]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/in.c
xnu-2050.48.11.tar.gz
[apple/xnu.git] / bsd / netinet / in.c
index 9db5f54b9c077ebae3729ad7301ec58b5c7664b9..1df980df6ba89101137506cd16fe91b810b5e3bc 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * Copyright (c) 1982, 1986, 1991, 1993
 #include <sys/sysctl.h>
 #include <sys/kern_event.h>
 #include <sys/syslog.h>
+#include <sys/mcache.h>
+#include <kern/zalloc.h>
+
+#include <pexpert/pexpert.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
 #include <net/route.h>
+#include <net/kpi_protocol.h>
 
 #include <netinet/in.h>
 #include <netinet/in_var.h>
 
 #include <sys/file.h>
 
+#if PF
+#include <net/pfvar.h>
+#endif /* PF */
 
 static int in_mask2len(struct in_addr *);
 static void in_len2mask(struct in_addr *, int);
-static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
-       struct ifnet *, struct proc *);
+static int in_lifaddr_ioctl(struct socket *, u_long, struct if_laddrreq *,
+    struct ifnet *, struct proc *);
+static int in_setrouter(struct ifnet *, int);
 
 static void    in_socktrim(struct sockaddr_in *);
 static int     in_ifinit(struct ifnet *,
            struct in_ifaddr *, struct sockaddr_in *, int);
 
-static int subnetsarelocal = 0;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW, 
-       &subnetsarelocal, 0, "");
+#define        IA_HASH_INIT(ia) {                                      \
+       (ia)->ia_hash.tqe_next = (void *)(uintptr_t)-1;         \
+       (ia)->ia_hash.tqe_prev = (void *)(uintptr_t)-1;         \
+}
 
-struct in_multihead in_multihead; /* XXX BSS initialization */
+#define        IA_IS_HASHED(ia)                                        \
+       (!((ia)->ia_hash.tqe_next == (void *)(uintptr_t)-1 ||   \
+       (ia)->ia_hash.tqe_prev == (void *)(uintptr_t)-1))
 
-extern lck_mtx_t *rt_mtx;
+static void in_iahash_remove(struct in_ifaddr *);
+static void in_iahash_insert(struct in_ifaddr *);
+static void in_iahash_insert_ptp(struct in_ifaddr *);
+static struct in_ifaddr *in_ifaddr_alloc(int);
+static void in_ifaddr_attached(struct ifaddr *);
+static void in_ifaddr_detached(struct ifaddr *);
+static void in_ifaddr_free(struct ifaddr *);
+static void in_ifaddr_trace(struct ifaddr *, int);
+
+static int subnetsarelocal = 0;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW | CTLFLAG_LOCKED,
+       &subnetsarelocal, 0, "");
 
 /* Track whether or not the SIOCARPIPLL ioctl has been called */
 __private_extern__     u_int32_t       ipv4_ll_arp_aware = 0;
 
+#define        INIFA_TRACE_HIST_SIZE   32      /* size of trace history */
+
+/* For gdb */
+__private_extern__ unsigned int inifa_trace_hist_size = INIFA_TRACE_HIST_SIZE;
+
+struct in_ifaddr_dbg {
+       struct in_ifaddr        inifa;                  /* in_ifaddr */
+       struct in_ifaddr        inifa_old;              /* saved in_ifaddr */
+       u_int16_t               inifa_refhold_cnt;      /* # of IFA_ADDREF */
+       u_int16_t               inifa_refrele_cnt;      /* # of IFA_REMREF */
+       /*
+        * Alloc and free callers.
+        */
+       ctrace_t                inifa_alloc;
+       ctrace_t                inifa_free;
+       /*
+        * Circular lists of IFA_ADDREF and IFA_REMREF callers.
+        */
+       ctrace_t                inifa_refhold[INIFA_TRACE_HIST_SIZE];
+       ctrace_t                inifa_refrele[INIFA_TRACE_HIST_SIZE];
+       /*
+        * Trash list linkage
+        */
+       TAILQ_ENTRY(in_ifaddr_dbg) inifa_trash_link;
+};
+
+/* List of trash in_ifaddr entries protected by inifa_trash_lock */
+static TAILQ_HEAD(, in_ifaddr_dbg) inifa_trash_head;
+static decl_lck_mtx_data(, inifa_trash_lock);
+
+#if DEBUG
+static unsigned int inifa_debug = 1;           /* debugging (enabled) */
+#else
+static unsigned int inifa_debug;               /* debugging (disabled) */
+#endif /* !DEBUG */
+static unsigned int inifa_size;                        /* size of zone element */
+static struct zone *inifa_zone;                        /* zone for in_ifaddr */
+
+#define        INIFA_ZONE_MAX          64              /* maximum elements in zone */
+#define        INIFA_ZONE_NAME         "in_ifaddr"     /* zone name */
+
+/*
+ * Return 1 if the address is
+ * - loopback
+ * - unicast or multicast link local
+ * - routed via a link level gateway
+ * - belongs to a directly connected (sub)net
+ */
+int
+inaddr_local(struct in_addr in)
+{
+       struct rtentry *rt;
+       struct sockaddr_in sin;
+       int local = 0;
+
+       if (ntohl(in.s_addr) == INADDR_LOOPBACK || IN_LINKLOCAL(ntohl(in.s_addr))) {
+               local = 1;
+       } else if (ntohl(in.s_addr) >= INADDR_UNSPEC_GROUP &&
+               ntohl(in.s_addr) <= INADDR_MAX_LOCAL_GROUP) {
+                       local = 1;
+       } else {
+               sin.sin_family = AF_INET;
+               sin.sin_len = sizeof (sin);
+               sin.sin_addr = in;
+               rt = rtalloc1((struct sockaddr *)&sin, 0, 0);
+
+               if (rt != NULL) {
+                       RT_LOCK_SPIN(rt);
+                       if (rt->rt_gateway->sa_family == AF_LINK ||
+                           (rt->rt_ifp->if_flags & IFF_LOOPBACK))
+                               local = 1;
+                       RT_UNLOCK(rt);
+                       rtfree(rt);
+               } else {
+                       local = in_localaddr(in);
+               }
+       }
+       return (local);
+}
+
 /*
  * Return 1 if an internet address is for a ``local'' host
  * (one to which we have a connection).  If subnetsarelocal
@@ -114,30 +223,37 @@ __private_extern__        u_int32_t       ipv4_ll_arp_aware = 0;
  * Otherwise, it includes only the directly-connected (sub)nets.
  */
 int
-in_localaddr(in)
-       struct in_addr in;
+in_localaddr(struct in_addr in)
 {
-       u_long i = ntohl(in.s_addr);
+       u_int32_t i = ntohl(in.s_addr);
        struct in_ifaddr *ia;
 
        if (subnetsarelocal) {
-               lck_mtx_lock(rt_mtx);
+               lck_rw_lock_shared(in_ifaddr_rwlock);
                for (ia = in_ifaddrhead.tqh_first; ia; 
-                    ia = ia->ia_link.tqe_next)
+                    ia = ia->ia_link.tqe_next) {
+                       IFA_LOCK(&ia->ia_ifa);
                        if ((i & ia->ia_netmask) == ia->ia_net) {
-                               lck_mtx_unlock(rt_mtx);
+                               IFA_UNLOCK(&ia->ia_ifa);
+                               lck_rw_done(in_ifaddr_rwlock);
                                return (1);
                        }
-               lck_mtx_unlock(rt_mtx);
+                       IFA_UNLOCK(&ia->ia_ifa);
+               }
+               lck_rw_done(in_ifaddr_rwlock);
        } else {
-               lck_mtx_lock(rt_mtx);
+               lck_rw_lock_shared(in_ifaddr_rwlock);
                for (ia = in_ifaddrhead.tqh_first; ia;
-                    ia = ia->ia_link.tqe_next)
+                    ia = ia->ia_link.tqe_next) {
+                       IFA_LOCK(&ia->ia_ifa);
                        if ((i & ia->ia_subnetmask) == ia->ia_subnet) {
-                               lck_mtx_unlock(rt_mtx);
+                               IFA_UNLOCK(&ia->ia_ifa);
+                               lck_rw_done(in_ifaddr_rwlock);
                                return (1);
                        }
-               lck_mtx_unlock(rt_mtx);
+                       IFA_UNLOCK(&ia->ia_ifa);
+               }
+               lck_rw_done(in_ifaddr_rwlock);
        }
        return (0);
 }
@@ -148,11 +264,10 @@ in_localaddr(in)
  * may be forwarded.
  */
 int
-in_canforward(in)
-       struct in_addr in;
+in_canforward(struct in_addr in)
 {
-       u_long i = ntohl(in.s_addr);
-       u_long net;
+       u_int32_t i = ntohl(in.s_addr);
+       u_int32_t net;
 
        if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
                return (0);
@@ -168,8 +283,7 @@ in_canforward(in)
  * Trim a mask in a sockaddr
  */
 static void
-in_socktrim(ap)
-struct sockaddr_in *ap;
+in_socktrim(struct sockaddr_in *ap)
 {
     char *cplim = (char *) &ap->sin_addr;
     char *cp = (char *) (&ap->sin_addr + 1);
@@ -183,10 +297,9 @@ struct sockaddr_in *ap;
 }
 
 static int
-in_mask2len(mask)
-       struct in_addr *mask;
+in_mask2len(struct in_addr *mask)
 {
-       int x, y;
+       size_t x, y;
        u_char *p;
 
        p = (u_char *)mask;
@@ -205,9 +318,7 @@ in_mask2len(mask)
 }
 
 static void
-in_len2mask(mask, len)
-       struct in_addr *mask;
-       int len;
+in_len2mask(struct in_addr *mask, int len)
 {
        int i;
        u_char *p;
@@ -222,41 +333,71 @@ in_len2mask(mask, len)
 
 static int in_interfaces;      /* number of external internet interfaces */
 
+static int
+in_domifattach(struct ifnet *ifp)
+{
+       int error;
+
+       if ((error = proto_plumb(PF_INET, ifp)) && error != EEXIST)
+               log(LOG_ERR, "%s: proto_plumb returned %d if=%s%d\n",
+                   __func__, error, ifp->if_name, ifp->if_unit);
+
+       return (error);
+}
+
 /*
  * Generic internet control operations (ioctl's).
  * Ifp is 0 if not an interface-specific ioctl.
+ *
+ * Returns:    0                       Success
+ *             EINVAL
+ *             EADDRNOTAVAIL
+ *             EDESTADDRREQ
+ *             EPERM
+ *             ENOBUFS
+ *             EBUSY
+ *             EOPNOTSUPP
+ *     proc_suser:EPERM
+ *     suser:EPERM
+ *     in_lifaddr_ioctl:???
+ *     dlil_ioctl:???
+ *     in_ifinit:???
+ *     dlil_plumb_protocol:???
+ *     dlil_unplumb_protocol:???
  */
 /* ARGSUSED */
 int
-in_control(
-       struct socket *so,
-       u_long cmd,
-       caddr_t data,
-       struct ifnet *ifp,
-       struct proc *p)
+in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
+    struct proc *p)
 {
-       struct ifreq *ifr = (struct ifreq *)data;
-       struct in_ifaddr *ia = 0, *iap;
+       struct in_ifaddr *ia = NULL;
        struct ifaddr *ifa;
-       struct in_ifaddr *oia;
-       struct in_aliasreq *ifra = (struct in_aliasreq *)data;
        struct sockaddr_in oldaddr;
-       int error, hostIsNew, maskIsNew;
-       u_long i;
-       struct kev_msg        ev_msg;
-       struct kev_in_data    in_event_data;
+       int error = 0;
+       int hostIsNew, maskIsNew;
+       struct kev_msg ev_msg;
+       struct kev_in_data in_event_data;
 
