diff --git a/sys/modules/Makefile b/sys/modules/Makefile
index 61f9066..7b3aea9 100644
--- a/sys/modules/Makefile
+++ b/sys/modules/Makefile
@@ -103,6 +103,7 @@ SUBDIR=	${_3dfx} \
 	${_ida} \
 	${_ie} \
 	if_bridge \
+	if_carp \
 	if_disc \
 	if_edsc \
 	if_ef \
diff --git a/sys/modules/if_carp/Makefile b/sys/modules/if_carp/Makefile
new file mode 100644
index 0000000..a280b3d
--- /dev/null
+++ b/sys/modules/if_carp/Makefile
@@ -0,0 +1,19 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../netinet
+
+KMOD=	if_carp
+SRCS=	ip_carp.c
+SRCS+=	opt_carp.h opt_bpf.h opt_inet.h opt_inet6.h vnode_if.h
+
+.if !defined(KERNBUILDDIR)
+opt_inet.h:
+	@echo "#define INET 1" > ${.TARGET}
+
+.if ${MK_INET6_SUPPORT} != "no"
+opt_inet6.h:
+	@echo "#define INET6 1" > ${.TARGET}
+.endif
+.endif
+
+.include <bsd.kmod.mk>
diff --git a/sys/net/if.c b/sys/net/if.c
index 4d4b676..8c51af6 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -87,9 +87,6 @@
 #include <netinet/if_ether.h>
 #include <netinet/vinet.h>
 #endif
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
 
 #include <security/mac/mac_framework.h>
 
@@ -114,6 +111,7 @@ SYSCTL_INT(_net_link, OID_AUTO, log_link_state_change, CTLFLAG_RW,
 void	(*bstp_linkstate_p)(struct ifnet *ifp, int state);
 void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
 void	(*lagg_linkstate_p)(struct ifnet *ifp, int state);
+void	(*carp_linkstate_p)(struct ifnet *ifp);
 
 struct mbuf *(*tbr_dequeue_ptr)(struct ifaltq *, int) = NULL;
 
@@ -1582,10 +1580,9 @@ if_unroute(struct ifnet *ifp, int flag, int fam)
 			pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
 	ifp->if_qflush(ifp);
 
-#ifdef DEV_CARP
 	if (ifp->if_carp)
-		carp_carpdev_state(ifp->if_carp);
-#endif
+		(*carp_linkstate_p)(ifp);
+
 	rt_ifmsg(ifp);
 }
 
@@ -1606,10 +1603,8 @@ if_route(struct ifnet *ifp, int flag, int fam)
 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
 		if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
 			pfctlinput(PRC_IFUP, ifa->ifa_addr);
-#ifdef DEV_CARP
 	if (ifp->if_carp)
-		carp_carpdev_state(ifp->if_carp);
-#endif
+		(*carp_linkstate_p)(ifp);
 	rt_ifmsg(ifp);
 #ifdef INET6
 	in6_if_up(ifp);
@@ -1660,10 +1655,8 @@ do_link_state_change(void *arg, int pending)
 	if ((ifp->if_type == IFT_ETHER || ifp->if_type == IFT_L2VLAN) &&
 	    IFP2AC(ifp)->ac_netgraph != NULL)
 		(*ng_ether_link_state_p)(ifp, link_state);
-#ifdef DEV_CARP
 	if (ifp->if_carp)
-		carp_carpdev_state(ifp->if_carp);
-#endif
+		(*carp_linkstate_p)(ifp);
 	if (ifp->if_bridge) {
 		KASSERT(bstp_linkstate_p != NULL,("if_bridge bstp not loaded!"));
 		(*bstp_linkstate_p)(ifp, link_state);
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index ef8cf5b..2c6edb5 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -122,9 +122,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/ip6_var.h>
 #include <netinet6/vinet6.h>
 #endif
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
 #include <machine/in_cksum.h>
 #include <netinet/if_ether.h> /* for struct arpcom */
 #include <net/bridgestp.h>
@@ -2127,6 +2124,8 @@ drop:
 	m_freem(m);
 }
 
