Pablo Neira Ayuso says:
====================
This batch contains one single patch with the l2tp match
for xtables, from James Chapman.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce an xtables add-on for matching L2TP packets. Supports L2TPv2
and L2TPv3 over IPv4 and IPv6. As well as filtering on L2TP tunnel-id
and session-id, the filtering decision can also include the L2TP
packet type (control or data), protocol version (2 or 3) and
encapsulation type (UDP or IP).
The most common use for this will likely be to filter L2TP data
packets of individual L2TP tunnels or sessions. While a u32 match can
be used, the L2TP protocol headers are such that field offsets differ
depending on bits set in the header, making rules for matching generic
L2TP connections cumbersome. This match extension takes care of all
that.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new table family and a new filter chain that you can
use to attach IPv4 and IPv6 rules. This should help to simplify
rule-set maintainance in dual-stack setups.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says: <pablo@netfilter.org>
====================
nftables updates for net-next
The following patchset contains nftables updates for your net-next tree,
they are:
* Add set operation to the meta expression by means of the select_ops()
infrastructure, this allows us to set the packet mark among other things.
From Arturo Borrero Gonzalez.
* Fix wrong format in sscanf in nf_tables_set_alloc_name(), from Daniel
Borkmann.
* Add new queue expression to nf_tables. These comes with two previous patches
to prepare this new feature, one to add mask in nf_tables_core to
evaluate the queue verdict appropriately and another to refactor common
code with xt_NFQUEUE, from Eric Leblond.
* Do not hide nftables from Kconfig if nfnetlink is not enabled, also from
Eric Leblond.
* Add the reject expression to nf_tables, this adds the missing TCP RST
support. It comes with an initial patch to refactor common code with
xt_NFQUEUE, again from Eric Leblond.
* Remove an unused variable assignment in nf_tables_dump_set(), from Michal
Nazarewicz.
* Remove the nft_meta_target code, now that Arturo added the set operation
to the meta expression, from me.
* Add help information for nf_tables to Kconfig, also from me.
* Allow to dump all sets by specifying NFPROTO_UNSPEC, similar feature is
available to other nf_tables objects, requested by Arturo, from me.
* Expose the table usage counter, so we can know how many chains are using
this table without dumping the list of chains, from Tomasz Bursztyka.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
It would be useful e.g. in a server or desktop environment to have
a facility in the notion of fine-grained "per application" or "per
application group" firewall policies. Probably, users in the mobile,
embedded area (e.g. Android based) with different security policy
requirements for application groups could have great benefit from
that as well. For example, with a little bit of configuration effort,
an admin could whitelist well-known applications, and thus block
otherwise unwanted "hard-to-track" applications like [1] from a
user's machine. Blocking is just one example, but it is not limited
to that, meaning we can have much different scenarios/policies that
netfilter allows us than just blocking, e.g. fine grained settings
where applications are allowed to connect/send traffic to, application
traffic marking/conntracking, application-specific packet mangling,
and so on.
Implementation of PID-based matching would not be appropriate
as they frequently change, and child tracking would make that
even more complex and ugly. Cgroups would be a perfect candidate
for accomplishing that as they associate a set of tasks with a
set of parameters for one or more subsystems, in our case the
netfilter subsystem, which, of course, can be combined with other
cgroup subsystems into something more complex if needed.
As mentioned, to overcome this constraint, such processes could
be placed into one or multiple cgroups where different fine-grained
rules can be defined depending on the application scenario, while
e.g. everything else that is not part of that could be dropped (or
vice versa), thus making life harder for unwanted processes to
communicate to the outside world. So, we make use of cgroups here
to track jobs and limit their resources in terms of iptables
policies; in other words, limiting, tracking, etc what they are
allowed to communicate.
In our case we're working on outgoing traffic based on which local
socket that originated from. Also, one doesn't even need to have
an a-prio knowledge of the application internals regarding their
particular use of ports or protocols. Matching is *extremly*
lightweight as we just test for the sk_classid marker of sockets,
originating from net_cls. net_cls and netfilter do not contradict
each other; in fact, each construct can live as standalone or they
can be used in combination with each other, which is perfectly fine,
plus it serves Tejun's requirement to not introduce a new cgroups
subsystem. Through this, we result in a very minimal and efficient
module, and don't add anything except netfilter code.
