xref: /openbsd-src/sbin/route/show.c (revision 25c4e8bd056e974b28f4a0ffd39d76c190a56013)
1 /*	$OpenBSD: show.c,v 1.120 2022/06/19 13:59:22 claudio Exp $	*/
2 /*	$NetBSD: show.c,v 1.1 1996/11/15 18:01:41 gwr Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/socket.h>
34 #include <sys/sysctl.h>
35 
36 #include <net/if.h>
37 #include <net/if_dl.h>
38 #include <net/if_types.h>
39 #include <net/route.h>
40 #include <net/rtable.h>
41 #include <netinet/in.h>
42 #include <netinet/if_ether.h>
43 #include <netmpls/mpls.h>
44 #include <arpa/inet.h>
45 
46 #include <err.h>
47 #include <errno.h>
48 #include <netdb.h>
49 #include <stdio.h>
50 #include <stddef.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <limits.h>
55 
56 #include "show.h"
57 
58 char	*any_ntoa(const struct sockaddr *);
59 char	*link_print(struct sockaddr *);
60 char	*label_print(struct sockaddr *);
61 
62 #define ROUNDUP(a) \
63 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
64 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
65 
66 /*
67  * Definitions for showing gateway flags.
68  */
69 struct bits {
70 	int	b_mask;
71 	char	b_val;
72 };
73 static const struct bits bits[] = {
74 	{ RTF_UP,	'U' },
75 	{ RTF_GATEWAY,	'G' },
76 	{ RTF_HOST,	'H' },
77 	{ RTF_REJECT,	'R' },
78 	{ RTF_DYNAMIC,	'D' },
79 	{ RTF_MODIFIED,	'M' },
80 	{ RTF_CLONING,	'C' },
81 	{ RTF_MULTICAST,'m' },
82 	{ RTF_LLINFO,	'L' },
83 	{ RTF_STATIC,	'S' },
84 	{ RTF_BLACKHOLE,'B' },
85 	{ RTF_PROTO3,	'3' },
86 	{ RTF_PROTO2,	'2' },
87 	{ RTF_PROTO1,	'1' },
88 	{ RTF_CLONED,	'c' },
89 	{ RTF_CACHED,	'h' },
90 	{ RTF_MPATH,	'P' },
91 	{ RTF_MPLS,	'T' },
92 	{ RTF_LOCAL,	'l' },
93 	{ RTF_BFD,	'F' },
94 	{ RTF_BROADCAST,'b' },
95 	{ RTF_CONNECTED,'n' },
96 	{ 0 }
97 };
98 
99 int	 WID_DST(int);
100 void	 pr_rthdr(int);
101 void	 p_rtentry(struct rt_msghdr *);
102 void	 pr_family(int);
103 void	 p_sockaddr_mpls(struct sockaddr *, struct sockaddr *, int, int);
104 void	 p_flags(int, char *);
105 char	*routename4(in_addr_t);
106 char	*routename6(struct sockaddr_in6 *);
107 char	*netname4(in_addr_t, struct sockaddr_in *);
108 char	*netname6(struct sockaddr_in6 *, struct sockaddr_in6 *);
109 
110 size_t
111 get_sysctl(const int *mib, u_int mcnt, char **buf)
112 {
113 	size_t needed;
114 
115 	while (1) {
116 		if (sysctl(mib, mcnt, NULL, &needed, NULL, 0) == -1)
117 			err(1, "sysctl-estimate");
118 		if (needed == 0)
119 			break;
120 		if ((*buf = realloc(*buf, needed)) == NULL)
121 			err(1, NULL);
122 		if (sysctl(mib, mcnt, *buf, &needed, NULL, 0) == -1) {
123 			if (errno == ENOMEM)
124 				continue;
125 			err(1, "sysctl");
126 		}
127 		break;
128 	}
129 
130 	return needed;
131 }
132 
133 /*
134  * Print preferred source address
135  */
136 void
137 printsource(int af, u_int tableid)
138 {
139 	struct sockaddr *sa;
140 	char *buf = NULL, *next, *lim = NULL;
141 	size_t needed;
142 	int mib[7], mcnt, size;
143 
144 	mib[0] = CTL_NET;
145 	mib[1] = PF_ROUTE;
146 	mib[2] = 0;
147 	mib[3] = af;
148 	mib[4] = NET_RT_SOURCE;
149 	mib[5] = tableid;
150 	mcnt = 6;
151 
152 	needed = get_sysctl(mib, mcnt, &buf);
153 	lim = buf + needed;
154 
155 	if (pledge("stdio", NULL) == -1)
156 		err(1, "pledge");
157 
158 	printf("Preferred source address set for rdomain %d\n", tableid);
159 
160 	if (buf) {
161 		for (next = buf; next < lim; next += size) {
162 			sa = (struct sockaddr *)next;
163 			switch (sa->sa_family) {
164 			case AF_INET:
165 				size = sizeof(struct sockaddr_in);
166 				printf("IPv4: ");
167 				break;
168 			case AF_INET6:
169 				size = sizeof(struct sockaddr_in6);
170 				printf("IPv6: ");
171 				break;
172 			}
173 			p_sockaddr(sa, NULL, RTF_HOST, WID_DST(sa->sa_family));
174 			printf("\n");
175 		}
176 	}
177 	free(buf);
178 
179 	exit(0);
180 }
181 /*
182  * Print routing tables.
