Commit graph

338 commits

Author SHA1 Message Date
Florian Westphal a5fedd43d5 netfilter: move skb_gso_segment into nfnetlink_queue module
skb_gso_segment is expensive, so it would be nice if we could
avoid it in the future. However, userspace needs to be prepared
to receive larger-than-mtu-packets (which will also have incorrect
l3/l4 checksums), so we cannot simply remove it.

The plan is to add a per-queue feature flag that userspace can
set when binding the queue.

The problem is that in nf_queue, we only have a queue number,
not the queue context/configuration settings.

This patch should have no impact other than the skb_gso_segment
call now being in a function that has access to the queue config
data.

A new size attribute in nf_queue_entry is needed so
nfnetlink_queue can duplicate the entry of the gso skb
when segmenting the skb while also copying the route key.

The follow up patch adds switch to disable skb_gso_segment when
queue config says so.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-29 20:09:05 +02:00
Patrick McHardy ec464e5dc5 netfilter: rename netlink related "pid" variables to "portid"
Get rid of the confusing mix of pid and portid and use portid consistently
for all netlink related socket identities.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-19 14:58:36 -04:00
Gao feng 30e0c6a6be netfilter: nf_log: prepare net namespace support for loggers
This patch adds netns support to nf_log and it prepares netns
support for existing loggers. It is composed of four major
changes.

1) nf_log_register has been split to two functions: nf_log_register
   and nf_log_set. The new nf_log_register is used to globally
   register the nf_logger and nf_log_set is used for enabling
   pernet support from nf_loggers.

   Per netns is not yet complete after this patch, it comes in
   separate follow up patches.

2) Add net as a parameter of nf_log_bind_pf. Per netns is not
   yet complete after this patch, it only allows to bind the
   nf_logger to the protocol family from init_net and it skips
   other cases.

3) Adapt all nf_log_packet callers to pass netns as parameter.
   After this patch, this function only works for init_net.

4) Make the sysctl net/netfilter/nf_log pernet.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-05 20:12:54 +02:00
Vladimir Davydov dece40e848 netfilter: nf_conntrack: speed up module removal path if netns in use
The patch introduces nf_conntrack_cleanup_net_list(), which cleanups
nf_conntrack for a list of netns and calls synchronize_net() only once
for them all. This should reduce netns destruction time.

I've measured cleanup time for 1k dummy net ns. Here are the results:

 <without the patch>
 # modprobe nf_conntrack
 # time modprobe -r nf_conntrack

 real	0m10.337s
 user	0m0.000s
 sys	0m0.376s

 <with the patch>
 # modprobe nf_conntrack
 # time modprobe -r nf_conntrack

 real    0m5.661s
 user    0m0.000s
 sys     0m0.216s

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-03-19 17:08:31 +01:00
Pablo Neira Ayuso b20ab9cc63 netfilter: nf_ct_helper: better logging for dropped packets
Connection tracking helpers have to drop packets under exceptional
situations. Currently, the user gets the following logging message
in case that happens:

	nf_ct_%s: dropping packet ...

However, depending on the helper, there are different reasons why a
packet can be dropped.

This patch modifies the existing code to provide more specific
error message in the scope of each helper to help users to debug
the reason why the packet has been dropped, ie:

	nf_ct_%s: dropping packet: reason ...

Thanks to Joe Perches for many formatting suggestions.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-19 02:48:05 +01:00
David S. Miller b640bee6d9 Merge branch 'master' of git://1984.lsi.us.es/nf-next
Pablo Neira Ayuso says:

====================
This batch contains netfilter updates for you net-next tree, they are:

* The new connlabel extension for x_tables, that allows us to attach
  labels to each conntrack flow. The kernel implementation uses a
  bitmask and there's a file in user-space that maps the bits with the
  corresponding string for each existing label. By now, you can attach
  up to 128 overlapping labels. From Florian Westphal.

* A new round of improvements for the netns support for conntrack.
  Gao feng has moved many of the initialization code of each module
  of the netns init path. He also made several code refactoring, that
  code looks cleaner to me now.

* Added documentation for all possible tweaks for nf_conntrack via
  sysctl, from Jiri Pirko.

* Cisco 7941/7945 IP phone support for our SIP conntrack helper,
  from Kevin Cernekee.

* Missing header file in the snmp helper, from Stephen Hemminger.

