xref: /dragonfly/contrib/dhcpcd/src/if-bsd.c (revision 3d33658b)
1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * BSD interface driver for dhcpcd
4  * Copyright (c) 2006-2019 Roy Marples <roy@marples.name>
5  * All rights reserved
6 
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/ioctl.h>
30 #include <sys/param.h>
31 #include <sys/socket.h>
32 #include <sys/stat.h>
33 #include <sys/sysctl.h>
34 #include <sys/time.h>
35 #include <sys/types.h>
36 #include <sys/uio.h>
37 #include <sys/utsname.h>
38 
39 #include "config.h"
40 
41 #include <arpa/inet.h>
42 #include <net/bpf.h>
43 #include <net/if.h>
44 #include <net/if_dl.h>
45 #include <net/if_media.h>
46 #include <net/route.h>
47 #include <netinet/if_ether.h>
48 #include <netinet/in.h>
49 #include <netinet/in_var.h>
50 #include <netinet6/in6_var.h>
51 #include <netinet6/nd6.h>
52 #ifdef __NetBSD__
53 #include <net/if_vlanvar.h> /* Needs netinet/if_ether.h */
54 #elif defined(__DragonFly__)
55 #include <net/vlan/if_vlan_var.h>
56 #else
57 #include <net/if_vlan_var.h>
58 #endif
59 #ifdef __DragonFly__
60 #  include <netproto/802_11/ieee80211_ioctl.h>
61 #elif __APPLE__
62   /* FIXME: Add apple includes so we can work out SSID */
63 #else
64 #  include <net80211/ieee80211.h>
65 #  include <net80211/ieee80211_ioctl.h>
66 #endif
67 
68 #include <assert.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <fnmatch.h>
72 #include <paths.h>
73 #include <stddef.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <unistd.h>
78 
79 #if defined(OpenBSD) && OpenBSD >= 201411
80 /* OpenBSD dropped the global setting from sysctl but left the #define
81  * which causes a EPERM error when trying to use it.
82  * I think both the error and keeping the define are wrong, so we #undef it. */
83 #undef IPV6CTL_ACCEPT_RTADV
84 #endif
85 
86 #include "common.h"
87 #include "dhcp.h"
88 #include "if.h"
89 #include "if-options.h"
90 #include "ipv4.h"
91 #include "ipv4ll.h"
92 #include "ipv6.h"
93 #include "ipv6nd.h"
94 #include "logerr.h"
95 #include "route.h"
96 #include "sa.h"
97 
98 #ifndef RT_ROUNDUP
99 #define RT_ROUNDUP(a)							      \
100 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
101 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len))
102 #endif
103 
104 #ifdef INET6
105 static void ifa_setscope(struct sockaddr_in6 *, unsigned int);
106 static unsigned int ifa_getscope(const struct sockaddr_in6 *);
107 #endif
108 
109 struct priv {
110 	int pf_inet6_fd;
111 };
112 
113 struct rtm
114 {
115 	struct rt_msghdr hdr;
116 	char buffer[sizeof(struct sockaddr_storage) * RTAX_MAX];
117 };
118 
119 int
120 if_init(__unused struct interface *iface)
121 {
122 	/* BSD promotes secondary address by default */
123 	return 0;
124 }
125 
126 int
127 if_conf(__unused struct interface *iface)
128 {
129 	/* No extra checks needed on BSD */
130 	return 0;
131 }
132 
133 int
134 if_opensockets_os(struct dhcpcd_ctx *ctx)
135 {
136 	struct priv *priv;
137 	int n;
138 #if defined(RO_MSGFILTER) || defined(ROUTE_MSGFILTER)
139 	unsigned char msgfilter[] = {
140 	    RTM_IFINFO,
141 #ifdef RTM_IFANNOUNCE
142 	    RTM_IFANNOUNCE,
143 #endif
144 	    RTM_ADD, RTM_CHANGE, RTM_DELETE, RTM_MISS,
145 #ifdef RTM_CHGADDR
146 	    RTM_CHGADDR,
147 #endif
148 	    RTM_NEWADDR, RTM_DELADDR
149 	};
150 #ifdef ROUTE_MSGFILTER
151 	unsigned int i, msgfilter_mask;
152 #endif
153 #endif
154 
155 	if ((priv = malloc(sizeof(*priv))) == NULL)
156 		return -1;
157 	ctx->priv = priv;
158 
159 #ifdef INET6
160 	priv->pf_inet6_fd = xsocket(PF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0);
161 	/* Don't return an error so we at least work on kernels witout INET6
162 	 * even though we expect INET6 support.
163 	 * We will fail noisily elsewhere anyway. */
164 #else
165 	priv->pf_inet6_fd = -1;
166 #endif
167 
168 #define SOCK_FLAGS	(SOCK_CLOEXEC | SOCK_NONBLOCK)
169 	ctx->link_fd = xsocket(PF_ROUTE, SOCK_RAW | SOCK_FLAGS, AF_UNSPEC);
170 #undef SOCK_FLAGS
171 	if (ctx->link_fd == -1)
172 		return -1;
173 
174 	/* Ignore our own route(4) messages.
175 	 * Sadly there is no way of doing this for route(4) messages
176 	 * generated from addresses we add/delete. */
177 	n = 0;
178 	if (setsockopt(ctx->link_fd, SOL_SOCKET, SO_USELOOPBACK,
179 	    &n, sizeof(n)) == -1)
180 		logerr("%s: SO_USELOOPBACK", __func__);
181 
182 #if defined(RO_MSGFILTER)
183 	if (setsockopt(ctx->link_fd, PF_ROUTE, RO_MSGFILTER,
184 	    &msgfilter, sizeof(msgfilter)) == -1)
185 		logerr(__func__);
186 #elif defined(ROUTE_MSGFILTER)
187 	/* Convert the array into a bitmask. */
188 	msgfilter_mask = 0;
189 	for (i = 0; i < __arraycount(msgfilter); i++)
190 		msgfilter_mask |= ROUTE_FILTER(msgfilter[i]);
191 	if (setsockopt(ctx->link_fd, PF_ROUTE, ROUTE_MSGFILTER,
192 	    &msgfilter_mask, sizeof(msgfilter_mask)) == -1)
193 		logerr(__func__);
194 #else
195 #warning kernel does not support route message filtering
196 #endif
197 
198 	return 0;
199 }
200 
201 void
202 if_closesockets_os(struct dhcpcd_ctx *ctx)
203 {
204 	struct priv *priv;
205 
206 	priv = (struct priv *)ctx->priv;
207 	if (priv->pf_inet6_fd != -1)
208 		close(priv->pf_inet6_fd);
209 }
210 
211 int
212 if_carrier(struct interface *ifp)
213 {
214 	struct ifmediareq ifmr = { .ifm_status = 0 };
215 
216 	strlcpy(ifmr.ifm_name, ifp->name, sizeof(ifmr.ifm_name));
217 	if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFMEDIA, &ifmr) == -1 ||
218 	    !(ifmr.ifm_status & IFM_AVALID))
219 		return LINK_UNKNOWN;
220 
221 	return (ifmr.ifm_status & IFM_ACTIVE) ? LINK_UP : LINK_DOWN;
222 }
223 
224 static void
225 if_linkaddr(struct sockaddr_dl *sdl, const struct interface *ifp)
226 {
227 
228 	memset(sdl, 0, sizeof(*sdl));
229 	sdl->sdl_family = AF_LINK;
230 	sdl->sdl_len = sizeof(*sdl);
231 	sdl->sdl_nlen = sdl->sdl_alen = sdl->sdl_slen = 0;
232 	sdl->sdl_index = (unsigned short)ifp->index;
233 }
234 
235 #if defined(SIOCG80211NWID) || defined(SIOCGETVLAN)
236 static int if_direct_ioctl(int s, const char *ifname,
237     unsigned long cmd, void *data)
238 {
239 
240 	strlcpy(data, ifname, IFNAMSIZ);
241 	return ioctl(s, cmd, data);
242 }
243 
244 static int if_indirect_ioctl(int s, const char *ifname,
245     unsigned long cmd, void *data)
246 {
247 	struct ifreq ifr;
248 
249 	memset(&ifr, 0, sizeof(ifr));
250 	ifr.ifr_data = data;
251 	return if_direct_ioctl(s, ifname, cmd, &ifr);
252 }
253 #endif
254 
255 static int
256 if_getssid1(int s, const char *ifname, void *ssid)
257 {
258 	int retval = -1;
259 #if defined(SIOCG80211NWID)
260 	struct ieee80211_nwid nwid;
261 #elif defined(IEEE80211_IOC_SSID)
262 	struct ieee80211req ireq;
263 	char nwid[IEEE80211_NWID_LEN];
264 #endif
265 
266 #if defined(SIOCG80211NWID) /* NetBSD */
267 	memset(&nwid, 0, sizeof(nwid));
268 	if (if_indirect_ioctl(s, ifname, SIOCG80211NWID, &nwid) == 0) {