+int (*carp_forus_p)(struct carp_if *, u_char *);
+
 /*
  * bridge_input:
  *
@@ -2235,17 +2234,12 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 		return (m);
 	}
 
-#ifdef DEV_CARP
-#   define OR_CARP_CHECK_WE_ARE_DST(iface) \
+#define OR_CARP_CHECK_WE_ARE_DST(iface) \
 	|| ((iface)->if_carp \
-	    && carp_forus((iface)->if_carp, eh->ether_dhost))
-#   define OR_CARP_CHECK_WE_ARE_SRC(iface) \
+	    && (*carp_forus_p)((iface)->if_carp, eh->ether_dhost))
+#define OR_CARP_CHECK_WE_ARE_SRC(iface) \
 	|| ((iface)->if_carp \
-	    && carp_forus((iface)->if_carp, eh->ether_shost))
-#else
-#   define OR_CARP_CHECK_WE_ARE_DST(iface)
-#   define OR_CARP_CHECK_WE_ARE_SRC(iface)
-#endif
+	    && (*carp_forus_p)((iface)->if_carp, eh->ether_shost))
 
 #ifdef INET6
 #   define OR_PFIL_HOOKED_INET6 \
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 38bf7d4..ca62352 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -81,10 +81,6 @@
 #include <netinet6/nd6.h>
 #endif
 
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
-
 #ifdef IPX
 #include <netipx/ipx.h>
 #include <netipx/ipx_if.h>
@@ -121,6 +117,9 @@ void	(*ng_ether_attach_p)(struct ifnet *ifp);
 void	(*ng_ether_detach_p)(struct ifnet *ifp);
 
 void	(*vlan_input_p)(struct ifnet *, struct mbuf *);
+int (*carp_forus_p)(struct ifnet *, u_char *);
+int (*carp_output_p)(struct ifnet *, struct mbuf *, struct sockaddr *,
+    struct rtentry *);
 
 /* if_bridge(4) support */
 struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *); 
@@ -396,11 +395,9 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 		return (error);
 	}
 
-#ifdef DEV_CARP
 	if (ifp->if_carp &&
-	    (error = carp_output(ifp, m, dst, NULL)))
+	    (error = (*carp_output_p)(ifp, m, dst, NULL)))
 		goto bad;
-#endif
 
 	/* Handle ng_ether(4) processing, if any */
 	if (IFP2AC(ifp)->ac_netgraph != NULL) {
@@ -702,7 +699,6 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
 			return;
 	}
 
-#ifdef DEV_CARP
 	/*
 	 * Clear M_PROMISC on frame so that carp(4) will see it when the
 	 * mbuf flows up to Layer 3.
@@ -713,11 +709,9 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
 	 * TODO: Maintain a hash table of ethernet addresses other than
 	 * ether_dhost which may be active on this ifp.
 	 */
-	if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost)) {
+	if (ifp->if_carp && (*carp_forus_p)(ifp, eh->ether_dhost))
 		m->m_flags &= ~M_PROMISC;
-	} else
-#endif
-	{
+	else {
 		/*
 		 * If the frame received was not for our MAC address, set the
 		 * M_PROMISC flag on the mbuf chain. The frame may need to
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 38e420e..fee8196 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -73,10 +73,6 @@ __FBSDID("$FreeBSD$");
 #include <net/if_arc.h>
 #include <net/iso88025.h>
 
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
-
 #include <security/mac/mac_framework.h>
 
 #define SIN(s) ((struct sockaddr_in *)s)
@@ -116,6 +112,8 @@ static void	arpintr(struct mbuf *);
 static void	arptimer(void *);
 #ifdef INET
 static void	in_arpinput(struct mbuf *);
+int		(*carp_iamatch_p)(struct ifnet *, struct in_ifaddr *, struct in_addr *,
+		    u_int8_t **);
 #endif
 
