xref: /titanic_41/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c (revision 5bbb4db2c3f208d12bf0fd11769728f9e5ba66a2)
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  * BOUND state of the DHCP client state machine.
26  */
27 
28 #include <sys/socket.h>
29 #include <sys/types.h>
30 #include <string.h>
31 #include <netinet/in.h>
32 #include <sys/sockio.h>
33 #include <unistd.h>
34 #include <time.h>
35 #include <arpa/inet.h>
36 #include <stdlib.h>
37 #include <search.h>
38 #include <sys/sysmacros.h>
39 #include <dhcp_hostconf.h>
40 #include <dhcpagent_util.h>
41 #include <dhcpmsg.h>
42 
43 #include "states.h"
44 #include "packet.h"
45 #include "util.h"
46 #include "agent.h"
47 #include "interface.h"
48 #include "script_handler.h"
49 
50 /*
51  * Possible outcomes for IPv6 binding attempt.
52  */
53 enum v6_bind_result {
54 	v6Restart,		/* report failure and restart state machine */
55 	v6Resent,		/* new Request message has been sent */
56 	v6Done			/* successful binding */
57 };
58 
59 static enum v6_bind_result configure_v6_leases(dhcp_smach_t *);
60 static boolean_t configure_v4_lease(dhcp_smach_t *);
61 static boolean_t configure_v4_timers(dhcp_smach_t *);
62 
63 /*
64  * bound_event_cb(): callback for script_start on the event EVENT_BOUND
65  *
66  *   input: dhcp_smach_t *: the state machine configured
67  *	    void *: unused
68  *  output: int: always 1
69  */
70 
71 /* ARGSUSED1 */
72 static int
73 bound_event_cb(dhcp_smach_t *dsmp, void *arg)
74 {
75 	if (dsmp->dsm_ia.ia_fd != -1)
76 		ipc_action_finish(dsmp, DHCP_IPC_SUCCESS);
77 	else
78 		async_finish(dsmp);
79 	return (1);
80 }
81 
82 /*
83  * dhcp_bound(): configures an state machine and interfaces using information
84  *		 contained in the ACK/Reply packet and sets up lease timers.
85  *		 Before starting, the requested address is verified by
86  *		 Duplicate Address Detection to make sure it's not in use.
87  *
88  *   input: dhcp_smach_t *: the state machine to move to bound
89  *	    PKT_LIST *: the ACK/Reply packet, or NULL to use dsmp->dsm_ack
90  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
91  */
92 
93 boolean_t
94 dhcp_bound(dhcp_smach_t *dsmp, PKT_LIST *ack)
95 {
96 	DHCPSTATE	oldstate;
97 	lease_t		new_lease;
98 	dhcp_lif_t	*lif;
99 	dhcp_lease_t	*dlp;
100 	enum v6_bind_result v6b;
101 
102 	if (ack != NULL) {
103 		/* If ack we're replacing is not the original, then free it */
104 		if (dsmp->dsm_ack != dsmp->dsm_orig_ack)
105 			free_pkt_entry(dsmp->dsm_ack);
106 		dsmp->dsm_ack = ack;
107 		/* Save the first ack as the original */
108 		if (dsmp->dsm_orig_ack == NULL)
109 			dsmp->dsm_orig_ack = ack;
110 	}
111 
112 	oldstate = dsmp->dsm_state;
113 	switch (oldstate) {
114 
115 	case ADOPTING:
116 		/* Note that adoption occurs only for IPv4 DHCP. */
117 
118 		/* Ignore BOOTP */
119 		if (ack->opts[CD_DHCP_TYPE] == NULL)
120 			return (B_FALSE);
121 
122 		/*
123 		 * if we're adopting a lease, the lease timers
124 		 * only provide an upper bound since we don't know
125 		 * from what time they are relative to.  assume we
126 		 * have a lease time of at most DHCP_ADOPT_LEASE_MAX.
127 		 */
128 		(void) memcpy(&new_lease, ack->opts[CD_LEASE_TIME]->value,
129 		    sizeof (lease_t));
130 
131 		new_lease = htonl(MIN(ntohl(new_lease), DHCP_ADOPT_LEASE_MAX));
132 
133 		(void) memcpy(ack->opts[CD_LEASE_TIME]->value, &new_lease,
134 		    sizeof (lease_t));
135 
136 		/*
137 		 * we have no idea when the REQUEST that generated
138 		 * this ACK was sent, but for diagnostic purposes
139 		 * we'll assume its close to the current time.
140 		 */
141 		dsmp->dsm_newstart_monosec = monosec();
142 
143 		if (dsmp->dsm_isv6) {
144 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
145 				return (v6b == v6Resent);
146 		} else {
147 			if (!configure_v4_lease(dsmp))
148 				return (B_FALSE);
149 
150 			if (!configure_v4_timers(dsmp))
151 				return (B_FALSE);
152 		}
153 
154 		dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
155 		break;
156 
157 	case SELECTING:
158 	case REQUESTING:
159 	case INIT_REBOOT:
160 
161 		if (dsmp->dsm_isv6) {
162 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
163 				return (v6b == v6Resent);
164 		} else {
165 			if (!configure_v4_lease(dsmp))
166 				return (B_FALSE);
167 
168 			if (!configure_v4_timers(dsmp))
169 				return (B_FALSE);
170 
171 			if (!clear_lif_deprecated(dsmp->dsm_lif))
172 				return (B_FALSE);
173 		}
174 
175 		/* Stop sending requests now */
176 		stop_pkt_retransmission(dsmp);
177 
178 		/*
179 		 * If we didn't end up with any usable leases, then we have a
180 		 * problem.
181 		 */
182 		if (dsmp->dsm_leases == NULL) {
183 			dhcpmsg(MSG_WARNING,
184 			    "dhcp_bound: no address lease established");
185 			return (B_FALSE);
186 		}
187 
188 		/*
189 		 * If this is a Rapid-Commit (selecting state) or if we're
190 		 * dealing with a reboot (init-reboot), then we will have a new
191 		 * server ID to save.
