Stop embedding struct ifnet at the top of driver softcs. Instead the

struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
 - Struct arpcom is no longer referenced in normal interface code.
   Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
   To enforce this ac_enaddr has been renamed to _ac_enaddr.
 - The second argument to ether_ifattach is now always the mac address
   from driver private storage rather than sometimes being ac_enaddr.

Reviewed by:	sobomax, sam

40 files changed, 847 insertions, 503 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 9c9ca7e..ac81ff1 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -1018,7 +1018,7 @@ bpf_setif(d, ifr)
 		if (ifp == NULL || ifp != theywant)
 			continue;
 		/* skip additional entry */
-		if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf)
+		if (bp->bif_driverp != &ifp->if_bpf)
 			continue;
 
 		mtx_unlock(&bpf_mtx);
diff --git a/sys/net/bridge.c b/sys/net/bridge.c
index 1011f10..82a24fa 100644
--- a/sys/net/bridge.c
+++ b/sys/net/bridge.c
@@ -352,7 +352,7 @@ add_cluster(u_int16_t cluster_id, struct ifnet *ifp)
     n_clusters++;
 found:
     c = clusters + i;		/* the right cluster ... */
-    ETHER_ADDR_COPY(c->my_macs[c->ports].etheraddr, IFP2AC(ifp)->ac_enaddr);
+    ETHER_ADDR_COPY(c->my_macs[c->ports].etheraddr, IFP2ENADDR(ifp));
     c->ports++;
     return c;
 bad:
diff --git a/sys/net/bridge.h b/sys/net/bridge.h
index 7eb3b2d..76594f5 100644
--- a/sys/net/bridge.h
+++ b/sys/net/bridge.h
@@ -42,7 +42,6 @@ struct cluster_softc;	/* opaque here, defined in bridge.c */
 
 struct bdg_softc {
     struct ifnet *ifp ;
-    /* also ((struct arpcom *)ifp)->ac_enaddr is the eth. addr */
     int flags ;
 #define IFF_BDG_PROMISC 0x0001  /* set promisc mode on this if.	*/
 #define IFF_MUTE        0x0002  /* mute this if for bridging.   */
diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index a1a487b..476e026 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -66,8 +66,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/if_ether.h>
 #include <net/if_bridgevar.h>
 
-#define sc_if ifb_ac.ac_if
-
 /* BPDU message types */
 #define	BSTP_MSGTYPE_CFG	0x00		/* Configuration */
 #define	BSTP_MSGTYPE_TCN	0x80		/* Topology chg notification */
@@ -1139,7 +1137,7 @@ bstp_tick(void *arg)
 			bstp_hold_timer_expiry(sc, bif);
 	}
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
 
 	BRIDGE_UNLOCK(sc);
diff --git a/sys/net/firewire.h b/sys/net/firewire.h
index 5c63a05..d47b822 100644
--- a/sys/net/firewire.h
+++ b/sys/net/firewire.h
@@ -121,7 +121,7 @@ struct fw_reass {
 STAILQ_HEAD(fw_reass_list, fw_reass);
 
 struct fw_com {
-	struct ifnet		fc_if;
+	struct ifnet		*fc_ifp;
 	struct fw_hwaddr	fc_hwaddr;
 	struct firewire_comm	*fc_fc;
 	uint8_t			fc_broadcast_channel;
@@ -129,6 +129,7 @@ struct fw_com {
 	uint16_t		fc_node;	/* our nodeid */
 	struct fw_reass_list	fc_frags;	/* partial datagrams */
 };
+#define	IFP2FWC(ifp)	((struct fw_com *)(ifp)->if_l2com)
 
 extern	void	firewire_input(struct ifnet *ifp, struct mbuf *m, uint16_t src);
 extern	void	firewire_ifattach(struct ifnet *, struct fw_hwaddr *);
diff --git a/sys/net/if.c b/sys/net/if.c
index d2d179f..4f3082a 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -127,6 +127,8 @@ struct	ifindex_entry *ifindex_table = NULL;
 int	ifqmaxlen = IFQ_MAXLEN;
 struct	ifnethead ifnet;	/* depend on static init XXX */
 struct	mtx ifnet_lock;
+static	if_com_alloc_t *if_com_alloc[256];
+static	if_com_free_t *if_com_free[256];
 
 static int	if_indexlim = 8;
 static struct	knlist ifklist;
@@ -143,6 +145,7 @@ static struct filterops netdev_filtops =
 SYSINIT(interfaces, SI_SUB_INIT_IF, SI_ORDER_FIRST, if_init, NULL)
 SYSINIT(interface_check, SI_SUB_PROTO_IF, SI_ORDER_FIRST, if_check, NULL)
 
+MALLOC_DEFINE(M_IFNET, "ifnet", "interface internals");
 MALLOC_DEFINE(M_IFADDR, "ifaddr", "interface address");
 MALLOC_DEFINE(M_IFMADDR, "ether_multi", "link-level multicast address");
 
@@ -291,10 +294,10 @@ if_grow(void)
 
 	if_indexlim <<= 1;
 	n = if_indexlim * sizeof(*e);
-	e = malloc(n, M_IFADDR, M_WAITOK | M_ZERO);
+	e = malloc(n, M_IFNET, M_WAITOK | M_ZERO);
 	if (ifindex_table != NULL) {
 		memcpy((caddr_t)e, (caddr_t)ifindex_table, n/2);
-		free((caddr_t)ifindex_table, M_IFADDR);
+		free((caddr_t)ifindex_table, M_IFNET);
 	}
 	ifindex_table = e;
 }
@@ -325,6 +328,7 @@ if_check(void *dummy __unused)
 	if_slowtimo(0);
 }
 
+/* XXX: should be locked. */
 static int
 if_findindex(struct ifnet *ifp)
 {
@@ -339,7 +343,7 @@ if_findindex(struct ifnet *ifp)
 	case IFT_ISO88025:
 	case IFT_L2VLAN:
 	case IFT_BRIDGE:
-		snprintf(eaddr, 18, "%6D", IFP2AC(ifp)->ac_enaddr, ":");
+		snprintf(eaddr, 18, "%6D", IFP2ENADDR(ifp), ":");
 		break;
 	default:
 		eaddr[0] = '\0';
@@ -376,6 +380,59 @@ found:
 }
 
 /*
+ * Allocate a struct ifnet and in index for an interface.
+ */
+struct ifnet*
+if_alloc(u_char type)
+{
+	struct ifnet *ifp;
+
+	ifp = malloc(sizeof(struct ifnet), M_IFNET, M_WAITOK|M_ZERO);
+
+	/* XXX: This should fail it index it is too big */
+	ifp->if_index = if_findindex(ifp);
+	if (ifp->if_index > if_index)
+		if_index = ifp->if_index;
+	if (if_index >= if_indexlim)
+		if_grow();
+
+	ifnet_byindex(ifp->if_index) = ifp;
+
+	ifp->if_type = type;
+
+	if (if_com_alloc[type] != NULL) {
+		ifp->if_l2com = if_com_alloc[type](type, ifp);
+		if (ifp->if_l2com == NULL)
+			free(ifp, M_IFNET);
+	}
+
+	return (ifp);
+}
+
+void
+if_free(struct ifnet *ifp)
+{
+
+	if_free_type(ifp, ifp->if_type);
+}
+
+void
+if_free_type(struct ifnet *ifp, u_char type)
+{
+
+	if (ifp != ifnet_byindex(ifp->if_index)) {
+		if_printf(ifp, "%s: value was not if_alloced, skipping\n",
+		    __func__);
+		return;
+	}
+
+	if (if_com_free[type] != NULL)
+		if_com_free[type](ifp->if_l2com, type);
+
+	free(ifp, M_IFNET);
+};
+
+/*
  * Attach an interface to the
  * list of "active" interfaces.
  */
@@ -387,6 +444,10 @@ if_attach(struct ifnet *ifp)
 	struct sockaddr_dl *sdl;
 	struct ifaddr *ifa;
 
+	if (ifp->if_index == 0 || ifp != ifnet_byindex(ifp->if_index))
+		panic ("%s: BUG: if_attach called without if_alloc'd input()\n",
+		    ifp->if_xname);
+
 	TASK_INIT(&ifp->if_starttask, 0, if_start_deferred, ifp);
 	TASK_INIT(&ifp->if_linktask, 0, do_link_state_change, ifp);
 	IF_AFDATA_LOCK_INIT(ifp);
@@ -407,20 +468,13 @@ if_attach(struct ifnet *ifp)
 	knlist_init(&ifp->if_klist, NULL);
 	getmicrotime(&ifp->if_lastchange);
 	ifp->if_data.ifi_epoch = time_uptime;
+	ifp->if_data.ifi_datalen = sizeof(struct if_data);
 
 #ifdef MAC
 	mac_init_ifnet(ifp);
 	mac_create_ifnet(ifp);
 #endif
 
-	ifp->if_index = if_findindex(ifp);
-	if (ifp->if_index > if_index)
-		if_index = ifp->if_index;
-	if (if_index >= if_indexlim)
-		if_grow();
-	ifp->if_data.ifi_datalen = sizeof(struct if_data);
-
-	ifnet_byindex(ifp->if_index) = ifp;
 	ifdev_byindex(ifp->if_index) = make_dev(&net_cdevsw,
 	    unit2minor(ifp->if_index),
 	    UID_ROOT, GID_WHEEL, 0600, "%s/%s",
@@ -572,7 +626,7 @@ if_purgeaddrs(struct ifnet *ifp)
 
 /*
  * Detach an interface, removing it from the
- * list of "active" interfaces.
+ * list of "active" interfaces and freeing the struct ifnet.
  */
 void
 if_detach(struct ifnet *ifp)
@@ -1942,7 +1996,7 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
 	case IFT_ISO88025:
 	case IFT_L2VLAN:
 	case IFT_BRIDGE:
-		bcopy(lladdr, IFP2AC(ifp)->ac_enaddr, len);
+		bcopy(lladdr, IFP2ENADDR(ifp), len);
 		/*
 		 * XXX We also need to store the lladdr in LLADDR(sdl),
 		 * which is done below. This is a pain because we must
@@ -2066,7 +2120,7 @@ if_start_deferred(void *context, int pending)
 	KASSERT(debug_mpsafenet != 0, ("if_start_deferred: debug.mpsafenet"));
 	GIANT_REQUIRED;
 
-	ifp = (struct ifnet *)context;
+	ifp = context;
 	(ifp->if_start)(ifp);
 }
 
@@ -2094,3 +2148,29 @@ if_handoff(struct ifqueue *ifq, struct mbuf *m, struct ifnet *ifp, int adjust)
 		if_start(ifp);
 	return (1);
 }
+
+void
+if_register_com_alloc(u_char type,
+    if_com_alloc_t *a, if_com_free_t *f)
+{
+	
+	KASSERT(if_com_alloc[type] == NULL,
+	    ("if_register_com_alloc: %d already registered", type));
+	KASSERT(if_com_free[type] == NULL,
+	    ("if_register_com_alloc: %d free already registered", type));
+
+	if_com_alloc[type] = a;
+	if_com_free[type] = f;
+}
+
+void
+if_deregister_com_alloc(u_char type)
+{
+	
+	KASSERT(if_com_alloc[type] == NULL,
+	    ("if_deregister_com_alloc: %d not registered", type));
+	KASSERT(if_com_free[type] == NULL,
+	    ("if_deregister_com_alloc: %d free not registered", type));
+	if_com_alloc[type] = NULL;
+	if_com_free[type] = NULL;
+}
diff --git a/sys/net/if_arc.h b/sys/net/if_arc.h
index 461f1b4..7274829 100644
--- a/sys/net/if_arc.h
+++ b/sys/net/if_arc.h
@@ -102,7 +102,7 @@ struct	arc_header {
 #define ARC_PHDS_MAXMTU		60480
 
 struct	arccom {
-	struct	  ifnet ac_if;		/* network-visible interface */
+	struct	  ifnet *ac_ifp;	/* network-visible interface */
 
 	u_int16_t ac_seqid;		/* seq. id used by PHDS encap. */
 
diff --git a/sys/net/if_arcsubr.c b/sys/net/if_arcsubr.c
index 39022ef..e944f49 100644
--- a/sys/net/if_arcsubr.c
+++ b/sys/net/if_arcsubr.c
@@ -80,8 +80,6 @@
 #include <netipx/ipx_if.h>
 #endif
 
-MODULE_VERSION(arcnet, 1);
-
 #define ARCNET_ALLOW_BROKEN_ARP
 
 static struct mbuf *arc_defrag(struct ifnet *, struct mbuf *);
@@ -254,7 +252,7 @@ arc_frag_init(ifp)
 {
 	struct arccom *ac;
 
-	ac = (struct arccom *)ifp;
+	ac = (struct arccom *)ifp->if_l2com;
 	ac->curr_frag = 0;
 }
 
@@ -266,7 +264,7 @@ arc_frag_next(ifp)
 	struct mbuf *m;
 	struct arc_header *ah;
 
-	ac = (struct arccom *)ifp;
+	ac = (struct arccom *)ifp->if_l2com;
 	if ((m = ac->curr_frag) == 0) {
 		int tfrags;
 
@@ -367,7 +365,7 @@ arc_defrag(ifp, m)
 	int newflen;
 	u_char src,dst,typ;
 
-	ac = (struct arccom *)ifp;
+	ac = (struct arccom *)ifp->if_l2com;
 
 	if (m->m_len < ARC_HDRNEWLEN) {
 		m = m_pullup(m, ARC_HDRNEWLEN);
@@ -641,7 +639,6 @@ arc_ifattach(ifp, lla)
 	struct arccom *ac;
 
 	if_attach(ifp);
-	ifp->if_type = IFT_ARCNET;
 	ifp->if_addrlen = 1;
 	ifp->if_hdrlen = ARC_HDRLEN;
 	ifp->if_mtu = 1500;
@@ -661,7 +658,7 @@ arc_ifattach(ifp, lla)
 	if (ifp->if_flags & IFF_BROADCAST)
 		ifp->if_flags |= IFF_MULTICAST|IFF_ALLMULTI;
 
-	ac = (struct arccom *)ifp;
+	ac = (struct arccom *)ifp->if_l2com;
 	ac->ac_seqid = (time_second) & 0xFFFF; /* try to make seqid unique */
 	if (lla == 0) {
 		/* XXX this message isn't entirely clear, to me -- cgd */
@@ -846,3 +843,50 @@ arc_resolvemulti(ifp, llsa, sa)
 		return EAFNOSUPPORT;
 	}
 }
+
+MALLOC_DEFINE(M_ARCCOM, "arccom", "ARCNET interface internals");
+
+static void*
+arc_alloc(u_char type, struct ifnet *ifp)
+{
+	struct arccom	*ac;
+	
+	ac = malloc(sizeof(struct arccom), M_ARCCOM, M_WAITOK | M_ZERO);
+	ac->ac_ifp = ifp;
+
+	return (ac);
+}
+
+static void
+arc_free(void *com, u_char type)
+{
+
+	free(com, M_ARCCOM);
+}
+
+static int
+arc_modevent(module_t mod, int type, void *data)
+{
+
+	switch (type) {
+	case MOD_LOAD:
+		if_register_com_alloc(IFT_ARCNET, arc_alloc, arc_free);
+		break;
+	case MOD_UNLOAD:
+		if_deregister_com_alloc(IFT_ARCNET);
+		break;
+	default:
+		return EOPNOTSUPP;
+	}
+
+	return (0);
+}
+
+static moduledata_t arc_mod = {
+	"arcnet",
+	arc_modevent,
+	0
+};
+
+DECLARE_MODULE(arcnet, arc_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
+MODULE_VERSION(arcnet, 1);
diff --git a/sys/net/if_arp.h b/sys/net/if_arp.h
index 71f078b..9aa63c6 100644
--- a/sys/net/if_arp.h
+++ b/sys/net/if_arp.h
@@ -99,21 +99,16 @@ struct arpreq {
 #ifdef _KERNEL
 /*
  * Structure shared between the ethernet driver modules and
- * the address resolution code.  For example, each ec_softc or il_softc
- * begins with this structure.
- * The code is written so that each *_softc _must_ begin with a
- * struct arpcom, which in turn _must_ begin with a struct ifnet.
+ * the address resolution code.
  */
 struct	arpcom {
-	/*
-	 * The ifnet struct _must_ be at the head of this structure.
-	 */
-	struct 	ifnet ac_if;		/* network-visible interface */
-	u_char	ac_enaddr[6];		/* ethernet hardware address */
-	int	now_unused;	/* XXX was length of ac_multiaddrs list */
+	struct 	ifnet *ac_ifp;		/* network-visible interface */
+	u_char	_ac_enaddr[6];		/* ethernet hardware address */
 	void	*ac_netgraph;		/* ng_ether(4) netgraph node info */
 };
-#define IFP2AC(ifp) ((struct arpcom *)(ifp))
+#define IFP2AC(ifp) ((struct arpcom *)(ifp->if_l2com))
+#define IFP2ENADDR(ifp) (IFP2AC(ifp)->_ac_enaddr)
+#define AC2IFP(ac) ((ac)->ac_ifp)
 
 #endif
 
diff --git a/sys/net/if_atm.h b/sys/net/if_atm.h
index 4084569..4b07f36 100644
--- a/sys/net/if_atm.h
+++ b/sys/net/if_atm.h
@@ -176,11 +176,12 @@ struct atmio_vcctable {
  * this structure.
  */
 struct ifatm {
-	struct ifnet	ifnet;		/* required by if_var.h */
+	struct ifnet	*ifp;
 	struct ifatm_mib mib;		/* exported data */
 	void		*phy;		/* usually SUNI */
 	void		*ngpriv;	/* netgraph link */
 };
+#define	IFP2IFATM(ifp)	((struct ifatm *)(ifp)->if_l2com)
 #endif
 
 /*
@@ -304,7 +305,7 @@ void	atm_event(struct ifnet *, u_int, void *);
 		_arg.vpi = (VPI);					\
 		_arg.vci = (VCI);					\
 		_arg.busy = (BUSY);					\
-		atm_event(&(ATMIF)->ifnet, ATMEV_FLOW_CONTROL, &_arg);	\
+		atm_event((ATMIF)->ifp, ATMEV_FLOW_CONTROL, &_arg);	\
 	} while (0)
 
 #define	ATMEV_SEND_VCC_CHANGED(ATMIF, VPI, VCI, UP)			\
@@ -313,16 +314,16 @@ void	atm_event(struct ifnet *, u_int, void *);
 		_arg.vpi = (VPI);					\
 		_arg.vci = (VCI);					\
 		_arg.up = (UP);						\
-		atm_event(&(ATMIF)->ifnet, ATMEV_VCC_CHANGED, &_arg);	\
+		atm_event((ATMIF)->ifp, ATMEV_VCC_CHANGED, &_arg);	\
 	} while (0)
 
 #define	ATMEV_SEND_IFSTATE_CHANGED(ATMIF, CARRIER)			\
 	do {								\
 		struct atmev_ifstate_changed _arg;			\
-		_arg.running = (((ATMIF)->ifnet.if_flags &		\
+		_arg.running = (((ATMIF)->ifp->if_flags &		\
 		    IFF_RUNNING) != 0);					\
 		_arg.carrier = ((CARRIER) != 0);			\
-		atm_event(&(ATMIF)->ifnet, ATMEV_IFSTATE_CHANGED, &_arg); \
+		atm_event((ATMIF)->ifp, ATMEV_IFSTATE_CHANGED, &_arg); \
 	} while (0)
 