 #ifndef VIMAGE_GLOBALS
@@ -471,9 +469,7 @@ in_arpinput(struct mbuf *m)
 	struct mbuf *m0;
 	int req_len;
 	int bridged = 0, is_bridge = 0;
-#ifdef DEV_CARP
 	int carp_match = 0;
-#endif
 	struct sockaddr_in sin;
 	sin.sin_len = sizeof(struct sockaddr_in);
 	sin.sin_family = AF_INET;
@@ -510,14 +506,12 @@ in_arpinput(struct mbuf *m)
 		    ia->ia_ifp == ifp) &&
 		    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
 			goto match;
-#ifdef DEV_CARP
 		if (ifp->if_carp != NULL &&
-		    carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
+		    (*carp_iamatch_p)(ifp, ia, &isaddr, &enaddr) &&
 		    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
 			carp_match = 1;
 			goto match;
 		}
-#endif
 	}
 	LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
 		if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
@@ -599,11 +593,7 @@ match:
 	IF_AFDATA_UNLOCK(ifp);
 	if (la != NULL) {
 		/* the following is not an error when doing bridging */
-		if (!bridged && la->lle_tbl->llt_ifp != ifp
-#ifdef DEV_CARP
-		    && (ifp->if_type != IFT_CARP || !carp_match)
-#endif
-			) {
+		if (!bridged && la->lle_tbl->llt_ifp != ifp && !carp_match) {
 			if (log_arp_wrong_iface)
 				log(LOG_ERR, "arp: %s is on %s "
 				    "but got reply from %*D on %s\n",
diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index bb3973c..de39b3f 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -794,13 +794,9 @@ in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
 	ia->ia_net = i & ia->ia_netmask;
 	ia->ia_subnet = i & ia->ia_subnetmask;
 	in_socktrim(&ia->ia_sockmask);
-#ifdef DEV_CARP
-	/*
-	 * XXX: carp(4) does not have interface route
-	 */
+	/* XXX: a special case for carp(4) */
 	if (ifp->if_type == IFT_CARP)
 		return (0);
-#endif
 	/*
 	 * Add route for the network.
 	 */
@@ -930,13 +926,12 @@ in_scrubprefix(struct in_ifaddr *target)
 		 * the route itself to it.  Make sure that routing daemons
 		 * get a heads-up.
 		 *
-		 * XXX: a special case for carp(4) interface
+		 * XXX: a special case for carp(4) interface - this should be more
+		 *      generally specified as an interface that doesn't support
+		 *      such action.
 		 */
-		if ((ia->ia_flags & IFA_ROUTE) == 0
-#ifdef DEV_CARP
-		    && (ia->ia_ifp->if_type != IFT_CARP)
-#endif
-							) {
+		if ((ia->ia_flags & IFA_ROUTE) == 0 &&
+		    (ia->ia_ifp->if_type != IFT_CARP)) {
 			rtinit(&(target->ia_ifa), (int)RTM_DELETE,
 			    rtinitflags(target));
 			target->ia_flags &= ~IFA_ROUTE;
diff --git a/sys/netinet/in_proto.c b/sys/netinet/in_proto.c
index c25f6eb..fdcfa4e 100644
--- a/sys/netinet/in_proto.c
+++ b/sys/netinet/in_proto.c
@@ -38,7 +38,6 @@ __FBSDID("$FreeBSD$");
 #include "opt_inet6.h"
 #include "opt_route.h"
 #include "opt_pf.h"
-#include "opt_carp.h"
 #include "opt_sctp.h"
 #include "opt_mpath.h"
 
@@ -94,10 +93,6 @@ static struct pr_usrreqs nousrreqs;
 #include <net/if_pfsync.h>
 #endif
 
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
-
 extern	struct domain inetdomain;
 
 /* Spacer for loadable protocols. */
@@ -319,18 +314,6 @@ struct protosw inetsw[] = {
 	.pr_usrreqs =		&rip_usrreqs
 },
 #endif	/* DEV_PFSYNC */
-#ifdef DEV_CARP
-{
-	.pr_type =		SOCK_RAW,
-	.pr_domain =		&inetdomain,
-	.pr_protocol =		IPPROTO_CARP,
-	.pr_flags =		PR_ATOMIC|PR_ADDR,
-	.pr_input =		carp_input,
-	.pr_output =		(pr_output_t*)rip_output,
-	.pr_ctloutput =		rip_ctloutput,
-	.pr_usrreqs =		&rip_usrreqs
-},
-#endif /* DEV_CARP */
 /* Spacer n-times for loadable protocols. */
 IPPROTOSPACER,
 IPPROTOSPACER,
@@ -340,6 +323,7 @@ IPPROTOSPACER,
 IPPROTOSPACER,
 IPPROTOSPACER,
 IPPROTOSPACER,
+IPPROTOSPACER,
 /* raw wildcard */
 {
 	.pr_type =		SOCK_RAW,
@@ -352,13 +336,16 @@ IPPROTOSPACER,
 },
 };
 
+#define	INETSW_SZ (sizeof(inetsw) / sizeof(inetsw[0]))
+#define	LAST_INETSW (&inetsw[INETSW_SZ])
+
 extern int in_inithead(void **, int);
 
 struct domain inetdomain = {
 	.dom_family =		AF_INET,
 	.dom_name =		"internet",
 	.dom_protosw =		inetsw,
-	.dom_protoswNPROTOSW =	&inetsw[sizeof(inetsw)/sizeof(inetsw[0])],
+	.dom_protoswNPROTOSW =	LAST_INETSW,
 #ifdef RADIX_MPATH
 	.dom_rtattach =		rn4_mpath_inithead,
 #else
@@ -370,6 +357,45 @@ struct domain inetdomain = {
 	.dom_ifdetach =		in_domifdetach
 };
 
+/* XXX: these protos should be in a header file */
+int in_proto_register(struct protosw *);
+int in_proto_unregister(short proto);
+
+int
+in_proto_register(struct protosw *pr) {
+	struct protosw *prp = inetsw, *pr_targ = NULL;
+
+	for (;prp <= LAST_INETSW;prp++) {
+		/* Q: Is it really reasonable to disallow more than one protocol
+		 *    handler for a given protocol? */
+		if (prp->pr_protocol == pr->pr_protocol)
+			return EINVAL;
+		if (pr_targ == NULL && prp->pr_protocol == PROTO_SPACER)
+			pr_targ = prp;
+	}
+
+	if (pr_targ == NULL)
+		return ENOSPC;
+
+	memcpy(prp, pr, sizeof(*prp));
+	return 0;
+}
+
+int
+in_proto_unregister(short proto) {
+	struct protosw *prp = inetsw;
+
+	for (;prp <= LAST_INETSW;prp++)
+		if (prp->pr_protocol == proto) {
+			prp->pr_domain = &inetdomain;
+			prp->pr_usrreqs = &nousrreqs;
+			prp->pr_protocol = PROTO_SPACER;
+			return 0;
+		}
+
+	return EEXIST;
+}
+
 DOMAIN_SET(inet);
 
 SYSCTL_NODE(_net,      PF_INET,		inet,	CTLFLAG_RW, 0,
@@ -395,6 +421,3 @@ SYSCTL_NODE(_net_inet, IPPROTO_RAW,	raw,	CTLFLAG_RW, 0,	"RAW");
 #ifdef DEV_PFSYNC
 SYSCTL_NODE(_net_inet, IPPROTO_PFSYNC,	pfsync,	CTLFLAG_RW, 0,	"PFSYNC");
 #endif
-#ifdef DEV_CARP
-SYSCTL_NODE(_net_inet, IPPROTO_CARP,	carp,	CTLFLAG_RW, 0,	"CARP");
-#endif
diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
index 33b5059..3295ff1 100644
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/time.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
+#include <sys/protosw.h>
 #include <sys/sysctl.h>
 #include <sys/syslog.h>
 #include <sys/signalvar.h>
@@ -75,6 +76,9 @@ __FBSDID("$FreeBSD$");
 #include <netinet/if_ether.h>
 #include <machine/in_cksum.h>
 #include <netinet/vinet.h>
+
+extern int in_proto_register(struct protosw *);
+extern int in_proto_unregister(short);
 #endif
 