183  */
184 void
185 p_rttables(int af, u_int tableid, char prio)
186 {
187 	struct rt_msghdr *rtm;
188 	char *buf = NULL, *next, *lim = NULL;
189 	size_t needed;
190 	int mib[7], mcnt;
191 
192 	mib[0] = CTL_NET;
193 	mib[1] = PF_ROUTE;
194 	mib[2] = 0;
195 	mib[3] = af;
196 	mib[4] = NET_RT_DUMP;
197 	mib[5] = prio;
198 	mib[6] = tableid;
199 	mcnt = 7;
200 
201 	needed = get_sysctl(mib, mcnt, &buf);
202 	lim = buf + needed;
203 
204 	if (pledge("stdio dns", NULL) == -1)
205 		err(1, "pledge");
206 
207 	printf("Routing tables\n");
208 
209 	if (buf) {
210 		for (next = buf; next < lim; next += rtm->rtm_msglen) {
211 			rtm = (struct rt_msghdr *)next;
212 			if (rtm->rtm_version != RTM_VERSION)
213 				continue;
214 			p_rtentry(rtm);
215 		}
216 	}
217 	free(buf);
218 }
219 
220 /*
221  * column widths; each followed by one space
222  * width of destination/gateway column
223  * strlen("fe80::aaaa:bbbb:cccc:dddd@gif0") == 30, strlen("/128") == 4
224  */
225 #define	WID_GW(af)	((af) == AF_INET6 ? 30 : 18)
226 
227 int
228 WID_DST(int af)
229 {
230 
231 	switch (af) {
232 	case AF_MPLS:
233 		return 9;
234 	case AF_INET6:
235 		return 34;
236 	default:
237 		return 18;
238 	}
239 }
240 
241 /*
242  * Print header for routing table columns.
243  */
244 void
245 pr_rthdr(int af)
246 {
247 	switch (af) {
248 	case PF_KEY:
249 		printf("%-18s %-5s %-18s %-5s %-5s %-22s\n",
250 		    "Source", "Port", "Destination",
251 		    "Port", "Proto", "SA(Address/Proto/Type/Direction)");
252 		break;
253 	case PF_MPLS:
254 		printf("%-9s %-9s %-6s %-18s %-6.6s %5.5s %8.8s %5.5s  %4.4s %s\n",
255 		    "In label", "Out label", "Op", "Gateway",
256 		    "Flags", "Refs", "Use", "Mtu", "Prio", "Interface");
257 		break;
258 	default:
259 		printf("%-*.*s %-*.*s %-6.6s %5.5s %8.8s %5.5s  %4.4s %s",
260 		    WID_DST(af), WID_DST(af), "Destination",
261 		    WID_GW(af), WID_GW(af), "Gateway",
262 		    "Flags", "Refs", "Use", "Mtu", "Prio", "Iface");
263 		if (verbose)
264 			printf(" %s", "Label");
265 		putchar('\n');
266 		break;
267 	}
268 }
269 
270 void
271 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
272 {
273 	int	i;
274 
275 	for (i = 0; i < RTAX_MAX; i++) {
276 		if (addrs & (1 << i)) {
277 			rti_info[i] = sa;
278 			sa = (struct sockaddr *)((char *)(sa) +
279 			    ROUNDUP(sa->sa_len));
280 		} else
281 			rti_info[i] = NULL;
282 	}
283 }
284 
285 /*
286  * Print a routing table entry.