 #define	ATMEV_SEND_ACR_CHANGED(ATMIF, VPI, VCI, ACR)			\
@@ -331,6 +332,6 @@ void	atm_event(struct ifnet *, u_int, void *);
 		_arg.vpi = (VPI);					\
 		_arg.vci = (VCI);					\
 		_arg.acr= (ACR);					\
-		atm_event(&(ATMIF)->ifnet, ATMEV_ACR_CHANGED, &_arg);	\
+		atm_event((ATMIF)->ifp, ATMEV_ACR_CHANGED, &_arg);	\
 	} while (0)
 #endif
diff --git a/sys/net/if_atmsubr.c b/sys/net/if_atmsubr.c
index a5f7b11..1350f5a 100644
--- a/sys/net/if_atmsubr.c
+++ b/sys/net/if_atmsubr.c
@@ -98,6 +98,8 @@ void	(*atm_harp_event_p)(struct ifnet *, uint32_t, void *);
 
 SYSCTL_NODE(_hw, OID_AUTO, atm, CTLFLAG_RW, 0, "ATM hardware");
 
+MALLOC_DEFINE(M_IFATM, "ifatm", "atm interface internals");
+
 #ifndef ETHERTYPE_IPV6
 #define	ETHERTYPE_IPV6	0x86dd
 #endif
@@ -359,9 +361,8 @@ atm_ifattach(struct ifnet *ifp)
 {
 	struct ifaddr *ifa;
 	struct sockaddr_dl *sdl;
-	struct ifatm *ifatm = ifp->if_softc;
+	struct ifatm *ifatm = ifp->if_l2com;
 
-	ifp->if_type = IFT_ATM;
 	ifp->if_addrlen = 0;
 	ifp->if_hdrlen = 0;
 	if_attach(ifp);
@@ -481,11 +482,46 @@ atm_event(struct ifnet *ifp, u_int event, void *arg)
 		(*atm_harp_event_p)(ifp, event, arg);
 }
 
+static void *
+atm_alloc(u_char type, struct ifnet *ifp)
+{
+	struct ifatm	*ifatm;
+
+	ifatm = malloc(sizeof(struct ifatm), M_IFATM, M_WAITOK | M_ZERO);
+	ifatm->ifp = ifp;
+
+	return (ifatm);
+}
+
+static void
+atm_free(void *com, u_char type)
+{
+
+	free(com, M_IFATM);
+}
+
+static int
+atm_modevent(module_t mod, int type, void *data)
+{
+	switch (type) {
+	case MOD_LOAD:
+		if_register_com_alloc(IFT_ATM, atm_alloc, atm_free);
+		break;
+	case MOD_UNLOAD:
+		if_deregister_com_alloc(IFT_ATM);
+		break;
+	default:
+		return (EOPNOTSUPP);
+	}
+
+	return (0);
+}
+
 static moduledata_t atm_mod = {
         "atm",
-        NULL,
+        atm_modevent,
         0
 };
                 
-DECLARE_MODULE(atm, atm_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
+DECLARE_MODULE(atm, atm_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 MODULE_VERSION(atm, 1);
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index df52232..0b4fa9d 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -130,7 +130,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_fw.h>
 #include <netinet/ip_dummynet.h>
 
-#define sc_if ifb_ac.ac_if
 /*
  * Size of the route hash table.  Must be a power of two.
  */
@@ -357,7 +356,7 @@ bridge_modevent(module_t mod, int type, void *data)
 	case MOD_UNLOAD:
 		if_clone_detach(&bridge_cloner);
 		while (!LIST_EMPTY(&bridge_list))
-			bridge_clone_destroy(&LIST_FIRST(&bridge_list)->sc_if);
+			bridge_clone_destroy(LIST_FIRST(&bridge_list)->sc_ifp);
 		uma_zdestroy(bridge_rtnode_zone);
 		bridge_input_p = NULL;
 		bridge_output_p = NULL;
@@ -419,10 +418,11 @@ bridge_clone_create(struct if_clone *ifc, int unit)
 {
 	struct bridge_softc *sc;
 	struct ifnet *ifp;
+	u_char eaddr[6];
 
 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
 	BRIDGE_LOCK_INIT(sc);
-	ifp = &sc->sc_if;
+	ifp = sc->sc_ifp;
 
 	sc->sc_brtmax = BRIDGE_RTABLE_MAX;
 	sc->sc_brttimeout = BRIDGE_RTABLE_TIMEOUT;
@@ -457,12 +457,12 @@ bridge_clone_create(struct if_clone *ifc, int unit)
 	 * Generate a random ethernet address and use the private AC:DE:48
 	 * OUI code.
 	 */
-	arc4rand( &sc->ifb_ac.ac_enaddr, ETHER_ADDR_LEN, 1);
-	sc->ifb_ac.ac_enaddr[0] = 0xAC;
-	sc->ifb_ac.ac_enaddr[1] = 0xDE;
-	sc->ifb_ac.ac_enaddr[2] = 0x48;
+	arc4rand(eaddr, ETHER_ADDR_LEN, 1);
+	eaddr[0] = 0xAC;
+	eaddr[1] = 0xDE;
+	eaddr[2] = 0x48;
 
-	ether_ifattach(ifp, sc->ifb_ac.ac_enaddr);
+	ether_ifattach(ifp, eaddr);
 	/* Now undo some of the damage... */
 	ifp->if_baudrate = 0;
 	ifp->if_type = IFT_BRIDGE;
@@ -693,7 +693,7 @@ bridge_delete_member(struct bridge_softc *sc, struct bridge_iflist *bif)
 
 	free(bif, M_DEVBUF);
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 }
 
@@ -711,7 +711,7 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
 	if (ifs == NULL)
 		return (ENOENT);
 
-	if (sc->sc_if.if_mtu != ifs->if_mtu)
+	if (sc->sc_ifp->if_mtu != ifs->if_mtu)
 		return (EINVAL);
 
 	if (ifs->if_bridge == sc)
@@ -753,7 +753,7 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
 	 */
 	LIST_INSERT_HEAD(&sc->sc_iflist, bif, bif_next);
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 	else
 		bstp_stop(sc);
@@ -830,7 +830,7 @@ bridge_ioctl_sifflags(struct bridge_softc *sc, void *arg)
 
 	bif->bif_flags = req->ifbr_ifsflags;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1031,7 +1031,7 @@ bridge_ioctl_spri(struct bridge_softc *sc, void *arg)
 
 	sc->sc_bridge_priority = param->ifbrp_prio;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1060,7 +1060,7 @@ bridge_ioctl_sht(struct bridge_softc *sc, void *arg)
 		return (EINVAL);
 	sc->sc_bridge_hello_time = param->ifbrp_hellotime << 8;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1089,7 +1089,7 @@ bridge_ioctl_sfd(struct bridge_softc *sc, void *arg)
 		return (EINVAL);
 	sc->sc_bridge_forward_delay = param->ifbrp_fwddelay << 8;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1118,7 +1118,7 @@ bridge_ioctl_sma(struct bridge_softc *sc, void *arg)
 		return (EINVAL);
 	sc->sc_bridge_max_age = param->ifbrp_maxage << 8;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1138,7 +1138,7 @@ bridge_ioctl_sifprio(struct bridge_softc *sc, void *arg)
 
 	bif->bif_priority = req->ifbr_priority;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1158,7 +1158,7 @@ bridge_ioctl_sifcost(struct bridge_softc *sc, void *arg)
 
 	bif->bif_path_cost = req->ifbr_path_cost;
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		bstp_initialization(sc);
 
 	return (0);
@@ -1193,7 +1193,7 @@ static void
 bridge_init(void *xsc)
 {
 	struct bridge_softc *sc = (struct bridge_softc *)xsc;
-	struct ifnet *ifp = &sc->sc_if;
+	struct ifnet *ifp = sc->sc_ifp;
 
 	if (ifp->if_flags & IFF_RUNNING)
 		return;
@@ -1246,7 +1246,7 @@ bridge_enqueue(struct bridge_softc *sc, struct ifnet *dst_ifp, struct mbuf *m,
 	m->m_pkthdr.csum_flags = 0;
 
 	if (runfilt && inet_pfil_hook.ph_busy_count >= 0) {
-		if (bridge_pfil(&m, &sc->sc_if, dst_ifp, PFIL_OUT) != 0)
+		if (bridge_pfil(&m, sc->sc_ifp, dst_ifp, PFIL_OUT) != 0)
 			return;
 	}
 	if (m == NULL)
@@ -1257,13 +1257,13 @@ bridge_enqueue(struct bridge_softc *sc, struct ifnet *dst_ifp, struct mbuf *m,
 	IFQ_ENQUEUE(&dst_ifp->if_snd, m, err);
 	if (err == 0) {
 
-		sc->sc_if.if_opackets++;
-		sc->sc_if.if_obytes += len;
+		sc->sc_ifp->if_opackets++;
+		sc->sc_ifp->if_obytes += len;
 
 		dst_ifp->if_obytes += len;
 
 		if (mflags & M_MCAST) {
-			sc->sc_if.if_omcasts++;
+			sc->sc_ifp->if_omcasts++;
 			dst_ifp->if_omcasts++;
 		}
 	}
@@ -1334,7 +1334,7 @@ bridge_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
 	 * go ahead and send out that interface.  Otherwise, the packet
 	 * is dropped below.
 	 */
-	if ((sc->sc_if.if_flags & IFF_RUNNING) == 0) {
+	if ((sc->sc_ifp->if_flags & IFF_RUNNING) == 0) {
 		dst_if = ifp;
 		goto sendunicast;
 	}
@@ -1384,7 +1384,7 @@ bridge_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
 			} else {
 				mc = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
 				if (mc == NULL) {
-					sc->sc_if.if_oerrors++;
+					sc->sc_ifp->if_oerrors++;
 					continue;
 				}
 			}
@@ -1472,10 +1472,10 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 
 	src_if = m->m_pkthdr.rcvif;
 	BRIDGE_LOCK_ASSERT(sc);
-	ifp = &sc->sc_if;
+	ifp = sc->sc_ifp;
 
-	sc->sc_if.if_ipackets++;
-	sc->sc_if.if_ibytes += m->m_pkthdr.len;
+	sc->sc_ifp->if_ipackets++;
+	sc->sc_ifp->if_ibytes += m->m_pkthdr.len;
 
 	/*
 	 * Look up the bridge_iflist.
@@ -1543,7 +1543,7 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 		}
 	} else {
 		/* ...forward it to all interfaces. */
-		sc->sc_if.if_imcasts++;
+		sc->sc_ifp->if_imcasts++;
 		dst_if = NULL;
 	}
 
@@ -1615,7 +1615,7 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 	struct ether_header *eh;
 	struct mbuf *mc;
 
-	if ((sc->sc_if.if_flags & IFF_RUNNING) == 0)
+	if ((sc->sc_ifp->if_flags & IFF_RUNNING) == 0)
 		return (m);
 
 	BRIDGE_LOCK(sc);
@@ -1627,7 +1627,7 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 
 	eh = mtod(m, struct ether_header *);
 
-	if (memcmp(eh->ether_dhost, sc->ifb_ac.ac_enaddr,
+	if (memcmp(eh->ether_dhost, IFP2ENADDR(sc->sc_ifp),
 	    ETHER_ADDR_LEN) == 0) {
 		/*
 		 * If the packet is for us, set the packets source as the
@@ -1640,9 +1640,9 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 		 */
 
 		/* Mark the packet as arriving on the bridge interface */
-		m->m_pkthdr.rcvif = &sc->sc_if;
-		BPF_MTAP(&sc->sc_if, m);
-		sc->sc_if.if_ipackets++;
+		m->m_pkthdr.rcvif = sc->sc_ifp;
+		BPF_MTAP(sc->sc_ifp, m);
+		sc->sc_ifp->if_ipackets++;
 
 		BRIDGE_UNLOCK(sc);
 		return (m);
@@ -1778,7 +1778,7 @@ bridge_broadcast(struct bridge_softc *sc, struct ifnet *src_if,
 		} else {
 			mc = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
 			if (mc == NULL) {
-				sc->sc_if.if_oerrors++;
+				sc->sc_ifp->if_oerrors++;
 				continue;
 			}
 		}
@@ -1909,7 +1909,7 @@ bridge_timer(void *arg)
 	bridge_rtage(sc);
 	BRIDGE_UNLOCK(sc);
 
-	if (sc->sc_if.if_flags & IFF_RUNNING)
+	if (sc->sc_ifp->if_flags & IFF_RUNNING)
 		callout_reset(&sc->sc_brcallout,
 		    bridge_rtable_prune_period * hz, bridge_timer, sc);
 }
diff --git a/sys/net/if_bridgevar.h b/sys/net/if_bridgevar.h
index 705ed85..1bc948b 100644
--- a/sys/net/if_bridgevar.h
+++ b/sys/net/if_bridgevar.h
@@ -262,7 +262,7 @@ struct bridge_rtnode {
  * Software state for each bridge.
  */
 struct bridge_softc {
-	struct arpcom		ifb_ac;		/* make this an interface */
+	struct ifnet		*sc_ifp;	/* make this an interface */
 	LIST_ENTRY(bridge_softc) sc_list;
 	struct mtx		sc_mtx;
 	struct cv		sc_cv;
diff --git a/sys/net/if_disc.c b/sys/net/if_disc.c
index 3068b44..7789b29 100644
--- a/sys/net/if_disc.c
+++ b/sys/net/if_disc.c
@@ -62,7 +62,7 @@
 #define DISCNAME	"disc"
 
 struct disc_softc {
-	struct ifnet sc_if;	/* must be first */
+	struct ifnet *sc_ifp;	/* must be first */
 	LIST_ENTRY(disc_softc) sc_list;
 };
 
@@ -86,8 +86,11 @@ disc_clone_create(struct if_clone *ifc, int unit)
 	struct disc_softc	*sc;
 
 	sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO);
-
-	ifp = &sc->sc_if;
+	ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
+	if (ifp == NULL) {
+		free(sc, M_DISC);
+		return (ENOSPC);
+	}
 
 	ifp->if_softc = sc;
 	if_initname(ifp, ifc->ifc_name, unit);
@@ -95,7 +98,6 @@ disc_clone_create(struct if_clone *ifc, int unit)
 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 	ifp->if_ioctl = discioctl;
 	ifp->if_output = discoutput;
-	ifp->if_type = IFT_LOOP;
 	ifp->if_hdrlen = 0;
 	ifp->if_addrlen = 0;
 	ifp->if_snd.ifq_maxlen = 20;
@@ -112,8 +114,9 @@ static void
 disc_destroy(struct disc_softc *sc)
 {
 
-	bpfdetach(&sc->sc_if);
-	if_detach(&sc->sc_if);
+	bpfdetach(sc->sc_ifp);
+	if_detach(sc->sc_ifp);
+	if_free(sc->sc_ifp);
 
 	free(sc, M_DISC);
 }
diff --git a/sys/net/if_ef.c b/sys/net/if_ef.c
index fa8ac6e..f615485 100644
--- a/sys/net/if_ef.c
+++ b/sys/net/if_ef.c
@@ -86,8 +86,8 @@
 #define EFERROR(format, args...) printf("%s: "format, __func__ ,## args)
 
 struct efnet {
-	struct arpcom	ef_ac;
-	struct ifnet *  ef_ifp;
+	struct ifnet	*ef_ifp;
+	struct ifnet	*ef_pifp;
 	int		ef_frametype;
 };
 
@@ -125,7 +125,7 @@ static int ef_unload(void);
 static int
 ef_attach(struct efnet *sc)
 {
-	struct ifnet *ifp = (struct ifnet*)&sc->ef_ac.ac_if;
+	struct ifnet *ifp = sc->ef_ifp;
 	struct ifaddr *ifa2;
 	struct sockaddr_dl *sdl2;
 
@@ -137,7 +137,7 @@ ef_attach(struct efnet *sc)
 	/*
 	 * Attach the interface
 	 */
-	ifa2 = ifaddr_byindex(sc->ef_ifp->if_index);
+	ifa2 = ifaddr_byindex(sc->ef_pifp->if_index);
 	sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
 	ether_ifattach(ifp, LLADDR(sdl2));
 
@@ -145,8 +145,6 @@ ef_attach(struct efnet *sc)
 	ifp->if_type = IFT_XETHER;
 	ifp->if_flags |= IFF_RUNNING;
 
-	bcopy(LLADDR(sdl2), sc->ef_ac.ac_enaddr, ETHER_ADDR_LEN);
-
 	EFDEBUG("%s: attached\n", ifp->if_xname);
 	return 1;
 }
@@ -157,24 +155,14 @@ ef_attach(struct efnet *sc)
 static int
 ef_detach(struct efnet *sc)
 {
-	struct ifnet *ifp = (struct ifnet*)&sc->ef_ac.ac_if;
+	struct ifnet *ifp = sc->ef_ifp;
 	int s;
 
 	s = splimp();
 
-	if (ifp->if_flags & IFF_UP) {
-		if_down(ifp);
-		if (ifp->if_flags & IFF_RUNNING) {
-		    /* find internet addresses and delete routes */
-		    register struct ifaddr *ifa;
-		    TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-			    rtinit(ifa, (int)RTM_DELETE, 0);
-		    }
-		}
-	}
-	IFNET_WLOCK();
-	TAILQ_REMOVE(&ifnet, ifp, if_link);
-	IFNET_WUNLOCK();
+	ether_ifdetach(ifp);
+	if_free(ifp);
+
 	splx(s);
 	return 0;
 }
@@ -227,7 +215,7 @@ ef_start(struct ifnet *ifp)
 	int error;
 
 	ifp->if_flags |= IFF_OACTIVE;
-	p = sc->ef_ifp;
+	p = sc->ef_pifp;
 
 	EFDEBUG("\n");
 	for (;;) {
@@ -377,7 +365,7 @@ ef_input(struct ifnet *ifp, struct ether_header *eh, struct mbuf *m)
 		EFDEBUG("Can't find if for %d\n", ft);
 		return EPROTONOSUPPORT;
 	}
-	eifp = &efp->ef_ac.ac_if;
+	eifp = efp->ef_ifp;
 	if ((eifp->if_flags & IFF_UP) == 0)
 		return EPROTONOSUPPORT;
 	eifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
@@ -486,9 +474,11 @@ ef_clone(struct ef_link *efl, int ft)
 	    M_WAITOK | M_ZERO);
 	if (efp == NULL)
 		return ENOMEM;
-	efp->ef_ifp = ifp;
+	efp->ef_pifp = ifp;
 	efp->ef_frametype = ft;
-	eifp = &efp->ef_ac.ac_if;
+	eifp = efp->ef_ifp = if_alloc(IFT_ETHER);
+	if (ifp == NULL)
+		return (ENOSPC);
 	snprintf(eifp->if_xname, IFNAMSIZ,
 	    "%sf%d", ifp->if_xname, efp->ef_frametype);
 	eifp->if_dname = "ef";
@@ -545,8 +535,11 @@ ef_load(void)
 			SLIST_INSERT_HEAD(&efdev, efl, el_next);
 		SLIST_FOREACH(efl, &efdev, el_next) {
 			for (d = 0; d < EF_NFT; d++)
-				if (efl->el_units[d])
+				if (efl->el_units[d]) {
+					if (efl->el_units[d]->ef_pifp != NULL)
+						if_free(efl->el_units[d]->ef_pifp);
 					free(efl->el_units[d], M_IFADDR);
+				}
 			free(efl, M_IFADDR);
 		}
 		return error;
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 6082624..cf0b299 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -125,6 +125,9 @@ static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
 static	int ether_resolvemulti(struct ifnet *, struct sockaddr **,
 		struct sockaddr *);
 
