text: /*
   * Copyright (c) 2003-2013 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) 1995, 1996, 1997, and 1998 WIDE Project.
   * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
   */
  
  /*
   * Copyright 1994, 1995 Massachusetts Institute of Technology
   *
   * Permission to use, copy, modify, and distribute this software and
   * its documentation for any purpose and without fee is hereby
   * granted, provided that both the above copyright notice and this
   * permission notice appear in all copies, that both the above
   * copyright notice and this permission notice appear in all
   * supporting documentation, and that the name of M.I.T. not be used
   * in advertising or publicity pertaining to distribution of the
   * software without specific, written prior permission.  M.I.T. makes
   * no representations about the suitability of this software for any
   * purpose.  It is provided "as is" without express or implied
   * warranty.
   *
   * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
   * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
   * SHALL M.I.T. 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.
   *
   */
  
  /*
   * This code does two things necessary for the enhanced TCP metrics to
   * function in a useful manner:
   *  1) It marks all non-host routes as `cloning', thus ensuring that
   *     every actual reference to such a route actually gets turned
   *     into a reference to a host route to the specific destination
   *     requested.
   *  2) When such routes lose all their references, it arranges for them
   *     to be deleted in some random collection of circumstances, so that
   *     a large quantity of stale routing data is not kept in kernel memory
   *     indefinitely.  See in6_rtqtimo() below for the exact mechanism.
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/kernel.h>
  #include <sys/sysctl.h>
  #include <kern/queue.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/protosw.h>
  #include <sys/mbuf.h>
  #include <sys/syslog.h>
  #include <sys/mcache.h>
  #include <kern/locks.h>
  
  #include <net/if.h>
  #include <net/route.h>
  #include <netinet/in.h>
  #include <netinet/ip_var.h>
  #include <netinet/in_var.h>
  
  #include <netinet/ip6.h>
  #include <netinet6/ip6_var.h>
  
  #include <netinet/icmp6.h>
  
  #include <netinet/tcp.h>
  #include <netinet/tcp_seq.h>
  #include <netinet/tcp_timer.h>
  #include <netinet/tcp_var.h>
  
  extern int	tvtohz(struct timeval *);
  
  static int in6_rtqtimo_run;		/* in6_rtqtimo is scheduled to run */
  static void in6_rtqtimo(void *);
  static void in6_sched_rtqtimo(struct timeval *);
  
  static struct radix_node *in6_addroute(void *, void *, struct radix_node_head *,
      struct radix_node *);
  static struct radix_node *in6_deleteroute(void *, void *,
      struct radix_node_head *);
  static struct radix_node *in6_matroute(void *, struct radix_node_head *);
  static struct radix_node *in6_matroute_args(void *, struct radix_node_head *,
      rn_matchf_t *, void *);
  static void in6_clsroute(struct radix_node *, struct radix_node_head *);
  static int in6_rtqkill(struct radix_node *, void *);
  
  #define	RTPRF_OURS		RTF_PROTO3	/* set on routes we manage */
  
  /*
   * Accessed by in6_addroute(), in6_deleteroute() and in6_rtqkill(), during
   * which the routing lock (rnh_lock) is held and thus protects the variable.
   */
  static int in6dynroutes;
  
  /*
   * Do what we need to do when inserting a route.
   */
  static struct radix_node *
  in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
      struct radix_node *treenodes)
  {
  	struct rtentry *rt = (struct rtentry *)treenodes;
  	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)(void *)rt_key(rt);
  	struct radix_node *ret;
  	char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
  	uint32_t flags = rt->rt_flags;
  	boolean_t verbose = (rt_verbose > 1);
  
  	lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
  	RT_LOCK_ASSERT_HELD(rt);
  
  	if (verbose)
  		rt_str(rt, dbuf, sizeof (dbuf), gbuf, sizeof (gbuf));
  
  	/*
  	 * If this is a dynamic route (which is created via Redirect) and
  	 * we already have the maximum acceptable number of such route entries,
  	 * reject creating a new one.  We could initiate garbage collection to
  	 * make available space right now, but the benefit would probably not
  	 * be worth the cleaning overhead; we only have to endure a slightly
  	 * suboptimal path even without the redirected route.
  	 */
  	if ((rt->rt_flags & RTF_DYNAMIC) &&
  	    ip6_maxdynroutes >= 0 && in6dynroutes >= ip6_maxdynroutes)
  		return (NULL);
  
