ipv4/route/rtnl: get mcast attributes when dst is multicast

Commit f1ce3062c538 (ipv4: Remove 'rt_dst' from 'struct rtable') removes the
call to ipmr_get_route(), which will get multicast parameters of the route.

I revert the part of the patch that remove this call. I think the goal was only
to get rid of rt_dst field.

The patch is only compiled-tested. My first idea was to remove ipmr_get_route()
because rt_fill_info() was the only user, but it seems the previous patch cleans
the code a bit too much ;-)

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

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index baa9b289d7ab4b0a3780872ed1d05d62b9293665..844a9ef60dbd89f459515101ebb0db6e7cfaa8a3 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2232,8 +2232,27 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src,
        error = rt->dst.error;
 
        if (rt_is_input_route(rt)) {
-               if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
-                       goto nla_put_failure;
+#ifdef CONFIG_IP_MROUTE
+               if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
+                   IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
+                       int err = ipmr_get_route(net, skb,
+                                                fl4->saddr, fl4->daddr,
+                                                r, nowait);
+                       if (err <= 0) {
+                               if (!nowait) {
+                                       if (err == 0)
+                                               return 0;
+                                       goto nla_put_failure;
+                               } else {
+                                       if (err == -EMSGSIZE)
+                                               goto nla_put_failure;
+                                       error = err;
+                               }
+                       }
+               } else
+#endif
+                       if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
+                               goto nla_put_failure;
        }
 
        if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)