xref: /netbsd-src/external/bsd/dhcpcd/dist/src/if-bsd.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*
2  * BSD interface driver for dhcpcd
3  * Copyright (c) 2006-2018 Roy Marples <roy@marples.name>
4  * All rights reserved
5 
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/ioctl.h>
29 #include <sys/param.h>
30 #include <sys/socket.h>
31 #include <sys/stat.h>
32 #include <sys/sysctl.h>
33 #include <sys/time.h>
34 #include <sys/types.h>
35 #include <sys/uio.h>
36 #include <sys/utsname.h>
37 
38 #include "config.h"
39 
40 #include <arpa/inet.h>
41 #include <net/bpf.h>
42 #include <net/if.h>
43 #include <net/if_dl.h>
44 #include <net/if_media.h>
45 #include <net/route.h>
46 #include <netinet/if_ether.h>
47 #include <netinet/in.h>
48 #include <netinet/in_var.h>
49 #include <netinet6/in6_var.h>
50 #include <netinet6/nd6.h>
51 #ifdef __NetBSD__
52 #include <net/if_vlanvar.h> /* Needs netinet/if_ether.h */
53 #else
54 #include <net/if_vlan_var.h>
55 #endif
56 #ifdef __DragonFly__
57 #  include <netproto/802_11/ieee80211_ioctl.h>
58 #elif __APPLE__
59   /* FIXME: Add apple includes so we can work out SSID */
60 #else
61 #  include <net80211/ieee80211.h>
62 #  include <net80211/ieee80211_ioctl.h>
63 #endif
64 
65 #include <assert.h>
66 #include <errno.h>
67 #include <fcntl.h>
68 #include <fnmatch.h>
69 #include <paths.h>
70 #include <stddef.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <string.h>
74 #include <unistd.h>
75 
76 #if defined(OpenBSD) && OpenBSD >= 201411
77 /* OpenBSD dropped the global setting from sysctl but left the #define
78  * which causes a EPERM error when trying to use it.
79  * I think both the error and keeping the define are wrong, so we #undef it. */
80 #undef IPV6CTL_ACCEPT_RTADV
81 #endif
82 
83 #include "common.h"
84 #include "dhcp.h"
85 #include "if.h"
86 #include "if-options.h"
87 #include "ipv4.h"
88 #include "ipv4ll.h"
89 #include "ipv6.h"
90 #include "ipv6nd.h"
91 #include "logerr.h"
92 #include "route.h"
93 #include "sa.h"
94 
95 #ifndef RT_ROUNDUP
96 #define RT_ROUNDUP(a)							      \
97 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
98 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len))
99 #endif
100 
101 #ifdef INET6
102 static void
103 ifa_scope(struct sockaddr_in6 *, unsigned int);
104 #endif
105 
106 struct priv {
107 	int pf_inet6_fd;
108 };
109 
110 int
111 if_init(__unused struct interface *iface)
112 {
113 	/* BSD promotes secondary address by default */
114 	return 0;
115 }
116 
117 int
118 if_conf(__unused struct interface *iface)
119 {
120 	/* No extra checks needed on BSD */
121 	return 0;
122 }
123 
124 int
125 if_opensockets_os(struct dhcpcd_ctx *ctx)
126 {
127 	struct priv *priv;
128 #if defined(RO_MSGFILTER) || defined(ROUTE_MSGFILTER)
129 	unsigned char msgfilter[] = {
130 	    RTM_IFINFO,
131 #ifdef RTM_IFANNOUNCE
132 	    RTM_IFANNOUNCE,
133 #endif
134 	    RTM_ADD, RTM_CHANGE, RTM_DELETE,
135 #ifdef RTM_CHGADDR
136 	    RTM_CHGADDR,
137 #endif
138 	    RTM_NEWADDR, RTM_DELADDR
139 	};
140 #ifdef ROUTE_MSGFILTER
141 	unsigned int i, msgfilter_mask;
142 #endif
143 #endif
144 
145 	if ((priv = malloc(sizeof(*priv))) == NULL)
146 		return -1;
147 	ctx->priv = priv;
148 
149 #ifdef INET6
150 	priv->pf_inet6_fd = xsocket(PF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
151 	/* Don't return an error so we at least work on kernels witout INET6
152 	 * even though we expect INET6 support.
153 	 * We will fail noisily elsewhere anyway. */
154 #else
155 	priv->pf_inet6_fd = -1;
156 #endif
157 
158 #define SOCK_FLAGS	(SOCK_CLOEXEC | SOCK_NONBLOCK)
159 	ctx->link_fd = xsocket(PF_ROUTE, SOCK_RAW | SOCK_FLAGS, AF_UNSPEC);
160 #undef SOCK_FLAGS
161 	if (ctx->link_fd == -1)
162 		return -1;
163 
164 #if defined(RO_MSGFILTER)
165 	if (setsockopt(ctx->link_fd, PF_ROUTE, RO_MSGFILTER,
166 	    &msgfilter, sizeof(msgfilter)) == -1)
167 		logerr(__func__);
168 #elif defined(ROUTE_MSGFILTER)
169 	/* Convert the array into a bitmask. */
170 	msgfilter_mask = 0;
171 	for (i = 0; i < __arraycount(msgfilter); i++)
172 		msgfilter_mask |= ROUTE_FILTER(msgfilter[i]);
173 	if (setsockopt(ctx->link_fd, PF_ROUTE, ROUTE_MSGFILTER,
174 	    &msgfilter_mask, sizeof(msgfilter_mask)) == -1)
175 		logerr(__func__);
176 #endif
177 
178 	return 0;
179 }
180 
181 void
182 if_closesockets_os(struct dhcpcd_ctx *ctx)
183 {
184 	struct priv *priv;
185 
186 	priv = (struct priv *)ctx->priv;
187 	if (priv->pf_inet6_fd != -1)
188 		close(priv->pf_inet6_fd);
189 }
190 
191 #if defined(INET) || defined(INET6)
192 static void
193 if_linkaddr(struct sockaddr_dl *sdl, const struct interface *ifp)
194 {
195 
196 	memset(sdl, 0, sizeof(*sdl));
197 	sdl->sdl_family = AF_LINK;
198 	sdl->sdl_len = sizeof(*sdl);
199 	sdl->sdl_nlen = sdl->sdl_alen = sdl->sdl_slen = 0;
200 	sdl->sdl_index = (unsigned short)ifp->index;
201 }
202 #endif
203 
204 #if defined(SIOCG80211NWID) || defined(SIOCGETVLAN)
205 static int if_direct_ioctl(int s, const char *ifname,
206     unsigned long cmd, void *data)
207 {
208 
209 	strlcpy(data, ifname, IFNAMSIZ);
210 	return ioctl(s, cmd, data);
211 }
212 
213 static int if_indirect_ioctl(int s, const char *ifname,
214     unsigned long cmd, void *data)
215 {
216 	struct ifreq ifr;
217 
218 	memset(&ifr, 0, sizeof(ifr));