269 		if (ssid == NULL)
270 			retval = nwid.i_len;
271 		else if (nwid.i_len > IF_SSIDLEN)
272 			errno = ENOBUFS;
273 		else {
274 			retval = nwid.i_len;
275 			memcpy(ssid, nwid.i_nwid, nwid.i_len);
276 		}
277 	}
278 #elif defined(IEEE80211_IOC_SSID) /* FreeBSD */
279 	memset(&ireq, 0, sizeof(ireq));
280 	strlcpy(ireq.i_name, ifname, sizeof(ireq.i_name));
281 	ireq.i_type = IEEE80211_IOC_SSID;
282 	ireq.i_val = -1;
283 	memset(nwid, 0, sizeof(nwid));
284 	ireq.i_data = &nwid;
285 	if (ioctl(s, SIOCG80211, &ireq) == 0) {
286 		if (ssid == NULL)
287 			retval = ireq.i_len;
288 		else if (ireq.i_len > IF_SSIDLEN)
289 			errno = ENOBUFS;
290 		else  {
291 			retval = ireq.i_len;
292 			memcpy(ssid, nwid, ireq.i_len);
293 		}
294 	}
295 #else
296 	errno = ENOSYS;
297 #endif
298 
299 	return retval;
300 }
301 
302 int
303 if_getssid(struct interface *ifp)
304 {
305 	int r;
306 
307 	r = if_getssid1(ifp->ctx->pf_inet_fd, ifp->name, ifp->ssid);
308 	if (r != -1)
309 		ifp->ssid_len = (unsigned int)r;
310 	else
311 		ifp->ssid_len = 0;
312 	ifp->ssid[ifp->ssid_len] = '\0';
313 	return r;
314 }
315 
316 /*
317  * FreeBSD allows for Virtual Access Points
318  * We need to check if the interface is a Virtual Interface Master
319  * and if so, don't use it.
320  * This check is made by virtue of being a IEEE80211 device but
321  * returning the SSID gives an error.
322  */
323 int
324 if_vimaster(const struct dhcpcd_ctx *ctx, const char *ifname)
325 {
326 	int r;
327 	struct ifmediareq ifmr;
328 
329 	memset(&ifmr, 0, sizeof(ifmr));
330 	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
331 	r = ioctl(ctx->pf_inet_fd, SIOCGIFMEDIA, &ifmr);
332 	if (r == -1)
333 		return -1;
334 	if (ifmr.ifm_status & IFM_AVALID &&
335 	    IFM_TYPE(ifmr.ifm_active) == IFM_IEEE80211)
336 	{
337 		if (if_getssid1(ctx->pf_inet_fd, ifname, NULL) == -1)
338 			return 1;
339 	}
340 	return 0;
341 }
342 
343 unsigned short
344 if_vlanid(const struct interface *ifp)
345 {
346 #ifdef SIOCGETVLAN
347 	struct vlanreq vlr;
348 
349 	memset(&vlr, 0, sizeof(vlr));
350 	if (if_indirect_ioctl(ifp->ctx->pf_inet_fd,
351 	    ifp->name, SIOCGETVLAN, &vlr) != 0)
352 		return 0; /* 0 means no VLANID */
353 	return vlr.vlr_tag;
354 #elif defined(SIOCGVNETID)
355 	struct ifreq ifr;
356 
357 	memset(&ifr, 0, sizeof(ifr));
358 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
359 	if (ioctl(ifp->ctx->pf_inet_fd, SIOCGVNETID, &ifr) != 0)
360 		return 0; /* 0 means no VLANID */
361 	return ifr.ifr_vnetid;
362 #else
363 	UNUSED(ifp);
364 	return 0; /* 0 means no VLANID */
365 #endif
366 }
367 
368 static int
369 get_addrs(int type, const void *data, size_t data_len,
370     const struct sockaddr **sa)
371 {
372 	const char *cp, *ep;
373 	int i;
374 
375 	cp = data;
376 	ep = cp + data_len;
377 	for (i = 0; i < RTAX_MAX; i++) {
378 		if (type & (1 << i)) {
379 			if (cp >= ep) {
380 				errno = EINVAL;
381 				return -1;
382 			}
383 			sa[i] = (const struct sockaddr *)cp;
384 			RT_ADVANCE(cp, sa[i]);
385 		} else
386 			sa[i] = NULL;
387 	}
388 
389 	return 0;
390 }
391 
392 static struct interface *
393 if_findsdl(struct dhcpcd_ctx *ctx, const struct sockaddr_dl *sdl)
394 {
395 
396 	if (sdl->sdl_index)
397 		return if_findindex(ctx->ifaces, sdl->sdl_index);
398 
399 	if (sdl->sdl_nlen) {
400 		char ifname[IF_NAMESIZE];
401 
402 		memcpy(ifname, sdl->sdl_data, sdl->sdl_nlen);
403 		ifname[sdl->sdl_nlen] = '\0';
404 		return if_find(ctx->ifaces, ifname);
405 	}
406 	if (sdl->sdl_alen) {
407 		struct interface *ifp;
408 
409 		TAILQ_FOREACH(ifp, ctx->ifaces, next) {
410 			if (ifp->hwlen == sdl->sdl_alen &&
411 			    memcmp(ifp->hwaddr,
412 			    sdl->sdl_data, sdl->sdl_alen) == 0)
413 				return ifp;
414 		}
415 	}
416 
417 	errno = ENOENT;
418 	return NULL;
419 }
420 
421 static struct interface *
422 if_findsa(struct dhcpcd_ctx *ctx, const struct sockaddr *sa)
423 {
424 	if (sa == NULL) {
425 		errno = EINVAL;
426 		return NULL;
427 	}
428 
429 	switch (sa->sa_family) {
430 	case AF_LINK:
431 	{
432 		const struct sockaddr_dl *sdl;
433 
434 		sdl = (const void *)sa;
435 		return if_findsdl(ctx, sdl);
436 	}
437 #ifdef INET
438 	case AF_INET:
439 	{
440 		const struct sockaddr_in *sin;
441 		struct ipv4_addr *ia;
442 
443 		sin = (const void *)sa;
444 		if ((ia = ipv4_findmaskaddr(ctx, &sin->sin_addr)))
445 			return ia->iface;
446 		break;
447 	}
448 #endif
449 #ifdef INET6
450 	case AF_INET6:
451 	{
452 		const struct sockaddr_in6 *sin;
453 		unsigned int scope;
454 		struct ipv6_addr *ia;
455 
456 		sin = (const void *)sa;
457 		scope = ifa_getscope(sin);
458 		if (scope != 0)
459 			return if_findindex(ctx->ifaces, scope);
460 		if ((ia = ipv6_findmaskaddr(ctx, &sin->sin6_addr)))
461 			return ia->iface;
462 		break;
463 	}
464 #endif
465 	default:
466 		errno = EAFNOSUPPORT;
467 		return NULL;
468 	}
469 
470 	errno = ENOENT;
471 	return NULL;
472 }
473 
474 static void
475 if_copysa(struct sockaddr *dst, const struct sockaddr *src)
476 {
477 
478 	assert(dst != NULL);
479 	assert(src != NULL);
480 
481 	memcpy(dst, src, src->sa_len);
482 #if defined(INET6) && defined(__KAME__)
483 	if (dst->sa_family == AF_INET6) {
484 		struct in6_addr *in6;
485 
486 		in6 = &satosin6(dst)->sin6_addr;
487 		if (IN6_IS_ADDR_LINKLOCAL(in6))
488 			in6->s6_addr[2] = in6->s6_addr[3] = '\0';
489 	}
490 #endif
491 }
492 
493 int
494 if_route(unsigned char cmd, const struct rt *rt)
495 {
496 	struct dhcpcd_ctx *ctx;
497 	struct rtm rtmsg;
498 	struct rt_msghdr *rtm = &rtmsg.hdr;
499 	char *bp = rtmsg.buffer;
500 	struct sockaddr_dl sdl;
501 	bool gateway_unspec;
502 
503 	assert(rt != NULL);
504 	assert(rt->rt_ifp != NULL);
505 	assert(rt->rt_ifp->ctx != NULL);
506 	ctx = rt->rt_ifp->ctx;
507 
508 #define ADDSA(sa) do {							      \
509 		memcpy(bp, (sa), (sa)->sa_len);				      \
510 		bp += RT_ROUNDUP((sa)->sa_len);				      \
511 	}  while (0 /* CONSTCOND */)
512 
513 	memset(&rtmsg, 0, sizeof(rtmsg));
514 	rtm->rtm_version = RTM_VERSION;
515 	rtm->rtm_type = cmd;
516 #ifdef __OpenBSD__
517 	rtm->rtm_pid = getpid();
518 #endif
519 	rtm->rtm_seq = ++ctx->seq;
520 	rtm->rtm_flags = (int)rt->rt_flags;
521 	rtm->rtm_addrs = RTA_DST;
522 #ifdef RTF_PINNED
523 	if (cmd != RTM_ADD)
524 		rtm->rtm_flags |= RTF_PINNED;
525 #endif
526 
527 	gateway_unspec = sa_is_unspecified(&rt->rt_gateway);
528 
529 	if (cmd == RTM_ADD || cmd == RTM_CHANGE) {
530 		bool netmask_bcast = sa_is_allones(&rt->rt_netmask);
531 
532 		rtm->rtm_flags |= RTF_UP;
533 		rtm->rtm_addrs |= RTA_GATEWAY;
534 		if (!(rtm->rtm_flags & RTF_REJECT) &&
535 		    !sa_is_loopback(&rt->rt_gateway))
536 		{
537 			rtm->rtm_index = (unsigned short)rt->rt_ifp->index;
538 /*
539  * OpenBSD rejects the message for on-link routes.
