text: /*
   * Copyright (c) 2000-2017 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
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   *
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   *
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
   */
  /*
   * Copyright (c) 1982, 1986, 1991, 1993, 1995
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)in_pcb.c	8.4 (Berkeley) 5/24/95
   * $FreeBSD: src/sys/netinet/in_pcb.c,v 1.59.2.17 2001/08/13 16:26:17 ume Exp $
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/malloc.h>
  #include <sys/mbuf.h>
  #include <sys/domain.h>
  #include <sys/protosw.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/proc.h>
  #include <sys/kernel.h>
  #include <sys/sysctl.h>
  #include <sys/mcache.h>
  #include <sys/kauth.h>
  #include <sys/priv.h>
  #include <sys/proc_uuid_policy.h>
  #include <sys/syslog.h>
  #include <sys/priv.h>
  #include <net/dlil.h>
  
  #include <libkern/OSAtomic.h>
  #include <kern/locks.h>
  
  #include <machine/limits.h>
  
  #include <kern/zalloc.h>
  
  #include <net/if.h>
  #include <net/if_types.h>
  #include <net/route.h>
  #include <net/flowhash.h>
  #include <net/flowadv.h>
  #include <net/ntstat.h>
  
  #include <netinet/in.h>
  #include <netinet/in_pcb.h>
  #include <netinet/in_var.h>
  #include <netinet/ip_var.h>
  #if INET6
  #include <netinet/ip6.h>
  #include <netinet6/ip6_var.h>
  #endif /* INET6 */
  
  #include <sys/kdebug.h>
  #include <sys/random.h>
  
  #include <dev/random/randomdev.h>
  #include <mach/boolean.h>
  
  #include <pexpert/pexpert.h>
  
  #if NECP
  #include <net/necp.h>
  #endif
  
  #include <sys/stat.h>
  #include <sys/ubc.h>
  #include <sys/vnode.h>
  
  static lck_grp_t	*inpcb_lock_grp;
  static lck_attr_t	*inpcb_lock_attr;
  static lck_grp_attr_t	*inpcb_lock_grp_attr;
  decl_lck_mtx_data(static, inpcb_lock);		/* global INPCB lock */
  decl_lck_mtx_data(static, inpcb_timeout_lock);
  
  static TAILQ_HEAD(, inpcbinfo) inpcb_head = TAILQ_HEAD_INITIALIZER(inpcb_head);
  
  static u_int16_t inpcb_timeout_run = 0;	/* INPCB timer is scheduled to run */
  static boolean_t inpcb_garbage_collecting = FALSE; /* gc timer is scheduled */
  static boolean_t inpcb_ticking = FALSE;		/* "slow" timer is scheduled */
  static boolean_t inpcb_fast_timer_on = FALSE;
  
  extern char *proc_best_name(proc_t);
  
  #define	INPCB_GCREQ_THRESHOLD	50000
  
  static thread_call_t inpcb_thread_call, inpcb_fast_thread_call;
  static void inpcb_sched_timeout(void);
  static void inpcb_sched_lazy_timeout(void);
  static void _inpcb_sched_timeout(unsigned int);
  static void inpcb_timeout(void *, void *);
  const int inpcb_timeout_lazy = 10;	/* 10 seconds leeway for lazy timers */
  extern int tvtohz(struct timeval *);
  
  #if CONFIG_PROC_UUID_POLICY
  static void inp_update_cellular_policy(struct inpcb *, boolean_t);
  #if NECP
  static void inp_update_necp_want_app_policy(struct inpcb *, boolean_t);
  #endif /* NECP */
  #endif /* !CONFIG_PROC_UUID_POLICY */
  
  #define	DBG_FNC_PCB_LOOKUP	NETDBG_CODE(DBG_NETTCP, (6 << 8))
  #define	DBG_FNC_PCB_HLOOKUP	NETDBG_CODE(DBG_NETTCP, ((6 << 8) | 1))
  
  /*
   * These configure the range of local port addresses assigned to
   * "unspecified" outgoing connections/packets/whatever.
   */
  int	ipport_lowfirstauto  = IPPORT_RESERVED - 1;	/* 1023 */
  int	ipport_lowlastauto = IPPORT_RESERVEDSTART;	/* 600 */
  int	ipport_firstauto = IPPORT_HIFIRSTAUTO;		/* 49152 */
  int	ipport_lastauto  = IPPORT_HILASTAUTO;		/* 65535 */
  int	ipport_hifirstauto = IPPORT_HIFIRSTAUTO;	/* 49152 */
  int	ipport_hilastauto  = IPPORT_HILASTAUTO;		/* 65535 */
  
  #define	RANGECHK(var, min, max) \
  	if ((var) < (min)) { (var) = (min); } \
  	else if ((var) > (max)) { (var) = (max); }
  
  static int
  sysctl_net_ipport_check SYSCTL_HANDLER_ARGS
  {
  #pragma unused(arg1, arg2)
  	int error;
  
  	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
  	if (!error) {
  		RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
  		RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
  		RANGECHK(ipport_firstauto, IPPORT_RESERVED, USHRT_MAX);
  		RANGECHK(ipport_lastauto, IPPORT_RESERVED, USHRT_MAX);
  		RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, USHRT_MAX);
  		RANGECHK(ipport_hilastauto, IPPORT_RESERVED, USHRT_MAX);
  	}
  	return (error);
  }
  
  #undef RANGECHK
  
  SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange,
  	CTLFLAG_RW|CTLFLAG_LOCKED, 0, "IP Ports");
  
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
  SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast,
  	CTLTYPE_INT|CTLFLAG_RW | CTLFLAG_LOCKED,
  	&ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");
  
  static uint32_t apn_fallbk_debug = 0;
  #define apn_fallbk_log(x)       do { if (apn_fallbk_debug >= 1) log x; } while (0)
  
  #if CONFIG_EMBEDDED
  static boolean_t apn_fallbk_enabled = TRUE;
  
  SYSCTL_DECL(_net_inet);
  SYSCTL_NODE(_net_inet, OID_AUTO, apn_fallback, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "APN Fallback");
  SYSCTL_UINT(_net_inet_apn_fallback, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_LOCKED,
      &apn_fallbk_debug, 0, "APN fallback debug enable");
  #else
  static boolean_t apn_fallbk_enabled = FALSE;
  #endif
  
  extern int	udp_use_randomport;
  extern int	tcp_use_randomport;
  
  /* Structs used for flowhash computation */
  struct inp_flowhash_key_addr {
  	union {
  		struct in_addr	v4;
  		struct in6_addr v6;
  		u_int8_t	addr8[16];
  		u_int16_t	addr16[8];
  		u_int32_t	addr32[4];
  	} infha;
  };
  
  struct inp_flowhash_key {
  	struct inp_flowhash_key_addr	infh_laddr;
  	struct inp_flowhash_key_addr	infh_faddr;
  	u_int32_t			infh_lport;
  	u_int32_t			infh_fport;
  	u_int32_t			infh_af;
  	u_int32_t			infh_proto;
  	u_int32_t			infh_rand1;
  	u_int32_t			infh_rand2;
  };
  
  static u_int32_t inp_hash_seed = 0;
  
  static int infc_cmp(const struct inpcb *, const struct inpcb *);
  
  /* Flags used by inp_fc_getinp */
  #define	INPFC_SOLOCKED	0x1
  #define	INPFC_REMOVE	0x2
  static struct inpcb *inp_fc_getinp(u_int32_t, u_int32_t);
  
  static void inp_fc_feedback(struct inpcb *);
  extern void tcp_remove_from_time_wait(struct inpcb *inp);
  
  decl_lck_mtx_data(static, inp_fc_lck);
  
  RB_HEAD(inp_fc_tree, inpcb) inp_fc_tree;
  RB_PROTOTYPE(inp_fc_tree, inpcb, infc_link, infc_cmp);
  RB_GENERATE(inp_fc_tree, inpcb, infc_link, infc_cmp);
  
  /*
   * Use this inp as a key to find an inp in the flowhash tree.
   * Accesses to it are protected by inp_fc_lck.
   */
  struct inpcb key_inp;
  
  /*
   * in_pcb.c: manage the Protocol Control Blocks.
   */
  
  void
  in_pcbinit(void)
  {
  	static int inpcb_initialized = 0;
  
  	VERIFY(!inpcb_initialized);
  	inpcb_initialized = 1;
  
  	inpcb_lock_grp_attr = lck_grp_attr_alloc_init();
  	inpcb_lock_grp = lck_grp_alloc_init("inpcb", inpcb_lock_grp_attr);
  	inpcb_lock_attr = lck_attr_alloc_init();
  	lck_mtx_init(&inpcb_lock, inpcb_lock_grp, inpcb_lock_attr);
  	lck_mtx_init(&inpcb_timeout_lock, inpcb_lock_grp, inpcb_lock_attr);
  	inpcb_thread_call = thread_call_allocate_with_priority(inpcb_timeout,
  	    NULL, THREAD_CALL_PRIORITY_KERNEL);
  	inpcb_fast_thread_call = thread_call_allocate_with_priority(
  	    inpcb_timeout, NULL, THREAD_CALL_PRIORITY_KERNEL);
  	if (inpcb_thread_call == NULL || inpcb_fast_thread_call == NULL)
  		panic("unable to alloc the inpcb thread call");
  
  	/*
  	 * Initialize data structures required to deliver
  	 * flow advisories.
  	 */
  	lck_mtx_init(&inp_fc_lck, inpcb_lock_grp, inpcb_lock_attr);
  	lck_mtx_lock(&inp_fc_lck);
  	RB_INIT(&inp_fc_tree);
  	bzero(&key_inp, sizeof(key_inp));
  	lck_mtx_unlock(&inp_fc_lck);
  }
  
  #define	INPCB_HAVE_TIMER_REQ(req)	(((req).intimer_lazy > 0) || \
  	((req).intimer_fast > 0) || ((req).intimer_nodelay > 0))
  static void
  inpcb_timeout(void *arg0, void *arg1)
  {
  #pragma unused(arg0, arg1)
  	struct inpcbinfo *ipi;
  	boolean_t t, gc;
  	struct intimercount gccnt, tmcnt;
  
  	/*
  	 * 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();
  
  	bzero(&gccnt, sizeof(gccnt));
  	bzero(&tmcnt, sizeof(tmcnt));
  
  	lck_mtx_lock_spin(&inpcb_timeout_lock);
  	gc = inpcb_garbage_collecting;
  	inpcb_garbage_collecting = FALSE;
  
  	t = inpcb_ticking;
  	inpcb_ticking = FALSE;
  
  	if (gc || t) {
  		lck_mtx_unlock(&inpcb_timeout_lock);
  
  		lck_mtx_lock(&inpcb_lock);
  		TAILQ_FOREACH(ipi, &inpcb_head, ipi_entry) {
  			if (INPCB_HAVE_TIMER_REQ(ipi->ipi_gc_req)) {
  				bzero(&ipi->ipi_gc_req,
  					sizeof(ipi->ipi_gc_req));
  				if (gc && ipi->ipi_gc != NULL) {
  					ipi->ipi_gc(ipi);
  					gccnt.intimer_lazy +=
  					    ipi->ipi_gc_req.intimer_lazy;
  					gccnt.intimer_fast +=
  					    ipi->ipi_gc_req.intimer_fast;
  					gccnt.intimer_nodelay +=
  					    ipi->ipi_gc_req.intimer_nodelay;
  				}
  			}
  			if (INPCB_HAVE_TIMER_REQ(ipi->ipi_timer_req)) {
  				bzero(&ipi->ipi_timer_req,
  					sizeof(ipi->ipi_timer_req));
  				if (t && ipi->ipi_timer != NULL) {
  					ipi->ipi_timer(ipi);
  					tmcnt.intimer_lazy +=
  					    ipi->ipi_timer_req.intimer_lazy;
  					tmcnt.intimer_fast +=
  					    ipi->ipi_timer_req.intimer_fast;
  					tmcnt.intimer_nodelay +=
  					    ipi->ipi_timer_req.intimer_nodelay;
  				}
  			}
  		}
  		lck_mtx_unlock(&inpcb_lock);
  		lck_mtx_lock_spin(&inpcb_timeout_lock);
  	}
  
  	/* lock was dropped above, so check first before overriding */
  	if (!inpcb_garbage_collecting)
  		inpcb_garbage_collecting = INPCB_HAVE_TIMER_REQ(gccnt);
  	if (!inpcb_ticking)
  		inpcb_ticking = INPCB_HAVE_TIMER_REQ(tmcnt);
  
  	/* re-arm the timer if there's work to do */
  	inpcb_timeout_run--;
  	VERIFY(inpcb_timeout_run >= 0 && inpcb_timeout_run < 2);
  
  	if (gccnt.intimer_nodelay > 0 || tmcnt.intimer_nodelay > 0)
  		inpcb_sched_timeout();
  	else if ((gccnt.intimer_fast + tmcnt.intimer_fast) <= 5)
  		/* be lazy when idle with little activity */
  		inpcb_sched_lazy_timeout();
  	else
  		inpcb_sched_timeout();
  
  	lck_mtx_unlock(&inpcb_timeout_lock);
  }
  
  static void
  inpcb_sched_timeout(void)
  {
  	_inpcb_sched_timeout(0);
  }
  
  static void
  inpcb_sched_lazy_timeout(void)
  {
  	_inpcb_sched_timeout(inpcb_timeout_lazy);
  }
  
  static void
  _inpcb_sched_timeout(unsigned int offset)
  {
  	uint64_t deadline, leeway;
  
  	clock_interval_to_deadline(1, NSEC_PER_SEC, &deadline);
  	LCK_MTX_ASSERT(&inpcb_timeout_lock, LCK_MTX_ASSERT_OWNED);
  	if (inpcb_timeout_run == 0 &&
  	    (inpcb_garbage_collecting || inpcb_ticking)) {
  		lck_mtx_convert_spin(&inpcb_timeout_lock);
  		inpcb_timeout_run++;
  		if (offset == 0) {
  			inpcb_fast_timer_on = TRUE;
  			thread_call_enter_delayed(inpcb_thread_call,
  			    deadline);
  		} else {
  			inpcb_fast_timer_on = FALSE;
  			clock_interval_to_absolutetime_interval(offset,
  			    NSEC_PER_SEC, &leeway);
  			thread_call_enter_delayed_with_leeway(
  			    inpcb_thread_call, NULL, deadline, leeway,
  			    THREAD_CALL_DELAY_LEEWAY);
  		}
  	} else if (inpcb_timeout_run == 1 &&
  	    offset == 0 && !inpcb_fast_timer_on) {
  		/*
  		 * Since the request was for a fast timer but the
  		 * scheduled timer is a lazy timer, try to schedule
  		 * another instance of fast timer also.
  		 */
  		lck_mtx_convert_spin(&inpcb_timeout_lock);
  		inpcb_timeout_run++;
  		inpcb_fast_timer_on = TRUE;
  		thread_call_enter_delayed(inpcb_fast_thread_call, deadline);
  	}
  }
  
  void
  inpcb_gc_sched(struct inpcbinfo *ipi, u_int32_t type)
  {
  	u_int32_t gccnt;
  
  	lck_mtx_lock_spin(&inpcb_timeout_lock);
  	inpcb_garbage_collecting = TRUE;
  	gccnt = ipi->ipi_gc_req.intimer_nodelay +
  		ipi->ipi_gc_req.intimer_fast;
  
  	if (gccnt > INPCB_GCREQ_THRESHOLD) {
  		type = INPCB_TIMER_FAST;
  	}
  
  	switch (type) {
  	case INPCB_TIMER_NODELAY:
  		atomic_add_32(&ipi->ipi_gc_req.intimer_nodelay, 1);
  		inpcb_sched_timeout();
  		break;
  	case INPCB_TIMER_FAST:
  		atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
  		inpcb_sched_timeout();
  		break;
  	default:
  		atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, 1);
  		inpcb_sched_lazy_timeout();
  		break;
  	}
  	lck_mtx_unlock(&inpcb_timeout_lock);
  }
  