192 		 */
193 		if (ack != NULL &&
194 		    (oldstate == SELECTING || oldstate == INIT_REBOOT) &&
195 		    dsmp->dsm_isv6 && !save_server_id(dsmp, ack)) {
196 			dhcpmsg(MSG_ERROR,
197 			    "dhcp_bound: unable to save server ID on %s",
198 			    dsmp->dsm_name);
199 			return (B_FALSE);
200 		}
201 
202 		/*
203 		 * We will continue configuring the interfaces via
204 		 * dhcp_bound_complete, once kernel DAD completes.  If no new
205 		 * leases were created (which can happen on an init-reboot used
206 		 * for link-up confirmation), then go straight to bound state.
207 		 */
208 		if (!set_smach_state(dsmp, PRE_BOUND))
209 			return (B_FALSE);
210 		if (dsmp->dsm_lif_wait == 0)
211 			dhcp_bound_complete(dsmp);
212 		break;
213 
214 	case PRE_BOUND:
215 	case BOUND:
216 	case INFORMATION:
217 		/* This is just a duplicate ack; silently ignore it */
218 		return (B_TRUE);
219 
220 	case RENEWING:
221 	case REBINDING:
222 
223 		if (dsmp->dsm_isv6) {
224 			if ((v6b = configure_v6_leases(dsmp)) != v6Done)
225 				return (v6b == v6Resent);
226 		} else {
227 			if (!configure_v4_timers(dsmp))
228 				return (B_FALSE);
229 			if (!clear_lif_deprecated(dsmp->dsm_lif))
230 				return (B_FALSE);
231 		}
232 
233 		/*
234 		 * If some or all of the leases were torn down by the server,
235 		 * then handle that as an expiry.  When the script is done
236 		 * running for the LOSS6 event, we'll end up back here.
237 		 */
238 		if ((lif = find_expired_lif(dsmp)) != NULL) {
239 			hold_lif(lif);
240 			dhcp_expire(NULL, lif);
241 			while ((lif = find_expired_lif(dsmp)) != NULL) {
242 				dlp = lif->lif_lease;
243 				unplumb_lif(lif);
244 				if (dlp->dl_nlifs == 0)
245 					remove_lease(dlp);
246 			}
247 			if (dsmp->dsm_leases == NULL)
248 				return (B_FALSE);
249 		}
250 
251 		if (oldstate == REBINDING && dsmp->dsm_isv6 &&
252 		    !save_server_id(dsmp, ack)) {
253 			return (B_FALSE);
254 		}
255 
256 		/*
257 		 * Handle Renew/Rebind that fails to address one of our leases.
258 		 * (Should just never happen, but RFC 3315 section 18.1.8
259 		 * requires it, and TAHI tests for it.)
260 		 */
261 		for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlp->dl_next) {
262 			if (dlp->dl_stale && dlp->dl_nlifs > 0)
263 				break;
264 		}
265 		if (dlp != NULL) {
266 			dhcpmsg(MSG_DEBUG, "dhcp_bound: lease not updated; "
267 			    "allow retransmit");
268 			return (B_TRUE);
269 		}
270 
271 		if (!set_smach_state(dsmp, BOUND))
272 			return (B_FALSE);
273 
274 		(void) script_start(dsmp, dsmp->dsm_isv6 ? EVENT_EXTEND6 :
275 		    EVENT_EXTEND, bound_event_cb, NULL, NULL);
276 
277 		dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
278 
279 		/* Stop sending requests now */
280 		stop_pkt_retransmission(dsmp);
281 		break;
282 
283 	case INFORM_SENT:
284 
285 		if (dsmp->dsm_isv6 && !save_server_id(dsmp, ack)) {
286 			return (B_FALSE);
287 		}
288 
289 		(void) bound_event_cb(dsmp, NULL);
290 		if (!set_smach_state(dsmp, INFORMATION))
291 			return (B_FALSE);
292 
293 		/* Stop sending requests now */
294 		stop_pkt_retransmission(dsmp);
295 		break;
296 
297 	default:
298 		/* something is really bizarre... */
299 		dhcpmsg(MSG_DEBUG,
300 		    "dhcp_bound: called in unexpected state: %s",
301 		    dhcp_state_to_string(dsmp->dsm_state));
302 		return (B_FALSE);
303 	}
304 
305 	/*
306 	 * remove any stale hostconf file that might be lying around for
307 	 * this state machine. (in general, it's harmless, since we'll write a
308 	 * fresh one when we exit anyway, but just to reduce confusion..)
309 	 */
310 
311 	(void) remove_hostconf(dsmp->dsm_name, dsmp->dsm_isv6);
312 	return (B_TRUE);
313 }
314 
315 /*
316  * dhcp_bound_complete(): complete interface configuration after DAD
317  *
318  *   input: dhcp_smach_t *: the state machine now ready
319  *  output: none
320  */
321 
322 void
323 dhcp_bound_complete(dhcp_smach_t *dsmp)
324 {
325 	PKT_LIST	*ack;
326 	DHCP_OPT	*router_list;
327 	int		i;
328 	DHCPSTATE	oldstate;
329 	dhcp_lif_t	*lif;
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, "dhcp_bound_complete: 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 	 * Note that we do not handle default routers on IPv4 logicals;
351 	 * see README for details.
