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Commit 66c77ff3 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: addrlabel: rework ip6addrlbl_get() 



If we allocate skb before the lookup, we can use RCU
without the need of ip6addrlbl_hold()

This means that the following patch can get rid of refcounting.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ee87d7a

net/ipv6/addrlabel.c

+13 −23
Original line number Diff line number Diff line
@@ -546,38 +546,28 @@ static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
		return -EINVAL;

	addr = nla_data(tb[IFAL_ADDRESS]);



	rcu_read_lock();

	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);

	if (p && !ip6addrlbl_hold(p))

		p = NULL;

	lseq = net->ipv6.ip6addrlbl_table.seq;

	rcu_read_unlock();



	if (!p) {

		err = -ESRCH;

		goto out;

	}



	skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);

	if (!skb) {

		ip6addrlbl_put(p);

	if (!skb)

		return -ENOBUFS;

	}



	err = -ESRCH;



	rcu_read_lock();

	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);

	lseq = net->ipv6.ip6addrlbl_table.seq;

	if (p)

		err = ip6addrlbl_fill(skb, p, lseq,

			      NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,

				      NETLINK_CB(in_skb).portid,

				      nlh->nlmsg_seq,

				      RTM_NEWADDRLABEL, 0);



	ip6addrlbl_put(p);

	rcu_read_unlock();



	if (err < 0) {

		WARN_ON(err == -EMSGSIZE);

		kfree_skb(skb);

		goto out;

	}



	} else {

		err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);

out:

	}

	return err;

}