Conntrack dump does not support kernel side filtering (only get exists,
but it returns only one entry. And user has to give a full valid tuple)

It means that userspace has to implement filtering after receiving many
irrelevant entries, consuming resources (conntrack table is sometimes
very huge, much more than a routing table for example).

This patch adds filtering in kernel side. To achieve this goal, we:

 * Add a new CTA_FILTER netlink attributes, actually a flag list to
   parametize filtering
 * Convert some *nlattr_to_tuple() functions, to allow a partial parsing
   of CTA_TUPLE_ORIG and CTA_TUPLE_REPLY (so nf_conntrack_tuple it not
   fully set)

Filtering is now possible on:
 * IP SRC/DST values
 * Ports for TCP and UDP flows
 * IMCP(v6) codes types and IDs

Filtering is done as an "AND" operator. For example, when flags
PROTO_SRC_PORT, PROTO_NUM and IP_SRC are sets, only entries matching all
values are dumped.

Changes since v1:
  Set NLM_F_DUMP_FILTERED in nlm flags if entries are filtered

Changes since v2:
  Move several constants to nf_internals.h
  Move a fix on netlink values check in a separate patch
  Add a check on not-supported flags
  Return EOPNOTSUPP if CDA_FILTER is set in ctnetlink_flush_conntrack
  (not yet implemented)
  Code style issues

Changes since v3:
  Fix compilation warning reported by kbuild test robot

Changes since v4:
  Fix a regression introduced in v3 (returned EINVAL for valid netlink
  messages without CTA_MARK)

Changes since v5:
  Change definition of CTA_FILTER_F_ALL
  Fix a regression when CTA_TUPLE_ZONE is not set

Signed-off-by: Romain Bellan <romain.bellan@wifirst.fr>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch allows you to NAT the network address prefix onto another
network address prefix, a.k.a. netmapping.

Userspace must specify the NF_NAT_RANGE_NETMAP flag and the prefix
address through the NFTA_NAT_REG_ADDR_MIN and NFTA_NAT_REG_ADDR_MAX
netlink attributes.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This bit indicates that the conntrack entry is offloaded to hardware
flow table. nf_conntrack entry will be tagged with [HW_OFFLOAD] if
it's offload to hardware.

cat /proc/net/nf_conntrack
	ipv4 2 tcp 6 \
	src=1.1.1.17 dst=1.1.1.16 sport=56394 dport=5001 \
	src=1.1.1.16 dst=1.1.1.17 sport=5001 dport=56394 [HW_OFFLOAD] \
	mark=0 zone=0 use=3

Note that HW_OFFLOAD/OFFLOAD/ASSURED are mutually exclusive.

Changelog:

* V1->V2:
- Remove check of lastused from stats. It was meant for cases such
  as removing driver module while traffic still running. Better to
  handle such cases from garbage collector.

Signed-off-by: Bodong Wang <bodong@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Stefano originally proposed to introduce this flag, users hit EOPNOTSUPP
in new binaries with old kernels when defining a set with ranges in
a concatenation.

Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Android has long had an extension to IDLETIMER to send netlink
messages to userspace, see:
  https://android.googlesource.com/kernel/common/+/refs/heads/android-mainline/include/uapi/linux/netfilter/xt_IDLETIMER.h#42
Note: this is idletimer target rev 1, there is no rev 0 in
the Android common kernel sources, see registration at:
  https://android.googlesource.com/kernel/common/+/refs/heads/android-mainline/net/netfilter/xt_IDLETIMER.c#483

When we compare that to upstream's new idletimer target rev 1:
  https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git/tree/include/uapi/linux/netfilter/xt_IDLETIMER.h#n46

We immediately notice that these two rev 1 structs are the
same size and layout, and that while timer_type and send_nl_msg
are differently named and serve a different purpose, they're
at the same offset.

This makes them impossible to tell apart - and thus one cannot
know in a mixed Android/vanilla environment whether one means
timer_type or send_nl_msg.

Since this is iptables/netfilter uapi it introduces a problem
between iptables (vanilla vs Android) userspace and kernel
(vanilla vs Android) if the two don't match each other.

Additionally when at some point in the future Android picks up
5.7+ it's not at all clear how to resolve the resulting merge
conflict.

Furthermore, since upgrading the kernel on old Android phones
is pretty much impossible there does not seem to be an easy way
out of this predicament.

The only thing I've been able to come up with is some super
disgusting kernel version >= 5.7 check in the iptables binary
to flip between different struct layouts.

By adding a dummy field to the vanilla Linux kernel header file
we can force the two structs to be compatible with each other.

Long term I think I would like to deprecate send_nl_msg out of
Android entirely, but I haven't quite been able to figure out
exactly how we depend on it.  It seems to be very similar to
sysfs notifications but with some extra info.

Currently it's actually always enabled whenever Android uses
the IDLETIMER target, so we could also probably entirely
remove it from the uapi in favour of just always enabling it,
but again we can't upgrade old kernels already in the field.

(Also note that this doesn't change the structure's size,
as it is simply fitting into the pre-existing padding, and
that since 5.7 hasn't been released yet, there's still time
to make this uapi visible change)

Cc: Manoj Basapathi <manojbm@codeaurora.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Add a new flag to turn on flowtable counters which are stored in the
conntrack entry.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Expose the NFT_FLOWTABLE_HW_OFFLOAD flag through uapi.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch allows users to specify the stateful expression for the
elements in this set via NFTA_SET_EXPR. This new feature allows you to
turn on counters for all of the elements in this set.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Like vxlan and erspan opts, geneve opts should also be supported in
nft_tunnel. The difference is geneve RFC (draft-ietf-nvo3-geneve-14)
allows a geneve packet to carry multiple geneve opts. So with this
patch, nftables/libnftnl would do:

  # nft add table ip filter
  # nft add chain ip filter input { type filter hook input priority 0 \; }
  # nft add tunnel filter geneve_02 { type geneve\; id 2\; \
    ip saddr 192.168.1.1\; ip daddr 192.168.1.2\; \
    sport 9000\; dport 9001\; dscp 1234\; ttl 64\; flags 1\; \
    opts \"1:1:34567890,2:2:12121212,3:3:1212121234567890\"\; }
  # nft list tunnels table filter
    table ip filter {
    	tunnel geneve_02 {
    		id 2
    		ip saddr 192.168.1.1
    		ip daddr 192.168.1.2
    		sport 9000
    		dport 9001
    		tos 18
    		ttl 64
    		flags 1
    		geneve opts 1:1:34567890,2:2:12121212,3:3:1212121234567890
    	}
    }

v1->v2:
  - no changes, just post it separately.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This is a snapshot of hardidletimer netfilter target.

This patch implements a hardidletimer 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)

Compared to IDLETIMER, HARDIDLETIMER can send notifications when
CPU is in suspend too, to notify the timer expiry.

v1->v2: Moved all functionality into IDLETIMER module to avoid
code duplication per comment from Florian.

Signed-off-by: Manoj Basapathi <manojbm@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>