xref: /titanic_50/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c (revision d9e728a2c2e62adeef072d782e4c8a7b34e7e8e8)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * BOUND state of the DHCP client state machine.
26  */
27 
28 #pragma ident	"%Z%%M%	%I%	%E% SMI"
29 
30 #include <sys/socket.h>
31 #include <sys/types.h>
32 #include <string.h>
33 #include <netinet/in.h>
34 #include <sys/sockio.h>
35 #include <unistd.h>
36 #include <time.h>
37 #include <arpa/inet.h>
38 #include <stdlib.h>
39 #include <search.h>
40 #include <sys/sysmacros.h>
41 #include <dhcp_hostconf.h>
42 #include <dhcpagent_util.h>
43 #include <dhcpmsg.h>
44 
45 #include "states.h"
46 #include "packet.h"
47 #include "util.h"
48 #include "agent.h"
49 #include "interface.h"
50 #include "script_handler.h"
51 
52 /*
53  * Possible outcomes for IPv6 binding attempt.
54  */
55 enum v6_bind_result {
56 	v6Restart,		/* report failure and restart state machine */
57 	v6Resent,		/* new Request message has been sent */
58 	v6Done			/* successful binding */
59 };
60 
61 static enum v6_bind_result configure_v6_leases(dhcp_smach_t *);
62 static boolean_t configure_v4_lease(dhcp_smach_t *);
63 static boolean_t configure_v4_timers(dhcp_smach_t *);
64 
65 /*
66  * bound_event_cb(): callback for script_start on the event EVENT_BOUND
67  *
68  *   input: dhcp_smach_t *: the state machine configured
69  *	    void *: unused
70  *  output: int: always 1
71  */
72 
73 /* ARGSUSED1 */
74 static int
75 bound_event_cb(dhcp_smach_t *dsmp, void *arg)
76 {
77 	if (dsmp->dsm_ia.ia_fd != -1)
78 		ipc_action_finish(dsmp, DHCP_IPC_SUCCESS);
79 	else
80 		async_finish(dsmp);
81 	return (1);
82 }
83 
84 /*
85  * dhcp_bound(): configures an state machine and interfaces using information
86  *		 contained in the ACK/Reply packet and sets up lease timers.
87  *		 Before starting, the requested address is verified by
88  *		 Duplicate Address Detection to make sure it's not in use.
89  *
90  *   input: dhcp_smach_t *: the state machine to move to bound
91  *	    PKT_LIST *: the ACK/Reply packet, or NULL to use dsmp->dsm_ack
92  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
93  */
94 
95 boolean_t
96 dhcp_bound(dhcp_smach_t *dsmp, PKT_LIST *ack)
97 {
98 	DHCPSTATE	oldstate;
99 	lease_t		new_lease;
100 	dhcp_lif_t	*lif;
101 	dhcp_lease_t	*dlp;
102 	enum v6_bind_result v6b;
103 
104 	if (ack != NULL) {
105 		/* If ack we're replacing is not the original, then free it */
106 		if (dsmp->dsm_ack != dsmp->dsm_orig_ack)
107 			free_pkt_entry(dsmp->dsm_ack);
108 		dsmp->dsm_ack = ack;
109 		/* Save the first ack as the original */
110 		if (dsmp->dsm_orig_ack == NULL)
111 			dsmp->dsm_orig_ack = ack;
112 	}
113 
114 	oldstate = dsmp->dsm_state;
115 	switch (oldstate) {
116 
117 	case ADOPTING:
118 		/* Note that adoption occurs only for IPv4 DHCP. */
119 
120 		/* Ignore BOOTP */
121 		if (ack->opts[CD_DHCP_TYPE] == NULL)
122 			return (B_FALSE);
123 
124 		/*
125 		 * if we're adopting a lease, the lease timers
126 		 * only provide an upper bound since we don't know
127 		 * from what time they are relative to.  assume we
128 		 * have a lease time of at most DHCP_ADOPT_LEASE_MAX.
129 		 */
130 		(void) memcpy(&new_lease, ack->opts[CD_LEASE_TIME]->value,
131 		    sizeof (lease_t));
132 
133 		new_lease = htonl(MIN(ntohl(new_lease), DHCP_ADOPT_LEASE_MAX));
134 
135 		(void) memcpy(ack->opts[CD_LEASE_TIME]->value, &new_lease,
136 		    sizeof (lease_t));
137 
138 		/*
139 		 * we have no idea when the REQUEST that generated
140 		 * this ACK was sent, but for diagnostic purposes
141 		 * we'll assume its close to the current time.
142 		 */
143 		dsmp->dsm_newstart_monosec = monosec();
144 
145 		if (dsmp->dsm_isv6) {
146 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
147 				return (v6b == v6Resent);
148 		} else {
149 			if (!configure_v4_lease(dsmp))
150 				return (B_FALSE);
151 
152 			if (!configure_v4_timers(dsmp))
153 				return (B_FALSE);
154 		}
155 
156 		dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
157 		break;
158 
159 	case SELECTING:
160 	case REQUESTING:
161 	case INIT_REBOOT:
162 
163 		if (dsmp->dsm_isv6) {
164 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
165 				return (v6b == v6Resent);
166 		} else {
167 			if (!configure_v4_lease(dsmp))
168 				return (B_FALSE);
169 
170 			if (!configure_v4_timers(dsmp))
171 				return (B_FALSE);
172 
173 			if (!clear_lif_deprecated(dsmp->dsm_lif))
174 				return (B_FALSE);
175 		}
176 
177 		/* Stop sending requests now */
178 		stop_pkt_retransmission(dsmp);
179 
180 		/*
181 		 * If we didn't end up with any usable leases, then we have a
182 		 * problem.
183 		 */
184 		if (dsmp->dsm_leases == NULL) {
185 			dhcpmsg(MSG_WARNING,
186 			    "dhcp_bound: no address lease established");
187 			return (B_FALSE);
188 		}
189 
190 		/*
191 		 * If this is a Rapid-Commit (selecting state) or if we're
192 		 * dealing with a reboot (init-reboot), then we will have a new
193 		 * server ID to save.