  void
  inpcb_timer_sched(struct inpcbinfo *ipi, u_int32_t type)
  {
  
  	lck_mtx_lock_spin(&inpcb_timeout_lock);
  	inpcb_ticking = TRUE;
  	switch (type) {
  	case INPCB_TIMER_NODELAY:
  		atomic_add_32(&ipi->ipi_timer_req.intimer_nodelay, 1);
  		inpcb_sched_timeout();
  		break;
  	case INPCB_TIMER_FAST:
  		atomic_add_32(&ipi->ipi_timer_req.intimer_fast, 1);
  		inpcb_sched_timeout();
  		break;
  	default:
  		atomic_add_32(&ipi->ipi_timer_req.intimer_lazy, 1);
  		inpcb_sched_lazy_timeout();
  		break;
  	}
  	lck_mtx_unlock(&inpcb_timeout_lock);
  }
  
  void
  in_pcbinfo_attach(struct inpcbinfo *ipi)
  {
  	struct inpcbinfo *ipi0;
  
  	lck_mtx_lock(&inpcb_lock);
  	TAILQ_FOREACH(ipi0, &inpcb_head, ipi_entry) {
  		if (ipi0 == ipi) {
  			panic("%s: ipi %p already in the list\n",
  			    __func__, ipi);
  			/* NOTREACHED */
  		}
  	}
  	TAILQ_INSERT_TAIL(&inpcb_head, ipi, ipi_entry);
  	lck_mtx_unlock(&inpcb_lock);
  }
  
  int
  in_pcbinfo_detach(struct inpcbinfo *ipi)
  {
  	struct inpcbinfo *ipi0;
  	int error = 0;
  
  	lck_mtx_lock(&inpcb_lock);
  	TAILQ_FOREACH(ipi0, &inpcb_head, ipi_entry) {
  		if (ipi0 == ipi)
  			break;
  	}
  	if (ipi0 != NULL)
  		TAILQ_REMOVE(&inpcb_head, ipi0, ipi_entry);
  	else
  		error = ENXIO;
  	lck_mtx_unlock(&inpcb_lock);
  
  	return (error);
  }
  
  /*
   * Allocate a PCB and associate it with the socket.
   *
   * Returns:	0			Success
   *		ENOBUFS
   *		ENOMEM
   */
  int
  in_pcballoc(struct socket *so, struct inpcbinfo *pcbinfo, struct proc *p)
  {
  #pragma unused(p)
  	struct inpcb *inp;
  	caddr_t	temp;
  #if CONFIG_MACF_NET
  	int mac_error;
  #endif /* CONFIG_MACF_NET */
  
  	if ((so->so_flags1 & SOF1_CACHED_IN_SOCK_LAYER) == 0) {
  		inp = (struct inpcb *)zalloc(pcbinfo->ipi_zone);
  		if (inp == NULL)
  			return (ENOBUFS);
  		bzero((caddr_t)inp, sizeof (*inp));
  	} else {
  		inp = (struct inpcb *)(void *)so->so_saved_pcb;
  		temp = inp->inp_saved_ppcb;
  		bzero((caddr_t)inp, sizeof (*inp));
  		inp->inp_saved_ppcb = temp;
  	}
  
  	inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
  	inp->inp_pcbinfo = pcbinfo;
  	inp->inp_socket = so;
  #if CONFIG_MACF_NET
  	mac_error = mac_inpcb_label_init(inp, M_WAITOK);
  	if (mac_error != 0) {
  		if ((so->so_flags1 & SOF1_CACHED_IN_SOCK_LAYER) == 0)
  			zfree(pcbinfo->ipi_zone, inp);
  		return (mac_error);
  	}
  	mac_inpcb_label_associate(so, inp);
  #endif /* CONFIG_MACF_NET */
  	/* make sure inp_stat is always 64-bit aligned */
  	inp->inp_stat = (struct inp_stat *)P2ROUNDUP(inp->inp_stat_store,
  	    sizeof (u_int64_t));
  	if (((uintptr_t)inp->inp_stat - (uintptr_t)inp->inp_stat_store) +
  	    sizeof (*inp->inp_stat) > sizeof (inp->inp_stat_store)) {
  		panic("%s: insufficient space to align inp_stat", __func__);
  		/* NOTREACHED */
  	}
  
  	/* make sure inp_cstat is always 64-bit aligned */
  	inp->inp_cstat = (struct inp_stat *)P2ROUNDUP(inp->inp_cstat_store,
  	    sizeof (u_int64_t));
  	if (((uintptr_t)inp->inp_cstat - (uintptr_t)inp->inp_cstat_store) +
  	    sizeof (*inp->inp_cstat) > sizeof (inp->inp_cstat_store)) {
  		panic("%s: insufficient space to align inp_cstat", __func__);
  		/* NOTREACHED */
  	}
  
  	/* make sure inp_wstat is always 64-bit aligned */
  	inp->inp_wstat = (struct inp_stat *)P2ROUNDUP(inp->inp_wstat_store,
  	    sizeof (u_int64_t));
  	if (((uintptr_t)inp->inp_wstat - (uintptr_t)inp->inp_wstat_store) +
  	    sizeof (*inp->inp_wstat) > sizeof (inp->inp_wstat_store)) {
  		panic("%s: insufficient space to align inp_wstat", __func__);
  		/* NOTREACHED */
  	}
  
  	/* make sure inp_Wstat is always 64-bit aligned */
  	inp->inp_Wstat = (struct inp_stat *)P2ROUNDUP(inp->inp_Wstat_store,
  	    sizeof (u_int64_t));
  	if (((uintptr_t)inp->inp_Wstat - (uintptr_t)inp->inp_Wstat_store) +
  	    sizeof (*inp->inp_Wstat) > sizeof (inp->inp_Wstat_store)) {
  		panic("%s: insufficient space to align inp_Wstat", __func__);
  		/* NOTREACHED */
  	}
  
  	so->so_pcb = (caddr_t)inp;
  
  	if (so->so_proto->pr_flags & PR_PCBLOCK) {
  		lck_mtx_init(&inp->inpcb_mtx, pcbinfo->ipi_lock_grp,
  		    pcbinfo->ipi_lock_attr);
  	}
  
  #if INET6
  	if (SOCK_DOM(so) == PF_INET6 && !ip6_mapped_addr_on)
  		inp->inp_flags |= IN6P_IPV6_V6ONLY;
  
  	if (ip6_auto_flowlabel)
  		inp->inp_flags |= IN6P_AUTOFLOWLABEL;
  #endif /* INET6 */
  	if (intcoproc_unrestricted)
  		inp->inp_flags2 |= INP2_INTCOPROC_ALLOWED;
  
  	(void) inp_update_policy(inp);
  
  	lck_rw_lock_exclusive(pcbinfo->ipi_lock);
  	inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
  	LIST_INSERT_HEAD(pcbinfo->ipi_listhead, inp, inp_list);
  	pcbinfo->ipi_count++;
  	lck_rw_done(pcbinfo->ipi_lock);
  	return (0);
  }
  
  /*
   * in_pcblookup_local_and_cleanup does everything
   * in_pcblookup_local does but it checks for a socket
   * that's going away. Since we know that the lock is
   * held read+write when this funciton is called, we
   * can safely dispose of this socket like the slow
   * timer would usually do and return NULL. This is
   * great for bind.
   */
  struct inpcb *
  in_pcblookup_local_and_cleanup(struct inpcbinfo *pcbinfo, struct in_addr laddr,
      u_int lport_arg, int wild_okay)
  {
  	struct inpcb *inp;
  
  	/* Perform normal lookup */
  	inp = in_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay);
  
  	/* Check if we found a match but it's waiting to be disposed */
  	if (inp != NULL && inp->inp_wantcnt == WNT_STOPUSING) {
  		struct socket *so = inp->inp_socket;
  
  		socket_lock(so, 0);
  
  		if (so->so_usecount == 0) {
  			if (inp->inp_state != INPCB_STATE_DEAD)
  				in_pcbdetach(inp);
  			in_pcbdispose(inp);	/* will unlock & destroy */
  			inp = NULL;
  		} else {
  			socket_unlock(so, 0);
  		}
  	}
  
  	return (inp);
  }
  
  static void
  in_pcb_conflict_post_msg(u_int16_t port)
  {
  	/*
  	 * Radar 5523020 send a kernel event notification if a
  	 * non-participating socket tries to bind the port a socket
  	 * who has set SOF_NOTIFYCONFLICT owns.
  	 */
  	struct kev_msg ev_msg;
  	struct kev_in_portinuse	in_portinuse;
  
  	bzero(&in_portinuse, sizeof (struct kev_in_portinuse));
  	bzero(&ev_msg, sizeof (struct kev_msg));
  	in_portinuse.port = ntohs(port);	/* port in host order */
  	in_portinuse.req_pid = proc_selfpid();
  	ev_msg.vendor_code = KEV_VENDOR_APPLE;
  	ev_msg.kev_class = KEV_NETWORK_CLASS;
  	ev_msg.kev_subclass = KEV_INET_SUBCLASS;
  	ev_msg.event_code = KEV_INET_PORTINUSE;
  	ev_msg.dv[0].data_ptr = &in_portinuse;
  	ev_msg.dv[0].data_length = sizeof (struct kev_in_portinuse);
  	ev_msg.dv[1].data_length = 0;
  	dlil_post_complete_msg(NULL, &ev_msg);
  }
  
  /*
   * Bind an INPCB to an address and/or port.  This routine should not alter
   * the caller-supplied local address "nam".
   *
   * Returns:	0			Success
   *		EADDRNOTAVAIL		Address not available.
   *		EINVAL			Invalid argument
   *		EAFNOSUPPORT		Address family not supported [notdef]
   *		EACCES			Permission denied
   *		EADDRINUSE		Address in use
   *		EAGAIN			Resource unavailable, try again
   *		priv_check_cred:EPERM	Operation not permitted
   */
  int
  in_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct proc *p)
  {
  	struct socket *so = inp->inp_socket;
  	unsigned short *lastport;
  	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
  	u_short lport = 0, rand_port = 0;
  	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
  	int error, randomport, conflict = 0;
  	boolean_t anonport = FALSE;
  	kauth_cred_t cred;
  	struct in_addr laddr;
  	struct ifnet *outif = NULL;
  
  	if (TAILQ_EMPTY(&in_ifaddrhead)) /* XXX broken! */
  		return (EADDRNOTAVAIL);
  	if (!(so->so_options & (SO_REUSEADDR|SO_REUSEPORT)))
  		wild = 1;
  
  	bzero(&laddr, sizeof(laddr));
  
  	socket_unlock(so, 0); /* keep reference on socket */
  	lck_rw_lock_exclusive(pcbinfo->ipi_lock);
  	if (inp->inp_lport != 0 || inp->inp_laddr.s_addr != INADDR_ANY) {
  		/* another thread completed the bind */
  		lck_rw_done(pcbinfo->ipi_lock);
  		socket_lock(so, 0);
  		return (EINVAL);
  	}
  
  	if (nam != NULL) {
  		if (nam->sa_len != sizeof (struct sockaddr_in)) {
  			lck_rw_done(pcbinfo->ipi_lock);
  			socket_lock(so, 0);
  			return (EINVAL);
  		}
  #if 0
  		/*
  		 * We should check the family, but old programs
  		 * incorrectly fail to initialize it.
  		 */
  		if (nam->sa_family != AF_INET) {
  			lck_rw_done(pcbinfo->ipi_lock);
  			socket_lock(so, 0);
  			return (EAFNOSUPPORT);
  		}
  #endif /* 0 */
  		lport = SIN(nam)->sin_port;
  
  		if (IN_MULTICAST(ntohl(SIN(nam)->sin_addr.s_addr))) {
  			/*
  			 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
  			 * allow complete duplication of binding if
  			 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
  			 * and a multicast address is bound on both
  			 * new and duplicated sockets.
  			 */
  			if (so->so_options & SO_REUSEADDR)
  				reuseport = SO_REUSEADDR|SO_REUSEPORT;
  		} else if (SIN(nam)->sin_addr.s_addr != INADDR_ANY) {
  			struct sockaddr_in sin;
  			struct ifaddr *ifa;
  
  			/* Sanitized for interface address searches */
  			bzero(&sin, sizeof (sin));
  			sin.sin_family = AF_INET;
  			sin.sin_len = sizeof (struct sockaddr_in);
  			sin.sin_addr.s_addr = SIN(nam)->sin_addr.s_addr;
  
  			ifa = ifa_ifwithaddr(SA(&sin));
  			if (ifa == NULL) {
  				lck_rw_done(pcbinfo->ipi_lock);
  				socket_lock(so, 0);
  				return (EADDRNOTAVAIL);
  			} else {
  				/*
  				 * Opportunistically determine the outbound
  				 * interface that may be used; this may not
  				 * hold true if we end up using a route
  				 * going over a different interface, e.g.
  				 * when sending to a local address.  This
  				 * will get updated again after sending.
  				 */
  				IFA_LOCK(ifa);
  				outif = ifa->ifa_ifp;
  				IFA_UNLOCK(ifa);
  				IFA_REMREF(ifa);
  			}
  		}
  		if (lport != 0) {
  			struct inpcb *t;
  			uid_t u;
  
  #if !CONFIG_EMBEDDED
  			if (ntohs(lport) < IPPORT_RESERVED) {
  				cred = kauth_cred_proc_ref(p);
  				error = priv_check_cred(cred,
  				    PRIV_NETINET_RESERVEDPORT, 0);
  				kauth_cred_unref(&cred);
  				if (error != 0) {
  					lck_rw_done(pcbinfo->ipi_lock);
  					socket_lock(so, 0);
  					return (EACCES);
  				}
  			}
  #endif /* !CONFIG_EMBEDDED */
  			if (!IN_MULTICAST(ntohl(SIN(nam)->sin_addr.s_addr)) &&
  			    (u = kauth_cred_getuid(so->so_cred)) != 0 &&
  			    (t = in_pcblookup_local_and_cleanup(
  			    inp->inp_pcbinfo, SIN(nam)->sin_addr, lport,
  			    INPLOOKUP_WILDCARD)) != NULL &&
  			    (SIN(nam)->sin_addr.s_addr != INADDR_ANY ||
  			    t->inp_laddr.s_addr != INADDR_ANY ||
  			    !(t->inp_socket->so_options & SO_REUSEPORT)) &&
  			    (u != kauth_cred_getuid(t->inp_socket->so_cred)) &&
  			    !(t->inp_socket->so_flags & SOF_REUSESHAREUID) &&
  			    (SIN(nam)->sin_addr.s_addr != INADDR_ANY ||
  			    t->inp_laddr.s_addr != INADDR_ANY)) {
  				if ((t->inp_socket->so_flags &
  				    SOF_NOTIFYCONFLICT) &&
  				    !(so->so_flags & SOF_NOTIFYCONFLICT))
  					conflict = 1;
  
  				lck_rw_done(pcbinfo->ipi_lock);
  
  				if (conflict)
  					in_pcb_conflict_post_msg(lport);
  
  				socket_lock(so, 0);
  				return (EADDRINUSE);
  			}
  			t = in_pcblookup_local_and_cleanup(pcbinfo,
  			    SIN(nam)->sin_addr, lport, wild);
  			if (t != NULL &&
  			    (reuseport & t->inp_socket->so_options) == 0) {
  #if INET6
  				if (SIN(nam)->sin_addr.s_addr != INADDR_ANY ||
  				    t->inp_laddr.s_addr != INADDR_ANY ||
  				    SOCK_DOM(so) != PF_INET6 ||
  				    SOCK_DOM(t->inp_socket) != PF_INET6)
  #endif /* INET6 */
  				{
  
  					if ((t->inp_socket->so_flags &
  					    SOF_NOTIFYCONFLICT) &&
  					    !(so->so_flags & SOF_NOTIFYCONFLICT))
  						conflict = 1;
  
  					lck_rw_done(pcbinfo->ipi_lock);
  
  					if (conflict)
  						in_pcb_conflict_post_msg(lport);
  					socket_lock(so, 0);
  					return (EADDRINUSE);
  				}
  			}
  		}
  		laddr = SIN(nam)->sin_addr;
  	}
  	if (lport == 0) {
  		u_short first, last;
  		int count;
  		bool found;
  
  		randomport = (so->so_flags & SOF_BINDRANDOMPORT) ||
  		    (so->so_type == SOCK_STREAM ? tcp_use_randomport :
  		    udp_use_randomport);
  
