Before f5efc69 ("netfilter: nf_tables: Add meta expression key for
bridge interface name"), the entire net/bridge/netfilter/ directory
depended on BRIDGE_NF_EBTABLES, ie. on ebtables. However, that
directory already contained the nf_tables bridge extension that
we should allow to compile separately. In f5efc69, we tried to
generalize this by using CONFIG_BRIDGE_NETFILTER which was not a good
idea since this option already existed and it is dedicated to enable
the Netfilter bridge IP/ARP filtering.

Let's try to fix this mess by:

1) making net/bridge/netfilter/ dependent on the toplevel
   CONFIG_NETFILTER option, just like we do with the net/netfilter and
   net/ipv{4,6}/netfilter/ directories.

2) Changing 'selects' to 'depends on' NETFILTER_XTABLES for
   BRIDGE_NF_EBTABLES. I believe this problem was already before
   f5efc69:

warning: (BRIDGE_NF_EBTABLES) selects NETFILTER_XTABLES which has
unmet direct dependencies (NET && INET && NETFILTER)

3) Fix ebtables/nf_tables bridge dependencies by making NF_TABLES_BRIDGE
   and BRIDGE_NF_EBTABLES dependent on BRIDGE and NETFILTER:

warning: (NF_TABLES_BRIDGE && BRIDGE_NF_EBTABLES) selects
BRIDGE_NETFILTER which has unmet direct dependencies (NET && BRIDGE &&
NETFILTER && INET && NETFILTER_ADVANCED)

net/built-in.o: In function `br_parse_ip_options':
br_netfilter.c:(.text+0x4a5ba): undefined reference to `ip_options_compile'
br_netfilter.c:(.text+0x4a5ed): undefined reference to `ip_options_rcv_srr'
net/built-in.o: In function `br_nf_pre_routing_finish':
br_netfilter.c:(.text+0x4a8a4): undefined reference to `ip_route_input_noref'
br_netfilter.c:(.text+0x4a987): undefined reference to `ip_route_output_flow'
make: *** [vmlinux] Error 1

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter/nftables updates for net-next

The following patchset contains Netfilter/nftables updates for net-next,
most relevantly they are:

1) Add set element update notification via netlink, from Arturo Borrero.

2) Put all object updates in one single message batch that is sent to
   kernel-space. Before this patch only rules where included in the batch.
   This series also introduces the generic transaction infrastructure so
   updates to all objects (tables, chains, rules and sets) are applied in
   an all-or-nothing fashion, these series from me.

3) Defer release of objects via call_rcu to reduce the time required to
   commit changes. The assumption is that all objects are destroyed in
   reverse order to ensure that dependencies betweem them are fulfilled
   (ie. rules and sets are destroyed first, then chains, and finally
   tables).

4) Allow to match by bridge port name, from Tomasz Bursztyka. This series
   include two patches to prepare this new feature.

5) Implement the proper set selection based on the characteristics of the
   data. The new infrastructure also allows you to specify your preferences
   in terms of memory and computational complexity so the underlying set
   type is also selected according to your needs, from Patrick McHardy.

6) Several cleanup patches for nft expressions, including one minor possible
   compilation breakage due to missing mark support, also from Patrick.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

NFT_META_BRI_IIFNAME to get packet input bridge interface name
NFT_META_BRI_OIFNAME to get packet output bridge interface name

Such meta key are accessible only through NFPROTO_BRIDGE family, on a
dedicated nft meta module: nft_meta_bridge.

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

All xtables variants suffer from the defect that the copy_to_user()
to copy the counters to user memory may fail after the table has
already been exchanged and thus exposed. Return an error at this
point will result in freeing the already exposed table. Any
subsequent packet processing will result in a kernel panic.

We can't copy the counters before exposing the new tables as we
want provide the counter state after the old table has been
unhooked. Therefore convert this into a silent error.

Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Convert the uses of memcpy to ether_addr_copy because
for some architectures it is smaller and faster.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We don't encode argument types into function names and since besides
nft_do_chain() there are only AF-specific versions, there is no risk
of confusion.

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

Minor nf_chain_type cleanups:

- reorder struct to plug a hoe
- rename struct module member to "owner" for consistency
- rename nf_hookfn array to "hooks" for consistency
- reorder initializers for better readability

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

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

In some cases we neither take a reference to the AF info nor to the
chain type, allowing the module to be unloaded while in use.

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

Add support to register chains to multiple hooks for different address
families for mixed IPv4/IPv6 tables.

Signed-off-by: Patrick McHardy <kaber@trash.net>