]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/ip_input.c
xnu-792.12.6.tar.gz
[apple/xnu.git] / bsd / netinet / ip_input.c
index 4ca8fece7d20e741f89620c21a9150729b8be26e..495dd0b2fdf3097b28bbe3411ad90b9394fa7ef8 100644 (file)
@@ -1,23 +1,31 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * This file contains Original Code and/or Modifications of Original Code 
+ * as defined in and that are subject to the Apple Public Source License 
+ * Version 2.0 (the 'License'). You may not use this file except in 
+ * compliance with the License.  The rights granted to you under the 
+ * License may not be used to create, or enable the creation or 
+ * redistribution of, unlawful or unlicensed copies of an Apple operating 
+ * system, or to circumvent, violate, or enable the circumvention or 
+ * violation of, any terms of an Apple operating system software license 
+ * agreement.
+ *
+ * Please obtain a copy of the License at 
+ * http://www.opensource.apple.com/apsl/ and read it before using this 
+ * file.
+ *
+ * The Original Code and all software distributed under the License are 
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
+ * Please see the License for the specific language governing rights and 
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  */
 /*
  * Copyright (c) 1982, 1986, 1988, 1993
  * SUCH DAMAGE.
  *
  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
- *     $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $
+ * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.25 2001/08/29 21:41:37 jesper Exp $
  */
 
 #define        _IP_VHL
 
-#include <stddef.h>
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/mbuf.h>
 #include <sys/sysctl.h>
 
 #include <kern/queue.h>
+#include <kern/locks.h>
 
 #include <net/if.h>
 #include <net/if_var.h>
 #include <net/if_dl.h>
 #include <net/route.h>
-#include <net/netisr.h>
+#include <net/kpi_protocol.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_var.h>
 #include <netinet/ip.h>
-#ifdef INET6
-#include <netinet/ip6.h>
-#include <netinet6/ip6_var.h>
-#endif
 #include <netinet/in_pcb.h>
 #include <netinet/ip_var.h>
 #include <netinet/ip_icmp.h>
 #include <sys/socketvar.h>
 
-#include <sys/kdebug.h>
+#include <netinet/ip_fw.h>
+#include <netinet/ip_divert.h>
 
+#include <netinet/kpi_ipfilter_var.h>
+
+/* needed for AUTOCONFIGURING: */
+#include <netinet/udp.h>
+#include <netinet/udp_var.h>
+#include <netinet/bootp.h>
+
+#include <sys/kdebug.h>
 
 #define DBG_LAYER_BEG          NETDBG_CODE(DBG_NETIP, 0)
 #define DBG_LAYER_END          NETDBG_CODE(DBG_NETIP, 2)
 #define DBG_FNC_IP_INPUT       NETDBG_CODE(DBG_NETIP, (2 << 8))
 
 
-#if IPFIREWALL
-#include <netinet/ip_fw.h>
-#endif
-
 #if IPSEC
 #include <netinet6/ipsec.h>
 #include <netkey/key.h>
-#include <netkey/key_debug.h>
 #endif
 
 #include "faith.h"
 #include <netinet/ip_dummynet.h>
 #endif
 
+#if IPSEC
+extern int ipsec_bypass;
+extern lck_mtx_t *sadb_mutex;
+#endif
+
 int rsvp_on = 0;
 static int ip_rsvp_on;
 struct socket *ip_rsvpd;
 
 int    ipforwarding = 0;
 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
-       &ipforwarding, 0, "");
+    &ipforwarding, 0, "Enable IP forwarding between interfaces");
 
 static int     ipsendredirects = 1; /* XXX */
 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
-       &ipsendredirects, 0, "");
+    &ipsendredirects, 0, "Enable sending IP redirects");
 
 int    ip_defttl = IPDEFTTL;
 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
-       &ip_defttl, 0, "");
+    &ip_defttl, 0, "Maximum TTL on IP packets");
 
 static int     ip_dosourceroute = 0;
 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
-       &ip_dosourceroute, 0, "");
+    &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
 
 static int     ip_acceptsourceroute = 0;
-SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
-       CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
+SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, 
+    CTLFLAG_RW, &ip_acceptsourceroute, 0, 
+    "Enable accepting source routed IP packets");
 
 static int     ip_keepfaith = 0;
 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
-       &ip_keepfaith,  0, "");
+       &ip_keepfaith,  0,
+       "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
+
+static int     nipq = 0;       /* total # of reass queues */
+static int     maxnipq;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
+       &maxnipq, 0,
+       "Maximum number of IPv4 fragment reassembly queue entries");
+
+static int    maxfragsperpacket;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
+       &maxfragsperpacket, 0,
+       "Maximum number of IPv4 fragments allowed per packet");
+
+static int    maxfrags;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfrags, CTLFLAG_RW,
+       &maxfrags, 0, "Maximum number of IPv4 fragments allowed");
+
+static int    currentfrags = 0;
+
+/*
+ * XXX - Setting ip_checkinterface mostly implements the receive side of
+ * the Strong ES model described in RFC 1122, but since the routing table
+ * and transmit implementation do not implement the Strong ES model,
+ * setting this to 1 results in an odd hybrid.
+ *
+ * XXX - ip_checkinterface currently must be disabled if you use ipnat
+ * to translate the destination address to another local interface.
+ *
+ * XXX - ip_checkinterface must be disabled if you add IP aliases
+ * to the loopback interface instead of the interface where the
+ * packets for those addresses are received.
+ */
+static int     ip_checkinterface = 0;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
+    &ip_checkinterface, 0, "Verify packet arrives on correct interface");
 
 #if DIAGNOSTIC
 static int     ipprintfs = 0;
@@ -157,54 +205,70 @@ struct protosw *ip_protox[IPPROTO_MAX];
 static int     ipqmaxlen = IFQ_MAXLEN;
 struct in_ifaddrhead in_ifaddrhead; /* first inet address */
 struct ifqueue ipintrq;
-SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
-       &ipintrq.ifq_maxlen, 0, "");
+SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
+    &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
-       &ipintrq.ifq_drops, 0, "");
+    &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
 
 struct ipstat ipstat;
 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RD,
-       &ipstat, ipstat, "");
+    &ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
 
 /* Packet reassembly stuff */
 #define IPREASS_NHASH_LOG2      6
 #define IPREASS_NHASH           (1 << IPREASS_NHASH_LOG2)
 #define IPREASS_HMASK           (IPREASS_NHASH - 1)
 #define IPREASS_HASH(x,y) \
-       ((((x) & 0xF | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
+       (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
 
 static struct ipq ipq[IPREASS_NHASH];
-static int    nipq = 0;         /* total # of reass queues */
-static int    maxnipq;
+static TAILQ_HEAD(ipq_list, ipq) ipq_list =
+       TAILQ_HEAD_INITIALIZER(ipq_list);
+const  int    ipintrq_present = 1;
+lck_mtx_t                      *ip_mutex;
+lck_attr_t             *ip_mutex_attr;
+lck_grp_t                      *ip_mutex_grp;
+lck_grp_attr_t *ip_mutex_grp_attr;
+lck_mtx_t              *inet_domain_mutex;
+extern lck_mtx_t               *domain_proto_mtx;
 
 #if IPCTL_DEFMTU
 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
-       &ip_mtu, 0, "");
+    &ip_mtu, 0, "Default MTU");
 #endif
 
-#if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1
-#undef COMPAT_IPFW
-#define COMPAT_IPFW 1
-#else
-#undef COMPAT_IPFW
+#if IPSTEALTH
+static int     ipstealth = 0;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
+    &ipstealth, 0, "");
 #endif
 
-#if COMPAT_IPFW
-
-#include <netinet/ip_fw.h>
 
 /* Firewall hooks */
 ip_fw_chk_t *ip_fw_chk_ptr;
-ip_fw_ctl_t *ip_fw_ctl_ptr;
+int fw_enable = 1 ;
+int fw_one_pass = 1;
 
 #if DUMMYNET
-ip_dn_ctl_t *ip_dn_ctl_ptr;
+ip_dn_io_t *ip_dn_io_ptr;
 #endif
 
-/* IP Network Address Translation (NAT) hooks */ 
-ip_nat_t *ip_nat_ptr;
-ip_nat_ctl_t *ip_nat_ctl_ptr;
-#endif
+int (*fr_checkp)(struct ip *, int, struct ifnet *, int, struct mbuf **) = NULL;
+
+SYSCTL_NODE(_net_inet_ip, OID_AUTO, linklocal, CTLFLAG_RW, 0, "link local");
+
+struct ip_linklocal_stat ip_linklocal_stat;
+SYSCTL_STRUCT(_net_inet_ip_linklocal, OID_AUTO, stat, CTLFLAG_RD,
+        &ip_linklocal_stat, ip_linklocal_stat,
+        "Number of link local packets with TTL less than 255");
+
+SYSCTL_NODE(_net_inet_ip_linklocal, OID_AUTO, in, CTLFLAG_RW, 0, "link local input");
+
+int ip_linklocal_in_allowbadttl = 1;
+SYSCTL_INT(_net_inet_ip_linklocal_in, OID_AUTO, allowbadttl, CTLFLAG_RW,
+        &ip_linklocal_in_allowbadttl, 0,
+        "Allow incoming link local packets with TTL less than 255");
+
 
 /*
  * We need to save the IP options in case a protocol wants to respond
@@ -221,44 +285,33 @@ static    struct ip_srcrt {
        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
 } ip_srcrt;
 
-#if IPDIVERT
-/*
- * Shared variable between ip_input() and ip_reass() to communicate
- * about which packets, once assembled from fragments, get diverted,
- * and to which port.
- */
-static u_short frag_divert_port;
+#ifdef __APPLE__
+extern struct mbuf*    m_dup(register struct mbuf *m, int how);
 #endif
 
