]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/ip_output.c
xnu-1699.22.81.tar.gz
[apple/xnu.git] / bsd / netinet / ip_output.c
index 047b6b7ceb3dc00b02fb169ba7ebe0065985931a..57f522919a7f2cbc19a127ac11a996e8194a96e0 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
 #include <sys/socketvar.h>
 #include <kern/locks.h>
 #include <sys/sysctl.h>
+#include <sys/mcache.h>
+
+#include <machine/endian.h>
+#include <pexpert/pexpert.h>
 
 #include <net/if.h>
 #include <net/if_dl.h>
+#include <net/if_types.h>
 #include <net/route.h>
+#include <net/ntstat.h>
+#include <net/net_osdep.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 
 #include <netinet/ip_fw.h>
 #include <netinet/ip_divert.h>
+#include <mach/sdt.h>
 
 #if DUMMYNET
 #include <netinet/ip_dummynet.h>
 #endif
 
+#if PF
+#include <net/pfvar.h>
+#endif /* PF */
+
 #if IPFIREWALL_FORWARD_DEBUG
 #define print_ip(a)     printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\
                                                  (ntohl(a.s_addr)>>16)&0xFF,\
 u_short ip_id;
 
 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
-static struct ifnet *ip_multicast_if(struct in_addr *, int *);
 static void    ip_mloopback(struct ifnet *, struct mbuf *,
        struct sockaddr_in *, int);
-static int     ip_getmoptions(struct sockopt *, struct ip_moptions *);
 static int     ip_pcbopts(int, struct mbuf **, struct mbuf *);
-static int     ip_setmoptions(struct sockopt *, struct ip_moptions **);
+static void    imo_trace(struct ip_moptions *, int);
 
 static void ip_out_cksum_stats(int, u_int32_t);
 static struct ifaddr *in_selectsrcif(struct ip *, struct route *, unsigned int);
-static void ip_bindif(struct inpcb *, unsigned int);
 
-int ip_createmoptions(struct ip_moptions **imop);
-int ip_addmembership(struct ip_moptions *imo, struct ip_mreq *mreq);
-int ip_dropmembership(struct ip_moptions *imo, struct ip_mreq *mreq);
 int    ip_optcopy(struct ip *, struct ip *);
 void in_delayed_cksum_offset(struct mbuf *, int );
 void in_cksum_offset(struct mbuf* , size_t );
 
 extern int (*fr_checkp)(struct ip *, int, struct ifnet *, int, struct mbuf **);
 
-extern u_long  route_generation;
-
 extern struct protosw inetsw[];
 
 extern struct ip_linklocal_stat ip_linklocal_stat;
@@ -171,18 +175,50 @@ extern int ipsec_bypass;
 #endif
 
 static int     ip_maxchainsent = 0;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, maxchainsent, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_ip, OID_AUTO, maxchainsent, CTLFLAG_RW | CTLFLAG_LOCKED,
     &ip_maxchainsent, 0, "use dlil_output_list");
 #if DEBUG
 static int forge_ce = 0;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, forge_ce, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_ip, OID_AUTO, forge_ce, CTLFLAG_RW | CTLFLAG_LOCKED,
     &forge_ce, 0, "Forge ECN CE");
 #endif /* DEBUG */
 
 static int ip_select_srcif_debug = 0;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, select_srcif_debug, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_ip, OID_AUTO, select_srcif_debug, CTLFLAG_RW | CTLFLAG_LOCKED,
     &ip_select_srcif_debug, 0, "log source interface selection debug info");
 
+#define        IMO_TRACE_HIST_SIZE     32      /* size of trace history */
+
+/* For gdb */
+__private_extern__ unsigned int imo_trace_hist_size = IMO_TRACE_HIST_SIZE;
+
+struct ip_moptions_dbg {
+       struct ip_moptions      imo;                    /* ip_moptions */
+       u_int16_t               imo_refhold_cnt;        /* # of IMO_ADDREF */
+       u_int16_t               imo_refrele_cnt;        /* # of IMO_REMREF */
+       /*
+        * Alloc and free callers.
+        */
+       ctrace_t                imo_alloc;
+       ctrace_t                imo_free;
+       /*
+        * Circular lists of IMO_ADDREF and IMO_REMREF callers.
+        */
+       ctrace_t                imo_refhold[IMO_TRACE_HIST_SIZE];
+       ctrace_t                imo_refrele[IMO_TRACE_HIST_SIZE];
+};
+
+#if DEBUG
+static unsigned int imo_debug = 1;     /* debugging (enabled) */
+#else
+static unsigned int imo_debug;         /* debugging (disabled) */
+#endif /* !DEBUG */
+static unsigned int imo_size;          /* size of zone element */
+static struct zone *imo_zone;          /* zone for ip_moptions */
+
+#define        IMO_ZONE_MAX            64              /* maximum elements in zone */
+#define        IMO_ZONE_NAME           "ip_moptions"   /* zone name */
+
 /*
  * IP output.  The packet in mbuf chain m contains a skeletal IP
  * header (with len, off, ttl, proto, tos, src, dst).
@@ -236,15 +272,16 @@ ip_output_list(
        struct ip_out_args *ipoa
        )
 {
-       struct ip *ip, *mhip;
+       struct ip *ip;
        struct ifnet *ifp = NULL;
-       struct mbuf *m = m0;
+       struct mbuf *m = m0, **mppn = NULL;
        int hlen = sizeof (struct ip);
-       int len = 0, off, error = 0;
+       int len = 0, error = 0;
        struct sockaddr_in *dst = NULL;
-       struct in_ifaddr *ia = NULL;
+       struct in_ifaddr *ia = NULL, *src_ia = NULL;
        int isbroadcast, sw_csum;
        struct in_addr pkt_dst;
+       struct ipf_pktopts *ippo = NULL, ipf_pktopts;
 #if IPSEC
        struct route iproute;
        struct socket *so = NULL;
@@ -254,18 +291,24 @@ ip_output_list(
        int fwd_rewrite_src = 0;
 #endif
 #if IPFIREWALL
+       int off;
        struct ip_fw_args args;
+       struct m_tag    *tag;
+       struct sockaddr_in *next_hop_from_ipfwd_tag = NULL;
 #endif
        int didfilter = 0;
        ipfilter_t inject_filter_ref = 0;
-       struct m_tag    *tag;
+#if DUMMYNET
        struct route    saved_route;
        struct ip_out_args saved_ipoa;
+       struct sockaddr_in dst_buf;
+#endif /* DUMMYNET */
        struct mbuf * packetlist;
-       int pktcnt = 0;
+       int pktcnt = 0, tso = 0;
+       u_int32_t       bytecnt = 0;
        unsigned int ifscope;
+       unsigned int nocell;
        boolean_t select_srcif;
-
        KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_START, 0,0,0,0,0);
 
        packetlist = m0;
@@ -275,33 +318,39 @@ ip_output_list(
        args.rule = NULL;
        args.divert_rule = 0;                   /* divert cookie */
        args.ipoa = NULL;
-       
+
+       if (SLIST_EMPTY(&m0->m_pkthdr.tags))
+               goto ipfw_tags_done;
+
        /* Grab info from mtags prepended to the chain */
 #if DUMMYNET
-       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DUMMYNET, NULL)) != NULL) {
+       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID,
+           KERNEL_TAG_TYPE_DUMMYNET, NULL)) != NULL) {
                struct dn_pkt_tag       *dn_tag;
-               
+
                dn_tag = (struct dn_pkt_tag *)(tag+1);
                args.rule = dn_tag->rule;
                opt = NULL;
                saved_route = dn_tag->ro;
                ro = &saved_route;
-                       
+
                imo = NULL;
-               dst = dn_tag->dn_dst;
+               bcopy(&dn_tag->dn_dst, &dst_buf, sizeof(dst_buf));
+               dst = &dst_buf;
                ifp = dn_tag->ifp;
                flags = dn_tag->flags;
                saved_ipoa = dn_tag->ipoa;
                ipoa = &saved_ipoa;
-               
+
                m_tag_delete(m0, tag);
        }
 #endif /* DUMMYNET */
 
 #if IPDIVERT
-       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DIVERT, NULL)) != NULL) {
+       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID,
+           KERNEL_TAG_TYPE_DIVERT, NULL)) != NULL) {
                struct divert_tag       *div_tag;
-               
+
                div_tag = (struct divert_tag *)(tag+1);
                args.divert_rule = div_tag->cookie;
 
@@ -309,18 +358,20 @@ ip_output_list(
        }
 #endif /* IPDIVERT */
 
-       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD, NULL)) != NULL) {
+       if ((tag = m_tag_locate(m0, KERNEL_MODULE_TAG_ID,
+           KERNEL_TAG_TYPE_IPFORWARD, NULL)) != NULL) {
                struct ip_fwd_tag       *ipfwd_tag;
-               
+
                ipfwd_tag = (struct ip_fwd_tag *)(tag+1);
-               args.next_hop = ipfwd_tag->next_hop;
+               next_hop_from_ipfwd_tag = ipfwd_tag->next_hop;
                
                m_tag_delete(m0, tag);
        }
+ipfw_tags_done:
 #endif /* IPFIREWALL */
 
        m = m0;
-       
+
 #if    DIAGNOSTIC
        if ( !m || (m->m_flags & M_PKTHDR) != 0)
                panic("ip_output no HDR");
@@ -329,37 +380,54 @@ ip_output_list(
                      mtod(m, struct ip *)->ip_p);
 #endif
 
+       bzero(&ipf_pktopts, sizeof(struct ipf_pktopts));
+       ippo = &ipf_pktopts;
+
        /*
-        * Do not perform source interface selection when forwarding.
         * At present the IP_OUTARGS flag implies a request for IP to
-        * perform source interface selection.
+        * perform source interface selection.  In the forwarding case,
+        * only the ifscope value is used, as source interface selection
+        * doesn't take place.
         */
-       if (ip_doscopedroute &&
-           (flags & (IP_OUTARGS | IP_FORWARDING)) == IP_OUTARGS) {
-               select_srcif = TRUE;
-               ifscope = ipoa->ipoa_ifscope;
+       if (ip_doscopedroute && (flags & IP_OUTARGS)) {
+               select_srcif = !(flags & IP_FORWARDING);
+               ifscope = ipoa->ipoa_boundif;
+               ipf_pktopts.ippo_flags = IPPOF_BOUND_IF;
+               ipf_pktopts.ippo_flags |= (ifscope << IPPOF_SHIFT_IFSCOPE);
        } else {
                select_srcif = FALSE;
                ifscope = IFSCOPE_NONE;
        }
 
+       if (flags & IP_OUTARGS) {
+               nocell = ipoa->ipoa_nocell;
+               if (nocell)
+                       ipf_pktopts.ippo_flags |= IPPOF_NO_IFT_CELLULAR;
+       } else {
+               nocell = 0;
+       }
+
 #if IPFIREWALL
        if (args.rule != NULL) {        /* dummynet already saw us */
-            ip = mtod(m, struct ip *);
-            hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
-           lck_mtx_lock(rt_mtx);
-            if (ro->ro_rt != NULL) 
-                ia = (struct in_ifaddr *)ro->ro_rt->rt_ifa;
-           if (ia)
-               ifaref(&ia->ia_ifa);
-           lck_mtx_unlock(rt_mtx);
+               ip = mtod(m, struct ip *);
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
+               if (ro->ro_rt != NULL) {
+                       RT_LOCK_SPIN(ro->ro_rt);
+                       ia = (struct in_ifaddr *)ro->ro_rt->rt_ifa;
+                       if (ia) {
+                               /* Become a regular mutex */
+                               RT_CONVERT_LOCK(ro->ro_rt);
+                               IFA_ADDREF(&ia->ia_ifa);
+                       }
+                       RT_UNLOCK(ro->ro_rt);
+               }
 #if IPSEC
-           if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) {
-               so = ipsec_getsocket(m);
-               (void)ipsec_setsocket(m, NULL);
+               if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) {
+                       so = ipsec_getsocket(m);
+                       (void)ipsec_setsocket(m, NULL);
                }
 #endif
-            goto sendit;
+               goto sendit;
        }
 #endif /* IPFIREWALL */
 
