xref: /openbsd-src/usr.sbin/arp/arp.c (revision c7e8ea31cd41a963f06f0a8ba93948b06aa6b4a4)
1 /*	$OpenBSD: arp.c,v 1.79 2017/04/19 05:36:12 natano Exp $ */
2 /*	$NetBSD: arp.c,v 1.12 1995/04/24 13:25:18 cgd Exp $ */
3 
4 /*
5  * Copyright (c) 1984, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Sun Microsystems, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 /*
37  * arp - display, set, delete arp table entries and wake up hosts.
38  */
39 
40 #include <sys/file.h>
41 #include <sys/socket.h>
42 #include <sys/sysctl.h>
43 #include <sys/time.h>
44 #include <sys/ioctl.h>
45 #include <net/bpf.h>
46 #include <net/if.h>
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/route.h>
50 #include <netinet/in.h>
51 #include <netinet/if_ether.h>
52 #include <arpa/inet.h>
53 
54 #include <netdb.h>
55 #include <errno.h>
56 #include <err.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <paths.h>
61 #include <unistd.h>
62 #include <limits.h>
63 #include <ifaddrs.h>
64 
65 void dump(void);
66 int delete(const char *);
67 void search(in_addr_t addr, void (*action)(struct sockaddr_dl *sdl,
68 	struct sockaddr_inarp *sin, struct rt_msghdr *rtm));
69 void print_entry(struct sockaddr_dl *sdl,
70 	struct sockaddr_inarp *sin, struct rt_msghdr *rtm);
71 void nuke_entry(struct sockaddr_dl *sdl,
72 	struct sockaddr_inarp *sin, struct rt_msghdr *rtm);
73 static char *ether_str(struct sockaddr_dl *);
74 int wake(const char *ether_addr, const char *iface);
75 int file(char *);
76 int get(const char *);
77 int getinetaddr(const char *, struct in_addr *);
78 void getsocket(void);
79 int rtget(struct sockaddr_inarp **, struct sockaddr_dl **);
80 int rtmsg(int);
81 int set(int, char **);
82 void usage(void);
83 static char *sec2str(time_t);
84 
85 static pid_t pid;
86 static int replace;	/* replace entries when adding */
87 static int nflag;	/* no reverse dns lookups */
88 static int aflag;	/* do it for all entries */
89 static int rtsock = -1;
90 static int rdomain;
91 
92 extern int h_errno;
93 
94 /* ROUNDUP() is nasty, but it is identical to what's in the kernel. */
95 #define ROUNDUP(a)					\
96 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
97 
98 /* which function we're supposed to do */
99 #define F_GET		1
100 #define F_SET		2
101 #define F_FILESET	3
102 #define F_DELETE	4
103 #define F_WAKE		5
104 
105 int
106 main(int argc, char *argv[])
107 {
108 	int		 ch, func = 0, error = 0;
109 	const char	*errstr;
110 
111 	pid = getpid();
112 	opterr = 0;
113 	rdomain = getrtable();
114 	while ((ch = getopt(argc, argv, "andsFfV:W")) != -1) {
115 		switch (ch) {
116 		case 'a':
117 			aflag = 1;
118 			break;
119 		case 'n':
120 			nflag = 1;
121 			break;
122 		case 'd':
123 			if (func)
124 				usage();
125 			func = F_DELETE;
126 			break;
127 		case 's':
128 			if (func)
129 				usage();
130 			func = F_SET;
131 			break;
132 		case 'F':
133 			replace = 1;
134 			break;
135 		case 'f':
136 			if (func)
137 				usage();
138 			func = F_FILESET;
139 			break;
140 		case 'V':
141 			rdomain = strtonum(optarg, 0, RT_TABLEID_MAX, &errstr);
142 			if (errstr != NULL) {
143 				warn("bad rdomain: %s", errstr);
144 				usage();
145 			}
146 			break;
147 		case 'W':
148 			if (func)
149 				usage();
150 			func = F_WAKE;
151 			break;
152 		default:
153 			usage();
154 			break;
155 		}
156 	}
157 	argc -= optind;
158 	argv += optind;
159 
160 	if (!func)
161 		func = F_GET;
162 
163 	switch (func) {
164 	case F_GET:
165 		if (aflag && argc == 0)
166 			dump();
167 		else if (!aflag && argc == 1)
168 			error = get(argv[0]);
169 		else
170 			usage();
171 		break;
172 	case F_SET:
173 		if (argc < 2 || argc > 5)
174 			usage();
175 		if (replace)
176 			delete(argv[0]);
177 		error = set(argc, argv) ? 1 : 0;
178 		break;
179 	case F_DELETE:
180 		if (aflag && argc == 0)
181 			search(0, nuke_entry);
182 		else if (!aflag && argc == 1)
183 			error = delete(argv[0]);
184 		else
185 			usage();
186 		break;
187 	case F_FILESET:
188 		if (argc != 1)
189 			usage();
190 		error = file(argv[0]);
191 		break;
192 	case F_WAKE:
193 		if (aflag || nflag || replace || rdomain > 0)
194 			usage();
195 		if (argc == 1)
196 			error = wake(argv[0], NULL);
197 		else if (argc == 2)
198 			error = wake(argv[0], argv[1]);
199 		else
200 			usage();
201 		break;
202 	}
203 	return (error);
204 }
205 
206 /*
207  * Process a file to set standard arp entries
208  */
209 int
210 file(char *name)
211 {
212 	char	 line[100], arg[5][50], *args[5];
213 	int	 i, retval;
214 	FILE	*fp;
215 
216 	if ((fp = fopen(name, "r")) == NULL)
217 		err(1, "cannot open %s", name);
218 	args[0] = &arg[0][0];
219 	args[1] = &arg[1][0];
220 	args[2] = &arg[2][0];
221 	args[3] = &arg[3][0];
222 	args[4] = &arg[4][0];
223 	retval = 0;
224 	while (fgets(line, sizeof(line), fp) != NULL) {
225 		i = sscanf(line, "%49s %49s %49s %49s %49s", arg[0], arg[1],
226 		    arg[2], arg[3], arg[4]);
227 		if (i < 2) {
228 			warnx("bad line: %s", line);
229 			retval = 1;
230 			continue;
231 		}
232 		if (replace)
233 			delete(arg[0]);
234 		if (set(i, args))
235 			retval = 1;
236 	}
237 	fclose(fp);
238 	return (retval);
239 }
240 
241 void
242 getsocket(void)
243 {
244 	socklen_t len = sizeof(rdomain);
245 
246 	if (rtsock >= 0)
247 		return;
248 	rtsock = socket(PF_ROUTE, SOCK_RAW, 0);
249 	if (rtsock < 0)
250 		err(1, "routing socket");
251 	if (setsockopt(rtsock, PF_ROUTE, ROUTE_TABLEFILTER, &rdomain, len) < 0)
252 		err(1, "ROUTE_TABLEFILTER");
253 
254 	if (pledge("stdio dns", NULL) == -1)
255 		err(1, "pledge");
256 }
257 
258 struct sockaddr_in	so_mask = { 8, 0, 0, { 0xffffffff } };
259 struct sockaddr_inarp	blank_sin = { sizeof(blank_sin), AF_INET }, sin_m;
260 struct sockaddr_dl	blank_sdl = { sizeof(blank_sdl), AF_LINK }, sdl_m;
261 struct sockaddr_dl	ifp_m = { sizeof(&ifp_m), AF_LINK };
