Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
LD init/built-in.o
net/built-in.o:(.data+0x4408): undefined reference to `nf_nat_tcp_seq_adjust'
make: *** [vmlinux] Error 1
This patch adds a new pointer hook (nfq_ct_nat_hook) similar to other existing
in Netfilter to solve our complicated configuration dependencies.
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
This patch allows you to include the conntrack information together
with the packet that is sent to user-space via NFQUEUE.
Previously, there was no integration between ctnetlink and
nfnetlink_queue. If you wanted to access conntrack information
from your libnetfilter_queue program, you required to query
ctnetlink from user-space to obtain it. Thus, delaying the packet
processing even more.
Including the conntrack information is optional, you can set it
via NFQA_CFG_F_CONNTRACK flag with the new NFQA_CFG_FLAGS attribute.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The mask option allows you put all address belonging that mask into
the same recent slot. This can be useful in case that recent is used
to detect attacks from the same network segment.
Tested for backward compatibility.
Signed-off-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.
Typical usage scenarios:
#include <linux/static_key.h>
struct static_key key = STATIC_KEY_INIT_TRUE;
if (static_key_false(&key))
do unlikely code
else
do likely code
Or:
if (static_key_true(&key))
do likely code
else
do unlikely code
The static key is modified via:
static_key_slow_inc(&key);
...
static_key_slow_dec(&key);
The 'slow' prefix makes it abundantly clear that this is an
expensive operation.
I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.
On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On configs where CONFIG_JUMP_LABEL=y, we can replace in fast path a
load/compare/conditional jump by a single jump with no dcache reference.
Jump target is modified as soon as nf_hooks[pf][hook] switches from
empty state to non empty states. jump_label state is kept outside of
nf_hooks array so has no cost on cpu caches.
This patch removes the test on CONFIG_NETFILTER_DEBUG : No need to call
nf_hook_slow() at all if nf_hooks[pf][hook] is empty, this didnt give
useful information, but slowed down things a lot.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several networking headers were depending upon the implicit
linux/sysctl.h include they get when including linux/net.h
Add explicit includes.
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6 fib lookup can set RT6_LOOKUP_F_IFACE flag to restrict search
to an interface, but this flag cannot be set via struct flowi.
Also, it cannot be set via ip6_route_output: this function uses the
passed sock struct to determine if this flag is required
(by testing for nonzero sk_bound_dev_if).
Work around this by passing in an artificial struct sk in case
'strict' argument is true.
This is required to replace the rt6_lookup call in xt_addrtype.c with
nf_afinfo->route().
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This is required to eventually replace the rt6_lookup call in
xt_addrtype.c with nf_afinfo->route().
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
If an skb is to be NF_QUEUE'd, but no program has opened the queue, the
packet is dropped.
This adds a v2 target revision of xt_NFQUEUE that allows packets to
continue through the ruleset instead.
Because the actual queueing happens outside of the target context, the
'bypass' flag has to be communicated back to the netfilter core.
Unfortunately the only choice to do this without adding a new function
argument is to use the target function return value (i.e. the verdict).
In the NF_QUEUE case, the upper 16bit already contain the queue number
to use. The previous patch reduced NF_VERDICT_MASK to 0xff, i.e.
we now have extra room for a new flag.
If a hook issued a NF_QUEUE verdict, then the netfilter core will
continue packet processing if the queueing hook
returns -ESRCH (== "this queue does not exist") and the new
NF_VERDICT_FLAG_QUEUE_BYPASS flag is set in the verdict value.
Note: If the queue exists, but userspace does not consume packets fast
enough, the skb will still be dropped.
Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
NF_VERDICT_MASK is currently 0xffff. This is because the upper
16 bits are used to store errno (for NF_DROP) or the queue number
(NF_QUEUE verdict).
As there are up to 0xffff different queues available, there is no more
room to store additional flags.
At the moment there are only 6 different verdicts, i.e. we can reduce
NF_VERDICT_MASK to 0xff to allow storing additional flags in the 0xff00 space.
NF_VERDICT_BITS would then be reduced to 8, but because the value is
exported to userspace, this might cause breakage; e.g.:
e.g. 'queuenr = (1 << NF_VERDICT_BITS) | NF_QUEUE' would now break.
Thus, remove NF_VERDICT_BITS usage in the kernel and move the old value
to the 'userspace compat' section.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
SELinux would like to pass certain fatal errors back up the stack. This patch
implements the generic netfilter support for this functionality.
Based-on-patch-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add some __rcu annotations and use helpers to reduce number of sparse
warnings (CONFIG_SPARSE_RCU_POINTER=y)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The NF_HOOK_COND returns 0 when it shouldn't due to what I believe to be an
error in the code as the order of operations is not what was intended. C will
evalutate == before =. Which means ret is getting set to the bool result,
rather than the return value of the function call. The code says
if (ret = function() == 1)
when it meant to say:
if ((ret = function()) == 1)
Normally the compiler would warn, but it doesn't notice it because its
a actually complex conditional and so the wrong code is wrapped in an explict
set of () [exactly what the compiler wants you to do if this was intentional].
Fixing this means that errors when netfilter denies a packet get propagated
back up the stack rather than lost.
Problem introduced by commit 2249065f (netfilter: get rid of the grossness
in netfilter.h).
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Patrick McHardy <kaber@trash.net>
Commit 2249065 ("netfilter: get rid of the grossness in netfilter.h")
inverted the logic for conditional hook invocation, breaking the
POST_ROUTING hook invoked by ip_output().
Correct the logic and remove an unnecessary initialization.
Reported-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.
Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.
Signed-off-by: David S. Miller <davem@davemloft.net>
