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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 /*
     26  * Copyright (c) 1990 Mentat Inc.
     27  */
     28 
     29 /*
     30  * This file contains routines that manipulate Internet Routing Entries (IREs).
     31  */
     32 #include <sys/types.h>
     33 #include <sys/stream.h>
     34 #include <sys/stropts.h>
     35 #include <sys/ddi.h>
     36 #include <sys/cmn_err.h>
     37 
     38 #include <sys/systm.h>
     39 #include <sys/param.h>
     40 #include <sys/socket.h>
     41 #include <net/if.h>
     42 #include <net/route.h>
     43 #include <netinet/in.h>
     44 #include <net/if_dl.h>
     45 #include <netinet/ip6.h>
     46 #include <netinet/icmp6.h>
     47 
     48 #include <inet/common.h>
     49 #include <inet/mi.h>
     50 #include <inet/ip.h>
     51 #include <inet/ip6.h>
     52 #include <inet/ip_ndp.h>
     53 #include <inet/ip_if.h>
     54 #include <inet/ip_ire.h>
     55 #include <inet/ipclassifier.h>
     56 #include <inet/nd.h>
     57 #include <sys/kmem.h>
     58 #include <sys/zone.h>
     59 
     60 #include <sys/tsol/label.h>
     61 #include <sys/tsol/tnet.h>
     62 
     63 static	ire_t	ire_null;
     64 
     65 static ire_t	*ire_ihandle_lookup_onlink_v6(ire_t *cire);
     66 static boolean_t ire_match_args_v6(ire_t *ire, const in6_addr_t *addr,
     67     const in6_addr_t *mask, const in6_addr_t *gateway, int type,
     68     const ipif_t *ipif, zoneid_t zoneid, uint32_t ihandle,
     69     const ts_label_t *tsl, int match_flags);
     70 static	ire_t	*ire_init_v6(ire_t *, const in6_addr_t *, const in6_addr_t *,
     71     const in6_addr_t *, const in6_addr_t *, uint_t *, queue_t *, queue_t *,
     72     ushort_t, ipif_t *, const in6_addr_t *, uint32_t, uint32_t, uint_t,
     73     const iulp_t *, tsol_gc_t *, tsol_gcgrp_t *, ip_stack_t *);
     74 static	ire_t	*ip6_ctable_lookup_impl(ire_ctable_args_t *);
     75 
     76 /*
     77  * Initialize the ire that is specific to IPv6 part and call
     78  * ire_init_common to finish it.
     79  */
     80 static ire_t *
     81 ire_init_v6(ire_t *ire, const in6_addr_t *v6addr, const in6_addr_t *v6mask,
     82     const in6_addr_t *v6src_addr, const in6_addr_t *v6gateway,
     83     uint_t *max_fragp, queue_t *rfq, queue_t *stq, ushort_t type,
     84     ipif_t *ipif, const in6_addr_t *v6cmask, uint32_t phandle,
     85     uint32_t ihandle, uint_t flags, const iulp_t *ulp_info, tsol_gc_t *gc,
     86     tsol_gcgrp_t *gcgrp, ip_stack_t *ipst)
     87 {
     88 
     89 	/*
     90 	 * Reject IRE security attribute creation/initialization
     91 	 * if system is not running in Trusted mode.
     92 	 */
     93 	if ((gc != NULL || gcgrp != NULL) && !is_system_labeled())
     94 		return (NULL);
     95 
     96 
     97 	BUMP_IRE_STATS(ipst->ips_ire_stats_v6, ire_stats_alloced);
     98 	ire->ire_addr_v6 = *v6addr;
     99 
    100 	if (v6src_addr != NULL)
    101 		ire->ire_src_addr_v6 = *v6src_addr;
    102 	if (v6mask != NULL) {
    103 		ire->ire_mask_v6 = *v6mask;
    104 		ire->ire_masklen = ip_mask_to_plen_v6(&ire->ire_mask_v6);
    105 	}
    106 	if (v6gateway != NULL)
    107 		ire->ire_gateway_addr_v6 = *v6gateway;
    108 
    109 	if (type == IRE_CACHE && v6cmask != NULL)
    110 		ire->ire_cmask_v6 = *v6cmask;
    111 
    112 	/*
    113 	 * Multirouted packets need to have a fragment header added so that
    114 	 * the receiver is able to discard duplicates according to their
    115 	 * fragment identifier.
    116 	 */
    117 	if (type == IRE_CACHE && (flags & RTF_MULTIRT)) {
    118 		ire->ire_frag_flag = IPH_FRAG_HDR;
    119 	}
    120 
    121 	/* ire_init_common will free the mblks upon encountering any failure */
    122 	if (!ire_init_common(ire, max_fragp, NULL, rfq, stq, type, ipif,
    123 	    phandle, ihandle, flags, IPV6_VERSION, ulp_info, gc, gcgrp, ipst))
    124 		return (NULL);
    125 
    126 	return (ire);
    127 }
    128 
    129 /*
    130  * Similar to ire_create_v6 except that it is called only when
    131  * we want to allocate ire as an mblk e.g. we have a external
    132  * resolver. Do we need this in IPv6 ?
    133  *
    134  * IPv6 initializes the ire_nce in ire_add_v6, which expects to
    135  * find the ire_nce to be null when it is called. So, although
    136  * we have a src_nce parameter (in the interest of matching up with
    137  * the argument list of the v4 version), we ignore the src_nce
    138  * argument here.
    139  */
    140 /* ARGSUSED */
    141 ire_t *
    142 ire_create_mp_v6(const in6_addr_t *v6addr, const in6_addr_t *v6mask,
    143     const in6_addr_t *v6src_addr, const in6_addr_t *v6gateway,
    144     nce_t *src_nce, queue_t *rfq, queue_t *stq, ushort_t type,
    145     ipif_t *ipif, const in6_addr_t *v6cmask,
    146     uint32_t phandle, uint32_t ihandle, uint_t flags, const iulp_t *ulp_info,
    147     tsol_gc_t *gc, tsol_gcgrp_t *gcgrp, ip_stack_t *ipst)
    148 {
    149 	ire_t	*ire;
    150 	ire_t	*ret_ire;
    151 	mblk_t	*mp;
    152 
    153 	ASSERT(!IN6_IS_ADDR_V4MAPPED(v6addr));
    154 
    155 	/* Allocate the new IRE. */
    156 	mp = allocb(sizeof (ire_t), BPRI_MED);
    157 	if (mp == NULL) {
    158 		ip1dbg(("ire_create_mp_v6: alloc failed\n"));
    159 		return (NULL);
    160 	}
    161 
    162 	ire = (ire_t *)mp->b_rptr;
    163 	mp->b_wptr = (uchar_t *)&ire[1];
    164 
    165 	/* Start clean. */
    166 	*ire = ire_null;
    167 	ire->ire_mp = mp;
    168 	mp->b_datap->db_type = IRE_DB_TYPE;
    169 
    170 	ret_ire = ire_init_v6(ire, v6addr, v6mask, v6src_addr, v6gateway,
    171 	    NULL, rfq, stq, type, ipif, v6cmask, phandle,
    172 	    ihandle, flags, ulp_info, gc, gcgrp, ipst);
    173 
    174 	if (ret_ire == NULL) {
    175 		freeb(ire->ire_mp);
    176 		return (NULL);
    177 	}
    178 	return (ire);
    179 }
    180 
    181 /*
    182  * ire_create_v6 is called to allocate and initialize a new IRE.
    183  *
    184  * NOTE : This is called as writer sometimes though not required
    185  * by this function.
    186  *
    187  * See comments above ire_create_mp_v6() for the rationale behind the
    188  * unused src_nce argument.
    189  */
    190 /* ARGSUSED */
    191 ire_t *
    192 ire_create_v6(const in6_addr_t *v6addr, const in6_addr_t *v6mask,
    193     const in6_addr_t *v6src_addr, const in6_addr_t *v6gateway,
    194     uint_t *max_fragp, nce_t *src_nce, queue_t *rfq, queue_t *stq,
    195     ushort_t type, ipif_t *ipif, const in6_addr_t *v6cmask,
    196     uint32_t phandle, uint32_t ihandle, uint_t flags, const iulp_t *ulp_info,
    197     tsol_gc_t *gc, tsol_gcgrp_t *gcgrp, ip_stack_t *ipst)
    198 {
    199 	ire_t	*ire;
    200 	ire_t	*ret_ire;
    201 
    202 	ASSERT(!IN6_IS_ADDR_V4MAPPED(v6addr));
    203 
    204 	ire = kmem_cache_alloc(ire_cache, KM_NOSLEEP);
    205 	if (ire == NULL) {
    206 		ip1dbg(("ire_create_v6: alloc failed\n"));
    207 		return (NULL);
    208 	}
    209 	*ire = ire_null;
    210 
    211 	ret_ire = ire_init_v6(ire, v6addr, v6mask, v6src_addr, v6gateway,
    212 	    max_fragp, rfq, stq, type, ipif, v6cmask, phandle,
    213 	    ihandle, flags, ulp_info, gc, gcgrp, ipst);
    214 
    215 	if (ret_ire == NULL) {
    216 		kmem_cache_free(ire_cache, ire);
    217 		return (NULL);
    218 	}
    219 	ASSERT(ret_ire == ire);
    220 	return (ire);
    221 }
    222 
    223 /*
    224  * Find an IRE_INTERFACE for the multicast group.
    225  * Allows different routes for multicast addresses
    226  * in the unicast routing table (akin to FF::0/8 but could be more specific)
    227  * which point at different interfaces. This is used when IPV6_MULTICAST_IF
    228  * isn't specified (when sending) and when IPV6_JOIN_GROUP doesn't
    229  * specify the interface to join on.
    230  *
    231  * Supports link-local addresses by following the ipif/ill when recursing.
    232  */
    233 ire_t *
    234 ire_lookup_multi_v6(const in6_addr_t *group, zoneid_t zoneid, ip_stack_t *ipst)
    235 {
    236 	ire_t	*ire;
    237 	ipif_t	*ipif = NULL;
    238 	int	match_flags = MATCH_IRE_TYPE;
    239 	in6_addr_t gw_addr_v6;
    240 
    241 	ire = ire_ftable_lookup_v6(group, 0, 0, 0, NULL, NULL,
    242 	    zoneid, 0, NULL, MATCH_IRE_DEFAULT, ipst);
    243 
    244 	/* We search a resolvable ire in case of multirouting. */
    245 	if ((ire != NULL) && (ire->ire_flags & RTF_MULTIRT)) {
    246 		ire_t *cire = NULL;
    247 		/*
    248 		 * If the route is not resolvable, the looked up ire
    249 		 * may be changed here. In that case, ire_multirt_lookup_v6()
    250 		 * IRE_REFRELE the original ire and change it.
    251 		 */
    252 		(void) ire_multirt_lookup_v6(&cire, &ire, MULTIRT_CACHEGW,
    253 		    NULL, ipst);
    254 		if (cire != NULL)
    255 			ire_refrele(cire);
    256 	}
    257 	if (ire == NULL)
    258 		return (NULL);
    259 	/*
    260 	 * Make sure we follow ire_ipif.
    261 	 *
    262 	 * We need to determine the interface route through
    263 	 * which the gateway will be reached.
    264 	 */
    265 	if (ire->ire_ipif != NULL) {
    266 		ipif = ire->ire_ipif;
    267 		match_flags |= MATCH_IRE_ILL;
    268 	}
    269 
    270 	switch (ire->ire_type) {
    271 	case IRE_DEFAULT:
    272 	case IRE_PREFIX:
    273 	case IRE_HOST:
    274 		mutex_enter(&ire->ire_lock);
    275 		gw_addr_v6 = ire->ire_gateway_addr_v6;
    276 		mutex_exit(&ire->ire_lock);
    277 		ire_refrele(ire);
    278 		ire = ire_ftable_lookup_v6(&gw_addr_v6, 0, 0,
    279 		    IRE_INTERFACE, ipif, NULL, zoneid, 0,
    280 		    NULL, match_flags, ipst);
    281 		return (ire);
    282 	case IRE_IF_NORESOLVER:
    283 	case IRE_IF_RESOLVER:
    284 		return (ire);
    285 	default:
    286 		ire_refrele(ire);
    287 		return (NULL);
    288 	}
    289 }
    290 
    291 /*
    292  * Return any local address.  We use this to target ourselves
    293  * when the src address was specified as 'default'.
    294  * Preference for IRE_LOCAL entries.
    295  */
    296 ire_t *
    297 ire_lookup_local_v6(zoneid_t zoneid, ip_stack_t *ipst)
    298 {
    299 	ire_t	*ire;
    300 	irb_t	*irb;
    301 	ire_t	*maybe = NULL;
    302 	int i;
    303 
    304 	for (i = 0; i < ipst->ips_ip6_cache_table_size;  i++) {
    305 		irb = &ipst->ips_ip_cache_table_v6[i];
    306 		if (irb->irb_ire == NULL)
    307 			continue;
    308 		rw_enter(&irb->irb_lock, RW_READER);
    309 		for (ire = irb->irb_ire; ire; ire = ire->ire_next) {
    310 			if ((ire->ire_marks & IRE_MARK_CONDEMNED) ||
    311 			    ire->ire_zoneid != zoneid &&
    312 			    ire->ire_zoneid != ALL_ZONES)
    313 				continue;
    314 			switch (ire->ire_type) {
    315 			case IRE_LOOPBACK:
    316 				if (maybe == NULL) {
    317 					IRE_REFHOLD(ire);
    318 					maybe = ire;
    319 				}
    320 				break;
    321 			case IRE_LOCAL:
    322 				if (maybe != NULL) {
    323 					ire_refrele(maybe);
    324 				}
    325 				IRE_REFHOLD(ire);
    326 				rw_exit(&irb->irb_lock);
    327 				return (ire);
    328 			}
    329 		}
    330 		rw_exit(&irb->irb_lock);
    331 	}
    332 	return (maybe);
    333 }
    334 
    335 /*
    336  * This function takes a mask and returns number of bits set in the
    337  * mask (the represented prefix length).  Assumes a contiguous mask.
    338  */
    339 int
    340 ip_mask_to_plen_v6(const in6_addr_t *v6mask)
    341 {
    342 	int		bits;
    343 	int		plen = IPV6_ABITS;
    344 	int		i;
    345 
    346 	for (i = 3; i >= 0; i--) {
    347 		if (v6mask->s6_addr32[i] == 0) {
    348 			plen -= 32;
    349 			continue;
    350 		}
    351 		bits = ffs(ntohl(v6mask->s6_addr32[i])) - 1;
    352 		if (bits == 0)
    353 			break;
    354 		plen -= bits;
    355 	}
    356 
    357 	return (plen);
    358 }
    359 
    360 /*
    361  * Convert a prefix length to the mask for that prefix.
    362  * Returns the argument bitmask.
    363  */
    364 in6_addr_t *
    365 ip_plen_to_mask_v6(uint_t plen, in6_addr_t *bitmask)
    366 {
    367 	uint32_t *ptr;
    368 
    369 	if (plen < 0 || plen > IPV6_ABITS)
    370 		return (NULL);
    371 	*bitmask = ipv6_all_zeros;
    372 
    373 	ptr = (uint32_t *)bitmask;
    374 	while (plen > 32) {
    375 		*ptr++ = 0xffffffffU;
    376 		plen -= 32;
    377 	}
    378 	*ptr = htonl(0xffffffffU << (32 - plen));
    379 	return (bitmask);
    380 }
    381 
    382 /*
    383  * Add a fully initialized IRE to an appropriate
    384  * table based on ire_type.
    385  *
    386  * The forward table contains IRE_PREFIX/IRE_HOST/IRE_HOST and
    387  * IRE_IF_RESOLVER/IRE_IF_NORESOLVER and IRE_DEFAULT.
    388  *
    389  * The cache table contains IRE_BROADCAST/IRE_LOCAL/IRE_LOOPBACK
    390  * and IRE_CACHE.
    391  *
    392  * NOTE : This function is called as writer though not required
    393  * by this function.