* Finally, a couple of fixes to resolve minor issues with these
  changes, from myself.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-27 00:56:10 -05:00
Tom Herbert 5ba24953e9 soreuseport: TCP/IPv6 implementation
Motivation for soreuseport would be something like a web server
binding to port 80 running with multiple threads, where each thread
might have it's own listener socket.  This could be done as an
alternative to other models: 1) have one listener thread which
dispatches completed connections to workers. 2) accept on a single
listener socket from multiple threads.  In case #1 the listener thread
can easily become the bottleneck with high connection turn-over rate.
In case #2, the proportion of connections accepted per thread tends
to be uneven under high connection load (assuming simple event loop:
while (1) { accept(); process() }, wakeup does not promote fairness
among the sockets.  We have seen the  disproportion to be as high
as 3:1 ratio between thread accepting most connections and the one
accepting the fewest.  With so_reusport the distribution is
uniform.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-23 13:44:01 -05:00
Tom Herbert da5e36308d soreuseport: TCP/IPv4 implementation
Allow multiple listener sockets to bind to the same port.

Motivation for soresuseport would be something like a web server
binding to port 80 running with multiple threads, where each thread
might have it's own listener socket.  This could be done as an
alternative to other models: 1) have one listener thread which
dispatches completed connections to workers. 2) accept on a single
listener socket from multiple threads.  In case #1 the listener thread
can easily become the bottleneck with high connection turn-over rate.
In case #2, the proportion of connections accepted per thread tends
to be uneven under high connection load (assuming simple event loop:
while (1) { accept(); process() }, wakeup does not promote fairness
among the sockets.  We have seen the  disproportion to be as high
as 3:1 ratio between thread accepting most connections and the one
accepting the fewest.  With so_reusport the distribution is
uniform.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-23 13:44:01 -05:00
Gao feng c296bb4d5d netfilter: nf_conntrack: refactor l4proto support for netns
Move the code that register/unregister l4proto to the
module_init/exit context.

Given that we have to modify some interfaces to accomodate
these changes, it is a good time to use shorter function names
for this using the nf_ct_* prefix instead of nf_conntrack_*,
that is:

nf_ct_l4proto_register
nf_ct_l4proto_pernet_register
nf_ct_l4proto_unregister
nf_ct_l4proto_pernet_unregister

We same many line breaks with it.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-23 14:40:53 +01:00
Gao feng 6330750d56 netfilter: nf_conntrack: refactor l3proto support for netns
Move the code that register/unregister l3proto to the
module_init/exit context.

Given that we have to modify some interfaces to accomodate
these changes, it is a good time to use shorter function names
for this using the nf_ct_* prefix instead of nf_conntrack_*,
that is:

nf_ct_l3proto_register
nf_ct_l3proto_pernet_register
nf_ct_l3proto_unregister
nf_ct_l3proto_pernet_unregister

We same many line breaks with it.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-23 14:39:20 +01:00
Gao feng 04d8700179 netfilter: nf_ct_proto: move initialization out of pernet_operations
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>
2013-01-23 12:56:33 +01:00
Gao feng 5f69b8f521 netfilter: nf_ct_labels: move initialization out of pernet_operations
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>
2013-01-23 12:56:23 +01:00
Gao feng 5e615b2200 netfilter: nf_ct_helper: move initialization out of pernet_operations
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>
2013-01-23 12:56:13 +01:00
Gao feng 8684094cf1 netfilter: nf_ct_timeout: move initialization out of pernet_operations
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>
2013-01-23 12:56:02 +01:00
Gao feng 3fe0f943d4 netfilter: nf_ct_ecache: move initialization out of pernet_operations
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>
2013-01-23 12:55:50 +01:00
Gao feng 73f4001a52 netfilter: nf_ct_tstamp: move initialization out of pernet_operations
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>
2013-01-23 12:55:39 +01:00
Gao feng b7ff3a1fae netfilter: nf_ct_acct: move initialization out of pernet_operations
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>
2013-01-23 12:55:29 +01:00
Gao feng 83b4dbe198 netfilter: nf_ct_expect: move initialization out of pernet_operations
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>
2013-01-23 12:55:00 +01:00
Gao feng f94161c1bb netfilter: nf_conntrack: move initialization out of pernet operations
nf_conntrack initialization and cleanup codes happens in pernet
operations function. This task should be done in module_init/exit.
We can't use init_net to identify if it's the right time to initialize
or cleanup since we cannot make assumption on the order netns are
created/destroyed.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-23 12:53:35 +01:00
Florian Westphal 9b21f6a909 netfilter: ctnetlink: allow userspace to modify labels
Add the ability to set/clear labels assigned to a conntrack
via ctnetlink.

