netlink: support setting devgroup parameters

If a rtnetlink request specifies a negative or zero ifindex and has no
interface name attribute, but has a group attribute, then the chenges
are made to all the interfaces belonging to the specified group.

Signed-off-by: Vlad Dogaru <ddvlad@rosedu.org>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 4 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 09062b07bf7f..a0b2eeb3b610 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1558,6 +1558,24 @@ err:
 }
 EXPORT_SYMBOL(rtnl_create_link);
 
+static int rtnl_group_changelink(struct net *net, int group,
+                struct ifinfomsg *ifm,
+                struct nlattr **tb)
+{
+        struct net_device *dev;
+        int err;
+
+        for_each_netdev(net, dev) {
+                if (dev->group == group) {
+                        err = do_setlink(dev, ifm, tb, NULL, 0);
+                        if (err < 0)
+                                return err;
+                }
+        }
+
+        return 0;
+}
+
 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
         struct net *net = sock_net(skb->sk);
@@ -1585,10 +1603,16 @@ replay:
         ifm = nlmsg_data(nlh);
         if (ifm->ifi_index > 0)
                 dev = __dev_get_by_index(net, ifm->ifi_index);
-        else if (ifname[0])
-                dev = __dev_get_by_name(net, ifname);
-        else
-                dev = NULL;
+        else {
+                if (ifname[0])
+                        dev = __dev_get_by_name(net, ifname);
+                else if (tb[IFLA_GROUP])
+                        return rtnl_group_changelink(net,
+                                        nla_get_u32(tb[IFLA_GROUP]),
+                                        ifm, tb);
+                else
+                        dev = NULL;
+        }
 
         err = validate_linkmsg(dev, tb);
         if (err < 0)