Due to the way percpu counters are allocated and freed in blocks,
it is not safe to free counters individually.  Currently all callers
do the right thing, but let's note this restriction.

Fixes: ae0ac0ed ("netfilter: x_tables: pack percpu counter allocations")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Merge assignment with return statement to directly return the value.
Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Replace opencoded implementation of nft_set_lookup_global() by call to
this function.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

To prepare shorter introduction of shorter function prefix.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Register conntrack hooks if the user adds NAT chains. Users get confused
with the existing behaviour since they will see no packets hitting this
chain until they add the first rule that refers to conntrack.

This patch adds new ->init() and ->free() indirections to chain types
that can be used by NAT chains to invoke the conntrack dependency.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

One module per supported filter chain family type takes too much memory
for very little code - too much modularization - place all chain filter
definitions in one single file.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use WARN_ON() instead since it should not happen that neither family
goes over NFPROTO_NUMPROTO nor there is already a chain of this type
already registered.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use nft_ prefix. By when I added chain types, I forgot to use the
nftables prefix. Rename enum nft_chain_type to enum nft_chain_types too,
otherwise there is an overlap.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Instead of unnecessary const declarations, use the generic functions to
save a little object space.

$ size net/bridge/netfilter/ebt_stp.o*
   text	   data	    bss	    dec	    hex	filename
   1250	    144	      0	   1394	    572	net/bridge/netfilter/ebt_stp.o.new
   1344	    144	      0	   1488	    5d0	net/bridge/netfilter/ebt_stp.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch adds initial documentation for the Netfilter flowtable
infrastructure.
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch is part of a proposal to add a string filter to
ebtables, which would be similar to the string filter in
iptables. Like iptables, the ebtables filter uses the xt_string
module.
Signed-off-by: Bernie Harris <bernie.harris@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Currently ebtables assumes that the revision number of all match
modules is 0, which is an issue when trying to use existing
xtables matches with ebtables. The solution is to modify ebtables
to allow extensions to specify a revision number, similar to
iptables. This gets passed down to the kernel, which is then able
to find the match module correctly.

To main binary backwards compatibility, the size of the ebt_entry
structures is not changed, only the size of the name field is
decreased by 1 byte to make room for the revision field.
Signed-off-by: Bernie Harris <bernie.harris@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

We already have ICMPv6 type/code matches (which can be used to distinguish
different types of MLD packets). Add support for IPv4 IGMP matches in the
same way.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

We already have ICMPv6 type/code matches. This adds support for IPv4 ICMP
matches in the same way.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch exposes synproxy information per-conntrack. Moreover, send
sequence adjustment events once server sends us the SYN,ACK packet, so
we can synchronize the sequence adjustment too for packets going as
reply from the server, as part of the synproxy logic.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Using pr_<loglevel>() is more concise than printk(KERN_<LOGLEVEL>).
This patch:
* Replace printks having a log level with the appropriate
pr_*() macros.
* Define pr_fmt() to include relevant name.
* Remove redundant prefixes from pr_*() calls.
* Indent the code where possible.
* Remove the useless output messages.
* Remove periods from messages.
Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch introduces a new feature that allows bitshifting (left
and right) operations to co-operate with existing iptables options.
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jack Ma <jack.ma@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

xtables uses ADD_COUNTER macro to increase
packet and byte count. ebtables also can use this.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

In preparation to enabling -Wvla, remove VLA and replace it
with dynamic memory allocation.

>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.

Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

In preparation to enabling -Wvla, remove VLA and replace it
with dynamic memory allocation.

>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.

Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

In preparation to enabling -Wvla, remove VLA and replace it
with dynamic memory allocation.

>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.

Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621

While at it, remove likely() notation which is not necessary from the
control plane code.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

All existing keys, except the NFT_CT_SRC and NFT_CT_DST are assumed to
have strict datatypes. This is causing problems with sets and
concatenations given the specific length of these keys is not known.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Florian Westphal <fw@strlen.de>

Currently, nf_conncount_count() counts the number of connections that
matches key and inserts a conntrack 'tuple' with the same key into the
accounting data structure.  This patch supports another use case that only
counts the number of connections where 'tuple' is not provided.  Therefore,
proper changes are made on nf_conncount_count() to support the case where
'tuple' is NULL.  This could be useful for querying statistics or
debugging purpose.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Remove parameter 'family' in nf_conncount_count() and count_tree().
It is because the parameter is not useful after commit 625c5561
("netfilter: connlimit: split xt_connlimit into front and backend").
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Assign true or false to boolean variables instead of an integer value.

This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

I placed the helpers within CONFIG_COMPAT section, move them
outside.

Fixes: 472ebdcd ("netfilter: x_tables: check error target size too")
Fixes: 07a9da51 ("netfilter: x_tables: check standard verdicts in core")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

As suggested by Eric, we need to make the xt_rateest
hash table and its lock per netns to reduce lock
contentions.

Cc: Florian Westphal <fw@strlen.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Harmless from kernel point of view, but again iptables assumes that
this is true when decoding ruleset coming from kernel.

If a (syzkaller generated) ruleset doesn't have the underflow/policy
stored as the last rule in the base chain, then iptables will abort()
because it doesn't find the chain policy.

libiptc assumes that the policy is the last rule in the basechain, which
is only true for iptables-generated rulesets.

Unfortunately this needs code duplication -- the functions need the
struct layout of the rule head, but that is different for
ip/ip6/arptables.

NB: pr_warn could be pr_debug but in case this break rulesets somehow its
useful to know why blob was rejected.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

no need to bother even trying to allocating huge compat offset arrays,
such ruleset is rejected later on anyway becaus we refuse to allocate
overly large rule blobs.

However, compat translation happens before blob allocation, so we should
add a check there too.

This is supposed to help with fuzzing by avoiding oom-killer.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

should have no impact, function still always returns 0.
This patch is only to ease review.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

allows to have size checks in a single spot.
This is supposed to reduce oom situations when fuzz-testing xtables.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This is a very conservative limit (134217728 rules), but good
enough to not trigger frequent oom from syzkaller.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Arbitrary limit, however, this still allows huge rulesets
(> 1 million rules).  This helps with automated fuzzer as it prevents
oom-killer invocation.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Harmless from kernel point of view, but iptables assumes that this is
true when decoding a ruleset.

iptables walks the dumped blob from kernel, and, for each entry that
creates a new chain it prints out rule/chain information.
Base chains (hook entry points) are thus only shown when they appear
in the rule blob.  One base chain that is referenced multiple times
in hook blob is then only printed once.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Allow followup patch to change on location instead of three.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Check that userspace ERROR target (custom user-defined chains) match
expected format, and the chain name is null terminated.

This is irrelevant for kernel, but iptables itself relies on sane input
when it dumps rules from kernel.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Userspace must provide a valid verdict to the standard target.

The verdict can be either a jump (signed int > 0), or a return code.

Allowed return codes are either RETURN (pop from stack), NF_ACCEPT, DROP
and QUEUE (latter is allowed for legacy reasons).

Jump offsets (verdict > 0) are checked in more detail later on when
loop-detection is performed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Now it's doing cleanup_entry for oldinfo under the xt_table lock,
but it's not really necessary. After the replacement job is done
in xt_replace_table, oldinfo is not used elsewhere any more, and
it can be freed without xt_table lock safely.

The important thing is that rtnl_lock is called in some xt_target
destroy, which means rtnl_lock, a big lock is used in xt_table
lock, a smaller one. It usually could be the reason why a dead
lock may happen.

Besides, all xt_target/match checkentry is called out of xt_table
lock. It's better also to move all cleanup_entry calling out of
xt_table lock, just as do_replace_finish does for ebtables.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>