diff options
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 36 |
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 |