 #ifdef INET6
@@ -84,6 +88,10 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
 #include <netinet6/vinet6.h>
+#include <netinet6/ip6protosw.h>
+
+extern int in6_proto_register(struct ip6protosw *);
+extern int in6_proto_unregister(short);
 #endif
 
 #include <crypto/sha1.h>
@@ -136,8 +144,27 @@ struct carp_softc {
 };
 #define	SC2IFP(sc)	((sc)->sc_ifp)
 
+/* These are external networking stack hooks for CARP */
+/* net/if.c */
+extern void (*carp_linkstate_p)(struct ifnet *);
+/* net/if_bridge.c net/if_ethersubr.c */
+extern struct ifnet *(*carp_forus_p)(struct ifnet *, u_char *);
+/* net/if_ethersubr.c */
+extern int (*carp_output_p)(struct ifnet *, struct mbuf *,
+    struct sockaddr *, struct rtentry *);
+/* netinet/if_ether.c */
+extern int (*carp_iamatch_p)(struct ifnet *, struct in_ifaddr *,
+    struct in_addr *, u_int8_t **);
+#ifdef INET6
+extern struct ifaddr *(*carp_iamatch6_p)(struct ifnet *, struct in6_addr *);
+extern caddr_t (*carp_macmatch6_p)(struct ifnet *, struct mbuf *,
+    const struct in6_addr *);
+#endif
+
 int carp_suppress_preempt = 0;
 int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 1, 0, 0 };	/* XXX for now */
+
+SYSCTL_NODE(_net_inet, IPPROTO_CARP,	carp,	CTLFLAG_RW, 0,	"CARP");
 SYSCTL_INT(_net_inet_carp, CARPCTL_ALLOW, allow, CTLFLAG_RW,
     &carp_opts[CARPCTL_ALLOW], 0, "Accept incoming CARP packets");
 SYSCTL_INT(_net_inet_carp, CARPCTL_PREEMPT, preempt, CTLFLAG_RW,
@@ -1134,10 +1161,10 @@ carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
 }
 
 int
-carp_iamatch(void *v, struct in_ifaddr *ia,
+carp_iamatch(struct ifnet *ifp, struct in_ifaddr *ia,
     struct in_addr *isaddr, u_int8_t **enaddr)
 {
-	struct carp_if *cif = v;
+	struct carp_if *cif = ifp->if_carp;
 	struct carp_softc *vh;
 	int index, count = 0;
 	struct ifaddr *ifa;
@@ -1206,9 +1233,9 @@ carp_iamatch(void *v, struct in_ifaddr *ia,
 
 #ifdef INET6
 struct ifaddr *
-carp_iamatch6(void *v, struct in6_addr *taddr)
+carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
 {
-	struct carp_if *cif = v;
+	struct carp_if *cif = ifp->if_carp;
 	struct carp_softc *vh;
 	struct ifaddr *ifa;
 
@@ -1230,11 +1257,11 @@ carp_iamatch6(void *v, struct in6_addr *taddr)
 	return (NULL);
 }
 
-void *
-carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
+caddr_t
+carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
 {
 	struct m_tag *mtag;
-	struct carp_if *cif = v;
+	struct carp_if *cif = ifp->if_carp;
 	struct carp_softc *sc;
 	struct ifaddr *ifa;
 
@@ -1269,9 +1296,9 @@ carp_macmatch6(void *v, struct mbuf *m, const struct in6_addr *taddr)
 #endif
 
 struct ifnet *
-carp_forus(void *v, void *dhost)
+carp_forus(struct ifnet *ifp, u_char *dhost)
 {
-	struct carp_if *cif = v;
+	struct carp_if *cif = ifp->if_carp;
 	struct carp_softc *vh;
 	u_int8_t *ena = dhost;
 
@@ -2167,9 +2194,9 @@ carp_set_state(struct carp_softc *sc, int state)
 }
 
 void
-carp_carpdev_state(void *v)
+carp_carpdev_state(struct ifnet *ifp)
 {
-	struct carp_if *cif = v;
+	struct carp_if *cif = ifp->if_carp;
 