194 		 */
195 		if (ack != NULL &&
196 		    (oldstate == SELECTING || oldstate == INIT_REBOOT) &&
197 		    dsmp->dsm_isv6 && !save_server_id(dsmp, ack)) {
198 			dhcpmsg(MSG_ERROR,
199 			    "dhcp_bound: unable to save server ID on %s",
200 			    dsmp->dsm_name);
201 			return (B_FALSE);
202 		}
203 
204 		/*
205 		 * We will continue configuring the interfaces via
206 		 * dhcp_bound_complete, once kernel DAD completes.  If no new
207 		 * leases were created (which can happen on an init-reboot used
208 		 * for link-up confirmation), then go straight to bound state.
209 		 */
210 		if (!set_smach_state(dsmp, PRE_BOUND))
211 			return (B_FALSE);
212 		if (dsmp->dsm_lif_wait == 0)
213 			dhcp_bound_complete(dsmp);
214 		break;
215 
216 	case PRE_BOUND:
217 	case BOUND:
218 		/* This is just a duplicate ack; silently ignore it */
219 		return (B_TRUE);
220 
221 	case RENEWING:
222 	case REBINDING:
223 
224 		if (dsmp->dsm_isv6) {
225 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
226 				return (v6b == v6Resent);
227 		} else {
228 			if (!configure_v4_timers(dsmp))
229 				return (B_FALSE);
230 			if (!clear_lif_deprecated(dsmp->dsm_lif))
231 				return (B_FALSE);
232 		}
233 
234 		/*
235 		 * If some or all of the leases were torn down by the server,
236 		 * then handle that as an expiry.  When the script is done
237 		 * running for the LOSS6 event, we'll end up back here.
238 		 */
239 		if ((lif = find_expired_lif(dsmp)) != NULL) {
240 			hold_lif(lif);
241 			dhcp_expire(NULL, lif);
242 			while ((lif = find_expired_lif(dsmp)) != NULL) {
243 				dlp = lif->lif_lease;
244 				unplumb_lif(lif);
245 				if (dlp->dl_nlifs == 0)
246 					remove_lease(dlp);
247 			}
248 			if (dsmp->dsm_leases == NULL)
249 				return (B_FALSE);
250 		}
251 
252 		if (oldstate == REBINDING && dsmp->dsm_isv6 &&
253 		    !save_server_id(dsmp, ack)) {
254 			return (B_FALSE);
255 		}
256 
257 		/*
258 		 * Handle Renew/Rebind that fails to address one of our leases.
259 		 * (Should just never happen, but RFC 3315 section 18.1.8
260 		 * requires it, and TAHI tests for it.)
261 		 */
262 		for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlp->dl_next) {
263 			if (dlp->dl_stale && dlp->dl_nlifs > 0)
264 				break;
265 		}
266 		if (dlp != NULL) {
267 			dhcpmsg(MSG_DEBUG, "dhcp_bound: lease not updated; "
268 			    "allow retransmit");
269 			return (B_TRUE);
270 		}
271 
272 		if (!set_smach_state(dsmp, BOUND))
273 			return (B_FALSE);
274 
275 		(void) script_start(dsmp, dsmp->dsm_isv6 ? EVENT_EXTEND6 :
276 		    EVENT_EXTEND, bound_event_cb, NULL, NULL);
277 
278 		dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
279 
280 		/* Stop sending requests now */
281 		stop_pkt_retransmission(dsmp);
282 		break;
283 
284 	case INFORM_SENT:
285 
286 		if (dsmp->dsm_isv6 && !save_server_id(dsmp, ack)) {
287 			return (B_FALSE);
288 		}
289 
290 		(void) bound_event_cb(dsmp, NULL);
291 		if (!set_smach_state(dsmp, INFORMATION))
292 			return (B_FALSE);
293 
294 		/* Stop sending requests now */
295 		stop_pkt_retransmission(dsmp);
296 		break;
297 
298 	default:
299 		/* something is really bizarre... */
300 		dhcpmsg(MSG_DEBUG,
301 		    "dhcp_bound: called in unexpected state: %s",
302 		    dhcp_state_to_string(dsmp->dsm_state));
303 		return (B_FALSE);
304 	}
305 
306 	/*
307 	 * remove any stale hostconf file that might be lying around for
308 	 * this state machine. (in general, it's harmless, since we'll write a
309 	 * fresh one when we exit anyway, but just to reduce confusion..)
310 	 */
311 
312 	(void) remove_hostconf(dsmp->dsm_name, dsmp->dsm_isv6);
313 	return (B_TRUE);
314 }
315 
316 /*
317  * dhcp_bound_complete(): complete interface configuration after DAD
318  *
319  *   input: dhcp_smach_t *: the state machine now ready
320  *  output: none
321  */
322 
323 void
324 dhcp_bound_complete(dhcp_smach_t *dsmp)
325 {
326 	PKT_LIST	*ack;
327 	DHCP_OPT	*router_list;
328 	int		i;
329 	DHCPSTATE	oldstate;
330 
331 	/*
332 	 * Do bound state entry processing only if running IPv4.  There's no
333 	 * need for this with DHCPv6 because link-locals are used for I/O and
334 	 * because DHCPv6 isn't entangled with routing.
335 	 */
336 	if (dsmp->dsm_isv6) {
337 		(void) set_smach_state(dsmp, BOUND);
338 		dhcpmsg(MSG_DEBUG, "configure_bound: bound %s",
339 		    dsmp->dsm_name);
340 		(void) script_start(dsmp, EVENT_BOUND6, bound_event_cb, NULL,
341 		    NULL);
342 		dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
343 		return;
344 	}
345 
346 	/*
347 	 * add each provided router; we'll clean them up when the
348 	 * state machine goes away or when our lease expires.