219 	ifr.ifr_data = data;
220 	return if_direct_ioctl(s, ifname, cmd, &ifr);
221 }
222 #endif
223 
224 static int
225 if_getssid1(int s, const char *ifname, void *ssid)
226 {
227 	int retval = -1;
228 #if defined(SIOCG80211NWID)
229 	struct ieee80211_nwid nwid;
230 #elif defined(IEEE80211_IOC_SSID)
231 	struct ieee80211req ireq;
232 	char nwid[IEEE80211_NWID_LEN];
233 #endif
234 
235 #if defined(SIOCG80211NWID) /* NetBSD */
236 	memset(&nwid, 0, sizeof(nwid));
237 	if (if_indirect_ioctl(s, ifname, SIOCG80211NWID, &nwid) == 0) {
238 		if (ssid == NULL)
239 			retval = nwid.i_len;
240 		else if (nwid.i_len > IF_SSIDLEN)
241 			errno = ENOBUFS;
242 		else {
243 			retval = nwid.i_len;
244 			memcpy(ssid, nwid.i_nwid, nwid.i_len);
245 		}
246 	}
247 #elif defined(IEEE80211_IOC_SSID) /* FreeBSD */
248 	memset(&ireq, 0, sizeof(ireq));
249 	strlcpy(ireq.i_name, ifname, sizeof(ireq.i_name));
250 	ireq.i_type = IEEE80211_IOC_SSID;
251 	ireq.i_val = -1;
252 	memset(nwid, 0, sizeof(nwid));
253 	ireq.i_data = &nwid;
254 	if (ioctl(s, SIOCG80211, &ireq) == 0) {
255 		if (ssid == NULL)
256 			retval = ireq.i_len;
257 		else if (ireq.i_len > IF_SSIDLEN)
258 			errno = ENOBUFS;
259 		else  {
260 			retval = ireq.i_len;
261 			memcpy(ssid, nwid, ireq.i_len);
262 		}
263 	}
264 #else
265 	errno = ENOSYS;
266 #endif
267 
268 	return retval;
269 }
270 
271 int
272 if_getssid(struct interface *ifp)
273 {
274 	int r;
275 
276 	r = if_getssid1(ifp->ctx->pf_inet_fd, ifp->name, ifp->ssid);
277 	if (r != -1)
278 		ifp->ssid_len = (unsigned int)r;
279 	else
280 		ifp->ssid_len = 0;
281 	ifp->ssid[ifp->ssid_len] = '\0';
282 	return r;
283 }
284 
285 /*
286  * FreeBSD allows for Virtual Access Points
287  * We need to check if the interface is a Virtual Interface Master
288  * and if so, don't use it.
289  * This check is made by virtue of being a IEEE80211 device but
290  * returning the SSID gives an error.
291  */
292 int
293 if_vimaster(const struct dhcpcd_ctx *ctx, const char *ifname)
294 {
295 	int r;
296 	struct ifmediareq ifmr;
297 
298 	memset(&ifmr, 0, sizeof(ifmr));
299 	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
300 	r = ioctl(ctx->pf_inet_fd, SIOCGIFMEDIA, &ifmr);
301 	if (r == -1)
302 		return -1;
303 	if (ifmr.ifm_status & IFM_AVALID &&
304 	    IFM_TYPE(ifmr.ifm_active) == IFM_IEEE80211)
305 	{
306 		if (if_getssid1(ctx->pf_inet_fd, ifname, NULL) == -1)
307 			return 1;
308 	}
309 	return 0;
310 }
311 
312 unsigned short
313 if_vlanid(const struct interface *ifp)
314 {
315 #ifdef SIOCGETVLAN
316 	struct vlanreq vlr;
317 
318 	memset(&vlr, 0, sizeof(vlr));
319 	if (if_indirect_ioctl(ifp->ctx->pf_inet_fd,
320 	    ifp->name, SIOCGETVLAN, &vlr) != 0)
321 		return 0; /* 0 means no VLANID */
322 	return vlr.vlr_tag;
323 #elif defined(SIOCGVNETID)
324 	struct ifreq ifr;
325 
326 	memset(&ifr, 0, sizeof(ifr));
327 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
328 	if (ioctl(ifp->ctx->pf_inet_fd, SIOCGVNETID, &ifr) != 0)
329 		return 0; /* 0 means no VLANID */
330 	return ifr.ifr_vnetid;
331 #else
332 	UNUSED(ifp);
333 	return 0; /* 0 means no VLANID */
334 #endif
335 }
336 
337 static void
338 get_addrs(int type, const void *data, const struct sockaddr **sa)
339 {
340 	const char *cp;
341 	int i;
342 
343 	cp = data;
344 	for (i = 0; i < RTAX_MAX; i++) {
345 		if (type & (1 << i)) {
346 			sa[i] = (const struct sockaddr *)cp;
347 			RT_ADVANCE(cp, sa[i]);
348 		} else
349 			sa[i] = NULL;
350 	}
351 }
352 
353 #if defined(INET) || defined(INET6)
354 static struct interface *
355 if_findsdl(struct dhcpcd_ctx *ctx, const struct sockaddr_dl *sdl)
356 {
357 
358 	if (sdl->sdl_index)
359 		return if_findindex(ctx->ifaces, sdl->sdl_index);
360 
361 	if (sdl->sdl_nlen) {
362 		char ifname[IF_NAMESIZE];
363 
364 		memcpy(ifname, sdl->sdl_data, sdl->sdl_nlen);
365 		ifname[sdl->sdl_nlen] = '\0';
366 		return if_find(ctx->ifaces, ifname);
367 	}
368 	if (sdl->sdl_alen) {
369 		struct interface *ifp;
370 
371 		TAILQ_FOREACH(ifp, ctx->ifaces, next) {
372 			if (ifp->hwlen == sdl->sdl_alen &&
373 			    memcmp(ifp->hwaddr,
374 			    sdl->sdl_data, sdl->sdl_alen) == 0)
375 				return ifp;
376 		}
377 	}
378 
379 	errno = ENOENT;
380 	return NULL;
381 }
382 
383 static struct interface *
384 if_findsa(struct dhcpcd_ctx *ctx, const struct sockaddr *sa)
385 {
386 	if (sa == NULL) {
387 		errno = EINVAL;
388 		return NULL;
389 	}
390 
391 	switch (sa->sa_family) {
392 	case AF_LINK:
393 	{
394 		const struct sockaddr_dl *sdl;
395 
396 		sdl = (const void *)sa;
397 		return if_findsdl(ctx, sdl);
398 	}
399 #ifdef INET
400 	case AF_INET:
401 	{
402 		const struct sockaddr_in *sin;
403 		struct ipv4_addr *ia;
404 
405 		sin = (const void *)sa;
406 		if ((ia = ipv4_findmaskaddr(ctx, &sin->sin_addr)))
407 			return ia->iface;
408 		break;
409 	}
410 #endif
411 #ifdef INET6
412 	case AF_INET6:
413 	{
414 		const struct sockaddr_in6 *sin;
415 		struct ipv6_addr *ia;
416 
417 		sin = (const void *)sa;
418 		if ((ia = ipv6_findmaskaddr(ctx, &sin->sin6_addr)))
419 			return ia->iface;
420 		break;
421 	}
422 #endif
423 	default:
424 		errno = EAFNOSUPPORT;
425 		return NULL;
426 	}
427 
428 	errno = ENOENT;
429 	return NULL;
430 }
431 
432 static void
433 if_copysa(struct sockaddr *dst, const struct sockaddr *src)
