SCTP GSO and hardware can do CRC32c computation after netfilter processing, so we can avoid calling sctp_compute_checksum() on skb if skb->ip_summed is equal to CHECKSUM_PARTIAL. Moreover, set skb->ip_summed to CHECKSUM_NONE when the NAT code computes the CRC, to prevent offloaders from computing it again (on ixgbe this resulted in a transmission with wrong L4 checksum). Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>