linux/include/net/netfilter, branch v2.6.32

netfilter: nf_nat: fix NAT issue in 2.6.30.4+

2009-11-06T08:43:42Z

Vitezslav Samel discovered that since 2.6.30.4+ active FTP can not work over NAT. The "cause" of the problem was a fix of unacknowledged data detection with NAT (commit a3a9f79e361e864f0e9d75ebe2a0cb43d17c4272). However, actually, that fix uncovered a long standing bug in TCP conntrack: when NAT was enabled, we simply updated the max of the right edge of the segments we have seen (td_end), by the offset NAT produced with changing IP/port in the data. However, we did not update the other parameter (td_maxend) which is affected by the NAT offset. Thus that could drift away from the correct value and thus resulted breaking active FTP. The patch below fixes the issue by *not* updating the conntrack parameters from NAT, but instead taking into account the NAT offsets in conntrack in a consistent way. (Updating from NAT would be more harder and expensive because it'd need to re-calculate parameters we already calculated in conntrack.) Signed-off-by: Jozsef Kadlecsik Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6

2009-09-11T01:17:09Z

netfilter: nfnetlink: constify message attributes and headers

2009-08-25T14:07:58Z

Signed-off-by: Patrick McHardy

net: restore gnet_stats_basic to previous definition

2009-08-18T04:33:49Z

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

2009-06-29T12:07:56Z

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

2009-06-13T10:30:52Z

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()

2009-06-13T10:28:22Z

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

2009-06-13T10:26:29Z

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

2009-06-10T12:32:47Z

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

2009-06-08T13:53:43Z

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