 	CARP_LOCK(cif);
 	carp_carpdev_state_locked(cif);
@@ -2221,6 +2248,35 @@ carp_sc_state_locked(struct carp_softc *sc)
 	return;
 }
 
+#ifdef INET
+extern  struct domain inetdomain;
+static struct protosw carp_pr = {
+	.pr_type =		SOCK_RAW,
+	.pr_domain =		&inetdomain,
+	.pr_protocol =		IPPROTO_CARP,
+	.pr_flags =		PR_ATOMIC|PR_ADDR,
+	.pr_input =		carp_input,
+	/* XXX: fix this type mismatch! */
+	.pr_output =		(pr_output_t *)rip_output,
+	.pr_ctloutput =		rip_ctloutput,
+	.pr_usrreqs =		&rip_usrreqs
+};
+#endif
+
+#ifdef INET6
+extern	struct domain inet6domain;
+static struct ip6protosw carp_pr6 = {
+	.pr_type =		SOCK_RAW,
+	.pr_domain =		&inet6domain,
+	.pr_protocol =		IPPROTO_CARP,
+	.pr_flags =		PR_ATOMIC|PR_ADDR,
+	.pr_input =		carp6_input,
+	.pr_output =		rip6_output,
+	.pr_ctloutput =		rip6_ctloutput,
+	.pr_usrreqs =		&rip6_usrreqs
+};
+#endif
+
 static int
 carp_modevent(module_t mod, int type, void *data)
 {
@@ -2233,9 +2289,29 @@ carp_modevent(module_t mod, int type, void *data)
 		mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
 		LIST_INIT(&carpif_list);
 		if_clone_attach(&carp_cloner);
+		carp_linkstate_p = carp_carpdev_state;
+		carp_forus_p = carp_forus;
+		carp_output_p = carp_output;
+		carp_iamatch_p = carp_iamatch;
+#ifdef INET6
+		carp_iamatch6_p = carp_iamatch6;
+		carp_macmatch6_p = carp_macmatch6;
+		in6_proto_register(&carp_pr6);
+#endif
+		in_proto_register(&carp_pr);
 		break;
 
 	case MOD_UNLOAD:
+		in_proto_unregister(IPPROTO_CARP);
+#ifdef INET6
+		in6_proto_unregister(IPPROTO_CARP);
+		carp_iamatch6_p = NULL;
+		carp_macmatch6_p = NULL;
+#endif
+		carp_linkstate_p = NULL;
+		carp_forus_p = NULL;
+		carp_output_p = NULL;
+		carp_iamatch_p = NULL;
 		EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
 		if_clone_detach(&carp_cloner);
 		mtx_destroy(&carp_mtx);
diff --git a/sys/netinet/ip_carp.h b/sys/netinet/ip_carp.h
index 47bb494..1e06806 100644
--- a/sys/netinet/ip_carp.h
+++ b/sys/netinet/ip_carp.h
@@ -157,15 +157,15 @@ struct carpreq {
 }
 
 #ifdef _KERNEL
-void		 carp_carpdev_state(void *);
+void		 carp_carpdev_state(struct ifnet *);
 void		 carp_input (struct mbuf *, int);
 int		 carp6_input (struct mbuf **, int *, int);
 int		 carp_output (struct ifnet *, struct mbuf *, struct sockaddr *,
 		     struct rtentry *);
-int		 carp_iamatch (void *, struct in_ifaddr *, struct in_addr *,
+int		 carp_iamatch (struct ifnet *, struct in_ifaddr *, struct in_addr *,
 		     u_int8_t **);
-struct ifaddr	*carp_iamatch6(void *, struct in6_addr *);
-void		*carp_macmatch6(void *, struct mbuf *, const struct in6_addr *);
-struct	ifnet	*carp_forus (void *, void *);
+struct ifaddr	*carp_iamatch6(struct ifnet *, struct in6_addr *);
+caddr_t		carp_macmatch6(struct ifnet *, struct mbuf *, const struct in6_addr *);
+struct	ifnet	*carp_forus (struct ifnet *, u_char *);
 #endif
 #endif /* _IP_CARP_H */
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index a294d0a..8356ab5 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -76,9 +76,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_options.h>
 #include <machine/in_cksum.h>
 #include <netinet/vinet.h>
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
 #ifdef IPSEC
 #include <netinet/ip_ipsec.h>
 #endif /* IPSEC */
@@ -574,9 +571,7 @@ passin:
 	 */
 	checkif = V_ip_checkinterface && (V_ipforwarding == 0) && 
 	    ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
-#ifdef DEV_CARP
 	    !ifp->if_carp &&
-#endif
 	    (dchg == 0);
 
