Commit 1a236766 authored by Xin Long's avatar Xin Long Committed by Jakub Kicinski
Browse files

ip_gre: remove CRC flag from dev features in gre_gso_segment 



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 527beb8e ("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 622e32b7 ("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: default avatarXin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/00439f24d5f69e2c6fa2beadc681d056c15c258f.1610772251.git.lucien.xin@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4eb5d4a5

net/ipv4/gre_offload.c

+4 −11
Original line number Diff line number Diff line
@@ -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);

		}

	} while ((skb = skb->next));

out:

	return segs;