349 	 */
350 
351 	ack = dsmp->dsm_ack;
352 	router_list = ack->opts[CD_ROUTER];
353 	if (router_list && (router_list->len % sizeof (ipaddr_t)) == 0) {
354 
355 		dsmp->dsm_nrouters = router_list->len / sizeof (ipaddr_t);
356 		dsmp->dsm_routers  = malloc(router_list->len);
357 		if (dsmp->dsm_routers == NULL) {
358 			dhcpmsg(MSG_ERR, "configure_bound: cannot allocate "
359 			    "default router list, ignoring default routers");
360 			dsmp->dsm_nrouters = 0;
361 		}
362 
363 		for (i = 0; i < dsmp->dsm_nrouters; i++) {
364 
365 			(void) memcpy(&dsmp->dsm_routers[i].s_addr,
366 			    router_list->value + (i * sizeof (ipaddr_t)),
367 			    sizeof (ipaddr_t));
368 
369 			if (!add_default_route(dsmp->dsm_name,
370 			    &dsmp->dsm_routers[i])) {
371 				dhcpmsg(MSG_ERR, "configure_bound: cannot add "
372 				    "default router %s on %s", inet_ntoa(
373 				    dsmp->dsm_routers[i]), dsmp->dsm_name);
374 				dsmp->dsm_routers[i].s_addr = htonl(INADDR_ANY);
375 				continue;
376 			}
377 
378 			dhcpmsg(MSG_INFO, "added default router %s on %s",
379 			    inet_ntoa(dsmp->dsm_routers[i]), dsmp->dsm_name);
380 		}
381 	}
382 
383 	oldstate = dsmp->dsm_state;
384 	if (!set_smach_state(dsmp, BOUND)) {
385 		dhcpmsg(MSG_ERR,
386 		    "configure_bound: cannot set bound state on %s",
387 		    dsmp->dsm_name);
388 		return;
389 	}
390 
391 	dhcpmsg(MSG_DEBUG, "configure_bound: bound %s", dsmp->dsm_name);
392 
393 	/*
394 	 * We're now committed to this binding, so if it came from BOOTP, set
395 	 * the flag.
396 	 */
397 
398 	if (ack->opts[CD_DHCP_TYPE] == NULL)
399 		dsmp->dsm_dflags |= DHCP_IF_BOOTP;
400 
401 	/*
402 	 * If the previous state was ADOPTING, event loop has not been started
403 	 * at this time; so don't run the EVENT_BOUND script.
404 	 */
405 	if (oldstate != ADOPTING) {
406 		(void) script_start(dsmp, EVENT_BOUND, bound_event_cb, NULL,
407 		    NULL);
408 	}
409 
410 	dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
411 }
412 
413 /*
414  * fuzzify(): adds some "fuzz" to a t1/t2 time, in accordance with RFC2131.
415  *	      We use up to plus or minus 2% jitter in the time.  This is a
416  *	      small value, but the timers involved are typically long.  A
417  *	      common T1 value is one day, and the fuzz is up to 28.8 minutes;
418  *	      plenty of time to make sure that individual clients don't renew
419  *	      all at the same time.
420  *
421  *   input: uint32_t: the number of seconds until lease expiration
422  *	    double: the approximate percentage of that time to return
423  *  output: double: a number approximating (sec * pct)
424  */
425 
426 static double
427 fuzzify(uint32_t sec, double pct)
428 {
429 	return (sec * (pct + (drand48() - 0.5) / 25.0));
430 }
431 
432 /*
433  * get_pkt_times(): pulls the lease times out of a v4 DHCP packet and stores
434  *		    them as host byte-order relative times in the passed in
435  *		    parameters.
436  *
437  *   input: PKT_LIST *: the packet to pull the packet times from
438  *	    lease_t *: where to store the relative lease time in hbo
439  *	    lease_t *: where to store the relative t1 time in hbo
440  *	    lease_t *: where to store the relative t2 time in hbo
441  *  output: void
442  */
443 
444 static void
445 get_pkt_times(PKT_LIST *ack, lease_t *lease, lease_t *t1, lease_t *t2)
446 {
447 	*lease	= DHCP_PERM;
448 	*t1	= DHCP_PERM;
449 	*t2	= DHCP_PERM;
450 
451 	if (ack->opts[CD_DHCP_TYPE] == NULL) {
452 		dhcpmsg(MSG_VERBOSE,
453 		    "get_pkt_times: BOOTP response; infinite lease");
454 		return;
455 	}
456 	if (ack->opts[CD_LEASE_TIME] == NULL) {
457 		dhcpmsg(MSG_VERBOSE,
458 		    "get_pkt_times: no lease option provided");
459 		return;
460 	}
461 	if (ack->opts[CD_LEASE_TIME]->len != sizeof (lease_t)) {
462 		dhcpmsg(MSG_VERBOSE, "get_pkt_times: invalid lease option");
463 	}
464 
465 	(void) memcpy(lease, ack->opts[CD_LEASE_TIME]->value, sizeof (lease_t));
466 	*lease = ntohl(*lease);
467 
468 	if (*lease == DHCP_PERM) {
469 		dhcpmsg(MSG_VERBOSE, "get_pkt_times: infinite lease granted");
470 		return;
471 	}
472 
473 	if (ack->opts[CD_T1_TIME] != NULL &&
474 	    ack->opts[CD_T1_TIME]->len == sizeof (lease_t)) {
475 		(void) memcpy(t1, ack->opts[CD_T1_TIME]->value, sizeof (*t1));
476 		*t1 = ntohl(*t1);
477 	}
478 
479 	if (ack->opts[CD_T2_TIME] != NULL &&
480 	    ack->opts[CD_T2_TIME]->len == sizeof (lease_t)) {
481 		(void) memcpy(t2, ack->opts[CD_T2_TIME]->value, sizeof (*t2));
482 		*t2 = ntohl(*t2);
483 	}
484 
485 	if ((*t1 == DHCP_PERM) || (*t1 >= *lease))
486 		*t1 = (lease_t)fuzzify(*lease, DHCP_T1_FACT);
487 
488 	if ((*t2 == DHCP_PERM) || (*t2 > *lease) || (*t2 <= *t1))
489 		*t2 = (lease_t)fuzzify(*lease, DHCP_T2_FACT);
490 
491 	dhcpmsg(MSG_VERBOSE, "get_pkt_times: lease %u t1 %u t2 %u",
492 	    *lease, *t1, *t2);
493 }
494 
495 /*
496  * configure_v4_timers(): configures the lease timers on a v4 state machine
497  *
498  *   input: dhcp_smach_t *: the state machine to configure
499  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
500  */
501 
502 static boolean_t
503 configure_v4_timers(dhcp_smach_t *dsmp)
504 {
505 	PKT_LIST	*ack = dsmp->dsm_ack;
506 	lease_t		lease, t1, t2;
507 	dhcp_lease_t	*dlp;
508 	dhcp_lif_t	*lif;
509 
510 	/* v4 has just one lease per state machine, and one LIF */
511 	dlp = dsmp->dsm_leases;
512 	lif = dlp->dl_lifs;
513 
514 	/*
515 	 * If it's DHCP, but there's no valid lease time, then complain,
516 	 * decline the lease and return error.