    394  */
    395 int
    396 ire_add_v6(ire_t **ire_p, queue_t *q, mblk_t *mp, ipsq_func_t func)
    397 {
    398 	ire_t	*ire1;
    399 	int	mask_table_index;
    400 	irb_t	*irb_ptr;
    401 	ire_t	**irep;
    402 	int	flags;
    403 	ire_t	*pire = NULL;
    404 	ill_t	*stq_ill;
    405 	boolean_t	ndp_g_lock_held = B_FALSE;
    406 	ire_t	*ire = *ire_p;
    407 	int	error;
    408 	ip_stack_t	*ipst = ire->ire_ipst;
    409 	uint_t	marks = 0;
    410 
    411 	ASSERT(ire->ire_ipversion == IPV6_VERSION);
    412 	ASSERT(ire->ire_mp == NULL); /* Calls should go through ire_add */
    413 	ASSERT(ire->ire_nce == NULL);
    414 
    415 	/*
    416 	 * IREs with source addresses hosted on interfaces that are under IPMP
    417 	 * should be hidden so that applications don't accidentally end up
    418 	 * sending packets with test addresses as their source addresses, or
    419 	 * sending out interfaces that are e.g. IFF_INACTIVE.  Hide them here.
    420 	 * (We let IREs with unspecified source addresses slip through since
    421 	 * ire_send_v6() will delete them automatically.)
    422 	 */
    423 	if (ire->ire_ipif != NULL && IS_UNDER_IPMP(ire->ire_ipif->ipif_ill) &&
    424 	    !IN6_IS_ADDR_UNSPECIFIED(&ire->ire_src_addr_v6)) {
    425 		DTRACE_PROBE1(ipmp__mark__testhidden, ire_t *, ire);
    426 		marks |= IRE_MARK_TESTHIDDEN;
    427 	}
    428 
    429 	/* Find the appropriate list head. */
    430 	switch (ire->ire_type) {
    431 	case IRE_HOST:
    432 		ire->ire_mask_v6 = ipv6_all_ones;
    433 		ire->ire_masklen = IPV6_ABITS;
    434 		ire->ire_marks |= marks;
    435 		if ((ire->ire_flags & RTF_SETSRC) == 0)
    436 			ire->ire_src_addr_v6 = ipv6_all_zeros;
    437 		break;
    438 	case IRE_CACHE:
    439 		ire->ire_mask_v6 = ipv6_all_ones;
    440 		ire->ire_masklen = IPV6_ABITS;
    441 		ire->ire_marks |= marks;
    442 		break;
    443 	case IRE_LOCAL:
    444 	case IRE_LOOPBACK:
    445 		ire->ire_mask_v6 = ipv6_all_ones;
    446 		ire->ire_masklen = IPV6_ABITS;
    447 		break;
    448 	case IRE_PREFIX:
    449 	case IRE_DEFAULT:
    450 		ire->ire_marks |= marks;
    451 		if ((ire->ire_flags & RTF_SETSRC) == 0)
    452 			ire->ire_src_addr_v6 = ipv6_all_zeros;
    453 		break;
    454 	case IRE_IF_RESOLVER:
    455 	case IRE_IF_NORESOLVER:
    456 		ire->ire_marks |= marks;
    457 		break;
    458 	default:
    459 		printf("ire_add_v6: ire %p has unrecognized IRE type (%d)\n",
    460 		    (void *)ire, ire->ire_type);
    461 		ire_delete(ire);
    462 		*ire_p = NULL;
    463 		return (EINVAL);
    464 	}
    465 
    466 	/* Make sure the address is properly masked. */
    467 	V6_MASK_COPY(ire->ire_addr_v6, ire->ire_mask_v6, ire->ire_addr_v6);
    468 
    469 	if ((ire->ire_type & IRE_CACHETABLE) == 0) {
    470 		/* IRE goes into Forward Table */
    471 		mask_table_index = ip_mask_to_plen_v6(&ire->ire_mask_v6);
    472 		if ((ipst->ips_ip_forwarding_table_v6[mask_table_index]) ==
    473 		    NULL) {
    474 			irb_t *ptr;
    475 			int i;
    476 
    477 			ptr = (irb_t *)mi_zalloc((
    478 			    ipst->ips_ip6_ftable_hash_size * sizeof (irb_t)));
    479 			if (ptr == NULL) {
    480 				ire_delete(ire);
    481 				*ire_p = NULL;
    482 				return (ENOMEM);
    483 			}
    484 			for (i = 0; i < ipst->ips_ip6_ftable_hash_size; i++) {
    485 				rw_init(&ptr[i].irb_lock, NULL,
    486 				    RW_DEFAULT, NULL);
    487 			}
    488 			mutex_enter(&ipst->ips_ire_ft_init_lock);
    489 			if (ipst->ips_ip_forwarding_table_v6[
    490 			    mask_table_index] == NULL) {
    491 				ipst->ips_ip_forwarding_table_v6[
    492 				    mask_table_index] = ptr;
    493 				mutex_exit(&ipst->ips_ire_ft_init_lock);
    494 			} else {
    495 				/*
    496 				 * Some other thread won the race in
    497 				 * initializing the forwarding table at the
    498 				 * same index.
    499 				 */
    500 				mutex_exit(&ipst->ips_ire_ft_init_lock);
    501 				for (i = 0; i < ipst->ips_ip6_ftable_hash_size;
    502 				    i++) {
    503 					rw_destroy(&ptr[i].irb_lock);
    504 				}
    505 				mi_free(ptr);
    506 			}
    507 		}
    508 		irb_ptr = &(ipst->ips_ip_forwarding_table_v6[mask_table_index][
    509 		    IRE_ADDR_MASK_HASH_V6(ire->ire_addr_v6, ire->ire_mask_v6,
    510 		    ipst->ips_ip6_ftable_hash_size)]);
    511 	} else {
    512 		irb_ptr = &(ipst->ips_ip_cache_table_v6[IRE_ADDR_HASH_V6(
    513 		    ire->ire_addr_v6, ipst->ips_ip6_cache_table_size)]);
    514 	}
    515 	/*
    516 	 * For xresolv interfaces (v6 interfaces with an external
    517 	 * address resolver), ip_newroute_v6/ip_newroute_ipif_v6
    518 	 * are unable to prevent the deletion of the interface route
    519 	 * while adding an IRE_CACHE for an on-link destination
    520 	 * in the IRE_IF_RESOLVER case, since the ire has to go to
    521 	 * the external resolver and return. We can't do a REFHOLD on the
    522 	 * associated interface ire for fear of the message being freed
    523 	 * if the external resolver can't resolve the address.
    524 	 * Here we look up the interface ire in the forwarding table
    525 	 * and make sure that the interface route has not been deleted.
    526 	 */
    527 	if (ire->ire_type == IRE_CACHE &&
    528 	    IN6_IS_ADDR_UNSPECIFIED(&ire->ire_gateway_addr_v6) &&
    529 	    (((ill_t *)ire->ire_stq->q_ptr)->ill_net_type == IRE_IF_RESOLVER) &&
    530 	    (((ill_t *)ire->ire_stq->q_ptr)->ill_flags & ILLF_XRESOLV)) {
    531 
    532 		pire = ire_ihandle_lookup_onlink_v6(ire);
    533 		if (pire == NULL) {
    534 			ire_delete(ire);
    535 			*ire_p = NULL;
    536 			return (EINVAL);
    537 		}
    538 		/* Prevent pire from getting deleted */
    539 		IRB_REFHOLD(pire->ire_bucket);
    540 		/* Has it been removed already? */
    541 		if (pire->ire_marks & IRE_MARK_CONDEMNED) {
    542 			IRB_REFRELE(pire->ire_bucket);
    543 			ire_refrele(pire);
    544 			ire_delete(ire);
    545 			*ire_p = NULL;
    546 			return (EINVAL);
    547 		}
    548 	}
    549 
    550 	flags = (MATCH_IRE_MASK | MATCH_IRE_TYPE | MATCH_IRE_GW);
    551 	/*
    552 	 * For IRE_CACHES, MATCH_IRE_IPIF is not enough to check
    553 	 * for duplicates because :
    554 	 *
    555 	 * 1) ire_ipif->ipif_ill and ire_stq->q_ptr could be
    556 	 *    pointing at different ills. A real duplicate is
    557 	 *    a match on both ire_ipif and ire_stq.
    558 	 *
    559 	 * 2) We could have multiple packets trying to create
    560 	 *    an IRE_CACHE for the same ill.
    561 	 *
    562 	 * Rather than looking at the packet, we depend on the above for
    563 	 * MATCH_IRE_ILL here.
    564 	 *
    565 	 * Unlike IPv4, MATCH_IRE_IPIF is needed here as we could have
    566 	 * multiple IRE_CACHES for an ill for the same destination
    567 	 * with various scoped addresses i.e represented by ipifs.
    568 	 *
    569 	 * MATCH_IRE_ILL is done implicitly below for IRE_CACHES.
    570 	 */
    571 	if (ire->ire_ipif != NULL)
    572 		flags |= MATCH_IRE_IPIF;
    573 
    574 	/*
    575 	 * If we are creating a hidden IRE, make sure we search for
    576 	 * hidden IREs when searching for duplicates below.
    577 	 * Otherwise, we might find an IRE on some other interface
    578 	 * that's not marked hidden.
    579 	 */
    580 	if (ire->ire_marks & IRE_MARK_TESTHIDDEN)
    581 		flags |= MATCH_IRE_MARK_TESTHIDDEN;
    582 
    583 	/*
    584 	 * Start the atomic add of the ire. Grab the ill locks,
    585 	 * ill_g_usesrc_lock and the bucket lock. Check for condemned.
    586 	 * To avoid lock order problems, get the ndp6.ndp_g_lock now itself.
    587 	 */
    588 	if (ire->ire_type == IRE_CACHE) {
    589 		mutex_enter(&ipst->ips_ndp6->ndp_g_lock);
    590 		ndp_g_lock_held = B_TRUE;
    591 	}
    592 
    593 	/*
    594 	 * If ipif or ill is changing ire_atomic_start() may queue the
    595 	 * request and return EINPROGRESS.
    596 	 */
    597 
    598 	error = ire_atomic_start(irb_ptr, ire, q, mp, func);
    599 	if (error != 0) {
    600 		if (ndp_g_lock_held)
    601 			mutex_exit(&ipst->ips_ndp6->ndp_g_lock);
    602 		/*
    603 		 * We don't know whether it is a valid ipif or not.
    604 		 * So, set it to NULL. This assumes that the ire has not added
    605 		 * a reference to the ipif.
    606 		 */
    607 		ire->ire_ipif = NULL;
    608 		ire_delete(ire);
    609 		if (pire != NULL) {
    610 			IRB_REFRELE(pire->ire_bucket);
    611 			ire_refrele(pire);
    612 		}
    613 		*ire_p = NULL;
    614 		return (error);
    615 	}
    616 	/*
    617 	 * To avoid creating ires having stale values for the ire_max_frag
    618 	 * we get the latest value atomically here. For more details
    619 	 * see the block comment in ip_sioctl_mtu and in DL_NOTE_SDU_CHANGE
    620 	 * in ip_rput_dlpi_writer
    621 	 */
    622 	if (ire->ire_max_fragp == NULL) {
    623 		if (IN6_IS_ADDR_MULTICAST(&ire->ire_addr_v6))
    624 			ire->ire_max_frag = ire->ire_ipif->ipif_mtu;
    625 		else
    626 			ire->ire_max_frag = pire->ire_max_frag;
    627 	} else {
    628 		uint_t  max_frag;
    629 
    630 		max_frag = *ire->ire_max_fragp;
    631 		ire->ire_max_fragp = NULL;
    632 		ire->ire_max_frag = max_frag;
    633 	}
    634 
    635 	/*
    636 	 * Atomically check for duplicate and insert in the table.
    637 	 */
    638 	for (ire1 = irb_ptr->irb_ire; ire1 != NULL; ire1 = ire1->ire_next) {
    639 		if (ire1->ire_marks & IRE_MARK_CONDEMNED)
    640 			continue;
    641 
    642 		if (ire->ire_type == IRE_CACHE) {
    643 			/*
    644 			 * We do MATCH_IRE_ILL implicitly here for IRE_CACHES.
    645 			 * As ire_ipif and ire_stq could point to two
    646 			 * different ills, we can't pass just ire_ipif to
    647 			 * ire_match_args and get a match on both ills.
    648 			 * This is just needed for duplicate checks here and
    649 			 * so we don't add an extra argument to
    650 			 * ire_match_args for this. Do it locally.
    651 			 *
    652 			 * NOTE : Currently there is no part of the code
    653 			 * that asks for both MATH_IRE_IPIF and MATCH_IRE_ILL
    654 			 * match for IRE_CACHEs. Thus we don't want to
    655 			 * extend the arguments to ire_match_args_v6.
    656 			 */
    657 			if (ire1->ire_stq != ire->ire_stq)
    658 				continue;
    659 			/*
    660 			 * Multiroute IRE_CACHEs for a given destination can
    661 			 * have the same ire_ipif, typically if their source
    662 			 * address is forced using RTF_SETSRC, and the same
    663 			 * send-to queue. We differentiate them using the parent
    664 			 * handle.
    665 			 */
    666 			if ((ire1->ire_flags & RTF_MULTIRT) &&
    667 			    (ire->ire_flags & RTF_MULTIRT) &&
    668 			    (ire1->ire_phandle != ire->ire_phandle))
    669 				continue;
    670 		}
    671 		if (ire1->ire_zoneid != ire->ire_zoneid)
    672 			continue;
    673 		if (ire_match_args_v6(ire1, &ire->ire_addr_v6,
    674 		    &ire->ire_mask_v6, &ire->ire_gateway_addr_v6,
    675 		    ire->ire_type, ire->ire_ipif, ire->ire_zoneid, 0, NULL,
    676 		    flags)) {
    677 			/*
    678 			 * Return the old ire after doing a REFHOLD.
    679 			 * As most of the callers continue to use the IRE
    680 			 * after adding, we return a held ire. This will
    681 			 * avoid a lookup in the caller again. If the callers
    682 			 * don't want to use it, they need to do a REFRELE.
    683 			 */
    684 			ip1dbg(("found dup ire existing %p new %p",
    685 			    (void *)ire1, (void *)ire));
    686 			IRE_REFHOLD(ire1);
    687 			if (ndp_g_lock_held)
    688 				mutex_exit(&ipst->ips_ndp6->ndp_g_lock);
    689 			ire_atomic_end(irb_ptr, ire);
    690 			ire_delete(ire);
    691 			if (pire != NULL) {
    692 				/*
    693 				 * Assert that it is
    694 				 * not yet removed from the list.
    695 				 */
    696 				ASSERT(pire->ire_ptpn != NULL);
    697 				IRB_REFRELE(pire->ire_bucket);
    698 				ire_refrele(pire);
    699 			}
    700 			*ire_p = ire1;
    701 			return (0);
    702 		}
    703 	}
    704 	if (ire->ire_type == IRE_CACHE) {
    705 		const in6_addr_t *addr_v6;
    706 		ill_t	*ill = ire_to_ill(ire);
    707 		char	buf[INET6_ADDRSTRLEN];
    708 		nce_t	*nce;
    709 
    710 		/*
    711 		 * All IRE_CACHE types must have a nce.  If this is
    712 		 * not the case the entry will not be added. We need
    713 		 * to make sure that if somebody deletes the nce
    714 		 * after we looked up, they will find this ire and
    715 		 * delete the ire. To delete this ire one needs the
    716 		 * bucket lock which we are still holding here. So,
    717 		 * even if the nce gets deleted after we looked up,
    718 		 * this ire  will get deleted.
    719 		 *
    720 		 * NOTE : Don't need the ire_lock for accessing
    721 		 * ire_gateway_addr_v6 as it is appearing first
    722 		 * time on the list and rts_setgwr_v6 could not
    723 		 * be changing this.
    724 		 */
    725 		addr_v6 = &ire->ire_gateway_addr_v6;
    726 		if (IN6_IS_ADDR_UNSPECIFIED(addr_v6))
    727 			addr_v6 = &ire->ire_addr_v6;
    728 
    729 		/* nce fastpath is per-ill; don't match across illgrp */
    730 		nce = ndp_lookup_v6(ill, B_FALSE, addr_v6, B_TRUE);
    731 		if (nce == NULL)
    732 			goto failed;
    733 
    734 		/* Pair of refhold, refrele just to get the tracing right */
    735 		NCE_REFHOLD_TO_REFHOLD_NOTR(nce);
    736 		/*
    737 		 * Atomically make sure that new IREs don't point
    738 		 * to an NCE that is logically deleted (CONDEMNED).
    739 		 * ndp_delete() first marks the NCE CONDEMNED.
    740 		 * This ensures that the nce_refcnt won't increase
    741 		 * due to new nce_lookups or due to addition of new IREs
    742 		 * pointing to this NCE. Then ndp_delete() cleans up
    743 		 * existing references. If we don't do it atomically here,
    744 		 * ndp_delete() -> nce_ire_delete() will not be able to
    745 		 * clean up the IRE list completely, and the nce_refcnt
    746 		 * won't go down to zero.