  		/*
  		 * Even though this looks similar to the code in
  		 * in6_pcbsetport, the v6 vs v4 checks are different.
  		 */
  		anonport = TRUE;
  		if (inp->inp_flags & INP_HIGHPORT) {
  			first = ipport_hifirstauto;	/* sysctl */
  			last  = ipport_hilastauto;
  			lastport = &pcbinfo->ipi_lasthi;
  		} else if (inp->inp_flags & INP_LOWPORT) {
  			cred = kauth_cred_proc_ref(p);
  			error = priv_check_cred(cred,
  			    PRIV_NETINET_RESERVEDPORT, 0);
  			kauth_cred_unref(&cred);
  			if (error != 0) {
  				lck_rw_done(pcbinfo->ipi_lock);
  				socket_lock(so, 0);
  				return (error);
  			}
  			first = ipport_lowfirstauto;	/* 1023 */
  			last  = ipport_lowlastauto;	/* 600 */
  			lastport = &pcbinfo->ipi_lastlow;
  		} else {
  			first = ipport_firstauto;	/* sysctl */
  			last  = ipport_lastauto;
  			lastport = &pcbinfo->ipi_lastport;
  		}
  		/* No point in randomizing if only one port is available */
  
  		if (first == last)
  			randomport = 0;
  		/*
  		 * Simple check to ensure all ports are not used up causing
  		 * a deadlock here.
  		 *
  		 * We split the two cases (up and down) so that the direction
  		 * is not being tested on each round of the loop.
  		 */
  		if (first > last) {
  			struct in_addr lookup_addr;
  
  			/*
  			 * counting down
  			 */
  			if (randomport) {
  				read_frandom(&rand_port, sizeof (rand_port));
  				*lastport =
  				    first - (rand_port % (first - last));
  			}
  			count = first - last;
  
  			lookup_addr = (laddr.s_addr != INADDR_ANY) ? laddr :
  			    inp->inp_laddr;
  
  			found = false;
  			do {
  				if (count-- < 0) {	/* completely used? */
  					lck_rw_done(pcbinfo->ipi_lock);
  					socket_lock(so, 0);
  					return (EADDRNOTAVAIL);
  				}
  				--*lastport;
  				if (*lastport > first || *lastport < last)
  					*lastport = first;
  				lport = htons(*lastport);
  
  				found = in_pcblookup_local_and_cleanup(pcbinfo,
  				    lookup_addr, lport, wild) == NULL;
  			} while (!found);
  		} else {
  			struct in_addr lookup_addr;
  
  			/*
  			 * counting up
  			 */
  			if (randomport) {
  				read_frandom(&rand_port, sizeof (rand_port));
  				*lastport =
  				    first + (rand_port % (first - last));
  			}
  			count = last - first;
  
  			lookup_addr = (laddr.s_addr != INADDR_ANY) ? laddr :
  			    inp->inp_laddr;
  
  			found = false;
  			do {
  				if (count-- < 0) {	/* completely used? */
  					lck_rw_done(pcbinfo->ipi_lock);
  					socket_lock(so, 0);
  					return (EADDRNOTAVAIL);
  				}
  				++*lastport;
  				if (*lastport < first || *lastport > last)
  					*lastport = first;
  				lport = htons(*lastport);
  
  				found = in_pcblookup_local_and_cleanup(pcbinfo,
  				    lookup_addr, lport, wild) == NULL;
  			} while (!found);
  		}
  	}
  	socket_lock(so, 0);
  
  	/*
  	 * We unlocked socket's protocol lock for a long time.
  	 * The socket might have been dropped/defuncted.
  	 * Checking if world has changed since.
  	 */
  	if (inp->inp_state == INPCB_STATE_DEAD) {
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (ECONNABORTED);
  	}
  
  	if (inp->inp_lport != 0 || inp->inp_laddr.s_addr != INADDR_ANY) {
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (EINVAL);
  	}
  
  	if (laddr.s_addr != INADDR_ANY) {
  		inp->inp_laddr = laddr;
  		inp->inp_last_outifp = outif;
  	}
  	inp->inp_lport = lport;
  	if (anonport)
  		inp->inp_flags |= INP_ANONPORT;
  
  	if (in_pcbinshash(inp, 1) != 0) {
  		inp->inp_laddr.s_addr = INADDR_ANY;
  		inp->inp_last_outifp = NULL;
  
  		inp->inp_lport = 0;
  		if (anonport)
  			inp->inp_flags &= ~INP_ANONPORT;
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (EAGAIN);
  	}
  	lck_rw_done(pcbinfo->ipi_lock);
  	sflt_notify(so, sock_evt_bound, NULL);
  	return (0);
  }
  
  #define	APN_FALLBACK_IP_FILTER(a)	\
  	(IN_LINKLOCAL(ntohl((a)->sin_addr.s_addr)) || \
  	 IN_LOOPBACK(ntohl((a)->sin_addr.s_addr)) || \
  	 IN_ZERONET(ntohl((a)->sin_addr.s_addr)) || \
  	 IN_MULTICAST(ntohl((a)->sin_addr.s_addr)) || \
  	 IN_PRIVATE(ntohl((a)->sin_addr.s_addr)))
  
  #define	APN_FALLBACK_NOTIF_INTERVAL	2 /* Magic Number */
  static uint64_t last_apn_fallback = 0;
  
  static boolean_t
  apn_fallback_required (proc_t proc, struct socket *so, struct sockaddr_in *p_dstv4)
  {
  	uint64_t timenow;
  	struct sockaddr_storage lookup_default_addr;
  	struct rtentry *rt = NULL;
  
  	VERIFY(proc != NULL);
  
  	if (apn_fallbk_enabled  == FALSE)
  		return FALSE;
  
  	if (proc == kernproc)
  		return FALSE;
  
  	if (so && (so->so_options & SO_NOAPNFALLBK))
  		return FALSE;
  
  	timenow = net_uptime();
  	if ((timenow - last_apn_fallback) < APN_FALLBACK_NOTIF_INTERVAL) {
  		apn_fallbk_log((LOG_INFO, "APN fallback notification throttled.\n"));
  		return FALSE;
  	}
  
  	if (p_dstv4 && APN_FALLBACK_IP_FILTER(p_dstv4))
  		return FALSE;
  
  	/* Check if we have unscoped IPv6 default route through cellular */
  	bzero(&lookup_default_addr, sizeof(lookup_default_addr));
  	lookup_default_addr.ss_family = AF_INET6;
  	lookup_default_addr.ss_len = sizeof(struct sockaddr_in6);
  
  	rt = rtalloc1((struct sockaddr *)&lookup_default_addr, 0, 0);
  	if (NULL == rt) {
  		apn_fallbk_log((LOG_INFO, "APN fallback notification could not find "
  		    "unscoped default IPv6 route.\n"));
  		return FALSE;
  	}
  
  	if (!IFNET_IS_CELLULAR(rt->rt_ifp)) {
  		rtfree(rt);
  		apn_fallbk_log((LOG_INFO, "APN fallback notification could not find "
  		    "unscoped default IPv6 route through cellular interface.\n"));
  		return FALSE;
  	}
  
  	/*
  	 * We have a default IPv6 route, ensure that
  	 * we do not have IPv4 default route before triggering
  	 * the event
  	 */
  	rtfree(rt);
  	rt = NULL;
  
  	bzero(&lookup_default_addr, sizeof(lookup_default_addr));
  	lookup_default_addr.ss_family = AF_INET;
  	lookup_default_addr.ss_len = sizeof(struct sockaddr_in);
  
  	rt = rtalloc1((struct sockaddr *)&lookup_default_addr, 0, 0);
  
  	if (rt) {
  		rtfree(rt);
  		rt = NULL;
  		apn_fallbk_log((LOG_INFO, "APN fallback notification found unscoped "
  		    "IPv4 default route!\n"));
  		return FALSE;
  	}
  
  	{
  		/*
  		 * We disable APN fallback if the binary is not a third-party app.
  		 * Note that platform daemons use their process name as a
  		 * bundle ID so we filter out bundle IDs without dots.
  		 */
  		const char *bundle_id = cs_identity_get(proc);
  		if (bundle_id == NULL ||
  		    bundle_id[0] == '\0' ||
  		    strchr(bundle_id, '.') == NULL ||
  		    strncmp(bundle_id, "com.apple.", sizeof("com.apple.") - 1) == 0) {
  			apn_fallbk_log((LOG_INFO, "Abort: APN fallback notification found first-"
  			    "party bundle ID \"%s\"!\n", (bundle_id ? bundle_id : "NULL")));
  			return FALSE;
  		}
  	}
  
  	{
  		/*
  		 * The Apple App Store IPv6 requirement started on
  		 * June 1st, 2016 at 12:00:00 AM PDT.
  		 * We disable APN fallback if the binary is more recent than that.
  		 * We check both atime and birthtime since birthtime is not always supported.
  		 */
  		static const long ipv6_start_date = 1464764400L;
  		vfs_context_t context;
  		struct stat64 sb;
  		int vn_stat_error;
  
  		bzero(&sb, sizeof(struct stat64));
  		context = vfs_context_create(NULL);
  		vn_stat_error = vn_stat(proc->p_textvp, &sb, NULL, 1, context);
  		(void)vfs_context_rele(context);
  
  		if (vn_stat_error != 0 ||
  		    sb.st_atimespec.tv_sec >= ipv6_start_date ||
  		    sb.st_birthtimespec.tv_sec >= ipv6_start_date) {
  			apn_fallbk_log((LOG_INFO, "Abort: APN fallback notification found binary "
  			    "too recent! (err %d atime %ld mtime %ld ctime %ld birthtime %ld)\n",
  			    vn_stat_error, sb.st_atimespec.tv_sec, sb.st_mtimespec.tv_sec,
  			    sb.st_ctimespec.tv_sec, sb.st_birthtimespec.tv_sec));
  			return FALSE;
  		}
  	}
  	return TRUE;
  }
  
  static void
  apn_fallback_trigger(proc_t proc)
  {
  	pid_t pid = 0;
  	struct kev_msg ev_msg;
  	struct kev_netevent_apnfallbk_data apnfallbk_data;
  
  	last_apn_fallback = net_uptime();
  	pid = proc_pid(proc);
  	uuid_t application_uuid;
  	uuid_clear(application_uuid);
  	proc_getexecutableuuid(proc, application_uuid,
  	    sizeof(application_uuid));
  
  	bzero(&ev_msg, sizeof (struct kev_msg));
  	ev_msg.vendor_code      = KEV_VENDOR_APPLE;
  	ev_msg.kev_class        = KEV_NETWORK_CLASS;
  	ev_msg.kev_subclass     = KEV_NETEVENT_SUBCLASS;
  	ev_msg.event_code       = KEV_NETEVENT_APNFALLBACK;
  
  	bzero(&apnfallbk_data, sizeof(apnfallbk_data));
  	apnfallbk_data.epid = pid;
  	uuid_copy(apnfallbk_data.euuid, application_uuid);
  
  	ev_msg.dv[0].data_ptr   = &apnfallbk_data;
  	ev_msg.dv[0].data_length = sizeof(apnfallbk_data);
  	kev_post_msg(&ev_msg);
  	apn_fallbk_log((LOG_INFO, "APN fallback notification issued.\n"));
  }
  
  /*
   * Transform old in_pcbconnect() into an inner subroutine for new
   * in_pcbconnect(); do some validity-checking on the remote address
   * (in "nam") and then determine local host address (i.e., which
   * interface) to use to access that remote host.
   *
   * This routine may alter the caller-supplied remote address "nam".
   *
   * The caller may override the bound-to-interface setting of the socket
   * by specifying the ifscope parameter (e.g. from IP_PKTINFO.)
   *
   * This routine might return an ifp with a reference held if the caller
   * provides a non-NULL outif, even in the error case.  The caller is
   * responsible for releasing its reference.
   *
   * Returns:	0			Success
   *		EINVAL			Invalid argument
   *		EAFNOSUPPORT		Address family not supported
   *		EADDRNOTAVAIL		Address not available
   */
  int
  in_pcbladdr(struct inpcb *inp, struct sockaddr *nam, struct in_addr *laddr,
      unsigned int ifscope, struct ifnet **outif, int raw)
  {
  	struct route *ro = &inp->inp_route;
  	struct in_ifaddr *ia = NULL;
  	struct sockaddr_in sin;
  	int error = 0;
  	boolean_t restricted = FALSE;
  
  	if (outif != NULL)
  		*outif = NULL;
  	if (nam->sa_len != sizeof (struct sockaddr_in))
  		return (EINVAL);
  	if (SIN(nam)->sin_family != AF_INET)
  		return (EAFNOSUPPORT);
  	if (raw == 0 && SIN(nam)->sin_port == 0)
  		return (EADDRNOTAVAIL);
  
  	/*
  	 * If the destination address is INADDR_ANY,
  	 * use the primary local address.
  	 * If the supplied address is INADDR_BROADCAST,
  	 * and the primary interface supports broadcast,
  	 * choose the broadcast address for that interface.
  	 */
  	if (raw == 0 && (SIN(nam)->sin_addr.s_addr == INADDR_ANY ||
  	    SIN(nam)->sin_addr.s_addr == (u_int32_t)INADDR_BROADCAST)) {
  		lck_rw_lock_shared(in_ifaddr_rwlock);
  		if (!TAILQ_EMPTY(&in_ifaddrhead)) {
  			ia = TAILQ_FIRST(&in_ifaddrhead);
  			IFA_LOCK_SPIN(&ia->ia_ifa);
  			if (SIN(nam)->sin_addr.s_addr == INADDR_ANY) {
  				SIN(nam)->sin_addr = IA_SIN(ia)->sin_addr;
  			} else if (ia->ia_ifp->if_flags & IFF_BROADCAST) {
  				SIN(nam)->sin_addr =
  				    SIN(&ia->ia_broadaddr)->sin_addr;
  			}
  			IFA_UNLOCK(&ia->ia_ifa);
  			ia = NULL;
  		}
  		lck_rw_done(in_ifaddr_rwlock);
  	}
  	/*
  	 * Otherwise, if the socket has already bound the source, just use it.
  	 */
  	if (inp->inp_laddr.s_addr != INADDR_ANY) {
  		VERIFY(ia == NULL);
  		*laddr = inp->inp_laddr;
  		return (0);
  	}
  
  	/*
  	 * If the ifscope is specified by the caller (e.g. IP_PKTINFO)
  	 * then it overrides the sticky ifscope set for the socket.
  	 */
  	if (ifscope == IFSCOPE_NONE && (inp->inp_flags & INP_BOUND_IF))
  		ifscope = inp->inp_boundifp->if_index;
  
