xfrm: Return dst directly from xfrm_lookup()

Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 2a86c89..c23bd8c 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -398,18 +398,14 @@
 	if (!fl.fl4_src)
 		fl.fl4_src = rt->rt_src;
 
-	err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0);
-	switch (err) {
-	case 0:
+	rt = (struct rtable *) xfrm_lookup(net, &rt->dst, &fl, NULL, 0);
+	if (!IS_ERR(rt)) {
 		if (rt != rt2)
 			return rt;
-		break;
-	case -EPERM:
+	} else if (PTR_ERR(rt) == -EPERM) {
 		rt = NULL;
-		break;
-	default:
-		return ERR_PTR(err);
-	}
+	} else
+		return rt;
 
 	err = xfrm_decode_session_reverse(skb_in, &fl, AF_INET);
 	if (err)
@@ -438,22 +434,18 @@
 	if (err)
 		goto relookup_failed;
 
-	err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL,
-			  XFRM_LOOKUP_ICMP);
-	switch (err) {
-	case 0:
+	rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, &fl, NULL, XFRM_LOOKUP_ICMP);
+	if (!IS_ERR(rt2)) {
 		dst_release(&rt->dst);
 		rt = rt2;
-		break;
-	case -EPERM:
-		return ERR_PTR(err);
-	default:
-		if (!rt)
-			return ERR_PTR(err);
-		break;
+	} else if (PTR_ERR(rt2) == -EPERM) {
+		if (rt)
+			dst_release(&rt->dst);
+		return rt2;
+	} else {
+		err = PTR_ERR(rt2);
+		goto relookup_failed;
 	}
-
-
 	return rt;
 
 relookup_failed:
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 994a1f2..9770bb4 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -69,7 +69,8 @@
 	    xfrm_decode_session(skb, &fl, AF_INET) == 0) {
 		struct dst_entry *dst = skb_dst(skb);
 		skb_dst_set(skb, NULL);
-		if (xfrm_lookup(net, &dst, &fl, skb->sk, 0))
+		dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
+		if (IS_ERR(dst))
 			return -1;
 		skb_dst_set(skb, dst);
 	}
@@ -102,7 +103,8 @@
 		dst = ((struct xfrm_dst *)dst)->route;
 	dst_hold(dst);
 
-	if (xfrm_lookup(dev_net(dst->dev), &dst, &fl, skb->sk, 0) < 0)
+	dst = xfrm_lookup(dev_net(dst->dev), dst, &fl, skb->sk, 0);
+	if (IS_ERR(dst))
 		return -1;
 
 	skb_dst_drop(skb);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e24e4cf..63d3700 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2730,7 +2730,12 @@
 			flp->fl4_src = (*rp)->rt_src;
 		if (!flp->fl4_dst)
 			flp->fl4_dst = (*rp)->rt_dst;
-		return xfrm_lookup(net, (struct dst_entry **)rp, flp, sk, 0);
+		*rp = (struct rtable *) xfrm_lookup(net, &(*rp)->dst, flp, sk, 0);
+		if (IS_ERR(*rp)) {
+			err = PTR_ERR(*rp);
+			*rp = NULL;
+			return err;
+		}
 	}
 
 	return 0;