@@ -374,7 +442,10 @@ loopit:
         * No need to proccess packet twice if we've 
         * already seen it
         */
-       inject_filter_ref = ipf_get_inject_filter(m);
+       if (!SLIST_EMPTY(&m->m_pkthdr.tags))
+               inject_filter_ref = ipf_get_inject_filter(m);
+       else
+               inject_filter_ref = 0;
 
        if (opt) {
                m = ip_insertoptions(m, opt, &len);
@@ -382,11 +453,29 @@ loopit:
        }
        ip = mtod(m, struct ip *);
 #if IPFIREWALL
+       /*
+        * rdar://8542331
+        *
+        * When dealing with a packet chain, we need to reset "next_hop" because 
+        * "dst" may have been changed to the gateway address below for the previous
+        * packet of the chain. This could cause the route to be inavertandly changed 
+        * to the route to the gateway address (instead of the route to the destination).
+        */
+       args.next_hop = next_hop_from_ipfwd_tag;
        pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
 #else
        pkt_dst = ip->ip_dst;
 #endif
 
+       /*
+        * We must not send if the packet is destined to network zero.
+        * RFC1122 3.2.1.3 (a) and (b).
+        */
+       if (IN_ZERONET(ntohl(pkt_dst.s_addr))) {
+               error = EHOSTUNREACH;
+               goto bad;
+       }
+
        /*
         * Fill in IP header.
         */
@@ -398,7 +487,7 @@ loopit:
 #else
                ip->ip_id = htons(ip_id++);
 #endif
-               OSAddAtomic(1, (SInt32*)&ipstat.ips_localout);
+               OSAddAtomic(1, &ipstat.ips_localout);
        } else {
                hlen = IP_VHL_HL(ip->ip_vhl) << 2;
        }
@@ -426,20 +515,27 @@ loopit:
         * cache with IPv6.
         */
 
-       lck_mtx_lock(rt_mtx);
        if (ro->ro_rt != NULL) {
                if (ro->ro_rt->generation_id != route_generation &&
                    ((flags & (IP_ROUTETOIF | IP_FORWARDING)) == 0) &&
-                   (ip->ip_src.s_addr != INADDR_ANY) &&
-                   (ifa_foraddr(ip->ip_src.s_addr) == 0)) {
-                       error = EADDRNOTAVAIL;
-                       lck_mtx_unlock(rt_mtx);
-                       goto bad;
+                   (ip->ip_src.s_addr != INADDR_ANY)) {
+                       src_ia = ifa_foraddr(ip->ip_src.s_addr);
+                       if (src_ia == NULL) {
+                               error = EADDRNOTAVAIL;
+                               goto bad;
+                       }
+                       IFA_REMREF(&src_ia->ia_ifa);
                }
+               /*
+                * Test rt_flags without holding rt_lock for performance
+                * reasons; if the route is down it will hopefully be
+                * caught by the layer below (since it uses this route
+                * as a hint) or during the next transmit.
+                */
                if ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
                    dst->sin_family != AF_INET ||
                    dst->sin_addr.s_addr != pkt_dst.s_addr) {
-                       rtfree_locked(ro->ro_rt);
+                       rtfree(ro->ro_rt);
                        ro->ro_rt = NULL;
                }
                /*
@@ -465,12 +561,11 @@ loopit:
 #define sintosa(sin)   ((struct sockaddr *)(sin))
        if (flags & IP_ROUTETOIF) {
                if (ia)
-                       ifafree(&ia->ia_ifa);
+                       IFA_REMREF(&ia->ia_ifa);
                if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0) {
                        if ((ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) {
-                               OSAddAtomic(1, (SInt32*)&ipstat.ips_noroute);
+                               OSAddAtomic(1, &ipstat.ips_noroute);
                                error = ENETUNREACH;
-                               lck_mtx_unlock(rt_mtx);
                                goto bad;
                        }
                }
@@ -478,24 +573,17 @@ loopit:
                ip->ip_ttl = 1;
                isbroadcast = in_broadcast(dst->sin_addr, ifp);
        } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) &&
-           imo != NULL && imo->imo_multicast_ifp != NULL) {
+           imo != NULL && (ifp = imo->imo_multicast_ifp) != NULL) {
                /*
                 * Bypass the normal routing lookup for multicast
                 * packets if the interface is specified.
                 */
-               ifp = imo->imo_multicast_ifp;
                isbroadcast = 0;
                if (ia != NULL)
-                       ifafree(&ia->ia_ifa);
-
-               /* Could use IFP_TO_IA instead but rt_mtx is already held */
-               for (ia = TAILQ_FIRST(&in_ifaddrhead);
-                   ia != NULL && ia->ia_ifp != ifp;
-                   ia = TAILQ_NEXT(ia, ia_link))
-                       continue;
+                       IFA_REMREF(&ia->ia_ifa);
 
-               if (ia != NULL)
-                       ifaref(&ia->ia_ifa);
+               /* Macro takes reference on ia */
+               IFP_TO_IA(ifp, ia);
        } else {
                boolean_t cloneok = FALSE;
                /*
@@ -507,7 +595,7 @@ loopit:
                 * route (for this PCB instance) before.
                 */
                if (select_srcif && ip->ip_src.s_addr != INADDR_ANY &&
-                   (ro->ro_rt == NULL ||
+                   (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP) ||
                    ro->ro_rt->generation_id != route_generation ||
                    !(ro->ro_flags & ROF_SRCIF_SELECTED))) {
                        struct ifaddr *ifa;
@@ -515,6 +603,18 @@ loopit:
                        /* Find the source interface */
                        ifa = in_selectsrcif(ip, ro, ifscope);
 
+                       /*
+                        * If the source address belongs to a cellular interface
+                        * and the caller forbids our using interfaces of such
+                        * type, pretend that there is no source address.
+                        */
+                       if (nocell && ifa != NULL &&
+                           ifa->ifa_ifp->if_type == IFT_CELLULAR) {
+                               IFA_REMREF(ifa);
+                               error = EADDRNOTAVAIL;
+                               goto bad;
+                       }
+
                        /*
                         * If the source address is spoofed (in the case
                         * of IP_RAWOUTPUT), or if this is destined for
@@ -525,7 +625,6 @@ loopit:
                        if (ifa == NULL && !(flags & IP_RAWOUTPUT) &&
                            ifscope != lo_ifp->if_index) {
                                error = EADDRNOTAVAIL;
-                               lck_mtx_unlock(rt_mtx);
                                goto bad;
                        }
 
@@ -546,7 +645,7 @@ loopit:
                        if (ifa != NULL) {
                                if (ifscope == IFSCOPE_NONE)
                                        ifscope = ifa->ifa_ifp->if_index;
-                               ifafree(ifa);
+                               IFA_REMREF(ifa);
                                cloneok = (!(flags & IP_RAWOUTPUT) &&
                                    !(IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))));
                        }
@@ -584,33 +683,72 @@ loopit:
                        if (cloneok || dst->sin_addr.s_addr == INADDR_BROADCAST)
                                ign &= ~RTF_PRCLONING;
 
-                       rtalloc_scoped_ign_locked(ro, ign, ifscope);
+                       /*
+                        * Loosen the route lookup criteria if the ifscope
+                        * corresponds to the loopback interface; this is
+                        * needed to support Application Layer Gateways
+                        * listening on loopback, in conjunction with packet
+                        * filter redirection rules.  The final source IP
+                        * address will be rewritten by the packet filter
+                        * prior to the RFC1122 loopback check below.
+                        */
+                       if (ifscope == lo_ifp->if_index)
+                               rtalloc_ign(ro, ign);
+                       else
+                               rtalloc_scoped_ign(ro, ign, ifscope);
+
+                       /*
+                        * If the route points to a cellular interface and the
+                        * caller forbids our using interfaces of such type,
+                        * pretend that there is no route.
+                        */
+                       if (nocell && ro->ro_rt != NULL) {
+                               RT_LOCK_SPIN(ro->ro_rt);
+                               if (ro->ro_rt->rt_ifp->if_type ==
+                                   IFT_CELLULAR) {
+                                       RT_UNLOCK(ro->ro_rt);
+                                       rtfree(ro->ro_rt);
+                                       ro->ro_rt = NULL;
+                               } else {
+                                       RT_UNLOCK(ro->ro_rt);
+                               }
+                       }
                }
 
                if (ro->ro_rt == NULL) {
-                       OSAddAtomic(1, (SInt32*)&ipstat.ips_noroute);
+                       OSAddAtomic(1, &ipstat.ips_noroute);
                        error = EHOSTUNREACH;
-                       lck_mtx_unlock(rt_mtx);
                        goto bad;
                }
 
                if (ia)
-                       ifafree(&ia->ia_ifa);
+                       IFA_REMREF(&ia->ia_ifa);
+               RT_LOCK_SPIN(ro->ro_rt);
                ia = ifatoia(ro->ro_rt->rt_ifa);
-               if (ia)
-                       ifaref(&ia->ia_ifa);
+               if (ia) {
+                       /* Become a regular mutex */
+                       RT_CONVERT_LOCK(ro->ro_rt);
+                       IFA_ADDREF(&ia->ia_ifa);
+               }
                ifp = ro->ro_rt->rt_ifp;
                ro->ro_rt->rt_use++;
                if (ro->ro_rt->rt_flags & RTF_GATEWAY)
                        dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
-               if (ro->ro_rt->rt_flags & RTF_HOST)
+               if (ro->ro_rt->rt_flags & RTF_HOST) {
                        isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
-               else
+               } else {
+                       /* Become a regular mutex */
+                       RT_CONVERT_LOCK(ro->ro_rt);
                        isbroadcast = in_broadcast(dst->sin_addr, ifp);
+               }
+               RT_UNLOCK(ro->ro_rt);
        }
-       lck_mtx_unlock(rt_mtx);
+
        if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
                struct in_multi *inm;
+               u_int32_t vif;
+               u_int8_t ttl = IP_DEFAULT_MULTICAST_TTL;
+               u_int8_t loop = IP_DEFAULT_MULTICAST_LOOP;
 
                m->m_flags |= M_MCAST;
                /*
@@ -623,24 +761,30 @@ loopit:
                 * See if the caller provided any multicast options
                 */
                if (imo != NULL) {
-                       if ((flags & IP_RAWOUTPUT) == 0) ip->ip_ttl = imo->imo_multicast_ttl;
-                       if (imo->imo_multicast_ifp != NULL) {
+                       IMO_LOCK(imo);
+                       vif = imo->imo_multicast_vif;
+                       ttl = imo->imo_multicast_ttl;
+                       loop = imo->imo_multicast_loop;
+                       if ((flags & IP_RAWOUTPUT) == 0)
+                               ip->ip_ttl = ttl;
+                       if (imo->imo_multicast_ifp != NULL)
                                ifp = imo->imo_multicast_ifp;
-                       }
+                       IMO_UNLOCK(imo);
 #if MROUTING
-                       if (imo->imo_multicast_vif != -1 && 
-                               ((flags & IP_RAWOUTPUT) == 0 || ip->ip_src.s_addr == INADDR_ANY))
-                               ip->ip_src.s_addr =
-                                       ip_mcast_src(imo->imo_multicast_vif);
+                       if (vif != -1 && ((flags & IP_RAWOUTPUT) == 0 ||
+                           ip->ip_src.s_addr == INADDR_ANY))
+                               ip->ip_src.s_addr = ip_mcast_src(vif);
 #endif /* MROUTING */
-               } else
-                       if ((flags & IP_RAWOUTPUT) == 0) ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
+               } else if ((flags & IP_RAWOUTPUT) == 0) {
+                       vif = -1;
+                       ip->ip_ttl = ttl;
+               }
                /*
                 * Confirm that the outgoing interface supports multicast.
                 */
-               if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
+               if (imo == NULL || vif == -1) {
                        if ((ifp->if_flags & IFF_MULTICAST) == 0) {
-                               OSAddAtomic(1, (SInt32*)&ipstat.ips_noroute);
+                               OSAddAtomic(1, &ipstat.ips_noroute);
                                error = ENETUNREACH;
                                goto bad;
                        }
@@ -650,26 +794,28 @@ loopit:
                 * of outgoing interface.
                 */
                if (ip->ip_src.s_addr == INADDR_ANY) {
-                       register struct in_ifaddr *ia1;
-                       lck_mtx_lock(rt_mtx);   
-                       TAILQ_FOREACH(ia1, &in_ifaddrhead, ia_link)
+                       struct in_ifaddr *ia1;
+                       lck_rw_lock_shared(in_ifaddr_rwlock);
+                       TAILQ_FOREACH(ia1, &in_ifaddrhead, ia_link) {
+                               IFA_LOCK_SPIN(&ia1->ia_ifa);
                                if (ia1->ia_ifp == ifp) {
                                        ip->ip_src = IA_SIN(ia1)->sin_addr;
-                                       
+                                       IFA_UNLOCK(&ia1->ia_ifa);
                                        break;
                                }
-                       lck_mtx_unlock(rt_mtx); 
+                               IFA_UNLOCK(&ia1->ia_ifa);
+                       }
+                       lck_rw_done(in_ifaddr_rwlock);
                        if (ip->ip_src.s_addr == INADDR_ANY) {
                                error = ENETUNREACH;
                                goto bad;
                        }
                }
 