    747 		 */
    748 		mutex_enter(&nce->nce_lock);
    749 		if (ill->ill_flags & ILLF_XRESOLV) {
    750 			/*
    751 			 * If we used an external resolver, we may not
    752 			 * have gone through neighbor discovery to get here.
    753 			 * Must update the nce_state before the next check.
    754 			 */
    755 			if (nce->nce_state == ND_INCOMPLETE)
    756 				nce->nce_state = ND_REACHABLE;
    757 		}
    758 		if (nce->nce_state == ND_INCOMPLETE ||
    759 		    (nce->nce_flags & NCE_F_CONDEMNED) ||
    760 		    (nce->nce_state == ND_UNREACHABLE)) {
    761 failed:
    762 			if (ndp_g_lock_held)
    763 				mutex_exit(&ipst->ips_ndp6->ndp_g_lock);
    764 			if (nce != NULL)
    765 				mutex_exit(&nce->nce_lock);
    766 			ire_atomic_end(irb_ptr, ire);
    767 			ip1dbg(("ire_add_v6: No nce for dst %s \n",
    768 			    inet_ntop(AF_INET6, &ire->ire_addr_v6,
    769 			    buf, sizeof (buf))));
    770 			ire_delete(ire);
    771 			if (pire != NULL) {
    772 				/*
    773 				 * Assert that it is
    774 				 * not yet removed from the list.
    775 				 */
    776 				ASSERT(pire->ire_ptpn != NULL);
    777 				IRB_REFRELE(pire->ire_bucket);
    778 				ire_refrele(pire);
    779 			}
    780 			if (nce != NULL)
    781 				NCE_REFRELE_NOTR(nce);
    782 			*ire_p = NULL;
    783 			return (EINVAL);
    784 		} else {
    785 			ire->ire_nce = nce;
    786 		}
    787 		mutex_exit(&nce->nce_lock);
    788 	}
    789 	/*
    790 	 * Find the first entry that matches ire_addr - provides
    791 	 * tail insertion. *irep will be null if no match.
    792 	 */
    793 	irep = (ire_t **)irb_ptr;
    794 	while ((ire1 = *irep) != NULL &&
    795 	    !IN6_ARE_ADDR_EQUAL(&ire->ire_addr_v6, &ire1->ire_addr_v6))
    796 		irep = &ire1->ire_next;
    797 	ASSERT(!(ire->ire_type & IRE_BROADCAST));
    798 
    799 	if (*irep != NULL) {
    800 		/*
    801 		 * Find the last ire which matches ire_addr_v6.
    802 		 * Needed to do tail insertion among entries with the same
    803 		 * ire_addr_v6.
    804 		 */
    805 		while (IN6_ARE_ADDR_EQUAL(&ire->ire_addr_v6,
    806 		    &ire1->ire_addr_v6)) {
    807 			irep = &ire1->ire_next;
    808 			ire1 = *irep;
    809 			if (ire1 == NULL)
    810 				break;
    811 		}
    812 	}
    813 
    814 	if (ire->ire_type == IRE_DEFAULT) {
    815 		/*
    816 		 * We keep a count of default gateways which is used when
    817 		 * assigning them as routes.
    818 		 */
    819 		ipst->ips_ipv6_ire_default_count++;
    820 		ASSERT(ipst->ips_ipv6_ire_default_count != 0); /* Wraparound */
    821 	}
    822 	/* Insert at *irep */
    823 	ire1 = *irep;
    824 	if (ire1 != NULL)
    825 		ire1->ire_ptpn = &ire->ire_next;
    826 	ire->ire_next = ire1;
    827 	/* Link the new one in. */
    828 	ire->ire_ptpn = irep;
    829 	/*
    830 	 * ire_walk routines de-reference ire_next without holding
    831 	 * a lock. Before we point to the new ire, we want to make
    832 	 * sure the store that sets the ire_next of the new ire
    833 	 * reaches global visibility, so that ire_walk routines
    834 	 * don't see a truncated list of ires i.e if the ire_next
    835 	 * of the new ire gets set after we do "*irep = ire" due
    836 	 * to re-ordering, the ire_walk thread will see a NULL
    837 	 * once it accesses the ire_next of the new ire.
    838 	 * membar_producer() makes sure that the following store
    839 	 * happens *after* all of the above stores.
    840 	 */
    841 	membar_producer();
    842 	*irep = ire;
    843 	ire->ire_bucket = irb_ptr;
    844 	/*
    845 	 * We return a bumped up IRE above. Keep it symmetrical
    846 	 * so that the callers will always have to release. This
    847 	 * helps the callers of this function because they continue
    848 	 * to use the IRE after adding and hence they don't have to
    849 	 * lookup again after we return the IRE.
    850 	 *
    851 	 * NOTE : We don't have to use atomics as this is appearing
    852 	 * in the list for the first time and no one else can bump
    853 	 * up the reference count on this yet.
    854 	 */
    855 	IRE_REFHOLD_LOCKED(ire);
    856 	BUMP_IRE_STATS(ipst->ips_ire_stats_v6, ire_stats_inserted);
    857 	irb_ptr->irb_ire_cnt++;
    858 	if (ire->ire_marks & IRE_MARK_TEMPORARY)
    859 		irb_ptr->irb_tmp_ire_cnt++;
    860 
    861 	if (ire->ire_ipif != NULL) {
    862 		DTRACE_PROBE3(ipif__incr__cnt, (ipif_t *), ire->ire_ipif,
    863 		    (char *), "ire", (void *), ire);
    864 		ire->ire_ipif->ipif_ire_cnt++;
    865 		if (ire->ire_stq != NULL) {
    866 			stq_ill = (ill_t *)ire->ire_stq->q_ptr;
    867 			DTRACE_PROBE3(ill__incr__cnt, (ill_t *), stq_ill,
    868 			    (char *), "ire", (void *), ire);
    869 			stq_ill->ill_ire_cnt++;
    870 		}
    871 	} else {
    872 		ASSERT(ire->ire_stq == NULL);
    873 	}
    874 
    875 	if (ndp_g_lock_held)
    876 		mutex_exit(&ipst->ips_ndp6->ndp_g_lock);
    877 	ire_atomic_end(irb_ptr, ire);
    878 
    879 	if (pire != NULL) {
    880 		/* Assert that it is not removed from the list yet */
    881 		ASSERT(pire->ire_ptpn != NULL);
    882 		IRB_REFRELE(pire->ire_bucket);
    883 		ire_refrele(pire);
    884 	}
    885 
    886 	if (ire->ire_type != IRE_CACHE) {
    887 		/*
    888 		 * For ire's with with host mask see if there is an entry
    889 		 * in the cache. If there is one flush the whole cache as
    890 		 * there might be multiple entries due to RTF_MULTIRT (CGTP).
    891 		 * If no entry is found than there is no need to flush the
    892 		 * cache.
    893 		 */
    894 
    895 		if (ip_mask_to_plen_v6(&ire->ire_mask_v6) == IPV6_ABITS) {
    896 			ire_t *lire;
    897 			lire = ire_ctable_lookup_v6(&ire->ire_addr_v6, NULL,
    898 			    IRE_CACHE, NULL, ALL_ZONES, NULL, MATCH_IRE_TYPE,
    899 			    ipst);
    900 			if (lire != NULL) {
    901 				ire_refrele(lire);
    902 				ire_flush_cache_v6(ire, IRE_FLUSH_ADD);
    903 			}
    904 		} else {
    905 			ire_flush_cache_v6(ire, IRE_FLUSH_ADD);
    906 		}
    907 	}
    908 
    909 	*ire_p = ire;
    910 	return (0);
    911 }
    912 
    913 /*
    914  * Search for all HOST REDIRECT routes that are
    915  * pointing at the specified gateway and
    916  * delete them. This routine is called only
    917  * when a default gateway is going away.
    918  */
    919 static void
    920 ire_delete_host_redirects_v6(const in6_addr_t *gateway, ip_stack_t *ipst)
    921 {
    922 	irb_t *irb_ptr;
    923 	irb_t *irb;
    924 	ire_t *ire;
    925 	in6_addr_t gw_addr_v6;
    926 	int i;
    927 
    928 	/* get the hash table for HOST routes */
    929 	irb_ptr = ipst->ips_ip_forwarding_table_v6[(IP6_MASK_TABLE_SIZE - 1)];
    930 	if (irb_ptr == NULL)
    931 		return;
    932 	for (i = 0; (i < ipst->ips_ip6_ftable_hash_size); i++) {
    933 		irb = &irb_ptr[i];
    934 		IRB_REFHOLD(irb);
    935 		for (ire = irb->irb_ire; ire != NULL; ire = ire->ire_next) {
    936 			if (!(ire->ire_flags & RTF_DYNAMIC))
    937 				continue;
    938 			mutex_enter(&ire->ire_lock);
    939 			gw_addr_v6 = ire->ire_gateway_addr_v6;
    940 			mutex_exit(&ire->ire_lock);
    941 			if (IN6_ARE_ADDR_EQUAL(&gw_addr_v6, gateway))
    942 				ire_delete(ire);
    943 		}
    944 		IRB_REFRELE(irb);
    945 	}
    946 }
    947 
    948 /*
    949  * Delete all the cache entries with this 'addr'. This is the IPv6 counterpart
    950  * of ip_ire_clookup_and_delete. The difference being this function does not
    951  * return any value. IPv6 processing of a gratuitous ARP, as it stands, is
    952  * different than IPv4 in that, regardless of the presence of a cache entry
    953  * for this address, an ire_walk_v6 is done. Another difference is that unlike
    954  * in the case of IPv4 this does not take an ipif_t argument, since it is only
    955  * called by ip_arp_news and the match is always only on the address.
    956  */
    957 void
    958 ip_ire_clookup_and_delete_v6(const in6_addr_t *addr, ip_stack_t *ipst)
    959 {
    960 	irb_t		*irb;
    961 	ire_t		*cire;
    962 	boolean_t	found = B_FALSE;
    963 
    964 	irb = &ipst->ips_ip_cache_table_v6[IRE_ADDR_HASH_V6(*addr,
    965 	    ipst->ips_ip6_cache_table_size)];
    966 	IRB_REFHOLD(irb);
    967 	for (cire = irb->irb_ire; cire != NULL; cire = cire->ire_next) {
    968 		if (cire->ire_marks & IRE_MARK_CONDEMNED)
    969 			continue;
    970 		if (IN6_ARE_ADDR_EQUAL(&cire->ire_addr_v6, addr)) {
    971 
    972 			/* This signifies start of a match */
    973 			if (!found)
    974 				found = B_TRUE;
    975 			if (cire->ire_type == IRE_CACHE) {
    976 				if (cire->ire_nce != NULL)
    977 					ndp_delete(cire->ire_nce);
    978 				ire_delete_v6(cire);
    979 			}
    980 		/* End of the match */
    981 		} else if (found)
    982 			break;
    983 	}
    984 	IRB_REFRELE(irb);
    985 }
    986 
    987 /*
    988  * Delete the specified IRE.
    989  * All calls should use ire_delete().
    990  * Sometimes called as writer though not required by this function.
    991  *
    992  * NOTE : This function is called only if the ire was added
    993  * in the list.
    994  */
    995 void
    996 ire_delete_v6(ire_t *ire)
    997 {
    998 	in6_addr_t gw_addr_v6;
    999 	ip_stack_t	*ipst = ire->ire_ipst;
   1000 
   1001 	ASSERT(ire->ire_refcnt >= 1);
   1002 	ASSERT(ire->ire_ipversion == IPV6_VERSION);
   1003 
   1004 	if (ire->ire_type != IRE_CACHE)
   1005 		ire_flush_cache_v6(ire, IRE_FLUSH_DELETE);
   1006 	if (ire->ire_type == IRE_DEFAULT) {
   1007 		/*
   1008 		 * when a default gateway is going away
   1009 		 * delete all the host redirects pointing at that
   1010 		 * gateway.
   1011 		 */
   1012 		mutex_enter(&ire->ire_lock);
   1013 		gw_addr_v6 = ire->ire_gateway_addr_v6;
   1014 		mutex_exit(&ire->ire_lock);
   1015 		ire_delete_host_redirects_v6(&gw_addr_v6, ipst);
   1016 	}
   1017 }
   1018 
   1019 /*
   1020  * ire_walk routine to delete all IRE_CACHE and IRE_HOST type redirect
   1021  * entries.
   1022  */
   1023 /*ARGSUSED1*/
   1024 void
   1025 ire_delete_cache_v6(ire_t *ire, char *arg)
   1026 {
   1027 	char    addrstr1[INET6_ADDRSTRLEN];
   1028 	char    addrstr2[INET6_ADDRSTRLEN];
   1029 
   1030 	if ((ire->ire_type & IRE_CACHE) ||
   1031 	    (ire->ire_flags & RTF_DYNAMIC)) {
   1032 		ip1dbg(("ire_delete_cache_v6: deleted %s type %d through %s\n",
   1033 		    inet_ntop(AF_INET6, &ire->ire_addr_v6,
   1034 		    addrstr1, sizeof (addrstr1)),
   1035 		    ire->ire_type,
   1036 		    inet_ntop(AF_INET6, &ire->ire_gateway_addr_v6,
   1037 		    addrstr2, sizeof (addrstr2))));
   1038 		ire_delete(ire);
   1039 	}
   1040 
   1041 }
   1042 
   1043 /*
   1044  * ire_walk routine to delete all IRE_CACHE/IRE_HOST type redirect entries
   1045  * that have a given gateway address.
   1046  */
   1047 void
   1048 ire_delete_cache_gw_v6(ire_t *ire, char *addr)
   1049 {
   1050 	in6_addr_t	*gw_addr = (in6_addr_t *)addr;
   1051 	char		buf1[INET6_ADDRSTRLEN];
   1052 	char		buf2[INET6_ADDRSTRLEN];
   1053 	in6_addr_t	ire_gw_addr_v6;
   1054 
   1055 	if (!(ire->ire_type & IRE_CACHE) &&
   1056 	    !(ire->ire_flags & RTF_DYNAMIC))
   1057 		return;
   1058 
   1059 	mutex_enter(&ire->ire_lock);
   1060 	ire_gw_addr_v6 = ire->ire_gateway_addr_v6;
   1061 	mutex_exit(&ire->ire_lock);
   1062 
   1063 	if (IN6_ARE_ADDR_EQUAL(&ire_gw_addr_v6, gw_addr)) {
   1064 		ip1dbg(("ire_delete_cache_gw_v6: deleted %s type %d to %s\n",
   1065 		    inet_ntop(AF_INET6, &ire->ire_src_addr_v6,
   1066 		    buf1, sizeof (buf1)),
   1067 		    ire->ire_type,
   1068 		    inet_ntop(AF_INET6, &ire_gw_addr_v6,
   1069 		    buf2, sizeof (buf2))));
   1070 		ire_delete(ire);
   1071 	}
   1072 }
   1073 
   1074 /*
   1075  * Remove all IRE_CACHE entries that match
   1076  * the ire specified.  (Sometimes called
   1077  * as writer though not required by this function.)
   1078  *
   1079  * The flag argument indicates if the
   1080  * flush request is due to addition
   1081  * of new route (IRE_FLUSH_ADD) or deletion of old
   1082  * route (IRE_FLUSH_DELETE).
   1083  *
   1084  * This routine takes only the IREs from the forwarding
   1085  * table and flushes the corresponding entries from
   1086  * the cache table.
   1087  *
   1088  * When flushing due to the deletion of an old route, it
   1089  * just checks the cache handles (ire_phandle and ire_ihandle) and
   1090  * deletes the ones that match.
   1091  *
   1092  * When flushing due to the creation of a new route, it checks
   1093  * if a cache entry's address matches the one in the IRE and
   1094  * that the cache entry's parent has a less specific mask than the
   1095  * one in IRE. The destination of such a cache entry could be the
   1096  * gateway for other cache entries, so we need to flush those as
   1097  * well by looking for gateway addresses matching the IRE's address.
   1098  */
   1099 void
   1100 ire_flush_cache_v6(ire_t *ire, int flag)
   1101 {
   1102 	int i;
   1103 	ire_t *cire;
   1104 	irb_t *irb;
   1105 	ip_stack_t	*ipst = ire->ire_ipst;
   1106 
   1107 	if (ire->ire_type & IRE_CACHE)
   1108 		return;
   1109 
   1110 	/*
   1111 	 * If a default is just created, there is no point
   1112 	 * in going through the cache, as there will not be any
   1113 	 * cached ires.
