[PPP] L2TP: Disallow non-UDP datagram sockets

With the addition of UDP-Lite we need to refine the socket check so
that only genuine UDP sockets are allowed through.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed