xref: /netbsd-src/usr.sbin/rtadvd/config.c (revision 796c32c94f6e154afc9de0f63da35c91bb739b45)
1 /*	$NetBSD: config.c,v 1.37 2017/11/06 15:15:04 christos Exp $	*/
2 /*	$KAME: config.c,v 1.93 2005/10/17 14:40:02 suz Exp $	*/
3 
4 /*
5  * Copyright (C) 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/ioctl.h>
35 #include <sys/socket.h>
36 #include <sys/time.h>
37 #include <sys/sysctl.h>
38 
39 #include <net/if.h>
40 #include <net/route.h>
41 #include <net/if_dl.h>
42 #ifdef __FreeBSD__
43 #include <net/if_var.h>
44 #endif
45 
46 #include <netinet/in.h>
47 #include <netinet/in_var.h>
48 #include <netinet/ip6.h>
49 #include <netinet6/ip6_var.h>
50 #include <netinet/icmp6.h>
51 #include <netinet6/nd6.h>
52 
53 #include <arpa/inet.h>
54 
55 #include <stdio.h>
56 #include <syslog.h>
57 #include <errno.h>
58 #include <string.h>
59 #include <stdlib.h>
60 #include <search.h>
61 #include <unistd.h>
62 #include <ifaddrs.h>
63 #include <inttypes.h>
64 
65 #include "rtadvd.h"
66 #include "advcap.h"
67 #include "timer.h"
68 #include "if.h"
69 #include "config.h"
70 #include "logit.h"
71 #include "prog_ops.h"
72 
73 #ifndef __arraycount
74 #define __arraycount(__x)	(sizeof(__x) / sizeof(__x[0]))
75 #endif
76 
77 static time_t prefix_timo = (60 * 120);	/* 2 hours.
78 					 * XXX: should be configurable. */
79 static struct rtadvd_timer *prefix_timeout(void *);
80 static void makeentry(char *, size_t, int, const char *);
81 static int getinet6sysctl(int);
82 
83 static size_t
84 encode_domain(char *dst, const char *src)
85 {
86 	ssize_t len;
87 	char *odst, *p;
88 
89 	odst = dst;
90 	while (src && (len = strlen(src)) != 0) {
91 		p = strchr(src, '.');
92 		*dst++ = len = MIN(63, p == NULL ? len : p - src);
93 		memcpy(dst, src, len);
94 		dst += len;
95 		if (p == NULL)
96 			break;
97 		src = p + 1;
98 	}
99 	*dst++ = '\0';
100 
101 	return dst - odst;
102 }
103 
104 void
105 free_rainfo(struct rainfo *rai)
106 {
107 	struct prefix *pfx;
108 	struct rtinfo *rti;
109 	struct rdnss *rdnss;
110 	struct rdnss_addr *rdnsa;
111 	struct dnssl *dnssl;
112 	struct dnssl_domain *dnsd;
113 
114 	rtadvd_remove_timer(&rai->timer);
115 
116 	while ((pfx = TAILQ_FIRST(&rai->prefix))) {
117 		TAILQ_REMOVE(&rai->prefix, pfx, next);
118 		free(pfx);
119 	}
120 
121 	while ((rti = TAILQ_FIRST(&rai->route))) {
122 		TAILQ_REMOVE(&rai->route, rti, next);
123 		free(rti);
124 	}
125 
126 	while ((rdnss = TAILQ_FIRST(&rai->rdnss))) {
127 		TAILQ_REMOVE(&rai->rdnss, rdnss, next);
128 		while ((rdnsa = TAILQ_FIRST(&rdnss->list))) {
129 			TAILQ_REMOVE(&rdnss->list, rdnsa, next);
130 			free(rdnsa);
131 		}
132 		free(rdnss);
133 	}
134 
135 	while ((dnssl = TAILQ_FIRST(&rai->dnssl))) {
136 		TAILQ_REMOVE(&rai->dnssl, dnssl, next);
137 		while ((dnsd = TAILQ_FIRST(&dnssl->list))) {
138 			TAILQ_REMOVE(&dnssl->list, dnsd, next);
139 			free(dnsd);
140 		}
141 		free(dnssl);
142 	}
143 
144 	free(rai->sdl);
145 	free(rai->ra_data);
146 	free(rai);
147 }
148 
149 void
150 getconfig(const char *intface, int exithard)
151 {
152 	int stat, c, i;
153 	char tbuf[BUFSIZ];
154 	struct rainfo *tmp, *rai;
155 	int32_t val;
156 	int64_t val64;
157 	char buf[BUFSIZ];
158 	char *bp = buf;
159 	char *addr, *flagstr, *ap;
160 	static int forwarding = -1;
161 	char entbuf[256], abuf[256];
162 	struct rdnss *rdnss;
163 	struct dnssl *dnssl;
164 
165 #define MUSTHAVE(var, cap)	\
166     do {								\
167 	int64_t t;							\
168 	if ((t = agetnum(cap)) < 0) {					\
169 		fprintf(stderr, "rtadvd: need %s for interface %s\n",	\
170 			cap, intface);					\
171 		goto errexit;						\
172 	}								\
173 	var = t;							\
174      } while (0)
175 #define MAYHAVE(var, cap, def)	\
176      do {								\
177 	if ((var = agetnum(cap)) < 0)					\
178 		var = def;						\
179      } while (0)
180 #define	ELM_MALLOC(p)					\
181 	do {								\
182 		p = calloc(1, sizeof(*p));				\
183 		if (p == NULL) {					\
184 			logit(LOG_ERR, "<%s> calloc failed: %m",	\
185 			    __func__);					\
186 			goto errexit;					\
187 		}							\
188 	} while(/*CONSTCOND*/0)
189 
190 	if (if_nametoindex(intface) == 0) {
191 		logit(LOG_INFO, "<%s> interface %s not found, ignoring",
192 		       __func__, intface);
193 		return;
194 	}
195 
196 	logit(LOG_DEBUG, "<%s> loading configuration for interface %s",
197 	       __func__, intface);
198 
199 	if ((stat = agetent(tbuf, intface)) <= 0) {
200 		memset(tbuf, 0, sizeof(tbuf));
201 		logit(LOG_INFO,
202 		       "<%s> %s isn't defined in the configuration file"
203 		       " or the configuration file doesn't exist."