-               ifnet_lock_shared(ifp);
-               IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
-               ifnet_lock_done(ifp);
-               if (inm != NULL &&
-                  (imo == NULL || imo->imo_multicast_loop)) {
+               in_multihead_lock_shared();
+               IN_LOOKUP_MULTI(&pkt_dst, ifp, inm);
+               in_multihead_lock_done();
+               if (inm != NULL && (imo == NULL || loop)) {
                        /*
                         * If we belong to the destination multicast group
                         * on the outgoing interface, and the caller did not
@@ -678,21 +824,23 @@ loopit:
                        if (!TAILQ_EMPTY(&ipv4_filters)) {
                                struct ipfilter *filter;
                                int seen = (inject_filter_ref == 0);
-                               struct ipf_pktopts *ippo = 0, ipf_pktopts;
 
-                               if (imo) {                                              
-                                       ippo = &ipf_pktopts;
-                                       ipf_pktopts.ippo_mcast_ifnet = imo->imo_multicast_ifp;
-                                       ipf_pktopts.ippo_mcast_ttl = imo->imo_multicast_ttl;
-                                       ipf_pktopts.ippo_mcast_loop = imo->imo_multicast_loop;
+                               if (imo != NULL) {
+                                       ipf_pktopts.ippo_flags |= IPPOF_MCAST_OPTS;
+                                       ipf_pktopts.ippo_mcast_ifnet = ifp;
+                                       ipf_pktopts.ippo_mcast_ttl = ttl;
+                                       ipf_pktopts.ippo_mcast_loop = loop;
                                }
-                               
+
                                ipf_ref();
-                               
+
                                /* 4135317 - always pass network byte order to filter */
+
+#if BYTE_ORDER != BIG_ENDIAN
                                HTONS(ip->ip_len);
                                HTONS(ip->ip_off);
-                               
+#endif
+
                                TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) {
                                        if (seen == 0) {
                                                if ((struct ipfilter *)inject_filter_ref == filter)
@@ -702,20 +850,25 @@ loopit:
                                                result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo);
                                                if (result == EJUSTRETURN) {
                                                        ipf_unref();
+                                                       INM_REMREF(inm);
                                                        goto done;
                                                }
                                                if (result != 0) {
                                                        ipf_unref();
+                                                       INM_REMREF(inm);
                                                        goto bad;
                                                }
                                        }
                                }
-                               
+
                                /* set back to host byte order */
                                ip = mtod(m, struct ip *);
+
+#if BYTE_ORDER != BIG_ENDIAN
                                NTOHS(ip->ip_len);
                                NTOHS(ip->ip_off);
-                               
+#endif
+
                                ipf_unref();
                                didfilter = 1;
                        }
@@ -743,15 +896,18 @@ loopit:
                                 * as prescribed by rsvpd.
                                 */
                                if (!rsvp_on)
-                                 imo = NULL;
+                                       imo = NULL;
                                if (ip_mforward(ip, ifp, m, imo) != 0) {
                                        m_freem(m);
+                                       if (inm != NULL)
+                                               INM_REMREF(inm);
                                        goto done;
                                }
                        }
                }
 #endif /* MROUTING */
-
+               if (inm != NULL)
+                       INM_REMREF(inm);
                /*
                 * Multicasts with a time-to-live of zero may be looped-
                 * back, above, but must not be transmitted on a network.
@@ -773,7 +929,9 @@ loopit:
         * of outgoing interface.
         */
        if (ip->ip_src.s_addr == INADDR_ANY) {
+               IFA_LOCK_SPIN(&ia->ia_ifa);
                ip->ip_src = IA_SIN(ia)->sin_addr;
+               IFA_UNLOCK(&ia->ia_ifa);
 #if IPFIREWALL_FORWARD
                /* Keep note that we did this - if the firewall changes
                 * the next-hop, our interface may change, changing the
@@ -810,6 +968,33 @@ loopit:
        }
 
 sendit:
+#if PF
+       /* Invoke outbound packet filter */
+       if ( PF_IS_ENABLED) {
+               int rc;
+               rc = pf_af_hook(ifp, mppn, &m, AF_INET, FALSE);
+               if (rc != 0) {
+                       if (packetlist == m0) {
+                               packetlist = m;
+                               mppn = NULL;
+                       }
+                       if (m != NULL) {
+                               m0 = m;
+                               /* Next packet in the chain */
+                               goto loopit;
+                       } else if (packetlist != NULL) {
+                               /* No more packet; send down the chain */
+                               goto sendchain;
+                       }
+                       /* Nothing left; we're done */
+                       goto done;
+               }
+               m0 = m;
+               ip = mtod(m, struct ip *);
+               pkt_dst = ip->ip_dst;
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+       }
+#endif /* PF */
         /*
          * Force IP TTL to 255 following draft-ietf-zeroconf-ipv4-linklocal.txt
          */
@@ -824,20 +1009,33 @@ sendit:
        if (!didfilter && !TAILQ_EMPTY(&ipv4_filters)) {
                struct ipfilter *filter;
                int seen = (inject_filter_ref == 0);
-               
+               ipf_pktopts.ippo_flags &= ~IPPOF_MCAST_OPTS;
+
+               /* Check that a TSO frame isn't passed to a filter.
+                * This could happen if a filter is inserted while
+                * TCP is sending the TSO packet.
+                */
+               if (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) {
+                       error = EMSGSIZE;
+                       goto bad;
+               }
+
                ipf_ref();
                
                /* 4135317 - always pass network byte order to filter */
+
+#if BYTE_ORDER != BIG_ENDIAN
                HTONS(ip->ip_len);
                HTONS(ip->ip_off);
-               
+#endif
+
                TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) {
                        if (seen == 0) {
                                if ((struct ipfilter *)inject_filter_ref == filter)
                                        seen = 1;
                        } else if (filter->ipf_filter.ipf_output) {
                                errno_t result;
-                               result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, 0);
+                               result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo);
                                if (result == EJUSTRETURN) {
                                        ipf_unref();
                                        goto done;
@@ -851,9 +1049,12 @@ sendit:
                
                /* set back to host byte order */
                ip = mtod(m, struct ip *);
+
+#if BYTE_ORDER != BIG_ENDIAN
                NTOHS(ip->ip_len);
                NTOHS(ip->ip_off);
-               
+#endif
+
                ipf_unref();
        }
 
@@ -932,8 +1133,15 @@ sendit:
                m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
        }
 
+
+#if BYTE_ORDER != BIG_ENDIAN
        HTONS(ip->ip_len);
        HTONS(ip->ip_off);
+#endif
+
+       DTRACE_IP6(send, struct mbuf *, m, struct inpcb *, NULL,
+               struct ip *, ip, struct ifnet *, ifp,
+               struct ip *, ip, struct ip6_hdr *, NULL);
 
        error = ipsec4_output(&state, sp, flags);
     
@@ -984,57 +1192,80 @@ sendit:
        hlen = ip->ip_hl << 2;
 #endif
        /* Check that there wasn't a route change and src is still valid */
-
-       lck_mtx_lock(rt_mtx);
-       if (ro->ro_rt && ro->ro_rt->generation_id != route_generation) {
-               if (ifa_foraddr(ip->ip_src.s_addr) == 0 && ((flags & (IP_ROUTETOIF | IP_FORWARDING)) == 0)) {
-                       error = EADDRNOTAVAIL;
-                       lck_mtx_unlock(rt_mtx);
-                       KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 5,0,0,0,0);
+       if (ro->ro_rt != NULL && ro->ro_rt->generation_id != route_generation) {
+               if ((src_ia = ifa_foraddr(ip->ip_src.s_addr)) == NULL &&
+                   ((flags & (IP_ROUTETOIF | IP_FORWARDING)) == 0)) {
+                       error = EADDRNOTAVAIL;
+                       KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END,
+                           5,0,0,0,0);
                        goto bad;
                }
-               rtfree_locked(ro->ro_rt);
+               rtfree(ro->ro_rt);
                ro->ro_rt = NULL;
+               if (src_ia != NULL)
+                       IFA_REMREF(&src_ia->ia_ifa);
        }
 
        if (ro->ro_rt == NULL) {
                if ((flags & IP_ROUTETOIF) == 0) {
-                       printf("ip_output: "
-                               "can't update route after IPsec processing\n");
-                       error = EHOSTUNREACH;   /*XXX*/ 
-                       lck_mtx_unlock(rt_mtx);
-                       KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 6,0,0,0,0);
+                       printf("ip_output: can't update route after "
+                           "IPsec processing\n");
+                       error = EHOSTUNREACH;   /*XXX*/
+                       KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END,
+                           6,0,0,0,0);
                        goto bad;
                }
        } else {
                if (ia)
-                       ifafree(&ia->ia_ifa);
+                       IFA_REMREF(&ia->ia_ifa);
+               RT_LOCK_SPIN(ro->ro_rt);
                ia = ifatoia(ro->ro_rt->rt_ifa);
-               if (ia)
-                       ifaref(&ia->ia_ifa);
+               if (ia) {
+                       /* Become a regular mutex */
+                       RT_CONVERT_LOCK(ro->ro_rt);
+                       IFA_ADDREF(&ia->ia_ifa);
+               }
                ifp = ro->ro_rt->rt_ifp;
+               RT_UNLOCK(ro->ro_rt);
        }
-       lck_mtx_unlock(rt_mtx);
 
        /* make it flipped, again. */
+
+#if BYTE_ORDER != BIG_ENDIAN
        NTOHS(ip->ip_len);
        NTOHS(ip->ip_off);
+#endif
+       
        KERNEL_DEBUG(DBG_FNC_IPSEC4_OUTPUT | DBG_FUNC_END, 7,0xff,0xff,0xff,0xff);
        
        /* Pass to filters again */
        if (!TAILQ_EMPTY(&ipv4_filters)) {
                struct ipfilter *filter;
                
+               ipf_pktopts.ippo_flags &= ~IPPOF_MCAST_OPTS;
+
+               /* Check that a TSO frame isn't passed to a filter.
+                * This could happen if a filter is inserted while
+                * TCP is sending the TSO packet.
+                */
+               if (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) {
+                       error = EMSGSIZE;
+                       goto bad;
+               }
+
                ipf_ref();
                
                /* 4135317 - always pass network byte order to filter */
+
+#if BYTE_ORDER != BIG_ENDIAN
                HTONS(ip->ip_len);
                HTONS(ip->ip_off);
-               
+#endif
+
                TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) {
                        if (filter->ipf_filter.ipf_output) {
                                errno_t result;
-                               result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, 0);
+                               result = filter->ipf_filter.ipf_output(filter->ipf_filter.cookie, (mbuf_t*)&m, ippo);
                                if (result == EJUSTRETURN) {
                                        ipf_unref();
                                        goto done;
@@ -1048,9 +1279,12 @@ sendit:
                
                /* set back to host byte order */
                ip = mtod(m, struct ip *);
+
+#if BYTE_ORDER != BIG_ENDIAN
                NTOHS(ip->ip_len);
                NTOHS(ip->ip_off);
-               
+#endif
+
                ipf_unref();
        }
 skip_ipsec:
@@ -1153,8 +1387,11 @@ skip_ipsec:
                        }
 
                        /* Restore packet header fields to original values */
+
+#if BYTE_ORDER != BIG_ENDIAN
                        HTONS(ip->ip_len);
                        HTONS(ip->ip_off);
+#endif
 
                        /* Deliver packet to divert input routine */
                        divert_packet(m, 0, off & 0xffff, args.divert_rule);
@@ -1203,35 +1440,42 @@ skip_ipsec:
                         * as the packet runs through ip_input() as
                         * it is done through a ISR.
                         */
+                       lck_rw_lock_shared(in_ifaddr_rwlock);
                        TAILQ_FOREACH(ia_fw, &in_ifaddrhead, ia_link) {
                                /*
                                 * If the addr to forward to is one
                                 * of ours, we pretend to
                                 * be the destination for this packet.
                                 */
+                               IFA_LOCK_SPIN(&ia_fw->ia_ifa);
                                if (IA_SIN(ia_fw)->sin_addr.s_addr ==
-                                                dst->sin_addr.s_addr)
+                                   dst->sin_addr.s_addr) {
+                                       IFA_UNLOCK(&ia_fw->ia_ifa);
                                        break;
+                               }
+                               IFA_UNLOCK(&ia_fw->ia_ifa);
                        }
-                       if (ia) {
+                       lck_rw_done(in_ifaddr_rwlock);
+                       if (ia_fw) {
                                /* tell ip_input "dont filter" */
                                struct m_tag            *fwd_tag;
                                struct ip_fwd_tag       *ipfwd_tag;
-                               
-                               fwd_tag = m_tag_alloc(KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD,
-                                               sizeof(struct sockaddr_in), M_NOWAIT);
+
+                               fwd_tag = m_tag_create(KERNEL_MODULE_TAG_ID,
+                                   KERNEL_TAG_TYPE_IPFORWARD,
+                                   sizeof (*ipfwd_tag), M_NOWAIT, m);
                                if (fwd_tag == NULL) {
                                        error = ENOBUFS;
                                        goto bad;
                                }
-                               
+
                                ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1);
                                ipfwd_tag->next_hop = args.next_hop;
 
                                m_tag_prepend(m, fwd_tag);
 
                                if (m->m_pkthdr.rcvif == NULL)
-                                       m->m_pkthdr.rcvif = ifunit("lo0");
+                                       m->m_pkthdr.rcvif = lo_ifp;
                                if ((~IF_HWASSIST_CSUM_FLAGS(m->m_pkthdr.rcvif->if_hwassist) & 
                                                m->m_pkthdr.csum_flags) == 0) {
                                        if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
@@ -1248,9 +1492,11 @@ skip_ipsec:
                                        m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
                                        ip->ip_sum = in_cksum(m, hlen);
                                }
+
+#if BYTE_ORDER != BIG_ENDIAN
                                HTONS(ip->ip_len);
                                HTONS(ip->ip_off);
-                               
+#endif                         
                                
                                /*  we need to call dlil_output to run filters
                                 *      and resync to avoid recursion loops.
@@ -1271,39 +1517,52 @@ skip_ipsec:
                         */
                        bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst));
 
-                       ro_fwd->ro_rt = 0;
-                       lck_mtx_lock(rt_mtx);
-                       rtalloc_ign_locked(ro_fwd, RTF_PRCLONING);
+                       ro_fwd->ro_rt = NULL;
+                       rtalloc_ign(ro_fwd, RTF_PRCLONING);
 
-                       if (ro_fwd->ro_rt == 0) {
-                               OSAddAtomic(1, (SInt32*)&ipstat.ips_noroute);
+                       if (ro_fwd->ro_rt == NULL) {
+                               OSAddAtomic(1, &ipstat.ips_noroute);
                                error = EHOSTUNREACH;
-                               lck_mtx_unlock(rt_mtx);
                                goto bad;
                        }
 
+                       RT_LOCK_SPIN(ro_fwd->ro_rt);
                        ia_fw = ifatoia(ro_fwd->ro_rt->rt_ifa);
+                       if (ia_fw != NULL) {
+                               /* Become a regular mutex */
+                               RT_CONVERT_LOCK(ro_fwd->ro_rt);
+                               IFA_ADDREF(&ia_fw->ia_ifa);
+                       }
                        ifp = ro_fwd->ro_rt->rt_ifp;
                        ro_fwd->ro_rt->rt_use++;
                        if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
                                dst = (struct sockaddr_in *)ro_fwd->ro_rt->rt_gateway;
-                       if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
+                       if (ro_fwd->ro_rt->rt_flags & RTF_HOST) {
                                isbroadcast =
                                    (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
-                       else
+                       } else {
+                               /* Become a regular mutex */
+                               RT_CONVERT_LOCK(ro_fwd->ro_rt);
                                isbroadcast = in_broadcast(dst->sin_addr, ifp);
-                       rtfree_locked(ro->ro_rt);
+                       }
+                       RT_UNLOCK(ro_fwd->ro_rt);
+                       rtfree(ro->ro_rt);
                        ro->ro_rt = ro_fwd->ro_rt;
                        dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
-                       lck_mtx_unlock(rt_mtx);
 
                        /*
                         * If we added a default src ip earlier,
                         * which would have been gotten from the-then
                         * interface, do it again, from the new one.
                         */
-                       if (fwd_rewrite_src)
-                               ip->ip_src = IA_SIN(ia_fw)->sin_addr;
+                       if (ia_fw != NULL) {
+                               if (fwd_rewrite_src) {
+                                       IFA_LOCK_SPIN(&ia_fw->ia_ifa);
+                                       ip->ip_src = IA_SIN(ia_fw)->sin_addr;
+                                       IFA_UNLOCK(&ia_fw->ia_ifa);
+                               }
+                               IFA_REMREF(&ia_fw->ia_ifa);
+                       }
                        goto pass ;
                }
 #endif /* IPFIREWALL_FORWARD */
@@ -1315,15 +1574,15 @@ skip_ipsec:
                error = EACCES; /* not sure this is the right error msg */
                goto done;
        }
-#endif /* IPFIREWALL */
 
 pass:
+#endif /* IPFIREWALL */
 #if __APPLE__
        /* Do not allow loopback address to wind up on a wire */
        if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
                 ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
                  (ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)) {
-               OSAddAtomic(1, (SInt32*)&ipstat.ips_badaddr);
+               OSAddAtomic(1, &ipstat.ips_badaddr);
                m_freem(m);
                /* 
                 * Do not simply drop the packet just like a firewall -- we want the 
@@ -1337,6 +1596,8 @@ pass:
        }
 #endif
        m->m_pkthdr.csum_flags |= CSUM_IP;
+       tso =  (ifp->if_hwassist & IFNET_TSO_IPV4) && (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4);
+                    
        sw_csum = m->m_pkthdr.csum_flags 
                & ~IF_HWASSIST_CSUM_FLAGS(ifp->if_hwassist);
 
@@ -1382,12 +1643,17 @@ pass:
         * If small enough for interface, or the interface will take
         * care of the fragmentation for us, can just send directly.
         */
-       if ((u_short)ip->ip_len <= ifp->if_mtu ||
+       if ((u_short)ip->ip_len <= ifp->if_mtu || tso ||
            ifp->if_hwassist & CSUM_FRAGMENT) {
-               struct rtentry *rte;
+               if (tso) 
+                       m->m_pkthdr.csum_flags |= CSUM_TSO_IPV4;
+                       
 
+#if BYTE_ORDER != BIG_ENDIAN
                HTONS(ip->ip_len);
                HTONS(ip->ip_off);
+#endif
+               
                ip->ip_sum = 0;
                if (sw_csum & CSUM_DELAY_IP) {
                        ip->ip_sum = in_cksum(m, hlen);
@@ -1407,31 +1673,29 @@ pass:
                        ipsec_delaux(m);
 #endif
                if (packetchain == 0) {
-                       lck_mtx_lock(rt_mtx);
-                       if ((rte = ro->ro_rt) != NULL)
-                               rtref(rte);
-                       lck_mtx_unlock(rt_mtx);
-                       error = ifnet_output(ifp, PF_INET, m, rte,
+                       if (ro->ro_rt && nstat_collect)
+                               nstat_route_tx(ro->ro_rt, 1, m->m_pkthdr.len, 0);
+                       error = ifnet_output(ifp, PF_INET, m, ro->ro_rt,
                            (struct sockaddr *)dst);
-                       if (rte != NULL)
-                               rtfree(rte);
                        goto done;
                }
                else { /* packet chaining allows us to reuse the route for all packets */
+                       bytecnt += m->m_pkthdr.len;
+                       mppn = &m->m_nextpkt;
                        m = m->m_nextpkt;
                        if (m == NULL) {
+#if PF
+sendchain:
+#endif /* PF */
                                if (pktcnt > ip_maxchainsent)
                                        ip_maxchainsent = pktcnt;
-                               lck_mtx_lock(rt_mtx);
-                               if ((rte = ro->ro_rt) != NULL)
-                                       rtref(rte);
-                               lck_mtx_unlock(rt_mtx);
+                               if (ro->ro_rt && nstat_collect)
+                                       nstat_route_tx(ro->ro_rt, pktcnt, bytecnt, 0);
                                //send
                                error = ifnet_output(ifp, PF_INET, packetlist,
-                                   rte, (struct sockaddr *)dst);
-                               if (rte != NULL)
-                                       rtfree(rte);
+                                   ro->ro_rt, (struct sockaddr *)dst);
                                pktcnt = 0;
+                               bytecnt = 0;
                                goto done;
        
                        }
@@ -1444,7 +1708,9 @@ pass:
         * Too large for interface; fragment if possible.
         * Must be able to put at least 8 bytes per fragment.
         */
-       if (ip->ip_off & IP_DF) {
+
+       if (ip->ip_off & IP_DF  || (m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) ||
+               pktcnt > 0) {
                error = EMSGSIZE;
                /*
                 * This case can happen if the user changed the MTU
@@ -1453,23 +1719,107 @@ pass:
                 * them, there is no way for one to update all its
                 * routes when the MTU is changed.
                 */
-               
-               lck_mtx_lock(rt_mtx);
-               if (ro->ro_rt && (ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST))
-                   && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU)
-                   && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
-                       ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
-               }
-               lck_mtx_unlock(rt_mtx);
-               OSAddAtomic(1, (SInt32*)&ipstat.ips_cantfrag);
+               if (ro->ro_rt) {
+                       RT_LOCK_SPIN(ro->ro_rt);
+                       if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST))
+                           && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU)
+                           && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
+                               ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
+                       }
+                       RT_UNLOCK(ro->ro_rt);
+               }
+               if (pktcnt > 0) {
+                       m0 = packetlist;
+               }
+               OSAddAtomic(1, &ipstat.ips_cantfrag);
                goto bad;
        }
-       len = (ifp->if_mtu - hlen) &~ 7;
-       if (len < 8) {
-               error = EMSGSIZE;
+
+       error = ip_fragment(m, ifp, ifp->if_mtu, sw_csum);
+       if (error != 0) {
+               m0 = m = NULL;
                goto bad;
        }
 
+       KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, 
+                    ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
+
+       for (m = m0; m; m = m0) {
+               m0 = m->m_nextpkt;
+               m->m_nextpkt = 0;
+#if IPSEC
+               /* clean ipsec history once it goes out of the node */
+               if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0)
+                       ipsec_delaux(m);
+#endif
+               if (error == 0) {
+#ifndef __APPLE__
+                       /* Record statistics for this interface address. */
+                       if (ia != NULL) {
+                               ia->ia_ifa.if_opackets++;
+                               ia->ia_ifa.if_obytes += m->m_pkthdr.len;
+                       }
+#endif
+                       if ((packetchain != 0)  && (pktcnt > 0))
+                               panic("ip_output: mix of packet in packetlist is wrong=%p", packetlist);
+                       if (ro->ro_rt && nstat_collect)
+                               nstat_route_tx(ro->ro_rt, 1, m->m_pkthdr.len, 0);
+                       error = ifnet_output(ifp, PF_INET, m, ro->ro_rt,
+                           (struct sockaddr *)dst);
+               } else
+                       m_freem(m);
+       }
+
+       if (error == 0)
+               OSAddAtomic(1, &ipstat.ips_fragmented);
+
+done:
+       if (ia) {
+               IFA_REMREF(&ia->ia_ifa);
+               ia = NULL;
+       }
+#if IPSEC
+       if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) {
+       if (ro == &iproute && ro->ro_rt) {
+               rtfree(ro->ro_rt);
+               ro->ro_rt = NULL;
+       }
+       if (sp != NULL) {
+               KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
+                       printf("DP ip_output call free SP:%x\n", sp));
+               key_freesp(sp, KEY_SADB_UNLOCKED);
+       }
+       }
+#endif /* IPSEC */
+
+       KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_END, error,0,0,0,0);
+       return (error);
+bad:
+       m_freem(m0);
+       goto done;
+}
+
+int
+ip_fragment(struct mbuf *m, struct ifnet *ifp, unsigned long mtu, int sw_csum)
+{
+       struct ip *ip, *mhip;
+       int len, hlen, mhlen, firstlen, off, error = 0;
+       struct mbuf **mnext = &m->m_nextpkt, *m0;
+       int nfrags = 1;
+
+       ip = mtod(m, struct ip *);
+#ifdef _IP_VHL
+       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+#else
+       hlen = ip->ip_hl << 2;
+#endif
+
+       firstlen = len = (mtu - hlen) &~ 7;
+       if (len < 8) {
+               m_freem(m);
+               return (EMSGSIZE);
+       }
+
        /*
         * if the interface will not calculate checksums on
         * fragmented packets, then do it here.
@@ -1480,12 +1830,6 @@ pass:
                m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
        }
 
-
-    {
-       int mhlen, firstlen = len;
-       struct mbuf **mnext = &m->m_nextpkt;
-       int nfrags = 1;
-
        /*
         * Loop through length of segment after first fragment,
         * make new header and copy data of each part and link onto chain.
@@ -1496,7 +1840,7 @@ pass:
                MGETHDR(m, M_DONTWAIT, MT_HEADER);      /* MAC-OK */
                if (m == 0) {
                        error = ENOBUFS;
-                       OSAddAtomic(1, (SInt32*)&ipstat.ips_odropped);
+                       OSAddAtomic(1, &ipstat.ips_odropped);
                        goto sendorfree;
                }
                m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
@@ -1520,7 +1864,7 @@ pass:
                if (m->m_next == 0) {
                        (void) m_free(m);
                        error = ENOBUFS;        /* ??? */
-                       OSAddAtomic(1, (SInt32*)&ipstat.ips_odropped);
+                       OSAddAtomic(1, &ipstat.ips_odropped);
                        goto sendorfree;
                }
                m->m_pkthdr.len = mhlen + len;
@@ -1530,7 +1874,11 @@ pass:
 #if CONFIG_MACF_NET
                mac_netinet_fragment(m0, m);
 #endif
+
+#if BYTE_ORDER != BIG_ENDIAN
                HTONS(mhip->ip_off);
+#endif
+
                mhip->ip_sum = 0;
                if (sw_csum & CSUM_DELAY_IP) {
                        mhip->ip_sum = in_cksum(m, mhlen);
@@ -1539,7 +1887,7 @@ pass:
                mnext = &m->m_nextpkt;
                nfrags++;
        }
-       OSAddAtomic(nfrags, (SInt32*)&ipstat.ips_ofragments);
+       OSAddAtomic(nfrags, &ipstat.ips_ofragments);
 
        /* set first/last markers for fragment chain */
        m->m_flags |= M_LASTFRAG;
@@ -1555,74 +1903,20 @@ pass:
        m->m_pkthdr.len = hlen + firstlen;
        ip->ip_len = htons((u_short)m->m_pkthdr.len);
        ip->ip_off |= IP_MF;
+
+#if BYTE_ORDER != BIG_ENDIAN
        HTONS(ip->ip_off);
+#endif
+       
        ip->ip_sum = 0;
        if (sw_csum & CSUM_DELAY_IP) {
                ip->ip_sum = in_cksum(m, hlen);
        }
 sendorfree:
+       if (error)
+               m_freem_list(m0);
 
-       KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, 
-                    ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
-
-       for (m = m0; m; m = m0) {
-               m0 = m->m_nextpkt;
-               m->m_nextpkt = 0;
-#if IPSEC
-               /* clean ipsec history once it goes out of the node */
-               if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0)
-                       ipsec_delaux(m);
-#endif
-               if (error == 0) {
-                       struct rtentry *rte;
-#ifndef __APPLE__
-                       /* Record statistics for this interface address. */
-                       if (ia != NULL) {
-                               ia->ia_ifa.if_opackets++;
-                               ia->ia_ifa.if_obytes += m->m_pkthdr.len;
-                       }
-#endif
-                       if ((packetchain != 0)  && (pktcnt > 0))
-                               panic("ip_output: mix of packet in packetlist is wrong=%p", packetlist);
-                       lck_mtx_lock(rt_mtx);
-                       if ((rte = ro->ro_rt) != NULL)
-                               rtref(rte);
-                       lck_mtx_unlock(rt_mtx);
-                       error = ifnet_output(ifp, PF_INET, m, rte,
-                           (struct sockaddr *)dst);
-                       if (rte != NULL)
-                               rtfree(rte);
-               } else
-                       m_freem(m);
-       }
-
-       if (error == 0)
-               OSAddAtomic(1, (SInt32*)&ipstat.ips_fragmented);
-    }
-done:
-       if (ia) {
-               ifafree(&ia->ia_ifa);
-               ia = NULL;
-       }
-#if IPSEC
-       if (ipsec_bypass == 0 && (flags & IP_NOIPSEC) == 0) {
-       if (ro == &iproute && ro->ro_rt) {
-               rtfree(ro->ro_rt);
-               ro->ro_rt = NULL;
-       }
-       if (sp != NULL) {
-               KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
-                       printf("DP ip_output call free SP:%x\n", sp));
-               key_freesp(sp, KEY_SADB_UNLOCKED);
-       }
-       }
-#endif /* IPSEC */
-
-       KERNEL_DEBUG(DBG_FNC_IP_OUTPUT | DBG_FUNC_END, error,0,0,0,0);
        return (error);
-bad:
-       m_freem(m0);
-       goto done;
 }
 
 static void
@@ -1647,8 +1941,11 @@ in_delayed_cksum_offset(struct mbuf *m0, int ip_offset)
        struct ip *ip;
        unsigned char buf[sizeof(struct ip)];
        u_short csum, offset, ip_len;
-       struct mbuf *m = m0;
-       
+
+        /* Save copy of first mbuf pointer and the ip_offset before modifying */
+        struct mbuf *m = m0;
+        int ip_offset_copy = ip_offset;
+
        while (ip_offset >= m->m_len) {
                ip_offset -= m->m_len;
                m = m->m_next;
@@ -1661,7 +1958,7 @@ in_delayed_cksum_offset(struct mbuf *m0, int ip_offset)
        /* Sometimes the IP header is not contiguous, yes this can happen! */
        if (ip_offset + sizeof(struct ip) > m->m_len) {
 #if DEBUG              
-               printf("delayed m_pullup, m->len: %ld  off: %d\n",
+               printf("delayed m_pullup, m->len: %d  off: %d\n",
                        m->m_len, ip_offset);
 #endif
                m_copydata(m, ip_offset, sizeof(struct ip), (caddr_t) buf);
@@ -1689,12 +1986,12 @@ in_delayed_cksum_offset(struct mbuf *m0, int ip_offset)
         * is bogus and we give up.
         */
        ip_len = ip->ip_len;
-       if (ip_len != (m0->m_pkthdr.len - ip_offset)) {
+       if (ip_len != (m0->m_pkthdr.len - ip_offset_copy)) {
                ip_len = SWAP16(ip_len);
-               if (ip_len != (m0->m_pkthdr.len - ip_offset)) {
+               if (ip_len != (m0->m_pkthdr.len - ip_offset_copy)) {
                        printf("in_delayed_cksum_offset: ip_len %d (%d) "
                            "doesn't match actual length %d\n", ip->ip_len,
-                           ip_len, (m0->m_pkthdr.len - ip_offset));
+                           ip_len, (m0->m_pkthdr.len - ip_offset_copy));
                        return;
                }
        }
@@ -1724,7 +2021,7 @@ in_delayed_cksum_offset(struct mbuf *m0, int ip_offset)
                char tmp[2];
                
 #if DEBUG
-               printf("delayed m_copyback, m->len: %ld  off: %d  p: %d\n",
+               printf("delayed m_copyback, m->len: %d  off: %d  p: %d\n",
                    m->m_len, offset + ip_offset, ip->ip_p);
 #endif
                *(u_short *)tmp = csum;
@@ -1746,6 +2043,10 @@ in_cksum_offset(struct mbuf* m, size_t ip_offset)
        int hlen = 0;
        unsigned char buf[sizeof(struct ip)];
        int swapped = 0;
+
+        /* Save copy of first mbuf pointer and the ip_offset before modifying */
+        struct mbuf* m0 = m;
+        size_t ip_offset_copy = ip_offset;
        
        while (ip_offset >= m->m_len) {
                ip_offset -= m->m_len;
@@ -1760,7 +2061,7 @@ in_cksum_offset(struct mbuf* m, size_t ip_offset)
        if (ip_offset + sizeof(struct ip) > m->m_len) {
 
 #if DEBUG
-               printf("in_cksum_offset - delayed m_pullup, m->len: %ld  off: %lu\n",
+               printf("in_cksum_offset - delayed m_pullup, m->len: %d  off: %lu\n",
                        m->m_len, ip_offset);
 #endif 
                m_copydata(m, ip_offset, sizeof(struct ip), (caddr_t) buf);
@@ -1793,15 +2094,15 @@ in_cksum_offset(struct mbuf* m, size_t ip_offset)
         * the length and check again.  If it still fails, then the packet
         * is bogus and we give up.
         */
-       if (ntohs(ip->ip_len) != (m->m_pkthdr.len - ip_offset)) {
+       if (ntohs(ip->ip_len) != (m0->m_pkthdr.len - ip_offset_copy)) {
                ip->ip_len = SWAP16(ip->ip_len);
                swapped = 1;
-               if (ntohs(ip->ip_len) != (m->m_pkthdr.len - ip_offset)) {
+               if (ntohs(ip->ip_len) != (m0->m_pkthdr.len - ip_offset_copy)) {
                        ip->ip_len = SWAP16(ip->ip_len);
                        printf("in_cksum_offset: ip_len %d (%d) "
                            "doesn't match actual length %lu\n",
                            ip->ip_len, SWAP16(ip->ip_len),
-                           (m->m_pkthdr.len - ip_offset));
+                           (m0->m_pkthdr.len - ip_offset_copy));
                        return;
                }
        }
@@ -1824,7 +2125,7 @@ in_cksum_offset(struct mbuf* m, size_t ip_offset)
                char tmp[2];
 
 #if DEBUG
-               printf("in_cksum_offset m_copyback, m->len: %lu  off: %lu  p: %d\n",
+               printf("in_cksum_offset m_copyback, m->len: %u  off: %lu  p: %d\n",
                    m->m_len, ip_offset + offsetof(struct ip, ip_sum), ip->ip_p);
 #endif
                *(u_short *)tmp = ip->ip_sum;
@@ -1960,7 +2261,8 @@ ip_ctloutput(so, sopt)
                                error = EMSGSIZE;
                                break;
                        }
-                       MGET(m, sopt->sopt_p ? M_WAIT : M_DONTWAIT, MT_HEADER);
+                       MGET(m, sopt->sopt_p != kernproc ? M_WAIT : M_DONTWAIT,
+                           MT_HEADER);
                        if (m == 0) {
                                error = ENOBUFS;
                                break;
@@ -1985,6 +2287,7 @@ ip_ctloutput(so, sopt)
 #if defined(NFAITH) && NFAITH > 0
                case IP_FAITH:
 #endif
+               case IP_RECVPKTINFO:
                        error = sooptcopyin(sopt, &optval, sizeof optval,
                                            sizeof optval);
                        if (error)
@@ -2029,6 +2332,9 @@ ip_ctloutput(so, sopt)
                                OPTSET(INP_FAITH);
                                break;
 #endif
+                       case IP_RECVPKTINFO:
+                               OPTSET(INP_PKTINFO);
+                               break;
                        }
                        break;
 #undef OPTSET
@@ -2065,14 +2371,14 @@ ip_ctloutput(so, sopt)
                                        break;
                        }
 
-                       if (sopt->sopt_valsize == 0 || ifname[0] == NULL) {
+                       if (sopt->sopt_valsize == 0 || ifname[0] == '\0') {
                                /* Unbind this socket from any interface */
                                ifscope = IFSCOPE_NONE;
                        } else {
                                ifnet_t ifp;
 
                                /* Verify name is NULL terminated */
-                               if (ifname[sopt->sopt_valsize - 1] != NULL) {
+                               if (ifname[sopt->sopt_valsize - 1] != '\0') {
                                        error = EINVAL;
                                        break;
                                }
@@ -2092,17 +2398,33 @@ ip_ctloutput(so, sopt)
                                 */
                                ifnet_release(ifp);
                        }
-                       ip_bindif(inp, ifscope);
+                       inp_bindif(inp, ifscope);
                }
                break;
 #endif
+               /*
+                * Multicast socket options are processed by the in_mcast
+                * module.
+                */
                case IP_MULTICAST_IF:
+               case IP_MULTICAST_IFINDEX:
                case IP_MULTICAST_VIF:
                case IP_MULTICAST_TTL:
                case IP_MULTICAST_LOOP:
                case IP_ADD_MEMBERSHIP:
                case IP_DROP_MEMBERSHIP:
-                       error = ip_setmoptions(sopt, &inp->inp_moptions);
+               case IP_ADD_SOURCE_MEMBERSHIP:
+               case IP_DROP_SOURCE_MEMBERSHIP:
+               case IP_BLOCK_SOURCE:
+               case IP_UNBLOCK_SOURCE:
+               case IP_MSFILTER:
+               case MCAST_JOIN_GROUP:
+               case MCAST_LEAVE_GROUP:
+               case MCAST_JOIN_SOURCE_GROUP:
+               case MCAST_LEAVE_SOURCE_GROUP:
+               case MCAST_BLOCK_SOURCE:
+               case MCAST_UNBLOCK_SOURCE:
+                       error = inp_setmoptions(inp, sopt);
                        break;
 
                case IP_PORTRANGE:
@@ -2142,16 +2464,11 @@ ip_ctloutput(so, sopt)
                        struct mbuf *m;
                        int optname;
 