 	/*
diff --git a/sys/netinet6/in6_proto.c b/sys/netinet6/in6_proto.c
index 8908d67..e55c2ba 100644
--- a/sys/netinet6/in6_proto.c
+++ b/sys/netinet6/in6_proto.c
@@ -68,7 +68,6 @@ __FBSDID("$FreeBSD$");
 #include "opt_ipsec.h"
 #include "opt_ipstealth.h"
 #include "opt_route.h"
-#include "opt_carp.h"
 #include "opt_sctp.h"
 #include "opt_mpath.h"
 
@@ -112,10 +111,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/pim6_var.h>
 #include <netinet6/nd6.h>
 
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
-
 #ifdef SCTP
 #include <netinet/in_pcb.h>
 #include <netinet/sctp_pcb.h>
@@ -142,6 +137,13 @@ static	struct pr_usrreqs nousrreqs;
 #define PR_LISTEN	0
 #define PR_ABRTACPTDIS	0
 
+#define	IPPROTO6SPACER			\
+{					\
+	.pr_domain = &inet6domain,	\
+	.pr_protocol = PROTO6_SPACER,	\
+	.pr_usrreqs = &nousrreqs,	\
+}
+
 struct ip6protosw inet6sw[] = {
 {
 	.pr_type =		0,
@@ -323,18 +325,12 @@ struct ip6protosw inet6sw[] = {
 	.pr_ctloutput =		rip6_ctloutput,
 	.pr_usrreqs =		&rip6_usrreqs
 },
-#ifdef DEV_CARP
-{
-	.pr_type =		SOCK_RAW,
-	.pr_domain =		&inet6domain,
-	.pr_protocol =		IPPROTO_CARP,
-	.pr_flags =		PR_ATOMIC|PR_ADDR,
-	.pr_input =		carp6_input,
-	.pr_output =		rip6_output,
-	.pr_ctloutput =		rip6_ctloutput,
-	.pr_usrreqs =		&rip6_usrreqs
-},
-#endif /* DEV_CARP */
+IPPROTO6SPACER,
+IPPROTO6SPACER,
+IPPROTO6SPACER,
+IPPROTO6SPACER,
+IPPROTO6SPACER,
+IPPROTO6SPACER,
 /* raw wildcard */
 {
 	.pr_type =		SOCK_RAW,
@@ -349,12 +345,14 @@ struct ip6protosw inet6sw[] = {
 
 extern int in6_inithead(void **, int);
 
+#define INET6SW_SZ (sizeof(inet6sw) / sizeof(inet6sw[0]))
+#define LAST_INET6SW (&inet6sw[INET6SW_SZ])
+
 struct domain inet6domain = {
 	.dom_family =		AF_INET6,
 	.dom_name =		"internet6",
 	.dom_protosw =		(struct protosw *)inet6sw,
-	.dom_protoswNPROTOSW =	(struct protosw *)
-				&inet6sw[sizeof(inet6sw)/sizeof(inet6sw[0])],
+	.dom_protoswNPROTOSW =	(struct protosw *)LAST_INET6SW,
 #ifdef RADIX_MPATH
 	.dom_rtattach =		rn6_mpath_inithead,
 #else
@@ -366,6 +364,43 @@ struct domain inet6domain = {
 	.dom_ifdetach =		in6_domifdetach
 };
 