+       bzero(&in_event_data, sizeof (struct kev_in_data));
+       bzero(&ev_msg, sizeof (struct kev_msg));
 
        switch (cmd) {
-       case SIOCALIFADDR:
-       case SIOCDLIFADDR:
-               if (p && (error = proc_suser(p)) != 0)
-                       return error;
-               /*fall through*/
-       case SIOCGLIFADDR:
-               if (!ifp)
-                       return EINVAL;
-               return in_lifaddr_ioctl(so, cmd, data, ifp, p);
+       case SIOCALIFADDR:              /* struct if_laddrreq */
+       case SIOCDLIFADDR:              /* struct if_laddrreq */
+               if ((error = proc_suser(p)) != 0)
+                       return (error);
+               /* FALLTHRU */
+       case SIOCGLIFADDR: {            /* struct if_laddrreq */
+               struct if_laddrreq iflr;
+
+               if (ifp == NULL)
+                       return (EINVAL);
+
+               bcopy(data, &iflr, sizeof (iflr));
+               error = in_lifaddr_ioctl(so, cmd, &iflr, ifp, p);
+               bcopy(&iflr, data, sizeof (iflr));
+               return (error);
+       }
        }
 
        /*
@@ -265,203 +406,361 @@ in_control(
         * If an alias address was specified, find that one instead of
         * the first one on the interface.
         */
-       if (ifp) {
-               lck_mtx_lock(rt_mtx);
-               for (iap = in_ifaddrhead.tqh_first; iap; 
-                    iap = iap->ia_link.tqe_next)
-                       if (iap->ia_ifp == ifp) {
-                               if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr ==
-                                   iap->ia_addr.sin_addr.s_addr) {
-                                       ia = iap;
+       if (ifp != NULL) {
+               struct in_ifaddr *iap;
+               struct sockaddr_in sin;
+
+               bcopy(&((struct ifreq *)(void *)data)->ifr_addr,
+                   &sin, sizeof (sin));
+
+               lck_rw_lock_shared(in_ifaddr_rwlock);
+               for (iap = in_ifaddrhead.tqh_first; iap != NULL;
+                    iap = iap->ia_link.tqe_next) {
+                       if (iap->ia_ifp != ifp)
+                               continue;
+
+                       IFA_LOCK(&iap->ia_ifa);
+                       if (sin.sin_addr.s_addr ==
+                           iap->ia_addr.sin_addr.s_addr) {
+                               ia = iap;
+                               IFA_UNLOCK(&iap->ia_ifa);
+                               break;
+                       } else if (ia == NULL) {
+                               ia = iap;
+                               if (sin.sin_family != AF_INET) {
+                                       IFA_UNLOCK(&iap->ia_ifa);
                                        break;
-                               } else if (ia == NULL) {
-                                       ia = iap;
-                                       if (ifr->ifr_addr.sa_family != AF_INET)
-                                               break;
                                }
                        }
-               lck_mtx_unlock(rt_mtx);
+                       IFA_UNLOCK(&iap->ia_ifa);
+               }
+               /* take a reference on ia before releasing lock */
+               if (ia != NULL)
+                       IFA_ADDREF(&ia->ia_ifa);
+               lck_rw_done(in_ifaddr_rwlock);
        }
+
        switch (cmd) {
-       case SIOCAUTOADDR:
-       case SIOCARPIPLL:
-               if (p && (error = proc_suser(p)) != 0)
-                       return error;
+       case SIOCAUTOADDR:              /* struct ifreq */
+       case SIOCARPIPLL:               /* struct ifreq */
+       case SIOCSETROUTERMODE:         /* struct ifreq */
+               if ((error = proc_suser(p)) != 0) {
+                       goto done;
+               }
+               if (ifp == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
+               }
                break;
 
-       case SIOCAIFADDR:
-       case SIOCDIFADDR:
-               if (ifp == 0)
-                       return (EADDRNOTAVAIL);
-               if (ifra->ifra_addr.sin_family == AF_INET) {
-                       lck_mtx_lock(rt_mtx);
+       case SIOCAIFADDR:               /* struct ifaliasreq */
+       case SIOCDIFADDR: {             /* struct ifreq */
+               struct sockaddr_in addr, dstaddr;
+
+               if (ifp == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
+               }
+
+               if (cmd == SIOCAIFADDR) {
+                       bcopy(&((struct in_aliasreq *)(void *)data)->
+                           ifra_addr, &addr, sizeof (addr));
+                       bcopy(&((struct in_aliasreq *)(void *)data)->
+                           ifra_dstaddr, &dstaddr, sizeof (dstaddr));
+               } else {
+                       VERIFY(cmd == SIOCDIFADDR);
+                       bcopy(&((struct ifreq *)(void *)data)->ifr_addr,
+                           &addr, sizeof (addr));
+                       bzero(&dstaddr, sizeof (dstaddr));
+               }
+
+               if (addr.sin_family == AF_INET) {
+                       struct in_ifaddr *oia;
+
+                       lck_rw_lock_shared(in_ifaddr_rwlock);
                        for (oia = ia; ia; ia = ia->ia_link.tqe_next) {
+                               IFA_LOCK(&ia->ia_ifa);
                                if (ia->ia_ifp == ifp  &&
                                    ia->ia_addr.sin_addr.s_addr ==
-                                   ifra->ifra_addr.sin_addr.s_addr)
+                                   addr.sin_addr.s_addr) {
+                                       IFA_ADDREF_LOCKED(&ia->ia_ifa);
+                                       IFA_UNLOCK(&ia->ia_ifa);
                                        break;
+                               }
+                               IFA_UNLOCK(&ia->ia_ifa);
                        }
-                       lck_mtx_unlock(rt_mtx);
-                       if ((ifp->if_flags & IFF_POINTOPOINT)
-                           && (cmd == SIOCAIFADDR)
-                           && (ifra->ifra_dstaddr.sin_addr.s_addr
-                               == INADDR_ANY)) {
-                               return EDESTADDRREQ;
+                       lck_rw_done(in_ifaddr_rwlock);
+                       if (oia != NULL)
+                               IFA_REMREF(&oia->ia_ifa);
+                       if ((ifp->if_flags & IFF_POINTOPOINT) &&
+                           (cmd == SIOCAIFADDR) &&
+                           (dstaddr.sin_addr.s_addr == INADDR_ANY)) {
+                               error = EDESTADDRREQ;
+                               goto done;
                        }
+               } else if (cmd == SIOCAIFADDR) {
+                       error = EINVAL;
+                       goto done;
+               }
+               if (cmd == SIOCDIFADDR && ia == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
                }
-        else if (cmd == SIOCAIFADDR)
-            return (EINVAL);
-               if (cmd == SIOCDIFADDR && ia == 0)
-                       return (EADDRNOTAVAIL);
                /* FALLTHROUGH */
-       case SIOCSIFADDR:
-       case SIOCSIFNETMASK:
-       case SIOCSIFDSTADDR:
-               if ((so->so_state & SS_PRIV) == 0)
-                       return (EPERM);
-
-               if (ifp == 0)
-                       return (EADDRNOTAVAIL);
-        if (ifra->ifra_addr.sin_family != AF_INET && cmd == SIOCSIFADDR)
-            return (EINVAL);
-               if (ia == (struct in_ifaddr *)0) {
-                       ia = (struct in_ifaddr *)
-                               _MALLOC(sizeof *ia, M_IFADDR, M_WAITOK);
-                       if (ia == (struct in_ifaddr *)NULL)
-                               return (ENOBUFS);
-                       bzero((caddr_t)ia, sizeof *ia);
-                       /*
-                        * Protect from ipintr() traversing address list
-                        * while we're modifying it.
-                        */
-                       
-                       ifa = &ia->ia_ifa;
+       }
+       case SIOCSIFADDR:               /* struct ifreq */
+       case SIOCSIFNETMASK:            /* struct ifreq */
+       case SIOCSIFDSTADDR: {          /* struct ifreq */
+               struct sockaddr_in addr;
+
+               if (cmd == SIOCAIFADDR) {
+                       /* fell thru from above; just repeat it */
+                       bcopy(&((struct in_aliasreq *)(void *)data)->
+                           ifra_addr, &addr, sizeof (addr));
+               } else {
+                       VERIFY(cmd == SIOCDIFADDR || cmd == SIOCSIFADDR ||
+                           cmd == SIOCSIFNETMASK || cmd == SIOCSIFDSTADDR);
+                       bcopy(&((struct ifreq *)(void *)data)->ifr_addr,
+                           &addr, sizeof (addr));
+               }
 
+               /* socket is NULL if called from in_purgeaddrs() */
+               if (so != NULL && (so->so_state & SS_PRIV) == 0) {
+                       error = EPERM;
+                       goto done;
+               }
+               /* in case it's NULL, make sure it came from the kernel */
+               if (so == NULL && p != kernproc) {
+                       error = EPERM;
+                       goto done;
+               }
+               if (ifp == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
+               }
+               if (addr.sin_family != AF_INET && cmd == SIOCSIFADDR) {
+                       error = EINVAL;
+                       goto done;
+               }
+               if (ia == NULL) {
+                       ia = in_ifaddr_alloc(M_WAITOK);
+                       if (ia == NULL) {
+                               error = ENOBUFS;
+                               goto done;
+                       }
+                       ifnet_lock_exclusive(ifp);
+                       ifa = &ia->ia_ifa;
+                       IFA_LOCK(ifa);
+                       /* Hold a reference for this routine */
+                       IFA_ADDREF_LOCKED(ifa);
+                       IA_HASH_INIT(ia);
                        ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
                        ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
                        ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
                        ia->ia_sockmask.sin_len = 8;
-                       ifnet_lock_exclusive(ifp);
                        if (ifp->if_flags & IFF_BROADCAST) {
-                               ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
+                               ia->ia_broadaddr.sin_len = sizeof (ia->ia_addr);
                                ia->ia_broadaddr.sin_family = AF_INET;
                        }
                        ia->ia_ifp = ifp;
                        if (!(ifp->if_flags & IFF_LOOPBACK))
                                in_interfaces++;
+                       /* if_attach_ifa() holds a reference for ifa_link */
                        if_attach_ifa(ifp, ifa);
+                       /*
+                        * If we have to go through in_ifinit(), make sure
+                        * to avoid installing route(s) based on this address
+                        * via PFC_IFUP event, before the link resolver (ARP)
+                        * initializes it.
+                        */
+                       if (cmd == SIOCAIFADDR || cmd == SIOCSIFADDR)
+                               ifa->ifa_debug |= IFD_NOTREADY;
+                       IFA_UNLOCK(ifa);
                        ifnet_lock_done(ifp);
-
-                       lck_mtx_lock(rt_mtx);
+                       lck_rw_lock_exclusive(in_ifaddr_rwlock);
+                       /* Hold a reference for ia_link */
+                       IFA_ADDREF(ifa);
                        TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
-                       lck_mtx_unlock(rt_mtx);
-
-                       /* Generic protocol plumbing */
-
-                       if (error = dlil_plumb_protocol(PF_INET, ifp)) {
-                               kprintf("in.c: warning can't plumb proto if=%s%n type %d error=%d\n",
-                                       ifp->if_name, ifp->if_unit, ifp->if_type, error);
-                               error = 0; /*discard error, can be cold with unsupported interfaces */
-                       }
-
+                       lck_rw_done(in_ifaddr_rwlock);
+                       /* discard error */
+                       (void) in_domifattach(ifp);
+                       error = 0;
                }
                break;
+       }
 
-       case SIOCPROTOATTACH:
-       case SIOCPROTODETACH:
-               if (p && (error = proc_suser(p)) != 0)
-                       return error;
-               if (ifp == 0)
-                       return (EADDRNOTAVAIL);
+       case SIOCPROTOATTACH:           /* struct ifreq */
+       case SIOCPROTODETACH:           /* struct ifreq */
+               if ((error = proc_suser(p)) != 0) {
+                       goto done;
+               }
+               if (ifp == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
+               }
                break;
-                
-       case SIOCSIFBRDADDR:
-#ifdef __APPLE__
-               if ((so->so_state & SS_PRIV) == 0)
-                       return (EPERM);
-#else
-               if (p && (error = suser(p)) != 0)
-                       return error;
-#endif
-               /* FALLTHROUGH */
 
-       case SIOCGIFADDR:
-       case SIOCGIFNETMASK:
-       case SIOCGIFDSTADDR:
-       case SIOCGIFBRDADDR:
-               if (ia == (struct in_ifaddr *)0)
-                       return (EADDRNOTAVAIL);
+       case SIOCSIFBRDADDR:            /* struct ifreq */
+               if ((so->so_state & SS_PRIV) == 0) {
+                       error = EPERM;
+                       goto done;
+               }
+               /* FALLTHROUGH */
+       case SIOCGIFADDR:               /* struct ifreq */
+       case SIOCGIFNETMASK:            /* struct ifreq */
+       case SIOCGIFDSTADDR:            /* struct ifreq */
+       case SIOCGIFBRDADDR:            /* struct ifreq */
+               if (ia == NULL) {
+                       error = EADDRNOTAVAIL;
+                       goto done;
+               }
                break;
        }
+
        switch (cmd) {
-       case SIOCAUTOADDR:
-               if (ifp == 0)
-                       return (EADDRNOTAVAIL);
+       case SIOCAUTOADDR: {            /* struct ifreq */
+               int intval;
+
+               VERIFY(ifp != NULL);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_intval,
+                   &intval, sizeof (intval));
+
                ifnet_lock_exclusive(ifp);
-               if (ifr->ifr_intval)
-                       ifp->if_eflags |= IFEF_AUTOCONFIGURING;
-               else
+               if (intval) {
+                       /*
+                        * An interface in IPv4 router mode implies that it
+                        * is configured with a static IP address and should
+                        * not act as a DHCP client; prevent SIOCAUTOADDR from
+                        * being set in that mode.
+                        */
+                       if (ifp->if_eflags & IFEF_IPV4_ROUTER) {
+                               intval = 0;     /* be safe; clear flag if set */
+                               error = EBUSY;
+                       } else {
+                               ifp->if_eflags |= IFEF_AUTOCONFIGURING;
+                       }
+               }
+               if (!intval)
                        ifp->if_eflags &= ~IFEF_AUTOCONFIGURING;
                ifnet_lock_done(ifp);
                break;
-       
-       case SIOCARPIPLL:
-               if (ifp == 0)
-                       return (EADDRNOTAVAIL);
+       }
+
+       case SIOCARPIPLL: {             /* struct ifreq */
+               int intval;
+
+               VERIFY(ifp != NULL);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_intval,
+                   &intval, sizeof (intval));
                ipv4_ll_arp_aware = 1;
+
                ifnet_lock_exclusive(ifp);
-               if (ifr->ifr_data)
-                       ifp->if_eflags |= IFEF_ARPLL;
-               else
+               if (intval) {
+                       /*
+                        * An interface in IPv4 router mode implies that it
+                        * is configured with a static IP address and should
+                        * not have to deal with IPv4 Link-Local Address;
+                        * prevent SIOCARPIPLL from being set in that mode.
+                        */
+                       if (ifp->if_eflags & IFEF_IPV4_ROUTER) {
+                               intval = 0;     /* be safe; clear flag if set */
+                               error = EBUSY;
+                       } else {
+                               ifp->if_eflags |= IFEF_ARPLL;
+                       }
+               }
+               if (!intval)
                        ifp->if_eflags &= ~IFEF_ARPLL;
                ifnet_lock_done(ifp);
                break;
+       }
 
-       case SIOCGIFADDR:
-               *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
+       case SIOCGIFADDR:               /* struct ifreq */
+               VERIFY(ia != NULL);
+               IFA_LOCK(&ia->ia_ifa);
+               bcopy(&ia->ia_addr, &((struct ifreq *)(void *)data)->ifr_addr,
+                   sizeof (struct sockaddr_in));
+               IFA_UNLOCK(&ia->ia_ifa);
                break;
 
-       case SIOCGIFBRDADDR:
-               if ((ifp->if_flags & IFF_BROADCAST) == 0)
-                       return (EINVAL);
-               *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
+       case SIOCGIFBRDADDR:            /* struct ifreq */
+               VERIFY(ia != NULL);
+               if ((ifp->if_flags & IFF_BROADCAST) == 0) {
+                       error = EINVAL;
+                       break;
+               }
+               IFA_LOCK(&ia->ia_ifa);
+               bcopy(&ia->ia_broadaddr,
+                   &((struct ifreq *)(void *)data)->ifr_broadaddr,
+                   sizeof (struct sockaddr_in));
+               IFA_UNLOCK(&ia->ia_ifa);
                break;
 
-       case SIOCGIFDSTADDR:
-               if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
-                       return (EINVAL);
-               *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
+       case SIOCGIFDSTADDR:            /* struct ifreq */
+               VERIFY(ia != NULL);
+               if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
+                       error = EINVAL;
+                       break;
+               }
+               IFA_LOCK(&ia->ia_ifa);
+               bcopy(&ia->ia_dstaddr,
+                   &((struct ifreq *)(void *)data)->ifr_dstaddr,
+                   sizeof (struct sockaddr_in));
+               IFA_UNLOCK(&ia->ia_ifa);
                break;
 
-       case SIOCGIFNETMASK:
-               *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
+       case SIOCGIFNETMASK:            /* struct ifreq */
+               VERIFY(ia != NULL);
+               IFA_LOCK(&ia->ia_ifa);
+               bcopy(&ia->ia_sockmask,
+                   &((struct ifreq *)(void *)data)->ifr_addr,
+                   sizeof (struct sockaddr_in));
+               IFA_UNLOCK(&ia->ia_ifa);
                break;
 
-       case SIOCSIFDSTADDR:
-               if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
-                       return (EINVAL);
+       case SIOCSIFDSTADDR:            /* struct ifreq */
+               VERIFY(ifp != NULL && ia != NULL);
+               if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
+                       error = EINVAL;
+                       break;
+               }
+               IFA_LOCK(&ia->ia_ifa);
                oldaddr = ia->ia_dstaddr;
-               ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
-               error = dlil_ioctl(PF_INET, ifp, SIOCSIFDSTADDR, (caddr_t)ia);
-               if (error == EOPNOTSUPP)
-                    error = 0;
-
+               bcopy(&((struct ifreq *)(void *)data)->ifr_dstaddr,
+                   &ia->ia_dstaddr, sizeof (struct sockaddr_in));
+               if (ia->ia_dstaddr.sin_family == AF_INET)
+                       ia->ia_dstaddr.sin_len = sizeof (struct sockaddr_in);
+               IFA_UNLOCK(&ia->ia_ifa);
+               /*
+                * NOTE: SIOCSIFDSTADDR is defined with struct ifreq
+                * as parameter, but here we are sending it down
+                * to the interface with a pointer to struct ifaddr,
+                * for legacy reasons.
+                */
+               error = ifnet_ioctl(ifp, PF_INET, SIOCSIFDSTADDR, ia);
+               IFA_LOCK(&ia->ia_ifa);
+               if (error == EOPNOTSUPP) {
+                       error = 0;
+               }
                if (error) {
-                    ia->ia_dstaddr = oldaddr;
-                    return error;
+                       ia->ia_dstaddr = oldaddr;
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       break;
                }
+               IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
 
                ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                ev_msg.kev_class      = KEV_NETWORK_CLASS;
                ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
-       
+
                ev_msg.event_code = KEV_INET_SIFDSTADDR;
 
-               if (ia->ia_ifa.ifa_dstaddr)
-                    in_event_data.ia_dstaddr = 
-                         ((struct sockaddr_in *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
-               else
-                    in_event_data.ia_dstaddr.s_addr  = 0;
+               if (ia->ia_ifa.ifa_dstaddr) {
+                       in_event_data.ia_dstaddr = ((struct sockaddr_in *)
+                           (void *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
+               } else {
+                       in_event_data.ia_dstaddr.s_addr = INADDR_ANY;
+               }
 
                in_event_data.ia_addr         = ia->ia_addr.sin_addr;
                in_event_data.ia_net          = ia->ia_net;
@@ -469,359 +768,461 @@ in_control(
                in_event_data.ia_subnet       = ia->ia_subnet;
                in_event_data.ia_subnetmask   = ia->ia_subnetmask;
                in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
-               strncpy(&in_event_data.link_data.if_name[0], ifp->if_name, IFNAMSIZ);
+               IFA_UNLOCK(&ia->ia_ifa);
+               (void) strncpy(&in_event_data.link_data.if_name[0],
+                   ifp->if_name, IFNAMSIZ);
                in_event_data.link_data.if_family = ifp->if_family;
-               in_event_data.link_data.if_unit  = (unsigned long) ifp->if_unit;
+               in_event_data.link_data.if_unit  = (u_int32_t) ifp->if_unit;
 
                ev_msg.dv[0].data_ptr    = &in_event_data;
-               ev_msg.dv[0].data_length      = sizeof(struct kev_in_data);
+               ev_msg.dv[0].data_length = sizeof (struct kev_in_data);
                ev_msg.dv[1].data_length = 0;
 
                kev_post_msg(&ev_msg);
 
-
+               lck_mtx_lock(rnh_lock);
+               IFA_LOCK(&ia->ia_ifa);
                if (ia->ia_flags & IFA_ROUTE) {
                        ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
-                       rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       rtinit_locked(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
+                       IFA_LOCK(&ia->ia_ifa);
                        ia->ia_ifa.ifa_dstaddr =
-                                       (struct sockaddr *)&ia->ia_dstaddr;
-                       rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
+                           (struct sockaddr *)&ia->ia_dstaddr;
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       rtinit_locked(&(ia->ia_ifa), (int)RTM_ADD,
+                           RTF_HOST|RTF_UP);
+               } else {
+                       IFA_UNLOCK(&ia->ia_ifa);
                }
+               lck_mtx_unlock(rnh_lock);
                break;
 
-       case SIOCSIFBRDADDR:
-               if ((ifp->if_flags & IFF_BROADCAST) == 0)
-                       return (EINVAL);
-               ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
+       case SIOCSIFBRDADDR:            /* struct ifreq */
+               VERIFY(ia != NULL);
+               if ((ifp->if_flags & IFF_BROADCAST) == 0) {
+                       error = EINVAL;
+                       break;
+               }
+               IFA_LOCK(&ia->ia_ifa);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_broadaddr,
+                   &ia->ia_broadaddr, sizeof (struct sockaddr_in));
 
                ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                ev_msg.kev_class      = KEV_NETWORK_CLASS;
                ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
-       
-               ev_msg.event_code = KEV_INET_SIFBRDADDR;
 
-               if (ia->ia_ifa.ifa_dstaddr)
-                    in_event_data.ia_dstaddr = 
-                         ((struct sockaddr_in *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
-               else
-                    in_event_data.ia_dstaddr.s_addr  = 0;
+               ev_msg.event_code = KEV_INET_SIFBRDADDR;
 