262 time_t			expire_time;
263 int			flags, export_only, doing_proxy, found_entry;
264 struct	{
265 	struct rt_msghdr	m_rtm;
266 	char			m_space[512];
267 }	m_rtmsg;
268 
269 /*
270  * Set an individual arp entry
271  */
272 int
273 set(int argc, char *argv[])
274 {
275 	struct sockaddr_inarp *sin;
276 	struct sockaddr_dl *sdl;
277 	struct rt_msghdr *rtm;
278 	char *eaddr = argv[1], *host = argv[0];
279 	struct ether_addr *ea;
280 
281 	sin = &sin_m;
282 	rtm = &(m_rtmsg.m_rtm);
283 
284 	getsocket();
285 	argc -= 2;
286 	argv += 2;
287 	sdl_m = blank_sdl;		/* struct copy */
288 	sin_m = blank_sin;		/* struct copy */
289 	if (getinetaddr(host, &sin->sin_addr) == -1)
290 		return (1);
291 	ea = ether_aton(eaddr);
292 	if (ea == NULL)
293 		errx(1, "invalid ethernet address: %s", eaddr);
294 	memcpy(LLADDR(&sdl_m), ea, sizeof(*ea));
295 	sdl_m.sdl_alen = 6;
296 	expire_time = 0;
297 	doing_proxy = flags = export_only = 0;
298 	while (argc-- > 0) {
299 		if (strncmp(argv[0], "temp", 4) == 0) {
300 			struct timeval now;
301 
302 			gettimeofday(&now, 0);
303 			expire_time = now.tv_sec + 20 * 60;
304 			if (flags & RTF_PERMANENT_ARP) {
305 				/* temp or permanent, not both */
306 				usage();
307 				return (0);
308 			}
309 		} else if (strncmp(argv[0], "pub", 3) == 0) {
310 			flags |= RTF_ANNOUNCE;
311 			doing_proxy = SIN_PROXY;
312 		} else if (strncmp(argv[0], "permanent", 9) == 0) {
313 			flags |= RTF_PERMANENT_ARP;
314 			if (expire_time != 0) {
315 				/* temp or permanent, not both */
316 				usage();
317 				return (0);
318 			}
319 		}
320 
321 		argv++;
322 	}
323 
324 tryagain:
325 	if (rtget(&sin, &sdl)) {
326 		warn("%s", host);
327 		return (1);
328 	}
329 
330 	if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
331 		if (sdl->sdl_family == AF_LINK &&
332 		    (rtm->rtm_flags & RTF_LLINFO) &&
333 		    !(rtm->rtm_flags & RTF_GATEWAY))
334 			switch (sdl->sdl_type) {
335 			case IFT_ETHER:
336 			case IFT_FDDI:
337 			case IFT_ISO88023:
338 			case IFT_ISO88024:
339 			case IFT_ISO88025:
340 			case IFT_CARP:
341 				goto overwrite;
342 			}
343 
344 		if (doing_proxy == 0) {
345 			printf("set: can only proxy for %s\n", host);
346 			return (1);
347 		}
348 		if (sin_m.sin_other & SIN_PROXY) {
349 			printf("set: proxy entry exists for non 802 device\n");
350 			return (1);
351 		}
352 		sin_m.sin_other = SIN_PROXY;
353 		export_only = 1;
354 		goto tryagain;
355 	}
356 
357 overwrite:
358 	if (sdl->sdl_family != AF_LINK) {
359 		printf("cannot intuit interface index and type for %s\n", host);
360 		return (1);
361 	}
362 	sdl_m.sdl_type = sdl->sdl_type;
363 	sdl_m.sdl_index = sdl->sdl_index;
364 	return (rtmsg(RTM_ADD));
365 }
366 
367 #define W_ADDR	36
368 #define W_LL	17
369 #define W_IF	7
370 
371 /*
372  * Display an individual arp entry
373  */
374 int
375 get(const char *host)
376 {
377 	struct sockaddr_inarp *sin;
378 
