Add exceed merge path on limit

[Saklak, Marcin via Bird-users]

Hi All,
I’m wondering if it’s possible to add a log entry whenever the merged path 
limit is exceeded.
For example, a route can have 64 next hops, but BIRD export to the kernel up to 
merge limit and skip rest of next hops.
I’d like to be able to detect when this happens.

Below is a potential solution for that:

---
nest/rt-attr.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index c8ef8e08..ef118cb0 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -323,6 +323,8 @@ nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, 
int ry, int max, lin
     n = &((*n)->next);
   }
   *n = NULL;
+  if (max == -1)
+    log(L_ERR "Exceeded merge paths on limit!");

   return root;
}
--
2.34.1

If you have any suggestions or a better approach, please let me know!

Best regards,
Marcin Sakłak