To allow userspace to only alter specific bits, Pablo suggested to add
a new CTA_LABELS_MASK attribute:

The new set of active labels is then determined via

active = (active & ~mask) ^ changeset

i.e., the mask selects those bits in the existing set that should be
changed.

This follows the same method already used by MARK and CONNMARK targets.

Omitting CTA_LABELS_MASK is the same as setting all bits in CTA_LABELS_MASK
to 1: The existing set is replaced by the one from userspace.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 00:28:17 +01:00
Florian Westphal c539f01717 netfilter: add connlabel conntrack extension
similar to connmarks, except labels are bit-based; i.e.
all labels may be attached to a flow at the same time.

Up to 128 labels are supported.  Supporting more labels
is possible, but requires increasing the ct offset delta
from u8 to u16 type due to increased extension sizes.

Mapping of bit-identifier to label name is done in userspace.

The extension is enabled at run-time once "-m connlabel" netfilter
rules are added.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 00:28:15 +01:00
Pablo Neira Ayuso 1e47ee8367 netfilter: nf_conntrack: fix BUG_ON while removing nf_conntrack with netns
canqun zhang reported that we're hitting BUG_ON in the
nf_conntrack_destroy path when calling kfree_skb while
rmmod'ing the nf_conntrack module.

Currently, the nf_ct_destroy hook is being set to NULL in the
destroy path of conntrack.init_net. However, this is a problem
since init_net may be destroyed before any other existing netns
(we cannot assume any specific ordering while releasing existing
netns according to what I read in recent emails).

Thanks to Gao feng for initial patch to address this issue.

Reported-by: canqun zhang <canqunzhang@gmail.com>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-12 14:12:36 +01:00
Jozsef Kadlecsik a0ecb85a2c netfilter: nf_nat: Handle routing changes in MASQUERADE target
When the route changes (backup default route, VPNs) which affect a
masqueraded target, the packets were sent out with the outdated source
address. The patch addresses the issue by comparing the outgoing interface
directly with the masqueraded interface in the nat table.

Events are inefficient in this case, because it'd require adding route
events to the network core and then scanning the whole conntrack table
and re-checking the route for all entry.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-12-03 15:14:20 +01:00
Florian Westphal 0360ae412d netfilter: kill support for per-af queue backends
We used to have several queueing backends, but nowadays only
nfnetlink_queue remains.

In light of this there doesn't seem to be a good reason to
support per-af registering -- just hook up nfnetlink_queue on module
load and remove it on unload.

This means that the userspace BIND/UNBIND_PF commands are now obsolete;
the kernel will ignore them.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-12-03 15:07:48 +01:00
Pablo Neira Ayuso 04dac0111d netfilter: nf_conntrack: improve nf_conn object traceability
This patch modifies the conntrack subsystem so that all existing
allocated conntrack objects can be found in any of the following
places:

* the hash table, this is the typical place for alive conntrack objects.
* the unconfirmed list, this is the place for newly created conntrack objects
  that are still traversing the stack.
* the dying list, this is where you can find conntrack objects that are dying
  or that should die anytime soon (eg. once the destroy event is delivered to
  the conntrackd daemon).

Thus, we make sure that we follow the track for all existing conntrack
objects. This patch, together with some extension of the ctnetlink interface
to dump the content of the dying and unconfirmed lists, will help in case
to debug suspected nf_conn object leaks.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-12-03 15:06:33 +01:00
Eric W. Biederman 15e473046c netlink: Rename pid to portid to avoid confusion
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>
2012-09-10 15:30:41 -04:00
Pablo Neira Ayuso ace1fe1231 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
This merges (3f509c6 netfilter: nf_nat_sip: fix incorrect handling
of EBUSY for RTCP expectation) to Patrick McHardy's IPv6 NAT changes.
2012-09-03 15:34:51 +02:00
Pablo Neira Ayuso 84b5ee939e netfilter: nf_conntrack: add nf_ct_timeout_lookup
This patch adds the new nf_ct_timeout_lookup function to encapsulate
the timeout policy attachment that is called in the nf_conntrack_in
path.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-03 13:33:03 +02:00
Pablo Neira Ayuso 5b423f6a40 netfilter: nf_conntrack: fix racy timer handling with reliable events
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>
2012-08-31 15:50:28 +02:00
Patrick McHardy b3f644fc82 netfilter: ip6tables: add MASQUERADE target
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:18 +02:00
Patrick McHardy 58a317f106 netfilter: ipv6: add IPv6 NAT support
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:17 +02:00
Patrick McHardy c7232c9979 netfilter: add protocol independent NAT core
Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:14 +02:00
Patrick McHardy 051966c0c6 netfilter: nf_nat: add protoff argument to packet mangling functions
For mangling IPv6 packets the protocol header offset needs to be known
by the NAT packet mangling functions. Add a so far unused protoff argument
and convert the conntrack and NAT helpers to use it in preparation of
IPv6 NAT.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:13 +02:00
David S. Miller 04c9f416e3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/batman-adv/bridge_loop_avoidance.c
	net/batman-adv/bridge_loop_avoidance.h
	net/batman-adv/soft-interface.c
	net/mac80211/mlme.c