   1114 	 */
   1115 	if (ire->ire_type == IRE_DEFAULT && flag == IRE_FLUSH_ADD)
   1116 		return;
   1117 	if (flag == IRE_FLUSH_ADD) {
   1118 		/*
   1119 		 * This selective flush is
   1120 		 * due to the addition of
   1121 		 * new IRE.
   1122 		 */
   1123 		for (i = 0; i < ipst->ips_ip6_cache_table_size; i++) {
   1124 			irb = &ipst->ips_ip_cache_table_v6[i];
   1125 			if ((cire = irb->irb_ire) == NULL)
   1126 				continue;
   1127 			IRB_REFHOLD(irb);
   1128 			for (cire = irb->irb_ire; cire != NULL;
   1129 			    cire = cire->ire_next) {
   1130 				if (cire->ire_type != IRE_CACHE)
   1131 					continue;
   1132 				/*
   1133 				 * If 'cire' belongs to the same subnet
   1134 				 * as the new ire being added, and 'cire'
   1135 				 * is derived from a prefix that is less
   1136 				 * specific than the new ire being added,
   1137 				 * we need to flush 'cire'; for instance,
   1138 				 * when a new interface comes up.
   1139 				 */
   1140 				if ((V6_MASK_EQ_2(cire->ire_addr_v6,
   1141 				    ire->ire_mask_v6, ire->ire_addr_v6) &&
   1142 				    (ip_mask_to_plen_v6(&cire->ire_cmask_v6) <=
   1143 				    ire->ire_masklen))) {
   1144 					ire_delete(cire);
   1145 					continue;
   1146 				}
   1147 				/*
   1148 				 * This is the case when the ire_gateway_addr
   1149 				 * of 'cire' belongs to the same subnet as
   1150 				 * the new ire being added.
   1151 				 * Flushing such ires is sometimes required to
   1152 				 * avoid misrouting: say we have a machine with
   1153 				 * two interfaces (I1 and I2), a default router
   1154 				 * R on the I1 subnet, and a host route to an
   1155 				 * off-link destination D with a gateway G on
   1156 				 * the I2 subnet.
   1157 				 * Under normal operation, we will have an
   1158 				 * on-link cache entry for G and an off-link
   1159 				 * cache entry for D with G as ire_gateway_addr,
   1160 				 * traffic to D will reach its destination
   1161 				 * through gateway G.
   1162 				 * If the administrator does 'ifconfig I2 down',
   1163 				 * the cache entries for D and G will be
   1164 				 * flushed. However, G will now be resolved as
   1165 				 * an off-link destination using R (the default
   1166 				 * router) as gateway. Then D will also be
   1167 				 * resolved as an off-link destination using G
   1168 				 * as gateway - this behavior is due to
   1169 				 * compatibility reasons, see comment in
   1170 				 * ire_ihandle_lookup_offlink(). Traffic to D
   1171 				 * will go to the router R and probably won't
   1172 				 * reach the destination.
   1173 				 * The administrator then does 'ifconfig I2 up'.
   1174 				 * Since G is on the I2 subnet, this routine
   1175 				 * will flush its cache entry. It must also
   1176 				 * flush the cache entry for D, otherwise
   1177 				 * traffic will stay misrouted until the IRE
   1178 				 * times out.
   1179 				 */
   1180 				if (V6_MASK_EQ_2(cire->ire_gateway_addr_v6,
   1181 				    ire->ire_mask_v6, ire->ire_addr_v6)) {
   1182 					ire_delete(cire);
   1183 					continue;
   1184 				}
   1185 			}
   1186 			IRB_REFRELE(irb);
   1187 		}
   1188 	} else {
   1189 		/*
   1190 		 * delete the cache entries based on
   1191 		 * handle in the IRE as this IRE is
   1192 		 * being deleted/changed.
   1193 		 */
   1194 		for (i = 0; i < ipst->ips_ip6_cache_table_size; i++) {
   1195 			irb = &ipst->ips_ip_cache_table_v6[i];
   1196 			if ((cire = irb->irb_ire) == NULL)
   1197 				continue;
   1198 			IRB_REFHOLD(irb);
   1199 			for (cire = irb->irb_ire; cire != NULL;
   1200 			    cire = cire->ire_next) {
   1201 				if (cire->ire_type != IRE_CACHE)
   1202 					continue;
   1203 				if ((cire->ire_phandle == 0 ||
   1204 				    cire->ire_phandle != ire->ire_phandle) &&
   1205 				    (cire->ire_ihandle == 0 ||
   1206 				    cire->ire_ihandle != ire->ire_ihandle))
   1207 					continue;
   1208 				ire_delete(cire);
   1209 			}
   1210 			IRB_REFRELE(irb);
   1211 		}
   1212 	}
   1213 }
   1214 
   1215 /*
   1216  * Matches the arguments passed with the values in the ire.
   1217  *
   1218  * Note: for match types that match using "ipif" passed in, ipif
   1219  * must be checked for non-NULL before calling this routine.
   1220  */
   1221 static boolean_t
   1222 ire_match_args_v6(ire_t *ire, const in6_addr_t *addr, const in6_addr_t *mask,
   1223     const in6_addr_t *gateway, int type, const ipif_t *ipif, zoneid_t zoneid,
   1224     uint32_t ihandle, const ts_label_t *tsl, int match_flags)
   1225 {
   1226 	in6_addr_t masked_addr;
   1227 	in6_addr_t gw_addr_v6;
   1228 	ill_t *ire_ill = NULL, *dst_ill;
   1229 	ill_t *ipif_ill = NULL;
   1230 	ipif_t	*src_ipif;
   1231 
   1232 	ASSERT(ire->ire_ipversion == IPV6_VERSION);
   1233 	ASSERT(addr != NULL);
   1234 	ASSERT(mask != NULL);
   1235 	ASSERT((!(match_flags & MATCH_IRE_GW)) || gateway != NULL);
   1236 	ASSERT((!(match_flags & MATCH_IRE_ILL)) ||
   1237 	    (ipif != NULL && ipif->ipif_isv6));
   1238 
   1239 	/*
   1240 	 * If MATCH_IRE_MARK_TESTHIDDEN is set, then only return the IRE if it
   1241 	 * is in fact hidden, to ensure the caller gets the right one.  One
   1242 	 * exception: if the caller passed MATCH_IRE_IHANDLE, then they
   1243 	 * already know the identity of the given IRE_INTERFACE entry and
   1244 	 * there's no point trying to hide it from them.
   1245 	 */
   1246 	if (ire->ire_marks & IRE_MARK_TESTHIDDEN) {
   1247 		if (match_flags & MATCH_IRE_IHANDLE)
   1248 			match_flags |= MATCH_IRE_MARK_TESTHIDDEN;
   1249 
   1250 		if (!(match_flags & MATCH_IRE_MARK_TESTHIDDEN))
   1251 			return (B_FALSE);
   1252 	}
   1253 
   1254 	if (zoneid != ALL_ZONES && zoneid != ire->ire_zoneid &&
   1255 	    ire->ire_zoneid != ALL_ZONES) {
   1256 		/*
   1257 		 * If MATCH_IRE_ZONEONLY has been set and the supplied zoneid is
   1258 		 * valid and does not match that of ire_zoneid, a failure to
   1259 		 * match is reported at this point. Otherwise, since some IREs
   1260 		 * that are available in the global zone can be used in local
   1261 		 * zones, additional checks need to be performed:
   1262 		 *
   1263 		 *	IRE_CACHE and IRE_LOOPBACK entries should
   1264 		 *	never be matched in this situation.
   1265 		 *
   1266 		 *	IRE entries that have an interface associated with them
   1267 		 *	should in general not match unless they are an IRE_LOCAL
   1268 		 *	or in the case when MATCH_IRE_DEFAULT has been set in
   1269 		 *	the caller.  In the case of the former, checking of the
   1270 		 *	other fields supplied should take place.
   1271 		 *
   1272 		 *	In the case where MATCH_IRE_DEFAULT has been set,
   1273 		 *	all of the ipif's associated with the IRE's ill are
   1274 		 *	checked to see if there is a matching zoneid.  If any
   1275 		 *	one ipif has a matching zoneid, this IRE is a
   1276 		 *	potential candidate so checking of the other fields
   1277 		 *	takes place.
   1278 		 *
   1279 		 *	In the case where the IRE_INTERFACE has a usable source
   1280 		 *	address (indicated by ill_usesrc_ifindex) in the
   1281 		 *	correct zone then it's permitted to return this IRE
   1282 		 */
   1283 		if (match_flags & MATCH_IRE_ZONEONLY)
   1284 			return (B_FALSE);
   1285 		if (ire->ire_type & (IRE_CACHE | IRE_LOOPBACK))
   1286 			return (B_FALSE);
   1287 		/*
   1288 		 * Note, IRE_INTERFACE can have the stq as NULL. For
   1289 		 * example, if the default multicast route is tied to
   1290 		 * the loopback address.
   1291 		 */
   1292 		if ((ire->ire_type & IRE_INTERFACE) &&
   1293 		    (ire->ire_stq != NULL)) {
   1294 			dst_ill = (ill_t *)ire->ire_stq->q_ptr;
   1295 			/*
   1296 			 * If there is a usable source address in the
   1297 			 * zone, then it's ok to return an
   1298 			 * IRE_INTERFACE
   1299 			 */
   1300 			if ((dst_ill->ill_usesrc_ifindex != 0) &&
   1301 			    (src_ipif = ipif_select_source_v6(dst_ill, addr,
   1302 			    B_FALSE, IPV6_PREFER_SRC_DEFAULT, zoneid))
   1303 			    != NULL) {
   1304 				ip3dbg(("ire_match_args: src_ipif %p"
   1305 				    " dst_ill %p", (void *)src_ipif,
   1306 				    (void *)dst_ill));
   1307 				ipif_refrele(src_ipif);
   1308 			} else {
   1309 				ip3dbg(("ire_match_args: src_ipif NULL"
   1310 				    " dst_ill %p\n", (void *)dst_ill));
   1311 				return (B_FALSE);
   1312 			}
   1313 		}
   1314 		if (ire->ire_ipif != NULL && ire->ire_type != IRE_LOCAL &&
   1315 		    !(ire->ire_type & IRE_INTERFACE)) {
   1316 			ipif_t	*tipif;
   1317 
   1318 			if ((match_flags & MATCH_IRE_DEFAULT) == 0)
   1319 				return (B_FALSE);
   1320 			mutex_enter(&ire->ire_ipif->ipif_ill->ill_lock);
   1321 			for (tipif = ire->ire_ipif->ipif_ill->ill_ipif;
   1322 			    tipif != NULL; tipif = tipif->ipif_next) {
   1323 				if (IPIF_CAN_LOOKUP(tipif) &&
   1324 				    (tipif->ipif_flags & IPIF_UP) &&
   1325 				    (tipif->ipif_zoneid == zoneid ||
   1326 				    tipif->ipif_zoneid == ALL_ZONES))
   1327 					break;
   1328 			}
   1329 			mutex_exit(&ire->ire_ipif->ipif_ill->ill_lock);
   1330 			if (tipif == NULL)
   1331 				return (B_FALSE);
   1332 		}
   1333 	}
   1334 
   1335 	if (match_flags & MATCH_IRE_GW) {
   1336 		mutex_enter(&ire->ire_lock);
   1337 		gw_addr_v6 = ire->ire_gateway_addr_v6;
   1338 		mutex_exit(&ire->ire_lock);
   1339 	}
   1340 
   1341 	/*
   1342 	 * For IRE_CACHE entries, MATCH_IRE_ILL means that somebody wants to
   1343 	 * send out ire_stq (ire_ipif for IRE_CACHE entries is just the means
   1344 	 * of getting a source address -- i.e., ire_src_addr_v6 ==
   1345 	 * ire->ire_ipif->ipif_v6src_addr).  ire_to_ill() handles this.
   1346 	 *
   1347 	 * NOTE: For IPMP, MATCH_IRE_ILL usually matches any ill in the group.
   1348 	 * However, if MATCH_IRE_MARK_TESTHIDDEN is set (i.e., the IRE is for
   1349 	 * IPMP test traffic), then the ill must match exactly.
   1350 	 */
   1351 	if (match_flags & MATCH_IRE_ILL) {
   1352 		ire_ill = ire_to_ill(ire);
   1353 		ipif_ill = ipif->ipif_ill;
   1354 	}
   1355 
   1356 	/* No ire_addr_v6 bits set past the mask */
   1357 	ASSERT(V6_MASK_EQ(ire->ire_addr_v6, ire->ire_mask_v6,
   1358 	    ire->ire_addr_v6));
   1359 	V6_MASK_COPY(*addr, *mask, masked_addr);
   1360 
   1361 	if (V6_MASK_EQ(*addr, *mask, ire->ire_addr_v6) &&
   1362 	    ((!(match_flags & MATCH_IRE_GW)) ||
   1363 	    IN6_ARE_ADDR_EQUAL(&gw_addr_v6, gateway)) &&
   1364 	    ((!(match_flags & MATCH_IRE_TYPE)) ||
   1365 	    (ire->ire_type & type)) &&
   1366 	    ((!(match_flags & MATCH_IRE_SRC)) ||
   1367 	    IN6_ARE_ADDR_EQUAL(&ire->ire_src_addr_v6,
   1368 	    &ipif->ipif_v6src_addr)) &&
   1369 	    ((!(match_flags & MATCH_IRE_IPIF)) ||
   1370 	    (ire->ire_ipif == ipif)) &&
   1371 	    ((!(match_flags & MATCH_IRE_MARK_TESTHIDDEN)) ||
   1372 	    (ire->ire_marks & IRE_MARK_TESTHIDDEN)) &&
   1373 	    ((!(match_flags & MATCH_IRE_ILL)) ||
   1374 	    (ire_ill == ipif_ill ||
   1375 	    (!(match_flags & MATCH_IRE_MARK_TESTHIDDEN) &&
   1376 	    ire_ill != NULL && IS_IN_SAME_ILLGRP(ipif_ill, ire_ill)))) &&
   1377 	    ((!(match_flags & MATCH_IRE_IHANDLE)) ||
   1378 	    (ire->ire_ihandle == ihandle)) &&
   1379 	    ((!(match_flags & MATCH_IRE_SECATTR)) ||
   1380 	    (!is_system_labeled()) ||
   1381 	    (tsol_ire_match_gwattr(ire, tsl) == 0))) {
   1382 		/* We found the matched IRE */
   1383 		return (B_TRUE);
   1384 	}
   1385 	return (B_FALSE);
   1386 }
   1387 
   1388 /*
   1389  * Lookup for a route in all the tables
   1390  */
   1391 ire_t *
   1392 ire_route_lookup_v6(const in6_addr_t *addr, const in6_addr_t *mask,
   1393     const in6_addr_t *gateway, int type, const ipif_t *ipif, ire_t **pire,
   1394     zoneid_t zoneid, const ts_label_t *tsl, int flags, ip_stack_t *ipst)
   1395 {
   1396 	ire_t *ire = NULL;
   1397 
   1398 	/*
   1399 	 * ire_match_args_v6() will dereference ipif MATCH_IRE_SRC or
   1400 	 * MATCH_IRE_ILL is set.
   1401 	 */
   1402 	if ((flags & (MATCH_IRE_SRC | MATCH_IRE_ILL)) && (ipif == NULL))
   1403 		return (NULL);
   1404 
   1405 	/*
   1406 	 * might be asking for a cache lookup,
   1407 	 * This is not best way to lookup cache,
   1408 	 * user should call ire_cache_lookup directly.
   1409 	 *
   1410 	 * If MATCH_IRE_TYPE was set, first lookup in the cache table and then
   1411 	 * in the forwarding table, if the applicable type flags were set.
   1412 	 */
   1413 	if ((flags & MATCH_IRE_TYPE) == 0 || (type & IRE_CACHETABLE) != 0) {
   1414 		ire = ire_ctable_lookup_v6(addr, gateway, type, ipif, zoneid,
   1415 		    tsl, flags, ipst);
   1416 		if (ire != NULL)
   1417 			return (ire);
   1418 	}
   1419 	if ((flags & MATCH_IRE_TYPE) == 0 || (type & IRE_FORWARDTABLE) != 0) {
   1420 		ire = ire_ftable_lookup_v6(addr, mask, gateway, type, ipif,
   1421 		    pire, zoneid, 0, tsl, flags, ipst);
   1422 	}
   1423 	return (ire);
   1424 }
   1425 
   1426 /*
   1427  * Lookup a route in forwarding table.
