1 /* $NetBSD: getnameinfo.c,v 1.60 2023/09/08 18:17:41 christos Exp $ */
2 /* $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 itojun Exp $ */
3
4 /*
5 * Copyright (c) 2000 Ben Harris.
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 /*
35 * Issues to be discussed:
36 * - Thread safe-ness must be checked
37 * - RFC2553 says that we should raise error on short buffer. X/Open says
38 * we need to truncate the result. We obey RFC2553 (and X/Open should be
39 * modified). ipngwg rough consensus seems to follow RFC2553.
40 * - What is "local" in NI_FQDN?
41 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
42 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
43 * sin6_scope_id is filled - standardization status?
44 * XXX breaks backward compat for code that expects no scopeid.
45 * beware on merge.
46 */
47
48 #include <sys/cdefs.h>
49 #if defined(LIBC_SCCS) && !defined(lint)
50 __RCSID("$NetBSD: getnameinfo.c,v 1.60 2023/09/08 18:17:41 christos Exp $");
51 #endif /* LIBC_SCCS and not lint */
52
53 #ifndef RUMP_ACTION
54 #include "namespace.h"
55 #endif
56 #include <sys/types.h>
57 #include <sys/socket.h>
58 #include <sys/un.h>
59 #include <net/if.h>
60 #include <net/if_dl.h>
61 #include <net/if_ieee1394.h>
62 #include <net/if_types.h>
63 #include <netatalk/at.h>
64 #include <netinet/in.h>
65 #include <arpa/inet.h>
66 #include <arpa/nameser.h>
67 #include <assert.h>
68 #include <limits.h>
69 #include <netdb.h>
70 #include <resolv.h>
71 #include <stddef.h>
72 #include <string.h>
73
74 #include "servent.h"
75 #include "hostent.h"
76
77 #ifndef RUMP_ACTION
78 #ifdef __weak_alias
79 __weak_alias(getnameinfo,_getnameinfo)
80 #endif
81 #endif
82
83 static const struct afd {
84 int a_af;
85 socklen_t a_addrlen;
86 socklen_t a_socklen;
87 int a_off;
88 } afdl [] = {
89 #ifdef INET6
90 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
91 offsetof(struct sockaddr_in6, sin6_addr)},
92 #endif
93 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
94 offsetof(struct sockaddr_in, sin_addr)},
95 {0, 0, 0, 0},
96 };
97
98 struct sockinet {
99 u_char si_len;
100 u_char si_family;
101 u_short si_port;
102 };
103
104 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *,
105 socklen_t, char *, socklen_t, int);
106 #ifdef INET6
107 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
108 socklen_t, int);
109 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
110 #endif
111 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *,
112 socklen_t, char *, socklen_t, int);
113 static int getnameinfo_local(const struct sockaddr *, socklen_t, char *,
114 socklen_t, char *, socklen_t, int);
115
116 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *,
117 socklen_t, char *, socklen_t, int);
118 static int hexname(const uint8_t *, size_t, char *, socklen_t);
119
120 /*
121 * Top-level getnameinfo() code. Look at the address family, and pick an
122 * appropriate function to call.
123 */
124 int
getnameinfo(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)125 getnameinfo(const struct sockaddr *sa, socklen_t salen,
126 char *host, socklen_t hostlen,
127 char *serv, socklen_t servlen,
128 int flags)
129 {
130
131 /*
132 * getnameinfo() accepts an salen of sizeof(struct sockaddr_storage)
133 * at maximum as shown in RFC 4038 Sec.6.2.3.
134 */
135 if (salen > sizeof(struct sockaddr_storage))
136 return EAI_FAMILY;
137
138 switch (sa->sa_family) {
139 case AF_APPLETALK:
140 return getnameinfo_atalk(sa, salen, host, hostlen,
141 serv, servlen, flags);
142 case AF_INET:
143 case AF_INET6:
144 return getnameinfo_inet(sa, salen, host, hostlen,
145 serv, servlen, flags);
146 case AF_LINK:
147 return getnameinfo_link(sa, salen, host, hostlen,
148 serv, servlen, flags);
149 case AF_LOCAL:
150 return getnameinfo_local(sa, salen, host, hostlen,
151 serv, servlen, flags);
152 default:
153 return EAI_FAMILY;
154 }
155 }
156
157 /*
158 * getnameinfo_atalk():
159 * Format an AppleTalk address into a printable format.