352 	 */
353 
354 	ack = dsmp->dsm_ack;
355 	router_list = ack->opts[CD_ROUTER];
356 	for (i = 0; i < dsmp->dsm_pillen; i++) {
357 		if (dsmp->dsm_pil[i] == CD_ROUTER)
358 			router_list = NULL;
359 	}
360 	lif = dsmp->dsm_lif;
361 	if (router_list != NULL &&
362 	    (router_list->len % sizeof (ipaddr_t)) == 0 &&
363 	    strchr(lif->lif_name, ':') == NULL &&
364 	    !lif->lif_pif->pif_under_ipmp) {
365 
366 		dsmp->dsm_nrouters = router_list->len / sizeof (ipaddr_t);
367 		dsmp->dsm_routers  = malloc(router_list->len);
368 		if (dsmp->dsm_routers == NULL) {
369 			dhcpmsg(MSG_ERR, "dhcp_bound_complete: cannot allocate "
370 			    "default router list, ignoring default routers");
371 			dsmp->dsm_nrouters = 0;
372 		}
373 
374 		for (i = 0; i < dsmp->dsm_nrouters; i++) {
375 
376 			(void) memcpy(&dsmp->dsm_routers[i].s_addr,
377 			    router_list->value + (i * sizeof (ipaddr_t)),
378 			    sizeof (ipaddr_t));
379 
380 			if (!add_default_route(lif->lif_pif->pif_index,
381 			    &dsmp->dsm_routers[i])) {
382 				dhcpmsg(MSG_ERR, "dhcp_bound_complete: cannot "
383 				    "add default router %s on %s", inet_ntoa(
384 				    dsmp->dsm_routers[i]), dsmp->dsm_name);
385 				dsmp->dsm_routers[i].s_addr = htonl(INADDR_ANY);
386 				continue;
387 			}
388 
389 			dhcpmsg(MSG_INFO, "added default router %s on %s",
390 			    inet_ntoa(dsmp->dsm_routers[i]), dsmp->dsm_name);
391 		}
392 	}
393 
394 	oldstate = dsmp->dsm_state;
395 	if (!set_smach_state(dsmp, BOUND)) {
396 		dhcpmsg(MSG_ERR,
397 		    "dhcp_bound_complete: cannot set bound state on %s",
398 		    dsmp->dsm_name);
399 		return;
400 	}
401 
402 	dhcpmsg(MSG_DEBUG, "dhcp_bound_complete: bound %s", dsmp->dsm_name);
403 
404 	/*
405 	 * We're now committed to this binding, so if it came from BOOTP, set
406 	 * the flag.
407 	 */
408 
409 	if (ack->opts[CD_DHCP_TYPE] == NULL)
410 		dsmp->dsm_dflags |= DHCP_IF_BOOTP;
411 
412 	/*
413 	 * If the previous state was ADOPTING, event loop has not been started
414 	 * at this time; so don't run the EVENT_BOUND script.
415 	 */
416 	if (oldstate != ADOPTING) {
417 		(void) script_start(dsmp, EVENT_BOUND, bound_event_cb, NULL,
418 		    NULL);
419 	}
420 
421 	dsmp->dsm_curstart_monosec = dsmp->dsm_newstart_monosec;
422 }
423 
424 /*
425  * fuzzify(): adds some "fuzz" to a t1/t2 time, in accordance with RFC2131.
426  *	      We use up to plus or minus 2% jitter in the time.  This is a
427  *	      small value, but the timers involved are typically long.  A
428  *	      common T1 value is one day, and the fuzz is up to 28.8 minutes;
429  *	      plenty of time to make sure that individual clients don't renew
430  *	      all at the same time.
431  *
432  *   input: uint32_t: the number of seconds until lease expiration
433  *	    double: the approximate percentage of that time to return
434  *  output: double: a number approximating (sec * pct)
435  */
436 
437 static double
438 fuzzify(uint32_t sec, double pct)
439 {
440 	return (sec * (pct + (drand48() - 0.5) / 25.0));
441 }
442 
443 /*
444  * get_pkt_times(): pulls the lease times out of a v4 DHCP packet and stores
445  *		    them as host byte-order relative times in the passed in
446  *		    parameters.
447  *
448  *   input: PKT_LIST *: the packet to pull the packet times from
449  *	    lease_t *: where to store the relative lease time in hbo
450  *	    lease_t *: where to store the relative t1 time in hbo
451  *	    lease_t *: where to store the relative t2 time in hbo
452  *  output: void
453  */
454 
455 static void
456 get_pkt_times(PKT_LIST *ack, lease_t *lease, lease_t *t1, lease_t *t2)
457 {
458 	*lease	= DHCP_PERM;
459 	*t1	= DHCP_PERM;
460 	*t2	= DHCP_PERM;
461 
462 	if (ack->opts[CD_DHCP_TYPE] == NULL) {
463 		dhcpmsg(MSG_VERBOSE,
464 		    "get_pkt_times: BOOTP response; infinite lease");
465 		return;
466 	}
467 	if (ack->opts[CD_LEASE_TIME] == NULL) {
468 		dhcpmsg(MSG_VERBOSE,
469 		    "get_pkt_times: no lease option provided");
470 		return;
471 	}
472 	if (ack->opts[CD_LEASE_TIME]->len != sizeof (lease_t)) {
473 		dhcpmsg(MSG_VERBOSE, "get_pkt_times: invalid lease option");
474 	}
475 
476 	(void) memcpy(lease, ack->opts[CD_LEASE_TIME]->value, sizeof (lease_t));
477 	*lease = ntohl(*lease);
478 
479 	if (*lease == DHCP_PERM) {
480 		dhcpmsg(MSG_VERBOSE, "get_pkt_times: infinite lease granted");
481 		return;
482 	}
483 
484 	if (ack->opts[CD_T1_TIME] != NULL &&
485 	    ack->opts[CD_T1_TIME]->len == sizeof (lease_t)) {
486 		(void) memcpy(t1, ack->opts[CD_T1_TIME]->value, sizeof (*t1));
487 		*t1 = ntohl(*t1);
488 	}
489 
490 	if (ack->opts[CD_T2_TIME] != NULL &&
491 	    ack->opts[CD_T2_TIME]->len == sizeof (lease_t)) {
492 		(void) memcpy(t2, ack->opts[CD_T2_TIME]->value, sizeof (*t2));
493 		*t2 = ntohl(*t2);
494 	}
495 
496 	if ((*t1 == DHCP_PERM) || (*t1 >= *lease))
497 		*t1 = (lease_t)fuzzify(*lease, DHCP_T1_FACT);
498 
499 	if ((*t2 == DHCP_PERM) || (*t2 > *lease) || (*t2 <= *t1))
500 		*t2 = (lease_t)fuzzify(*lease, DHCP_T2_FACT);
501 
502 	dhcpmsg(MSG_VERBOSE, "get_pkt_times: lease %u t1 %u t2 %u",
503 	    *lease, *t1, *t2);
504 }
505 
506 /*
507  * configure_v4_timers(): configures the lease timers on a v4 state machine
508  *
509  *   input: dhcp_smach_t *: the state machine to configure
510  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
511  */
512 
513 static boolean_t
514 configure_v4_timers(dhcp_smach_t *dsmp)
515 {
516 	PKT_LIST	*ack = dsmp->dsm_ack;
517 	lease_t		lease, t1, t2;
518 	dhcp_lease_t	*dlp;
519 	dhcp_lif_t	*lif;
520 
521 	/* v4 has just one lease per state machine, and one LIF */
522 	dlp = dsmp->dsm_leases;
523 	lif = dlp->dl_lifs;
524 
525 	/*
526 	 * If it's DHCP, but there's no valid lease time, then complain,
527 	 * decline the lease and return error.
