Commit graph

98 commits

Author SHA1 Message Date
Patrick McHardy
48b1de4c11 netfilter: add SYNPROXY core/target
Add a SYNPROXY for netfilter. The code is split into two parts, the synproxy
core with common functions and an address family specific target.

The SYNPROXY receives the connection request from the client, responds with
a SYN/ACK containing a SYN cookie and announcing a zero window and checks
whether the final ACK from the client contains a valid cookie.

It then establishes a connection to the original destination and, if
successful, sends a window update to the client with the window size
announced by the server.

Support for timestamps, SACK, window scaling and MSS options can be
statically configured as target parameters if the features of the server
are known. If timestamps are used, the timestamp value sent back to
the client in the SYN/ACK will be different from the real timestamp of
the server. In order to now break PAWS, the timestamps are translated in
the direction server->client.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-08-28 00:27:54 +02:00
Patrick McHardy
41d73ec053 netfilter: nf_conntrack: make sequence number adjustments usuable without NAT
Split out sequence number adjustments from NAT and move them to the conntrack
core to make them usable for SYN proxying. The sequence number adjustment
information is moved to a seperate extend. The extend is added to new
conntracks when a NAT mapping is set up for a connection using a helper.

As a side effect, this saves 24 bytes per connection with NAT in the common
case that a connection does not have a helper assigned.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-08-28 00:26:48 +02:00
Florian Westphal
fd158d79d3 netfilter: tproxy: remove nf_tproxy_core, keep tw sk assigned to skb
The module was "permanent", due to the special tproxy skb->destructor.
Nowadays we have tcp early demux and its sock_edemux destructor in
networking core which can be used instead.

Thanks to early demux changes the input path now also handles
"skb->sk is tw socket" correctly, so this no longer needs the special
handling introduced with commit d503b30bd6
(netfilter: tproxy: do not assign timewait sockets to skb->sk).

Thus:
- move assign_sock function to where its needed
- don't prevent timewait sockets from being assigned to the skb
- remove nf_tproxy_core.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-07-31 16:39:40 +02:00
Willem de Bruijn
e6f30c7317 netfilter: x_tables: add xt_bpf match
Support arbitrary linux socket filter (BPF) programs as x_tables
match rules. This allows for very expressive filters, and on
platforms with BPF JIT appears competitive with traditional
hardcoded iptables rules using the u32 match.

The size of the filter has been artificially limited to 64
instructions maximum to avoid bloating the size of each rule
using this new match.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-21 12:20:19 +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
Jan Engelhardt
2cbc78a29e netfilter: combine ipt_REDIRECT and ip6t_REDIRECT
Combine more modules since the actual code is so small anyway that the
kmod metadata and the module in its loaded state totally outweighs the
combined actual code size.

IP_NF_TARGET_REDIRECT becomes a compat option; IP6_NF_TARGET_REDIRECT
is completely eliminated since it has not see a release yet.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-21 12:12:05 +02:00
Jan Engelhardt
b3d54b3e40 netfilter: combine ipt_NETMAP and ip6t_NETMAP
Combine more modules since the actual code is so small anyway that the
kmod metadata and the module in its loaded state totally outweighs the
combined actual code size.

IP_NF_TARGET_NETMAP becomes a compat option; IP6_NF_TARGET_NETMAP
is completely eliminated since it has not see a release yet.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-21 12:11:08 +02:00
Pablo Neira Ayuso
00545bec94 netfilter: fix crash during boot if NAT has been compiled built-in
(c7232c9 netfilter: add protocol independent NAT core) introduced a
problem that leads to crashing during boot due to NULL pointer
dereference. It seems that xt_nat calls xt_register_target() before
xt_init():

net/netfilter/x_tables.c:static struct xt_af *xt; is NULL and we crash on
xt_register_target(struct xt_target *target)
{
        u_int8_t af = target->family;
        int ret;

        ret = mutex_lock_interruptible(&xt[af].mutex);
...