+/* XXX: should be in an arp support file, not here */
+MALLOC_DEFINE(M_ARPCOM, "arpcom", "802.* interface internals");
+
 #define senderr(e) do { error = (e); goto bad;} while (0)
 
 #if defined(INET) || defined(INET6)
@@ -285,7 +288,7 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 		(void)memcpy(eh->ether_shost, esrc,
 			sizeof(eh->ether_shost));
 	else
-		(void)memcpy(eh->ether_shost, IFP2AC(ifp)->ac_enaddr,
+		(void)memcpy(eh->ether_shost, IFP2ENADDR(ifp),
 			sizeof(eh->ether_shost));
 
        /*
@@ -670,7 +673,7 @@ ether_demux(struct ifnet *ifp, struct mbuf *m)
 		/*
 		 * XXX: Okay, we need to call carp_forus() and - if it is for
 		 * us jump over code that does the normal check
-		 * "ac_enaddr == ether_dhost". The check sequence is a bit
+		 * "IFP2ENADDR(ifp) == ether_dhost". The check sequence is a bit
 		 * different from OpenBSD, so we jump over as few code as
 		 * possible, to catch _all_ sanity checks. This needs
 		 * evaluation, to see if the carp ether_dhost values break any
@@ -694,7 +697,7 @@ ether_demux(struct ifnet *ifp, struct mbuf *m)
 		if ((ifp->if_flags & IFF_PROMISC) != 0
 		    && !ETHER_IS_MULTICAST(eh->ether_dhost)
 		    && bcmp(eh->ether_dhost,
-		      IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN) != 0
+		      IFP2ENADDR(ifp), ETHER_ADDR_LEN) != 0
 		    && (ifp->if_flags & IFF_PPROMISC) == 0) {
 			    m_freem(m);
 			    return;
@@ -891,7 +894,6 @@ ether_ifattach(struct ifnet *ifp, const u_int8_t *llc)
 	struct ifaddr *ifa;
 	struct sockaddr_dl *sdl;
 
-	ifp->if_type = IFT_ETHER;
 	ifp->if_addrlen = ETHER_ADDR_LEN;
 	ifp->if_hdrlen = ETHER_HDR_LEN;
 	if_attach(ifp);
@@ -913,8 +915,8 @@ ether_ifattach(struct ifnet *ifp, const u_int8_t *llc)
 	 * XXX: This doesn't belong here; we do it until
 	 * XXX:  all drivers are cleaned up
 	 */
-	if (llc != IFP2AC(ifp)->ac_enaddr)
-		bcopy(llc, IFP2AC(ifp)->ac_enaddr, ifp->if_addrlen);
+	if (llc != IFP2ENADDR(ifp))
+		bcopy(llc, IFP2ENADDR(ifp), ifp->if_addrlen);
 
 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
 	if (ng_ether_attach_p != NULL)
@@ -1051,16 +1053,15 @@ ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
 		case AF_IPX:
 			{
 			struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
-			struct arpcom *ac = IFP2AC(ifp);
 
 			if (ipx_nullhost(*ina))
 				ina->x_host =
 				    *(union ipx_host *)
-				    ac->ac_enaddr;
+				    IFP2ENADDR(ifp);
 			else {
 				bcopy((caddr_t) ina->x_host.c_host,
-				      (caddr_t) ac->ac_enaddr,
-				      sizeof(ac->ac_enaddr));
+				      (caddr_t) IFP2ENADDR(ifp),
+				      ETHER_ADDR_LEN);
 			}
 
 			/*
@@ -1081,7 +1082,7 @@ ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
 			struct sockaddr *sa;
 
 			sa = (struct sockaddr *) & ifr->ifr_data;
-			bcopy(IFP2AC(ifp)->ac_enaddr,
+			bcopy(IFP2ENADDR(ifp),
 			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
 		}
 		break;
@@ -1182,11 +1183,47 @@ ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
 	}
 }
 
+static void*
+ether_alloc(u_char type, struct ifnet *ifp)
+{
+	struct arpcom	*ac;
+	
+	ac = malloc(sizeof(struct arpcom), M_ARPCOM, M_WAITOK | M_ZERO);
+	ac->ac_ifp = ifp;
+
+	return (ac);
+}
+
+static void
+ether_free(void *com, u_char type)
+{
+
+	free(com, M_ARPCOM);
+}
+
+static int
+ether_modevent(module_t mod, int type, void *data)
+{
+
+	switch (type) {
+	case MOD_LOAD:
+		if_register_com_alloc(IFT_ETHER, ether_alloc, ether_free);
+		break;
+	case MOD_UNLOAD:
+		if_deregister_com_alloc(IFT_ETHER);
+		break;
+	default:
+		return EOPNOTSUPP;
+	}
+
+	return (0);
+}
+
 static moduledata_t ether_mod = {
 	"ether",
-	NULL,
+	ether_modevent,
 	0
 };
 
-DECLARE_MODULE(ether, ether_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
+DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 MODULE_VERSION(ether, 1);
diff --git a/sys/net/if_faith.c b/sys/net/if_faith.c
index 392ff0d..5835811 100644
--- a/sys/net/if_faith.c
+++ b/sys/net/if_faith.c
@@ -83,7 +83,7 @@
 #define FAITHNAME	"faith"
 
 struct faith_softc {
-	struct ifnet sc_if;	/* must be first */
+	struct ifnet *sc_ifp;
 	LIST_ENTRY(faith_softc) sc_list;
 };
 
@@ -165,24 +165,29 @@ faith_clone_create(ifc, unit)
 	struct if_clone *ifc;
 	int unit;
 {
+	struct ifnet *ifp;
 	struct faith_softc *sc;
 
 	sc = malloc(sizeof(struct faith_softc), M_FAITH, M_WAITOK | M_ZERO);
+	ifp = sc->sc_ifp = if_alloc(IFT_FAITH);
+	if (ifp == NULL) {
+		free(sc, M_FAITH);
+		return (ENOSPC);
+	}
 
-	sc->sc_if.if_softc = sc;
-	if_initname(&sc->sc_if, ifc->ifc_name, unit);
+	ifp->if_softc = sc;
+	if_initname(sc->sc_ifp, ifc->ifc_name, unit);
 
-	sc->sc_if.if_mtu = FAITHMTU;
+	ifp->if_mtu = FAITHMTU;
 	/* Change to BROADCAST experimentaly to announce its prefix. */
-	sc->sc_if.if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST;
-	sc->sc_if.if_ioctl = faithioctl;
-	sc->sc_if.if_output = faithoutput;
-	sc->sc_if.if_type = IFT_FAITH;
-	sc->sc_if.if_hdrlen = 0;
-	sc->sc_if.if_addrlen = 0;
-	sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen;
-	if_attach(&sc->sc_if);
-	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int));
+	ifp->if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST;
+	ifp->if_ioctl = faithioctl;
+	ifp->if_output = faithoutput;
+	ifp->if_hdrlen = 0;
+	ifp->if_addrlen = 0;
+	ifp->if_snd.ifq_maxlen = ifqmaxlen;
+	if_attach(ifp);
+	bpfattach(ifp, DLT_NULL, sizeof(u_int));
 	mtx_lock(&faith_mtx);
 	LIST_INSERT_HEAD(&faith_softc_list, sc, sc_list);
 	mtx_unlock(&faith_mtx);
@@ -193,8 +198,9 @@ static void
 faith_destroy(struct faith_softc *sc)
 {
 
-	bpfdetach(&sc->sc_if);
-	if_detach(&sc->sc_if);
+	bpfdetach(sc->sc_ifp);
+	if_detach(sc->sc_ifp);
+	if_free(sc->sc_ifp);
 	free(sc, M_FAITH);
 }
 
@@ -202,7 +208,7 @@ static void
 faith_clone_destroy(ifp)
 	struct ifnet *ifp;
 {
-	struct faith_softc *sc = (void *) ifp;
+	struct faith_softc *sc = ifp->if_softc;
 
 	mtx_lock(&faith_mtx);
 	LIST_REMOVE(sc, sc_list);
diff --git a/sys/net/if_fddisubr.c b/sys/net/if_fddisubr.c
index 6cc8e20..dd6b451 100644
--- a/sys/net/if_fddisubr.c
+++ b/sys/net/if_fddisubr.c
@@ -308,7 +308,7 @@ fddi_output(ifp, m, dst, rt0)
 	if (hdrcmplt)
 		bcopy((caddr_t)esrc, (caddr_t)fh->fddi_shost, FDDI_ADDR_LEN);
 	else
-		bcopy(IFP2AC(ifp)->ac_enaddr, (caddr_t)fh->fddi_shost,
+		bcopy(IFP2ENADDR(ifp), (caddr_t)fh->fddi_shost,
 			FDDI_ADDR_LEN);
 
 	/*
@@ -418,7 +418,7 @@ fddi_input(ifp, m)
 	 * is in promiscuous mode.
 	 */
 	if ((ifp->if_flags & IFF_PROMISC) && ((fh->fddi_dhost[0] & 1) == 0) &&
-	    (bcmp(IFP2AC(ifp)->ac_enaddr, (caddr_t)fh->fddi_dhost,
+	    (bcmp(IFP2ENADDR(ifp), (caddr_t)fh->fddi_dhost,
 	     FDDI_ADDR_LEN) != 0))
 		goto dropanyway;
 
@@ -585,7 +585,7 @@ fddi_ifattach(ifp, bpf)
 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
 	sdl->sdl_type = IFT_FDDI;
 	sdl->sdl_alen = ifp->if_addrlen;
-	bcopy(IFP2AC(ifp)->ac_enaddr, LLADDR(sdl), ifp->if_addrlen);
+	bcopy(IFP2ENADDR(ifp), LLADDR(sdl), ifp->if_addrlen);
 
 	if (bpf)
 		bpfattach(ifp, DLT_FDDI, FDDI_HDR_LEN);
@@ -638,18 +638,16 @@ fddi_ioctl (ifp, command, data)
 		 */
 		case AF_IPX: {
 				struct ipx_addr *ina;
-				struct arpcom *ac;
 
 				ina = &(IA_SIPX(ifa)->sipx_addr);
-				ac = IFP2AC(ifp);
 
 				if (ipx_nullhost(*ina)) {
 					ina->x_host = *(union ipx_host *)
-							ac->ac_enaddr;
+							IFP2ENADDR(ifp);
 				} else {
 					bcopy((caddr_t) ina->x_host.c_host,
-					      (caddr_t) ac->ac_enaddr,
-					      sizeof(ac->ac_enaddr));
+					      (caddr_t) IFP2ENADDR(ifp),
+					      ETHER_ADDR_LEN);
 				}
 	
 				/*
@@ -668,7 +666,7 @@ fddi_ioctl (ifp, command, data)
 			struct sockaddr *sa;
 
 			sa = (struct sockaddr *) & ifr->ifr_data;
-			bcopy(IFP2AC(ifp)->ac_enaddr,
+			bcopy(IFP2ENADDR(ifp),
 			      (caddr_t) sa->sa_data, FDDI_ADDR_LEN);
 
 		}
diff --git a/sys/net/if_fwsubr.c b/sys/net/if_fwsubr.c
index 7cbd7ac..b3884b5 100644
--- a/sys/net/if_fwsubr.c
+++ b/sys/net/if_fwsubr.c
@@ -40,6 +40,7 @@
 #include <sys/mac.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
+#include <sys/module.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>
 
@@ -63,6 +64,8 @@
 
 #define IFP2FC(IFP) ((struct fw_com *)IFP)
 
+MALLOC_DEFINE(M_FWCOM, "fw_com", "firewire interface internals");
+
 struct fw_hwaddr firewire_broadcastaddr = {
 	0xffffffff,
 	0xffffffff,
@@ -76,7 +79,7 @@ static int
 firewire_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
     struct rtentry *rt0)
 {
-	struct fw_com *fc = (struct fw_com *) ifp;
+	struct fw_com *fc = IFP2FC(ifp);
 	int error, type;
 	struct rtentry *rt;
 	struct m_tag *mtag;
@@ -167,7 +170,7 @@ firewire_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 #ifdef INET6
 	case AF_INET6:
 		if (unicast) {
-			error = nd6_storelladdr(&fc->fc_if, rt, m, dst,
+			error = nd6_storelladdr(fc->fc_ifp, rt, m, dst,
 			    (u_char *) destfw);
 			if (error)
 				return (error);
@@ -492,7 +495,7 @@ bad:
 void
 firewire_input(struct ifnet *ifp, struct mbuf *m, uint16_t src)
 {
-	struct fw_com *fc = (struct fw_com *) ifp;
+	struct fw_com *fc = IFP2FC(ifp);
 	union fw_encap *enc;
 	int type, isr;
 
@@ -740,7 +743,7 @@ firewire_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
 void
 firewire_ifattach(struct ifnet *ifp, struct fw_hwaddr *llc)
 {
-	struct fw_com *fc = (struct fw_com *) ifp;
+	struct fw_com *fc = IFP2FC(ifp);
 	struct ifaddr *ifa;
 	struct sockaddr_dl *sdl;
 	static const char* speeds[] = {
@@ -751,7 +754,6 @@ firewire_ifattach(struct ifnet *ifp, struct fw_hwaddr *llc)
 	fc->fc_speed = llc->sspd;
 	STAILQ_INIT(&fc->fc_frags);
 
-	ifp->if_type = IFT_IEEE1394;
 	ifp->if_addrlen = sizeof(struct fw_hwaddr);
 	ifp->if_hdrlen = 0;
 	if_attach(ifp);
@@ -788,7 +790,7 @@ firewire_ifdetach(struct ifnet *ifp)
 void
 firewire_busreset(struct ifnet *ifp)
 {
-	struct fw_com *fc = (struct fw_com *) ifp;
+	struct fw_com *fc = IFP2FC(ifp);
 	struct fw_reass *r;
 	struct mbuf *m;
 
@@ -805,3 +807,49 @@ firewire_busreset(struct ifnet *ifp)
 		free(r, M_TEMP);
 	}
 }
+
+static void *
+firewire_alloc(u_char type, struct ifnet *ifp)
+{
+	struct fw_com	*fc;
+
+	fc = malloc(sizeof(struct fw_com), M_FWCOM, M_WAITOK | M_ZERO);
+	fc->fc_ifp = ifp;
+
+	return (fc);
+}
+
+static void
+firewire_free(void *com, u_char type)
+{
+
+	free(com, M_FWCOM);
+}
+
+static int
+firewire_modevent(module_t mod, int type, void *data)
+{
+
+	switch (type) {
+	case MOD_LOAD:
+		if_register_com_alloc(IFT_IEEE1394,
+		    firewire_alloc, firewire_free);
+		break;
+	case MOD_UNLOAD:
+		if_deregister_com_alloc(IFT_IEEE1394);
+		break;
+	default:
+		return (EOPNOTSUPP);
+	}
+
+	return (0);
+}
+
+static moduledata_t firewire_mod = {
+	"firewire",
+	firewire_modevent,
+	0
+};
+
+DECLARE_MODULE(firewire, firewire_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
+MODULE_VERSION(firewire, 1);
diff --git a/sys/net/if_gif.c b/sys/net/if_gif.c
index 6d00fd8..4c243b6 100644
--- a/sys/net/if_gif.c
+++ b/sys/net/if_gif.c
@@ -144,9 +144,14 @@ gif_clone_create(ifc, unit)
 	struct gif_softc *sc;
 
 	sc = malloc(sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
+	GIF2IFP(sc) = if_alloc(IFT_GIF);
+	if (GIF2IFP(sc) == NULL) {
+		free(sc, M_GIF);
+		return (ENOSPC);
+	}
 
-	sc->gif_if.if_softc = sc;
-	if_initname(&sc->gif_if, ifc->ifc_name, unit);
+	GIF2IFP(sc)->if_softc = sc;
+	if_initname(GIF2IFP(sc), ifc->ifc_name, unit);
 
 	gifattach0(sc);
 
@@ -163,27 +168,26 @@ gifattach0(sc)
 
 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
 
-	sc->gif_if.if_addrlen = 0;
-	sc->gif_if.if_mtu    = GIF_MTU;
-	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
+	GIF2IFP(sc)->if_addrlen = 0;
+	GIF2IFP(sc)->if_mtu    = GIF_MTU;
+	GIF2IFP(sc)->if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
 #if 0
 	/* turn off ingress filter */
-	sc->gif_if.if_flags  |= IFF_LINK2;
-#endif
-	sc->gif_if.if_ioctl  = gif_ioctl;
-	sc->gif_if.if_output = gif_output;
-	sc->gif_if.if_type   = IFT_GIF;
-	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
-	if_attach(&sc->gif_if);
-	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
+	GIF2IFP(sc)->if_flags  |= IFF_LINK2;
+#endif
+	GIF2IFP(sc)->if_ioctl  = gif_ioctl;
+	GIF2IFP(sc)->if_output = gif_output;
+	GIF2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
+	if_attach(GIF2IFP(sc));
+	bpfattach(GIF2IFP(sc), DLT_NULL, sizeof(u_int));
 	if (ng_gif_attach_p != NULL)
-		(*ng_gif_attach_p)(&sc->gif_if);
+		(*ng_gif_attach_p)(GIF2IFP(sc));
 }
 
 static void
 gif_destroy(struct gif_softc *sc)
 {
-	struct ifnet *ifp = &sc->gif_if;
+	struct ifnet *ifp = GIF2IFP(sc);
 	int err;
 
 	gif_delete_tunnel(ifp);
@@ -204,6 +208,7 @@ gif_destroy(struct gif_softc *sc)
 		(*ng_gif_detach_p)(ifp);
 	bpfdetach(ifp);
 	if_detach(ifp);
+	if_free(ifp);
 
 	free(sc, M_GIF);
 }
@@ -284,7 +289,7 @@ gif_encapcheck(m, off, proto, arg)
 	if (sc == NULL)
 		return 0;
 
-	if ((sc->gif_if.if_flags & IFF_UP) == 0)
+	if ((GIF2IFP(sc)->if_flags & IFF_UP) == 0)
 		return 0;
 
 	/* no physical address */
@@ -339,7 +344,7 @@ gif_output(ifp, m, dst, rt)
 	struct sockaddr *dst;
 	struct rtentry *rt;	/* added in net2 */
 {
-	struct gif_softc *sc = (struct gif_softc*)ifp;
+	struct gif_softc *sc = ifp->if_softc;
 	struct m_tag *mtag;
 	int error = 0;
 	int gif_called;
@@ -507,7 +512,7 @@ gif_ioctl(ifp, cmd, data)
 	u_long cmd;
 	caddr_t data;
 {
-	struct gif_softc *sc  = (struct gif_softc*)ifp;
+	struct gif_softc *sc  = ifp->if_softc;
 	struct ifreq     *ifr = (struct ifreq*)data;
 	int error = 0, size;
 	struct sockaddr *dst, *src;
@@ -628,12 +633,12 @@ gif_ioctl(ifp, cmd, data)
 			break;
 		}
 
-		error = gif_set_tunnel(&sc->gif_if, src, dst);
+		error = gif_set_tunnel(GIF2IFP(sc), src, dst);
 		break;
 