379 	sin = &sin_m;
380 	sin_m = blank_sin;		/* struct copy */
381 	if (getinetaddr(host, &sin->sin_addr) == -1)
382 		exit(1);
383 
384 	printf("%-*.*s %-*.*s %*.*s %-9.9s %5s\n",
385 	    W_ADDR, W_ADDR, "Host", W_LL, W_LL, "Ethernet Address",
386 	    W_IF, W_IF, "Netif", "Expire", "Flags");
387 
388 	search(sin->sin_addr.s_addr, print_entry);
389 	if (found_entry == 0) {
390 		printf("%-*.*s no entry\n", W_ADDR, W_ADDR,
391 		    inet_ntoa(sin->sin_addr));
392 		return (1);
393 	}
394 	return (0);
395 }
396 
397 /*
398  * Delete an arp entry
399  */
400 int
401 delete(const char *host)
402 {
403 	struct sockaddr_inarp *sin;
404 	struct rt_msghdr *rtm;
405 	struct sockaddr_dl *sdl;
406 
407 	sin = &sin_m;
408 	rtm = &m_rtmsg.m_rtm;
409 
410 	getsocket();
411 	sin_m = blank_sin;		/* struct copy */
412 	if (getinetaddr(host, &sin->sin_addr) == -1)
413 		return (1);
414 tryagain:
415 	if (rtget(&sin, &sdl)) {
416 		warn("%s", host);
417 		return (1);
418 	}
419 	if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
420 		if (sdl->sdl_family == AF_LINK && rtm->rtm_flags & RTF_LLINFO) {
421 			if (rtm->rtm_flags & RTF_LOCAL)
422 				return (0);
423 		    	if (!(rtm->rtm_flags & RTF_GATEWAY))
424 				switch (sdl->sdl_type) {
425 				case IFT_ETHER:
426 				case IFT_FDDI:
427 				case IFT_ISO88023:
428 				case IFT_ISO88024:
429 				case IFT_ISO88025:
430 				case IFT_CARP:
431 					goto delete;
432 				}
433 		}
434 	}
435 
436 	if (sin_m.sin_other & SIN_PROXY) {
437 		warnx("delete: can't locate %s", host);
438 		return (1);
439 	} else {
440 		sin_m.sin_other = SIN_PROXY;
441 		goto tryagain;
442 	}
443 delete:
444 	if (sdl->sdl_family != AF_LINK) {
445 		printf("cannot locate %s\n", host);
446 		return (1);
447 	}
448 	if (rtmsg(RTM_DELETE))
449 		return (1);
450 	printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
451 	return (0);
452 }
453 
454 /*
455  * Search the entire arp table, and do some action on matching entries.
456  */
457 void
458 search(in_addr_t addr, void (*action)(struct sockaddr_dl *sdl,
459     struct sockaddr_inarp *sin, struct rt_msghdr *rtm))
460 {
461 	int mib[7];
462 	size_t needed;
463 	char *lim, *buf = NULL, *next;
464 	struct rt_msghdr *rtm;
465 	struct sockaddr_inarp *sin;
466 	struct sockaddr_dl *sdl;
467 
468 	mib[0] = CTL_NET;
469 	mib[1] = PF_ROUTE;
470 	mib[2] = 0;
471 	mib[3] = AF_INET;
472 	mib[4] = NET_RT_FLAGS;
473 	mib[5] = RTF_LLINFO;
474 	mib[6] = rdomain;
475 	while (1) {
476 		if (sysctl(mib, 7, NULL, &needed, NULL, 0) == -1)
477 			err(1, "route-sysctl-estimate");
478 		if (needed == 0)
479 			return;
480 		if ((buf = realloc(buf, needed)) == NULL)
481 			err(1, "malloc");
482 		if (sysctl(mib, 7, buf, &needed, NULL, 0) == -1) {
483 			if (errno == ENOMEM)
484 				continue;
485 			err(1, "actual retrieval of routing table");
486 		}
487 		lim = buf + needed;
488 		break;
489 	}
490 	for (next = buf; next < lim; next += rtm->rtm_msglen) {