+               if (ia->ia_ifa.ifa_dstaddr) {
+                       in_event_data.ia_dstaddr = ((struct sockaddr_in *)
+                           (void *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
+               } else {
+                       in_event_data.ia_dstaddr.s_addr = INADDR_ANY;
+               }
                in_event_data.ia_addr         = ia->ia_addr.sin_addr;
                in_event_data.ia_net          = ia->ia_net;
                in_event_data.ia_netmask      = ia->ia_netmask;
                in_event_data.ia_subnet       = ia->ia_subnet;
                in_event_data.ia_subnetmask   = ia->ia_subnetmask;
                in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
-               strncpy(&in_event_data.link_data.if_name[0], ifp->if_name, IFNAMSIZ);
+               IFA_UNLOCK(&ia->ia_ifa);
+               (void) strncpy(&in_event_data.link_data.if_name[0],
+                   ifp->if_name, IFNAMSIZ);
                in_event_data.link_data.if_family = ifp->if_family;
-               in_event_data.link_data.if_unit  = (unsigned long) ifp->if_unit;
+               in_event_data.link_data.if_unit  = (u_int32_t) ifp->if_unit;
 
                ev_msg.dv[0].data_ptr    = &in_event_data;
-               ev_msg.dv[0].data_length      = sizeof(struct kev_in_data);
+               ev_msg.dv[0].data_length = sizeof (struct kev_in_data);
                ev_msg.dv[1].data_length = 0;
 
                kev_post_msg(&ev_msg);
+               break;
+
+       case SIOCSIFADDR: {             /* struct ifreq */
+               struct sockaddr_in addr;
 
+               VERIFY(ifp != NULL && ia != NULL);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_addr,
+                   &addr, sizeof (addr));
+               /*
+                * If this is a new address, the reference count for the
+                * hash table has been taken at creation time above.
+                */
+               error = in_ifinit(ifp, ia, &addr, 1);
+#if PF
+               if (!error)
+                       (void) pf_ifaddr_hook(ifp, cmd);
+#endif /* PF */
                break;
+       }
 
-       case SIOCSIFADDR:
-               return (in_ifinit(ifp, ia,
-                   (struct sockaddr_in *) &ifr->ifr_addr, 1));
-
-       case SIOCPROTOATTACH:
-               error = dlil_plumb_protocol(PF_INET, ifp);
-               if (error)
-                       return(error);
-                break;
-                
-       case SIOCPROTODETACH:
-                // if an ip address is still present, refuse to detach
+       case SIOCPROTOATTACH:           /* struct ifreq */
+               VERIFY(ifp != NULL);
+               error = in_domifattach(ifp);
+               break;
+
+       case SIOCPROTODETACH:           /* struct ifreq */
+               VERIFY(ifp != NULL);
+                /*
+                * If an IPv4 address is still present, refuse to detach.
+                */
                ifnet_lock_shared(ifp);
-               TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 
-                       if (ifa->ifa_addr->sa_family == AF_INET)
+               TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+                       IFA_LOCK(ifa);
+                       if (ifa->ifa_addr->sa_family == AF_INET) {
+                               IFA_UNLOCK(ifa);
                                break;
+                       }
+                       IFA_UNLOCK(ifa);
+               }
                ifnet_lock_done(ifp);
-               if (ifa != 0)
-                       return EBUSY;
+               if (ifa != NULL) {
+                       error =  EBUSY;
+                       break;
+               }
 
-               error = dlil_unplumb_protocol(PF_INET, ifp);
-               if (error)
-                       return(error);
+               error = proto_unplumb(PF_INET, ifp);
                break;
-               
 
-       case SIOCSIFNETMASK:
-               i = ifra->ifra_addr.sin_addr.s_addr;
+       case SIOCSETROUTERMODE: {       /* struct ifreq */
+               int intval;
+
+               VERIFY(ifp != NULL);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_intval,
+                   &intval, sizeof (intval));
+
+               error = in_setrouter(ifp, intval);
+               break;
+       }
+
+       case SIOCSIFNETMASK: {          /* struct ifreq */
+               struct sockaddr_in addr;
+               in_addr_t i;
+
+               VERIFY(ifp != NULL && ia != NULL);
+               bcopy(&((struct ifreq *)(void *)data)->ifr_addr,
+                   &addr, sizeof (addr));
+               i = addr.sin_addr.s_addr;
+
+               IFA_LOCK(&ia->ia_ifa);
                ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
                ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                ev_msg.kev_class      = KEV_NETWORK_CLASS;
                ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
-       
-               ev_msg.event_code = KEV_INET_SIFNETMASK;
 
-               if (ia->ia_ifa.ifa_dstaddr)
-                    in_event_data.ia_dstaddr = 
-                         ((struct sockaddr_in *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
-               else
-                    in_event_data.ia_dstaddr.s_addr  = 0;
+               ev_msg.event_code = KEV_INET_SIFNETMASK;
 
+               if (ia->ia_ifa.ifa_dstaddr) {
+                    in_event_data.ia_dstaddr = ((struct sockaddr_in *)
+                        (void *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
+               } else {
+                       in_event_data.ia_dstaddr.s_addr = INADDR_ANY;
+               }
                in_event_data.ia_addr         = ia->ia_addr.sin_addr;
                in_event_data.ia_net          = ia->ia_net;
                in_event_data.ia_netmask      = ia->ia_netmask;
                in_event_data.ia_subnet       = ia->ia_subnet;
                in_event_data.ia_subnetmask   = ia->ia_subnetmask;
                in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
-               strncpy(&in_event_data.link_data.if_name[0], ifp->if_name, IFNAMSIZ);
+               IFA_UNLOCK(&ia->ia_ifa);
+               (void) strncpy(&in_event_data.link_data.if_name[0],
+                   ifp->if_name, IFNAMSIZ);
                in_event_data.link_data.if_family = ifp->if_family;
-               in_event_data.link_data.if_unit  = (unsigned long) ifp->if_unit;
+               in_event_data.link_data.if_unit  = (u_int32_t) ifp->if_unit;
 
                ev_msg.dv[0].data_ptr    = &in_event_data;
-               ev_msg.dv[0].data_length      = sizeof(struct kev_in_data);
+               ev_msg.dv[0].data_length = sizeof (struct kev_in_data);
                ev_msg.dv[1].data_length = 0;
 
                kev_post_msg(&ev_msg);
-
                break;
+       }
+
+       case SIOCAIFADDR: {             /* struct ifaliasreq */
+               struct sockaddr_in addr, broadaddr, mask;
+
+               VERIFY(ifp != NULL && ia != NULL);
+               bcopy(&((struct ifaliasreq *)(void *)data)->ifra_addr,
+                   &addr, sizeof (addr));
+               bcopy(&((struct ifaliasreq *)(void *)data)->ifra_broadaddr,
+                   &broadaddr, sizeof (broadaddr));
+               bcopy(&((struct ifaliasreq *)(void *)data)->ifra_mask,
+                   &mask, sizeof (mask));
 
-       case SIOCAIFADDR:
                maskIsNew = 0;
                hostIsNew = 1;
                error = 0;
+
+               IFA_LOCK(&ia->ia_ifa);
                if (ia->ia_addr.sin_family == AF_INET) {
-                       if (ifra->ifra_addr.sin_len == 0) {
-                               ifra->ifra_addr = ia->ia_addr;
+                       if (addr.sin_len == 0) {
+                               addr = ia->ia_addr;
                                hostIsNew = 0;
-                       } else if (ifra->ifra_addr.sin_addr.s_addr ==
-                                              ia->ia_addr.sin_addr.s_addr)
+                       } else if (addr.sin_addr.s_addr ==
+                           ia->ia_addr.sin_addr.s_addr) {
                                hostIsNew = 0;
+                       }
                }
-               if (ifra->ifra_mask.sin_len) {
+               if (mask.sin_len) {
+                       IFA_UNLOCK(&ia->ia_ifa);
                        in_ifscrub(ifp, ia, 0);
-                       ia->ia_sockmask = ifra->ifra_mask;
+                       IFA_LOCK(&ia->ia_ifa);
+                       ia->ia_sockmask = mask;
                        ia->ia_subnetmask =
                             ntohl(ia->ia_sockmask.sin_addr.s_addr);
                        maskIsNew = 1;
                }
                if ((ifp->if_flags & IFF_POINTOPOINT) &&
-                   (ifra->ifra_dstaddr.sin_family == AF_INET)) {
+                   (broadaddr.sin_family == AF_INET)) {
+                       IFA_UNLOCK(&ia->ia_ifa);
                        in_ifscrub(ifp, ia, 0);
-                       ia->ia_dstaddr = ifra->ifra_dstaddr;
+                       IFA_LOCK(&ia->ia_ifa);
+                       ia->ia_dstaddr = broadaddr;
+                       ia->ia_dstaddr.sin_len = sizeof (struct sockaddr_in);
                        maskIsNew  = 1; /* We lie; but the effect's the same */
                }
-               if (ifra->ifra_addr.sin_family == AF_INET &&
-                   (hostIsNew || maskIsNew)) {
-                       error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
+               if (addr.sin_family == AF_INET && (hostIsNew || maskIsNew)) {
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       error = in_ifinit(ifp, ia, &addr, 0);
+               } else {
+                       IFA_UNLOCK(&ia->ia_ifa);
                }
+#if PF
+               if (!error)
+                       (void) pf_ifaddr_hook(ifp, cmd);
+#endif /* PF */
+               IFA_LOCK(&ia->ia_ifa);
                if ((ifp->if_flags & IFF_BROADCAST) &&
-                   (ifra->ifra_broadaddr.sin_family == AF_INET))
-                       ia->ia_broadaddr = ifra->ifra_broadaddr;
+                   (broadaddr.sin_family == AF_INET))
+                       ia->ia_broadaddr = broadaddr;
 
                /*
                 * Report event.
                 */
-
                if ((error == 0) || (error == EEXIST)) {
-                    ev_msg.vendor_code    = KEV_VENDOR_APPLE;
-                    ev_msg.kev_class      = KEV_NETWORK_CLASS;
-                    ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
-
-                    if (hostIsNew)
-                         ev_msg.event_code = KEV_INET_NEW_ADDR;
-                    else
-                         ev_msg.event_code = KEV_INET_CHANGED_ADDR;
-
-                    if (ia->ia_ifa.ifa_dstaddr)
-                         in_event_data.ia_dstaddr = 
-                              ((struct sockaddr_in *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
-                    else
-                         in_event_data.ia_dstaddr.s_addr  = 0;
-
-                    in_event_data.ia_addr         = ia->ia_addr.sin_addr;
-                    in_event_data.ia_net          = ia->ia_net;
-                    in_event_data.ia_netmask      = ia->ia_netmask;
-                    in_event_data.ia_subnet       = ia->ia_subnet;
-                    in_event_data.ia_subnetmask   = ia->ia_subnetmask;
-                    in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
-                    strncpy(&in_event_data.link_data.if_name[0], ifp->if_name, IFNAMSIZ);
-                    in_event_data.link_data.if_family = ifp->if_family;
-                    in_event_data.link_data.if_unit  = (unsigned long) ifp->if_unit;
-
-                    ev_msg.dv[0].data_ptr    = &in_event_data;
-                    ev_msg.dv[0].data_length      = sizeof(struct kev_in_data);
-                    ev_msg.dv[1].data_length = 0;
-
-                    kev_post_msg(&ev_msg);
+                       ev_msg.vendor_code    = KEV_VENDOR_APPLE;
+                       ev_msg.kev_class      = KEV_NETWORK_CLASS;
+                       ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
+
+                       if (hostIsNew)
+                               ev_msg.event_code = KEV_INET_NEW_ADDR;
+                       else
+                               ev_msg.event_code = KEV_INET_CHANGED_ADDR;
+
+                       if (ia->ia_ifa.ifa_dstaddr) {
+                               in_event_data.ia_dstaddr =
+                                   ((struct sockaddr_in *)(void *)ia->
+                                   ia_ifa.ifa_dstaddr)->sin_addr;
+                       } else {
+                               in_event_data.ia_dstaddr.s_addr = INADDR_ANY;
+                       }
+                       in_event_data.ia_addr         = ia->ia_addr.sin_addr;
+                       in_event_data.ia_net          = ia->ia_net;
+                       in_event_data.ia_netmask      = ia->ia_netmask;
+                       in_event_data.ia_subnet       = ia->ia_subnet;
+                       in_event_data.ia_subnetmask   = ia->ia_subnetmask;
+                       in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       (void) strncpy(&in_event_data.link_data.if_name[0],
+                           ifp->if_name, IFNAMSIZ);
+                       in_event_data.link_data.if_family = ifp->if_family;
+                       in_event_data.link_data.if_unit = ifp->if_unit;
+
+                       ev_msg.dv[0].data_ptr    = &in_event_data;
+                       ev_msg.dv[0].data_length = sizeof (struct kev_in_data);
+                       ev_msg.dv[1].data_length = 0;
+
+                       kev_post_msg(&ev_msg);
+               } else {
+                       IFA_UNLOCK(&ia->ia_ifa);
                }
+               break;
+       }
 