Fix this by changing the linking order, to make sure that x_tables
comes before xt_nat.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-05 18:35:51 +02:00
Cong Wang
965505015b netfilter: remove xt_NOTRACK
It was scheduled to be removed for a long time.

Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netfilter@vger.kernel.org
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-03 13:36:40 +02:00
Pablo Neira Ayuso
320ff567f2 netfilter: nf_nat: support IPv6 in TFTP NAT helper
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:24 +02:00
Pablo Neira Ayuso
5901b6be88 netfilter: nf_nat: support IPv6 in IRC NAT helper
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:23 +02:00
Patrick McHardy
9a66482106 netfilter: nf_nat: support IPv6 in SIP NAT helper
Add IPv6 support to the SIP NAT helper. There are no functional differences
to IPv4 NAT, just different formats for addresses.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:22 +02:00
Patrick McHardy
ee6eb96673 netfilter: nf_nat: support IPv6 in amanda NAT helper
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:21 +02:00
Patrick McHardy
d33cbeeb1a netfilter: nf_nat: support IPv6 in FTP NAT helper
Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:20 +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
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
6e9c2db3aa netfilter: fix compilation of the nfnl_cthelper if NF_CONNTRACK is unset
This patch fixes the compilation of net/netfilter/nfnetlink_cthelper.c
if CONFIG_NF_CONNTRACK is not set.

This patch also moves the definition of the cthelper infrastructure to
the scope of NF_CONNTRACK things.

I have also renamed NETFILTER_NETLINK_CTHELPER by NF_CT_NETLINK_HELPER,
to use similar names to other nf_conntrack_netlink extensions. Better now
that this has been only for two days in David's tree.

Two new dependencies have been added:

* NF_CT_NETLINK
* NETFILTER_NETLINK_QUEUE

Since these infrastructure requires both ctnetlink and nfqueue.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-19 01:25:08 +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
Hans Schillstrom
cf308a1fae netfilter: add xt_hmark target for hash-based skb marking
The target allows you to create rules in the "raw" and "mangle" tables
which set the skbuff mark by means of hash calculation within a given
range. The nfmark can influence the routing method (see "Use netfilter
MARK value as routing key") and can also be used by other subsystems to
change their behaviour.

[ Part of this patch has been refactorized and modified by Pablo Neira Ayuso ]

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-05-09 12:54:05 +02:00
Pablo Neira Ayuso
dd70507241 netfilter: nf_ct_ext: add timeout extension
This patch adds the timeout extension, which allows you to attach
specific timeout policies to flows.

This extension is only used by the template conntrack.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-03-07 17:41:25 +01:00
Pablo Neira Ayuso
5097846230 netfilter: add cttimeout infrastructure for fine timeout tuning
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>
2012-03-07 17:41:22 +01:00
Richard Weinberger
6939c33a75 netfilter: merge ipt_LOG and ip6_LOG into xt_LOG
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>
2012-03-07 17:40:49 +01:00
Jan Engelhardt
d446a8202c netfilter: xtables: move ipt_ecn to xt_ecn
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>
2011-12-27 20:31:31 +01:00
Pablo Neira Ayuso
ceb98d03ea netfilter: xtables: add nfacct match to support extended accounting
This patch adds the match that allows to perform extended
accounting. It requires the new nfnetlink_acct infrastructure.

 # 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

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-12-25 02:43:17 +01:00
Pablo Neira Ayuso
9413902796 netfilter: add extended accounting infrastructure over nfnetlink
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>
2011-12-25 02:43:03 +01:00
Florian Westphal
de81bbea17 netfilter: ipt_addrtype: rename to xt_addrtype
Followup patch will add ipv6 support.

ipt_addrtype.h is retained for compatibility reasons, but no longer used
by the kernel.

Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-03-15 20:16:20 +01:00
Patrick McHardy
9291747f11 netfilter: xtables: add device group match
Add a new 'devgroup' match to match on the device group of the
incoming and outgoing network device of a packet.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-02-03 00:05:43 +01:00
Jozsef Kadlecsik
d956798d82 netfilter: xtables: "set" match and "SET" target support
The patch adds the combined module of the "SET" target and "set" match
to netfilter. Both the previous and the current revisions are supported.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-02-01 15:56:00 +01:00
Jozsef Kadlecsik
a7b4f989a6 netfilter: ipset: IP set core support
The patch adds the IP set core support to the kernel.

The IP set core implements a netlink (nfnetlink) based protocol by which
one can create, destroy, flush, rename, swap, list, save, restore sets,
and add, delete, test elements from userspace. For simplicity (and backward
compatibilty and for not to force ip(6)tables to be linked with a netlink
library) reasons a small getsockopt-based protocol is also kept in order
to communicate with the ip(6)tables match and target.

The netlink protocol passes all u16, etc values in network order with
NLA_F_NET_BYTEORDER flag. The protocol enforces the proper use of the
NLA_F_NESTED and NLA_F_NET_BYTEORDER flags.

For other kernel subsystems (netfilter match and target) the API contains
the functions to add, delete and test elements in sets and the required calls
to get/put refereces to the sets before those operations can be performed.

The set types (which are implemented in independent modules) are stored
in a simple RCU protected list. A set type may have variants: for example
without timeout or with timeout support, for IPv4 or for IPv6. The sets
(i.e. the pointers to the sets) are stored in an array. The sets are
identified by their index in the array, which makes possible easy and
fast swapping of sets. The array is protected indirectly by the nfnl
mutex from nfnetlink. The content of the sets are protected by the rwlock
of the set.

There are functional differences between the add/del/test functions
for the kernel and userspace:

- kernel add/del/test: works on the current packet (i.e. one element)
- kernel test: may trigger an "add" operation  in order to fill
  out unspecified parts of the element from the packet (like MAC address)
- userspace add/del: works on the netlink message and thus possibly
  on multiple elements from the IPSET_ATTR_ADT container attribute.
- userspace add: may trigger resizing of a set

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-02-01 15:28:35 +01:00
Pablo Neira Ayuso
a992ca2a04 netfilter: nf_conntrack_tstamp: add flow-based timestamp extension
This patch adds flow-based timestamping for conntracks. This
conntrack extension is disabled by default. Basically, we use
two 64-bits variables to store the creation timestamp once the
conntrack has been confirmed and the other to store the deletion
time. This extension is disabled by default, to enable it, you
have to:

echo 1 > /proc/sys/net/netfilter/nf_conntrack_timestamp

This patch allows to save memory for user-space flow-based
loogers such as ulogd2. In short, ulogd2 does not need to
keep a hashtable with the conntrack in user-space to know
when they were created and destroyed, instead we use the
kernel timestamp. If we want to have a sane IPFIX implementation
in user-space, this nanosecs resolution timestamps are also
useful. Other custom user-space applications can benefit from
this via libnetfilter_conntrack.

This patch modifies the /proc output to display the delta time
in seconds since the flow start. You can also obtain the
flow-start date by means of the conntrack-tools.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-01-19 16:00:07 +01:00
Jiri Olsa
93557f53e1 netfilter: nf_conntrack: nf_conntrack snmp helper
Adding support for SNMP broadcast connection tracking. The SNMP
broadcast requests are now paired with the SNMP responses.
Thus allowing using SNMP broadcasts with firewall enabled.

Please refer to the following conversation:
http://marc.info/?l=netfilter-devel&m=125992205006600&w=2

Patrick McHardy wrote:
> > The best solution would be to add generic broadcast tracking, the
> > use of expectations for this is a bit of abuse.
> > The second best choice I guess would be to move the help() function
> > to a shared module and generalize it so it can be used for both.
This patch implements the "second best choice".

Since the netbios-ns conntrack module uses the same helper
functionality as the snmp, only one helper function is added
for both snmp and netbios-ns modules into the new object -
nf_conntrack_broadcast.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-01-18 18:12:24 +01:00
Thomas Graf
43f393caec netfilter: audit target to record accepted/dropped packets
This patch adds a new netfilter target which creates audit records
for packets traversing a certain chain.

