vrf: add CRC32c offload to device features

SCTP sockets originated in a VRF can improve their performance if CRC32c
computation is delegated to underlying devices: update device features,
setting NETIF_F_SCTP_CRC. Iterating the following command in the topology
proposed with [1],

# ip vrf exec vrf-h2 netperf -H 192.0.2.1 -t SCTP_STREAM -- -m 10K

the measured throughput in Mbit/s improved from 2395 ± 1% to 2720 ± 1%.

[1] https://www.spinics.net/lists/netdev/msg486007.html

Signed-off-by: Davide Caratti <[e-mail]>
Reviewed-by: Marcelo Ricardo Leitner <[e-mail]>
Acked-by: David Ahern <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/vrf.c

···
 
 	/* enable offload features */
 	dev->features   |= NETIF_F_GSO_SOFTWARE;
-	dev->features   |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
+	dev->features   |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
 	dev->features   |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
 
 	dev->hw_features = dev->features;