-               return (error);
-
-       case SIOCDIFADDR:
-               error = dlil_ioctl(PF_INET, ifp, SIOCDIFADDR, (caddr_t)ia);
+       case SIOCDIFADDR:               /* struct ifreq */
+               VERIFY(ifp != NULL && ia != NULL);
+               error = ifnet_ioctl(ifp, PF_INET, SIOCDIFADDR, ia);
                if (error == EOPNOTSUPP)
                        error = 0;
-               if (error)
-                   return error;
+               if (error != 0) {
+                       break;
+               }
 
                /* Fill out the kernel event information */
                ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                ev_msg.kev_class      = KEV_NETWORK_CLASS;
                ev_msg.kev_subclass   = KEV_INET_SUBCLASS;
-               
-               ev_msg.event_code = KEV_INET_ADDR_DELETED;
 
-               if (ia->ia_ifa.ifa_dstaddr)
-                    in_event_data.ia_dstaddr = 
-                         ((struct sockaddr_in *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
-               else
-                    in_event_data.ia_dstaddr.s_addr  = 0;
+               ev_msg.event_code = KEV_INET_ADDR_DELETED;
 
+               IFA_LOCK(&ia->ia_ifa);
+               if (ia->ia_ifa.ifa_dstaddr) {
+                    in_event_data.ia_dstaddr = ((struct sockaddr_in *)
+                        (void *)ia->ia_ifa.ifa_dstaddr)->sin_addr;
+               } else {
+                       in_event_data.ia_dstaddr.s_addr = INADDR_ANY;
+               }
                in_event_data.ia_addr         = ia->ia_addr.sin_addr;
                in_event_data.ia_net          = ia->ia_net;
                in_event_data.ia_netmask      = ia->ia_netmask;
                in_event_data.ia_subnet       = ia->ia_subnet;
                in_event_data.ia_subnetmask   = ia->ia_subnetmask;
                in_event_data.ia_netbroadcast = ia->ia_netbroadcast;
-               strncpy(&in_event_data.link_data.if_name[0], ifp->if_name, IFNAMSIZ);
+               IFA_UNLOCK(&ia->ia_ifa);
+               (void) strncpy(&in_event_data.link_data.if_name[0],
+                   ifp->if_name, IFNAMSIZ);
                in_event_data.link_data.if_family = ifp->if_family;
-               in_event_data.link_data.if_unit  = (unsigned long) ifp->if_unit;
+               in_event_data.link_data.if_unit  = (u_int32_t) ifp->if_unit;
 
                ev_msg.dv[0].data_ptr    = &in_event_data;
                ev_msg.dv[0].data_length = sizeof(struct kev_in_data);
                ev_msg.dv[1].data_length = 0;
 
-               lck_mtx_lock(rt_mtx);
+               ifa = &ia->ia_ifa;
+               lck_rw_lock_exclusive(in_ifaddr_rwlock);
+               /* Release ia_link reference */
+               IFA_REMREF(ifa);
                TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
+               IFA_LOCK(ifa);
+               if (IA_IS_HASHED(ia))
+                       in_iahash_remove(ia);
+               IFA_UNLOCK(ifa);
+               lck_rw_done(in_ifaddr_rwlock);
+
                /*
                 * in_ifscrub kills the interface route.
                 */
-               in_ifscrub(ifp, ia, 1);
-               ifa = &ia->ia_ifa;
-               lck_mtx_unlock(rt_mtx);
+               in_ifscrub(ifp, ia, 0);
                ifnet_lock_exclusive(ifp);
+               IFA_LOCK(ifa);
+               /* if_detach_ifa() releases ifa_link reference */
                if_detach_ifa(ifp, ifa);
-               ifafree(&ia->ia_ifa);
-        
-#ifdef __APPLE__
-       /*
-        * If the interface supports multicast, and no address is left,
-        * remove the "all hosts" multicast group from that interface.
-        */
-               if (ifp->if_flags & IFF_MULTICAST) {
-                       struct in_addr addr;
-                       struct in_multi *inm = NULL;
-
-                       TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 
-                               if (ifa->ifa_addr->sa_family == AF_INET)
+               /* Our reference to this address is dropped at the bottom */
+               IFA_UNLOCK(ifa);
+
+              /*
+               * If the interface supports multicast, and no address is left,
+               * remove the "all hosts" multicast group from that interface.
+               */
+               if ((ifp->if_flags & IFF_MULTICAST) != 0 ||
+                       ifp->if_allhostsinm != NULL ) {
+
+                       TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+                               IFA_LOCK(ifa);
+                               if (ifa->ifa_addr->sa_family == AF_INET) {
+                                       IFA_UNLOCK(ifa);
                                        break;
-
-                       if (ifa == 0) {
-                               addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
-                               IN_LOOKUP_MULTI(addr, ifp, inm);
+                               }
+                               IFA_UNLOCK(ifa);
                        }
                        ifnet_lock_done(ifp);
-                       if (inm)
-                               in_delmulti(&inm);
-               } else 
+
+                       lck_mtx_lock(&ifp->if_addrconfig_lock);
+                       if (ifa == NULL && ifp->if_allhostsinm != NULL) {
+                               struct in_multi *inm = ifp->if_allhostsinm;
+                               ifp->if_allhostsinm = NULL;
+
+                               in_delmulti(inm);
+                               /* release the reference for allhostsinm */
+                               INM_REMREF(inm);
+                       }
+                       lck_mtx_unlock(&ifp->if_addrconfig_lock);
+               } else {
                        ifnet_lock_done(ifp);
-#endif
+               }
 
                /* Post the kernel event */
                kev_post_msg(&ev_msg);
+
+               /*
+                * See if there is any IPV4 address left and if so,
+                * reconfigure KDP to use current primary address.
+                */
+               ifa = ifa_ifpgetprimary(ifp, AF_INET);
+               if (ifa != NULL) {
+                       /*
+                        * NOTE: SIOCSIFADDR is defined with struct ifreq
+                        * as parameter, but here we are sending it down
+                        * to the interface with a pointer to struct ifaddr,
+                        * for legacy reasons.
+                        */
+                       error = ifnet_ioctl(ifp, PF_INET, SIOCSIFADDR, ifa);
+                       if (error == EOPNOTSUPP)
+                               error = 0;
+
+                       /* Release reference from ifa_ifpgetprimary() */
+                       IFA_REMREF(ifa);
+               }
+#if PF
+               (void) pf_ifaddr_hook(ifp, cmd);
+#endif /* PF */
                break;
 
 #ifdef __APPLE__
-    case SIOCSETOT: {
-        /*
-         * Inspiration from tcp_ctloutput() and ip_ctloutput()
-         * Special ioctl for OpenTransport sockets
-         */
-        struct inpcb   *inp, *cloned_inp;
-        int                    error2 = 0;
-        int                    cloned_fd = *(int *)data;
-
-        inp = sotoinpcb(so);
-        if (inp == NULL) {
-            break;
-        }
-
-        /* let's make sure it's either -1 or a valid file descriptor */
-        if (cloned_fd != -1) {
-            struct socket      *cloned_so;
-            error2 = file_socket(cloned_fd, &cloned_so);
-            if (error2){
-                break;
-            }
-            cloned_inp = sotoinpcb(cloned_so);
+       case SIOCSETOT: {               /* int */
+               /*
+                * Inspiration from tcp_ctloutput() and ip_ctloutput()
+                * Special ioctl for OpenTransport sockets
+                */
+               struct inpcb *inp, *cloned_inp;
+               int error2 = 0;
+               int cloned_fd;
+
+               bcopy(data, &cloned_fd, sizeof (cloned_fd));
+
+               inp = sotoinpcb(so);
+               if (inp == NULL) {
+                       break;
+               }
+
+               /* let's make sure it's either -1 or a valid file descriptor */
+               if (cloned_fd != -1) {
+                       struct socket   *cloned_so;
+                       error2 = file_socket(cloned_fd, &cloned_so);
+                       if (error2) {
+                               break;
+                       }
+                       cloned_inp = sotoinpcb(cloned_so);
                        file_drop(cloned_fd);
-        } else {
-            cloned_inp = NULL;
-        }
-
-        if (cloned_inp == NULL) {
-            /* OT always uses IP_PORTRANGE_HIGH */
-            inp->inp_flags &= ~(INP_LOWPORT);
-            inp->inp_flags |= INP_HIGHPORT;
-            /* For UDP, OT allows broadcast by default */
-            if (so->so_type == SOCK_DGRAM)
-                so->so_options |= SO_BROADCAST;
-            /* For TCP we want to see MSG_OOB when receive urgent data */
-            else if (so->so_type == SOCK_STREAM)
-                so->so_options |= SO_WANTOOBFLAG;
-        } else {
-            inp->inp_ip_tos = cloned_inp->inp_ip_tos;
-            inp->inp_ip_ttl = cloned_inp->inp_ip_ttl;
-            inp->inp_flags = cloned_inp->inp_flags;
-
-            /* Multicast options */
-            if (cloned_inp->inp_moptions != NULL) {
-                int                    i;
-                struct ip_moptions     *cloned_imo = cloned_inp->inp_moptions;
-                struct ip_moptions     *imo = inp->inp_moptions;
-
-                if (imo == NULL) {
-                    /*
-                     * No multicast option buffer attached to the pcb;
-                     * allocate one.
-                     */
-                    imo = (struct ip_moptions*)
-                        _MALLOC(sizeof(*imo), M_IPMOPTS, M_WAITOK);
-                    if (imo == NULL) {
-                        error2 = ENOBUFS;
-                        break;
-                    }
-                    inp->inp_moptions = imo;
-                }
-                imo->imo_multicast_ifp = cloned_imo->imo_multicast_ifp;
-                imo->imo_multicast_vif = cloned_imo->imo_multicast_vif;
-                imo->imo_multicast_ttl = cloned_imo->imo_multicast_ttl;
-                imo->imo_multicast_loop = cloned_imo->imo_multicast_loop;
-                imo->imo_num_memberships = cloned_imo->imo_num_memberships;
-                for (i = 0; i < cloned_imo->imo_num_memberships; i++) {
-                    imo->imo_membership[i] =
-                    in_addmulti(&cloned_imo->imo_membership[i]->inm_addr,
-                                cloned_imo->imo_membership[i]->inm_ifp);
-                                       if (imo->imo_membership[i] == NULL) {
-                                               error2 = ENOBUFS;
-                                               break;
-                                       }
-                }
-                if (i < cloned_imo->imo_num_memberships) {
-                       /* Failed, perform cleanup */
-                       for (i--; i >= 0; i--)
-                               in_delmulti(&imo->imo_membership[i]);
-                       imo->imo_num_memberships = 0;
-                       break;
-                }
-            }
-        }
-        break;
-    }
+               } else {
+                       cloned_inp = NULL;
+               }
+
+               if (cloned_inp == NULL) {
+                       /* OT always uses IP_PORTRANGE_HIGH */
+                       inp->inp_flags &= ~(INP_LOWPORT);
+                       inp->inp_flags |= INP_HIGHPORT;
+                       /*
+                        * For UDP, OT allows broadcast by default;
+                        * for TCP we want to see MSG_OOB when we
+                        * receive urgent data.
+                        */
+                       if (so->so_type == SOCK_DGRAM)
+                               so->so_options |= SO_BROADCAST;
+                       else if (so->so_type == SOCK_STREAM)
+                               so->so_options |= SO_WANTOOBFLAG;
+               } else {
+                       inp->inp_ip_tos = cloned_inp->inp_ip_tos;
+                       inp->inp_ip_ttl = cloned_inp->inp_ip_ttl;
+                       inp->inp_flags = cloned_inp->inp_flags;
+
+                       /* Multicast options */
+                       if (cloned_inp->inp_moptions != NULL)
+                               error2 = imo_clone(cloned_inp, inp);
+               }
+               break;
+       }
 #endif /* __APPLE__ */
 