204 		       " Treat it as default",
205 		        __func__, intface);
206 	}
207 
208 	ELM_MALLOC(tmp);
209 	TAILQ_INIT(&tmp->prefix);
210 	TAILQ_INIT(&tmp->route);
211 	TAILQ_INIT(&tmp->rdnss);
212 	TAILQ_INIT(&tmp->dnssl);
213 
214 	/* check if we are allowed to forward packets (if not determined) */
215 	if (forwarding < 0) {
216 		if ((forwarding = getinet6sysctl(IPV6CTL_FORWARDING)) < 0)
217 			exit(1);
218 	}
219 
220 	/* get interface information */
221 	if (agetflag("nolladdr"))
222 		tmp->advlinkopt = 0;
223 	else
224 		tmp->advlinkopt = 1;
225 	if (tmp->advlinkopt) {
226 		if ((tmp->sdl = if_nametosdl(intface)) == NULL) {
227 			logit(LOG_ERR,
228 			       "<%s> can't get information of %s",
229 			       __func__, intface);
230 			goto errexit;
231 		}
232 		tmp->ifindex = tmp->sdl->sdl_index;
233 	} else {
234 		tmp->ifindex = if_nametoindex(intface);
235 		if (tmp->ifindex == 0) {
236 			logit(LOG_ERR,
237 			       "<%s> can't get information of %s",
238 			       __func__, intface);
239 			goto errexit;
240 		}
241 	}
242 	tmp->ifflags = if_getflags(tmp->ifindex, 0);
243 	strlcpy(tmp->ifname, intface, sizeof(tmp->ifname));
244 	if ((tmp->phymtu = if_getmtu(intface)) == 0) {
245 		tmp->phymtu = IPV6_MMTU;
246 		logit(LOG_WARNING,
247 		       "<%s> can't get interface mtu of %s. Treat as %d",
248 		       __func__, intface, IPV6_MMTU);
249 	}
250 
251 	/*
252 	 * set router configuration variables.
253 	 */
254 	MAYHAVE(val, "maxinterval", DEF_MAXRTRADVINTERVAL);
255 	if (val < MIN_MAXINTERVAL || val > MAX_MAXINTERVAL) {
256 		logit(LOG_ERR,
257 		       "<%s> maxinterval (%d) on %s is invalid "
258 		       "(must be between %u and %u)", __func__, val,
259 		       intface, MIN_MAXINTERVAL, MAX_MAXINTERVAL);
260 		goto errexit;
261 	}
262 	tmp->maxinterval = val;
263 	MAYHAVE(val, "mininterval", tmp->maxinterval/3);
264 	if (val < MIN_MININTERVAL || val > (tmp->maxinterval * 3) / 4) {
265 		logit(LOG_ERR,
266 		       "<%s> mininterval (%d) on %s is invalid "
267 		       "(must be between %u and %d)",
268 		       __func__, val, intface, MIN_MININTERVAL,
269 		       (tmp->maxinterval * 3) / 4);
270 		goto errexit;
271 	}
272 	tmp->mininterval = val;
273 
274 	MAYHAVE(val, "chlim", DEF_ADVCURHOPLIMIT);
275 	tmp->hoplimit = val & 0xff;
276 
277 	if ((flagstr = (char *)agetstr("raflags", &bp))) {
278 		val = 0;
279 		if (strchr(flagstr, 'm'))
280 			val |= ND_RA_FLAG_MANAGED;
281 		if (strchr(flagstr, 'o'))
282 			val |= ND_RA_FLAG_OTHER;
283 		if (strchr(flagstr, 'h'))
284 			val |= ND_RA_FLAG_RTPREF_HIGH;
285 		if (strchr(flagstr, 'l')) {
286 			if ((val & ND_RA_FLAG_RTPREF_HIGH)) {
287 				logit(LOG_ERR, "<%s> the \'h\' and \'l\'"
288 				    " router flags are exclusive", __func__);
289 				goto errexit;
290 			}
291 			val |= ND_RA_FLAG_RTPREF_LOW;
292 		}
293 	} else {
294 		MAYHAVE(val, "raflags", 0);
295 	}
296 	tmp->managedflg = val & ND_RA_FLAG_MANAGED;
297 	tmp->otherflg = val & ND_RA_FLAG_OTHER;
298 #ifndef ND_RA_FLAG_RTPREF_MASK
299 #define ND_RA_FLAG_RTPREF_MASK	0x18 /* 00011000 */
300 #define ND_RA_FLAG_RTPREF_RSV	0x10 /* 00010000 */
301 #endif
302 	tmp->rtpref = val & ND_RA_FLAG_RTPREF_MASK;
303 	if (tmp->rtpref == ND_RA_FLAG_RTPREF_RSV) {
304 		logit(LOG_ERR, "<%s> invalid router preference (%02x) on %s",
305 		       __func__, tmp->rtpref, intface);
306 		goto errexit;
307 	}
308 
309 	MAYHAVE(val, "rltime", DEF_ADVROUTERLIFETIME);
310 	if (val && (val < tmp->maxinterval || val > MAXROUTERLIFETIME)) {
311 		logit(LOG_ERR,
312 		       "<%s> router lifetime (%d) on %s is invalid "
313 		       "(must be 0 or between %d and %d)",
314 		       __func__, val, intface,
315 		       tmp->maxinterval, MAXROUTERLIFETIME);
316 		goto errexit;
317 	}
318 	/*
319 	 * Basically, hosts MUST NOT send Router Advertisement messages at any
320 	 * time (RFC 2461, Section 6.2.3). However, it would sometimes be
321 	 * useful to allow hosts to advertise some parameters such as prefix
322 	 * information and link MTU. Thus, we allow hosts to invoke rtadvd
323 	 * only when router lifetime (on every advertising interface) is
324 	 * explicitly set zero. (see also the above section)
325 	 */
326 	if (val && forwarding == 0) {
327 		logit(LOG_ERR,
328 		       "<%s> non zero router lifetime is specified for %s, "
329 		       "which must not be allowed for hosts.  you must "
330 		       "change router lifetime or enable IPv6 forwarding.",
331 		       __func__, intface);
332 		goto errexit;
333 	}
334 	tmp->lifetime = val & 0xffff;
335 
336 	MAYHAVE(val, "rtime", DEF_ADVREACHABLETIME);
337 	if (val < 0 || val > MAXREACHABLETIME) {
338 		logit(LOG_ERR,
339 		       "<%s> reachable time (%d) on %s is invalid "
340 		       "(must be no greater than %d)",
341 		       __func__, val, intface, MAXREACHABLETIME);
342 		goto errexit;
343 	}
344 	tmp->reachabletime = (uint32_t)val;
345 
346 	MAYHAVE(val64, "retrans", DEF_ADVRETRANSTIMER);
347 	if (val64 < 0 || val64 > 0xffffffff) {
348 		logit(LOG_ERR, "<%s> retrans time (%lld) on %s out of range",
349 		       __func__, (long long)val64, intface);
350 		goto errexit;
351 	}
352 	tmp->retranstimer = (uint32_t)val64;
353 
354 	if (agetnum("hapref") != -1 || agetnum("hatime") != -1) {
355 		logit(LOG_ERR,
356 		       "<%s> mobile-ip6 configuration not supported",
357 		       __func__);
358 		goto errexit;
359 	}
360 	/* prefix information */
361 
362 	/*
363 	 * This is an implementation specific parameter to consider
364 	 * link propagation delays and poorly synchronized clocks when
365 	 * checking consistency of advertised lifetimes.