540  * FreeBSD-12 kernel apparently panics.
541  * I can't replicate the panic, but better safe than sorry!
542  * https://roy.marples.name/archives/dhcpcd-discuss/0002286.html
543  *
544  * Neither OS currently allows IPv6 address sharing anyway, so let's
545  * try to encourage someone to fix that by logging a waring during compile.
546  */
547 #if defined(__FreeBSD__) || defined(__OpenBSD__)
548 #warning kernel does not allow IPv6 address sharing
549 			if (!gateway_unspec || rt->rt_dest.sa_family!=AF_INET6)
550 #endif
551 			rtm->rtm_addrs |= RTA_IFP;
552 			if (!sa_is_unspecified(&rt->rt_ifa))
553 				rtm->rtm_addrs |= RTA_IFA;
554 		}
555 		if (netmask_bcast)
556 			rtm->rtm_flags |= RTF_HOST;
557 		/* Network routes are cloning or connected if supported.
558 		 * All other routes are static. */
559 		if (gateway_unspec) {
560 #ifdef RTF_CLONING
561 			rtm->rtm_flags |= RTF_CLONING;
562 #endif
563 #ifdef RTF_CONNECTED
564 			rtm->rtm_flags |= RTF_CONNECTED;
565 #endif
566 #ifdef RTP_CONNECTED
567 			rtm->rtm_priority = RTP_CONNECTED;
568 #endif
569 #ifdef RTF_CLONING
570 			if (netmask_bcast) {
571 				/*
572 				 * We add a cloning network route for a single
573 				 * host. Traffic to the host will generate a
574 				 * cloned route and the hardware address will
575 				 * resolve correctly.
576 				 * It might be more correct to use RTF_HOST
577 				 * instead of RTF_CLONING, and that does work,
578 				 * but some OS generate an arp warning
579 				 * diagnostic which we don't want to do.
580 				 */
581 				rtm->rtm_flags &= ~RTF_HOST;
582 			}
583 #endif
584 		} else
585 			rtm->rtm_flags |= RTF_GATEWAY;
586 
587 		/* Emulate the kernel by marking address generated
588 		 * network routes non-static. */
589 		if (!(rt->rt_dflags & RTDF_IFA_ROUTE))
590 			rtm->rtm_flags |= RTF_STATIC;
591 
592 		if (rt->rt_mtu != 0) {
593 			rtm->rtm_inits |= RTV_MTU;
594 			rtm->rtm_rmx.rmx_mtu = rt->rt_mtu;
595 		}
596 	}
597 
598 	if (!(rtm->rtm_flags & RTF_HOST))
599 		rtm->rtm_addrs |= RTA_NETMASK;
600 
601 	if_linkaddr(&sdl, rt->rt_ifp);
602 
603 	ADDSA(&rt->rt_dest);
604 
605 	if (rtm->rtm_addrs & RTA_GATEWAY) {
606 		if (gateway_unspec)
607 			ADDSA((struct sockaddr *)&sdl);
608 		else {
609 			union sa_ss gateway;
610 
611 			if_copysa(&gateway.sa, &rt->rt_gateway);
612 #ifdef INET6
613 			if (gateway.sa.sa_family == AF_INET6)
614 				ifa_setscope(&gateway.sin6, rt->rt_ifp->index);
615 #endif
616 			ADDSA(&gateway.sa);
617 		}
618 	}
619 
620 	if (rtm->rtm_addrs & RTA_NETMASK)
621 		ADDSA(&rt->rt_netmask);
622 
623 	if (rtm->rtm_addrs & RTA_IFP)
624 		ADDSA((struct sockaddr *)&sdl);
625 
626 	if (rtm->rtm_addrs & RTA_IFA)
627 		ADDSA(&rt->rt_ifa);
628 
629 #undef ADDSA
630 
631 	rtm->rtm_msglen = (unsigned short)(bp - (char *)rtm);
632 	if (write(ctx->link_fd, rtm, rtm->rtm_msglen) == -1)
633 		return -1;
634 	return 0;
635 }
636 
637 static int
638 if_copyrt(struct dhcpcd_ctx *ctx, struct rt *rt, const struct rt_msghdr *rtm)
639 {
640 	const struct sockaddr *rti_info[RTAX_MAX];
641 
642 	if (!(rtm->rtm_addrs & RTA_DST)) {
643 		errno = EINVAL;
644 		return -1;
645 	}
646 	if (rtm->rtm_type != RTM_MISS && !(rtm->rtm_addrs & RTA_GATEWAY)) {
647 		errno = EINVAL;
648 		return -1;
649 	}
650 #ifdef RTF_CLONED
651 	if (rtm->rtm_flags & RTF_CLONED) {
652 		errno = ENOTSUP;
653 		return -1;
654 	}
655 #endif
656 #ifdef RTF_WASCLONED
657 	if (rtm->rtm_flags & RTF_WASCLONED) {
658 		errno = ENOTSUP;
659 		return -1;
660 	}
661 #endif
662 #ifdef RTF_LOCAL
663 	if (rtm->rtm_flags & RTF_LOCAL) {
664 		errno = ENOTSUP;
665 		return -1;
666 	}
667 #endif
668 #ifdef RTF_BROADCAST
669 	if (rtm->rtm_flags & RTF_BROADCAST) {
670 		errno = ENOTSUP;
671 		return -1;
672 	}
673 #endif
674 
675 	if (get_addrs(rtm->rtm_addrs, (const char *)rtm + sizeof(*rtm),
676 	              rtm->rtm_msglen - sizeof(*rtm), rti_info) == -1)
677 		return -1;
678 	memset(rt, 0, sizeof(*rt));
679 
680 	rt->rt_flags = (unsigned int)rtm->rtm_flags;
681 	if_copysa(&rt->rt_dest, rti_info[RTAX_DST]);
682 	if (rtm->rtm_addrs & RTA_NETMASK) {
683 		if_copysa(&rt->rt_netmask, rti_info[RTAX_NETMASK]);
684 		if (rt->rt_netmask.sa_family == 255) /* Why? */
685 			rt->rt_netmask.sa_family = rt->rt_dest.sa_family;
686 	}
687 
688 	/* dhcpcd likes an unspecified gateway to indicate via the link.