  	/*
  	 * If route is known or can be allocated now,
  	 * our src addr is taken from the i/f, else punt.
  	 * Note that we should check the address family of the cached
  	 * destination, in case of sharing the cache with IPv6.
  	 */
  	if (ro->ro_rt != NULL)
  		RT_LOCK_SPIN(ro->ro_rt);
  	if (ROUTE_UNUSABLE(ro) || ro->ro_dst.sa_family != AF_INET ||
  	    SIN(&ro->ro_dst)->sin_addr.s_addr != SIN(nam)->sin_addr.s_addr ||
  	    (inp->inp_socket->so_options & SO_DONTROUTE)) {
  		if (ro->ro_rt != NULL)
  			RT_UNLOCK(ro->ro_rt);
  		ROUTE_RELEASE(ro);
  	}
  	if (!(inp->inp_socket->so_options & SO_DONTROUTE) &&
  	    (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL)) {
  		if (ro->ro_rt != NULL)
  			RT_UNLOCK(ro->ro_rt);
  		ROUTE_RELEASE(ro);
  		/* No route yet, so try to acquire one */
  		bzero(&ro->ro_dst, sizeof (struct sockaddr_in));
  		ro->ro_dst.sa_family = AF_INET;
  		ro->ro_dst.sa_len = sizeof (struct sockaddr_in);
  		SIN(&ro->ro_dst)->sin_addr = SIN(nam)->sin_addr;
  		rtalloc_scoped(ro, ifscope);
  		if (ro->ro_rt != NULL)
  			RT_LOCK_SPIN(ro->ro_rt);
  	}
  	/* Sanitized local copy for interface address searches */
  	bzero(&sin, sizeof (sin));
  	sin.sin_family = AF_INET;
  	sin.sin_len = sizeof (struct sockaddr_in);
  	sin.sin_addr.s_addr = SIN(nam)->sin_addr.s_addr;
  	/*
  	 * If we did not find (or use) a route, assume dest is reachable
  	 * on a directly connected network and try to find a corresponding
  	 * interface to take the source address from.
  	 */
  	if (ro->ro_rt == NULL) {
  		proc_t proc = current_proc();
  
  		VERIFY(ia == NULL);
  		ia = ifatoia(ifa_ifwithdstaddr(SA(&sin)));
  		if (ia == NULL)
  			ia = ifatoia(ifa_ifwithnet_scoped(SA(&sin), ifscope));
  		error = ((ia == NULL) ? ENETUNREACH : 0);
  
  		if (apn_fallback_required(proc, inp->inp_socket,
  		    (void *)nam))
  			apn_fallback_trigger(proc);
  
  		goto done;
  	}
  	RT_LOCK_ASSERT_HELD(ro->ro_rt);
  	/*
  	 * If the outgoing interface on the route found is not
  	 * a loopback interface, use the address from that interface.
  	 */
  	if (!(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK)) {
  		VERIFY(ia == NULL);
  		/*
  		 * If the route points to a cellular interface and the
  		 * caller forbids our using interfaces of such type,
  		 * pretend that there is no route.
  		 * Apply the same logic for expensive interfaces.
  		 */
  		if (inp_restricted_send(inp, ro->ro_rt->rt_ifp)) {
  			RT_UNLOCK(ro->ro_rt);
  			ROUTE_RELEASE(ro);
  			error = EHOSTUNREACH;
  			restricted = TRUE;
  		} else {
  			/* Become a regular mutex */
  			RT_CONVERT_LOCK(ro->ro_rt);
  			ia = ifatoia(ro->ro_rt->rt_ifa);
  			IFA_ADDREF(&ia->ia_ifa);
  			RT_UNLOCK(ro->ro_rt);
  			error = 0;
  		}
  		goto done;
  	}
  	VERIFY(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK);
  	RT_UNLOCK(ro->ro_rt);
  	/*
  	 * The outgoing interface is marked with 'loopback net', so a route
  	 * to ourselves is here.
  	 * Try to find the interface of the destination address and then
  	 * take the address from there. That interface is not necessarily
  	 * a loopback interface.
  	 */
  	VERIFY(ia == NULL);
  	ia = ifatoia(ifa_ifwithdstaddr(SA(&sin)));
  	if (ia == NULL)
  		ia = ifatoia(ifa_ifwithaddr_scoped(SA(&sin), ifscope));
  	if (ia == NULL)
  		ia = ifatoia(ifa_ifwithnet_scoped(SA(&sin), ifscope));
  	if (ia == NULL) {
  		RT_LOCK(ro->ro_rt);
  		ia = ifatoia(ro->ro_rt->rt_ifa);
  		if (ia != NULL)
  			IFA_ADDREF(&ia->ia_ifa);
  		RT_UNLOCK(ro->ro_rt);
  	}
  	error = ((ia == NULL) ? ENETUNREACH : 0);
  
  done:
  	/*
  	 * If the destination address is multicast and an outgoing
  	 * interface has been set as a multicast option, use the
  	 * address of that interface as our source address.
  	 */
  	if (IN_MULTICAST(ntohl(SIN(nam)->sin_addr.s_addr)) &&
  	    inp->inp_moptions != NULL) {
  		struct ip_moptions *imo;
  		struct ifnet *ifp;
  
  		imo = inp->inp_moptions;
  		IMO_LOCK(imo);
  		if (imo->imo_multicast_ifp != NULL && (ia == NULL ||
  		    ia->ia_ifp != imo->imo_multicast_ifp)) {
  			ifp = imo->imo_multicast_ifp;
  			if (ia != NULL)
  				IFA_REMREF(&ia->ia_ifa);
  			lck_rw_lock_shared(in_ifaddr_rwlock);
  			TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
  				if (ia->ia_ifp == ifp)
  					break;
  			}
  			if (ia != NULL)
  				IFA_ADDREF(&ia->ia_ifa);
  			lck_rw_done(in_ifaddr_rwlock);
  			if (ia == NULL)
  				error = EADDRNOTAVAIL;
  			else
  				error = 0;
  		}
  		IMO_UNLOCK(imo);
  	}
  	/*
  	 * Don't do pcblookup call here; return interface in laddr
  	 * and exit to caller, that will do the lookup.
  	 */
  	if (ia != NULL) {
  		/*
  		 * If the source address belongs to a cellular interface
  		 * and the socket forbids our using interfaces of such
  		 * type, pretend that there is no source address.
  		 * Apply the same logic for expensive interfaces.
  		 */
  		IFA_LOCK_SPIN(&ia->ia_ifa);
  		if (inp_restricted_send(inp, ia->ia_ifa.ifa_ifp)) {
  			IFA_UNLOCK(&ia->ia_ifa);
  			error = EHOSTUNREACH;
  			restricted = TRUE;
  		} else if (error == 0) {
  			*laddr = ia->ia_addr.sin_addr;
  			if (outif != NULL) {
  				struct ifnet *ifp;
  
  				if (ro->ro_rt != NULL)
  					ifp = ro->ro_rt->rt_ifp;
  				else
  					ifp = ia->ia_ifp;
  
  				VERIFY(ifp != NULL);
  				IFA_CONVERT_LOCK(&ia->ia_ifa);
  				ifnet_reference(ifp);	/* for caller */
  				if (*outif != NULL)
  					ifnet_release(*outif);
  				*outif = ifp;
  			}
  			IFA_UNLOCK(&ia->ia_ifa);
  		} else {
  			IFA_UNLOCK(&ia->ia_ifa);
  		}
  		IFA_REMREF(&ia->ia_ifa);
  		ia = NULL;
  	}
  
  	if (restricted && error == EHOSTUNREACH) {
  		soevent(inp->inp_socket, (SO_FILT_HINT_LOCKED |
  		    SO_FILT_HINT_IFDENIED));
  	}
  
  	return (error);
  }
  
  /*
   * Outer subroutine:
   * Connect from a socket to a specified address.
   * Both address and port must be specified in argument sin.
   * If don't have a local address for this socket yet,
   * then pick one.
   *
   * The caller may override the bound-to-interface setting of the socket
   * by specifying the ifscope parameter (e.g. from IP_PKTINFO.)
   */
  int
  in_pcbconnect(struct inpcb *inp, struct sockaddr *nam, struct proc *p,
      unsigned int ifscope, struct ifnet **outif)
  {
  	struct in_addr laddr;
  	struct sockaddr_in *sin = (struct sockaddr_in *)(void *)nam;
  	struct inpcb *pcb;
  	int error;
  	struct socket *so = inp->inp_socket;
  
  	/*
  	 *   Call inner routine, to assign local interface address.
  	 */
  	if ((error = in_pcbladdr(inp, nam, &laddr, ifscope, outif, 0)) != 0)
  		return (error);
  
  	socket_unlock(so, 0);
  	pcb = in_pcblookup_hash(inp->inp_pcbinfo, sin->sin_addr, sin->sin_port,
  	    inp->inp_laddr.s_addr ? inp->inp_laddr : laddr,
  	    inp->inp_lport, 0, NULL);
  	socket_lock(so, 0);
  
  	/*
  	 * Check if the socket is still in a valid state. When we unlock this
  	 * embryonic socket, it can get aborted if another thread is closing
  	 * the listener (radar 7947600).
  	 */
  	if ((so->so_flags & SOF_ABORTED) != 0)
  		return (ECONNREFUSED);
  
  	if (pcb != NULL) {
  		in_pcb_checkstate(pcb, WNT_RELEASE, pcb == inp ? 1 : 0);
  		return (EADDRINUSE);
  	}
  	if (inp->inp_laddr.s_addr == INADDR_ANY) {
  		if (inp->inp_lport == 0) {
  			error = in_pcbbind(inp, NULL, p);
  			if (error)
  				return (error);
  		}
  		if (!lck_rw_try_lock_exclusive(inp->inp_pcbinfo->ipi_lock)) {
  			/*
  			 * Lock inversion issue, mostly with udp
  			 * multicast packets.
  			 */
  			socket_unlock(so, 0);
  			lck_rw_lock_exclusive(inp->inp_pcbinfo->ipi_lock);
  			socket_lock(so, 0);
  		}
  		inp->inp_laddr = laddr;
  		/* no reference needed */
  		inp->inp_last_outifp = (outif != NULL) ? *outif : NULL;
  		inp->inp_flags |= INP_INADDR_ANY;
  	} else {
  		/*
  		 * Usage of IP_PKTINFO, without local port already
  		 * speficified will cause kernel to panic,
  		 * see rdar://problem/18508185.
  		 * For now returning error to avoid a kernel panic
  		 * This routines can be refactored and handle this better
  		 * in future.
  		 */
  		if (inp->inp_lport == 0)
  			return (EINVAL);
  		if (!lck_rw_try_lock_exclusive(inp->inp_pcbinfo->ipi_lock)) {
  			/*
  			 * Lock inversion issue, mostly with udp
  			 * multicast packets.
  			 */
  			socket_unlock(so, 0);
  			lck_rw_lock_exclusive(inp->inp_pcbinfo->ipi_lock);
  			socket_lock(so, 0);
  		}
  	}
  	inp->inp_faddr = sin->sin_addr;
  	inp->inp_fport = sin->sin_port;
  	if (nstat_collect && SOCK_PROTO(so) == IPPROTO_UDP)
  		nstat_pcb_invalidate_cache(inp);
  	in_pcbrehash(inp);
  	lck_rw_done(inp->inp_pcbinfo->ipi_lock);
  	return (0);
  }
  
  void
  in_pcbdisconnect(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  
  	if (nstat_collect && SOCK_PROTO(so) == IPPROTO_UDP)
  		nstat_pcb_cache(inp);
  
  	inp->inp_faddr.s_addr = INADDR_ANY;
  	inp->inp_fport = 0;
  
  	if (!lck_rw_try_lock_exclusive(inp->inp_pcbinfo->ipi_lock)) {
  		/* lock inversion issue, mostly with udp multicast packets */
  		socket_unlock(so, 0);
  		lck_rw_lock_exclusive(inp->inp_pcbinfo->ipi_lock);
  		socket_lock(so, 0);
  	}
  
  	in_pcbrehash(inp);
  	lck_rw_done(inp->inp_pcbinfo->ipi_lock);
  	/*
  	 * A multipath subflow socket would have its SS_NOFDREF set by default,
  	 * so check for SOF_MP_SUBFLOW socket flag before detaching the PCB;
  	 * when the socket is closed for real, SOF_MP_SUBFLOW would be cleared.
  	 */
  	if (!(so->so_flags & SOF_MP_SUBFLOW) && (so->so_state & SS_NOFDREF))
  		in_pcbdetach(inp);
  }
  
  void
  in_pcbdetach(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  
  	if (so->so_pcb == NULL) {
  		/* PCB has been disposed */
  		panic("%s: inp=%p so=%p proto=%d so_pcb is null!\n", __func__,
  		    inp, so, SOCK_PROTO(so));
  		/* NOTREACHED */
  	}
  
  #if IPSEC
  	if (inp->inp_sp != NULL) {
  		(void) ipsec4_delete_pcbpolicy(inp);
  	}
  #endif /* IPSEC */
  
  	if (inp->inp_stat != NULL && SOCK_PROTO(so) == IPPROTO_UDP) {
  		if (inp->inp_stat->rxpackets == 0 && inp->inp_stat->txpackets == 0) {
  			INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet_dgram_no_data);
  		}
  	}
  
  	/*
  	 * Let NetworkStatistics know this PCB is going away
  	 * before we detach it.
  	 */
  	if (nstat_collect &&
  	    (SOCK_PROTO(so) == IPPROTO_TCP || SOCK_PROTO(so) == IPPROTO_UDP))
  		nstat_pcb_detach(inp);
  
  	/* Free memory buffer held for generating keep alives */
  	if (inp->inp_keepalive_data != NULL) {
  		FREE(inp->inp_keepalive_data, M_TEMP);
  		inp->inp_keepalive_data = NULL;
  	}
  
  	/* mark socket state as dead */
  	if (in_pcb_checkstate(inp, WNT_STOPUSING, 1) != WNT_STOPUSING) {
  		panic("%s: so=%p proto=%d couldn't set to STOPUSING\n",
  		    __func__, so, SOCK_PROTO(so));
  		/* NOTREACHED */
  	}
  
  	if (!(so->so_flags & SOF_PCBCLEARING)) {
  		struct ip_moptions *imo;
  
  		inp->inp_vflag = 0;
  		if (inp->inp_options != NULL) {
  			(void) m_free(inp->inp_options);
  			inp->inp_options = NULL;
  		}
  		ROUTE_RELEASE(&inp->inp_route);
  		imo = inp->inp_moptions;
  		inp->inp_moptions = NULL;
  		sofreelastref(so, 0);
  		inp->inp_state = INPCB_STATE_DEAD;
  		/* makes sure we're not called twice from so_close */
  		so->so_flags |= SOF_PCBCLEARING;
  
  		inpcb_gc_sched(inp->inp_pcbinfo, INPCB_TIMER_FAST);
  
  		/*
  		 * See inp_join_group() for why we need to unlock
  		 */
  		if (imo != NULL) {
  			socket_unlock(so, 0);
  			IMO_REMREF(imo);
  			socket_lock(so, 0);
  		}
  	}
  }
  
  
  void
  in_pcbdispose(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  	struct inpcbinfo *ipi = inp->inp_pcbinfo;
  
  	if (so != NULL && so->so_usecount != 0) {
  		panic("%s: so %p [%d,%d] usecount %d lockhistory %s\n",
  		    __func__, so, SOCK_DOM(so), SOCK_TYPE(so), so->so_usecount,
  		    solockhistory_nr(so));
  		/* NOTREACHED */
  	} else if (inp->inp_wantcnt != WNT_STOPUSING) {
  		if (so != NULL) {
  			panic_plain("%s: inp %p invalid wantcnt %d, so %p "
  			    "[%d,%d] usecount %d retaincnt %d state 0x%x "
  			    "flags 0x%x lockhistory %s\n", __func__, inp,
  			    inp->inp_wantcnt, so, SOCK_DOM(so), SOCK_TYPE(so),
  			    so->so_usecount, so->so_retaincnt, so->so_state,
  			    so->so_flags, solockhistory_nr(so));
  			/* NOTREACHED */
  		} else {
  			panic("%s: inp %p invalid wantcnt %d no socket\n",
  			    __func__, inp, inp->inp_wantcnt);
  			/* NOTREACHED */
  		}
  	}
  
