vti6: Support inter address family tunneling.

With this patch we can tunnel ipv4 traffic via a vti6
interface. A vti6 interface can now have an ipv4 address
and ipv4 traffic can be routed via a vti6 interface.
The resulting traffic is xfrm transformed and tunneled
through ipv6 if matching IPsec policies and states are
present.

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

1 files changed, 34 insertions, 15 deletions

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 226854a3c392..8d189aae7c96 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -380,30 +380,22 @@ vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
  * vti6_xmit - send a packet
  *   @skb: the outgoing socket buffer
  *   @dev: the outgoing tunnel device
+ *   @fl: the flow informations for the xfrm_lookup
  **/
-static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
+static int
+vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 {
         struct ip6_tnl *t = netdev_priv(dev);
         struct net_device_stats *stats = &t->dev->stats;
         struct dst_entry *dst = skb_dst(skb);
-        struct flowi fl;
-        struct ipv6hdr *ipv6h = ipv6_hdr(skb);
         struct net_device *tdev;
         int err = -1;
 
-        if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
-            !ip6_tnl_xmit_ctl(t) || vti6_addr_conflict(t, ipv6h))
-                return err;
-
-        memset(&fl, 0, sizeof(fl));
-        skb->mark = be32_to_cpu(t->parms.o_key);
-        xfrm_decode_session(skb, &fl, AF_INET6);
-
         if (!dst)
                 goto tx_err_link_failure;
 
         dst_hold(dst);
-        dst = xfrm_lookup(t->net, dst, &fl, NULL, 0);
+        dst = xfrm_lookup(t->net, dst, fl, NULL, 0);
         if (IS_ERR(dst)) {
                 err = PTR_ERR(dst);
                 dst = NULL;
@@ -422,12 +414,22 @@ static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
                 goto tx_err_dst_release;
         }
 
-        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);
+        err = dst_output(skb);
+        if (net_xmit_eval(err) == 0) {
+                struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
+
+                u64_stats_update_begin(&tstats->syncp);
+                tstats->tx_bytes += skb->len;
+                tstats->tx_packets++;
+                u64_stats_update_end(&tstats->syncp);
+        } else {
+                stats->tx_errors++;
+                stats->tx_aborted_errors++;
+        }
 
         return 0;
 tx_err_link_failure:
@@ -443,16 +445,33 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct ip6_tnl *t = netdev_priv(dev);
         struct net_device_stats *stats = &t->dev->stats;
+        struct ipv6hdr *ipv6h;
+        struct flowi fl;
         int ret;
 
+        memset(&fl, 0, sizeof(fl));
+        skb->mark = be32_to_cpu(t->parms.o_key);
+
         switch (skb->protocol) {
         case htons(ETH_P_IPV6):
-                ret = vti6_xmit(skb, dev);
+                ipv6h = ipv6_hdr(skb);
+
+                if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
+                    !ip6_tnl_xmit_ctl(t) || vti6_addr_conflict(t, ipv6h))
+                        goto tx_err;
+
+                xfrm_decode_session(skb, &fl, AF_INET6);
+                memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+                break;
+        case htons(ETH_P_IP):
+                xfrm_decode_session(skb, &fl, AF_INET);
+                memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
                 break;
         default:
                 goto tx_err;
         }
 
+        ret = vti6_xmit(skb, dev, &fl);
         if (ret < 0)
                 goto tx_err;