287  */
288 void
289 p_rtentry(struct rt_msghdr *rtm)
290 {
291 	static int	 old_af = -1;
292 	struct sockaddr	*sa = (struct sockaddr *)((char *)rtm + rtm->rtm_hdrlen);
293 	struct sockaddr	*mask, *rti_info[RTAX_MAX];
294 	char		 ifbuf[IF_NAMESIZE];
295 	char		*label;
296 
297 	if (sa->sa_family == AF_KEY)
298 		return;
299 
300 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
301 
302 	if (Fflag && rti_info[RTAX_GATEWAY]->sa_family != sa->sa_family) {
303 		return;
304 	}
305 
306 	if (strlen(so_label.rtlabel.sr_label)) {
307 		if (!rti_info[RTAX_LABEL])
308 			return;
309 		label = ((struct sockaddr_rtlabel *)rti_info[RTAX_LABEL])->
310 		    sr_label;
311 		if (strcmp(label, so_label.rtlabel.sr_label))
312 			return;
313 	}
314 
315 	if (old_af != sa->sa_family) {
316 		old_af = sa->sa_family;
317 		pr_family(sa->sa_family);
318 		pr_rthdr(sa->sa_family);
319 	}
320 
321 	mask = rti_info[RTAX_NETMASK];
322 	if ((sa = rti_info[RTAX_DST]) == NULL)
323 		return;
324 
325 	p_sockaddr(sa, mask, rtm->rtm_flags, WID_DST(sa->sa_family));
326 	p_sockaddr_mpls(sa, rti_info[RTAX_SRC], rtm->rtm_mpls,
327 	    WID_DST(sa->sa_family));
328 
329 	p_sockaddr(rti_info[RTAX_GATEWAY], NULL, RTF_HOST,
330 	    WID_GW(sa->sa_family));
331 
332 	p_flags(rtm->rtm_flags, "%-6.6s ");
333 	printf("%5u %8llu ", rtm->rtm_rmx.rmx_refcnt,
334 	    rtm->rtm_rmx.rmx_pksent);
335 	if (rtm->rtm_rmx.rmx_mtu)
336 		printf("%5u ", rtm->rtm_rmx.rmx_mtu);
337 	else
338 		printf("%5s ", "-");
339 	putchar((rtm->rtm_rmx.rmx_locks & RTV_MTU) ? 'L' : ' ');
340 	printf("  %2d %-5.16s", rtm->rtm_priority,
341 	    if_indextoname(rtm->rtm_index, ifbuf));
342 	if (verbose && rti_info[RTAX_LABEL])
343 		printf(" %s", routename(rti_info[RTAX_LABEL]));
344 	putchar('\n');
345 }
346 
347 /*
348  * Print address family header before a section of the routing table.
349  */
350 void
351 pr_family(int af)
352 {
353 	char *afname;
354 
355 	switch (af) {
356 	case AF_INET:
357 		afname = "Internet";
358 		break;
359 	case AF_INET6:
360 		afname = "Internet6";
361 		break;
362 	case PF_KEY:
363 		afname = "Encap";
364 		break;
365 	case AF_MPLS:
366 		afname = "MPLS";
367 		break;
368 	default:
369 		afname = NULL;
370 		break;
371 	}
372 	if (afname)
373 		printf("\n%s:\n", afname);
374 	else
375 		printf("\nProtocol Family %d:\n", af);
376 }
377 
378 void
379 p_sockaddr(struct sockaddr *sa, struct sockaddr *mask, int flags, int width)
380 {
381 	char *cp;
382 
383 	switch (sa->sa_family) {
384 	case AF_INET6:
385 	    {
386 		struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa;
387 #ifdef __KAME__
388 		struct in6_addr *in6 = &sa6->sin6_addr;
389 
390 		/*
391 		 * XXX: This is a special workaround for KAME kernels.
392 		 * sin6_scope_id field of SA should be set in the future.
