ip6tnl: advertise tunnel param via rtnl

It is usefull for daemons that monitor link event to have the full parameters of
these interfaces when a rtnl message is sent.
It allows also to dump them via rtnetlink.

It is based on what is done for GRE tunnels.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 60 insertions, 0 deletions

diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h
index ccb21d585bf4..c1bf0b5a8da1 100644
--- a/include/uapi/linux/if_tunnel.h
+++ b/include/uapi/linux/if_tunnel.h
@@ -44,6 +44,9 @@ enum {
         IFLA_IPTUN_REMOTE,
         IFLA_IPTUN_TTL,
         IFLA_IPTUN_TOS,
+        IFLA_IPTUN_ENCAP_LIMIT,
+        IFLA_IPTUN_FLOWINFO,
+        IFLA_IPTUN_FLAGS,
         __IFLA_IPTUN_MAX,
 };
 #define IFLA_IPTUN_MAX  (__IFLA_IPTUN_MAX - 1)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 09482f723064..424ed45ef122 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -83,6 +83,7 @@ static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
 
 static int ip6_tnl_dev_init(struct net_device *dev);
 static void ip6_tnl_dev_setup(struct net_device *dev);
+static struct rtnl_link_ops ip6_link_ops __read_mostly;
 
 static int ip6_tnl_net_id __read_mostly;
 struct ip6_tnl_net {
@@ -299,6 +300,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
                 goto failed_free;
 
         strcpy(t->parms.name, dev->name);
+        dev->rtnl_link_ops = &ip6_link_ops;
 
         dev_hold(dev);
         ip6_tnl_link(ip6n, t);
@@ -1504,6 +1506,55 @@ static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
         return 0;
 }
 
+static size_t ip6_get_size(const struct net_device *dev)
+{
+        return
+                /* IFLA_IPTUN_LINK */
+                nla_total_size(4) +
+                /* IFLA_IPTUN_LOCAL */
+                nla_total_size(sizeof(struct in6_addr)) +
+                /* IFLA_IPTUN_REMOTE */
+                nla_total_size(sizeof(struct in6_addr)) +
+                /* IFLA_IPTUN_TTL */
+                nla_total_size(1) +
+                /* IFLA_IPTUN_ENCAP_LIMIT */
+                nla_total_size(1) +
+                /* IFLA_IPTUN_FLOWINFO */
+                nla_total_size(4) +
+                /* IFLA_IPTUN_FLAGS */
+                nla_total_size(4) +
+                0;
+}
+
+static int ip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+        struct ip6_tnl *tunnel = netdev_priv(dev);
+        struct __ip6_tnl_parm *parm = &tunnel->parms;
+
+        if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
+            nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
+                    &parm->raddr) ||
+            nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
+                    &parm->laddr) ||
+            nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
+            nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
+            nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
+            nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags))
+                goto nla_put_failure;
+        return 0;
+
+nla_put_failure:
+        return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops ip6_link_ops __read_mostly = {
+        .kind           = "ip6tnl",
+        .maxtype        = IFLA_IPTUN_MAX,
+        .priv_size      = sizeof(struct ip6_tnl),
+        .get_size       = ip6_get_size,
+        .fill_info      = ip6_fill_info,
+};
+
 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
         .handler        = ip4ip6_rcv,
         .err_handler    = ip4ip6_err,
@@ -1612,9 +1663,14 @@ static int __init ip6_tunnel_init(void)
                 pr_err("%s: can't register ip6ip6\n", __func__);
                 goto out_ip6ip6;
         }
+        err = rtnl_link_register(&ip6_link_ops);
+        if (err < 0)
+                goto rtnl_link_failed;
 
         return 0;
 
+rtnl_link_failed:
+        xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
 out_ip6ip6:
         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
 out_ip4ip6:
@@ -1629,6 +1685,7 @@ out_pernet:
 
 static void __exit ip6_tunnel_cleanup(void)
 {
+        rtnl_link_unregister(&ip6_link_ops);
         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
                 pr_info("%s: can't deregister ip4ip6\n", __func__);