From b17adf073594974b05a60ddaaa6e36da4eac4831 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>
Date: Mon, 10 May 2021 19:49:43 +0200
Subject: [PATCH] BSD: Propagate OS-level IFF_MULTICAST to internal
 IF_MULTICAST flag

The BSD code did not propagate the OS-level IFF_MULTICAST flag to the
Bird-internal IF_MULTICAST flag, which causes problems with Wireguard
interfaces on FreeBSD. The Linux sysdep code does propagate the flag
already, so just copy over the same check and flag update.
---
 sysdep/bsd/krt-sock.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sysdep/bsd/krt-sock.c b/sysdep/bsd/krt-sock.c
index ea0cc4d9..5c905bc9 100644
--- a/sysdep/bsd/krt-sock.c
+++ b/sysdep/bsd/krt-sock.c
@@ -665,6 +665,9 @@ krt_read_ifinfo(struct ks_msg *msg, int scan)
   else
     f.flags |= IF_MULTIACCESS;      /* NBMA */
 
+  if (fl & IFF_MULTICAST)
+    f.flags |= IF_MULTICAST;
+
   iface = if_update(&f);
 
   if (!scan)