 #ifdef SIOCDIFPHYADDR
 	case SIOCDIFPHYADDR:
-		gif_delete_tunnel(&sc->gif_if);
+		gif_delete_tunnel(GIF2IFP(sc));
 		break;
 #endif
 			
@@ -751,7 +756,7 @@ gif_set_tunnel(ifp, src, dst)
 	struct sockaddr *src;
 	struct sockaddr *dst;
 {
-	struct gif_softc *sc = (struct gif_softc *)ifp;
+	struct gif_softc *sc = ifp->if_softc;
 	struct gif_softc *sc2;
 	struct sockaddr *osrc, *odst, *sa;
 	int s;
@@ -860,7 +865,7 @@ void
 gif_delete_tunnel(ifp)
 	struct ifnet *ifp;
 {
-	struct gif_softc *sc = (struct gif_softc *)ifp;
+	struct gif_softc *sc = ifp->if_softc;
 	int s;
 
 	s = splnet();
diff --git a/sys/net/if_gif.h b/sys/net/if_gif.h
index dc92ae1..831c7f7 100644
--- a/sys/net/if_gif.h
+++ b/sys/net/if_gif.h
@@ -56,7 +56,7 @@ extern	void (*ng_gif_attach_p)(struct ifnet *ifp);
 extern	void (*ng_gif_detach_p)(struct ifnet *ifp);
 
 struct gif_softc {
-	struct ifnet	gif_if;	   /* common area - must be at the top */
+	struct ifnet	*gif_ifp;
 	struct sockaddr	*gif_psrc; /* Physical src addr */
 	struct sockaddr	*gif_pdst; /* Physical dst addr */
 	union {
@@ -71,6 +71,7 @@ struct gif_softc {
 	void		*gif_netgraph;	/* ng_gif(4) netgraph node info */
 	LIST_ENTRY(gif_softc) gif_list; /* all gif's are linked */
 };
+#define	GIF2IFP(sc)	((sc)->gif_ifp)
 
 #define gif_ro gifsc_gifscr.gifscr_ro
 #ifdef INET6
diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index a2a7831..407784d 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -169,24 +169,24 @@ gre_clone_create(ifc, unit)
 
 	sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
 
-	if_initname(&sc->sc_if, ifc->ifc_name, unit);
-	sc->sc_if.if_softc = sc;
-	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
-	sc->sc_if.if_type = IFT_TUNNEL;
-	sc->sc_if.if_addrlen = 0;
-	sc->sc_if.if_hdrlen = 24; /* IP + GRE */
-	sc->sc_if.if_mtu = GREMTU;
-	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
-	sc->sc_if.if_output = gre_output;
-	sc->sc_if.if_ioctl = gre_ioctl;
+	if_initname(GRE2IFP(sc), ifc->ifc_name, unit);
+	GRE2IFP(sc)->if_softc = sc;
+	GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
+	GRE2IFP(sc)->if_type = IFT_TUNNEL;
+	GRE2IFP(sc)->if_addrlen = 0;
+	GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */
+	GRE2IFP(sc)->if_mtu = GREMTU;
+	GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
+	GRE2IFP(sc)->if_output = gre_output;
+	GRE2IFP(sc)->if_ioctl = gre_ioctl;
 	sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
 	sc->g_proto = IPPROTO_GRE;
-	sc->sc_if.if_flags |= IFF_LINK0;
+	GRE2IFP(sc)->if_flags |= IFF_LINK0;
 	sc->encap = NULL;
 	sc->called = 0;
 	sc->wccp_ver = WCCP_V1;
-	if_attach(&sc->sc_if);
-	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
+	if_attach(GRE2IFP(sc));
+	bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
 	mtx_lock(&gre_mtx);
 	LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
 	mtx_unlock(&gre_mtx);
@@ -201,8 +201,9 @@ gre_destroy(struct gre_softc *sc)
 	if (sc->encap != NULL)
 		encap_detach(sc->encap);
 #endif
-	bpfdetach(&sc->sc_if);
-	if_detach(&sc->sc_if);
+	bpfdetach(GRE2IFP(sc));
+	if_detach(GRE2IFP(sc));
+	if_free(GRE2IFP(sc));
 	free(sc, M_GRE);
 }
 
@@ -239,7 +240,7 @@ gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 	 */
 	if (++(sc->called) > max_gre_nesting) {
 		printf("%s: gre_output: recursively called too many "
-		       "times(%d)\n", if_name(&sc->sc_if), sc->called);
+		       "times(%d)\n", if_name(GRE2IFP(sc)), sc->called);
 		m_freem(m);
 		error = EIO;    /* is there better errno? */
 		goto end;
@@ -444,7 +445,7 @@ gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		ifp->if_mtu = ifr->ifr_mtu;
 		break;
 	case SIOCGIFMTU:
-		ifr->ifr_mtu = sc->sc_if.if_mtu;
+		ifr->ifr_mtu = GRE2IFP(sc)->if_mtu;
 		break;
 	case SIOCADDMULTI:
 	case SIOCDELMULTI:
@@ -524,7 +525,7 @@ gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 				&in_gre_protosw : &in_mobile_protosw, sc);
 			if (sc->encap == NULL)
 				printf("%s: unable to attach encap\n",
-				    if_name(&sc->sc_if));
+				    if_name(GRE2IFP(sc)));
 #endif
 			if (sc->route.ro_rt != 0) /* free old route */
 				RTFREE(sc->route.ro_rt);
@@ -670,7 +671,7 @@ gre_compute_route(struct gre_softc *sc)
 	 * but this is not possible. Should work though. XXX
 	 * there is a simpler way ...
 	 */
-	if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
+	if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) {
 		a = ntohl(sc->g_dst.s_addr);
 		b = a & 0x01;
 		c = a & 0xfffffffe;
@@ -681,7 +682,7 @@ gre_compute_route(struct gre_softc *sc)
 	}
 
 #ifdef DIAGNOSTIC
-	printf("%s: searching for a route to %s", if_name(&sc->sc_if),
+	printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)),
 	    inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
 #endif
 
@@ -705,7 +706,7 @@ gre_compute_route(struct gre_softc *sc)
 	 * now change it back - else ip_output will just drop
 	 * the route and search one to this interface ...
 	 */
-	if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
+	if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0)
 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
 
 #ifdef DIAGNOSTIC
diff --git a/sys/net/if_gre.h b/sys/net/if_gre.h
index ef9fa4e..6c8e853 100644
--- a/sys/net/if_gre.h
+++ b/sys/net/if_gre.h
@@ -55,7 +55,7 @@ typedef enum {
 } wccp_ver_t;
 
 struct gre_softc {
-	struct ifnet sc_if;
+	struct ifnet *sc_ifp;
 	LIST_ENTRY(gre_softc) sc_list;
 	int gre_unit;
 	int gre_flags;
@@ -71,6 +71,7 @@ struct gre_softc {
 
 	wccp_ver_t wccp_ver;	/* version of the WCCP */
 };
+#define	GRE2IFP(sc)	((sc)->sc_ifp)
 
 
 struct gre_h {
diff --git a/sys/net/if_iso88025subr.c b/sys/net/if_iso88025subr.c
index ff88371..d497143 100644
--- a/sys/net/if_iso88025subr.c
+++ b/sys/net/if_iso88025subr.c
@@ -123,7 +123,7 @@ iso88025_ifattach(struct ifnet *ifp, int bpf)
     sdl = (struct sockaddr_dl *)ifa->ifa_addr;
     sdl->sdl_type = IFT_ISO88025;
     sdl->sdl_alen = ifp->if_addrlen;
-    bcopy(IFP2AC(ifp)->ac_enaddr, LLADDR(sdl), ifp->if_addrlen);
+    bcopy(IFP2ENADDR(ifp), LLADDR(sdl), ifp->if_addrlen);
 
     if (bpf)
         bpfattach(ifp, DLT_IEEE802, ISO88025_HDR_LEN);
@@ -176,17 +176,15 @@ iso88025_ioctl(struct ifnet *ifp, int command, caddr_t data)
                  */
                 case AF_IPX: {
 				struct ipx_addr *ina;
-				struct arpcom *ac;
 
 				ina = &(IA_SIPX(ifa)->sipx_addr);
-				ac = IFP2AC(ifp);
 
 				if (ipx_nullhost(*ina))
 					ina->x_host = *(union ipx_host *)
-							ac->ac_enaddr;
+							IFP2ENADDR(ifp);
 				else
 					bcopy((caddr_t) ina->x_host.c_host,
-					      (caddr_t) ac->ac_enaddr,
+					      (caddr_t) IFP2ENADDR(ifp),
 					      ISO88025_ADDR_LEN);
 
 				/*
@@ -206,7 +204,7 @@ iso88025_ioctl(struct ifnet *ifp, int command, caddr_t data)
                         struct sockaddr *sa;
 
                         sa = (struct sockaddr *) & ifr->ifr_data;
-                        bcopy(IFP2AC(ifp)->ac_enaddr,
+                        bcopy(IFP2ENADDR(ifp),
                               (caddr_t) sa->sa_data, ISO88025_ADDR_LEN);
                 }
                 break;
@@ -272,7 +270,7 @@ iso88025_output(ifp, m, dst, rt0)
 	/* Generate a generic 802.5 header for the packet */
 	gen_th.ac = TR_AC;
 	gen_th.fc = TR_LLC_FRAME;
-	(void)memcpy((caddr_t)gen_th.iso88025_shost, IFP2AC(ifp)->ac_enaddr,
+	(void)memcpy((caddr_t)gen_th.iso88025_shost, IFP2ENADDR(ifp),
 		     ISO88025_ADDR_LEN);
 	if (rif_len) {
 		gen_th.iso88025_shost[0] |= TR_RII;
@@ -517,7 +515,7 @@ iso88025_input(ifp, m)
 	 */
 	if ((ifp->if_flags & IFF_PROMISC) &&
 	    ((th->iso88025_dhost[0] & 1) == 0) &&
-	     (bcmp(IFP2AC(ifp)->ac_enaddr, (caddr_t) th->iso88025_dhost,
+	     (bcmp(IFP2ENADDR(ifp), (caddr_t) th->iso88025_dhost,
 	     ISO88025_ADDR_LEN) != 0))
 		goto dropanyway;
 
@@ -638,7 +636,6 @@ iso88025_input(ifp, m)
 			int i;
 			u_char c;
 
-			ac = IFP2AC(ifp);
 			c = l->llc_dsap;
 
 			if (th->iso88025_shost[0] & TR_RII) { /* XXX */
@@ -648,7 +645,7 @@ iso88025_input(ifp, m)
 			l->llc_dsap = l->llc_ssap;
 			l->llc_ssap = c;
 			if (m->m_flags & (M_BCAST | M_MCAST))
-				bcopy((caddr_t)ac->ac_enaddr, 
+				bcopy((caddr_t)IFP2ENADDR(ifp),
 				      (caddr_t)th->iso88025_dhost,
 					ISO88025_ADDR_LEN);
 			sa.sa_family = AF_UNSPEC;
@@ -774,9 +771,48 @@ iso88025_resolvemulti (ifp, llsa, sa)
 	return (0);
 }
 
+MALLOC_DEFINE(M_ISO88025, "arpcom", "802.5 interface internals");
+
+static void*
+iso88025_alloc(u_char type, struct ifnet *ifp)
+{
+	struct arpcom	*ac;
+ 
+        ac = malloc(sizeof(struct arpcom), M_ISO88025, M_WAITOK | M_ZERO);
+	ac->ac_ifp = ifp;
+
+	return (ac);
+} 
+
+static void
+iso88025_free(void *com, u_char type)
+{
+ 
+        free(com, M_ISO88025);
+}
+ 
+static int
+iso88025_modevent(module_t mod, int type, void *data)
+{
+  
+        switch (type) {
+        case MOD_LOAD:
+                if_register_com_alloc(IFT_ISO88025, iso88025_alloc,
+                    iso88025_free);
+                break;
+        case MOD_UNLOAD:
+                if_deregister_com_alloc(IFT_ISO88025);
+                break;
+        default:
+                return EOPNOTSUPP;
+        }
+
+        return (0);
+}
+
 static moduledata_t iso88025_mod = {
 	"iso88025",
-	NULL,
+	iso88025_modevent,
 	0
 };
 
diff --git a/sys/net/if_loop.c b/sys/net/if_loop.c
index a48ab8c..d10d859 100644
--- a/sys/net/if_loop.c
+++ b/sys/net/if_loop.c
@@ -93,7 +93,7 @@
 #define LONAME	"lo"
 
 struct lo_softc {
-	struct	ifnet sc_if;		/* network-visible interface */
+	struct	ifnet *sc_ifp;
 	LIST_ENTRY(lo_softc) sc_next;
 };
 
@@ -129,6 +129,7 @@ lo_clone_destroy(ifp)
 	mtx_unlock(&lo_mtx);
 	bpfdetach(ifp);
 	if_detach(ifp);
+	if_free(ifp);
 	free(sc, M_LO);
 }
 
@@ -137,25 +138,30 @@ lo_clone_create(ifc, unit)
 	struct if_clone *ifc;
 	int unit;
 {
+	struct ifnet *ifp;
 	struct lo_softc *sc;
 
 	MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO);
+	ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
+	if (ifp == NULL) {
+		free(sc, M_LO);
+		return (ENOSPC);
+	}
 
-	if_initname(&sc->sc_if, ifc->ifc_name, unit);
-	sc->sc_if.if_mtu = LOMTU;
-	sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST;
-	sc->sc_if.if_ioctl = loioctl;
-	sc->sc_if.if_output = looutput;
-	sc->sc_if.if_type = IFT_LOOP;
-	sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen;
-	sc->sc_if.if_softc = sc;
-	if_attach(&sc->sc_if);
-	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int));
+	if_initname(ifp, ifc->ifc_name, unit);
+	ifp->if_mtu = LOMTU;
+	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
+	ifp->if_ioctl = loioctl;
+	ifp->if_output = looutput;
+	ifp->if_snd.ifq_maxlen = ifqmaxlen;
+	ifp->if_softc = sc;
+	if_attach(ifp);
+	bpfattach(ifp, DLT_NULL, sizeof(u_int));
 	mtx_lock(&lo_mtx);
 	LIST_INSERT_HEAD(&lo_list, sc, sc_next);
 	mtx_unlock(&lo_mtx);
 	if (loif == NULL)
-		loif = &sc->sc_if;
+		loif = ifp;
 
 	return (0);
 }
diff --git a/sys/net/if_ppp.c b/sys/net/if_ppp.c
index cece192..b59ed39 100644
--- a/sys/net/if_ppp.c
+++ b/sys/net/if_ppp.c
@@ -223,26 +223,32 @@ static struct compressor *ppp_compressors[8] = {
 static int
 ppp_clone_create(struct if_clone *ifc, int unit)
 {
+	struct ifnet		*ifp;
 	struct ppp_softc	*sc;
 
 	sc = malloc(sizeof(struct ppp_softc), M_PPP, M_WAITOK | M_ZERO);
-	sc->sc_if.if_softc = sc;
-	if_initname(&sc->sc_if, ifc->ifc_name, unit);
-	sc->sc_if.if_mtu = PPP_MTU;
-	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
-	sc->sc_if.if_type = IFT_PPP;
-	sc->sc_if.if_hdrlen = PPP_HDRLEN;
-	sc->sc_if.if_ioctl = pppsioctl;
-	sc->sc_if.if_output = pppoutput;
-	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
+	ifp = sc->sc_ifp = if_alloc(IFT_PPP);
+	if (ifp == NULL) {
+		free(sc, M_PPP);
+		return (ENOSPC);
+	}
+
+	ifp->if_softc = sc;
+	if_initname(ifp, ifc->ifc_name, unit);
+	ifp->if_mtu = PPP_MTU;
+	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
+	ifp->if_hdrlen = PPP_HDRLEN;
+	ifp->if_ioctl = pppsioctl;
+	ifp->if_output = pppoutput;
+	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
 	mtx_init(&sc->sc_inq.ifq_mtx, "ppp_inq", NULL, MTX_DEF);
 	mtx_init(&sc->sc_fastq.ifq_mtx, "ppp_fastq", NULL, MTX_DEF);
 	mtx_init(&sc->sc_rawq.ifq_mtx, "ppp_rawq", NULL, MTX_DEF);
-	if_attach(&sc->sc_if);
-	bpfattach(&sc->sc_if, DLT_PPP, PPP_HDRLEN);
+	if_attach(ifp);
+	bpfattach(ifp, DLT_PPP, PPP_HDRLEN);
 
 	PPP_LIST_LOCK();
 	LIST_INSERT_HEAD(&ppp_softc_list, sc, sc_list);
@@ -256,9 +262,10 @@ ppp_destroy(struct ppp_softc *sc)
 {
 	struct ifnet *ifp;
 
-	ifp = &sc->sc_if;
+	ifp = PPP2IFP(sc);
 	bpfdetach(ifp);
 	if_detach(ifp);
+	if_free(ifp);
 	mtx_destroy(&sc->sc_rawq.ifq_mtx);
 	mtx_destroy(&sc->sc_fastq.ifq_mtx);
 	mtx_destroy(&sc->sc_inq.ifq_mtx);
@@ -396,9 +403,9 @@ pppdealloc(sc)
 {
     struct mbuf *m;
 
-    if_down(&sc->sc_if);
-    sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
-    getmicrotime(&sc->sc_if.if_lastchange);
+    if_down(PPP2IFP(sc));
+    PPP2IFP(sc)->if_flags &= ~(IFF_UP|IFF_RUNNING);
+    getmicrotime(&PPP2IFP(sc)->if_lastchange);
     sc->sc_devp = NULL;
     sc->sc_xfer = 0;
     IF_DRAIN(&sc->sc_rawq);
@@ -467,7 +474,7 @@ pppioctl(sc, cmd, data, flag, td)
 	break;
 
     case PPPIOCGUNIT:
-	*(int *)data = sc->sc_if.if_dunit;
+	*(int *)data = PPP2IFP(sc)->if_dunit;
 	break;
 
     case PPPIOCGFLAGS:
@@ -547,7 +554,7 @@ pppioctl(sc, cmd, data, flag, td)
 		    sc->sc_xc_state = (*cp)->comp_alloc(ccp_option, nb);
 		    if (sc->sc_xc_state == NULL) {
 			if (sc->sc_flags & SC_DEBUG)
-			    if_printf(&sc->sc_if, "comp_alloc failed\n");
+			    if_printf(PPP2IFP(sc), "comp_alloc failed\n");
 			error = ENOBUFS;
 		    }
 		    splimp();
@@ -561,7 +568,7 @@ pppioctl(sc, cmd, data, flag, td)
 		    sc->sc_rc_state = (*cp)->decomp_alloc(ccp_option, nb);
 		    if (sc->sc_rc_state == NULL) {
 			if (sc->sc_flags & SC_DEBUG)
-			    if_printf(&sc->sc_if, "decomp_alloc failed\n");
+			    if_printf(PPP2IFP(sc), "decomp_alloc failed\n");
 			error = ENOBUFS;
 		    }
 		    splimp();
@@ -571,7 +578,7 @@ pppioctl(sc, cmd, data, flag, td)
 		break;
 	    }
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "no compressor for [%x %x %x], %x\n",
+	    if_printf(PPP2IFP(sc), "no compressor for [%x %x %x], %x\n",
 		   ccp_option[0], ccp_option[1], ccp_option[2], nb);
 	error = EINVAL;		/* no handler found */
         break;
@@ -724,14 +731,14 @@ pppsioctl(ifp, cmd, data)
 	if (ifr->ifr_mtu > PPP_MAXMTU)
 	    error = EINVAL;
 	else {
-	    sc->sc_if.if_mtu = ifr->ifr_mtu;
+	    PPP2IFP(sc)->if_mtu = ifr->ifr_mtu;
 	    if (sc->sc_setmtu)
 		    (*sc->sc_setmtu)(sc);
 	}
 	break;
 
     case SIOCGIFMTU:
-	ifr->ifr_mtu = sc->sc_if.if_mtu;
+	ifr->ifr_mtu = PPP2IFP(sc)->if_mtu;
 	break;
 
     case SIOCADDMULTI:
@@ -959,7 +966,7 @@ pppoutput(ifp, m0, dst, rtp)
 	if (_IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
 	    _IF_DROP(ifq);
 	    IF_UNLOCK(ifq);
-	    sc->sc_if.if_oerrors++;
+	    PPP2IFP(sc)->if_oerrors++;
 	    sc->sc_stats.ppp_oerrors++;
 	    error = ENOBUFS;
 	    goto bad;
@@ -1010,9 +1017,9 @@ ppp_requeue(sc)
 	    *mpp = m->m_nextpkt;
 	    m->m_nextpkt = NULL;
 	    ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq:
-	        (struct ifqueue *)&sc->sc_if.if_snd;
+	        (struct ifqueue *)&PPP2IFP(sc)->if_snd;
             if (! IF_HANDOFF(ifq, m, NULL)) {
-		sc->sc_if.if_oerrors++;
+		PPP2IFP(sc)->if_oerrors++;
 		sc->sc_stats.ppp_oerrors++;
 	    }
 	    break;
@@ -1067,7 +1074,7 @@ ppp_dequeue(sc)
      */
     IF_DEQUEUE(&sc->sc_fastq, m);
     if (m == NULL)
-	IF_DEQUEUE(&sc->sc_if.if_snd, m);
+	IF_DEQUEUE(&PPP2IFP(sc)->if_snd, m);
     if (m == NULL)
 	return NULL;
 