   1428  * specific lookup is indicated by passing the
   1429  * required parameters and indicating the
   1430  * match required in flag field.
   1431  *
   1432  * Looking for default route can be done in three ways
   1433  * 1) pass mask as ipv6_all_zeros and set MATCH_IRE_MASK in flags field
   1434  *    along with other matches.
   1435  * 2) pass type as IRE_DEFAULT and set MATCH_IRE_TYPE in flags
   1436  *    field along with other matches.
   1437  * 3) if the destination and mask are passed as zeros.
   1438  *
   1439  * A request to return a default route if no route
   1440  * is found, can be specified by setting MATCH_IRE_DEFAULT
   1441  * in flags.
   1442  *
   1443  * It does not support recursion more than one level. It
   1444  * will do recursive lookup only when the lookup maps to
   1445  * a prefix or default route and MATCH_IRE_RECURSIVE flag is passed.
   1446  *
   1447  * If the routing table is setup to allow more than one level
   1448  * of recursion, the cleaning up cache table will not work resulting
   1449  * in invalid routing.
   1450  *
   1451  * Supports link-local addresses by following the ipif/ill when recursing.
   1452  *
   1453  * NOTE : When this function returns NULL, pire has already been released.
   1454  *	  pire is valid only when this function successfully returns an
   1455  *	  ire.
   1456  */
   1457 ire_t *
   1458 ire_ftable_lookup_v6(const in6_addr_t *addr, const in6_addr_t *mask,
   1459     const in6_addr_t *gateway, int type, const ipif_t *ipif, ire_t **pire,
   1460     zoneid_t zoneid, uint32_t ihandle, const ts_label_t *tsl, int flags,
   1461     ip_stack_t *ipst)
   1462 {
   1463 	irb_t *irb_ptr;
   1464 	ire_t	*rire;
   1465 	ire_t *ire = NULL;
   1466 	ire_t	*saved_ire;
   1467 	nce_t	*nce;
   1468 	int i;
   1469 	in6_addr_t gw_addr_v6;
   1470 
   1471 	ASSERT(addr != NULL);
   1472 	ASSERT((!(flags & MATCH_IRE_MASK)) || mask != NULL);
   1473 	ASSERT((!(flags & MATCH_IRE_GW)) || gateway != NULL);
   1474 	ASSERT(ipif == NULL || ipif->ipif_isv6);
   1475 
   1476 	/*
   1477 	 * When we return NULL from this function, we should make
   1478 	 * sure that *pire is NULL so that the callers will not
   1479 	 * wrongly REFRELE the pire.
   1480 	 */
   1481 	if (pire != NULL)
   1482 		*pire = NULL;
   1483 	/*
   1484 	 * ire_match_args_v6() will dereference ipif MATCH_IRE_SRC or
   1485 	 * MATCH_IRE_ILL is set.
   1486 	 */
   1487 	if ((flags & (MATCH_IRE_SRC | MATCH_IRE_ILL)) && (ipif == NULL))
   1488 		return (NULL);
   1489 
   1490 	/*
   1491 	 * If the mask is known, the lookup
   1492 	 * is simple, if the mask is not known
   1493 	 * we need to search.
   1494 	 */
   1495 	if (flags & MATCH_IRE_MASK) {
   1496 		uint_t masklen;
   1497 
   1498 		masklen = ip_mask_to_plen_v6(mask);
   1499 		if (ipst->ips_ip_forwarding_table_v6[masklen] == NULL)
   1500 			return (NULL);
   1501 		irb_ptr = &(ipst->ips_ip_forwarding_table_v6[masklen][
   1502 		    IRE_ADDR_MASK_HASH_V6(*addr, *mask,
   1503 		    ipst->ips_ip6_ftable_hash_size)]);
   1504 		rw_enter(&irb_ptr->irb_lock, RW_READER);
   1505 		for (ire = irb_ptr->irb_ire; ire != NULL;
   1506 		    ire = ire->ire_next) {
   1507 			if (ire->ire_marks & IRE_MARK_CONDEMNED)
   1508 				continue;
   1509 			if (ire_match_args_v6(ire, addr, mask, gateway, type,
   1510 			    ipif, zoneid, ihandle, tsl, flags))
   1511 				goto found_ire;
   1512 		}
   1513 		rw_exit(&irb_ptr->irb_lock);
   1514 	} else {
   1515 		/*
   1516 		 * In this case we don't know the mask, we need to
   1517 		 * search the table assuming different mask sizes.
   1518 		 * we start with 128 bit mask, we don't allow default here.
   1519 		 */
   1520 		for (i = (IP6_MASK_TABLE_SIZE - 1); i > 0; i--) {
   1521 			in6_addr_t tmpmask;
   1522 
   1523 			if ((ipst->ips_ip_forwarding_table_v6[i]) == NULL)
   1524 				continue;
   1525 			(void) ip_plen_to_mask_v6(i, &tmpmask);
   1526 			irb_ptr = &ipst->ips_ip_forwarding_table_v6[i][
   1527 			    IRE_ADDR_MASK_HASH_V6(*addr, tmpmask,
   1528 			    ipst->ips_ip6_ftable_hash_size)];
   1529 			rw_enter(&irb_ptr->irb_lock, RW_READER);
   1530 			for (ire = irb_ptr->irb_ire; ire != NULL;
   1531 			    ire = ire->ire_next) {
   1532 				if (ire->ire_marks & IRE_MARK_CONDEMNED)
   1533 					continue;
   1534 				if (ire_match_args_v6(ire, addr,
   1535 				    &ire->ire_mask_v6, gateway, type, ipif,
   1536 				    zoneid, ihandle, tsl, flags))
   1537 					goto found_ire;
   1538 			}
   1539 			rw_exit(&irb_ptr->irb_lock);
   1540 		}
   1541 	}
   1542 
   1543 	/*
   1544 	 * We come here if no route has yet been found.
   1545 	 *
   1546 	 * Handle the case where default route is
   1547 	 * requested by specifying type as one of the possible
   1548 	 * types for that can have a zero mask (IRE_DEFAULT and IRE_INTERFACE).
   1549 	 *
   1550 	 * If MATCH_IRE_MASK is specified, then the appropriate default route
   1551 	 * would have been found above if it exists so it isn't looked up here.
   1552 	 * If MATCH_IRE_DEFAULT was also specified, then a default route will be
   1553 	 * searched for later.
   1554 	 */
   1555 	if ((flags & (MATCH_IRE_TYPE | MATCH_IRE_MASK)) == MATCH_IRE_TYPE &&
   1556 	    (type & (IRE_DEFAULT | IRE_INTERFACE))) {
   1557 		if (ipst->ips_ip_forwarding_table_v6[0] != NULL) {
   1558 			/* addr & mask is zero for defaults */
   1559 			irb_ptr = &ipst->ips_ip_forwarding_table_v6[0][
   1560 			    IRE_ADDR_HASH_V6(ipv6_all_zeros,
   1561 			    ipst->ips_ip6_ftable_hash_size)];
   1562 			rw_enter(&irb_ptr->irb_lock, RW_READER);
   1563 			for (ire = irb_ptr->irb_ire; ire != NULL;
   1564 			    ire = ire->ire_next) {
   1565 
   1566 				if (ire->ire_marks & IRE_MARK_CONDEMNED)
   1567 					continue;
   1568 
   1569 				if (ire_match_args_v6(ire, addr,
   1570 				    &ipv6_all_zeros, gateway, type, ipif,
   1571 				    zoneid, ihandle, tsl, flags))
   1572 					goto found_ire;
   1573 			}
   1574 			rw_exit(&irb_ptr->irb_lock);
   1575 		}
   1576 	}
   1577 	/*
   1578 	 * We come here only if no route is found.
   1579 	 * see if the default route can be used which is allowed
   1580 	 * only if the default matching criteria is specified.
   1581 	 * The ipv6_ire_default_count tracks the number of IRE_DEFAULT
   1582 	 * entries. However, the ip_forwarding_table_v6[0] also contains
   1583 	 * interface routes thus the count can be zero.
   1584 	 */
   1585 	saved_ire = NULL;
   1586 	if ((flags & (MATCH_IRE_DEFAULT | MATCH_IRE_MASK)) ==
   1587 	    MATCH_IRE_DEFAULT) {
   1588 		ire_t	*ire_origin;
   1589 		uint_t	g_index;
   1590 		uint_t	index;
   1591 
   1592 		if (ipst->ips_ip_forwarding_table_v6[0] == NULL)
   1593 			return (NULL);
   1594 		irb_ptr = &(ipst->ips_ip_forwarding_table_v6[0])[0];
   1595 
   1596 		/*
   1597 		 * Keep a tab on the bucket while looking the IRE_DEFAULT
   1598 		 * entries. We need to keep track of a particular IRE
   1599 		 * (ire_origin) so this ensures that it will not be unlinked
   1600 		 * from the hash list during the recursive lookup below.
   1601 		 */
   1602 		IRB_REFHOLD(irb_ptr);
   1603 		ire = irb_ptr->irb_ire;
   1604 		if (ire == NULL) {
   1605 			IRB_REFRELE(irb_ptr);
   1606 			return (NULL);
   1607 		}
   1608 
   1609 		/*
   1610 		 * Get the index first, since it can be changed by other
   1611 		 * threads. Then get to the right default route skipping
   1612 		 * default interface routes if any. As we hold a reference on
   1613 		 * the IRE bucket, ipv6_ire_default_count can only increase so
   1614 		 * we can't reach the end of the hash list unexpectedly.
   1615 		 */
   1616 		if (ipst->ips_ipv6_ire_default_count != 0) {
   1617 			g_index = ipst->ips_ipv6_ire_default_index++;
   1618 			index = g_index % ipst->ips_ipv6_ire_default_count;
   1619 			while (index != 0) {
   1620 				if (!(ire->ire_type & IRE_INTERFACE))
   1621 					index--;
   1622 				ire = ire->ire_next;
   1623 			}
   1624 			ASSERT(ire != NULL);
   1625 		} else {
   1626 			/*
   1627 			 * No default route, so we only have default interface
   1628 			 * routes: don't enter the first loop.
   1629 			 */
   1630 			ire = NULL;
   1631 		}
   1632 
   1633 		/*
   1634 		 * Round-robin the default routers list looking for a neighbor
   1635 		 * that matches the passed in parameters and is reachable.  If
   1636 		 * none found, just return a route from the default router list
   1637 		 * if it exists. If we can't find a default route (IRE_DEFAULT),
   1638 		 * look for interface default routes.
   1639 		 * We start with the ire we found above and we walk the hash
   1640 		 * list until we're back where we started, see
   1641 		 * ire_get_next_default_ire(). It doesn't matter if default
   1642 		 * routes are added or deleted by other threads - we know this
   1643 		 * ire will stay in the list because we hold a reference on the
   1644 		 * ire bucket.
   1645 		 * NB: if we only have interface default routes, ire is NULL so
   1646 		 * we don't even enter this loop (see above).
   1647 		 */
   1648 		ire_origin = ire;
   1649 		for (; ire != NULL;
   1650 		    ire = ire_get_next_default_ire(ire, ire_origin)) {
   1651 
   1652 			if (ire_match_args_v6(ire, addr,
   1653 			    &ipv6_all_zeros, gateway, type, ipif,
   1654 			    zoneid, ihandle, tsl, flags)) {
   1655 				int match_flags;
   1656 
   1657 				/*
   1658 				 * We have something to work with.
   1659 				 * If we can find a resolved/reachable
   1660 				 * entry, we will use this. Otherwise
   1661 				 * we'll try to find an entry that has
   1662 				 * a resolved cache entry. We will fallback
   1663 				 * on this if we don't find anything else.
   1664 				 */
   1665 				if (saved_ire == NULL)
   1666 					saved_ire = ire;
   1667 				mutex_enter(&ire->ire_lock);
   1668 				gw_addr_v6 = ire->ire_gateway_addr_v6;
   1669 				mutex_exit(&ire->ire_lock);
   1670 				match_flags = MATCH_IRE_ILL | MATCH_IRE_SECATTR;
   1671 				rire = ire_ctable_lookup_v6(&gw_addr_v6, NULL,
   1672 				    0, ire->ire_ipif, zoneid, tsl, match_flags,
   1673 				    ipst);
   1674 				if (rire != NULL) {
   1675 					nce = rire->ire_nce;
   1676 					if (nce != NULL &&
   1677 					    NCE_ISREACHABLE(nce) &&
   1678 					    nce->nce_flags & NCE_F_ISROUTER) {
   1679 						ire_refrele(rire);
   1680 						IRE_REFHOLD(ire);
   1681 						IRB_REFRELE(irb_ptr);
   1682 						goto found_ire_held;
   1683 					} else if (nce != NULL &&
   1684 					    !(nce->nce_flags &
   1685 					    NCE_F_ISROUTER)) {
   1686 						/*
   1687 						 * Make sure we don't use
   1688 						 * this ire
   1689 						 */
   1690 						if (saved_ire == ire)
   1691 							saved_ire = NULL;
   1692 					}
   1693 					ire_refrele(rire);
   1694 				} else if (ipst->
   1695 				    ips_ipv6_ire_default_count > 1 &&
   1696 				    zoneid != GLOBAL_ZONEID) {
   1697 					/*
   1698 					 * When we're in a local zone, we're
   1699 					 * only interested in default routers
   1700 					 * that are reachable through ipifs
   1701 					 * within our zone.
   1702 					 * The potentially expensive call to
   1703 					 * ire_route_lookup_v6() is avoided when
   1704 					 * we have only one default route.
   1705 					 */
   1706 					int ire_match_flags = MATCH_IRE_TYPE |
   1707 					    MATCH_IRE_SECATTR;
   1708 
   1709 					if (ire->ire_ipif != NULL) {
   1710 						ire_match_flags |=
   1711 						    MATCH_IRE_ILL;
   1712 					}
   1713 					rire = ire_route_lookup_v6(&gw_addr_v6,
   1714 					    NULL, NULL, IRE_INTERFACE,
   1715 					    ire->ire_ipif, NULL,
   1716 					    zoneid, tsl, ire_match_flags, ipst);
   1717 					if (rire != NULL) {
   1718 						ire_refrele(rire);
   1719 						saved_ire = ire;
   1720 					} else if (saved_ire == ire) {
   1721 						/*
   1722 						 * Make sure we don't use
   1723 						 * this ire
   1724 						 */
   1725 						saved_ire = NULL;
   1726 					}
   1727 				}
   1728 			}
   1729 		}
   1730 		if (saved_ire != NULL) {
   1731 			ire = saved_ire;
   1732 			IRE_REFHOLD(ire);
   1733 			IRB_REFRELE(irb_ptr);
   1734 			goto found_ire_held;
   1735 		} else {
   1736 			/*
   1737 			 * Look for a interface default route matching the
   1738 			 * args passed in. No round robin here. Just pick
   1739 			 * the right one.
   1740 			 */
   1741 			for (ire = irb_ptr->irb_ire; ire != NULL;
   1742 			    ire = ire->ire_next) {
   1743 
   1744 				if (!(ire->ire_type & IRE_INTERFACE))
   1745 					continue;
   1746 
   1747 				if (ire->ire_marks & IRE_MARK_CONDEMNED)
   1748 					continue;
   1749 
   1750 				if (ire_match_args_v6(ire, addr,
   1751 				    &ipv6_all_zeros, gateway, type, ipif,
   1752 				    zoneid, ihandle, tsl, flags)) {
   1753 					IRE_REFHOLD(ire);
   1754 					IRB_REFRELE(irb_ptr);
   1755 					goto found_ire_held;
   1756 				}
   1757 			}
   1758 			IRB_REFRELE(irb_ptr);
   1759 		}
   1760 	}
   1761 	ASSERT(ire == NULL);
   1762 	ip1dbg(("ire_ftable_lookup_v6: returning NULL ire"));
   1763 	return (NULL);
   1764 found_ire:
   1765 	ASSERT((ire->ire_marks & IRE_MARK_CONDEMNED) == 0);
   1766 	IRE_REFHOLD(ire);
   1767 	rw_exit(&irb_ptr->irb_lock);
   1768 
   1769 found_ire_held:
   1770 	if ((flags & MATCH_IRE_RJ_BHOLE) &&
   1771 	    (ire->ire_flags & (RTF_BLACKHOLE | RTF_REJECT))) {
   1772 		return (ire);
   1773 	}
   1774 	/*
   1775 	 * At this point, IRE that was found must be an IRE_FORWARDTABLE
   1776 	 * or IRE_CACHETABLE type.  If this is a recursive lookup and an
   1777 	 * IRE_INTERFACE type was found, return that.  If it was some other
   1778 	 * IRE_FORWARDTABLE type of IRE (one of the prefix types), then it
   1779 	 * is necessary to fill in the  parent IRE pointed to by pire, and
   1780 	 * then lookup the gateway address of  the parent.  For backwards
   1781 	 * compatiblity, if this lookup returns an
   1782 	 * IRE other than a IRE_CACHETABLE or IRE_INTERFACE, then one more level
   1783 	 * of lookup is done.
