xref: /netbsd-src/usr.sbin/arp/arp.c (revision 2ead7eac293d9909052581ccfb0733bea7c991e5)
1 /*	$NetBSD: arp.c,v 1.68 2020/09/15 11:14:16 roy Exp $ */
2 
3 /*
4  * Copyright (c) 1984, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Sun Microsystems, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 __COPYRIGHT("@(#) Copyright (c) 1984, 1993\
38  The Regents of the University of California.  All rights reserved.");
39 #endif /* not lint */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)arp.c	8.3 (Berkeley) 4/28/95";
44 #else
45 __RCSID("$NetBSD: arp.c,v 1.68 2020/09/15 11:14:16 roy Exp $");
46 #endif
47 #endif /* not lint */
48 
49 /*
50  * arp - display, set, and delete arp table entries
51  */
52 
53 #include <sys/param.h>
54 #include <sys/file.h>
55 #include <sys/socket.h>
56 #include <sys/sysctl.h>
57 #include <sys/ioctl.h>
58 
59 #include <net/if.h>
60 #include <net/if_dl.h>
61 #include <net/if_ether.h>
62 #include <net/if_types.h>
63 #include <net/nd.h>
64 #include <net/route.h>
65 #include <netinet/in.h>
66 #include <netinet/in_var.h>
67 #include <netinet/if_inarp.h>
68 #include <arpa/inet.h>
69 
70 #include <err.h>
71 #include <errno.h>
72 #include <netdb.h>
73 #include <nlist.h>
74 #include <paths.h>
75 #include <stdio.h>
76 #include <stdlib.h>
77 #include <string.h>
78 #include <unistd.h>
79 #include <ifaddrs.h>
80 
81 #include "prog_ops.h"
82 
83 static int is_llinfo(const struct sockaddr_dl *, int);
84 static int delete_one(struct rt_msghdr *);
85 static void dump(uint32_t);
86 static void delete(const char *, const char *);
87 static void sdl_print(const struct sockaddr_dl *);
88 static int getifname(u_int16_t, char *, size_t);
89 static int atosdl(const char *, struct sockaddr_dl *);
90 static int file(const char *);
91 static void get(const char *);
92 static int getinetaddr(const char *, struct in_addr *);
93 static int getsocket(void);
94 static int getetheraddr(struct in_addr, struct sockaddr_dl *);
95 static struct rt_msghdr * rtmsg(const int, const int,  struct rt_msghdr *,
96 	const struct sockaddr_inarp *, const struct sockaddr_dl *);
97 static struct in_nbrinfo * getnbrinfo(const char *, struct in_addr *);
98 static const char * sec2str(time_t);
99 static int set(int, char **);
100 static void usage(void) __dead;
101 
102 static int aflag, nflag, vflag;
103 static struct sockaddr_in so_mask = {
104 	.sin_len = 8,
105 	.sin_addr = {
106 		.s_addr = 0xffffffff
107 	}
108 };
109 static struct sockaddr_inarp blank_sin = {
110 	.sin_len = sizeof(blank_sin),
111 	.sin_family = AF_INET
112 };
113 static struct sockaddr_dl blank_sdl = {
114 	.sdl_len = sizeof(blank_sdl),
115 	.sdl_family = AF_LINK
116 };
117 
118 static int expire_time, flags, export_only, doing_proxy, found_entry;
119 
120 int
main(int argc,char ** argv)121 main(int argc, char **argv)
122 {
123 	int ch;
124 	int op = 0;
125 
126 	setprogname(argv[0]);
127 
128 	while ((ch = getopt(argc, argv, "andsfv")) != -1)
