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Commit fc1e64e1 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net/ipv6: Add support for onlink flag 



Similar to IPv4 allow routes to be added with the RTNH_F_ONLINK flag.
The onlink option requires a gateway and a nexthop device. Any unicast
gateway is allowed (including IPv4 mapped addresses and unresolved
ones) as long as the gateway is not a local address and if it resolves
it must match the given device.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f4797b33

net/ipv6/route.c

+50 −1
Original line number Diff line number Diff line
@@ -2470,6 +2470,31 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net, 
	return rt;

}



static int ip6_route_check_nh_onlink(struct net *net,

				     struct fib6_config *cfg,

				     struct net_device *dev,

				     struct netlink_ext_ack *extack)

{

	u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;

	const struct in6_addr *gw_addr = &cfg->fc_gateway;

	u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;

	struct rt6_info *grt;

	int err;



	err = 0;

	grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);

	if (grt) {

		if (grt->rt6i_flags & flags || dev != grt->dst.dev) {

			NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");

			err = -EINVAL;

		}



		ip6_rt_put(grt);

	}



	return err;

}



static int ip6_route_check_nh(struct net *net,

			      struct fib6_config *cfg,

			      struct net_device **_dev,
@@ -2572,6 +2597,21 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
	if (cfg->fc_metric == 0)

		cfg->fc_metric = IP6_RT_PRIO_USER;



	if (cfg->fc_flags & RTNH_F_ONLINK) {

		if (!dev) {

			NL_SET_ERR_MSG(extack,

				       "Nexthop device required for onlink");

			err = -ENODEV;

			goto out;

		}



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

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

			err = -ENETDOWN;

			goto out;

		}

	}



	err = -ENOBUFS;

	if (cfg->fc_nlinfo.nlh &&

	    !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
@@ -2732,7 +2772,12 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
				goto out;

			}



			if (cfg->fc_flags & RTNH_F_ONLINK) {

				err = ip6_route_check_nh_onlink(net, cfg, dev,

								extack);

			} else {

				err = ip6_route_check_nh(net, cfg, &dev, &idev);

			}

			if (err)

				goto out;

		}
@@ -2774,6 +2819,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
	if (!(rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST)) &&

	    !netif_carrier_ok(dev))

		rt->rt6i_nh_flags |= RTNH_F_LINKDOWN;

	rt->rt6i_nh_flags |= (cfg->fc_flags & RTNH_F_ONLINK);

	rt->dst.dev = dev;

	rt->rt6i_idev = idev;

	rt->rt6i_table = table;
@@ -3843,6 +3889,8 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (rtm->rtm_flags & RTM_F_CLONED)

		cfg->fc_flags |= RTF_CACHE;



	cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);



	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;

	cfg->fc_nlinfo.nlh = nlh;

	cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
@@ -4248,6 +4296,7 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct rt6_info *rt, 
			goto nla_put_failure;

	}



	*flags |= (rt->rt6i_nh_flags & RTNH_F_ONLINK);

	if (rt->rt6i_nh_flags & RTNH_F_OFFLOAD)

		*flags |= RTNH_F_OFFLOAD;