This patch adds receive path support for IPv6 with fou.

- Add address family to fou structure for open sockets. This supports
  AF_INET and AF_INET6. Lookups for fou ports are performed on both the
  port number and family.
- In fou and gue receive adjust tot_len in IPv4 header or payload_len
  based on address family.
- Allow AF_INET6 in FOU_ATTR_AF netlink attribute.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Create __fou_build_header and __gue_build_header. These implement the
protocol generic parts of building the fou and gue header.
fou_build_header and gue_build_header implement the IPv4 specific
functions and call the __*_build_header functions.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use helper function to set up UDP tunnel related information for a fou
socket.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In netdevice.h we removed the structure in net-next that is being
changes in 'net'.  In macsec.c and rtnetlink.c we have overlaps
between fixes in 'net' and the u64 attribute changes in 'net-next'.

The mlx5 conflicts have to do with vxlan support dependencies.

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

UDP tunnel segmentation code relies on the inner offsets being set for
an UDP tunnel GSO packet, but the inner *_complete() functions will
set the inner offsets only if 'encapsulation' is set before calling
them.  Currently, udp_gro_complete() sets 'encapsulation' only after
the inner *_complete() functions are done.  This causes the inner
offsets having invalid values after udp_gro_complete() returns, which
in turn will make it impossible to properly segment the packet in case
it needs to be forwarded, which would be visible to the user either as
invalid packets being sent or as packet loss.

This patch fixes this by setting skb's 'encapsulation' in
udp_gro_complete() before calling into the inner complete functions,
and by making each possible UDP tunnel gro_complete() callback set the
inner_mac_header to the beginning of the tunnel payload.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Reviewed-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The setting of the UDP tunnel GSO type is already performed by
udp[46]_gro_complete().

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch updates the IP tunnel core function iptunnel_handle_offloads so
that we return an int and do not free the skb inside the function.  This
actually allows us to clean up several paths in several tunnels so that we
can free the skb at one point in the path without having to have a
secondary path if we are supporting tunnel offloads.

In addition it should resolve some double-free issues I have found in the
tunnels paths as I believe it is possible for us to end up triggering such
an event in the case of fou or gue.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes an issue I found in which we were dropping frames if we
had enabled checksums on GRE headers that were encapsulated by either FOU
or GUE.  Without this patch I was barely able to get 1 Gb/s of throughput.
With this patch applied I am now at least getting around 6 Gb/s.

The issue is due to the fact that with FOU or GUE applied we do not provide
a transport offset pointing to the GRE header, nor do we offload it in
software as the GRE header is completely skipped by GSO and treated like a
VXLAN or GENEVE type header.  As such we need to prevent the stack from
generating it and also prevent GRE from generating it via any interface we
create.

Fixes: c3483384ee511 ("gro: Allow tunnel stacking in the case of FOU/GUE")
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adapt gue_gro_receive, gue_gro_complete to take a socket argument.
Don't set udp_offloads any more.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>