366 	 */
367 	MAYHAVE(val, "clockskew", 0);
368 	tmp->clockskew = val;
369 
370 	tmp->pfxs = 0;
371 	for (i = -1; i < MAXPREFIX; i++) {
372 		struct prefix *pfx;
373 
374 		makeentry(entbuf, sizeof(entbuf), i, "addr");
375 		addr = (char *)agetstr(entbuf, &bp);
376 		if (addr == NULL)
377 			continue;
378 
379 		/* allocate memory to store prefix information */
380 		if ((pfx = calloc(1, sizeof(*pfx))) == NULL) {
381 			logit(LOG_ERR,
382 			       "<%s> can't allocate memory: %m",
383 			       __func__);
384 			goto errexit;
385 		}
386 
387 		TAILQ_INSERT_TAIL(&tmp->prefix, pfx, next);
388 		tmp->pfxs++;
389 		pfx->rainfo = tmp;
390 
391 		pfx->origin = PREFIX_FROM_CONFIG;
392 
393 		if (inet_pton(AF_INET6, addr, &pfx->prefix) != 1) {
394 			logit(LOG_ERR,
395 			       "<%s> inet_pton failed for %s",
396 			       __func__, addr);
397 			goto errexit;
398 		}
399 		if (IN6_IS_ADDR_MULTICAST(&pfx->prefix)) {
400 			logit(LOG_ERR,
401 			       "<%s> multicast prefix (%s) must "
402 			       "not be advertised on %s",
403 			       __func__, addr, intface);
404 			goto errexit;
405 		}
406 		if (IN6_IS_ADDR_LINKLOCAL(&pfx->prefix))
407 			logit(LOG_NOTICE,
408 			       "<%s> link-local prefix (%s) will be"
409 			       " advertised on %s",
410 			       __func__, addr, intface);
411 
412 		makeentry(entbuf, sizeof(entbuf), i, "prefixlen");
413 		MAYHAVE(val, entbuf, 64);
414 		if (val < 0 || val > 128) {
415 			logit(LOG_ERR, "<%s> prefixlen (%d) for %s "
416 			       "on %s out of range",
417 			       __func__, val, addr, intface);
418 			goto errexit;
419 		}
420 		pfx->prefixlen = (int)val;
421 
422 		makeentry(entbuf, sizeof(entbuf), i, "pinfoflags");
423 		if ((flagstr = (char *)agetstr(entbuf, &bp))) {
424 			val = 0;
425 			if (strchr(flagstr, 'l'))
426 				val |= ND_OPT_PI_FLAG_ONLINK;
427 			if (strchr(flagstr, 'a'))
428 				val |= ND_OPT_PI_FLAG_AUTO;
429 		} else {
430 			MAYHAVE(val, entbuf,
431 			    (ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO));
432 		}
433 		pfx->onlinkflg = val & ND_OPT_PI_FLAG_ONLINK;
434 		pfx->autoconfflg = val & ND_OPT_PI_FLAG_AUTO;
435 
436 		makeentry(entbuf, sizeof(entbuf), i, "vltime");
437 		MAYHAVE(val64, entbuf, DEF_ADVVALIDLIFETIME);
438 		if (val64 < 0 || val64 > 0xffffffff) {
439 			logit(LOG_ERR, "<%s> vltime (%lld) for "
440 			    "%s/%d on %s is out of range",
441 			    __func__, (long long)val64,
442 			    addr, pfx->prefixlen, intface);
443 			goto errexit;
444 		}
445 		pfx->validlifetime = (uint32_t)val64;
446 
447 		makeentry(entbuf, sizeof(entbuf), i, "vltimedecr");
448 		if (agetflag(entbuf)) {
449 			struct timespec now;
450 			prog_clock_gettime(CLOCK_MONOTONIC, &now);
451 			pfx->vltimeexpire =
452 				now.tv_sec + pfx->validlifetime;
453 		}
454 
455 		makeentry(entbuf, sizeof(entbuf), i, "pltime");
456 		MAYHAVE(val64, entbuf, DEF_ADVPREFERREDLIFETIME);
457 		if (val64 < 0 || val64 > 0xffffffff) {
458 			logit(LOG_ERR,
459 			    "<%s> pltime (%lld) for %s/%d on %s "
460 			    "is out of range",
461 			    __func__, (long long)val64,
462 			    addr, pfx->prefixlen, intface);
463 			goto errexit;
464 		}
465 		pfx->preflifetime = (uint32_t)val64;
466 
467 		makeentry(entbuf, sizeof(entbuf), i, "pltimedecr");
468 		if (agetflag(entbuf)) {
469 			struct timespec now;
470 			prog_clock_gettime(CLOCK_MONOTONIC, &now);
471 			pfx->pltimeexpire =
472 				now.tv_sec + pfx->preflifetime;
473 		}
474 	}
475 	if (TAILQ_FIRST(&tmp->prefix) == NULL && !agetflag("noifprefix"))
476 		get_prefix(tmp);
477 
478 	MAYHAVE(val64, "mtu", 0);
479 	if (val64 < 0 || val64 > 0xffffffff) {
480 		logit(LOG_ERR,
481 		       "<%s> mtu (%" PRIi64 ") on %s out of range",
482 		       __func__, val64, intface);
483 		goto errexit;
484 	}
485 	tmp->linkmtu = (uint32_t)val64;
486 	if (tmp->linkmtu == 0) {
487 		char *mtustr;
488 
489 		if ((mtustr = (char *)agetstr("mtu", &bp)) &&
490 		    strcmp(mtustr, "auto") == 0)
491 			tmp->linkmtu = tmp->phymtu;
492 	}
493 	else if (tmp->linkmtu < IPV6_MMTU || tmp->linkmtu > tmp->phymtu) {
494 		logit(LOG_ERR,
495 		       "<%s> advertised link mtu (%d) on %s is invalid (must "
496 		       "be between least MTU (%d) and physical link MTU (%d)",
497 		       __func__, tmp->linkmtu, intface,
498 		       IPV6_MMTU, tmp->phymtu);
499 		goto errexit;
500 	}
501 
502 #ifdef SIOCSIFINFO_IN6
503 	{
504 		struct in6_ndireq ndi;
505 		int s;
506 
507 		if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
508 			logit(LOG_ERR, "<%s> socket: %m", __func__);
509 			goto errexit;
510 		}
511 		memset(&ndi, 0, sizeof(ndi));
512 		strncpy(ndi.ifname, intface, IFNAMSIZ);
513 		if (prog_ioctl(s, SIOCGIFINFO_IN6, &ndi) < 0) {
514 			logit(LOG_INFO, "<%s> ioctl:SIOCGIFINFO_IN6 at %s: %m",
515 			     __func__, intface);
516 		}
517 
518 		/* reflect the RA info to the host variables in kernel */
519 		ndi.ndi.chlim = tmp->hoplimit;
520 		ndi.ndi.retrans = tmp->retranstimer;
521 		ndi.ndi.basereachable = tmp->reachabletime;
522 		if (prog_ioctl(s, SIOCSIFINFO_IN6, &ndi) < 0) {
523 			logit(LOG_INFO, "<%s> ioctl:SIOCSIFINFO_IN6 at %s: %m",
524 			     __func__, intface);
525 		}
526 		prog_close(s);
527 	}
528 #endif
529 
530 	/* route information */
531 	for (i = -1; i < MAXROUTE; i++) {
532 		struct rtinfo *rti;
533 		char oentbuf[256];
534 
535 		makeentry(entbuf, sizeof(entbuf), i, "rtprefix");
536 		addr = (char *)agetstr(entbuf, &bp);
537 		if (addr == NULL) {
538 			makeentry(oentbuf, sizeof(oentbuf), i, "rtrprefix");
539 			addr = (char *)agetstr(oentbuf, &bp);
540 			if (addr) {
541 				fprintf(stderr, "%s was obsoleted.  Use %s.\n",
542 					oentbuf, entbuf);
543 			}
544 		}
545 		if (addr == NULL)
546 			continue;
547 
548 		ELM_MALLOC(rti);
549 		memset(rti, 0, sizeof(*rti));
550 
551 		/* link into chain */
552 		TAILQ_INSERT_TAIL(&tmp->route, rti, next);
553 
554 		if (inet_pton(AF_INET6, addr, &rti->prefix) != 1) {
555 			logit(LOG_ERR, "<%s> inet_pton failed for %s",
556 			       __func__, addr);
557 			goto errexit;
558 		}
559 #if 0
560 		/*
561 		 * XXX: currently there's no restriction in route information
562 		 * prefix according to
563 		 * draft-ietf-ipngwg-router-selection-00.txt.
