Merge branch 'selftests-fcnal'

Guillaume Nault says:

====================
selftests: fcnal: Test SO_DONTROUTE socket option.

The objective is to cover kernel paths that use the RTO_ONLINK flag
in .flowi4_tos. This way we'll be able to safely remove this flag in
the future by properly setting .flowi4_scope instead. With these
selftests in place, we can make sure this won't introduce regressions.

For more context, the final objective is to convert .flowi4_tos to
dscp_t, to ensure that ECN bits don't influence route and fib-rule
lookups (see commit a410a0cf9885 ("ipv6: Define dscp_t and stop taking
ECN bits into account in fib6-rules")).

These selftests only cover IPv4, as SO_DONTROUTE has no effect on IPv6
sockets.

v2:
  - Use two different nettest options for setting SO_DONTROUTE either
    on the server or on the client socket.

  - Use the above feature to run a single 'nettest -B' instance per
    test (instead of having two nettest processes for server and
    client).
====================

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