-struct sockaddr_in *ip_fw_fwd_addr;
-
-static void save_rte __P((u_char *, struct in_addr));
-static int      ip_dooptions __P((struct mbuf *));
-#ifndef NATPT
-static
+static void    save_rte(u_char *, struct in_addr);
+static int     ip_dooptions(struct mbuf *, int, struct sockaddr_in *, struct route *ipforward_rt);
+static void    ip_forward(struct mbuf *, int, struct sockaddr_in *, struct route *ipforward_rt);
+static void    ip_freef(struct ipq *);
+#if IPDIVERT
+#ifdef IPDIVERT_44
+static struct  mbuf *ip_reass(struct mbuf *,
+                       struct ipq *, struct ipq *, u_int32_t *, u_int16_t *);
+#else
+static struct  mbuf *ip_reass(struct mbuf *,
+                       struct ipq *, struct ipq *, u_int16_t *, u_int16_t *);
 #endif
-void    ip_forward __P((struct mbuf *, int));
-static void     ip_freef __P((struct ipq *));
-static struct ip *
-        ip_reass __P((struct mbuf *, struct ipq *, struct ipq *));
-static struct in_ifaddr *
-        ip_rtaddr __P((struct in_addr));
-void   ipintr __P((void));
-
-#if PM
-extern int     doNatFil;
-extern int     doRoute;
-
-extern int              pm_in      __P((struct ifnet *, struct ip *, struct mbuf *));
-extern struct route    *pm_route   __P((struct mbuf *));
+#else
+static struct  mbuf *ip_reass(struct mbuf *, struct ipq *, struct ipq *);
 #endif
+void   ipintr(void);
 
-#if defined(NATPT)
-extern int             ip6_protocol_tr;
-
-int     natpt_in4      __P((struct mbuf *, struct mbuf **));
+#if RANDOM_IP_ID
+extern u_short ip_id;
+#endif
 
-#endif /* NATPT        */
+extern u_long  route_generation;
+extern int apple_hwcksum_rx;
 
 /*
  * IP initialization: fill in IP protocol switch table.
@@ -270,11 +323,13 @@ ip_init()
        register struct protosw *pr;
        register int i;
        static ip_initialized = 0;
+       struct timeval timenow;
+
 
        if (!ip_initialized)
        {
                TAILQ_INIT(&in_ifaddrhead);
-               pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
+               pr = pffindproto_locked(PF_INET, IPPROTO_RAW, SOCK_RAW);
                if (pr == 0)
                        panic("ip_init");
                for (i = 0; i < IPPROTO_MAX; i++)
@@ -288,20 +343,44 @@ ip_init()
                for (i = 0; i < IPREASS_NHASH; i++)
                    ipq[i].next = ipq[i].prev = &ipq[i];
 
-               maxnipq = nmbclusters/4;
+       maxnipq = nmbclusters / 32;
+       maxfrags = maxnipq * 2;
+       maxfragsperpacket = 128; /* enough for 64k in 512 byte fragments */
 
-               ip_id = time_second & 0xffff;
-               ipintrq.ifq_maxlen = ipqmaxlen;
-#if DUMMYNET
-               ip_dn_init();
-#endif
-#if IPNAT
-               ip_nat_init();
+#if RANDOM_IP_ID
+               getmicrouptime(&timenow);
+               ip_id = timenow.tv_sec & 0xffff;
 #endif
+               ipintrq.ifq_maxlen = ipqmaxlen;
+
+               ipf_init();
+
+               ip_mutex_grp_attr  = lck_grp_attr_alloc_init();
+               lck_grp_attr_setdefault(ip_mutex_grp_attr);
+
+               ip_mutex_grp = lck_grp_alloc_init("ip", ip_mutex_grp_attr);
+
+               ip_mutex_attr = lck_attr_alloc_init();
+
+               lck_attr_setdefault(ip_mutex_attr);
+
+               if ((ip_mutex = lck_mtx_alloc_init(ip_mutex_grp, ip_mutex_attr)) == NULL) {
+                       printf("ip_init: can't alloc ip_mutex\n");
+                       return;
+               }
+
                ip_initialized = 1;
        }
 }
 
+static void
+ip_proto_input(
+       protocol_family_t       protocol,
+       mbuf_t                          packet)
+{
+       ip_input(packet);
+}
+
 /* Initialize the PF_INET domain, and add in the pre-defined protos */
 void
 in_dinit()
@@ -312,17 +391,93 @@ in_dinit()
        extern int in_proto_count; 
 
        if (!inetdomain_initted)
-       {       kprintf("Initing %d protosw entries\n", in_proto_count);
+       {
+               kprintf("Initing %d protosw entries\n", in_proto_count);
                dp = &inetdomain;
+               dp->dom_flags = DOM_REENTRANT;
 
                for (i=0, pr = &inetsw[0]; i<in_proto_count; i++, pr++)
                        net_add_proto(pr, dp);
+               inet_domain_mutex = dp->dom_mtx;
                inetdomain_initted = 1;
+       
+               lck_mtx_unlock(domain_proto_mtx);       
+               proto_register_input(PF_INET, ip_proto_input, NULL);
+               lck_mtx_lock(domain_proto_mtx); 
        }
 }
 
+__private_extern__ void
+ip_proto_dispatch_in(
+                                       struct mbuf     *m,
+                                       int                     hlen,
+                                       u_int8_t        proto,
+                                       ipfilter_t      inject_ipfref)
+{
+       struct ipfilter *filter;
+       int seen = (inject_ipfref == 0);
+       int     changed_header = 0;
+       struct ip *ip;
+
+       if (!TAILQ_EMPTY(&ipv4_filters)) {      
+               ipf_ref();
+               TAILQ_FOREACH(filter, &ipv4_filters, ipf_link) {
+                       if (seen == 0) {
+                               if ((struct ipfilter *)inject_ipfref == filter)
+                                       seen = 1;
+                       } else if (filter->ipf_filter.ipf_input) {
+                               errno_t result;
+               
+                               if (changed_header == 0) {
+                                       changed_header = 1;
+                                       ip = mtod(m, struct ip *);
+                                       ip->ip_len = htons(ip->ip_len + hlen);
+                                       ip->ip_off = htons(ip->ip_off);
+                                       ip->ip_sum = 0;
+                                       ip->ip_sum = in_cksum(m, hlen);
+                               }
+                               result = filter->ipf_filter.ipf_input(
+                                       filter->ipf_filter.cookie, (mbuf_t*)&m, hlen, proto);
+                               if (result == EJUSTRETURN) {
+                                       ipf_unref();
+                                       return;
+                               }
+                               if (result != 0) {
+                                       ipf_unref();
+                                       m_freem(m);
+                                       return;
+                               }
+       }
+               }
+               ipf_unref();
+       }
+       /*
+        * If there isn't a specific lock for the protocol
+        * we're about to call, use the generic lock for AF_INET.
+        * otherwise let the protocol deal with its own locking
+        */
+       ip = mtod(m, struct ip *);
+       
+       if (changed_header) {
+               ip->ip_len = ntohs(ip->ip_len) - hlen;
+               ip->ip_off = ntohs(ip->ip_off);
+       }
+       
+       if (!(ip_protox[ip->ip_p]->pr_flags & PR_PROTOLOCK)) {
+               lck_mtx_lock(inet_domain_mutex);
+               (*ip_protox[ip->ip_p]->pr_input)(m, hlen);
+               lck_mtx_unlock(inet_domain_mutex);
+       }       
+       else     
+               (*ip_protox[ip->ip_p]->pr_input)(m, hlen);
+               
+}
+
+/* 
+ * ipforward_rt cleared in in_addroute()
+ * when a new route is successfully created.
+ */
 static struct  sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
-static struct  route ipforward_rt;
 
 /*
  * Ip input routine.  Checksum and byte swap header.  If fragmented
@@ -333,46 +488,80 @@ ip_input(struct mbuf *m)
 {
        struct ip *ip;
        struct ipq *fp;
-       struct in_ifaddr *ia;
-       int    i, hlen, mff;
+       struct in_ifaddr *ia = NULL;
+       int    i, hlen, mff, checkif;
        u_short sum;
-#if !IPDIVERT /* dummy variable for the firewall code to play with */
-        u_short ip_divert_cookie = 0 ;
-#endif
-#if COMPAT_IPFW
-       struct ip_fw_chain *rule = NULL ;
-#endif
+       struct in_addr pkt_dst;
+       u_int32_t div_info = 0;         /* packet divert/tee info */
+       struct ip_fw_args args;
+       ipfilter_t inject_filter_ref = 0;
+       struct m_tag    *tag;
+       struct route    ipforward_rt = { 0 };
+       
+       lck_mtx_lock(ip_mutex);
+
+       args.eh = NULL;
+       args.oif = NULL;
+       args.rule = NULL;
+       args.divert_rule = 0;                   /* divert cookie */
+       args.next_hop = NULL;
+
+       /* Grab info from mtags prepended to the chain */
+#if DUMMYNET
+       if ((tag = m_tag_locate(m, 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;
+               
+               m_tag_delete(m, tag);
+       }
+#endif /* DUMMYNET */
 
-#if IPFIREWALL && DUMMYNET
-        /*
-         * dummynet packet are prepended a vestigial mbuf with
-         * m_type = MT_DUMMYNET and m_data pointing to the matching
-         * rule.
-         */
-        if (m->m_type == MT_DUMMYNET) {
-            struct mbuf *m0 = m ;
-            rule = (struct ip_fw_chain *)(m->m_data) ;
-            m = m->m_next ;
-            FREE(m0, M_IPFW);
-            ip = mtod(m, struct ip *);
-            hlen = IP_VHL_HL(ip->ip_vhl) << 2;
-            goto iphack ;
-        } else
-            rule = NULL ;
-#endif
+       if ((tag = m_tag_locate(m, 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;
 