434 {
435 
436 	assert(dst != NULL);
437 	assert(src != NULL);
438 
439 	memcpy(dst, src, src->sa_len);
440 #if defined(INET6) && defined(__KAME__)
441 	if (dst->sa_family == AF_INET6) {
442 		struct in6_addr *in6;
443 
444 		in6 = &satosin6(dst)->sin6_addr;
445 		if (IN6_IS_ADDR_LINKLOCAL(in6))
446 			in6->s6_addr[2] = in6->s6_addr[3] = '\0';
447 	}
448 #endif
449 }
450 
451 int
452 if_route(unsigned char cmd, const struct rt *rt)
453 {
454 	struct dhcpcd_ctx *ctx;
455 	struct rtm
456 	{
457 		struct rt_msghdr hdr;
458 		char buffer[sizeof(struct sockaddr_storage) * RTAX_MAX];
459 	} rtmsg;
460 	struct rt_msghdr *rtm = &rtmsg.hdr;
461 	char *bp = rtmsg.buffer;
462 	struct sockaddr_dl sdl;
463 	bool gateway_unspec;
464 
465 	assert(rt != NULL);
466 	ctx = rt->rt_ifp->ctx;
467 
468 	if ((cmd == RTM_ADD || cmd == RTM_DELETE || cmd == RTM_CHANGE) &&
469 	    ctx->options & DHCPCD_DAEMONISE &&
470 	    !(ctx->options & DHCPCD_DAEMONISED))
471 		ctx->options |= DHCPCD_RTM_PPID;
472 
473 #define ADDSA(sa) do {							      \
474 		memcpy(bp, (sa), (sa)->sa_len);				      \
475 		bp += RT_ROUNDUP((sa)->sa_len);				      \
476 	}  while (0 /* CONSTCOND */)
477 
478 	memset(&rtmsg, 0, sizeof(rtmsg));
479 	rtm->rtm_version = RTM_VERSION;
480 	rtm->rtm_type = cmd;
481 #ifdef __OpenBSD__
482 	rtm->rtm_pid = getpid();
483 #endif
484 	rtm->rtm_seq = ++ctx->seq;
485 	rtm->rtm_flags = (int)rt->rt_flags;
486 	rtm->rtm_addrs = RTA_DST;
487 #ifdef RTF_PINNED
488 	if (cmd != RTM_ADD)
489 		rtm->rtm_flags |= RTF_PINNED;
490 #endif
491 
492 	gateway_unspec = sa_is_unspecified(&rt->rt_gateway);
493 
494 	if (cmd == RTM_ADD || cmd == RTM_CHANGE) {
495 		bool netmask_bcast = sa_is_allones(&rt->rt_netmask);
496 
497 		rtm->rtm_flags |= RTF_UP;
498 		rtm->rtm_addrs |= RTA_GATEWAY;
499 		if (!(rtm->rtm_flags & RTF_REJECT) &&
500 		    !sa_is_loopback(&rt->rt_gateway))
501 		{
502 			rtm->rtm_index = (unsigned short)rt->rt_ifp->index;
503 			if (!gateway_unspec)
504 				rtm->rtm_addrs |= RTA_IFP;
505 			if (!sa_is_unspecified(&rt->rt_ifa))
506 				rtm->rtm_addrs |= RTA_IFA;
507 		}
508 		if (netmask_bcast)
509 			rtm->rtm_flags |= RTF_HOST;
510 		/* Network routes are cloning or connected if supported.
511 		 * All other routes are static. */
512 		if (gateway_unspec) {
513 #ifdef RTF_CLONING
514 			rtm->rtm_flags |= RTF_CLONING;
515 #endif
516 #ifdef RTF_CONNECTED
517 			rtm->rtm_flags |= RTF_CONNECTED;
518 #endif
519 #ifdef RTP_CONNECTED
520 			rtm->rtm_priority = RTP_CONNECTED;
521 #endif
522 #ifdef RTF_CLONING
523 			if (netmask_bcast) {
524 				/*
525 				 * We add a cloning network route for a single
526 				 * host. Traffic to the host will generate a
527 				 * cloned route and the hardware address will
528 				 * resolve correctly.
529 				 * It might be more correct to use RTF_HOST
530 				 * instead of RTF_CLONING, and that does work,
531 				 * but some OS generate an arp warning
532 				 * diagnostic which we don't want to do.
533 				 */
534 				rtm->rtm_flags &= ~RTF_HOST;
535 			}
536 #endif
537 		} else
538 			rtm->rtm_flags |= RTF_GATEWAY;
539 
540 		/* Emulate the kernel by marking address generated
541 		 * network routes non-static. */
542 		if (!(rt->rt_dflags & RTDF_IFA_ROUTE))
543 			rtm->rtm_flags |= RTF_STATIC;
544 
545 		if (rt->rt_mtu != 0) {
546 			rtm->rtm_inits |= RTV_MTU;
547 			rtm->rtm_rmx.rmx_mtu = rt->rt_mtu;
548 		}
549 	}
550 
551 	if (!(rtm->rtm_flags & RTF_HOST))
552 		rtm->rtm_addrs |= RTA_NETMASK;
553 
554 	if_linkaddr(&sdl, rt->rt_ifp);
555 
556 	ADDSA(&rt->rt_dest);
557 
558 	if (rtm->rtm_addrs & RTA_GATEWAY) {
559 		if (gateway_unspec)
560 			ADDSA((struct sockaddr *)&sdl);
561 		else {
562 			union sa_ss gateway;
563 
564 			if_copysa(&gateway.sa, &rt->rt_gateway);
565 #ifdef INET6
566 			if (gateway.sa.sa_family == AF_INET6)
567 				ifa_scope(&gateway.sin6, rt->rt_ifp->index);
568 #endif
569 			ADDSA(&gateway.sa);
570 		}
571 	}
572 
573 	if (rtm->rtm_addrs & RTA_NETMASK)
574 		ADDSA(&rt->rt_netmask);
575 
576 	if (rtm->rtm_addrs & RTA_IFP)
577 		ADDSA((struct sockaddr *)&sdl);
578 
579 	if (rtm->rtm_addrs & RTA_IFA)
580 		ADDSA(&rt->rt_ifa);
581 
582 #undef ADDSA
583 
584 	rtm->rtm_msglen = (unsigned short)(bp - (char *)rtm);
585 	if (write(ctx->link_fd, rtm, rtm->rtm_msglen) == -1)
586 		return -1;
587 	ctx->sseq = ctx->seq;
588 	return 0;
589 }
590 
591 static int
592 if_copyrt(struct dhcpcd_ctx *ctx, struct rt *rt, const struct rt_msghdr *rtm)
593 {
594 	const struct sockaddr *rti_info[RTAX_MAX];
595 
596 	if (~rtm->rtm_addrs & (RTA_DST | RTA_GATEWAY))
597 		return -1;
598 #ifdef RTF_CLONED
599 	if (rtm->rtm_flags & RTF_CLONED)
600 		return -1;
601 #endif
602 #ifdef RTF_LOCAL
603 	if (rtm->rtm_flags & RTF_LOCAL)
604 		return -1;
605 #endif
606 #ifdef RTF_BROADCAST
607 	if (rtm->rtm_flags & RTF_BROADCAST)
608 		return -1;
609 #endif
610 
611 	get_addrs(rtm->rtm_addrs, rtm + 1, rti_info);
612 	memset(rt, 0, sizeof(*rt));
613 
614 	rt->rt_flags = (unsigned int)rtm->rtm_flags;
615 	if_copysa(&rt->rt_dest, rti_info[RTAX_DST]);
616 	if (rtm->rtm_addrs & RTA_NETMASK) {
617 		if_copysa(&rt->rt_netmask, rti_info[RTAX_NETMASK]);
618 		if (rt->rt_netmask.sa_family == 255) /* Why? */
619 			rt->rt_netmask.sa_family = rt->rt_dest.sa_family;
620 	}