517 	 */
518 	if (ack->opts[CD_DHCP_TYPE] != NULL &&
519 	    (ack->opts[CD_LEASE_TIME] == NULL ||
520 	    ack->opts[CD_LEASE_TIME]->len != sizeof (lease_t))) {
521 		lif_mark_decline(lif, "Missing or corrupted lease time");
522 		send_declines(dsmp);
523 		dhcpmsg(MSG_WARNING, "configure_v4_timers: %s lease time in "
524 		    "ACK on %s", ack->opts[CD_LEASE_TIME] == NULL ? "missing" :
525 		    "corrupt", dsmp->dsm_name);
526 		return (B_FALSE);
527 	}
528 
529 	/* Stop the T1 and T2 timers */
530 	cancel_lease_timers(dlp);
531 
532 	/* Stop the LEASE timer */
533 	cancel_lif_timers(lif);
534 
535 	/*
536 	 * type has already been verified as ACK.  if type is not set,
537 	 * then we got a BOOTP packet.  we now fetch the t1, t2, and
538 	 * lease options out of the packet into variables.  they are
539 	 * returned as relative host-byte-ordered times.
540 	 */
541 
542 	get_pkt_times(ack, &lease, &t1, &t2);
543 
544 	/*
545 	 * if the current lease is mysteriously close to the new
546 	 * lease, warn the user.  unless there's less than a minute
547 	 * left, round to the closest minute.
548 	 */
549 
550 	if (lif->lif_expire.dt_start != 0 &&
551 	    abs((dsmp->dsm_newstart_monosec + lease) -
552 	    (dsmp->dsm_curstart_monosec + lif->lif_expire.dt_start)) <
553 	    DHCP_LEASE_EPS) {
554 		const char *noext = "configure_v4_timers: lease renewed but "
555 		    "time not extended";
556 		int msg_level;
557 		uint_t minleft;
558 
559 		if (lif->lif_expire.dt_start < DHCP_LEASE_ERROR_THRESH)
560 			msg_level = MSG_ERROR;
561 		else
562 			msg_level = MSG_VERBOSE;
563 
564 		minleft = (lif->lif_expire.dt_start + 30) / 60;
565 
566 		if (lif->lif_expire.dt_start < 60) {
567 			dhcpmsg(msg_level, "%s; expires in %d seconds",
568 			    noext, lif->lif_expire.dt_start);
569 		} else if (minleft == 1) {
570 			dhcpmsg(msg_level, "%s; expires in 1 minute", noext);
571 		} else if (minleft > 120) {
572 			dhcpmsg(msg_level, "%s; expires in %d hours",
573 			    noext, (minleft + 30) / 60);
574 		} else {
575 			dhcpmsg(msg_level, "%s; expires in %d minutes",
576 			    noext, minleft);
577 		}
578 	}
579 
580 	init_timer(&dlp->dl_t1, t1);
581 	init_timer(&dlp->dl_t2, t2);
582 	init_timer(&lif->lif_expire, lease);
583 
584 	if (lease == DHCP_PERM) {
585 		dhcpmsg(MSG_INFO,
586 		    "configure_v4_timers: %s acquired permanent lease",
587 		    dsmp->dsm_name);
588 		return (B_TRUE);
589 	}
590 
591 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s acquired lease, expires %s",
592 	    dsmp->dsm_name,
593 	    monosec_to_string(dsmp->dsm_newstart_monosec + lease));
594 
595 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s begins renewal at %s",
596 	    dsmp->dsm_name, monosec_to_string(dsmp->dsm_newstart_monosec +
597 	    dlp->dl_t1.dt_start));
598 
599 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s begins rebinding at %s",
600 	    dsmp->dsm_name, monosec_to_string(dsmp->dsm_newstart_monosec +
601 	    dlp->dl_t2.dt_start));
602 
603 	/*
604 	 * according to RFC2131, there is no minimum lease time, but don't
605 	 * set up renew/rebind timers if lease is shorter than DHCP_REBIND_MIN.
606 	 */
607 
608 	if (!schedule_lif_timer(lif, &lif->lif_expire, dhcp_expire))
609 		goto failure;
610 
611 	if (lease < DHCP_REBIND_MIN) {
612 		dhcpmsg(MSG_WARNING, "configure_v4_timers: lease on %s is for "
613 		    "less than %d seconds!", dsmp->dsm_name, DHCP_REBIND_MIN);
614 		return (B_TRUE);
615 	}
616 
617 	if (!schedule_lease_timer(dlp, &dlp->dl_t1, dhcp_renew))
618 		goto failure;
619 
620 	if (!schedule_lease_timer(dlp, &dlp->dl_t2, dhcp_rebind))
621 		goto failure;
622 
623 	return (B_TRUE);
624 
625 failure:
626 	cancel_lease_timers(dlp);
627 	cancel_lif_timers(lif);
628 	dhcpmsg(MSG_WARNING,
629 	    "configure_v4_timers: cannot schedule lease timers");
630 	return (B_FALSE);
631 }
632 
633 /*
634  * configure_v6_leases(): configures the IPv6 leases on a state machine from
635  *			  the current DHCPv6 ACK.  We need to scan the ACK,
636  *			  create a lease for each IA_NA, and a new LIF for each
637  *			  IAADDR.