  	LCK_RW_ASSERT(ipi->ipi_lock, LCK_RW_ASSERT_EXCLUSIVE);
  
  	inp->inp_gencnt = ++ipi->ipi_gencnt;
  	/* access ipi in in_pcbremlists */
  	in_pcbremlists(inp);
  
  	if (so != NULL) {
  		if (so->so_proto->pr_flags & PR_PCBLOCK) {
  			sofreelastref(so, 0);
  			if (so->so_rcv.sb_cc > 0 || so->so_snd.sb_cc > 0) {
  				/*
  				 * selthreadclear() already called
  				 * during sofreelastref() above.
  				 */
  				sbrelease(&so->so_rcv);
  				sbrelease(&so->so_snd);
  			}
  			if (so->so_head != NULL) {
  				panic("%s: so=%p head still exist\n",
  				    __func__, so);
  				/* NOTREACHED */
  			}
  			lck_mtx_unlock(&inp->inpcb_mtx);
  
  #if NECP
  			necp_inpcb_remove_cb(inp);
  #endif /* NECP */
  
  			lck_mtx_destroy(&inp->inpcb_mtx, ipi->ipi_lock_grp);
  		}
  		/* makes sure we're not called twice from so_close */
  		so->so_flags |= SOF_PCBCLEARING;
  		so->so_saved_pcb = (caddr_t)inp;
  		so->so_pcb = NULL;
  		inp->inp_socket = NULL;
  #if CONFIG_MACF_NET
  		mac_inpcb_label_destroy(inp);
  #endif /* CONFIG_MACF_NET */
  #if NECP
  		necp_inpcb_dispose(inp);
  #endif /* NECP */
  		/*
  		 * In case there a route cached after a detach (possible
  		 * in the tcp case), make sure that it is freed before
  		 * we deallocate the structure.
  		 */
  		ROUTE_RELEASE(&inp->inp_route);
  		if ((so->so_flags1 & SOF1_CACHED_IN_SOCK_LAYER) == 0) {
  			zfree(ipi->ipi_zone, inp);
  		}
  		sodealloc(so);
  	}
  }
  
  /*
   * The calling convention of in_getsockaddr() and in_getpeeraddr() was
   * modified to match the pru_sockaddr() and pru_peeraddr() entry points
   * in struct pr_usrreqs, so that protocols can just reference then directly
   * without the need for a wrapper function.
   */
  int
  in_getsockaddr(struct socket *so, struct sockaddr **nam)
  {
  	struct inpcb *inp;
  	struct sockaddr_in *sin;
  
  	/*
  	 * Do the malloc first in case it blocks.
  	 */
  	MALLOC(sin, struct sockaddr_in *, sizeof (*sin), M_SONAME, M_WAITOK);
  	if (sin == NULL)
  		return (ENOBUFS);
  	bzero(sin, sizeof (*sin));
  	sin->sin_family = AF_INET;
  	sin->sin_len = sizeof (*sin);
  
  	if ((inp = sotoinpcb(so)) == NULL) {
  		FREE(sin, M_SONAME);
  		return (EINVAL);
  	}
  	sin->sin_port = inp->inp_lport;
  	sin->sin_addr = inp->inp_laddr;
  
  	*nam = (struct sockaddr *)sin;
  	return (0);
  }
  
  int
  in_getsockaddr_s(struct socket *so, struct sockaddr_in *ss)
  {
  	struct sockaddr_in *sin = ss;
  	struct inpcb *inp;
  
  	VERIFY(ss != NULL);
  	bzero(ss, sizeof (*ss));
  
  	sin->sin_family = AF_INET;
  	sin->sin_len = sizeof (*sin);
  
  	if ((inp = sotoinpcb(so)) == NULL)
  		return (EINVAL);
  
  	sin->sin_port = inp->inp_lport;
  	sin->sin_addr = inp->inp_laddr;
  	return (0);
  }
  
  int
  in_getpeeraddr(struct socket *so, struct sockaddr **nam)
  {
  	struct inpcb *inp;
  	struct sockaddr_in *sin;
  
  	/*
  	 * Do the malloc first in case it blocks.
  	 */
  	MALLOC(sin, struct sockaddr_in *, sizeof (*sin), M_SONAME, M_WAITOK);
  	if (sin == NULL)
  		return (ENOBUFS);
  	bzero((caddr_t)sin, sizeof (*sin));
  	sin->sin_family = AF_INET;
  	sin->sin_len = sizeof (*sin);
  
  	if ((inp = sotoinpcb(so)) == NULL) {
  		FREE(sin, M_SONAME);
  		return (EINVAL);
  	}
  	sin->sin_port = inp->inp_fport;
  	sin->sin_addr = inp->inp_faddr;
  
  	*nam = (struct sockaddr *)sin;
  	return (0);
  }
  
  void
  in_pcbnotifyall(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      int errno, void (*notify)(struct inpcb *, int))
  {
  	struct inpcb *inp;
  
  	lck_rw_lock_shared(pcbinfo->ipi_lock);
  
  	LIST_FOREACH(inp, pcbinfo->ipi_listhead, inp_list) {
  #if INET6
  		if (!(inp->inp_vflag & INP_IPV4))
  			continue;
  #endif /* INET6 */
  		if (inp->inp_faddr.s_addr != faddr.s_addr ||
  		    inp->inp_socket == NULL)
  			continue;
  		if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
  			continue;
  		socket_lock(inp->inp_socket, 1);
  		(*notify)(inp, errno);
  		(void) in_pcb_checkstate(inp, WNT_RELEASE, 1);
  		socket_unlock(inp->inp_socket, 1);
  	}
  	lck_rw_done(pcbinfo->ipi_lock);
  }
  
  /*
   * Check for alternatives when higher level complains
   * about service problems.  For now, invalidate cached
   * routing information.  If the route was created dynamically
   * (by a redirect), time to try a default gateway again.
   */
  void
  in_losing(struct inpcb *inp)
  {
  	boolean_t release = FALSE;
  	struct rtentry *rt;
  
  	if ((rt = inp->inp_route.ro_rt) != NULL) {
  		struct in_ifaddr *ia = NULL;
  
  		RT_LOCK(rt);
  		if (rt->rt_flags & RTF_DYNAMIC) {
  			/*
  			 * Prevent another thread from modifying rt_key,
  			 * rt_gateway via rt_setgate() after rt_lock is
  			 * dropped by marking the route as defunct.
  			 */
  			rt->rt_flags |= RTF_CONDEMNED;
  			RT_UNLOCK(rt);
  			(void) rtrequest(RTM_DELETE, rt_key(rt),
  			    rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
  		} else {
  			RT_UNLOCK(rt);
  		}
  		/* if the address is gone keep the old route in the pcb */
  		if (inp->inp_laddr.s_addr != INADDR_ANY &&
  		    (ia = ifa_foraddr(inp->inp_laddr.s_addr)) != NULL) {
  			/*
  			 * Address is around; ditch the route.  A new route
  			 * can be allocated the next time output is attempted.
  			 */
  			release = TRUE;
  		}
  		if (ia != NULL)
  			IFA_REMREF(&ia->ia_ifa);
  	}
  	if (rt == NULL || release)
  		ROUTE_RELEASE(&inp->inp_route);
  }
  
  /*
   * After a routing change, flush old routing
   * and allocate a (hopefully) better one.
   */
  void
  in_rtchange(struct inpcb *inp, int errno)
  {
  #pragma unused(errno)
  	boolean_t release = FALSE;
  	struct rtentry *rt;
  
  	if ((rt = inp->inp_route.ro_rt) != NULL) {
  		struct in_ifaddr *ia = NULL;
  
  		/* if address is gone, keep the old route */
  		if (inp->inp_laddr.s_addr != INADDR_ANY &&
  		    (ia = ifa_foraddr(inp->inp_laddr.s_addr)) != NULL) {
  			/*
  			 * Address is around; ditch the route.  A new route
  			 * can be allocated the next time output is attempted.
  			 */
  			release = TRUE;
  		}
  		if (ia != NULL)
  			IFA_REMREF(&ia->ia_ifa);
  	}
  	if (rt == NULL || release)
  		ROUTE_RELEASE(&inp->inp_route);
  }
  
  /*
   * Lookup a PCB based on the local address and port.
   */
  struct inpcb *
  in_pcblookup_local(struct inpcbinfo *pcbinfo, struct in_addr laddr,
      unsigned int lport_arg, int wild_okay)
  {
  	struct inpcb *inp;
  	int matchwild = 3, wildcard;
  	u_short lport = lport_arg;
  
  	KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_START, 0, 0, 0, 0, 0);
  
  	if (!wild_okay) {
  		struct inpcbhead *head;
  		/*
  		 * Look for an unconnected (wildcard foreign addr) PCB that
  		 * matches the local address and port we're looking for.
  		 */
  		head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
  		    pcbinfo->ipi_hashmask)];
  		LIST_FOREACH(inp, head, inp_hash) {
  #if INET6
  			if (!(inp->inp_vflag & INP_IPV4))
  				continue;
  #endif /* INET6 */
  			if (inp->inp_faddr.s_addr == INADDR_ANY &&
  			    inp->inp_laddr.s_addr == laddr.s_addr &&
  			    inp->inp_lport == lport) {
  				/*
  				 * Found.
  				 */
  				return (inp);
  			}
  		}
  		/*
  		 * Not found.
  		 */
  		KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_END, 0, 0, 0, 0, 0);
  		return (NULL);
  	} else {
  		struct inpcbporthead *porthash;
  		struct inpcbport *phd;
  		struct inpcb *match = NULL;
  		/*
  		 * Best fit PCB lookup.
  		 *
  		 * First see if this local port is in use by looking on the
  		 * port hash list.
  		 */
  		porthash = &pcbinfo->ipi_porthashbase[INP_PCBPORTHASH(lport,
  		    pcbinfo->ipi_porthashmask)];
  		LIST_FOREACH(phd, porthash, phd_hash) {
  			if (phd->phd_port == lport)
  				break;
  		}
  		if (phd != NULL) {
  			/*
  			 * Port is in use by one or more PCBs. Look for best
  			 * fit.
  			 */
  			LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
  				wildcard = 0;
  #if INET6
  				if (!(inp->inp_vflag & INP_IPV4))
  					continue;
  #endif /* INET6 */
  				if (inp->inp_faddr.s_addr != INADDR_ANY)
  					wildcard++;
  				if (inp->inp_laddr.s_addr != INADDR_ANY) {
  					if (laddr.s_addr == INADDR_ANY)
  						wildcard++;
  					else if (inp->inp_laddr.s_addr !=
  					    laddr.s_addr)
  						continue;
  				} else {
  					if (laddr.s_addr != INADDR_ANY)
  						wildcard++;
  				}
  				if (wildcard < matchwild) {
  					match = inp;
  					matchwild = wildcard;
  					if (matchwild == 0) {
  						break;
  					}
  				}
  			}
  		}
  		KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_END, match,
  		    0, 0, 0, 0);
  		return (match);
  	}
  }
  
  /*
   * Check if PCB exists in hash list.
   */
  int
  in_pcblookup_hash_exists(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      u_int fport_arg, struct in_addr laddr, u_int lport_arg, int wildcard,
      uid_t *uid, gid_t *gid, struct ifnet *ifp)
  {
  	struct inpcbhead *head;
  	struct inpcb *inp;
  	u_short fport = fport_arg, lport = lport_arg;
  	int found = 0;
  	struct inpcb *local_wild = NULL;
  #if INET6
  	struct inpcb *local_wild_mapped = NULL;
  #endif /* INET6 */
  
  	*uid = UID_MAX;
  	*gid = GID_MAX;
  
  	/*
  	 * We may have found the pcb in the last lookup - check this first.
  	 */
  
  	lck_rw_lock_shared(pcbinfo->ipi_lock);
  
  	/*
  	 * First look for an exact match.
  	 */
  	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr.s_addr, lport, fport,
  	    pcbinfo->ipi_hashmask)];
  	LIST_FOREACH(inp, head, inp_hash) {
  #if INET6
  		if (!(inp->inp_vflag & INP_IPV4))
  			continue;
  #endif /* INET6 */
  		if (inp_restricted_recv(inp, ifp))
  			continue;
  
  		if (inp->inp_faddr.s_addr == faddr.s_addr &&
  		    inp->inp_laddr.s_addr == laddr.s_addr &&
  		    inp->inp_fport == fport &&
  		    inp->inp_lport == lport) {
  			if ((found = (inp->inp_socket != NULL))) {
  				/*
  				 * Found.
  				 */
  				*uid = kauth_cred_getuid(
  				    inp->inp_socket->so_cred);
  				*gid = kauth_cred_getgid(
  				    inp->inp_socket->so_cred);
  			}
  			lck_rw_done(pcbinfo->ipi_lock);
  			return (found);
  		}
  	}
  
  	if (!wildcard) {
  		/*
  		 * Not found.
  		 */
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (0);
  	}
  
  	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
  	    pcbinfo->ipi_hashmask)];
  	LIST_FOREACH(inp, head, inp_hash) {
  #if INET6
  		if (!(inp->inp_vflag & INP_IPV4))
  			continue;
  #endif /* INET6 */
  		if (inp_restricted_recv(inp, ifp))
  			continue;
  
  		if (inp->inp_faddr.s_addr == INADDR_ANY &&
  		    inp->inp_lport == lport) {
  			if (inp->inp_laddr.s_addr == laddr.s_addr) {
  				if ((found = (inp->inp_socket != NULL))) {
  					*uid = kauth_cred_getuid(
  					    inp->inp_socket->so_cred);
  					*gid = kauth_cred_getgid(
  					    inp->inp_socket->so_cred);
  				}
  				lck_rw_done(pcbinfo->ipi_lock);
  				return (found);
  			} else if (inp->inp_laddr.s_addr == INADDR_ANY) {
  #if INET6
  				if (inp->inp_socket &&
  				    SOCK_CHECK_DOM(inp->inp_socket, PF_INET6))
  					local_wild_mapped = inp;
  				else
  #endif /* INET6 */
  					local_wild = inp;
  			}
  		}
  	}
  	if (local_wild == NULL) {
  #if INET6
  		if (local_wild_mapped != NULL) {
  			if ((found = (local_wild_mapped->inp_socket != NULL))) {
  				*uid = kauth_cred_getuid(
  				    local_wild_mapped->inp_socket->so_cred);
  				*gid = kauth_cred_getgid(
  				    local_wild_mapped->inp_socket->so_cred);
  			}
  			lck_rw_done(pcbinfo->ipi_lock);
  			return (found);
  		}
  #endif /* INET6 */
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (0);
  	}
  	if ((found = (local_wild->inp_socket != NULL))) {
  		*uid = kauth_cred_getuid(
  		    local_wild->inp_socket->so_cred);
  		*gid = kauth_cred_getgid(
  		    local_wild->inp_socket->so_cred);
  	}
  	lck_rw_done(pcbinfo->ipi_lock);
  	return (found);
  }
  
  /*
   * Lookup PCB in hash list.
   */
  struct inpcb *
  in_pcblookup_hash(struct inpcbinfo *pcbinfo, struct in_addr faddr,
      u_int fport_arg, struct in_addr laddr, u_int lport_arg, int wildcard,
      struct ifnet *ifp)
  {
  	struct inpcbhead *head;
  	struct inpcb *inp;
  	u_short fport = fport_arg, lport = lport_arg;
  	struct inpcb *local_wild = NULL;
  #if INET6
  	struct inpcb *local_wild_mapped = NULL;
  #endif /* INET6 */
  
  	/*
  	 * We may have found the pcb in the last lookup - check this first.
  	 */
  
  	lck_rw_lock_shared(pcbinfo->ipi_lock);
  
  	/*
  	 * First look for an exact match.
  	 */
  	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr.s_addr, lport, fport,
  	    pcbinfo->ipi_hashmask)];
  	LIST_FOREACH(inp, head, inp_hash) {
  #if INET6
  		if (!(inp->inp_vflag & INP_IPV4))
  			continue;
  #endif /* INET6 */
  		if (inp_restricted_recv(inp, ifp))
  			continue;
  
  		if (inp->inp_faddr.s_addr == faddr.s_addr &&
  		    inp->inp_laddr.s_addr == laddr.s_addr &&
  		    inp->inp_fport == fport &&
  		    inp->inp_lport == lport) {
  			/*
  			 * Found.
  			 */
  			if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) !=
  			    WNT_STOPUSING) {
  				lck_rw_done(pcbinfo->ipi_lock);
  				return (inp);
  			} else {
  				/* it's there but dead, say it isn't found */
  				lck_rw_done(pcbinfo->ipi_lock);
  				return (NULL);
  			}
  		}
  	}
  
  	if (!wildcard) {
  		/*
  		 * Not found.
  		 */
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (NULL);
  	}
  