+               m_tag_delete(m, tag);
+       }
+       if ((tag = m_tag_locate(m, 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;
+
+               m_tag_delete(m, tag);
+       }
+       
 #if    DIAGNOSTIC
        if (m == NULL || (m->m_flags & M_PKTHDR) == 0)
                panic("ip_input no HDR");
 #endif
+
+       if (args.rule) {        /* dummynet already filtered us */
+            ip = mtod(m, struct ip *);
+            hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+            inject_filter_ref = ipf_get_inject_filter(m);
+            goto iphack ;
+       }
+       
        /*
-        * If no IP addresses have been set yet but the interfaces
-        * are receiving, can't do anything with incoming packets yet.
-        * XXX This is broken! We should be able to receive broadcasts
-        * and multicasts even without any local addresses configured.
+        * No need to proccess packet twice if we've 
+        * already seen it
         */
-       if (TAILQ_EMPTY(&in_ifaddrhead))
-               goto bad;
+       inject_filter_ref = ipf_get_inject_filter(m);
+       if (inject_filter_ref != 0) {
+               lck_mtx_unlock(ip_mutex);
+               ip = mtod(m, struct ip *);
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+               ip->ip_len = ntohs(ip->ip_len) - hlen;
+               ip->ip_off = ntohs(ip->ip_off);
+               ip_proto_dispatch_in(m, hlen, ip->ip_p, inject_filter_ref);
+               return;
+       }
+
        ipstat.ips_total++;
 
        if (m->m_pkthdr.len < sizeof(struct ip))
@@ -381,6 +570,7 @@ ip_input(struct mbuf *m)
        if (m->m_len < sizeof (struct ip) &&
            (m = m_pullup(m, sizeof (struct ip))) == 0) {
                ipstat.ips_toosmall++;
+               lck_mtx_unlock(ip_mutex);
                return;
        }
        ip = mtod(m, struct ip *);
@@ -401,19 +591,43 @@ ip_input(struct mbuf *m)
        if (hlen > m->m_len) {
                if ((m = m_pullup(m, hlen)) == 0) {
                        ipstat.ips_badhlen++;
+                       lck_mtx_unlock(ip_mutex);
                        return;
                }
                ip = mtod(m, struct ip *);
        }
 
-       if (m->m_pkthdr.rcvif->if_hwassist == 0)        
-               m->m_pkthdr.csum_flags = 0;
+       /* 127/8 must not appear on wire - RFC1122 */
+       if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
+           (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
+               if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
+                       ipstat.ips_badaddr++;
+                       goto bad;
+               }
+       }
 
-        if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
-                sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
-        } else 
-               sum = in_cksum(m, hlen);
+       /* IPv4 Link-Local Addresses as defined in <draft-ietf-zeroconf-ipv4-linklocal-05.txt> */
+       if ((IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) || 
+           IN_LINKLOCAL(ntohl(ip->ip_src.s_addr)))) {
+               ip_linklocal_stat.iplls_in_total++;
+               if (ip->ip_ttl != MAXTTL) {
+                       ip_linklocal_stat.iplls_in_badttl++;
+                       /* Silently drop link local traffic with bad TTL */
+                       if (!ip_linklocal_in_allowbadttl)
+                               goto bad;
+               }
+       }
+       if ((IF_HWASSIST_CSUM_FLAGS(m->m_pkthdr.rcvif->if_hwassist) == 0) 
+           || (apple_hwcksum_rx == 0) ||
+          ((m->m_pkthdr.csum_flags & CSUM_TCP_SUM16) && ip->ip_p != IPPROTO_TCP)) {
+                       m->m_pkthdr.csum_flags = 0; /* invalidate HW generated checksum flags */
+       }
 
+       if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
+               sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
+       } else {
+               sum = in_cksum(m, hlen);
+       }
        if (sum) {
                ipstat.ips_badsum++;
                goto bad;
@@ -427,7 +641,6 @@ ip_input(struct mbuf *m)
                ipstat.ips_badlen++;
                goto bad;
        }
-       NTOHS(ip->ip_id);
        NTOHS(ip->ip_off);
 
        /*
@@ -442,12 +655,22 @@ tooshort:
                goto bad;
        }
        if (m->m_pkthdr.len > ip->ip_len) {
+               /* Invalidate hwcksuming */
+               m->m_pkthdr.csum_flags = 0;
+               m->m_pkthdr.csum_data = 0;
+
                if (m->m_len == m->m_pkthdr.len) {
                        m->m_len = ip->ip_len;
                        m->m_pkthdr.len = ip->ip_len;
                } else
                        m_adj(m, ip->ip_len - m->m_pkthdr.len);
        }
+
+#if IPSEC
+       if (ipsec_bypass == 0 && ipsec_gethist(m, NULL))
+               goto pass;
+#endif
+
        /*
         * IpHack's section.
         * Right now when no processing on packet has done
@@ -463,95 +686,73 @@ tooshort:
 #if defined(IPFIREWALL) && defined(DUMMYNET)
 iphack:
 #endif
-#if COMPAT_IPFW
-       if (ip_fw_chk_ptr) {
+       /*
+        * Check if we want to allow this packet to be processed.
+        * Consider it to be bad if not.
+        */
+       if (fr_checkp) {
+               struct  mbuf    *m1 = m;
+
+               if (fr_checkp(ip, hlen, m->m_pkthdr.rcvif, 0, &m1) || !m1) {
+                       lck_mtx_unlock(ip_mutex);
+                       return;
+               }
+               ip = mtod(m = m1, struct ip *);
+       }
+       if (fw_enable && IPFW_LOADED) {
 #if IPFIREWALL_FORWARD
                /*
                 * If we've been forwarded from the output side, then
                 * skip the firewall a second time
                 */
-               if (ip_fw_fwd_addr)
+               if (args.next_hop)
                        goto ours;
 #endif /* IPFIREWALL_FORWARD */
-               i = (*ip_fw_chk_ptr)(&ip, hlen, NULL, &ip_divert_cookie,
-                                       &m, &rule, &ip_fw_fwd_addr);
-               /*
-                * see the comment in ip_output for the return values
-                * produced by the firewall.
-                */
-               if (!m) /* packet discarded by firewall */
-                       return ;
-               if (i == 0 && ip_fw_fwd_addr == NULL) /* common case */
-                       goto pass ;
+
+               args.m = m;
+               lck_mtx_unlock(ip_mutex);
+
+               i = ip_fw_chk_ptr(&args);
+               m = args.m;
+
+               if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
+                       if (m)
+                               m_freem(m);
+                       return;
+               }
+               ip = mtod(m, struct ip *); /* just in case m changed */
+               if (i == 0 && args.next_hop == NULL) {  /* common case */
+                       lck_mtx_lock(ip_mutex);
+                       goto pass;
+               }
 #if DUMMYNET
-                if (i & 0x10000) {
-                        /* send packet to the appropriate pipe */
-                        dummynet_io(i&0xffff,DN_TO_IP_IN,m,NULL,NULL,0, rule);
-                       return ;
+                if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG) != 0) {
+                       /* Send packet to the appropriate pipe */
+                       ip_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args);
+                       return;
                }
-#endif
+#endif /* DUMMYNET */
 #if IPDIVERT
-               if (i > 0 && i < 0x10000) {
-                       /* Divert packet */
-                       frag_divert_port = i & 0xffff ;
+               if (i != 0 && (i & IP_FW_PORT_DYNT_FLAG) == 0) {
+                       /* Divert or tee packet */
+                       lck_mtx_lock(ip_mutex);
+                       div_info = i;
                        goto ours;
                }
 #endif
 #if IPFIREWALL_FORWARD
-               if (i == 0 && ip_fw_fwd_addr != NULL)
-                       goto pass ;
+               if (i == 0 && args.next_hop != NULL) {
+                       lck_mtx_lock(ip_mutex);
+                       goto pass;
+               }
 #endif
                /*
                 * if we get here, the packet must be dropped
                 */
-                       m_freem(m);
-                       return;
-       }
-pass:
-
-        if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN)) {
-#if IPFIREWALL_FORWARD
-               ip_fw_fwd_addr = NULL;
-#endif
-               return;
-       }
-#endif /* !COMPAT_IPFW */
-
-#if defined(PM)
-       /*
-        * Process ip-filter/NAT.
-        * Return TRUE  if this packed is discarded.
-        * Return FALSE if this packed is accepted.
-        */
-
-       if (doNatFil && pm_in(m->m_pkthdr.rcvif, ip, m))
-           return;
-#endif
-
-#if defined(NATPT)
-       /*
-        *
-        */
-       if (ip6_protocol_tr)
-       {
-           struct mbuf *m1 = NULL;
-           
-           switch (natpt_in4(m, &m1))
-           {
-             case IPPROTO_IP:                                  goto dooptions;
-             case IPPROTO_IPV4:        ip_forward(m1, 0);      break;
-             case IPPROTO_IPV6:        ip6_forward(m1, 1);     break;
-             case IPPROTO_MAX:                 /* discard this packet  */
-             default:
-           }
-
-           if (m != m1)
                m_freem(m);
-
-           return;
+               return;
        }
-  dooptions:
-#endif
+pass:
 
        /*
         * Process options and, if not destined for us,
@@ -560,10 +761,8 @@ pass:
         * to be sent and the original packet to be freed).
         */
        ip_nhops = 0;           /* for source routed packets */
-       if (hlen > sizeof (struct ip) && ip_dooptions(m)) {
-#if IPFIREWALL_FORWARD
-               ip_fw_fwd_addr = NULL;
-#endif
+       if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, args.next_hop, &ipforward_rt)) {
+               lck_mtx_unlock(ip_mutex);
                return;
        }
 
