tree a0f7e868672699b451a5053824eea0df16ce07cc
parent 129858fa0b1ab3072155718b74bf91e440c2d73f
author R. Parameswaran <parameswaran.r7@gmail.com> 1491436235 -0700
committer David S. Miller <davem@davemloft.net> 1491511411 -0700

New kernel function to get IP overhead on a socket.

A new function, kernel_sock_ip_overhead(), is provided
to calculate the cumulative overhead imposed by the IP
Header and IP options, if any, on a socket's payload.
The new function returns an overhead of zero for sockets
that do not belong to the IPv4 or IPv6 address families.
This is used in the L2TP code path to compute the
total outer IP overhead on the L2TP tunnel socket when
calculating the default MTU for Ethernet pseudowires.

Signed-off-by: R. Parameswaran <rparames@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>