net: blackhole route should always be recalculated

Jianzhao Wang · davem330 · commit ae2688d59b5f · 2010-09-08T14:35:43.000-07:00
Blackhole routes are used when xfrm_lookup() returns -EREMOTE (error triggered by IKE for example), hence this kind of route is always temporary and so we should check if a better route exists for next packets. Bug has been introduced by commit d11a4dc. Signed-off-by: Jianzhao Wang <jianzhao.wang@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
@@ -2738,6 +2738,11 @@ int __ip_route_output_key(struct net *net, struct rtable **rp,
 }
 EXPORT_SYMBOL_GPL(__ip_route_output_key);
 
+static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
+{
+	return NULL;
+}
+
 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
 {
 }
@@ -2746,7 +2751,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = {
 	.family			=	AF_INET,
 	.protocol		=	cpu_to_be16(ETH_P_IP),
 	.destroy		=	ipv4_dst_destroy,
-	.check			=	ipv4_dst_check,
+	.check			=	ipv4_blackhole_dst_check,
 	.update_pmtu		=	ipv4_rt_blackhole_update_pmtu,
 	.entries		=	ATOMIC_INIT(0),
 };

Original file line number	Diff line number	Diff line change
`@@ -2738,6 +2738,11 @@ int __ip_route_output_key(struct net net, struct rtable *rp,`
`2738`	`2738`	`}`
`2739`	`2739`	`EXPORT_SYMBOL_GPL(__ip_route_output_key);`
`2740`	`2740`
	`2741`	`+static struct dst_entry ipv4_blackhole_dst_check(struct dst_entry dst, u32 cookie)`
	`2742`	`+{`
	`2743`	`+ return NULL;`
	`2744`	`+}`
	`2745`	`+`
`2741`	`2746`	`static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)`
`2742`	`2747`	`{`
`2743`	`2748`	`}`
`@@ -2746,7 +2751,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = {`
`2746`	`2751`	`.family = AF_INET,`
`2747`	`2752`	`.protocol = cpu_to_be16(ETH_P_IP),`
`2748`	`2753`	`.destroy = ipv4_dst_destroy,`
`2749`		`- .check = ipv4_dst_check,`
	`2754`	`+ .check = ipv4_blackhole_dst_check,`
`2750`	`2755`	`.update_pmtu = ipv4_rt_blackhole_update_pmtu,`
`2751`	`2756`	`.entries = ATOMIC_INIT(0),`
`2752`	`2757`	`};`