mptcp: Transform callback_list to hlist to win 8 bytes

There is absolutly no interest to make this a circular list. So, use
hlist to win 8 bytes in mptcp_cb.

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: Add addr_signal flag in mpcb

In the fast data-path we make a call to addr_signal for every single
packet. This redirects us to the path-manager who will need to access
its private structure and thus generate cache-misses in the fast path.

The path-manager should indicate to the MPTCP-layer if a call to
addr_signal is actually necessary. So, this patch adds this flag and
sets/unsets it in the fullmesh path-manager.

With this change, we never enter the path-manager in the fast-path if it
is not absolutly necessary.

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: move meta_sk-field in mptcp_cb together with it's use-case pattern

To benefit from cache-locality we move it there where it is actually
used, for subflow establishment.

It was used at mptcp_update_sndbuf as well, but this has simply been
mitigated by changing the parameter of the function.

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: Group together field for connection/subflow closure

Benefits cache-locality

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: Group together field for subflow closure and establishment

Benefits cache-locality

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: Group together field for subflow establishment and path-management

Benefits cache-locality.

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>
mptcp: Group together field for data transmission/reception

Benefits cache-locality

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Gregory Detal <gregory.detal@uclouvain.be>