One possible, minimal usage example (many other iptables options
can be applied obviously):
1) Configuring cgroups if not already done, e.g.:
mkdir /sys/fs/cgroup/net_cls
mount -t cgroup -o net_cls net_cls /sys/fs/cgroup/net_cls
mkdir /sys/fs/cgroup/net_cls/0
echo 1 > /sys/fs/cgroup/net_cls/0/net_cls.classid
(resp. a real flow handle id for tc)
2) Configuring netfilter (iptables-nftables), e.g.:
iptables -A OUTPUT -m cgroup ! --cgroup 1 -j DROP
3) Running applications, e.g.:
ping 208.67.222.222 <pid:1799>
echo 1799 > /sys/fs/cgroup/net_cls/0/tasks
64 bytes from 208.67.222.222: icmp_seq=44 ttl=49 time=11.9 ms
[...]
ping 208.67.220.220 <pid:1804>
ping: sendmsg: Operation not permitted
[...]
echo 1804 > /sys/fs/cgroup/net_cls/0/tasks
64 bytes from 208.67.220.220: icmp_seq=89 ttl=56 time=19.0 ms
[...]
Of course, real-world deployments would make use of cgroups user
space toolsuite, or own custom policy daemons dynamically moving
applications from/to various cgroups.
[1] http://www.blackhat.com/presentations/bh-europe-06/bh-eu-06-biondi/bh-eu-06-biondi-up.pdf
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: cgroups@vger.kernel.org
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch moves nft_reject_ipv4 to nft_reject and adds support
for IPv6 protocol. This patch uses functions included in nf_reject.h
to implement reject by TCP reset.
The code has to be build as a module if NF_TABLES_IPV6 is also a
module to avoid compilation error due to usage of IPv6 functions.
This has been done in Kconfig by using the construct:
depends on NF_TABLES_IPV6 || !NF_TABLES_IPV6
This seems a bit weird in terms of syntax but works perfectly.
Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In e035b77 ("netfilter: nf_tables: nft_meta module get/set ops"),
we got the meta target merged into the existing meta expression.
So let's get rid of this dead code now that we fully support that
feature.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With this plugin, user could specify IPComp tagged with certain
CPI that host not interested will be DROPped or any other action.
For example:
iptables -A INPUT -p 108 -m ipcomp --ipcompspi 0x87 -j DROP
ip6tables -A INPUT -p 108 -m ipcomp --ipcompspi 0x87 -j DROP
Then input IPComp packet with CPI equates 0x87 will not reach
upper layer anymore.
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new nft module named "nft_queue" which provides
a new nftables expression that allows you to enqueue packets to
userspace via the nfnetlink_queue subsystem. It provides the same
level of functionality as NFQUEUE and it shares some code with it.
Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch generalizes the NAT expression to support both IPv4 and IPv6
using the existing IPv4/IPv6 NAT infrastructure. This also adds the
NAT chain type for IPv6.
This patch collapses the following patches that were posted to the
netfilter-devel mailing list, from Tomasz:
* nf_tables: Change NFTA_NAT_ attributes to better semantic significance
* nf_tables: Split IPv4 NAT into NAT expression and IPv4 NAT chain
* nf_tables: Add support for IPv6 NAT expression
* nf_tables: Add support for IPv6 NAT chain
* nf_tables: Fix up build issue on IPv6 NAT support
And, from Pablo Neira Ayuso:
* fix missing dependencies in nft_chain_nat
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the x_tables compatibility layer. This allows you
to use existing x_tables matches and targets from nf_tables.
This compatibility later allows us to use existing matches/targets
for features that are still missing in nf_tables. We can progressively
replace them with native nf_tables extensions. It also provides the
userspace compatibility software that allows you to express the
rule-set using the iptables syntax but using the nf_tables kernel
components.
In order to get this compatibility layer working, I've done the
following things:
* add NFNL_SUBSYS_NFT_COMPAT: this new nfnetlink subsystem is used
to query the x_tables match/target revision, so we don't need to
use the native x_table getsockopt interface.
* emulate xt structures: this required extending the struct nft_pktinfo
to include the fragment offset, which is already obtained from
ip[6]_tables and that is used by some matches/targets.
* add support for default policy to base chains, required to emulate
x_tables.
* add NFTA_CHAIN_USE attribute to obtain the number of references to
chains, required by x_tables emulation.
* add chain packet/byte counters using per-cpu.
* support 32-64 bits compat.
For historical reasons, this patch includes the following patches
that were posted in the netfilter-devel mailing list.