689 	 * However we need to know if gateway was a link with an address. */
690 	if (rtm->rtm_addrs & RTA_GATEWAY) {
691 		if (rti_info[RTAX_GATEWAY]->sa_family == AF_LINK) {
692 			const struct sockaddr_dl *sdl;
693 
694 			sdl = (const struct sockaddr_dl*)
695 			    (const void *)rti_info[RTAX_GATEWAY];
696 			if (sdl->sdl_alen != 0)
697 				rt->rt_dflags |= RTDF_GATELINK;
698 		} else if (rtm->rtm_flags & RTF_GATEWAY)
699 			if_copysa(&rt->rt_gateway, rti_info[RTAX_GATEWAY]);
700 	}
701 
702 	if (rtm->rtm_addrs & RTA_IFA)
703 		if_copysa(&rt->rt_ifa, rti_info[RTAX_IFA]);
704 
705 	rt->rt_mtu = (unsigned int)rtm->rtm_rmx.rmx_mtu;
706 
707 	if (rtm->rtm_index)
708 		rt->rt_ifp = if_findindex(ctx->ifaces, rtm->rtm_index);
709 	else if (rtm->rtm_addrs & RTA_IFP)
710 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_IFP]);
711 	else if (rtm->rtm_addrs & RTA_GATEWAY)
712 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_GATEWAY]);
713 	else
714 		rt->rt_ifp = if_findsa(ctx, rti_info[RTAX_DST]);
715 
716 	if (rt->rt_ifp == NULL && rtm->rtm_type == RTM_MISS)
717 		rt->rt_ifp = if_find(ctx->ifaces, "lo0");
718 
719 	if (rt->rt_ifp == NULL) {
720 		errno = ESRCH;
721 		return -1;
722 	}
723 	return 0;
724 }
725 
726 int
727 if_initrt(struct dhcpcd_ctx *ctx, rb_tree_t *kroutes, int af)
728 {
729 	struct rt_msghdr *rtm;
730 	int mib[6];
731 	size_t needed;
732 	char *buf, *p, *end;
733 	struct rt rt, *rtn;
734 
735 	mib[0] = CTL_NET;
736 	mib[1] = PF_ROUTE;
737 	mib[2] = 0;
738 	mib[3] = af;
739 	mib[4] = NET_RT_DUMP;
740 	mib[5] = 0;
741 
742 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
743 		return -1;
744 	if (needed == 0)
745 		return 0;
746 	if ((buf = malloc(needed)) == NULL)
747 		return -1;
748 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1) {
749 		free(buf);
750 		return -1;
751 	}
752 
753 	end = buf + needed;
754 	for (p = buf; p < end; p += rtm->rtm_msglen) {
755 		rtm = (void *)p;
756 		if (p + rtm->rtm_msglen >= end) {
757 			errno = EINVAL;
758 			break;
759 		}
760 		if (if_copyrt(ctx, &rt, rtm) != 0)
761 			continue;
762 		if ((rtn = rt_new(rt.rt_ifp)) == NULL) {
763 			logerr(__func__);
764 			break;
765 		}
766 		memcpy(rtn, &rt, sizeof(*rtn));
767 		if (rb_tree_insert_node(kroutes, rtn) != rtn)
768 			rt_free(rtn);
769 	}
770 	free(buf);
771 	return p == end ? 0 : -1;
772 }
773 
774 #ifdef INET
775 int
776 if_address(unsigned char cmd, const struct ipv4_addr *ia)
777 {
778 	int r;
779 	struct in_aliasreq ifra;
780 
781 	memset(&ifra, 0, sizeof(ifra));
782 	strlcpy(ifra.ifra_name, ia->iface->name, sizeof(ifra.ifra_name));
783 
784 #define ADDADDR(var, addr) do {						      \
785 		(var)->sin_family = AF_INET;				      \
786 		(var)->sin_len = sizeof(*(var));			      \
787 		(var)->sin_addr = *(addr);				      \
788 	} while (/*CONSTCOND*/0)
789 	ADDADDR(&ifra.ifra_addr, &ia->addr);
790 	ADDADDR(&ifra.ifra_mask, &ia->mask);
791 	if (cmd == RTM_NEWADDR && ia->brd.s_addr != INADDR_ANY)
792 		ADDADDR(&ifra.ifra_broadaddr, &ia->brd);
793 #undef ADDADDR
794 
795 	r = ioctl(ia->iface->ctx->pf_inet_fd,
796 	    cmd == RTM_DELADDR ? SIOCDIFADDR : SIOCAIFADDR, &ifra);
797 	return r;
798 }
799 
800 
801 
802 #if !(defined(HAVE_IFADDRS_ADDRFLAGS) && defined(HAVE_IFAM_ADDRFLAGS))
803 int
804 if_addrflags(const struct interface *ifp, const struct in_addr *addr,
805     __unused const char *alias)
806 {
807 #ifdef SIOCGIFAFLAG_IN
808 	struct ifreq ifr;
809 	struct sockaddr_in *sin;
810 
811 	memset(&ifr, 0, sizeof(ifr));
812 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
813 	sin = (void *)&ifr.ifr_addr;
814 	sin->sin_family = AF_INET;
815 	sin->sin_addr = *addr;
816 	if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFAFLAG_IN, &ifr) == -1)
817 		return -1;
818 	return ifr.ifr_addrflags;
819 #else
820 	UNUSED(ifp);
821 	UNUSED(addr);
822 	return 0;
823 #endif
824 }
825 #endif
826 #endif /* INET */
827 
828 #ifdef INET6
829 static void
830 ifa_setscope(struct sockaddr_in6 *sin, unsigned int ifindex)
831 {
832 
833 #ifdef __KAME__
834 	/* KAME based systems want to store the scope inside the sin6_addr
835 	 * for link local addresses */
836 	if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr)) {
837 		uint16_t scope = htons((uint16_t)ifindex);
838 		memcpy(&sin->sin6_addr.s6_addr[2], &scope,
839 		    sizeof(scope));
840 	}
841 	sin->sin6_scope_id = 0;
842 #else
843 	if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr))
844 		sin->sin6_scope_id = ifindex;
845 	else
846 		sin->sin6_scope_id = 0;
847 #endif
848 }
849 
850 static unsigned int
851 ifa_getscope(const struct sockaddr_in6 *sin)
852 {
853 #ifdef __KAME__
854 	uint16_t scope;
855 #endif
856 
857 	if (!IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr))
858 		return 0;
859 #ifdef __KAME__
860 	memcpy(&scope, &sin->sin6_addr.s6_addr[2], sizeof(scope));
861 	return (unsigned int)ntohs(scope);
862 #else
863 	return (unsigned int)sin->sin6_scope_id;
864 #endif
865 }
866 
867 int
868 if_address6(unsigned char cmd, const struct ipv6_addr *ia)
869 {
870 	struct in6_aliasreq ifa;
871 	struct in6_addr mask;
872 	struct priv *priv;
873 
874 	priv = (struct priv *)ia->iface->ctx->priv;
875 
876 	memset(&ifa, 0, sizeof(ifa));
877 	strlcpy(ifa.ifra_name, ia->iface->name, sizeof(ifa.ifra_name));
878 	/*
879 	 * We should not set IN6_IFF_TENTATIVE as the kernel should be
880 	 * able to work out if it's a new address or not.
881 	 *
882 	 * We should set IN6_IFF_AUTOCONF, but the kernel won't let us.
883 	 * This is probably a safety measure, but still it's not entirely right
884 	 * either.