        default:
-               return EOPNOTSUPP;
+               error = EOPNOTSUPP;
        }
-       return (0);
+ done:
+       if (ia != NULL) {
+               IFA_REMREF(&ia->ia_ifa);
+       }
+       return (error);
 }
 
 /*
@@ -841,21 +1242,12 @@ in_control(
  *     other values may be returned from in_ioctl()
  */
 static int
-in_lifaddr_ioctl(
-       struct socket *so,
-       u_long cmd,
-       caddr_t data,
-       struct ifnet *ifp,
-       struct proc *p)
+in_lifaddr_ioctl(struct socket *so, u_long cmd, struct if_laddrreq *iflr,
+    struct ifnet *ifp, struct proc *p)
 {
-       struct if_laddrreq *iflr = (struct if_laddrreq *)data;
        struct ifaddr *ifa;
 
-       /* sanity checks */
-       if (!data || !ifp) {
-               panic("invalid argument to in_lifaddr_ioctl");
-               /*NOTRECHED*/
-       }
+       VERIFY(ifp != NULL);
 
        switch (cmd) {
        case SIOCGLIFADDR:
@@ -914,7 +1306,8 @@ in_lifaddr_ioctl(
        case SIOCDLIFADDR:
            {
                struct in_ifaddr *ia;
-               struct in_addr mask, candidate, match;
+               struct in_addr mask, candidate;
+               struct in_addr match = { 0 };
                struct sockaddr_in *sin;
                int cmp;
 
@@ -948,21 +1341,30 @@ in_lifaddr_ioctl(
 
                ifnet_lock_shared(ifp);
                TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-                       if (ifa->ifa_addr->sa_family != AF_INET6)
+                       IFA_LOCK(ifa);
+                       if (ifa->ifa_addr->sa_family != AF_INET6) {
+                               IFA_UNLOCK(ifa);
                                continue;
-                       if (!cmp)
+                       }
+                       if (!cmp) {
+                               IFA_UNLOCK(ifa);
                                break;
+                       }
                        candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
                        candidate.s_addr &= mask.s_addr;
+                       IFA_UNLOCK(ifa);
                        if (candidate.s_addr == match.s_addr)
                                break;
                }
+               if (ifa != NULL)
+                       IFA_ADDREF(ifa);
                ifnet_lock_done(ifp);
                if (!ifa)
                        return EADDRNOTAVAIL;
                ia = (struct in_ifaddr *)ifa;
 
                if (cmd == SIOCGLIFADDR) {
+                       IFA_LOCK(ifa);
                        /* fill in the if_laddrreq structure */
                        bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
 
@@ -977,6 +1379,8 @@ in_lifaddr_ioctl(
 
                        iflr->flags = 0;        /*XXX*/
 
+                       IFA_UNLOCK(ifa);
+                       IFA_REMREF(ifa);
                        return 0;
                } else {
                        struct in_aliasreq ifra;
@@ -986,6 +1390,7 @@ in_lifaddr_ioctl(
                        bcopy(iflr->iflr_name, ifra.ifra_name,
                                sizeof(ifra.ifra_name));
 
+                       IFA_LOCK(ifa);
                        bcopy(&ia->ia_addr, &ifra.ifra_addr,
                                ia->ia_addr.sin_len);
                        if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
@@ -994,7 +1399,8 @@ in_lifaddr_ioctl(
                        }
                        bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
                                ia->ia_sockmask.sin_len);
-
+                       IFA_UNLOCK(ifa);
+                       IFA_REMREF(ifa);
                        return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
                                          ifp, p);
                }
@@ -1004,27 +1410,151 @@ in_lifaddr_ioctl(
        return EOPNOTSUPP;      /*just for safety*/
 }
 
+/*
+ * Handle SIOCSETROUTERMODE to set or clear the IPv4 router mode flag on
+ * the interface.  When in this mode, IPv4 Link-Local Address support is
+ * disabled in ARP, and DHCP client support is disabled in IP input; turning
+ * any of them on would cause an error to be returned.  Entering or exiting
+ * this mode will result in the removal of IPv4 addresses currently configured
+ * on the interface.
+ */
+static int
+in_setrouter(struct ifnet *ifp, int enable)
+{
+       if (ifp->if_flags & IFF_LOOPBACK)
+               return (ENODEV);
+
+       ifnet_lock_exclusive(ifp);
+       if (enable) {
+               ifp->if_eflags |= IFEF_IPV4_ROUTER;
+               ifp->if_eflags &= ~(IFEF_ARPLL | IFEF_AUTOCONFIGURING);
+       } else {
+               ifp->if_eflags &= ~IFEF_IPV4_ROUTER;
+       }
+       ifnet_lock_done(ifp);
+
+       /* purge all IPv4 addresses configured on this interface */
+       in_purgeaddrs(ifp);
+
+       return (0);
+}
+
 /*
  * Delete any existing route for an interface.
  */
 void
-in_ifscrub(
-       struct ifnet *ifp,
-       struct in_ifaddr *ia,
-       int locked)
+in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia, int locked)
 {
-
-       if ((ia->ia_flags & IFA_ROUTE) == 0)
+       IFA_LOCK(&ia->ia_ifa);
+       if ((ia->ia_flags & IFA_ROUTE) == 0) {
+               IFA_UNLOCK(&ia->ia_ifa);
                return;
+       }
+       IFA_UNLOCK(&ia->ia_ifa);
        if (!locked)
-               lck_mtx_lock(rt_mtx);
+               lck_mtx_lock(rnh_lock);
        if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
                rtinit_locked(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
        else
                rtinit_locked(&(ia->ia_ifa), (int)RTM_DELETE, 0);
+       IFA_LOCK(&ia->ia_ifa);
        ia->ia_flags &= ~IFA_ROUTE;
+       IFA_UNLOCK(&ia->ia_ifa);
        if (!locked)
-               lck_mtx_unlock(rt_mtx);
+               lck_mtx_unlock(rnh_lock);
+}
+
+/*
+ * Caller must hold in_ifaddr_rwlock as writer.
+ */
+static void
+in_iahash_remove(struct in_ifaddr *ia)
+{
+        lck_rw_assert(in_ifaddr_rwlock, LCK_RW_ASSERT_EXCLUSIVE);
+       IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
+
+       if (!IA_IS_HASHED(ia)) {
+               panic("attempt to remove wrong ia %p from hash table\n", ia);
+               /* NOTREACHED */
+       }
+       TAILQ_REMOVE(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
+       IA_HASH_INIT(ia);
+       if (IFA_REMREF_LOCKED(&ia->ia_ifa) == NULL) {
+               panic("%s: unexpected (missing) refcnt ifa=%p", __func__,
+                   &ia->ia_ifa);
+               /* NOTREACHED */
+       }
+}
+
+/*
+ * Caller must hold in_ifaddr_rwlock as writer.
+ */
+static void
+in_iahash_insert(struct in_ifaddr *ia)
+{
+        lck_rw_assert(in_ifaddr_rwlock, LCK_RW_ASSERT_EXCLUSIVE);
+       IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
+
+       if (ia->ia_addr.sin_family != AF_INET) {
+               panic("attempt to insert wrong ia %p into hash table\n", ia);
+               /* NOTREACHED */
+       } else if (IA_IS_HASHED(ia)) {
+               panic("attempt to double-insert ia %p into hash table\n", ia);
+               /* NOTREACHED */
+       }
+       TAILQ_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
+       IFA_ADDREF_LOCKED(&ia->ia_ifa);
+}
+
+/*
+ * Some point to point interfaces that are tunnels
+ * borrow the address from an underlying interface (e.g.
+ * VPN server). In order for source address selection logic to 
+ * find the underlying interface first, we add the address 
+ * of borrowing point to point interfaces at the end of the list.
+ * (see rdar://6733789)
+ *
+ * Caller must hold in_ifaddr_rwlock as writer.
+ */
+static void
+in_iahash_insert_ptp(struct in_ifaddr *ia)
+{
+       struct in_ifaddr *tmp_ifa;
+       struct ifnet *tmp_ifp;
+
+        lck_rw_assert(in_ifaddr_rwlock, LCK_RW_ASSERT_EXCLUSIVE);
+       IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
+
+       if (ia->ia_addr.sin_family != AF_INET) {
+               panic("attempt to insert wrong ia %p into hash table\n", ia);
+               /* NOTREACHED */
+       } else if (IA_IS_HASHED(ia)) {
+               panic("attempt to double-insert ia %p into hash table\n", ia);
+               /* NOTREACHED */
+       }
+       IFA_UNLOCK(&ia->ia_ifa);
+       TAILQ_FOREACH(tmp_ifa, INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
+           ia_hash) {
+               IFA_LOCK(&tmp_ifa->ia_ifa);
+               /* ia->ia_addr won't change, so check without lock */
+               if (IA_SIN(tmp_ifa)->sin_addr.s_addr ==
+                   ia->ia_addr.sin_addr.s_addr) {
+                       IFA_UNLOCK(&tmp_ifa->ia_ifa);
+                       break;
+               }
+               IFA_UNLOCK(&tmp_ifa->ia_ifa);
+       }
+       tmp_ifp = (tmp_ifa == NULL) ? NULL : tmp_ifa->ia_ifp;
+
+       IFA_LOCK(&ia->ia_ifa);
+       if (tmp_ifp == NULL) {
+               TAILQ_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
+                   ia, ia_hash);
+       } else {
+               TAILQ_INSERT_TAIL(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
+                   ia, ia_hash);
+       }
+       IFA_ADDREF_LOCKED(&ia->ia_ifa);
 }
 