528 	 */
529 	if (ack->opts[CD_DHCP_TYPE] != NULL &&
530 	    (ack->opts[CD_LEASE_TIME] == NULL ||
531 	    ack->opts[CD_LEASE_TIME]->len != sizeof (lease_t))) {
532 		lif_mark_decline(lif, "Missing or corrupted lease time");
533 		send_declines(dsmp);
534 		dhcpmsg(MSG_WARNING, "configure_v4_timers: %s lease time in "
535 		    "ACK on %s", ack->opts[CD_LEASE_TIME] == NULL ? "missing" :
536 		    "corrupt", dsmp->dsm_name);
537 		return (B_FALSE);
538 	}
539 
540 	/* Stop the T1 and T2 timers */
541 	cancel_lease_timers(dlp);
542 
543 	/* Stop the LEASE timer */
544 	cancel_lif_timers(lif);
545 
546 	/*
547 	 * type has already been verified as ACK.  if type is not set,
548 	 * then we got a BOOTP packet.  we now fetch the t1, t2, and
549 	 * lease options out of the packet into variables.  they are
550 	 * returned as relative host-byte-ordered times.
551 	 */
552 
553 	get_pkt_times(ack, &lease, &t1, &t2);
554 
555 	/*
556 	 * if the current lease is mysteriously close to the new
557 	 * lease, warn the user.  unless there's less than a minute
558 	 * left, round to the closest minute.
559 	 */
560 
561 	if (lif->lif_expire.dt_start != 0 &&
562 	    abs((dsmp->dsm_newstart_monosec + lease) -
563 	    (dsmp->dsm_curstart_monosec + lif->lif_expire.dt_start)) <
564 	    DHCP_LEASE_EPS) {
565 		const char *noext = "configure_v4_timers: lease renewed but "
566 		    "time not extended";
567 		int msg_level;
568 		uint_t minleft;
569 
570 		if (lif->lif_expire.dt_start < DHCP_LEASE_ERROR_THRESH)
571 			msg_level = MSG_ERROR;
572 		else
573 			msg_level = MSG_VERBOSE;
574 
575 		minleft = (lif->lif_expire.dt_start + 30) / 60;
576 
577 		if (lif->lif_expire.dt_start < 60) {
578 			dhcpmsg(msg_level, "%s; expires in %d seconds",
579 			    noext, lif->lif_expire.dt_start);
580 		} else if (minleft == 1) {
581 			dhcpmsg(msg_level, "%s; expires in 1 minute", noext);
582 		} else if (minleft > 120) {
583 			dhcpmsg(msg_level, "%s; expires in %d hours",
584 			    noext, (minleft + 30) / 60);
585 		} else {
586 			dhcpmsg(msg_level, "%s; expires in %d minutes",
587 			    noext, minleft);
588 		}
589 	}
590 
591 	init_timer(&dlp->dl_t1, t1);
592 	init_timer(&dlp->dl_t2, t2);
593 	init_timer(&lif->lif_expire, lease);
594 
595 	if (lease == DHCP_PERM) {
596 		dhcpmsg(MSG_INFO,
597 		    "configure_v4_timers: %s acquired permanent lease",
598 		    dsmp->dsm_name);
599 		return (B_TRUE);
600 	}
601 
602 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s acquired lease, expires %s",
603 	    dsmp->dsm_name,
604 	    monosec_to_string(dsmp->dsm_newstart_monosec + lease));
605 
606 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s begins renewal at %s",
607 	    dsmp->dsm_name, monosec_to_string(dsmp->dsm_newstart_monosec +
608 	    dlp->dl_t1.dt_start));
609 
610 	dhcpmsg(MSG_INFO, "configure_v4_timers: %s begins rebinding at %s",
611 	    dsmp->dsm_name, monosec_to_string(dsmp->dsm_newstart_monosec +
612 	    dlp->dl_t2.dt_start));
613 
614 	/*
615 	 * according to RFC2131, there is no minimum lease time, but don't
616 	 * set up renew/rebind timers if lease is shorter than DHCP_REBIND_MIN.
617 	 */
618 
619 	if (!schedule_lif_timer(lif, &lif->lif_expire, dhcp_expire))
620 		goto failure;
621 
622 	if (lease < DHCP_REBIND_MIN) {
623 		dhcpmsg(MSG_WARNING, "configure_v4_timers: lease on %s is for "
624 		    "less than %d seconds!", dsmp->dsm_name, DHCP_REBIND_MIN);
625 		return (B_TRUE);
626 	}
627 
628 	if (!schedule_lease_timer(dlp, &dlp->dl_t1, dhcp_renew))
629 		goto failure;
630 
631 	if (!schedule_lease_timer(dlp, &dlp->dl_t2, dhcp_rebind))
632 		goto failure;
633 
634 	return (B_TRUE);
635 
636 failure:
637 	cancel_lease_timers(dlp);
638 	cancel_lif_timers(lif);
639 	dhcpmsg(MSG_WARNING,
640 	    "configure_v4_timers: cannot schedule lease timers");
641 	return (B_FALSE);
642 }
643 
644 /*
645  * configure_v6_leases(): configures the IPv6 leases on a state machine from
646  *			  the current DHCPv6 ACK.  We need to scan the ACK,
647  *			  create a lease for each IA_NA, and a new LIF for each
648  *			  IAADDR.