885 	 */
886 #if 0
887 	if (ia->autoconf)
888 		ifa.ifra_flags |= IN6_IFF_AUTOCONF;
889 #endif
890 #if defined(__FreeBSD__) || defined(__DragonFly__)
891 	if (ia->addr_flags & IN6_IFF_TENTATIVE)
892 		ifa.ifra_flags |= IN6_IFF_TENTATIVE;
893 #endif
894 #ifdef IPV6_MANGETEMPADDR
895 	if (ia->flags & IPV6_AF_TEMPORARY)
896 		ifa.ifra_flags |= IN6_IFF_TEMPORARY;
897 #endif
898 
899 #define ADDADDR(v, addr) {						      \
900 		(v)->sin6_family = AF_INET6;				      \
901 		(v)->sin6_len = sizeof(*v);				      \
902 		(v)->sin6_addr = *(addr);				      \
903 	}
904 
905 	ADDADDR(&ifa.ifra_addr, &ia->addr);
906 	ifa_setscope(&ifa.ifra_addr, ia->iface->index);
907 	ipv6_mask(&mask, ia->prefix_len);
908 	ADDADDR(&ifa.ifra_prefixmask, &mask);
909 
910 #undef ADDADDR
911 
912 	/*
913 	 * Every BSD kernel wants to add the prefix of the address to it's
914 	 * list of RA received prefixes.
915 	 * THIS IS WRONG because there (as the comments in the kernel state)
916 	 * is no API for managing prefix lifetime and the kernel should not
917 	 * pretend it's from a RA either.
918 	 *
919 	 * The issue is that the very first assigned prefix will inherit the
920 	 * lifetime of the address, but any subsequent alteration of the
921 	 * address OR it's lifetime will not affect the prefix lifetime.
922 	 * As such, we cannot stop the prefix from timing out and then
923 	 * constantly removing the prefix route dhcpcd is capable of adding
924 	 * in it's absense.
925 	 *
926 	 * What we can do to mitigate the issue is to add the address with
927 	 * infinite lifetimes, so the prefix route will never time out.
928 	 * Once done, we can then set lifetimes on the address and all is good.
929 	 * The downside of this approach is that we need to manually remove
930 	 * the kernel route because it has no lifetime, but this is OK as
931 	 * dhcpcd will handle this too.
932 	 *
933 	 * This issue is discussed on the NetBSD mailing lists here:
934 	 * http://mail-index.netbsd.org/tech-net/2016/08/05/msg006044.html
935 	 *
936 	 * Fixed in NetBSD-7.99.36
937 	 * NOT fixed in FreeBSD - bug 195197
938 	 * Fixed in OpenBSD-5.9
939 	 */
940 
941 #if !((defined(__NetBSD_Version__) && __NetBSD_Version__ >= 799003600) || \
942       (defined(__OpenBSD__) && OpenBSD >= 201605))
943 	if (cmd == RTM_NEWADDR && !(ia->flags & IPV6_AF_ADDED)) {
944 		ifa.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
945 		ifa.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
946 		(void)ioctl(priv->pf_inet6_fd, SIOCAIFADDR_IN6, &ifa);
947 	}
948 #endif
949 
950 #if defined(__OpenBSD__) && OpenBSD <= 201705
951 	/* BUT OpenBSD older than 6.2 does not reset the address lifetime
952 	 * for subsequent calls...
953 	 * Luckily dhcpcd will remove the lease when it expires so
954 	 * just set an infinite lifetime, unless a temporary address. */
955 	if (ifa.ifra_flags & IN6_IFF_PRIVACY) {
956 		ifa.ifra_lifetime.ia6t_vltime = ia->prefix_vltime;
957 		ifa.ifra_lifetime.ia6t_pltime = ia->prefix_pltime;
958 	} else {
959 		ifa.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
960 		ifa.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
961 	}
962 #else
963 	ifa.ifra_lifetime.ia6t_vltime = ia->prefix_vltime;
964 	ifa.ifra_lifetime.ia6t_pltime = ia->prefix_pltime;
965 #endif
966 
967 	return ioctl(priv->pf_inet6_fd,
968 	    cmd == RTM_DELADDR ? SIOCDIFADDR_IN6 : SIOCAIFADDR_IN6, &ifa);
969 }
970 
971 int
972 if_addrflags6(const struct interface *ifp, const struct in6_addr *addr,
973     __unused const char *alias)
974 {
975 	int flags;
976 	struct in6_ifreq ifr6;
977 	struct priv *priv;
978 
979 	memset(&ifr6, 0, sizeof(ifr6));
980 	strlcpy(ifr6.ifr_name, ifp->name, sizeof(ifr6.ifr_name));
981 	ifr6.ifr_addr.sin6_family = AF_INET6;
982 	ifr6.ifr_addr.sin6_addr = *addr;
983 	ifa_setscope(&ifr6.ifr_addr, ifp->index);
984 	priv = (struct priv *)ifp->ctx->priv;
985 	if (ioctl(priv->pf_inet6_fd, SIOCGIFAFLAG_IN6, &ifr6) != -1)
986 		flags = ifr6.ifr_ifru.ifru_flags6;
987 	else
988 		flags = -1;
989 	return flags;
990 }
991 
992 int
993 if_getlifetime6(struct ipv6_addr *ia)
994 {
995 	struct in6_ifreq ifr6;
996 	time_t t;
997 	struct in6_addrlifetime *lifetime;
998 	struct priv *priv;
999 
1000 	memset(&ifr6, 0, sizeof(ifr6));
1001 	strlcpy(ifr6.ifr_name, ia->iface->name, sizeof(ifr6.ifr_name));
1002 	ifr6.ifr_addr.sin6_family = AF_INET6;
1003 	ifr6.ifr_addr.sin6_addr = ia->addr;
1004 	ifa_setscope(&ifr6.ifr_addr, ia->iface->index);
1005 	priv = (struct priv *)ia->iface->ctx->priv;
1006 	if (ioctl(priv->pf_inet6_fd, SIOCGIFALIFETIME_IN6, &ifr6) == -1)
1007 		return -1;
1008 	clock_gettime(CLOCK_MONOTONIC, &ia->created);
1009 
1010 #if defined(__FreeBSD__) || defined(__DragonFly__)
1011 	t = ia->created.tv_sec;
1012 #else
1013 	t = time(NULL);
1014 #endif
1015 
1016 	lifetime = &ifr6.ifr_ifru.ifru_lifetime;
1017 	if (lifetime->ia6t_preferred)
1018 		ia->prefix_pltime = (uint32_t)(lifetime->ia6t_preferred -
1019 		    MIN(t, lifetime->ia6t_preferred));
1020 	else
1021 		ia->prefix_pltime = ND6_INFINITE_LIFETIME;
1022 	if (lifetime->ia6t_expire) {
1023 		ia->prefix_vltime = (uint32_t)(lifetime->ia6t_expire -
1024 		    MIN(t, lifetime->ia6t_expire));
1025 		/* Calculate the created time */
1026 		ia->created.tv_sec -= lifetime->ia6t_vltime - ia->prefix_vltime;
1027 	} else
1028 		ia->prefix_vltime = ND6_INFINITE_LIFETIME;
1029 	return 0;
1030 }
1031 #endif
1032 
1033 static int
1034 if_announce(struct dhcpcd_ctx *ctx, const struct if_announcemsghdr *ifan)
1035 {
1036 
1037 	if (ifan->ifan_msglen < sizeof(*ifan)) {
1038 		errno = EINVAL;
1039 		return -1;
1040 	}
1041 
1042 	switch(ifan->ifan_what) {
1043 	case IFAN_ARRIVAL:
1044 		return dhcpcd_handleinterface(ctx, 1, ifan->ifan_name);
1045 	case IFAN_DEPARTURE:
1046 		return dhcpcd_handleinterface(ctx, -1, ifan->ifan_name);
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 static int
1053 if_ifinfo(struct dhcpcd_ctx *ctx, const struct if_msghdr *ifm)
1054 {
1055 	struct interface *ifp;
1056 	int link_state;
1057 
1058 	if (ifm->ifm_msglen < sizeof(*ifm)) {
1059 		errno = EINVAL;
1060 		return -1;
1061 	}
1062 
1063 	if ((ifp = if_findindex(ctx->ifaces, ifm->ifm_index)) == NULL)
1064 		return 0;
1065 
1066 	switch (ifm->ifm_data.ifi_link_state) {
1067 	case LINK_STATE_UNKNOWN:
1068 		link_state = LINK_UNKNOWN;
1069 		break;
1070 	case LINK_STATE_UP:
1071 		link_state = LINK_UP;
1072 		break;
1073 	default:
1074 		link_state = LINK_DOWN;
1075 		break;
1076 	}
1077 
1078 	dhcpcd_handlecarrier(ctx, link_state,
1079 	    (unsigned int)ifm->ifm_flags, ifp->name);
1080 	return 0;
1081 }
1082 
1083 static int
1084 if_rtm(struct dhcpcd_ctx *ctx, const struct rt_msghdr *rtm)
1085 {
1086 	struct rt rt;
1087 
1088 	if (rtm->rtm_msglen < sizeof(*rtm)) {
1089 		errno = EINVAL;
1090 		return -1;
1091 	}
1092 
1093 	/* Ignore errors. */
1094 	if (rtm->rtm_errno != 0)
1095 		return 0;
1096 
1097 	if (if_copyrt(ctx, &rt, rtm) == -1)
1098 		return errno == ENOTSUP ? 0 : -1;
1099 
1100 #ifdef INET6
1101 	/*
1102 	 * BSD announces host routes.
