]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/ip_input.c
xnu-3247.1.106.tar.gz
[apple/xnu.git] / bsd / netinet / ip_input.c
index 6953044bd753bbe4bd4a05bde07d85da5e84ad20..994bbf8a3736c4f924ff1b71e1749b4d6c03c899 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * 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
  * 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,
@@ -22,7 +22,7 @@
  * 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_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
@@ -58,7 +58,6 @@
  * SUCH DAMAGE.
  *
  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
- * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.25 2001/08/29 21:41:37 jesper Exp $
  */
 /*
  * NOTICE: This file was modified by SPARTA, Inc. in 2007 to introduce
 #include <sys/syslog.h>
 #include <sys/sysctl.h>
 #include <sys/mcache.h>
+#include <sys/socketvar.h>
+#include <sys/kdebug.h>
 #include <mach/mach_time.h>
+#include <mach/sdt.h>
 
 #include <machine/endian.h>
+#include <dev/random/randomdev.h>
 
 #include <kern/queue.h>
 #include <kern/locks.h>
+#include <libkern/OSAtomic.h>
 
 #include <pexpert/pexpert.h>
 
 #include <net/route.h>
 #include <net/kpi_protocol.h>
 #include <net/ntstat.h>
+#include <net/dlil.h>
+#include <net/classq/classq.h>
+#include <net/net_perf.h>
+#if PF
+#include <net/pfvar.h>
+#endif /* PF */
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_pcb.h>
 #include <netinet/ip_var.h>
 #include <netinet/ip_icmp.h>
-#include <sys/socketvar.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 <mach/sdt.h>
+#include <netinet/lro_ext.h>
+
+#if DUMMYNET
+#include <netinet/ip_dummynet.h>
+#endif /* DUMMYNET */
 
 #if CONFIG_MACF_NET
 #include <security/mac_framework.h>
-#endif
-
-#include <sys/kdebug.h>
-#include <libkern/OSAtomic.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))
-
+#endif /* CONFIG_MACF_NET */
 
 #if IPSEC
 #include <netinet6/ipsec.h>
 #include <netkey/key.h>
-#endif
-
-#if DUMMYNET
-#include <netinet/ip_dummynet.h>
-#endif
+#endif /* IPSEC */
 
-#if PF
-#include <net/pfvar.h>
-#endif /* PF */
-
-#include <netinet/lro_ext.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 IPSEC
 extern int ipsec_bypass;
 extern lck_mtx_t *sadb_mutex;
 
-lck_grp_t         *sadb_stat_mutex_grp;
-lck_grp_attr_t    *sadb_stat_mutex_grp_attr;
-lck_attr_t        *sadb_stat_mutex_attr;
+lck_grp_t      *sadb_stat_mutex_grp;
+lck_grp_attr_t *sadb_stat_mutex_grp_attr;
+lck_attr_t     *sadb_stat_mutex_attr;
 decl_lck_mtx_data(, sadb_stat_mutex_data);
-lck_mtx_t         *sadb_stat_mutex = &sadb_stat_mutex_data;
+lck_mtx_t      *sadb_stat_mutex = &sadb_stat_mutex_data;
+#endif /* IPSEC */
 
-#endif
+MBUFQ_HEAD(fq_head);
+
+static int frag_timeout_run;           /* frag timer is scheduled to run */
+static void frag_timeout(void *);
+static void frag_sched_timeout(void);
+
+static struct ipq *ipq_alloc(int);
+static void ipq_free(struct ipq *);
+static void ipq_updateparams(void);
+static void ip_input_second_pass(struct mbuf *, struct ifnet *,
+    u_int32_t, int, int, struct ip_fw_in_args *, int);
 
-int rsvp_on = 0;
-static int ip_rsvp_on;
-struct socket *ip_rsvpd;
+decl_lck_mtx_data(static, ipqlock);
+static lck_attr_t      *ipqlock_attr;
+static lck_grp_t       *ipqlock_grp;
+static lck_grp_attr_t  *ipqlock_grp_attr;
+
+/* 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)
+
+/* IP fragment reassembly queues (protected by ipqlock) */
+static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH]; /* ip reassembly queues */
+static int maxnipq;                    /* max packets in reass queues */
+static u_int32_t maxfragsperpacket;    /* max frags/packet in reass queues */
+static u_int32_t nipq;                 /* # of packets in reass queues */
+static u_int32_t ipq_limit;            /* ipq allocation limit */
+static u_int32_t ipq_count;            /* current # of allocated ipq's */
 
 static int sysctl_ipforwarding SYSCTL_HANDLER_ARGS;
+static int sysctl_maxnipq SYSCTL_HANDLER_ARGS;
+static int sysctl_maxfragsperpacket SYSCTL_HANDLER_ARGS;
+static int sysctl_reset_ip_input_stats SYSCTL_HANDLER_ARGS;
+static int sysctl_ip_input_measure_bins SYSCTL_HANDLER_ARGS;
+static int sysctl_ip_input_getperf SYSCTL_HANDLER_ARGS;
 
-int    ipforwarding = 0;
+int ipforwarding = 0;
 SYSCTL_PROC(_net_inet_ip, IPCTL_FORWARDING, forwarding,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &ipforwarding, 0,
-    sysctl_ipforwarding, "I", "Enable IP forwarding between interfaces");
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &ipforwarding, 0,
+       sysctl_ipforwarding, "I", "Enable IP forwarding between interfaces");
 
-static int     ipsendredirects = 1; /* XXX */
-SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ipsendredirects, 0, "Enable sending IP redirects");
+static int ipsendredirects = 1; /* XXX */
+SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &ipsendredirects, 0,
+       "Enable sending IP redirects");
 
-int    ip_defttl = IPDEFTTL;
+int ip_defttl = IPDEFTTL;
 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ip_defttl, 0, "Maximum TTL on IP packets");
-
-static int     ip_dosourceroute = 0;
-SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &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 | CTLFLAG_LOCKED, &ip_acceptsourceroute, 0, 
-    "Enable accepting source routed IP packets");
-
-static int     ip_keepfaith = 0;
-SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RD | CTLFLAG_LOCKED,
-       &ip_keepfaith,  0, "");
-
-static int     nipq = 0;       /* total # of reass queues */
-static int     maxnipq;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &maxnipq, 0,
-       "Maximum number of IPv4 fragment reassembly queue entries");
-
-static int    maxfragsperpacket;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &maxfragsperpacket, 0,
-       "Maximum number of IPv4 fragments allowed per packet");
+       &ip_defttl, 0, "Maximum TTL on IP packets");
+
+static int ip_dosourceroute = 0;
+SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &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 | CTLFLAG_LOCKED, &ip_acceptsourceroute, 0,
+       "Enable accepting source routed IP packets");
+
+static int ip_sendsourcequench = 0;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &ip_sendsourcequench, 0,
+       "Enable the transmission of source quench packets");
 
-static int    maxfrags;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfrags, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &maxfrags, 0, "Maximum number of IPv4 fragments allowed");
+SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets,
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &maxnipq, 0, sysctl_maxnipq,
+       "I", "Maximum number of IPv4 fragment reassembly queue entries");
 
-static int    currentfrags = 0;
+SYSCTL_UINT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD | CTLFLAG_LOCKED,
+       &nipq, 0, "Current number of IPv4 fragment reassembly queue entries");
 
-int    ip_doscopedroute = 1;
+SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragsperpacket,
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &maxfragsperpacket, 0,
+       sysctl_maxfragsperpacket, "I",
+       "Maximum number of IPv4 fragments allowed per packet");
+
+int ip_doscopedroute = 1;
 SYSCTL_INT(_net_inet_ip, OID_AUTO, scopedroute, CTLFLAG_RD | CTLFLAG_LOCKED,
-     &ip_doscopedroute, 0, "Enable IPv4 scoped routing");
+       &ip_doscopedroute, 0, "Enable IPv4 scoped routing");
 
-int    ip_restrictrecvif = 1;
-SYSCTL_INT(_net_inet_ip, OID_AUTO, restrictrecvif, CTLFLAG_RW | CTLFLAG_LOCKED,
-     &ip_restrictrecvif, 0, "Enable inbound interface restrictions");
+static uint32_t ip_adj_clear_hwcksum = 0;
+SYSCTL_UINT(_net_inet_ip, OID_AUTO, adj_clear_hwcksum,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &ip_adj_clear_hwcksum, 0,
+       "Invalidate hwcksum info when adjusting length");
 
 /*
  * XXX - Setting ip_checkinterface mostly implements the receive side of
@@ -227,19 +253,40 @@ SYSCTL_INT(_net_inet_ip, OID_AUTO, restrictrecvif, CTLFLAG_RW | CTLFLAG_LOCKED,
  * to the loopback interface instead of the interface where the
  * packets for those addresses are received.
  */
-static int     ip_checkinterface = 0;
+static int ip_checkinterface = 0;
 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ip_checkinterface, 0, "Verify packet arrives on correct interface");
+       &ip_checkinterface, 0, "Verify packet arrives on correct interface");
+
+static int ip_chaining = 1;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, rx_chaining, CTLFLAG_RW | CTLFLAG_LOCKED,
+       &ip_chaining, 1, "Do receive side ip address based chaining");
+
+static int ip_chainsz = 6;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, rx_chainsz, CTLFLAG_RW | CTLFLAG_LOCKED,
+       &ip_chainsz, 1, "IP receive side max chaining");
+
+static int ip_input_measure = 0;
+SYSCTL_PROC(_net_inet_ip, OID_AUTO, input_perf,
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+       &ip_input_measure, 0, sysctl_reset_ip_input_stats, "I", "Do time measurement");
+
+static uint64_t ip_input_measure_bins = 0;
+SYSCTL_PROC(_net_inet_ip, OID_AUTO, input_perf_bins,
+       CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED, &ip_input_measure_bins, 0,
+       sysctl_ip_input_measure_bins, "I",
+       "bins for chaining performance data histogram");
+
+static net_perf_t net_perf;
+SYSCTL_PROC(_net_inet_ip, OID_AUTO, input_perf_data,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+       0, 0, sysctl_ip_input_getperf, "S,net_perf",
+       "IP input performance data (struct net_perf, net/net_perf.h)");
 
 #if DIAGNOSTIC
-static int     ipprintfs = 0;
+static int ipprintfs = 0;
 #endif
 
-extern int in_proto_count; 
-extern struct domain inetdomain;
-extern struct protosw inetsw[];
 struct protosw *ip_protox[IPPROTO_MAX];
-static int     ipqmaxlen = IFQ_MAXLEN;
 
 static lck_grp_attr_t  *in_ifaddr_rwlock_grp_attr;
 static lck_grp_t       *in_ifaddr_rwlock_grp;
@@ -255,44 +302,23 @@ struct in_ifaddrhashhead *in_ifaddrhashtbl;       /* inet addr hash table  */
 static u_int32_t inaddr_nhash;                 /* hash table size */
 static u_int32_t inaddr_hashp;                 /* next largest prime */
 
-struct ifqueue ipintrq;
-SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
-SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD | CTLFLAG_LOCKED,
-    &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
-
+static int ip_getstat SYSCTL_HANDLER_ARGS;
 struct ipstat ipstat;
-SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RD | CTLFLAG_LOCKED,
-    &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)
-
-static struct ipq ipq[IPREASS_NHASH];
-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;
+SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+       0, 0, ip_getstat, "S,ipstat",
+       "IP statistics (struct ipstat, netinet/ip_var.h)");
 
 #if IPCTL_DEFMTU
 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ip_mtu, 0, "Default MTU");
-#endif
+       &ip_mtu, 0, "Default MTU");
+#endif /* IPCTL_DEFMTU */
 
 #if IPSTEALTH
 static int     ipstealth = 0;
 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ipstealth, 0, "");
-#endif
-
+       &ipstealth, 0, "");
+#endif /* IPSTEALTH */
 
 /* Firewall hooks */
 #if IPFIREWALL
@@ -304,21 +330,23 @@ int fw_one_pass = 0;
 
 #if DUMMYNET
 ip_dn_io_t *ip_dn_io_ptr;
-#endif
+#endif /* DUMMYNET */
 
-SYSCTL_NODE(_net_inet_ip, OID_AUTO, linklocal, CTLFLAG_RW | CTLFLAG_LOCKED, 0, "link local");
+SYSCTL_NODE(_net_inet_ip, OID_AUTO, linklocal,
+       CTLFLAG_RW | CTLFLAG_LOCKED, 0, "link local");
 
 struct ip_linklocal_stat ip_linklocal_stat;
-SYSCTL_STRUCT(_net_inet_ip_linklocal, OID_AUTO, stat, CTLFLAG_RD | CTLFLAG_LOCKED,
-        &ip_linklocal_stat, ip_linklocal_stat,
-        "Number of link local packets with TTL less than 255");
+SYSCTL_STRUCT(_net_inet_ip_linklocal, OID_AUTO, stat,
+       CTLFLAG_RD | CTLFLAG_LOCKED, &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 | CTLFLAG_LOCKED, 0, "link local input");
+SYSCTL_NODE(_net_inet_ip_linklocal, OID_AUTO, in,
+       CTLFLAG_RW | CTLFLAG_LOCKED, 0, "link local input");
 
 int ip_linklocal_in_allowbadttl = 1;
-SYSCTL_INT(_net_inet_ip_linklocal_in, OID_AUTO, allowbadttl, CTLFLAG_RW | CTLFLAG_LOCKED,
-        &ip_linklocal_in_allowbadttl, 0,
-        "Allow incoming link local packets with TTL less than 255");
+SYSCTL_INT(_net_inet_ip_linklocal_in, OID_AUTO, allowbadttl,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &ip_linklocal_in_allowbadttl, 0,
+       "Allow incoming link local packets with TTL less than 255");
 
 
 /*
@@ -333,38 +361,30 @@ static    struct ip_srcrt {
        struct  in_addr dst;                    /* final destination */
        char    nop;                            /* one NOP to align */
        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
-       struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
+       struct  in_addr route[MAX_IPOPTLEN / sizeof (struct in_addr)];
 } ip_srcrt;
 
-static void    in_ifaddrhashtbl_init(void);
-static void    save_rte(u_char *, struct in_addr);
-static int     ip_dooptions(struct mbuf *, int, struct sockaddr_in *);
-static void    ip_forward(struct mbuf *, int, struct sockaddr_in *);
-static void    ip_freef(struct ipq *);
+static void in_ifaddrhashtbl_init(void);
+static void save_rte(u_char *, struct in_addr);
+static int ip_dooptions(struct mbuf *, int, struct sockaddr_in *);
+static void ip_forward(struct mbuf *, int, struct sockaddr_in *);
+static void frag_freef(struct ipqhead *, 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
-#else
-static struct  mbuf *ip_reass(struct mbuf *, struct ipq *, struct ipq *);
-#endif
+static struct mbuf *ip_reass(struct mbuf *, u_int32_t *, u_int16_t *);
+#else /* !IPDIVERT_44 */
+static struct mbuf *ip_reass(struct mbuf *, u_int16_t *, u_int16_t *);
+#endif /* !IPDIVERT_44 */
+#else /* !IPDIVERT */
+static struct mbuf *ip_reass(struct mbuf *);
+#endif /* !IPDIVERT */
 static void ip_fwd_route_copyout(struct ifnet *, struct route *);
 static void ip_fwd_route_copyin(struct ifnet *, struct route *);
-void   ipintr(void);
-void   in_dinit(void);
 static inline u_short ip_cksum(struct mbuf *, int);
 
-#if RANDOM_IP_ID
-extern u_short ip_id;
-
-int    ip_use_randomid = 1;
+int ip_use_randomid = 1;
 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW | CTLFLAG_LOCKED,
-    &ip_use_randomid, 0, "Randomize IP packets IDs");
-#endif
+       &ip_use_randomid, 0, "Randomize IP packets IDs");
 
 /*
  * On platforms which require strict alignment (currently for anything but
@@ -382,14 +402,14 @@ SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW | CTLFLAG_LOCKED,
                struct ifnet *__ifp = (_ifp);                           \
                atomic_add_64(&(__ifp)->if_alignerrs, 1);               \
                if (((_m)->m_flags & M_PKTHDR) &&                       \
-                   (_m)->m_pkthdr.header != NULL)                      \
-                       (_m)->m_pkthdr.header = NULL;                   \
+                   (_m)->m_pkthdr.pkt_hdr != NULL)                     \
+                       (_m)->m_pkthdr.pkt_hdr = NULL;                  \
                _n = m_defrag_offset(_m, max_linkhdr, M_NOWAIT);        \
                if (_n == NULL) {                                       \
                        atomic_add_32(&ipstat.ips_toosmall, 1);         \
                        m_freem(_m);                                    \
                        (_m) = NULL;                                    \
-                       _action                                         \
+                       _action;                                        \
                } else {                                                \
                        VERIFY(_n != (_m));                             \
                        (_m) = _n;                                      \
@@ -398,90 +418,112 @@ SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW | CTLFLAG_LOCKED,
 } while (0)
 #endif /* !__i386__ && !__x86_64__ */
 
+/*
+ * GRE input handler function, settable via ip_gre_register_input() for PPTP.
+ */
+static gre_input_func_t gre_input_func;
+
 /*
  * IP initialization: fill in IP protocol switch table.
  * All protocols not implemented in kernel go to raw IP protocol handler.
  */
 void
-ip_init(void)
+ip_init(struct protosw *pp, struct domain *dp)
 {
+       static int ip_initialized = 0;
        struct protosw *pr;
+       struct timeval tv;
        int i;
-       static int ip_initialized = 0;
 
-       if (!ip_initialized)
-       {
-               PE_parse_boot_argn("net.inet.ip.scopedroute",
-                   &ip_doscopedroute, sizeof (ip_doscopedroute));
-
-               in_ifaddr_init();
-
-               in_ifaddr_rwlock_grp_attr = lck_grp_attr_alloc_init();
-               in_ifaddr_rwlock_grp = lck_grp_alloc_init("in_ifaddr_rwlock",
-                   in_ifaddr_rwlock_grp_attr);
-               in_ifaddr_rwlock_attr = lck_attr_alloc_init();
-               lck_rw_init(in_ifaddr_rwlock, in_ifaddr_rwlock_grp,
-                   in_ifaddr_rwlock_attr);
-
-               TAILQ_INIT(&in_ifaddrhead);
-               in_ifaddrhashtbl_init();
-
-               ip_moptions_init();
-
-               pr = pffindproto_locked(PF_INET, IPPROTO_RAW, SOCK_RAW);
-               if (pr == 0)
-                       panic("ip_init");
-               for (i = 0; i < IPPROTO_MAX; i++)
-                       ip_protox[i] = pr;
-               for (pr = inetdomain.dom_protosw; pr; pr = pr->pr_next) {
-                       if (pr->pr_domain == NULL)
-                               continue;    /* If uninitialized, skip */
-                       if (pr->pr_domain->dom_family == PF_INET &&
-                           pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
-                               ip_protox[pr->pr_protocol] = pr;
-               }
-               for (i = 0; i < IPREASS_NHASH; i++)
-                   ipq[i].next = ipq[i].prev = &ipq[i];
+       domain_proto_mtx_lock_assert_held();
+       VERIFY((pp->pr_flags & (PR_INITIALIZED|PR_ATTACHED)) == PR_ATTACHED);
 
-       maxnipq = nmbclusters / 32;
-       maxfrags = maxnipq * 2;
-       maxfragsperpacket = 128; /* enough for 64k in 512 byte fragments */
+       /* ipq_alloc() uses mbufs for IP fragment queue structures */
+       _CASSERT(sizeof (struct ipq) <= _MLEN);
 
-#if RANDOM_IP_ID
-               {
-                       struct timeval timenow;
-                       getmicrotime(&timenow);
-                       ip_id = timenow.tv_sec & 0xffff;
-               }
-#endif
-               ipintrq.ifq_maxlen = ipqmaxlen;
+       /*
+        * Some ioctls (e.g. SIOCAIFADDR) use ifaliasreq struct, which is
+        * interchangeable with in_aliasreq; they must have the same size.
+        */
+       _CASSERT(sizeof (struct ifaliasreq) == sizeof (struct in_aliasreq));
 