  	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
  	    pcbinfo->ipi_hashmask)];
  	LIST_FOREACH(inp, head, inp_hash) {
  #if INET6
  		if (!(inp->inp_vflag & INP_IPV4))
  			continue;
  #endif /* INET6 */
  		if (inp_restricted_recv(inp, ifp))
  			continue;
  
  		if (inp->inp_faddr.s_addr == INADDR_ANY &&
  		    inp->inp_lport == lport) {
  			if (inp->inp_laddr.s_addr == laddr.s_addr) {
  				if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) !=
  				    WNT_STOPUSING) {
  					lck_rw_done(pcbinfo->ipi_lock);
  					return (inp);
  				} else {
  					/* it's dead; say it isn't found */
  					lck_rw_done(pcbinfo->ipi_lock);
  					return (NULL);
  				}
  			} else if (inp->inp_laddr.s_addr == INADDR_ANY) {
  #if INET6
  				if (SOCK_CHECK_DOM(inp->inp_socket, PF_INET6))
  					local_wild_mapped = inp;
  				else
  #endif /* INET6 */
  					local_wild = inp;
  			}
  		}
  	}
  	if (local_wild == NULL) {
  #if INET6
  		if (local_wild_mapped != NULL) {
  			if (in_pcb_checkstate(local_wild_mapped,
  			    WNT_ACQUIRE, 0) != WNT_STOPUSING) {
  				lck_rw_done(pcbinfo->ipi_lock);
  				return (local_wild_mapped);
  			} else {
  				/* it's dead; say it isn't found */
  				lck_rw_done(pcbinfo->ipi_lock);
  				return (NULL);
  			}
  		}
  #endif /* INET6 */
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (NULL);
  	}
  	if (in_pcb_checkstate(local_wild, WNT_ACQUIRE, 0) != WNT_STOPUSING) {
  		lck_rw_done(pcbinfo->ipi_lock);
  		return (local_wild);
  	}
  	/*
  	 * It's either not found or is already dead.
  	 */
  	lck_rw_done(pcbinfo->ipi_lock);
  	return (NULL);
  }
  
  /*
   * @brief	Insert PCB onto various hash lists.
   *
   * @param	inp Pointer to internet protocol control block
   * @param	locked	Implies if ipi_lock (protecting pcb list)
   * 		is already locked or not.
   *
   * @return	int error on failure and 0 on success
   */
  int
  in_pcbinshash(struct inpcb *inp, int locked)
  {
  	struct inpcbhead *pcbhash;
  	struct inpcbporthead *pcbporthash;
  	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
  	struct inpcbport *phd;
  	u_int32_t hashkey_faddr;
  
  	if (!locked) {
  		if (!lck_rw_try_lock_exclusive(pcbinfo->ipi_lock)) {
  			/*
  			 * Lock inversion issue, mostly with udp
  			 * multicast packets
  			 */
  			socket_unlock(inp->inp_socket, 0);
  			lck_rw_lock_exclusive(pcbinfo->ipi_lock);
  			socket_lock(inp->inp_socket, 0);
  		}
  	}
  
  	/*
  	 * This routine or its caller may have given up
  	 * socket's protocol lock briefly.
  	 * During that time the socket may have been dropped.
  	 * Safe-guarding against that.
  	 */
  	if (inp->inp_state == INPCB_STATE_DEAD) {
  		if (!locked) {
  			lck_rw_done(pcbinfo->ipi_lock);
  		}
  		return (ECONNABORTED);
  	}
  
  
  #if INET6
  	if (inp->inp_vflag & INP_IPV6)
  		hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
  	else
  #endif /* INET6 */
  		hashkey_faddr = inp->inp_faddr.s_addr;
  
  	inp->inp_hash_element = INP_PCBHASH(hashkey_faddr, inp->inp_lport,
  	    inp->inp_fport, pcbinfo->ipi_hashmask);
  
  	pcbhash = &pcbinfo->ipi_hashbase[inp->inp_hash_element];
  
  	pcbporthash = &pcbinfo->ipi_porthashbase[INP_PCBPORTHASH(inp->inp_lport,
  	    pcbinfo->ipi_porthashmask)];
  
  	/*
  	 * Go through port list and look for a head for this lport.
  	 */
  	LIST_FOREACH(phd, pcbporthash, phd_hash) {
  		if (phd->phd_port == inp->inp_lport)
  			break;
  	}
  
  	/*
  	 * If none exists, malloc one and tack it on.
  	 */
  	if (phd == NULL) {
  		MALLOC(phd, struct inpcbport *, sizeof (struct inpcbport),
  		    M_PCB, M_WAITOK);
  		if (phd == NULL) {
  			if (!locked)
  				lck_rw_done(pcbinfo->ipi_lock);
  			return (ENOBUFS); /* XXX */
  		}
  		phd->phd_port = inp->inp_lport;
  		LIST_INIT(&phd->phd_pcblist);
  		LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
  	}
  
  	VERIFY(!(inp->inp_flags2 & INP2_INHASHLIST));
  
  
  	inp->inp_phd = phd;
  	LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
  	LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
  	inp->inp_flags2 |= INP2_INHASHLIST;
  
  	if (!locked)
  		lck_rw_done(pcbinfo->ipi_lock);
  
  #if NECP
  	// This call catches the original setting of the local address
  	inp_update_necp_policy(inp, NULL, NULL, 0);
  #endif /* NECP */
  
  	return (0);
  }
  
  /*
   * Move PCB to the proper hash bucket when { faddr, fport } have  been
   * changed. NOTE: This does not handle the case of the lport changing (the
   * hashed port list would have to be updated as well), so the lport must
   * not change after in_pcbinshash() has been called.
   */
  void
  in_pcbrehash(struct inpcb *inp)
  {
  	struct inpcbhead *head;
  	u_int32_t hashkey_faddr;
  
  #if INET6
  	if (inp->inp_vflag & INP_IPV6)
  		hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
  	else
  #endif /* INET6 */
  		hashkey_faddr = inp->inp_faddr.s_addr;
  
  	inp->inp_hash_element = INP_PCBHASH(hashkey_faddr, inp->inp_lport,
  	    inp->inp_fport, inp->inp_pcbinfo->ipi_hashmask);
  	head = &inp->inp_pcbinfo->ipi_hashbase[inp->inp_hash_element];
  
  	if (inp->inp_flags2 & INP2_INHASHLIST) {
  		LIST_REMOVE(inp, inp_hash);
  		inp->inp_flags2 &= ~INP2_INHASHLIST;
  	}
  
  	VERIFY(!(inp->inp_flags2 & INP2_INHASHLIST));
  	LIST_INSERT_HEAD(head, inp, inp_hash);
  	inp->inp_flags2 |= INP2_INHASHLIST;
  
  #if NECP
  	// This call catches updates to the remote addresses
  	inp_update_necp_policy(inp, NULL, NULL, 0);
  #endif /* NECP */
  }
  
  /*
   * Remove PCB from various lists.
   * Must be called pcbinfo lock is held in exclusive mode.
   */
  void
  in_pcbremlists(struct inpcb *inp)
  {
  	inp->inp_gencnt = ++inp->inp_pcbinfo->ipi_gencnt;
  
  	/*
  	 * Check if it's in hashlist -- an inp is placed in hashlist when
  	 * it's local port gets assigned. So it should also be present
  	 * in the port list.
  	 */
  	if (inp->inp_flags2 & INP2_INHASHLIST) {
  		struct inpcbport *phd = inp->inp_phd;
  
  		VERIFY(phd != NULL && inp->inp_lport > 0);
  
  		LIST_REMOVE(inp, inp_hash);
  		inp->inp_hash.le_next = NULL;
  		inp->inp_hash.le_prev = NULL;
  
  		LIST_REMOVE(inp, inp_portlist);
  		inp->inp_portlist.le_next = NULL;
  		inp->inp_portlist.le_prev = NULL;
  		if (LIST_EMPTY(&phd->phd_pcblist)) {
  			LIST_REMOVE(phd, phd_hash);
  			FREE(phd, M_PCB);
  		}
  		inp->inp_phd = NULL;
  		inp->inp_flags2 &= ~INP2_INHASHLIST;
  	}
  	VERIFY(!(inp->inp_flags2 & INP2_INHASHLIST));
  
  	if (inp->inp_flags2 & INP2_TIMEWAIT) {
  		/* Remove from time-wait queue */
  		tcp_remove_from_time_wait(inp);
  		inp->inp_flags2 &= ~INP2_TIMEWAIT;
  		VERIFY(inp->inp_pcbinfo->ipi_twcount != 0);
  		inp->inp_pcbinfo->ipi_twcount--;
  	} else {
  		/* Remove from global inp list if it is not time-wait */
  		LIST_REMOVE(inp, inp_list);
  	}
  
  	if (inp->inp_flags2 & INP2_IN_FCTREE) {
  		inp_fc_getinp(inp->inp_flowhash, (INPFC_SOLOCKED|INPFC_REMOVE));
  		VERIFY(!(inp->inp_flags2 & INP2_IN_FCTREE));
  	}
  
  	inp->inp_pcbinfo->ipi_count--;
  }
  
  /*
   * Mechanism used to defer the memory release of PCBs
   * The pcb list will contain the pcb until the reaper can clean it up if
   * the following conditions are met:
   *	1) state "DEAD",
   *	2) wantcnt is STOPUSING
   *	3) usecount is 0
   * This function will be called to either mark the pcb as
   */
  int
  in_pcb_checkstate(struct inpcb *pcb, int mode, int locked)
  {
  	volatile UInt32 *wantcnt = (volatile UInt32 *)&pcb->inp_wantcnt;
  	UInt32 origwant;
  	UInt32 newwant;
  
  	switch (mode) {
  	case WNT_STOPUSING:
  		/*
  		 * Try to mark the pcb as ready for recycling.  CAS with
  		 * STOPUSING, if success we're good, if it's in use, will
  		 * be marked later
  		 */
  		if (locked == 0)
  			socket_lock(pcb->inp_socket, 1);
  		pcb->inp_state = INPCB_STATE_DEAD;
  
  stopusing:
  		if (pcb->inp_socket->so_usecount < 0) {
  			panic("%s: pcb=%p so=%p usecount is negative\n",
  			    __func__, pcb, pcb->inp_socket);
  			/* NOTREACHED */
  		}
  		if (locked == 0)
  			socket_unlock(pcb->inp_socket, 1);
  
  		inpcb_gc_sched(pcb->inp_pcbinfo, INPCB_TIMER_FAST);
  
  		origwant = *wantcnt;
  		if ((UInt16) origwant == 0xffff) /* should stop using */
  			return (WNT_STOPUSING);
  		newwant = 0xffff;
  		if ((UInt16) origwant == 0) {
  			/* try to mark it as unsuable now */
  			OSCompareAndSwap(origwant, newwant, wantcnt);
  		}
  		return (WNT_STOPUSING);
  
  	case WNT_ACQUIRE:
  		/*
  		 * Try to increase reference to pcb.  If WNT_STOPUSING
  		 * should bail out.  If socket state DEAD, try to set count
  		 * to STOPUSING, return failed otherwise increase cnt.
  		 */
  		do {
  			origwant = *wantcnt;
  			if ((UInt16) origwant == 0xffff) {
  				/* should stop using */
  				return (WNT_STOPUSING);
  			}
  			newwant = origwant + 1;
  		} while (!OSCompareAndSwap(origwant, newwant, wantcnt));
  		return (WNT_ACQUIRE);
  
  	case WNT_RELEASE:
  		/*
  		 * Release reference.  If result is null and pcb state
  		 * is DEAD, set wanted bit to STOPUSING
  		 */
  		if (locked == 0)
  			socket_lock(pcb->inp_socket, 1);
  
  		do {
  			origwant = *wantcnt;
  			if ((UInt16) origwant == 0x0) {
  				panic("%s: pcb=%p release with zero count",
  				    __func__, pcb);
  				/* NOTREACHED */
  			}
  			if ((UInt16) origwant == 0xffff) {
  				/* should stop using */
  				if (locked == 0)
  					socket_unlock(pcb->inp_socket, 1);
  				return (WNT_STOPUSING);
  			}
  			newwant = origwant - 1;
  		} while (!OSCompareAndSwap(origwant, newwant, wantcnt));
  
  		if (pcb->inp_state == INPCB_STATE_DEAD)
  			goto stopusing;
  		if (pcb->inp_socket->so_usecount < 0) {
  			panic("%s: RELEASE pcb=%p so=%p usecount is negative\n",
  			    __func__, pcb, pcb->inp_socket);
  			/* NOTREACHED */
  		}
  
  		if (locked == 0)
  			socket_unlock(pcb->inp_socket, 1);
  		return (WNT_RELEASE);
  
  	default:
  		panic("%s: so=%p not a valid state =%x\n", __func__,
  		    pcb->inp_socket, mode);
  		/* NOTREACHED */
  	}
  
  	/* NOTREACHED */
  	return (mode);
  }
  
  /*
   * inpcb_to_compat copies specific bits of an inpcb to a inpcb_compat.
   * The inpcb_compat data structure is passed to user space and must
   * not change. We intentionally avoid copying pointers.
   */
  void
  inpcb_to_compat(struct inpcb *inp, struct inpcb_compat *inp_compat)
  {
  	bzero(inp_compat, sizeof (*inp_compat));
  	inp_compat->inp_fport = inp->inp_fport;
  	inp_compat->inp_lport = inp->inp_lport;
  	inp_compat->nat_owner = 0;
  	inp_compat->nat_cookie = 0;
  	inp_compat->inp_gencnt = inp->inp_gencnt;
  	inp_compat->inp_flags = inp->inp_flags;
  	inp_compat->inp_flow = inp->inp_flow;
  	inp_compat->inp_vflag = inp->inp_vflag;
  	inp_compat->inp_ip_ttl = inp->inp_ip_ttl;
  	inp_compat->inp_ip_p = inp->inp_ip_p;
  	inp_compat->inp_dependfaddr.inp6_foreign =
  	    inp->inp_dependfaddr.inp6_foreign;
  	inp_compat->inp_dependladdr.inp6_local =
  	    inp->inp_dependladdr.inp6_local;
  	inp_compat->inp_depend4.inp4_ip_tos = inp->inp_depend4.inp4_ip_tos;
  	inp_compat->inp_depend6.inp6_hlim = 0;
  	inp_compat->inp_depend6.inp6_cksum = inp->inp_depend6.inp6_cksum;
  	inp_compat->inp_depend6.inp6_ifindex = 0;
  	inp_compat->inp_depend6.inp6_hops = inp->inp_depend6.inp6_hops;
  }
  
  #if !CONFIG_EMBEDDED
  void
  inpcb_to_xinpcb64(struct inpcb *inp, struct xinpcb64 *xinp)
  {
  	xinp->inp_fport = inp->inp_fport;
  	xinp->inp_lport = inp->inp_lport;
  	xinp->inp_gencnt = inp->inp_gencnt;
  	xinp->inp_flags = inp->inp_flags;
  	xinp->inp_flow = inp->inp_flow;
  	xinp->inp_vflag = inp->inp_vflag;
  	xinp->inp_ip_ttl = inp->inp_ip_ttl;
  	xinp->inp_ip_p = inp->inp_ip_p;
  	xinp->inp_dependfaddr.inp6_foreign = inp->inp_dependfaddr.inp6_foreign;
  	xinp->inp_dependladdr.inp6_local = inp->inp_dependladdr.inp6_local;
  	xinp->inp_depend4.inp4_ip_tos = inp->inp_depend4.inp4_ip_tos;
  	xinp->inp_depend6.inp6_hlim = 0;
  	xinp->inp_depend6.inp6_cksum = inp->inp_depend6.inp6_cksum;
  	xinp->inp_depend6.inp6_ifindex = 0;
  	xinp->inp_depend6.inp6_hops = inp->inp_depend6.inp6_hops;
  }
  #endif /* !CONFIG_EMBEDDED */
  