From Pablo Neira Ayuso:
* nf_tables: add default policy to base chains
* netfilter: nf_tables: add NFTA_CHAIN_USE attribute
* nf_tables: nft_compat: private data of target and matches in contiguous area
* nf_tables: validate hooks for compat match/target
* nf_tables: nft_compat: release cached matches/targets
* nf_tables: x_tables support as a compile time option
* nf_tables: fix alias for xtables over nftables module
* nf_tables: add packet and byte counters per chain
* nf_tables: fix per-chain counter stats if no counters are passed
* nf_tables: don't bump chain stats
* nf_tables: add protocol and flags for xtables over nf_tables
* nf_tables: add ip[6]t_entry emulation
* nf_tables: move specific layer 3 compat code to nf_tables_ipv[4|6]
* nf_tables: support 32bits-64bits x_tables compat
* nf_tables: fix compilation if CONFIG_COMPAT is disabled
From Patrick McHardy:
* nf_tables: move policy to struct nft_base_chain
* nf_tables: send notifications for base chain policy changes
From Alexander Primak:
* nf_tables: remove the duplicate NF_INET_LOCAL_OUT
From Nicolas Dichtel:
* nf_tables: fix compilation when nf-netlink is a module
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the new netlink API for maintaining nf_tables sets
independently of the ruleset. The API supports the following operations:
- creation of sets
- deletion of sets
- querying of specific sets
- dumping of all sets
- addition of set elements
- removal of set elements
- dumping of all set elements
Sets are identified by name, each table defines an individual namespace.
The name of a set may be allocated automatically, this is mostly useful
in combination with the NFT_SET_ANONYMOUS flag, which destroys a set
automatically once the last reference has been released.
Sets can be marked constant, meaning they're not allowed to change while
linked to a rule. This allows to perform lockless operation for set
types that would otherwise require locking.
Additionally, if the implementation supports it, sets can (as before) be
used as maps, associating a data value with each key (or range), by
specifying the NFT_SET_MAP flag and can be used for interval queries by
specifying the NFT_SET_INTERVAL flag.
Set elements are added and removed incrementally. All element operations
support batching, reducing netlink message and set lookup overhead.
The old "set" and "hash" expressions are replaced by a generic "lookup"
expression, which binds to the specified set. Userspace is not aware
of the actual set implementation used by the kernel anymore, all
configuration options are generic.
Currently the implementation selection logic is largely missing and the
kernel will simply use the first registered implementation supporting the
requested operation. Eventually, the plan is to have userspace supply a
description of the data characteristics and select the implementation
based on expected performance and memory use.
This patch includes the new 'lookup' expression to look up for element
matching in the set.
This patch includes kernel-doc descriptions for this set API and it
also includes the following fixes.
From Patrick McHardy:
* netfilter: nf_tables: fix set element data type in dumps
* netfilter: nf_tables: fix indentation of struct nft_set_elem comments
* netfilter: nf_tables: fix oops in nft_validate_data_load()
* netfilter: nf_tables: fix oops while listing sets of built-in tables
* netfilter: nf_tables: destroy anonymous sets immediately if binding fails
* netfilter: nf_tables: propagate context to set iter callback
* netfilter: nf_tables: add loop detection
From Pablo Neira Ayuso:
* netfilter: nf_tables: allow to dump all existing sets
* netfilter: nf_tables: fix wrong type for flags variable in newelem
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds nftables which is the intended successor of iptables.
This packet filtering framework reuses the existing netfilter hooks,
the connection tracking system, the NAT subsystem, the transparent
proxying engine, the logging infrastructure and the userspace packet
queueing facilities.
In a nutshell, nftables provides a pseudo-state machine with 4 general
purpose registers of 128 bits and 1 specific purpose register to store
verdicts. This pseudo-machine comes with an extensible instruction set,
a.k.a. "expressions" in the nftables jargon. The expressions included
in this patch provide the basic functionality, they are:
* bitwise: to perform bitwise operations.
* byteorder: to change from host/network endianess.
* cmp: to compare data with the content of the registers.
* counter: to enable counters on rules.
* ct: to store conntrack keys into register.
* exthdr: to match IPv6 extension headers.
* immediate: to load data into registers.
* limit: to limit matching based on packet rate.
* log: to log packets.
* meta: to match metainformation that usually comes with the skbuff.
* nat: to perform Network Address Translation.
* payload: to fetch data from the packet payload and store it into
registers.
