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Commit a3d12891 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

rtnetlink: rtnl_setlink() and rtnl_getlink() changes 



rtnl_getlink() & rtnl_setlink() run with RTNL held, we can use
__dev_get_by_index() and __dev_get_by_name() variants and avoid
dev_hold()/dev_put()

Adds to rtnl_getlink() the capability to find a device by its name,
not only by its index.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a61f8026

net/core/rtnetlink.c

+19 −19
Original line number Diff line number Diff line
@@ -910,9 +910,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	err = -EINVAL;

	ifm = nlmsg_data(nlh);

	if (ifm->ifi_index > 0)

		dev = dev_get_by_index(net, ifm->ifi_index);

		dev = __dev_get_by_index(net, ifm->ifi_index);

	else if (tb[IFLA_IFNAME])

		dev = dev_get_by_name(net, ifname);

		dev = __dev_get_by_name(net, ifname);

	else

		goto errout;
@@ -922,11 +922,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	}



	if ((err = validate_linkmsg(dev, tb)) < 0)

		goto errout_dev;

		goto errout;



	err = do_setlink(dev, ifm, tb, ifname, 0);

errout_dev:

	dev_put(dev);

errout:

	return err;

}
@@ -1154,6 +1152,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 
{

	struct net *net = sock_net(skb->sk);

	struct ifinfomsg *ifm;

	char ifname[IFNAMSIZ];

	struct nlattr *tb[IFLA_MAX+1];

	struct net_device *dev = NULL;

	struct sk_buff *nskb;
@@ -1163,19 +1162,23 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 
	if (err < 0)

		return err;



	if (tb[IFLA_IFNAME])

		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);



	ifm = nlmsg_data(nlh);

	if (ifm->ifi_index > 0) {

		dev = dev_get_by_index(net, ifm->ifi_index);

	if (ifm->ifi_index > 0)

		dev = __dev_get_by_index(net, ifm->ifi_index);

	else if (tb[IFLA_IFNAME])

		dev = __dev_get_by_name(net, ifname);

	else

		return -EINVAL;



	if (dev == NULL)

		return -ENODEV;

	} else

		return -EINVAL;



	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);

	if (nskb == NULL) {

		err = -ENOBUFS;

		goto errout;

	}

	if (nskb == NULL)

		return -ENOBUFS;



	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,

			       nlh->nlmsg_seq, 0, 0);
@@ -1183,11 +1186,8 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 
		/* -EMSGSIZE implies BUG in if_nlmsg_size */

		WARN_ON(err == -EMSGSIZE);

		kfree_skb(nskb);

		goto errout;

	}

	} else

		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);

errout:

	dev_put(dev);



	return err;

}