[PATCH] babel: Drop check for IF_MULTICAST interface flag

[Toke Høiland-Jørgensen]

The babel protocol code was checking interfaces for the IF_MULTICAST flag
and refusing to run if this isn't present. However, there are cases where
this flag doesn't correspond to the actual capability of sending multicast
packets. For instance, Wireguard interfaces on FreeBSD doesn't set the
required flags, but Babel will run just fine over such an interface given
the right configuration.

Since we're also checking for the presence of a link-local addresses right
below the flag check, we don't really need it. So let's just drop the check
and trust that users will only configure Babel on interfaces that can
handle the traffic.

Reported-by: Stefan Haller <stefan.haller at stha.de>
Signed-off-by: Toke Høiland-Jørgensen <toke at toke.dk>
---
 proto/babel/babel.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/proto/babel/babel.c b/proto/babel/babel.c
index 4b6b9d7f9f6f..297b86b06a46 100644
--- a/proto/babel/babel.c
+++ b/proto/babel/babel.c
@@ -1658,10 +1658,6 @@ babel_if_notify(struct proto *P, unsigned flags, struct iface *iface)
     if (!(iface->flags & IF_UP))
       return;
 
-    /* We only speak multicast */
-    if (!(iface->flags & IF_MULTICAST))
-      return;
-
     /* Ignore ifaces without link-local address */
     if (!iface->llv6)
       return;
@@ -1736,10 +1732,6 @@ babel_reconfigure_ifaces(struct babel_proto *p, struct babel_config *cf)
     if (!(iface->flags & IF_UP))
       continue;
 
-    /* Ignore non-multicast ifaces */
-    if (!(iface->flags & IF_MULTICAST))
-      continue;
-
     /* Ignore ifaces without link-local address */
     if (!iface->llv6)
       continue;
-- 
2.31.1