  /*
   * The following routines implement this scheme:
   *
   * Callers of ip_output() that intend to cache the route in the inpcb pass
   * a local copy of the struct route to ip_output().  Using a local copy of
   * the cached route significantly simplifies things as IP no longer has to
   * worry about having exclusive access to the passed in struct route, since
   * it's defined in the caller's stack; in essence, this allows for a lock-
   * less operation when updating the struct route at the IP level and below,
   * whenever necessary. The scheme works as follows:
   *
   * Prior to dropping the socket's lock and calling ip_output(), the caller
   * copies the struct route from the inpcb into its stack, and adds a reference
   * to the cached route entry, if there was any.  The socket's lock is then
   * dropped and ip_output() is called with a pointer to the copy of struct
   * route defined on the stack (not to the one in the inpcb.)
   *
   * Upon returning from ip_output(), the caller then acquires the socket's
   * lock and synchronizes the cache; if there is no route cached in the inpcb,
   * it copies the local copy of struct route (which may or may not contain any
   * route) back into the cache; otherwise, if the inpcb has a route cached in
   * it, the one in the local copy will be freed, if there's any.  Trashing the
   * cached route in the inpcb can be avoided because ip_output() is single-
   * threaded per-PCB (i.e. multiple transmits on a PCB are always serialized
   * by the socket/transport layer.)
   */
  void
  inp_route_copyout(struct inpcb *inp, struct route *dst)
  {
  	struct route *src = &inp->inp_route;
  
  	socket_lock_assert_owned(inp->inp_socket);
  
  	/*
  	 * If the route in the PCB is stale or not for IPv4, blow it away;
  	 * this is possible in the case of IPv4-mapped address case.
  	 */
  	if (ROUTE_UNUSABLE(src) || rt_key(src->ro_rt)->sa_family != AF_INET)
  		ROUTE_RELEASE(src);
  
  	route_copyout(dst, src, sizeof (*dst));
  }
  
  void
  inp_route_copyin(struct inpcb *inp, struct route *src)
  {
  	struct route *dst = &inp->inp_route;
  
  	socket_lock_assert_owned(inp->inp_socket);
  
  	/* Minor sanity check */
  	if (src->ro_rt != NULL && rt_key(src->ro_rt)->sa_family != AF_INET)
  		panic("%s: wrong or corrupted route: %p", __func__, src);
  
  	route_copyin(src, dst, sizeof (*src));
  }
  
  /*
   * Handler for setting IP_BOUND_IF/IPV6_BOUND_IF socket option.
   */
  int
  inp_bindif(struct inpcb *inp, unsigned int ifscope, struct ifnet **pifp)
  {
  	struct ifnet *ifp = NULL;
  
  	ifnet_head_lock_shared();
  	if ((ifscope > (unsigned)if_index) || (ifscope != IFSCOPE_NONE &&
  	    (ifp = ifindex2ifnet[ifscope]) == NULL)) {
  		ifnet_head_done();
  		return (ENXIO);
  	}
  	ifnet_head_done();
  
  	VERIFY(ifp != NULL || ifscope == IFSCOPE_NONE);
  
  	/*
  	 * A zero interface scope value indicates an "unbind".
  	 * Otherwise, take in whatever value the app desires;
  	 * the app may already know the scope (or force itself
  	 * to such a scope) ahead of time before the interface
  	 * gets attached.  It doesn't matter either way; any
  	 * route lookup from this point on will require an
  	 * exact match for the embedded interface scope.
  	 */
  	inp->inp_boundifp = ifp;
  	if (inp->inp_boundifp == NULL)
  		inp->inp_flags &= ~INP_BOUND_IF;
  	else
  		inp->inp_flags |= INP_BOUND_IF;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  
  	if (pifp != NULL)
  		*pifp = ifp;
  
  	return (0);
  }
  
  /*
   * Handler for setting IP_NO_IFT_CELLULAR/IPV6_NO_IFT_CELLULAR socket option,
   * as well as for setting PROC_UUID_NO_CELLULAR policy.
   */
  void
  inp_set_nocellular(struct inpcb *inp)
  {
  	inp->inp_flags |= INP_NO_IFT_CELLULAR;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  /*
   * Handler for clearing IP_NO_IFT_CELLULAR/IPV6_NO_IFT_CELLULAR socket option,
   * as well as for clearing PROC_UUID_NO_CELLULAR policy.
   */
  void
  inp_clear_nocellular(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  
  	/*
  	 * SO_RESTRICT_DENY_CELLULAR socket restriction issued on the socket
  	 * has a higher precendence than INP_NO_IFT_CELLULAR.  Clear the flag
  	 * if and only if the socket is unrestricted.
  	 */
  	if (so != NULL && !(so->so_restrictions & SO_RESTRICT_DENY_CELLULAR)) {
  		inp->inp_flags &= ~INP_NO_IFT_CELLULAR;
  
  		/* Blow away any cached route in the PCB */
  		ROUTE_RELEASE(&inp->inp_route);
  	}
  }
  
  void
  inp_set_noexpensive(struct inpcb *inp)
  {
  	inp->inp_flags2 |= INP2_NO_IFF_EXPENSIVE;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  void
  inp_set_awdl_unrestricted(struct inpcb *inp)
  {
  	inp->inp_flags2 |= INP2_AWDL_UNRESTRICTED;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  boolean_t
  inp_get_awdl_unrestricted(struct inpcb *inp)
  {
  	return (inp->inp_flags2 & INP2_AWDL_UNRESTRICTED) ? TRUE : FALSE;
  }
  
  void
  inp_clear_awdl_unrestricted(struct inpcb *inp)
  {
  	inp->inp_flags2 &= ~INP2_AWDL_UNRESTRICTED;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  void
  inp_set_intcoproc_allowed(struct inpcb *inp)
  {
  	inp->inp_flags2 |= INP2_INTCOPROC_ALLOWED;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  boolean_t
  inp_get_intcoproc_allowed(struct inpcb *inp)
  {
  	return (inp->inp_flags2 & INP2_INTCOPROC_ALLOWED) ? TRUE : FALSE;
  }
  
  void
  inp_clear_intcoproc_allowed(struct inpcb *inp)
  {
  	inp->inp_flags2 &= ~INP2_INTCOPROC_ALLOWED;
  
  	/* Blow away any cached route in the PCB */
  	ROUTE_RELEASE(&inp->inp_route);
  }
  
  #if NECP
  /*
   * Called when PROC_UUID_NECP_APP_POLICY is set.
   */
  void
  inp_set_want_app_policy(struct inpcb *inp)
  {
  	inp->inp_flags2 |= INP2_WANT_APP_POLICY;
  }
  
  /*
   * Called when PROC_UUID_NECP_APP_POLICY is cleared.
   */
  void
  inp_clear_want_app_policy(struct inpcb *inp)
  {
  	inp->inp_flags2 &= ~INP2_WANT_APP_POLICY;
  }
  #endif /* NECP */
  
  /*
   * Calculate flow hash for an inp, used by an interface to identify a
   * flow. When an interface provides flow control advisory, this flow
   * hash is used as an identifier.
   */
  u_int32_t
  inp_calc_flowhash(struct inpcb *inp)
  {
  	struct inp_flowhash_key fh __attribute__((aligned(8)));
  	u_int32_t flowhash = 0;
  	struct inpcb *tmp_inp = NULL;
  
  	if (inp_hash_seed == 0)
  		inp_hash_seed = RandomULong();
  
  	bzero(&fh, sizeof (fh));
  
  	bcopy(&inp->inp_dependladdr, &fh.infh_laddr, sizeof (fh.infh_laddr));
  	bcopy(&inp->inp_dependfaddr, &fh.infh_faddr, sizeof (fh.infh_faddr));
  
  	fh.infh_lport = inp->inp_lport;
  	fh.infh_fport = inp->inp_fport;
  	fh.infh_af = (inp->inp_vflag & INP_IPV6) ? AF_INET6 : AF_INET;
  	fh.infh_proto = inp->inp_ip_p;
  	fh.infh_rand1 = RandomULong();
  	fh.infh_rand2 = RandomULong();
  
  try_again:
  	flowhash = net_flowhash(&fh, sizeof (fh), inp_hash_seed);
  	if (flowhash == 0) {
  		/* try to get a non-zero flowhash */
  		inp_hash_seed = RandomULong();
  		goto try_again;
  	}
  
  	inp->inp_flowhash = flowhash;
  
  	/* Insert the inp into inp_fc_tree */
  	lck_mtx_lock_spin(&inp_fc_lck);
  	tmp_inp = RB_FIND(inp_fc_tree, &inp_fc_tree, inp);
  	if (tmp_inp != NULL) {
  		/*
  		 * There is a different inp with the same flowhash.
  		 * There can be a collision on flow hash but the
  		 * probability is low.  Let's recompute the
  		 * flowhash.
  		 */
  		lck_mtx_unlock(&inp_fc_lck);
  		/* recompute hash seed */
  		inp_hash_seed = RandomULong();
  		goto try_again;
  	}
  
  	RB_INSERT(inp_fc_tree, &inp_fc_tree, inp);
  	inp->inp_flags2 |= INP2_IN_FCTREE;
  	lck_mtx_unlock(&inp_fc_lck);
  
  	return (flowhash);
  }
  
  void
  inp_flowadv(uint32_t flowhash)
  {
  	struct inpcb *inp;
  
  	inp = inp_fc_getinp(flowhash, 0);
  
  	if (inp == NULL)
  		return;
  	inp_fc_feedback(inp);
  }
  
  /*
   * Function to compare inp_fc_entries in inp flow control tree
   */
  static inline int
  infc_cmp(const struct inpcb *inp1, const struct inpcb *inp2)
  {
  	return (memcmp(&(inp1->inp_flowhash), &(inp2->inp_flowhash),
  	    sizeof(inp1->inp_flowhash)));
  }
  
  static struct inpcb *
  inp_fc_getinp(u_int32_t flowhash, u_int32_t flags)
  {
  	struct inpcb *inp = NULL;
  	int locked = (flags & INPFC_SOLOCKED) ? 1 : 0;
  
  	lck_mtx_lock_spin(&inp_fc_lck);
  	key_inp.inp_flowhash = flowhash;
  	inp = RB_FIND(inp_fc_tree, &inp_fc_tree, &key_inp);
  	if (inp == NULL) {
  		/* inp is not present, return */
  		lck_mtx_unlock(&inp_fc_lck);
  		return (NULL);
  	}
  
  	if (flags & INPFC_REMOVE) {
  		RB_REMOVE(inp_fc_tree, &inp_fc_tree, inp);
  		lck_mtx_unlock(&inp_fc_lck);
  
  		bzero(&(inp->infc_link), sizeof (inp->infc_link));
  		inp->inp_flags2 &= ~INP2_IN_FCTREE;
  		return (NULL);
  	}
  
  	if (in_pcb_checkstate(inp, WNT_ACQUIRE, locked) == WNT_STOPUSING)
  		inp = NULL;
  	lck_mtx_unlock(&inp_fc_lck);
  
  	return (inp);
  }
  
  static void
  inp_fc_feedback(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  
  	/* we already hold a want_cnt on this inp, socket can't be null */
  	VERIFY(so != NULL);
  	socket_lock(so, 1);
  
  	if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
  		socket_unlock(so, 1);
  		return;
  	}
  
  	if (inp->inp_sndinprog_cnt > 0)
  		inp->inp_flags |= INP_FC_FEEDBACK;
  
  	/*
  	 * Return if the connection is not in flow-controlled state.
  	 * This can happen if the connection experienced
  	 * loss while it was in flow controlled state
  	 */
  	if (!INP_WAIT_FOR_IF_FEEDBACK(inp)) {
  		socket_unlock(so, 1);
  		return;
  	}
  	inp_reset_fc_state(inp);
  
  	if (SOCK_TYPE(so) == SOCK_STREAM)
  		inp_fc_unthrottle_tcp(inp);
  
  	socket_unlock(so, 1);
  }
  
  void
  inp_reset_fc_state(struct inpcb *inp)
  {
  	struct socket *so = inp->inp_socket;
  	int suspended = (INP_IS_FLOW_SUSPENDED(inp)) ? 1 : 0;
  	int needwakeup = (INP_WAIT_FOR_IF_FEEDBACK(inp)) ? 1 : 0;
  
  	inp->inp_flags &= ~(INP_FLOW_CONTROLLED | INP_FLOW_SUSPENDED);
  
  	if (suspended) {
  		so->so_flags &= ~(SOF_SUSPENDED);
  		soevent(so, (SO_FILT_HINT_LOCKED | SO_FILT_HINT_RESUME));
  	}
  
  	/* Give a write wakeup to unblock the socket */
  	if (needwakeup)
  		sowwakeup(so);
  }
  
  int
  inp_set_fc_state(struct inpcb *inp, int advcode)
  {
  	struct inpcb *tmp_inp = NULL;
  	/*
  	 * If there was a feedback from the interface when
  	 * send operation was in progress, we should ignore
  	 * this flow advisory to avoid a race between setting
  	 * flow controlled state and receiving feedback from
  	 * the interface
  	 */
  	if (inp->inp_flags & INP_FC_FEEDBACK)
  		return (0);
  
  	inp->inp_flags &= ~(INP_FLOW_CONTROLLED | INP_FLOW_SUSPENDED);
  	if ((tmp_inp = inp_fc_getinp(inp->inp_flowhash,
  	    INPFC_SOLOCKED)) != NULL) {
  		if (in_pcb_checkstate(tmp_inp, WNT_RELEASE, 1) == WNT_STOPUSING)
  			return (0);
  		VERIFY(tmp_inp == inp);
  		switch (advcode) {
  		case FADV_FLOW_CONTROLLED:
  			inp->inp_flags |= INP_FLOW_CONTROLLED;
  			break;
  		case FADV_SUSPENDED:
  			inp->inp_flags |= INP_FLOW_SUSPENDED;
  			soevent(inp->inp_socket,
  			    (SO_FILT_HINT_LOCKED | SO_FILT_HINT_SUSPEND));
  
  			/* Record the fact that suspend event was sent */
  			inp->inp_socket->so_flags |= SOF_SUSPENDED;
  			break;
  		}
  		return (1);
  	}
  	return (0);
  }
  
  /*
   * Handler for SO_FLUSH socket option.
   */
  int
  inp_flush(struct inpcb *inp, int optval)
  {
  	u_int32_t flowhash = inp->inp_flowhash;
  	struct ifnet *rtifp, *oifp;
  
  	/* Either all classes or one of the valid ones */
  	if (optval != SO_TC_ALL && !SO_VALID_TC(optval))
  		return (EINVAL);
  
  	/* We need a flow hash for identification */
  	if (flowhash == 0)
  		return (0);
  