638  *
639  *   input: dhcp_smach_t *: the machine to configure (with a valid dsm_ack)
640  *  output: enum v6_bind_result: restart, resend, or done
641  */
642 
643 static enum v6_bind_result
644 configure_v6_leases(dhcp_smach_t *dsmp)
645 {
646 	const dhcpv6_option_t *d6o, *d6so, *d6sso;
647 	const char *optbase, *estr, *msg;
648 	uint_t olen, solen, ssolen, msglen;
649 	dhcpv6_ia_na_t d6in;
650 	dhcpv6_iaaddr_t d6ia;
651 	dhcp_lease_t *dlp;
652 	uint32_t shortest;
653 	dhcp_lif_t *lif;
654 	uint_t nlifs;
655 	boolean_t got_iana = B_FALSE;
656 	uint_t scode;
657 
658 	for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlp->dl_next)
659 		dlp->dl_stale = B_TRUE;
660 
661 	d6o = NULL;
662 	while ((d6o = dhcpv6_pkt_option(dsmp->dsm_ack, d6o, DHCPV6_OPT_IA_NA,
663 	    &olen)) != NULL) {
664 		if (olen < sizeof (d6in)) {
665 			dhcpmsg(MSG_WARNING,
666 			    "configure_v6_leases: garbled IA_NA");
667 			continue;
668 		}
669 
670 		/*
671 		 * Check the IAID.  It should be for our controlling LIF.  If a
672 		 * single state machine needs to use multiple IAIDs, then this
673 		 * will need to change.
674 		 */
675 		(void) memcpy(&d6in, d6o, sizeof (d6in));
676 		d6in.d6in_iaid = ntohl(d6in.d6in_iaid);
677 		if (d6in.d6in_iaid != dsmp->dsm_lif->lif_iaid) {
678 			dhcpmsg(MSG_WARNING, "configure_v6_leases: ignored "
679 			    "IA_NA for IAID %x (not %x)", d6in.d6in_iaid,
680 			    dsmp->dsm_lif->lif_iaid);
681 			continue;
682 		}
683 
684 		/*
685 		 * See notes below; there's only one IA_NA and a single IAID
686 		 * for now.
687 		 */
688 		if ((dlp = dsmp->dsm_leases) != NULL)
689 			dlp->dl_stale = B_FALSE;
690 
691 		/*
692 		 * Note that some bug-ridden servers will try to give us
693 		 * multiple IA_NA options for a single IAID.  We ignore
694 		 * duplicates.
695 		 */
696 		if (got_iana) {
697 			dhcpmsg(MSG_WARNING, "configure_v6_leases: unexpected "
698 			    "extra IA_NA ignored");
699 			continue;
700 		}
701 
702 		d6in.d6in_t1 = ntohl(d6in.d6in_t1);
703 		d6in.d6in_t2 = ntohl(d6in.d6in_t2);
704 
705 		/* RFC 3315 required check for invalid T1/T2 combinations */
706 		if (d6in.d6in_t1 > d6in.d6in_t2 && d6in.d6in_t2 != 0) {
707 			dhcpmsg(MSG_WARNING, "configure_v6_leases: ignored "
708 			    "IA_NA with invalid T1 %u > T2 %u", d6in.d6in_t1,
709 			    d6in.d6in_t2);
710 			continue;
711 		}
712 
713 		/*
714 		 * There may be a status code here.  Process if present.
715 		 */
716 		optbase = (const char *)d6o + sizeof (d6in);
717 		olen -= sizeof (d6in);
718 		d6so = dhcpv6_find_option(optbase, olen, NULL,
719 		    DHCPV6_OPT_STATUS_CODE, &solen);
720 		scode = dhcpv6_status_code(d6so, solen, &estr, &msg, &msglen);
721 		if (scode != DHCPV6_STAT_SUCCESS) {
722 			dhcpmsg(MSG_WARNING,
723 			    "configure_v6_leases: IA_NA: %s: %.*s",
724 			    estr, msglen, msg);
725 		}
726 		print_server_msg(dsmp, msg, msglen);
727 
728 		/*
729 		 * Other errors are possible here.  According to RFC 3315
730 		 * section 18.1.8, we ignore the entire IA if it gives the "no
731 		 * addresses" status code.  We may try another server if we
732 		 * like -- we instead opt to allow the addresses to expire and
733 		 * then try a new server.
734 		 *
735 		 * If the status code is "no binding," then we must go back and
736 		 * redo the Request.  Surprisingly, it doesn't matter if it's
737 		 * any other code.
738 		 */
739 		if (scode == DHCPV6_STAT_NOADDRS) {
740 			dhcpmsg(MSG_DEBUG, "configure_v6_leases: ignoring "
741 			    "no-addrs status in IA_NA");
742 			continue;
743 		}
744 
745 		if (scode == DHCPV6_STAT_NOBINDING) {
746 			send_v6_request(dsmp);
747 			return (v6Resent);
748 		}
749 
750 		/*
751 		 * Find or create the lease structure.  This part is simple,
752 		 * because we support only IA_NA and a single IAID.  This means
753 		 * there's only one lease structure.  The design supports
754 		 * multiple lease structures so that IA_TA and IA_PD can be
755 		 * added later.
756 		 */
757 		if ((dlp = dsmp->dsm_leases) == NULL &&
758 		    (dlp = insert_lease(dsmp)) == NULL) {
759 			dhcpmsg(MSG_ERROR, "configure_v6_leases: unable to "
760 			    "allocate memory for lease");
761 			return (v6Restart);
762 		}
763 
764 		/*
765 		 * Iterate over the IAADDR options contained within this IA_NA.
766 		 */
767 		shortest = DHCPV6_INFTIME;
768 		d6so = NULL;
769 		while ((d6so = dhcpv6_find_option(optbase, olen, d6so,
770 		    DHCPV6_OPT_IAADDR, &solen)) != NULL) {
771 			if (solen < sizeof (d6ia)) {
772 				dhcpmsg(MSG_WARNING,
773 				    "configure_v6_leases: garbled IAADDR");
774 				continue;
775 			}
776 			(void) memcpy(&d6ia, d6so, sizeof (d6ia));
777 
778 			d6ia.d6ia_preflife = ntohl(d6ia.d6ia_preflife);
779 			d6ia.d6ia_vallife = ntohl(d6ia.d6ia_vallife);
780 
781 			/* RFC 3315 required validity check */
782 			if (d6ia.d6ia_preflife > d6ia.d6ia_vallife) {
783 				dhcpmsg(MSG_WARNING,
784 				    "configure_v6_leases: ignored IAADDR with "
785 				    "preferred lifetime %u > valid %u",
786 				    d6ia.d6ia_preflife, d6ia.d6ia_vallife);
787 				continue;
788 			}
789 
790 			/*
791 			 * RFC 3315 allows a status code to be buried inside
792 			 * the IAADDR option.  Look for it, and process if
793 			 * present.  Process in a manner similar to that for
794 			 * the IA itself; TAHI checks for this.  Real servers
795 			 * likely won't do this.
