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Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c36
1 files changed, 33 insertions, 3 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index cd76b3cb709..278f46f5011 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1085,8 +1085,35 @@ restart:
now = jiffies;
if (!rt_caching(dev_net(rt->u.dst.dev))) {
- rt_drop(rt);
- return 0;
+ /*
+ * If we're not caching, just tell the caller we
+ * were successful and don't touch the route. The
+ * caller hold the sole reference to the cache entry, and
+ * it will be released when the caller is done with it.
+ * If we drop it here, the callers have no way to resolve routes
+ * when we're not caching. Instead, just point *rp at rt, so
+ * the caller gets a single use out of the route
+ * Note that we do rt_free on this new route entry, so that
+ * once its refcount hits zero, we are still able to reap it
+ * (Thanks Alexey)
+ * Note also the rt_free uses call_rcu. We don't actually
+ * need rcu protection here, this is just our path to get
+ * on the route gc list.
+ */
+
+ if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
+ int err = arp_bind_neighbour(&rt->u.dst);
+ if (err) {
+ if (net_ratelimit())
+ printk(KERN_WARNING
+ "Neighbour table failure & not caching routes.\n");
+ rt_drop(rt);
+ return err;
+ }
+ }
+
+ rt_free(rt);
+ goto skip_hashing;
}
rthp = &rt_hash_table[hash].chain;
@@ -1203,7 +1230,8 @@ restart:
#if RT_CACHE_DEBUG >= 2
if (rt->u.dst.rt_next) {
struct rtable *trt;
- printk(KERN_DEBUG "rt_cache @%02x: %pI4", hash, &rt->rt_dst);
+ printk(KERN_DEBUG "rt_cache @%02x: %pI4",
+ hash, &rt->rt_dst);
for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
printk(" . %pI4", &trt->rt_dst);
printk("\n");
@@ -1217,6 +1245,8 @@ restart:
rcu_assign_pointer(rt_hash_table[hash].chain, rt);
spin_unlock_bh(rt_hash_lock_addr(hash));
+
+skip_hashing:
if (rp)
*rp = rt;
else