@@ -1137,7 +1144,7 @@ ppp_dequeue(sc)
 
 	slen = m_length(m, NULL);
 	clen = (*sc->sc_xcomp->compress)
-	    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
+	    (sc->sc_xc_state, &mcomp, m, slen, PPP2IFP(sc)->if_mtu + PPP_HDRLEN);
 	if (mcomp != NULL) {
 	    if (sc->sc_flags & SC_CCP_UP) {
 		/* Send the compressed packet instead of the original. */
@@ -1192,7 +1199,7 @@ pppintr()
     LIST_FOREACH(sc, &ppp_softc_list, sc_list) {
 	s = splimp();
 	if (!(sc->sc_flags & SC_TBUSY)
-	    && (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head)) {
+	    && (PPP2IFP(sc)->if_snd.ifq_head || sc->sc_fastq.ifq_head)) {
 	    sc->sc_flags |= SC_TBUSY;
 	    splx(s);
 	    (*sc->sc_start)(sc);
@@ -1205,7 +1212,7 @@ pppintr()
 	    if (m == NULL)
 		break;
 #ifdef MAC
-	    mac_create_mbuf_from_ifnet(&sc->sc_if, m);
+	    mac_create_mbuf_from_ifnet(PPP2IFP(sc), m);
 #endif
 	    ppp_inproc(sc, m);
 	}
@@ -1273,7 +1280,7 @@ ppp_ccp(sc, m, rcvd)
 		if (sc->sc_xc_state != NULL
 		    && (*sc->sc_xcomp->comp_init)
 			(sc->sc_xc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
-			 sc->sc_if.if_dunit, 0, sc->sc_flags & SC_DEBUG)) {
+			 PPP2IFP(sc)->if_dunit, 0, sc->sc_flags & SC_DEBUG)) {
 		    s = splimp();
 		    sc->sc_flags |= SC_COMP_RUN;
 		    splx(s);
@@ -1283,7 +1290,7 @@ ppp_ccp(sc, m, rcvd)
 		if (sc->sc_rc_state != NULL
 		    && (*sc->sc_rcomp->decomp_init)
 			(sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
-			 sc->sc_if.if_dunit, 0, sc->sc_mru,
+			 PPP2IFP(sc)->if_dunit, 0, sc->sc_mru,
 			 sc->sc_flags & SC_DEBUG)) {
 		    s = splimp();
 		    sc->sc_flags |= SC_DECOMP_RUN;
@@ -1363,7 +1370,7 @@ ppp_inproc(sc, m)
     struct ppp_softc *sc;
     struct mbuf *m;
 {
-    struct ifnet *ifp = &sc->sc_if;
+    struct ifnet *ifp = PPP2IFP(sc);
     int isr;
     int s, ilen = 0, xlen, proto, rv;
     u_char *cp, adrs, ctrl;
@@ -1577,7 +1584,7 @@ ppp_inproc(sc, m)
     }
 
     /* See if bpf wants to look at the packet. */
-    BPF_MTAP(&sc->sc_if, m);
+    BPF_MTAP(PPP2IFP(sc), m);
 
     isr = -1;
     switch (proto) {
@@ -1605,7 +1612,7 @@ ppp_inproc(sc, m)
 	/*
 	 * IPX packet - take off the ppp header and pass it up to IPX.
 	 */
-	if ((sc->sc_if.if_flags & IFF_UP) == 0
+	if ((PPP2IFP(sc)->if_flags & IFF_UP) == 0
 	    /* XXX: || sc->sc_npmode[NP_IPX] != NPMODE_PASS*/) {
 	    /* interface is down - drop the packet. */
 	    m_freem(m);
@@ -1649,7 +1656,7 @@ ppp_inproc(sc, m)
  bad:
     if (m)
         m_freem(m);
-    sc->sc_if.if_ierrors++;
+    PPP2IFP(sc)->if_ierrors++;
     sc->sc_stats.ppp_ierrors++;
 }
 
diff --git a/sys/net/if_pppvar.h b/sys/net/if_pppvar.h
index daa263c..f103df5 100644
--- a/sys/net/if_pppvar.h
+++ b/sys/net/if_pppvar.h
@@ -54,7 +54,7 @@
  * Structure describing each ppp unit.
  */
 struct ppp_softc {
-	struct	ifnet sc_if;		/* network-visible interface */
+	struct	ifnet *sc_ifp;		/* network-visible interface */
 /*hi*/	u_int	sc_flags;		/* control/status bits; see if_ppp.h */
 	struct	callout_handle sc_ch;	/* Used for scheduling timeouts */
 	void	*sc_devp;		/* pointer to device-dep structure */
@@ -99,6 +99,7 @@ struct ppp_softc {
 	int	sc_rawin_count;		/* # in sc_rawin */
 	LIST_ENTRY(ppp_softc) sc_list;
 };
+#define	PPP2IFP(sc)	((sc)->sc_ifp)
 
 struct	ppp_softc *pppalloc(pid_t pid);
 void	pppdealloc(struct ppp_softc *sc);
diff --git a/sys/net/if_sl.c b/sys/net/if_sl.c
index 0617037..a03ba1c 100644
--- a/sys/net/if_sl.c
+++ b/sys/net/if_sl.c
@@ -231,10 +231,10 @@ static size_t st_unit_max = 0;
 static int
 slisunitfree(int unit)
 {
-	struct sl_softc *nc;
+	struct sl_softc *sc;
 
-	LIST_FOREACH(nc, &sl_list, sl_next) {
-		if (nc->sc_if.if_dunit == unit)
+	LIST_FOREACH(sc, &sl_list, sl_next) {
+		if (SL2IFP(sc)->if_dunit == unit)
 			return (0);
 	}
 	return (1);
@@ -291,6 +291,11 @@ slcreate(void)
 	struct mbuf *m;
 
 	MALLOC(sc, struct sl_softc *, sizeof(*sc), M_SL, M_WAITOK | M_ZERO);
+	sc->sc_ifp = if_alloc(IFT_SLIP);
+	if (sc->sc_ifp == NULL) {
+		free(sc, M_SL);
+		return (NULL);
+	}
 
 	m = m_gethdr(M_TRYWAIT, MT_DATA);
 	if (m != NULL) {
@@ -313,22 +318,21 @@ slcreate(void)
 	sc->sc_mp = sc->sc_buf;
 	sl_compress_init(&sc->sc_comp, -1);
 
-	sc->sc_if.if_softc = sc;
-	sc->sc_if.if_mtu = SLMTU;
-	sc->sc_if.if_flags =
+	SL2IFP(sc)->if_softc = sc;
+	SL2IFP(sc)->if_mtu = SLMTU;
+	SL2IFP(sc)->if_flags =
 #ifdef SLIP_IFF_OPTS
 	    SLIP_IFF_OPTS;
 #else
 	    IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST | IFF_NEEDSGIANT;
 #endif
-	sc->sc_if.if_type = IFT_SLIP;
-	sc->sc_if.if_ioctl = slioctl;
-	sc->sc_if.if_output = sloutput;
-	sc->sc_if.if_start = slstart;
-	sc->sc_if.if_snd.ifq_maxlen = 50;
+	SL2IFP(sc)->if_ioctl = slioctl;
+	SL2IFP(sc)->if_output = sloutput;
+	SL2IFP(sc)->if_start = slstart;
+	SL2IFP(sc)->if_snd.ifq_maxlen = 50;
 	sc->sc_fastq.ifq_maxlen = 32;
-	sc->sc_if.if_linkmib = sc;
-	sc->sc_if.if_linkmiblen = sizeof *sc;
+	SL2IFP(sc)->if_linkmib = sc;
+	SL2IFP(sc)->if_linkmiblen = sizeof *sc;
 	mtx_init(&sc->sc_fastq.ifq_mtx, "sl_fastq", NULL, MTX_DEF);
 
 	/*
@@ -341,11 +345,11 @@ slcreate(void)
 			continue;
 		break;
 	}
-	if_initname(&sc->sc_if, "sl", unit);
+	if_initname(SL2IFP(sc), "sl", unit);
 	LIST_INSERT_HEAD(&sl_list, sc, sl_next);
 
-	if_attach(&sc->sc_if);
-	bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
+	if_attach(SL2IFP(sc));
+	bpfattach(SL2IFP(sc), DLT_SLIP, SLIP_HDRLEN);
 
 	return sc;
 }
@@ -371,7 +375,7 @@ slopen(struct cdev *dev, register struct tty *tp)
 
 	tp->t_hotchar = FRAME_END;
 	sc->sc_ttyp = tp;
-	sc->sc_if.if_baudrate = tp->t_ospeed;
+	SL2IFP(sc)->if_baudrate = tp->t_ospeed;
 	ttyflush(tp, FREAD | FWRITE);
 
 	/*
@@ -386,12 +390,12 @@ slopen(struct cdev *dev, register struct tty *tp)
 	 */
 	clist_alloc_cblocks(&tp->t_canq, 0, 0);
 	clist_alloc_cblocks(&tp->t_outq,
-	    SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1,
-	    SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1);
+	    SLIP_HIWAT + 2 * SL2IFP(sc)->if_mtu + 1,
+	    SLIP_HIWAT + 2 * SL2IFP(sc)->if_mtu + 1);
 	clist_alloc_cblocks(&tp->t_rawq, 0, 0);
 
 	s = splnet();
-	if_up(&sc->sc_if);
+	if_up(SL2IFP(sc));
 	splx(s);
 	return (0);
 }
@@ -399,8 +403,9 @@ slopen(struct cdev *dev, register struct tty *tp)
 static void
 sldestroy(struct sl_softc *sc)
 {
-	bpfdetach(&sc->sc_if);
-	if_detach(&sc->sc_if);
+	bpfdetach(SL2IFP(sc));
+	if_detach(SL2IFP(sc));
+	if_free(SL2IFP(sc));
 	LIST_REMOVE(sc, sl_next);
 	m_free(sc->sc_mbuf);
 	mtx_destroy(&sc->sc_fastq.ifq_mtx);
@@ -437,7 +442,7 @@ slclose(struct tty *tp, int flag)
 			sc->sc_keepalive = 0;
 			untimeout(sl_keepalive, sc, sc->sc_kahandle);
 		}
-		if_down(&sc->sc_if);
+		if_down(SL2IFP(sc));
 		sc->sc_ttyp = NULL;
 		sldestroy(sc);
 	}
@@ -460,7 +465,7 @@ sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
 	s = splimp();
 	switch (cmd) {
 	case SLIOCGUNIT:
-		*(int *)data = sc->sc_if.if_dunit;
+		*(int *)data = SL2IFP(sc)->if_dunit;
 		break;
 
 	case SLIOCSUNIT:
@@ -469,27 +474,27 @@ sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
 			splx(s);
 			return (ENXIO);
 		}
-		if (sc->sc_if.if_dunit != unit) {
+		if (SL2IFP(sc)->if_dunit != unit) {
 			if (!slisunitfree(unit)) {
 				splx(s);
 				return (ENXIO);
 			}
 
-			wasup = sc->sc_if.if_flags & IFF_UP;
-			bpfdetach(&sc->sc_if);
-			if_detach(&sc->sc_if);
+			wasup = SL2IFP(sc)->if_flags & IFF_UP;
+			bpfdetach(SL2IFP(sc));
+			if_detach(SL2IFP(sc));
 			LIST_REMOVE(sc, sl_next);
-			if_initname(&sc->sc_if, "sl", unit);
+			if_initname(SL2IFP(sc), "sl", unit);
 			LIST_INSERT_HEAD(&sl_list, sc, sl_next);
-			if_attach(&sc->sc_if);
-			bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
+			if_attach(SL2IFP(sc));
+			bpfattach(SL2IFP(sc), DLT_SLIP, SLIP_HDRLEN);
 			if (wasup)
-				if_up(&sc->sc_if);
+				if_up(SL2IFP(sc));
 			else
-				if_down(&sc->sc_if);
+				if_down(SL2IFP(sc));
 			clist_alloc_cblocks(&tp->t_outq,
-			    SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1,
-			    SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1);
+			    SLIP_HIWAT + 2 * SL2IFP(sc)->if_mtu + 1,
+			    SLIP_HIWAT + 2 * SL2IFP(sc)->if_mtu + 1);
 		}
 		slmarkstatic(unit);
 		break;
@@ -559,7 +564,7 @@ sloutput(struct ifnet *ifp, register struct mbuf *m, struct sockaddr *dst,
 	if (dst->sa_family != AF_INET) {
 		if_printf(ifp, "af%d not supported\n", dst->sa_family);
 		m_freem(m);
-		sc->sc_if.if_noproto++;
+		SL2IFP(sc)->if_noproto++;
 		return (EAFNOSUPPORT);
 	}
 
@@ -572,17 +577,17 @@ sloutput(struct ifnet *ifp, register struct mbuf *m, struct sockaddr *dst,
 		return (EHOSTUNREACH);
 	}
 	ip = mtod(m, struct ip *);
-	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
+	if (SL2IFP(sc)->if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
 		m_freem(m);
 		return (ENETRESET);		/* XXX ? */
 	}
 	if (ip->ip_tos & IPTOS_LOWDELAY &&
-	    !ALTQ_IS_ENABLED(&sc->sc_if.if_snd))
-		error = !(IF_HANDOFF(&sc->sc_fastq, m, &sc->sc_if));
+	    !ALTQ_IS_ENABLED(&SL2IFP(sc)->if_snd))
+		error = !(IF_HANDOFF(&sc->sc_fastq, m, SL2IFP(sc)));
 	else
-		IFQ_HANDOFF(&sc->sc_if, m, error);
+		IFQ_HANDOFF(SL2IFP(sc), m, error);
 	if (error) {
-		sc->sc_if.if_oerrors++;
+		SL2IFP(sc)->if_oerrors++;
 		return (ENOBUFS);
 	}
 	return (0);
@@ -644,9 +649,9 @@ sltstart(struct tty *tp)
 		s = splimp();
 		IF_DEQUEUE(&sc->sc_fastq, m);
 		if (m)
-			sc->sc_if.if_omcasts++;		/* XXX */
+			SL2IFP(sc)->if_omcasts++;		/* XXX */
 		else
-			IF_DEQUEUE(&sc->sc_if.if_snd, m);
+			IF_DEQUEUE(&SL2IFP(sc)->if_snd, m);
 		splx(s);
 		if (m == NULL)
 			return 0;
@@ -657,7 +662,7 @@ sltstart(struct tty *tp)
 		 * queueing, and the connection id compression will get
 		 * munged when this happens.
 		 */
-		if (sc->sc_if.if_bpf) {
+		if (SL2IFP(sc)->if_bpf) {
 			/*
 			 * We need to save the TCP/IP header before it's
 			 * compressed.  To avoid complicated code, we just
@@ -687,11 +692,11 @@ sltstart(struct tty *tp)
 		}
 		ip = mtod(m, struct ip *);
 		if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) {
-			if (sc->sc_if.if_flags & SC_COMPRESS)
+			if (SL2IFP(sc)->if_flags & SC_COMPRESS)
 				*mtod(m, u_char *) |= sl_compress_tcp(m, ip,
 				    &sc->sc_comp, 1);
 		}
-		if (sc->sc_if.if_bpf && sc->bpfbuf) {
+		if (SL2IFP(sc)->if_bpf && sc->bpfbuf) {
 			/*
 			 * Put the SLIP pseudo-"link header" in place.  The
 			 * compressed header is now at the beginning of the
@@ -699,7 +704,7 @@ sltstart(struct tty *tp)
 			 */
 			sc->bpfbuf[SLX_DIR] = SLIPDIR_OUT;
 			bcopy(mtod(m, caddr_t), &sc->bpfbuf[SLX_CHDR], CHDR_LEN);
-			BPF_TAP(&sc->sc_if, sc->bpfbuf, len + SLIP_HDRLEN);
+			BPF_TAP(SL2IFP(sc), sc->bpfbuf, len + SLIP_HDRLEN);
 		}
 
 		/*
@@ -712,7 +717,7 @@ sltstart(struct tty *tp)
 		 */
 		if (cfreecount < CLISTRESERVE + SLTMAX) {
 			m_freem(m);
-			sc->sc_if.if_collisions++;
+			SL2IFP(sc)->if_collisions++;
 			continue;
 		}
 
@@ -723,7 +728,7 @@ sltstart(struct tty *tp)
 		 * the line may have been idle for some time.
 		 */
 		if (tp->t_outq.c_cc == 0) {
-			++sc->sc_if.if_obytes;
+			++SL2IFP(sc)->if_obytes;
 			(void) putc(FRAME_END, &tp->t_outq);
 		}
 
@@ -755,7 +760,7 @@ sltstart(struct tty *tp)
 					if (b_to_q((char *)bp, cp - bp,
 					    &tp->t_outq))
 						break;
-					sc->sc_if.if_obytes += cp - bp;
+					SL2IFP(sc)->if_obytes += cp - bp;
 				}
 				/*
 				 * If there are characters left in the mbuf,
@@ -771,7 +776,7 @@ sltstart(struct tty *tp)
 						(void) unputc(&tp->t_outq);
 						break;
 					}
-					sc->sc_if.if_obytes += 2;
+					SL2IFP(sc)->if_obytes += 2;
 				}
 			}
 			m = m_free(m);
@@ -787,10 +792,10 @@ sltstart(struct tty *tp)
 			 */
 			(void) unputc(&tp->t_outq);
 			(void) putc(FRAME_END, &tp->t_outq);
-			sc->sc_if.if_collisions++;
+			SL2IFP(sc)->if_collisions++;
 		} else {
-			++sc->sc_if.if_obytes;
-			sc->sc_if.if_opackets++;
+			++SL2IFP(sc)->if_obytes;
+			SL2IFP(sc)->if_opackets++;
 		}
 	}
 	return 0;
@@ -837,7 +842,7 @@ sl_btom(struct sl_softc *sc, register int len)
 
 	m->m_len = len;
 	m->m_pkthdr.len = len;
-	m->m_pkthdr.rcvif = &sc->sc_if;
+	m->m_pkthdr.rcvif = SL2IFP(sc);
 	return (m);
 }
 
