There's no way to have a negative number of addresses configured on a
carp(4) interface.
This hack might have been required in the past when the SIOCDIFADDR
handler was doing "sc->sc_naddrs--" but it is definitively dead code
now.
Ok to kill it?
Index: netinet/ip_carp.c
===================================================================
RCS file: /home/ncvs/src/sys/netinet/ip_carp.c,v
retrieving revision 1.229
diff -u -p -r1.229 ip_carp.c
--- netinet/ip_carp.c 30 Apr 2014 10:04:33 -0000 1.229
+++ netinet/ip_carp.c 26 Jun 2014 09:48:01 -0000
@@ -1697,24 +1697,6 @@ carp_set_ifp(struct carp_softc *sc, stru
if (sc->sc_carpdev != NULL)
carpdetach(sc);
- /* join multicast groups */
- if (sc->sc_naddrs < 0 &&
- (error = carp_join_multicast(sc)) != 0) {
- if (ncif != NULL)
- free(ncif, M_IFADDR);
- return (error);
- }
-
-#ifdef INET6
- if (sc->sc_naddrs6 < 0 &&
- (error = carp_join_multicast6(sc)) != 0) {
- if (ncif != NULL)
- free(ncif, M_IFADDR);
- carp_multicast_cleanup(sc);
- return (error);
- }
-#endif
-
/* attach carp interface to physical interface */
if (ncif != NULL)
ifp->if_carp = (caddr_t)ncif;