621 	/* dhcpcd likes an unspecified gateway to indicate via the link. */
622 	if (rt->rt_flags & RTF_GATEWAY &&
623 	    rti_info[RTAX_GATEWAY]->sa_family != AF_LINK)
624 		if_copysa(&rt->rt_gateway, rti_info[RTAX_GATEWAY]);
625 	if (rtm->rtm_addrs & RTA_IFA)
626 		if_copysa(&rt->rt_ifa, rti_info[RTAX_IFA]);
627 	rt->rt_mtu = (unsigned int)rtm->rtm_rmx.rmx_mtu;
628 
629 	if (rtm->rtm_index)
630 		rt->rt_ifp = if_findindex(ctx->ifaces, rtm->rtm_index);
631 	else if (rtm->rtm_addrs & RTA_IFP)
632 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_IFP]);
633 	else if (rtm->rtm_addrs & RTA_GATEWAY)
634 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_GATEWAY]);
635 	else
636 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_DST]);
637 
638 	if (rt->rt_ifp == NULL) {
639 		errno = ESRCH;
640 		return -1;
641 	}
642 	return 0;
643 }
644 
645 int
646 if_initrt(struct dhcpcd_ctx *ctx, int af)
647 {
648 	struct rt_msghdr *rtm;
649 	int mib[6];
650 	size_t needed;
651 	char *buf, *p, *end;
652 	struct rt rt;
653 
654 	rt_headclear(&ctx->kroutes, af);
655 
656 	mib[0] = CTL_NET;
657 	mib[1] = PF_ROUTE;
658 	mib[2] = 0;
659 	mib[3] = af;
660 	mib[4] = NET_RT_DUMP;
661 	mib[5] = 0;
662 
663 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
664 		return -1;
665 	if (needed == 0)
666 		return 0;
667 	if ((buf = malloc(needed)) == NULL)
668 		return -1;
669 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1) {
670 		free(buf);
671 		return -1;
672 	}
673 
674 	end = buf + needed;
675 	for (p = buf; p < end; p += rtm->rtm_msglen) {
676 		rtm = (void *)p;
677 		if (if_copyrt(ctx, &rt, rtm) == 0) {
678 			rt.rt_dflags |= RTDF_INIT;
679 			rt_recvrt(RTM_ADD, &rt);
680 		}
681 	}
682 	free(buf);
683 	return 0;
684 }
685 
686 #endif
687 
688 #ifdef INET
689 int
690 if_address(unsigned char cmd, const struct ipv4_addr *ia)
691 {
692 	int r;
693 	struct in_aliasreq ifra;
694 
695 	memset(&ifra, 0, sizeof(ifra));
696 	strlcpy(ifra.ifra_name, ia->iface->name, sizeof(ifra.ifra_name));
697 
698 #define ADDADDR(var, addr) do {						      \
699 		(var)->sin_family = AF_INET;				      \
700 		(var)->sin_len = sizeof(*(var));			      \
701 		(var)->sin_addr = *(addr);				      \
702 	} while (/*CONSTCOND*/0)
703 	ADDADDR(&ifra.ifra_addr, &ia->addr);
704 	ADDADDR(&ifra.ifra_mask, &ia->mask);
705 	if (cmd == RTM_NEWADDR && ia->brd.s_addr != INADDR_ANY)
706 		ADDADDR(&ifra.ifra_broadaddr, &ia->brd);
707 #undef ADDADDR
708 
709 	r = ioctl(ia->iface->ctx->pf_inet_fd,
710 	    cmd == RTM_DELADDR ? SIOCDIFADDR : SIOCAIFADDR, &ifra);
711 	return r;
712 }
713 
714 
715 
716 #if !(defined(HAVE_IFADDRS_ADDRFLAGS) && defined(HAVE_IFAM_ADDRFLAGS))
717 int
718 if_addrflags(const struct interface *ifp, const struct in_addr *addr,
719     __unused const char *alias)
720 {
721 #ifdef SIOCGIFAFLAG_IN
722 	struct ifreq ifr;
723 	struct sockaddr_in *sin;
724 
725 	memset(&ifr, 0, sizeof(ifr));
726 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
727 	sin = (void *)&ifr.ifr_addr;
728 	sin->sin_family = AF_INET;
729 	sin->sin_addr = *addr;
730 	if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFAFLAG_IN, &ifr) == -1)
731 		return -1;
732 	return ifr.ifr_addrflags;
733 #else
734 	UNUSED(ifp);
735 	UNUSED(addr);
736 	return 0;
737 #endif
738 }
739 #endif
740 #endif /* INET */
741 
742 #ifdef INET6
743 static void
744 ifa_scope(struct sockaddr_in6 *sin, unsigned int ifindex)
745 {
746 
747 #ifdef __KAME__
748 	/* KAME based systems want to store the scope inside the sin6_addr
749 	 * for link local addresses */
750 	if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr)) {
751 		uint16_t scope = htons((uint16_t)ifindex);
752 		memcpy(&sin->sin6_addr.s6_addr[2], &scope,
753 		    sizeof(scope));
754 	}
755 	sin->sin6_scope_id = 0;
756 #else
757 	if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr))
758 		sin->sin6_scope_id = ifindex;
759 	else
760 		sin->sin6_scope_id = 0;
761 #endif
762 }
763 
764 int
765 if_address6(unsigned char cmd, const struct ipv6_addr *ia)
766 {
767 	struct in6_aliasreq ifa;
768 	struct in6_addr mask;
769 	struct priv *priv;
770 
771 	priv = (struct priv *)ia->iface->ctx->priv;
772 
773 	memset(&ifa, 0, sizeof(ifa));
774 	strlcpy(ifa.ifra_name, ia->iface->name, sizeof(ifa.ifra_name));
775 	/*
776 	 * We should not set IN6_IFF_TENTATIVE as the kernel should be
777 	 * able to work out if it's a new address or not.
778 	 *
779 	 * We should set IN6_IFF_AUTOCONF, but the kernel won't let us.
780 	 * This is probably a safety measure, but still it's not entirely right
781 	 * either.
782 	 */
783 #if 0
784 	if (ia->autoconf)
785 		ifa.ifra_flags |= IN6_IFF_AUTOCONF;
786 #endif
787 #ifdef IPV6_MANGETEMPADDR
788 	if (ia->flags & IPV6_AF_TEMPORARY)
789 		ifa.ifra_flags |= IN6_IFF_TEMPORARY;
790 #endif
791 
792 #define ADDADDR(v, addr) {						      \
793 		(v)->sin6_family = AF_INET6;				      \
794 		(v)->sin6_len = sizeof(*v);				      \
795 		(v)->sin6_addr = *(addr);				      \
796 	}
797 
798 	ADDADDR(&ifa.ifra_addr, &ia->addr);
799 	ifa_scope(&ifa.ifra_addr, ia->iface->index);
800 	ipv6_mask(&mask, ia->prefix_len);
801 	ADDADDR(&ifa.ifra_prefixmask, &mask);
802 
803 #undef ADDADDR
804 
805 	/*
806 	 * Every BSD kernel wants to add the prefix of the address to it's
807 	 * list of RA received prefixes.
