From 3189a290f98d3d3b76536ab61e9ff95751ed8124 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Mon, 5 Dec 2016 15:33:57 +0100 Subject: [PATCH] netfilter: nat: skip checksum on offload SCTP packets 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_nat_proto_sctp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_nat_proto_sctp.c b/net/netfilter/nf_nat_proto_sctp.c index 2e14108..31d3586 100644 --- a/net/netfilter/nf_nat_proto_sctp.c +++ b/net/netfilter/nf_nat_proto_sctp.c @@ -47,7 +47,10 @@ sctp_manip_pkt(struct sk_buff *skb, hdr->dest = tuple->dst.u.sctp.port; } - hdr->checksum = sctp_compute_cksum(skb, hdroff); + if (skb->ip_summed != CHECKSUM_PARTIAL) { + hdr->checksum = sctp_compute_cksum(skb, hdroff); + skb->ip_summed = CHECKSUM_NONE; + } return true; } -- 2.7.4