned] <noident>
net/netfilter/xt_NFQUEUE.c:69:10: got restricted unsigned int
net/netfilter/xt_NFQUEUE.c:70:10: warning: incorrect type in assignment (different base types)
net/netfilter/xt_NFQUEUE.c:70:10: expected unsigned int [unsigned] <noident>
net/netfilter/xt_NFQUEUE.c:70:10: got restricted unsigned int
net/netfilter/xt_NFQUEUE.c:71:10: warning: incorrect type in assignment (different base types)
net/netfilter/xt_NFQUEUE.c:71:10: expected unsigned int [unsigned] <noident>
net/netfilter/xt_NFQUEUE.c:71:10: got restricted unsigned int
net/netfilter/xt_cluster.c:20:55: warning: incorrect type in return expression (different base types)
net/netfilter/xt_cluster.c:20:55: expected unsigned int
net/netfilter/xt_cluster.c:20:55: got restricted unsigned int const [usertype] ip
net/netfilter/xt_cluster.c:20:55: warning: incorrect type in return expression (different base types)
net/netfilter/xt_cluster.c:20:55: expected unsigned int
net/netfilter/xt_cluster.c:20:55: got restricted unsigned int const [usertype] ip
Signed-off-by: Patrick McHardy <kaber@trash.net>
The RCU protected conntrack hash lookup only checks whether the entry
has a refcount of zero to decide whether it is stale. This is not
sufficient, entries are explicitly removed while there is at least
one reference left, possibly more. Explicitly check whether the entry
has been marked as dying to fix this.
Signed-off-by: Patrick McHardy <kaber@trash.net>
New connection tracking entries are inserted into the hash before they
are fully set up, namely the CONFIRMED bit is not set and the timer not
started yet. This can theoretically lead to a race with timer, which
would set the timeout value to a relative value, most likely already in
the past.
Perform hash insertion as the final step to fix this.
Signed-off-by: Patrick McHardy <kaber@trash.net>
death_by_timeout() might delete a conntrack from hash list
and insert it in dying list.
nf_ct_delete_from_lists(ct);
nf_ct_insert_dying_list(ct);
I believe a (lockless) reader could *catch* ct while doing a lookup
and miss the end of its chain.
(nulls lookup algo must check the null value at the end of lookup and
should restart if the null value is not the expected one.
cf Documentation/RCU/rculist_nulls.txt for details)
We need to change nf_conntrack_init_net() and use a different "null" value,
guaranteed not being used in regular lists. Choose very large values, since
hash table uses [0..size-1] null values.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch improves ctnetlink event reliability if one broadcast
listener has set the NETLINK_BROADCAST_ERROR socket option.
The logic is the following: if an event delivery fails, we keep
the undelivered events in the missed event cache. Once the next
packet arrives, we add the new events (if any) to the missed
events in the cache and we try a new delivery, and so on. Thus,
if ctnetlink fails to deliver an event, we try to deliver them
once we see a new packet. Therefore, we may lose state
transitions but the userspace process gets in sync at some point.
At worst case, if no events were delivered to userspace, we make
sure that destroy events are successfully delivered. Basically,
if ctnetlink fails to deliver the destroy event, we remove the
conntrack entry from the hashes and we insert them in the dying
list, which contains inactive entries. Then, the conntrack timer
is added with an extra grace timeout of random32() % 15 seconds
to trigger the event again (this grace timeout is tunable via
/proc). The use of a limited random timeout value allows
distributing the "destroy" resends, thus, avoiding accumulating
lots "destroy" events at the same time. Event delivery may
re-order but we can identify them by means of the tuple plus
the conntrack ID.
The maximum number of conntrack entries (active or inactive) is
still handled by nf_conntrack_max. Thus, we may start dropping
packets at some point if we accumulate a lot of inactive conntrack
entries that did not successfully report the destroy event to
userspace.
During my stress tests consisting of setting a very small buffer
of 2048 bytes for conntrackd and the NETLINK_BROADCAST_ERROR socket
flag, and generating lots of very small connections, I noticed
very few destroy entries on the fly waiting to be resend.
A simple way to test this patch consist of creating a lot of
entries, set a very small Netlink buffer in conntrackd (+ a patch
which is not in the git tree to set the BROADCAST_ERROR flag)
and invoke `conntrack -F'.
For expectations, no changes are introduced in this patch.
Currently, event delivery is only done for new expectations (no
events from expectation expiration, removal and confirmation).
In that case, they need a per-expectation event cache to implement
the same idea that is exposed in this patch.
This patch can be useful to provide reliable flow-accouting. We
still have to add a new conntrack extension to store the creation
and destroy time.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch moves the helper destruction to a function that lives
in nf_conntrack_helper.c. This new function is used in the patch
to add ctnetlink reliable event delivery.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch reworks the per-cpu event caching to use the conntrack
extension infrastructure.
The main drawback is that we consume more memory per conntrack
if event delivery is enabled. This patch is required by the
reliable event delivery that follows to this patch.
BTW, this patch allows you to enable/disable event delivery via
/proc/sys/net/netfilter/nf_conntrack_events in runtime, although
you can still disable event caching as compilation option.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Use mod_timer_pending() instead of atomic sequence of del_timer()/
add_timer(). mod_timer_pending() does not rearm an inactive timer,
so we don't need the conntrack lock anymore to make sure we don't
accidentally rearm a timer of a conntrack which is in the process
of being destroyed.
With this change, we don't need to take the global lock anymore at all,
counter updates can be performed under the per-conntrack lock.
Signed-off-by: Patrick McHardy <kaber@trash.net>