129 		switch((char)ch) {
130 		case 'a':
131 			aflag = 1;
132 			break;
133 		case 'd':
134 		case 's':
135 		case 'f':
136 			if (op)
137 				usage();
138 			op = ch;
139 			break;
140 		case 'n':
141 			nflag = 1;
142 			break;
143 		case 'v':
144 			vflag = 1;
145 			break;
146 		default:
147 			usage();
148 		}
149 	argc -= optind;
150 	argv += optind;
151 
152 	if (!op && aflag)
153 		op = 'a';
154 
155 	if (prog_init && prog_init() == -1)
156 		err(1, "init failed");
157 
158 	switch((char)op) {
159 	case 'a':
160 		dump(0);
161 		break;
162 	case 'd':
163 		if (aflag && argc == 0)
164 			delete(NULL, NULL);
165 		else {
166 			if (aflag || argc < 1 || argc > 2)
167 				usage();
168 			delete(argv[0], argv[1]);
169 		}
170 		break;
171 	case 's':
172 		if (argc < 2 || argc > 7)
173 			usage();
174 		return (set(argc, argv) ? 1 : 0);
175 	case 'f':
176 		if (argc != 1)
177 			usage();
178 		return (file(argv[0]));
179 	default:
180 		if (argc != 1)
181 			usage();
182 		get(argv[0]);
183 		break;
184 	}
185 	return (0);
186 }
187 
188 /*
189  * Process a file to set standard arp entries
190  */
191 static int
file(const char * name)192 file(const char *name)
193 {
194 	char *line, *argv[5];
195 	int i, retval;
196 	FILE *fp;
197 
198 	if (!strcmp(name, "-")) {
199 		fp = stdin;
200 	} else {
201 		fp = fopen(name, "r");
202 		if (fp == NULL) {
203 			err(1, "Cannot open %s", name);
204 		}
205 	}
206 	retval = 0;
207 	for (; (line = fparseln(fp, NULL, NULL, NULL, 0)) != NULL; free(line)) {
208 		char **ap, *inputstring;
209 
210 		inputstring = line;
211 		for (ap = argv; ap < &argv[sizeof(argv) / sizeof(argv[0])] &&
212 		    (*ap = stresep(&inputstring, " \t", '\\')) != NULL;) {
213 			if (**ap != '\0')
214 				ap++;
215 		}
216 		i = ap - argv;
217 		if (i < 2) {
218 			warnx("bad line: %s", line);
219 			retval = 1;
220 			continue;
221 		}
222 		if (set(i, argv))
223 			retval = 1;
224 	}
225 	if (fp != stdin)
226 		(void)fclose(fp);
227 	return retval;
228 }
229 
230 static int
getsocket(void)231 getsocket(void)
232 {
233 	int s;
234 	s = prog_socket(PF_ROUTE, SOCK_RAW, 0);
235 	if (s < 0)
236 		err(1, "socket");
237 	return s;
238 }
239 
240 static int
getlink(const char * name,struct sockaddr_dl * sdl)241 getlink(const char *name, struct sockaddr_dl *sdl)
242 {
243 	struct ifaddrs *ifap, *ifa;
244 
245 	if (getifaddrs(&ifap) != 0) {
246 		warn("getifaddrs");
247 		return 0;
248 	}
249 
250 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
251 		if (ifa->ifa_addr->sa_family != AF_LINK)
252 			continue;
253 		if (strcmp(ifa->ifa_name, name) != 0)
254 			continue;
255 		memcpy(sdl, ifa->ifa_addr, sizeof(*sdl));
256 		freeifaddrs(ifap);
257 		return 1;
258 	}
259 	freeifaddrs(ifap);
260 	return 0;
261 }
262 
263 /*
264  * Set an individual arp entry
265  */
266 static int
set(int argc,char ** argv)267 set(int argc, char **argv)
268 {
269 	struct sockaddr_inarp *sina;
270 	struct sockaddr_dl *sdl = NULL;
