net: ipv4: Fix rtnexthop len when RTA_FLOW is present

[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ]

Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop()
to get the length of rtnexthop correct.

Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 2ec062a..4d431d7 100644 (file)
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -553,5 +553,5 @@ int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
                     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, u8 rt_family);
+                   int nh_weight, u8 rt_family, u32 nh_tclassid);
 #endif  /* _NET_FIB_H */

diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 4c8c9fe..fd87d72 100644 (file)
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -211,7 +211,7 @@ 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, rt_family) < 0)
+               if (fib_add_nexthop(skb, nhc, weight, rt_family, 0) < 0)
                        return -EMSGSIZE;
        }
 

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 1f75dc6..642503e 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1663,7 +1663,7 @@ 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, u8 rt_family)
+                   int nh_weight, u8 rt_family, u32 nh_tclassid)
 {
        const struct net_device *dev = nhc->nhc_dev;
        struct rtnexthop *rtnh;
@@ -1681,6 +1681,9 @@ int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
 
        rtnh->rtnh_flags = flags;
 
+       if (nh_tclassid && nla_put_u32(skb, RTA_FLOW, nh_tclassid))
+               goto nla_put_failure;
+
        /* length of rtnetlink header + attributes */
        rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
 
@@ -1708,14 +1711,13 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
        }
 
        for_nexthops(fi) {
-               if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,
-                                   AF_INET) < 0)
-                       goto nla_put_failure;
+               u32 nh_tclassid = 0;
 #ifdef CONFIG_IP_ROUTE_CLASSID
-               if (nh->nh_tclassid &&
-                   nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
-                       goto nla_put_failure;
+               nh_tclassid = nh->nh_tclassid;
 #endif
+               if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,
+                                   AF_INET, nh_tclassid) < 0)
+                       goto nla_put_failure;
        } endfor_nexthops(fi);
 
 mp_end:

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 168a7b4..a68a7d7 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5566,14 +5566,15 @@ 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, AF_INET6) < 0)
+                                   rt->fib6_nh->fib_nh_weight, AF_INET6,
+                                   0) < 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,
-                                           AF_INET6) < 0)
+                                           AF_INET6, 0) < 0)
                                goto nla_put_failure;
                }