808 	 * THIS IS WRONG because there (as the comments in the kernel state)
809 	 * is no API for managing prefix lifetime and the kernel should not
810 	 * pretend it's from a RA either.
811 	 *
812 	 * The issue is that the very first assigned prefix will inherit the
813 	 * lifetime of the address, but any subsequent alteration of the
814 	 * address OR it's lifetime will not affect the prefix lifetime.
815 	 * As such, we cannot stop the prefix from timing out and then
816 	 * constantly removing the prefix route dhcpcd is capable of adding
817 	 * in it's absense.
818 	 *
819 	 * What we can do to mitigate the issue is to add the address with
820 	 * infinite lifetimes, so the prefix route will never time out.
821 	 * Once done, we can then set lifetimes on the address and all is good.
822 	 * The downside of this approach is that we need to manually remove
823 	 * the kernel route because it has no lifetime, but this is OK as
824 	 * dhcpcd will handle this too.
825 	 *
826 	 * This issue is discussed on the NetBSD mailing lists here:
827 	 * http://mail-index.netbsd.org/tech-net/2016/08/05/msg006044.html
828 	 *
829 	 * Fixed in NetBSD-7.99.36
830 	 * NOT fixed in FreeBSD - bug 195197
831 	 * Fixed in OpenBSD-5.9
832 	 */
833 
834 #if !((defined(__NetBSD_Version__) && __NetBSD_Version__ >= 799003600) || \
835       (defined(__OpenBSD__) && OpenBSD >= 201605))
836 	if (cmd == RTM_NEWADDR && !(ia->flags & IPV6_AF_ADDED)) {
837 		ifa.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
838 		ifa.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
839 		(void)ioctl(priv->pf_inet6_fd, SIOCAIFADDR_IN6, &ifa);
840 	}
841 #endif
842 
843 #if defined(__OpenBSD__) && OpenBSD <= 201705
844 	/* BUT OpenBSD older than 6.2 does not reset the address lifetime
845 	 * for subsequent calls...
846 	 * Luckily dhcpcd will remove the lease when it expires so
847 	 * just set an infinite lifetime, unless a temporary address. */
848 	if (ifa.ifra_flags & IN6_IFF_PRIVACY) {
849 		ifa.ifra_lifetime.ia6t_vltime = ia->prefix_vltime;
850 		ifa.ifra_lifetime.ia6t_pltime = ia->prefix_pltime;
851 	} else {
852 		ifa.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
853 		ifa.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
854 	}
855 #else
856 	ifa.ifra_lifetime.ia6t_vltime = ia->prefix_vltime;
857 	ifa.ifra_lifetime.ia6t_pltime = ia->prefix_pltime;
858 #endif
859 
860 	return ioctl(priv->pf_inet6_fd,
861 	    cmd == RTM_DELADDR ? SIOCDIFADDR_IN6 : SIOCAIFADDR_IN6, &ifa);
862 }
863 
864 #if !(defined(HAVE_IFADDRS_ADDRFLAGS) && defined(HAVE_IFAM_ADDRFLAGS))
865 int
866 if_addrflags6(const struct interface *ifp, const struct in6_addr *addr,
867     __unused const char *alias)
868 {
869 	int flags;
870 	struct in6_ifreq ifr6;
871 	struct priv *priv;
872 
873 	memset(&ifr6, 0, sizeof(ifr6));
874 	strlcpy(ifr6.ifr_name, ifp->name, sizeof(ifr6.ifr_name));
875 	ifr6.ifr_addr.sin6_family = AF_INET6;
876 	ifr6.ifr_addr.sin6_addr = *addr;
877 	ifa_scope(&ifr6.ifr_addr, ifp->index);
878 	priv = (struct priv *)ifp->ctx->priv;
879 	if (ioctl(priv->pf_inet6_fd, SIOCGIFAFLAG_IN6, &ifr6) != -1)
880 		flags = ifr6.ifr_ifru.ifru_flags6;
881 	else
882 		flags = -1;
883 	return flags;
884 }
885 #endif
886 
887 int
888 if_getlifetime6(struct ipv6_addr *ia)
889 {
890 	struct in6_ifreq ifr6;
891 	time_t t;
892 	struct in6_addrlifetime *lifetime;
893 	struct priv *priv;
894 
895 	memset(&ifr6, 0, sizeof(ifr6));
896 	strlcpy(ifr6.ifr_name, ia->iface->name, sizeof(ifr6.ifr_name));
897 	ifr6.ifr_addr.sin6_family = AF_INET6;
898 	ifr6.ifr_addr.sin6_addr = ia->addr;
899 	ifa_scope(&ifr6.ifr_addr, ia->iface->index);
900 	priv = (struct priv *)ia->iface->ctx->priv;
901 	if (ioctl(priv->pf_inet6_fd, SIOCGIFALIFETIME_IN6, &ifr6) == -1)
902 		return -1;
903 
904 	t = time(NULL);
905 	lifetime = &ifr6.ifr_ifru.ifru_lifetime;
906 
907 	if (lifetime->ia6t_preferred)
908 		ia->prefix_pltime = (uint32_t)(lifetime->ia6t_preferred -
909 		    MIN(t, lifetime->ia6t_preferred));
910 	else
911 		ia->prefix_pltime = ND6_INFINITE_LIFETIME;
912 	if (lifetime->ia6t_expire) {
913 		ia->prefix_vltime = (uint32_t)(lifetime->ia6t_expire -
914 		    MIN(t, lifetime->ia6t_expire));
915 		/* Calculate the created time */
916 		clock_gettime(CLOCK_MONOTONIC, &ia->created);
917 		ia->created.tv_sec -= lifetime->ia6t_vltime - ia->prefix_vltime;
918 	} else
919 		ia->prefix_vltime = ND6_INFINITE_LIFETIME;
920 	return 0;
921 }
922 #endif
923 
924 static void
925 if_announce(struct dhcpcd_ctx *ctx, const struct if_announcemsghdr *ifan)
926 {
927 
928 	switch(ifan->ifan_what) {
929 	case IFAN_ARRIVAL:
930 		dhcpcd_handleinterface(ctx, 1, ifan->ifan_name);
931 		break;
932 	case IFAN_DEPARTURE:
933 		dhcpcd_handleinterface(ctx, -1, ifan->ifan_name);
934 		break;
935 	}
936 }
937 
938 static void
939 if_ifinfo(struct dhcpcd_ctx *ctx, const struct if_msghdr *ifm)
940 {
941 	struct interface *ifp;
942 	int link_state;
943 
944 	if ((ifp = if_findindex(ctx->ifaces, ifm->ifm_index)) == NULL)
945 		return;
946 	switch (ifm->ifm_data.ifi_link_state) {
947 	case LINK_STATE_DOWN:
948 		link_state = LINK_DOWN;
949 		break;
950 	case LINK_STATE_UP:
951 		/* dhcpcd considers the link down if IFF_UP is not set. */
952 		link_state = ifm->ifm_flags & IFF_UP ? LINK_UP : LINK_DOWN;
953 		break;
954 	default:
955 		/* handle_carrier will re-load the interface flags and check for
956 		 * IFF_RUNNING as some drivers that don't handle link state also
957 		 * don't set IFF_RUNNING when this routing message is generated.
