Commit ed6e380d authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

neighbour: Convert RTM_GETNEIGH to RCU. 



Only __dev_get_by_index() is the RTNL dependant in neigh_get().

Let's replace it with dev_get_by_index_rcu() and convert RTM_GETNEIGH
to RCU.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-10-kuniyu@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cc03492c

net/core/neighbour.c

+15 −10
Original line number Diff line number Diff line
@@ -3049,27 +3049,29 @@ static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
	if (!skb)

		return -ENOBUFS;



	rcu_read_lock();



	tbl = neigh_find_table(ndm->ndm_family);

	if (!tbl) {

		NL_SET_ERR_MSG(extack, "Unsupported family in header for neighbor get request");

		err = -EAFNOSUPPORT;

		goto err_free_skb;

		goto err_unlock;

	}



	if (nla_len(tb[NDA_DST]) != (int)tbl->key_len) {

		NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request");

		err = -EINVAL;

		goto err_free_skb;

		goto err_unlock;

	}



	dst = nla_data(tb[NDA_DST]);



	if (ndm->ndm_ifindex) {

		dev = __dev_get_by_index(net, ndm->ndm_ifindex);

		dev = dev_get_by_index_rcu(net, ndm->ndm_ifindex);

		if (!dev) {

			NL_SET_ERR_MSG(extack, "Unknown device ifindex");

			err = -ENODEV;

			goto err_free_skb;

			goto err_unlock;

		}

	}
@@ -3080,28 +3082,31 @@ static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
		if (!pn) {

			NL_SET_ERR_MSG(extack, "Proxy neighbour entry not found");

			err = -ENOENT;

			goto err_free_skb;

			goto err_unlock;

		}



		err = pneigh_fill_info(skb, pn, pid, seq, RTM_NEWNEIGH, 0, tbl);

		if (err)

			goto err_free_skb;

			goto err_unlock;

	} else {

		neigh = neigh_lookup(tbl, dst, dev);

		if (!neigh) {

			NL_SET_ERR_MSG(extack, "Neighbour entry not found");

			err = -ENOENT;

			goto err_free_skb;

			goto err_unlock;

		}



		err = neigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0);

		neigh_release(neigh);

		if (err)

			goto err_free_skb;

			goto err_unlock;

	}



	rcu_read_unlock();



	return rtnl_unicast(skb, net, pid);

err_free_skb:

err_unlock:

	rcu_read_unlock();

	kfree_skb(skb);

	return err;

}
@@ -3904,7 +3909,7 @@ static const struct rtnl_msg_handler neigh_rtnl_msg_handlers[] __initconst = { 
	{.msgtype = RTM_NEWNEIGH, .doit = neigh_add},

	{.msgtype = RTM_DELNEIGH, .doit = neigh_delete},

	{.msgtype = RTM_GETNEIGH, .doit = neigh_get, .dumpit = neigh_dump_info,

	 .flags = RTNL_FLAG_DUMP_UNLOCKED},

	 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},

	{.msgtype = RTM_GETNEIGHTBL, .dumpit = neightbl_dump_info},

	{.msgtype = RTM_SETNEIGHTBL, .doit = neightbl_set},

};