linux.git/include/net/netfilter, branch v2.6.31

net: restore gnet_stats_basic to previous definition

2009-08-18T04:33:49+00:00

In 5e140dfc1fe87eae27846f193086724806b33c7d "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 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

netfilter: tcp conntrack: fix unacknowledged data detection with NAT

2009-06-29T12:07:56+00:00

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 
Signed-off-by: Patrick McHardy

netfilter: conntrack: optional reliable conntrack event delivery

2009-06-13T10:30:52+00:00

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 
Signed-off-by: Patrick McHardy

netfilter: conntrack: move helper destruction to nf_ct_helper_destroy()

2009-06-13T10:28:22+00:00

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 
Signed-off-by: Patrick McHardy

netfilter: conntrack: move event caching to conntrack extension infrastructure

2009-06-13T10:26:29+00:00

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 
Signed-off-by: Patrick McHardy

netfilter: nf_conntrack: use per-conntrack locks for protocol data

2009-06-10T12:32:47+00:00

Introduce per-conntrack locks and use them instead of the global protocol
locks to avoid contention. Especially tcp_lock shows up very high in
profiles on larger machines.

This will also allow to simplify the upcoming reliable event delivery patches.

Signed-off-by: Patrick McHardy

netfilter: nf_ct_icmp: keep the ICMP ct entries longer

2009-06-08T13:53:43+00:00

Current conntrack code kills the ICMP conntrack entry as soon as
the first reply is received. This is incorrect, as we then see only
the first ICMP echo reply out of several possible duplicates as
ESTABLISHED, while the rest will be INVALID. Also this unnecessarily
increases the conntrackd traffic on H-A firewalls.

Make all the ICMP conntrack entries (including the replied ones)
last for the default of nf_conntrack_icmp{,v6}_timeout seconds.

Signed-off-by: Jan "Yenya" Kasprzak 
Signed-off-by: Patrick McHardy

netfilter: conntrack: replace notify chain by function pointer

2009-06-03T08:32:06+00:00

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

netfilter: conntrack: simplify event caching system

2009-06-02T18:08:46+00:00

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

netfilter: conntrack: remove events flags from userspace exposed file

2009-06-02T18:08:44+00:00

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