net: skb->rtable accessor

Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb

Delete skb->rtable field

Setting rtable is not allowed, just set dst instead as rtable is an alias.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 8eb3e61..cb2c50d 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -393,7 +393,7 @@
 		return 0;
 
 	/* Is this a broadcast address? */
-	if (skb && skb->rtable->rt_flags & RTCF_BROADCAST)
+	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
 		return 0;
 
 	return 1;
@@ -572,7 +572,7 @@
 /* What interface did this skb arrive on? */
 static int sctp_v4_skb_iif(const struct sk_buff *skb)
 {
-	return skb->rtable->rt_iif;
+	return skb_rtable(skb)->rt_iif;
 }
 
 /* Was this packet marked by Explicit Congestion Notification? */
@@ -848,8 +848,8 @@
 
 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n",
 			  __func__, skb, skb->len,
-			  &skb->rtable->rt_src,
-			  &skb->rtable->rt_dst);
+			  &skb_rtable(skb)->rt_src,
+			  &skb_rtable(skb)->rt_dst);
 
 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;