796 			 */
797 			d6sso = dhcpv6_find_option((const char *)d6so +
798 			    sizeof (d6ia), solen - sizeof (d6ia), NULL,
799 			    DHCPV6_OPT_STATUS_CODE, &ssolen);
800 			scode = dhcpv6_status_code(d6sso, ssolen, &estr, &msg,
801 			    &msglen);
802 			print_server_msg(dsmp, msg, msglen);
803 			if (scode == DHCPV6_STAT_NOADDRS) {
804 				dhcpmsg(MSG_DEBUG, "configure_v6_leases: "
805 				    "ignoring no-addrs status in IAADDR");
806 				continue;
807 			}
808 			if (scode == DHCPV6_STAT_NOBINDING) {
809 				send_v6_request(dsmp);
810 				return (v6Resent);
811 			}
812 			if (scode != DHCPV6_STAT_SUCCESS) {
813 				dhcpmsg(MSG_WARNING,
814 				    "configure_v6_leases: IAADDR: %s", estr);
815 			}
816 
817 			/*
818 			 * Locate the existing LIF within the lease associated
819 			 * with this address, if any.
820 			 */
821 			lif = dlp->dl_lifs;
822 			for (nlifs = dlp->dl_nlifs; nlifs > 0;
823 			    nlifs--, lif = lif->lif_next) {
824 				if (IN6_ARE_ADDR_EQUAL(&d6ia.d6ia_addr,
825 				    &lif->lif_v6addr))
826 					break;
827 			}
828 
829 			/*
830 			 * If the server has set the lifetime to zero, then
831 			 * delete the LIF.  Otherwise, set the new LIF expiry
832 			 * time, adding the LIF if necessary.
833 			 */
834 			if (d6ia.d6ia_vallife == 0) {
835 				/* If it was found, then it's expired */
836 				if (nlifs != 0) {
837 					dhcpmsg(MSG_DEBUG,
838 					    "configure_v6_leases: lif %s has "
839 					    "expired", lif->lif_name);
840 					lif->lif_expired = B_TRUE;
841 				}
842 				continue;
843 			}
844 
845 			/* If it wasn't found, then create it now. */
846 			if (nlifs == 0) {
847 				lif = plumb_lif(dsmp->dsm_lif->lif_pif,
848 				    &d6ia.d6ia_addr);
849 				if (lif == NULL)
850 					continue;
851 				if (++dlp->dl_nlifs == 1) {
852 					dlp->dl_lifs = lif;
853 				} else {
854 					remque(lif);
855 					insque(lif, dlp->dl_lifs);
856 				}
857 				lif->lif_lease = dlp;
858 				lif->lif_dad_wait = _B_TRUE;
859 				dsmp->dsm_lif_wait++;
860 			} else {
861 				/* If it was found, cancel timer */
862 				cancel_lif_timers(lif);
863 				if (d6ia.d6ia_preflife != 0 &&
864 				    !clear_lif_deprecated(lif)) {
865 					unplumb_lif(lif);
866 					continue;
867 				}
868 			}
869 
870 			/* Set the new expiry timers */
871 			init_timer(&lif->lif_preferred, d6ia.d6ia_preflife);
872 			init_timer(&lif->lif_expire, d6ia.d6ia_vallife);
873 
874 			/*
875 			 * If the preferred lifetime is over now, then the LIF
876 			 * is deprecated.  If it's the same as the expiry time,
877 			 * then we don't need a separate timer for it.
878 			 */
879 			if (d6ia.d6ia_preflife == 0) {
880 				set_lif_deprecated(lif);
881 			} else if (d6ia.d6ia_preflife != DHCPV6_INFTIME &&
882 			    d6ia.d6ia_preflife != d6ia.d6ia_vallife &&
883 			    !schedule_lif_timer(lif, &lif->lif_preferred,
884 			    dhcp_deprecate)) {
885 				unplumb_lif(lif);
886 				continue;
887 			}
888 
889 			if (d6ia.d6ia_vallife != DHCPV6_INFTIME &&
890 			    !schedule_lif_timer(lif, &lif->lif_expire,
891 			    dhcp_expire)) {
892 				unplumb_lif(lif);
893 				continue;
894 			}
895 
896 			if (d6ia.d6ia_preflife < shortest)
897 				shortest = d6ia.d6ia_preflife;
898 		}
899 
900 		if (dlp->dl_nlifs == 0) {
901 			dhcpmsg(MSG_WARNING,
902 			    "configure_v6_leases: no IAADDRs found in IA_NA");
903 			remove_lease(dlp);
904 			continue;
905 		}
906 
907 		if (d6in.d6in_t1 == 0 && d6in.d6in_t2 == 0) {
908 			/* Default values from RFC 3315: 0.5 and 0.8 */
909 			if ((d6in.d6in_t1 = shortest / 2) == 0)
910 				d6in.d6in_t1 = 1;
911 			d6in.d6in_t2 = shortest - shortest / 5;
912 		}
913 
914 		cancel_lease_timers(dlp);
915 		init_timer(&dlp->dl_t1, d6in.d6in_t1);
916 		init_timer(&dlp->dl_t2, d6in.d6in_t2);
917 
918 		if ((d6in.d6in_t1 != DHCPV6_INFTIME &&
919 		    !schedule_lease_timer(dlp, &dlp->dl_t1, dhcp_renew)) ||
920 		    (d6in.d6in_t2 != DHCPV6_INFTIME &&
921 		    !schedule_lease_timer(dlp, &dlp->dl_t2, dhcp_rebind))) {
922 			dhcpmsg(MSG_WARNING, "configure_v6_leases: unable to "
923 			    "set renew/rebind timers");
924 		} else {
925 			got_iana = B_TRUE;
926 		}
927 	}
928 
929 	if (!got_iana) {
930 		dhcpmsg(MSG_WARNING,
931 		    "configure_v6_leases: no usable IA_NA option found");
932 	}
933 
934 	return (v6Done);
935 }
936 
937 /*
938  * configure_v4_lease(): configures the IPv4 lease on a state machine from
939  *			 the current DHCP ACK.  There's only one lease and LIF
940  *			 per state machine in IPv4.