With merge help from Antonio Quartulli (batman-adv) and
Stephen Rothwell (drivers/net/usb/qmi_wwan.c).

The net/mac80211/mlme.c conflict seemed easy enough, accounting for a
conversion to some new tracing macros.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:56:33 -07:00
Pablo Neira Ayuso 6bd0405bb4 netfilter: nf_ct_ecache: fix crash with multiple containers, one shutting down
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>
2012-07-09 10:53:19 +02:00
Pablo Neira Ayuso 08911475d1 netfilter: nf_conntrack: generalize nf_ct_l4proto_net
This patch generalizes nf_ct_l4proto_net by splitting it into chunks and
moving the corresponding protocol part to where it really belongs to.

To clarify, note that we follow two different approaches to support per-net
depending if it's built-in or run-time loadable protocol tracker.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
2012-07-04 19:37:22 +02:00
Gao feng f28997e27a netfilter: nf_conntrack: add nf_ct_kfree_compat_sysctl_table
This patch is a cleanup.

It adds nf_ct_kfree_compat_sysctl_table to release l4proto's
compat sysctl table and set the compat sysctl table point to NULL.

This new function will be used by follow-up patches.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-27 18:36:25 +02:00
Gao feng f1caad2745 netfilter: nf_conntrack: prepare l4proto->init_net cleanup
l4proto->init contain quite redundant code. We can simplify this
by adding a new parameter l3proto.

This patch prepares that code simplification.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-27 18:31:14 +02:00
Pablo Neira Ayuso 674147e211 netfilter: fix missing symbols if CONFIG_NETFILTER_NETLINK_QUEUE_CT unset
ERROR: "nfqnl_ct_parse" [net/netfilter/nfnetlink_queue.ko] undefined!
ERROR: "nfqnl_ct_seq_adjust" [net/netfilter/nfnetlink_queue.ko] undefined!
ERROR: "nfqnl_ct_put" [net/netfilter/nfnetlink_queue.ko] undefined!
ERROR: "nfqnl_ct_get" [net/netfilter/nfnetlink_queue.ko] undefined!

We have to use CONFIG_NETFILTER_NETLINK_QUEUE_CT in
include/net/netfilter/nfnetlink_queue.h, not CONFIG_NF_CONNTRACK.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-18 21:09:17 -07:00
Pablo Neira Ayuso 7c62234547 netfilter: nfnetlink_queue: fix compilation with NF_CONNTRACK disabled
In "9cb0176 netfilter: add glue code to integrate nfnetlink_queue and ctnetlink"
the compilation with NF_CONNTRACK disabled is broken. This patch fixes this
issue.

I have moved the conntrack part into nfnetlink_queue_ct.c to avoid
peppering the entire nfnetlink_queue.c code with ifdefs.

I also needed to rename nfnetlink_queue.c to nfnetlink_queue_pkt.c
to update the net/netfilter/Makefile to support conditional compilation
of the conntrack integration.

This patch also adds CONFIG_NETFILTER_QUEUE_CT in case you want to explicitly
disable the integration between nf_conntrack and nfnetlink_queue.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-19 04:44:57 +02:00
Pablo Neira Ayuso 12f7a50533 netfilter: add user-space connection tracking helper infrastructure
There are good reasons to supports helpers in user-space instead:

* Rapid connection tracking helper development, as developing code
  in user-space is usually faster.

* Reliability: A buggy helper does not crash the kernel. Moreover,
  we can monitor the helper process and restart it in case of problems.

