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This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).
When event delivery fails, re-delivery is attempted via work queue.
Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.
The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.
Joint work with Pablo Neira Ayuso.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.
Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Move the global initial codes to the module_init/exit context.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.
I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.
I have successfully built an allyesconfig kernel with this change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Existing code assumes that del_timer returns true for alive conntrack
entries. However, this is not true if reliable events are enabled.
In that case, del_timer may return true for entries that were
just inserted in the dying list. Note that packets / ctnetlink may
hold references to conntrack entries that were just inserted to such
list.
This patch fixes the issue by adding an independent timer for
event delivery. This increases the size of the ecache extension.
Still we can revisit this later and use variable size extensions
to allocate this area on demand.
Tested-by: Oliver Smith <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Hans reports that he's still hitting:
BUG: unable to handle kernel NULL pointer dereference at 000000000000027c
IP: [<ffffffff813615db>] netlink_has_listeners+0xb/0x60
PGD 0
Oops: 0000 [#3] PREEMPT SMP
CPU 0
It happens when adding a number of containers with do:
nfct_query(h, NFCT_Q_CREATE, ct);
and most likely one namespace shuts down.
this problem was supposed to be fixed by:
70e9942 netfilter: nf_conntrack: make event callback registration per-netns
Still, it was missing one rcu_access_pointer to check if the callback
is set or not.
Reported-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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This patch fixes an oops that can be triggered following this recipe:
0) make sure nf_conntrack_netlink and nf_conntrack_ipv4 are loaded.
1) container is started.
2) connect to it via lxc-console.
3) generate some traffic with the container to create some conntrack
entries in its table.
4) stop the container: you hit one oops because the conntrack table
cleanup tries to report the destroy event to user-space but the
per-netns nfnetlink socket has already gone (as the nfnetlink
socket is per-netns but event callback registration is global).
To fix this situation, we make the ctnl_notifier per-netns so the
callback is registered/unregistered if the container is
created/destroyed.
Alex Bligh and Alexey Dobriyan originally proposed one small patch to
check if the nfnetlink socket is gone in nfnetlink_has_listeners,
but this is a very visited path for events, thus, it may reduce
performance and it looks a bit hackish to check for the nfnetlink
socket only to workaround this situation. As a result, I decided
to follow the bigger path choice, which seems to look nicer to me.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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For the following rule:
iptables -I PREROUTING -t raw -j CT --ctevents assured
The event delivered looks like the following:
[UPDATE] tcp 6 src=192.168.0.2 dst=192.168.1.2 sport=37041 dport=80 src=192.168.1.2 dst=192.168.1.100 sport=80 dport=37041 [ASSURED]
Note that the TCP protocol state is not included. For that reason
the CT event filtering is not very useful for conntrackd.
To resolve this issue, instead of conditionally setting the CT events
bits based on the ctmask, we always set them and perform the filtering
in the late stage, just before the delivery.
Thus, the event delivered looks like the following:
[UPDATE] tcp 6 432000 ESTABLISHED src=192.168.0.2 dst=192.168.1.2 sport=37041 dport=80 src=192.168.1.2 dst=192.168.1.100 sport=80 dport=37041 [ASSURED]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Add some __rcu annotations and use helpers to reduce number of sparse
warnings (CONFIG_SPARSE_RCU_POINTER=y)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Less IDs make nf_ct_ext smaller.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Add two masks for conntrack end expectation events to struct nf_conntrack_ecache
and use them to filter events. Their default value is "all events" when the
event sysctl is on and "no events" when it is off. A following patch will add
specific initializations. Expectation events depend on the ecache struct of
their master conntrack.
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Split up the IPCT_STATUS event into an IPCT_REPLY event, which is generated
when the IPS_SEEN_REPLY bit is set, and an IPCT_ASSURED event, which is
generated when the IPS_ASSURED bit is set.
