ipv6: Be smarter with null_entry handling in ip6_pol_route_lookup

Clean up the fib6_null_entry handling in ip6_pol_route_lookup.
rt6_device_match can return fib6_null_entry, but fib6_multipath_select
can not. Consolidate the fib6_null_entry handling and on the final
null_entry check set rt and goto out - no need to defer to a second
check after rt6_find_cached_rt.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2019-04-09 14:41:16 -07:00 committed by David S. Miller
parent 30c15f0338
commit af52a52cba
1 changed files with 13 additions and 12 deletions

View File

@ -1062,36 +1062,37 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
f6i = rcu_dereference(fn->leaf);
if (!f6i) {
if (!f6i)
f6i = net->ipv6.fib6_null_entry;
} else {
else
f6i = rt6_device_match(net, f6i, &fl6->saddr,
fl6->flowi6_oif, flags);
if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0)
f6i = fib6_multipath_select(net, f6i, fl6,
fl6->flowi6_oif, skb,
flags);
}
if (f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto restart;
rt = net->ipv6.ip6_null_entry;
dst_hold(&rt->dst);
goto out;
}
trace_fib6_table_lookup(net, f6i, table, fl6);
if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0)
f6i = fib6_multipath_select(net, f6i, fl6, fl6->flowi6_oif, skb,
flags);
/* Search through exception table */
rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
if (rt) {
if (ip6_hold_safe(net, &rt))
dst_use_noref(&rt->dst, jiffies);
} else if (f6i == net->ipv6.fib6_null_entry) {
rt = net->ipv6.ip6_null_entry;
dst_hold(&rt->dst);
} else {
rt = ip6_create_rt_rcu(f6i);
}
out:
trace_fib6_table_lookup(net, f6i, table, fl6);
rcu_read_unlock();
return rt;