Commit 5b98324e authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

ipv6: Allow routes to use nexthop objects 



Add support for RTA_NH_ID attribute to allow a user to specify a
nexthop id to use with a route. fc_nh_id is added to fib6_config to
hold the value passed in the RTA_NH_ID attribute. If a nexthop id
is given, the gateway, device, encap and multipath attributes can
not be set.

Update ip6_route_del to check metric and protocol before nexthop
specs. If fc_nh_id is set, then it must match the id in the route
entry. Since IPv6 allows delete of a cached entry (an exception),
add ip6_del_cached_rt_nh to cycle through all of the fib6_nh in
a fib entry if it is using a nexthop.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6c48ea5f

include/net/ip6_fib.h

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct fib6_config { 
	u16		fc_delete_all_nh : 1,

			fc_ignore_dev_down:1,

			__unused : 14;

	u32		fc_nh_id;



	struct in6_addr	fc_dst;

	struct in6_addr	fc_src;

net/ipv6/route.c

+81 −8
Original line number Diff line number Diff line
@@ -3531,6 +3531,16 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, 
		goto out;

	}

#endif

	if (cfg->fc_nh_id) {

		nh = nexthop_find_by_id(net, cfg->fc_nh_id);

		if (!nh) {

			NL_SET_ERR_MSG(extack, "Nexthop id does not exist");

			goto out;

		}

		err = fib6_check_nexthop(nh, cfg, extack);

		if (err)

			goto out;

	}



	err = -ENOBUFS;

	if (cfg->fc_nlinfo.nlh &&
@@ -3762,6 +3772,30 @@ static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt, 
	return 0;

}



struct fib6_nh_del_cached_rt_arg {

	struct fib6_config *cfg;

	struct fib6_info *f6i;

};



static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)

{

	struct fib6_nh_del_cached_rt_arg *arg = _arg;

	int rc;



	rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);

	return rc != -ESRCH ? rc : 0;

}



static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)

{

	struct fib6_nh_del_cached_rt_arg arg = {

		.cfg = cfg,

		.f6i = f6i

	};



	return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);

}



static int ip6_route_del(struct fib6_config *cfg,

			 struct netlink_ext_ack *extack)

{
@@ -3787,11 +3821,20 @@ static int ip6_route_del(struct fib6_config *cfg, 
		for_each_fib6_node_rt_rcu(fn) {

			struct fib6_nh *nh;



			nh = rt->fib6_nh;

			if (rt->nh && rt->nh->id != cfg->fc_nh_id)

				continue;



			if (cfg->fc_flags & RTF_CACHE) {

				int rc;

				int rc = 0;



				if (rt->nh) {

					rc = ip6_del_cached_rt_nh(cfg, rt);

				} else if (cfg->fc_nh_id) {

					continue;

				} else {

					nh = rt->fib6_nh;

					rc = ip6_del_cached_rt(cfg, rt, nh);

				}

				if (rc != -ESRCH) {

					rcu_read_unlock();

					return rc;
@@ -3799,6 +3842,23 @@ static int ip6_route_del(struct fib6_config *cfg, 
				continue;

			}



			if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)

				continue;

			if (cfg->fc_protocol &&

			    cfg->fc_protocol != rt->fib6_protocol)

				continue;



			if (rt->nh) {

				if (!fib6_info_hold_safe(rt))

					continue;

				rcu_read_unlock();



				return __ip6_del_rt(rt, &cfg->fc_nlinfo);

			}

			if (cfg->fc_nh_id)

				continue;



			nh = rt->fib6_nh;

			if (cfg->fc_ifindex &&

			    (!nh->fib_nh_dev ||

			     nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
@@ -3806,10 +3866,6 @@ static int ip6_route_del(struct fib6_config *cfg, 
			if (cfg->fc_flags & RTF_GATEWAY &&

			    !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))

				continue;

			if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)

				continue;

			if (cfg->fc_protocol && cfg->fc_protocol != rt->fib6_protocol)

				continue;

			if (!fib6_info_hold_safe(rt))

				continue;

			rcu_read_unlock();
@@ -4709,6 +4765,7 @@ static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 
	[RTA_IP_PROTO]		= { .type = NLA_U8 },

	[RTA_SPORT]		= { .type = NLA_U16 },

	[RTA_DPORT]		= { .type = NLA_U16 },

	[RTA_NH_ID]		= { .type = NLA_U32 },

};



static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -4755,6 +4812,16 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 


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



	if (tb[RTA_NH_ID]) {

		if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||

		    tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {

			NL_SET_ERR_MSG(extack,

				       "Nexthop specification and nexthop id are mutually exclusive");

			goto errout;

		}

		cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);

	}



	if (tb[RTA_GATEWAY]) {

		cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);

		cfg->fc_flags |= RTF_GATEWAY;
@@ -5089,6 +5156,12 @@ static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (err < 0)

		return err;



	if (cfg.fc_nh_id &&

	    !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {

		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");

		return -EINVAL;

	}



	if (cfg.fc_mp)

		return ip6_route_multipath_del(&cfg, extack);

	else {

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