@@ -862,9 +867,9 @@ slinput(int c, struct tty *tp)
 	}
 	c &= TTY_CHARMASK;
 
-	++sc->sc_if.if_ibytes;
+	++SL2IFP(sc)->if_ibytes;
 
-	if (sc->sc_if.if_flags & IFF_DEBUG) {
+	if (SL2IFP(sc)->if_flags & IFF_DEBUG) {
 		if (c == ABT_ESC) {
 			/*
 			 * If we have a previous abort, see whether
@@ -917,7 +922,7 @@ slinput(int c, struct tty *tp)
 			/* less than min length packet - ignore */
 			goto newpack;
 
-		if (sc->sc_if.if_bpf) {
+		if (SL2IFP(sc)->if_bpf) {
 			/*
 			 * Save the compressed header, so we
 			 * can tack it on later.  Note that we
@@ -941,22 +946,22 @@ slinput(int c, struct tty *tp)
 			 * it's a reasonable packet, decompress it and then
 			 * enable compression.  Otherwise, drop it.
 			 */
-			if (sc->sc_if.if_flags & SC_COMPRESS) {
+			if (SL2IFP(sc)->if_flags & SC_COMPRESS) {
 				len = sl_uncompress_tcp(&sc->sc_buf, len,
 							(u_int)c, &sc->sc_comp);
 				if (len <= 0)
 					goto error;
-			} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
+			} else if ((SL2IFP(sc)->if_flags & SC_AUTOCOMP) &&
 			    c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
 				len = sl_uncompress_tcp(&sc->sc_buf, len,
 							(u_int)c, &sc->sc_comp);
 				if (len <= 0)
 					goto error;
-				sc->sc_if.if_flags |= SC_COMPRESS;
+				SL2IFP(sc)->if_flags |= SC_COMPRESS;
 			} else
 				goto error;
 		}
-		if (sc->sc_if.if_bpf) {
+		if (SL2IFP(sc)->if_bpf) {
 			/*
 			 * Put the SLIP pseudo-"link header" in place.
 			 * We couldn't do this any earlier since
@@ -967,21 +972,21 @@ slinput(int c, struct tty *tp)
 
 			hp[SLX_DIR] = SLIPDIR_IN;
 			bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN);
-			BPF_TAP(&sc->sc_if, hp, len + SLIP_HDRLEN);
+			BPF_TAP(SL2IFP(sc), hp, len + SLIP_HDRLEN);
 		}
 		m = sl_btom(sc, len);
 		if (m == NULL)
 			goto error;
 
-		sc->sc_if.if_ipackets++;
+		SL2IFP(sc)->if_ipackets++;
 
-		if ((sc->sc_if.if_flags & IFF_UP) == 0) {
+		if ((SL2IFP(sc)->if_flags & IFF_UP) == 0) {
 			m_freem(m);
 			goto newpack;
 		}
 		if (netisr_queue(NETISR_IP, m)) {	/* (0) on success. */
-			sc->sc_if.if_ierrors++;
-			sc->sc_if.if_iqdrops++;
+			SL2IFP(sc)->if_ierrors++;
+			SL2IFP(sc)->if_iqdrops++;
 		}
 		goto newpack;
 	}
@@ -995,7 +1000,7 @@ slinput(int c, struct tty *tp)
 	sc->sc_flags |= SC_ERROR;
 
 error:
-	sc->sc_if.if_ierrors++;
+	SL2IFP(sc)->if_ierrors++;
 newpack:
 	sc->sc_mp = sc->sc_buf = sc->sc_ep - SLRMAX;
 	sc->sc_escape = 0;
@@ -1103,7 +1108,7 @@ sl_outfill(void *chan)
 	if (sc->sc_outfill && tp != NULL) {
 		if (sc->sc_flags & SC_OUTWAIT) {
 			s = splimp ();
-			++sc->sc_if.if_obytes;
+			++SL2IFP(sc)->if_obytes;
 			(void) putc(FRAME_END, &tp->t_outq);
 			(*tp->t_oproc)(tp);
 			splx (s);
diff --git a/sys/net/if_slvar.h b/sys/net/if_slvar.h
index 2de9533..e6b6d2c 100644
--- a/sys/net/if_slvar.h
+++ b/sys/net/if_slvar.h
@@ -43,7 +43,7 @@
  *  of sl_softc.)
  */
 struct sl_softc {
-	struct	ifnet sc_if;		/* network-visible interface */
+	struct	ifnet *sc_ifp;		/* network-visible interface */
 	struct	ifqueue sc_fastq;	/* interactive output queue */
 	struct	tty *sc_ttyp;		/* pointer to tty structure */
 	struct	mbuf *sc_mbuf;		/* pointer to mbuf containing buffer */
@@ -67,6 +67,7 @@ struct sl_softc {
 	LIST_ENTRY(sl_softc) sl_next;
 	u_char	*bpfbuf;		/* hang buffer for bpf here */
 };
+#define	SL2IFP(sc)	((sc)->sc_ifp)
 
 /* internal flags */
 #define	SC_ERROR	0x0001		/* had an input error */
diff --git a/sys/net/if_sppp.h b/sys/net/if_sppp.h
index 39267ae..97f94b3 100644
--- a/sys/net/if_sppp.h
+++ b/sys/net/if_sppp.h
@@ -136,8 +136,7 @@ struct spppreq {
 
 #ifdef _KERNEL
 struct sppp {
-	/* NB: pp_if _must_ be first */
-	struct  ifnet pp_if;    /* network interface data */
+	struct  ifnet *pp_ifp;    /* network interface data */
 	struct  ifqueue pp_fastq; /* fast output queue */
 	struct	ifqueue pp_cpq;	/* PPP control protocol queue */
 	struct  sppp *pp_next;  /* next interface in keepalive list */
@@ -204,6 +203,8 @@ struct sppp {
 	void	(*if_start) (struct ifnet *);
 	struct callout ifstart_callout; /* if_start () scheduler */
 };
+#define IFP2SP(ifp)	((struct sppp *)(ifp)->if_l2com)
+#define SP2IFP(sp)	((sp)->pp_ifp)
 
 /* bits for pp_flags */
 #define PP_KEEPALIVE    0x01    /* use keepalive protocol */
diff --git a/sys/net/if_spppfr.c b/sys/net/if_spppfr.c
index 7989df9..ae4f959 100644
--- a/sys/net/if_spppfr.c
+++ b/sys/net/if_spppfr.c
@@ -159,7 +159,7 @@ struct arp_req {
 
 /* almost every function needs these */
 #define STDDCL							\
-	struct ifnet *ifp = &sp->pp_if;				\
+	struct ifnet *ifp = SP2IFP(sp);				\
 	int debug = ifp->if_flags & IFF_DEBUG
 
 static void sppp_fr_arp (struct sppp *sp, struct arp_req *req, u_short addr);
diff --git a/sys/net/if_spppsubr.c b/sys/net/if_spppsubr.c
index d7cf484..b1cd8fe 100644
--- a/sys/net/if_spppsubr.c
+++ b/sys/net/if_spppsubr.c
@@ -198,6 +198,8 @@
 #define STATE_ACK_SENT	8
 #define STATE_OPENED	9
 
+MALLOC_DEFINE(M_SPPP, "sppp", "synchronous PPP interface internals");
+
 struct ppp_header {
 	u_char address;
 	u_char control;
@@ -264,22 +266,22 @@ struct cp {
 
 #define SPPP_LOCK(sp) \
 		do { \
-		    if (!((sp)->pp_if.if_flags & IFF_NEEDSGIANT)) \
+		    if (!(SP2IFP(sp)->if_flags & IFF_NEEDSGIANT)) \
 			mtx_lock (&(sp)->mtx); \
 		} while (0)
 #define SPPP_UNLOCK(sp) \
 		do { \
-		    if (!((sp)->pp_if.if_flags & IFF_NEEDSGIANT)) \
+		    if (!(SP2IFP(sp)->if_flags & IFF_NEEDSGIANT)) \
 			mtx_unlock (&(sp)->mtx); \
 		} while (0)
 
 #define SPPP_LOCK_ASSERT(sp) \
 		do { \
-		    if (!((sp)->pp_if.if_flags & IFF_NEEDSGIANT)) \
+		    if (!(SP2IFP(sp)->if_flags & IFF_NEEDSGIANT)) \
 			mtx_assert (&(sp)->mtx, MA_OWNED); \
 		} while (0)
 #define SPPP_LOCK_OWNED(sp) \
-		(!((sp)->pp_if.if_flags & IFF_NEEDSGIANT) && \
+		(!(SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) && \
 		 mtx_owned (&sp->mtx))
 
 #ifdef INET
@@ -300,7 +302,7 @@ static const u_short interactive_ports[8] = {
 
 /* almost every function needs these */
 #define STDDCL							\
-	struct ifnet *ifp = &sp->pp_if;				\
+	struct ifnet *ifp = SP2IFP(sp);				\
 	int debug = ifp->if_flags & IFF_DEBUG
 
 static int sppp_output(struct ifnet *ifp, struct mbuf *m,
@@ -490,13 +492,39 @@ static const struct cp *cps[IDX_COUNT] = {
 	&chap,			/* IDX_CHAP */
 };
 
+static void*
+sppp_alloc(u_char type, struct ifnet *ifp)
+{
+	struct sppp	*sp;
+
+        sp = malloc(sizeof(struct sppp), M_SPPP, M_WAITOK | M_ZERO);
+	sp->pp_ifp = ifp;
+
+	return (sp);
+}
+
+static void
+sppp_free(void *com, u_char type)
+{
+
+	free(com, M_SPPP);
+}
+
 static int
 sppp_modevent(module_t mod, int type, void *unused)
 {
 	switch (type) {
 	case MOD_LOAD:
+		/*
+		 * XXX: should probably be IFT_SPPP, but it's fairly
+		 * harmless to allocate struct sppp's for non-sppp
+		 * interfaces.
+		 */
+
+		if_register_com_alloc(IFT_PPP, sppp_alloc, sppp_free);
 		break;
 	case MOD_UNLOAD:
+		/* if_deregister_com_alloc(IFT_PPP); */
 		return EACCES;
 	default:
 		return EOPNOTSUPP;
@@ -523,7 +551,7 @@ sppp_input(struct ifnet *ifp, struct mbuf *m)
 {
 	struct ppp_header *h;
 	int isr = -1;
-	struct sppp *sp = (struct sppp *)ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	u_char *iphdr;
 	int hlen, vjlen, do_account = 0;
 	int debug;
@@ -708,7 +736,7 @@ sppp_input(struct ifnet *ifp, struct mbuf *m)
 			++ifp->if_noproto;
 			goto invalid;
 		case CISCO_KEEPALIVE:
-			sppp_cisco_input ((struct sppp*) ifp, m);
+			sppp_cisco_input (sp, m);
 			m_freem (m);
 			SPPP_UNLOCK(sp);
 			return;
@@ -769,7 +797,7 @@ sppp_ifstart_sched(void *dummy)
 {
 	struct sppp *sp = dummy;
 	
-	sp->if_start(&sp->pp_if);
+	sp->if_start(SP2IFP(sp));
 }
 
 /* if_start () wrapper function. We use it to schedule real if_start () for
@@ -778,7 +806,7 @@ sppp_ifstart_sched(void *dummy)
 static void
 sppp_ifstart(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 
 	if (SPPP_LOCK_OWNED(sp)) {
 		if (callout_pending(&sp->ifstart_callout))
@@ -797,7 +825,7 @@ static int
 sppp_output(struct ifnet *ifp, struct mbuf *m,
 	    struct sockaddr *dst, struct rtentry *rt)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	struct ppp_header *h;
 	struct ifqueue *ifq = NULL;
 	int s, error, rv = 0;
@@ -1039,7 +1067,7 @@ out:
 void
 sppp_attach(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 
 	/* Initialize mtx lock */
 	mtx_init(&sp->mtx, "sppp", MTX_NETWORK_LOCK, MTX_DEF | MTX_RECURSE);
@@ -1050,14 +1078,13 @@ sppp_attach(struct ifnet *ifp)
 	callout_reset(&sp->keepalive_callout, hz * 10, sppp_keepalive,
  		    (void *)sp); 
 
-	sp->pp_if.if_mtu = PP_MTU;
-	sp->pp_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
-	sp->pp_if.if_type = IFT_PPP;
-	sp->pp_if.if_output = sppp_output;
+	ifp->if_mtu = PP_MTU;
+	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
+	ifp->if_output = sppp_output;
 #if 0
 	sp->pp_flags = PP_KEEPALIVE;
 #endif
- 	sp->pp_if.if_snd.ifq_maxlen = 32;
+ 	ifp->if_snd.ifq_maxlen = 32;
  	sp->pp_fastq.ifq_maxlen = 32;
  	sp->pp_cpq.ifq_maxlen = 20;
 	sp->pp_loopcnt = 0;
@@ -1095,7 +1122,7 @@ sppp_attach(struct ifnet *ifp)
 void
 sppp_detach(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	int i;
 
 	KASSERT(mtx_initialized(&sp->mtx), ("sppp mutex is not initialized"));
@@ -1121,9 +1148,9 @@ sppp_detach(struct ifnet *ifp)
 static void
 sppp_flush_unlocked(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 
-	sppp_qflush ((struct ifqueue *)&sp->pp_if.if_snd);
+	sppp_qflush ((struct ifqueue *)&SP2IFP(sp)->if_snd);
 	sppp_qflush (&sp->pp_fastq);
 	sppp_qflush (&sp->pp_cpq);
 }
@@ -1131,7 +1158,7 @@ sppp_flush_unlocked(struct ifnet *ifp)
 void
 sppp_flush(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 
 	SPPP_LOCK(sp);
 	sppp_flush_unlocked (ifp);
@@ -1144,13 +1171,13 @@ sppp_flush(struct ifnet *ifp)
 int
 sppp_isempty(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	int empty, s;
 
 	s = splimp();
 	SPPP_LOCK(sp);
 	empty = !sp->pp_fastq.ifq_head && !sp->pp_cpq.ifq_head &&
-		!sp->pp_if.if_snd.ifq_head;
+		!SP2IFP(sp)->if_snd.ifq_head;
 	SPPP_UNLOCK(sp);
 	splx(s);
 	return (empty);
@@ -1162,7 +1189,7 @@ sppp_isempty(struct ifnet *ifp)
 struct mbuf *
 sppp_dequeue(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	struct mbuf *m;
 	int s;
 
@@ -1180,7 +1207,7 @@ sppp_dequeue(struct ifnet *ifp)
 	     sp->pp_mode == PP_FR)) {
 		IF_DEQUEUE(&sp->pp_fastq, m);
 		if (m == NULL)
-			IF_DEQUEUE (&sp->pp_if.if_snd, m);
+			IF_DEQUEUE (&SP2IFP(sp)->if_snd, m);
 	}
 	SPPP_UNLOCK(sp);
 	splx(s);
@@ -1193,7 +1220,7 @@ sppp_dequeue(struct ifnet *ifp)
 struct mbuf *
 sppp_pick(struct ifnet *ifp)
 {
-	struct sppp *sp = (struct sppp*)ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	struct mbuf *m;
 	int s;
 
@@ -1206,7 +1233,7 @@ sppp_pick(struct ifnet *ifp)
 	     sp->pp_mode == IFF_CISCO ||
 	     sp->pp_mode == PP_FR))
 		if ((m = sp->pp_fastq.ifq_head) == NULL)
-			m = sp->pp_if.if_snd.ifq_head;
+			m = SP2IFP(sp)->if_snd.ifq_head;
 	SPPP_UNLOCK(sp);
 	splx (s);
 	return (m);
@@ -1219,7 +1246,7 @@ int
 sppp_ioctl(struct ifnet *ifp, IOCTL_CMD_T cmd, void *data)
 {
 	struct ifreq *ifr = (struct ifreq*) data;
-	struct sppp *sp = (struct sppp*) ifp;
+	struct sppp *sp = IFP2SP(ifp);
 	int s, rv, going_up, going_down, newmode;
 
 	s = splimp();
@@ -2207,7 +2234,7 @@ sppp_lcp_init(struct sppp *sp)
 	sp->lcp.max_configure = 10;
 	sp->lcp.max_failure = 10;
  	callout_init(&sp->ch[IDX_LCP],
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
 }
 
 static void
@@ -2902,7 +2929,7 @@ sppp_ipcp_init(struct sppp *sp)
 	sp->pp_seq[IDX_IPCP] = 0;
 	sp->pp_rseq[IDX_IPCP] = 0;
  	callout_init(&sp->ch[IDX_IPCP],
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
 }
 
 static void
@@ -2985,7 +3012,7 @@ static int
 sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *r, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
 	u_long hisaddr, desiredaddr;
 	int gotmyaddr = 0;
@@ -3193,7 +3220,7 @@ static void
 sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int debug = ifp->if_flags & IFF_DEBUG;
 
 	len -= 4;
@@ -3237,7 +3264,7 @@ static void
 sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int debug = ifp->if_flags & IFF_DEBUG;
 	int desiredcomp;
 	u_long wantaddr;
@@ -3386,7 +3413,7 @@ sppp_ipv6cp_init(struct sppp *sp)
 	sp->pp_seq[IDX_IPV6CP] = 0;
 	sp->pp_rseq[IDX_IPV6CP] = 0;
  	callout_init(&sp->ch[IDX_IPV6CP],
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
 }
 
 static void
@@ -3455,7 +3482,7 @@ static int
 sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *r, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
 	struct in6_addr myaddr, desiredaddr, suggestaddr;
 	int ifidcount;
@@ -3544,7 +3571,7 @@ sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
 			nohisaddr = IN6_IS_ADDR_UNSPECIFIED(&desiredaddr);
 
 			desiredaddr.s6_addr16[0] = htons(0xfe80);
-			desiredaddr.s6_addr16[1] = htons(sp->pp_if.if_index);
+			desiredaddr.s6_addr16[1] = htons(SP2IFP(sp)->if_index);
 
 			if (!collision && !nohisaddr) {
 				/* no collision, hisaddr known - Conf-Ack */
@@ -3614,7 +3641,7 @@ static void
 sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int debug = ifp->if_flags & IFF_DEBUG;
 
 	len -= 4;
@@ -3659,7 +3686,7 @@ static void
 sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
 {
 	u_char *buf, *p;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int debug = ifp->if_flags & IFF_DEBUG;
 	struct in6_addr suggestaddr;
 
