[PATCH] OSPF: don't skip next-hop resolve for PtP link for v2 and v3 with IPv6

[Soha Jin via Bird-users]

This is a hack for Linux kernel, who does not support device-only routes for
IPv6 multipath.

Signed-off-by: Soha Jin <s...@jin.sh>
---
 proto/ospf/rt.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index efcd4e17..54372070 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -1796,13 +1796,6 @@ calc_next_hop(struct ospf_area *oa, struct 
top_hash_entry *en,
     if (ifa->type == OSPF_IT_VLINK)
       return new_nexthop(p, IPA_NONE, NULL, 0);
 
-    /*
-     * The type of the ospf_iface is PtP and the iface is a physical PtP link,
-     * so we can simply use the iface, and skip further resolving.
-     */
-    if (ifa->type == OSPF_IT_PTP && !(ifa->iface->flags & IF_MULTIACCESS))
-      return new_nexthop(p, IPA_NONE, ifa->iface, ifa->ecmp_weight);
-
     if (ospf_is_v2(p) || ospf_is_ip6(p))
     {
       /*
@@ -1819,6 +1812,15 @@ calc_next_hop(struct ospf_area *oa, struct 
top_hash_entry *en,
     }
     else
     {
+      /*
+       * The type of the ospf_iface is PtP and the iface is a physical PtP 
link,
+       * so we can simply use the iface, and skip further resolving.
+       * HACK: Linux kernel doesn't support device-only routes for IPv6
+       * multipath, that's why this if-branch is placed here rather than above.
+       */
+      if (ifa->type == OSPF_IT_PTP && !(ifa->iface->flags & IF_MULTIACCESS))
+       return new_nexthop(p, IPA_NONE, ifa->iface, ifa->ecmp_weight);
+
       /*
        * Next-hop is taken from lladdr field of Link-LSA, based on Neighbor
        * Iface ID (nif) field in our Router-LSA, which is just nbr->iface_id.
-- 
2.39.2