1103 	 * As such, we should be notified of reachability by its
1104 	 * existance with a hardware address.
1105 	 * Ensure we don't call this for a newly incomplete state.
1106 	 */
1107 	if (rt.rt_dest.sa_family == AF_INET6 &&
1108 	    (rt.rt_flags & RTF_HOST || rtm->rtm_type == RTM_MISS) &&
1109 	    !(rtm->rtm_type == RTM_ADD && !(rt.rt_dflags & RTDF_GATELINK)))
1110 	{
1111 		bool reachable;
1112 
1113 		reachable = (rtm->rtm_type == RTM_ADD ||
1114 		    rtm->rtm_type == RTM_CHANGE) &&
1115 		    rt.rt_dflags & RTDF_GATELINK;
1116 		ipv6nd_neighbour(ctx, &rt.rt_ss_dest.sin6.sin6_addr, reachable);
1117 	}
1118 #endif
1119 
1120 	if (rtm->rtm_type != RTM_MISS)
1121 		rt_recvrt(rtm->rtm_type, &rt, rtm->rtm_pid);
1122 	return 0;
1123 }
1124 
1125 static int
1126 if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
1127 {
1128 	struct interface *ifp;
1129 	const struct sockaddr *rti_info[RTAX_MAX];
1130 	int addrflags;
1131 	pid_t pid;
1132 
1133 	if (ifam->ifam_msglen < sizeof(*ifam)) {
1134 		errno = EINVAL;
1135 		return -1;
1136 	}
1137 	if (~ifam->ifam_addrs & RTA_IFA)
1138 		return 0;
1139 	if ((ifp = if_findindex(ctx->ifaces, ifam->ifam_index)) == NULL)
1140 		return 0;
1141 
1142 	if (get_addrs(ifam->ifam_addrs, (const char *)ifam + sizeof(*ifam),
1143 		      ifam->ifam_msglen - sizeof(*ifam), rti_info) == -1)
1144 		return -1;
1145 
1146 #ifdef HAVE_IFAM_PID
1147 	pid = ifam->ifam_pid;
1148 #else
1149 	pid = 0;
1150 #endif
1151 
1152 #ifdef HAVE_IFAM_ADDRFLAGS
1153 	addrflags = ifam->ifam_addrflags;
1154 #endif
1155 	switch (rti_info[RTAX_IFA]->sa_family) {
1156 	case AF_LINK:
1157 	{
1158 		struct sockaddr_dl sdl;
1159 
1160 #ifdef RTM_CHGADDR
1161 		if (ifam->ifam_type != RTM_CHGADDR)
1162 			break;
1163 #else
1164 		if (ifam->ifam_type != RTM_NEWADDR)
1165 			break;
1166 #endif
1167 		memcpy(&sdl, rti_info[RTAX_IFA], rti_info[RTAX_IFA]->sa_len);
1168 		dhcpcd_handlehwaddr(ctx, ifp->name, CLLADDR(&sdl),sdl.sdl_alen);
1169 		break;
1170 	}
1171 #ifdef INET
1172 	case AF_INET:
1173 	case 255: /* FIXME: Why 255? */
1174 	{
1175 		const struct sockaddr_in *sin;
1176 		struct in_addr addr, mask, bcast;
1177 
1178 		sin = (const void *)rti_info[RTAX_IFA];
1179 		addr.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1180 		    sin->sin_addr.s_addr : INADDR_ANY;
1181 		sin = (const void *)rti_info[RTAX_NETMASK];
1182 		mask.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1183 		    sin->sin_addr.s_addr : INADDR_ANY;
1184 		sin = (const void *)rti_info[RTAX_BRD];
1185 		bcast.s_addr = sin != NULL && sin->sin_family == AF_INET ?
1186 		    sin->sin_addr.s_addr : INADDR_ANY;
1187 
1188 #if defined(__NetBSD_Version__) && __NetBSD_Version__ < 800000000
1189 		/*
1190 		 * NetBSD-7 and older send an invalid broadcast address.
1191 		 * So we need to query the actual address to get
1192 		 * the right one.
1193 		 */
1194 		{
1195 #else
1196 		/*
1197 		 * If the address was deleted, lets check if it's
1198 		 * a late message and it still exists (maybe modified).
1199 		 * If so, ignore it as deleting an address causes
1200 		 * dhcpcd to drop any lease to which it belongs.
1201 		 */
1202 		if (ifam->ifam_type == RTM_DELADDR) {
1203 #endif
1204 #ifdef SIOCGIFALIAS
1205 			struct in_aliasreq ifra;
1206 
1207 			memset(&ifra, 0, sizeof(ifra));
1208 			strlcpy(ifra.ifra_name, ifp->name,
1209 			    sizeof(ifra.ifra_name));
1210 			ifra.ifra_addr.sin_family = AF_INET;
1211 			ifra.ifra_addr.sin_len = sizeof(ifra.ifra_addr);
1212 			ifra.ifra_addr.sin_addr = addr;
1213 			if (ioctl(ctx->pf_inet_fd, SIOCGIFALIAS, &ifra) == -1) {
1214 				if (errno != ENXIO && errno != EADDRNOTAVAIL)
1215 					logerr("%s: SIOCGIFALIAS", __func__);
1216 				if (ifam->ifam_type != RTM_DELADDR)
1217 					break;
1218 			}
1219 #if defined(__NetBSD_Version__) && __NetBSD_Version__ < 800000000
1220 			else
1221 				bcast = ifra.ifra_broadaddr.sin_addr;
1222 #endif
1223 #else
1224 #warning No SIOCGIFALIAS support
1225 			/*
1226 			 * No SIOCGIFALIAS? That sucks!
1227 			 * This makes this call very heavy weight, but we
1228 			 * really need to know if the message is late or not.
1229 			 */
1230 			const struct sockaddr *sa;
1231 			struct ifaddrs *ifaddrs = NULL, *ifa;
1232 
1233 			sa = rti_info[RTAX_IFA];
1234 			getifaddrs(&ifaddrs);
1235 			for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
1236 				if (ifa->ifa_addr == NULL)
1237 					continue;
1238 				if (sa_cmp(ifa->ifa_addr, sa) == 0 &&
1239 				    strcmp(ifa->ifa_name, ifp->name) == 0)
1240 					break;
1241 			}
1242 			freeifaddrs(ifaddrs);
1243 			if (ifa != NULL)
1244 				return 0;
1245 #endif
1246 		}
1247 
1248 #ifndef HAVE_IFAM_ADDRFLAGS
1249 		if (ifam->ifam_type == RTM_DELADDR)
1250 			addrflags = 0 ;
1251 		else if ((addrflags = if_addrflags(ifp, &addr, NULL)) == -1) {
1252 			if (errno != EADDRNOTAVAIL)
1253 				logerr("%s: if_addrflags", __func__);
1254 			break;
1255 		}
1256 #endif
1257 
1258 		ipv4_handleifa(ctx, ifam->ifam_type, NULL, ifp->name,
1259 		    &addr, &mask, &bcast, addrflags, pid);
1260 		break;
1261 	}
1262 #endif
1263 #ifdef INET6
1264 	case AF_INET6:
1265 	{
1266 		struct in6_addr addr6, mask6;
1267 		const struct sockaddr_in6 *sin6;
1268 		int flags;
1269 
1270 		sin6 = (const void *)rti_info[RTAX_IFA];
1271 		addr6 = sin6->sin6_addr;
1272 		sin6 = (const void *)rti_info[RTAX_NETMASK];
1273 		mask6 = sin6->sin6_addr;
1274 
1275 		/*
1276 		 * If the address was deleted, lets check if it's
1277 		 * a late message and it still exists (maybe modified).
