ip_tunnel: Add ip tunnel dst_cache in ip_md_tunnel_xmit

Add ip tunnel dst cache in ip_md_tunnel_xmit to make more
efficient for the route lookup.

Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index c4f5602308edca064297fe8764764f65ebe84569..f98fc4c983a506f996661c1f6cb6010fcbe374e8 100644 (file)
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -555,10 +555,11 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, u8 proto)
        struct ip_tunnel_info *tun_info;
        const struct ip_tunnel_key *key;
        const struct iphdr *inner_iph;
-       struct rtable *rt;
+       struct rtable *rt = NULL;
        struct flowi4 fl4;
        __be16 df = 0;
        u8 tos, ttl;
+       bool use_cache;
 
        tun_info = skb_tunnel_info(skb);
        if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
@@ -578,10 +579,19 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, u8 proto)
                            RT_TOS(tos), tunnel->parms.link, tunnel->fwmark);
        if (tunnel->encap.type != TUNNEL_ENCAP_NONE)
                goto tx_error;
-       rt = ip_route_output_key(tunnel->net, &fl4);
-       if (IS_ERR(rt)) {
-               dev->stats.tx_carrier_errors++;
-               goto tx_error;
+
+       use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
+       if (use_cache)
+               rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl4.saddr);
+       if (!rt) {
+               rt = ip_route_output_key(tunnel->net, &fl4);
+               if (IS_ERR(rt)) {
+                       dev->stats.tx_carrier_errors++;
+                       goto tx_error;
+               }
+               if (use_cache)
+                       dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
+                                         fl4.saddr);
        }
        if (rt->dst.dev == dev) {
                ip_rt_put(rt);