Commit caa07457 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

nexthop: Move NHA_OIF validation to rtm_to_nh_config_rtnl(). 



NHA_OIF needs to look up a device by __dev_get_by_index(),
which requires RTNL.

Let's move NHA_OIF validation to rtm_to_nh_config_rtnl().

Note that the proceeding checks made the original !cfg->nh_fdb
check redundant.

  NHA_FDB is set           -> NHA_OIF cannot be set
  NHA_FDB is set but false -> NHA_OIF must be set
  NHA_FDB is not set       -> NHA_OIF must be set

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250319230743.65267-4-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 9b9674f3

net/ipv4/nexthop.c

+23 −20
Original line number Diff line number Diff line
@@ -3134,25 +3134,6 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 
		goto out;

	}



	if (!cfg->nh_fdb && tb[NHA_OIF]) {

		cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);

		if (cfg->nh_ifindex)

			cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);



		if (!cfg->dev) {

			NL_SET_ERR_MSG(extack, "Invalid device index");

			goto out;

		} else if (!(cfg->dev->flags & IFF_UP)) {

			NL_SET_ERR_MSG(extack, "Nexthop device is not up");

			err = -ENETDOWN;

			goto out;

		} else if (!netif_carrier_ok(cfg->dev)) {

			NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");

			err = -ENETDOWN;

			goto out;

		}

	}



	err = -EINVAL;

	if (tb[NHA_GATEWAY]) {

		struct nlattr *gwa = tb[NHA_GATEWAY];
@@ -3216,11 +3197,33 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 
}



static int rtm_to_nh_config_rtnl(struct net *net, struct nlattr **tb,

				 struct nh_config *cfg,

				 struct netlink_ext_ack *extack)

{

	if (tb[NHA_GROUP])

		return nh_check_attr_group_rtnl(net, tb, extack);



	if (tb[NHA_OIF]) {

		cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);

		if (cfg->nh_ifindex)

			cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);



		if (!cfg->dev) {

			NL_SET_ERR_MSG(extack, "Invalid device index");

			return -EINVAL;

		}



		if (!(cfg->dev->flags & IFF_UP)) {

			NL_SET_ERR_MSG(extack, "Nexthop device is not up");

			return -ENETDOWN;

		}



		if (!netif_carrier_ok(cfg->dev)) {

			NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");

			return -ENETDOWN;

		}

	}



	return 0;

}
@@ -3244,7 +3247,7 @@ static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (err)

		goto out;



	err = rtm_to_nh_config_rtnl(net, tb, extack);

	err = rtm_to_nh_config_rtnl(net, tb, &cfg, extack);

	if (err)

		goto out;