491 		rtm = (struct rt_msghdr *)next;
492 		if (rtm->rtm_version != RTM_VERSION)
493 			continue;
494 		sin = (struct sockaddr_inarp *)(next + rtm->rtm_hdrlen);
495 		sdl = (struct sockaddr_dl *)(sin + 1);
496 		if (addr) {
497 			if (addr != sin->sin_addr.s_addr)
498 				continue;
499 			found_entry = 1;
500 		}
501 		(*action)(sdl, sin, rtm);
502 	}
503 	free(buf);
504 }
505 
506 /*
507  * Dump the entire ARP table
508  */
509 void
510 dump(void)
511 {
512 	printf("%-*.*s %-*.*s %*.*s %-9.9s %5s\n",
513 	    W_ADDR, W_ADDR, "Host", W_LL, W_LL, "Ethernet Address",
514 	    W_IF, W_IF, "Netif", "Expire", "Flags");
515 
516 	search(0, print_entry);
517 }
518 
519 /*
520  * Display an arp entry
521  */
522 void
523 print_entry(struct sockaddr_dl *sdl, struct sockaddr_inarp *sin,
524     struct rt_msghdr *rtm)
525 {
526 	char ifix_buf[IFNAMSIZ], *ifname, *host;
527 	struct hostent *hp = NULL;
528 	int addrwidth, llwidth, ifwidth ;
529 	struct timeval now;
530 
531 	gettimeofday(&now, 0);
532 
533 	if (nflag == 0)
534 		hp = gethostbyaddr((caddr_t)&(sin->sin_addr),
535 		    sizeof(sin->sin_addr), AF_INET);
536 	if (hp)
537 		host = hp->h_name;
538 	else
539 		host = inet_ntoa(sin->sin_addr);
540 
541 	addrwidth = strlen(host);
542 	if (addrwidth < W_ADDR)
543 		addrwidth = W_ADDR;
544 	llwidth = strlen(ether_str(sdl));
545 	if (W_ADDR + W_LL - addrwidth > llwidth)
546 		llwidth = W_ADDR + W_LL - addrwidth;
547 	ifname = if_indextoname(sdl->sdl_index, ifix_buf);
548 	if (!ifname)
549 		ifname = "?";
550 	ifwidth = strlen(ifname);
551 	if (W_ADDR + W_LL + W_IF - addrwidth - llwidth > ifwidth)
552 		ifwidth = W_ADDR + W_LL + W_IF - addrwidth - llwidth;
553 
554 	printf("%-*.*s %-*.*s %*.*s", addrwidth, addrwidth, host,
555 	    llwidth, llwidth, ether_str(sdl), ifwidth, ifwidth, ifname);
556 
557 	if (rtm->rtm_flags & (RTF_PERMANENT_ARP|RTF_LOCAL))
558 		printf(" %-9.9s", "permanent");
559 	else if (rtm->rtm_rmx.rmx_expire == 0)
560 		printf(" %-9.9s", "static");
561 	else if (rtm->rtm_rmx.rmx_expire > now.tv_sec)
562 		printf(" %-9.9s",
563 		    sec2str(rtm->rtm_rmx.rmx_expire - now.tv_sec));
564 	else
565 		printf(" %-9.9s", "expired");
566 
567 	printf(" %s%s\n",
568 	    (rtm->rtm_flags & RTF_LOCAL) ? "l" : "",
569 	    (rtm->rtm_flags & RTF_ANNOUNCE) ? "p" : "");
570 }
571 
572 /*
573  * Nuke an arp entry
574  */
575 void
576 nuke_entry(struct sockaddr_dl *sdl, struct sockaddr_inarp *sin,
577     struct rt_msghdr *rtm)
578 {
579 	char ip[20];
580 
581 	strlcpy(ip, inet_ntoa(sin->sin_addr), sizeof(ip));
582 	delete(ip);
583 }
584 
585 static char *
586 ether_str(struct sockaddr_dl *sdl)
587 {
588 	static char hbuf[NI_MAXHOST];
589 	u_char *cp;
590 
591 	if (sdl->sdl_alen) {
592 		cp = (u_char *)LLADDR(sdl);
593 		snprintf(hbuf, sizeof(hbuf), "%02x:%02x:%02x:%02x:%02x:%02x",
594 		    cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
