MRP doesn't implement the periodictimer in 802.1Q, so it never retries
if packets get lost.  I ran into this problem when MRP sent a MVRP
JoinIn before the interface was fully up.  The JoinIn was lost, MRP
didn't retry, and MVRP registration failed.

Tested against Juniper QFabric switches
Signed-off-by: NNoel Burton-Krahn <noel@burton-krahn.com>
Acked-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit fb745e9a ("net/802/mrp: fix possible race condition when
calling mrp_pdu_queue()") introduced a lockdep splat.

[   19.735147] =================================
[   19.735235] [ INFO: inconsistent lock state ]
[   19.735324] 3.9.2-build-0063 #4 Not tainted
[   19.735412] ---------------------------------
[   19.735500] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[   19.735592] rmmod/1840 [HC0[0]:SC0[0]:HE1:SE1] takes:
[   19.735682]  (&(&app->lock)->rlock#2){+.?...}, at: [<f862bb5b>]
mrp_uninit_applicant+0x69/0xba [mrp]

app->lock is normally taken under softirq context, so disable BH to
avoid the splat.
Reported-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: David Ward <david.ward@ll.mit.edu>
Cc: Cong Wang <amwang@redhat.com>
Tested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

(Adapted from a very similar change to net/802/garp.c by Cong Wang.)

mrp_pdu_queue() should ways be called with the applicant spin lock.
mrp_uninit_applicant() only holds the rtnl lock which is not enough;
a race is possible because mrp_rcv() is called in BH context:

	mrp_rcv()
	  |->mrp_pdu_parse_msg()
	    |->mrp_pdu_parse_vecattr()
	      |->mrp_pdu_parse_vecattr_event()
	        |-> mrp_attr_event()
	          |-> mrp_pdu_append_vecattr_event()
	            |-> mrp_pdu_queue()

Cc: Cong Wang <amwang@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Acked-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sparse spotted local function that could be static.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial implementation of the Multiple Registration Protocol (MRP)
from IEEE 802.1Q-2011, based on the existing implementation of the
Generic Attribute Registration Protocol (GARP).
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Acked-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>