This patch is to let it always do CRC checksum in sctp_gso_segment() by removing CRC flag from the dev features in gre_gso_segment() for SCTP over GRE, just as it does in Commit 527beb8ef9c0 ("udp: support sctp over udp in skb_udp_tunnel_segment") for SCTP over UDP. It could set csum/csum_start in GSO CB properly in sctp_gso_segment() after that commit, so it would do checksum with gso_make_checksum() in gre_gso_segment(), and Commit 622e32b7d4a6 ("net: gre: recompute gre csum for sctp over gre tunnels") can be reverted now. Note that when need_csum is false, we can still leave CRC checksum of SCTP to HW by not clearing this CRC flag if it's supported, as Jakub and Alex noticed. v1->v2: - improve the changelog. - fix "rev xmas tree" in varibles declaration. v2->v3: - remove CRC flag from dev features only when need_csum is true. Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> --- net/ipv4/gre_offload.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c index e0a2465..10bc49b 100644 --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -15,10 +15,10 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, netdev_features_t features) { int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); - bool need_csum, need_recompute_csum, gso_partial; struct sk_buff *segs = ERR_PTR(-EINVAL); u16 mac_offset = skb->mac_header; __be16 protocol = skb->protocol; + bool need_csum, gso_partial; u16 mac_len = skb->mac_len; int gre_offset, outer_hlen; @@ -41,10 +41,11 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, skb->protocol = skb->inner_protocol; need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM); - need_recompute_csum = skb->csum_not_inet; skb->encap_hdr_csum = need_csum; features &= skb->dev->hw_enc_features; + if (need_csum) + features &= ~NETIF_F_SCTP_CRC; /* segment inner packet. */ segs = skb_mac_gso_segment(skb, features); @@ -99,15 +100,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, } *(pcsum + 1) = 0; - if (need_recompute_csum && !skb_is_gso(skb)) { - __wsum csum; - - csum = skb_checksum(skb, gre_offset, - skb->len - gre_offset, 0); - *pcsum = csum_fold(csum); - } else { - *pcsum = gso_make_checksum(skb, 0); - } + *pcsum = gso_make_checksum(skb, 0); } while ((skb = skb->next)); out: return segs; -- 2.1.0