958 		 * As such, it is a race ...*/
959 		link_state = LINK_UNKNOWN;
960 		break;
961 	}
962 	dhcpcd_handlecarrier(ctx, link_state,
963 	    (unsigned int)ifm->ifm_flags, ifp->name);
964 }
965 
966 static int
967 if_ownmsgpid(struct dhcpcd_ctx *ctx, pid_t pid, int seq)
968 {
969 
970 	/* Ignore messages generated by us */
971 	if (getpid() == pid) {
972 		ctx->options &= ~DHCPCD_RTM_PPID;
973 		return 1;
974 	}
975 
976 	/* Ignore messages sent by the parent after forking */
977 	if ((ctx->options &
978 	    (DHCPCD_RTM_PPID | DHCPCD_DAEMONISED)) ==
979 	    (DHCPCD_RTM_PPID | DHCPCD_DAEMONISED) &&
980 	    ctx->ppid == pid)
981 	{
982 		/* If this is the last successful message sent,
983 		 * clear the check flag as it's possible another
984 		 * process could re-use the same pid and also
985 		 * manipulate the routing table. */
986 		if (ctx->pseq == seq)
987 			ctx->options &= ~DHCPCD_RTM_PPID;
988 		return 1;
989 	}
990 
991 	/* Not a message we made. */
992 	return 0;
993 }
994 
995 static void
996 if_rtm(struct dhcpcd_ctx *ctx, const struct rt_msghdr *rtm)
997 {
998 	struct rt rt;
999 
1000 	if (if_ownmsgpid(ctx, rtm->rtm_pid, rtm->rtm_seq))
1001 		return;
1002 
1003 	/* Ignore errors. */
1004 	if (rtm->rtm_errno != 0)
1005 		return;
1006 
1007 	if (if_copyrt(ctx, &rt, rtm) == -1)
1008 		return;
1009 
1010 #ifdef INET6
1011 	/*
1012 	 * BSD announces host routes.
1013 	 * As such, we should be notified of reachability by its
1014 	 * existance with a hardware address.
1015 	 */
1016 	if (rt.rt_dest.sa_family == AF_INET6 && rt.rt_flags & RTF_HOST) {
1017 		struct sockaddr_in6 dest;
1018 		struct sockaddr_dl sdl;
1019 
1020 		memcpy(&dest, &rt.rt_dest, rt.rt_dest.sa_len);
1021 		if (rt.rt_gateway.sa_family == AF_LINK)
1022 			memcpy(&sdl, &rt.rt_gateway, rt.rt_gateway.sa_len);
1023 		else
1024 			sdl.sdl_alen = 0;
1025 		ipv6nd_neighbour(ctx, &dest.sin6_addr,
1026 		    rtm->rtm_type != RTM_DELETE && sdl.sdl_alen ?
1027 		    IPV6ND_REACHABLE : 0);
1028 	}
1029 #endif
1030 
1031 	rt_recvrt(rtm->rtm_type, &rt);
1032 }
1033 
1034 static void
1035 if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
1036 {
1037 	struct interface *ifp;
1038 	const struct sockaddr *rti_info[RTAX_MAX];
1039 	int addrflags;
1040 	pid_t pid;
1041 
1042 	if ((ifp = if_findindex(ctx->ifaces, ifam->ifam_index)) == NULL)
1043 		return;
1044 	get_addrs(ifam->ifam_addrs, ifam + 1, rti_info);
1045 	if (rti_info[RTAX_IFA] == NULL)
1046 		return;
1047 
1048 #ifdef HAVE_IFAM_PID
1049 	if (if_ownmsgpid(ctx, ifam->ifam_pid, 0)) {
1050 #ifdef HAVE_IFAM_ADDRFLAGS
1051 		/* If the kernel isn't doing DAD for the newly added
1052 		 * address we need to let it through. */
1053 		if (ifam->ifam_type != RTM_NEWADDR)
1054 			return;
1055 		switch (rti_info[RTAX_IFA]->sa_family) {
1056 		case AF_INET:
1057 			if (ifam->ifam_addrflags & IN_IFF_TENTATIVE)
1058 				return;
1059 			break;
1060 		case AF_INET6:
1061 			if (ifam->ifam_addrflags & IN6_IFF_TENTATIVE)
1062 				return;
1063 			break;
1064 		default:
1065 			return;
1066 		}
1067 #endif
1068 	}
1069 	pid = ifam->ifam_pid;
1070 #else
1071 	pid = 0;
1072 #endif
1073 
1074 #ifdef HAVE_IFAM_ADDRFLAGS
1075 	addrflags = ifam->ifam_addrflags;
1076 #endif
1077 	switch (rti_info[RTAX_IFA]->sa_family) {
1078 	case AF_LINK:
1079 	{
1080 		struct sockaddr_dl sdl;
1081 
1082 #ifdef RTM_CHGADDR
1083 		if (ifam->ifam_type != RTM_CHGADDR)
1084 			break;
1085 #else
1086 		if (ifam->ifam_type != RTM_NEWADDR)
1087 			break;
1088 #endif
1089 		memcpy(&sdl, rti_info[RTAX_IFA], rti_info[RTAX_IFA]->sa_len);
1090 		dhcpcd_handlehwaddr(ctx, ifp->name, CLLADDR(&sdl),sdl.sdl_alen);
1091 		break;
1092 	}
1093 #ifdef INET
1094 	case AF_INET:
1095 	case 255: /* FIXME: Why 255? */
1096 	{
1097 		const struct sockaddr_in *sin;
1098 		struct in_addr addr, mask, bcast;
1099 
1100 		sin = (const void *)rti_info[RTAX_IFA];
1101 		addr.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1102 		    sin->sin_addr.s_addr : INADDR_ANY;
1103 		sin = (const void *)rti_info[RTAX_NETMASK];
1104 		mask.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1105 		    sin->sin_addr.s_addr : INADDR_ANY;
1106 		sin = (const void *)rti_info[RTAX_BRD];
1107 		bcast.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1108 		    sin->sin_addr.s_addr : INADDR_ANY;
1109 
1110 #if defined(__FreeBSD__) || defined(__DragonFly__)
1111 		/* FreeBSD sends RTM_DELADDR for each assigned address
1112 		 * to an interface just brought down.
1113 		 * This is wrong, because the address still exists.
1114 		 * So we need to ignore it.