@@ -3687,7 +3714,7 @@ sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
 				break;
 			bzero(&suggestaddr, sizeof(suggestaddr));
 			suggestaddr.s6_addr16[0] = htons(0xfe80);
-			suggestaddr.s6_addr16[1] = htons(sp->pp_if.if_index);
+			suggestaddr.s6_addr16[1] = htons(SP2IFP(sp)->if_index);
 			bcopy(&p[2], &suggestaddr.s6_addr[8], 8);
 
 			sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
@@ -4187,7 +4214,7 @@ sppp_chap_init(struct sppp *sp)
 	sp->pp_seq[IDX_CHAP] = 0;
 	sp->pp_rseq[IDX_CHAP] = 0;
  	callout_init(&sp->ch[IDX_CHAP],
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
 }
 
 static void
@@ -4527,9 +4554,9 @@ sppp_pap_init(struct sppp *sp)
 	sp->pp_seq[IDX_PAP] = 0;
 	sp->pp_rseq[IDX_PAP] = 0;
  	callout_init(&sp->ch[IDX_PAP],
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
  	callout_init(&sp->pap_my_to_ch,
-		    (sp->pp_if.if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
+		    (SP2IFP(sp)->if_flags & IFF_NEEDSGIANT) ? 0 : CALLOUT_MPSAFE);
 }
 
 static void
@@ -4781,7 +4808,7 @@ static void
 sppp_keepalive(void *dummy)
 {
 	struct sppp *sp = (struct sppp*)dummy;
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	int s;
 
 	s = splimp();
@@ -4838,7 +4865,7 @@ out:
 void
 sppp_get_ip_addrs(struct sppp *sp, u_long *src, u_long *dst, u_long *srcmask)
 {
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	struct ifaddr *ifa;
 	struct sockaddr_in *si, *sm;
 	u_long ssrc, ddst;
@@ -4966,7 +4993,7 @@ static void
 sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src, struct in6_addr *dst,
 		   struct in6_addr *srcmask)
 {
-	struct ifnet *ifp = &sp->pp_if;
+	struct ifnet *ifp = SP2IFP(sp);
 	struct ifaddr *ifa;
 	struct sockaddr_in6 *si, *sm;
 	struct in6_addr ssrc, ddst;
diff --git a/sys/net/if_stf.c b/sys/net/if_stf.c
index 6c9c468..072c505 100644
--- a/sys/net/if_stf.c
+++ b/sys/net/if_stf.c
@@ -131,7 +131,7 @@
 #define GET_V4(x)	((caddr_t)(&(x)->s6_addr16[1]))
 
 struct stf_softc {
-	struct ifnet	sc_if;	   /* common area */
+	struct ifnet	*sc_ifp;
 	union {
 		struct route  __sc_ro4;
 		struct route_in6 __sc_ro6; /* just for safety */
@@ -140,6 +140,7 @@ struct stf_softc {
 	const struct encaptab *encap_cookie;
 	LIST_ENTRY(stf_softc) sc_list;	/* all stf's are linked */
 };
+#define STF2IFP(sc)	((sc)->sc_ifp)
 
 /*
  * All mutable global variables in if_stf.c are protected by stf_mtx.
@@ -214,7 +215,12 @@ stf_clone_create(struct if_clone *ifc, char *name, size_t len)
 		return (err);
 
 	sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
-	ifp = &sc->sc_if;
+	ifp = sc->sc_ifp = if_alloc(IFT_STF);
+	if (ifp == NULL) {
+		free(sc, M_STF);
+		ifc_free_unit(ifc, unit);
+		return (ENOSPC);
+	}
 	/*
 	 * Set the name manually rather then using if_initname because
 	 * we don't conform to the default naming convention for interfaces.
@@ -235,7 +241,6 @@ stf_clone_create(struct if_clone *ifc, char *name, size_t len)
 	ifp->if_mtu    = IPV6_MMTU;
 	ifp->if_ioctl  = stf_ioctl;
 	ifp->if_output = stf_output;
-	ifp->if_type   = IFT_STF;
 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
 	if_attach(ifp);
 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
@@ -252,8 +257,9 @@ stf_destroy(struct stf_softc *sc)
 
 	err = encap_detach(sc->encap_cookie);
 	KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
-	bpfdetach(&sc->sc_if);
-	if_detach(&sc->sc_if);
+	bpfdetach(STF2IFP(sc));
+	if_detach(STF2IFP(sc));
+	if_free(STF2IFP(sc));
 
 	free(sc, M_STF);
 }
@@ -261,7 +267,7 @@ stf_destroy(struct stf_softc *sc)
 static int
 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
 {
-	struct stf_softc *sc = (void *) ifp;
+	struct stf_softc *sc = ifp->if_softc;
 
 	mtx_lock(&stf_mtx);
 	LIST_REMOVE(sc, sc_list);
@@ -332,11 +338,11 @@ stf_encapcheck(m, off, proto, arg)
 	if (sc == NULL)
 		return 0;
 
-	if ((sc->sc_if.if_flags & IFF_UP) == 0)
+	if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
 		return 0;
 
 	/* IFF_LINK0 means "no decapsulation" */
-	if ((sc->sc_if.if_flags & IFF_LINK0) != 0)
+	if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
 		return 0;
 
 	if (proto != IPPROTO_IPV6)
@@ -348,7 +354,7 @@ stf_encapcheck(m, off, proto, arg)
 	if (ip.ip_v != 4)
 		return 0;
 
-	ia6 = stf_getsrcifa6(&sc->sc_if);
+	ia6 = stf_getsrcifa6(STF2IFP(sc));
 	if (ia6 == NULL)
 		return 0;
 
@@ -440,7 +446,7 @@ stf_output(ifp, m, dst, rt)
 	}
 #endif
 
-	sc = (struct stf_softc*)ifp;
+	sc = ifp->if_softc;
 	dst6 = (struct sockaddr_in6 *)dst;
 
 	/* just in case */
@@ -609,7 +615,7 @@ stf_checkaddr4(sc, in, inifp)
 	/*
 	 * perform ingress filter
 	 */
-	if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) {
+	if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
 		struct sockaddr_in sin;
 		struct rtentry *rt;
 
@@ -621,7 +627,7 @@ stf_checkaddr4(sc, in, inifp)
 		if (!rt || rt->rt_ifp != inifp) {
 #if 0
 			log(LOG_WARNING, "%s: packet from 0x%x dropped "
-			    "due to ingress filter\n", if_name(&sc->sc_if),
+			    "due to ingress filter\n", if_name(STF2IFP(sc)),
 			    (u_int32_t)ntohl(sin.sin_addr.s_addr));
 #endif
 			if (rt)
@@ -684,12 +690,12 @@ in_stf_input(m, off)
 
 	sc = (struct stf_softc *)encap_getarg(m);
 
-	if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) {
+	if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
 		m_freem(m);
 		return;
 	}
 
-	ifp = &sc->sc_if;
+	ifp = STF2IFP(sc);
 
 #ifdef MAC
 	mac_create_mbuf_from_ifnet(ifp, m);
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c
index dc76f44..f6ee9b0 100644
--- a/sys/net/if_tap.c
+++ b/sys/net/if_tap.c
@@ -62,6 +62,7 @@
 #include <net/if.h>
 #include <net/if_arp.h>
 #include <net/route.h>
+#include <net/if_types.h>
 
 #include <netinet/in.h>
 
@@ -191,7 +192,7 @@ tapmodevent(mod, type, data)
 			SLIST_REMOVE_HEAD(&taphead, tap_next);
 			mtx_unlock(&tapmtx);
 
-			ifp = &tp->tap_if;
+			ifp = tp->tap_ifp;
 
 			TAPDEBUG("detaching %s\n", ifp->if_xname);
 
@@ -202,6 +203,7 @@ tapmodevent(mod, type, data)
 			destroy_dev(tp->tap_dev);
 			s = splimp();
 			ether_ifdetach(ifp);
+			if_free_type(ifp, IFT_ETHER);
 			splx(s);
 
 			mtx_destroy(&tp->tap_mtx);
@@ -284,6 +286,7 @@ tapcreate(dev)
 	unsigned short		 macaddr_hi;
 	int			 unit, s;
 	char			*name = NULL;
+	u_char			eaddr[6];
 
 	dev->si_flags &= ~SI_CHEAPCLONE;
 
@@ -309,12 +312,14 @@ tapcreate(dev)
 
 	/* generate fake MAC address: 00 bd xx xx xx unit_no */
 	macaddr_hi = htons(0x00bd);
-	bcopy(&macaddr_hi, &tp->arpcom.ac_enaddr[0], sizeof(short));
-	bcopy(&ticks, &tp->arpcom.ac_enaddr[2], sizeof(long));
-	tp->arpcom.ac_enaddr[5] = (u_char)unit;
+	bcopy(&macaddr_hi, eaddr, sizeof(short));
+	bcopy(&ticks, &eaddr[2], sizeof(long));
+	eaddr[5] = (u_char)unit;
 
 	/* fill the rest and attach interface */
-	ifp = &tp->tap_if;
+	ifp = tp->tap_ifp = if_alloc(IFT_ETHER);
+	if (ifp == NULL)
+		panic("%s%d: can not if_alloc()", name, unit);
 	ifp->if_softc = tp;
 	if_initname(ifp, name, unit);
 	ifp->if_init = tapifinit;
@@ -328,7 +333,7 @@ tapcreate(dev)
 	tp->tap_dev = dev;
 
 	s = splimp();
-	ether_ifattach(ifp, tp->arpcom.ac_enaddr);
+	ether_ifattach(ifp, eaddr);
 	splx(s);
 
 	mtx_lock(&tp->tap_mtx);
@@ -379,10 +384,10 @@ tapopen(dev, flag, mode, td)
 		return (EBUSY);
 	}
 
-	bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr));
+	bcopy(IFP2ENADDR(tp->tap_ifp), tp->ether_addr, sizeof(tp->ether_addr));
 	tp->tap_pid = td->td_proc->p_pid;
 	tp->tap_flags |= TAP_OPEN;
-	ifp = &tp->tap_if;
+	ifp = tp->tap_ifp;
 	mtx_unlock(&tp->tap_mtx);
 
 	s = splimp();
@@ -410,7 +415,7 @@ tapclose(dev, foo, bar, td)
 {
 	struct ifaddr *ifa;
 	struct tap_softc	*tp = dev->si_drv1;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 	int			s;
 
 	/* junk all pending output */
@@ -462,7 +467,7 @@ tapifinit(xtp)
 	void	*xtp;
 {
 	struct tap_softc	*tp = (struct tap_softc *)xtp;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 
 	TAPDEBUG("initializing %s\n", ifp->if_xname);
 
@@ -601,7 +606,7 @@ tapioctl(dev, cmd, data, flag, td)
 	struct thread	*td;
 {
 	struct tap_softc	*tp = dev->si_drv1;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 	struct tapinfo		*tapp = NULL;
 	int			 s;
 	int			 f;
@@ -723,7 +728,7 @@ tapread(dev, uio, flag)
 	int		 flag;
 {
 	struct tap_softc	*tp = dev->si_drv1;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 	struct mbuf		*m = NULL;
 	int			 error = 0, len, s;
 
@@ -797,7 +802,7 @@ tapwrite(dev, uio, flag)
 	int		 flag;
 {
 	struct tap_softc	*tp = dev->si_drv1;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 	struct mbuf		*m;
 	int			 error = 0;
 
@@ -843,7 +848,7 @@ tappoll(dev, events, td)
 	struct thread	*td;
 {
 	struct tap_softc	*tp = dev->si_drv1;
-	struct ifnet		*ifp = &tp->tap_if;
+	struct ifnet		*ifp = tp->tap_ifp;
 	int			 s, revents = 0;
 
 	TAPDEBUG("%s polling, minor = %#x\n", 
diff --git a/sys/net/if_tapvar.h b/sys/net/if_tapvar.h
index 1017bae..21bac50 100644
--- a/sys/net/if_tapvar.h
+++ b/sys/net/if_tapvar.h
@@ -46,8 +46,7 @@
  * Other fields locked by owning subsystems.
  */
 struct tap_softc {
-	struct arpcom	arpcom;			/* ethernet common data      */
-#define tap_if		arpcom.ac_if
+	struct ifnet	*tap_ifp;
 	u_short		tap_flags;		/* misc flags                */
 #define	TAP_OPEN	(1 << 0)
 #define	TAP_INITED	(1 << 1)
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index cd209cb..310ff49 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -85,11 +85,12 @@ struct tun_softc {
 	 * being slightly stale informationally.
 	 */
 	pid_t	tun_pid;		/* owning pid */
-	struct	ifnet tun_if;		/* the interface */
+	struct	ifnet *tun_ifp;		/* the interface */
 	struct  sigio *tun_sigio;	/* information for async I/O */
 	struct	selinfo	tun_rsel;	/* read select */
 	struct mtx	tun_mtx;	/* protect mutable softc fields */
 };
+#define TUN2IFP(sc)	((sc)->tun_ifp)
 
 #define TUNDEBUG	if (tundebug) if_printf
 #define	TUNNAME		"tun"
@@ -169,11 +170,12 @@ tun_destroy(struct tun_softc *tp)
 
 	/* Unlocked read. */
 	KASSERT((tp->tun_flags & TUN_OPEN) == 0,
-	    ("tununits is out of sync - unit %d", tp->tun_if.if_dunit));
+	    ("tununits is out of sync - unit %d", TUN2IFP(tp)->if_dunit));
 
 	dev = tp->tun_dev;
-	bpfdetach(&tp->tun_if);
-	if_detach(&tp->tun_if);
+	bpfdetach(TUN2IFP(tp));
+	if_detach(TUN2IFP(tp));
+	if_free(TUN2IFP(tp));
 	destroy_dev(dev);
 	mtx_destroy(&tp->tun_mtx);
 	free(tp, M_TUN);
@@ -250,6 +252,7 @@ tunstart(struct ifnet *ifp)
 	selwakeuppri(&tp->tun_rsel, PZERO + 1);
 }
 
+/* XXX: should return an error code so it can fail. */
 static void
 tuncreate(struct cdev *dev)
 {
@@ -266,14 +269,16 @@ tuncreate(struct cdev *dev)
 	TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
 	mtx_unlock(&tunmtx);
 
-	ifp = &sc->tun_if;
+	ifp = sc->tun_ifp = if_alloc(IFT_PPP);
+	if (ifp == NULL)
+		panic("%s%d: failed to if_alloc() interface.\n",
+		    TUNNAME, dev2unit(dev));
 	if_initname(ifp, TUNNAME, dev2unit(dev));
 	ifp->if_mtu = TUNMTU;
 	ifp->if_ioctl = tunifioctl;
 	ifp->if_output = tunoutput;
 	ifp->if_start = tunstart;
 	ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
-	ifp->if_type = IFT_PPP;
 	ifp->if_softc = sc;
 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 	ifp->if_snd.ifq_drv_maxlen = 0;
@@ -315,7 +320,7 @@ tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
 
 	tp->tun_flags |= TUN_OPEN;
 	mtx_unlock(&tp->tun_mtx);
-	ifp = &tp->tun_if;
+	ifp = TUN2IFP(tp);
 	TUNDEBUG(ifp, "open\n");
 
 	return (0);
@@ -333,7 +338,7 @@ tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
 	int s;
 
 	tp = dev->si_drv1;
-	ifp = &tp->tun_if;
+	ifp = TUN2IFP(tp);
 
 	mtx_lock(&tp->tun_mtx);
 	tp->tun_flags &= ~TUN_OPEN;
@@ -568,18 +573,18 @@ tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td
 		tunp = (struct tuninfo *)data;
 		if (tunp->mtu < IF_MINMTU)
 			return (EINVAL);
-		if (tp->tun_if.if_mtu != tunp->mtu
+		if (TUN2IFP(tp)->if_mtu != tunp->mtu
 		&& (error = suser(td)) != 0)
 			return (error);
-		tp->tun_if.if_mtu = tunp->mtu;
-		tp->tun_if.if_type = tunp->type;
-		tp->tun_if.if_baudrate = tunp->baudrate;
+		TUN2IFP(tp)->if_mtu = tunp->mtu;
+		TUN2IFP(tp)->if_type = tunp->type;
+		TUN2IFP(tp)->if_baudrate = tunp->baudrate;
 		break;
 	case TUNGIFINFO:
 		tunp = (struct tuninfo *)data;
-		tunp->mtu = tp->tun_if.if_mtu;
-		tunp->type = tp->tun_if.if_type;
-		tunp->baudrate = tp->tun_if.if_baudrate;
+		tunp->mtu = TUN2IFP(tp)->if_mtu;
+		tunp->type = TUN2IFP(tp)->if_type;
+		tunp->baudrate = TUN2IFP(tp)->if_baudrate;
 		break;
 	case TUNSDEBUG:
 		tundebug = *(int *)data;
@@ -613,15 +618,15 @@ tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td
 		break;
 	case TUNSIFMODE:
 		/* deny this if UP */
-		if (tp->tun_if.if_flags & IFF_UP)
+		if (TUN2IFP(tp)->if_flags & IFF_UP)
 			return(EBUSY);
 
 		switch (*(int *)data & ~IFF_MULTICAST) {
 		case IFF_POINTOPOINT:
 		case IFF_BROADCAST:
-			tp->tun_if.if_flags &=
+			TUN2IFP(tp)->if_flags &=
 			    ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
-			tp->tun_if.if_flags |= *(int *)data;
+			TUN2IFP(tp)->if_flags |= *(int *)data;
 			break;
 		default:
 			return(EINVAL);
@@ -644,13 +649,13 @@ tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td
 		break;
 	case FIONREAD:
 		s = splimp();
-		if (!IFQ_IS_EMPTY(&tp->tun_if.if_snd)) {
+		if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
 			struct mbuf *mb;
-			IFQ_LOCK(&tp->tun_if.if_snd);
-			IFQ_POLL_NOLOCK(&tp->tun_if.if_snd, mb);
+			IFQ_LOCK(&TUN2IFP(tp)->if_snd);
+			IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
 			for( *(int *)data = 0; mb != 0; mb = mb->m_next)
 				*(int *)data += mb->m_len;
-			IFQ_UNLOCK(&tp->tun_if.if_snd);
+			IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
 		} else
 			*(int *)data = 0;
 		splx(s);
@@ -685,7 +690,7 @@ static	int
 tunread(struct cdev *dev, struct uio *uio, int flag)
 {
 	struct tun_softc *tp = dev->si_drv1;
-	struct ifnet	*ifp = &tp->tun_if;
+	struct ifnet	*ifp = TUN2IFP(tp);
 	struct mbuf	*m;
 	int		error=0, len, s;
 
@@ -741,7 +746,7 @@ static	int
 tunwrite(struct cdev *dev, struct uio *uio, int flag)
 {
 	struct tun_softc *tp = dev->si_drv1;
-	struct ifnet	*ifp = &tp->tun_if;
+	struct ifnet	*ifp = TUN2IFP(tp);
 	struct mbuf	*m;
 	int		error = 0;
 	uint32_t	family;
@@ -831,7 +836,7 @@ tunpoll(struct cdev *dev, int events, struct thread *td)
 {
 	int		s;
 	struct tun_softc *tp = dev->si_drv1;
-	struct ifnet	*ifp = &tp->tun_if;
+	struct ifnet	*ifp = TUN2IFP(tp);
 	int		revents = 0;
 	struct mbuf	*m;
 
diff --git a/sys/net/if_types.h b/sys/net/if_types.h
index 1dff5c2..2d25b69 100644
--- a/sys/net/if_types.h
+++ b/sys/net/if_types.h
@@ -249,4 +249,5 @@
 #define	IFT_PFLOG	0xf6
 #define	IFT_PFSYNC	0xf7
 #define	IFT_CARP	0xf8	/* Common Address Redundancy Protocol */
+#define IFT_IPXIP	0xf9
 #endif /* !_NET_IF_TYPES_H_ */
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index b189a70..4b0f421 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -109,27 +109,9 @@ struct	ifqueue {
  * (Would like to call this struct ``if'', but C isn't PL/1.)
  */
 