-                        if (sopt->sopt_valsize > MCLBYTES) {
-                                error = EMSGSIZE;
-                                break;
-                        }
                        if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
                                break;
                        if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
                                break;
-                       priv = (sopt->sopt_p != NULL &&
-                               proc_suser(sopt->sopt_p) != 0) ? 0 : 1;
+                       priv = (proc_suser(sopt->sopt_p) == 0);
                        if (m) {
                                req = mtod(m, caddr_t);
                                len = m->m_len;
@@ -2171,10 +2488,13 @@ ip_ctloutput(so, sopt)
                        if (error) 
                                break;
 
-                       if (background) 
-                               so->so_traffic_mgt_flags |= TRAFFIC_MGT_SO_BACKGROUND;
-                       else 
-                               so->so_traffic_mgt_flags &= ~TRAFFIC_MGT_SO_BACKGROUND;
+                       if (background) {
+                               socket_set_traffic_mgt_flags_locked(so,
+                                   TRAFFIC_MGT_SO_BACKGROUND);
+                       } else {
+                               socket_clear_traffic_mgt_flags_locked(so,
+                                   TRAFFIC_MGT_SO_BACKGROUND);
+                       }
 
                        break;
                }
@@ -2192,11 +2512,11 @@ ip_ctloutput(so, sopt)
                 * on the destination address type (e.g.  unicast, multicast,
                 * or broadcast if applicable) or whether or not the host is
                 * directly reachable.  Note that in the multicast transmit
-                * case, IP_MULTICAST_IF takes precedence over IP_BOUND_IF,
-                * since the former practically bypasses the routing table;
-                * in this case, IP_BOUND_IF sets the default interface used
-                * for sending multicast packets in the absence of an explicit
-                * transmit interface set via IP_MULTICAST_IF.
+                * case, IP_MULTICAST_{IF,IFINDEX} takes precedence over
+                * IP_BOUND_IF, since the former practically bypasses the
+                * routing table; in this case, IP_BOUND_IF sets the default
+                * interface used for sending multicast packets in the absence
+                * of an explicit multicast transmit interface.
                 */
                case IP_BOUND_IF:
                        /* This option is settable only for IPv4 */
@@ -2211,7 +2531,28 @@ ip_ctloutput(so, sopt)
                        if (error)
                                break;
 
-                       ip_bindif(inp, optval);
+                       inp_bindif(inp, optval);
+                       break;
+
+               case IP_NO_IFT_CELLULAR:
+                       /* This option is settable only for IPv4 */
+                       if (!(inp->inp_vflag & INP_IPV4)) {
+                               error = EINVAL;
+                               break;
+                       }
+
+                       error = sooptcopyin(sopt, &optval, sizeof (optval),
+                           sizeof (optval));
+
+                       if (error)
+                               break;
+
+                       error = inp_nocellular(inp, optval);
+                       break;
+
+               case IP_OUT_IF:
+                       /* This option is not settable */
+                       error = EINVAL;
                        break;
 
                default:
@@ -2244,6 +2585,7 @@ ip_ctloutput(so, sopt)
 #if defined(NFAITH) && NFAITH > 0
                case IP_FAITH:
 #endif
+               case IP_RECVPKTINFO:
                        switch (sopt->sopt_name) {
 
                        case IP_TOS:
@@ -2290,17 +2632,20 @@ ip_ctloutput(so, sopt)
                                optval = OPTBIT(INP_FAITH);
                                break;
 #endif
+                       case IP_RECVPKTINFO:
+                               optval = OPTBIT(INP_PKTINFO);
+                               break;
                        }
                        error = sooptcopyout(sopt, &optval, sizeof optval);
                        break;
 
                case IP_MULTICAST_IF:
+               case IP_MULTICAST_IFINDEX:
                case IP_MULTICAST_VIF:
                case IP_MULTICAST_TTL:
                case IP_MULTICAST_LOOP:
-               case IP_ADD_MEMBERSHIP:
-               case IP_DROP_MEMBERSHIP:
-                       error = ip_getmoptions(sopt, inp->inp_moptions);
+               case IP_MSFILTER:
+                       error = inp_getmoptions(inp, sopt);
                        break;
 
 #if IPSEC
@@ -2326,7 +2671,7 @@ ip_ctloutput(so, sopt)
 #if TRAFFIC_MGT
                case IP_TRAFFIC_MGT_BACKGROUND:
                {
-                       unsigned        background = so->so_traffic_mgt_flags;
+                       unsigned        background = (so->so_traffic_mgt_flags &  TRAFFIC_MGT_SO_BACKGROUND);
                        return (sooptcopyout(sopt, &background, sizeof(background)));
                        break;
                }
@@ -2338,6 +2683,16 @@ ip_ctloutput(so, sopt)
                        error = sooptcopyout(sopt, &optval, sizeof (optval));
                        break;
 
+               case IP_NO_IFT_CELLULAR:
+                       optval = (inp->inp_flags & INP_NO_IFT_CELLULAR) ? 1 : 0;
+                       error = sooptcopyout(sopt, &optval, sizeof (optval));
+                       break;
+
+               case IP_OUT_IF:
+                       optval = inp->inp_last_outif;
+                       error = sooptcopyout(sopt, &optval, sizeof (optval));
+                       break;
+
                default:
                        error = ENOPROTOOPT;
                        break;
@@ -2452,466 +2807,138 @@ bad:
        return (EINVAL);
 }
 
-/*
- * XXX
- * The whole multicast option thing needs to be re-thought.
- * Several of these options are equally applicable to non-multicast
- * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
- * standard option (IP_TTL).
- */
-
-/*
- * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
- */
-static struct ifnet *
-ip_multicast_if(a, ifindexp)
-       struct in_addr *a;
-       int *ifindexp;
+void
+ip_moptions_init(void)
 {
-       int ifindex;
-       struct ifnet *ifp;
+       PE_parse_boot_argn("ifa_debug", &imo_debug, sizeof (imo_debug));
 
-       if (ifindexp)
-               *ifindexp = 0;
-       if (ntohl(a->s_addr) >> 24 == 0) {
-               ifindex = ntohl(a->s_addr) & 0xffffff;
-               ifnet_head_lock_shared();
-               if (ifindex < 0 || if_index < ifindex) {
-                       ifnet_head_done();
-                       return NULL;
-               }
-               ifp = ifindex2ifnet[ifindex];
-               ifnet_head_done();
-               if (ifindexp)
-                       *ifindexp = ifindex;
-       } else {
-               INADDR_TO_IFP(*a, ifp);
+       imo_size = (imo_debug == 0) ? sizeof (struct ip_moptions) :
+           sizeof (struct ip_moptions_dbg);
+
+       imo_zone = zinit(imo_size, IMO_ZONE_MAX * imo_size, 0,
+           IMO_ZONE_NAME);
+       if (imo_zone == NULL) {
+               panic("%s: failed allocating %s", __func__, IMO_ZONE_NAME);
+               /* NOTREACHED */
        }
-       return ifp;
+       zone_change(imo_zone, Z_EXPAND, TRUE);
 }
 
-/*
- * Set the IP multicast options in response to user setsockopt().
- */
-static int
-ip_setmoptions(sopt, imop)
-       struct sockopt *sopt;
-       struct ip_moptions **imop;
+void
+imo_addref(struct ip_moptions *imo, int locked)
 {
-       int error = 0;
-       int i;
-       struct in_addr addr;
-       struct ip_mreq mreq;
-       struct ifnet *ifp = NULL;
-       struct ip_moptions *imo = *imop;
-       int ifindex;
+       if (!locked)
+               IMO_LOCK(imo);
+       else
+               IMO_LOCK_ASSERT_HELD(imo);
 
-       if (imo == NULL) {
-               /*
-                * No multicast option buffer attached to the pcb;
-                * allocate one and initialize to default values.
-                */
-               error = ip_createmoptions(imop);
-               if (error != 0)
-                       return error;
-               imo = *imop;
+       if (++imo->imo_refcnt == 0) {
+               panic("%s: imo %p wraparound refcnt\n", __func__, imo);
+               /* NOTREACHED */
+       } else if (imo->imo_trace != NULL) {
+               (*imo->imo_trace)(imo, TRUE);
        }
 
-       switch (sopt->sopt_name) {
-       /* store an index number for the vif you wanna use in the send */
-#if MROUTING
-       case IP_MULTICAST_VIF:
-               if (legal_vif_num == 0) {
-                       error = EOPNOTSUPP;
-                       break;
-               }
-               error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
-               if (error)
-                       break;
-               if (!legal_vif_num(i) && (i != -1)) {
-                       error = EINVAL;
-                       break;
-               }
-               imo->imo_multicast_vif = i;
-               break;
-#endif /* MROUTING */
-
-       case IP_MULTICAST_IF:
-               /*
-                * Select the interface for outgoing multicast packets.
-                */
-               error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
-               if (error)
-                       break;
-               /*
-                * INADDR_ANY is used to remove a previous selection.
-                * When no interface is selected, a default one is
-                * chosen every time a multicast packet is sent.
-                */
-               if (addr.s_addr == INADDR_ANY) {
-                       imo->imo_multicast_ifp = NULL;
-                       break;
-               }
-               /*
-                * The selected interface is identified by its local
-                * IP address.  Find the interface and confirm that
-                * it supports multicasting.
-                */
-               ifp = ip_multicast_if(&addr, &ifindex);
-               if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
-                       error = EADDRNOTAVAIL;
-                       break;
-               }
-               imo->imo_multicast_ifp = ifp;
-               if (ifindex)
-                       imo->imo_multicast_addr = addr;
-               else
-                       imo->imo_multicast_addr.s_addr = INADDR_ANY;
-               break;
-
-       case IP_MULTICAST_TTL:
-               /*
-                * Set the IP time-to-live for outgoing multicast packets.
-                * The original multicast API required a char argument,
-                * which is inconsistent with the rest of the socket API.
-                * We allow either a char or an int.
-                */
-               if (sopt->sopt_valsize == 1) {
-                       u_char ttl;
-                       error = sooptcopyin(sopt, &ttl, 1, 1);
-                       if (error)
-                               break;
-                       imo->imo_multicast_ttl = ttl;
-               } else {
-                       u_int ttl;
-                       error = sooptcopyin(sopt, &ttl, sizeof ttl, 
-                                           sizeof ttl);
-                       if (error)
-                               break;
-                       if (ttl > 255)
-                               error = EINVAL;
-                       else
-                               imo->imo_multicast_ttl = ttl;
-               }
-               break;
-
-       case IP_MULTICAST_LOOP:
-               /*
-                * Set the loopback flag for outgoing multicast packets.
-                * Must be zero or one.  The original multicast API required a
-                * char argument, which is inconsistent with the rest
-                * of the socket API.  We allow either a char or an int.
-                */
-               if (sopt->sopt_valsize == 1) {
-                       u_char loop;
-                       error = sooptcopyin(sopt, &loop, 1, 1);
-                       if (error)
-                               break;
-                       imo->imo_multicast_loop = !!loop;
-               } else {
-                       u_int loop;
-                       error = sooptcopyin(sopt, &loop, sizeof loop,
-                                           sizeof loop);
-                       if (error)
-                               break;
-                       imo->imo_multicast_loop = !!loop;
-               }
-               break;
-
-       case IP_ADD_MEMBERSHIP:
-               /*
-                * Add a multicast group membership.
-                * Group must be a valid IP multicast address.
-                */
-               error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
-               if (error)
-                       break;
-               
-               error = ip_addmembership(imo, &mreq);
-               break;
+       if (!locked)
+               IMO_UNLOCK(imo);
+}
 
-       case IP_DROP_MEMBERSHIP:
-               /*
-                * Drop a multicast group membership.
-                * Group must be a valid IP multicast address.
-                */
-               error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
-               if (error)
-                       break;
-               
-               error = ip_dropmembership(imo, &mreq);
-               break;
+void
+imo_remref(struct ip_moptions *imo)
+{
+       int i;
 