-               ipf_init();
+       if (ip_initialized)
+               return;
+       ip_initialized = 1;
 
-               ip_mutex_grp_attr  = lck_grp_attr_alloc_init();
+       PE_parse_boot_argn("net.inet.ip.scopedroute",
+           &ip_doscopedroute, sizeof (ip_doscopedroute));
 
-               ip_mutex_grp = lck_grp_alloc_init("ip", ip_mutex_grp_attr);
+       in_ifaddr_init();
 
-               ip_mutex_attr = lck_attr_alloc_init();
+       in_ifaddr_rwlock_grp_attr = lck_grp_attr_alloc_init();
+       in_ifaddr_rwlock_grp = lck_grp_alloc_init("in_ifaddr_rwlock",
+           in_ifaddr_rwlock_grp_attr);
+       in_ifaddr_rwlock_attr = lck_attr_alloc_init();
+       lck_rw_init(in_ifaddr_rwlock, in_ifaddr_rwlock_grp,
+           in_ifaddr_rwlock_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;
+       TAILQ_INIT(&in_ifaddrhead);
+       in_ifaddrhashtbl_init();
+
+       ip_moptions_init();
+
+       pr = pffindproto_locked(PF_INET, IPPROTO_RAW, SOCK_RAW);
+       if (pr == NULL) {
+               panic("%s: Unable to find [PF_INET,IPPROTO_RAW,SOCK_RAW]\n",
+                   __func__);
+               /* NOTREACHED */
+       }
+
+       /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
+       for (i = 0; i < IPPROTO_MAX; i++)
+               ip_protox[i] = pr;
+       /*
+        * Cycle through IP protocols and put them into the appropriate place
+        * in ip_protox[], skipping protocols IPPROTO_{IP,RAW}.
+        */
+       VERIFY(dp == inetdomain && dp->dom_family == PF_INET);
+       TAILQ_FOREACH(pr, &dp->dom_protosw, pr_entry) {
+               VERIFY(pr->pr_domain == dp);
+               if (pr->pr_protocol != 0 && pr->pr_protocol != IPPROTO_RAW) {
+                       /* Be careful to only index valid IP protocols. */
+                       if (pr->pr_protocol < IPPROTO_MAX)
+                               ip_protox[pr->pr_protocol] = pr;
                }
+       }
 
-#if IPSEC
-       
-               sadb_stat_mutex_grp_attr = lck_grp_attr_alloc_init();
-               sadb_stat_mutex_grp = lck_grp_alloc_init("sadb_stat", sadb_stat_mutex_grp_attr);
-               sadb_stat_mutex_attr = lck_attr_alloc_init();
+       /* IP fragment reassembly queue lock */
+       ipqlock_grp_attr  = lck_grp_attr_alloc_init();
+       ipqlock_grp = lck_grp_alloc_init("ipqlock", ipqlock_grp_attr);
+       ipqlock_attr = lck_attr_alloc_init();
+       lck_mtx_init(&ipqlock, ipqlock_grp, ipqlock_attr);
 
-               lck_mtx_init(sadb_stat_mutex, sadb_stat_mutex_grp, sadb_stat_mutex_attr);
+       lck_mtx_lock(&ipqlock);
+       /* Initialize IP reassembly queue. */
+       for (i = 0; i < IPREASS_NHASH; i++)
+               TAILQ_INIT(&ipq[i]);
 
-#endif
-               arp_init();
+       maxnipq = nmbclusters / 32;
+       maxfragsperpacket = 128; /* enough for 64k in 512 byte fragments */
+       ipq_updateparams();
+       lck_mtx_unlock(&ipqlock);
 
-               ip_initialized = 1;
-       }
+       getmicrotime(&tv);
+       ip_id = RandomULong() ^ tv.tv_usec;
+       ip_initid();
+
+       ipf_init();
+
+#if IPSEC
+       sadb_stat_mutex_grp_attr = lck_grp_attr_alloc_init();
+       sadb_stat_mutex_grp = lck_grp_alloc_init("sadb_stat",
+           sadb_stat_mutex_grp_attr);
+       sadb_stat_mutex_attr = lck_attr_alloc_init();
+       lck_mtx_init(sadb_stat_mutex, sadb_stat_mutex_grp,
+           sadb_stat_mutex_attr);
+
+#endif
+       arp_init();
 }
 
 /*
@@ -495,7 +537,8 @@ in_ifaddrhashtbl_init(void)
        if (in_ifaddrhashtbl != NULL)
                return;
 
-       PE_parse_boot_argn("inaddr_nhash", &inaddr_nhash, sizeof (inaddr_nhash));
+       PE_parse_boot_argn("inaddr_nhash", &inaddr_nhash,
+           sizeof (inaddr_nhash));
        if (inaddr_nhash == 0)
                inaddr_nhash = INADDR_NHASH;
 
@@ -536,53 +579,10 @@ inaddr_hashval(u_int32_t key)
                return (0);
 }
 
-static void
-ip_proto_input(
-       protocol_family_t       __unused protocol,
-       mbuf_t                          packet_list)
-{
-       mbuf_t  packet;
-       int how_many = 0 ;
-       
-       /* ip_input should handle a list of packets but does not yet */
-       
-       for (packet = packet_list; packet; packet = packet_list) {
-               how_many++;
-               packet_list = mbuf_nextpkt(packet);
-               mbuf_setnextpkt(packet, NULL);
-               ip_input(packet);
-       }
-}
-
-/* Initialize the PF_INET domain, and add in the pre-defined protos */
-void
-in_dinit(void)
-{
-       int i;
-       struct protosw *pr;
-       struct domain *dp;
-       static int inetdomain_initted = 0;
-
-       if (!inetdomain_initted)
-       {
-               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;
-       
-               domain_proto_mtx_unlock(TRUE);
-               proto_register_input(PF_INET, ip_proto_input, NULL, 1);
-               domain_proto_mtx_lock();
-       }
-}
-
 void
 ip_proto_dispatch_in_wrapper(struct mbuf *m, int hlen, u_int8_t proto)
 {
-       ip_proto_dispatch_in(m, hlen, proto, 0); 
+       ip_proto_dispatch_in(m, hlen, proto, 0);
 }
 
 __private_extern__ void
@@ -590,7 +590,7 @@ 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 seen = (inject_ipfref == NULL);
        int     changed_header = 0;
        struct ip *ip;
        void (*pr_input)(struct mbuf *, int len);
@@ -611,18 +611,21 @@ ip_proto_dispatch_in(struct mbuf *m, int hlen, u_int8_t proto,
                                         * into filter(s).
                                         */
                                        IP_HDR_ALIGNMENT_FIXUP(m,
-                                           m->m_pkthdr.rcvif,
-                                           ipf_unref(); return;);
+                                           m->m_pkthdr.rcvif, ipf_unref());
+
+                                       /* ipf_unref() already called */
+                                       if (m == NULL)
+                                               return;
 
                                        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);
+                                       ip->ip_sum = ip_cksum_hdr_in(m, hlen);
                                }
                                result = filter->ipf_filter.ipf_input(
-                                   filter->ipf_filter.cookie, (mbuf_t*)&m,
+                                   filter->ipf_filter.cookie, (mbuf_t *)&m,
                                    hlen, proto);
                                if (result == EJUSTRETURN) {
                                        ipf_unref();
@@ -639,7 +642,7 @@ ip_proto_dispatch_in(struct mbuf *m, int hlen, u_int8_t proto,
        }
 
        /* Perform IP header alignment fixup (post-filters), if needed */
-       IP_HDR_ALIGNMENT_FIXUP(m, m->m_pkthdr.rcvif, return;);
+       IP_HDR_ALIGNMENT_FIXUP(m, m->m_pkthdr.rcvif, return);
 