1115 		 * Oddly enough this only happens for INET addresses. */
1116 		if (ifam->ifam_type == RTM_DELADDR) {
1117 			struct ifreq ifr;
1118 			struct sockaddr_in *ifr_sin;
1119 
1120 			memset(&ifr, 0, sizeof(ifr));
1121 			strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
1122 			ifr_sin = (void *)&ifr.ifr_addr;
1123 			ifr_sin->sin_family = AF_INET;
1124 			ifr_sin->sin_addr = addr;
1125 			if (ioctl(ctx->pf_inet_fd, SIOCGIFADDR, &ifr) == 0) {
1126 				logwarnx("%s: ignored false RTM_DELADDR for %s",
1127 				    ifp->name, inet_ntoa(addr));
1128 				break;
1129 			}
1130 		}
1131 #endif
1132 
1133 #ifndef HAVE_IFAM_ADDRFLAGS
1134 		if (ifam->ifam_type == RTM_DELADDR)
1135 			addrflags = 0 ;
1136 		else if ((addrflags = if_addrflags(ifp, &addr, NULL)) == -1) {
1137 			logerr("%s: if_addrflags: %s",
1138 			    ifp->name, inet_ntoa(addr));
1139 			break;
1140 		}
1141 #endif
1142 
1143 		ipv4_handleifa(ctx, ifam->ifam_type, NULL, ifp->name,
1144 		    &addr, &mask, &bcast, addrflags, pid);
1145 		break;
1146 	}
1147 #endif
1148 #ifdef INET6
1149 	case AF_INET6:
1150 	{
1151 		struct in6_addr addr6, mask6;
1152 		const struct sockaddr_in6 *sin6;
1153 
1154 		sin6 = (const void *)rti_info[RTAX_IFA];
1155 		addr6 = sin6->sin6_addr;
1156 		sin6 = (const void *)rti_info[RTAX_NETMASK];
1157 		mask6 = sin6->sin6_addr;
1158 
1159 #ifndef HAVE_IFAM_ADDRFLAGS
1160 		if (ifam->ifam_type == RTM_DELADDR)
1161 		    addrflags = 0;
1162 		else if ((addrflags = if_addrflags6(ifp, &addr6, NULL)) == -1) {
1163 			logerr("%s: if_addrflags6", ifp->name);
1164 			break;
1165 		}
1166 #endif
1167 
1168 #ifdef __KAME__
1169 		if (IN6_IS_ADDR_LINKLOCAL(&addr6))
1170 			/* Remove the scope from the address */
1171 			addr6.s6_addr[2] = addr6.s6_addr[3] = '\0';
1172 #endif
1173 
1174 		ipv6_handleifa(ctx, ifam->ifam_type, NULL,
1175 		    ifp->name, &addr6, ipv6_prefixlen(&mask6), addrflags, pid);
1176 		break;
1177 	}
1178 #endif
1179 	}
1180 }
1181 
1182 static void
1183 if_dispatch(struct dhcpcd_ctx *ctx, const struct rt_msghdr *rtm)
1184 {
1185 
1186 	if (rtm->rtm_version != RTM_VERSION)
1187 		return;
1188 
1189 	switch(rtm->rtm_type) {
1190 #ifdef RTM_IFANNOUNCE
1191 	case RTM_IFANNOUNCE:
1192 		if_announce(ctx, (const void *)rtm);
1193 		break;
1194 #endif
1195 	case RTM_IFINFO:
1196 		if_ifinfo(ctx, (const void *)rtm);
1197 		break;
1198 	case RTM_ADD:		/* FALLTHROUGH */
1199 	case RTM_CHANGE:	/* FALLTHROUGH */
1200 	case RTM_DELETE:
1201 		if_rtm(ctx, (const void *)rtm);
1202 		break;
1203 #ifdef RTM_CHGADDR
1204 	case RTM_CHGADDR:	/* FALLTHROUGH */
1205 #endif
1206 	case RTM_DELADDR:	/* FALLTHROUGH */
1207 	case RTM_NEWADDR:
1208 		if_ifa(ctx, (const void *)rtm);
1209 		break;
1210 #ifdef RTM_DESYNC
1211 	case RTM_DESYNC:
1212 		dhcpcd_linkoverflow(ctx);
1213 		break;
1214 #endif
1215 	}
1216 }
1217 
1218 int
1219 if_handlelink(struct dhcpcd_ctx *ctx)
1220 {
1221 	struct msghdr msg;
1222 	ssize_t len;
1223 
1224 	memset(&msg, 0, sizeof(msg));
1225 	msg.msg_iov = ctx->iov;
1226 	msg.msg_iovlen = 1;
1227 
1228 	len = recvmsg_realloc(ctx->link_fd, &msg, 0);
1229 	if (len == -1)
1230 		return -1;
1231 	if (len != 0)
1232 		if_dispatch(ctx, ctx->iov[0].iov_base);
1233 	return 0;
1234 }
1235 
1236 #ifndef SYS_NMLN	/* OSX */
1237 #  define SYS_NMLN 256
1238 #endif
1239 #ifndef HW_MACHINE_ARCH
1240 #  ifdef HW_MODEL	/* OpenBSD */
1241 #    define HW_MACHINE_ARCH HW_MODEL
1242 #  endif
1243 #endif
1244 int
1245 if_machinearch(char *str, size_t len)
1246 {
1247 	int mib[2] = { CTL_HW, HW_MACHINE_ARCH };
1248 	char march[SYS_NMLN];
1249 	size_t marchlen = sizeof(march);
1250 
1251 	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]),
1252 	    march, &marchlen, NULL, 0) != 0)
1253 		return -1;
1254 	return snprintf(str, len, ":%s", march);
1255 }
1256 
1257 #ifdef INET6
1258 #if (defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)) || \
1259     defined(IPV6CTL_USETEMPADDR) || defined(IPV6CTL_TEMPVLTIME)
1260 #define get_inet6_sysctl(code) inet6_sysctl(code, 0, 0)
1261 #define set_inet6_sysctl(code, val) inet6_sysctl(code, val, 1)
1262 static int
1263 inet6_sysctl(int code, int val, int action)
1264 {
1265 	int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
1266 	size_t size;
1267 
1268 	mib[3] = code;
1269 	size = sizeof(val);
1270 	if (action) {
1271 		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]),
1272 		    NULL, 0, &val, size) == -1)
1273 			return -1;
1274 		return 0;
1275 	}
1276 	if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), &val, &size, NULL, 0) == -1)
1277 		return -1;
1278 	return val;
1279 }
1280 #endif
1281 
1282 #ifdef IPV6_MANAGETEMPADDR
1283 #ifndef IPV6CTL_TEMPVLTIME
1284 #define get_inet6_sysctlbyname(code) inet6_sysctlbyname(code, 0, 0)
1285 #define set_inet6_sysctlbyname(code, val) inet6_sysctlbyname(code, val, 1)
1286 static int
1287 inet6_sysctlbyname(const char *name, int val, int action)
1288 {
1289 	size_t size;
1290 
1291 	size = sizeof(val);
1292 	if (action) {
1293 		if (sysctlbyname(name, NULL, 0, &val, size) == -1)
1294 			return -1;
1295 		return 0;
1296 	}
1297 	if (sysctlbyname(name, &val, &size, NULL, 0) == -1)
1298 		return -1;
1299 	return val;
1300 }
1301 #endif
1302 
1303 int
1304 ip6_use_tempaddr(__unused const char *ifname)
1305 {
1306 	int val;
1307 
1308 #ifdef IPV6CTL_USETEMPADDR
1309 	val = get_inet6_sysctl(IPV6CTL_USETEMPADDR);
1310 #else
1311 	val = get_inet6_sysctlbyname("net.inet6.ip6.use_tempaddr");
1312 #endif
1313 	return val == -1 ? 0 : val;
1314 }
1315 
1316 int
1317 ip6_temp_preferred_lifetime(__unused const char *ifname)
1318 {
1319 	int val;
1320 
1321 #ifdef IPV6CTL_TEMPPLTIME
1322 	val = get_inet6_sysctl(IPV6CTL_TEMPPLTIME);
1323 #else
1324 	val = get_inet6_sysctlbyname("net.inet6.ip6.temppltime");
1325 #endif
1326 	return val < 0 ? TEMP_PREFERRED_LIFETIME : val;
1327 }
1328 
1329 int
1330 ip6_temp_valid_lifetime(__unused const char *ifname)
1331 {
1332 	int val;
1333 
1334 #ifdef IPV6CTL_TEMPVLTIME
1335 	val = get_inet6_sysctl(IPV6CTL_TEMPVLTIME);
1336 #else
1337 	val = get_inet6_sysctlbyname("net.inet6.ip6.tempvltime");
1338 #endif
1339 	return val < 0 ? TEMP_VALID_LIFETIME : val;
1340 }
1341 #endif
1342 
1343 #ifdef SIOCIFAFATTACH
1344 static int
1345 af_attach(int s, const struct interface *ifp, int af)
1346 {
1347 	struct if_afreq ifar;
1348 
1349 	strlcpy(ifar.ifar_name, ifp->name, sizeof(ifar.ifar_name));
1350 	ifar.ifar_af = af;
1351 	return ioctl(s, SIOCIFAFATTACH, (void *)&ifar);
1352 }
1353 #endif
1354 
1355 #ifdef SIOCGIFXFLAGS
1356 static int
1357 set_ifxflags(int s, const struct interface *ifp)
1358 {
1359 	struct ifreq ifr;
1360 	int flags;
1361 
1362 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
1363 	if (ioctl(s, SIOCGIFXFLAGS, (void *)&ifr) == -1)
1364 		return -1;
1365 	flags = ifr.ifr_flags;
1366 #ifdef IFXF_NOINET6
1367 	flags &= ~IFXF_NOINET6;
1368 #endif
1369 	/*
1370 	 * If not doing autoconf, don't disable the kernel from doing it.