  	/*
  	 * For IPv6, all unicast non-host routes are automatically cloning.
  	 */
  	if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
  		rt->rt_flags |= RTF_MULTICAST;
  
  	if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST)))
  		rt->rt_flags |= RTF_PRCLONING;
  
  	/*
  	 * A little bit of help for both IPv6 output and input:
  	 *   For local addresses, we make sure that RTF_LOCAL is set,
  	 *   with the thought that this might one day be used to speed up
  	 *   ip_input().
  	 *
  	 * We also mark routes to multicast addresses as such, because
  	 * it's easy to do and might be useful (but this is much more
  	 * dubious since it's so easy to inspect the address).  (This
  	 * is done above.)
  	 *
  	 * XXX
  	 * should elaborate the code.
  	 */
  	if (rt->rt_flags & RTF_HOST) {
  		IFA_LOCK_SPIN(rt->rt_ifa);
  		if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)->
  		    sin6_addr, &sin6->sin6_addr)) {
  			rt->rt_flags |= RTF_LOCAL;
  		}
  		IFA_UNLOCK(rt->rt_ifa);
  	}
  
  	if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
  	    rt->rt_ifp)
  		rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
  
  	ret = rn_addroute(v_arg, n_arg, head, treenodes);
  	if (ret == NULL && (rt->rt_flags & RTF_HOST)) {
  		struct rtentry *rt2;
  		/*
  		 * We are trying to add a host route, but can't.
  		 * Find out if it is because of an
  		 * ND6 entry and delete it if so.
  		 */
  		rt2 = rtalloc1_scoped_locked((struct sockaddr *)sin6, 0,
  		    RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
  		if (rt2 != NULL) {
  			char dbufc[MAX_IPv6_STR_LEN];
  
  			RT_LOCK(rt2);
  			if (verbose)
  				rt_str(rt2, dbufc, sizeof (dbufc), NULL, 0);
  
  			if ((rt2->rt_flags & RTF_LLINFO) &&
  			    (rt2->rt_flags & RTF_HOST) &&
  			    rt2->rt_gateway != NULL &&
  			    rt2->rt_gateway->sa_family == AF_LINK) {
  				if (verbose) {
  					log(LOG_DEBUG, "%s: unable to insert "
  					    "route to %s:%s, flags=%b, due to "
  					    "existing ND6 route %s->%s "
  					    "flags=%b, attempting to delete\n",
  					    __func__, dbuf,
  					    (rt->rt_ifp != NULL) ?
  					    rt->rt_ifp->if_xname : "",
  					    rt->rt_flags, RTF_BITS,
  					    dbufc, (rt2->rt_ifp != NULL) ?
  					    rt2->rt_ifp->if_xname : "",
  					    rt2->rt_flags, RTF_BITS);
  				}
  				/*
  				 * Safe to drop rt_lock and use rt_key,
  				 * rt_gateway, since holding rnh_lock here
  				 * prevents another thread from calling
  				 * rt_setgate() on this route.
  				 */
  				RT_UNLOCK(rt2);
  				(void) rtrequest_locked(RTM_DELETE, rt_key(rt2),
  				    rt2->rt_gateway, rt_mask(rt2),
  				    rt2->rt_flags, NULL);
  				ret = rn_addroute(v_arg, n_arg, head,
  				    treenodes);
  			} else {
  				RT_UNLOCK(rt2);
  			}
  			rtfree_locked(rt2);
  		}
  	} else if (ret == NULL && (rt->rt_flags & RTF_CLONING)) {
  		struct rtentry *rt2;
  		/*
  		 * We are trying to add a net route, but can't.
  		 * The following case should be allowed, so we'll make a
  		 * special check for this:
  		 *	Two IPv6 addresses with the same prefix is assigned
  		 *	to a single interrface.
  		 *	# ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
  		 *	# ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
  		 *	In this case, (*1) and (*2) want to add the same
  		 *	net route entry, 3ffe:0501:: -> if0.
  		 *	This case should not raise an error.
  		 */
  		rt2 = rtalloc1_scoped_locked((struct sockaddr *)sin6, 0,
  		    RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
  		if (rt2 != NULL) {
  			RT_LOCK(rt2);
  			if ((rt2->rt_flags & (RTF_CLONING|RTF_HOST|
  			    RTF_GATEWAY)) == RTF_CLONING &&
  			    rt2->rt_gateway &&
  			    rt2->rt_gateway->sa_family == AF_LINK &&
  			    rt2->rt_ifp == rt->rt_ifp) {
  				ret = rt2->rt_nodes;
  			}
  			RT_UNLOCK(rt2);
  			rtfree_locked(rt2);
  		}
  	}
  
