openvswitch: delete the unncessary skb_pull_rcsum call in ovs_ct_nat_execute

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2163374
Upstream Status: linux.git

commit bf14f49
Author: Xin Long <lucien.xin@gmail.com>
Date:   Thu Dec 8 11:56:08 2022 -0500

    openvswitch: delete the unncessary skb_pull_rcsum call in ovs_ct_nat_execute

    The calls to ovs_ct_nat_execute() are as below:

      ovs_ct_execute()
        ovs_ct_lookup()
          __ovs_ct_lookup()
            ovs_ct_nat()
              ovs_ct_nat_execute()
        ovs_ct_commit()
          __ovs_ct_lookup()
            ovs_ct_nat()
              ovs_ct_nat_execute()

    and since skb_pull_rcsum() and skb_push_rcsum() are already
    called in ovs_ct_execute(), there's no need to do it again
    in ovs_ct_nat_execute().

    Reviewed-by: Saeed Mahameed <saeed@kernel.org>
    Acked-by: Aaron Conole <aconole@redhat.com>
    Signed-off-by: Xin Long <lucien.xin@gmail.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Antoine Tenart <atenart@redhat.com>

Author: atenart

net/openvswitch/conntrack.c

@@ -794,10 +794,7 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 			      const struct nf_nat_range2 *range,
 			      enum nf_nat_manip_type maniptype, struct sw_flow_key *key)
 {
-	int hooknum, nh_off, err = NF_ACCEPT;
-
-	nh_off = skb_network_offset(skb);
-	skb_pull_rcsum(skb, nh_off);
+	int hooknum, err = NF_ACCEPT;
 
 	/* See HOOK2MANIP(). */
 	if (maniptype == NF_NAT_MANIP_SRC)
@@ -814,7 +811,7 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 							   hooknum))
 				err = NF_DROP;
-			goto push;
+			goto out;
 		} else if (IS_ENABLED(CONFIG_IPV6) &&
 			   skb->protocol == htons(ETH_P_IPV6)) {
 			__be16 frag_off;
@@ -829,7 +826,7 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 								     hooknum,
 								     hdrlen))
 					err = NF_DROP;
-				goto push;
+				goto out;
 			}
 		}
 		/* Non-ICMP, fall thru to initialize if needed. */
@@ -847,7 +844,7 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 				? nf_nat_setup_info(ct, range, maniptype)
 				: nf_nat_alloc_null_binding(ct, hooknum);
 			if (err != NF_ACCEPT)
-				goto push;
+				goto out;
 		}
 		break;
 
@@ -857,13 +854,11 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 
 	default:
 		err = NF_DROP;
-		goto push;
+		goto out;
 	}
 
 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
-push:
-	skb_push_rcsum(skb, nh_off);
-
+out:
 	/* Update the flow key if NAT successful. */
 	if (err == NF_ACCEPT)
 		ovs_nat_update_key(key, skb, maniptype);