  	/* Grab the interfaces from the route and pcb */
  	rtifp = ((inp->inp_route.ro_rt != NULL) ?
  	    inp->inp_route.ro_rt->rt_ifp : NULL);
  	oifp = inp->inp_last_outifp;
  
  	if (rtifp != NULL)
  		if_qflush_sc(rtifp, so_tc2msc(optval), flowhash, NULL, NULL, 0);
  	if (oifp != NULL && oifp != rtifp)
  		if_qflush_sc(oifp, so_tc2msc(optval), flowhash, NULL, NULL, 0);
  
  	return (0);
  }
  
  /*
   * Clear the INP_INADDR_ANY flag (special case for PPP only)
   */
  void
  inp_clear_INP_INADDR_ANY(struct socket *so)
  {
  	struct inpcb *inp = NULL;
  
  	socket_lock(so, 1);
  	inp = sotoinpcb(so);
  	if (inp) {
  		inp->inp_flags &= ~INP_INADDR_ANY;
  	}
  	socket_unlock(so, 1);
  }
  
  void
  inp_get_soprocinfo(struct inpcb *inp, struct so_procinfo *soprocinfo)
  {
  	struct socket *so = inp->inp_socket;
  
  	soprocinfo->spi_pid = so->last_pid;
  	if (so->last_pid != 0)
  		uuid_copy(soprocinfo->spi_uuid, so->last_uuid);
  	/*
  	 * When not delegated, the effective pid is the same as the real pid
  	 */
  	if (so->so_flags & SOF_DELEGATED) {
  		soprocinfo->spi_delegated = 1;
  		soprocinfo->spi_epid = so->e_pid;
  		uuid_copy(soprocinfo->spi_euuid, so->e_uuid);
  	} else {
  		soprocinfo->spi_delegated = 0;
  		soprocinfo->spi_epid = so->last_pid;
  	}
  }
  
  int
  inp_findinpcb_procinfo(struct inpcbinfo *pcbinfo, uint32_t flowhash,
      struct so_procinfo *soprocinfo)
  {
  	struct inpcb *inp = NULL;
  	int found = 0;
  
  	bzero(soprocinfo, sizeof (struct so_procinfo));
  
  	if (!flowhash)
  		return (-1);
  
  	lck_rw_lock_shared(pcbinfo->ipi_lock);
  	LIST_FOREACH(inp, pcbinfo->ipi_listhead, inp_list) {
  		if (inp->inp_state != INPCB_STATE_DEAD &&
  		    inp->inp_socket != NULL &&
  		    inp->inp_flowhash == flowhash) {
  			found = 1;
  			inp_get_soprocinfo(inp, soprocinfo);
  			break;
  		}
  	}
  	lck_rw_done(pcbinfo->ipi_lock);
  
  	return (found);
  }
  
  #if CONFIG_PROC_UUID_POLICY
  static void
  inp_update_cellular_policy(struct inpcb *inp, boolean_t set)
  {
  	struct socket *so = inp->inp_socket;
  	int before, after;
  
  	VERIFY(so != NULL);
  	VERIFY(inp->inp_state != INPCB_STATE_DEAD);
  
  	before = INP_NO_CELLULAR(inp);
  	if (set) {
  		inp_set_nocellular(inp);
  	} else {
  		inp_clear_nocellular(inp);
  	}
  	after = INP_NO_CELLULAR(inp);
  	if (net_io_policy_log && (before != after)) {
  		static const char *ok = "OK";
  		static const char *nok = "NOACCESS";
  		uuid_string_t euuid_buf;
  		pid_t epid;
  
  		if (so->so_flags & SOF_DELEGATED) {
  			uuid_unparse(so->e_uuid, euuid_buf);
  			epid = so->e_pid;
  		} else {
  			uuid_unparse(so->last_uuid, euuid_buf);
  			epid = so->last_pid;
  		}
  
  		/* allow this socket to generate another notification event */
  		so->so_ifdenied_notifies = 0;
  
  		log(LOG_DEBUG, "%s: so 0x%llx [%d,%d] epid %d "
  		    "euuid %s%s %s->%s\n", __func__,
  		    (uint64_t)VM_KERNEL_ADDRPERM(so), SOCK_DOM(so),
  		    SOCK_TYPE(so), epid, euuid_buf,
  		    (so->so_flags & SOF_DELEGATED) ?
  		    " [delegated]" : "",
  		    ((before < after) ? ok : nok),
  		    ((before < after) ? nok : ok));
  	}
  }
  
  #if NECP
  static void
  inp_update_necp_want_app_policy(struct inpcb *inp, boolean_t set)
  {
  	struct socket *so = inp->inp_socket;
  	int before, after;
  
  	VERIFY(so != NULL);
  	VERIFY(inp->inp_state != INPCB_STATE_DEAD);
  
  	before = (inp->inp_flags2 & INP2_WANT_APP_POLICY);
  	if (set) {
  		inp_set_want_app_policy(inp);
  	} else {
  		inp_clear_want_app_policy(inp);
  	}
  	after = (inp->inp_flags2 & INP2_WANT_APP_POLICY);
  	if (net_io_policy_log && (before != after)) {
  		static const char *wanted = "WANTED";
  		static const char *unwanted = "UNWANTED";
  		uuid_string_t euuid_buf;
  		pid_t epid;
  
  		if (so->so_flags & SOF_DELEGATED) {
  			uuid_unparse(so->e_uuid, euuid_buf);
  			epid = so->e_pid;
  		} else {
  			uuid_unparse(so->last_uuid, euuid_buf);
  			epid = so->last_pid;
  		}
  
  		log(LOG_DEBUG, "%s: so 0x%llx [%d,%d] epid %d "
  		    "euuid %s%s %s->%s\n", __func__,
  		    (uint64_t)VM_KERNEL_ADDRPERM(so), SOCK_DOM(so),
  		    SOCK_TYPE(so), epid, euuid_buf,
  		    (so->so_flags & SOF_DELEGATED) ?
  		    " [delegated]" : "",
  		    ((before < after) ? unwanted : wanted),
  		    ((before < after) ? wanted : unwanted));
  	}
  }
  #endif /* NECP */
  #endif /* !CONFIG_PROC_UUID_POLICY */
  
  #if NECP
  void
  inp_update_necp_policy(struct inpcb *inp, struct sockaddr *override_local_addr, struct sockaddr *override_remote_addr, u_int override_bound_interface)
  {
  	necp_socket_find_policy_match(inp, override_local_addr, override_remote_addr, override_bound_interface);
  	if (necp_socket_should_rescope(inp) &&
  		inp->inp_lport == 0 &&
  		inp->inp_laddr.s_addr == INADDR_ANY &&
  		IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
  		// If we should rescope, and the socket is not yet bound
  		inp_bindif(inp, necp_socket_get_rescope_if_index(inp), NULL);
  	}
  }
  #endif /* NECP */
  
  int
  inp_update_policy(struct inpcb *inp)
  {
  #if CONFIG_PROC_UUID_POLICY
  	struct socket *so = inp->inp_socket;
  	uint32_t pflags = 0;
  	int32_t ogencnt;
  	int err = 0;
  
  	if (!net_io_policy_uuid ||
  	    so == NULL || inp->inp_state == INPCB_STATE_DEAD)
  		return (0);
  
  	/*
  	 * Kernel-created sockets that aren't delegating other sockets
  	 * are currently exempted from UUID policy checks.
  	 */
  	if (so->last_pid == 0 && !(so->so_flags & SOF_DELEGATED))
  		return (0);
  
  	ogencnt = so->so_policy_gencnt;
  	err = proc_uuid_policy_lookup(((so->so_flags & SOF_DELEGATED) ?
  	    so->e_uuid : so->last_uuid), &pflags, &so->so_policy_gencnt);
  
  	/*
  	 * Discard cached generation count if the entry is gone (ENOENT),
  	 * so that we go thru the checks below.
  	 */
  	if (err == ENOENT && ogencnt != 0)
  		so->so_policy_gencnt = 0;
  
  	/*
  	 * If the generation count has changed, inspect the policy flags
  	 * and act accordingly.  If a policy flag was previously set and
  	 * the UUID is no longer present in the table (ENOENT), treat it
  	 * as if the flag has been cleared.
  	 */
  	if ((err == 0 || err == ENOENT) && ogencnt != so->so_policy_gencnt) {
  		/* update cellular policy for this socket */
  		if (err == 0 && (pflags & PROC_UUID_NO_CELLULAR)) {
  			inp_update_cellular_policy(inp, TRUE);
  		} else if (!(pflags & PROC_UUID_NO_CELLULAR)) {
  			inp_update_cellular_policy(inp, FALSE);
  		}
  #if NECP
  		/* update necp want app policy for this socket */
  		if (err == 0 && (pflags & PROC_UUID_NECP_APP_POLICY)) {
  			inp_update_necp_want_app_policy(inp, TRUE);
  		} else if (!(pflags & PROC_UUID_NECP_APP_POLICY)) {
  			inp_update_necp_want_app_policy(inp, FALSE);
  		}
  #endif /* NECP */
  	}
  
  	return ((err == ENOENT) ? 0 : err);
  #else /* !CONFIG_PROC_UUID_POLICY */
  #pragma unused(inp)
  	return (0);
  #endif /* !CONFIG_PROC_UUID_POLICY */
  }
  
  static unsigned int log_restricted;
  SYSCTL_DECL(_net_inet);
  SYSCTL_INT(_net_inet, OID_AUTO, log_restricted,
      CTLFLAG_RW | CTLFLAG_LOCKED, &log_restricted, 0,
      "Log network restrictions");
  /*
   * Called when we need to enforce policy restrictions in the input path.
   *
   * Returns TRUE if we're not allowed to receive data, otherwise FALSE.
   */
  static boolean_t
  _inp_restricted_recv(struct inpcb *inp, struct ifnet *ifp)
  {
  	VERIFY(inp != NULL);
  
  	/*
  	 * Inbound restrictions.
  	 */
  	if (!sorestrictrecv)
  		return (FALSE);
  
  	if (ifp == NULL)
  		return (FALSE);
  
  	if (IFNET_IS_CELLULAR(ifp) && INP_NO_CELLULAR(inp))
  		return (TRUE);
  
  	if (IFNET_IS_EXPENSIVE(ifp) && INP_NO_EXPENSIVE(inp))
  		return (TRUE);
  
  	if (IFNET_IS_AWDL_RESTRICTED(ifp) && !INP_AWDL_UNRESTRICTED(inp))
  		return (TRUE);
  
  	if (!(ifp->if_eflags & IFEF_RESTRICTED_RECV))
  		return (FALSE);
  
  	if (inp->inp_flags & INP_RECV_ANYIF)
  		return (FALSE);
  
  	if ((inp->inp_flags & INP_BOUND_IF) && inp->inp_boundifp == ifp)
  		return (FALSE);
  
  	if (IFNET_IS_INTCOPROC(ifp) && !INP_INTCOPROC_ALLOWED(inp))
  		return (TRUE);
  
  	return (TRUE);
  }
  
  boolean_t
  inp_restricted_recv(struct inpcb *inp, struct ifnet *ifp)
  {
  	boolean_t ret;
  
  	ret = _inp_restricted_recv(inp, ifp);
  	if (ret == TRUE && log_restricted) {
  		printf("pid %d (%s) is unable to receive packets on %s\n",
  		    current_proc()->p_pid, proc_best_name(current_proc()),
  		    ifp->if_xname);
  	}
  	return (ret);
  }
  
  /*
   * Called when we need to enforce policy restrictions in the output path.
   *
   * Returns TRUE if we're not allowed to send data out, otherwise FALSE.
   */
  static boolean_t
  _inp_restricted_send(struct inpcb *inp, struct ifnet *ifp)
  {
  	VERIFY(inp != NULL);
  
  	/*
  	 * Outbound restrictions.
  	 */
  	if (!sorestrictsend)
  		return (FALSE);
  
  	if (ifp == NULL)
  		return (FALSE);
  
  	if (IFNET_IS_CELLULAR(ifp) && INP_NO_CELLULAR(inp))
  		return (TRUE);
  
  	if (IFNET_IS_EXPENSIVE(ifp) && INP_NO_EXPENSIVE(inp))
  		return (TRUE);
  
  	if (IFNET_IS_AWDL_RESTRICTED(ifp) && !INP_AWDL_UNRESTRICTED(inp))
  		return (TRUE);
  
  	if (IFNET_IS_INTCOPROC(ifp) && !INP_INTCOPROC_ALLOWED(inp))
  		return (TRUE);
  
  	return (FALSE);
  }
  
  boolean_t
  inp_restricted_send(struct inpcb *inp, struct ifnet *ifp)
  {
  	boolean_t ret;
  
  	ret = _inp_restricted_send(inp, ifp);
  	if (ret == TRUE && log_restricted) {
  		printf("pid %d (%s) is unable to transmit packets on %s\n",
  		    current_proc()->p_pid, proc_best_name(current_proc()),
  		    ifp->if_xname);
  	}
  	return (ret);
  }
  
  inline void
  inp_count_sndbytes(struct inpcb *inp, u_int32_t th_ack)
  {
  	struct ifnet *ifp = inp->inp_last_outifp;
  	struct socket *so = inp->inp_socket;
  	if (ifp != NULL && !(so->so_flags & SOF_MP_SUBFLOW) &&
  	    (ifp->if_type == IFT_CELLULAR ||
  	    ifp->if_subfamily == IFNET_SUBFAMILY_WIFI)) {
  		int32_t unsent;
  
  		so->so_snd.sb_flags |= SB_SNDBYTE_CNT;
  
  		/*
  		 * There can be data outstanding before the connection
  		 * becomes established -- TFO case
  		 */
  		if (so->so_snd.sb_cc > 0)
  			inp_incr_sndbytes_total(so, so->so_snd.sb_cc);
  
  		unsent = inp_get_sndbytes_allunsent(so, th_ack);
  		if (unsent > 0)
  			inp_incr_sndbytes_unsent(so, unsent);
  	}
  }
  
  inline void
  inp_incr_sndbytes_total(struct socket *so, int32_t len)
  {
  	struct inpcb *inp = (struct inpcb *)so->so_pcb;
  	struct ifnet *ifp = inp->inp_last_outifp;
  
  	if (ifp != NULL) {
  		VERIFY(ifp->if_sndbyte_total >= 0);
  		OSAddAtomic64(len, &ifp->if_sndbyte_total);
  	}
  }
  
  inline void
  inp_decr_sndbytes_total(struct socket *so, int32_t len)
  {
  	struct inpcb *inp = (struct inpcb *)so->so_pcb;
  	struct ifnet *ifp = inp->inp_last_outifp;
  
  	if (ifp != NULL) {
  		VERIFY(ifp->if_sndbyte_total >= len);
  		OSAddAtomic64(-len, &ifp->if_sndbyte_total);
  	}
  }
  
  inline void
  inp_incr_sndbytes_unsent(struct socket *so, int32_t len)
  {
  	struct inpcb *inp = (struct inpcb *)so->so_pcb;
  	struct ifnet *ifp = inp->inp_last_outifp;
  
  	if (ifp != NULL) {
  		VERIFY(ifp->if_sndbyte_unsent >= 0);
  		OSAddAtomic64(len, &ifp->if_sndbyte_unsent);
  	}
  }
  
  inline void
  inp_decr_sndbytes_unsent(struct socket *so, int32_t len)
  {
  	struct inpcb *inp = (struct inpcb *)so->so_pcb;
  	struct ifnet *ifp = inp->inp_last_outifp;
  
  	if (so == NULL || !(so->so_snd.sb_flags & SB_SNDBYTE_CNT))
  		return;
  
  	if (ifp != NULL) {
  		if (ifp->if_sndbyte_unsent >= len)
  			OSAddAtomic64(-len, &ifp->if_sndbyte_unsent);
  		else
  			ifp->if_sndbyte_unsent = 0;
  	}
  }
  
  inline void
  inp_decr_sndbytes_allunsent(struct socket *so, u_int32_t th_ack)
  {
  	int32_t len;
  
  	if (so == NULL || !(so->so_snd.sb_flags & SB_SNDBYTE_CNT))
  		return;
  
  	len = inp_get_sndbytes_allunsent(so, th_ack);
  	inp_decr_sndbytes_unsent(so, len);
  }
  
  
  inline void
  inp_set_activity_bitmap(struct inpcb *inp)
  {
  	in_stat_set_activity_bitmap(&inp->inp_nw_activity, net_uptime());
  }
  
  inline void
  inp_get_activity_bitmap(struct inpcb *inp, activity_bitmap_t *ab)
  {
  	bcopy(&inp->inp_nw_activity, ab, sizeof (*ab));
  }
  