  	if (ret != NULL && (rt->rt_flags & RTF_DYNAMIC))
  		in6dynroutes++;
  
  	if (!verbose)
  		goto done;
  
  	if (ret != NULL) {
  		if (flags != rt->rt_flags) {
  			log(LOG_DEBUG, "%s: route to %s->%s->%s inserted, "
  			    "oflags=%b, flags=%b\n", __func__,
  			    dbuf, gbuf, (rt->rt_ifp != NULL) ?
  			    rt->rt_ifp->if_xname : "", flags, RTF_BITS,
  			    rt->rt_flags, RTF_BITS);
  		} else {
  			log(LOG_DEBUG, "%s: route to %s->%s->%s inserted, "
  			    "flags=%b\n", __func__, dbuf, gbuf,
  			    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  			    rt->rt_flags, RTF_BITS);
  		}
  	} else {
  		log(LOG_DEBUG, "%s: unable to insert route to %s->%s->%s, "
  		    "flags=%b, already exists\n", __func__, dbuf, gbuf,
  		    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  		    rt->rt_flags, RTF_BITS);
  	}
  done:
  	return (ret);
  }
  
  static struct radix_node *
  in6_deleteroute(void *v_arg, void *netmask_arg, struct radix_node_head *head)
  {
  	struct radix_node *rn;
  
  	lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
  
  	rn = rn_delete(v_arg, netmask_arg, head);
  	if (rn != NULL) {
  		struct rtentry *rt = (struct rtentry *)rn;
  
  		RT_LOCK(rt);
  		if (rt->rt_flags & RTF_DYNAMIC)
  			in6dynroutes--;
  		if (rt_verbose > 1) {
  			char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
  
  			rt_str(rt, dbuf, sizeof (dbuf), gbuf, sizeof (gbuf));
  			log(LOG_DEBUG, "%s: route to %s->%s->%s deleted, "
  			    "flags=%b\n", __func__, dbuf, gbuf,
  			    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  			    rt->rt_flags, RTF_BITS);
  		}
  		RT_UNLOCK(rt);
  	}
  	return (rn);
  }
  
  /*
   * Validate (unexpire) an expiring AF_INET6 route.
   */
  struct radix_node *
  in6_validate(struct radix_node *rn)
  {
  	struct rtentry *rt = (struct rtentry *)rn;
  
  	RT_LOCK_ASSERT_HELD(rt);
  
  	/* This is first reference? */
  	if (rt->rt_refcnt == 0) {
  		if (rt_verbose > 2) {
  			char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
  
  			rt_str(rt, dbuf, sizeof (dbuf), gbuf, sizeof (gbuf));
  			log(LOG_DEBUG, "%s: route to %s->%s->%s validated, "
  			    "flags=%b\n", __func__, dbuf, gbuf,
  			    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  			    rt->rt_flags, RTF_BITS);
  		}
  
  		/*
  		 * It's one of ours; unexpire it.  If the timer is already
  		 * scheduled, let it run later as it won't re-arm itself
  		 * if there's nothing to do.
  		 */
  		if (rt->rt_flags & RTPRF_OURS) {
  			rt->rt_flags &= ~RTPRF_OURS;
  			rt_setexpire(rt, 0);
  		}
  	}
  	return (rn);
  }
  
  /*
   * Similar to in6_matroute_args except without the leaf-matching parameters.
   */
  static struct radix_node *
  in6_matroute(void *v_arg, struct radix_node_head *head)
  {
  	return (in6_matroute_args(v_arg, head, NULL, NULL));
  }
  
  /*
   * This code is the inverse of in6_clsroute: on first reference, if we
   * were managing the route, stop doing so and set the expiration timer
   * back off again.
   */
  static struct radix_node *
  in6_matroute_args(void *v_arg, struct radix_node_head *head,
      rn_matchf_t *f, void *w)
  {
  	struct radix_node *rn = rn_match_args(v_arg, head, f, w);
  
  	if (rn != NULL) {
  		RT_LOCK_SPIN((struct rtentry *)rn);
  		in6_validate(rn);
  		RT_UNLOCK((struct rtentry *)rn);
  	}
  	return (rn);
  }
  