393 		 */
394 		if ((IN6_IS_ADDR_LINKLOCAL(in6) ||
395 		    IN6_IS_ADDR_MC_LINKLOCAL(in6) ||
396 		    IN6_IS_ADDR_MC_INTFACELOCAL(in6)) &&
397 		    sa6->sin6_scope_id == 0) {
398 			/* XXX: override is ok? */
399 			sa6->sin6_scope_id = (u_int32_t)ntohs(*(u_short *)
400 			    &in6->s6_addr[2]);
401 			*(u_short *)&in6->s6_addr[2] = 0;
402 		}
403 #endif
404 		if (flags & RTF_HOST)
405 			cp = routename((struct sockaddr *)sa6);
406 		else
407 			cp = netname((struct sockaddr *)sa6, mask);
408 		break;
409 	    }
410 	case AF_MPLS:
411 		return;
412 	default:
413 		if ((flags & RTF_HOST) || mask == NULL)
414 			cp = routename(sa);
415 		else
416 			cp = netname(sa, mask);
417 		break;
418 	}
419 	if (width < 0)
420 		printf("%s", cp);
421 	else {
422 		if (nflag)
423 			printf("%-*s ", width, cp);
424 		else
425 			printf("%-*.*s ", width, width, cp);
426 	}
427 }
428 
429 static char line[HOST_NAME_MAX+1];
430 static char domain[HOST_NAME_MAX+1];
431 
432 void
433 p_sockaddr_mpls(struct sockaddr *in, struct sockaddr *out, int flags, int width)
434 {
435 	if (in->sa_family != AF_MPLS)
436 		return;
437 
438 	if (flags & MPLS_OP_POP || flags == MPLS_OP_LOCAL) {
439 		printf("%-*s ", width, label_print(in));
440 		printf("%-*s ", width, label_print(NULL));
441 	} else {
442 		printf("%-*s ", width, label_print(in));
443 		printf("%-*s ", width, label_print(out));
444 	}
445 
446 	printf("%-6s ", mpls_op(flags));
447 }
448 
449 void
450 p_flags(int f, char *format)
451 {
452 	char name[33], *flags;
453 	const struct bits *p = bits;
454 
455 	for (flags = name; p->b_mask && flags < &name[sizeof(name) - 2]; p++)
456 		if (p->b_mask & f)
457 			*flags++ = p->b_val;
458 	*flags = '\0';
459 	printf(format, name);
460 }
461 
462 char *
463 routename(struct sockaddr *sa)
464 {
465 	char *cp = NULL;
466 	static int first = 1;
467 
468 	if (first) {
469 		first = 0;
470 		if (gethostname(domain, sizeof(domain)) == 0 &&
471 		    (cp = strchr(domain, '.')))
472 			(void)strlcpy(domain, cp + 1, sizeof(domain));
473 		else
474 			domain[0] = '\0';
475 		cp = NULL;
476 	}
477 
478 	if (sa->sa_len == 0) {
479 		(void)strlcpy(line, "default", sizeof(line));
480 		return (line);
481 	}
482 
483 	switch (sa->sa_family) {
484 	case AF_INET:
485 		return
486 		    (routename4(((struct sockaddr_in *)sa)->sin_addr.s_addr));
487 
488 	case AF_INET6:
489 	    {
490 		struct sockaddr_in6 sin6;
491 
492 		memset(&sin6, 0, sizeof(sin6));
493 		memcpy(&sin6, sa, sa->sa_len);
494 		sin6.sin6_len = sizeof(struct sockaddr_in6);
495 		sin6.sin6_family = AF_INET6;
496 #ifdef __KAME__
497 		if (sa->sa_len == sizeof(struct sockaddr_in6) &&
498 		    (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr) ||
499 		     IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr) ||
500 		     IN6_IS_ADDR_MC_INTFACELOCAL(&sin6.sin6_addr)) &&
501 		    sin6.sin6_scope_id == 0) {
502 			sin6.sin6_scope_id =
503 			    ntohs(*(u_int16_t *)&sin6.sin6_addr.s6_addr[2]);
504 			sin6.sin6_addr.s6_addr[2] = 0;
505 			sin6.sin6_addr.s6_addr[3] = 0;
