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>

1 files changed, 22 insertions, 15 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 28205e5..f20060a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1064,7 +1064,8 @@ work_done:
 out:	return 0;
 }
 
-static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
+static int rt_intern_hash(unsigned hash, struct rtable *rt,
+			  struct rtable **rp, struct sk_buff *skb)
 {
 	struct rtable	*rth, **rthp;
 	unsigned long	now;
@@ -1114,7 +1115,10 @@ restart:
 			spin_unlock_bh(rt_hash_lock_addr(hash));
 
 			rt_drop(rt);
-			*rp = rth;
+			if (rp)
+				*rp = rth;
+			else
+				skb->dst = &rth->u.dst;
 			return 0;
 		}
 
@@ -1210,7 +1214,10 @@ restart:
 	rcu_assign_pointer(rt_hash_table[hash].chain, rt);
 
 	spin_unlock_bh(rt_hash_lock_addr(hash));
-	*rp = rt;
+	if (rp)
+		*rp = rt;
+	else
+		skb->dst = &rt->u.dst;
 	return 0;
 }
 
@@ -1407,7 +1414,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 							&netevent);
 
 				rt_del(hash, rth);
-				if (!rt_intern_hash(hash, rt, &rt))
+				if (!rt_intern_hash(hash, rt, &rt, NULL))
 					ip_rt_put(rt);
 				goto do_next;
 			}
@@ -1473,7 +1480,7 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 
 void ip_rt_send_redirect(struct sk_buff *skb)
 {
-	struct rtable *rt = skb->rtable;
+	struct rtable *rt = skb_rtable(skb);
 	struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
 
 	if (!in_dev)
@@ -1521,7 +1528,7 @@ out:
 
 static int ip_error(struct sk_buff *skb)
 {
-	struct rtable *rt = skb->rtable;
+	struct rtable *rt = skb_rtable(skb);
 	unsigned long now;
 	int code;
 
@@ -1698,7 +1705,7 @@ static void ipv4_link_failure(struct sk_buff *skb)
 
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 
-	rt = skb->rtable;
+	rt = skb_rtable(skb);
 	if (rt)
 		dst_set_expires(&rt->u.dst, 0);
 }
@@ -1858,7 +1865,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 	in_dev_put(in_dev);
 	hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
-	return rt_intern_hash(hash, rth, &skb->rtable);
+	return rt_intern_hash(hash, rth, NULL, skb);
 
 e_nobufs:
 	in_dev_put(in_dev);
@@ -2019,7 +2026,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
 	/* put it into the cache */
 	hash = rt_hash(daddr, saddr, fl->iif,
 		       rt_genid(dev_net(rth->u.dst.dev)));
-	return rt_intern_hash(hash, rth, &skb->rtable);
+	return rt_intern_hash(hash, rth, NULL, skb);
 }
 
 /*
@@ -2175,7 +2182,7 @@ local_input:
 	}
 	rth->rt_type	= res.type;
 	hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
-	err = rt_intern_hash(hash, rth, &skb->rtable);
+	err = rt_intern_hash(hash, rth, NULL, skb);
 	goto done;
 
 no_route:
@@ -2244,7 +2251,7 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 			dst_use(&rth->u.dst, jiffies);
 			RT_CACHE_STAT_INC(in_hit);
 			rcu_read_unlock();
-			skb->rtable = rth;
+			skb->dst = &rth->u.dst;
 			return 0;
 		}
 		RT_CACHE_STAT_INC(in_hlist_search);
@@ -2420,7 +2427,7 @@ static int ip_mkroute_output(struct rtable **rp,
 	if (err == 0) {
 		hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
 			       rt_genid(dev_net(dev_out)));
-		err = rt_intern_hash(hash, rth, rp);
+		err = rt_intern_hash(hash, rth, rp, NULL);
 	}
 
 	return err;
@@ -2763,7 +2770,7 @@ static int rt_fill_info(struct net *net,
 			struct sk_buff *skb, u32 pid, u32 seq, int event,
 			int nowait, unsigned int flags)
 {
-	struct rtable *rt = skb->rtable;
+	struct rtable *rt = skb_rtable(skb);
 	struct rtmsg *r;
 	struct nlmsghdr *nlh;
 	long expires;
@@ -2907,7 +2914,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
 		err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
 		local_bh_enable();
 
-		rt = skb->rtable;
+		rt = skb_rtable(skb);
 		if (err == 0 && rt->u.dst.error)
 			err = -rt->u.dst.error;
 	} else {
@@ -2927,7 +2934,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
 	if (err)
 		goto errout_free;
 
-	skb->rtable = rt;
+	skb->dst = &rt->u.dst;
 	if (rtm->rtm_flags & RTM_F_NOTIFY)
 		rt->rt_flags |= RTCF_NOTIFY;