* Security: Avoid complex string matching and mangling in kernel-space
  running in privileged mode. Going further, we can even think about
  running user-space helpers as a non-root process.

* Extensibility: It allows the development of very specific helpers (most
  likely non-standard proprietary protocols) that are very likely not to be
  accepted for mainline inclusion in the form of kernel-space connection
  tracking helpers.

This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).

I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.

Basic operation, in a few steps:

1) Register user-space helper by means of `nfct':

 nfct helper add ftp inet tcp

 [ It must be a valid existing helper supported by conntrack-tools ]

2) Add rules to enable the FTP user-space helper which is
   used to track traffic going to TCP port 21.

For locally generated packets:

 iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp

For non-locally generated packets:

 iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp

3) Run the test conntrackd in helper mode (see example files under
   doc/helper/conntrackd.conf

 conntrackd

4) Generate FTP traffic going, if everything is OK, then conntrackd
   should create expectations (you can check that with `conntrack':

 conntrack -E expect

    [NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp

This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.

The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:40:02 +02:00
Pablo Neira Ayuso ae243bee39 netfilter: ctnetlink: add CTA_HELP_INFO attribute
This attribute can be used to modify and to dump the internal
protocol information.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:09:15 +02:00
Pablo Neira Ayuso 8c88f87cb2 netfilter: nfnetlink_queue: add NAT TCP sequence adjustment if packet mangled
User-space programs that receive traffic via NFQUEUE may mangle packets.
If NAT is enabled, this usually puzzles sequence tracking, leading to
traffic disruptions.

With this patch, nfnl_queue will make the corresponding NAT TCP sequence
adjustment if:

1) The packet has been mangled,
2) the NFQA_CFG_F_CONNTRACK flag has been set, and
3) NAT is detected.

There are some records on the Internet complaning about this issue:
http://stackoverflow.com/questions/260757/packet-mangling-utilities-besides-iptables

By now, we only support TCP since we have no helpers for DCCP or SCTP.
Better to add this if we ever have some helper over those layer 4 protocols.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:09:08 +02:00
Pablo Neira Ayuso 1afc56794e netfilter: nf_ct_helper: implement variable length helper private data
This patch uses the new variable length conntrack extensions.

Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.

This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:55 +02:00
Pablo Neira Ayuso 3cf4c7e381 netfilter: nf_ct_ext: support variable length extensions
We can now define conntrack extensions of variable size. This
patch is useful to get rid of these unions:

union nf_conntrack_help
union nf_conntrack_proto
union nf_conntrack_nat_help

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:49 +02:00
Pablo Neira Ayuso 3a8fc53a45 netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names
This patch modifies the struct nf_conntrack_helper to allocate
the room for the helper name. The maximum length is 16 bytes
(this was already introduced in 2.6.24).

For the maximum length for expectation policy names, I have
also selected 16 bytes.

This patch is required by the follow-up patch to support
user-space connection tracking helpers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:39 +02:00
Gao feng 8264deb818 netfilter: nf_conntrack: add namespace support for cttimeout
This patch adds namespace support for cttimeout.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-07 14:58:41 +02:00
Pablo Neira Ayuso e76d0af5e4 netfilter: nf_conntrack: remove now unused sysctl for nf_conntrack_l[3|4]proto
Since the sysctl data for l[3|4]proto now resides in pernet nf_proto_net.
We can now remove this unused fields from struct nf_contrack_l[3,4]proto.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-07 14:58:41 +02:00
Gao feng 15f585bd76 netfilter: nf_ct_generic: add namespace support
This patch adds namespace support for the generic layer 4 protocol
tracker.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-07 14:58:39 +02:00
Gao feng 524a53e5ad netfilter: nf_conntrack: prepare namespace support for l3 protocol trackers
This patch prepares the namespace support for layer 3 protocol trackers.
Basically, this modifies the following interfaces:

* nf_ct_l3proto_[un]register_sysctl.
* nf_conntrack_l3proto_[un]register.

We add a new nf_ct_l3proto_net is used to get the pernet data of l3proto.

This adds rhe new struct nf_ip_net that is used to store the sysctl header
and l3proto_ipv4,l4proto_tcp(6),l4proto_udp(6),l4proto_icmp(v6) because the
protos such tcp and tcp6 use the same data,so making nf_ip_net as a field
of netns_ct is the easiest way to manager it.

This patch also adds init_net to struct nf_conntrack_l3proto to initial
the layer 3 protocol pernet data.

Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-07 14:58:39 +02:00