   1784 	 */
   1785 	if (flags & MATCH_IRE_RECURSIVE) {
   1786 		const ipif_t *gw_ipif;
   1787 		int match_flags = MATCH_IRE_DSTONLY;
   1788 
   1789 		if (ire->ire_type & IRE_INTERFACE)
   1790 			return (ire);
   1791 		if (pire != NULL)
   1792 			*pire = ire;
   1793 		/*
   1794 		 * If we can't find an IRE_INTERFACE or the caller has not
   1795 		 * asked for pire, we need to REFRELE the saved_ire.
   1796 		 */
   1797 		saved_ire = ire;
   1798 
   1799 		if (ire->ire_ipif != NULL)
   1800 			match_flags |= MATCH_IRE_ILL;
   1801 
   1802 		mutex_enter(&ire->ire_lock);
   1803 		gw_addr_v6 = ire->ire_gateway_addr_v6;
   1804 		mutex_exit(&ire->ire_lock);
   1805 
   1806 		ire = ire_route_lookup_v6(&gw_addr_v6, NULL, NULL, 0,
   1807 		    ire->ire_ipif, NULL, zoneid, tsl, match_flags, ipst);
   1808 		if (ire == NULL) {
   1809 			/*
   1810 			 * In this case we have to deal with the
   1811 			 * MATCH_IRE_PARENT flag, which means the
   1812 			 * parent has to be returned if ire is NULL.
   1813 			 * The aim of this is to have (at least) a starting
   1814 			 * ire when we want to look at all of the ires in a
   1815 			 * bucket aimed at a single destination (as is the
   1816 			 * case in ip_newroute_v6 for the RTF_MULTIRT
   1817 			 * flagged routes).
   1818 			 */
   1819 			if (flags & MATCH_IRE_PARENT) {
   1820 				if (pire != NULL) {
   1821 					/*
   1822 					 * Need an extra REFHOLD, if the
   1823 					 * parent ire is returned via both
   1824 					 * ire and pire.
   1825 					 */
   1826 					IRE_REFHOLD(saved_ire);
   1827 				}
   1828 				ire = saved_ire;
   1829 			} else {
   1830 				ire_refrele(saved_ire);
   1831 				if (pire != NULL)
   1832 					*pire = NULL;
   1833 			}
   1834 			return (ire);
   1835 		}
   1836 		if (ire->ire_type & (IRE_CACHETABLE | IRE_INTERFACE)) {
   1837 			/*
   1838 			 * If the caller did not ask for pire, release
   1839 			 * it now.
   1840 			 */
   1841 			if (pire == NULL) {
   1842 				ire_refrele(saved_ire);
   1843 			}
   1844 			return (ire);
   1845 		}
   1846 		match_flags |= MATCH_IRE_TYPE;
   1847 		mutex_enter(&ire->ire_lock);
   1848 		gw_addr_v6 = ire->ire_gateway_addr_v6;
   1849 		mutex_exit(&ire->ire_lock);
   1850 		gw_ipif = ire->ire_ipif;
   1851 		ire_refrele(ire);
   1852 		ire = ire_route_lookup_v6(&gw_addr_v6, NULL, NULL,
   1853 		    (IRE_CACHETABLE | IRE_INTERFACE), gw_ipif, NULL, zoneid,
   1854 		    NULL, match_flags, ipst);
   1855 		if (ire == NULL) {
   1856 			/*
   1857 			 * In this case we have to deal with the
   1858 			 * MATCH_IRE_PARENT flag, which means the
   1859 			 * parent has to be returned if ire is NULL.
   1860 			 * The aim of this is to have (at least) a starting
   1861 			 * ire when we want to look at all of the ires in a
   1862 			 * bucket aimed at a single destination (as is the
   1863 			 * case in ip_newroute_v6 for the RTF_MULTIRT
   1864 			 * flagged routes).
   1865 			 */
   1866 			if (flags & MATCH_IRE_PARENT) {
   1867 				if (pire != NULL) {
   1868 					/*
   1869 					 * Need an extra REFHOLD, if the
   1870 					 * parent ire is returned via both
   1871 					 * ire and pire.
   1872 					 */
   1873 					IRE_REFHOLD(saved_ire);
   1874 				}
   1875 				ire = saved_ire;
   1876 			} else {
   1877 				ire_refrele(saved_ire);
   1878 				if (pire != NULL)
   1879 					*pire = NULL;
   1880 			}
   1881 			return (ire);
   1882 		} else if (pire == NULL) {
   1883 			/*
   1884 			 * If the caller did not ask for pire, release
   1885 			 * it now.
   1886 			 */
   1887 			ire_refrele(saved_ire);
   1888 		}
   1889 		return (ire);
   1890 	}
   1891 
   1892 	ASSERT(pire == NULL || *pire == NULL);
   1893 	return (ire);
   1894 }
   1895 
   1896 /*
   1897  * Delete the IRE cache for the gateway and all IRE caches whose
   1898  * ire_gateway_addr_v6 points to this gateway, and allow them to
   1899  * be created on demand by ip_newroute_v6.
   1900  */
   1901 void
   1902 ire_clookup_delete_cache_gw_v6(const in6_addr_t *addr, zoneid_t zoneid,
   1903 	ip_stack_t *ipst)
   1904 {
   1905 	irb_t *irb;
   1906 	ire_t *ire;
   1907 
   1908 	irb = &ipst->ips_ip_cache_table_v6[IRE_ADDR_HASH_V6(*addr,
   1909 	    ipst->ips_ip6_cache_table_size)];
   1910 	IRB_REFHOLD(irb);
   1911 	for (ire = irb->irb_ire; ire != NULL; ire = ire->ire_next) {
   1912 		if (ire->ire_marks & IRE_MARK_CONDEMNED)
   1913 			continue;
   1914 
   1915 		ASSERT(IN6_ARE_ADDR_EQUAL(&ire->ire_mask_v6, &ipv6_all_ones));
   1916 		if (ire_match_args_v6(ire, addr, &ire->ire_mask_v6, 0,
   1917 		    IRE_CACHE, NULL, zoneid, 0, NULL, MATCH_IRE_TYPE)) {
   1918 			ire_delete(ire);
   1919 		}
   1920 	}
   1921 	IRB_REFRELE(irb);
   1922 
   1923 	ire_walk_v6(ire_delete_cache_gw_v6, (char *)addr, zoneid, ipst);
   1924 }
   1925 
   1926 /*
   1927  * Looks up cache table for a route.
   1928  * specific lookup can be indicated by
   1929  * passing the MATCH_* flags and the
   1930  * necessary parameters.
   1931  */
   1932 ire_t *
   1933 ire_ctable_lookup_v6(const in6_addr_t *addr, const in6_addr_t *gateway,
   1934     int type, const ipif_t *ipif, zoneid_t zoneid, const ts_label_t *tsl,
   1935     int flags, ip_stack_t *ipst)
   1936 {
   1937 	ire_ctable_args_t	margs;
   1938 
   1939 	margs.ict_addr = (void *)addr;
   1940 	margs.ict_gateway = (void *)gateway;
   1941 	margs.ict_type = type;
   1942 	margs.ict_ipif = ipif;
   1943 	margs.ict_zoneid = zoneid;
   1944 	margs.ict_tsl = tsl;
   1945 	margs.ict_flags = flags;
   1946 	margs.ict_ipst = ipst;
   1947 	margs.ict_wq = NULL;
   1948 
   1949 	return (ip6_ctable_lookup_impl(&margs));
   1950 }
   1951 
   1952 /*
   1953  * Lookup cache.
   1954  *
   1955  * In general the zoneid has to match (where ALL_ZONES match all of them).
   1956  * But for IRE_LOCAL we also need to handle the case where L2 should
   1957  * conceptually loop back the packet. This is necessary since neither
   1958  * Ethernet drivers nor Ethernet hardware loops back packets sent to their
   1959  * own MAC address. This loopback is needed when the normal
   1960  * routes (ignoring IREs with different zoneids) would send out the packet on
   1961  * the same ill as the ill with which this IRE_LOCAL is associated.
   1962  *
   1963  * Earlier versions of this code always matched an IRE_LOCAL independently of
   1964  * the zoneid. We preserve that earlier behavior when
   1965  * ip_restrict_interzone_loopback is turned off.
   1966  */
   1967 ire_t *
   1968 ire_cache_lookup_v6(const in6_addr_t *addr, zoneid_t zoneid,
   1969     const ts_label_t *tsl, ip_stack_t *ipst)
   1970 {
   1971 	irb_t *irb_ptr;
   1972 	ire_t *ire;
   1973 
   1974 	irb_ptr = &ipst->ips_ip_cache_table_v6[IRE_ADDR_HASH_V6(*addr,
   1975 	    ipst->ips_ip6_cache_table_size)];
   1976 	rw_enter(&irb_ptr->irb_lock, RW_READER);
   1977 	for (ire = irb_ptr->irb_ire; ire; ire = ire->ire_next) {
   1978 		if (ire->ire_marks & (IRE_MARK_CONDEMNED|IRE_MARK_TESTHIDDEN))
   1979 			continue;
   1980 		if (IN6_ARE_ADDR_EQUAL(&ire->ire_addr_v6, addr)) {
   1981 			/*
   1982 			 * Finally, check if the security policy has any
   1983 			 * restriction on using this route for the specified
   1984 			 * message.
   1985 			 */
   1986 			if (tsl != NULL &&
   1987 			    ire->ire_gw_secattr != NULL &&
   1988 			    tsol_ire_match_gwattr(ire, tsl) != 0) {
   1989 				continue;
   1990 			}
   1991 
   1992 			if (zoneid == ALL_ZONES || ire->ire_zoneid == zoneid ||
   1993 			    ire->ire_zoneid == ALL_ZONES) {
   1994 				IRE_REFHOLD(ire);
   1995 				rw_exit(&irb_ptr->irb_lock);
   1996 				return (ire);
   1997 			}
   1998 
   1999 			if (ire->ire_type == IRE_LOCAL) {
   2000 				if (ipst->ips_ip_restrict_interzone_loopback &&
   2001 				    !ire_local_ok_across_zones(ire, zoneid,
   2002 				    (void *)addr, tsl, ipst))
   2003 					continue;
   2004 
   2005 				IRE_REFHOLD(ire);
   2006 				rw_exit(&irb_ptr->irb_lock);
   2007 				return (ire);
   2008 			}
   2009 		}
   2010 	}
   2011 	rw_exit(&irb_ptr->irb_lock);
   2012 	return (NULL);
   2013 }
   2014 
   2015 /*
   2016  * Locate the interface ire that is tied to the cache ire 'cire' via
   2017  * cire->ire_ihandle.
   2018  *
   2019  * We are trying to create the cache ire for an onlink destn. or
   2020  * gateway in 'cire'. We are called from ire_add_v6() in the IRE_IF_RESOLVER
   2021  * case for xresolv interfaces, after the ire has come back from
   2022  * an external resolver.
   2023  */
   2024 static ire_t *
   2025 ire_ihandle_lookup_onlink_v6(ire_t *cire)
   2026 {
   2027 	ire_t	*ire;
   2028 	int	match_flags;
   2029 	int	i;
   2030 	int	j;
   2031 	irb_t	*irb_ptr;
   2032 	ip_stack_t	*ipst = cire->ire_ipst;
   2033 
   2034 	ASSERT(cire != NULL);
   2035 
   2036 	match_flags =  MATCH_IRE_TYPE | MATCH_IRE_IHANDLE | MATCH_IRE_MASK;
   2037 	/*
   2038 	 * We know that the mask of the interface ire equals cire->ire_cmask.
   2039 	 * (When ip_newroute_v6() created 'cire' for an on-link destn.
   2040 	 * it set its cmask from the interface ire's mask)
   2041 	 */
   2042 	ire = ire_ftable_lookup_v6(&cire->ire_addr_v6, &cire->ire_cmask_v6,
   2043 	    NULL, IRE_INTERFACE, NULL, NULL, ALL_ZONES, cire->ire_ihandle,
   2044 	    NULL, match_flags, ipst);
   2045 	if (ire != NULL)
   2046 		return (ire);
   2047 	/*
   2048 	 * If we didn't find an interface ire above, we can't declare failure.
   2049 	 * For backwards compatibility, we need to support prefix routes
   2050 	 * pointing to next hop gateways that are not on-link.
   2051 	 *
   2052 	 * In the resolver/noresolver case, ip_newroute_v6() thinks
   2053 	 * it is creating the cache ire for an onlink destination in 'cire'.
   2054 	 * But 'cire' is not actually onlink, because ire_ftable_lookup_v6()
   2055 	 * cheated it, by doing ire_route_lookup_v6() twice and returning an
   2056 	 * interface ire.
   2057 	 *
   2058 	 * Eg. default	-	gw1			(line 1)
   2059 	 *	gw1	-	gw2			(line 2)
   2060 	 *	gw2	-	hme0			(line 3)
   2061 	 *
   2062 	 * In the above example, ip_newroute_v6() tried to create the cache ire
   2063 	 * 'cire' for gw1, based on the interface route in line 3. The
   2064 	 * ire_ftable_lookup_v6() above fails, because there is
   2065 	 * no interface route to reach gw1. (it is gw2). We fall thru below.
   2066 	 *
   2067 	 * Do a brute force search based on the ihandle in a subset of the
   2068 	 * forwarding tables, corresponding to cire->ire_cmask_v6. Otherwise
   2069 	 * things become very complex, since we don't have 'pire' in this
   2070 	 * case. (Also note that this method is not possible in the offlink
   2071 	 * case because we don't know the mask)
   2072 	 */
   2073 	i = ip_mask_to_plen_v6(&cire->ire_cmask_v6);
   2074 	if ((ipst->ips_ip_forwarding_table_v6[i]) == NULL)
   2075 		return (NULL);
   2076 	for (j = 0; j < ipst->ips_ip6_ftable_hash_size; j++) {
   2077 		irb_ptr = &ipst->ips_ip_forwarding_table_v6[i][j];
   2078 		rw_enter(&irb_ptr->irb_lock, RW_READER);
   2079 		for (ire = irb_ptr->irb_ire; ire != NULL;
   2080 		    ire = ire->ire_next) {
   2081 			if (ire->ire_marks & IRE_MARK_CONDEMNED)
   2082 				continue;
   2083 			if ((ire->ire_type & IRE_INTERFACE) &&
   2084 			    (ire->ire_ihandle == cire->ire_ihandle)) {
   2085 				IRE_REFHOLD(ire);
   2086 				rw_exit(&irb_ptr->irb_lock);
   2087 				return (ire);
   2088 			}
   2089 		}
   2090 		rw_exit(&irb_ptr->irb_lock);
   2091 	}
   2092 	return (NULL);
   2093 }
   2094 
   2095 
   2096 /*
   2097  * Locate the interface ire that is tied to the cache ire 'cire' via
   2098  * cire->ire_ihandle.
   2099  *
   2100  * We are trying to create the cache ire for an offlink destn based
   2101  * on the cache ire of the gateway in 'cire'. 'pire' is the prefix ire
   2102  * as found by ip_newroute_v6(). We are called from ip_newroute_v6() in
   2103  * the IRE_CACHE case.
   2104  */
   2105 ire_t *
   2106 ire_ihandle_lookup_offlink_v6(ire_t *cire, ire_t *pire)
   2107 {
   2108 	ire_t	*ire;
   2109 	int	match_flags;
   2110 	in6_addr_t	gw_addr;
   2111 	ipif_t		*gw_ipif;
   2112 	ip_stack_t	*ipst = cire->ire_ipst;
   2113 
   2114 	ASSERT(cire != NULL && pire != NULL);
   2115 
   2116 	match_flags =  MATCH_IRE_TYPE | MATCH_IRE_IHANDLE | MATCH_IRE_MASK;
   2117 	if (pire->ire_ipif != NULL)
   2118 		match_flags |= MATCH_IRE_ILL;
   2119 	/*
   2120 	 * We know that the mask of the interface ire equals cire->ire_cmask.