It can be used to record packets which are rejected administraively
as follows:

  -N AUDIT_DROP
  -A AUDIT_DROP -j AUDIT --type DROP
  -A AUDIT_DROP -j DROP

a rule which would typically drop or reject a packet would then
invoke the new chain to record packets before dropping them.

  -j AUDIT_DROP

The module is protocol independant and works for iptables, ip6tables
and ebtables.

The following information is logged:
 - netfilter hook
 - packet length
 - incomming/outgoing interface
 - MAC src/dst/proto for ethernet packets
 - src/dst/protocol address for IPv4/IPv6
 - src/dst port for TCP/UDP/UDPLITE
 - icmp type/code

Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-01-16 18:10:28 +01:00
Eric Dumazet
e8648a1fdb netfilter: add xt_cpu match
In some situations a CPU match permits a better spreading of
connections, or select targets only for a given cpu.

With Remote Packet Steering or multiqueue NIC and appropriate IRQ
affinities, we can distribute trafic on available cpus, per session.
(all RX packets for a given flow is handled by a given cpu)

Some legacy applications being not SMP friendly, one way to scale a
server is to run multiple copies of them.

Instead of randomly choosing an instance, we can use the cpu number as a
key so that softirq handler for a whole instance is running on a single
cpu, maximizing cache effects in TCP/UDP stacks.

Using NAT for example, a four ways machine might run four copies of
server application, using a separate listening port for each instance,
but still presenting an unique external port :

iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 0 \
        -j REDIRECT --to-port 8080

iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 1 \
        -j REDIRECT --to-port 8081

iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 2 \
        -j REDIRECT --to-port 8082

iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 3 \
        -j REDIRECT --to-port 8083

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-07-23 12:59:36 +02:00
Hannes Eder
9c3e1c3967 netfilter: xt_ipvs (netfilter matcher for IPVS)
This implements the kernel-space side of the netfilter matcher xt_ipvs.

[ minor fixes by Simon Horman <horms@verge.net.au> ]
Signed-off-by: Hannes Eder <heder@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
[ Patrick: added xt_ipvs.h to Kbuild ]
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-07-23 12:42:58 +02:00
Michael S. Tsirkin
edf0e1fb0d netfilter: add CHECKSUM target
This adds a `CHECKSUM' target, which can be used in the iptables mangle
table.

You can use this target to compute and fill in the checksum in
a packet that lacks a checksum.  This is particularly useful,
if you need to work around old applications such as dhcp clients,
that do not work well with checksum offloads, but don't want to
disable checksum offload in your device.

The problem happens in the field with virtualized applications.
For reference, see Red Hat bz 605555, as well as
http://www.spinics.net/lists/kvm/msg37660.html

Typical expected use (helps old dhclient binary running in a VM):
iptables -A POSTROUTING -t mangle -p udp --dport bootpc \
	-j CHECKSUM --checksum-fill

Includes fixes by Jan Engelhardt <jengelh@medozas.de>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-07-15 17:20:46 +02:00
Luciano Coelho
0902b469bd netfilter: xtables: idletimer target implementation
This patch implements an idletimer Xtables target that can be used to
identify when interfaces have been idle for a certain period of time.

Timers are identified by labels and are created when a rule is set with a new
label.  The rules also take a timeout value (in seconds) as an option.  If
more than one rule uses the same timer label, the timer will be restarted
whenever any of the rules get a hit.

One entry for each timer is created in sysfs.  This attribute contains the
timer remaining for the timer to expire.  The attributes are located under
the xt_idletimer class:

/sys/class/xt_idletimer/timers/<label>

When the timer expires, the target module sends a sysfs notification to the
userspace, which can then decide what to do (eg. disconnect to save power).

