babeld: During intf startup, ignore address already in use

When listening on a multicast group.  No need to actually
fail the operation when it's already being used.

Let's not treat the Address already in use error message
as one that is stopping everything from working.  Especially
since multiple interface events cause this to happen.

Without this, if config is read in before full connection
to zebra, babel will never establish neighbors.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/babeld/babel_interface.c b/babeld/babel_interface.c
index cc50898017..4ca875206f 100644
--- a/babeld/babel_interface.c
+++ b/babeld/babel_interface.c
@@ -632,15 +632,15 @@ interface_recalculate(struct interface *ifp)
 
     rc = setsockopt(protocol_socket, IPPROTO_IPV6, IPV6_JOIN_GROUP,
                     (char*)&mreq, sizeof(mreq));
-    if(rc < 0) {
-        flog_err_sys(EC_LIB_SOCKET,
-		  "setsockopt(IPV6_JOIN_GROUP) on interface '%s': %s",
-                  ifp->name, safe_strerror(errno));
-        /* This is probably due to a missing link-local address,
-         so down this interface, and wait until the main loop
-         tries to up it again. */
-        interface_reset(ifp);
-        return -1;
+    if (rc < 0 && errno != EADDRINUSE) {
+	    flog_err_sys(EC_LIB_SOCKET,
+			 "setsockopt(IPV6_JOIN_GROUP) on interface '%s': %s",
+			 ifp->name, safe_strerror(errno));
+	    /* This is probably due to a missing link-local address,
+	     so down this interface, and wait until the main loop
+	     tries to up it again. */
+	    interface_reset(ifp);
+	    return -1;
     }
 
     set_timeout(&babel_ifp->hello_timeout, babel_ifp->hello_interval);