net: skb->dst accessors

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 0ef4e30..9402a7f 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -84,7 +84,7 @@
 	case htons(ETH_P_IPV6):
 		return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
 	default:
-		return addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+		return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 	}
 }
 
@@ -163,7 +163,7 @@
 		break;
 	}
 	default:
-		res = addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+		res = addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 	}
 
 	return res;
@@ -251,8 +251,8 @@
 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 {
 #ifdef CONFIG_NET_CLS_ROUTE
-	if (skb->dst)
-		return skb->dst->tclassid;
+	if (skb_dst(skb))
+		return skb_dst(skb)->tclassid;
 #endif
 	return 0;
 }
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index bdf1f41..dd872d5 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -137,7 +137,7 @@
 	u32 id, h;
 	int iif, dont_cache = 0;
 
-	if ((dst = skb->dst) == NULL)
+	if ((dst = skb_dst(skb)) == NULL)
 		goto failure;
 
 	id = dst->tclassid;
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index b6b588b..266151a 100644
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -246,11 +246,11 @@
 
 META_COLLECTOR(int_rtclassid)
 {
-	if (unlikely(skb->dst == NULL))
+	if (unlikely(skb_dst(skb) == NULL))
 		*err = -1;
 	else
 #ifdef CONFIG_NET_CLS_ROUTE
-		dst->value = skb->dst->tclassid;
+		dst->value = skb_dst(skb)->tclassid;
 #else
 		dst->value = 0;
 #endif
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 33133d2..8706920 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -149,7 +149,7 @@
 		break;
 	}
 	default:
-		h = (unsigned long)skb->dst ^ skb->protocol;
+		h = (unsigned long)skb_dst(skb) ^ skb->protocol;
 		h2 = (unsigned long)skb->sk;
 	}
 
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index a886496..cb1cb1e 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -222,7 +222,7 @@
 {
 	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
 	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
-	struct neighbour *mn = skb->dst->neighbour;
+	struct neighbour *mn = skb_dst(skb)->neighbour;
 	struct neighbour *n = q->ncache;
 
 	if (mn->tbl == NULL)
@@ -262,8 +262,8 @@
 		return -ENODEV;
 
 	if (dev->header_ops == NULL ||
-	    skb->dst == NULL ||
-	    skb->dst->neighbour == NULL)
+	    skb_dst(skb) == NULL ||
+	    skb_dst(skb)->neighbour == NULL)
 		return 0;
 	return __teql_resolve(skb, skb_res, dev);
 }