Cc: Timo Teras <timo.teras@iki.fi>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-15 15:04:00 +02:00
Jan Engelhardt
e281b19897 netfilter: xtables: inclusion of xt_TEE
xt_TEE can be used to clone and reroute a packet. This can for
example be used to copy traffic at a router for logging purposes
to another dedicated machine.

References: http://www.gossamer-threads.com/lists/iptables/devel/68781
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-19 14:17:47 +02:00
Jan Engelhardt
b8f00ba27e netfilter: xtables: merge xt_CONNMARK into xt_connmark
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-17 15:48:36 +01:00
Jan Engelhardt
28b949885f netfilter: xtables: merge xt_MARK into xt_mark
Two arguments for combining the two:
- xt_mark is pretty useless without xt_MARK
- the actual code is so small anyway that the kmod metadata and the module
  in its loaded state totally outweighs the combined actual code size.

i586-before:
-rw-r--r-- 1 jengelh users 3821 Feb 10 01:01 xt_MARK.ko
-rw-r--r-- 1 jengelh users 2592 Feb 10 00:04 xt_MARK.o
-rw-r--r-- 1 jengelh users 3274 Feb 10 01:01 xt_mark.ko
-rw-r--r-- 1 jengelh users 2108 Feb 10 00:05 xt_mark.o
   text    data     bss     dec     hex filename
    354     264       0     618     26a xt_MARK.o
    223     176       0     399     18f xt_mark.o
And the runtime size is like 14 KB.

i586-after:
-rw-r--r-- 1 jengelh users 3264 Feb 18 17:28 xt_mark.o

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2010-03-17 15:48:36 +01:00
Patrick McHardy
84f3bb9ae9 netfilter: xtables: add CT target
Add a new target for the raw table, which can be used to specify conntrack
parameters for specific connections, f.i. the conntrack helper.

The target attaches a "template" connection tracking entry to the skb, which
is used by the conntrack core when initializing a new conntrack.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-03 17:17:06 +01:00
Evgeniy Polyakov
11eeef41d5 netfilter: passive OS fingerprint xtables match
Passive OS fingerprinting netfilter module allows to passively detect
remote OS and perform various netfilter actions based on that knowledge.
This module compares some data (WS, MSS, options and it's order, ttl, df
and others) from packets with SYN bit set with dynamically loaded OS
fingerprints.

Fingerprint matching rules can be downloaded from OpenBSD source tree
or found in archive and loaded via netfilter netlink subsystem into
the kernel via special util found in archive.

Archive contains library file (also attached), which was shipped
with iptables extensions some time ago (at least when ipt_osf existed
in patch-o-matic).

Following changes were made in this release:
 * added NLM_F_CREATE/NLM_F_EXCL checks
 * dropped _rcu list traversing helpers in the protected add/remove calls
 * dropped unneded structures, debug prints, obscure comment and check

Fingerprints can be downloaded from
http://www.openbsd.org/cgi-bin/cvsweb/src/etc/pf.os
or can be found in archive

Example usage:
-d switch removes fingerprints

Please consider for inclusion.
Thank you.

Passive OS fingerprint homepage (archives, examples):
http://www.ioremap.net/projects/osf

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-06-08 17:01:51 +02:00
Pablo Neira Ayuso
0269ea4937 netfilter: xtables: add cluster match
This patch adds the iptables cluster match. This match can be used
to deploy gateway and back-end load-sharing clusters. The cluster
can be composed of 32 nodes maximum (although I have only tested
this with two nodes, so I cannot tell what is the real scalability
limit of this solution in terms of cluster nodes).

