sit: use dst_cache in ipip6_tunnel_xmit

Same as other ip tunnel, use dst_cache in xmit action to avoid
unnecessary fib lookups.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 8061089..b2ccbc4 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -900,12 +900,17 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
                           RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
                           0, dst, tiph->saddr, 0, 0,
                           sock_net_uid(tunnel->net, NULL));
-       rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 
-       if (IS_ERR(rt)) {
-               dev->stats.tx_carrier_errors++;
-               goto tx_error_icmp;
+       rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
+       if (!rt) {
+               rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
+               if (IS_ERR(rt)) {
+                       dev->stats.tx_carrier_errors++;
+                       goto tx_error_icmp;
+               }
+               dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
        }
+
        if (rt->rt_type != RTN_UNICAST) {
                ip_rt_put(rt);
                dev->stats.tx_carrier_errors++;