1371 	 * If we need to, we should have another option actively disable it.
1372 	 */
1373 	if (ifp->options->options & DHCPCD_IPV6RS)
1374 		flags &= ~IFXF_AUTOCONF6;
1375 	if (ifr.ifr_flags == flags)
1376 		return 0;
1377 	ifr.ifr_flags = flags;
1378 	return ioctl(s, SIOCSIFXFLAGS, (void *)&ifr);
1379 }
1380 #endif
1381 
1382 /* OpenBSD removed ND6 flags entirely, so we need to check for their
1383  * existance. */
1384 #if defined(ND6_IFF_AUTO_LINKLOCAL) || \
1385     defined(ND6_IFF_PERFORMNUD) || \
1386     defined(ND6_IFF_ACCEPT_RTADV) || \
1387     defined(ND6_IFF_OVERRIDE_RTADV) || \
1388     defined(ND6_IFF_IFDISABLED)
1389 #define	ND6_NDI_FLAGS
1390 #endif
1391 
1392 void
1393 if_setup_inet6(const struct interface *ifp)
1394 {
1395 	struct priv *priv;
1396 	int s;
1397 #ifdef ND6_NDI_FLAGS
1398 	struct in6_ndireq nd;
1399 	int flags;
1400 #endif
1401 
1402 	priv = (struct priv *)ifp->ctx->priv;
1403 	s = priv->pf_inet6_fd;
1404 
1405 #ifdef ND6_NDI_FLAGS
1406 	memset(&nd, 0, sizeof(nd));
1407 	strlcpy(nd.ifname, ifp->name, sizeof(nd.ifname));
1408 	if (ioctl(s, SIOCGIFINFO_IN6, &nd) == -1)
1409 		logerr("%s: SIOCGIFINFO_FLAGS", ifp->name);
1410 	flags = (int)nd.ndi.flags;
1411 #endif
1412 
1413 #ifdef ND6_IFF_AUTO_LINKLOCAL
1414 	/* Unlike the kernel,
1415 	 * dhcpcd make make a stable private address. */
1416 	flags &= ~ND6_IFF_AUTO_LINKLOCAL;
1417 #endif
1418 
1419 #ifdef ND6_IFF_PERFORMNUD
1420 	/* NUD is kind of essential. */
1421 	flags |= ND6_IFF_PERFORMNUD;
1422 #endif
1423 
1424 #ifdef ND6_IFF_IFDISABLED
1425 	/* Ensure the interface is not disabled. */
1426 	flags &= ~ND6_IFF_IFDISABLED;
1427 #endif
1428 
1429 	/*
1430 	 * If not doing autoconf, don't disable the kernel from doing it.
1431 	 * If we need to, we should have another option actively disable it.
1432 	 */
1433 #ifdef ND6_IFF_ACCEPT_RTADV
1434 	if (ifp->options->options & DHCPCD_IPV6RS)
1435 		flags &= ~ND6_IFF_ACCEPT_RTADV;
1436 #ifdef ND6_IFF_OVERRIDE_RTADV
1437 	if (ifp->options->options & DHCPCD_IPV6RS)
1438 		flags |= ND6_IFF_OVERRIDE_RTADV;
1439 #endif
1440 #endif
1441 
1442 #ifdef ND6_NDI_FLAGS
1443 	if (nd.ndi.flags != (uint32_t)flags) {
1444 		nd.ndi.flags = (uint32_t)flags;
1445 		if (ioctl(s, SIOCSIFINFO_FLAGS, &nd) == -1)
1446 			logerr("%s: SIOCSIFINFO_FLAGS", ifp->name);
1447 	}
1448 #endif
1449 
1450 	/* Enabling IPv6 by whatever means must be the
1451 	 * last action undertaken to ensure kernel RS and
1452 	 * LLADDR auto configuration are disabled where applicable. */
1453 #ifdef SIOCIFAFATTACH
1454 	if (af_attach(s, ifp, AF_INET6) == -1)
1455 		logerr("%s: af_attach", ifp->name);
1456 #endif
1457 
1458 #ifdef SIOCGIFXFLAGS
1459 	if (set_ifxflags(s, ifp) == -1)
1460 		logerr("%s: set_ifxflags", ifp->name);
1461 #endif
1462 
1463 #if defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)
1464 	/* If we cannot control ra per interface, disable it globally. */
1465 	if (ifp->options->options & DHCPCD_IPV6RS) {
1466 		int ra = get_inet6_sysctl(IPV6CTL_ACCEPT_RTADV);
1467 
1468 		if (ra == -1) {
1469 			if (errno != ENOENT)
1470 				logerr("IPV6CTL_ACCEPT_RTADV");
1471 		else if (ra != 0)
1472 			if (set_inet6_sysctl(IPV6CTL_ACCEPT_RTADV, 0) == -1)
1473 				logerr("IPV6CTL_ACCEPT_RTADV");
1474 		}
1475 	}
1476 #endif
1477 
1478 #if defined(IPV6CTL_ACCEPT_RTADV) || defined(ND6_IFF_ACCEPT_RTADV)
1479 	/* Flush the kernel knowledge of advertised routers
1480 	 * and prefixes so the kernel does not expire prefixes
1481 	 * and default routes we are trying to own. */
1482 	if (ifp->options->options & DHCPCD_IPV6RS) {
1483 		char ifname[IFNAMSIZ + 8];
1484 
1485 		strlcpy(ifname, ifp->name, sizeof(ifname));
1486 		if (ioctl(s, SIOCSRTRFLUSH_IN6, (void *)&ifname) == -1 &&
1487 		    errno != ENOTSUP)
1488 			logwarn("SIOCSRTRFLUSH_IN6");
1489 		if (ioctl(s, SIOCSPFXFLUSH_IN6, (void *)&ifname) == -1 &&
1490 		    errno != ENOTSUP)
1491 			logwarn("SIOCSPFXFLUSH_IN6");
1492 	}
1493 #endif
1494 }
1495 #endif
1496