1278 		 * If so, ignore it as deleting an address causes
1279 		 * dhcpcd to drop any lease to which it belongs.
1280 		 */
1281 		if (ifam->ifam_type == RTM_DELADDR) {
1282 			flags = if_addrflags6(ifp, &addr6, NULL);
1283 			if (flags != -1)
1284 				break;
1285 			addrflags = 0;
1286 		}
1287 #ifndef HAVE_IFAM_ADDRFLAGS
1288 		else if ((addrflags = if_addrflags6(ifp, &addr6, NULL)) == -1) {
1289 			if (errno != EADDRNOTAVAIL)
1290 				logerr("%s: if_addrflags6", __func__);
1291 			break;
1292 		}
1293 #endif
1294 
1295 #ifdef __KAME__
1296 		if (IN6_IS_ADDR_LINKLOCAL(&addr6))
1297 			/* Remove the scope from the address */
1298 			addr6.s6_addr[2] = addr6.s6_addr[3] = '\0';
1299 #endif
1300 
1301 		ipv6_handleifa(ctx, ifam->ifam_type, NULL,
1302 		    ifp->name, &addr6, ipv6_prefixlen(&mask6), addrflags, pid);
1303 		break;
1304 	}
1305 #endif
1306 	}
1307 
1308 	return 0;
1309 }
1310 
1311 static int
1312 if_dispatch(struct dhcpcd_ctx *ctx, const struct rt_msghdr *rtm)
1313 {
1314 
1315 	if (rtm->rtm_version != RTM_VERSION)
1316 		return 0;
1317 
1318 	switch(rtm->rtm_type) {
1319 #ifdef RTM_IFANNOUNCE
1320 	case RTM_IFANNOUNCE:
1321 		return if_announce(ctx, (const void *)rtm);
1322 #endif
1323 	case RTM_IFINFO:
1324 		return if_ifinfo(ctx, (const void *)rtm);
1325 	case RTM_ADD:		/* FALLTHROUGH */
1326 	case RTM_CHANGE:	/* FALLTHROUGH */
1327 	case RTM_DELETE:	/* FALLTHROUGH */
1328 	case RTM_MISS:
1329 		return if_rtm(ctx, (const void *)rtm);
1330 #ifdef RTM_CHGADDR
1331 	case RTM_CHGADDR:	/* FALLTHROUGH */
1332 #endif
1333 	case RTM_DELADDR:	/* FALLTHROUGH */
1334 	case RTM_NEWADDR:
1335 		return if_ifa(ctx, (const void *)rtm);
1336 #ifdef RTM_DESYNC
1337 	case RTM_DESYNC:
1338 		dhcpcd_linkoverflow(ctx);
1339 #elif !defined(SO_RERROR)
1340 #warning cannot detect route socket overflow within kernel
1341 #endif
1342 	}
1343 
1344 	return 0;
1345 }
1346 
1347 __CTASSERT(offsetof(struct rt_msghdr, rtm_msglen) == 0);
1348 int
1349 if_handlelink(struct dhcpcd_ctx *ctx)
1350 {
1351 	struct rtm rtm;
1352 	ssize_t len;
1353 
1354 	len = read(ctx->link_fd, &rtm, sizeof(rtm));
1355 	if (len == -1)
1356 		return -1;
1357 	if (len == 0)
1358 		return 0;
1359 	if ((size_t)len < sizeof(rtm.hdr.rtm_msglen) ||
1360 	    len != rtm.hdr.rtm_msglen)
1361 	{
1362 		errno = EINVAL;
1363 		return -1;
1364 	}
1365 	/*
1366 	 * Coverity thinks that the data could be tainted from here.
1367 	 * I have no idea how because the length of the data we read
1368 	 * is guarded by len and checked to match rtm_msglen.
1369 	 * The issue seems to be related to extracting the addresses
1370 	 * at the end of the header, but seems to have no issues with the
1371 	 * equivalent call in if_initrt.
1372 	 */
1373 	/* coverity[tainted_data] */
1374 	return if_dispatch(ctx, &rtm.hdr);
1375 }
1376 
1377 #ifndef SYS_NMLN	/* OSX */
1378 #  define SYS_NMLN 256
1379 #endif
1380 #ifndef HW_MACHINE_ARCH
1381 #  ifdef HW_MODEL	/* OpenBSD */
1382 #    define HW_MACHINE_ARCH HW_MODEL
1383 #  endif
1384 #endif
1385 int
1386 if_machinearch(char *str, size_t len)
1387 {
1388 	int mib[2] = { CTL_HW, HW_MACHINE_ARCH };
1389 	char march[SYS_NMLN];
1390 	size_t marchlen = sizeof(march);
1391 
1392 	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]),
1393 	    march, &marchlen, NULL, 0) != 0)
1394 		return -1;
1395 	return snprintf(str, len, ":%s", march);
1396 }
1397 
1398 #ifdef INET6
1399 #if (defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)) || \
1400     defined(IPV6CTL_USETEMPADDR) || defined(IPV6CTL_TEMPVLTIME) || \
1401     defined(IPV6CTL_FORWARDING)
1402 #define get_inet6_sysctl(code) inet6_sysctl(code, 0, 0)
1403 #define set_inet6_sysctl(code, val) inet6_sysctl(code, val, 1)
1404 static int
1405 inet6_sysctl(int code, int val, int action)
1406 {
1407 	int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
1408 	size_t size;
1409 
1410 	mib[3] = code;
1411 	size = sizeof(val);
1412 	if (action) {
1413 		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]),
1414 		    NULL, 0, &val, size) == -1)
1415 			return -1;
1416 		return 0;
1417 	}
1418 	if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), &val, &size, NULL, 0) == -1)
1419 		return -1;
1420 	return val;
1421 }
1422 #endif
1423 
1424 #ifdef IPV6_MANAGETEMPADDR
1425 #ifndef IPV6CTL_TEMPVLTIME
1426 #define get_inet6_sysctlbyname(code) inet6_sysctlbyname(code, 0, 0)
1427 #define set_inet6_sysctlbyname(code, val) inet6_sysctlbyname(code, val, 1)
1428 static int
1429 inet6_sysctlbyname(const char *name, int val, int action)
1430 {
1431 	size_t size;
1432 
1433 	size = sizeof(val);
1434 	if (action) {
1435 		if (sysctlbyname(name, NULL, 0, &val, size) == -1)
1436 			return -1;
1437 		return 0;
1438 	}
1439 	if (sysctlbyname(name, &val, &size, NULL, 0) == -1)
1440 		return -1;
1441 	return val;
1442 }
1443 #endif
1444 
1445 int
1446 ip6_use_tempaddr(__unused const char *ifname)
1447 {
1448 	int val;
1449 
1450 #ifdef IPV6CTL_USETEMPADDR
1451 	val = get_inet6_sysctl(IPV6CTL_USETEMPADDR);
1452 #else
1453 	val = get_inet6_sysctlbyname("net.inet6.ip6.use_tempaddr");
1454 #endif
1455 	return val == -1 ? 0 : val;
1456 }
1457 
1458 int
1459 ip6_temp_preferred_lifetime(__unused const char *ifname)
1460 {
1461 	int val;
1462 
1463 #ifdef IPV6CTL_TEMPPLTIME
1464 	val = get_inet6_sysctl(IPV6CTL_TEMPPLTIME);
1465 #else
1466 	val = get_inet6_sysctlbyname("net.inet6.ip6.temppltime");
1467 #endif
1468 	return val < 0 ? TEMP_PREFERRED_LIFETIME : val;
1469 }
1470 
1471 int
1472 ip6_temp_valid_lifetime(__unused const char *ifname)
1473 {
1474 	int val;
1475 
1476 #ifdef IPV6CTL_TEMPVLTIME
1477 	val = get_inet6_sysctl(IPV6CTL_TEMPVLTIME);
1478 #else
1479 	val = get_inet6_sysctlbyname("net.inet6.ip6.tempvltime");
1480 #endif
1481 	return val < 0 ? TEMP_VALID_LIFETIME : val;
1482 }
1483 #endif
1484 
1485 int
1486 ip6_forwarding(__unused const char *ifname)
1487 {
1488 	int val;
1489 
1490 #ifdef IPV6CTL_FORWARDING
1491 	val = get_inet6_sysctl(IPV6CTL_FORWARDING);
1492 #else
1493 	val = get_inet6_sysctlbyname("net.inet6.ip6.forwarding");
1494 #endif
1495 	return val < 0 ? 0 : val;
1496 }
1497 
1498 #ifdef SIOCIFAFATTACH
1499 static int
1500 af_attach(int s, const struct interface *ifp, int af)
1501 {
1502 	struct if_afreq ifar;
1503 
1504 	strlcpy(ifar.ifar_name, ifp->name, sizeof(ifar.ifar_name));
1505 	ifar.ifar_af = af;
1506 	return ioctl(s, SIOCIFAFATTACH, (void *)&ifar);
1507 }
1508 #endif
1509 
1510 #ifdef SIOCGIFXFLAGS
1511 static int
1512 set_ifxflags(int s, const struct interface *ifp)
1513 {
1514 	struct ifreq ifr;
1515 	int flags;
1516 
1517 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
1518 	if (ioctl(s, SIOCGIFXFLAGS, (void *)&ifr) == -1)
1519 		return -1;
1520 	flags = ifr.ifr_flags;
1521 #ifdef IFXF_NOINET6
1522 	flags &= ~IFXF_NOINET6;
1523 #endif
1524 	/*
1525 	 * If not doing autoconf, don't disable the kernel from doing it.
