pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
- if (pcpu_rt)
- ip6_hold_safe(NULL, &pcpu_rt);
-
return pcpu_rt;
}
struct rt6_info *pcpu_rt, *prev, **p;
pcpu_rt = ip6_rt_pcpu_alloc(res);
- if (!pcpu_rt) {
- dst_hold(&net->ipv6.ip6_null_entry->dst);
- return net->ipv6.ip6_null_entry;
- }
+ if (!pcpu_rt)
+ return NULL;
- dst_hold(&pcpu_rt->dst);
p = this_cpu_ptr(res->nh->rt6i_pcpu);
prev = cmpxchg(p, NULL, pcpu_rt);
BUG_ON(prev);
const struct sk_buff *skb, int flags)
{
struct fib6_result res = {};
- struct rt6_info *rt;
+ struct rt6_info *rt = NULL;
int strict = 0;
+ WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
+ !rcu_read_lock_held());
+
strict |= flags & RT6_LOOKUP_F_IFACE;
strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
if (net->ipv6.devconf_all->forwarding == 0)
rcu_read_lock();
fib6_table_lookup(net, table, oif, fl6, &res, strict);
- if (res.f6i == net->ipv6.fib6_null_entry) {
- rt = net->ipv6.ip6_null_entry;
- rcu_read_unlock();
- dst_hold(&rt->dst);
- return rt;
- }
+ if (res.f6i == net->ipv6.fib6_null_entry)
+ goto out;
fib6_select_path(net, &res, fl6, oif, false, skb, strict);
/*Search through exception table */
rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
if (rt) {
- if (ip6_hold_safe(net, &rt))
- dst_use_noref(&rt->dst, jiffies);
-
- rcu_read_unlock();
- return rt;
+ goto out;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
!res.nh->fib_nh_gw_family)) {
/* Create a RTF_CACHE clone which will not be
* the daddr in the skb during the neighbor look-up is different
* from the fl6->daddr used to look-up route here.
*/
- struct rt6_info *uncached_rt;
+ rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
- uncached_rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
-
- rcu_read_unlock();
-
- if (uncached_rt) {
- /* Uncached_rt's refcnt is taken during ip6_rt_cache_alloc()
- * No need for another dst_hold()
+ if (rt) {
+ /* 1 refcnt is taken during ip6_rt_cache_alloc().
+ * As rt6_uncached_list_add() does not consume refcnt,
+ * this refcnt is always returned to the caller even
+ * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
*/
- rt6_uncached_list_add(uncached_rt);
+ rt6_uncached_list_add(rt);
atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
- } else {
- uncached_rt = net->ipv6.ip6_null_entry;
- dst_hold(&uncached_rt->dst);
- }
+ rcu_read_unlock();
- return uncached_rt;
+ return rt;
+ }
} else {
/* Get a percpu copy */
-
- struct rt6_info *pcpu_rt;
-
local_bh_disable();
- pcpu_rt = rt6_get_pcpu_route(&res);
+ rt = rt6_get_pcpu_route(&res);
- if (!pcpu_rt)
- pcpu_rt = rt6_make_pcpu_route(net, &res);
+ if (!rt)
+ rt = rt6_make_pcpu_route(net, &res);
local_bh_enable();
- rcu_read_unlock();
-
- return pcpu_rt;
}
+out:
+ if (!rt)
+ rt = net->ipv6.ip6_null_entry;
+ if (!(flags & RT6_LOOKUP_F_DST_NOREF))
+ ip6_hold_safe(net, &rt);
+ rcu_read_unlock();
+
+ return rt;
}
EXPORT_SYMBOL_GPL(ip6_pol_route);