Assuming that all the nodes see all packets (see below for an
example on how to do that if your switch does not allow this), the
cluster match decides if this node has to handle a packet given:

	(jhash(source IP) % total_nodes) & node_mask

For related connections, the master conntrack is used. The following
is an example of its use to deploy a gateway cluster composed of two
nodes (where this is the node 1):

iptables -I PREROUTING -t mangle -i eth1 -m cluster \
	--cluster-total-nodes 2 --cluster-local-node 1 \
	--cluster-proc-name eth1 -j MARK --set-mark 0xffff
iptables -A PREROUTING -t mangle -i eth1 \
	-m mark ! --mark 0xffff -j DROP
iptables -A PREROUTING -t mangle -i eth2 -m cluster \
	--cluster-total-nodes 2 --cluster-local-node 1 \
	--cluster-proc-name eth2 -j MARK --set-mark 0xffff
iptables -A PREROUTING -t mangle -i eth2 \
	-m mark ! --mark 0xffff -j DROP

And the following commands to make all nodes see the same packets:

ip maddr add 01:00:5e:00:01:01 dev eth1
ip maddr add 01:00:5e:00:01:02 dev eth2
arptables -I OUTPUT -o eth1 --h-length 6 \
	-j mangle --mangle-mac-s 01:00:5e:00:01:01
arptables -I INPUT -i eth1 --h-length 6 \
	--destination-mac 01:00:5e:00:01:01 \
	-j mangle --mangle-mac-d 00:zz:yy:xx:5a:27
arptables -I OUTPUT -o eth2 --h-length 6 \
	-j mangle --mangle-mac-s 01:00:5e:00:01:02
arptables -I INPUT -i eth2 --h-length 6 \
	--destination-mac 01:00:5e:00:01:02 \
	-j mangle --mangle-mac-d 00:zz:yy:xx:5a:27

In the case of TCP connections, pickup facility has to be disabled
to avoid marking TCP ACK packets coming in the reply direction as
valid.

echo 0 > /proc/sys/net/netfilter/nf_conntrack_tcp_loose

BTW, some final notes:

 * This match mangles the skbuff pkt_type in case that it detects
PACKET_MULTICAST for a non-multicast address. This may be done in
a PKTTYPE target for this sole purpose.
 * This match supersedes the CLUSTERIP target.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-03-16 17:10:36 +01:00
Adam Nielsen
268cb38e18 netfilter: x_tables: add LED trigger target
Kernel module providing implementation of LED netfilter target.  Each
instance of the target appears as a led-trigger device, which can be
associated with one or more LEDs in /sys/class/leds/

Signed-off-by: Adam Nielsen <a.nielsen@shikadi.net>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-02-20 10:55:14 +01:00
Jan Engelhardt
cfac5ef7b9 netfilter: Combine ipt_ttl and ip6t_hl source
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-02-18 18:39:31 +01:00
Jan Engelhardt
563d36eb3f netfilter: Combine ipt_TTL and ip6t_HL source
Suggested by: James King <t.james.king@gmail.com>

Similarly to commit c9fd496809, merge
TTL and HL. Since HL does not depend on any IPv6-specific function,
no new module dependencies would arise.

With slight adjustments to the Kconfig help text.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-02-18 18:38:40 +01:00
David S. Miller
db2bf2476b Merge branch 'lvs-next-2.6' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-2.6
Conflicts:

	net/netfilter/Kconfig
2008-10-08 14:26:36 -07:00
KOVACS Krisztian
e84392707e netfilter: iptables TPROXY target
The TPROXY target implements redirection of non-local TCP/UDP traffic to local
sockets. Additionally, it's possible to manipulate the packet mark if and only
if a socket has been found. (We need this because we cannot use multiple
targets in the same iptables rule.)

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:12 +02:00
KOVACS Krisztian
136cdc71fd netfilter: iptables socket match
Add iptables 'socket' match, which matches packets for which a TCP/UDP
socket lookup succeeds.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:12 +02:00
KOVACS Krisztian
9ad2d745a2 netfilter: iptables tproxy core
The iptables tproxy core is a module that contains the common routines used by
various tproxy related modules (TPROXY target and socket match)

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:12 +02:00
Jan Engelhardt
e948b20a71 netfilter: rename ipt_recent to xt_recent
Like with other modules (such as ipt_state), ipt_recent.h is changed
to forward definitions to (IOW include) xt_recent.h, and xt_recent.c
is changed to use the new constant names.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:00 +02:00