941  *
942  *   input: dhcp_smach_t *: the machine to configure (with a valid dsm_ack)
943  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
944  */
945 
946 static boolean_t
947 configure_v4_lease(dhcp_smach_t *dsmp)
948 {
949 	struct lifreq		lifr;
950 	struct sockaddr_in	*sin;
951 	PKT_LIST		*ack = dsmp->dsm_ack;
952 	dhcp_lease_t		*dlp;
953 	dhcp_lif_t		*lif;
954 	uint32_t		addrhbo;
955 	struct in_addr		inaddr;
956 
957 	/*
958 	 * if we're using DHCP, then we'll have a valid CD_SERVER_ID
959 	 * (we checked in dhcp_acknak()); set it now so that
960 	 * dsmp->dsm_server is valid in case we need to send_decline().
961 	 * note that we use comparisons against opts[CD_DHCP_TYPE]
962 	 * since we haven't set DHCP_IF_BOOTP yet (we don't do that
963 	 * until we're sure we want the offered address.)
964 	 */
965 
966 	if (ack->opts[CD_DHCP_TYPE] != NULL) {
967 		(void) memcpy(&inaddr, ack->opts[CD_SERVER_ID]->value,
968 		    sizeof (inaddr));
969 		IN6_INADDR_TO_V4MAPPED(&inaddr, &dsmp->dsm_server);
970 	}
971 
972 	/*
973 	 * There needs to be exactly one lease for IPv4, and that lease
974 	 * controls the main LIF for the state machine.  If it doesn't exist
975 	 * yet, then create it now.
976 	 */
977 	if ((dlp = dsmp->dsm_leases) == NULL &&
978 	    (dlp = insert_lease(dsmp)) == NULL) {
979 		dhcpmsg(MSG_ERROR, "configure_v4_lease: unable to allocate "
980 		    "memory for lease");
981 		return (B_FALSE);
982 	}
983 	if (dlp->dl_nlifs == 0) {
984 		dlp->dl_lifs = dsmp->dsm_lif;
985 		dlp->dl_nlifs = 1;
986 
987 		/* The lease holds a reference on the LIF */
988 		hold_lif(dlp->dl_lifs);
989 		dlp->dl_lifs->lif_lease = dlp;
990 	}
991 
992 	lif = dlp->dl_lifs;
993 
994 	IN6_INADDR_TO_V4MAPPED(&ack->pkt->yiaddr, &lif->lif_v6addr);
995 	addrhbo = ntohl(ack->pkt->yiaddr.s_addr);
996 	if ((addrhbo & IN_CLASSA_NET) == 0 ||
997 	    (addrhbo >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
998 	    IN_CLASSD(addrhbo)) {
999 		dhcpmsg(MSG_ERROR,
1000 		    "configure_v4_lease: got invalid IP address %s for %s",
1001 		    inet_ntoa(ack->pkt->yiaddr), lif->lif_name);
1002 		return (B_FALSE);
1003 	}
1004 
1005 	(void) memset(&lifr, 0, sizeof (struct lifreq));
1006 	(void) strlcpy(lifr.lifr_name, lif->lif_name, LIFNAMSIZ);
1007 
1008 	/*
1009 	 * bring the interface online.  note that there is no optimal
1010 	 * order here: it is considered bad taste (and in > solaris 7,
1011 	 * likely illegal) to bring an interface up before it has an
1012 	 * ip address.  however, due to an apparent bug in sun fddi
1013 	 * 5.0, fddi will not obtain a network routing entry unless
1014 	 * the interface is brought up before it has an ip address.
1015 	 * we take the lesser of the two evils; if fddi customers have
1016 	 * problems, they can get a newer fddi distribution which
1017 	 * fixes the problem.
1018 	 */
1019 
1020 	sin = (struct sockaddr_in *)&lifr.lifr_addr;
1021 	sin->sin_family = AF_INET;
1022 
1023 	(void) memset(&lif->lif_v6mask, 0xff, sizeof (lif->lif_v6mask));
1024 	if (ack->opts[CD_SUBNETMASK] != NULL &&
1025 	    ack->opts[CD_SUBNETMASK]->len == sizeof (inaddr)) {
1026 
1027 		(void) memcpy(&inaddr, ack->opts[CD_SUBNETMASK]->value,
1028 		    sizeof (inaddr));
1029 
1030 	} else {
1031 
1032 		if (ack->opts[CD_SUBNETMASK] != NULL &&
1033 		    ack->opts[CD_SUBNETMASK]->len != sizeof (inaddr)) {
1034 			dhcpmsg(MSG_WARNING, "configure_v4_lease: specified "
1035 			    "subnet mask length is %d instead of %d, ignoring",
1036 			    ack->opts[CD_SUBNETMASK]->len, sizeof (ipaddr_t));
1037 		} else {
1038 			dhcpmsg(MSG_WARNING, "configure_v4_lease: no IP "
1039 			    "netmask specified for %s, making best guess",
1040 			    lif->lif_name);
1041 		}
1042 
1043 		/*
1044 		 * no legitimate IP subnet mask specified..  use best
1045 		 * guess.  recall that lif_addr is in network order, so
1046 		 * imagine it's 0x11223344: then when it is read into
1047 		 * a register on x86, it becomes 0x44332211, so we
1048 		 * must ntohl() it to convert it to 0x11223344 in
1049 		 * order to use the macros in <netinet/in.h>.