-       default:
-               error = EOPNOTSUPP;
-               break;
+       IMO_LOCK(imo);
+       if (imo->imo_refcnt == 0) {
+               panic("%s: imo %p negative refcnt", __func__, imo);
+               /* NOTREACHED */
+       } else if (imo->imo_trace != NULL) {
+               (*imo->imo_trace)(imo, FALSE);
        }
 
-       /*
-        * If all options have default values, no need to keep the mbuf.
-        */
-       if (imo->imo_multicast_ifp == NULL &&
-           imo->imo_multicast_vif == (u_long)-1 &&
-           imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
-           imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
-           imo->imo_num_memberships == 0) {
-               FREE(*imop, M_IPMOPTS);
-               *imop = NULL;
+       --imo->imo_refcnt;
+       if (imo->imo_refcnt > 0) {
+               IMO_UNLOCK(imo);
+               return;
        }
 
-       return (error);
-}
+       for (i = 0; i < imo->imo_num_memberships; ++i) {
+               struct in_mfilter *imf;
 
-/*
- * Set the IP multicast options in response to user setsockopt().
- */
-__private_extern__ int
-ip_createmoptions(
-       struct ip_moptions **imop)
-{
-       struct ip_moptions *imo;
-       imo = (struct ip_moptions*) _MALLOC(sizeof(*imo), M_IPMOPTS,
-               M_WAITOK);
-
-       if (imo == NULL)
-               return (ENOBUFS);
-       *imop = imo;
-       imo->imo_multicast_ifp = NULL;
-       imo->imo_multicast_addr.s_addr = INADDR_ANY;
-       imo->imo_multicast_vif = -1;
-       imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
-       imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
-       imo->imo_num_memberships = 0;
-       
-       return 0;
-}
+               imf = imo->imo_mfilters ? &imo->imo_mfilters[i] : NULL;
+               if (imf != NULL)
+                       imf_leave(imf);
 
-/*
- * Add membership to an IPv4 multicast.
- */
-__private_extern__ int
-ip_addmembership(
-       struct ip_moptions *imo,
-       struct ip_mreq *mreq)
-{
-       struct route ro;
-       struct sockaddr_in *dst;
-       struct ifnet *ifp = NULL;
-       int error = 0;
-       int i;
-       
-       if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) {
-               error = EINVAL;
-               return error;
-       }
-       /*
-        * If no interface address was provided, use the interface of
-        * the route to the given multicast address.
-        */
-       if (mreq->imr_interface.s_addr == INADDR_ANY) {
-               bzero((caddr_t)&ro, sizeof(ro));
-               dst = (struct sockaddr_in *)&ro.ro_dst;
-               dst->sin_len = sizeof(*dst);
-               dst->sin_family = AF_INET;
-               dst->sin_addr = mreq->imr_multiaddr;
-               lck_mtx_lock(rt_mtx);
-               rtalloc_ign_locked(&ro, 0UL);
-               if (ro.ro_rt != NULL) {
-                       ifp = ro.ro_rt->rt_ifp;
-                       rtfree_locked(ro.ro_rt);
-               }
-               else {
-                       /* If there's no default route, try using loopback */
-                       mreq->imr_interface.s_addr = INADDR_LOOPBACK;
-               }
-               lck_mtx_unlock(rt_mtx);
-       }
-       
-       if (ifp == NULL) {
-               ifp = ip_multicast_if(&mreq->imr_interface, NULL);
-       }
+               (void) in_leavegroup(imo->imo_membership[i], imf);
 
-       /*
-        * See if we found an interface, and confirm that it
-        * supports multicast.
-        */
-       if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
-               error = EADDRNOTAVAIL;
-               return error;
-       }
-       /*
-        * See if the membership already exists or if all the
-        * membership slots are full.
-        */
-       for (i = 0; i < imo->imo_num_memberships; ++i) {
-               if (imo->imo_membership[i]->inm_ifp == ifp &&
-                       imo->imo_membership[i]->inm_addr.s_addr
-                                       == mreq->imr_multiaddr.s_addr)
-                       break;
-       }
-       if (i < imo->imo_num_memberships) {
-               error = EADDRINUSE;
-               return error;
+               if (imf != NULL)
+                       imf_purge(imf);
+
+               INM_REMREF(imo->imo_membership[i]);
+               imo->imo_membership[i] = NULL;
        }
-       if (i == IP_MAX_MEMBERSHIPS) {
-               error = ETOOMANYREFS;
-               return error;
+       imo->imo_num_memberships = 0;
+       if (imo->imo_mfilters != NULL) {
+               FREE(imo->imo_mfilters, M_INMFILTER);
+               imo->imo_mfilters = NULL;
        }
-       /*
-        * Everything looks good; add a new record to the multicast
-        * address list for the given interface.
-        */
-       if ((imo->imo_membership[i] =
-               in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) {
-               error = ENOBUFS;
-               return error;
+       if (imo->imo_membership != NULL) {
+               FREE(imo->imo_membership, M_IPMOPTS);
+               imo->imo_membership = NULL;
        }
-       ++imo->imo_num_memberships;
-       
-       return error;
-}
+       IMO_UNLOCK(imo);
 
-/*
- * Drop membership of an IPv4 multicast.
- */
-__private_extern__ int
-ip_dropmembership(
-       struct ip_moptions *imo,
-       struct ip_mreq *mreq)
-{
-       int error = 0;
-       struct ifnet* ifp = NULL;
-       int i;
-       
-       if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) {
-               error = EINVAL;
-               return error;
-       }
+       lck_mtx_destroy(&imo->imo_lock, ifa_mtx_grp);
 
-       /*
-        * If an interface address was specified, get a pointer
-        * to its ifnet structure.
-        */
-       if (mreq->imr_interface.s_addr == INADDR_ANY)
-               ifp = NULL;
-       else {
-               ifp = ip_multicast_if(&mreq->imr_interface, NULL);
-               if (ifp == NULL) {
-                       error = EADDRNOTAVAIL;
-                       return error;
-               }
-       }
-       /*
-        * Find the membership in the membership array.
-        */
-       for (i = 0; i < imo->imo_num_memberships; ++i) {
-               if ((ifp == NULL ||
-                        imo->imo_membership[i]->inm_ifp == ifp) &&
-                        imo->imo_membership[i]->inm_addr.s_addr ==
-                        mreq->imr_multiaddr.s_addr)
-                       break;
-       }
-       if (i == imo->imo_num_memberships) {
-               error = EADDRNOTAVAIL;
-               return error;
+       if (!(imo->imo_debug & IFD_ALLOC)) {
+               panic("%s: imo %p cannot be freed", __func__, imo);
+               /* NOTREACHED */
        }
-       /*
-        * Give up the multicast address record to which the
-        * membership points.
-        */
-       in_delmulti(&imo->imo_membership[i]);
-       /*
-        * Remove the gap in the membership array.
-        */
-       for (++i; i < imo->imo_num_memberships; ++i)
-               imo->imo_membership[i-1] = imo->imo_membership[i];
-       --imo->imo_num_memberships;
-       
-       return error;
+       zfree(imo_zone, imo);
 }
 
-/*
- * Return the IP multicast options in response to user getsockopt().
- */
-static int
-ip_getmoptions(sopt, imo)
-       struct sockopt *sopt;
-       register struct ip_moptions *imo;
+static void
+imo_trace(struct ip_moptions *imo, int refhold)
 {
-       struct in_addr addr;
-       struct in_ifaddr *ia;
-       int error, optval;
-       u_char coptval;
-
-       error = 0;
-       switch (sopt->sopt_name) {
-#if MROUTING
-       case IP_MULTICAST_VIF: 
-               if (imo != NULL)
-                       optval = imo->imo_multicast_vif;
-               else
-                       optval = -1;
-               error = sooptcopyout(sopt, &optval, sizeof optval);
-               break;
-#endif /* MROUTING */
-
-       case IP_MULTICAST_IF:
-               if (imo == NULL || imo->imo_multicast_ifp == NULL)
-                       addr.s_addr = INADDR_ANY;
-               else if (imo->imo_multicast_addr.s_addr) {
-                       /* return the value user has set */
-                       addr = imo->imo_multicast_addr;
-               } else {
-                       IFP_TO_IA(imo->imo_multicast_ifp, ia);
-                       addr.s_addr = (ia == NULL) ? INADDR_ANY
-                               : IA_SIN(ia)->sin_addr.s_addr;
-               }
-               error = sooptcopyout(sopt, &addr, sizeof addr);
-               break;
-
-       case IP_MULTICAST_TTL:
-               if (imo == 0)
-                       optval = coptval = IP_DEFAULT_MULTICAST_TTL;
-               else
-                       optval = coptval = imo->imo_multicast_ttl;
-               if (sopt->sopt_valsize == 1)
-                       error = sooptcopyout(sopt, &coptval, 1);
-               else
-                       error = sooptcopyout(sopt, &optval, sizeof optval);
-               break;
-
-       case IP_MULTICAST_LOOP:
-               if (imo == 0)
-                       optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
-               else
-                       optval = coptval = imo->imo_multicast_loop;
-               if (sopt->sopt_valsize == 1)
-                       error = sooptcopyout(sopt, &coptval, 1);
-               else
-                       error = sooptcopyout(sopt, &optval, sizeof optval);
-               break;
-
-       default:
-               error = ENOPROTOOPT;
-               break;
+       struct ip_moptions_dbg *imo_dbg = (struct ip_moptions_dbg *)imo;
+       ctrace_t *tr;
+       u_int32_t idx;
+       u_int16_t *cnt;
+
+       if (!(imo->imo_debug & IFD_DEBUG)) {
+               panic("%s: imo %p has no debug structure", __func__, imo);
+               /* NOTREACHED */
+       }
+       if (refhold) {
+               cnt = &imo_dbg->imo_refhold_cnt;
+               tr = imo_dbg->imo_refhold;
+       } else {
+               cnt = &imo_dbg->imo_refrele_cnt;
+               tr = imo_dbg->imo_refrele;
        }
-       return (error);
+
+       idx = atomic_add_16_ov(cnt, 1) % IMO_TRACE_HIST_SIZE;
+       ctrace_record(&tr[idx]);
 }
 
-/*
- * Discard the IP multicast options.
- */
-void
-ip_freemoptions(imo)
-       register struct ip_moptions *imo;
+struct ip_moptions *
+ip_allocmoptions(int how)
 {
-       register int i;
+       struct ip_moptions *imo;
 
+       imo = (how == M_WAITOK) ? zalloc(imo_zone) : zalloc_noblock(imo_zone);
        if (imo != NULL) {
-               for (i = 0; i < imo->imo_num_memberships; ++i)
-                       in_delmulti(&imo->imo_membership[i]);
-               FREE(imo, M_IPMOPTS);
+               bzero(imo, imo_size);
+               lck_mtx_init(&imo->imo_lock, ifa_mtx_grp, ifa_mtx_attr);
+               imo->imo_debug |= IFD_ALLOC;
+               if (imo_debug != 0) {
+                       imo->imo_debug |= IFD_DEBUG;
+                       imo->imo_trace = imo_trace;
+               }
+               IMO_ADDREF(imo);
        }
+
+       return (imo);
 }
 
 /*
@@ -2944,8 +2971,12 @@ ip_mloopback(ifp, m, dst, hlen)
         * than the interface's MTU.  Can this possibly matter?
         */
        ip = mtod(copym, struct ip *);
+
+#if BYTE_ORDER != BIG_ENDIAN
        HTONS(ip->ip_len);
        HTONS(ip->ip_off);
+#endif
+       
        ip->ip_sum = 0;
        ip->ip_sum = in_cksum(copym, hlen);
        /*
@@ -2983,9 +3014,17 @@ ip_mloopback(ifp, m, dst, hlen)
                            CSUM_IP_CHECKED | CSUM_IP_VALID;
                        copym->m_pkthdr.csum_data = 0xffff;
                } else {
+
+#if BYTE_ORDER != BIG_ENDIAN
                        NTOHS(ip->ip_len);
+#endif
+                       
                        in_delayed_cksum(copym);
+
+#if BYTE_ORDER != BIG_ENDIAN
                        HTONS(ip->ip_len);
+#endif
+               
                }
         }
 
@@ -3013,26 +3052,31 @@ ip_mloopback(ifp, m, dst, hlen)
 
 /*
  * Given a source IP address (and route, if available), determine the best
- * interface to send the packet from.
+ * interface to send the packet from.  Checking for (and updating) the
+ * ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done
+ * without any locks based on the assumption that ip_output() is single-
+ * threaded per-pcb, i.e. for any given pcb there can only be one thread
+ * performing output at the IP layer.
+ *
+ * This routine is analogous to in6_selectroute() for IPv6.
  */
 static struct ifaddr *
 in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
 {
        struct ifaddr *ifa = NULL;
-       struct sockaddr src = { sizeof (struct sockaddr_in), AF_INET, { 0, } };
+       struct in_addr src = ip->ip_src;
+       struct in_addr dst = ip->ip_dst;
        struct ifnet *rt_ifp;
-       char ip_src[16], ip_dst[16];
+       char s_src[MAX_IPv4_STR_LEN], s_dst[MAX_IPv4_STR_LEN];
 
        if (ip_select_srcif_debug) {
-               (void) inet_ntop(AF_INET, &ip->ip_src.s_addr, ip_src,
-                   sizeof (ip_src));
-               (void) inet_ntop(AF_INET, &ip->ip_dst.s_addr, ip_dst,
-                   sizeof (ip_dst));
+               (void) inet_ntop(AF_INET, &src.s_addr, s_src, sizeof (s_src));
+               (void) inet_ntop(AF_INET, &dst.s_addr, s_dst, sizeof (s_dst));
        }
 
-       lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED);
+       if (ro->ro_rt != NULL)
+               RT_LOCK(ro->ro_rt);
 
-       ((struct sockaddr_in *)&src)->sin_addr.s_addr = ip->ip_src.s_addr;
        rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL;
 
        /*
@@ -3056,25 +3100,39 @@ in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
                 */
                if (scope == IFSCOPE_NONE) {
                        scope = rt_ifp->if_index;
-                       if (scope != get_primary_ifscope() &&
+                       if (scope != get_primary_ifscope(AF_INET) &&
                            ro->ro_rt->generation_id != route_generation)
-                               scope = get_primary_ifscope();
+                               scope = get_primary_ifscope(AF_INET);
                }
 
-               ifa = ifa_ifwithaddr_scoped(&src, scope);
+               ifa = (struct ifaddr *)ifa_foraddr_scoped(src.s_addr, scope);
+
+               if (ifa == NULL && ip->ip_p != IPPROTO_UDP &&
+                   ip->ip_p != IPPROTO_TCP && ipforwarding) {
+                       /*
+                        * If forwarding is enabled, and if the packet isn't
+                        * TCP or UDP, check if the source address belongs
+                        * to one of our own interfaces; if so, demote the
+                        * interface scope and do a route lookup right below.
+                        */
+                       ifa = (struct ifaddr *)ifa_foraddr(src.s_addr);
+                       if (ifa != NULL) {
+                               IFA_REMREF(ifa);
+                               ifa = NULL;
+                               ifscope = IFSCOPE_NONE;
+                       }
+               }
 
                if (ip_select_srcif_debug && ifa != NULL) {
                        if (ro->ro_rt != NULL) {
-                               printf("%s->%s ifscope %d->%d ifa_if %s%d "
-                                   "ro_if %s%d\n", ip_src, ip_dst, ifscope,
-                                   scope, ifa->ifa_ifp->if_name,
-                                   ifa->ifa_ifp->if_unit, rt_ifp->if_name,
-                                   rt_ifp->if_unit);
+                               printf("%s->%s ifscope %d->%d ifa_if %s "
+                                   "ro_if %s\n", s_src, s_dst, ifscope,
+                                   scope, if_name(ifa->ifa_ifp),
+                                   if_name(rt_ifp));
                        } else {
-                               printf("%s->%s ifscope %d->%d ifa_if %s%d\n",
-                                   ip_src, ip_dst, ifscope, scope,
-                                   ifa->ifa_ifp->if_name,
-                                   ifa->ifa_ifp->if_unit);
+                               printf("%s->%s ifscope %d->%d ifa_if %s\n",
+                                   s_src, s_dst, ifscope, scope,
+                                   if_name(ifa->ifa_ifp));
                        }
                }
        }
@@ -3090,15 +3148,113 @@ in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
         *      found interface.
         */
        if (ifa == NULL && ifscope == IFSCOPE_NONE) {
-               ifa = ifa_ifwithaddr(&src);
+               ifa = (struct ifaddr *)ifa_foraddr(src.s_addr);
+
+               /*
+                * If we have the IP address, but not the route, we don't
+                * really know whether or not it belongs to the correct
+                * interface (it could be shared across multiple interfaces.)
+                * The only way to find out is to do a route lookup.
+                */
+               if (ifa != NULL && ro->ro_rt == NULL) {
+                       struct rtentry *rt;
+                       struct sockaddr_in sin;
+                       struct ifaddr *oifa = NULL;
+
+                       bzero(&sin, sizeof (sin));
+                       sin.sin_family = AF_INET;
+                       sin.sin_len = sizeof (sin);
+                       sin.sin_addr = dst;
+
+                       lck_mtx_lock(rnh_lock);
+                       if ((rt = rt_lookup(TRUE, (struct sockaddr *)&sin, NULL,
+                           rt_tables[AF_INET], IFSCOPE_NONE)) != NULL) {
+                               RT_LOCK(rt);
+                               /*
+                                * If the route uses a different interface,
+                                * use that one instead.  The IP address of
+                                * the ifaddr that we pick up here is not
+                                * relevant.
+                                */
+                               if (ifa->ifa_ifp != rt->rt_ifp) {
+                                       oifa = ifa;
+                                       ifa = rt->rt_ifa;
+                                       IFA_ADDREF(ifa);
+                                       RT_UNLOCK(rt);
+                               } else {
+                                       RT_UNLOCK(rt);
+                               }
+                               rtfree_locked(rt);
+                       }
+                       lck_mtx_unlock(rnh_lock);
+
+                       if (oifa != NULL) {
+                               struct ifaddr *iifa;
+
+                               /*
+                                * See if the interface pointed to by the
+                                * route is configured with the source IP
+                                * address of the packet.
+                                */
+                               iifa = (struct ifaddr *)ifa_foraddr_scoped(
+                                   src.s_addr, ifa->ifa_ifp->if_index);
+
+                               if (iifa != NULL) {
+                                       /*
+                                        * Found it; drop the original one
+                                        * as well as the route interface
+                                        * address, and use this instead.
+                                        */
+                                       IFA_REMREF(oifa);
+                                       IFA_REMREF(ifa);
+                                       ifa = iifa;
+                               } else if (!ipforwarding ||
+                                   (rt->rt_flags & RTF_GATEWAY)) {
+                                       /*
+                                        * This interface doesn't have that
+                                        * source IP address; drop the route
+                                        * interface address and just use the
+                                        * original one, and let the caller
+                                        * do a scoped route lookup.
+                                        */
+                                       IFA_REMREF(ifa);
+                                       ifa = oifa;
+                               } else {
+                                       /*
+                                        * Forwarding is enabled and the source
+                                        * address belongs to one of our own
+                                        * interfaces which isn't the outgoing
+                                        * interface, and we have a route, and
+                                        * the destination is on a network that
+                                        * is directly attached (onlink); drop
+                                        * the original one and use the route
+                                        * interface address instead.
+                                        */
+                                       IFA_REMREF(oifa);
+                               }
+                       }
+               } else if (ifa != NULL && ro->ro_rt != NULL &&
+                   !(ro->ro_rt->rt_flags & RTF_GATEWAY) &&
+                   ifa->ifa_ifp != ro->ro_rt->rt_ifp && ipforwarding) {
+                       /*
+                        * Forwarding is enabled and the source address belongs
+                        * to one of our own interfaces which isn't the same
+                        * as the interface used by the known route; drop the
+                        * original one and use the route interface address.
+                        */
+                       IFA_REMREF(ifa);
+                       ifa = ro->ro_rt->rt_ifa;
+                       IFA_ADDREF(ifa);
+               }
 
                if (ip_select_srcif_debug && ifa != NULL) {
-                       printf("%s->%s ifscope %d ifa_if %s%d\n",
-                           ip_src, ip_dst, ifscope, ifa->ifa_ifp->if_name,
-                           ifa->ifa_ifp->if_unit);
+                       printf("%s->%s ifscope %d ifa_if %s\n",
+                           s_src, s_dst, ifscope, if_name(ifa->ifa_ifp));
                }
        }
 
+       if (ro->ro_rt != NULL)
+               RT_LOCK_ASSERT_HELD(ro->ro_rt);
        /*
         * If there is a non-loopback route with the wrong interface, or if
         * there is no interface configured with such an address, blow it
@@ -3110,20 +3266,19 @@ in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
            !(ro->ro_rt->rt_flags & RTF_UP))) {
                if (ip_select_srcif_debug) {
                        if (ifa != NULL) {
-                               printf("%s->%s ifscope %d ro_if %s%d != "
-                                   "ifa_if %s%d (cached route cleared)\n",
-                                   ip_src, ip_dst, ifscope, rt_ifp->if_name,
-                                   rt_ifp->if_unit, ifa->ifa_ifp->if_name,
-                                   ifa->ifa_ifp->if_unit);
+                               printf("%s->%s ifscope %d ro_if %s != "
+                                   "ifa_if %s (cached route cleared)\n",
+                                   s_src, s_dst, ifscope, if_name(rt_ifp),
+                                   if_name(ifa->ifa_ifp));
                        } else {
-                               printf("%s->%s ifscope %d ro_if %s%d "
+                               printf("%s->%s ifscope %d ro_if %s "
                                    "(no ifa_if found)\n",
-                                   ip_src, ip_dst, ifscope, rt_ifp->if_name,
-                                   rt_ifp->if_unit);
+                                   s_src, s_dst, ifscope, if_name(rt_ifp));
                        }
                }
 
-               rtfree_locked(ro->ro_rt);
+               RT_UNLOCK(ro->ro_rt);
+               rtfree(ro->ro_rt);
                ro->ro_rt = NULL;
                ro->ro_flags &= ~ROF_SRCIF_SELECTED;
 
@@ -3137,16 +3292,16 @@ in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
                 * but other shared subnets; for now we explicitly test only
                 * for the former case and save the latter for future.
                 */
-               if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) &&
-                   !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr)) && ifa != NULL) {
-                       ifafree(ifa);
+               if (IN_LINKLOCAL(ntohl(dst.s_addr)) &&
+                   !IN_LINKLOCAL(ntohl(src.s_addr)) && ifa != NULL) {
+                       IFA_REMREF(ifa);
                        ifa = NULL;
                }
        }
 
        if (ip_select_srcif_debug && ifa == NULL) {
                printf("%s->%s ifscope %d (neither ro_if/ifa_if found)\n",
-                   ip_src, ip_dst, ifscope);
+                   s_src, s_dst, ifscope);
        }
 
        /*
@@ -3157,42 +3312,15 @@ in_selectsrcif(struct ip *ip, struct route *ro, unsigned int ifscope)
         * otherwise we want to come back here again when the route points
         * to the interface over which the ARP reply arrives on.
         */
-       if (ro->ro_rt != NULL && (!IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) ||
+       if (ro->ro_rt != NULL && (!IN_LINKLOCAL(ntohl(dst.s_addr)) ||
            (ro->ro_rt->rt_gateway->sa_family == AF_LINK &&
            SDL(ro->ro_rt->rt_gateway)->sdl_alen != 0))) {
                ro->ro_flags |= ROF_SRCIF_SELECTED;
                ro->ro_rt->generation_id = route_generation;
        }
 
-       return (ifa);
-}
-
-/*
- * Handler for setting IP_FORCE_OUT_IFP or IP_BOUND_IF socket option.
- */
-static void
-ip_bindif(struct inpcb *inp, unsigned int ifscope)
-{
-       /*
-        * A zero interface scope value indicates an "unbind".
-        * Otherwise, take in whatever value the app desires;
-        * the app may already know the scope (or force itself
-        * to such a scope) ahead of time before the interface
-        * gets attached.  It doesn't matter either way; any
-        * route lookup from this point on will require an
-        * exact match for the embedded interface scope.
-        */
-       inp->inp_boundif = ifscope;
-       if (inp->inp_boundif == IFSCOPE_NONE)
-               inp->inp_flags &= ~INP_BOUND_IF;
-       else
-               inp->inp_flags |= INP_BOUND_IF;
+       if (ro->ro_rt != NULL)
+               RT_UNLOCK(ro->ro_rt);
 
-       lck_mtx_lock(rt_mtx);
-       /* Blow away any cached route in the PCB */
-       if (inp->inp_route.ro_rt != NULL) {
-               rtfree_locked(inp->inp_route.ro_rt);
-               inp->inp_route.ro_rt = NULL;
-       }
-       lck_mtx_unlock(rt_mtx);
+       return (ifa);
 }