bgpd: Do not start BGP session if BFD profile is in shutdown state

If we do:

```
bfd
 profile foo
  shutdown
```

The session is dropped, but immediately established again because we don't
have a proper check on BFD.

If BFD is administratively shutdown, ignore starting the session.

Fixes: https://github.com/FRRouting/frr/issues/16186

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/bfd.c b/lib/bfd.c
index 2222bb9547..4535fc1233 100644
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -1334,3 +1334,9 @@ int bfd_nht_update(const struct prefix *match, const struct zapi_route *route)
 
 	return 0;
 }
+
+bool bfd_session_is_down(const struct bfd_session_params *session)
+{
+	return session->bss.state == BSS_DOWN ||
+	       session->bss.state == BSS_ADMIN_DOWN;
+}