271 	struct rt_msghdr *rtm;
272 	char *host = argv[0], *eaddr;
273 	struct sockaddr_inarp sin_m = blank_sin; /* struct copy */
274 	struct sockaddr_dl sdl_m = blank_sdl; /* struct copy */
275 	int s;
276 
277 	eaddr = argv[1];
278 
279 	s = getsocket();
280 	argc -= 2;
281 	argv += 2;
282 
283 	if (getinetaddr(host, &sin_m.sin_addr) == -1) {
284 		prog_close(s);
285 		return (1);
286 	}
287 	if (strcmp(eaddr, "auto") != 0 && atosdl(eaddr, &sdl_m))
288 		warnx("invalid link-level address '%s'", eaddr);
289 	doing_proxy = flags = export_only = expire_time = 0;
290 	for (; argc-- > 0; argv++) {
291 		if (strncmp(argv[0], "temp", 4) == 0) {
292 			struct timeval timev;
293 			(void)gettimeofday(&timev, 0);
294 			expire_time = timev.tv_sec + 20 * 60;
295 		}
296 		else if (strncmp(argv[0], "pub", 3) == 0) {
297 			flags |= RTF_ANNOUNCE;
298 			doing_proxy = 1;
299 			if (argc && strncmp(argv[1], "pro", 3) == 0) {
300 				export_only = 1;
301 				argc--; argv++;
302 			}
303 		} else if (strncmp(argv[0], "trail", 5) == 0) {
304 			warnx("%s: Sending trailers is no longer supported",
305 			    host);
306 		} else if (strcmp(argv[0], "ifscope") == 0) {
307 			if (argc == 0) {
308 				warnx("missing interface for ifscope");
309 				continue;
310 			}
311 			argc--;
312 			argv++;
313 			if (!getlink(argv[0], &sdl_m))
314 				warnx("cannot get link address for %s", argv[0]);
315 		}
316 
317 	}
318 	if (doing_proxy && strcmp(eaddr, "auto") == 0) {
319 		if (getetheraddr(sin_m.sin_addr, &sdl_m) == -1) {
320 			prog_close(s);
321 			return 1;
322 		}
323 	}
324 tryagain:
325 	rtm = rtmsg(s, RTM_GET, NULL, &sin_m, &sdl_m);
326 	if (rtm == NULL) {
327 		warn("%s", host);
328 		prog_close(s);
329 		return (1);
330 	}
331 	sina = (struct sockaddr_inarp *)(void *)(rtm + 1);
332 	sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(sina->sin_len) +
333 	    (char *)(void *)sina);
334 	if (sina->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
335 		if (is_llinfo(sdl, rtm->rtm_flags))
336 			goto overwrite;
337 		if (doing_proxy == 0) {
338 			warnx("set: can only proxy for %s", host);
339 			prog_close(s);
340 			return (1);
341 		}
342 		if (sin_m.sin_other & SIN_PROXY) {
343 			warnx("set: proxy entry exists for non 802 device");
344 			prog_close(s);
345 			return (1);
346 		}
347 		sin_m.sin_other = SIN_PROXY;
348 		export_only = 1;
349 		goto tryagain;
350 	}
351 overwrite:
352 	if (sdl->sdl_family != AF_LINK) {
353 		warnx("cannot intuit interface index and type for %s",
354 		    host);
355 		prog_close(s);
356 		return (1);
357 	}
358 	sdl_m.sdl_type = sdl->sdl_type;
359 	sdl_m.sdl_index = sdl->sdl_index;
360 	sin_m.sin_other = 0;
361 	if (doing_proxy && export_only)
362 		sin_m.sin_other = SIN_PROXY;
363 	rtm = rtmsg(s, RTM_ADD, NULL, &sin_m, &sdl_m);
364 	if (vflag)
365 		(void)printf("%s (%s) added\n", host, eaddr);
366 	prog_close(s);
367 	return (rtm == NULL) ? 1 : 0;
368 }
369 
370 /*