 /*
@@ -1038,30 +1568,99 @@ in_ifinit(
        struct sockaddr_in *sin,
        int scrub)
 {
-       u_long i = ntohl(sin->sin_addr.s_addr);
+       u_int32_t i = ntohl(sin->sin_addr.s_addr);
        struct sockaddr_in oldaddr;
        int flags = RTF_UP, error;
+       struct ifaddr *ifa0;
+       unsigned int cmd;
+       int oldremoved = 0;
+
+       /* Take an extra reference for this routine */
+       IFA_ADDREF(&ia->ia_ifa);
 
+       lck_rw_lock_exclusive(in_ifaddr_rwlock);
+       IFA_LOCK(&ia->ia_ifa);
        oldaddr = ia->ia_addr;
+       if (IA_IS_HASHED(ia)) {
+               oldremoved = 1;
+               in_iahash_remove(ia);
+       }
        ia->ia_addr = *sin;
+       ia->ia_addr.sin_len = sizeof (*sin);
+       if ((ifp->if_flags & IFF_POINTOPOINT))
+               in_iahash_insert_ptp(ia);
+       else
+               in_iahash_insert(ia);
+       IFA_UNLOCK(&ia->ia_ifa);
+       lck_rw_done(in_ifaddr_rwlock);
 
        /*
-        * Give the interface a chance to initialize
-        * if this is its first address,
-        * and to validate the address if necessary.
+        * Give the interface a chance to initialize if this is its first
+        * address, and to validate the address if necessary.  Send down
+        * SIOCSIFADDR for first address, and SIOCAIFADDR for alias(es).
+        * We find the first IPV4 address assigned to it and check if this
+        * is the same as the one passed into this routine.
         */
-       error = dlil_ioctl(PF_INET, ifp, SIOCSIFADDR, (caddr_t)ia);
+       ifa0 = ifa_ifpgetprimary(ifp, AF_INET);
+       cmd = (&ia->ia_ifa == ifa0) ? SIOCSIFADDR : SIOCAIFADDR;
+       error = ifnet_ioctl(ifp, PF_INET, cmd, ia);
        if (error == EOPNOTSUPP)
-            error = 0;
+               error = 0;
+       /*
+        * If we've just sent down SIOCAIFADDR, send another ioctl down
+        * for SIOCSIFADDR for the first IPV4 address of the interface,
+        * because an address change on one of the addresses will result
+        * in the removal of the previous first IPV4 address.  KDP needs
+        * be reconfigured with the current primary IPV4 address.
+        */
+       if (error == 0 && cmd == SIOCAIFADDR) {
+               /*
+                * NOTE: SIOCSIFADDR is defined with struct ifreq
+                * as parameter, but here we are sending it down
+                * to the interface with a pointer to struct ifaddr,
+                * for legacy reasons.
+                */
+               error = ifnet_ioctl(ifp, PF_INET, SIOCSIFADDR, ifa0);
+               if (error == EOPNOTSUPP)
+                       error = 0;
+       }
+
+       /* Release reference from ifa_ifpgetprimary() */
+       IFA_REMREF(ifa0);
+
        if (error) {
+               lck_rw_lock_exclusive(in_ifaddr_rwlock);
+               IFA_LOCK(&ia->ia_ifa);
+               if (IA_IS_HASHED(ia))
+                       in_iahash_remove(ia);
                ia->ia_addr = oldaddr;
+               if (oldremoved) {
+                       if ((ifp->if_flags & IFF_POINTOPOINT))
+                               in_iahash_insert_ptp(ia);
+                       else
+                               in_iahash_insert(ia);
+               }
+               IFA_UNLOCK(&ia->ia_ifa);
+               lck_rw_done(in_ifaddr_rwlock);
+               /* Release extra reference taken above */
+               IFA_REMREF(&ia->ia_ifa);
                return (error);
        }
+       lck_mtx_lock(rnh_lock);
+       IFA_LOCK(&ia->ia_ifa);
+       /*
+        * Address has been initialized by the link resolver (ARP)
+        * via ifnet_ioctl() above; it may now generate route(s).
+        */
+       ia->ia_ifa.ifa_debug &= ~IFD_NOTREADY;
        if (scrub) {
                ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
-               in_ifscrub(ifp, ia, 0);
+               IFA_UNLOCK(&ia->ia_ifa);
+               in_ifscrub(ifp, ia, 1);
+               IFA_LOCK(&ia->ia_ifa);
                ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
        }
+       IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
        if (IN_CLASSA(i))
                ia->ia_netmask = IN_CLASSA_NET;
        else if (IN_CLASSB(i))
@@ -1094,12 +1693,24 @@ in_ifinit(
                ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
                flags |= RTF_HOST;
        } else if (ifp->if_flags & IFF_POINTOPOINT) {
-               if (ia->ia_dstaddr.sin_family != AF_INET)
+               if (ia->ia_dstaddr.sin_family != AF_INET) {
+                       IFA_UNLOCK(&ia->ia_ifa);
+                       lck_mtx_unlock(rnh_lock);
+                       /* Release extra reference taken above */
+                       IFA_REMREF(&ia->ia_ifa);
                        return (0);
+               }
+               ia->ia_dstaddr.sin_len = sizeof (*sin);
                flags |= RTF_HOST;
        }
-       if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
+       IFA_UNLOCK(&ia->ia_ifa);
+       if ((error = rtinit_locked(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) {
+               IFA_LOCK(&ia->ia_ifa);
                ia->ia_flags |= IFA_ROUTE;
+               IFA_UNLOCK(&ia->ia_ifa);
+       }
+       lck_mtx_unlock(rnh_lock);
+
        /* XXX check if the subnet route points to the same interface */
        if (error == EEXIST)
                error = 0;
@@ -1109,16 +1720,29 @@ in_ifinit(
         * multicast group on that interface.
         */
        if (ifp->if_flags & IFF_MULTICAST) {
-               struct in_multi *inm;
                struct in_addr addr;
 
+               lck_mtx_lock(&ifp->if_addrconfig_lock);
                addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
-               ifnet_lock_shared(ifp);
-               IN_LOOKUP_MULTI(addr, ifp, inm);
-               ifnet_lock_done(ifp);
-               if (inm == 0)
-                       in_addmulti(&addr, ifp);
+               if (ifp->if_allhostsinm == NULL) {
+                       struct in_multi *inm;
+                       inm = in_addmulti(&addr, ifp);
+
+                       if (inm != NULL) {
+                               /* keep the reference on inm added by 
+                                * in_addmulti above for storing the 
+                                * pointer in allhostsinm 
+                                */
+                               ifp->if_allhostsinm = inm;
+                       } else {
+                               printf("Failed to add membership to all-hosts multicast address on interface %s%d\n", ifp->if_name, ifp->if_unit);
+                       }
+               }
+               lck_mtx_unlock(&ifp->if_addrconfig_lock);
        }
+
+       /* Release extra reference taken above */
+       IFA_REMREF(&ia->ia_ifa);
        return (error);
 }
 
@@ -1127,18 +1751,15 @@ in_ifinit(
  * Return 1 if the address might be a local broadcast address.
  */
 int
-in_broadcast(
-       struct in_addr in,
-       struct ifnet *ifp)
+in_broadcast(struct in_addr in, struct ifnet *ifp)
 {
        struct ifaddr *ifa;
-       u_long t;
+       u_int32_t t;
 
-       if (in.s_addr == INADDR_BROADCAST ||
-           in.s_addr == INADDR_ANY)
-               return 1;
+       if (in.s_addr == INADDR_BROADCAST || in.s_addr == INADDR_ANY)
+               return (1);
        if ((ifp->if_flags & IFF_BROADCAST) == 0)
-               return 0;
+               return (0);
        t = ntohl(in.s_addr);
        /*
         * Look through the list of addresses for a match
@@ -1147,10 +1768,7 @@ in_broadcast(
 #define ia ((struct in_ifaddr *)ifa)
        ifnet_lock_shared(ifp);
        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-               if (ifa->ifa_addr == NULL) {
-                       ifnet_lock_done(ifp);
-                       return (0);
-               }
+               IFA_LOCK(ifa);
                if (ifa->ifa_addr->sa_family == AF_INET &&
                    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
                     in.s_addr == ia->ia_netbroadcast.s_addr ||
@@ -1163,158 +1781,258 @@ in_broadcast(
                      * only exist when an interface gets a secondary
                      * address.
                      */
-                    ia->ia_subnetmask != (u_long)0xffffffff) {
+                    ia->ia_subnetmask != (u_int32_t)0xffffffff) {
+                       IFA_UNLOCK(ifa);
                        ifnet_lock_done(ifp);
-                       return 1;
+                       return (1);
                }
+               IFA_UNLOCK(ifa);
        }
        ifnet_lock_done(ifp);
        return (0);
 #undef ia
 }
 
-static void
-in_free_inm(
-       void*   ifma_protospec)
+void
+in_purgeaddrs(struct ifnet *ifp)
 {
-       struct in_multi *inm = ifma_protospec;
-       
+       struct ifaddr **ifap;
+       int err, i;
+
        /*
-        * No remaining claims to this record; let IGMP know that
-        * we are leaving the multicast group.
+        * Be nice, and try the civilized way first.  If we can't get
+        * rid of them this way, then do it the rough way.  We must
+        * only get here during detach time, after the ifnet has been
+        * removed from the global list and arrays.
         */
-       igmp_leavegroup(inm);
-       lck_mtx_lock(rt_mtx);
-       LIST_REMOVE(inm, inm_link);
-       lck_mtx_unlock(rt_mtx);
-       FREE(inm, M_IPMADDR);
+       err = ifnet_get_address_list_family_internal(ifp, &ifap, AF_INET, 1,
+           M_WAITOK);
+       if (err == 0 && ifap != NULL) {
+               for (i = 0; ifap[i] != NULL; i++) {
+                       struct ifaliasreq ifr;
+                       struct ifaddr *ifa;
+
+                       ifa = ifap[i];
+                       bzero(&ifr, sizeof (ifr));
+                       IFA_LOCK(ifa);
+                       ifr.ifra_addr = *ifa->ifa_addr;
+                       if (ifa->ifa_dstaddr != NULL)
+                               ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
+                       IFA_UNLOCK(ifa);
+                       err = in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr, ifp,
+                           kernproc);
+                       /* if we lost the race, ignore it */
+                       if (err == EADDRNOTAVAIL)
+                               err = 0;
+                       if (err != 0) {
+                               char s_addr[MAX_IPv4_STR_LEN];
+                               char s_dstaddr[MAX_IPv4_STR_LEN];
+                               struct in_addr *s, *d;
+
+                               IFA_LOCK(ifa);
+                               s = &((struct sockaddr_in *)
+                                   (void *)ifa->ifa_addr)->sin_addr;
+                               d = &((struct sockaddr_in *)
+                                   (void *)ifa->ifa_dstaddr)->sin_addr;
+                               (void) inet_ntop(AF_INET, &s->s_addr, s_addr,
+                                   sizeof (s_addr));
+                               (void) inet_ntop(AF_INET, &d->s_addr, s_dstaddr,
+                                   sizeof (s_dstaddr));
+                               IFA_UNLOCK(ifa);
+
+                               printf("%s: SIOCDIFADDR ifp=%p ifa_addr=%s "
+                                   "ifa_dstaddr=%s (err=%d)\n", __func__, ifp,
+                                   s_addr, s_dstaddr, err);
+                       }
+               }
+               ifnet_free_address_list(ifap);
+       } else if (err != 0 && err != ENXIO) {
+               printf("%s: error retrieving list of AF_INET addresses for "
+                   "ifp=%p (err=%d)\n", __func__, ifp, err);
+       }
+}
+
+int inet_aton(char *cp, struct in_addr *pin);
+int
+inet_aton(char * cp, struct in_addr * pin)
+{
+    u_char * b = (unsigned char *)pin;
+    int           i;
+    char * p;
+
+    for (p = cp, i = 0; i < 4; i++) {
+       u_int32_t l = strtoul(p, 0, 0);
+       if (l > 255)
+           return (FALSE);
+       b[i] = l;
+       p = strchr(p, '.');
+       if (i < 3 && p == NULL)
+           return (FALSE);
+       p++;
+    }
+    return (TRUE);
+}
+
+int inet_ntoa2(struct in_addr * pin, char * cp, const int len);
+int inet_ntoa2(struct in_addr * pin, char * cp, const int len)
+{
+    int ret;
+
+    /* address is in network byte order */
+   ret = snprintf(cp, len, "%u.%u.%u.%u", pin->s_addr & 0xFF, 
+                  (pin->s_addr >> 8) & 0xFF, (pin->s_addr >> 16) & 0xFF,
+                  (pin->s_addr >> 24) & 0xFF);
+
+   return ret < len ? TRUE : FALSE;
 }
 