649  *
650  *   input: dhcp_smach_t *: the machine to configure (with a valid dsm_ack)
651  *  output: enum v6_bind_result: restart, resend, or done
652  */
653 
654 static enum v6_bind_result
655 configure_v6_leases(dhcp_smach_t *dsmp)
656 {
657 	const dhcpv6_option_t *d6o, *d6so, *d6sso;
658 	const char *optbase, *estr, *msg;
659 	uint_t olen, solen, ssolen, msglen;
660 	dhcpv6_ia_na_t d6in;
661 	dhcpv6_iaaddr_t d6ia;
662 	dhcp_lease_t *dlp;
663 	uint32_t shortest;
664 	dhcp_lif_t *lif;
665 	uint_t nlifs;
666 	boolean_t got_iana = B_FALSE;
667 	uint_t scode;
668 
669 	for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlp->dl_next)
670 		dlp->dl_stale = B_TRUE;
671 
672 	d6o = NULL;
673 	while ((d6o = dhcpv6_pkt_option(dsmp->dsm_ack, d6o, DHCPV6_OPT_IA_NA,
674 	    &olen)) != NULL) {
675 		if (olen < sizeof (d6in)) {
676 			dhcpmsg(MSG_WARNING,
677 			    "configure_v6_leases: garbled IA_NA");
678 			continue;
679 		}
680 
681 		/*
682 		 * Check the IAID.  It should be for our controlling LIF.  If a
683 		 * single state machine needs to use multiple IAIDs, then this
684 		 * will need to change.
685 		 */
686 		(void) memcpy(&d6in, d6o, sizeof (d6in));
687 		d6in.d6in_iaid = ntohl(d6in.d6in_iaid);
688 		if (d6in.d6in_iaid != dsmp->dsm_lif->lif_iaid) {
689 			dhcpmsg(MSG_WARNING, "configure_v6_leases: ignored "
690 			    "IA_NA for IAID %x (not %x)", d6in.d6in_iaid,
691 			    dsmp->dsm_lif->lif_iaid);
692 			continue;
693 		}
694 
695 		/*
696 		 * See notes below; there's only one IA_NA and a single IAID
697 		 * for now.
698 		 */
699 		if ((dlp = dsmp->dsm_leases) != NULL)
700 			dlp->dl_stale = B_FALSE;
701 
702 		/*
703 		 * Note that some bug-ridden servers will try to give us
704 		 * multiple IA_NA options for a single IAID.  We ignore
705 		 * duplicates.
706 		 */
707 		if (got_iana) {
708 			dhcpmsg(MSG_WARNING, "configure_v6_leases: unexpected "
709 			    "extra IA_NA ignored");
710 			continue;
711 		}
712 
713 		d6in.d6in_t1 = ntohl(d6in.d6in_t1);
714 		d6in.d6in_t2 = ntohl(d6in.d6in_t2);
715 
716 		/* RFC 3315 required check for invalid T1/T2 combinations */
717 		if (d6in.d6in_t1 > d6in.d6in_t2 && d6in.d6in_t2 != 0) {
718 			dhcpmsg(MSG_WARNING, "configure_v6_leases: ignored "
719 			    "IA_NA with invalid T1 %u > T2 %u", d6in.d6in_t1,
720 			    d6in.d6in_t2);
721 			continue;
722 		}
723 
724 		/*
725 		 * There may be a status code here.  Process if present.
726 		 */
727 		optbase = (const char *)d6o + sizeof (d6in);
728 		olen -= sizeof (d6in);
729 		d6so = dhcpv6_find_option(optbase, olen, NULL,
730 		    DHCPV6_OPT_STATUS_CODE, &solen);
731 		scode = dhcpv6_status_code(d6so, solen, &estr, &msg, &msglen);
732 		if (scode != DHCPV6_STAT_SUCCESS) {
733 			dhcpmsg(MSG_WARNING,
734 			    "configure_v6_leases: IA_NA: %s: %.*s",
735 			    estr, msglen, msg);
736 		}
737 		print_server_msg(dsmp, msg, msglen);
738 
739 		/*
740 		 * Other errors are possible here.  According to RFC 3315
741 		 * section 18.1.8, we ignore the entire IA if it gives the "no
742 		 * addresses" status code.  We may try another server if we
743 		 * like -- we instead opt to allow the addresses to expire and
744 		 * then try a new server.
745 		 *
746 		 * If the status code is "no binding," then we must go back and
747 		 * redo the Request.  Surprisingly, it doesn't matter if it's
748 		 * any other code.
749 		 */
750 		if (scode == DHCPV6_STAT_NOADDRS) {
751 			dhcpmsg(MSG_DEBUG, "configure_v6_leases: ignoring "
752 			    "no-addrs status in IA_NA");
753 			continue;
754 		}
755 
756 		if (scode == DHCPV6_STAT_NOBINDING) {
757 			send_v6_request(dsmp);
758 			return (v6Resent);
759 		}
760 
761 		/*
762 		 * Find or create the lease structure.  This part is simple,
763 		 * because we support only IA_NA and a single IAID.  This means
764 		 * there's only one lease structure.  The design supports
765 		 * multiple lease structures so that IA_TA and IA_PD can be
766 		 * added later.
767 		 */
768 		if ((dlp = dsmp->dsm_leases) == NULL &&
769 		    (dlp = insert_lease(dsmp)) == NULL) {
770 			dhcpmsg(MSG_ERROR, "configure_v6_leases: unable to "
771 			    "allocate memory for lease");
772 			return (v6Restart);
773 		}
774 
775 		/*
776 		 * Iterate over the IAADDR options contained within this IA_NA.