371  * Display an individual arp entry
372  */
373 static void
get(const char * host)374 get(const char *host)
375 {
376 	struct sockaddr_inarp sin = blank_sin; /* struct copy */
377 
378 	if (getinetaddr(host, &sin.sin_addr) == -1)
379 		exit(1);
380 	dump(sin.sin_addr.s_addr);
381 	if (found_entry == 0)
382 		errx(1, "%s (%s) -- no entry", host, inet_ntoa(sin.sin_addr));
383 }
384 
385 
386 static int
is_llinfo(const struct sockaddr_dl * sdl,int rtflags)387 is_llinfo(const struct sockaddr_dl *sdl, int rtflags)
388 {
389 	if (sdl->sdl_family != AF_LINK ||
390 	    (rtflags & (RTF_LLDATA|RTF_GATEWAY)) != RTF_LLDATA)
391 		return 0;
392 
393 	switch (sdl->sdl_type) {
394 	case IFT_ETHER:
395 	case IFT_FDDI:
396 	case IFT_ISO88023:
397 	case IFT_ISO88024:
398 	case IFT_ISO88025:
399 	case IFT_ARCNET:
400 		return 1;
401 	default:
402 		return 0;
403 	}
404 }
405 
406 /*
407  * Delete an arp entry
408  */
409 int
delete_one(struct rt_msghdr * rtm)410 delete_one(struct rt_msghdr *rtm)
411 {
412 	struct sockaddr_inarp *sina;
413 	struct sockaddr_dl *sdl;
414 	int s;
415 
416 	s = getsocket();
417 	sina = (struct sockaddr_inarp *)(void *)(rtm + 1);
418 	sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(sina->sin_len) +
419 	    (char *)(void *)sina);
420 	if (sdl->sdl_family != AF_LINK) {
421 		prog_close(s);
422 		return (1);
423 	}
424 	rtm = rtmsg(s, RTM_DELETE, rtm, sina, sdl);
425 	prog_close(s);
426 	if (rtm == NULL)
427 		return (1);
428 	return (0);
429 }
430 
431 /*
432  * Dump the entire arp table
433  */
434 void
dump(uint32_t addr)435 dump(uint32_t addr)
436 {
437 	int mib[6];
438 	size_t needed;
439 	char ifname[IFNAMSIZ];
440 	char *lim, *buf, *next;
441         const char *host;
442 	struct rt_msghdr *rtm;
443 	struct sockaddr_inarp *sina;
444 	struct sockaddr_dl *sdl;
445 	struct hostent *hp;
446 	struct timeval tim;
447 	struct in_nbrinfo *nbi;
448 
449 	mib[0] = CTL_NET;
450 	mib[1] = PF_ROUTE;
451 	mib[2] = 0;
452 	mib[3] = AF_INET;
453 	mib[4] = NET_RT_FLAGS;
454 	mib[5] = 0;
455 	if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
456 		err(1, "route-sysctl-estimate");
457 	if (needed == 0)
458 		return;
459 	if ((buf = malloc(needed)) == NULL)
460 		err(1, "malloc");
461 	if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
462 		err(1, "actual retrieval of routing table");
463 	lim = buf + needed;
464 	for (next = buf; next < lim; next += rtm->rtm_msglen) {
465 		rtm = (struct rt_msghdr *)(void *)next;
466 		sina = (struct sockaddr_inarp *)(void *)(rtm + 1);
467 		sdl = (struct sockaddr_dl *)(void *)
468 		    (RT_ROUNDUP(sina->sin_len) + (char *)(void *)sina);
469 		if (addr) {
470 			if (addr != sina->sin_addr.s_addr)
471 				continue;
472 			found_entry = 1;
473 		}
474 		if (nflag == 0)
475 			hp = gethostbyaddr((const char *)(void *)
476 			    &(sina->sin_addr),
477 			    sizeof sina->sin_addr, AF_INET);
478 		else
479 			hp = NULL;
480 
481 		host = hp ? hp->h_name : "?";
482 