In combination with a following patch to support selective event delivery,
this can be used for "sparse" conntrack replication: start replicating the
conntrack entry after it reached the ASSURED state and that way it's SYN-flood
resistant.
Signed-off-by: Patrick McHardy <kaber@trash.net>
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This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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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>
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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>
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This patch removes the notify chain infrastructure and replace it
by a simple function pointer. This issue has been mentioned in the
mailing list several times: the use of the notify chain adds
too much overhead for something that is only used by ctnetlink.
This patch also changes nfnetlink_send(). It seems that gfp_any()
returns GFP_KERNEL for user-context request, like those via
ctnetlink, inside the RCU read-side section which is not valid.
Using GFP_KERNEL is also evil since netlink may schedule(),
this leads to "scheduling while atomic" bug reports.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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This patch simplifies the conntrack event caching system by removing
several events:
* IPCT_[*]_VOLATILE, IPCT_HELPINFO and IPCT_NATINFO has been deleted
since the have no clients.
* IPCT_COUNTER_FILLING which is a leftover of the 32-bits counter
days.
* IPCT_REFRESH which is not of any use since we always include the
timeout in the messages.
After this patch, the existing events are:
* IPCT_NEW, IPCT_RELATED and IPCT_DESTROY, that are used to identify
addition and deletion of entries.
* IPCT_STATUS, that notes that the status bits have changes,
eg. IPS_SEEN_REPLY and IPS_ASSURED.
* IPCT_PROTOINFO, that reports that internal protocol information has
changed, eg. the TCP, DCCP and SCTP protocol state.
* IPCT_HELPER, that a helper has been assigned or unassigned to this
entry.
* IPCT_MARK and IPCT_SECMARK, that reports that the mark has changed, this
covers the case when a mark is set to zero.
* IPCT_NATSEQADJ, to report that there's updates in the NAT sequence
adjustment.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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This patch moves the event flags from linux/netfilter/nf_conntrack_common.h
to net/netfilter/nf_conntrack_ecache.h. This flags are not of any use
from userspace.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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As for now, the creation and update of conntracks via ctnetlink do not
propagate an event to userspace. This can result in inconsistent situations
if several userspace processes modify the connection tracking table by means
of ctnetlink at the same time. Specifically, using the conntrack command
line tool and conntrackd at the same time can trigger unconsistencies.
This patch also modifies the event cache infrastructure to pass the
process PID and the ECHO flag to nfnetlink_send() to report back
to userspace if the process that triggered the change needs so.
Based on a suggestion from Patrick McHardy.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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The dummy version of 'nf_conntrack_event_cache()' (used when the
NF_CONNTRACK_EVENTS config option is not enabled) had not been updated
when the calling convention changed.
This was introduced by commit a71996fccce4b2086a26036aa3c915365ca36926
("netfilter: netns nf_conntrack: pass conntrack to
nf_conntrack_event_cache() not skb")
Tssk.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch add missing braces of today's net-next-2.6:
include/net/netfilter/nf_conntrack_ecache.h
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Heh, last minute proof-reading of this patch made me think,
that this is actually unneeded, simply because "ct" pointers will be
different for different conntracks in different netns, just like they
are different in one netns.
Not so sure anymore.
[Patrick: pointers will be different, flushing can only be done while
inactive though and thus it needs to be per netns]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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This is cleaner, we already know conntrack to which event is relevant.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Currently there is a wild mix of nf_conntrack_expect_, nf_ct_exp_,
expect_, exp_, ...
Consistently use nf_ct_ as prefix for exported functions.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch splits out the event cache into its own file
nf_conntrack_ecache.c
Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
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Florian Westphal
Joe Perches
Gao feng
Eric W. Biederman
Pablo Neira Ayuso
David S. Miller
Eric Dumazet
Changli Gao
Patrick McHardy
Linus Torvalds
Guo-Fu Tseng
Alexey Dobriyan
Martin Josefsson