564 		 * However, I think the similar restriction be necessary.
565 		 */
566 		MAYHAVE(val64, entbuf, DEF_ADVVALIDLIFETIME);
567 		if (IN6_IS_ADDR_MULTICAST(&rti->prefix)) {
568 			logit(LOG_ERR,
569 			       "<%s> multicast route (%s) must "
570 			       "not be advertised on %s",
571 			       __func__, addr, intface);
572 			goto errexit;
573 		}
574 		if (IN6_IS_ADDR_LINKLOCAL(&rti->prefix)) {
575 			logit(LOG_NOTICE,
576 			       "<%s> link-local route (%s) will "
577 			       "be advertised on %s",
578 			       __func__, addr, intface);
579 			goto errexit;
580 		}
581 #endif
582 
583 		makeentry(entbuf, sizeof(entbuf), i, "rtplen");
584 		/* XXX: 256 is a magic number for compatibility check. */
585 		MAYHAVE(val, entbuf, 256);
586 		if (val == 256) {
587 			makeentry(oentbuf, sizeof(oentbuf), i, "rtrplen");
588 			MAYHAVE(val, oentbuf, 256);
589 			if (val != 256) {
590 				fprintf(stderr, "%s was obsoleted.  Use %s.\n",
591 					oentbuf, entbuf);
592 			} else
593 				val = 64;
594 		}
595 		if (val < 0 || val > 128) {
596 			logit(LOG_ERR, "<%s> prefixlen (%d) for %s on %s "
597 			       "out of range",
598 			       __func__, val, addr, intface);
599 			goto errexit;
600 		}
601 		rti->prefixlen = (int)val;
602 
603 		makeentry(entbuf, sizeof(entbuf), i, "rtflags");
604 		if ((flagstr = (char *)agetstr(entbuf, &bp))) {
605 			val = 0;
606 			if (strchr(flagstr, 'h'))
607 				val |= ND_RA_FLAG_RTPREF_HIGH;
608 			if (strchr(flagstr, 'l')) {
609 				if ((val & ND_RA_FLAG_RTPREF_HIGH)) {
610 					logit(LOG_ERR,
611 					    "<%s> the \'h\' and \'l\' route"
612 					    " preferences are exclusive",
613 					    __func__);
614 					goto errexit;
615 				}
616 				val |= ND_RA_FLAG_RTPREF_LOW;
617 			}
618 		} else
619 			MAYHAVE(val, entbuf, 256); /* XXX */
620 		if (val == 256) {
621 			makeentry(oentbuf, sizeof(oentbuf), i, "rtrflags");
622 			MAYHAVE(val, oentbuf, 256);
623 			if (val != 256) {
624 				fprintf(stderr, "%s was obsoleted.  Use %s.\n",
625 					oentbuf, entbuf);
626 			} else
627 				val = 0;
628 		}
629 		rti->rtpref = val & ND_RA_FLAG_RTPREF_MASK;
630 		if (rti->rtpref == ND_RA_FLAG_RTPREF_RSV) {
631 			logit(LOG_ERR, "<%s> invalid route preference (%02x) "
632 			       "for %s/%d on %s",
633 			       __func__, rti->rtpref, addr,
634 			       rti->prefixlen, intface);
635 			goto errexit;
636 		}
637 
638 		/*
639 		 * Since the spec does not a default value, we should make
640 		 * this entry mandatory.  However, FreeBSD 4.4 has shipped
641 		 * with this field being optional, we use the router lifetime
642 		 * as an ad-hoc default value with a warning message.
643 		 */
644 		makeentry(entbuf, sizeof(entbuf), i, "rtltime");
645 		MAYHAVE(val64, entbuf, -1);
646 		if (val64 == -1) {
647 			makeentry(oentbuf, sizeof(oentbuf), i, "rtrltime");
648 			MAYHAVE(val64, oentbuf, -1);
649 			if (val64 != -1) {
650 				fprintf(stderr, "%s was obsoleted.  Use %s.\n",
651 					oentbuf, entbuf);
652 			} else {
653 				fprintf(stderr, "%s should be specified "
654 					"for interface %s.\n",
655 					entbuf, intface);
656 				val64 = tmp->lifetime;
657 			}
658 		}
659 		if (val64 < 0 || val64 > 0xffffffff) {
660 			logit(LOG_ERR, "<%s> route lifetime (%lld) for "
661 			    "%s/%d on %s out of range", __func__,
662 			    (long long)val64, addr, rti->prefixlen, intface);
663 			goto errexit;
664 		}
665 		rti->ltime = (uint32_t)val64;
666 	}
667 
668 	/* RDNSS */
669 	for (i = -1; i < MAXRDNSS; i++) {
670 		struct rdnss_addr *rdnsa;
671 
672 		makeentry(entbuf, sizeof(entbuf), i, "rdnss");
673 		addr = (char *)agetstr(entbuf, &bp);
674 		if (addr == NULL)
675 			continue;
676 
677 		ELM_MALLOC(rdnss);
678 		TAILQ_INSERT_TAIL(&tmp->rdnss, rdnss, next);
679 		TAILQ_INIT(&rdnss->list);
680 
681 		for (ap = addr; ap - addr < (ssize_t)strlen(addr); ap += c+1) {
682 			c = strcspn(ap, ",");
683 			strncpy(abuf, ap, c);
684 			abuf[c] = '\0';
685 			ELM_MALLOC(rdnsa);
686 			TAILQ_INSERT_TAIL(&rdnss->list, rdnsa, next);
687 			if (inet_pton(AF_INET6, abuf, &rdnsa->addr) != 1) {
688 				logit(LOG_ERR, "<%s> inet_pton failed for %s",
689 			           __func__, addr);
690 				goto errexit;
691 			}
692 		}
693 
694 		makeentry(entbuf, sizeof(entbuf), i, "rdnssltime");
695 		MAYHAVE(val64, entbuf, tmp->maxinterval * 3 / 2);
696 		if (val64 < tmp->maxinterval ||
697 		    val64 > tmp->maxinterval * 2)
698 		{
699 			logit(LOG_ERR, "<%s> %s (%lld) on %s is invalid",
700 		    	     __func__, entbuf, (long long)val64, intface);
701 			goto errexit;
702 		}
703 		rdnss->lifetime = (uint32_t)val64;
704 
705 	}
706 
707 	/* DNSSL */
708 	TAILQ_INIT(&tmp->dnssl);
709 	for (i = -1; i < MAXDNSSL; i++) {
710 		struct dnssl_domain *dnsd;
711 
712 		makeentry(entbuf, sizeof(entbuf), i, "dnssl");
713 		addr = (char *)agetstr(entbuf, &bp);
714 		if (addr == NULL)
715 			continue;
716 
717 		ELM_MALLOC(dnssl);
718 		TAILQ_INSERT_TAIL(&tmp->dnssl, dnssl, next);
719 		TAILQ_INIT(&dnssl->list);
720 
721 		for (ap = addr; ap - addr < (ssize_t)strlen(addr); ap += c+1) {