483 		(void)printf("%s (%s) at ", host, inet_ntoa(sina->sin_addr));
484 		if (sdl->sdl_alen)
485 			sdl_print(sdl);
486 		else
487 			(void)printf("(incomplete)");
488 
489 		if (sdl->sdl_index) {
490 			if (getifname(sdl->sdl_index, ifname, sizeof(ifname)) == 0)
491 				(void)printf(" on %s", ifname);
492 		}
493 
494 		if (sina->sin_other & SIN_PROXY)
495 			(void)printf(" published (proxy only)");
496 		if (rtm->rtm_addrs & RTA_NETMASK) {
497 			sina = (struct sockaddr_inarp *)(void *)
498 			    (RT_ROUNDUP(sdl->sdl_len) + (char *)(void *)sdl);
499 			if (sina->sin_addr.s_addr == 0xffffffff)
500 				(void)printf(" published");
501 			if (sina->sin_len != 8)
502 				(void)printf("(weird)");
503 		}
504 
505 		if (sdl->sdl_index == 0)
506 			goto done;
507 		(void)gettimeofday(&tim, 0);
508 		nbi = getnbrinfo(ifname, &sina->sin_addr);
509 		if (nbi != NULL) {
510 			if (nbi->expire > tim.tv_sec) {
511 				(void)printf(" %s",
512 				    sec2str(nbi->expire - tim.tv_sec));
513 			} else if (nbi->expire == 0)
514 				(void)printf(" %s", "permanent");
515 			else
516 				(void)printf(" %s", "expired");
517 
518 			switch (nbi->state) {
519 			case ND_LLINFO_NOSTATE:
520 				(void)printf(" N");
521 				break;
522 			case ND_LLINFO_WAITDELETE:
523 				(void)printf(" W");
524 				break;
525 			case ND_LLINFO_INCOMPLETE:
526 				(void)printf(" I");
527 				break;
528 			case ND_LLINFO_REACHABLE:
529 				(void)printf(" R");
530 				break;
531 			case ND_LLINFO_STALE:
532 				(void)printf(" S");
533 				break;
534 			case ND_LLINFO_DELAY:
535 				(void)printf(" D");
536 				break;
537 			case ND_LLINFO_PROBE:
538 				(void)printf(" P");
539 				break;
540 			case ND_LLINFO_UNREACHABLE:
541 				(void)printf(" U");
542 				break;
543 			default:
544 				(void)printf(" ?");
545 				break;
546 			}
547 		}
548 
549 done:
550 		(void)printf("\n");
551 	}
552 	free(buf);
553 }
554 
555 /*
556  * Delete the entire arp table
557  */
558 void
delete(const char * host,const char * info)559 delete(const char *host, const char *info)
560 {
561 	int mib[6];
562 	char addr[sizeof("000.000.000.000\0")];
563 	size_t needed;
564 	char *lim, *buf, *next;
565 	struct rt_msghdr *rtm;
566 	struct sockaddr_inarp *sina;
567 	struct sockaddr_inarp sin_m = blank_sin; /* struct copy */
568 	bool found = false;
569 
570 	if (host != NULL) {
571 		int ret = getinetaddr(host, &sin_m.sin_addr);
572 		if (ret == -1)
573 			return;
574 	}
575 	if (info && strncmp(info, "pro", 3) == 0)
576 		sin_m.sin_other = SIN_PROXY;
577 
578 retry:
579 	mib[0] = CTL_NET;
580 	mib[1] = PF_ROUTE;
581 	mib[2] = 0;
582 	mib[3] = AF_INET;
583 	mib[4] = NET_RT_FLAGS;
584 	mib[5] = RTF_LLDATA;
585 	if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
586 		err(1, "route-sysctl-estimate");
587 	if (needed == 0)
588 		return;
589 	if ((buf = malloc(needed)) == NULL)
590 		err(1, "malloc");
591 	if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
592 		free(buf);