        /*
         * If there isn't a specific lock for the protocol
@@ -662,8 +665,1080 @@ ip_proto_dispatch_in(struct mbuf *m, int hlen, u_int8_t proto,
        } else {
                pr_input(m, hlen);
        }
-}
+}
+
+struct pktchain_elm {
+       struct mbuf     *pkte_head;
+       struct mbuf     *pkte_tail;
+       struct in_addr  pkte_saddr;
+       struct in_addr  pkte_daddr;
+       uint16_t        pkte_npkts;
+       uint16_t        pkte_proto;
+       uint32_t        pkte_nbytes;
+};
+
+typedef struct pktchain_elm pktchain_elm_t;
+
+/* Store upto PKTTBL_SZ unique flows on the stack */
+#define PKTTBL_SZ      7
+
+static struct mbuf *
+ip_chain_insert(struct mbuf *packet, pktchain_elm_t *tbl)
+{
+       struct ip*      ip;
+       int             pkttbl_idx = 0;
+
+       ip = mtod(packet, struct ip*);
+
+       /* reusing the hash function from inaddr_hashval */
+       pkttbl_idx = inaddr_hashval(ntohs(ip->ip_src.s_addr)) % PKTTBL_SZ;
+       if (tbl[pkttbl_idx].pkte_head == NULL) {
+               tbl[pkttbl_idx].pkte_head = packet;
+               tbl[pkttbl_idx].pkte_saddr.s_addr = ip->ip_src.s_addr;
+               tbl[pkttbl_idx].pkte_daddr.s_addr = ip->ip_dst.s_addr;
+               tbl[pkttbl_idx].pkte_proto = ip->ip_p;
+       } else {
+               if ((ip->ip_dst.s_addr == tbl[pkttbl_idx].pkte_daddr.s_addr) &&
+                   (ip->ip_src.s_addr == tbl[pkttbl_idx].pkte_saddr.s_addr) &&
+                   (ip->ip_p == tbl[pkttbl_idx].pkte_proto)) {
+               } else {
+                       return (packet);
+               }
+       }
+       if (tbl[pkttbl_idx].pkte_tail != NULL)
+               mbuf_setnextpkt(tbl[pkttbl_idx].pkte_tail, packet);
+
+       tbl[pkttbl_idx].pkte_tail = packet;
+       tbl[pkttbl_idx].pkte_npkts += 1;
+       tbl[pkttbl_idx].pkte_nbytes += packet->m_pkthdr.len;
+       return (NULL);
+}
+
+/* args is a dummy variable here for backward compatibility */
+static void
+ip_input_second_pass_loop_tbl(pktchain_elm_t *tbl, struct ip_fw_in_args *args)
+{
+       int i = 0;
+
+       for (i = 0; i < PKTTBL_SZ; i++) {
+               if (tbl[i].pkte_head != NULL) {
+                       struct mbuf *m = tbl[i].pkte_head;
+                       ip_input_second_pass(m, m->m_pkthdr.rcvif, 0,
+                           tbl[i].pkte_npkts, tbl[i].pkte_nbytes, args, 0);
+
+                       if (tbl[i].pkte_npkts > 2)
+                               ipstat.ips_rxc_chainsz_gt2++;
+                       if (tbl[i].pkte_npkts > 4)
+                               ipstat.ips_rxc_chainsz_gt4++;
+
+                       if (ip_input_measure)
+                               net_perf_histogram(&net_perf, tbl[i].pkte_npkts);
+
+                       tbl[i].pkte_head = tbl[i].pkte_tail = NULL;
+                       tbl[i].pkte_npkts = 0;
+                       tbl[i].pkte_nbytes = 0;
+                       /* no need to initialize address and protocol in tbl */
+               }
+       }
+}
+
+static void
+ip_input_cpout_args(struct ip_fw_in_args *args, struct ip_fw_args *args1,
+    boolean_t *done_init)
+{
+       if (*done_init == FALSE) {
+               bzero(args1, sizeof(struct ip_fw_args));
+               *done_init = TRUE;
+       }
+       args1->fwa_next_hop = args->fwai_next_hop;
+       args1->fwa_ipfw_rule = args->fwai_ipfw_rule;
+       args1->fwa_pf_rule = args->fwai_pf_rule;
+       args1->fwa_divert_rule = args->fwai_divert_rule;
+}
+
+static void
+ip_input_cpin_args(struct ip_fw_args *args1, struct ip_fw_in_args *args)
+{
+       args->fwai_next_hop = args1->fwa_next_hop;
+       args->fwai_ipfw_rule = args1->fwa_ipfw_rule;
+       args->fwai_pf_rule = args1->fwa_pf_rule;
+       args->fwai_divert_rule = args1->fwa_divert_rule;
+}
+
+typedef enum {
+       IPINPUT_DOCHAIN = 0,
+       IPINPUT_DONTCHAIN,
+       IPINPUT_FREED,
+       IPINPUT_DONE
+} ipinput_chain_ret_t;
+
+static void
+ip_input_update_nstat(struct ifnet *ifp, struct in_addr src_ip,
+    u_int32_t packets, u_int32_t bytes)
+{
+       if (nstat_collect) {
+               struct rtentry *rt = ifnet_cached_rtlookup_inet(ifp,
+                   src_ip);
+               if (rt != NULL) {
+                       nstat_route_rx(rt, packets, bytes, 0);
+                       rtfree(rt);
+               }
+       }
+}
+
+static void
+ip_input_dispatch_chain(struct mbuf *m)
+{
+       struct mbuf *tmp_mbuf = m;
+       struct mbuf *nxt_mbuf = NULL;
+       struct ip *ip = NULL;
+       unsigned int hlen;
+
+       ip = mtod(tmp_mbuf, struct ip *);
+       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+       while(tmp_mbuf) {
+               nxt_mbuf = mbuf_nextpkt(tmp_mbuf);
+               mbuf_setnextpkt(tmp_mbuf, NULL);
+
+               if ((sw_lro) && (ip->ip_p == IPPROTO_TCP))
+                       tmp_mbuf = tcp_lro(tmp_mbuf, hlen);
+               if (tmp_mbuf)
+                       ip_proto_dispatch_in(tmp_mbuf, hlen, ip->ip_p, 0);
+               tmp_mbuf = nxt_mbuf;
+               if (tmp_mbuf) {
+                       ip = mtod(tmp_mbuf, struct ip *);
+                       /* first mbuf of chain already has adjusted ip_len */
+                       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+                       ip->ip_len -= hlen;
+               }
+       }
+}
+
+static void
+ip_input_setdst_chain(struct mbuf *m, uint32_t ifindex, struct in_ifaddr *ia)
+{
+       struct mbuf *tmp_mbuf = m;
+
+       while (tmp_mbuf) {
+               ip_setdstifaddr_info(tmp_mbuf, ifindex, ia);
+               tmp_mbuf = mbuf_nextpkt(tmp_mbuf);
+       }
+}
+
+/*
+ * First pass does all essential packet validation and places on a per flow
+ * queue for doing operations that have same outcome for all packets of a flow.
+ * div_info is packet divert/tee info
+ */
+static ipinput_chain_ret_t
+ip_input_first_pass(struct mbuf *m, u_int32_t *div_info,
+    struct ip_fw_in_args *args, int *ours, struct mbuf **modm)
+{
+       struct ip       *ip;
+       struct ifnet    *inifp;
+       unsigned int    hlen;
+       int             retval = IPINPUT_DOCHAIN;
+       int             len = 0;
+       struct in_addr  src_ip;
+#if IPFIREWALL
+       int             i;
+#endif
+#if IPFIREWALL || DUMMYNET
+       struct m_tag            *copy;
+       struct m_tag            *p;
+       boolean_t               delete = FALSE;
+       struct ip_fw_args       args1;
+       boolean_t               init = FALSE;
+#endif
+       ipfilter_t inject_filter_ref = NULL;
+
+#if !IPFIREWALL
+#pragma unused (args)
+#endif
+
+#if !IPDIVERT
+#pragma unused (div_info)
+#pragma unused (ours)
+#endif
+
+#if !IPFIREWALL_FORWARD
+#pragma unused (ours)
+#endif
+
+       /* Check if the mbuf is still valid after interface filter processing */
+       MBUF_INPUT_CHECK(m, m->m_pkthdr.rcvif);
+       inifp = mbuf_pkthdr_rcvif(m);
+       VERIFY(inifp != NULL);
+
+       /* Perform IP header alignment fixup, if needed */
+       IP_HDR_ALIGNMENT_FIXUP(m, inifp, goto bad);
+
+       m->m_pkthdr.pkt_flags &= ~PKTF_FORWARDED;
+
+#if IPFIREWALL || DUMMYNET
+
+       /*
+        * Don't bother searching for tag(s) if there's none.
+        */
+       if (SLIST_EMPTY(&m->m_pkthdr.tags))
+               goto ipfw_tags_done;
+
+       /* Grab info from mtags prepended to the chain */
+       p = m_tag_first(m);
+       while (p) {
+               if (p->m_tag_id == KERNEL_MODULE_TAG_ID) {
+#if DUMMYNET
+                       if (p->m_tag_type == KERNEL_TAG_TYPE_DUMMYNET) {
+                               struct dn_pkt_tag *dn_tag;
+
+                               dn_tag = (struct dn_pkt_tag *)(p+1);
+                               args->fwai_ipfw_rule = dn_tag->dn_ipfw_rule;
+                               args->fwai_pf_rule = dn_tag->dn_pf_rule;
+                               delete = TRUE;
+                       }
+#endif
+
+#if IPDIVERT
+                       if (p->m_tag_type == KERNEL_TAG_TYPE_DIVERT) {
+                               struct divert_tag *div_tag;
+
+                               div_tag = (struct divert_tag *)(p+1);
+                               args->fwai_divert_rule = div_tag->cookie;
+                               delete = TRUE;
+                       }
+#endif
+
+                       if (p->m_tag_type == KERNEL_TAG_TYPE_IPFORWARD) {
+                               struct ip_fwd_tag *ipfwd_tag;
+
+                               ipfwd_tag = (struct ip_fwd_tag *)(p+1);
+                               args->fwai_next_hop = ipfwd_tag->next_hop;
+                               delete = TRUE;
+                       }
+
+                       if (delete) {
+                               copy = p;
+                               p = m_tag_next(m, p);
+                               m_tag_delete(m, copy);
+                       } else  {
+                               p = m_tag_next(m, p);
+                       }
+               } else {
+                       p = m_tag_next(m, p);
+               }
+       }
+
+#if DIAGNOSTIC
+       if (m == NULL || !(m->m_flags & M_PKTHDR))
+               panic("ip_input no HDR");
+#endif
+
+#if DUMMYNET
+       if (args->fwai_ipfw_rule || args->fwai_pf_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);
+#if IPFIREWALL
+               if (args->fwai_ipfw_rule)
+                       goto iphack;
+#endif /* IPFIREWALL */
+               if (args->fwai_pf_rule)
+                       goto check_with_pf;
+       }
+#endif /* DUMMYNET */
+ipfw_tags_done:
+#endif /* IPFIREWALL || DUMMYNET */
+
+       /*
+        * No need to process packet twice if we've already seen it.
+        */
+       if (!SLIST_EMPTY(&m->m_pkthdr.tags))
+               inject_filter_ref = ipf_get_inject_filter(m);
+       if (inject_filter_ref != NULL) {
+               ip = mtod(m, struct ip *);
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+
+               DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
+                   struct ip *, ip, struct ifnet *, inifp,
+                   struct ip *, ip, struct ip6_hdr *, NULL);
+
+               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 (IPINPUT_DONE);
+       }
+
+       if (m->m_pkthdr.len < sizeof (struct ip)) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_tooshort);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+       if (m->m_len < sizeof (struct ip) &&
+           (m = m_pullup(m, sizeof (struct ip))) == NULL) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_toosmall);
+               return (IPINPUT_FREED);
+       }
+
+       ip = mtod(m, struct ip *);
+       *modm = m;
+
+       KERNEL_DEBUG(DBG_LAYER_BEG, ip->ip_dst.s_addr, ip->ip_src.s_addr,
+           ip->ip_p, ip->ip_off, ip->ip_len);
+
+       if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_badvers);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+       if (hlen < sizeof (struct ip)) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_badhlen);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+       if (hlen > m->m_len) {
+               if ((m = m_pullup(m, hlen)) == NULL) {
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       OSAddAtomic(1, &ipstat.ips_badhlen);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       return (IPINPUT_FREED);
+               }
+               ip = mtod(m, struct ip *);
+               *modm = m;
+       }
+
+       /* 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) {
+               /*
+                * Allow for the following exceptions:
+                *
+                *   1. If the packet was sent to loopback (i.e. rcvif
+                *      would have been set earlier at output time.)
+                *
+                *   2. If the packet was sent out on loopback from a local
+                *      source address which belongs to a non-loopback
+                *      interface (i.e. rcvif may not necessarily be a
+                *      loopback interface, hence the test for PKTF_LOOP.)
+                *      Unlike IPv6, there is no interface scope ID, and
+                *      therefore we don't care so much about PKTF_IFINFO.
+                */
+               if (!(inifp->if_flags & IFF_LOOPBACK) &&
+                    !(m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       OSAddAtomic(1, &ipstat.ips_badaddr);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       m_freem(m);
+                       return (IPINPUT_FREED);
+               }
+       }
+
+       /* IPv4 Link-Local Addresses as defined in RFC3927 */
+       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) {
+                       OSAddAtomic(1, &ip_linklocal_stat.iplls_in_badttl);
+                       /* Silently drop link local traffic with bad TTL */
+                       if (!ip_linklocal_in_allowbadttl) {
+                               OSAddAtomic(1, &ipstat.ips_total);
+                               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                               m_freem(m);
+                               return (IPINPUT_FREED);
+                       }
+               }
+       }
+
+       if (ip_cksum(m, hlen)) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+       DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
+           struct ip *, ip, struct ifnet *, inifp,
+           struct ip *, ip, struct ip6_hdr *, NULL);
+
+       /*
+        * Convert fields to host representation.
+        */
+#if BYTE_ORDER != BIG_ENDIAN
+       NTOHS(ip->ip_len);
+#endif
+
+       if (ip->ip_len < hlen) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_badlen);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+#if BYTE_ORDER != BIG_ENDIAN
+       NTOHS(ip->ip_off);
+#endif
+
+       /*
+        * Check that the amount of data in the buffers
+        * is as at least much as the IP header would have us expect.
+        * Trim mbufs if longer than we expect.
+        * Drop packet if shorter than we expect.
+        */
+       if (m->m_pkthdr.len < ip->ip_len) {
+               OSAddAtomic(1, &ipstat.ips_total);
+               OSAddAtomic(1, &ipstat.ips_tooshort);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               return (IPINPUT_FREED);
+       }
+
+       if (m->m_pkthdr.len > ip->ip_len) {
+               /*
+                * Invalidate hardware checksum info if ip_adj_clear_hwcksum
+                * is set; useful to handle buggy drivers.  Note that this
+                * should not be enabled by default, as we may get here due
+                * to link-layer padding.
+                */
+               if (ip_adj_clear_hwcksum &&
+                   (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
+                   !(inifp->if_flags & IFF_LOOPBACK) &&
+                   !(m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
+                       m->m_pkthdr.csum_flags &= ~CSUM_DATA_VALID;
+                       m->m_pkthdr.csum_data = 0;
+                       ipstat.ips_adj_hwcsum_clr++;
+               }
+
+               ipstat.ips_adj++;
+               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);
+       }
+
+       /* for consistency */
+       m->m_pkthdr.pkt_proto = ip->ip_p;
+
+       /* for netstat route statistics */
+       src_ip = ip->ip_src;
+       len = m->m_pkthdr.len;
+
+#if DUMMYNET
+check_with_pf:
+#endif
+#if PF
+       /* Invoke inbound packet filter */
+       if (PF_IS_ENABLED) {
+               int error;
+               ip_input_cpout_args(args, &args1, &init);
+
+#if DUMMYNET
+               error = pf_af_hook(inifp, NULL, &m, AF_INET, TRUE, &args1);
+#else
+               error = pf_af_hook(inifp, NULL, &m, AF_INET, TRUE, NULL);
+#endif /* DUMMYNET */
+               if (error != 0 || m == NULL) {
+                       if (m != NULL) {
+                               panic("%s: unexpected packet %p\n",
+                                   __func__, m);
+                               /* NOTREACHED */
+                       }
+                       /* Already freed by callee */
+                       ip_input_update_nstat(inifp, src_ip, 1, len);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       return (IPINPUT_FREED);
+               }
+               ip = mtod(m, struct ip *);
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+               *modm = m;
+               ip_input_cpin_args(&args1, args);
+       }
+#endif /* PF */
+
+#if IPSEC
+       if (ipsec_bypass == 0 && ipsec_gethist(m, NULL)) {
+               retval = IPINPUT_DONTCHAIN; /* XXX scope for chaining here? */
+               goto pass;
+       }
+#endif
+
+#if IPFIREWALL
+#if DUMMYNET
+iphack:
+#endif /* DUMMYNET */
+       /*
+        * Check if we want to allow this packet to be processed.
+        * Consider it to be bad if not.
+        */
+       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 (args->fwai_next_hop) {
+                       *ours = 1;
+                       return (IPINPUT_DONTCHAIN);
+               }
+#endif /* IPFIREWALL_FORWARD */
+               ip_input_cpout_args(args, &args1, &init);
+               args1.fwa_m = m;
+
+               i = ip_fw_chk_ptr(&args1);
+               m = args1.fwa_m;
+
+               if ((i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
+                       if (m)
+                               m_freem(m);
+                       ip_input_update_nstat(inifp, src_ip, 1, len);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       return (IPINPUT_FREED);
+               }
+               ip = mtod(m, struct ip *); /* just in case m changed */
+               *modm = m;
+               ip_input_cpin_args(&args1, args);
+
+               if (i == 0 && args->fwai_next_hop == NULL) { /* common case */
+                       goto pass;
+               }
+#if DUMMYNET
+               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, &args1,
+                           DN_CLIENT_IPFW);
+                       ip_input_update_nstat(inifp, src_ip, 1, len);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       return (IPINPUT_FREED);
+               }
+#endif /* DUMMYNET */
+#if IPDIVERT
+               if (i != 0 && (i & IP_FW_PORT_DYNT_FLAG) == 0) {
+                       /* Divert or tee packet */
+                       *div_info = i;
+                       *ours = 1;
+                       return (IPINPUT_DONTCHAIN);
+               }
+#endif
+#if IPFIREWALL_FORWARD
+               if (i == 0 && args->fwai_next_hop != NULL) {
+                       retval = IPINPUT_DONTCHAIN;
+                       goto pass;
+               }
+#endif
+               /*
+                * if we get here, the packet must be dropped
+                */
+               ip_input_update_nstat(inifp, src_ip, 1, len);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               m_freem(m);
+               OSAddAtomic(1, &ipstat.ips_total);
+               return (IPINPUT_FREED);
+       }
+#endif /* IPFIREWALL */
+#if IPSEC | IPFIREWALL
+pass:
+#endif
+       /*
+        * Process options and, if not destined for us,
+        * ship it on.  ip_dooptions returns 1 when an
+        * error was detected (causing an icmp message
+        * to be sent and the original packet to be freed).
+        */
+       ip_nhops = 0;           /* for source routed packets */
+#if IPFIREWALL
+       if (hlen > sizeof (struct ip) &&
+           ip_dooptions(m, 0, args->fwai_next_hop)) {
+#else /* !IPFIREWALL */
+       if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, NULL)) {
+#endif /* !IPFIREWALL */
+               ip_input_update_nstat(inifp, src_ip, 1, len);
+               KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+               OSAddAtomic(1, &ipstat.ips_total);
+               return (IPINPUT_FREED);
+       }
+
+       /*
+        * Don't chain fragmented packets as the process of determining
+        * if it is our fragment or someone else's plus the complexity of
+        * divert and fw args makes it harder to do chaining.
+        */
+       if (ip->ip_off & ~(IP_DF | IP_RF))
+               return (IPINPUT_DONTCHAIN);
+
+       /* Allow DHCP/BootP responses through */
+       if ((inifp->if_eflags & IFEF_AUTOCONFIGURING) &&
+           hlen == sizeof (struct ip) && ip->ip_p == IPPROTO_UDP) {
+               struct udpiphdr *ui;
+
+               if (m->m_len < sizeof (struct udpiphdr) &&
+                   (m = m_pullup(m, sizeof (struct udpiphdr))) == NULL) {
+                       OSAddAtomic(1, &udpstat.udps_hdrops);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       OSAddAtomic(1, &ipstat.ips_total);
+                       return (IPINPUT_FREED);
+               }
+               *modm = m;
+               ui = mtod(m, struct udpiphdr *);
+               if (ntohs(ui->ui_dport) == IPPORT_BOOTPC) {
+                       ip_setdstifaddr_info(m, inifp->if_index, NULL);
+                       return (IPINPUT_DONTCHAIN);
+               }
+       }
+
+       /* Avoid chaining raw sockets as ipsec checks occur later for them */
+       if (ip_protox[ip->ip_p]->pr_flags & PR_LASTHDR)
+               return (IPINPUT_DONTCHAIN);
+
+       return (retval);
+#if !defined(__i386__) && !defined(__x86_64__)
+bad:
+       m_freem(m);
+       return (IPINPUT_FREED);
+#endif
+}
+
+static void
+ip_input_second_pass(struct mbuf *m, struct ifnet *inifp, u_int32_t div_info,
+    int npkts_in_chain, int bytes_in_chain, struct ip_fw_in_args *args, int ours)
+{
+       unsigned int            checkif;
+       struct mbuf             *tmp_mbuf = NULL;
+       struct in_ifaddr        *ia = NULL;
+       struct in_addr          pkt_dst;
+       unsigned int            hlen;
+
+#if !IPFIREWALL
+#pragma unused (args)
+#endif
+
+#if !IPDIVERT
+#pragma unused (div_info)
+#endif
+
+       struct ip *ip = mtod(m, struct ip *);
+       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+
+       OSAddAtomic(npkts_in_chain, &ipstat.ips_total);
+
+       /*
+        * Naively assume we can attribute inbound data to the route we would
+        * use to send to this destination. Asymmetric routing breaks this
+        * assumption, but it still allows us to account for traffic from
+        * a remote node in the routing table.
+        * this has a very significant performance impact so we bypass
+        * if nstat_collect is disabled. We may also bypass if the
+        * protocol is tcp in the future because tcp will have a route that
+        * we can use to attribute the data to. That does mean we would not
+        * account for forwarded tcp traffic.
+        */
+       ip_input_update_nstat(inifp, ip->ip_src, npkts_in_chain,
+           bytes_in_chain);
+
+       if (ours)
+               goto ours;
+
+       /*
+        * 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).
+        */
+       tmp_mbuf = m;
+       if (TAILQ_EMPTY(&in_ifaddrhead)) {
+               while (tmp_mbuf) {
+                       if (!(tmp_mbuf->m_flags & (M_MCAST|M_BCAST))) {
+                               ip_setdstifaddr_info(tmp_mbuf, inifp->if_index,
+                                   NULL);
+                       }
+                       tmp_mbuf = mbuf_nextpkt(tmp_mbuf);
+               }
+               goto ours;
+       }
+       /*
+        * Cache the destination address of the packet; this may be
+        * changed by use of 'ipfw fwd'.
+        */
+#if IPFIREWALL
+       pkt_dst = args->fwai_next_hop == NULL ?
+           ip->ip_dst : args->fwai_next_hop->sin_addr;
+#else /* !IPFIREWALL */
+       pkt_dst = ip->ip_dst;
+#endif /* !IPFIREWALL */
+
+       /*
+        * 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) &&
+           !(inifp->if_flags & IFF_LOOPBACK) &&
+           !(m->m_pkthdr.pkt_flags & PKTF_LOOP)
+#if IPFIREWALL
+           && (args->fwai_next_hop == NULL);
+#else /* !IPFIREWALL */
+               ;
+#endif /* !IPFIREWALL */
+
+       /*
+        * Check for exact addresses in the hash bucket.
+        */
+       lck_rw_lock_shared(in_ifaddr_rwlock);
+       TAILQ_FOREACH(ia, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
+               /*
+                * If the address matches, verify that the packet
+                * arrived via the correct interface if checking is
+                * enabled.
+                */
+               if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
+                   (!checkif || ia->ia_ifp == inifp)) {
+                       ip_input_setdst_chain(m, 0, ia);
+                       lck_rw_done(in_ifaddr_rwlock);
+                       goto ours;
+               }
+       }
+       lck_rw_done(in_ifaddr_rwlock);
+
+       /*
+        * Check for broadcast addresses.
+        *
+        * Only accept broadcast packets that arrive via the matching
+        * interface.  Reception of forwarded directed broadcasts would be
+        * handled via ip_forward() and ether_frameout() with the loopback
+        * into the stack for SIMPLEX interfaces handled by ether_frameout().
+        */
+       if (inifp->if_flags & IFF_BROADCAST) {
+               struct ifaddr *ifa;
+
+               ifnet_lock_shared(inifp);
+               TAILQ_FOREACH(ifa, &inifp->if_addrhead, ifa_link) {
+                       if (ifa->ifa_addr->sa_family != AF_INET) {
+                               continue;
+                       }
+                       ia = ifatoia(ifa);
+                       if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
+                           pkt_dst.s_addr || ia->ia_netbroadcast.s_addr ==
+                           pkt_dst.s_addr) {
+                               ip_input_setdst_chain(m, 0, ia);
+                               ifnet_lock_done(inifp);
+                               goto ours;
+                       }
+               }
+               ifnet_lock_done(inifp);
+       }
+
+       if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
+               struct in_multi *inm;
+               /*
+                * See if we belong to the destination multicast group on the
+                * arrival interface.
+                */
+               in_multihead_lock_shared();
+               IN_LOOKUP_MULTI(&ip->ip_dst, inifp, inm);
+               in_multihead_lock_done();
+               if (inm == NULL) {
+                       OSAddAtomic(npkts_in_chain, &ipstat.ips_notmember);
+                       m_freem_list(m);
+                       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+                       return;
+               }
+               ip_input_setdst_chain(m, inifp->if_index, NULL);
+               INM_REMREF(inm);
+               goto ours;
+       }
+
+       if (ip->ip_dst.s_addr == (u_int32_t)INADDR_BROADCAST ||
+           ip->ip_dst.s_addr == INADDR_ANY) {
+               ip_input_setdst_chain(m, inifp->if_index, NULL);
+               goto ours;
+       }
+
+       if (ip->ip_p == IPPROTO_UDP) {
+               struct udpiphdr *ui;
+               ui = mtod(m, struct udpiphdr *);
+               if (ntohs(ui->ui_dport) == IPPORT_BOOTPC) {
+                       goto ours;
+               }
+       }
+
+       tmp_mbuf = m;
+       struct mbuf *nxt_mbuf = NULL;
+       while (tmp_mbuf) {
+               nxt_mbuf = mbuf_nextpkt(tmp_mbuf);
+               /*
+                * Not for us; forward if possible and desirable.
+                */
+               mbuf_setnextpkt(tmp_mbuf, NULL);
+               if (ipforwarding == 0) {
+                       OSAddAtomic(1, &ipstat.ips_cantforward);
+                       m_freem(tmp_mbuf);
+               } else {
+#if IPFIREWALL
+                       ip_forward(tmp_mbuf, 0, args->fwai_next_hop);
+#else
+                       ip_forward(tmp_mbuf, 0, NULL);
+#endif
+               }
+               tmp_mbuf = nxt_mbuf;
+       }
+       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+       return;
+ours:
+       /*
+        * If offset or IP_MF are set, must reassemble.
+        */
+       if (ip->ip_off & ~(IP_DF | IP_RF)) {
+               VERIFY(npkts_in_chain == 1);
+               /*
+                * ip_reass() will return a different mbuf, and update
+                * the divert info in div_info and args->fwai_divert_rule.
+                */
+#if IPDIVERT
+               m = ip_reass(m, (u_int16_t *)&div_info, &args->fwai_divert_rule);
+#else
+               m = ip_reass(m);
+#endif
+               if (m == NULL)
+                       return;
+               ip = mtod(m, struct ip *);
+               /* Get the header length of the reassembled packet */
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+#if IPDIVERT
+               /* Restore original checksum before diverting packet */
+               if (div_info != 0) {
+                       VERIFY(npkts_in_chain == 1);
+#if BYTE_ORDER != BIG_ENDIAN
+                       HTONS(ip->ip_len);
+                       HTONS(ip->ip_off);
+#endif
+                       ip->ip_sum = 0;
+                       ip->ip_sum = ip_cksum_hdr_in(m, hlen);
+#if BYTE_ORDER != BIG_ENDIAN
+                       NTOHS(ip->ip_off);
+                       NTOHS(ip->ip_len);
+#endif
+               }
+#endif
+       }
+
+       /*
+        * Further protocols expect the packet length to be w/o the
+        * IP header.
+        */
+       ip->ip_len -= hlen;
+
+#if IPDIVERT
+       /*
+        * 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 (div_info != 0) {
+               struct mbuf *clone = NULL;
+               VERIFY(npkts_in_chain == 1);
+
+               /* Clone packet if we're doing a 'tee' */
+               if (div_info & IP_FW_PORT_TEE_FLAG)
+                       clone = m_dup(m, M_DONTWAIT);
+
+               /* Restore packet header fields to original values */
+               ip->ip_len += hlen;
+
+#if BYTE_ORDER != BIG_ENDIAN
+               HTONS(ip->ip_len);
+               HTONS(ip->ip_off);
+#endif
+               /* Deliver packet to divert input routine */
+               OSAddAtomic(1, &ipstat.ips_delivered);
+               divert_packet(m, 1, div_info & 0xffff, args->fwai_divert_rule);
+
+               /* If 'tee', continue with original packet */
+               if (clone == NULL) {
+                       return;
+               }
+               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)) {
+               VERIFY(npkts_in_chain == 1);
+               if (ipsec4_in_reject(m, NULL)) {
+                       IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
+                       goto bad;
+               }
+       }
+#endif /* IPSEC */
+
+       /*
+        * Switch out to protocol's input routine.
+        */
+       OSAddAtomic(npkts_in_chain, &ipstat.ips_delivered);
+
+#if IPFIREWALL
+       if (args->fwai_next_hop && ip->ip_p == IPPROTO_TCP) {
+               /* TCP needs IPFORWARD info if available */
+               struct m_tag *fwd_tag;
+               struct ip_fwd_tag *ipfwd_tag;
+
+               VERIFY(npkts_in_chain == 1);
+               fwd_tag = m_tag_create(KERNEL_MODULE_TAG_ID,
+                   KERNEL_TAG_TYPE_IPFORWARD, sizeof (*ipfwd_tag),
+                   M_NOWAIT, m);
+               if (fwd_tag == NULL)
+                       goto bad;
+
+               ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1);
+               ipfwd_tag->next_hop = args->fwai_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);
+
+               /* 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);
+
+               ip_input_dispatch_chain(m);
+
+       }
+#else /* !IPFIREWALL */
+       ip_input_dispatch_chain(m);
+
+#endif /* !IPFIREWALL */
+       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+       return;
+bad:
+       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
+       m_freem(m);
+}
+
+void
+ip_input_process_list(struct mbuf *packet_list)
+{
+       pktchain_elm_t  pktchain_tbl[PKTTBL_SZ];
+
+       struct mbuf     *packet = NULL;
+       struct mbuf     *modm = NULL; /* modified mbuf */
+       int             retval = 0;
+       u_int32_t       div_info = 0;
+       int             ours = 0;
+       struct timeval start_tv;
+       int     num_pkts = 0;
+       int chain = 0;
+       struct ip_fw_in_args       args;
+
+       if (ip_chaining == 0) {
+               struct mbuf *m = packet_list;
+               if (ip_input_measure)
+                       net_perf_start_time(&net_perf, &start_tv);
+               while (m) {
+                       packet_list = mbuf_nextpkt(m);
+                       mbuf_setnextpkt(m, NULL);
+                       ip_input(m);
+                       m = packet_list;
+                       num_pkts++;
+               }
+               if (ip_input_measure)
+                       net_perf_measure_time(&net_perf, &start_tv, num_pkts);
+               return;
+       }
+       if (ip_input_measure)
+               net_perf_start_time(&net_perf, &start_tv);
+
+       bzero(&pktchain_tbl, sizeof(pktchain_tbl));
+restart_list_process:
+       chain = 0;
+       for (packet = packet_list; packet; packet = packet_list) {
+               packet_list = mbuf_nextpkt(packet);
+               mbuf_setnextpkt(packet, NULL);
+
+               num_pkts++;
+               modm = NULL;
+               div_info = 0;
+               bzero(&args, sizeof (args));
+
+               retval = ip_input_first_pass(packet, &div_info, &args,
+                   &ours, &modm);
+
+               if (retval == IPINPUT_DOCHAIN) {
+                       if (modm)
+                               packet = modm;
+                       packet = ip_chain_insert(packet, &pktchain_tbl[0]);
+                       if (packet == NULL) {
+                               ipstat.ips_rxc_chained++;
+                               chain++;
+                               if (chain > ip_chainsz)
+                                       break;
+                       } else {
+                               ipstat.ips_rxc_collisions++;
+                               break;
+                       }
+               } else if (retval == IPINPUT_DONTCHAIN) {
+                       /* in order to preserve order, exit from chaining */
+                       if (modm)
+                               packet = modm;
+                       ipstat.ips_rxc_notchain++;
+                       break;
+               } else {
+                       /* packet was freed or delivered, do nothing. */
+               }
+       }
+
+       /* do second pass here for pktchain_tbl */
+       if (chain)
+               ip_input_second_pass_loop_tbl(&pktchain_tbl[0], &args);
+
+       if (packet) {
+               /*
+                * equivalent update in chaining case if performed in
+                * ip_input_second_pass_loop_tbl().
+                */
+               if (ip_input_measure)
+                       net_perf_histogram(&net_perf, 1);
+
+               ip_input_second_pass(packet, packet->m_pkthdr.rcvif, div_info,
+                   1, packet->m_pkthdr.len, &args, ours);
+       }
+
+       if (packet_list)
+               goto restart_list_process;
 
