net-tc: extract skip classify bit from tc_verd

Packets sent by the IFB device skip subsequent tc classification.
A single bit governs this state. Move it out of tc_verd in
anticipation of removing that __u16 completely.

The new bitfield tc_skip_classify temporarily uses one bit of a
hole, until tc_verd is removed completely in a follow-up patch.

Remove the bit hole comment. It could be 2, 3, 4 or 5 bits long.
With that many options, little value in documenting it.

Introduce a helper function to deduplicate the logic in the two
sites that check this bit.

The field tc_skip_classify is set only in IFB on skbs cloned in
act_mirred, so original packet sources do not have to clear the
bit when reusing packets (notably, pktgen and octeon).

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 7 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 2095c83ce773..f04715a57300 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -426,11 +426,9 @@ int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 {
 	int ret = -1, i;
 
-	if (skb->tc_verd & TC_NCLS) {
-		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
-		ret = TC_ACT_OK;
-		goto exec_done;
-	}
+	if (skb_skip_tc_classify(skb))
+		return TC_ACT_OK;
+
 	for (i = 0; i < nr_actions; i++) {
 		const struct tc_action *a = actions[i];
 
@@ -439,9 +437,8 @@ repeat:
 		if (ret == TC_ACT_REPEAT)
 			goto repeat;	/* we need a ttl - JHS */
 		if (ret != TC_ACT_PIPE)
-			goto exec_done;
+			break;
 	}
-exec_done:
 	return ret;
 }
 EXPORT_SYMBOL(tcf_action_exec);