593 		if (errno == ENOBUFS)
594 			goto retry;
595 		err(1, "actual retrieval of routing table");
596 	}
597 	lim = buf + needed;
598 
599 	for (next = buf; next < lim; next += rtm->rtm_msglen) {
600 		int ret;
601 		rtm = (struct rt_msghdr *)(void *)next;
602 		sina = (struct sockaddr_inarp *)(void *)(rtm + 1);
603 		if (host != NULL &&
604 		    sina->sin_addr.s_addr != sin_m.sin_addr.s_addr)
605 			continue;
606 		found = true;
607 		ret = delete_one(rtm);
608 		if (vflag && ret == 0) {
609 			snprintf(addr, sizeof(addr), "%s",
610 			    inet_ntoa(sina->sin_addr));
611 			(void)printf("%s (%s) deleted\n",
612 			    host != NULL ? host : addr, addr);
613 		}
614 	}
615 	if (host != NULL && !found)
616 		warnx("delete: can't locate %s", host);
617 	free(buf);
618 }
619 
620 void
sdl_print(const struct sockaddr_dl * sdl)621 sdl_print(const struct sockaddr_dl *sdl)
622 {
623 	char hbuf[NI_MAXHOST];
624 
625 	if (getnameinfo((const struct sockaddr *)(const void *)sdl,
626 	    (socklen_t)sdl->sdl_len,
627 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
628 		(void)printf("<invalid>");
629 	else
630 		(void)printf("%s", hbuf);
631 }
632 
633 static int
atosdl(const char * ss,struct sockaddr_dl * sdl)634 atosdl(const char *ss, struct sockaddr_dl *sdl)
635 {
636 	int i;
637 	unsigned long b;
638 	char *endp;
639 	char *p;
640 	char *t, *r;
641 
642 	p = LLADDR(sdl);
643 	endp = ((char *)(void *)sdl) + sdl->sdl_len;
644 	i = 0;
645 
646 	b = strtoul(ss, &t, 16);
647 	if (b > 255 || t == ss)
648 		return 1;
649 
650 	*p++ = (char)b;
651 	++i;
652 	while ((p < endp) && (*t++ == ':')) {
653 		b = strtoul(t, &r, 16);
654 		if (b > 255 || r == t)
655 			break;
656 		*p++ = (char)b;
657 		++i;
658 		t = r;
659 	}
660 	sdl->sdl_alen = i;
661 
662 	return 0;
663 }
664 
665 static void
usage(void)666 usage(void)
667 {
668 	const char *progname;
669 
670 	progname = getprogname();
671 	(void)fprintf(stderr, "Usage: %s [-n] hostname\n", progname);
672 	(void)fprintf(stderr, "       %s [-nv] -a\n", progname);
673 	(void)fprintf(stderr, "       %s [-v] -d [-a|hostname [proxy]]\n",
674 	    progname);
675 	(void)fprintf(stderr, "       %s -s hostname ether_addr [temp] [pub [proxy]]\n",
676 	    progname);
677 	(void)fprintf(stderr, "       %s -f filename\n", progname);
678 	exit(1);
679 }
680 
681 static struct rt_msghdr *
rtmsg(const int s,const int cmd,struct rt_msghdr * _rtm,const struct sockaddr_inarp * sin,const struct sockaddr_dl * sdl)682 rtmsg(const int s, const int cmd, struct rt_msghdr *_rtm,
683     const struct sockaddr_inarp *sin, const struct sockaddr_dl *sdl)
684 {
685 	static int seq;
686 	struct rt_msghdr *rtm = _rtm;
687 	char *cp;
688 	int l;
689 	static struct {
690 		struct	rt_msghdr m_rtm;
691 		char	m_space[512];
692 	} m_rtmsg;
693 	pid_t pid;
694 
695 	errno = 0;
696 	if (rtm != NULL) {
697 		memcpy(&m_rtmsg, rtm, rtm->rtm_msglen);
698 		rtm = &m_rtmsg.m_rtm;
699 		goto doit;
700 	}