+       if (ip_input_measure)
+               net_perf_measure_time(&net_perf, &start_tv, num_pkts);
+}
 /*
  * Ip input routine.  Checksum and byte swap header.  If fragmented
  * try to reassemble.  Process options.  Pass to next level.
@@ -672,9 +1747,8 @@ void
 ip_input(struct mbuf *m)
 {
        struct ip *ip;
-       struct ipq *fp;
        struct in_ifaddr *ia = NULL;
-       unsigned int    hlen, checkif;
+       unsigned int hlen, checkif;
        u_short sum = 0;
        struct in_addr pkt_dst;
 #if IPFIREWALL
@@ -685,16 +1759,23 @@ ip_input(struct mbuf *m)
        struct ip_fw_args args;
        struct m_tag    *tag;
 #endif
-       ipfilter_t inject_filter_ref = 0;
+       ipfilter_t inject_filter_ref = NULL;
+       struct ifnet *inifp;
 
        /* Check if the mbuf is still valid after interface filter processing */
        MBUF_INPUT_CHECK(m, m->m_pkthdr.rcvif);
+       inifp = m->m_pkthdr.rcvif;
+       VERIFY(inifp != NULL);
+
+       ipstat.ips_rxc_notlist++;
 
        /* Perform IP header alignment fixup, if needed */
-       IP_HDR_ALIGNMENT_FIXUP(m, m->m_pkthdr.rcvif, goto bad;);
+       IP_HDR_ALIGNMENT_FIXUP(m, inifp, goto bad);
+
+       m->m_pkthdr.pkt_flags &= ~PKTF_FORWARDED;
 
 #if IPFIREWALL || DUMMYNET
-       bzero(&args, sizeof(struct ip_fw_args));
+       bzero(&args, sizeof (struct ip_fw_args));
 
        /*
         * Don't bother searching for tag(s) if there's none.
@@ -706,7 +1787,7 @@ ip_input(struct mbuf *m)
 #if DUMMYNET
        if ((tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID,
            KERNEL_TAG_TYPE_DUMMYNET, NULL)) != NULL) {
-               struct dn_pkt_tag       *dn_tag;
+               struct dn_pkt_tag *dn_tag;
 
                dn_tag = (struct dn_pkt_tag *)(tag+1);
                args.fwa_ipfw_rule = dn_tag->dn_ipfw_rule;
@@ -719,7 +1800,7 @@ ip_input(struct mbuf *m)
 #if IPDIVERT
        if ((tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID,
            KERNEL_TAG_TYPE_DIVERT, NULL)) != NULL) {
-               struct divert_tag       *div_tag;
+               struct divert_tag *div_tag;
 
                div_tag = (struct divert_tag *)(tag+1);
                args.fwa_divert_rule = div_tag->cookie;
@@ -730,7 +1811,7 @@ ip_input(struct mbuf *m)
 
        if ((tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID,
            KERNEL_TAG_TYPE_IPFORWARD, NULL)) != NULL) {
-               struct ip_fwd_tag       *ipfwd_tag;
+               struct ip_fwd_tag *ipfwd_tag;
 
                ipfwd_tag = (struct ip_fwd_tag *)(tag+1);
                args.fwa_next_hop = ipfwd_tag->next_hop;
@@ -739,12 +1820,13 @@ ip_input(struct mbuf *m)
        }
 
 #if    DIAGNOSTIC
-       if (m == NULL || (m->m_flags & M_PKTHDR) == 0)
+       if (m == NULL || !(m->m_flags & M_PKTHDR))
                panic("ip_input no HDR");
 #endif
 
 #if DUMMYNET
-       if (args.fwa_ipfw_rule || args.fwa_pf_rule) {   /* dummynet already filtered us */
+       if (args.fwa_ipfw_rule || args.fwa_pf_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);
@@ -757,21 +1839,21 @@ ip_input(struct mbuf *m)
        }
 #endif /* DUMMYNET */
 ipfw_tags_done:
-#endif /* IPFIREWALL || DUMMYNET*/
+#endif /* IPFIREWALL || DUMMYNET */
 
        /*
         * No need to process packet twice if we've already seen it.
         */
        if (!SLIST_EMPTY(&m->m_pkthdr.tags))
                inject_filter_ref = ipf_get_inject_filter(m);
-       if (inject_filter_ref != 0) {
+       if (inject_filter_ref != NULL) {
                ip = mtod(m, struct ip *);
                hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 
-               DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL, 
-                       struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
-                       struct ip *, ip, struct ip6_hdr *, NULL);
-               
+               DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
+                   struct ip *, ip, struct ifnet *, inifp,
+                   struct ip *, ip, struct ip6_hdr *, NULL);
+
                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);
@@ -779,18 +1861,18 @@ ipfw_tags_done:
        }
 
        OSAddAtomic(1, &ipstat.ips_total);
-       if (m->m_pkthdr.len < sizeof(struct ip))
+       if (m->m_pkthdr.len < sizeof (struct ip))
                goto tooshort;
 
        if (m->m_len < sizeof (struct ip) &&
-           (m = m_pullup(m, sizeof (struct ip))) == 0) {
+           (m = m_pullup(m, sizeof (struct ip))) == NULL) {
                OSAddAtomic(1, &ipstat.ips_toosmall);
                return;
        }
        ip = mtod(m, struct ip *);
 
-       KERNEL_DEBUG(DBG_LAYER_BEG, ip->ip_dst.s_addr, 
-                    ip->ip_src.s_addr, ip->ip_p, ip->ip_off, ip->ip_len);
+       KERNEL_DEBUG(DBG_LAYER_BEG, ip->ip_dst.s_addr, ip->ip_src.s_addr,
+           ip->ip_p, ip->ip_off, ip->ip_len);
 
        if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
                OSAddAtomic(1, &ipstat.ips_badvers);
@@ -798,12 +1880,12 @@ ipfw_tags_done:
        }
 
        hlen = IP_VHL_HL(ip->ip_vhl) << 2;
-       if (hlen < sizeof(struct ip)) { /* minimum header length */
+       if (hlen < sizeof (struct ip)) {        /* minimum header length */
                OSAddAtomic(1, &ipstat.ips_badhlen);
                goto bad;
        }
        if (hlen > m->m_len) {
-               if ((m = m_pullup(m, hlen)) == 0) {
+               if ((m = m_pullup(m, hlen)) == NULL) {
                        OSAddAtomic(1, &ipstat.ips_badhlen);
                        return;
                }
@@ -813,14 +1895,28 @@ ipfw_tags_done:
        /* 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) {
+               /*
+                * Allow for the following exceptions:
+                *
+                *   1. If the packet was sent to loopback (i.e. rcvif
+                *      would have been set earlier at output time.)
+                *
+                *   2. If the packet was sent out on loopback from a local
+                *      source address which belongs to a non-loopback
+                *      interface (i.e. rcvif may not necessarily be a
+                *      loopback interface, hence the test for PKTF_LOOP.)
+                *      Unlike IPv6, there is no interface scope ID, and
+                *      therefore we don't care so much about PKTF_IFINFO.
+                */
+               if (!(inifp->if_flags & IFF_LOOPBACK) &&
+                   !(m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
                        OSAddAtomic(1, &ipstat.ips_badaddr);
                        goto bad;
                }
        }
 
-       /* IPv4 Link-Local Addresses as defined in <draft-ietf-zeroconf-ipv4-linklocal-05.txt> */
-       if ((IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) || 
+       /* IPv4 Link-Local Addresses as defined in RFC3927 */
+       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) {
@@ -836,13 +1932,13 @@ ipfw_tags_done:
                goto bad;
        }
 
-       DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL, 
-               struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
-               struct ip *, ip, struct ip6_hdr *, NULL);
+       DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
+           struct ip *, ip, struct ifnet *, inifp,
+           struct ip *, ip, struct ip6_hdr *, NULL);
 
        /*
         * Naively assume we can attribute inbound data to the route we would
-        * use to send to this destination. Asymetric routing breaks this
+        * use to send to this destination. Asymmetric routing breaks this
         * assumption, but it still allows us to account for traffic from
         * a remote node in the routing table.
         * this has a very significant performance impact so we bypass
@@ -853,7 +1949,7 @@ ipfw_tags_done:
         */
        if (nstat_collect) {
                struct rtentry *rt =
-                   ifnet_cached_rtlookup_inet(m->m_pkthdr.rcvif, ip->ip_src);
+                   ifnet_cached_rtlookup_inet(inifp, ip->ip_src);
                if (rt != NULL) {
                        nstat_route_rx(rt, 1, m->m_pkthdr.len, 0);
                        rtfree(rt);
@@ -866,7 +1962,7 @@ ipfw_tags_done:
 #if BYTE_ORDER != BIG_ENDIAN
        NTOHS(ip->ip_len);
 #endif
-       
+
        if (ip->ip_len < hlen) {
                OSAddAtomic(1, &ipstat.ips_badlen);
                goto bad;
@@ -887,10 +1983,22 @@ 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;
+               /*
+                * Invalidate hardware checksum info if ip_adj_clear_hwcksum
+                * is set; useful to handle buggy drivers.  Note that this
+                * should not be enabled by default, as we may get here due
+                * to link-layer padding.
+                */
+               if (ip_adj_clear_hwcksum &&
+                   (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
+                   !(inifp->if_flags & IFF_LOOPBACK) &&
+                   !(m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
+                       m->m_pkthdr.csum_flags &= ~CSUM_DATA_VALID;
+                       m->m_pkthdr.csum_data = 0;
+                       ipstat.ips_adj_hwcsum_clr++;
+               }
 
+               ipstat.ips_adj++;
                if (m->m_len == m->m_pkthdr.len) {
                        m->m_len = ip->ip_len;
                        m->m_pkthdr.len = ip->ip_len;
@@ -898,6 +2006,8 @@ tooshort:
                        m_adj(m, ip->ip_len - m->m_pkthdr.len);
        }
 
+       /* for consistency */
+       m->m_pkthdr.pkt_proto = ip->ip_p;
 
 #if DUMMYNET
 check_with_pf:
@@ -907,13 +2017,14 @@ check_with_pf:
        if (PF_IS_ENABLED) {
                int error;
 #if DUMMYNET
-               error = pf_af_hook(m->m_pkthdr.rcvif, NULL, &m, AF_INET, TRUE, &args);
+               error = pf_af_hook(inifp, NULL, &m, AF_INET, TRUE, &args);
 #else
-               error = pf_af_hook(m->m_pkthdr.rcvif, NULL, &m, AF_INET, TRUE, NULL);
+               error = pf_af_hook(inifp, NULL, &m, AF_INET, TRUE, NULL);
 #endif /* DUMMYNET */
                if (error != 0 || m == NULL) {
                        if (m != NULL) {
-                               panic("%s: unexpected packet %p\n", __func__, m);
+                               panic("%s: unexpected packet %p\n",
+                                   __func__, m);
                                /* NOTREACHED */
                        }
                        /* Already freed by callee */
@@ -952,20 +2063,21 @@ iphack:
                i = ip_fw_chk_ptr(&args);
                m = args.fwa_m;
 
-               if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
+               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.fwa_next_hop == NULL) {      /* common case */
+
+               if (i == 0 && args.fwa_next_hop == NULL) { /* common case */
                        goto pass;
                }
 #if DUMMYNET
-                if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG) != 0) {
+               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, DN_CLIENT_IPFW);
+                       ip_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args,
+                           DN_CLIENT_IPFW);
                        return;
                }
 #endif /* DUMMYNET */
@@ -988,8 +2100,9 @@ iphack:
                return;
        }
 #endif /* IPFIREWALL */
+#if IPSEC | IPFIREWALL
 pass:
-
+#endif
        /*
         * Process options and, if not destined for us,
         * ship it on.  ip_dooptions returns 1 when an
@@ -998,31 +2111,24 @@ pass:
         */
        ip_nhops = 0;           /* for source routed packets */
 #if IPFIREWALL
-       if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, args.fwa_next_hop)) {
-#else
+       if (hlen > sizeof (struct ip) &&
+           ip_dooptions(m, 0, args.fwa_next_hop)) {
+#else /* !IPFIREWALL */
        if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, NULL)) {
-#endif
+#endif /* !IPFIREWALL */
                return;
        }
 
-        /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
-         * matter if it is destined to another node, or whether it is 
-         * a multicast one, RSVP wants it! and prevents it from being forwarded
-         * anywhere else. Also checks if the rsvp daemon is running before
-        * grabbing the packet.
-         */
-       if (rsvp_on && ip->ip_p==IPPROTO_RSVP) 
-               goto ours;
-
        /*
         * 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).
         */
-       if (TAILQ_EMPTY(&in_ifaddrhead) &&
-           (m->m_flags & (M_MCAST|M_BCAST)) == 0)
+       if (TAILQ_EMPTY(&in_ifaddrhead) && !(m->m_flags & (M_MCAST|M_BCAST))) {
+               ip_setdstifaddr_info(m, inifp->if_index, NULL);
                goto ours;
+       }
 
        /*
         * Cache the destination address of the packet; this may be
@@ -1031,9 +2137,9 @@ pass:
 #if IPFIREWALL
        pkt_dst = args.fwa_next_hop == NULL ?
            ip->ip_dst : args.fwa_next_hop->sin_addr;
-#else
+#else /* !IPFIREWALL */
        pkt_dst = ip->ip_dst;
-#endif
+#endif /* !IPFIREWALL */
 
        /*
         * Enable a consistency check between the destination address
@@ -1049,13 +2155,14 @@ pass:
         * 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)
+       checkif = ip_checkinterface && (ipforwarding == 0) &&
+           !(inifp->if_flags & IFF_LOOPBACK) &&
+           !(m->m_pkthdr.pkt_flags & PKTF_LOOP)
 #if IPFIREWALL
            && (args.fwa_next_hop == NULL);
-#else
+#else /* !IPFIREWALL */
                ;
-#endif
+#endif /* !IPFIREWALL */
 
        /*
         * Check for exact addresses in the hash bucket.
@@ -1067,14 +2174,12 @@ pass:
                 * arrived via the correct interface if checking is
                 * enabled.
                 */
-               IFA_LOCK_SPIN(&ia->ia_ifa);
-               if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr && 
-                   (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) {
-                       IFA_UNLOCK(&ia->ia_ifa);
+               if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
+                   (!checkif || ia->ia_ifp == inifp)) {
+                       ip_setdstifaddr_info(m, 0, ia);
                        lck_rw_done(in_ifaddr_rwlock);
                        goto ours;
                }
-               IFA_UNLOCK(&ia->ia_ifa);
        }
        lck_rw_done(in_ifaddr_rwlock);
 
@@ -1086,93 +2191,63 @@ pass:
         * handled via ip_forward() and ether_frameout() with the loopback
         * into the stack for SIMPLEX interfaces handled by ether_frameout().
         */
-       if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
+       if (inifp->if_flags & IFF_BROADCAST) {
                struct ifaddr *ifa;
-               struct ifnet *ifp = m->m_pkthdr.rcvif;
-               ifnet_lock_shared(ifp);
-               TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-                       IFA_LOCK_SPIN(ifa);
+
+               ifnet_lock_shared(inifp);
+               TAILQ_FOREACH(ifa, &inifp->if_addrhead, ifa_link) {
                        if (ifa->ifa_addr->sa_family != AF_INET) {
-                               IFA_UNLOCK(ifa);
                                continue;
                        }
                        ia = ifatoia(ifa);
                        if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
                            pkt_dst.s_addr || ia->ia_netbroadcast.s_addr ==
                            pkt_dst.s_addr) {
-                               IFA_UNLOCK(ifa);
-                               ifnet_lock_done(ifp);
+                               ip_setdstifaddr_info(m, 0, ia);
+                               ifnet_lock_done(inifp);
                                goto ours;
                        }
-                       IFA_UNLOCK(ifa);
                }
-               ifnet_lock_done(ifp);
+               ifnet_lock_done(inifp);
        }
 
        if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
                struct in_multi *inm;
-               struct ifnet *ifp = m->m_pkthdr.rcvif;
-#if MROUTING
-               if (ip_mrouter) {
-                       /*
-                        * If we are acting as a multicast router, all
-                        * incoming multicast packets are passed to the
-                        * kernel-level multicast forwarding function.
-                        * 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.
-                        */
-                       lck_mtx_lock(ip_mutex);
-                       if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
-                               OSAddAtomic(1, &ipstat.ips_cantforward);
-                               m_freem(m);
-                               lck_mtx_unlock(ip_mutex);
-                               return;
-                       }
-
-                       /*
-                        * The process-level routing daemon needs to receive
-                        * all multicast IGMP packets, whether or not this
-                        * host belongs to their destination groups.
-                        */
-                       if (ip->ip_p == IPPROTO_IGMP)
-                               goto ours;
-                       OSAddAtomic(1, &ipstat.ips_forward);
-               }
-#endif /* MROUTING */
                /*
                 * See if we belong to the destination multicast group on the
                 * arrival interface.
                 */
                in_multihead_lock_shared();
-               IN_LOOKUP_MULTI(&ip->ip_dst, ifp, inm);
+               IN_LOOKUP_MULTI(&ip->ip_dst, inifp, inm);
                in_multihead_lock_done();
                if (inm == NULL) {
                        OSAddAtomic(1, &ipstat.ips_notmember);
                        m_freem(m);
                        return;
                }
+               ip_setdstifaddr_info(m, inifp->if_index, NULL);
                INM_REMREF(inm);
                goto ours;
        }
-       if (ip->ip_dst.s_addr == (u_int32_t)INADDR_BROADCAST)
-               goto ours;
-       if (ip->ip_dst.s_addr == INADDR_ANY)
+       if (ip->ip_dst.s_addr == (u_int32_t)INADDR_BROADCAST ||
+           ip->ip_dst.s_addr == INADDR_ANY) {
+               ip_setdstifaddr_info(m, inifp->if_index, NULL);
                goto ours;
+       }
 