@@ -578,40 +777,79 @@ pass:
 
        /*
         * Check our list of addresses, to see if the packet is for us.
+        * If we don't have any addresses, assume any unicast packet
+        * we receive might be for us (and let the upper layers deal
+        * with it).
         */
-       for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
-                                       ia = TAILQ_NEXT(ia, ia_link)) {
-#define        satosin(sa)     ((struct sockaddr_in *)(sa))
+       if (TAILQ_EMPTY(&in_ifaddrhead) &&
+           (m->m_flags & (M_MCAST|M_BCAST)) == 0)
+               goto ours;
 
-               if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
-                       goto ours;
+       /*
+        * Cache the destination address of the packet; this may be
+        * changed by use of 'ipfw fwd'.
+        */
+       pkt_dst = args.next_hop == NULL ?
+           ip->ip_dst : args.next_hop->sin_addr;
 
-               if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
-                       goto ours;
+       /*
+        * Enable a consistency check between the destination address
+        * and the arrival interface for a unicast packet (the RFC 1122
+        * strong ES model) if IP forwarding is disabled and the packet
+        * is not locally generated and the packet is not subject to
+        * 'ipfw fwd'.
+        *
+        * XXX - Checking also should be disabled if the destination
+        * address is ipnat'ed to a different interface.
+        *
+        * XXX - Checking is incompatible with IP aliases added
+        * to the loopback interface instead of the interface where
+        * the packets are received.
+        */
+       checkif = ip_checkinterface && (ipforwarding == 0) && 
+           ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
+           (args.next_hop == NULL);
 
-#if IPFIREWALL_FORWARD
+       lck_mtx_lock(rt_mtx);
+       TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
+#define        satosin(sa)     ((struct sockaddr_in *)(sa))
+
+               if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
+                       lck_mtx_unlock(rt_mtx);
+                       goto ours;
+               }
+               
                /*
-                * If the addr to forward to is one of ours, we pretend to
-                * be the destination for this packet.
+                * If the address matches, verify that the packet
+                * arrived via the correct interface if checking is
+                * enabled.
                 */
-               if (ip_fw_fwd_addr == NULL) {
-                       if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
-                               goto ours;
-               } else if (IA_SIN(ia)->sin_addr.s_addr ==
-                                        ip_fw_fwd_addr->sin_addr.s_addr)
-                       goto ours;
-#else
-               if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
+               if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr && 
+                   (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) {
+                       lck_mtx_unlock(rt_mtx);
                        goto ours;
-#endif
-               if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
+               }
+               /*
+                * Only accept broadcast packets that arrive via the
+                * matching interface.  Reception of forwarded directed
+                * broadcasts would be handled via ip_forward() and
+                * ether_output() with the loopback into the stack for
+                * SIMPLEX interfaces handled by ether_output().
+                */
+               if ((!checkif || ia->ia_ifp == m->m_pkthdr.rcvif) &&
+                   ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
                        if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
-                           ip->ip_dst.s_addr)
+                           pkt_dst.s_addr) {
+                               lck_mtx_unlock(rt_mtx);
                                goto ours;
-                       if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
+                       }
+                       if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr) {
+                               lck_mtx_unlock(rt_mtx);
                                goto ours;
+                       }
                }
        }
+       lck_mtx_unlock(rt_mtx);
        if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
                struct in_multi *inm;
                if (ip_mrouter) {
@@ -622,21 +860,17 @@ pass:
                         * The packet is returned (relatively) intact; if
                         * ip_mforward() returns a non-zero value, the packet
                         * must be discarded, else it may be accepted below.
-                        *
-                        * (The IP ident field is put in the same byte order
-                        * as expected when ip_mforward() is called from
-                        * ip_output().)
                         */
-                       ip->ip_id = htons(ip->ip_id);
-                       if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
+                       if (ip_mforward &&
+                           ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
                                ipstat.ips_cantforward++;
                                m_freem(m);
+                               lck_mtx_unlock(ip_mutex);
                                return;
                        }
-                       ip->ip_id = ntohs(ip->ip_id);
 
                        /*
-                        * The process-level routing demon needs to receive
+                        * The process-level routing daemon needs to receive
                         * all multicast IGMP packets, whether or not this
                         * host belongs to their destination groups.
                         */
@@ -652,6 +886,7 @@ pass:
                if (inm == NULL) {
                        ipstat.ips_notmember++;
                        m_freem(m);
+                       lck_mtx_unlock(ip_mutex);
                        return;
                }
                goto ours;
@@ -661,13 +896,26 @@ pass:
        if (ip->ip_dst.s_addr == INADDR_ANY)
                goto ours;
 
-       if (m->m_pkthdr.rcvif 
+       /* Allow DHCP/BootP responses through */
+       if (m->m_pkthdr.rcvif != NULL
            && (m->m_pkthdr.rcvif->if_eflags & IFEF_AUTOCONFIGURING)
+           && hlen == sizeof(struct ip)
            && ip->ip_p == IPPROTO_UDP) {
-               goto ours;
+               struct udpiphdr *ui;
+               if (m->m_len < sizeof(struct udpiphdr)
+                   && (m = m_pullup(m, sizeof(struct udpiphdr))) == 0) {
+                       udpstat.udps_hdrops++;
+                       lck_mtx_unlock(ip_mutex);
+                       return;
+               }
+               ui = mtod(m, struct udpiphdr *);
+               if (ntohs(ui->ui_dport) == IPPORT_BOOTPC) {
+                       goto ours;
+               }
+               ip = mtod(m, struct ip *); /* in case it changed */
        }
 
-#if defined(NFAITH) && NFAITH > 0
+#if defined(NFAITH) && 0 < NFAITH
        /*
         * FAITH(Firewall Aided Internet Translator)
         */
@@ -677,23 +925,31 @@ pass:
                                goto ours;
                }
                m_freem(m);
+               lck_mtx_unlock(ip_mutex);
                return;
        }
 #endif
+       lck_mtx_unlock(ip_mutex);
        /*
         * Not for us; forward if possible and desirable.
         */
        if (ipforwarding == 0) {
                ipstat.ips_cantforward++;
                m_freem(m);
-       } else
-               ip_forward(m, 0);
-#if IPFIREWALL_FORWARD
-       ip_fw_fwd_addr = NULL;
-#endif
+       } else {
+               ip_forward(m, 0, args.next_hop, &ipforward_rt);
+       }
        return;
 
 ours:
+#ifndef __APPLE__
+       /* Darwin does not have an if_data in ifaddr */
+       /* Count the packet in the ip address stats */
+       if (ia != NULL) {
+               ia->ia_ifa.if_ipackets++;
+               ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
+       }
+#endif
 
        /*
         * If offset or IP_MF are set, must reassemble.
@@ -703,20 +959,38 @@ ours:
         * but it's not worth the time; just let them time out.)
         */
        if (ip->ip_off & (IP_MF | IP_OFFMASK | IP_RF)) {
-               if (m->m_flags & M_EXT) {               /* XXX */
-                       if ((m = m_pullup(m, hlen)) == 0) {
-                               ipstat.ips_toosmall++;
-#if IPDIVERT
-                               frag_divert_port = 0;
-                               ip_divert_cookie = 0;
-#endif
-#if IPFIREWALL_FORWARD
-                               ip_fw_fwd_addr = NULL;
-#endif
-                               return;
+
+               /* If maxnipq is 0, never accept fragments. */
+               if (maxnipq == 0) {
+                       ipstat.ips_fragments++;
+                       ipstat.ips_fragdropped++;
+                       goto bad;
+               }
+               
+               /*
+                * If we will exceed the number of fragments in queues, timeout the
+                * oldest fragemented packet to make space.
+                */
+               if (currentfrags >= maxfrags) {
+                       fp = TAILQ_LAST(&ipq_list, ipq_list);
+                       ipstat.ips_fragtimeout += fp->ipq_nfrags;
+                       
+                       if (ip->ip_id == fp->ipq_id &&
+                               ip->ip_src.s_addr == fp->ipq_src.s_addr &&
+                               ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
+                               ip->ip_p == fp->ipq_p) {
+                               /*
+                                * If we match the fragment queue we were going to
+                                * discard, drop this packet too.
+                                */
+                               ipstat.ips_fragdropped++;
+                               ip_freef(fp);
+                               goto bad;
                        }
-                       ip = mtod(m, struct ip *);
+                       
+                       ip_freef(fp);
                }
+
                sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
                /*
                 * Look for queue of fragments
@@ -729,168 +1003,202 @@ ours:
                            ip->ip_p == fp->ipq_p)
                                goto found;
 
-               fp = 0;
-
-               /* check if there's a place for the new queue */
-               if (nipq > maxnipq) {
+               /*
+                * Enforce upper bound on number of fragmented packets
+                * for which we attempt reassembly;
+                * If maxnipq is -1, accept all fragments without limitation.
+                */
+               if ((nipq > maxnipq) && (maxnipq > 0)) {
                    /*
-                    * drop something from the tail of the current queue
-                    * before proceeding further
+                    * drop the oldest fragment before proceeding further
                     */
-                   if (ipq[sum].prev == &ipq[sum]) {   /* gak */
-                       for (i = 0; i < IPREASS_NHASH; i++) {
-                           if (ipq[i].prev != &ipq[i]) {
-                               ip_freef(ipq[i].prev);
-                               break;
-                           }
-                       }
-                   } else
-                       ip_freef(ipq[sum].prev);
+                   fp = TAILQ_LAST(&ipq_list, ipq_list);
+                   ipstat.ips_fragtimeout += fp->ipq_nfrags;
+                   ip_freef(fp);
                }
+
+               fp = NULL;
+
 found:
                /*
                 * Adjust ip_len to not reflect header,
-                * set ip_mff if more fragments are expected,
                 * convert offset of this to bytes.
                 */
                ip->ip_len -= hlen;
-               mff = (ip->ip_off & IP_MF) != 0;
-               if (mff) {
+               if (ip->ip_off & IP_MF) {
                        /*
                         * Make sure that fragments have a data length
-                        * that's a non-zero multiple of 8 bytes.
+                                * that's a non-zero multiple of 8 bytes.
                         */
                        if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
                                ipstat.ips_toosmall++; /* XXX */
                                goto bad;
                        }
                        m->m_flags |= M_FRAG;
+               } else {
+                       /* Clear the flag in case packet comes from loopback */
+                       m->m_flags &= ~M_FRAG;
                }
                ip->ip_off <<= 3;
 