  SYSCTL_DECL(_net_inet6_ip6);
  
  /* one hour is ``really old'' */
  static uint32_t rtq_reallyold = 60*60;
  SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
  	CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_reallyold, 0, "");
  
  /* never automatically crank down to less */
  static uint32_t rtq_minreallyold = 10;
  SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
  	CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_minreallyold, 0, "");
  
  /* 128 cached routes is ``too many'' */
  static uint32_t rtq_toomany = 128;
  SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
  	CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_toomany, 0, "");
  
  /*
   * On last reference drop, mark the route as belong to us so that it can be
   * timed out.
   */
  static void
  in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
  {
  #pragma unused(head)
  	char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
  	struct rtentry *rt = (struct rtentry *)rn;
  	boolean_t verbose = (rt_verbose > 1);
  
  	lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
  	RT_LOCK_ASSERT_HELD(rt);
  
  	if (!(rt->rt_flags & RTF_UP))
  		return;		/* prophylactic measures */
  
  	if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST)
  		return;
  
  	if (rt->rt_flags & RTPRF_OURS)
  		return;
  
  	if (!(rt->rt_flags & (RTF_WASCLONED | RTF_DYNAMIC)))
  		return;
  
  	if (verbose)
  		rt_str(rt, dbuf, sizeof (dbuf), gbuf, sizeof (gbuf));
  
  	/*
  	 * Delete the route immediately if RTF_DELCLONE is set or
  	 * if route caching is disabled (rtq_reallyold set to 0).
  	 * Otherwise, let it expire and be deleted by in6_rtqkill().
  	 */
  	if ((rt->rt_flags & RTF_DELCLONE) || rtq_reallyold == 0) {
  		int err;
  
  		if (verbose) {
  			log(LOG_DEBUG, "%s: deleting route to %s->%s->%s, "
  			    "flags=%b\n", __func__, dbuf, gbuf,
  			    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  			    rt->rt_flags, RTF_BITS);
  		}
  		/*
  		 * Delete the route from the radix tree but since we are
  		 * called when the route's reference count is 0, don't
  		 * deallocate it until we return from this routine by
  		 * telling rtrequest that we're interested in it.
  		 * Safe to drop rt_lock and use rt_key, rt_gateway,
  		 * since holding rnh_lock here prevents another thread
  		 * from calling rt_setgate() on this route.
  		 */
  		RT_UNLOCK(rt);
  		err = rtrequest_locked(RTM_DELETE, rt_key(rt),
  		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, &rt);
  		if (err == 0) {
  			/* Now let the caller free it */
  			RT_LOCK(rt);
  			RT_REMREF_LOCKED(rt);
  		} else {
  			RT_LOCK(rt);
  			if (!verbose)
  				rt_str(rt, dbuf, sizeof (dbuf),
  				    gbuf, sizeof (gbuf));
  			log(LOG_ERR, "%s: error deleting route to "
  			    "%s->%s->%s, flags=%b, err=%d\n", __func__,
  			    dbuf, gbuf, (rt->rt_ifp != NULL) ?
  			    rt->rt_ifp->if_xname : "", rt->rt_flags,
  			    RTF_BITS, err);
  		}
  	} else {
  		uint64_t timenow;
  
  		timenow = net_uptime();
  		rt->rt_flags |= RTPRF_OURS;
  		rt_setexpire(rt, timenow + rtq_reallyold);
  
  		if (verbose) {
  			log(LOG_DEBUG, "%s: route to %s->%s->%s invalidated, "
  			    "flags=%b, expire=T+%u\n", __func__, dbuf, gbuf,
  			    (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
  			    rt->rt_flags, RTF_BITS, rt->rt_expire - timenow);
  		}
  
  		/* We have at least one entry; arm the timer if not already */
  		in6_sched_rtqtimo(NULL);
  	}
  }
  
  struct rtqk_arg {
  	struct radix_node_head *rnh;
  	int updating;
  	int draining;
  	uint32_t killed;
  	uint32_t found;
  	uint64_t nextstop;
  };
  
  /*
   * Get rid of old routes.  When draining, this deletes everything, even when
   * the timeout is not expired yet.  This also applies if the route is dynamic
   * and there are sufficiently large number of such routes (more than a half of
   * maximum).  When updating, this makes sure that nothing has a timeout longer
   * than the current value of rtq_reallyold.
   */
  static int
  in6_rtqkill(struct radix_node *rn, void *rock)
  {
  	struct rtqk_arg *ap = rock;
  	struct rtentry *rt = (struct rtentry *)rn;
  	boolean_t verbose = (rt_verbose > 1);
  	uint64_t timenow;
  	int err;
  
  	timenow = net_uptime();
  	lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
  