        /* 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) {
+       if ((inifp->if_eflags & IFEF_AUTOCONFIGURING) &&
+           hlen == sizeof (struct ip) && ip->ip_p == IPPROTO_UDP) {
                struct udpiphdr *ui;
-               if (m->m_len < sizeof(struct udpiphdr)
-                   && (m = m_pullup(m, sizeof(struct udpiphdr))) == 0) {
+
+               if (m->m_len < sizeof (struct udpiphdr) &&
+                   (m = m_pullup(m, sizeof (struct udpiphdr))) == NULL) {
                        OSAddAtomic(1, &udpstat.udps_hdrops);
                        return;
                }
                ui = mtod(m, struct udpiphdr *);
                if (ntohs(ui->ui_dport) == IPPORT_BOOTPC) {
+                       ip_setdstifaddr_info(m, inifp->if_index, NULL);
                        goto ours;
                }
                ip = mtod(m, struct ip *); /* in case it changed */
@@ -1196,147 +2271,44 @@ pass:
 ours:
        /*
         * If offset or IP_MF are set, must reassemble.
-        * Otherwise, nothing need be done.
-        * (We could look in the reassembly queue to see
-        * if the packet was previously fragmented,
-        * but it's not worth the time; just let them time out.)
         */
-       if (ip->ip_off & (IP_MF | IP_OFFMASK | IP_RF)) {
-
-               /* If maxnipq is 0, never accept fragments. */
-               if (maxnipq == 0) {
-
-                       OSAddAtomic(1, &ipstat.ips_fragments);
-                       OSAddAtomic(1, &ipstat.ips_fragdropped);
-                       goto bad;
-               }
-               
-               /*
-                * If we will exceed the number of fragments in queues, timeout the
-                * oldest fragemented packet to make space.
-                */
-               lck_mtx_lock(ip_mutex); 
-               if (currentfrags >= maxfrags) {
-                       fp = TAILQ_LAST(&ipq_list, ipq_list);
-                       OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragtimeout);
-                       
-                       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.
-                                */
-                               OSAddAtomic(1, &ipstat.ips_fragdropped);
-                               ip_freef(fp);
-                               lck_mtx_unlock(ip_mutex); 
-                               goto bad;
-                       }
-                       
-                       ip_freef(fp);
-               }
-
-               sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
-               /*
-                * Look for queue of fragments
-                * of this datagram.
-                */
-               for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
-                       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 &&
-#if CONFIG_MACF_NET
-                           mac_ipq_label_compare(m, fp) &&
-#endif
-                           ip->ip_p == fp->ipq_p)
-                               goto found;
-
-               /*
-                * 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 the oldest fragment before proceeding further
-                    */
-                   fp = TAILQ_LAST(&ipq_list, ipq_list);
-                   OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragtimeout);
-                   ip_freef(fp);
-               }
-
-               fp = NULL;
-
-found:
-               /*
-                * Adjust ip_len to not reflect header,
-                * convert offset of this to bytes.
-                */
-               ip->ip_len -= hlen;
-               if (ip->ip_off & IP_MF) {
-                       /*
-                        * Make sure that fragments have a data length
-                                * that's a non-zero multiple of 8 bytes.
-                        */
-                       if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
-                               OSAddAtomic(1, &ipstat.ips_toosmall);
-                               lck_mtx_unlock(ip_mutex);
-                               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 (ip->ip_off & ~(IP_DF | IP_RF)) {
                /*
-                * Attempt reassembly; if it succeeds, proceed.
                 * ip_reass() will return a different mbuf, and update
                 * the divert info in div_info and args.fwa_divert_rule.
                 */
-                       OSAddAtomic(1, &ipstat.ips_fragments);
-                       m->m_pkthdr.header = ip;
 #if IPDIVERT
-                       m = ip_reass(m, fp, &ipq[sum],
-                           (u_int16_t *)&div_info, &args.fwa_divert_rule);
+               m = ip_reass(m, (u_int16_t *)&div_info, &args.fwa_divert_rule);
 #else
-                       m = ip_reass(m, fp, &ipq[sum]);
+               m = ip_reass(m);
 #endif
-                       if (m == 0) {
-                               lck_mtx_unlock(ip_mutex);
-                               return;
-                       }
-                       OSAddAtomic(1, &ipstat.ips_reassembled);
-                       ip = mtod(m, struct ip *);
-                       /* Get the header length of the reassembled packet */
-                       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
-
+               if (m == NULL)
+                       return;
+               ip = mtod(m, struct ip *);
+               /* Get the header length of the reassembled packet */
+               hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 #if IPDIVERT
-                       /* Restore original checksum before diverting packet */
-                       if (div_info != 0) {
-                               ip->ip_len += hlen;
-
+               /* Restore original checksum before diverting packet */
+               if (div_info != 0) {
 #if BYTE_ORDER != BIG_ENDIAN
-                               HTONS(ip->ip_len);
-                               HTONS(ip->ip_off);
+                       HTONS(ip->ip_len);
+                       HTONS(ip->ip_off);
 #endif
-                               
-                               ip->ip_sum = 0;
-                               ip->ip_sum = in_cksum(m, hlen);
-
+                       ip->ip_sum = 0;
+                       ip->ip_sum = ip_cksum_hdr_in(m, hlen);
 #if BYTE_ORDER != BIG_ENDIAN
-                               NTOHS(ip->ip_off);
-                               NTOHS(ip->ip_len);
+                       NTOHS(ip->ip_off);
+                       NTOHS(ip->ip_len);
 #endif
-                               
-                               ip->ip_len -= hlen;
-                       }
+               }
 #endif
-               lck_mtx_unlock(ip_mutex);
-               } else
-               ip->ip_len -= hlen;
+       }
+
+       /*
+        * Further protocols expect the packet length to be w/o the
+        * IP header.
+        */
+       ip->ip_len -= hlen;
 
 #if IPDIVERT
        /*
@@ -1349,7 +2321,7 @@ found:
                struct mbuf *clone = NULL;
 
                /* Clone packet if we're doing a 'tee' */
-               if ((div_info & IP_FW_PORT_TEE_FLAG) != 0)
+               if (div_info & IP_FW_PORT_TEE_FLAG)
                        clone = m_dup(m, M_DONTWAIT);
 
                /* Restore packet header fields to original values */
@@ -1378,69 +2350,136 @@ found:
         * 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) {
+       if (ipsec_bypass == 0 && (ip_protox[ip->ip_p]->pr_flags & PR_LASTHDR)) {
                if (ipsec4_in_reject(m, NULL)) {
                        IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
-                       goto bad;       
+                       goto bad;
                }
        }
-#endif
+#endif /* IPSEC */
 
        /*
         * Switch out to protocol's input routine.
         */
        OSAddAtomic(1, &ipstat.ips_delivered);
-       {
+
 #if IPFIREWALL
-               if (args.fwa_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_create(KERNEL_MODULE_TAG_ID,
-                           KERNEL_TAG_TYPE_IPFORWARD, sizeof (*ipfwd_tag),
-                           M_NOWAIT, m);
-                       if (fwd_tag == NULL) {
-                               goto bad;
-                       }
-                       
-                       ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1);
-                       ipfwd_tag->next_hop = args.fwa_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);
-       
-                       if (sw_lro) {
-                               m = tcp_lro(m, hlen);
-                               if (m == NULL)
-                                       return;
-                       }               
-                       /* 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);
-               
-                       ip_proto_dispatch_in(m, hlen, ip->ip_p, 0);
-               }
-#else
+       if (args.fwa_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_create(KERNEL_MODULE_TAG_ID,
+                   KERNEL_TAG_TYPE_IPFORWARD, sizeof (*ipfwd_tag),
+                   M_NOWAIT, m);
+               if (fwd_tag == NULL)
+                       goto bad;
+
+               ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1);
+               ipfwd_tag->next_hop = args.fwa_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);
+
+               /* 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);
+
                if ((sw_lro) && (ip->ip_p == IPPROTO_TCP)) {
                        m = tcp_lro(m, hlen);
                        if (m == NULL)
                                return;
                }
+
                ip_proto_dispatch_in(m, hlen, ip->ip_p, 0);
-#endif
-               
-               return;
        }
+#else /* !IPFIREWALL */
+       if ((sw_lro) && (ip->ip_p == IPPROTO_TCP)) {
+               m = tcp_lro(m, hlen);
+               if (m == NULL)
+                       return;
+       }
+       ip_proto_dispatch_in(m, hlen, ip->ip_p, 0);
+#endif /* !IPFIREWALL */
+       return;
+
 bad:
-       KERNEL_DEBUG(DBG_LAYER_END, 0,0,0,0,0);
+       KERNEL_DEBUG(DBG_LAYER_END, 0, 0, 0, 0, 0);
        m_freem(m);
 }
 
+static void
+ipq_updateparams(void)
+{
+       lck_mtx_assert(&ipqlock, LCK_MTX_ASSERT_OWNED);
+       /*
+        * -1 for unlimited allocation.
+        */
+       if (maxnipq < 0)
+               ipq_limit = 0;
+       /*
+        * Positive number for specific bound.
+        */
+       if (maxnipq > 0)
+               ipq_limit = maxnipq;
+       /*
+        * Zero specifies no further fragment queue allocation -- set the
+        * bound very low, but rely on implementation elsewhere to actually
+        * prevent allocation and reclaim current queues.
+        */
+       if (maxnipq == 0)
+               ipq_limit = 1;
+       /*
+        * Arm the purge timer if not already and if there's work to do
+        */
+       frag_sched_timeout();
+}
+
+static int
+sysctl_maxnipq SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int error, i;
+
+       lck_mtx_lock(&ipqlock);
+       i = maxnipq;
+       error = sysctl_handle_int(oidp, &i, 0, req);
+       if (error || req->newptr == USER_ADDR_NULL)
+               goto done;
+       /* impose bounds */
+       if (i < -1 || i > (nmbclusters / 4)) {
+               error = EINVAL;
+               goto done;
+       }
+       maxnipq = i;
+       ipq_updateparams();
+done:
+       lck_mtx_unlock(&ipqlock);
+       return (error);
+}
+
+static int
+sysctl_maxfragsperpacket SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int error, i;
+
+       lck_mtx_lock(&ipqlock);
+       i = maxfragsperpacket;
+       error = sysctl_handle_int(oidp, &i, 0, req);
+       if (error || req->newptr == USER_ADDR_NULL)
+               goto done;
+       maxfragsperpacket = i;
+       ipq_updateparams();     /* see if we need to arm timer */
+done:
+       lck_mtx_unlock(&ipqlock);
+       return (error);
+}
+
 /*
  * Take incoming datagram fragment and try to reassemble it into
  * whole datagram.  If a chain for reassembly of this datagram already
@@ -1448,29 +2487,176 @@ bad:
  *
  * When IPDIVERT enabled, keep additional state with each packet that
  * tells us if we need to divert or tee the packet we're building.
+ *
+ * The IP header is *NOT* adjusted out of iplen.
  */
-
 static struct mbuf *
 #if IPDIVERT
-ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where,
+ip_reass(struct mbuf *m,
 #ifdef IPDIVERT_44
-        u_int32_t *divinfo,
+    u_int32_t *divinfo,
 #else /* IPDIVERT_44 */
-        u_int16_t *divinfo,
+    u_int16_t *divinfo,
 #endif /* IPDIVERT_44 */
-        u_int16_t *divcookie)
+    u_int16_t *divcookie)
 #else /* IPDIVERT */
-ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
+ip_reass(struct mbuf *m)
 #endif /* IPDIVERT */
 {
-       struct ip *ip = mtod(m, struct ip *);
-       struct mbuf *p = 0, *q, *nq;
-       struct mbuf *t;
-       int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
-       int i, next;
+       struct ip *ip;
+       struct mbuf *p, *q, *nq, *t;
+       struct ipq *fp = NULL;
+       struct ipqhead *head;
+       int i, hlen, next;
        u_int8_t ecn, ecn0;
+       uint32_t csum, csum_flags;
+       uint16_t hash;
+       struct fq_head dfq;
+
+       MBUFQ_INIT(&dfq);       /* for deferred frees */
+
+       /* If maxnipq or maxfragsperpacket is 0, never accept fragments. */
+       if (maxnipq == 0 || maxfragsperpacket == 0) {
+               ipstat.ips_fragments++;
+               ipstat.ips_fragdropped++;
+               m_freem(m);
+               if (nipq > 0) {
+                       lck_mtx_lock(&ipqlock);
+                       frag_sched_timeout();   /* purge stale fragments */
+                       lck_mtx_unlock(&ipqlock);
+               }
+               return (NULL);
+       }
+
+       ip = mtod(m, struct ip *);
+       hlen = IP_VHL_HL(ip->ip_vhl) << 2;
+
+       lck_mtx_lock(&ipqlock);
+
+       hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
+       head = &ipq[hash];
+
+       /*
+        * Look for queue of fragments
+        * of this datagram.
+        */
+       TAILQ_FOREACH(fp, head, ipq_list) {
+               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 &&
+#if CONFIG_MACF_NET
+                   mac_ipq_label_compare(m, fp) &&
+#endif
+                   ip->ip_p == fp->ipq_p)
+                       goto found;
+       }
+
+       fp = NULL;
+
+       /*
+        * Attempt to trim the number of allocated fragment queues if it
+        * exceeds the administrative limit.
+        */
+       if ((nipq > (unsigned)maxnipq) && (maxnipq > 0)) {
+               /*
+                * drop something from the tail of the current queue
+                * before proceeding further
+                */
+               struct ipq *fq = TAILQ_LAST(head, ipqhead);
+               if (fq == NULL) {   /* gak */
+                       for (i = 0; i < IPREASS_NHASH; i++) {
+                               struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
+                               if (r) {
+                                       ipstat.ips_fragtimeout += r->ipq_nfrags;
+                                       frag_freef(&ipq[i], r);
+                                       break;
+                               }
+                       }
+               } else {
+                       ipstat.ips_fragtimeout += fq->ipq_nfrags;
+                       frag_freef(head, fq);
+               }
+       }
+
+found:
+       /*
+        * Leverage partial checksum offload for IP fragments.  Narrow down
+        * the scope to cover only UDP without IP options, as that is the
+        * most common case.
+        *
+        * Perform 1's complement adjustment of octets that got included/
+        * excluded in the hardware-calculated checksum value.  Ignore cases
+        * where the value includes or excludes the IP header span, as the
+        * sum for those octets would already be 0xffff and thus no-op.
+        */
+       if (ip->ip_p == IPPROTO_UDP && hlen == sizeof (struct ip) &&
+           (m->m_pkthdr.csum_flags &
+           (CSUM_DATA_VALID | CSUM_PARTIAL | CSUM_PSEUDO_HDR)) ==
+           (CSUM_DATA_VALID | CSUM_PARTIAL)) {
+               uint32_t start;
+
+               start = m->m_pkthdr.csum_rx_start;
+               csum = m->m_pkthdr.csum_rx_val;
+
+               if (start != 0 && start != hlen) {
+#if BYTE_ORDER != BIG_ENDIAN
+                       if (start < hlen) {
+                               HTONS(ip->ip_len);
+                               HTONS(ip->ip_off);
+                       }
+#endif
+                       /* callee folds in sum */
+                       csum = m_adj_sum16(m, start, hlen, csum);
+#if BYTE_ORDER != BIG_ENDIAN
+                       if (start < hlen) {
+                               NTOHS(ip->ip_off);
+                               NTOHS(ip->ip_len);
+                       }
+#endif
+               }
+               csum_flags = m->m_pkthdr.csum_flags;
+       } else {
+               csum = 0;
+               csum_flags = 0;
+       }
 
-       lck_mtx_assert(ip_mutex, LCK_MTX_ASSERT_OWNED);
+       /* Invalidate checksum */
+       m->m_pkthdr.csum_flags &= ~CSUM_DATA_VALID;
+
+       ipstat.ips_fragments++;
+
+       /*
+        * Adjust ip_len to not reflect header,
+        * convert offset of this to bytes.
+        */
+       ip->ip_len -= hlen;
+       if (ip->ip_off & IP_MF) {
+               /*
+                * Make sure that fragments have a data length
+                * that's a non-zero multiple of 8 bytes.
+                */
+               if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
+                       OSAddAtomic(1, &ipstat.ips_toosmall);
+                       /*
+                        * Reassembly queue may have been found if previous
+                        * fragments were valid; given that this one is bad,
+                        * we need to drop it.  Make sure to set fp to NULL
+                        * if not already, since we don't want to decrement
+                        * ipq_nfrags as it doesn't include this packet.
+                        */
+                       fp = NULL;
+                       goto dropfrag;
+               }
+               m->m_flags |= M_FRAG;
+       } else {
+               /* Clear the flag in case packet comes from loopback */
+               m->m_flags &= ~M_FRAG;
+       }
+       ip->ip_off <<= 3;
+
+       m->m_pkthdr.pkt_hdr = ip;
+
+       /* Previous ip_reass() started here. */
        /*
         * Presence of header sizes in mbufs
         * would confuse code below.
@@ -1478,24 +2664,22 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
        m->m_data += hlen;
        m->m_len -= hlen;
 
-       if (m->m_pkthdr.csum_flags & CSUM_TCP_SUM16) 
-                       m->m_pkthdr.csum_flags = 0;
        /*
         * If first fragment to arrive, create a reassembly queue.
         */
-       if (fp == 0) {
-               if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
+       if (fp == NULL) {
+               fp = ipq_alloc(M_DONTWAIT);
+               if (fp == NULL)
                        goto dropfrag;
-               fp = mtod(t, struct ipq *);
 #if CONFIG_MACF_NET
                if (mac_ipq_label_init(fp, M_NOWAIT) != 0) {
-                       m_free(t);
+                       ipq_free(fp);
                        fp = NULL;
                        goto dropfrag;
                }
                mac_ipq_label_associate(m, fp);
 #endif
-               insque((void*)fp, (void*)where);
+               TAILQ_INSERT_HEAD(head, fp, ipq_list);
                nipq++;
                fp->ipq_nfrags = 1;
                fp->ipq_ttl = IPFRAGTTL;
@@ -1505,16 +2689,32 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
                fp->ipq_dst = ip->ip_dst;
                fp->ipq_frags = m;
                m->m_nextpkt = NULL;
+               /*
+                * If the first fragment has valid checksum offload
+                * info, the rest of fragments are eligible as well.
+                */
+               if (csum_flags != 0) {
+                       fp->ipq_csum = csum;
+                       fp->ipq_csum_flags = csum_flags;
+               }
 #if IPDIVERT
+               /*
+                * Transfer firewall instructions to the fragment structure.
+                * Only trust info in the fragment at offset 0.
+                */
+               if (ip->ip_off == 0) {
 #ifdef IPDIVERT_44
-               fp->ipq_div_info = 0;
+                       fp->ipq_div_info = *divinfo;
 #else
-               fp->ipq_divert = 0;
-#endif
-               fp->ipq_div_cookie = 0;
+                       fp->ipq_divert = *divinfo;
 #endif
-               TAILQ_INSERT_HEAD(&ipq_list, fp, ipq_list);
-               goto inserted;
+                       fp->ipq_div_cookie = *divcookie;
+               }
+               *divinfo = 0;
+               *divcookie = 0;
+#endif /* IPDIVERT */
+               m = NULL;       /* nothing to return */
+               goto done;
        } else {
                fp->ipq_nfrags++;
 #if CONFIG_MACF_NET
@@ -1522,7 +2722,7 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
 #endif
        }
 
-#define GETIP(m)       ((struct ip*)((m)->m_pkthdr.header))
+#define        GETIP(m)        ((struct ip *)((m)->m_pkthdr.pkt_hdr))
 
        /*
         * Handle ECN by comparing this segment with the first one;
@@ -1553,7 +2753,7 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
         * 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
+        * If some of the data is dropped from the preceding
         * segment, then it's checksum is invalidated.
         */
        if (p) {
@@ -1562,7 +2762,7 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
                        if (i >= ip->ip_len)
                                goto dropfrag;
                        m_adj(m, i);
-                       m->m_pkthdr.csum_flags = 0;
+                       fp->ipq_csum_flags = 0;
                        ip->ip_off += i;
                        ip->ip_len -= i;
                }
@@ -1578,25 +2778,32 @@ ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where)
         * if they are completely covered, dequeue them.
         */
        for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
-            q = nq) {
-               i = (ip->ip_off + ip->ip_len) -
-                   GETIP(q)->ip_off;
+           q = nq) {
+               i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
                if (i < GETIP(q)->ip_len) {
                        GETIP(q)->ip_len -= i;
                        GETIP(q)->ip_off += i;
                        m_adj(q, i);
-                       q->m_pkthdr.csum_flags = 0;
+                       fp->ipq_csum_flags = 0;
                        break;
                }
                nq = q->m_nextpkt;
                m->m_nextpkt = nq;
-               OSAddAtomic(1, &ipstat.ips_fragdropped);
+               ipstat.ips_fragdropped++;
                fp->ipq_nfrags--;
-               m_freem(q);
+               /* defer freeing until after lock is dropped */
+               MBUFQ_ENQUEUE(&dfq, q);
        }
 
