Commit 7bdf4de1 authored by Donald Sharp's avatar Donald Sharp Committed by David S. Miller
Browse files

net: Properly update v4 routes with v6 nexthop 



When creating a v4 route that uses a v6 nexthop from a nexthop group.
Allow the kernel to properly send the nexthop as v6 via the RTA_VIA
attribute.

Broken behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via 254.128.0.0 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

Fixed behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via inet6 fe80::9 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

v2, v3: Addresses code review comments from David Ahern

Fixes: dcb1ecb5 (“ipv4: Prepare for fib6_nh from a nexthop object”)
Signed-off-by: default avatarDonald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9752c83

include/net/ip_fib.h

+2 −2
Original line number Diff line number Diff line
@@ -513,7 +513,7 @@ int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 
			  struct netlink_callback *cb);



int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,

		     unsigned char *flags, bool skip_oif);

		     u8 rt_family, unsigned char *flags, bool skip_oif);

int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,

		    int nh_weight);

		    int nh_weight, u8 rt_family);

#endif  /* _NET_FIB_H */

include/net/nexthop.h

+3 −2
Original line number Diff line number Diff line
@@ -161,7 +161,8 @@ struct nexthop *nexthop_mpath_select(const struct nexthop *nh, int nhsel) 
}



static inline

int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh)

int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh,

			    u8 rt_family)

{

	struct nh_group *nhg = rtnl_dereference(nh->nh_grp);

	int i;
@@ -172,7 +173,7 @@ int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh) 
		struct fib_nh_common *nhc = &nhi->fib_nhc;

		int weight = nhg->nh_entries[i].weight;



		if (fib_add_nexthop(skb, nhc, weight) < 0)

		if (fib_add_nexthop(skb, nhc, weight, rt_family) < 0)

			return -EMSGSIZE;

	}

net/ipv4/fib_semantics.c

+8 −7
Original line number Diff line number Diff line
@@ -1582,7 +1582,7 @@ failure: 
}



int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,

		     unsigned char *flags, bool skip_oif)

		     u8 rt_family, unsigned char *flags, bool skip_oif)

{

	if (nhc->nhc_flags & RTNH_F_DEAD)

		*flags |= RTNH_F_DEAD;
@@ -1613,7 +1613,7 @@ int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc, 
		/* if gateway family does not match nexthop family

		 * gateway is encoded as RTA_VIA

		 */

		if (nhc->nhc_gw_family != nhc->nhc_family) {

		if (rt_family != nhc->nhc_gw_family) {

			int alen = sizeof(struct in6_addr);

			struct nlattr *nla;

			struct rtvia *via;
@@ -1654,7 +1654,7 @@ EXPORT_SYMBOL_GPL(fib_nexthop_info); 


#if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6)

int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,

		    int nh_weight)

		    int nh_weight, u8 rt_family)

{

	const struct net_device *dev = nhc->nhc_dev;

	struct rtnexthop *rtnh;
@@ -1667,7 +1667,7 @@ int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, 
	rtnh->rtnh_hops = nh_weight - 1;

	rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;



	if (fib_nexthop_info(skb, nhc, &flags, true) < 0)

	if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0)

		goto nla_put_failure;



	rtnh->rtnh_flags = flags;
@@ -1693,13 +1693,14 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) 
		goto nla_put_failure;



	if (unlikely(fi->nh)) {

		if (nexthop_mpath_fill_node(skb, fi->nh) < 0)

		if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0)

			goto nla_put_failure;

		goto mp_end;

	}



	for_nexthops(fi) {

		if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight) < 0)

		if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,

				    AF_INET) < 0)

			goto nla_put_failure;

#ifdef CONFIG_IP_ROUTE_CLASSID

		if (nh->nh_tclassid &&
@@ -1775,7 +1776,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, 
		const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);

		unsigned char flags = 0;



		if (fib_nexthop_info(skb, nhc, &flags, false) < 0)

		if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0)

			goto nla_put_failure;



		rtm->rtm_flags = flags;

net/ipv6/route.c

+6 −5
Original line number Diff line number Diff line
@@ -5333,7 +5333,7 @@ static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh, 
		if (!mp)

			goto nla_put_failure;



		if (nexthop_mpath_fill_node(skb, nh))

		if (nexthop_mpath_fill_node(skb, nh, AF_INET6))

			goto nla_put_failure;



		nla_nest_end(skb, mp);
@@ -5341,7 +5341,7 @@ static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh, 
		struct fib6_nh *fib6_nh;



		fib6_nh = nexthop_fib6_nh(nh);

		if (fib_nexthop_info(skb, &fib6_nh->nh_common,

		if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,

				     flags, false) < 0)

			goto nla_put_failure;

	}
@@ -5470,13 +5470,14 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, 
			goto nla_put_failure;



		if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,

				    rt->fib6_nh->fib_nh_weight) < 0)

				    rt->fib6_nh->fib_nh_weight, AF_INET6) < 0)

			goto nla_put_failure;



		list_for_each_entry_safe(sibling, next_sibling,

					 &rt->fib6_siblings, fib6_siblings) {

			if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,

					    sibling->fib6_nh->fib_nh_weight) < 0)

					    sibling->fib6_nh->fib_nh_weight,

					    AF_INET6) < 0)

				goto nla_put_failure;

		}
@@ -5493,7 +5494,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, 


		rtm->rtm_flags |= nh_flags;

	} else {

		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common,

		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,

				     &nh_flags, false) < 0)

			goto nla_put_failure;

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