  	RT_LOCK(rt);
  	if (rt->rt_flags & RTPRF_OURS) {
  		char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
  
  		if (verbose)
  			rt_str(rt, dbuf, sizeof (dbuf), gbuf, sizeof (gbuf));
  
  		ap->found++;
  		VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0);
  		VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0);
  		if (ap->draining || rt->rt_expire <= timenow ||
  		    ((rt->rt_flags & RTF_DYNAMIC) && ip6_maxdynroutes >= 0 &&
  		    in6dynroutes > ip6_maxdynroutes / 2)) {
  			if (rt->rt_refcnt > 0) {
  				panic("%s: route %p marked with RTPRF_OURS "
  				    "with non-zero refcnt (%u)", __func__,
  				    rt, rt->rt_refcnt);
  				/* NOTREACHED */
  			}
  			if (verbose) {
  				log(LOG_DEBUG, "%s: deleting route to "
  				    "%s->%s->%s, flags=%b, draining=%d\n",
  				    __func__, dbuf, gbuf, (rt->rt_ifp != NULL) ?
  				    rt->rt_ifp->if_xname : "", rt->rt_flags,
  				    RTF_BITS, ap->draining);
  			}
  			RT_ADDREF_LOCKED(rt);	/* for us to free below */
  			/*
  			 * Delete this route since we're done with it;
  			 * the route may be freed afterwards, so we
  			 * can no longer refer to 'rt' upon returning
  			 * from rtrequest().  Safe to drop rt_lock and
  			 * use rt_key, rt_gateway, since holding rnh_lock
  			 * here prevents another thread from calling
  			 * rt_setgate() on this route.
  			 */
  			RT_UNLOCK(rt);
  			err = rtrequest_locked(RTM_DELETE, rt_key(rt),
  			    rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
  			if (err != 0) {
  				RT_LOCK(rt);
  				if (!verbose)
  					rt_str(rt, dbuf, sizeof (dbuf),
  					    gbuf, sizeof (gbuf));
  				log(LOG_ERR, "%s: error deleting route to "
  				    "%s->%s->%s, flags=%b, err=%d\n", __func__,
  				    dbuf, gbuf, (rt->rt_ifp != NULL) ?
  				    rt->rt_ifp->if_xname : "", rt->rt_flags,
  				    RTF_BITS, err);
  				RT_UNLOCK(rt);
  			} else {
  				ap->killed++;
  			}
  			rtfree_locked(rt);
  		} else {
  			uint64_t expire = (rt->rt_expire - timenow);
  
  			if (ap->updating && expire > rtq_reallyold) {
  				rt_setexpire(rt, timenow + rtq_reallyold);
  				if (verbose) {
  					log(LOG_DEBUG, "%s: route to "
  					    "%s->%s->%s, flags=%b, adjusted "
  					    "expire=T+%u (was T+%u)\n",
  					    __func__, dbuf, gbuf,
  					    (rt->rt_ifp != NULL) ?
  					    rt->rt_ifp->if_xname : "",
  					    rt->rt_flags, RTF_BITS,
  					    (rt->rt_expire - timenow), expire);
  				}
  			}
  			ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
  			RT_UNLOCK(rt);
  		}
  	} else {
  		RT_UNLOCK(rt);
  	}
  
  	return (0);
  }
  
  #define	RTQ_TIMEOUT	60*10	/* run no less than once every ten minutes */
  static int rtq_timeout = RTQ_TIMEOUT;
  
  static void
  in6_rtqtimo(void *targ)
  {
  #pragma unused(targ)
  	struct radix_node_head *rnh;
  	struct rtqk_arg arg;
  	struct timeval atv;
  	static uint64_t last_adjusted_timeout = 0;
  	boolean_t verbose = (rt_verbose > 1);
  	uint64_t timenow;
  	uint32_t ours;
  
  	lck_mtx_lock(rnh_lock);
  	rnh = rt_tables[AF_INET6];
  	VERIFY(rnh != NULL);
  