 /*
- * Add an address to the list of IP multicast addresses for a given interface.
+ * Called as part of ip_init
  */
-struct in_multi *
-in_addmulti(
-       struct in_addr *ap,
-       struct ifnet *ifp)
+void
+in_ifaddr_init(void)
 {
-       struct in_multi *inm;
-       int error;
-       struct sockaddr_in sin;
-       struct ifmultiaddr *ifma;
+       in_multi_init();
 
-       /*
-        * Call generic routine to add membership or increment
-        * refcount.  It wants addresses in the form of a sockaddr,
-        * so we build one here (being careful to zero the unused bytes).
-        */
-       bzero(&sin, sizeof sin);
-       sin.sin_family = AF_INET;
-       sin.sin_len = sizeof sin;
-       sin.sin_addr = *ap;
-       error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
-       if (error) {
-               return 0;
-       }
+       PE_parse_boot_argn("ifa_debug", &inifa_debug, sizeof (inifa_debug));
 
-       /*
-        * If ifma->ifma_protospec is null, then if_addmulti() created
-        * a new record.  Otherwise, we are done.
-        */
-       if (ifma->ifma_protospec != 0) {
-               return ifma->ifma_protospec;
-       }
+       inifa_size = (inifa_debug == 0) ? sizeof (struct in_ifaddr) :
+           sizeof (struct in_ifaddr_dbg);
 
-       inm = (struct in_multi *) _MALLOC(sizeof(*inm), M_IPMADDR, M_WAITOK);
-       if (inm == NULL) {
-               return (NULL);
+       inifa_zone = zinit(inifa_size, INIFA_ZONE_MAX * inifa_size,
+           0, INIFA_ZONE_NAME);
+       if (inifa_zone == NULL) {
+               panic("%s: failed allocating %s", __func__, INIFA_ZONE_NAME);
+               /* NOTREACHED */
        }
+       zone_change(inifa_zone, Z_EXPAND, TRUE);
+       zone_change(inifa_zone, Z_CALLERACCT, FALSE);
 
-       bzero(inm, sizeof *inm);
-       inm->inm_addr = *ap;
-       inm->inm_ifp = ifp;
-       inm->inm_ifma = ifma;
-       lck_mtx_lock(rt_mtx);
-       if (ifma->ifma_protospec == NULL) {
-               ifma->ifma_protospec = inm;
-               ifma->ifma_free = in_free_inm;
-               LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
-       }
-       lck_mtx_unlock(rt_mtx);
-       
-       if (ifma->ifma_protospec != inm) {
-               _FREE(inm, M_IPMADDR);
-               return ifma->ifma_protospec;
+       lck_mtx_init(&inifa_trash_lock, ifa_mtx_grp, ifa_mtx_attr);
+       TAILQ_INIT(&inifa_trash_head);
+}
+
+static struct in_ifaddr *
+in_ifaddr_alloc(int how)
+{
+       struct in_ifaddr *inifa;
+
+       inifa = (how == M_WAITOK) ? zalloc(inifa_zone) :
+           zalloc_noblock(inifa_zone);
+       if (inifa != NULL) {
+               bzero(inifa, inifa_size);
+               inifa->ia_ifa.ifa_free = in_ifaddr_free;
+               inifa->ia_ifa.ifa_debug |= IFD_ALLOC;
+               ifa_lock_init(&inifa->ia_ifa);
+               if (inifa_debug != 0) {
+                       struct in_ifaddr_dbg *inifa_dbg =
+                           (struct in_ifaddr_dbg *)inifa;
+                       inifa->ia_ifa.ifa_debug |= IFD_DEBUG;
+                       inifa->ia_ifa.ifa_trace = in_ifaddr_trace;
+                       inifa->ia_ifa.ifa_attached = in_ifaddr_attached;
+                       inifa->ia_ifa.ifa_detached = in_ifaddr_detached;
+                       ctrace_record(&inifa_dbg->inifa_alloc);
+               }
        }
+       return (inifa);
+}
 
-       /*
-        * Let IGMP know that we have joined a new IP multicast group.
-        */
-       error = igmp_joingroup(inm);
-       if (error) {
-               char addrbuf[16];
-               
-               /*
-                * We can't free the inm because someone else may already be
-                * using it. Once we put it in to ifma->ifma_protospec, it
-                * must exist as long as the ifma does. Might be nice to flag
-                * the error so we can try igmp_joingroup the next time through.
-                */
-               log(LOG_ERR, "igmp_joingroup error %d joining multicast %s on %s%d\n",
-                       error, inet_ntop(AF_INET, &sin.sin_addr, addrbuf, sizeof(addrbuf)),
-                       ifp->if_name, ifp->if_unit);
+static void
+in_ifaddr_free(struct ifaddr *ifa)
+{
+       IFA_LOCK_ASSERT_HELD(ifa);
+
+       if (ifa->ifa_refcnt != 0) {
+               panic("%s: ifa %p bad ref cnt", __func__, ifa);
+               /* NOTREACHED */
+       } if (!(ifa->ifa_debug & IFD_ALLOC)) {
+               panic("%s: ifa %p cannot be freed", __func__, ifa);
+               /* NOTREACHED */
        }
-       
-       return (inm);
+       if (ifa->ifa_debug & IFD_DEBUG) {
+               struct in_ifaddr_dbg *inifa_dbg = (struct in_ifaddr_dbg *)ifa;
+               ctrace_record(&inifa_dbg->inifa_free);
+               bcopy(&inifa_dbg->inifa, &inifa_dbg->inifa_old,
+                   sizeof (struct in_ifaddr));
+               if (ifa->ifa_debug & IFD_TRASHED) {
+                       /* Become a regular mutex, just in case */
+                       IFA_CONVERT_LOCK(ifa);
+                       lck_mtx_lock(&inifa_trash_lock);
+                       TAILQ_REMOVE(&inifa_trash_head, inifa_dbg,
+                           inifa_trash_link);
+                       lck_mtx_unlock(&inifa_trash_lock);
+                       ifa->ifa_debug &= ~IFD_TRASHED;
+               }
+       }
+       IFA_UNLOCK(ifa);
+       ifa_lock_destroy(ifa);
+       bzero(ifa, sizeof (struct in_ifaddr));
+       zfree(inifa_zone, ifa);
 }
 
-/*
- * Delete a multicast address record.
- */
-void
-in_delmulti(
-       struct in_multi **inm)
+static void
+in_ifaddr_attached(struct ifaddr *ifa)
 {
-       struct in_multi *inm2;
-       
-       lck_mtx_lock(rt_mtx);
-       LIST_FOREACH(inm2, &in_multihead, inm_link) {
-               if (inm2 == *inm)
-                       break;
+       struct in_ifaddr_dbg *inifa_dbg = (struct in_ifaddr_dbg *)ifa;
+
+       IFA_LOCK_ASSERT_HELD(ifa);
+
+       if (!(ifa->ifa_debug & IFD_DEBUG)) {
+               panic("%s: ifa %p has no debug structure", __func__, ifa);
+               /* NOTREACHED */
        }
-       if (inm2 != *inm) {
-               lck_mtx_unlock(rt_mtx);
-               printf("in_delmulti - ignorning invalid inm (0x%x)\n", *inm);
-               return;
+       if (ifa->ifa_debug & IFD_TRASHED) {
+               /* Become a regular mutex, just in case */
+               IFA_CONVERT_LOCK(ifa);
+               lck_mtx_lock(&inifa_trash_lock);
+               TAILQ_REMOVE(&inifa_trash_head, inifa_dbg, inifa_trash_link);
+               lck_mtx_unlock(&inifa_trash_lock);
+               ifa->ifa_debug &= ~IFD_TRASHED;
        }
-       lck_mtx_unlock(rt_mtx);
-       
-       /* We intentionally do this a bit differently than BSD */
-       if ((*inm)->inm_ifma) {
-               if_delmultiaddr((*inm)->inm_ifma, 0);
-               ifma_release((*inm)->inm_ifma);
+}
+
+static void
+in_ifaddr_detached(struct ifaddr *ifa)
+{
+       struct in_ifaddr_dbg *inifa_dbg = (struct in_ifaddr_dbg *)ifa;
+
+       IFA_LOCK_ASSERT_HELD(ifa);
+
+       if (!(ifa->ifa_debug & IFD_DEBUG)) {
+               panic("%s: ifa %p has no debug structure", __func__, ifa);
+               /* NOTREACHED */
+       } else if (ifa->ifa_debug & IFD_TRASHED) {
+               panic("%s: ifa %p is already in trash list", __func__, ifa);
+               /* NOTREACHED */
        }
-       *inm = NULL;
+       ifa->ifa_debug |= IFD_TRASHED;
+       /* Become a regular mutex, just in case */
+       IFA_CONVERT_LOCK(ifa);
+       lck_mtx_lock(&inifa_trash_lock);
+       TAILQ_INSERT_TAIL(&inifa_trash_head, inifa_dbg, inifa_trash_link);
+       lck_mtx_unlock(&inifa_trash_lock);
 }
 
-#if !NFSCLIENT
-int
-inet_aton(char * cp, struct in_addr * pin)
+static void
+in_ifaddr_trace(struct ifaddr *ifa, int refhold)
 {
-    u_char * b = (char *)pin;
-    int           i;
-    char * p;
+       struct in_ifaddr_dbg *inifa_dbg = (struct in_ifaddr_dbg *)ifa;
+       ctrace_t *tr;
+       u_int32_t idx;
+       u_int16_t *cnt;
+
+       if (!(ifa->ifa_debug & IFD_DEBUG)) {
+               panic("%s: ifa %p has no debug structure", __func__, ifa);
+               /* NOTREACHED */
+       }
+       if (refhold) {
+               cnt = &inifa_dbg->inifa_refhold_cnt;
+               tr = inifa_dbg->inifa_refhold;
+       } else {
+               cnt = &inifa_dbg->inifa_refrele_cnt;
+               tr = inifa_dbg->inifa_refrele;
+       }
 
-    for (p = cp, i = 0; i < 4; i++) {
-       u_long l = strtoul(p, 0, 0);
-       if (l > 255)
-           return (FALSE);
-       b[i] = l;
-       p = strchr(p, '.');
-       if (i < 3 && p == NULL)
-           return (FALSE);
-       p++;
-    }
-    return (TRUE);
+       idx = atomic_add_16_ov(cnt, 1) % INIFA_TRACE_HIST_SIZE;
+       ctrace_record(&tr[idx]);
 }
-#endif