-inserted:
-       currentfrags++;
+       /*
+        * If this fragment contains similar checksum offload info
+        * as that of the existing ones, accumulate checksum.  Otherwise,
+        * invalidate checksum offload info for the entire datagram.
+        */
+       if (csum_flags != 0 && csum_flags == fp->ipq_csum_flags)
+               fp->ipq_csum += csum;
+       else if (fp->ipq_csum_flags != 0)
+               fp->ipq_csum_flags = 0;
 
 #if IPDIVERT
        /*
@@ -1605,15 +2812,15 @@ inserted:
         */
        if (ip->ip_off == 0) {
 #ifdef IPDIVERT_44
-       fp->ipq_div_info = *divinfo;
+               fp->ipq_div_info = *divinfo;
 #else
-       fp->ipq_divert = *divinfo;
+               fp->ipq_divert = *divinfo;
 #endif
-       fp->ipq_div_cookie = *divcookie;
+               fp->ipq_div_cookie = *divcookie;
        }
        *divinfo = 0;
        *divcookie = 0;
-#endif
+#endif /* IPDIVERT */
 
        /*
         * Check for complete reassembly and perform frag per packet
@@ -1629,20 +2836,22 @@ inserted:
        for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
                if (GETIP(q)->ip_off != next) {
                        if (fp->ipq_nfrags > maxfragsperpacket) {
-                               OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragdropped);
-                               ip_freef(fp);
+                               ipstat.ips_fragdropped += fp->ipq_nfrags;
+                               frag_freef(head, fp);
                        }
-                       return (0);
+                       m = NULL;       /* nothing to return */
+                       goto done;
                }
                next += GETIP(q)->ip_len;
        }
        /* Make sure the last packet didn't have the IP_MF flag */
        if (p->m_flags & M_FRAG) {
                if (fp->ipq_nfrags > maxfragsperpacket) {
-                       OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragdropped);
-                       ip_freef(fp);
+                       ipstat.ips_fragdropped += fp->ipq_nfrags;
+                       frag_freef(head, fp);
                }
-               return (0);
+               m = NULL;               /* nothing to return */
+               goto done;
        }
 
        /*
@@ -1651,10 +2860,11 @@ inserted:
        q = fp->ipq_frags;
        ip = GETIP(q);
        if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
-               OSAddAtomic(1, &ipstat.ips_toolong);
-               OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragdropped);
-               ip_freef(fp);
-               return (0);
+               ipstat.ips_toolong++;
+               ipstat.ips_fragdropped += fp->ipq_nfrags;
+               frag_freef(head, fp);
+               m = NULL;               /* nothing to return */
+               goto done;
        }
 
        /*
@@ -1662,22 +2872,39 @@ inserted:
         */
        m = q;
        t = m->m_next;
-       m->m_next = 0;
+       m->m_next = NULL;
        m_cat(m, t);
        nq = q->m_nextpkt;
-       q->m_nextpkt = 0;
+       q->m_nextpkt = NULL;
        for (q = nq; q != NULL; q = nq) {
                nq = q->m_nextpkt;
                q->m_nextpkt = NULL;
-               if (q->m_pkthdr.csum_flags & CSUM_TCP_SUM16) 
-                       m->m_pkthdr.csum_flags = 0;
-               else {
-                       m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
-                       m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
-               }
                m_cat(m, q);
        }
 
+       /*
+        * Store partial hardware checksum info from the fragment queue;
+        * the receive start offset is set to 20 bytes (see code at the
+        * top of this routine.)
+        */
+       if (fp->ipq_csum_flags != 0) {
+               csum = fp->ipq_csum;
+
+               ADDCARRY(csum);
+
+               m->m_pkthdr.csum_rx_val = csum;
+               m->m_pkthdr.csum_rx_start = sizeof (struct ip);
+               m->m_pkthdr.csum_flags = fp->ipq_csum_flags;
+       } else if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) ||
+           (m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
+               /* loopback checksums are always OK */
+               m->m_pkthdr.csum_data = 0xffff;
+               m->m_pkthdr.csum_flags &= ~CSUM_PARTIAL;
+               m->m_pkthdr.csum_flags =
+                   CSUM_DATA_VALID | CSUM_PSEUDO_HDR |
+                   CSUM_IP_CHECKED | CSUM_IP_VALID;
+       }
+
 #if IPDIVERT
        /*
         * Extract firewall instructions from the fragment structure.
@@ -1688,48 +2915,69 @@ inserted:
        *divinfo = fp->ipq_divert;
 #endif
        *divcookie = fp->ipq_div_cookie;
-#endif
+#endif /* IPDIVERT */
 
 #if CONFIG_MACF_NET
        mac_mbuf_label_associate_ipq(fp, m);
        mac_ipq_label_destroy(fp);
 #endif
        /*
-        * Create header for new ip packet by
-        * modifying header of first packet;
-        * dequeue and discard fragment reassembly header.
+        * Create header for new ip packet by modifying header of first
+        * packet; dequeue and discard fragment reassembly header.
         * Make header visible.
         */
-       ip->ip_len = next;
+       ip->ip_len = (IP_VHL_HL(ip->ip_vhl) << 2) + next;
        ip->ip_src = fp->ipq_src;
        ip->ip_dst = fp->ipq_dst;
-       remque((void*)fp);
-       TAILQ_REMOVE(&ipq_list, fp, ipq_list);
-       currentfrags -= fp->ipq_nfrags;
-       nipq--;
-       (void) m_free(dtom(fp));
+
+       fp->ipq_frags = NULL;   /* return to caller as 'm' */
+       frag_freef(head, fp);
+       fp = NULL;
+
        m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
        m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
        /* some debugging cruft by sklower, below, will go away soon */
-       if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
-               int plen = 0;
-               for (t = m; t; t = t->m_next)
-                       plen += t->m_len;
-               m->m_pkthdr.len = plen;
-       }
+       if (m->m_flags & M_PKTHDR)      /* XXX this should be done elsewhere */
+               m_fixhdr(m);
+       ipstat.ips_reassembled++;
+
+       /* arm the purge timer if not already and if there's work to do */
+       frag_sched_timeout();
+       lck_mtx_unlock(&ipqlock);
+       /* perform deferred free (if needed) now that lock is dropped */
+       if (!MBUFQ_EMPTY(&dfq))
+               MBUFQ_DRAIN(&dfq);
+       VERIFY(MBUFQ_EMPTY(&dfq));
        return (m);
 
+done:
+       VERIFY(m == NULL);
+       /* arm the purge timer if not already and if there's work to do */
+       frag_sched_timeout();
+       lck_mtx_unlock(&ipqlock);
+       /* perform deferred free (if needed) */
+       if (!MBUFQ_EMPTY(&dfq))
+               MBUFQ_DRAIN(&dfq);
+       VERIFY(MBUFQ_EMPTY(&dfq));
+       return (NULL);
+
 dropfrag:
 #if IPDIVERT
        *divinfo = 0;
        *divcookie = 0;
-#endif
-       OSAddAtomic(1, &ipstat.ips_fragdropped);
-       if (fp != 0)
+#endif /* IPDIVERT */
+       ipstat.ips_fragdropped++;
+       if (fp != NULL)
                fp->ipq_nfrags--;
+       /* arm the purge timer if not already and if there's work to do */
+       frag_sched_timeout();
+       lck_mtx_unlock(&ipqlock);
        m_freem(m);
-       return (0);
-
+       /* perform deferred free (if needed) */
+       if (!MBUFQ_EMPTY(&dfq))
+               MBUFQ_DRAIN(&dfq);
+       VERIFY(MBUFQ_EMPTY(&dfq));
+       return (NULL);
 #undef GETIP
 }
 
@@ -1738,38 +2986,47 @@ dropfrag:
  * associated datagrams.
  */
 static void
-ip_freef(struct ipq *fp)
+frag_freef(struct ipqhead *fhp, struct ipq *fp)
 {
-       lck_mtx_assert(ip_mutex, LCK_MTX_ASSERT_OWNED);
-       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));
+       lck_mtx_assert(&ipqlock, LCK_MTX_ASSERT_OWNED);
+
+       fp->ipq_nfrags = 0;
+       if (fp->ipq_frags != NULL) {
+               m_freem_list(fp->ipq_frags);
+               fp->ipq_frags = NULL;
+       }
+       TAILQ_REMOVE(fhp, fp, ipq_list);
        nipq--;
+       ipq_free(fp);
 }
 
 /*
- * IP timer processing;
- * if a timer expires on a reassembly
- * queue, discard it.
+ * IP reassembly timer processing
  */
-void
-ip_slowtimo(void)
+static void
+frag_timeout(void *arg)
 {
+#pragma unused(arg)
        struct ipq *fp;
        int i;
-       lck_mtx_lock(ip_mutex);
+
+       /*
+        * Update coarse-grained networking timestamp (in sec.); the idea
+        * is to piggy-back on the timeout callout to update the counter
+        * returnable via net_uptime().
+        */
+       net_update_uptime();
+
+       lck_mtx_lock(&ipqlock);
        for (i = 0; i < IPREASS_NHASH; i++) {
-               fp = ipq[i].next;
-               if (fp == 0)
-                       continue;
-               while (fp != &ipq[i]) {
-                       --fp->ipq_ttl;
-                       fp = fp->next;
-                       if (fp->prev->ipq_ttl == 0) {
-                               OSAddAtomic(fp->ipq_nfrags, &ipstat.ips_fragtimeout);
-                               ip_freef(fp->prev);
+               for (fp = TAILQ_FIRST(&ipq[i]); fp; ) {
+                       struct ipq *fpp;
+
+                       fpp = fp;
+                       fp = TAILQ_NEXT(fp, ipq_list);
+                       if (--fpp->ipq_ttl == 0) {
+                               ipstat.ips_fragtimeout += fpp->ipq_nfrags;
+                               frag_freef(&ipq[i], fpp);
                        }
                }
        }
@@ -1778,35 +3035,93 @@ ip_slowtimo(void)
         * (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])) {
-                               OSAddAtomic(ipq[i].next->ipq_nfrags, &ipstat.ips_fragdropped);
-                               ip_freef(ipq[i].next);
+       if (maxnipq >= 0 && nipq > (unsigned)maxnipq) {
+               for (i = 0; i < IPREASS_NHASH; i++) {
+                       while (nipq > (unsigned)maxnipq &&
+                           !TAILQ_EMPTY(&ipq[i])) {
+                               ipstat.ips_fragdropped +=
+                                   TAILQ_FIRST(&ipq[i])->ipq_nfrags;
+                               frag_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
                        }
                }
        }
-       lck_mtx_unlock(ip_mutex);
+       /* re-arm the purge timer if there's work to do */
+       frag_timeout_run = 0;
+       frag_sched_timeout();
+       lck_mtx_unlock(&ipqlock);
+}
+
+static void
+frag_sched_timeout(void)
+{
+       lck_mtx_assert(&ipqlock, LCK_MTX_ASSERT_OWNED);
+
+       if (!frag_timeout_run && nipq > 0) {
+               frag_timeout_run = 1;
+               timeout(frag_timeout, NULL, hz);
+       }
 }
 
 /*
  * Drain off all datagram fragments.
  */
-void
-ip_drain(void)
+static void
+frag_drain(void)
 {
-       int     i;
+       int i;
 
-       lck_mtx_lock(ip_mutex);
+       lck_mtx_lock(&ipqlock);
        for (i = 0; i < IPREASS_NHASH; i++) {
-               while (ipq[i].next != &ipq[i]) {
-                       OSAddAtomic(ipq[i].next->ipq_nfrags, &ipstat.ips_fragdropped);
-                       ip_freef(ipq[i].next);
+               while (!TAILQ_EMPTY(&ipq[i])) {
+                       ipstat.ips_fragdropped +=
+                           TAILQ_FIRST(&ipq[i])->ipq_nfrags;
+                       frag_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
                }
        }
-       lck_mtx_unlock(ip_mutex);
-       in_rtqdrain();
+       lck_mtx_unlock(&ipqlock);
+}
+
+static struct ipq *
+ipq_alloc(int how)
+{
+       struct mbuf *t;
+       struct ipq *fp;
+
+       /*
+        * See comments in ipq_updateparams().  Keep the count separate
+        * from nipq since the latter represents the elements already
+        * in the reassembly queues.
+        */
+       if (ipq_limit > 0 && ipq_count > ipq_limit)
+               return (NULL);
+
+       t = m_get(how, MT_FTABLE);
+       if (t != NULL) {
+               atomic_add_32(&ipq_count, 1);
+               fp = mtod(t, struct ipq *);
+               bzero(fp, sizeof (*fp));
+       } else {
+               fp = NULL;
+       }
+       return (fp);
+}
+
+static void
+ipq_free(struct ipq *fp)
+{
+       (void) m_free(dtom(fp));
+       atomic_add_32(&ipq_count, -1);
+}
+
+/*
+ * Drain callback
+ */
+void
+ip_drain(void)
+{
+       frag_drain();           /* fragments */
+       in_rtqdrain();          /* protocol cloned routes */
+       in_arpdrain(NULL);      /* cloned routes: ARP */
 }
 
 /*
@@ -1822,17 +3137,18 @@ ip_drain(void)
  * 0 if the packet should be processed further.
  */
 static int
-ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
+ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
 {
+#pragma unused(pass)
        struct ip *ip = mtod(m, struct ip *);
        u_char *cp;
        struct ip_timestamp *ipt;
        struct in_ifaddr *ia;
        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
        struct in_addr *sin, dst;
-       n_time ntime;
+       u_int32_t ntime;
        struct sockaddr_in ipaddr = {
-           sizeof (ipaddr), AF_INET , 0 , { 0 }, { 0, } };
+           sizeof (ipaddr), AF_INET, 0, { 0 }, { 0, } };
 
        /* Expect 32-bit aligned data pointer on strict-align platforms */
        MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
@@ -1847,12 +3163,13 @@ ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
                if (opt == IPOPT_NOP)
                        optlen = 1;
                else {
-                       if (cnt < IPOPT_OLEN + sizeof(*cp)) {
+                       if (cnt < IPOPT_OLEN + sizeof (*cp)) {
                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                                goto bad;
                        }
                        optlen = cp[IPOPT_OLEN];
-                       if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
+                       if (optlen < IPOPT_OLEN + sizeof (*cp) ||
+                           optlen > cnt) {
                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                                goto bad;
                        }
@@ -1873,7 +3190,7 @@ ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
                 */
                case IPOPT_LSRR:
                case IPOPT_SSRR:
-                       if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
+                       if (optlen < IPOPT_OFFSET + sizeof (*cp)) {
                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                                goto bad;
                        }
@@ -1882,9 +3199,8 @@ ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
                                goto bad;
                        }
                        ipaddr.sin_addr = ip->ip_dst;
-                       ia = (struct in_ifaddr *)
-                               ifa_ifwithaddr((struct sockaddr *)&ipaddr);
-                       if (ia == 0) {
+                       ia = (struct in_ifaddr *)ifa_ifwithaddr(SA(&ipaddr));
+                       if (ia == NULL) {
                                if (opt == IPOPT_SSRR) {
                                        type = ICMP_UNREACH;
                                        code = ICMP_UNREACH_SRCFAIL;
@@ -1897,13 +3213,12 @@ ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
                                 * yet; nothing to do except forward.
                                 */
                                break;
-                       }
-                       else {
+                       } else {
                                IFA_REMREF(&ia->ia_ifa);
                                ia = NULL;
                        }
                        off--;                  /* 0 origin */
-                       if (off > optlen - (int)sizeof(struct in_addr)) {
+                       if (off > optlen - (int)sizeof (struct in_addr)) {
                                /*
                                 * End of source route.  Should be for us.
                                 */
@@ -1922,15 +3237,19 @@ ip_dooptions(struct mbuf *m, __unused int pass, struct sockaddr_in *next_hop)
                                         */
 nosourcerouting:
                                        log(LOG_WARNING,
-                                           "attempted source route from %s to %s\n",
-                                           inet_ntop(AF_INET, &ip->ip_src, buf, sizeof(buf)),
-                                           inet_ntop(AF_INET, &ip->ip_dst, buf2, sizeof(buf2)));
+                                           "attempted source route from %s "
+                                           "to %s\n",
+                                           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;
                                } else {
                                        /*
-                                        * Not acting as a router, so silently drop.
+                                        * Not acting as a router,
+                                        * so silently drop.
                                         */
                                        OSAddAtomic(1, &ipstat.ips_cantforward);
                                        m_freem(m);
@@ -1941,32 +3260,31 @@ nosourcerouting:
                        /*
                         * locate outgoing interface
                         */
-                       (void)memcpy(&ipaddr.sin_addr, cp + off,
-                           sizeof(ipaddr.sin_addr));
+                       (void) memcpy(&ipaddr.sin_addr, cp + off,
+                           sizeof (ipaddr.sin_addr));
 
                        if (opt == IPOPT_SSRR) {
 #define        INA     struct in_ifaddr *
                                if ((ia = (INA)ifa_ifwithdstaddr(
-                                   (struct sockaddr *)&ipaddr)) == 0) {
-                                       ia = (INA)ifa_ifwithnet(
-                                           (struct sockaddr *)&ipaddr);
+                                   SA(&ipaddr))) == NULL) {
+                                       ia = (INA)ifa_ifwithnet(SA(&ipaddr));
                                }
                        } else {
                                ia = ip_rtaddr(ipaddr.sin_addr);
                        }
-                       if (ia == 0) {
+                       if (ia == NULL) {
                                type = ICMP_UNREACH;
                                code = ICMP_UNREACH_SRCFAIL;
                                goto bad;
                        }
                        ip->ip_dst = ipaddr.sin_addr;
                        IFA_LOCK(&ia->ia_ifa);
-                       (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
-                           sizeof(struct in_addr));
+                       (void) memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
+                           sizeof (struct in_addr));
                        IFA_UNLOCK(&ia->ia_ifa);
                        IFA_REMREF(&ia->ia_ifa);
                        ia = NULL;
-                       cp[IPOPT_OFFSET] += sizeof(struct in_addr);
+                       cp[IPOPT_OFFSET] += sizeof (struct in_addr);
                        /*
                         * Let ip_intr's mcast routing check handle mcast pkts
                         */
@@ -1974,7 +3292,7 @@ nosourcerouting:
                        break;
 
                case IPOPT_RR:
-                       if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
+                       if (optlen < IPOPT_OFFSET + sizeof (*cp)) {
                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                                goto bad;
                        }
@@ -1986,29 +3304,28 @@ nosourcerouting:
                         * If no space remains, ignore.
                         */
                        off--;                  /* 0 origin */
-                       if (off > optlen - (int)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));
+                       (void) memcpy(&ipaddr.sin_addr, &ip->ip_dst,
+                           sizeof (ipaddr.sin_addr));
                        /*
                         * locate outgoing interface; if we're the destination,
                         * use the incoming interface (should be same).
                         */
-                       if ((ia = (INA)ifa_ifwithaddr((struct sockaddr *)
-                           &ipaddr)) == 0) {
-                               if ((ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
+                       if ((ia = (INA)ifa_ifwithaddr(SA(&ipaddr))) == NULL) {
+                               if ((ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
                                        type = ICMP_UNREACH;
                                        code = ICMP_UNREACH_HOST;
                                        goto bad;
                                }
                        }
                        IFA_LOCK(&ia->ia_ifa);
-                       (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
-                           sizeof(struct in_addr));
+                       (void) memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
+                           sizeof (struct in_addr));
                        IFA_UNLOCK(&ia->ia_ifa);
                        IFA_REMREF(&ia->ia_ifa);
                        ia = NULL;
-                       cp[IPOPT_OFFSET] += sizeof(struct in_addr);
+                       cp[IPOPT_OFFSET] += sizeof (struct in_addr);
                        break;
 
                case IPOPT_TS:
@@ -2023,7 +3340,7 @@ nosourcerouting:
                                goto bad;
                        }
                        if (ipt->ipt_ptr >
-                           ipt->ipt_len - (int)sizeof(int32_t)) {
+                           ipt->ipt_len - (int)sizeof (int32_t)) {
                                if (++ipt->ipt_oflw == 0) {
                                        code = (u_char *)&ipt->ipt_ptr -
                                            (u_char *)ip;
@@ -2038,41 +3355,41 @@ nosourcerouting:
                                break;
 