                /*
-                * If datagram marked as having more fragments
-                * or if this is not the first fragment,
-                * attempt reassembly; if it succeeds, proceed.
+                * Attempt reassembly; if it succeeds, proceed.
+                * ip_reass() will return a different mbuf, and update
+                * the divert info in div_info and args.divert_rule.
                 */
-               if (mff || ip->ip_off) {
                        ipstat.ips_fragments++;
                        m->m_pkthdr.header = ip;
-                       ip = ip_reass(m, fp, &ipq[sum]);
-                       if (ip == 0) {
-#if    IPFIREWALL_FORWARD
-                               ip_fw_fwd_addr = NULL;
+#if IPDIVERT
+                       m = ip_reass(m,
+                           fp, &ipq[sum], &div_info, &args.divert_rule);
+#else
+                       m = ip_reass(m, fp, &ipq[sum]);
 #endif
+                       if (m == 0) {
+                               lck_mtx_unlock(ip_mutex);
                                return;
                        }
-                       /* Get the length of the reassembled packets header */
-                       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
                        ipstat.ips_reassembled++;
-                       m = dtom(ip);
+                       ip = mtod(m, struct ip *);
+                       /* Get the header length of the reassembled packet */
+                       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 #if IPDIVERT
-                       if (frag_divert_port) {
-                               struct mbuf m;
-                               m.m_next = 0;
-                               m.m_len = hlen;
-                               m.m_data = (char *) ip;
+                       /* Restore original checksum before diverting packet */
+                       if (div_info != 0) {
                                ip->ip_len += hlen;
                                HTONS(ip->ip_len);
                                HTONS(ip->ip_off);
-                               HTONS(ip->ip_id);
                                ip->ip_sum = 0;
-                               ip->ip_sum = in_cksum(&m, hlen);
-                               NTOHS(ip->ip_id);
+                               ip->ip_sum = in_cksum(m, hlen);
                                NTOHS(ip->ip_off);
                                NTOHS(ip->ip_len);
                                ip->ip_len -= hlen;
                        }
 #endif
                } else
-                       if (fp)
-                               ip_freef(fp);
-       } else
                ip->ip_len -= hlen;
 
 #if IPDIVERT
        /*
-        * Divert reassembled packets to the divert protocol if required
-        *  If divert port is null then cookie should be too,
-        * so we shouldn't need to clear them here. Assume ip_divert does so.
+        * Divert or tee packet to the divert protocol if required.
+        *
+        * If div_info is zero then cookie should be too, so we shouldn't
+        * need to clear them here.  Assume divert_packet() does so also.
         */
-       if (frag_divert_port) {
+       if (div_info != 0) {
+               struct mbuf *clone = NULL;
+
+               /* Clone packet if we're doing a 'tee' */
+               if ((div_info & IP_FW_PORT_TEE_FLAG) != 0)
+                       clone = m_dup(m, M_DONTWAIT);
+
+               /* Restore packet header fields to original values */
+               ip->ip_len += hlen;
+               HTONS(ip->ip_len);
+               HTONS(ip->ip_off);
+
+               /* Deliver packet to divert input routine */
                ipstat.ips_delivered++;
-               ip_divert_port = frag_divert_port;
-               frag_divert_port = 0;
-               (*ip_protox[IPPROTO_DIVERT]->pr_input)(m, hlen);
-               return;
-       }
+               lck_mtx_unlock(ip_mutex);
+               divert_packet(m, 1, div_info & 0xffff, args.divert_rule);
 
-       /* Don't let packets divert themselves */
-       if (ip->ip_p == IPPROTO_DIVERT) {
-               ipstat.ips_noproto++;
-               goto bad;
+               /* If 'tee', continue with original packet */
+               if (clone == NULL) {
+                       return;
+               }
+               lck_mtx_lock(ip_mutex);
+               m = clone;
+               ip = mtod(m, struct ip *);
        }
+#endif
 
+#if IPSEC
+       /*
+        * enforce IPsec policy checking if we are seeing last header.
+        * note that we do not visit this with protocols with pcb layer
+        * code - like udp/tcp/raw ip.
+        */
+       if (ipsec_bypass == 0 && (ip_protox[ip->ip_p]->pr_flags & PR_LASTHDR) != 0) {
+               lck_mtx_lock(sadb_mutex);
+               if (ipsec4_in_reject(m, NULL)) {
+                       ipsecstat.in_polvio++;
+                       lck_mtx_unlock(sadb_mutex);
+                       goto bad;
+               }
+               lck_mtx_unlock(sadb_mutex);
+       }
 #endif
 
        /*
         * Switch out to protocol's input routine.
         */
        ipstat.ips_delivered++;
-
-       KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, 
-                    ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
-
-       (*ip_protox[ip->ip_p]->pr_input)(m, hlen);
-#if    IPFIREWALL_FORWARD
-       ip_fw_fwd_addr = NULL;  /* tcp needed it */
-#endif
-       return;
+       {
+               if (args.next_hop && ip->ip_p == IPPROTO_TCP) {
+                       /* TCP needs IPFORWARD info if available */
+                       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);
+                       if (fwd_tag == NULL) {
+                               goto bad;
+                       }
+                       
+                       ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1);
+                       ipfwd_tag->next_hop = args.next_hop;
+
+                       m_tag_prepend(m, fwd_tag);
+       
+                       KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, 
+                            ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
+       
+                       lck_mtx_unlock(ip_mutex);
+       
+                       /* TCP deals with its own locking */
+                       ip_proto_dispatch_in(m, hlen, ip->ip_p, 0);
+               } else {
+                       KERNEL_DEBUG(DBG_LAYER_END, ip->ip_dst.s_addr, 
+                            ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
+               
+                       lck_mtx_unlock(ip_mutex);
+                       ip_proto_dispatch_in(m, hlen, ip->ip_p, 0);
+               }
+               
+               return;
+       }
 bad:
-#if    IPFIREWALL_FORWARD
-       ip_fw_fwd_addr = NULL;
-#endif
        KERNEL_DEBUG(DBG_LAYER_END, 0,0,0,0,0);
+       lck_mtx_unlock(ip_mutex);
        m_freem(m);
 }
 
 /*
- * IP software interrupt routine - to go away sometime soon
+ * Take incoming datagram fragment and try to reassemble it into
+ * whole datagram.  If a chain for reassembly of this datagram already
+ * exists, then it is given as fp; otherwise have to make a chain.
+ *
+ * When IPDIVERT enabled, keep additional state with each packet that
+ * tells us if we need to divert or tee the packet we're building.
  */
-void
-ipintr(void)
-{
-       int s;
-       struct mbuf *m;
-
-       KERNEL_DEBUG(DBG_FNC_IP_INPUT | DBG_FUNC_START, 0,0,0,0,0);
-
-       while(1) {
-               s = splimp();
-               IF_DEQUEUE(&ipintrq, m);
-               splx(s);
-               if (m == 0) {
-                 KERNEL_DEBUG(DBG_FNC_IP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
-                 return;
-               }
-
-               ip_input(m);
-       }
-}
 
-NETISR_SET(NETISR_IP, ipintr);
-  
-/*
- * Take incoming datagram fragment and try to
- * reassemble it into whole datagram.  If a chain for
- * reassembly of this datagram already exists, then it
- * is given as fp; otherwise have to make a chain.
- */
-static struct ip *
+static struct mbuf *
+#if IPDIVERT
+ip_reass(m, fp, where, divinfo, divcookie)
+#else
 ip_reass(m, fp, where)
+#endif
        register struct mbuf *m;
        register struct ipq *fp;
        struct   ipq    *where;
+#if IPDIVERT
+#ifdef IPDIVERT_44
+       u_int32_t *divinfo;
+#else
+       u_int16_t *divinfo;
+#endif
+       u_int16_t *divcookie;
+#endif
 {
        struct ip *ip = mtod(m, struct ip *);
        register struct mbuf *p = 0, *q, *nq;
@@ -914,8 +1222,9 @@ ip_reass(m, fp, where)
                if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
                        goto dropfrag;
                fp = mtod(t, struct ipq *);
-               insque((void *) fp, (void *) where);
+               insque((void*)fp, (void*)where);
                nipq++;
+               fp->ipq_nfrags = 1;
                fp->ipq_ttl = IPFRAGTTL;
                fp->ipq_p = ip->ip_p;
                fp->ipq_id = ip->ip_id;
@@ -924,10 +1233,17 @@ ip_reass(m, fp, where)
                fp->ipq_frags = m;
                m->m_nextpkt = NULL;
 #if IPDIVERT
+#ifdef IPDIVERT_44
+               fp->ipq_div_info = 0;
+#else
                fp->ipq_divert = 0;
+#endif
                fp->ipq_div_cookie = 0;
 #endif
+               TAILQ_INSERT_HEAD(&ipq_list, fp, ipq_list);
                goto inserted;
+       } else {
+               fp->ipq_nfrags++;
        }
 
