bridge: set fake_rtable's dst to NULL to avoid kernel Oops

when bridge is deleted before tap/vif device's delete, kernel may
encounter an oops because of NULL reference to fake_rtable's dst.
Set fake_rtable's dst to NULL before sending packets out can solve
this problem.

v4 reformat, change br_drop_fake_rtable(skb) to {}

v3 enrich commit header

v2 introducing new flag DST_FAKE_RTABLE to dst_entry struct.

[ Use "do { } while (0)" for nop br_drop_fake_rtable()
  implementation -DaveM ]

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Peter Huang <peter.huangpeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If user has configured a MAC address that is not one of the existing
ports of the bridge, then we need to add a special entry in the forwarding
table. This forwarding table entry has no outgoing port so it has to be
treated a little differently. The special entry is reported by the netlink
interface with ifindex of bridge, but ignored by the old interface since there
is no usable way to put it in the ABI.

Reported-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since nf_bridge_maybe_copy_header() may change the length of skb,
we should check the length of skb after it to handle the ppoe skbs.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add modern __rcu annotatations to bridge multicast table.
Use newer hlist macros to avoid direct access to hlist internals.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	net/ipv4/ip_output.c

The bridge multicast patches introduced an OOM crash in the forward
path, when deliver_clone fails to clone the skb.

Reported-by: Mark Wagner <mwagner@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are multiple problems with the newly added netpoll support:

1) Use-after-free on each netpoll packet.
2) Invoking unsafe code on netpoll/IRQ path.
3) Breaks when netpoll is enabled on the underlying device.

This patch fixes all of these problems.  In particular, we now
allocate proper netpoll structures for each underlying device.

We only allow netpoll to be enabled on the bridge when all the
devices underneath it support netpoll.  Once it is enabled, we
do not allow non-netpoll devices to join the bridge (until netpoll
is disabled again).

This allows us to do away with the npinfo juggling that caused
problem number 1.

Incidentally this patch fixes number 2 by bypassing unsafe code
such as multicast snooping and netfilter.

Reported-by: Qianfeng Zhang <frzhang@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	net/bridge/br_device.c
	net/bridge/br_forward.c

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

Based on the previous patch, make bridge support netpoll by:

1) implement the 2 methods to support netpoll for bridge;

2) modify netpoll during forwarding packets via bridge;

3) disable netpoll support of bridge when a netpoll-unabled device
   is added to bridge;

4) enable netpoll support when all underlying devices support netpoll.

Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move some declarations around to make it clearer which variables
are being used inside loop.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>