Adds a new property for hash set types, where if a set is created
with the 'forceadd' option and the set becomes full the next addition
to the set may succeed and evict a random entry from the set.

To keep overhead low eviction is done very simply. It checks to see
which bucket the new entry would be added. If the bucket's pos value
is non-zero (meaning there's at least one entry in the bucket) it
replaces the first entry in the bucket. If pos is zero, then it continues
down the normal add process.

This property is useful if you have a set for 'ban' lists where it may
not matter if you release some entries from the set early.

Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

commit 2dfb973c0dcc6d2211 (add markmask for hash:ip,mark data type)
inserted IPSET_ATTR_MARKMASK in-between other enum values, i.e.
changing values of all further attributes.  This causes 'ipset list'
segfault on existing kernels since ipset no longer finds
IPSET_ATTR_MEMSIZE (it has a different value on kernel side).

Jozsef points out it should be moved below IPSET_ATTR_MARK which
works since there is some extra reserved space after that value.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

Introduce packet mark mask for hash:ip,mark data type. This allows to
set mark bit filter for the ip set.

Change-Id: Id8dd9ca7e64477c4f7b022a1d9c1a5b187f1c96e

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

Introduce packet mark support with new ip,mark hash set. This includes
userspace and kernelspace code, hash:ip,mark set tests and man page
updates.

The intended use of ip,mark set is similar to the ip:port type, but for
protocols which don't use a predictable port number. Instead of port
number it matches a firewall mark determined by a layer 7 filtering
program like opendpi.

As well as allowing or blocking traffic it will also be used for
accounting packets and bytes sent for each protocol.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

This allows us to store user comment strings, but it could be also
used to store any kind of information that the user application needs
to link to the rule.

Scratch 8 bits for the new ulen field that indicates the length the
user data area. 4 bits from the handle (so it's 42 bits long, according
to Patrick, it would last 139 years with 1000 new rules per second)
and 4 bits from dlen (so the expression data area is 4K, which seems
sufficient by now even considering the compatibility layer).

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>

This also adds NF_CT_LABELS_MAX_SIZE so it can be re-used
as BUILD_BUG_ON in nft_ct.

At this time, nft doesn't yet support writing to the label area;
when this changes the label->words handling needs to be moved
out of xt_connlabel.c into nf_conntrack_labels.c.

Also removes a useless run-time check: words cannot grow beyond
4 (32 bit) or 2 (64bit) since xt_connlabel enforces a maximum of
128 labels.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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 kernel support for setting properties of tracked
connections. Currently, only connmark is supported. One use-case
for this feature is to provide the same functionality as
-j CONNMARK --save-mark in iptables.

Some restructuring was needed to implement the set op. The new
structure follows that of nft_meta.

Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>