701 	(void)memset(&m_rtmsg, 0, sizeof(m_rtmsg));
702 	rtm = &m_rtmsg.m_rtm;
703 	cp = m_rtmsg.m_space;
704 
705 	rtm->rtm_flags = flags;
706 	rtm->rtm_version = RTM_VERSION;
707 
708 	switch (cmd) {
709 	default:
710 		errx(1, "internal wrong cmd");
711 		/*NOTREACHED*/
712 	case RTM_ADD:
713 		rtm->rtm_addrs |= RTA_GATEWAY;
714 		rtm->rtm_rmx.rmx_expire = expire_time;
715 		rtm->rtm_inits = RTV_EXPIRE;
716 		rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA);
717 		if (doing_proxy) {
718 			if (!export_only) {
719 				rtm->rtm_addrs |= RTA_NETMASK;
720 				rtm->rtm_flags &= ~RTF_HOST;
721 			}
722 		}
723 		rtm->rtm_addrs |= RTA_DST;
724 		break;
725 	case RTM_GET:
726 		rtm->rtm_flags |= RTF_LLDATA;
727 		rtm->rtm_addrs |= RTA_DST | RTA_GATEWAY;
728 	}
729 
730 #define NEXTADDR(w, s) \
731 	if (rtm->rtm_addrs & (w)) { \
732 		(void)memcpy(cp, &s, \
733 		    (size_t)((const struct sockaddr *)&s)->sa_len); \
734 		RT_ADVANCE(cp, ((const struct sockaddr *)&s)); \
735 	}
736 
737 	NEXTADDR(RTA_DST, *sin);
738 	NEXTADDR(RTA_GATEWAY, *sdl);
739 	NEXTADDR(RTA_NETMASK, so_mask);
740 
741 	rtm->rtm_msglen = cp - (char *)(void *)&m_rtmsg;
742 doit:
743 	l = rtm->rtm_msglen;
744 	rtm->rtm_seq = ++seq;
745 	rtm->rtm_type = cmd;
746 	if (prog_write(s, &m_rtmsg, (size_t)l) < 0) {
747 		if (errno != ESRCH || cmd != RTM_DELETE) {
748 			warn("writing to routing socket");
749 			return NULL;
750 		}
751 	}
752 
753 	pid = prog_getpid();
754 	do {
755 		l = prog_read(s, &m_rtmsg, sizeof(m_rtmsg));
756 	} while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
757 	if (l < 0)
758 		warn("read from routing socket");
759 	return rtm;
760 }
761 
762 static int
getinetaddr(const char * host,struct in_addr * inap)763 getinetaddr(const char *host, struct in_addr *inap)
764 {
765 	struct hostent *hp;
766 
767 	if (inet_aton(host, inap) == 1)
768 		return (0);
769 	if ((hp = gethostbyname(host)) == NULL) {
770 		warnx("%s: %s", host, hstrerror(h_errno));
771 		return (-1);
772 	}
773 	(void)memcpy(inap, hp->h_addr, sizeof(*inap));
774 	return (0);
775 }
776 
777 static int
getifname(u_int16_t ifindex,char * ifname,size_t l)778 getifname(u_int16_t ifindex, char *ifname, size_t l)
779 {
780 	int i;
781 	struct ifaddrs *addr;
782 	const struct sockaddr_dl *sdl;
783 	static struct ifaddrs* ifaddrs = NULL;
784 
785 	if (ifaddrs == NULL) {
786 		i = getifaddrs(&ifaddrs);
787 		if (i != 0)
788 			err(1, "getifaddrs");
789 	}
790 
791 	for (addr = ifaddrs; addr; addr = addr->ifa_next) {
792 		if (addr->ifa_addr == NULL ||
793 		    addr->ifa_addr->sa_family != AF_LINK)
794 			continue;
795 
796 		sdl = (const struct sockaddr_dl *)(void *)addr->ifa_addr;
797 		if (sdl && sdl->sdl_index == ifindex) {
798 			(void) strlcpy(ifname, addr->ifa_name, l);
799 			return 0;
800 		}
801 	}
802 
803 	return -1;
804 }
805 
806 static int
getetheraddr(struct in_addr ipaddr,struct sockaddr_dl * sdl)807 getetheraddr(struct in_addr ipaddr, struct sockaddr_dl *sdl)
808 {