                        case IPOPT_TS_TSANDADDR:
-                               if (ipt->ipt_ptr - 1 + sizeof(n_time) +
-                                   sizeof(struct in_addr) > ipt->ipt_len) {
+                               if (ipt->ipt_ptr - 1 + sizeof (n_time) +
+                                   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((struct sockaddr *)
-                                   &ipaddr, m->m_pkthdr.rcvif);
-                               if (ia == 0)
+                               ia = (INA)ifaof_ifpforaddr(SA(&ipaddr),
+                                   m->m_pkthdr.rcvif);
+                               if (ia == NULL)
                                        continue;
                                IFA_LOCK(&ia->ia_ifa);
-                               (void)memcpy(sin, &IA_SIN(ia)->sin_addr,
-                                   sizeof(struct in_addr));
+                               (void) memcpy(sin, &IA_SIN(ia)->sin_addr,
+                                   sizeof (struct in_addr));
                                IFA_UNLOCK(&ia->ia_ifa);
-                               ipt->ipt_ptr += sizeof(struct in_addr);
+                               ipt->ipt_ptr += sizeof (struct in_addr);
                                IFA_REMREF(&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) {
+                               if (ipt->ipt_ptr - 1 + sizeof (n_time) +
+                                   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 ((ia = (struct in_ifaddr*)ifa_ifwithaddr(
-                                   (struct sockaddr *)&ipaddr)) == 0)
+                               (void) memcpy(&ipaddr.sin_addr, sin,
+                                   sizeof (struct in_addr));
+                               if ((ia = (struct in_ifaddr *)ifa_ifwithaddr(
+                                   SA(&ipaddr))) == NULL)
                                        continue;
                                IFA_REMREF(&ia->ia_ifa);
                                ia = NULL;
-                               ipt->ipt_ptr += sizeof(struct in_addr);
+                               ipt->ipt_ptr += sizeof (struct in_addr);
                                break;
 
                        default:
@@ -2082,9 +3399,9 @@ nosourcerouting:
                                goto bad;
                        }
                        ntime = iptime();
-                       (void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
-                           sizeof(n_time));
-                       ipt->ipt_ptr += sizeof(n_time);
+                       (void) memcpy(cp + ipt->ipt_ptr - 1, &ntime,
+                           sizeof (n_time));
+                       ipt->ipt_ptr += sizeof (n_time);
                }
        }
        if (forward && ipforwarding) {
@@ -2093,12 +3410,72 @@ nosourcerouting:
        }
        return (0);
 bad:
-       ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2;   /* XXX icmp_error adds in hdr length */
        icmp_error(m, type, code, 0, 0);
        OSAddAtomic(1, &ipstat.ips_badoptions);
        return (1);
 }
 
+/*
+ * Check for the presence of the IP Router Alert option [RFC2113]
+ * in the header of an IPv4 datagram.
+ *
+ * This call is not intended for use from the forwarding path; it is here
+ * so that protocol domains may check for the presence of the option.
+ * Given how FreeBSD's IPv4 stack is currently structured, the Router Alert
+ * option does not have much relevance to the implementation, though this
+ * may change in future.
+ * Router alert options SHOULD be passed if running in IPSTEALTH mode and
+ * we are not the endpoint.
+ * Length checks on individual options should already have been peformed
+ * by ip_dooptions() therefore they are folded under DIAGNOSTIC here.
+ *
+ * Return zero if not present or options are invalid, non-zero if present.
+ */
+int
+ip_checkrouteralert(struct mbuf *m)
+{
+       struct ip *ip = mtod(m, struct ip *);
+       u_char *cp;
+       int opt, optlen, cnt, found_ra;
+
+       found_ra = 0;
+       cp = (u_char *)(ip + 1);
+       cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
+       for (; cnt > 0; cnt -= optlen, cp += optlen) {
+               opt = cp[IPOPT_OPTVAL];
+               if (opt == IPOPT_EOL)
+                       break;
+               if (opt == IPOPT_NOP)
+                       optlen = 1;
+               else {
+#ifdef DIAGNOSTIC
+                       if (cnt < IPOPT_OLEN + sizeof (*cp))
+                               break;
+#endif
+                       optlen = cp[IPOPT_OLEN];
+#ifdef DIAGNOSTIC
+                       if (optlen < IPOPT_OLEN + sizeof (*cp) || optlen > cnt)
+                               break;
+#endif
+               }
+               switch (opt) {
+               case IPOPT_RA:
+#ifdef DIAGNOSTIC
+                       if (optlen != IPOPT_OFFSET + sizeof (uint16_t) ||
+                           (*((uint16_t *)(void *)&cp[IPOPT_OFFSET]) != 0))
+                               break;
+                       else
+#endif
+                               found_ra = 1;
+                       break;
+               default:
+                       break;
+               }
+       }
+
+       return (found_ra);
+}
+
 /*
  * Given address of next destination (final or next hop),
  * return internet address info of interface to be used to get there.
@@ -2111,20 +3488,22 @@ ip_rtaddr(struct in_addr dst)
        struct route ro;
 
        bzero(&ro, sizeof (ro));
-       sin = (struct sockaddr_in *)(void *)&ro.ro_dst;
+       sin = SIN(&ro.ro_dst);
        sin->sin_family = AF_INET;
        sin->sin_len = sizeof (*sin);
        sin->sin_addr = dst;
 
        rtalloc_ign(&ro, RTF_PRCLONING);
-       if (ro.ro_rt == NULL)
+       if (ro.ro_rt == NULL) {
+               ROUTE_RELEASE(&ro);
                return (NULL);
+       }
 
        RT_LOCK(ro.ro_rt);
        if ((rt_ifa = ro.ro_rt->rt_ifa) != NULL)
                IFA_ADDREF(rt_ifa);
        RT_UNLOCK(ro.ro_rt);
-       rtfree(ro.ro_rt);
+       ROUTE_RELEASE(&ro);
 
        return ((struct in_ifaddr *)rt_ifa);
 }
@@ -2143,10 +3522,10 @@ save_rte(u_char *option, struct in_addr dst)
        if (ipprintfs)
                printf("save_rte: olen %d\n", olen);
 #endif
-       if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
+       if (olen > sizeof (ip_srcrt) - (1 + sizeof (dst)))
                return;
        bcopy(option, ip_srcrt.srcopt, olen);
-       ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
+       ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof (struct in_addr);
        ip_srcrt.dst = dst;
 }
 
@@ -2162,16 +3541,17 @@ ip_srcroute(void)
        struct mbuf *m;
 
        if (ip_nhops == 0)
-               return ((struct mbuf *)0);
+               return (NULL);
+
        m = m_get(M_DONTWAIT, MT_HEADER);
-       if (m == 0)
-               return ((struct mbuf *)0);
+       if (m == NULL)
+               return (NULL);
 
-#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
+#define        OPTSIZ  (sizeof (ip_srcrt.nop) + sizeof (ip_srcrt.srcopt))
 
        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
-       m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
-           OPTSIZ;
+       m->m_len = ip_nhops * sizeof (struct in_addr) +
+           sizeof (struct in_addr) + OPTSIZ;
 #if DIAGNOSTIC
        if (ipprintfs)
                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
@@ -2184,7 +3564,8 @@ ip_srcroute(void)
        *(mtod(m, struct in_addr *)) = *p--;
 #if DIAGNOSTIC
        if (ipprintfs)
-               printf(" hops %lx", (u_int32_t)ntohl(mtod(m, struct in_addr *)->s_addr));
+               printf(" hops %lx",
+                   (u_int32_t)ntohl(mtod(m, struct in_addr *)->s_addr));
 #endif
 
        /*
@@ -2192,10 +3573,10 @@ ip_srcroute(void)
         */
        ip_srcrt.nop = IPOPT_NOP;
        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
-       (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
+       (void) memcpy(mtod(m, caddr_t) + sizeof (struct in_addr),
            &ip_srcrt.nop, OPTSIZ);
        q = (struct in_addr *)(void *)(mtod(m, caddr_t) +
-           sizeof(struct in_addr) + OPTSIZ);
+           sizeof (struct in_addr) + OPTSIZ);
 #undef OPTSIZ
        /*
         * Record return path as an IP source route,
@@ -2227,8 +3608,9 @@ ip_srcroute(void)
  * XXX should be deleted; last arg currently ignored.
  */
 void
-ip_stripoptions(struct mbuf *m, __unused struct mbuf *mopt)
+ip_stripoptions(struct mbuf *m, struct mbuf *mopt)
 {
+#pragma unused(mopt)
        int i;
        struct ip *ip = mtod(m, struct ip *);
        caddr_t opts;
@@ -2244,7 +3626,7 @@ ip_stripoptions(struct mbuf *m, __unused struct mbuf *mopt)
        m->m_len -= olen;
        if (m->m_flags & M_PKTHDR)
                m->m_pkthdr.len -= olen;
-       ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
+       ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof (struct ip) >> 2);
 }
 
 u_char inetctlerrmap[PRC_NCMDS] = {
@@ -2273,8 +3655,7 @@ sysctl_ipforwarding SYSCTL_HANDLER_ARGS
                        struct ifnet *ifp = ifindex2ifnet[i];
                        if (ifp != NULL) {
                                lck_mtx_lock(&ifp->if_cached_route_lock);
-                               if (ifp->if_fwd_route.ro_rt != NULL)
-                                       rtfree(ifp->if_fwd_route.ro_rt);
+                               ROUTE_RELEASE(&ifp->if_fwd_route);
                                bzero(&ifp->if_fwd_route,
                                    sizeof (ifp->if_fwd_route));
                                lck_mtx_unlock(&ifp->if_cached_route_lock);
@@ -2303,7 +3684,7 @@ ip_fwd_route_copyout(struct ifnet *ifp, struct route *dst)
        if (src->ro_rt != NULL && rt_key(src->ro_rt)->sa_family != AF_INET)
                panic("%s: wrong or corrupted route: %p", __func__, src);
 
-       route_copyout(dst, src, sizeof(*dst));
+       route_copyout(dst, src, sizeof (*dst));
 
        lck_mtx_unlock(&ifp->if_cached_route_lock);
 }
@@ -2321,7 +3702,7 @@ ip_fwd_route_copyin(struct ifnet *ifp, struct route *src)
                panic("%s: wrong or corrupted route: %p", __func__, src);
 
        if (ifp->if_fwd_cacheok)
-               route_copyin(src, dst, sizeof(*src));
+               route_copyin(src, dst, sizeof (*src));
 
        lck_mtx_unlock(&ifp->if_cached_route_lock);
 }
@@ -2354,9 +3735,13 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
        struct mbuf *mcopy;
        n_long dest;
        struct in_addr pkt_dst;
-       u_int32_t nextmtu = 0;
-       struct ip_out_args ipoa = { IFSCOPE_NONE, { 0 }, 0 };
-       struct ifnet *ifp = m->m_pkthdr.rcvif;
+       u_int32_t nextmtu = 0, len;
+       struct ip_out_args ipoa = { IFSCOPE_NONE, { 0 }, 0, 0 };
+       struct ifnet *rcvifp = m->m_pkthdr.rcvif;
+#if IPSEC
+       struct secpolicy *sp = NULL;
+       int ipsecerror;
+#endif /* IPSEC */
 #if PF
        struct pf_mtag *pf_mtag;
 #endif /* PF */
@@ -2367,10 +3752,10 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
         * 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;
-#else
+       pkt_dst = ((next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst);
+#else /* !IPFIREWALL */
        pkt_dst = ip->ip_dst;
-#endif
+#endif /* !IPFIREWALL */
 
 #if DIAGNOSTIC
        if (ipprintfs)
@@ -2379,14 +3764,14 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
                    ip->ip_ttl);
 #endif
 
-       if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(pkt_dst) == 0) {
+       if (m->m_flags & (M_BCAST|M_MCAST) || !in_canforward(pkt_dst)) {
                OSAddAtomic(1, &ipstat.ips_cantforward);
                m_freem(m);
                return;
        }
 #if IPSTEALTH
        if (!ipstealth) {
-#endif
+#endif /* IPSTEALTH */
                if (ip->ip_ttl <= IPTTLDEC) {
                        icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
                            dest, 0);
@@ -2394,7 +3779,7 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
                }
 #if IPSTEALTH
        }
-#endif
+#endif /* IPSTEALTH */
 
 #if PF
        pf_mtag = pf_find_mtag(m);
@@ -2404,16 +3789,12 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
        }
 #endif /* PF */
 
-       ip_fwd_route_copyout(ifp, &fwd_rt);
+       ip_fwd_route_copyout(rcvifp, &fwd_rt);
+
+       sin = SIN(&fwd_rt.ro_dst);
+       if (ROUTE_UNUSABLE(&fwd_rt) || pkt_dst.s_addr != sin->sin_addr.s_addr) {
+               ROUTE_RELEASE(&fwd_rt);
 
-       sin = (struct sockaddr_in *)(void *)&fwd_rt.ro_dst;
-       if (fwd_rt.ro_rt == NULL ||
-           fwd_rt.ro_rt->generation_id != route_generation ||
-           pkt_dst.s_addr != sin->sin_addr.s_addr) {
-               if (fwd_rt.ro_rt != NULL) {
-                       rtfree(fwd_rt.ro_rt);
-                       fwd_rt.ro_rt = NULL;
-               }
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof (*sin);
                sin->sin_addr = pkt_dst;
@@ -2445,11 +3826,11 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
 
 #if IPSTEALTH
        if (!ipstealth) {
-#endif
+#endif /* IPSTEALTH */
                ip->ip_ttl -= IPTTLDEC;
 #if IPSTEALTH
        }
-#endif
+#endif /* IPSTEALTH */
 
        /*
         * If forwarding packet using same interface that it came in on,
@@ -2461,8 +3842,8 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
         */
        RT_LOCK_SPIN(rt);
        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
-           (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
-           satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
+           !(rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) &&
+           satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
            ipsendredirects && !srcrt && rt->rt_ifa != NULL) {
                struct in_ifaddr *ia = (struct in_ifaddr *)rt->rt_ifa;
                u_int32_t src = ntohl(ip->ip_src.s_addr);
@@ -2475,12 +3856,16 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
                                dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
                        else
                                dest = pkt_dst.s_addr;
-                       /* Router requirements says to only send host redirects */
+                       /*
+                        * Router requirements says to only send
+                        * host redirects.
+                        */
                        type = ICMP_REDIRECT;
                        code = ICMP_REDIRECT_HOST;
 #if DIAGNOSTIC
                        if (ipprintfs)
-                               printf("redirect (%d) to %lx\n", code, (u_int32_t)dest);
+                               printf("redirect (%d) to %lx\n", code,
+                                   (u_int32_t)dest);
 #endif
                }
                IFA_UNLOCK(&ia->ia_ifa);
@@ -2488,10 +3873,10 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
        RT_UNLOCK(rt);
 
 #if IPFIREWALL
-       if (next_hop) {
+       if (next_hop != NULL) {
                /* Pass IPFORWARD info if available */
                struct m_tag *tag;
-               struct ip_fwd_tag       *ipfwd_tag;
+               struct ip_fwd_tag *ipfwd_tag;
 
                tag = m_tag_create(KERNEL_MODULE_TAG_ID,
                    KERNEL_TAG_TYPE_IPFORWARD,
@@ -2507,21 +3892,34 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
 
                m_tag_prepend(m, tag);
        }
-#endif
-       error = ip_output_list(m, 0, NULL, &fwd_rt,
-           IP_FORWARDING | IP_OUTARGS, 0, &ipoa);
+#endif /* IPFIREWALL */
+
+       /* Mark this packet as being forwarded from another interface */
+       m->m_pkthdr.pkt_flags |= PKTF_FORWARDED;
+       len = m_pktlen(m);
+
+       error = ip_output(m, NULL, &fwd_rt, IP_FORWARDING | IP_OUTARGS,
+           NULL, &ipoa);
 
        /* Refresh rt since the route could have changed while in IP */
        rt = fwd_rt.ro_rt;
 
-       if (error) {
+       if (error != 0) {
                OSAddAtomic(1, &ipstat.ips_cantforward);
        } else {
+               /*
+                * Increment stats on the source interface; the ones
+                * for destination interface has been taken care of
+                * during output above by virtue of PKTF_FORWARDED.
+                */
+               rcvifp->if_fpackets++;
+               rcvifp->if_fbytes += len;
+
                OSAddAtomic(1, &ipstat.ips_forward);
-               if (type)
+               if (type != 0) {
                        OSAddAtomic(1, &ipstat.ips_redirectsent);
-               else {
-                       if (mcopy) {
+               else {
+                       if (mcopy != NULL) {
                                /*
                                 * If we didn't have to go thru ipflow and
                                 * the packet was successfully consumed by
@@ -2537,7 +3935,6 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
                goto done;
 
        switch (error) {
-
        case 0:                         /* forwarded, but need redirect */
                /* type, code set above */
                break;
@@ -2554,105 +3951,107 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
        case EMSGSIZE:
                type = ICMP_UNREACH;
                code = ICMP_UNREACH_NEEDFRAG;
-#ifndef IPSEC
-               if (rt != NULL) {
+
+               if (rt == NULL) {
+                       break;
+               } else {
                        RT_LOCK_SPIN(rt);
                        if (rt->rt_ifp != NULL)
                                nextmtu = rt->rt_ifp->if_mtu;
                        RT_UNLOCK(rt);
                }
-#else
+#ifdef IPSEC
+               if (ipsec_bypass)
+                       break;
+
                /*
                 * If the packet is routed over IPsec tunnel, tell the
                 * originator the tunnel MTU.
                 *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
                 * XXX quickhack!!!
                 */
-               if (rt != NULL) {
-                       struct secpolicy *sp = NULL;
-                       int ipsecerror;
-                       int ipsechdr;
-                       struct route *ro;
+               sp = ipsec4_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
+                   IP_FORWARDING, &ipsecerror);
 
-                       RT_LOCK_SPIN(rt);
-                       if (rt->rt_ifp != NULL)
-                               nextmtu = rt->rt_ifp->if_mtu;
-                       RT_UNLOCK(rt);
+               if (sp == NULL)
+                       break;
 
-                       if (ipsec_bypass) {
-                               OSAddAtomic(1, &ipstat.ips_cantfrag);
-                               break;
-                       }
-                       sp = ipsec4_getpolicybyaddr(mcopy,
-                                                   IPSEC_DIR_OUTBOUND,
-                                                   IP_FORWARDING,
-                                                   &ipsecerror);
+               /*
+                * find the correct route for outer IPv4
+                * header, compute tunnel MTU.
+                */
+               nextmtu = 0;
 
-                       if (sp != NULL) {
-                               /* count IPsec header size */
-                               ipsechdr = ipsec_hdrsiz(sp);
+               if (sp->req != NULL &&
+                   sp->req->saidx.mode == IPSEC_MODE_TUNNEL) {
+                       struct secasindex saidx;
+                       struct secasvar *sav;
+                       struct route *ro;
+                       struct ip *ipm;
+                       int ipsechdr;
 