722 			c = strcspn(ap, ",");
723 			strncpy(abuf, ap, c);
724 			abuf[c] = '\0';
725 			ELM_MALLOC(dnsd);
726 			TAILQ_INSERT_TAIL(&dnssl->list, dnsd, next);
727 			dnsd->len = encode_domain(dnsd->domain, abuf);
728 		}
729 
730 		makeentry(entbuf, sizeof(entbuf), i, "dnsslltime");
731 		MAYHAVE(val64, entbuf, tmp->maxinterval * 3 / 2);
732 		if (val64 < tmp->maxinterval ||
733 		    val64 > tmp->maxinterval * 2)
734 		{
735 			logit(LOG_ERR, "<%s> %s (%lld) on %s is invalid",
736 		    	     __func__, entbuf, (long long)val64, intface);
737 			goto errexit;
738 		}
739 		dnssl->lifetime = (uint32_t)val64;
740 
741 	}
742 
743 	TAILQ_FOREACH(rai, &ralist, next) {
744 		if (rai->ifindex == tmp->ifindex) {
745 			TAILQ_REMOVE(&ralist, rai, next);
746 			/* If we already have a leaving RA use that
747 			 * as this config hasn't been advertised */
748 			if (rai->leaving) {
749 				tmp->leaving = rai->leaving;
750 				free_rainfo(rai);
751 				rai = tmp->leaving;
752 				rai->leaving_for = tmp;
753 				break;
754 			}
755 			rai->lifetime = 0;
756 			TAILQ_FOREACH(rdnss, &rai->rdnss, next)
757 				rdnss->lifetime = 0;
758 			TAILQ_FOREACH(dnssl, &rai->dnssl, next)
759 				dnssl->lifetime = 0;
760 			rai->leaving_for = tmp;
761 			tmp->leaving = rai;
762 			rai->initcounter = MAX_INITIAL_RTR_ADVERTISEMENTS;
763 			rai->mininterval = MIN_DELAY_BETWEEN_RAS;
764 			rai->maxinterval = MIN_DELAY_BETWEEN_RAS;
765 			rai->leaving_adv = MAX_FINAL_RTR_ADVERTISEMENTS;
766 			if (rai->timer == NULL)
767 				rai->timer = rtadvd_add_timer(ra_timeout,
768 							      ra_timer_update,
769 							      rai, rai);
770 			ra_timer_update((void *)rai, &rai->timer->tm);
771 			rtadvd_set_timer(&rai->timer->tm, rai->timer);
772 			break;
773 		}
774 	}
775 
776 	/* okey */
777 	TAILQ_INSERT_TAIL(&ralist, tmp, next);
778 
779 	/* construct the sending packet */
780 	make_packet(tmp);
781 
782 	/* set timer */
783 	if (rai)
784 		return;
785 	tmp->timer = rtadvd_add_timer(ra_timeout, ra_timer_update,
786 				      tmp, tmp);
787 	ra_timer_set_short_delay(tmp);
788 
789 	return;
790 
791 errexit:
792 	if (exithard)
793 		exit(1);
794 	free_rainfo(tmp);
795 }
796 
797 void
798 get_prefix(struct rainfo *rai)
799 {
800 	struct ifaddrs *ifap, *ifa;
801 	struct prefix *pp;
802 	struct in6_addr *a;
803 	unsigned char *p, *ep, *m, *lim;
804 	char ntopbuf[INET6_ADDRSTRLEN];
805 
806 	if (getifaddrs(&ifap) < 0) {
807 		logit(LOG_ERR,
808 		       "<%s> can't get interface addresses",
809 		       __func__);
810 		exit(1);
811 	}
812 
813 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
814 		int plen;
815 
816 		if (strcmp(ifa->ifa_name, rai->ifname) != 0)
817 			continue;
818 		if (ifa->ifa_addr->sa_family != AF_INET6)
819 			continue;
820 		a = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
821 		if (IN6_IS_ADDR_LINKLOCAL(a))
822 			continue;
823 		/* get prefix length */
824 		m = (unsigned char *)&((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_addr;
825 		lim = (unsigned char *)(ifa->ifa_netmask) + ifa->ifa_netmask->sa_len;
826 		plen = prefixlen(m, lim);
827 		if (plen <= 0 || plen > 128) {
828 			logit(LOG_ERR, "<%s> failed to get prefixlen "
829 			       "or prefix is invalid",
830 			       __func__);
831 			exit(1);
832 		}
833 		if (plen == 128)	/* XXX */
834 			continue;
835 		if (find_prefix(rai, a, plen)) {
836 			/* ignore a duplicated prefix. */
837 			continue;
838 		}
839 
840 		/* allocate memory to store prefix info. */
841 		if ((pp = calloc(1, sizeof(*pp))) == NULL) {
842 			logit(LOG_ERR,
843 			       "<%s> can't get allocate buffer for prefix",
844 			       __func__);
845 			exit(1);
846 		}
847 
848 		/* set prefix, sweep bits outside of prefixlen */
849 		pp->prefixlen = plen;
850 		memcpy(&pp->prefix, a, sizeof(*a));
851 		if (1)
852 		{
853 			p = (unsigned char *)&pp->prefix;
854 			ep = (unsigned char *)(&pp->prefix + 1);
855 			while (m < lim && p < ep)
856 				*p++ &= *m++;
857 			while (p < ep)
858 				*p++ = 0x00;
859 		}
860 	        if (!inet_ntop(AF_INET6, &pp->prefix, ntopbuf,
861 	            sizeof(ntopbuf))) {
862 			logit(LOG_ERR, "<%s> inet_ntop failed", __func__);
863 			exit(1);
864 		}
865 		logit(LOG_DEBUG,
866 		       "<%s> add %s/%d to prefix list on %s",
867 		       __func__, ntopbuf, pp->prefixlen, rai->ifname);
868 
869 		/* set other fields with protocol defaults */
870 		pp->validlifetime = DEF_ADVVALIDLIFETIME;
871 		pp->preflifetime = DEF_ADVPREFERREDLIFETIME;
872 		pp->onlinkflg = 1;
873 		pp->autoconfflg = 1;
874 		pp->origin = PREFIX_FROM_KERNEL;
875 		pp->rainfo = rai;
876 
877 		/* link into chain */
878 		TAILQ_INSERT_TAIL(&rai->prefix, pp, next);
879 		rai->pfxs++;
880 	}
881 
882 	freeifaddrs(ifap);
883 }
884 
885 static void
886 makeentry(char *buf, size_t len, int id, const char *string)
887 {
888 
889 	if (id < 0)
890 		strlcpy(buf, string, len);
891 	else
892 		snprintf(buf, len, "%s%d", string, id);
893 }
894 
895 /*
896  * Add a prefix to the list of specified interface and reconstruct
897  * the outgoing packet.