 #define GETIP(m)       ((struct ip*)((m)->m_pkthdr.header))
@@ -944,14 +1260,17 @@ ip_reass(m, fp, where)
         * our data already.  If so, drop the data from the incoming
         * segment.  If it provides all of our data, drop us, otherwise
         * stick new segment in the proper place.
+        *
+        * If some of the data is dropped from the the preceding
+        * segment, then it's checksum is invalidated.
         */
        if (p) {
                i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
                if (i > 0) {
                        if (i >= ip->ip_len)
                                goto dropfrag;
-                       m_adj(dtom(ip), i);
-                        m->m_pkthdr.csum_flags = 0;
+                       m_adj(m, i);
+                       m->m_pkthdr.csum_flags = 0;
                        ip->ip_off += i;
                        ip->ip_len -= i;
                }
@@ -974,40 +1293,65 @@ ip_reass(m, fp, where)
                        GETIP(q)->ip_len -= i;
                        GETIP(q)->ip_off += i;
                        m_adj(q, i);
-                        q->m_pkthdr.csum_flags = 0;
+                       q->m_pkthdr.csum_flags = 0;
                        break;
                }
                nq = q->m_nextpkt;
                m->m_nextpkt = nq;
+               ipstat.ips_fragdropped++;
+               fp->ipq_nfrags--;
                m_freem(q);
        }
 
 inserted:
+       currentfrags++;
 
 #if IPDIVERT
        /*
-        * Any fragment diverting causes the whole packet to divert
+        * Transfer firewall instructions to the fragment structure.
+        * Only trust info in the fragment at offset 0.
         */
-       if (frag_divert_port) {
-               fp->ipq_divert = frag_divert_port;
-               fp->ipq_div_cookie = ip_divert_cookie;
+       if (ip->ip_off == 0) {
+#ifdef IPDIVERT_44
+       fp->ipq_div_info = *divinfo;
+#else
+       fp->ipq_divert = *divinfo;
+#endif
+       fp->ipq_div_cookie = *divcookie;
        }
-       frag_divert_port = 0;
-       ip_divert_cookie = 0;
+       *divinfo = 0;
+       *divcookie = 0;
 #endif
 
        /*
-        * Check for complete reassembly.
+        * Check for complete reassembly and perform frag per packet
+        * limiting.
+        *
+        * Frag limiting is performed here so that the nth frag has
+        * a chance to complete the packet before we drop the packet.
+        * As a result, n+1 frags are actually allowed per packet, but
+        * only n will ever be stored. (n = maxfragsperpacket.)
+        *
         */
        next = 0;
        for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
-               if (GETIP(q)->ip_off != next)
+               if (GETIP(q)->ip_off != next) {
+                       if (fp->ipq_nfrags > maxfragsperpacket) {
+                               ipstat.ips_fragdropped += fp->ipq_nfrags;
+                               ip_freef(fp);
+                       }
                        return (0);
+               }
                next += GETIP(q)->ip_len;
        }
        /* Make sure the last packet didn't have the IP_MF flag */
-       if (p->m_flags & M_FRAG)
+       if (p->m_flags & M_FRAG) {
+               if (fp->ipq_nfrags > maxfragsperpacket) {
+                       ipstat.ips_fragdropped += fp->ipq_nfrags;
+                       ip_freef(fp);
+               }
                return (0);
+       }
 
        /*
         * Reassembly is complete.  Make sure the packet is a sane size.
@@ -1016,6 +1360,7 @@ inserted:
        ip = GETIP(q);
        if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
                ipstat.ips_toolong++;
+               ipstat.ips_fragdropped += fp->ipq_nfrags;
                ip_freef(fp);
                return (0);
        }
@@ -1033,20 +1378,24 @@ inserted:
                nq = q->m_nextpkt;
                q->m_nextpkt = NULL;
                if (q->m_pkthdr.csum_flags & CSUM_TCP_SUM16) 
-                       m->m_pkthdr.csum_flags = 0;
+                       m->m_pkthdr.csum_flags = 0;
                else {
-                       m->m_pkthdr.csum_data += q->m_pkthdr.csum_data ;
-                               m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
+                       m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
+                       m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
                }
                m_cat(m, q);
        }
 
 #if IPDIVERT
        /*
-        * extract divert port for packet, if any
+        * Extract firewall instructions from the fragment structure.
         */
-       frag_divert_port = fp->ipq_divert;
-       ip_divert_cookie = fp->ipq_div_cookie;
+#ifdef IPDIVERT_44
+       *divinfo = fp->ipq_div_info;
+#else
+       *divinfo = fp->ipq_divert;
+#endif
+       *divcookie = fp->ipq_div_cookie;
 #endif
 
        /*
@@ -1058,7 +1407,9 @@ inserted:
        ip->ip_len = next;
        ip->ip_src = fp->ipq_src;
        ip->ip_dst = fp->ipq_dst;
-       remque((void *) fp);
+       remque((void*)fp);
+       TAILQ_REMOVE(&ipq_list, fp, ipq_list);
+       currentfrags -= fp->ipq_nfrags;
        nipq--;
        (void) m_free(dtom(fp));
        m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
@@ -1066,18 +1417,20 @@ inserted:
        /* some debugging cruft by sklower, below, will go away soon */
        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
                register int plen = 0;
-               for (t = m; m; m = m->m_next)
-                       plen += m->m_len;
-               t->m_pkthdr.len = plen;
+               for (t = m; t; t = t->m_next)
+                       plen += t->m_len;
+               m->m_pkthdr.len = plen;
        }
-       return (ip);
+       return (m);
 
 dropfrag:
 #if IPDIVERT
-       frag_divert_port = 0;
-       ip_divert_cookie = 0;
+       *divinfo = 0;
+       *divcookie = 0;
 #endif
        ipstat.ips_fragdropped++;
+       if (fp != 0)
+               fp->ipq_nfrags--;
        m_freem(m);
        return (0);
 
@@ -1092,14 +1445,10 @@ static void
 ip_freef(fp)
        struct ipq *fp;
 {
-       register struct mbuf *q;
-
-       while (fp->ipq_frags) {
-               q = fp->ipq_frags;
-               fp->ipq_frags = q->m_nextpkt;
-               m_freem(q);
-       }
-       remque((void *) fp);
+       currentfrags -= fp->ipq_nfrags;
+       m_freem_list(fp->ipq_frags);
+       remque((void*)fp);
+       TAILQ_REMOVE(&ipq_list, fp, ipq_list);
        (void) m_free(dtom(fp));
        nipq--;
 }
@@ -1113,9 +1462,8 @@ void
 ip_slowtimo()
 {
        register struct ipq *fp;
-       int s = splnet();
        int i;
-
+       lck_mtx_lock(ip_mutex);
        for (i = 0; i < IPREASS_NHASH; i++) {
                fp = ipq[i].next;
                if (fp == 0)
@@ -1124,13 +1472,28 @@ ip_slowtimo()
                        --fp->ipq_ttl;
                        fp = fp->next;
                        if (fp->prev->ipq_ttl == 0) {
-                               ipstat.ips_fragtimeout++;
+                               ipstat.ips_fragtimeout += fp->prev->ipq_nfrags;
                                ip_freef(fp->prev);
                        }
                }
        }
+       /*
+        * If we are over the maximum number of fragments
+        * (due to the limit being lowered), drain off
+        * enough to get down to the new limit.
+        */
+       if (maxnipq >= 0 && nipq > maxnipq) {
+       for (i = 0; i < IPREASS_NHASH; i++) {
+                       while (nipq > maxnipq &&
+                               (ipq[i].next != &ipq[i])) {
+                               ipstat.ips_fragdropped +=
+                                   ipq[i].next->ipq_nfrags;
+                               ip_freef(ipq[i].next);
+                       }
+               }
+       }
        ipflow_slowtimo();
-       splx(s);
+       lck_mtx_unlock(ip_mutex);
 }
 
 /*
@@ -1141,12 +1504,14 @@ ip_drain()
 {
        int     i;
 
+       lck_mtx_lock(ip_mutex);
        for (i = 0; i < IPREASS_NHASH; i++) {
                while (ipq[i].next != &ipq[i]) {
-                       ipstat.ips_fragdropped++;
+                       ipstat.ips_fragdropped += ipq[i].next->ipq_nfrags;
                        ip_freef(ipq[i].next);
                }
        }
+       lck_mtx_unlock(ip_mutex);
        in_rtqdrain();
 }
 
@@ -1154,12 +1519,16 @@ ip_drain()
  * Do option processing on a datagram,
  * possibly discarding it if bad options are encountered,
  * or forwarding it if source-routed.
+ * The pass argument is used when operating in the IPSTEALTH
+ * mode to tell what options to process:
+ * [LS]SRR (pass 0) or the others (pass 1).
+ * The reason for as many as two passes is that when doing IPSTEALTH,
+ * non-routing options should be processed only if the packet is for us.
  * Returns 1 if packet has been forwarded/freed,
  * 0 if the packet should be processed further.
  */
 static int
-ip_dooptions(m)
-       struct mbuf *m;
+ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop, struct route *ipforward_rt)
 {
        register struct ip *ip = mtod(m, struct ip *);
        register u_char *cp;
@@ -1180,7 +1549,7 @@ ip_dooptions(m)
                        optlen = 1;
                else {
                        if (cnt < IPOPT_OLEN + sizeof(*cp)) {
-                               code = &cp[IPOPT_OLEN] - (u_char *)ip;
+                               code = &cp[IPOPT_OLEN] - (u_char *)ip;
                                goto bad;
                        }
                        optlen = cp[IPOPT_OLEN];
@@ -1205,6 +1574,10 @@ ip_dooptions(m)
                 */
                case IPOPT_LSRR:
                case IPOPT_SSRR:
+                       if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
+                               code = &cp[IPOPT_OLEN] - (u_char *)ip;
+                               goto bad;
+                       }
                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                                goto bad;
@@ -1226,8 +1599,12 @@ ip_dooptions(m)
                                 */
                                break;
                        }
+                       else {
+                               ifafree(&ia->ia_ifa);
+                               ia = NULL;
+                       }
                        off--;                  /* 0 origin */
-                       if (off > optlen - sizeof(struct in_addr)) {
+                       if (off > optlen - (int)sizeof(struct in_addr)) {
                                /*
                                 * End of source route.  Should be for us.
                                 */
@@ -1239,15 +1616,16 @@ ip_dooptions(m)
 