809 	struct ifaddrs *ifaddrs, *addr;
810 	in_addr_t ina, mask;
811 	char ifname[IFNAMSIZ];
812 
813 	if (getifaddrs(&ifaddrs) != 0) {
814 		warn("getifaddrs");
815 		return -1;
816 	}
817 
818 	for (addr = ifaddrs; addr; addr = addr->ifa_next) {
819 		if (addr->ifa_addr == NULL ||
820 		    addr->ifa_addr->sa_family != AF_INET)
821 			continue;
822 		if ((addr->ifa_flags & (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|
823 		    IFF_LOOPBACK|IFF_NOARP)) != (IFF_UP|IFF_BROADCAST))
824 			continue;
825 
826 		mask = ((struct sockaddr_in *)(void *)addr->ifa_netmask)->sin_addr.s_addr;
827 		ina = ((struct sockaddr_in *)(void *)addr->ifa_addr)->sin_addr.s_addr;
828 		if ((ipaddr.s_addr & mask) != (ina & mask))
829 			continue;
830 		strlcpy(ifname, addr->ifa_name, sizeof(ifname));
831 		break;
832 	}
833 	if (addr == NULL) {
834 		warnx("No interface matched %s", inet_ntoa(ipaddr));
835 		freeifaddrs(ifaddrs);
836 		return -1;
837 	}
838 
839 	for (addr = ifaddrs; addr; addr = addr->ifa_next) {
840 		if (addr->ifa_addr == NULL ||
841 		    addr->ifa_addr->sa_family != AF_LINK)
842 			continue;
843 		if (strcmp(ifname, addr->ifa_name) != 0)
844 			continue;
845 		memcpy(sdl, addr->ifa_addr, sizeof(*sdl));
846 		freeifaddrs(ifaddrs);
847 		return 0;
848 	}
849 	warnx("No link address for interface %s", ifname);
850 	freeifaddrs(ifaddrs);
851 	return -1;
852 }
853 
854 static struct in_nbrinfo *
getnbrinfo(const char * ifname,struct in_addr * addr)855 getnbrinfo(const char *ifname, struct in_addr *addr)
856 {
857 	static struct in_nbrinfo nbi, *nbip;
858 	int s;
859 
860 	if ((s = prog_socket(AF_INET, SOCK_DGRAM, 0)) == -1)
861 		err(1, "socket");
862 
863 	(void)memset(&nbi, 0, sizeof(nbi));
864 	(void)strlcpy(nbi.ifname, ifname, sizeof(nbi.ifname));
865 	nbi.addr = *addr;
866 	if (prog_ioctl(s, SIOCGNBRINFO, &nbi) == -1) {
867 		warn("ioctl(SIOCGNBRINFO)");
868 		nbip = NULL;
869 	} else
870 		nbip = &nbi;
871 	(void)prog_close(s);
872 
873 	return nbip;
874 }
875 
876 static const char *
sec2str(time_t total)877 sec2str(time_t total)
878 {
879 	static char result[256];
880 	int days, hours, mins, secs;
881 	int first = 1;
882 	char *p = result;
883 	char *ep = &result[sizeof(result)];
884 	int n;
885 
886 	days = total / 3600 / 24;
887 	hours = (total / 3600) % 24;
888 	mins = (total / 60) % 60;
889 	secs = total % 60;
890 
891 	if (days) {
892 		first = 0;
893 		n = snprintf(p, (size_t)(ep - p), "%dd", days);
894 		if (n < 0 || n >= ep - p)
895 			return "?";
896 		p += n;
897 	}
898 	if (!first || hours) {
899 		first = 0;
900 		n = snprintf(p, (size_t)(ep - p), "%dh", hours);
901 		if (n < 0 || n >= ep - p)
902 			return "?";
903 		p += n;
904 	}
905 	if (!first || mins) {
906 		first = 0;
907 		n = snprintf(p, (size_t)(ep - p), "%dm", mins);
908 		if (n < 0 || n >= ep - p)
909 			return "?";
910 		p += n;
911 	}
912 	(void)snprintf(p, (size_t)(ep - p), "%ds", secs);
913 
914 	return(result);
915 }
916