898  * The prefix must not be in the list.
899  * XXX: other parameters of the prefix(e.g. lifetime) should be
900  * able to be specified.
901  */
902 static void
903 add_prefix(struct rainfo *rai, struct in6_prefixreq *ipr)
904 {
905 	struct prefix *prefix;
906 	char ntopbuf[INET6_ADDRSTRLEN];
907 
908 	if ((prefix = calloc(1, sizeof(*prefix))) == NULL) {
909 		logit(LOG_ERR, "<%s> memory allocation failed",
910 		       __func__);
911 		return;		/* XXX: error or exit? */
912 	}
913 	prefix->prefix = ipr->ipr_prefix.sin6_addr;
914 	prefix->prefixlen = ipr->ipr_plen;
915 	prefix->validlifetime = ipr->ipr_vltime;
916 	prefix->preflifetime = ipr->ipr_pltime;
917 	prefix->onlinkflg = ipr->ipr_raf_onlink;
918 	prefix->autoconfflg = ipr->ipr_raf_auto;
919 	prefix->origin = PREFIX_FROM_DYNAMIC;
920 
921 	prefix->rainfo = rai;
922 	TAILQ_INSERT_TAIL(&rai->prefix, prefix, next);
923 	rai->pfxs++;
924 
925 	logit(LOG_DEBUG, "<%s> new prefix %s/%d was added on %s",
926 	       __func__, inet_ntop(AF_INET6, &ipr->ipr_prefix.sin6_addr,
927 				       ntopbuf, INET6_ADDRSTRLEN),
928 	       ipr->ipr_plen, rai->ifname);
929 
930 	/* free the previous packet */
931 	free(rai->ra_data);
932 	rai->ra_data = NULL;
933 
934 	/* reconstruct the packet */
935 	make_packet(rai);
936 }
937 
938 /*
939  * Delete a prefix to the list of specified interface and reconstruct
940  * the outgoing packet.
941  * The prefix must be in the list.
942  */
943 void
944 delete_prefix(struct prefix *prefix)
945 {
946 	char ntopbuf[INET6_ADDRSTRLEN];
947 	struct rainfo *rai = prefix->rainfo;
948 
949 	TAILQ_REMOVE(&rai->prefix, prefix, next);
950 	rai->pfxs--;
951 	logit(LOG_DEBUG, "<%s> prefix %s/%d was deleted on %s",
952 	       __func__, inet_ntop(AF_INET6, &prefix->prefix,
953 				       ntopbuf, INET6_ADDRSTRLEN),
954 	       prefix->prefixlen, rai->ifname);
955 	rtadvd_remove_timer(&prefix->timer);
956 	free(prefix);
957 }
958 
959 void
960 invalidate_prefix(struct prefix *prefix)
961 {
962 	char ntopbuf[INET6_ADDRSTRLEN];
963 	struct timespec timo;
964 	struct rainfo *rai = prefix->rainfo;
965 
966 	if (prefix->timer) {	/* sanity check */
967 		logit(LOG_ERR,
968 		    "<%s> assumption failure: timer already exists",
969 		    __func__);
970 		exit(1);
971 	}
972 
973 	logit(LOG_DEBUG, "<%s> prefix %s/%d was invalidated on %s, "
974 	    "will expire in %ld seconds", __func__,
975 	    inet_ntop(AF_INET6, &prefix->prefix, ntopbuf, INET6_ADDRSTRLEN),
976 	    prefix->prefixlen, rai->ifname, (long)prefix_timo);
977 
978 	/* set the expiration timer */
979 	prefix->timer = rtadvd_add_timer(prefix_timeout, NULL, prefix, NULL);
980 	if (prefix->timer == NULL) {
981 		logit(LOG_ERR, "<%s> failed to add a timer for a prefix. "
982 		    "remove the prefix", __func__);
983 		delete_prefix(prefix);
984 	}
985 	timo.tv_sec = prefix_timo;
986 	timo.tv_nsec = 0;
987 	rtadvd_set_timer(&timo, prefix->timer);
988 }
989 
990 static struct rtadvd_timer *
991 prefix_timeout(void *arg)
992 {
993 	struct prefix *prefix = (struct prefix *)arg;
994 
995 	delete_prefix(prefix);
996 
997 	return(NULL);
998 }
999 
1000 void
1001 update_prefix(struct prefix * prefix)
1002 {
1003 	char ntopbuf[INET6_ADDRSTRLEN];
1004 	struct rainfo *rai = prefix->rainfo;
1005 
1006 	if (prefix->timer == NULL) { /* sanity check */
1007 		logit(LOG_ERR,
1008 		    "<%s> assumption failure: timer does not exist",
1009 		    __func__);
1010 		exit(1);
1011 	}
1012 
1013 	logit(LOG_DEBUG, "<%s> prefix %s/%d was re-enabled on %s",
1014 	    __func__, inet_ntop(AF_INET6, &prefix->prefix, ntopbuf,
1015 	    INET6_ADDRSTRLEN), prefix->prefixlen, rai->ifname);
1016 
1017 	/* stop the expiration timer */
1018 	rtadvd_remove_timer(&prefix->timer);
1019 }
1020 
1021 /*
1022  * Try to get an in6_prefixreq contents for a prefix which matches
1023  * ipr->ipr_prefix and ipr->ipr_plen and belongs to
1024  * the interface whose name is ipr->ipr_name[].
1025  */
1026 static int
1027 init_prefix(struct in6_prefixreq *ipr)
1028 {
1029 #if 0
1030 	int s;
1031 
1032 	if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
1033 		logit(LOG_ERR, "<%s> socket: %m", __func__);
1034 		exit(1);
1035 	}
1036 
1037 	if (prog_ioctl(s, SIOCGIFPREFIX_IN6, ipr) < 0) {
1038 		logit(LOG_INFO, "<%s> ioctl:SIOCGIFPREFIX: %m", __func__);
1039 
1040 		ipr->ipr_vltime = DEF_ADVVALIDLIFETIME;
1041 		ipr->ipr_pltime = DEF_ADVPREFERREDLIFETIME;
1042 		ipr->ipr_raf_onlink = 1;
1043 		ipr->ipr_raf_auto = 1;
1044 		/* omit other field initialization */
1045 	}
1046 	else if (ipr->ipr_origin < PR_ORIG_RR) {
1047 		char ntopbuf[INET6_ADDRSTRLEN];
1048 
1049 		logit(LOG_WARNING, "<%s> Added prefix(%s)'s origin %d is"
1050 		       "lower than PR_ORIG_RR(router renumbering)."