   2121 	 * (When ip_newroute_v6() created 'cire' for an on-link destn. it set
   2122 	 * its cmask from the interface ire's mask)
   2123 	 */
   2124 	ire = ire_ftable_lookup_v6(&cire->ire_addr_v6, &cire->ire_cmask_v6, 0,
   2125 	    IRE_INTERFACE, pire->ire_ipif, NULL, ALL_ZONES, cire->ire_ihandle,
   2126 	    NULL, match_flags, ipst);
   2127 	if (ire != NULL)
   2128 		return (ire);
   2129 	/*
   2130 	 * If we didn't find an interface ire above, we can't declare failure.
   2131 	 * For backwards compatibility, we need to support prefix routes
   2132 	 * pointing to next hop gateways that are not on-link.
   2133 	 *
   2134 	 * Assume we are trying to ping some offlink destn, and we have the
   2135 	 * routing table below.
   2136 	 *
   2137 	 * Eg.	default	- gw1		<--- pire	(line 1)
   2138 	 *	gw1	- gw2				(line 2)
   2139 	 *	gw2	- hme0				(line 3)
   2140 	 *
   2141 	 * If we already have a cache ire for gw1 in 'cire', the
   2142 	 * ire_ftable_lookup_v6 above would have failed, since there is no
   2143 	 * interface ire to reach gw1. We will fallthru below.
   2144 	 *
   2145 	 * Here we duplicate the steps that ire_ftable_lookup_v6() did in
   2146 	 * getting 'cire' from 'pire', in the MATCH_IRE_RECURSIVE case.
   2147 	 * The differences are the following
   2148 	 * i.   We want the interface ire only, so we call
   2149 	 *	ire_ftable_lookup_v6() instead of ire_route_lookup_v6()
   2150 	 * ii.  We look for only prefix routes in the 1st call below.
   2151 	 * ii.  We want to match on the ihandle in the 2nd call below.
   2152 	 */
   2153 	match_flags =  MATCH_IRE_TYPE;
   2154 	if (pire->ire_ipif != NULL)
   2155 		match_flags |= MATCH_IRE_ILL;
   2156 
   2157 	mutex_enter(&pire->ire_lock);
   2158 	gw_addr = pire->ire_gateway_addr_v6;
   2159 	mutex_exit(&pire->ire_lock);
   2160 	ire = ire_ftable_lookup_v6(&gw_addr, 0, 0, IRE_OFFSUBNET,
   2161 	    pire->ire_ipif, NULL, ALL_ZONES, 0, NULL, match_flags, ipst);
   2162 	if (ire == NULL)
   2163 		return (NULL);
   2164 	/*
   2165 	 * At this point 'ire' corresponds to the entry shown in line 2.
   2166 	 * gw_addr is 'gw2' in the example above.
   2167 	 */
   2168 	mutex_enter(&ire->ire_lock);
   2169 	gw_addr = ire->ire_gateway_addr_v6;
   2170 	mutex_exit(&ire->ire_lock);
   2171 	gw_ipif = ire->ire_ipif;
   2172 	ire_refrele(ire);
   2173 
   2174 	match_flags |= MATCH_IRE_IHANDLE;
   2175 	ire = ire_ftable_lookup_v6(&gw_addr, 0, 0, IRE_INTERFACE,
   2176 	    gw_ipif, NULL, ALL_ZONES, cire->ire_ihandle,
   2177 	    NULL, match_flags, ipst);
   2178 	return (ire);
   2179 }
   2180 
   2181 /*
   2182  * Return the IRE_LOOPBACK, IRE_IF_RESOLVER or IRE_IF_NORESOLVER
   2183  * ire associated with the specified ipif.
   2184  *
   2185  * This might occasionally be called when IPIF_UP is not set since
   2186  * the IPV6_MULTICAST_IF as well as creating interface routes
   2187  * allows specifying a down ipif (ipif_lookup* match ipifs that are down).
   2188  *
   2189  * Note that if IPIF_NOLOCAL, IPIF_NOXMIT, or IPIF_DEPRECATED is set on
   2190  * the ipif this routine might return NULL.
   2191  * (Sometimes called as writer though not required by this function.)
   2192  */
   2193 ire_t *
   2194 ipif_to_ire_v6(const ipif_t *ipif)
   2195 {
   2196 	ire_t	*ire;
   2197 	ip_stack_t *ipst = ipif->ipif_ill->ill_ipst;
   2198 	uint_t	match_flags = MATCH_IRE_TYPE | MATCH_IRE_IPIF;
   2199 
   2200 	/*
   2201 	 * IRE_INTERFACE entries for ills under IPMP are IRE_MARK_TESTHIDDEN
   2202 	 * so that they aren't accidentally returned.  However, if the
   2203 	 * caller's ipif is on an ill under IPMP, there's no need to hide 'em.
   2204 	 */
   2205 	if (IS_UNDER_IPMP(ipif->ipif_ill))
   2206 		match_flags |= MATCH_IRE_MARK_TESTHIDDEN;
   2207 
   2208 	ASSERT(ipif->ipif_isv6);
   2209 	if (ipif->ipif_ire_type == IRE_LOOPBACK) {
   2210 		ire = ire_ctable_lookup_v6(&ipif->ipif_v6lcl_addr, NULL,
   2211 		    IRE_LOOPBACK, ipif, ALL_ZONES, NULL, match_flags, ipst);
   2212 	} else if (ipif->ipif_flags & IPIF_POINTOPOINT) {
   2213 		/* In this case we need to lookup destination address. */
   2214 		ire = ire_ftable_lookup_v6(&ipif->ipif_v6pp_dst_addr,
   2215 		    &ipv6_all_ones, NULL, IRE_INTERFACE, ipif, NULL, ALL_ZONES,
   2216 		    0, NULL, (match_flags | MATCH_IRE_MASK), ipst);
   2217 	} else {
   2218 		ire = ire_ftable_lookup_v6(&ipif->ipif_v6subnet,
   2219 		    &ipif->ipif_v6net_mask, NULL, IRE_INTERFACE, ipif, NULL,
   2220 		    ALL_ZONES, 0, NULL, (match_flags | MATCH_IRE_MASK), ipst);
   2221 	}
   2222 	return (ire);
   2223 }
   2224 
   2225 /*
   2226  * Return B_TRUE if a multirt route is resolvable
   2227  * (or if no route is resolved yet), B_FALSE otherwise.
   2228  * This only works in the global zone.
   2229  */
   2230 boolean_t
   2231 ire_multirt_need_resolve_v6(const in6_addr_t *v6dstp, const ts_label_t *tsl,
   2232     ip_stack_t *ipst)
   2233 {
   2234 	ire_t	*first_fire;
   2235 	ire_t	*first_cire;
   2236 	ire_t	*fire;
   2237 	ire_t	*cire;
   2238 	irb_t	*firb;
   2239 	irb_t	*cirb;
   2240 	int	unres_cnt = 0;
   2241 	boolean_t resolvable = B_FALSE;
   2242 
   2243 	/* Retrieve the first IRE_HOST that matches the destination */
   2244 	first_fire = ire_ftable_lookup_v6(v6dstp, &ipv6_all_ones, 0, IRE_HOST,
   2245 	    NULL, NULL, ALL_ZONES, 0, tsl, MATCH_IRE_MASK | MATCH_IRE_TYPE |
   2246 	    MATCH_IRE_SECATTR, ipst);
   2247 
   2248 	/* No route at all */
   2249 	if (first_fire == NULL) {
   2250 		return (B_TRUE);
   2251 	}
   2252 
   2253 	firb = first_fire->ire_bucket;
   2254 	ASSERT(firb);
   2255 
   2256 	/* Retrieve the first IRE_CACHE ire for that destination. */
   2257 	first_cire = ire_cache_lookup_v6(v6dstp, GLOBAL_ZONEID, tsl, ipst);
   2258 
   2259 	/* No resolved route. */
   2260 	if (first_cire == NULL) {
   2261 		ire_refrele(first_fire);
   2262 		return (B_TRUE);
   2263 	}
   2264 
   2265 	/* At least one route is resolved. */
   2266 
   2267 	cirb = first_cire->ire_bucket;
   2268 	ASSERT(cirb);
   2269 
   2270 	/* Count the number of routes to that dest that are declared. */
   2271 	IRB_REFHOLD(firb);
   2272 	for (fire = first_fire; fire != NULL; fire = fire->ire_next) {
   2273 		if (!(fire->ire_flags & RTF_MULTIRT))
   2274 			continue;
   2275 		if (!IN6_ARE_ADDR_EQUAL(&fire->ire_addr_v6, v6dstp))
   2276 			continue;
   2277 		unres_cnt++;
   2278 	}
   2279 	IRB_REFRELE(firb);
   2280 
   2281 
   2282 	/* Then subtract the number of routes to that dst that are resolved */
   2283 	IRB_REFHOLD(cirb);
   2284 	for (cire = first_cire; cire != NULL; cire = cire->ire_next) {
   2285 		if (!(cire->ire_flags & RTF_MULTIRT))
   2286 			continue;
   2287 		if (!IN6_ARE_ADDR_EQUAL(&cire->ire_addr_v6, v6dstp))
   2288 			continue;
   2289 		if (cire->ire_marks & (IRE_MARK_CONDEMNED|IRE_MARK_TESTHIDDEN))
   2290 			continue;
   2291 		unres_cnt--;
   2292 	}
   2293 	IRB_REFRELE(cirb);
   2294 
   2295 	/* At least one route is unresolved; search for a resolvable route. */
   2296 	if (unres_cnt > 0)
   2297 		resolvable = ire_multirt_lookup_v6(&first_cire, &first_fire,
   2298 		    MULTIRT_USESTAMP|MULTIRT_CACHEGW, tsl, ipst);
   2299 
   2300 	if (first_fire)
   2301 		ire_refrele(first_fire);
   2302 
   2303 	if (first_cire)
   2304 		ire_refrele(first_cire);
   2305 
   2306 	return (resolvable);
   2307 }
   2308 
   2309 
   2310 /*
   2311  * Return B_TRUE and update *ire_arg and *fire_arg
   2312  * if at least one resolvable route is found.
   2313  * Return B_FALSE otherwise (all routes are resolved or
   2314  * the remaining unresolved routes are all unresolvable).
   2315  * This only works in the global zone.
   2316  */
   2317 boolean_t
   2318 ire_multirt_lookup_v6(ire_t **ire_arg, ire_t **fire_arg, uint32_t flags,
   2319     const ts_label_t *tsl, ip_stack_t *ipst)
   2320 {
   2321 	clock_t	delta;
   2322 	ire_t	*best_fire = NULL;
   2323 	ire_t	*best_cire = NULL;
   2324 	ire_t	*first_fire;
   2325 	ire_t	*first_cire;
   2326 	ire_t	*fire;
   2327 	ire_t	*cire;
   2328 	irb_t	*firb = NULL;
   2329 	irb_t	*cirb = NULL;
   2330 	ire_t	*gw_ire;
   2331 	boolean_t	already_resolved;
   2332 	boolean_t	res;
   2333 	in6_addr_t	v6dst;
   2334 	in6_addr_t	v6gw;
   2335 
   2336 	ip2dbg(("ire_multirt_lookup_v6: *ire_arg %p, *fire_arg %p, "
   2337 	    "flags %04x\n", (void *)*ire_arg, (void *)*fire_arg, flags));
   2338 
   2339 	ASSERT(ire_arg);
   2340 	ASSERT(fire_arg);
   2341 
   2342 	/* Not an IRE_HOST ire; give up. */
   2343 	if ((*fire_arg == NULL) ||
   2344 	    ((*fire_arg)->ire_type != IRE_HOST)) {
   2345 		return (B_FALSE);
   2346 	}
   2347 
   2348 	/* This is the first IRE_HOST ire for that destination. */
   2349 	first_fire = *fire_arg;
   2350 	firb = first_fire->ire_bucket;
   2351 	ASSERT(firb);
   2352 
   2353 	mutex_enter(&first_fire->ire_lock);
   2354 	v6dst = first_fire->ire_addr_v6;
   2355 	mutex_exit(&first_fire->ire_lock);
   2356 
   2357 	ip2dbg(("ire_multirt_lookup_v6: dst %08x\n",
   2358 	    ntohl(V4_PART_OF_V6(v6dst))));
   2359 
   2360 	/*
   2361 	 * Retrieve the first IRE_CACHE ire for that destination;
   2362 	 * if we don't find one, no route for that dest is
   2363 	 * resolved yet.
   2364 	 */
   2365 	first_cire = ire_cache_lookup_v6(&v6dst, GLOBAL_ZONEID, tsl, ipst);
   2366 	if (first_cire) {
   2367 		cirb = first_cire->ire_bucket;
   2368 	}
   2369 
   2370 	ip2dbg(("ire_multirt_lookup_v6: first_cire %p\n", (void *)first_cire));
   2371 
   2372 	/*
   2373 	 * Search for a resolvable route, giving the top priority
   2374 	 * to routes that can be resolved without any call to the resolver.
   2375 	 */
   2376 	IRB_REFHOLD(firb);
   2377 
   2378 	if (!IN6_IS_ADDR_MULTICAST(&v6dst)) {
   2379 		/*
   2380 		 * For all multiroute IRE_HOST ires for that destination,
   2381 		 * check if the route via the IRE_HOST's gateway is
   2382 		 * resolved yet.
   2383 		 */
   2384 		for (fire = first_fire; fire != NULL; fire = fire->ire_next) {
   2385 
   2386 			if (!(fire->ire_flags & RTF_MULTIRT))
   2387 				continue;
   2388 			if (!IN6_ARE_ADDR_EQUAL(&fire->ire_addr_v6, &v6dst))
   2389 				continue;
   2390 
   2391 			if (fire->ire_gw_secattr != NULL &&
   2392 			    tsol_ire_match_gwattr(fire, tsl) != 0) {
   2393 				continue;
   2394 			}
   2395 
   2396 			mutex_enter(&fire->ire_lock);
   2397 			v6gw = fire->ire_gateway_addr_v6;
   2398 			mutex_exit(&fire->ire_lock);
   2399 
   2400 			ip2dbg(("ire_multirt_lookup_v6: fire %p, "
   2401 			    "ire_addr %08x, ire_gateway_addr %08x\n",
   2402 			    (void *)fire,
   2403 			    ntohl(V4_PART_OF_V6(fire->ire_addr_v6)),
   2404 			    ntohl(V4_PART_OF_V6(v6gw))));
   2405 
   2406 			already_resolved = B_FALSE;
   2407 
   2408 			if (first_cire) {
   2409 				ASSERT(cirb);
   2410 
   2411 				IRB_REFHOLD(cirb);
   2412 				/*
   2413 				 * For all IRE_CACHE ires for that
   2414 				 * destination.
   2415 				 */
   2416 				for (cire = first_cire;
   2417 				    cire != NULL;
   2418 				    cire = cire->ire_next) {
   2419 
   2420 					if (!(cire->ire_flags & RTF_MULTIRT))
   2421 						continue;
   2422 					if (!IN6_ARE_ADDR_EQUAL(
   2423 					    &cire->ire_addr_v6, &v6dst))
   2424 						continue;
   2425 					if (cire->ire_marks &
   2426 					    (IRE_MARK_CONDEMNED|
   2427 					    IRE_MARK_TESTHIDDEN))
   2428 						continue;
   2429 
   2430 					if (cire->ire_gw_secattr != NULL &&
   2431 					    tsol_ire_match_gwattr(cire,
   2432 					    tsl) != 0) {
   2433 						continue;
   2434 					}
   2435 
   2436 					/*
   2437 					 * Check if the IRE_CACHE's gateway
   2438 					 * matches the IRE_HOST's gateway.
   2439 					 */
   2440 					if (IN6_ARE_ADDR_EQUAL(
   2441 					    &cire->ire_gateway_addr_v6,
   2442 					    &v6gw)) {
   2443 						already_resolved = B_TRUE;
   2444 						break;
   2445 					}
   2446 				}
   2447 				IRB_REFRELE(cirb);
   2448 			}
   2449 
   2450 			/*
   2451 			 * This route is already resolved;
   2452 			 * proceed with next one.
   2453 			 */
   2454 			if (already_resolved) {
   2455 				ip2dbg(("ire_multirt_lookup_v6: found cire %p, "
   2456 				    "already resolved\n", (void *)cire));
   2457 				continue;
   2458 			}
   2459 
   2460 			/*
   2461 			 * The route is unresolved; is it actually
   2462 			 * resolvable, i.e. is there a cache or a resolver
   2463 			 * for the gateway?