1050 		 */
1051 
1052 		if (IN_CLASSA(addrhbo))
1053 			inaddr.s_addr = htonl(IN_CLASSA_NET);
1054 		else if (IN_CLASSB(addrhbo))
1055 			inaddr.s_addr = htonl(IN_CLASSB_NET);
1056 		else	/* must be class c */
1057 			inaddr.s_addr = htonl(IN_CLASSC_NET);
1058 	}
1059 	lif->lif_v6mask._S6_un._S6_u32[3] = inaddr.s_addr;
1060 
1061 	sin->sin_addr = inaddr;
1062 	dhcpmsg(MSG_INFO, "configure_v4_lease: setting IP netmask to %s on %s",
1063 	    inet_ntoa(sin->sin_addr), lif->lif_name);
1064 
1065 	if (ioctl(v4_sock_fd, SIOCSLIFNETMASK, &lifr) == -1) {
1066 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot set IP netmask "
1067 		    "on %s", lif->lif_name);
1068 		return (B_FALSE);
1069 	}
1070 
1071 	IN6_V4MAPPED_TO_INADDR(&lif->lif_v6addr, &sin->sin_addr);
1072 	dhcpmsg(MSG_INFO, "configure_v4_lease: setting IP address to %s on %s",
1073 	    inet_ntoa(sin->sin_addr), lif->lif_name);
1074 
1075 	if (ioctl(v4_sock_fd, SIOCSLIFADDR, &lifr) == -1) {
1076 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot set IP address "
1077 		    "on %s", lif->lif_name);
1078 		return (B_FALSE);
1079 	}
1080 
1081 	if (ioctl(v4_sock_fd, SIOCGLIFFLAGS, &lifr) == -1) {
1082 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot get interface "
1083 		    "flags for %s", lif->lif_name);
1084 		return (B_FALSE);
1085 	}
1086 
1087 	lifr.lifr_flags |= IFF_UP;
1088 	if (ioctl(v4_sock_fd, SIOCSLIFFLAGS, &lifr) == -1) {
1089 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot set interface "
1090 		    "flags for %s", lif->lif_name);
1091 		return (B_FALSE);
1092 	}
1093 	lif->lif_flags = lifr.lifr_flags;
1094 
1095 	lif->lif_dad_wait = B_TRUE;
1096 	dsmp->dsm_lif_wait++;
1097 
1098 	if (ack->opts[CD_BROADCASTADDR] != NULL &&
1099 	    ack->opts[CD_BROADCASTADDR]->len == sizeof (inaddr)) {
1100 
1101 		(void) memcpy(&inaddr, ack->opts[CD_BROADCASTADDR]->value,
1102 		    sizeof (inaddr));
1103 
1104 	} else {
1105 
1106 		if (ack->opts[CD_BROADCASTADDR] != NULL &&
1107 		    ack->opts[CD_BROADCASTADDR]->len != sizeof (inaddr)) {
1108 			dhcpmsg(MSG_WARNING, "configure_v4_lease: specified "
1109 			    "broadcast address length is %d instead of %d, "
1110 			    "ignoring", ack->opts[CD_BROADCASTADDR]->len,
1111 			    sizeof (inaddr));
1112 		} else {
1113 			dhcpmsg(MSG_WARNING, "configure_v4_lease: no IP "
1114 			    "broadcast specified for %s, making best guess",
1115 			    lif->lif_name);
1116 		}
1117 
1118 		/*
1119 		 * no legitimate IP broadcast specified.  compute it
1120 		 * from the IP address and netmask.
1121 		 */
1122 
1123 		IN6_V4MAPPED_TO_INADDR(&lif->lif_v6addr, &inaddr);
1124 		inaddr.s_addr |= ~lif->lif_v6mask._S6_un._S6_u32[3];
1125 	}
1126 
1127 	/*
1128 	 * the kernel will set the broadcast address for us as part of
1129 	 * bringing the interface up.  since experience has shown that dhcp
1130 	 * servers sometimes provide a bogus broadcast address, we let the
1131 	 * kernel set it so that it's guaranteed to be correct.
1132 	 *
1133 	 * also, note any inconsistencies and save the broadcast address the
1134 	 * kernel set so that we can watch for changes to it.
1135 	 */
1136 
1137 	if (ioctl(v4_sock_fd, SIOCGLIFBRDADDR, &lifr) == -1) {
1138 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot get broadcast "
1139 		    "address for %s", lif->lif_name);
1140 		return (B_FALSE);
1141 	}
1142 
1143 	if (inaddr.s_addr != sin->sin_addr.s_addr) {
1144 		dhcpmsg(MSG_WARNING, "configure_v4_lease: incorrect broadcast "
1145 		    "address %s specified for %s; ignoring", inet_ntoa(inaddr),
1146 		    lif->lif_name);
1147 	}
1148 
1149 	lif->lif_broadcast = sin->sin_addr.s_addr;
1150 	dhcpmsg(MSG_INFO,
1151 	    "configure_v4_lease: using broadcast address %s on %s",
1152 	    inet_ntoa(inaddr), lif->lif_name);
1153 	return (B_TRUE);
1154 }
1155 
1156 /*
1157  * save_server_id(): save off the new DHCPv6 Server ID
1158  *
1159  *   input: dhcp_smach_t *: the state machine to use
1160  *	    PKT_LIST *: the packet with the Reply message
1161  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
1162  */
1163 
1164 boolean_t
1165 save_server_id(dhcp_smach_t *dsmp, PKT_LIST *msg)
1166 {
1167 	const dhcpv6_option_t *d6o;
1168 	uint_t olen;
1169 
1170 	d6o = dhcpv6_pkt_option(msg, NULL, DHCPV6_OPT_SERVERID, &olen);
1171 	if (d6o == NULL)
1172 		return (B_FALSE);
1173 	olen -= sizeof (*d6o);
1174 	free(dsmp->dsm_serverid);
1175 	if ((dsmp->dsm_serverid = malloc(olen)) == NULL) {
1176 		return (B_FALSE);
1177 	} else {
1178 		dsmp->dsm_serveridlen = olen;
1179 		(void) memcpy(dsmp->dsm_serverid, d6o + 1, olen);
1180 		return (B_TRUE);
1181 	}
1182 }
1183