506 		}
507 #endif
508 		return (routename6(&sin6));
509 	    }
510 
511 	case AF_LINK:
512 		return (link_print(sa));
513 	case AF_MPLS:
514 		return (label_print(sa));
515 	case AF_UNSPEC:
516 		if (sa->sa_len == sizeof(struct sockaddr_rtlabel)) {
517 			static char name[RTLABEL_LEN + 2];
518 			struct sockaddr_rtlabel *sr;
519 
520 			sr = (struct sockaddr_rtlabel *)sa;
521 			snprintf(name, sizeof(name), "\"%s\"", sr->sr_label);
522 			return (name);
523 		}
524 		/* FALLTHROUGH */
525 	default:
526 		(void)snprintf(line, sizeof(line), "(%d) %s",
527 		    sa->sa_family, any_ntoa(sa));
528 		break;
529 	}
530 	return (line);
531 }
532 
533 char *
534 routename4(in_addr_t in)
535 {
536 	char		*cp = NULL;
537 	struct in_addr	 ina;
538 	struct hostent	*hp;
539 
540 	if (!cp && !nflag) {
541 		if ((hp = gethostbyaddr((char *)&in,
542 		    sizeof(in), AF_INET)) != NULL) {
543 			if ((cp = strchr(hp->h_name, '.')) &&
544 			    !strcmp(cp + 1, domain))
545 				*cp = '\0';
546 			cp = hp->h_name;
547 		}
548 	}
549 	ina.s_addr = in;
550 	strlcpy(line, cp ? cp : inet_ntoa(ina), sizeof(line));
551 
552 	return (line);
553 }
554 
555 char *
556 routename6(struct sockaddr_in6 *sin6)
557 {
558 	int	 niflags = 0;
559 
560 	if (nflag)
561 		niflags |= NI_NUMERICHOST;
562 	else
563 		niflags |= NI_NOFQDN;
564 
565 	if (getnameinfo((struct sockaddr *)sin6, sin6->sin6_len,
566 	    line, sizeof(line), NULL, 0, niflags) != 0)
567 		strncpy(line, "invalid", sizeof(line));
568 
569 	return (line);
570 }
571 
572 char *
573 netname4(in_addr_t in, struct sockaddr_in *maskp)
574 {
575 	char *cp = NULL;
576 	struct hostent *hp;
577 	in_addr_t mask;
578 	int mbits;
579 
580 	mask = maskp && maskp->sin_len != 0 ? ntohl(maskp->sin_addr.s_addr) : 0;
581 	if (!nflag && in != INADDR_ANY) {
582 		if ((hp = gethostbyaddr((char *)&in,
583 		    sizeof(in), AF_INET)) != NULL)
584 			cp = hp->h_name;
585 	}
586 	if (in == INADDR_ANY && mask == INADDR_ANY)
587 		cp = "default";
588 	mbits = mask ? 33 - ffs(mask) : 0;
589 	in = ntohl(in);
590 	if (cp)
591 		strlcpy(line, cp, sizeof(line));
592 #define C(x)	((x) & 0xff)
593 	else if (mbits < 9)
594 		snprintf(line, sizeof(line), "%u/%d", C(in >> 24), mbits);
595 	else if (mbits < 17)
596 		snprintf(line, sizeof(line), "%u.%u/%d",
597 		    C(in >> 24) , C(in >> 16), mbits);
598 	else if (mbits < 25)
599 		snprintf(line, sizeof(line), "%u.%u.%u/%d",
600 		    C(in >> 24), C(in >> 16), C(in >> 8), mbits);
601 	else
602 		snprintf(line, sizeof(line), "%u.%u.%u.%u/%d", C(in >> 24),
603 		    C(in >> 16), C(in >> 8), C(in), mbits);
604 #undef C
605 	return (line);
606 }
607 
608 char *
609 netname6(struct sockaddr_in6 *sa6, struct sockaddr_in6 *mask)
610 {
611 	struct sockaddr_in6 sin6;
612 	u_char *p;
613 	int masklen, final = 0, illegal = 0;
614 	int i, lim, flag, error;
615 	char hbuf[NI_MAXHOST];
616 
617 	sin6 = *sa6;
618 
619 	flag = 0;
620 	masklen = 0;
621 	if (mask) {
622 		lim = mask->sin6_len - offsetof(struct sockaddr_in6, sin6_addr);
623 		lim = lim < (int)sizeof(struct in6_addr) ?