777 		 */
778 		shortest = DHCPV6_INFTIME;
779 		d6so = NULL;
780 		while ((d6so = dhcpv6_find_option(optbase, olen, d6so,
781 		    DHCPV6_OPT_IAADDR, &solen)) != NULL) {
782 			if (solen < sizeof (d6ia)) {
783 				dhcpmsg(MSG_WARNING,
784 				    "configure_v6_leases: garbled IAADDR");
785 				continue;
786 			}
787 			(void) memcpy(&d6ia, d6so, sizeof (d6ia));
788 
789 			d6ia.d6ia_preflife = ntohl(d6ia.d6ia_preflife);
790 			d6ia.d6ia_vallife = ntohl(d6ia.d6ia_vallife);
791 
792 			/* RFC 3315 required validity check */
793 			if (d6ia.d6ia_preflife > d6ia.d6ia_vallife) {
794 				dhcpmsg(MSG_WARNING,
795 				    "configure_v6_leases: ignored IAADDR with "
796 				    "preferred lifetime %u > valid %u",
797 				    d6ia.d6ia_preflife, d6ia.d6ia_vallife);
798 				continue;
799 			}
800 
801 			/*
802 			 * RFC 3315 allows a status code to be buried inside
803 			 * the IAADDR option.  Look for it, and process if
804 			 * present.  Process in a manner similar to that for
805 			 * the IA itself; TAHI checks for this.  Real servers
806 			 * likely won't do this.
807 			 */
808 			d6sso = dhcpv6_find_option((const char *)d6so +
809 			    sizeof (d6ia), solen - sizeof (d6ia), NULL,
810 			    DHCPV6_OPT_STATUS_CODE, &ssolen);
811 			scode = dhcpv6_status_code(d6sso, ssolen, &estr, &msg,
812 			    &msglen);
813 			print_server_msg(dsmp, msg, msglen);
814 			if (scode == DHCPV6_STAT_NOADDRS) {
815 				dhcpmsg(MSG_DEBUG, "configure_v6_leases: "
816 				    "ignoring no-addrs status in IAADDR");
817 				continue;
818 			}
819 			if (scode == DHCPV6_STAT_NOBINDING) {
820 				send_v6_request(dsmp);
821 				return (v6Resent);
822 			}
823 			if (scode != DHCPV6_STAT_SUCCESS) {
824 				dhcpmsg(MSG_WARNING,
825 				    "configure_v6_leases: IAADDR: %s", estr);
826 			}
827 
828 			/*
829 			 * Locate the existing LIF within the lease associated
830 			 * with this address, if any.
831 			 */
832 			lif = dlp->dl_lifs;
833 			for (nlifs = dlp->dl_nlifs; nlifs > 0;
834 			    nlifs--, lif = lif->lif_next) {
835 				if (IN6_ARE_ADDR_EQUAL(&d6ia.d6ia_addr,
836 				    &lif->lif_v6addr))
837 					break;
838 			}
839 
840 			/*
841 			 * If the server has set the lifetime to zero, then
842 			 * delete the LIF.  Otherwise, set the new LIF expiry
843 			 * time, adding the LIF if necessary.
844 			 */
845 			if (d6ia.d6ia_vallife == 0) {
846 				/* If it was found, then it's expired */
847 				if (nlifs != 0) {
848 					dhcpmsg(MSG_DEBUG,
849 					    "configure_v6_leases: lif %s has "
850 					    "expired", lif->lif_name);
851 					lif->lif_expired = B_TRUE;
852 				}
853 				continue;
854 			}
855 
856 			/* If it wasn't found, then create it now. */
857 			if (nlifs == 0) {
858 				lif = plumb_lif(dsmp->dsm_lif->lif_pif,
859 				    &d6ia.d6ia_addr);
860 				if (lif == NULL)
861 					continue;
862 				if (++dlp->dl_nlifs == 1) {
863 					dlp->dl_lifs = lif;
864 				} else {
865 					remque(lif);
866 					insque(lif, dlp->dl_lifs);
867 				}
868 				lif->lif_lease = dlp;
869 				lif->lif_dad_wait = _B_TRUE;
870 				dsmp->dsm_lif_wait++;
871 			} else {
872 				/* If it was found, cancel timer */
873 				cancel_lif_timers(lif);
874 				if (d6ia.d6ia_preflife != 0 &&
875 				    !clear_lif_deprecated(lif)) {
876 					unplumb_lif(lif);
877 					continue;
878 				}
879 			}
880 
881 			/* Set the new expiry timers */
882 			init_timer(&lif->lif_preferred, d6ia.d6ia_preflife);
883 			init_timer(&lif->lif_expire, d6ia.d6ia_vallife);
884 
885 			/*
886 			 * If the preferred lifetime is over now, then the LIF
887 			 * is deprecated.  If it's the same as the expiry time,
888 			 * then we don't need a separate timer for it.
889 			 */
890 			if (d6ia.d6ia_preflife == 0) {
891 				set_lif_deprecated(lif);
892 			} else if (d6ia.d6ia_preflife != DHCPV6_INFTIME &&
893 			    d6ia.d6ia_preflife != d6ia.d6ia_vallife &&
894 			    !schedule_lif_timer(lif, &lif->lif_preferred,
895 			    dhcp_deprecate)) {
896 				unplumb_lif(lif);
897 				continue;
898 			}
899 
900 			if (d6ia.d6ia_vallife != DHCPV6_INFTIME &&
901 			    !schedule_lif_timer(lif, &lif->lif_expire,
902 			    dhcp_expire)) {
903 				unplumb_lif(lif);
904 				continue;
905 			}
906 
907 			if (d6ia.d6ia_preflife < shortest)
908 				shortest = d6ia.d6ia_preflife;
909 		}
910 
911 		if (dlp->dl_nlifs == 0) {
912 			dhcpmsg(MSG_WARNING,
913 			    "configure_v6_leases: no IAADDRs found in IA_NA");
914 			remove_lease(dlp);
915 			continue;
916 		}
917 
918 		if (d6in.d6in_t1 == 0 && d6in.d6in_t2 == 0) {
919 			/* Default values from RFC 3315: 0.5 and 0.8 */
920 			if ((d6in.d6in_t1 = shortest / 2) == 0)
921 				d6in.d6in_t1 = 1;
922 			d6in.d6in_t2 = shortest - shortest / 5;
923 		}
924 
925 		cancel_lease_timers(dlp);
926 		init_timer(&dlp->dl_t1, d6in.d6in_t1);
927 		init_timer(&dlp->dl_t2, d6in.d6in_t2);
928 
929 		if ((d6in.d6in_t1 != DHCPV6_INFTIME &&
930 		    !schedule_lease_timer(dlp, &dlp->dl_t1, dhcp_renew)) ||
931 		    (d6in.d6in_t2 != DHCPV6_INFTIME &&
932 		    !schedule_lease_timer(dlp, &dlp->dl_t2, dhcp_rebind))) {
933 			dhcpmsg(MSG_WARNING, "configure_v6_leases: unable to "
934 			    "set renew/rebind timers");
935 		} else {
936 			got_iana = B_TRUE;
937 		}
938 	}
939 
940 	if (!got_iana) {
941 		dhcpmsg(MSG_WARNING,
942 		    "configure_v6_leases: no usable IA_NA option found");
943 	}
944 
945 	return (v6Done);
946 }
947 
948 /*
949  * configure_v4_lease(): configures the IPv4 lease on a state machine from
950  *			 the current DHCP ACK.  There's only one lease and LIF
951  *			 per state machine in IPv4.