1051 		       "This should not happen if I am router", __func__,
1052 		       inet_ntop(AF_INET6, &ipr->ipr_prefix.sin6_addr, ntopbuf,
1053 				 sizeof(ntopbuf)), ipr->ipr_origin);
1054 		prog_close(s);
1055 		return 1;
1056 	}
1057 
1058 	prog_close(s);
1059 	return 0;
1060 #else
1061 	ipr->ipr_vltime = DEF_ADVVALIDLIFETIME;
1062 	ipr->ipr_pltime = DEF_ADVPREFERREDLIFETIME;
1063 	ipr->ipr_raf_onlink = 1;
1064 	ipr->ipr_raf_auto = 1;
1065 	return 0;
1066 #endif
1067 }
1068 
1069 void
1070 make_prefix(struct rainfo *rai, int ifindex, struct in6_addr *addr, int plen)
1071 {
1072 	struct in6_prefixreq ipr;
1073 
1074 	memset(&ipr, 0, sizeof(ipr));
1075 	if (if_indextoname(ifindex, ipr.ipr_name) == NULL) {
1076 		logit(LOG_ERR, "<%s> Prefix added interface No.%d doesn't"
1077 		       "exist. This should not happen: %m", __func__,
1078 		       ifindex);
1079 		exit(1);
1080 	}
1081 	ipr.ipr_prefix.sin6_len = sizeof(ipr.ipr_prefix);
1082 	ipr.ipr_prefix.sin6_family = AF_INET6;
1083 	ipr.ipr_prefix.sin6_addr = *addr;
1084 	ipr.ipr_plen = plen;
1085 
1086 	if (init_prefix(&ipr))
1087 		return; /* init failed by some error */
1088 	add_prefix(rai, &ipr);
1089 }
1090 
1091 void
1092 make_packet(struct rainfo *rainfo)
1093 {
1094 	size_t packlen, lladdroptlen = 0;
1095 	char *buf;
1096 	struct nd_router_advert *ra;
1097 	struct nd_opt_prefix_info *ndopt_pi;
1098 	struct nd_opt_mtu *ndopt_mtu;
1099 	struct prefix *pfx;
1100 	struct nd_opt_route_info *ndopt_rti;
1101 	struct rtinfo *rti;
1102 	struct nd_opt_rdnss *ndopt_rdnss;
1103 	struct rdnss *rdns;
1104 	struct rdnss_addr *rdnsa;
1105 	struct nd_opt_dnssl *ndopt_dnssl;
1106 	struct dnssl *dnsl;
1107 	struct dnssl_domain *dnsd;
1108 	size_t len, plen;
1109 
1110 	/* calculate total length */
1111 	packlen = sizeof(struct nd_router_advert);
1112 	if (rainfo->advlinkopt) {
1113 		if ((lladdroptlen = lladdropt_length(rainfo->sdl)) == 0) {
1114 			logit(LOG_INFO,
1115 			       "<%s> link-layer address option has"
1116 			       " null length on %s.  Treat as not included.",
1117 			       __func__, rainfo->ifname);
1118 			rainfo->advlinkopt = 0;
1119 		}
1120 		packlen += lladdroptlen;
1121 	}
1122 	if (TAILQ_FIRST(&rainfo->prefix) != NULL)
1123 		packlen += sizeof(struct nd_opt_prefix_info) * rainfo->pfxs;
1124 	if (rainfo->linkmtu)
1125 		packlen += sizeof(struct nd_opt_mtu);
1126 	TAILQ_FOREACH(rti, &rainfo->route, next)
1127 		packlen += sizeof(struct nd_opt_route_info) +
1128 			   ((rti->prefixlen + 0x3f) >> 6) * 8;
1129 
1130 	TAILQ_FOREACH(rdns, &rainfo->rdnss, next) {
1131 		packlen += sizeof(struct nd_opt_rdnss);
1132 		TAILQ_FOREACH(rdnsa, &rdns->list, next)
1133 			packlen += sizeof(rdnsa->addr);
1134 	}
1135 	TAILQ_FOREACH(dnsl, &rainfo->dnssl, next) {
1136 		packlen += sizeof(struct nd_opt_dnssl);
1137 		len = 0;
1138 		TAILQ_FOREACH(dnsd, &dnsl->list, next)
1139 			len += dnsd->len;
1140 		len += len % 8 ? 8 - len % 8 : 0;
1141 		packlen += len;
1142 	}
1143 
1144 	/* allocate memory for the packet */
1145 	if ((buf = realloc(rainfo->ra_data, packlen)) == NULL) {
1146 		logit(LOG_ERR,
1147 		       "<%s> can't get enough memory for an RA packet %m",
1148 		       __func__);
1149 		exit(1);
1150 	}
1151 	rainfo->ra_data = buf;
1152 	/* XXX: what if packlen > 576? */
1153 	rainfo->ra_datalen = packlen;
1154 #define CHECKLEN(size) \
1155 	do { \
1156 		if (buf + size > rainfo->ra_data + packlen) { \
1157 			logit(LOG_ERR, \
1158 			    "<%s, %d> RA packet does not fit in %zu",\
1159 			    __func__, __LINE__, packlen); \
1160 			exit(1); \
1161 		} \
1162 	} while (/*CONSTCOND*/0)
1163 	/*
1164 	 * construct the packet
1165 	 */
1166 	CHECKLEN(sizeof(*ra));
1167 	ra = (struct nd_router_advert *)buf;
1168 	ra->nd_ra_type = ND_ROUTER_ADVERT;
1169 	ra->nd_ra_code = 0;
1170 	ra->nd_ra_cksum = 0;
1171 	ra->nd_ra_curhoplimit = (uint8_t)(0xff & rainfo->hoplimit);
1172 	ra->nd_ra_flags_reserved = 0; /* just in case */
1173 	/*
1174 	 * XXX: the router preference field, which is a 2-bit field, should be
1175 	 * initialized before other fields.
