odp-util: Remove unnecessary TOS ECN bits rewrite for tunnels

For tunnels, TOS ECN bits are never wildcard for the reason that they
are always inherited. OVS will create a rewrite action if we add rule
to modify other IP headers. But it also adds an extra ECN rewrite for
the action because of this ECN un-wildcarding.

It seems no error because the ECN bits to be changed are same in this
case. But as rule can't be offloaded to hardware, the unnecssary ECN
rewrite should be removed.

Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>

diff --git a/lib/odp-util.c b/lib/odp-util.c
index 6db241ab0e9f0d81349cdc1e57159047e2826ee9..95c584be34585915ec658f63d080ed9ec5a349ae 100644 (file)
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -6962,6 +6962,11 @@ commit_set_ipv4_action(const struct flow *flow, struct flow *base_flow,
     mask.ipv4_proto = 0;        /* Not writeable. */
     mask.ipv4_frag = 0;         /* Not writable. */
 
+    if (flow_tnl_dst_is_set(&base_flow->tunnel) &&
+        ((base_flow->nw_tos ^ flow->nw_tos) & IP_ECN_MASK) == 0) {
+        mask.ipv4_tos &= ~IP_ECN_MASK;
+    }
+
     if (commit(OVS_KEY_ATTR_IPV4, use_masked, &key, &base, &mask, sizeof key,
                odp_actions)) {
         put_ipv4_key(&base, base_flow, false);
@@ -7012,6 +7017,11 @@ commit_set_ipv6_action(const struct flow *flow, struct flow *base_flow,
     mask.ipv6_proto = 0;        /* Not writeable. */
     mask.ipv6_frag = 0;         /* Not writable. */
 
+    if (flow_tnl_dst_is_set(&base_flow->tunnel) &&
+        ((base_flow->nw_tos ^ flow->nw_tos) & IP_ECN_MASK) == 0) {
+        mask.ipv6_tclass &= ~IP_ECN_MASK;
+    }
+
     if (commit(OVS_KEY_ATTR_IPV6, use_masked, &key, &base, &mask, sizeof key,
                odp_actions)) {
         put_ipv6_key(&base, base_flow, false);