   2464 			 */
   2465 			gw_ire = ire_route_lookup_v6(&v6gw, 0, 0, 0, NULL, NULL,
   2466 			    ALL_ZONES, tsl, MATCH_IRE_RECURSIVE |
   2467 			    MATCH_IRE_SECATTR, ipst);
   2468 
   2469 			ip2dbg(("ire_multirt_lookup_v6: looked up gw_ire %p\n",
   2470 			    (void *)gw_ire));
   2471 
   2472 			/*
   2473 			 * This route can be resolved without any call to the
   2474 			 * resolver; if the MULTIRT_CACHEGW flag is set,
   2475 			 * give the top priority to this ire and exit the
   2476 			 * loop.
   2477 			 * This occurs when an resolver reply is processed
   2478 			 * through ip_wput_nondata()
   2479 			 */
   2480 			if ((flags & MULTIRT_CACHEGW) &&
   2481 			    (gw_ire != NULL) &&
   2482 			    (gw_ire->ire_type & IRE_CACHETABLE)) {
   2483 				/*
   2484 				 * Release the resolver associated to the
   2485 				 * previous candidate best ire, if any.
   2486 				 */
   2487 				if (best_cire) {
   2488 					ire_refrele(best_cire);
   2489 					ASSERT(best_fire);
   2490 				}
   2491 
   2492 				best_fire = fire;
   2493 				best_cire = gw_ire;
   2494 
   2495 				ip2dbg(("ire_multirt_lookup_v6: found top prio "
   2496 				    "best_fire %p, best_cire %p\n",
   2497 				    (void *)best_fire, (void *)best_cire));
   2498 				break;
   2499 			}
   2500 
   2501 			/*
   2502 			 * Compute the time elapsed since our preceding
   2503 			 * attempt to  resolve that route.
   2504 			 * If the MULTIRT_USESTAMP flag is set, we take that
   2505 			 * route into account only if this time interval
   2506 			 * exceeds ip_multirt_resolution_interval;
   2507 			 * this prevents us from attempting to resolve a
   2508 			 * broken route upon each sending of a packet.
   2509 			 */
   2510 			delta = lbolt - fire->ire_last_used_time;
   2511 			delta = TICK_TO_MSEC(delta);
   2512 
   2513 			res = (boolean_t)
   2514 			    ((delta > ipst->
   2515 			    ips_ip_multirt_resolution_interval) ||
   2516 			    (!(flags & MULTIRT_USESTAMP)));
   2517 
   2518 			ip2dbg(("ire_multirt_lookup_v6: fire %p, delta %lu, "
   2519 			    "res %d\n",
   2520 			    (void *)fire, delta, res));
   2521 
   2522 			if (res) {
   2523 				/*
   2524 				 * A resolver exists for the gateway: save
   2525 				 * the current IRE_HOST ire as a candidate
   2526 				 * best ire. If we later discover that a
   2527 				 * top priority ire exists (i.e. no need to
   2528 				 * call the resolver), then this new ire
   2529 				 * will be preferred to the current one.
   2530 				 */
   2531 				if (gw_ire != NULL) {
   2532 					if (best_fire == NULL) {
   2533 						ASSERT(best_cire == NULL);
   2534 
   2535 						best_fire = fire;
   2536 						best_cire = gw_ire;
   2537 
   2538 						ip2dbg(("ire_multirt_lookup_v6:"
   2539 						    "found candidate "
   2540 						    "best_fire %p, "
   2541 						    "best_cire %p\n",
   2542 						    (void *)best_fire,
   2543 						    (void *)best_cire));
   2544 
   2545 						/*
   2546 						 * If MULTIRT_CACHEGW is not
   2547 						 * set, we ignore the top
   2548 						 * priority ires that can
   2549 						 * be resolved without any
   2550 						 * call to the resolver;
   2551 						 * In that case, there is
   2552 						 * actually no need
   2553 						 * to continue the loop.
   2554 						 */
   2555 						if (!(flags &
   2556 						    MULTIRT_CACHEGW)) {
   2557 							break;
   2558 						}
   2559 						continue;
   2560 					}
   2561 				} else {
   2562 					/*
   2563 					 * No resolver for the gateway: the
   2564 					 * route is not resolvable.
   2565 					 * If the MULTIRT_SETSTAMP flag is
   2566 					 * set, we stamp the IRE_HOST ire,
   2567 					 * so we will not select it again
   2568 					 * during this resolution interval.
   2569 					 */
   2570 					if (flags & MULTIRT_SETSTAMP)
   2571 						fire->ire_last_used_time =
   2572 						    lbolt;
   2573 				}
   2574 			}
   2575 
   2576 			if (gw_ire != NULL)
   2577 				ire_refrele(gw_ire);
   2578 		}
   2579 	} else { /* IN6_IS_ADDR_MULTICAST(&v6dst) */
   2580 
   2581 		for (fire = first_fire;
   2582 		    fire != NULL;
   2583 		    fire = fire->ire_next) {
   2584 
   2585 			if (!(fire->ire_flags & RTF_MULTIRT))
   2586 				continue;
   2587 			if (!IN6_ARE_ADDR_EQUAL(&fire->ire_addr_v6, &v6dst))
   2588 				continue;
   2589 
   2590 			if (fire->ire_gw_secattr != NULL &&
   2591 			    tsol_ire_match_gwattr(fire, tsl) != 0) {
   2592 				continue;
   2593 			}
   2594 
   2595 			already_resolved = B_FALSE;
   2596 
   2597 			mutex_enter(&fire->ire_lock);
   2598 			v6gw = fire->ire_gateway_addr_v6;
   2599 			mutex_exit(&fire->ire_lock);
   2600 
   2601 			gw_ire = ire_ftable_lookup_v6(&v6gw, 0, 0,
   2602 			    IRE_INTERFACE, NULL, NULL, ALL_ZONES, 0, tsl,
   2603 			    MATCH_IRE_RECURSIVE | MATCH_IRE_TYPE |
   2604 			    MATCH_IRE_SECATTR, ipst);
   2605 
   2606 			/* No resolver for the gateway; we skip this ire. */
   2607 			if (gw_ire == NULL) {
   2608 				continue;
   2609 			}
   2610 
   2611 			if (first_cire) {
   2612 
   2613 				IRB_REFHOLD(cirb);
   2614 				/*
   2615 				 * For all IRE_CACHE ires for that
   2616 				 * destination.
   2617 				 */
   2618 				for (cire = first_cire;
   2619 				    cire != NULL;
   2620 				    cire = cire->ire_next) {
   2621 
   2622 					if (!(cire->ire_flags & RTF_MULTIRT))
   2623 						continue;
   2624 					if (!IN6_ARE_ADDR_EQUAL(
   2625 					    &cire->ire_addr_v6, &v6dst))
   2626 						continue;
   2627 					if (cire->ire_marks &
   2628 					    IRE_MARK_CONDEMNED)
   2629 						continue;
   2630 
   2631 					if (cire->ire_gw_secattr != NULL &&
   2632 					    tsol_ire_match_gwattr(cire,
   2633 					    tsl) != 0) {
   2634 						continue;
   2635 					}
   2636 
   2637 					/*
   2638 					 * Cache entries are linked to the
   2639 					 * parent routes using the parent handle
   2640 					 * (ire_phandle). If no cache entry has
   2641 					 * the same handle as fire, fire is
   2642 					 * still unresolved.
   2643 					 */
   2644 					ASSERT(cire->ire_phandle != 0);
   2645 					if (cire->ire_phandle ==
   2646 					    fire->ire_phandle) {
   2647 						already_resolved = B_TRUE;
   2648 						break;
   2649 					}
   2650 				}
   2651 				IRB_REFRELE(cirb);
   2652 			}
   2653 
   2654 			/*
   2655 			 * This route is already resolved; proceed with
   2656 			 * next one.
   2657 			 */
   2658 			if (already_resolved) {
   2659 				ire_refrele(gw_ire);
   2660 				continue;
   2661 			}
   2662 
   2663 			/*
   2664 			 * Compute the time elapsed since our preceding
   2665 			 * attempt to resolve that route.
   2666 			 * If the MULTIRT_USESTAMP flag is set, we take
   2667 			 * that route into account only if this time
   2668 			 * interval exceeds ip_multirt_resolution_interval;
   2669 			 * this prevents us from attempting to resolve a
   2670 			 * broken route upon each sending of a packet.
   2671 			 */
   2672 			delta = lbolt - fire->ire_last_used_time;
   2673 			delta = TICK_TO_MSEC(delta);
   2674 
   2675 			res = (boolean_t)
   2676 			    ((delta > ipst->
   2677 			    ips_ip_multirt_resolution_interval) ||
   2678 			    (!(flags & MULTIRT_USESTAMP)));
   2679 
   2680 			ip3dbg(("ire_multirt_lookup_v6: fire %p, delta %lx, "
   2681 			    "flags %04x, res %d\n",
   2682 			    (void *)fire, delta, flags, res));
   2683 
   2684 			if (res) {
   2685 				if (best_cire) {
   2686 					/*
   2687 					 * Release the resolver associated
   2688 					 * to the preceding candidate best
   2689 					 * ire, if any.
   2690 					 */
   2691 					ire_refrele(best_cire);
   2692 					ASSERT(best_fire);
   2693 				}
   2694 				best_fire = fire;
   2695 				best_cire = gw_ire;
   2696 				continue;
   2697 			}
   2698 
   2699 			ire_refrele(gw_ire);
   2700 		}
   2701 	}
   2702 
   2703 	if (best_fire) {
   2704 		IRE_REFHOLD(best_fire);
   2705 	}
   2706 	IRB_REFRELE(firb);
   2707 
   2708 	/* Release the first IRE_CACHE we initially looked up, if any. */
   2709 	if (first_cire)
   2710 		ire_refrele(first_cire);
   2711 
   2712 	/* Found a resolvable route. */
   2713 	if (best_fire) {
   2714 		ASSERT(best_cire);
   2715 
   2716 		if (*fire_arg)
   2717 			ire_refrele(*fire_arg);
   2718 		if (*ire_arg)
   2719 			ire_refrele(*ire_arg);
   2720 
   2721 		/*
   2722 		 * Update the passed arguments with the
   2723 		 * resolvable multirt route we found
   2724 		 */
   2725 		*fire_arg = best_fire;
   2726 		*ire_arg = best_cire;
   2727 
   2728 		ip2dbg(("ire_multirt_lookup_v6: returning B_TRUE, "
   2729 		    "*fire_arg %p, *ire_arg %p\n",
   2730 		    (void *)best_fire, (void *)best_cire));
   2731 
   2732 		return (B_TRUE);
   2733 	}
   2734 
   2735 	ASSERT(best_cire == NULL);
   2736 
   2737 	ip2dbg(("ire_multirt_lookup_v6: returning B_FALSE, *fire_arg %p, "
   2738 	    "*ire_arg %p\n",
   2739 	    (void *)*fire_arg, (void *)*ire_arg));
   2740 
   2741 	/* No resolvable route. */
   2742 	return (B_FALSE);
   2743 }
   2744 
   2745 
   2746 /*
   2747  * Find an IRE_OFFSUBNET IRE entry for the multicast address 'v6dstp'
   2748  * that goes through 'ipif'. As a fallback, a route that goes through
   2749  * ipif->ipif_ill can be returned.
   2750  */
   2751 ire_t *
   2752 ipif_lookup_multi_ire_v6(ipif_t *ipif, const in6_addr_t *v6dstp)
   2753 {
   2754 	ire_t	*ire;
   2755 	ire_t	*save_ire = NULL;
   2756 	ire_t   *gw_ire;
   2757 	irb_t   *irb;
   2758 	in6_addr_t v6gw;
   2759 	int	match_flags = MATCH_IRE_TYPE | MATCH_IRE_ILL;
   2760 	ip_stack_t	*ipst = ipif->ipif_ill->ill_ipst;
   2761 
   2762 	ire = ire_ftable_lookup_v6(v6dstp, 0, 0, 0, NULL, NULL, ALL_ZONES, 0,
   2763 	    NULL, MATCH_IRE_DEFAULT, ipst);
   2764 
   2765 	if (ire == NULL)
   2766 		return (NULL);
   2767 
   2768 	irb = ire->ire_bucket;
   2769 	ASSERT(irb);
   2770 
   2771 	IRB_REFHOLD(irb);
   2772 	ire_refrele(ire);
   2773 	for (ire = irb->irb_ire; ire != NULL; ire = ire->ire_next) {
   2774 		if (!IN6_ARE_ADDR_EQUAL(&ire->ire_addr_v6, v6dstp) ||
   2775 		    (ipif->ipif_zoneid != ire->ire_zoneid &&
   2776 		    ire->ire_zoneid != ALL_ZONES)) {
   2777 			continue;
   2778 		}
   2779 
   2780 		switch (ire->ire_type) {
   2781 		case IRE_DEFAULT:
   2782 		case IRE_PREFIX:
   2783 		case IRE_HOST:
   2784 			mutex_enter(&ire->ire_lock);
   2785 			v6gw = ire->ire_gateway_addr_v6;
   2786 			mutex_exit(&ire->ire_lock);
   2787 			gw_ire = ire_ftable_lookup_v6(&v6gw, 0, 0,
   2788 			    IRE_INTERFACE, ipif, NULL, ALL_ZONES, 0,
   2789 			    NULL, match_flags, ipst);
   2790 
   2791 			if (gw_ire != NULL) {
   2792 				if (save_ire != NULL) {
   2793 					ire_refrele(save_ire);
   2794 				}
   2795 				IRE_REFHOLD(ire);
   2796 				if (gw_ire->ire_ipif == ipif) {
   2797 					ire_refrele(gw_ire);
   2798 
   2799 					IRB_REFRELE(irb);
   2800 					return (ire);
   2801 				}
   2802 				ire_refrele(gw_ire);
   2803 				save_ire = ire;
   2804 			}
   2805 			break;
   2806 		case IRE_IF_NORESOLVER:
   2807 		case IRE_IF_RESOLVER:
   2808 			if (ire->ire_ipif == ipif) {
   2809 				if (save_ire != NULL) {
   2810 					ire_refrele(save_ire);
   2811 				}
   2812 				IRE_REFHOLD(ire);
   2813 
   2814 				IRB_REFRELE(irb);
   2815 				return (ire);
   2816 			}
   2817 			break;
   2818 		}
   2819 	}
   2820 	IRB_REFRELE(irb);
   2821 
   2822 	return (save_ire);
   2823 }
   2824 
   2825 /*
   2826  * This is the implementation of the IPv6 IRE cache lookup procedure.
   2827  * Separating the interface from the implementation allows additional
   2828  * flexibility when specifying search criteria.
   2829  */
   2830 static ire_t *
   2831 ip6_ctable_lookup_impl(ire_ctable_args_t *margs)
   2832 {
   2833 	irb_t			*irb_ptr;
   2834 	ire_t			*ire;
   2835 	ip_stack_t		*ipst = margs->ict_ipst;
   2836 
   2837 	if ((margs->ict_flags & (MATCH_IRE_SRC | MATCH_IRE_ILL)) &&
   2838 	    (margs->ict_ipif == NULL)) {
   2839 		return (NULL);
   2840 	}
   2841 
   2842 	irb_ptr = &ipst->ips_ip_cache_table_v6[IRE_ADDR_HASH_V6(
   2843 	    *((in6_addr_t *)(margs->ict_addr)),
   2844 	    ipst->ips_ip6_cache_table_size)];
   2845 	rw_enter(&irb_ptr->irb_lock, RW_READER);
   2846 	for (ire = irb_ptr->irb_ire; ire != NULL; ire = ire->ire_next) {
   2847 		if (ire->ire_marks & IRE_MARK_CONDEMNED)
   2848 			continue;
   2849 		ASSERT(IN6_ARE_ADDR_EQUAL(&ire->ire_mask_v6, &ipv6_all_ones));
   2850 		if (ire_match_args_v6(ire, (in6_addr_t *)margs->ict_addr,
   2851 		    &ire->ire_mask_v6, (in6_addr_t *)margs->ict_gateway,
   2852 		    margs->ict_type, margs->ict_ipif, margs->ict_zoneid, 0,
   2853 		    margs->ict_tsl, margs->ict_flags)) {
   2854 			IRE_REFHOLD(ire);
   2855 			rw_exit(&irb_ptr->irb_lock);
   2856 			return (ire);
   2857 		}
   2858 	}
   2859 
   2860 	rw_exit(&irb_ptr->irb_lock);
   2861 	return (NULL);
   2862 }
   2863