Index: net/if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
retrieving revision 1.537
diff -u -p -r1.537 if.c
--- net/if.c	10 Jan 2018 23:50:39 -0000	1.537
+++ net/if.c	12 Jan 2018 01:50:44 -0000
@@ -1005,11 +1005,6 @@ if_deactivate(struct ifnet *ifp)
 	 */
 	dohooks(ifp->if_detachhooks, HOOK_REMOVE | HOOK_FREE);
 
-#if NCARP > 0
-	/* Remove the interface from any carp group it is a part of.  */
-	if (ifp->if_type != IFT_CARP && !SRPL_EMPTY_LOCKED(&ifp->if_carp))
-		carp_ifdetach(ifp);
-#endif
 	NET_UNLOCK();
 }
 
Index: netinet/ip_carp.c
===================================================================
RCS file: /cvs/src/sys/netinet/ip_carp.c,v
retrieving revision 1.325
diff -u -p -r1.325 ip_carp.c
--- netinet/ip_carp.c	12 Jan 2018 00:36:13 -0000	1.325
+++ netinet/ip_carp.c	12 Jan 2018 01:50:44 -0000
@@ -133,6 +133,7 @@ struct carp_softc {
 #define	sc_carpdev	sc_ac.ac_if.if_carpdev
 	void *ah_cookie;
 	void *lh_cookie;
+	void *dh_cookie;
 	struct ip_moptions sc_imo;
 #ifdef INET6
 	struct ip6_moptions sc_im6o;
@@ -215,7 +216,7 @@ int	carp_proto_input_if(struct ifnet *, 
 int	carp6_proto_input_if(struct ifnet *, struct mbuf **, int *, int);
 #endif
 void	carpattach(int);
-void	carpdetach(struct carp_softc *);
+void	carpdetach(void *);
 int	carp_prepare_ad(struct mbuf *, struct carp_vhost_entry *,
 	    struct carp_header *);
 void	carp_send_ad_all(void);
@@ -901,8 +902,9 @@ carp_del_all_timeouts(struct carp_softc 
 }
 
 void
-carpdetach(struct carp_softc *sc)
+carpdetach(void *arg)
 {
+	struct carp_softc *sc = arg;
 	struct ifnet *ifp0;
 	struct srpl *cif;
 
@@ -929,26 +931,13 @@ carpdetach(struct carp_softc *sc)
 	/* Restore previous input handler. */
 	if_ih_remove(ifp0, carp_input, NULL);
 
-	if (sc->lh_cookie != NULL)
-		hook_disestablish(ifp0->if_linkstatehooks, sc->lh_cookie);
-
 	SRPL_REMOVE_LOCKED(&carp_sc_rc, cif, sc, carp_softc, sc_list);
 	if (SRPL_EMPTY_LOCKED(cif))
 		ifpromisc(ifp0, 0);
 	sc->sc_carpdev = NULL;
-}
-
-/* Detach an interface from the carp. */
-void
-carp_ifdetach(struct ifnet *ifp0)
-{
-	struct carp_softc *sc, *nextsc;
-	struct srpl *cif = &ifp0->if_carp;
 
-	KERNEL_ASSERT_LOCKED(); /* touching if_carp */
-
-	SRPL_FOREACH_SAFE_LOCKED(sc, cif, sc_list, nextsc)
-		carpdetach(sc);
+	hook_disestablish(ifp0->if_linkstatehooks, sc->lh_cookie);
+	hook_disestablish(ifp0->if_detachhooks, sc->dh_cookie);
 }
 
 void
@@ -1697,13 +1686,27 @@ carp_set_ifp(struct carp_softc *sc, stru
 	if (ifp0->if_type != IFT_ETHER)
 		return (EINVAL);
 
+	sc->dh_cookie = hook_establish(ifp0->if_detachhooks, 0,
+            carpdetach, sc);
+	if (sc->dh_cookie == NULL)
+		return (ENOMEM);
+
+	sc->lh_cookie = hook_establish(ifp0->if_linkstatehooks, 1,
+	    carp_carpdev_state, ifp0);
+	if (sc->lh_cookie == NULL) {
+		error = ENOMEM;
+		goto rm_dh;
+	}
+
 	cif = &ifp0->if_carp;
 	if (SRPL_EMPTY_LOCKED(cif)) {
 		if ((error = ifpromisc(ifp0, 1)))
-			return (error);
+			goto rm_lh;
 
-	} else if (carp_check_dup_vhids(sc, cif, NULL))
-		return (EINVAL);
+	} else if (carp_check_dup_vhids(sc, cif, NULL)) {
+		error = EINVAL;
+		goto rm_lh;
+	}
 
 	/* detach from old interface */
 	if (sc->sc_carpdev != NULL)
@@ -1744,15 +1747,19 @@ carp_set_ifp(struct carp_softc *sc, stru
 		sc->sc_if.if_flags |= IFF_UP;
 	carp_set_enaddr(sc);
 
-	sc->lh_cookie = hook_establish(ifp0->if_linkstatehooks, 1,
-	    carp_carpdev_state, ifp0);
-
 	/* Change input handler of the physical interface. */
 	if_ih_insert(ifp0, carp_input, NULL);
 
 	carp_carpdev_state(ifp0);
 
 	return (0);
+
+rm_lh:
+	hook_disestablish(ifp0->if_linkstatehooks, sc->lh_cookie);
+rm_dh:
+	hook_disestablish(ifp0->if_detachhooks, sc->dh_cookie);
+
+	return (error);
 }
 
 void
Index: netinet/ip_carp.h
===================================================================
RCS file: /cvs/src/sys/netinet/ip_carp.h,v
retrieving revision 1.45
diff -u -p -r1.45 ip_carp.h
--- netinet/ip_carp.h	10 Jan 2018 23:50:39 -0000	1.45
+++ netinet/ip_carp.h	12 Jan 2018 01:50:44 -0000
@@ -193,7 +193,6 @@ carpstat_inc(enum carpstat_counters c)
 	counters_inc(carpcounters, c);
 }
 
-void		 carp_ifdetach (struct ifnet *);
 int		 carp_proto_input(struct mbuf **, int *, int, int);
 void		 carp_carpdev_state(void *);
 void		 carp_group_demote_adj(struct ifnet *, int, char *);