                        if (!ip_dosourceroute) {
                                if (ipforwarding) {
-                                       char buf[16]; /* aaa.bbb.ccc.ddd\0 */
+                                       char buf[MAX_IPv4_STR_LEN];
+                                       char buf2[MAX_IPv4_STR_LEN];
                                        /*
                                         * Acting as a router, so generate ICMP
                                         */
 nosourcerouting:
-                                       strcpy(buf, inet_ntoa(ip->ip_dst));
-                                       log(LOG_WARNING, 
+                                       log(LOG_WARNING,
                                            "attempted source route from %s to %s\n",
-                                           inet_ntoa(ip->ip_src), buf);
+                                           inet_ntop(AF_INET, &ip->ip_src, buf, sizeof(buf)),
+                                           inet_ntop(AF_INET, &ip->ip_dst, buf2, sizeof(buf2)));
                                        type = ICMP_UNREACH;
                                        code = ICMP_UNREACH_SRCFAIL;
                                        goto bad;
@@ -1270,10 +1648,12 @@ nosourcerouting:
                        if (opt == IPOPT_SSRR) {
 #define        INA     struct in_ifaddr *
 #define        SA      struct sockaddr *
-                           if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
-                               ia = (INA)ifa_ifwithnet((SA)&ipaddr);
-                       } else
-                               ia = ip_rtaddr(ipaddr.sin_addr);
+                           if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0) {
+                                       ia = (INA)ifa_ifwithnet((SA)&ipaddr);
+                               }
+                       } else {
+                               ia = ip_rtaddr(ipaddr.sin_addr, ipforward_rt);
+                       }
                        if (ia == 0) {
                                type = ICMP_UNREACH;
                                code = ICMP_UNREACH_SRCFAIL;
@@ -1282,6 +1662,8 @@ nosourcerouting:
                        ip->ip_dst = ipaddr.sin_addr;
                        (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
                            sizeof(struct in_addr));
+                       ifafree(&ia->ia_ifa);
+                       ia = NULL;
                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                        /*
                         * Let ip_intr's mcast routing check handle mcast pkts
@@ -1302,7 +1684,7 @@ nosourcerouting:
                         * If no space remains, ignore.
                         */
                        off--;                  /* 0 origin */
-                       if (off > optlen - sizeof(struct in_addr))
+                       if (off > optlen - (int)sizeof(struct in_addr))
                                break;
                        (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
                            sizeof(ipaddr.sin_addr));
@@ -1310,25 +1692,38 @@ nosourcerouting:
                         * locate outgoing interface; if we're the destination,
                         * use the incoming interface (should be same).
                         */
-                       if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
-                           (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
-                               type = ICMP_UNREACH;
-                               code = ICMP_UNREACH_HOST;
-                               goto bad;
+                       if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0) {
+                               if ((ia = ip_rtaddr(ipaddr.sin_addr, ipforward_rt)) == 0) {
+                                       type = ICMP_UNREACH;
+                                       code = ICMP_UNREACH_HOST;
+                                       goto bad;
+                               }
                        }
                        (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
                            sizeof(struct in_addr));
+                       ifafree(&ia->ia_ifa);
+                       ia = NULL;
                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                        break;
 
                case IPOPT_TS:
                        code = cp - (u_char *)ip;
                        ipt = (struct ip_timestamp *)cp;
-                       if (ipt->ipt_len < 5)
+                       if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
+                               code = (u_char *)&ipt->ipt_len - (u_char *)ip;
+                               goto bad;
+                       }
+                       if (ipt->ipt_ptr < 5) {
+                               code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
                                goto bad;
-                       if (ipt->ipt_ptr > ipt->ipt_len - sizeof(int32_t)) {
-                               if (++ipt->ipt_oflw == 0)
+                       }
+                       if (ipt->ipt_ptr >
+                           ipt->ipt_len - (int)sizeof(int32_t)) {
+                               if (++ipt->ipt_oflw == 0) {
+                                       code = (u_char *)&ipt->ipt_ptr -
+                                           (u_char *)ip;
                                        goto bad;
+                               }
                                break;
                        }
                        sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
@@ -1339,8 +1734,11 @@ nosourcerouting:
 
                        case IPOPT_TS_TSANDADDR:
                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
-                                   sizeof(struct in_addr) > ipt->ipt_len)
+                                   sizeof(struct in_addr) > ipt->ipt_len) {
+                                       code = (u_char *)&ipt->ipt_ptr -
+                                           (u_char *)ip;
                                        goto bad;
+                               }
                                ipaddr.sin_addr = dst;
                                ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
                                                            m->m_pkthdr.rcvif);
@@ -1349,20 +1747,30 @@ nosourcerouting:
                                (void)memcpy(sin, &IA_SIN(ia)->sin_addr,
                                    sizeof(struct in_addr));
                                ipt->ipt_ptr += sizeof(struct in_addr);
+                               ifafree(&ia->ia_ifa);
+                               ia = NULL;
                                break;
 
                        case IPOPT_TS_PRESPEC:
                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
-                                   sizeof(struct in_addr) > ipt->ipt_len)
+                                   sizeof(struct in_addr) > ipt->ipt_len) {
+                                       code = (u_char *)&ipt->ipt_ptr -
+                                           (u_char *)ip;
                                        goto bad;
+                               }
                                (void)memcpy(&ipaddr.sin_addr, sin,
                                    sizeof(struct in_addr));
-                               if (ifa_ifwithaddr((SA)&ipaddr) == 0)
+                               if ((ia = (struct in_ifaddr*)ifa_ifwithaddr((SA)&ipaddr)) == 0)
                                        continue;
+                               ifafree(&ia->ia_ifa);
+                               ia = NULL;
                                ipt->ipt_ptr += sizeof(struct in_addr);
                                break;
 
                        default:
+                               /* XXX can't take &ipt->ipt_flg */
+                               code = (u_char *)&ipt->ipt_ptr -
+                                   (u_char *)ip + 1;
                                goto bad;
                        }
                        ntime = iptime();
@@ -1372,13 +1780,15 @@ nosourcerouting:
                }
        }
        if (forward && ipforwarding) {
-               ip_forward(m, 1);
+               ip_forward(m, 1, next_hop, ipforward_rt);
                return (1);
        }
        return (0);
 bad:
        ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2;   /* XXX icmp_error adds in hdr length */
+       lck_mtx_unlock(ip_mutex);
        icmp_error(m, type, code, 0, 0);
+       lck_mtx_lock(ip_mutex);
        ipstat.ips_badoptions++;
        return (1);
 }
@@ -1387,28 +1797,37 @@ bad:
  * Given address of next destination (final or next hop),
  * return internet address info of interface to be used to get there.
  */
-static struct in_ifaddr *
-ip_rtaddr(dst)
-        struct in_addr dst;
+struct in_ifaddr *
+ip_rtaddr(dst, rt)
+       struct in_addr dst;
+       struct route *rt;
 {
        register struct sockaddr_in *sin;
 
-       sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
+       sin = (struct sockaddr_in *)&rt->ro_dst;
 
-       if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) {
-               if (ipforward_rt.ro_rt) {
-                       RTFREE(ipforward_rt.ro_rt);
-                       ipforward_rt.ro_rt = 0;
+       lck_mtx_lock(rt_mtx);
+       if (rt->ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr ||
+               rt->ro_rt->generation_id != route_generation) {
+               if (rt->ro_rt) {
+                       rtfree_locked(rt->ro_rt);
+                       rt->ro_rt = 0;
                }
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(*sin);
                sin->sin_addr = dst;
 
-               rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
+               rtalloc_ign_locked(rt, RTF_PRCLONING);
        }
-       if (ipforward_rt.ro_rt == 0)
+       if (rt->ro_rt == 0) {
+               lck_mtx_unlock(rt_mtx);
                return ((struct in_ifaddr *)0);
-       return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
+       }
+
+       if (rt->ro_rt->rt_ifa)
+               ifaref(rt->ro_rt->rt_ifa);
+       lck_mtx_unlock(rt_mtx);
+       return ((struct in_ifaddr *) rt->ro_rt->rt_ifa);
 }
 
 /*
@@ -1536,7 +1955,7 @@ u_char inetctlerrmap[PRC_NCMDS] = {
        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
        EMSGSIZE,       EHOSTUNREACH,   0,              0,
        0,              0,              0,              0,
-       ENOPROTOOPT
+       ENOPROTOOPT,    ECONNREFUSED
 };
 
 /*
@@ -1553,13 +1972,8 @@ u_char inetctlerrmap[PRC_NCMDS] = {
  * The srcrt parameter indicates whether the packet is being forwarded
  * via a source route.
  */
-#ifndef NATPT
-static
-#endif
-void
-ip_forward(m, srcrt)
-       struct mbuf *m;
-       int srcrt;
+static void
+ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop, struct route *ipforward_rt)
 {
        register struct ip *ip = mtod(m, struct ip *);
        register struct sockaddr_in *sin;
@@ -1567,75 +1981,88 @@ ip_forward(m, srcrt)
        int error, type = 0, code = 0;
        struct mbuf *mcopy;
        n_long dest;
+       struct in_addr pkt_dst;
        struct ifnet *destifp;
 #if IPSEC
        struct ifnet dummyifp;
 #endif
 
        dest = 0;
+       /*
+        * Cache the destination address of the packet; this may be
+        * changed by use of 'ipfw fwd'.
+        */
+       pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
+
 #if DIAGNOSTIC
        if (ipprintfs)
                printf("forward: src %lx dst %lx ttl %x\n",
-                   (u_long)ip->ip_src.s_addr, (u_long)ip->ip_dst.s_addr,
+                   (u_long)ip->ip_src.s_addr, (u_long)pkt_dst.s_addr,
                    ip->ip_ttl);
 #endif
 
