ip_tunnel: Add ip tunnel tun_info type dst_cache in ip_tunnel_xmit

ip l add dev tun type gretap key 1000

Non-tunnel-dst ip tunnel device can send packet through lwtunnel
This patch provide the tun_inf dst cache support for this mode.

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 893f013..2973067 100644 (file)
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -654,14 +654,17 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
                    const struct iphdr *tnl_params, u8 protocol)
 {
        struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct ip_tunnel_info *tun_info = NULL;
        const struct iphdr *inner_iph;
-       struct flowi4 fl4;
-       u8     tos, ttl;
-       __be16 df;
-       struct rtable *rt;              /* Route to the other host */
        unsigned int max_headroom;      /* The extra header space needed */
-       __be32 dst;
+       struct rtable *rt = NULL;               /* Route to the other host */
+       bool use_cache = false;
+       struct flowi4 fl4;
+       bool md = false;
        bool connected;
+       u8 tos, ttl;
+       __be32 dst;
+       __be16 df;
 
        inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
        connected = (tunnel->parms.iph.daddr != 0);
@@ -671,7 +674,6 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
        dst = tnl_params->daddr;
        if (dst == 0) {
                /* NBMA tunnel */
-               struct ip_tunnel_info *tun_info;
 
                if (!skb_dst(skb)) {
                        dev->stats.tx_fifo_errors++;
@@ -681,8 +683,11 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
                tun_info = skb_tunnel_info(skb);
                if (tun_info && (tun_info->mode & IP_TUNNEL_INFO_TX) &&
                    ip_tunnel_info_af(tun_info) == AF_INET &&
-                   tun_info->key.u.ipv4.dst)
+                   tun_info->key.u.ipv4.dst) {
                        dst = tun_info->key.u.ipv4.dst;
+                       md = true;
+                       connected = true;
+               }
                else if (skb->protocol == htons(ETH_P_IP)) {
                        rt = skb_rtable(skb);
                        dst = rt_nexthop(rt, inner_iph->daddr);
@@ -721,7 +726,8 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
                else
                        goto tx_error;
 
-               connected = false;
+               if (!md)
+                       connected = false;
        }
 
        tos = tnl_params->tos;
@@ -743,8 +749,15 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
        if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
                goto tx_error;
 
-       rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr) :
-                        NULL;
+       if (connected && md) {
+               use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
+               if (use_cache)
+                       rt = dst_cache_get_ip4(&tun_info->dst_cache,
+                                              &fl4.saddr);
+       } else {
+               rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache,
+                                               &fl4.saddr) : NULL;
+       }
 
        if (!rt) {
                rt = ip_route_output_key(tunnel->net, &fl4);
@@ -753,7 +766,10 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
                        dev->stats.tx_carrier_errors++;
                        goto tx_error;
                }
-               if (connected)
+               if (use_cache)
+                       dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
+                                         fl4.saddr);
+               else if (!md && connected)
                        dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst,
                                          fl4.saddr);
        }