624 		    lim : (int)sizeof(struct in6_addr);
625 		for (p = (u_char *)&mask->sin6_addr, i = 0; i < lim; p++) {
626 			if (final && *p) {
627 				illegal++;
628 				sin6.sin6_addr.s6_addr[i++] = 0x00;
629 				continue;
630 			}
631 
632 			switch (*p & 0xff) {
633 			case 0xff:
634 				masklen += 8;
635 				break;
636 			case 0xfe:
637 				masklen += 7;
638 				final++;
639 				break;
640 			case 0xfc:
641 				masklen += 6;
642 				final++;
643 				break;
644 			case 0xf8:
645 				masklen += 5;
646 				final++;
647 				break;
648 			case 0xf0:
649 				masklen += 4;
650 				final++;
651 				break;
652 			case 0xe0:
653 				masklen += 3;
654 				final++;
655 				break;
656 			case 0xc0:
657 				masklen += 2;
658 				final++;
659 				break;
660 			case 0x80:
661 				masklen += 1;
662 				final++;
663 				break;
664 			case 0x00:
665 				final++;
666 				break;
667 			default:
668 				final++;
669 				illegal++;
670 				break;
671 			}
672 
673 			if (!illegal)
674 				sin6.sin6_addr.s6_addr[i++] &= *p;
675 			else
676 				sin6.sin6_addr.s6_addr[i++] = 0x00;
677 		}
678 		while (i < (int)sizeof(struct in6_addr))
679 			sin6.sin6_addr.s6_addr[i++] = 0x00;
680 	} else
681 		masklen = 128;
682 
683 	if (masklen == 0 && IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr))
684 		return ("default");
685 
686 	if (illegal)
687 		warnx("illegal prefixlen");
688 
689 	if (nflag)
690 		flag |= NI_NUMERICHOST;
691 	error = getnameinfo((struct sockaddr *)&sin6, sin6.sin6_len,
692 	    hbuf, sizeof(hbuf), NULL, 0, flag);
693 	if (error)
694 		snprintf(hbuf, sizeof(hbuf), "invalid");
695 
696 	snprintf(line, sizeof(line), "%s/%d", hbuf, masklen);
697 	return (line);
698 }
699 
700 /*
701  * Return the name of the network whose address is given.
702  * The address is assumed to be that of a net or subnet, not a host.
703  */
704 char *
705 netname(struct sockaddr *sa, struct sockaddr *mask)
706 {
707 	switch (sa->sa_family) {
708 	case AF_INET:
709 		return netname4(((struct sockaddr_in *)sa)->sin_addr.s_addr,
710 		    (struct sockaddr_in *)mask);
711 	case AF_INET6:
712 		return netname6((struct sockaddr_in6 *)sa,
713 		    (struct sockaddr_in6 *)mask);
714 	case AF_LINK:
715 		return (link_print(sa));
716 	case AF_MPLS:
717 		return (label_print(sa));
718 	default:
719 		snprintf(line, sizeof(line), "af %d: %s",
720 		    sa->sa_family, any_ntoa(sa));
721 		break;
722 	}
723 	return (line);
724 }
725 
726 static const char hexlist[] = "0123456789abcdef";
727 
728 char *
729 any_ntoa(const struct sockaddr *sa)
730 {
731 	static char obuf[240];
732 	const char *in = sa->sa_data;
733 	char *out = obuf;
734 	int len = sa->sa_len - offsetof(struct sockaddr, sa_data);
735 
736 	*out++ = 'Q';
737 	do {
738 		*out++ = hexlist[(*in >> 4) & 15];
739 		*out++ = hexlist[(*in++)    & 15];
740 		*out++ = '.';
741 	} while (--len > 0 && (out + 3) < &obuf[sizeof(obuf) - 1]);
742 	out[-1] = '\0';
743 	return (obuf);
744 }
745 
746 char *
747 link_print(struct sockaddr *sa)
748 {
749 	struct sockaddr_dl	*sdl = (struct sockaddr_dl *)sa;
750 	u_char			*lla = (u_char *)sdl->sdl_data + sdl->sdl_nlen;
751 
752 	if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 &&
753 	    sdl->sdl_slen == 0) {
754 		(void)snprintf(line, sizeof(line), "link#%d", sdl->sdl_index);
755 		return (line);
756 	}
757 	switch (sdl->sdl_type) {
758 	case IFT_ETHER:
759 	case IFT_CARP:
760 		return (ether_ntoa((struct ether_addr *)lla));
761 	default:
762 		return (link_ntoa(sdl));
763 	}
764 }
765 
766 char *
767 mpls_op(u_int32_t type)
768 {
769 	switch (type & (MPLS_OP_PUSH | MPLS_OP_POP | MPLS_OP_SWAP)) {
770 	case MPLS_OP_LOCAL:
771 		return ("LOCAL");
772 	case MPLS_OP_POP:
773 		return ("POP");
774 	case MPLS_OP_SWAP:
775 		return ("SWAP");
776 	case MPLS_OP_PUSH:
777 		return ("PUSH");
778 	default:
779 		return ("?");
780 	}
781 }
782 
783 char *
784 label_print(struct sockaddr *sa)
785 {
786 	struct sockaddr_mpls	*smpls = (struct sockaddr_mpls *)sa;
787 
788 	if (smpls)
789 		(void)snprintf(line, sizeof(line), "%u",
790 		    ntohl(smpls->smpls_label) >> MPLS_LABEL_OFFSET);
791 	else
792 		(void)snprintf(line, sizeof(line), "-");
793 
794 	return (line);
795 }
796