linux.git/net/netfilter/xt_connbytes.c, branch v6.16

netfilter: xtables: avoid NFPROTO_UNSPEC where needed

2024-10-09T21:20:46+00:00

syzbot managed to call xt_cluster match via ebtables:

WARNING: CPU: 0 PID: 11 at net/netfilter/xt_cluster.c:72 xt_cluster_mt+0x196/0x780
[..]
ebt_do_table+0x174b/0x2a40

Module registers to NFPROTO_UNSPEC, but it assumes ipv4/ipv6 packet
processing. As this is only useful to restrict locally terminating
TCP/UDP traffic, register this for ipv4 and ipv6 family only.

Pablo points out that this is a general issue, direct users of the
set/getsockopt interface can call into targets/matches that were only
intended for use with ip(6)tables.

Check all UNSPEC matches and targets for similar issues:

- matches and targets are fine except if they assume skb_network_header()
is valid -- this is only true when called from inet layer: ip(6) stack
pulls the ip/ipv6 header into linear data area.
- targets that return XT_CONTINUE or other xtables verdicts must be
restricted too, they are incompatbile with the ebtables traverser, e.g.
EBT_CONTINUE is a completely different value than XT_CONTINUE.

Most matches/targets are changed to register for NFPROTO_IPV4/IPV6, as
they are provided for use by ip(6)tables.

The MARK target is also used by arptables, so register for NFPROTO_ARP too.

While at it, bail out if connbytes fails to enable the corresponding
conntrack family.

This change passes the selftests in iptables.git.

Reported-by: syzbot+256c348558aa5cf611a9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netfilter-devel/66fec2e2.050a0220.9ec68.0047.GAE@google.com/
Fixes: 0269ea493734 ("netfilter: xtables: add cluster match")
Signed-off-by: Florian Westphal
Co-developed-by: Pablo Neira Ayuso
Signed-off-by: Pablo Neira Ayuso

netfilter: x_tables: use pr ratelimiting in all remaining spots

2018-02-14T20:05:38+00:00

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: add and use nf_ct_netns_get/put

2016-12-04T20:16:50+00:00

currently aliased to try_module_get/_put.
Will be changed in next patch when we add functions to make use of ->net
argument to store usercount per l3proto tracker.

This is needed to avoid registering the conntrack hooks in all netns and
later only enable connection tracking in those that need conntrack.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: Convert pr_warning to pr_warn

2014-09-10T19:40:10+00:00

Use the more common pr_warn.

Other miscellanea:

o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

netfilter: introduce nf_conn_acct structure

2013-11-03T20:48:49+00:00

Encapsulate counters for both directions into nf_conn_acct. During
that process also consistently name pointers to the extend 'acct',
not 'counters'. This patch is a cleanup.

Signed-off-by: Holger Eitzenberger 
Signed-off-by: Pablo Neira Ayuso

Merge branch 'nf-next' of git://1984.lsi.us.es/net-next

2011-12-25T07:21:45+00:00

netfilter: xt_connbytes: handle negation correctly

2011-12-23T13:50:19+00:00

"! --connbytes 23:42" should match if the packet/byte count is not in range.

As there is no explict "invert match" toggle in the match structure,
userspace swaps the from and to arguments
(i.e., as if "--connbytes 42:23" were given).

However, "what <= 23 && what >= 42" will always be false.

Change things so we use "||" in case "from" is larger than "to".

This change may look like it breaks backwards compatibility when "to" is 0.
However, older iptables binaries will refuse "connbytes 42:0",
and current releases treat it to mean "! --connbytes 0:42",
so we should be fine.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_conntrack: use atomic64 for accounting counters

2011-12-18T00:19:19+00:00

We can use atomic64_t infrastructure to avoid taking a spinlock in fast
path, and remove inaccuracies while reading values in
ctnetlink_dump_counters() and connbytes_mt() on 32bit arches.

Suggested by Pablo.

Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso

netfilter: xt_connbytes: Force CT accounting to be enabled

2010-06-25T12:44:07+00:00

Check at rule install time that CT accounting is enabled. Force it
to be enabled if not while also emitting a warning since this is not
the default state.

This is in preparation for deprecating CONFIG_NF_CT_ACCT upon which
CONFIG_NETFILTER_XT_MATCH_CONNBYTES depended being set.

Added 2 CT accounting support functions:

nf_ct_acct_enabled() - Get CT accounting state.
nf_ct_set_acct() - Enable/disable CT accountuing.

Signed-off-by: Tim Gardner 
Acked-by: Jan Engelhardt 
Signed-off-by: Patrick McHardy

netfilter: xtables: deconstify struct xt_action_param for matches

2010-05-11T16:33:37+00:00

In future, layer-3 matches will be an xt module of their own, and
need to set the fragoff and thoff fields. Adding more pointers would
needlessy increase memory requirements (esp. so for 64-bit, where
pointers are wider).

Signed-off-by: Jan Engelhardt