vti6: Remove dst_entry caching

Unlike ip6_tunnel, vti6 can lookup multiple different dst entries,
dependent of the configured xfrm states. Therefore it does not make
sense to cache a dst_entry.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 18 insertions, 24 deletions

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 864914399391..f5ba4d42b4ae 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -278,7 +278,6 @@ static void vti6_dev_uninit(struct net_device *dev)
                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
         else
                 vti6_tnl_unlink(ip6n, t);
-        ip6_tnl_dst_reset(t);
         dev_put(dev);
 }
 
@@ -356,11 +355,10 @@ vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
  **/
 static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
 {
-        struct net *net = dev_net(dev);
         struct ip6_tnl *t = netdev_priv(dev);
         struct net_device_stats *stats = &t->dev->stats;
-        struct dst_entry *dst = NULL, *ndst = NULL;
-        struct flowi6 fl6;
+        struct dst_entry *dst = skb_dst(skb);
+        struct flowi fl;
         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
         struct net_device *tdev;
         int err = -1;
@@ -369,21 +367,19 @@ static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
             !ip6_tnl_xmit_ctl(t) || vti6_addr_conflict(t, ipv6h))
                 return err;
 
-        dst = ip6_tnl_dst_check(t);
-        if (!dst) {
-                memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
+        memset(&fl, 0, sizeof(fl));
+        skb->mark = be32_to_cpu(t->parms.o_key);
+        xfrm_decode_session(skb, &fl, AF_INET6);
 
-                ndst = ip6_route_output(net, NULL, &fl6);
+        if (!dst)
+                goto tx_err_link_failure;
 
-                if (ndst->error)
-                        goto tx_err_link_failure;
-                ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(&fl6), NULL, 0);
-                if (IS_ERR(ndst)) {
-                        err = PTR_ERR(ndst);
-                        ndst = NULL;
-                        goto tx_err_link_failure;
-                }
-                dst = ndst;
+        dst_hold(dst);
+        dst = xfrm_lookup(t->net, dst, &fl, NULL, 0);
+        if (IS_ERR(dst)) {
+                err = PTR_ERR(dst);
+                dst = NULL;
+                goto tx_err_link_failure;
         }
 
         if (!dst->xfrm || dst->xfrm->props.mode != XFRM_MODE_TUNNEL)
@@ -399,21 +395,19 @@ static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
         }
 
 
-        skb_dst_drop(skb);
-        skb_dst_set_noref(skb, dst);
+        memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+        skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
+        skb_dst_set(skb, dst);
+        skb->dev = skb_dst(skb)->dev;
 
         ip6tunnel_xmit(skb, dev);
-        if (ndst) {
-                dev->mtu = dst_mtu(ndst);
-                ip6_tnl_dst_store(t, ndst);
-        }
 
         return 0;
 tx_err_link_failure:
         stats->tx_carrier_errors++;
         dst_link_failure(skb);
 tx_err_dst_release:
-        dst_release(ndst);
+        dst_release(dst);
         return err;
 }