tc: remove unused redirect ttl

improves ingress+u32 performance from 22.4 Mpps to 22.9 Mpps
Signed-off-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/pkt_cls.h

@@ -65,11 +65,13 @@ bits 9,10,11: redirect counter -  redirect TTL. Loop avoidance
 #define SET_TC_NCLS(v)   ( TC_NCLS | (v & ~TC_NCLS))
 #define CLR_TC_NCLS(v)   ( v & ~TC_NCLS)
 
+#ifndef __KERNEL__
 #define S_TC_RTTL          _TC_MAKE32(9)
 #define M_TC_RTTL          _TC_MAKEMASK(3,S_TC_RTTL)
 #define G_TC_RTTL(x)       _TC_GETVALUE(x,S_TC_RTTL,M_TC_RTTL)
 #define V_TC_RTTL(x)       _TC_MAKEVALUE(x,S_TC_RTTL)
 #define SET_TC_RTTL(v,n)   ((V_TC_RTTL(n)) | (v & ~M_TC_RTTL))
+#endif
 
 #define S_TC_AT          _TC_MAKE32(12)
 #define M_TC_AT          _TC_MAKEMASK(2,S_TC_AT)

net/core/dev.c

@@ -3531,18 +3531,9 @@ EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
  */
 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
 {
-	struct net_device *dev = skb->dev;
-	u32 ttl = G_TC_RTTL(skb->tc_verd);
 	int result = TC_ACT_OK;
 	struct Qdisc *q;
 
-	if (unlikely(MAX_RED_LOOP < ttl++)) {
-		net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
-				     skb->skb_iif, dev->ifindex);
-		return TC_ACT_SHOT;
-	}
-
-	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
 
 	q = rcu_dereference(rxq->qdisc);