+/* XXX: these should go in a header file */
+int in6_proto_register(struct ip6protosw *);
+int in6_proto_unregister(short);
+
+int
+in6_proto_register(struct ip6protosw *pr) {
+	struct ip6protosw *prp = inet6sw, *pr_targ = NULL;
+
+	for (;prp <= LAST_INET6SW;prp++) {
+		if (prp->pr_protocol == pr->pr_protocol)
+			return EINVAL;
+		if (pr_targ == NULL && prp->pr_protocol == PROTO_SPACER)
+			pr_targ = prp;
+	}
+
+	if (pr_targ == NULL)
+		return ENOSPC;
+
+	memcpy(prp, pr, sizeof(*prp));
+	return 0;
+}
+
+int
+in6_proto_unregister(short proto) {
+	struct ip6protosw *prp;
+
+	for (prp = inet6sw;prp <= LAST_INET6SW;prp++)
+		if (prp->pr_protocol == proto) {
+			prp->pr_domain = &inet6domain;
+			prp->pr_usrreqs = &nousrreqs;
+			prp->pr_protocol = PROTO_SPACER;
+			return 0;
+		}
+
+	return EEXIST;
+}
+
 DOMAIN_SET(inet6);
 
 /*
diff --git a/sys/netinet6/ip6protosw.h b/sys/netinet6/ip6protosw.h
index 2a7cea4..dd6d0d4 100644
--- a/sys/netinet6/ip6protosw.h
+++ b/sys/netinet6/ip6protosw.h
@@ -141,6 +141,14 @@ struct ip6protosw {
 
 #ifdef _KERNEL
 extern struct ip6protosw inet6sw[];
+
+/*
+ * from sys/protosw.h:
+ * This number should be defined again within each protocol family to avoid
+ * confusion.
+ */
+#define	PROTO6_SPACER	32767		/* spacer for loadable protocols */
+
 #endif
 
 #endif /* !_NETINET6_IP6PROTOSW_H_ */
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index c83a245..dea5032 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -76,10 +76,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/icmp6.h>
 #include <netinet6/vinet6.h>
 
-#ifdef DEV_CARP
-#include <netinet/ip_carp.h>
-#endif
-
 #define SDL(s) ((struct sockaddr_dl *)s)
 
 struct dadq;
@@ -91,6 +87,10 @@ static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
 static void nd6_dad_ns_input(struct ifaddr *);
 static void nd6_dad_na_input(struct ifaddr *);
 
+struct ifaddr *(*carp_iamatch6_p)(struct ifnet *, struct in6_addr *);
+caddr_t (*carp_macmatch6_p)(struct ifnet *, struct mbuf *,
+    const struct in6_addr *);
+
 #ifdef VIMAGE_GLOBALS
 int dad_ignore_ns;
 int dad_maxtry;
@@ -225,14 +225,12 @@ nd6_ns_input(struct mbuf *m, int off, int icmp6len)
 	 * (3) "tentative" address on which DAD is being performed.
 	 */
 	/* (1) and (3) check. */
-#ifdef DEV_CARP
-	if (ifp->if_carp)
-		ifa = carp_iamatch6(ifp->if_carp, &taddr6);
-	if (ifa == NULL)
+	if (ifp->if_carp) {
+		ifa = (*carp_iamatch6_p)(ifp, &taddr6);
+		if (ifa == NULL)
+			ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
+	} else
 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
-#else
-	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
-#endif
 
 	/* (2) check. */
 	if (ifa == NULL) {
@@ -1024,14 +1022,12 @@ nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
 		 * my address) use lladdr configured for the interface.
 		 */
 		if (sdl0 == NULL) {
-#ifdef DEV_CARP
-			if (ifp->if_carp)
-				mac = carp_macmatch6(ifp->if_carp, m, taddr6);
-			if (mac == NULL)
+			if (ifp->if_carp) {
+				mac = (*carp_macmatch6_p)(ifp, m, taddr6);
+				if (mac == NULL)
+					mac = nd6_ifptomac(ifp);
+			} else
 				mac = nd6_ifptomac(ifp);
-#else
-			mac = nd6_ifptomac(ifp);
-#endif
 		} else if (sdl0->sa_family == AF_LINK) {
 			struct sockaddr_dl *sdl;
 			sdl = (struct sockaddr_dl *)sdl0;