952  *
953  *   input: dhcp_smach_t *: the machine to configure (with a valid dsm_ack)
954  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
955  */
956 
957 static boolean_t
958 configure_v4_lease(dhcp_smach_t *dsmp)
959 {
960 	struct lifreq		lifr;
961 	struct sockaddr_in	*sin;
962 	PKT_LIST		*ack = dsmp->dsm_ack;
963 	dhcp_lease_t		*dlp;
964 	dhcp_lif_t		*lif;
965 	uint32_t		addrhbo;
966 	struct in_addr		inaddr;
967 
968 	/*
969 	 * if we're using DHCP, then we'll have a valid CD_SERVER_ID
970 	 * (we checked in dhcp_acknak()); set it now so that
971 	 * dsmp->dsm_server is valid in case we need to send_decline().
972 	 * note that we use comparisons against opts[CD_DHCP_TYPE]
973 	 * since we haven't set DHCP_IF_BOOTP yet (we don't do that
974 	 * until we're sure we want the offered address.)
975 	 */
976 
977 	if (ack->opts[CD_DHCP_TYPE] != NULL) {
978 		(void) memcpy(&inaddr, ack->opts[CD_SERVER_ID]->value,
979 		    sizeof (inaddr));
980 		IN6_INADDR_TO_V4MAPPED(&inaddr, &dsmp->dsm_server);
981 	}
982 
983 	/*
984 	 * There needs to be exactly one lease for IPv4, and that lease
985 	 * controls the main LIF for the state machine.  If it doesn't exist
986 	 * yet, then create it now.
987 	 */
988 	if ((dlp = dsmp->dsm_leases) == NULL &&
989 	    (dlp = insert_lease(dsmp)) == NULL) {
990 		dhcpmsg(MSG_ERROR, "configure_v4_lease: unable to allocate "
991 		    "memory for lease");
992 		return (B_FALSE);
993 	}
994 	if (dlp->dl_nlifs == 0) {
995 		dlp->dl_lifs = dsmp->dsm_lif;
996 		dlp->dl_nlifs = 1;
997 
998 		/* The lease holds a reference on the LIF */
999 		hold_lif(dlp->dl_lifs);
1000 		dlp->dl_lifs->lif_lease = dlp;
1001 	}
1002 
1003 	lif = dlp->dl_lifs;
1004 
1005 	IN6_INADDR_TO_V4MAPPED(&ack->pkt->yiaddr, &lif->lif_v6addr);
1006 	addrhbo = ntohl(ack->pkt->yiaddr.s_addr);
1007 	if ((addrhbo & IN_CLASSA_NET) == 0 ||
1008 	    (addrhbo >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
1009 	    IN_CLASSD(addrhbo)) {
1010 		dhcpmsg(MSG_ERROR,
1011 		    "configure_v4_lease: got invalid IP address %s for %s",
1012 		    inet_ntoa(ack->pkt->yiaddr), lif->lif_name);
1013 		return (B_FALSE);
1014 	}
1015 
1016 	(void) memset(&lifr, 0, sizeof (struct lifreq));
1017 	(void) strlcpy(lifr.lifr_name, lif->lif_name, LIFNAMSIZ);
1018 
1019 	/*
1020 	 * bring the interface online.  note that there is no optimal
1021 	 * order here: it is considered bad taste (and in > solaris 7,
1022 	 * likely illegal) to bring an interface up before it has an
1023 	 * ip address.  however, due to an apparent bug in sun fddi
1024 	 * 5.0, fddi will not obtain a network routing entry unless
1025 	 * the interface is brought up before it has an ip address.
1026 	 * we take the lesser of the two evils; if fddi customers have
1027 	 * problems, they can get a newer fddi distribution which
1028 	 * fixes the problem.
1029 	 */
1030 
1031 	sin = (struct sockaddr_in *)&lifr.lifr_addr;
1032 	sin->sin_family = AF_INET;
1033 
1034 	(void) memset(&lif->lif_v6mask, 0xff, sizeof (lif->lif_v6mask));
1035 	if (ack->opts[CD_SUBNETMASK] != NULL &&
1036 	    ack->opts[CD_SUBNETMASK]->len == sizeof (inaddr)) {
1037 
1038 		(void) memcpy(&inaddr, ack->opts[CD_SUBNETMASK]->value,
1039 		    sizeof (inaddr));
1040 
1041 	} else {
1042 
1043 		if (ack->opts[CD_SUBNETMASK] != NULL &&
1044 		    ack->opts[CD_SUBNETMASK]->len != sizeof (inaddr)) {
1045 			dhcpmsg(MSG_WARNING, "configure_v4_lease: specified "
1046 			    "subnet mask length is %d instead of %d, ignoring",
1047 			    ack->opts[CD_SUBNETMASK]->len, sizeof (ipaddr_t));
1048 		} else {
1049 			dhcpmsg(MSG_WARNING, "configure_v4_lease: no IP "
1050 			    "netmask specified for %s, making best guess",
1051 			    lif->lif_name);
1052 		}
1053 
1054 		/*
1055 		 * no legitimate IP subnet mask specified..  use best
1056 		 * guess.  recall that lif_addr is in network order, so
1057 		 * imagine it's 0x11223344: then when it is read into
1058 		 * a register on x86, it becomes 0x44332211, so we
1059 		 * must ntohl() it to convert it to 0x11223344 in
1060 		 * order to use the macros in <netinet/in.h>.