  	/* Get the timestamp after we acquire the lock for better accuracy */
  	timenow = net_uptime();
  	if (verbose) {
  		log(LOG_DEBUG, "%s: initial nextstop is T+%u seconds\n",
  		    __func__, rtq_timeout);
  	}
  	bzero(&arg, sizeof (arg));
  	arg.rnh = rnh;
  	arg.nextstop = timenow + rtq_timeout;
  	rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
  	if (verbose) {
  		log(LOG_DEBUG, "%s: found %u, killed %u\n", __func__,
  		    arg.found, arg.killed);
  	}
  	/*
  	 * Attempt to be somewhat dynamic about this:
  	 * If there are ``too many'' routes sitting around taking up space,
  	 * then crank down the timeout, and see if we can't make some more
  	 * go away.  However, we make sure that we will never adjust more
  	 * than once in rtq_timeout seconds, to keep from cranking down too
  	 * hard.
  	 */
  	ours = (arg.found - arg.killed);
  	if (ours > rtq_toomany &&
  	    ((timenow - last_adjusted_timeout) >= (uint64_t)rtq_timeout) &&
  	    rtq_reallyold > rtq_minreallyold) {
  		rtq_reallyold = 2 * rtq_reallyold / 3;
  		if (rtq_reallyold < rtq_minreallyold)
  			rtq_reallyold = rtq_minreallyold;
  
  		last_adjusted_timeout = timenow;
  		if (verbose) {
  			log(LOG_DEBUG, "%s: adjusted rtq_reallyold to %d "
  			    "seconds\n", __func__, rtq_reallyold);
  		}
  		arg.found = arg.killed = 0;
  		arg.updating = 1;
  		rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
  	}
  
  	atv.tv_usec = 0;
  	atv.tv_sec = arg.nextstop - timenow;
  	/* re-arm the timer only if there's work to do */
  	in6_rtqtimo_run = 0;
  	if (ours > 0)
  		in6_sched_rtqtimo(&atv);
  	else if (verbose)
  		log(LOG_DEBUG, "%s: not rescheduling timer\n", __func__);
  	lck_mtx_unlock(rnh_lock);
  }
  
  static void
  in6_sched_rtqtimo(struct timeval *atv)
  {
  	lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
  
  	if (!in6_rtqtimo_run) {
  		struct timeval tv;
  
  		if (atv == NULL) {
  			tv.tv_usec = 0;
  			tv.tv_sec = MAX(rtq_timeout / 10, 1);
  			atv = &tv;
  		}
  		if (rt_verbose > 1) {
  			log(LOG_DEBUG, "%s: timer scheduled in "
  			    "T+%llus.%lluu\n", __func__,
  			    (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec);
  		}
  		in6_rtqtimo_run = 1;
  		timeout(in6_rtqtimo, NULL, tvtohz(atv));
  	}
  }
  
  void
  in6_rtqdrain(void)
  {
  	struct radix_node_head *rnh;
  	struct rtqk_arg arg;
  
  	if (rt_verbose > 1)
  		log(LOG_DEBUG, "%s: draining routes\n", __func__);
  
  	lck_mtx_lock(rnh_lock);
  	rnh = rt_tables[AF_INET6];
  	VERIFY(rnh != NULL);
  	bzero(&arg, sizeof (arg));
  	arg.rnh = rnh;
  	arg.draining = 1;
  	rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
  	lck_mtx_unlock(rnh_lock);
  }
  
  /*
   * Initialize our routing tree.
   */
  int
  in6_inithead(void **head, int off)
  {
  	struct radix_node_head *rnh;
  
  	/* If called from route_init(), make sure it is exactly once */
  	VERIFY(head != (void **)&rt_tables[AF_INET6] || *head == NULL);
  
  	if (!rn_inithead(head, off))
  		return (0);
  
  	/*
  	 * We can get here from nfs_subs.c as well, in which case this
  	 * won't be for the real routing table and thus we're done;
  	 * this also takes care of the case when we're called more than
  	 * once from anywhere but route_init().
  	 */
  	if (head != (void **)&rt_tables[AF_INET6])
  		return (1);	/* only do this for the real routing table */
  
  	rnh = *head;
  	rnh->rnh_addaddr = in6_addroute;
  	rnh->rnh_deladdr = in6_deleteroute;
  	rnh->rnh_matchaddr = in6_matroute;
  	rnh->rnh_matchaddr_args = in6_matroute_args;
  	rnh->rnh_close = in6_clsroute;
  	return (1);
  }
  