Merge branch 'mptcp-RM_ADDR-ADD_ADDR-enhancements'

Geliang Tang says:

====================
mptcp: RM_ADDR/ADD_ADDR enhancements

This series include two enhancements for the MPTCP path management,
namely RM_ADDR support and ADD_ADDR echo support, as specified by RFC
sections 3.4.1 and 3.4.2.

1 RM_ADDR support include 9 patches (1-3 and 8-13):

Patch 1 is the helper for patch 2, these two patches add the RM_ADDR
outgoing functions, which are derived from ADD_ADDR's corresponding
functions.

Patch 3 adds the RM_ADDR incoming logic, when RM_ADDR suboption is
received, close the subflow matching the rm_id, and update PM counter.

Patch 8 is the main remove routine. When the PM netlink removes an address,
we traverse all the existing msk sockets to find the relevant sockets. Then
trigger the RM_ADDR signal and remove the subflow which using this local
address, this subflow removing functions has been implemented in patch 9.

Finally, patches 10-13 are the self-tests for RM_ADDR.

2 ADD_ADDR echo support include 7 patches (4-7 and 14-16).

Patch 4 adds the ADD_ADDR echo logic, when the ADD_ADDR suboption has been
received, send out the same ADD_ADDR suboption with echo-flag, and no HMAC
included.

Patches 5 and 6 are the self-tests for ADD_ADDR echo. Patch 7 is a little
cleaning up.

Patch 14 and 15 are the helpers for patch 16. These three patches add
the ADD_ADDR retransmition when no ADD_ADDR echo is received.
====================

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