1526 	 * If we need to, we should have another option actively disable it.
1527 	 *
1528 	 * OpenBSD moved from kernel based SLAAC to userland via slaacd(8).
1529 	 * It has a similar featureset to dhcpcd such as stable private
1530 	 * addresses, but lacks the ability to handle DNS inside the RA
1531 	 * which is a serious shortfall in this day and age.
1532 	 * Appease their user base by working alongside slaacd(8) if
1533 	 * dhcpcd is instructed not to do auto configuration of addresses.
1534 	 */
1535 #if defined(ND6_IFF_ACCEPT_RTADV)
1536 #define	BSD_AUTOCONF	DHCPCD_IPV6RS
1537 #else
1538 #define	BSD_AUTOCONF	DHCPCD_IPV6RA_AUTOCONF
1539 #endif
1540 	if (ifp->options->options & BSD_AUTOCONF)
1541 		flags &= ~IFXF_AUTOCONF6;
1542 	if (ifr.ifr_flags == flags)
1543 		return 0;
1544 	ifr.ifr_flags = flags;
1545 	return ioctl(s, SIOCSIFXFLAGS, (void *)&ifr);
1546 }
1547 #endif
1548 
1549 /* OpenBSD removed ND6 flags entirely, so we need to check for their
1550  * existance. */
1551 #if defined(ND6_IFF_AUTO_LINKLOCAL) || \
1552     defined(ND6_IFF_PERFORMNUD) || \
1553     defined(ND6_IFF_ACCEPT_RTADV) || \
1554     defined(ND6_IFF_OVERRIDE_RTADV) || \
1555     defined(ND6_IFF_IFDISABLED)
1556 #define	ND6_NDI_FLAGS
1557 #endif
1558 
1559 void
1560 if_setup_inet6(const struct interface *ifp)
1561 {
1562 	struct priv *priv;
1563 	int s;
1564 #ifdef ND6_NDI_FLAGS
1565 	struct in6_ndireq nd;
1566 	int flags;
1567 #endif
1568 
1569 	priv = (struct priv *)ifp->ctx->priv;
1570 	s = priv->pf_inet6_fd;
1571 
1572 #ifdef ND6_NDI_FLAGS
1573 	memset(&nd, 0, sizeof(nd));
1574 	strlcpy(nd.ifname, ifp->name, sizeof(nd.ifname));
1575 	if (ioctl(s, SIOCGIFINFO_IN6, &nd) == -1)
1576 		logerr("%s: SIOCGIFINFO_FLAGS", ifp->name);
1577 	flags = (int)nd.ndi.flags;
1578 #endif
1579 
1580 #ifdef ND6_IFF_AUTO_LINKLOCAL
1581 	/* Unlike the kernel,
1582 	 * dhcpcd make make a stable private address. */
1583 	flags &= ~ND6_IFF_AUTO_LINKLOCAL;
1584 #endif
1585 
1586 #ifdef ND6_IFF_PERFORMNUD
1587 	/* NUD is kind of essential. */
1588 	flags |= ND6_IFF_PERFORMNUD;
1589 #endif
1590 
1591 #ifdef ND6_IFF_IFDISABLED
1592 	/* Ensure the interface is not disabled. */
1593 	flags &= ~ND6_IFF_IFDISABLED;
1594 #endif
1595 
1596 	/*
1597 	 * If not doing autoconf, don't disable the kernel from doing it.
1598 	 * If we need to, we should have another option actively disable it.
1599 	 */
1600 #ifdef ND6_IFF_ACCEPT_RTADV
1601 	if (ifp->options->options & DHCPCD_IPV6RS)
1602 		flags &= ~ND6_IFF_ACCEPT_RTADV;
1603 #ifdef ND6_IFF_OVERRIDE_RTADV
1604 	if (ifp->options->options & DHCPCD_IPV6RS)
1605 		flags |= ND6_IFF_OVERRIDE_RTADV;
1606 #endif
1607 #endif
1608 
1609 #ifdef ND6_NDI_FLAGS
1610 	if (nd.ndi.flags != (uint32_t)flags) {
1611 		nd.ndi.flags = (uint32_t)flags;
1612 		if (ioctl(s, SIOCSIFINFO_FLAGS, &nd) == -1)
1613 			logerr("%s: SIOCSIFINFO_FLAGS", ifp->name);
1614 	}
1615 #endif
1616 
1617 	/* Enabling IPv6 by whatever means must be the
1618 	 * last action undertaken to ensure kernel RS and
1619 	 * LLADDR auto configuration are disabled where applicable. */
1620 #ifdef SIOCIFAFATTACH
1621 	if (af_attach(s, ifp, AF_INET6) == -1)
1622 		logerr("%s: af_attach", ifp->name);
1623 #endif
1624 
1625 #ifdef SIOCGIFXFLAGS
1626 	if (set_ifxflags(s, ifp) == -1)
1627 		logerr("%s: set_ifxflags", ifp->name);
1628 #endif
1629 
1630 #if defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)
1631 	/* If we cannot control ra per interface, disable it globally. */
1632 	if (ifp->options->options & DHCPCD_IPV6RS) {
1633 		int ra = get_inet6_sysctl(IPV6CTL_ACCEPT_RTADV);
1634 
1635 		if (ra == -1) {
1636 			if (errno != ENOENT)
1637 				logerr("IPV6CTL_ACCEPT_RTADV");
1638 		else if (ra != 0)
1639 			if (set_inet6_sysctl(IPV6CTL_ACCEPT_RTADV, 0) == -1)
1640 				logerr("IPV6CTL_ACCEPT_RTADV");
1641 		}
1642 	}
1643 #endif
1644 
1645 #if defined(IPV6CTL_ACCEPT_RTADV) || defined(ND6_IFF_ACCEPT_RTADV)
1646 	/* Flush the kernel knowledge of advertised routers
1647 	 * and prefixes so the kernel does not expire prefixes
1648 	 * and default routes we are trying to own. */
1649 	if (ifp->options->options & DHCPCD_IPV6RS) {
1650 		struct in6_ifreq ifr;
1651 
1652 		memset(&ifr, 0, sizeof(ifr));
1653 		strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
1654 		if (ioctl(s, SIOCSRTRFLUSH_IN6, &ifr) == -1 &&
1655 		    errno != ENOTSUP)
1656 			logwarn("SIOCSRTRFLUSH_IN6");
1657 		if (ioctl(s, SIOCSPFXFLUSH_IN6, &ifr) == -1 &&
1658 		    errno != ENOTSUP)
1659 			logwarn("SIOCSPFXFLUSH_IN6");
1660 	}
1661 #endif
1662 }
1663 #endif
1664