 
-       if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
+       if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(pkt_dst) == 0) {
                ipstat.ips_cantforward++;
                m_freem(m);
                return;
        }
-       HTONS(ip->ip_id);
-       if (ip->ip_ttl <= IPTTLDEC) {
-               icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
-               return;
-       }
-       ip->ip_ttl -= IPTTLDEC;
-
-#if defined(PM)
-       if (doRoute)
-       {
-           struct  route   *ipfw_rt;
-
-           if ((ipfw_rt = pm_route(m)) != NULL)
-           {
-               mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
-#if IPSEC
-               ipsec_setsocket(m, NULL);
-#endif /*IPSEC*/
-               error = ip_output(m, (struct mbuf *)0, ipfw_rt,
-                                 IP_FORWARDING | IP_PROTOCOLROUTE , 0);
-               goto    clearAway;
-           }
-
+#if IPSTEALTH
+       if (!ipstealth) {
+#endif
+               if (ip->ip_ttl <= IPTTLDEC) {
+                       icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
+                           dest, 0);
+                       return;
+               }
+#if IPSTEALTH
        }
 #endif
 
-       sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
-       if ((rt = ipforward_rt.ro_rt) == 0 ||
-           ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
-               if (ipforward_rt.ro_rt) {
-                       RTFREE(ipforward_rt.ro_rt);
-                       ipforward_rt.ro_rt = 0;
+       sin = (struct sockaddr_in *)&ipforward_rt->ro_dst;
+       if ((rt = ipforward_rt->ro_rt) == 0 ||
+           pkt_dst.s_addr != sin->sin_addr.s_addr ||
+           ipforward_rt->ro_rt->generation_id != route_generation) {
+               if (ipforward_rt->ro_rt) {
+                       rtfree(ipforward_rt->ro_rt);
+                       ipforward_rt->ro_rt = 0;
                }
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(*sin);
-               sin->sin_addr = ip->ip_dst;
+               sin->sin_addr = pkt_dst;
 
-               rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
-               if (ipforward_rt.ro_rt == 0) {
+               rtalloc_ign(ipforward_rt, RTF_PRCLONING);
+               if (ipforward_rt->ro_rt == 0) {
                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
                        return;
                }
-               rt = ipforward_rt.ro_rt;
+               rt = ipforward_rt->ro_rt;
        }
 
        /*
-        * Save at most 64 bytes of the packet in case
-        * we need to generate an ICMP message to the src.
+        * Save the IP header and at most 8 bytes of the payload,
+        * in case we need to generate an ICMP message to the src.
+        *
+        * We don't use m_copy() because it might return a reference
+        * to a shared cluster. Both this function and ip_output()
+        * assume exclusive access to the IP header in `m', so any
+        * data in a cluster may change before we reach icmp_error().
         */
-       mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
+       MGET(mcopy, M_DONTWAIT, m->m_type);
+       if (mcopy != NULL) {
+               M_COPY_PKTHDR(mcopy, m);
+               mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
+                   (int)ip->ip_len);
+               m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
+       }
+
+#if IPSTEALTH
+       if (!ipstealth) {
+#endif
+               ip->ip_ttl -= IPTTLDEC;
+#if IPSTEALTH
+       }
+#endif
 
        /*
         * If forwarding packet using same interface that it came in on,
@@ -1658,7 +2085,7 @@ ip_forward(m, srcrt)
                    if (rt->rt_flags & RTF_GATEWAY)
                        dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
                    else
-                       dest = ip->ip_dst.s_addr;
+                       dest = pkt_dst.s_addr;
                    /* Router requirements says to only send host redirects */
                    type = ICMP_REDIRECT;
                    code = ICMP_REDIRECT_HOST;
@@ -1669,14 +2096,28 @@ ip_forward(m, srcrt)
                }
        }
 
-#if IPSEC
-       ipsec_setsocket(m, NULL);
-#endif /*IPSEC*/
-       error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 
+    {
+       if (next_hop) {
+               /* Pass IPFORWARD info if available */
+               struct m_tag *tag;
+               struct ip_fwd_tag       *ipfwd_tag;
+               
+               tag = m_tag_alloc(KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD,
+                               sizeof(struct sockaddr_in), M_NOWAIT);
+               if (tag == NULL) {
+                       error = ENOBUFS;
+                       m_freem(m);
+                       return;
+               }
+               
+               ipfwd_tag = (struct ip_fwd_tag *)(tag+1);
+               ipfwd_tag->next_hop = next_hop;
+
+               m_tag_prepend(m, tag);
+       }
+       error = ip_output_list(m, 0, (struct mbuf *)0, ipforward_rt, 
                          IP_FORWARDING, 0);
-#if defined(PM)
-      clearAway:;
-#endif
+    }
        if (error)
                ipstat.ips_cantforward++;
        else {
@@ -1685,7 +2126,7 @@ ip_forward(m, srcrt)
                        ipstat.ips_redirectsent++;
                else {
                        if (mcopy) {
-                               ipflow_create(&ipforward_rt, mcopy);
+                               ipflow_create(ipforward_rt, mcopy);
                                m_freem(mcopy);
                        }
                        return;
@@ -1714,8 +2155,8 @@ ip_forward(m, srcrt)
                type = ICMP_UNREACH;
                code = ICMP_UNREACH_NEEDFRAG;
 #ifndef IPSEC
-               if (ipforward_rt.ro_rt)
-                       destifp = ipforward_rt.ro_rt->rt_ifp;
+               if (ipforward_rt->ro_rt)
+                       destifp = ipforward_rt->ro_rt->rt_ifp;
 #else
                /*
                 * If the packet is routed over IPsec tunnel, tell the
@@ -1723,19 +2164,25 @@ ip_forward(m, srcrt)
                 *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
                 * XXX quickhack!!!
                 */
-               if (ipforward_rt.ro_rt) {
+               if (ipforward_rt->ro_rt) {
                        struct secpolicy *sp = NULL;
                        int ipsecerror;
                        int ipsechdr;
                        struct route *ro;
 
+                       if (ipsec_bypass) {
+                               destifp = ipforward_rt->ro_rt->rt_ifp;
+                               ipstat.ips_cantfrag++;
+                               break;
+                       }
+                       lck_mtx_lock(sadb_mutex);
                        sp = ipsec4_getpolicybyaddr(mcopy,
-                                               IPSEC_DIR_OUTBOUND,
+                                                   IPSEC_DIR_OUTBOUND,
                                                    IP_FORWARDING,
                                                    &ipsecerror);
 
                        if (sp == NULL)
-                               destifp = ipforward_rt.ro_rt->rt_ifp;
+                               destifp = ipforward_rt->ro_rt->rt_ifp;
                        else {
                                /* count IPsec header size */
                                ipsechdr = ipsec4_hdrsiz(mcopy,
@@ -1766,6 +2213,7 @@ ip_forward(m, srcrt)
 
                                key_freesp(sp);
                        }
+                       lck_mtx_unlock(sadb_mutex);
                }
 #endif /*IPSEC*/
                ipstat.ips_cantfrag++;
@@ -1775,16 +2223,20 @@ ip_forward(m, srcrt)
                type = ICMP_SOURCEQUENCH;
                code = 0;
                break;
+
+       case EACCES:                    /* ipfw denied packet */
+               m_freem(mcopy);
+               return;
        }
        icmp_error(mcopy, type, code, dest, destifp);
 }
 
 void
-ip_savecontrol(inp, mp, ip, m)
-       register struct inpcb *inp;
-       register struct mbuf **mp;
-       register struct ip *ip;
-       register struct mbuf *m;
+ip_savecontrol(
+       register struct inpcb *inp,
+       register struct mbuf **mp,
+       register struct ip *ip,
+       register struct mbuf *m)
 {
        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                struct timeval tv;
@@ -1830,10 +2282,15 @@ ip_savecontrol(inp, mp, ip, m)
                struct sockaddr_dl *sdp;
                struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
 
+               ifnet_head_lock_shared();
                if (((ifp = m->m_pkthdr.rcvif)) 
                && ( ifp->if_index && (ifp->if_index <= if_index))) {
-                       sdp = (struct sockaddr_dl *)(ifnet_addrs
-                                       [ifp->if_index - 1]->ifa_addr);
+                       struct ifaddr *ifa = ifnet_addrs[ifp->if_index - 1];
+                       
+                       if (!ifa || !ifa->ifa_addr)
+                               goto makedummy;
+                       
+                       sdp = (struct sockaddr_dl *)ifa->ifa_addr;
                        /*
                         * Change our mind and don't try copy.
                         */
@@ -1850,11 +2307,16 @@ makedummy:
                        sdl2->sdl_index = 0;
                        sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
                }
+               ifnet_head_done();
                *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
                        IP_RECVIF, IPPROTO_IP);
                if (*mp)
                        mp = &(*mp)->m_next;
        }
+       if (inp->inp_flags & INP_RECVTTL) {
+               *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl, sizeof(ip->ip_ttl), IP_RECVTTL, IPPROTO_IP);
+               if (*mp) mp = &(*mp)->m_next;
+       }
 }
 
 int