* reject (IPv4 only): to explicitly close connection, eg. TCP RST.
Using this instruction-set, the userspace utility 'nft' can transform
the rules expressed in human-readable text representation (using a
new syntax, inspired by tcpdump) to nftables bytecode.
nftables also inherits the table, chain and rule objects from
iptables, but in a more configurable way, and it also includes the
original datatype-agnostic set infrastructure with mapping support.
This set infrastructure is enhanced in the follow up patch (netfilter:
nf_tables: add netlink set API).
This patch includes the following components:
* the netlink API: net/netfilter/nf_tables_api.c and
include/uapi/netfilter/nf_tables.h
* the packet filter core: net/netfilter/nf_tables_core.c
* the expressions (described above): net/netfilter/nft_*.c
* the filter tables: arp, IPv4, IPv6 and bridge:
net/ipv4/netfilter/nf_tables_ipv4.c
net/ipv6/netfilter/nf_tables_ipv6.c
net/ipv4/netfilter/nf_tables_arp.c
net/bridge/netfilter/nf_tables_bridge.c
* the NAT table (IPv4 only):
net/ipv4/netfilter/nf_table_nat_ipv4.c
* the route table (similar to mangle):
net/ipv4/netfilter/nf_table_route_ipv4.c
net/ipv6/netfilter/nf_table_route_ipv6.c
* internal definitions under:
include/net/netfilter/nf_tables.h
include/net/netfilter/nf_tables_core.h
* It also includes an skeleton expression:
net/netfilter/nft_expr_template.c
and the preliminary implementation of the meta target
net/netfilter/nft_meta_target.c
It also includes a change in struct nf_hook_ops to add a new
pointer to store private data to the hook, that is used to store
the rule list per chain.
This patch is based on the patch from Patrick McHardy, plus merged
accumulated cleanups, fixes and small enhancements to the nftables
code that has been done since 2009, which are:
From Patrick McHardy:
* nf_tables: adjust netlink handler function signatures
* nf_tables: only retry table lookup after successful table module load
* nf_tables: fix event notification echo and avoid unnecessary messages
* nft_ct: add l3proto support
* nf_tables: pass expression context to nft_validate_data_load()
* nf_tables: remove redundant definition
* nft_ct: fix maxattr initialization
* nf_tables: fix invalid event type in nf_tables_getrule()
* nf_tables: simplify nft_data_init() usage
* nf_tables: build in more core modules
* nf_tables: fix double lookup expression unregistation
* nf_tables: move expression initialization to nf_tables_core.c
* nf_tables: build in payload module
* nf_tables: use NFPROTO constants
* nf_tables: rename pid variables to portid
* nf_tables: save 48 bits per rule
* nf_tables: introduce chain rename
* nf_tables: check for duplicate names on chain rename
* nf_tables: remove ability to specify handles for new rules
* nf_tables: return error for rule change request
* nf_tables: return error for NLM_F_REPLACE without rule handle
* nf_tables: include NLM_F_APPEND/NLM_F_REPLACE flags in rule notification
* nf_tables: fix NLM_F_MULTI usage in netlink notifications
* nf_tables: include NLM_F_APPEND in rule dumps
From Pablo Neira Ayuso:
* nf_tables: fix stack overflow in nf_tables_newrule
* nf_tables: nft_ct: fix compilation warning
* nf_tables: nft_ct: fix crash with invalid packets
* nft_log: group and qthreshold are 2^16
* nf_tables: nft_meta: fix socket uid,gid handling
* nft_counter: allow to restore counters
* nf_tables: fix module autoload
* nf_tables: allow to remove all rules placed in one chain
* nf_tables: use 64-bits rule handle instead of 16-bits
* nf_tables: fix chain after rule deletion
* nf_tables: improve deletion performance
* nf_tables: add missing code in route chain type
* nf_tables: rise maximum number of expressions from 12 to 128
* nf_tables: don't delete table if in use
* nf_tables: fix basechain release
From Tomasz Bursztyka:
* nf_tables: Add support for changing users chain's name
* nf_tables: Change chain's name to be fixed sized
* nf_tables: Add support for replacing a rule by another one
* nf_tables: Update uapi nftables netlink header documentation
From Florian Westphal:
* nft_log: group is u16, snaplen u32
From Phil Oester:
* nf_tables: operational limit match
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
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>
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>
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>
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>
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>
(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>
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>
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>
Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
David S. Miller