Commit Graph

10 Commits

Author SHA1 Message Date
Yafang Shao a0badcc665 netfilter: conntrack: register sysctl table for gre
This patch adds two sysctl knobs for GRE:

	net.netfilter.nf_conntrack_gre_timeout = 30
	net.netfilter.nf_conntrack_gre_timeout_stream = 180

Update the Documentation as well.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-21 00:51:25 +01:00
Florian Westphal 294304e4c5 netfilter: conntrack: udp: set stream timeout to 2 minutes
We have no explicit signal when a UDP stream has terminated, peers just
stop sending.

For suspected stream connections a timeout of two minutes is sane to keep
NAT mapping alive a while longer.

It matches tcp conntracks 'timewait' default timeout value.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-21 00:48:46 +01:00
Olivier Gayot bb38ccce88 docs: networking: fix minor typos in various documentation files
This patch fixes some typos/misspelling errors in the
Documentation/networking files.

Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04 17:21:28 -04:00
Florian Westphal 4d3a57f23d netfilter: conntrack: do not enable connection tracking unless needed
Discussion during NFWS 2017 in Faro has shown that the current
conntrack behaviour is unreasonable.

Even if conntrack module is loaded on behalf of a single net namespace,
its turned on for all namespaces, which is expensive.  Commit
481fa37347 ("netfilter: conntrack: add nf_conntrack_default_on sysctl")
attempted to provide an alternative to the 'default on' behaviour by
adding a sysctl to change it.

However, as Eric points out, the sysctl only becomes available
once the module is loaded, and then its too late.

So we either have to move the sysctl to the core, or, alternatively,
change conntrack to become active only once the rule set requires this.

This does the latter, conntrack is only enabled when a rule needs it.

Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31 20:42:00 +02:00
Florian Westphal 481fa37347 netfilter: conntrack: add nf_conntrack_default_on sysctl
This switch (default on) can be used to disable automatic registration
of connection tracking functionality in newly created network
namespaces.

This means that when net namespace goes down (or the tracker protocol
module is unloaded) we *might* have to unregister the hooks.

We can either add another per-netns variable that tells if
the hooks got registered by default, or, alternatively, just call
the protocol _put() function and have the callee deal with a possible
'extra' put() operation that doesn't pair with a get() one.

This uses the latter approach, i.e. a put() without a get has no effect.

Conntrack is still enabled automatically regardless of the new sysctl
setting if the new net namespace requires connection tracking, e.g. when
NAT rules are created.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-04 21:17:25 +01:00
Florian Westphal 486dcf43da netfilter: fix nf_conntrack_helper documentation
Since kernel 4.7 this defaults to off.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-24 12:50:24 +01:00
Nicolas Dichtel 4f76de5f23 netfilter: conntrack: remove obsolete sysctl (nf_conntrack_events_retry_timeout)
This entry has been removed in commit 9500507c61.

Fixes: 9500507c61 ("netfilter: conntrack: remove timer from ecache extension")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-17 17:38:18 +02:00
Florian Westphal 3183ab8997 netfilter: conntrack: allow increasing bucket size via sysctl too
No need to restrict this to module parameter.

We export a copy of the real hash size -- when user alters the value we
allocate the new table, copy entries etc before we update the real size
to the requested one.

This is also needed because the real size is used by concurrent readers
and cannot be changed without synchronizing the conntrack generation
seqcnt.

We only allow changing this value from the initial net namespace.

Tested using http-client-benchmark vs. httpterm with concurrent

while true;do
 echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets
done

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:28 +02:00
Marcelo Leitner 88eab472ec netfilter: conntrack: adjust nf_conntrack_buckets default value
Manually bumping either nf_conntrack_buckets or nf_conntrack_max has
become a common task as our Linux servers tend to serve more and more
clients/applications, so let's adjust nf_conntrack_buckets this to a
more updated value.

Now for systems with more than 4GB of memory, nf_conntrack_buckets
becomes 65536 instead of 16384, resulting in nf_conntrack_max=256k
entries.

Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-12-23 14:20:10 +01:00
Jiri Pirko c9f9e0e159 netfilter: doc: add nf_conntrack sysctl api documentation
I grepped through the code and picked bits about nf_conntrack sysctl api
and put that into one documentation file.

[ I have mangled this patch including comments from several grammar
  improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>,
  any new grammar error is my mistake --pablo ]

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-21 12:50:06 +01:00