595 	} else
596 		snprintf(hbuf, sizeof(hbuf), "(incomplete)");
597 
598 	return(hbuf);
599 }
600 
601 void
602 usage(void)
603 {
604 	fprintf(stderr, "usage: arp [-adn] [-V rdomain] hostname\n");
605 	fprintf(stderr, "       arp [-F] [-f file] [-V rdomain] "
606 	    "-s hostname ether_addr\n"
607 	    "           [temp | permanent] [pub]\n");
608 	fprintf(stderr, "       arp -W ether_addr [iface]\n");
609 	exit(1);
610 }
611 
612 int
613 rtmsg(int cmd)
614 {
615 	static int seq;
616 	struct rt_msghdr *rtm;
617 	char *cp;
618 	int l;
619 
620 	rtm = &m_rtmsg.m_rtm;
621 	cp = m_rtmsg.m_space;
622 	errno = 0;
623 
624 	if (cmd == RTM_DELETE)
625 		goto doit;
626 	memset(&m_rtmsg, 0, sizeof(m_rtmsg));
627 	rtm->rtm_flags = flags;
628 	rtm->rtm_version = RTM_VERSION;
629 	rtm->rtm_hdrlen = sizeof(*rtm);
630 	rtm->rtm_tableid = rdomain;
631 
632 	switch (cmd) {
633 	default:
634 		errx(1, "internal wrong cmd");
635 		/*NOTREACHED*/
636 	case RTM_ADD:
637 		rtm->rtm_addrs |= RTA_GATEWAY;
638 		rtm->rtm_rmx.rmx_expire = expire_time;
639 		rtm->rtm_inits = RTV_EXPIRE;
640 		rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
641 		sin_m.sin_other = 0;
642 		if (doing_proxy) {
643 			if (export_only)
644 				sin_m.sin_other = SIN_PROXY;
645 			else {
646 				rtm->rtm_addrs |= RTA_NETMASK;
647 				rtm->rtm_flags &= ~RTF_HOST;
648 			}
649 		}
650 		/* FALLTHROUGH */
651 	case RTM_GET:
652 		rtm->rtm_addrs |= (RTA_DST | RTA_IFP);
653 	}
654 
655 #define NEXTADDR(w, s)					\
656 	if (rtm->rtm_addrs & (w)) {			\
657 		memcpy(cp, &s, sizeof(s));		\
658 		cp += ROUNDUP(sizeof(s));		\
659 	}
660 
661 	NEXTADDR(RTA_DST, sin_m);
662 	NEXTADDR(RTA_GATEWAY, sdl_m);
663 	NEXTADDR(RTA_NETMASK, so_mask);
664 	NEXTADDR(RTA_IFP, ifp_m);
665 
666 	rtm->rtm_msglen = cp - (char *)&m_rtmsg;
667 doit:
668 	l = rtm->rtm_msglen;
669 	rtm->rtm_seq = ++seq;
670 	rtm->rtm_type = cmd;
671 	if (write(rtsock, (char *)&m_rtmsg, l) < 0)
672 		if (errno != ESRCH || cmd != RTM_DELETE) {
673 			warn("writing to routing socket");
674 			return (-1);
675 		}
676 
677 	do {
678 		l = read(rtsock, (char *)&m_rtmsg, sizeof(m_rtmsg));
679 	} while (l > 0 && (rtm->rtm_version != RTM_VERSION ||
680 	    rtm->rtm_seq != seq || rtm->rtm_pid != pid));
681 
682 	if (l < 0)
683 		warn("read from routing socket");
684 	return (0);
685 }
686 
687 int
688 rtget(struct sockaddr_inarp **sinp, struct sockaddr_dl **sdlp)
689 {
690 	struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
691 	struct sockaddr_inarp *sin = NULL;
692 	struct sockaddr_dl *sdl = NULL;
693 	struct sockaddr *sa;
694 	char *cp;
695 	unsigned int i;
696 
697 	if (rtmsg(RTM_GET) < 0)
698 		return (1);
699 
700 	if (rtm->rtm_addrs) {
701 		cp = ((char *)rtm + rtm->rtm_hdrlen);
702 		for (i = 1; i; i <<= 1) {
703 			if (i & rtm->rtm_addrs) {
704 				sa = (struct sockaddr *)cp;
705 				switch (i) {
706 				case RTA_DST:
707 					sin = (struct sockaddr_inarp *)sa;
708 					break;
709 				case RTA_IFP:
710 					sdl = (struct sockaddr_dl *)sa;
711 					break;
712 				default:
713 					break;
714 				}
715 				cp += ROUNDUP(sa->sa_len);
716 			}
717 		}
718 	}
719 
720 	if (sin == NULL || sdl == NULL)
721 		return (1);
722 
723 	*sinp = sin;
724 	*sdlp = sdl;
725 
726 	return (0);
727 }
728 
729 int
730 getinetaddr(const char *host, struct in_addr *inap)
731 {
732 	struct hostent *hp;
733 
734 	if (inet_aton(host, inap) == 1)
735 		return (0);
736 	if ((hp = gethostbyname(host)) == NULL) {
737 		warnx("%s: %s", host, hstrerror(h_errno));
738 		return (-1);
739 	}
740 	memcpy(inap, hp->h_addr, sizeof(*inap));
741 	return (0);
742 }
743 
744 static char *
745 sec2str(time_t total)
746 {
747 	static char result[256];
748 	int days, hours, mins, secs;
749 	int first = 1;
750 	char *p = result;
751 	char *ep = &result[sizeof(result)];
752 	int n;
753 
754 	days = total / 3600 / 24;
755 	hours = (total / 3600) % 24;
756 	mins = (total / 60) % 60;
757 	secs = total % 60;
758 
759 	if (days) {
760 		first = 0;
761 		n = snprintf(p, ep - p, "%dd", days);
762 		if (n < 0 || n >= ep - p)
763 			return "?";
764 		p += n;
765 	}
766 	if (!first || hours) {
767 		first = 0;
768 		n = snprintf(p, ep - p, "%dh", hours);
769 		if (n < 0 || n >= ep - p)
770 			return "?";
771 		p += n;
772 	}
773 	if (!first || mins) {
774 		first = 0;
775 		n = snprintf(p, ep - p, "%dm", mins);
776 		if (n < 0 || n >= ep - p)
777 			return "?";
778 		p += n;
779 	}
780 	snprintf(p, ep - p, "%ds", secs);
781 
782 	return(result);
783 }
784 
785 /*
786  * Copyright (c) 2011 Jasper Lievisse Adriaanse <jasper@openbsd.org>
787  * Copyright (C) 2006,2007,2008,2009 Marc Balmer <mbalmer@openbsd.org>
788  * Copyright (C) 2000 Eugene M. Kim.  All rights reserved.
789  *
790  * Redistribution and use in source and binary forms, with or without
791  * modification, are permitted provided that the following conditions
792  * are met:
793  *
794  * 1. Redistributions of source code must retain the above copyright
795  *    notice, this list of conditions and the following disclaimer.
796  * 2. Author's name may not be used endorse or promote products derived
797  *    from this software without specific prior written permission.
798  *
799  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
800  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
801  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
802  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
803  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
804  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
805  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
806  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
807  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
808  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
809  * POSSIBILITY OF SUCH DAMAGE.