1176 	 */
1177 	ra->nd_ra_flags_reserved = 0xff & rainfo->rtpref;
1178 	ra->nd_ra_flags_reserved |=
1179 		rainfo->managedflg ? ND_RA_FLAG_MANAGED : 0;
1180 	ra->nd_ra_flags_reserved |=
1181 		rainfo->otherflg ? ND_RA_FLAG_OTHER : 0;
1182 	ra->nd_ra_router_lifetime = htons(rainfo->lifetime);
1183 	ra->nd_ra_reachable = htonl(rainfo->reachabletime);
1184 	ra->nd_ra_retransmit = htonl(rainfo->retranstimer);
1185 	buf += sizeof(*ra);
1186 
1187 	if (rainfo->advlinkopt) {
1188 		CHECKLEN(sizeof(struct nd_opt_hdr));
1189 		lladdropt_fill(rainfo->sdl, (struct nd_opt_hdr *)buf);
1190 		buf += lladdroptlen;
1191 	}
1192 
1193 	if (rainfo->linkmtu) {
1194 		CHECKLEN(sizeof(*ndopt_mtu));
1195 		ndopt_mtu = (struct nd_opt_mtu *)buf;
1196 		ndopt_mtu->nd_opt_mtu_type = ND_OPT_MTU;
1197 		ndopt_mtu->nd_opt_mtu_len = 1;
1198 		ndopt_mtu->nd_opt_mtu_reserved = 0;
1199 		ndopt_mtu->nd_opt_mtu_mtu = htonl(rainfo->linkmtu);
1200 		buf += sizeof(struct nd_opt_mtu);
1201 	}
1202 
1203 	TAILQ_FOREACH(pfx, &rainfo->prefix, next) {
1204 		uint32_t vltime, pltime;
1205 		struct timespec now;
1206 
1207 		CHECKLEN(sizeof(*ndopt_pi));
1208 		ndopt_pi = (struct nd_opt_prefix_info *)buf;
1209 		ndopt_pi->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
1210 		ndopt_pi->nd_opt_pi_len = 4;
1211 		ndopt_pi->nd_opt_pi_prefix_len = pfx->prefixlen;
1212 		ndopt_pi->nd_opt_pi_flags_reserved = 0;
1213 		if (pfx->onlinkflg)
1214 			ndopt_pi->nd_opt_pi_flags_reserved |=
1215 				ND_OPT_PI_FLAG_ONLINK;
1216 		if (pfx->autoconfflg)
1217 			ndopt_pi->nd_opt_pi_flags_reserved |=
1218 				ND_OPT_PI_FLAG_AUTO;
1219 		if (pfx->timer)
1220 			vltime = 0;
1221 		else {
1222 			if (pfx->vltimeexpire || pfx->pltimeexpire)
1223 				prog_clock_gettime(CLOCK_MONOTONIC, &now);
1224 			if (pfx->vltimeexpire == 0)
1225 				vltime = pfx->validlifetime;
1226 			else
1227 				vltime = (pfx->vltimeexpire > now.tv_sec) ?
1228 				    pfx->vltimeexpire - now.tv_sec : 0;
1229 		}
1230 		if (pfx->timer)
1231 			pltime = 0;
1232 		else {
1233 			if (pfx->pltimeexpire == 0)
1234 				pltime = pfx->preflifetime;
1235 			else
1236 				pltime = (pfx->pltimeexpire > now.tv_sec) ?
1237 				    pfx->pltimeexpire - now.tv_sec : 0;
1238 		}
1239 		if (vltime < pltime) {
1240 			/*
1241 			 * this can happen if vltime is decrement but pltime
1242 			 * is not.
1243 			 */
1244 			pltime = vltime;
1245 		}
1246 		ndopt_pi->nd_opt_pi_valid_time = htonl(vltime);
1247 		ndopt_pi->nd_opt_pi_preferred_time = htonl(pltime);
1248 		ndopt_pi->nd_opt_pi_reserved2 = 0;
1249 		ndopt_pi->nd_opt_pi_prefix = pfx->prefix;
1250 
1251 		buf += sizeof(struct nd_opt_prefix_info);
1252 	}
1253 
1254 	TAILQ_FOREACH(rti, &rainfo->route, next) {
1255 		uint8_t psize = (rti->prefixlen + 0x3f) >> 6;
1256 
1257 		CHECKLEN(sizeof(*ndopt_rti));
1258 		ndopt_rti = (struct nd_opt_route_info *)buf;
1259 		ndopt_rti->nd_opt_rti_type = ND_OPT_ROUTE_INFO;
1260 		ndopt_rti->nd_opt_rti_len = 1 + psize;
1261 		ndopt_rti->nd_opt_rti_prefixlen = rti->prefixlen;
1262 		ndopt_rti->nd_opt_rti_flags = 0xff & rti->rtpref;
1263 		ndopt_rti->nd_opt_rti_lifetime = htonl(rti->ltime);
1264 		memcpy(ndopt_rti + 1, &rti->prefix, psize * 8);
1265 		buf += sizeof(struct nd_opt_route_info) + psize * 8;
1266 	}
1267 
1268 	TAILQ_FOREACH(rdns, &rainfo->rdnss, next) {
1269 		CHECKLEN(sizeof(*ndopt_rdnss));
1270 		ndopt_rdnss = (struct nd_opt_rdnss *)buf;
1271 		ndopt_rdnss->nd_opt_rdnss_type = ND_OPT_RDNSS;
1272 		ndopt_rdnss->nd_opt_rdnss_len = 1;
1273 		ndopt_rdnss->nd_opt_rdnss_reserved = 0;
1274 		ndopt_rdnss->nd_opt_rdnss_lifetime = htonl(rdns->lifetime);
1275 		buf += sizeof(*ndopt_rdnss);
1276 
1277 		TAILQ_FOREACH(rdnsa, &rdns->list, next) {
1278 			CHECKLEN(sizeof(rdnsa->addr));
1279 			memcpy(buf, &rdnsa->addr, sizeof(rdnsa->addr));
1280 			ndopt_rdnss->nd_opt_rdnss_len += 2;
1281 			buf += sizeof(rdnsa->addr);
1282 		}
1283 	}
1284 
1285 	TAILQ_FOREACH(dnsl, &rainfo->dnssl, next) {
1286 		CHECKLEN(sizeof(*ndopt_dnssl));
1287 		ndopt_dnssl = (struct nd_opt_dnssl *)buf;
1288 		ndopt_dnssl->nd_opt_dnssl_type = ND_OPT_DNSSL;
1289 		ndopt_dnssl->nd_opt_dnssl_len = 0;
1290 		ndopt_dnssl->nd_opt_dnssl_reserved = 0;
1291 		ndopt_dnssl->nd_opt_dnssl_lifetime = htonl(dnsl->lifetime);
1292 		buf += sizeof(*ndopt_dnssl);
1293 
1294 		TAILQ_FOREACH(dnsd, &dnsl->list, next) {
1295 			CHECKLEN(dnsd->len);
1296 			memcpy(buf, dnsd->domain, dnsd->len);
1297 			buf += dnsd->len;
1298 		}
1299 		/* Ensure our length is padded correctly */
1300 		len = buf - (char *)ndopt_dnssl;
1301 		plen = len % 8 ? 8 - len % 8 : 0;
1302 		CHECKLEN(plen);
1303 		memset(buf, 0, plen);
1304 		buf += plen;
1305 		ndopt_dnssl->nd_opt_dnssl_len = (len + plen) / 8;
1306 	}
1307 	memset(buf, 0, packlen - (buf - rainfo->ra_data));
1308 }
1309 
1310 static int
1311 getinet6sysctl(int code)
1312 {
1313 	const int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, code };
1314 	int value;
1315 	size_t size;
1316 
1317 	size = sizeof(value);
1318 	if (prog_sysctl(mib, __arraycount(mib), &value, &size, NULL, 0)
1319 	    < 0) {
1320 		logit(LOG_ERR, "<%s>: failed to get ip6 sysctl(%d): %m",
1321 		       __func__, code);
1322 		return -1;
1323 	}
1324 	else
1325 		return value;
1326 }
1327