1061 		 */
1062 
1063 		if (IN_CLASSA(addrhbo))
1064 			inaddr.s_addr = htonl(IN_CLASSA_NET);
1065 		else if (IN_CLASSB(addrhbo))
1066 			inaddr.s_addr = htonl(IN_CLASSB_NET);
1067 		else if (IN_CLASSC(addrhbo))
1068 			inaddr.s_addr = htonl(IN_CLASSC_NET);
1069 		else {
1070 			/*
1071 			 * Cant be Class D as that is multicast
1072 			 * Must be Class E
1073 			 */
1074 			inaddr.s_addr =  htonl(IN_CLASSE_NET);
1075 		}
1076 	}
1077 	lif->lif_v6mask._S6_un._S6_u32[3] = inaddr.s_addr;
1078 
1079 	sin->sin_addr = inaddr;
1080 	dhcpmsg(MSG_INFO, "configure_v4_lease: setting IP netmask to %s on %s",
1081 	    inet_ntoa(sin->sin_addr), lif->lif_name);
1082 
1083 	if (ioctl(v4_sock_fd, SIOCSLIFNETMASK, &lifr) == -1) {
1084 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot set IP netmask "
1085 		    "on %s", lif->lif_name);
1086 		return (B_FALSE);
1087 	}
1088 
1089 	IN6_V4MAPPED_TO_INADDR(&lif->lif_v6addr, &sin->sin_addr);
1090 	dhcpmsg(MSG_INFO, "configure_v4_lease: setting IP address to %s on %s",
1091 	    inet_ntoa(sin->sin_addr), lif->lif_name);
1092 
1093 	if (ioctl(v4_sock_fd, SIOCSLIFADDR, &lifr) == -1) {
1094 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot set IP address "
1095 		    "on %s", lif->lif_name);
1096 		return (B_FALSE);
1097 	}
1098 
1099 	if (!lif->lif_dad_wait) {
1100 		lif->lif_dad_wait = _B_TRUE;
1101 		dsmp->dsm_lif_wait++;
1102 	}
1103 
1104 	if (ack->opts[CD_BROADCASTADDR] != NULL &&
1105 	    ack->opts[CD_BROADCASTADDR]->len == sizeof (inaddr)) {
1106 
1107 		(void) memcpy(&inaddr, ack->opts[CD_BROADCASTADDR]->value,
1108 		    sizeof (inaddr));
1109 
1110 	} else {
1111 
1112 		if (ack->opts[CD_BROADCASTADDR] != NULL &&
1113 		    ack->opts[CD_BROADCASTADDR]->len != sizeof (inaddr)) {
1114 			dhcpmsg(MSG_WARNING, "configure_v4_lease: specified "
1115 			    "broadcast address length is %d instead of %d, "
1116 			    "ignoring", ack->opts[CD_BROADCASTADDR]->len,
1117 			    sizeof (inaddr));
1118 		} else {
1119 			dhcpmsg(MSG_WARNING, "configure_v4_lease: no IP "
1120 			    "broadcast specified for %s, making best guess",
1121 			    lif->lif_name);
1122 		}
1123 
1124 		/*
1125 		 * no legitimate IP broadcast specified.  compute it
1126 		 * from the IP address and netmask.
1127 		 */
1128 
1129 		IN6_V4MAPPED_TO_INADDR(&lif->lif_v6addr, &inaddr);
1130 		inaddr.s_addr |= ~lif->lif_v6mask._S6_un._S6_u32[3];
1131 	}
1132 
1133 	/*
1134 	 * the kernel will set the broadcast address for us as part of
1135 	 * bringing the interface up.  since experience has shown that dhcp
1136 	 * servers sometimes provide a bogus broadcast address, we let the
1137 	 * kernel set it so that it's guaranteed to be correct.
1138 	 *
1139 	 * also, note any inconsistencies and save the broadcast address the
1140 	 * kernel set so that we can watch for changes to it.
1141 	 */
1142 
1143 	if (ioctl(v4_sock_fd, SIOCGLIFBRDADDR, &lifr) == -1) {
1144 		dhcpmsg(MSG_ERR, "configure_v4_lease: cannot get broadcast "
1145 		    "address for %s", lif->lif_name);
1146 		return (B_FALSE);
1147 	}
1148 
1149 	if (inaddr.s_addr != sin->sin_addr.s_addr) {
1150 		dhcpmsg(MSG_WARNING, "configure_v4_lease: incorrect broadcast "
1151 		    "address %s specified for %s; ignoring", inet_ntoa(inaddr),
1152 		    lif->lif_name);
1153 	}
1154 
1155 	lif->lif_broadcast = sin->sin_addr.s_addr;
1156 	dhcpmsg(MSG_INFO,
1157 	    "configure_v4_lease: using broadcast address %s on %s",
1158 	    inet_ntoa(inaddr), lif->lif_name);
1159 	return (B_TRUE);
1160 }
1161 
1162 /*
1163  * save_server_id(): save off the new DHCPv6 Server ID
1164  *
1165  *   input: dhcp_smach_t *: the state machine to use
1166  *	    PKT_LIST *: the packet with the Reply message
1167  *  output: boolean_t: B_TRUE on success, B_FALSE on failure
1168  */
1169 
1170 boolean_t
1171 save_server_id(dhcp_smach_t *dsmp, PKT_LIST *msg)
1172 {
1173 	const dhcpv6_option_t *d6o;
1174 	uint_t olen;
1175 
1176 	d6o = dhcpv6_pkt_option(msg, NULL, DHCPV6_OPT_SERVERID, &olen);
1177 	if (d6o == NULL)
1178 		return (B_FALSE);
1179 	olen -= sizeof (*d6o);
1180 	free(dsmp->dsm_serverid);
1181 	if ((dsmp->dsm_serverid = malloc(olen)) == NULL) {
1182 		return (B_FALSE);
1183 	} else {
1184 		dsmp->dsm_serveridlen = olen;
1185 		(void) memcpy(dsmp->dsm_serverid, d6o + 1, olen);
1186 		return (B_TRUE);
1187 	}
1188 }
1189