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: dcb1ecb50edf (“ipv4: Prepare for fib6_nh from a nexthop object”)
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 4c81846ccce8c2e16e3effd0ab4573e07887255c..ab1ca9e238d2726507596b8a5408bc97a9f5e3d0 100644 (file)
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -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 */

diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 95f766c31c907fff2427de084e517fd1c3740073..331ebbc94fe7846ed3563b6050c1d24e0d9a150c 100644 (file)
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -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;
        }
 

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 2db089e10ba0ee524ce50cec26c19137002a9992..0913a090b2bf4232d82b6294051d4924052f66b1 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -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;

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 977cfd09e2a329bad2ab559c5b67c66fa0149e8b..85bcd97f7a72f7fac78ad04a21aa2f6ffd1b38eb 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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;