810  */
811 
812 int	do_wakeup(const char *, const char *, int);
813 int	bind_if_to_bpf(const char *, int);
814 int	get_ether(const char *, struct ether_addr *);
815 int	send_frame(int, const struct ether_addr *);
816 
817 int
818 wake(const char *ether_addr, const char *iface)
819 {
820 	struct ifaddrs		*ifa, *ifap;
821 	char			*pname = NULL;
822 	int			 bpf;
823 
824 	if ((bpf = open("/dev/bpf", O_RDWR)) == -1)
825 		err(1, "Failed to bind to bpf");
826 
827 	if (iface == NULL) {
828 		if (getifaddrs(&ifa) == -1)
829 			errx(1, "Could not get interface addresses.");
830 
831 		for (ifap = ifa; ifap != NULL; ifap = ifap->ifa_next){
832 			if (pname && !strcmp(pname, ifap->ifa_name))
833 				continue;
834 			pname = ifap->ifa_name;
835 
836 			/*
837 			 * We're only interested in sending the WoL frame on
838 			 * certain interfaces. So skip the loopback interface,
839 			 * as well as point-to-point and down interfaces.
840 			 */
841 			if ((ifap->ifa_flags & IFF_LOOPBACK) ||
842 			    (ifap->ifa_flags & IFF_POINTOPOINT) ||
843 			    (!(ifap->ifa_flags & IFF_UP)) ||
844 			    (!(ifap->ifa_flags & IFF_BROADCAST)))
845 				continue;
846 
847 			do_wakeup(ether_addr, ifap->ifa_name, bpf);
848 		}
849 		freeifaddrs(ifa);
850 	} else {
851 		do_wakeup(ether_addr, iface, bpf);
852 	}
853 
854 	(void)close(bpf);
855 
856 	return 0;
857 }
858 
859 int
860 do_wakeup(const char *eaddr, const char *iface, int bpf)
861 {
862 	struct ether_addr	 macaddr;
863 
864 	if (get_ether(eaddr, &macaddr) != 0)
865 		errx(1, "Invalid Ethernet address: %s", eaddr);
866 	if (bind_if_to_bpf(iface, bpf) != 0)
867 		errx(1, "Failed to bind %s to bpf.", iface);
868 	if (send_frame(bpf, &macaddr) != 0)
869 		errx(1, "Failed to send WoL frame on %s", iface);
870 	return 0;
871 }
872 
873 int
874 bind_if_to_bpf(const char *ifname, int bpf)
875 {
876 	struct ifreq ifr;
877 	u_int dlt;
878 
879 	if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
880 	    sizeof(ifr.ifr_name))
881 		return -1;
882 	if (ioctl(bpf, BIOCSETIF, &ifr) == -1)
883 		return -1;
884 	if (ioctl(bpf, BIOCGDLT, &dlt) == -1)
885 		return -1;
886 	if (dlt != DLT_EN10MB)
887 		return -1;
888 	return 0;
889 }
890 
891 int
892 get_ether(const char *text, struct ether_addr *addr)
893 {
894 	struct ether_addr *eaddr;
895 
896 	eaddr = ether_aton(text);
897 
898 	if (eaddr == NULL) {
899 		if (ether_hostton(text, addr))
900 			return -1;
901 	} else {
902 		*addr = *eaddr;
903 		return 0;
904 	}
905 
906 	return 0;
907 }
908 
909 #define SYNC_LEN 6
910 #define DESTADDR_COUNT 16
911 
912 int
913 send_frame(int bpf, const struct ether_addr *addr)
914 {
915 	struct {
916 		struct ether_header hdr;
917 		u_char sync[SYNC_LEN];
918 		u_char dest[ETHER_ADDR_LEN * DESTADDR_COUNT];
919 	} __packed pkt;
920 	u_char *p;
921 	int i;
922 
923 	(void)memset(&pkt, 0, sizeof(pkt));
924 	(void)memset(&pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
925 	pkt.hdr.ether_type = htons(0);
926 	(void)memset(pkt.sync, 0xff, SYNC_LEN);
927 	for (p = pkt.dest, i = 0; i < DESTADDR_COUNT; p += ETHER_ADDR_LEN, i++)
928 		bcopy(addr->ether_addr_octet, p, ETHER_ADDR_LEN);
929 	if (write(bpf, &pkt, sizeof(pkt)) != sizeof(pkt))
930 		return (errno);
931 	return (0);
932 }
933