-                               /*
-                                * find the correct route for outer IPv4
-                                * header, compute tunnel MTU.
-                                */
-                               nextmtu = 0;
-
-                               if (sp->req != NULL) {
-                                       if (sp->req->saidx.mode == IPSEC_MODE_TUNNEL) {
-                                               struct secasindex saidx;
-                                               struct ip *ipm;
-                                               struct secasvar *sav;
-
-                                               ipm = mtod(mcopy, struct ip *);
-                                               bcopy(&sp->req->saidx, &saidx, sizeof(saidx));
-                                               saidx.mode = sp->req->saidx.mode;
-                                               saidx.reqid = sp->req->saidx.reqid;
-                                               sin = (struct sockaddr_in *)&saidx.src;
-                                               if (sin->sin_len == 0) {
-                                                       sin->sin_len = sizeof(*sin);
-                                                       sin->sin_family = AF_INET;
-                                                       sin->sin_port = IPSEC_PORT_ANY;
-                                                       bcopy(&ipm->ip_src, &sin->sin_addr,
-                                                               sizeof(sin->sin_addr));
-                                               }
-                                               sin = (struct sockaddr_in *)&saidx.dst;
-                                               if (sin->sin_len == 0) {
-                                                       sin->sin_len = sizeof(*sin);
-                                                       sin->sin_family = AF_INET;
-                                                       sin->sin_port = IPSEC_PORT_ANY;
-                                                       bcopy(&ipm->ip_dst, &sin->sin_addr,
-                                                               sizeof(sin->sin_addr));
-                                               }
-                                               sav = key_allocsa_policy(&saidx);
-                                               if (sav != NULL) {
-                                                       lck_mtx_lock(sadb_mutex);
-                                                       if (sav->sah != NULL) {
-                                                               ro = &sav->sah->sa_route;
-                                                               if (ro->ro_rt != NULL) {
-                                                                       RT_LOCK(ro->ro_rt);
-                                                                       if (ro->ro_rt->rt_ifp != NULL) {
-                                                                               nextmtu = ro->ro_rt->rt_ifp->if_mtu;
-                                                                               nextmtu -= ipsechdr;
-                                                                       }
-                                                                       RT_UNLOCK(ro->ro_rt);
-                                                               }
-                                                       }
-                                                       key_freesav(sav, KEY_SADB_LOCKED);
-                                                       lck_mtx_unlock(sadb_mutex);
+                       /* count IPsec header size */
+                       ipsechdr = ipsec_hdrsiz(sp);
+
+                       ipm = mtod(mcopy, struct ip *);
+                       bcopy(&sp->req->saidx, &saidx, sizeof (saidx));
+                       saidx.mode = sp->req->saidx.mode;
+                       saidx.reqid = sp->req->saidx.reqid;
+                       sin = SIN(&saidx.src);
+                       if (sin->sin_len == 0) {
+                               sin->sin_len = sizeof (*sin);
+                               sin->sin_family = AF_INET;
+                               sin->sin_port = IPSEC_PORT_ANY;
+                               bcopy(&ipm->ip_src, &sin->sin_addr,
+                                   sizeof (sin->sin_addr));
+                       }
+                       sin = SIN(&saidx.dst);
+                       if (sin->sin_len == 0) {
+                               sin->sin_len = sizeof (*sin);
+                               sin->sin_family = AF_INET;
+                               sin->sin_port = IPSEC_PORT_ANY;
+                               bcopy(&ipm->ip_dst, &sin->sin_addr,
+                                   sizeof (sin->sin_addr));
+                       }
+                       sav = key_allocsa_policy(&saidx);
+                       if (sav != NULL) {
+                               lck_mtx_lock(sadb_mutex);
+                               if (sav->sah != NULL) {
+                                       ro = &sav->sah->sa_route;
+                                       if (ro->ro_rt != NULL) {
+                                               RT_LOCK(ro->ro_rt);
+                                               if (ro->ro_rt->rt_ifp != NULL) {
+                                                       nextmtu = ro->ro_rt->
+                                                           rt_ifp->if_mtu;
+                                                       nextmtu -= ipsechdr;
                                                }
+                                               RT_UNLOCK(ro->ro_rt);
                                        }
                                }
-                               key_freesp(sp, KEY_SADB_UNLOCKED);
+                               key_freesav(sav, KEY_SADB_LOCKED);
+                               lck_mtx_unlock(sadb_mutex);
                        }
                }
-#endif /*IPSEC*/
-               OSAddAtomic(1, &ipstat.ips_cantfrag);
+               key_freesp(sp, KEY_SADB_UNLOCKED);
+#endif /* IPSEC */
                break;
 
        case ENOBUFS:
-               type = ICMP_SOURCEQUENCH;
-               code = 0;
+               /*
+                * A router should not generate ICMP_SOURCEQUENCH as
+                * required in RFC1812 Requirements for IP Version 4 Routers.
+                * Source quench could be a big problem under DoS attacks,
+                * or if the underlying interface is rate-limited.
+                * Those who need source quench packets may re-enable them
+                * via the net.inet.ip.sendsourcequench sysctl.
+                */
+               if (ip_sendsourcequench == 0) {
+                       m_freem(mcopy);
+                       goto done;
+               } else {
+                       type = ICMP_SOURCEQUENCH;
+                       code = 0;
+               }
                break;
 
        case EACCES:                    /* ipfw denied packet */
@@ -2660,125 +4059,128 @@ ip_forward(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
                goto done;
        }
 
+       if (type == ICMP_UNREACH && code == ICMP_UNREACH_NEEDFRAG)
+               OSAddAtomic(1, &ipstat.ips_cantfrag);
+
        icmp_error(mcopy, type, code, dest, nextmtu);
 done:
-       ip_fwd_route_copyin(ifp, &fwd_rt);
+       ip_fwd_route_copyin(rcvifp, &fwd_rt);
 }
 
 int
-ip_savecontrol(
-       struct inpcb *inp,
-       struct mbuf **mp,
-       struct ip *ip,
-       struct mbuf *m)
+ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
+    struct mbuf *m)
 {
        *mp = NULL;
        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                struct timeval tv;
 
-               microtime(&tv);
-               mp = sbcreatecontrol_mbuf((caddr_t) &tv, sizeof(tv),
-                       SCM_TIMESTAMP, SOL_SOCKET, mp);
+               getmicrotime(&tv);
+               mp = sbcreatecontrol_mbuf((caddr_t)&tv, sizeof (tv),
+                   SCM_TIMESTAMP, SOL_SOCKET, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
-       if ((inp->inp_socket->so_options & SO_TIMESTAMP_MONOTONIC) != 0) {
+       if (inp->inp_socket->so_options & SO_TIMESTAMP_MONOTONIC) {
                uint64_t time;
 
                time = mach_absolute_time();
-               mp = sbcreatecontrol_mbuf((caddr_t) &time, sizeof(time),
-                       SCM_TIMESTAMP_MONOTONIC, SOL_SOCKET, mp);
-               
+               mp = sbcreatecontrol_mbuf((caddr_t)&time, sizeof (time),
+                   SCM_TIMESTAMP_MONOTONIC, SOL_SOCKET, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
-       } 
+       }
        if (inp->inp_flags & INP_RECVDSTADDR) {
-               mp = sbcreatecontrol_mbuf((caddr_t) &ip->ip_dst,
-                       sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)&ip->ip_dst,
+                   sizeof (struct in_addr), IP_RECVDSTADDR, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
 #ifdef notyet
-       /* XXX
+       /*
+        * XXX
         * Moving these out of udp_input() made them even more broken
         * than they already were.
         */
        /* options were tossed already */
        if (inp->inp_flags & INP_RECVOPTS) {
-               mp = sbcreatecontrol_mbuf((caddr_t) opts_deleted_above,
-                       sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)opts_deleted_above,
+                   sizeof (struct in_addr), IP_RECVOPTS, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
        /* ip_srcroute doesn't do what we want here, need to fix */
        if (inp->inp_flags & INP_RECVRETOPTS) {
-               mp = sbcreatecontrol_mbuf((caddr_t) ip_srcroute(),
-                       sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)ip_srcroute(),
+                   sizeof (struct in_addr), IP_RECVRETOPTS, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
-#endif
+#endif /* notyet */
        if (inp->inp_flags & INP_RECVIF) {
                struct ifnet *ifp;
-               struct sdlbuf {
-                       struct sockaddr_dl sdl;
-                       u_char  pad[32];
-               } sdlbuf;
-               struct sockaddr_dl *sdp;
-               struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
+               uint8_t sdlbuf[SOCK_MAXADDRLEN + 1];
+               struct sockaddr_dl *sdl2 = SDL(&sdlbuf);
+
+               /*
+                * Make sure to accomodate the largest possible
+                * size of SA(if_lladdr)->sa_len.
+                */
+               _CASSERT(sizeof (sdlbuf) == (SOCK_MAXADDRLEN + 1));
 
                ifnet_head_lock_shared();
                if ((ifp = m->m_pkthdr.rcvif) != NULL &&
                    ifp->if_index && (ifp->if_index <= if_index)) {
                        struct ifaddr *ifa = ifnet_addrs[ifp->if_index - 1];
+                       struct sockaddr_dl *sdp;
 
                        if (!ifa || !ifa->ifa_addr)
                                goto makedummy;
 
                        IFA_LOCK_SPIN(ifa);
-                       sdp = (struct sockaddr_dl *)(void *)ifa->ifa_addr;
+                       sdp = SDL(ifa->ifa_addr);
                        /*
                         * Change our mind and don't try copy.
                         */
-                       if ((sdp->sdl_family != AF_LINK) ||
-                           (sdp->sdl_len > sizeof(sdlbuf))) {
+                       if (sdp->sdl_family != AF_LINK) {
                                IFA_UNLOCK(ifa);
                                goto makedummy;
                        }
+                       /* the above _CASSERT ensures sdl_len fits in sdlbuf */
                        bcopy(sdp, sdl2, sdp->sdl_len);
                        IFA_UNLOCK(ifa);
                } else {
 makedummy:
-                       sdl2->sdl_len
-                               = offsetof(struct sockaddr_dl, sdl_data[0]);
+                       sdl2->sdl_len =
+                           offsetof(struct sockaddr_dl, sdl_data[0]);
                        sdl2->sdl_family = AF_LINK;
                        sdl2->sdl_index = 0;
                        sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
                }
                ifnet_head_done();
-               mp = sbcreatecontrol_mbuf((caddr_t) sdl2, sdl2->sdl_len,
-                       IP_RECVIF, IPPROTO_IP, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)sdl2, sdl2->sdl_len,
+                   IP_RECVIF, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
        if (inp->inp_flags & INP_RECVTTL) {
-               mp = sbcreatecontrol_mbuf((caddr_t)&ip->ip_ttl, sizeof(ip->ip_ttl), 
-                       IP_RECVTTL, IPPROTO_IP, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)&ip->ip_ttl,
+                   sizeof (ip->ip_ttl), IP_RECVTTL, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
-       if ((inp->inp_socket->so_flags & SOF_RECV_TRAFFIC_CLASS) != 0) {
+       if (inp->inp_socket->so_flags & SOF_RECV_TRAFFIC_CLASS) {
                int tc = m_get_traffic_class(m);
 
-               mp = sbcreatecontrol_mbuf((caddr_t) &tc, sizeof(tc),
-                       SO_TRAFFIC_CLASS, SOL_SOCKET, mp);
+               mp = sbcreatecontrol_mbuf((caddr_t)&tc, sizeof (tc),
+                   SO_TRAFFIC_CLASS, SOL_SOCKET, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
@@ -2786,105 +4188,224 @@ makedummy:
        if (inp->inp_flags & INP_PKTINFO) {
                struct in_pktinfo pi;
 
-               bzero(&pi, sizeof(struct in_pktinfo));
-               bcopy(&ip->ip_dst, &pi.ipi_addr, sizeof(struct in_addr));
-               pi.ipi_ifindex = (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
-               
-               mp = sbcreatecontrol_mbuf((caddr_t)&pi, sizeof(struct in_pktinfo), 
-                       IP_RECVPKTINFO, IPPROTO_IP, mp);
+               bzero(&pi, sizeof (struct in_pktinfo));
+               bcopy(&ip->ip_dst, &pi.ipi_addr, sizeof (struct in_addr));
+               pi.ipi_ifindex = (m != NULL && m->m_pkthdr.rcvif != NULL) ?
+                   m->m_pkthdr.rcvif->if_index : 0;
+
+               mp = sbcreatecontrol_mbuf((caddr_t)&pi,
+                   sizeof (struct in_pktinfo), IP_RECVPKTINFO, IPPROTO_IP, mp);
                if (*mp == NULL) {
                        goto no_mbufs;
                }
        }
-       return 0;
+       return (0);
 
 no_mbufs:
        ipstat.ips_pktdropcntrl++;
-       return ENOBUFS;
+       return (ENOBUFS);
 }
 
-int
-ip_rsvp_init(struct socket *so)
+static inline u_short
+ip_cksum(struct mbuf *m, int hlen)
 {
-       if (so->so_type != SOCK_RAW ||
-           so->so_proto->pr_protocol != IPPROTO_RSVP)
-         return EOPNOTSUPP;
+       u_short sum;
+
+       if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
+               sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
+       } else if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
+           !(m->m_pkthdr.pkt_flags & PKTF_LOOP)) {
+               /*
+                * The packet arrived on an interface which isn't capable
+                * of performing IP header checksum; compute it now.
+                */
+               sum = ip_cksum_hdr_in(m, hlen);
+       } else {
+               sum = 0;
+               m->m_pkthdr.csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR |
+                   CSUM_IP_CHECKED | CSUM_IP_VALID);
+               m->m_pkthdr.csum_data = 0xffff;
+       }
+
+       if (sum != 0)
+               OSAddAtomic(1, &ipstat.ips_badsum);
+
+       return (sum);
+}
+
+static int
+ip_getstat SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       if (req->oldptr == USER_ADDR_NULL)
+               req->oldlen = (size_t)sizeof (struct ipstat);
 
-       if (ip_rsvpd != NULL)
-         return EADDRINUSE;
+       return (SYSCTL_OUT(req, &ipstat, MIN(sizeof (ipstat), req->oldlen)));
+}
+
+void
+ip_setsrcifaddr_info(struct mbuf *m, uint32_t src_idx, struct in_ifaddr *ia)
+{
+       VERIFY(m->m_flags & M_PKTHDR);
 
-       ip_rsvpd = so;
        /*
-        * This may seem silly, but we need to be sure we don't over-increment
-        * the RSVP counter, in case something slips up.
+        * If the source ifaddr is specified, pick up the information
+        * from there; otherwise just grab the passed-in ifindex as the
+        * caller may not have the ifaddr available.
         */
-       if (!ip_rsvp_on) {
-               ip_rsvp_on = 1;
-               rsvp_on++;
+       if (ia != NULL) {
+               m->m_pkthdr.pkt_flags |= PKTF_IFAINFO;
+               m->m_pkthdr.src_ifindex = ia->ia_ifp->if_index;
+       } else {
+               m->m_pkthdr.src_ifindex = src_idx;
+               if (src_idx != 0)
+                       m->m_pkthdr.pkt_flags |= PKTF_IFAINFO;
        }
-
-       return 0;
 }
 
-int
-ip_rsvp_done(void)
+void
+ip_setdstifaddr_info(struct mbuf *m, uint32_t dst_idx, struct in_ifaddr *ia)
 {
-       ip_rsvpd = NULL;
+       VERIFY(m->m_flags & M_PKTHDR);
+
        /*
-        * This may seem silly, but we need to be sure we don't over-decrement
-        * the RSVP counter, in case something slips up.
+        * If the destination ifaddr is specified, pick up the information
+        * from there; otherwise just grab the passed-in ifindex as the
+        * caller may not have the ifaddr available.
         */
-       if (ip_rsvp_on) {
-               ip_rsvp_on = 0;
-               rsvp_on--;
+       if (ia != NULL) {
+               m->m_pkthdr.pkt_flags |= PKTF_IFAINFO;
+               m->m_pkthdr.dst_ifindex = ia->ia_ifp->if_index;
+       } else {
+               m->m_pkthdr.dst_ifindex = dst_idx;
+               if (dst_idx != 0)
+                       m->m_pkthdr.pkt_flags |= PKTF_IFAINFO;
        }
-       return 0;
 }
 
-static inline u_short
-ip_cksum(struct mbuf *m, int hlen)
+int
+ip_getsrcifaddr_info(struct mbuf *m, uint32_t *src_idx, uint32_t *iaf)
 {
+       VERIFY(m->m_flags & M_PKTHDR);
 
-       u_short sum;
-       struct ip *ip;
+       if (!(m->m_pkthdr.pkt_flags & PKTF_IFAINFO))
+               return (-1);
 
-       ip = mtod(m, struct ip *);
+       if (src_idx != NULL)
+               *src_idx = m->m_pkthdr.src_ifindex;
 
-       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 (iaf != NULL)
+               *iaf = 0;
 
+       return (0);
+}
+
+int
+ip_getdstifaddr_info(struct mbuf *m, uint32_t *dst_idx, uint32_t *iaf)
+{
+       VERIFY(m->m_flags & M_PKTHDR);
+
+       if (!(m->m_pkthdr.pkt_flags & PKTF_IFAINFO))
+               return (-1);
+
+       if (dst_idx != NULL)
+               *dst_idx = m->m_pkthdr.dst_ifindex;
+
+       if (iaf != NULL)
+               *iaf = 0;
+
+       return (0);
+}
+
+/*
+ * Protocol input handler for IPPROTO_GRE.
+ */
+void
+gre_input(struct mbuf *m, int off)
+{
+       gre_input_func_t fn = gre_input_func;
+
+       /*
+        * If there is a registered GRE input handler, pass mbuf to it.
+        */
+       if (fn != NULL) {
+               lck_mtx_unlock(inet_domain_mutex);
+               m = fn(m, off, (mtod(m, struct ip *))->ip_p);
+               lck_mtx_lock(inet_domain_mutex);
        }
 
-       if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
-               sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
-       } else if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) ||
-                   apple_hwcksum_tx == 0) {
-               /*
-                * Either this is not loopback packet coming from an interface
-                * that does not support checksum offloading, or it is loopback
-                * packet that has undergone software checksumming at the send
-                * side because apple_hwcksum_tx was set to 0.  In this case,
-                * calculate the checksum in software to validate the packet.
-                */
-               sum = in_cksum(m, hlen);
-       } else {
-               /*
-                * This is a loopback packet without any valid checksum since
-                * the send side has bypassed it (apple_hwcksum_tx set to 1).
-                * We get here because apple_hwcksum_rx was set to 0, and so
-                * we pretend that all is well.
-                */
-               sum = 0;
-               m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR |
-                           CSUM_IP_CHECKED | CSUM_IP_VALID;
-           m->m_pkthdr.csum_data = 0xffff;
+       /*
+        * If no matching tunnel that is up is found, we inject
+        * the mbuf to raw ip socket to see if anyone picks it up.
+        */
+       if (m != NULL)
+               rip_input(m, off);
+}
+
+/*
+ * Private KPI for PPP/PPTP.
+ */
+int
+ip_gre_register_input(gre_input_func_t fn)
+{
+       lck_mtx_lock(inet_domain_mutex);
+       gre_input_func = fn;
+       lck_mtx_unlock(inet_domain_mutex);
+
+       return (0);
+}
+
+static int
+sysctl_reset_ip_input_stats SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int error, i;
+
+       i = ip_input_measure;
+       error = sysctl_handle_int(oidp, &i, 0, req);
+       if (error || req->newptr == USER_ADDR_NULL)
+               goto done;
+       /* impose bounds */
+       if (i < 0 || i > 1) {
+               error = EINVAL;
+               goto done;
+       }
+       if (ip_input_measure != i && i == 1) {
+               net_perf_initialize(&net_perf, ip_input_measure_bins);
        }
+       ip_input_measure = i;
+done:
+       return (error);
+}
 
-       if (sum) {
-               OSAddAtomic(1, &ipstat.ips_badsum);
+static int
+sysctl_ip_input_measure_bins SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int error;
+       uint64_t i;
+
+       i = ip_input_measure_bins;
+       error = sysctl_handle_quad(oidp, &i, 0, req);
+       if (error || req->newptr == USER_ADDR_NULL)
+               goto done;
+       /* validate data */
+       if (!net_perf_validate_bins(i)) {
+               error = EINVAL;
+               goto done;
        }
+       ip_input_measure_bins = i;
+done:
+       return (error);
+}
 
-       return sum;
+static int
+sysctl_ip_input_getperf SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       if (req->oldptr == USER_ADDR_NULL)
+               req->oldlen = (size_t)sizeof (struct ipstat);
+
+       return (SYSCTL_OUT(req, &net_perf, MIN(sizeof (net_perf), req->oldlen)));
 }
+