-/*
- * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with
- * one of these structures, typically held within an arpcom structure.
- *
- *	struct <foo>_softc {
- *		struct arpcom {
- *			struct  ifnet ac_if;
- *			...
- *		} <arpcom> ;
- *		...
- *	};
- *
- * The assumption is used in a number of places, including many
- * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
- *
- * Unfortunately devices' softc are opaque, so we depend on this layout
- * to locate the struct ifnet from the softc in the generic code.
- * 
- */
 struct ifnet {
 	void	*if_softc;		/* pointer to driver state */
+	void	*if_l2com;		/* pointer to protocol bits */
 	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
 	const char *if_dname;		/* driver name */
@@ -628,11 +610,14 @@ extern	int if_index;
 
 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
 int	if_allmulti(struct ifnet *, int);
+struct	ifnet* if_alloc(u_char);
 void	if_attach(struct ifnet *);
 int	if_delmulti(struct ifnet *, struct sockaddr *);
 void	if_detach(struct ifnet *);
 void	if_purgeaddrs(struct ifnet *);
 void	if_down(struct ifnet *);
+void	if_free(struct ifnet *);
+void	if_free_type(struct ifnet *, u_char);
 void	if_initname(struct ifnet *, const char *, int);
 void	if_link_state_change(struct ifnet *, int);
 int	if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
@@ -652,6 +637,11 @@ struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 struct	ifmultiaddr *ifmaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 int	if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
 
+typedef	void *if_com_alloc_t(u_char type, struct ifnet *ifp);
+typedef	void if_com_free_t(void *com, u_char type);
+void	if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
+void	if_deregister_com_alloc(u_char type);
+
 #define IF_LLADDR(ifp)							\
     LLADDR((struct sockaddr_dl *) ifaddr_byindex((ifp)->if_index)->ifa_addr)
 
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 77cc178..f909dbe 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -76,7 +76,7 @@ struct vlan_mc_entry {
 };
 
 struct	ifvlan {
-	struct	arpcom ifv_ac;	/* make this an interface */
+	struct	ifnet *ifv_ifp;
 	struct	ifnet *ifv_p;	/* parent inteface of this vlan */
 	struct	ifv_linkmib {
 		int	ifvm_parent;
@@ -90,7 +90,6 @@ struct	ifvlan {
 	LIST_ENTRY(ifvlan) ifv_list;
 	int	ifv_flags;
 };
-#define	ifv_if	ifv_ac.ac_if
 #define	ifv_tag	ifv_mib.ifvm_tag
 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
@@ -244,7 +243,7 @@ vlan_modevent(module_t mod, int type, void *data)
 		vlan_link_state_p = NULL;
 		while (!LIST_EMPTY(&ifv_list))
 			vlan_clone_destroy(&vlan_cloner,
-			    &LIST_FIRST(&ifv_list)->ifv_if);
+			    LIST_FIRST(&ifv_list)->ifv_ifp);
 		VLAN_LOCK_DESTROY();
 		break;
 	default:
@@ -323,6 +322,7 @@ vlan_clone_create(struct if_clone *ifc, char *name, size_t len)
 	struct ifvlan *ifv;
 	struct ifnet *ifp;
 	struct ifnet *p;
+	u_char eaddr[6] = {0,0,0,0,0,0};
 
 	if ((p = vlan_clone_match_ethertag(ifc, name, &tag)) != NULL) {
 		ethertag = 1;
@@ -359,7 +359,12 @@ vlan_clone_create(struct if_clone *ifc, char *name, size_t len)
 	}
 
 	ifv = malloc(sizeof(struct ifvlan), M_VLAN, M_WAITOK | M_ZERO);
-	ifp = &ifv->ifv_if;
+	ifp = ifv->ifv_ifp = if_alloc(IFT_ETHER);
+	if (ifp == NULL) {
+		ifc_free_unit(ifc, unit);
+		free(ifv, M_VLAN);
+		return (ENOSPC);
+	}
 	SLIST_INIT(&ifv->vlan_mc_listhead);
 
 	ifp->if_softc = ifv;
@@ -379,7 +384,7 @@ vlan_clone_create(struct if_clone *ifc, char *name, size_t len)
 	ifp->if_start = vlan_start;
 	ifp->if_ioctl = vlan_ioctl;
 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
-	ether_ifattach(ifp, ifv->ifv_ac.ac_enaddr);
+	ether_ifattach(ifp, eaddr);
 	/* Now undo some of the damage... */
 	ifp->if_baudrate = 0;
 	ifp->if_type = IFT_L2VLAN;
@@ -402,6 +407,7 @@ vlan_clone_create(struct if_clone *ifc, char *name, size_t len)
 			vlan_unconfig(ifp);
 			VLAN_UNLOCK();
 			ether_ifdetach(ifp);
+			if_free_type(ifp, IFT_ETHER);
 			free(ifv, M_VLAN);
 
 			return (error);
@@ -431,6 +437,7 @@ vlan_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
 	VLAN_UNLOCK();
 
 	ether_ifdetach(ifp);
+	if_free(ifp);
 
 	free(ifv, M_VLAN);
 
@@ -600,7 +607,7 @@ vlan_input(struct ifnet *ifp, struct mbuf *m)
 		if (ifp == ifv->ifv_p && tag == ifv->ifv_tag)
 			break;
 
-	if (ifv == NULL || (ifv->ifv_if.if_flags & IFF_UP) == 0) {
+	if (ifv == NULL || (ifv->ifv_ifp->if_flags & IFF_UP) == 0) {
 		VLAN_UNLOCK();
 		m_freem(m);
 		ifp->if_noproto++;
@@ -626,11 +633,11 @@ vlan_input(struct ifnet *ifp, struct mbuf *m)
 		m_adj(m, ETHER_VLAN_ENCAP_LEN);
 	}
 
-	m->m_pkthdr.rcvif = &ifv->ifv_if;
-	ifv->ifv_if.if_ipackets++;
+	m->m_pkthdr.rcvif = ifv->ifv_ifp;
+	ifv->ifv_ifp->if_ipackets++;
 
 	/* Pass it back through the parent's input routine. */
-	(*ifp->if_input)(&ifv->ifv_if, m);
+	(*ifp->if_input)(ifv->ifv_ifp, m);
 }
 
 static int
@@ -680,14 +687,14 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p)
 	}
 
 	ifv->ifv_p = p;
-	ifv->ifv_if.if_mtu = p->if_mtu - ifv->ifv_mtufudge;
+	ifv->ifv_ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
 	/*
 	 * Copy only a selected subset of flags from the parent.
 	 * Other flags are none of our business.
 	 */
-	ifv->ifv_if.if_flags = (p->if_flags &
+	ifv->ifv_ifp->if_flags = (p->if_flags &
 	    (IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX | IFF_POINTOPOINT));
-	ifv->ifv_if.if_link_state = p->if_link_state;
+	ifv->ifv_ifp->if_link_state = p->if_link_state;
 
 #if 0
 	/*
@@ -701,27 +708,27 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p)
 	 * assisted checksumming flags.
 	 */
 	if (p->if_capabilities & IFCAP_VLAN_HWTAGGING)
-		ifv->ifv_if.if_capabilities |= p->if_capabilities & IFCAP_HWCSUM;
+		ifv->ifv_ifpif_capabilities |= p->if_capabilities & IFCAP_HWCSUM;
 #endif
 
 	/*
 	 * Set up our ``Ethernet address'' to reflect the underlying
 	 * physical interface's.
 	 */
-	ifa1 = ifaddr_byindex(ifv->ifv_if.if_index);
+	ifa1 = ifaddr_byindex(ifv->ifv_ifp->if_index);
 	ifa2 = ifaddr_byindex(p->if_index);
 	sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr;
 	sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
 	sdl1->sdl_type = IFT_ETHER;
 	sdl1->sdl_alen = ETHER_ADDR_LEN;
 	bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
-	bcopy(LLADDR(sdl2), ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);
+	bcopy(LLADDR(sdl2), IFP2ENADDR(ifv->ifv_ifp), ETHER_ADDR_LEN);
 
 	/*
 	 * Configure multicast addresses that may already be
 	 * joined on the vlan device.
 	 */
-	(void)vlan_setmulti(&ifv->ifv_if); /* XXX: VLAN lock held */
+	(void)vlan_setmulti(ifv->ifv_ifp); /* XXX: VLAN lock held */
 
 	return (0);
 }
@@ -772,17 +779,17 @@ vlan_unconfig(struct ifnet *ifp)
 
 	/* Disconnect from parent. */
 	ifv->ifv_p = NULL;
-	ifv->ifv_if.if_mtu = ETHERMTU;		/* XXX why not 0? */
+	ifv->ifv_ifp->if_mtu = ETHERMTU;		/* XXX why not 0? */
 	ifv->ifv_flags = 0;
-	ifv->ifv_if.if_link_state = LINK_STATE_UNKNOWN;
+	ifv->ifv_ifp->if_link_state = LINK_STATE_UNKNOWN;
 
 	/* Clear our MAC address. */
-	ifa = ifaddr_byindex(ifv->ifv_if.if_index);
+	ifa = ifaddr_byindex(ifv->ifv_ifp->if_index);
 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
 	sdl->sdl_type = IFT_ETHER;
 	sdl->sdl_alen = ETHER_ADDR_LEN;
 	bzero(LLADDR(sdl), ETHER_ADDR_LEN);
-	bzero(ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);
+	bzero(IFP2ENADDR(ifv->ifv_ifp), ETHER_ADDR_LEN);
 
 	return (0);
 }
@@ -819,7 +826,7 @@ vlan_link_state(struct ifnet *ifp, int link)
 	VLAN_LOCK();
 	LIST_FOREACH(ifv, &ifv_list, ifv_list) {
 		if (ifv->ifv_p == ifp)
-			if_link_state_change(&ifv->ifv_if,
+			if_link_state_change(ifv->ifv_ifp,
 			    ifv->ifv_p->if_link_state);
 	}
 	VLAN_UNLOCK();
@@ -846,7 +853,7 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		switch (ifa->ifa_addr->sa_family) {
 #ifdef INET
 		case AF_INET:
-			arp_ifinit(&ifv->ifv_if, ifa);
+			arp_ifinit(ifv->ifv_ifp, ifa);
 			break;
 #endif
 		default:
@@ -859,7 +866,7 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 			struct sockaddr *sa;
 
 			sa = (struct sockaddr *) &ifr->ifr_data;
-			bcopy(IFP2AC(ifp)->ac_enaddr, (caddr_t)sa->sa_data,
+			bcopy(IFP2ENADDR(ifp), (caddr_t)sa->sa_data,
 			    ETHER_ADDR_LEN);
 		}
 		break;
diff --git a/sys/net/ppp_tty.c b/sys/net/ppp_tty.c
index 3c25bab..38647f2 100644
--- a/sys/net/ppp_tty.c
+++ b/sys/net/ppp_tty.c
@@ -207,9 +207,9 @@ pppopen(dev, tp)
     sc->sc_setmtu = pppasyncsetmtu;
     sc->sc_outm = NULL;
     pppgetm(sc);
-    sc->sc_if.if_flags |= IFF_RUNNING;
-    getmicrotime(&sc->sc_if.if_lastchange);
-    sc->sc_if.if_baudrate = tp->t_ospeed;
+    PPP2IFP(sc)->if_flags |= IFF_RUNNING;
+    getmicrotime(&PPP2IFP(sc)->if_lastchange);
+    PPP2IFP(sc)->if_baudrate = tp->t_ospeed;
 
     tp->t_hotchar = PPP_FLAG;
     ttyflush(tp, FREAD | FWRITE);
@@ -220,8 +220,8 @@ pppopen(dev, tp)
      * We also pass 1 byte tokens through t_canq...
      */
     clist_alloc_cblocks(&tp->t_canq, 1, 1);
-    clist_alloc_cblocks(&tp->t_outq, sc->sc_if.if_mtu + PPP_HIWAT,
-			sc->sc_if.if_mtu + PPP_HIWAT);
+    clist_alloc_cblocks(&tp->t_outq, PPP2IFP(sc)->if_mtu + PPP_HIWAT,
+			PPP2IFP(sc)->if_mtu + PPP_HIWAT);
     clist_alloc_cblocks(&tp->t_rawq, 0, 0);
 
     splx(s);
@@ -293,8 +293,8 @@ register struct ppp_softc *sc;
 
     s = spltty();
     if (tp != NULL)
-	clist_alloc_cblocks(&tp->t_outq, sc->sc_if.if_mtu + PPP_HIWAT,
-			     sc->sc_if.if_mtu + PPP_HIWAT);
+	clist_alloc_cblocks(&tp->t_outq, PPP2IFP(sc)->if_mtu + PPP_HIWAT,
+			     PPP2IFP(sc)->if_mtu + PPP_HIWAT);
     splx(s);
 }
 
@@ -379,7 +379,7 @@ pppwrite(tp, uio, flag)
 	return (EINVAL);
     if (sc == NULL)
 	return EIO;
-    if (uio->uio_resid > sc->sc_if.if_mtu + PPP_HDRLEN ||
+    if (uio->uio_resid > PPP2IFP(sc)->if_mtu + PPP_HDRLEN ||
 	uio->uio_resid < PPP_HDRLEN)
 	return (EMSGSIZE);
 
@@ -410,7 +410,7 @@ pppwrite(tp, uio, flag)
     m0->m_len -= PPP_HDRLEN;
 
     /* call the upper layer to "transmit" it... */
-    error = pppoutput(&sc->sc_if, m0, &dst, (struct rtentry *)0);
+    error = pppoutput(PPP2IFP(sc), m0, &dst, (struct rtentry *)0);
     splx(s);
     return (error);
 }
@@ -576,7 +576,7 @@ pppasyncstart(sc)
 
 	    /* Calculate the FCS for the first mbuf's worth. */
 	    sc->sc_outfcs = pppfcs(PPP_INITFCS, mtod(m, u_char *), m->m_len);
-	    getmicrotime(&sc->sc_if.if_lastchange);
+	    getmicrotime(&PPP2IFP(sc)->if_lastchange);
 	}
 
 	for (;;) {
@@ -839,14 +839,14 @@ pppinput(c, tp)
 
     if ((tp->t_state & TS_CONNECTED) == 0) {
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "no carrier\n");
+	    if_printf(PPP2IFP(sc), "no carrier\n");
 	goto flush;
     }
 
     if (c & TTY_ERRORMASK) {
 	/* framing error or overrun on this char - abort packet */
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "line error %x\n", c & TTY_ERRORMASK);
+	    if_printf(PPP2IFP(sc), "line error %x\n", c & TTY_ERRORMASK);
 	goto flush;
     }
 
@@ -902,9 +902,9 @@ pppinput(c, tp)
 	    sc->sc_flags |= SC_PKTLOST;	/* note the dropped packet */
 	    if ((sc->sc_flags & (SC_FLUSH | SC_ESCAPED)) == 0){
 		if (sc->sc_flags & SC_DEBUG)
-		    if_printf(&sc->sc_if, "bad fcs %x, pkt len %d\n",
+		    if_printf(PPP2IFP(sc), "bad fcs %x, pkt len %d\n",
 			   sc->sc_fcs, ilen);
-		sc->sc_if.if_ierrors++;
+		PPP2IFP(sc)->if_ierrors++;
 		sc->sc_stats.ppp_ierrors++;
 	    } else
 		sc->sc_flags &= ~(SC_FLUSH | SC_ESCAPED);
@@ -915,9 +915,9 @@ pppinput(c, tp)
 	if (ilen < PPP_HDRLEN + PPP_FCSLEN) {
 	    if (ilen) {
 		if (sc->sc_flags & SC_DEBUG)
-		    if_printf(&sc->sc_if, "too short (%d)\n", ilen);
+		    if_printf(PPP2IFP(sc), "too short (%d)\n", ilen);
 		s = spltty();
-		sc->sc_if.if_ierrors++;
+		PPP2IFP(sc)->if_ierrors++;
 		sc->sc_stats.ppp_ierrors++;
 		sc->sc_flags |= SC_PKTLOST;
 		splx(s);
@@ -987,7 +987,7 @@ pppinput(c, tp)
 	    pppgetm(sc);
 	    if (sc->sc_m == NULL) {
 		if (sc->sc_flags & SC_DEBUG)
-		    if_printf(&sc->sc_if, "no input mbufs!\n");
+		    if_printf(PPP2IFP(sc), "no input mbufs!\n");
 		goto flush;
 	    }
 	}
@@ -1000,7 +1000,7 @@ pppinput(c, tp)
 	if (c != PPP_ALLSTATIONS) {
 	    if (sc->sc_flags & SC_REJ_COMP_AC) {
 		if (sc->sc_flags & SC_DEBUG)
-		    if_printf(&sc->sc_if,
+		    if_printf(PPP2IFP(sc),
 		              "garbage received: 0x%x (need 0xFF)\n", c);
 		goto flush;
 	    }
@@ -1012,7 +1012,7 @@ pppinput(c, tp)
     }
     if (sc->sc_ilen == 1 && c != PPP_UI) {
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "missing UI (0x3), got 0x%x\n", c);
+	    if_printf(PPP2IFP(sc), "missing UI (0x3), got 0x%x\n", c);
 	goto flush;
     }
     if (sc->sc_ilen == 2 && (c & 1) == 1) {
@@ -1023,7 +1023,7 @@ pppinput(c, tp)
     }
     if (sc->sc_ilen == 3 && (c & 1) == 0) {
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "bad protocol %x\n",
+	    if_printf(PPP2IFP(sc), "bad protocol %x\n",
 		      (sc->sc_mp[-1] << 8) + c);
 	goto flush;
     }
@@ -1031,7 +1031,7 @@ pppinput(c, tp)
     /* packet beyond configured mru? */
     if (++sc->sc_ilen > sc->sc_mru + PPP_HDRLEN + PPP_FCSLEN) {
 	if (sc->sc_flags & SC_DEBUG)
-	    if_printf(&sc->sc_if, "packet too big\n");
+	    if_printf(PPP2IFP(sc), "packet too big\n");
 	goto flush;
     }
 
@@ -1042,7 +1042,7 @@ pppinput(c, tp)
 	    pppgetm(sc);
 	    if (m->m_next == NULL) {
 		if (sc->sc_flags & SC_DEBUG)
-		    if_printf(&sc->sc_if, "too few input mbufs!\n");
+		    if_printf(PPP2IFP(sc), "too few input mbufs!\n");
 		goto flush;
 	    }
 	}
@@ -1060,7 +1060,7 @@ pppinput(c, tp)
  flush:
     if (!(sc->sc_flags & SC_FLUSH)) {
 	s = spltty();
-	sc->sc_if.if_ierrors++;
+	PPP2IFP(sc)->if_ierrors++;
 	sc->sc_stats.ppp_ierrors++;
 	sc->sc_flags |= SC_FLUSH;
 	splx(s);
@@ -1081,7 +1081,7 @@ ppplogchar(sc, c)
 	sc->sc_rawin[sc->sc_rawin_count++] = c;
     if (sc->sc_rawin_count >= sizeof(sc->sc_rawin)
 	|| (c < 0 && sc->sc_rawin_count > 0)) {
-	printf("%s input: %*D", sc->sc_if.if_xname,
+	printf("%s input: %*D", PPP2IFP(sc)->if_xname,
 		sc->sc_rawin_count, sc->sc_rawin, " ");
 	sc->sc_rawin_count = 0;
     }