Explicit helper attachment via the CT target is broken with NAT
if non-standard ports are used. This problem was hidden behind
the automatic helper assignment routine. Thus, it becomes more
noticeable now that we can disable the automatic helper assignment
with Eric Leblond's:
9e8ac5a netfilter: nf_ct_helper: allow to disable automatic helper assignment
Basically, nf_conntrack_alter_reply asks for looking up the helper
up if NAT is enabled. Unfortunately, we don't have the conntrack
template at that point anymore.
Since we don't want to rely on the automatic helper assignment,
we can skip the second look-up and stick to the helper that was
attached by iptables. With the CT target, the user is in full
control of helper attachment, thus, the policy is to trust what
the user explicitly configures via iptables (no automatic magic
anymore).
Interestingly, this bug was hidden by the automatic helper look-up
code. But it can be easily trigger if you attach the helper in
a non-standard port, eg.
iptables -I PREROUTING -t raw -p tcp --dport 8888 \
-j CT --helper ftp
And you disabled the automatic helper assignment.
I added the IPS_HELPER_BIT that allows us to differenciate between
a helper that has been explicitly attached and those that have been
automatically assigned. I didn't come up with a better solution
(having backward compatibility in mind).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.
Signed-off-by: David S. Miller <davem@davemloft.net>
When using the xt_set.h header in userspace, one will get these gcc
reports:
ipset/ip_set.h:184:1: error: unknown type name "u16"
In file included from libxt_SET.c:21:0:
netfilter/xt_set.h:61:2: error: unknown type name "u32"
netfilter/xt_set.h:62:2: error: unknown type name "u32"
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows you to attach the timeout policy via the
CT target, it adds a new revision of the target to ensure
backward compatibility. Moreover, it also contains the glue
code to stick the timeout object defined via nfnetlink_cttimeout
to the given flow.
Example usage (it requires installing the nfct tool and
libnetfilter_cttimeout):
1) create the timeout policy:
nfct timeout add tcp-policy0 inet tcp \
established 1000 close 10 time_wait 10 last_ack 10
2) attach the timeout policy to the packet:
iptables -I PREROUTING -t raw -p tcp -j CT --timeout tcp-policy0
You have to install the following user-space software:
a) libnetfilter_cttimeout:
git://git.netfilter.org/libnetfilter_cttimeout
b) nfct:
git://git.netfilter.org/nfct
You also have to get iptables with -j CT --timeout support.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the infrastructure to add fine timeout tuning
over nfnetlink. Now you can use the NFNL_SUBSYS_CTNETLINK_TIMEOUT
subsystem to create/delete/dump timeout objects that contain some
specific timeout policy for one flow.
The follow up patches will allow you attach timeout policy object
to conntrack via the CT target and the conntrack extension
infrastructure.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch moves the retransmission and unacknowledged timeouts
to the tcp_timeouts array. This change is required by follow-up
patches.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ipt_LOG and ip6_LOG have a lot of common code, merge them
to reduce duplicate code.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows you to set expectfn which is specifically used
by the NAT side of most of the existing conntrack helpers.
I have added a symbol map that uses a string as key to look up for
the function that is attached to the expectation object. This is
the best solution I came out with to solve this issue.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Timed out entries were still matched till the garbage collector
purged them out. The fix is verified in the testsuite.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The "nomatch" keyword and option is added to the hash:*net* types,
by which one can add exception entries to sets. Example:
ipset create test hash:net
ipset add test 192.168.0/24
ipset add test 192.168.0/30 nomatch
In this case the IP addresses from 192.168.0/24 except 192.168.0/30
match the elements of the set.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the set is full, the SET target cannot add more elements.
Log warning so that the admin got notified about it.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ipset is actually using NFPROTO values rather than AF (xt_set passes
that along).
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds CTA_MARK_MASK which, together with CTA_MARK, allows
you to selectively send conntrack entries to user-space by
returning those that match mark & mask.
With this, we can save cycles in the building and the parsing of
the entries that may be later on filtered out in user-space by using
the ctmark & mask.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch partially reverts:
3d058d7 netfilter: rework user-space expectation helper support
that was applied during the 3.2 development cycle.
After this patch, the tree remains just like before patch bc01bef,
that initially added the preliminary infrastructure.
I decided to partially revert this patch because the approach
that I proposed to resolve this problem is broken in NAT setups.
Moreover, a new infrastructure will be submitted for the 3.3.x
development cycle that resolve the existing issues while
providing a neat solution.
Since nobody has been seriously using this infrastructure in
user-space, the removal of this feature should affect any know
FOSS project (to my knowledge).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: Remove irqsafe_cpu_xxx variants
Fix up conflict in arch/x86/include/asm/percpu.h due to clash with
cebef5beed ("x86: Fix and improve percpu_cmpxchg{8,16}b_double()")
which edited the (now removed) irqsafe_cpu_cmpxchg*_double code.
Use the new macro and struct names in xt_ecn.h, and put the old
definitions into a definition-forwarding ipt_ecn.h.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Prepare the ECN match for augmentation by an IPv6 counterpart. Since
no symbol dependencies to ipv6.ko are added, having a single ecn match
module is the more so welcome.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently have two ways to account traffic in netfilter:
- iptables chain and rule counters:
# iptables -L -n -v
Chain INPUT (policy DROP 3 packets, 867 bytes)
pkts bytes target prot opt in out source destination
8 1104 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
- use flow-based accounting provided by ctnetlink:
# conntrack -L
tcp 6 431999 ESTABLISHED src=192.168.1.130 dst=212.106.219.168 sport=58152 dport=80 packets=47 bytes=7654 src=212.106.219.168 dst=192.168.1.130 sport=80 dport=58152 packets=49 bytes=66340 [ASSURED] mark=0 use=1
While trying to display real-time accounting statistics, we require
to pool the kernel periodically to obtain this information. This is
OK if the number of flows is relatively low. However, in case that
the number of flows is huge, we can spend a considerable amount of
cycles to iterate over the list of flows that have been obtained.
Moreover, if we want to obtain the sum of the flow accounting results
that match some criteria, we have to iterate over the whole list of
existing flows, look for matchings and update the counters.
This patch adds the extended accounting infrastructure for
nfnetlink which aims to allow displaying real-time traffic accounting
without the need of complicated and resource-consuming implementation
in user-space. Basically, this new infrastructure allows you to create
accounting objects. One accounting object is composed of packet and
byte counters.
In order to manipulate create accounting objects, you require the
new libnetfilter_acct library. It contains several examples of use:
libnetfilter_acct/examples# ./nfacct-add http-traffic
libnetfilter_acct/examples# ./nfacct-get
http-traffic = { pkts = 000000000000, bytes = 000000000000 };
Then, you can use one of this accounting objects in several iptables
rules using the new nfacct match (which comes in a follow-up patch):
# iptables -I INPUT -p tcp --sport 80 -m nfacct --nfacct-name http-traffic
# iptables -I OUTPUT -p tcp --dport 80 -m nfacct --nfacct-name http-traffic
The idea is simple: if one packet matches the rule, the nfacct match
updates the counters.
Thanks to Patrick McHardy, Eric Dumazet, Changli Gao for reviewing and
providing feedback for this contribution.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Export the NAT definitions to userspace. So far userspace (specifically,
iptables) has been copying the headers files from include/net. Also
rename some structures and definitions in preparation for IPv6 NAT.
Since these have never been officially exported, this doesn't affect
existing userspace code.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
