1 files changed, 72 insertions, 3 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index cb76e3c725a0..8603cfb271f2 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2396,7 +2396,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 
                 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
                 dev_out = ip_dev_find(oldflp->fl4_src);
-                if ((dev_out == NULL) && !(sysctl_ip_nonlocal_bind))
+                if (dev_out == NULL)
                         goto out;
 
                 /* I removed check for oif == dev_out->oif here.
@@ -2407,7 +2407,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                       of another iface. --ANK
                  */
 
-                if (dev_out && oldflp->oif == 0
+                if (oldflp->oif == 0
                     && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
                         /* Special hack: user can direct multicasts
                            and limited broadcast via necessary interface
@@ -2598,6 +2598,69 @@ int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
 
 EXPORT_SYMBOL_GPL(__ip_route_output_key);
 
+static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+}
+
+static struct dst_ops ipv4_dst_blackhole_ops = {
+        .family                 =       AF_INET,
+        .protocol               =       __constant_htons(ETH_P_IP),
+        .destroy                =       ipv4_dst_destroy,
+        .check                  =       ipv4_dst_check,
+        .update_pmtu            =       ipv4_rt_blackhole_update_pmtu,
+        .entry_size             =       sizeof(struct rtable),
+};
+
+
+static int ipv4_blackhole_output(struct sk_buff *skb)
+{
+        kfree_skb(skb);
+        return 0;
+}
+
+static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp, struct sock *sk)
+{
+        struct rtable *ort = *rp;
+        struct rtable *rt = (struct rtable *)
+                dst_alloc(&ipv4_dst_blackhole_ops);
+
+        if (rt) {
+                struct dst_entry *new = &rt->u.dst;
+
+                atomic_set(&new->__refcnt, 1);
+                new->__use = 1;
+                new->input = ipv4_blackhole_output;
+                new->output = ipv4_blackhole_output;
+                memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
+
+                new->dev = ort->u.dst.dev;
+                if (new->dev)
+                        dev_hold(new->dev);
+
+                rt->fl = ort->fl;
+
+                rt->idev = ort->idev;
+                if (rt->idev)
+                        in_dev_hold(rt->idev);
+                rt->rt_flags = ort->rt_flags;
+                rt->rt_type = ort->rt_type;
+                rt->rt_dst = ort->rt_dst;
+                rt->rt_src = ort->rt_src;
+                rt->rt_iif = ort->rt_iif;
+                rt->rt_gateway = ort->rt_gateway;
+                rt->rt_spec_dst = ort->rt_spec_dst;
+                rt->peer = ort->peer;
+                if (rt->peer)
+                        atomic_inc(&rt->peer->refcnt);
+
+                dst_free(new);
+        }
+
+        dst_release(&(*rp)->u.dst);
+        *rp = rt;
+        return (rt ? 0 : -ENOMEM);
+}
+
 int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
 {
         int err;
@@ -2610,7 +2673,11 @@ int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk,
                         flp->fl4_src = (*rp)->rt_src;
                 if (!flp->fl4_dst)
                         flp->fl4_dst = (*rp)->rt_dst;
-                return xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
+                err = __xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
+                if (err == -EREMOTE)
+                        err = ipv4_dst_blackhole(rp, flp, sk);
+
+                return err;
         }
 
         return 0;
@@ -3139,6 +3206,8 @@ int __init ip_rt_init(void)
                 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
 
+        ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
+
         rt_hash_table = (struct rt_hash_bucket *)
                 alloc_large_system_hash("IP route cache",
                                         sizeof(struct rt_hash_bucket),