160 */
161 /* ARGSUSED */
162 static int
getnameinfo_atalk(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)163 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen,
164 char *host, socklen_t hostlen, char *serv, socklen_t servlen,
165 int flags)
166 {
167 char numserv[8];
168 int n, m=0;
169
170 const struct sockaddr_at *sat =
171 (const struct sockaddr_at *)(const void *)sa;
172
173 if (serv != NULL && servlen > 0) {
174 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port);
175 if (strlen(numserv) + 1 > servlen)
176 return EAI_MEMORY;
177 strlcpy(serv, numserv, servlen);
178 }
179
180 n = snprintf(host, hostlen, "%u.%u",
181 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
182
183 if (n < 0 || (socklen_t)(m+n) >= hostlen)
184 goto errout;
185
186 m += n;
187
188 if (sat->sat_range.r_netrange.nr_phase) {
189 n = snprintf(host+m, hostlen-m, " phase %u",
190 sat->sat_range.r_netrange.nr_phase);
191
192 if (n < 0 || (socklen_t)(m+n) >= hostlen)
193 goto errout;
194
195 m += n;
196 }
197 if (sat->sat_range.r_netrange.nr_firstnet) {
198 n = snprintf(host+m, hostlen-m, " range %u - %u",
199 ntohs(sat->sat_range.r_netrange.nr_firstnet),
200 ntohs(sat->sat_range.r_netrange.nr_lastnet ));
201
202 if (n < 0 || (socklen_t)(m+n) >= hostlen)
203 goto errout;
204
205 m += n;
206 }
207
208 return 0;
209
210 errout:
211 if (host && hostlen>0)
212 host[m] = '\0'; /* XXX ??? */
213
214 return EAI_MEMORY;
215 }
216
217 /*
218 * getnameinfo_local():
219 * Format an local address into a printable format.
220 */
221 /* ARGSUSED */
222 static int
getnameinfo_local(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)223 getnameinfo_local(const struct sockaddr *sa, socklen_t salen,
224 char *host, socklen_t hostlen, char *serv, socklen_t servlen,
225 int flags)
226 {
227 const struct sockaddr_un *sun =
228 (const struct sockaddr_un *)(const void *)sa;
229
230 if (salen <= sizeof(*sun) - sizeof(sun->sun_path))
231 return EAI_FAMILY;
232
233 if (serv != NULL && servlen > 0)
234 serv[0] = '\0';
235
236 if (host && hostlen > 0)
237 strlcpy(host, sun->sun_path,
238 MIN(sizeof(sun->sun_path) + 1, hostlen));
239
240 return 0;
241 }
242
243 /*
244 * getnameinfo_inet():
245 * Format an IPv4 or IPv6 sockaddr into a printable string.
246 */
247 static int
getnameinfo_inet(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)248 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen,
249 char *host, socklen_t hostlen,
250 char *serv, socklen_t servlen,
251 int flags)
252 {
253 const struct afd *afd;
254 struct servent *sp;
255 struct hostent *hp;
256 u_short port;
257 int family, i;
258 const char *addr;
259 uint32_t v4a;
260 char numserv[512];
261 char numaddr[512];
262
263 /* sa is checked below */
264 /* host may be NULL */
265 /* serv may be NULL */
266
267 if (sa == NULL)
268 return EAI_FAIL;
269
270 family = sa->sa_family;
271 for (i = 0; afdl[i].a_af; i++)
272 if (afdl[i].a_af == family) {
273 afd = &afdl[i];
274 goto found;
275 }
276 return EAI_FAMILY;
277
278 found:
279 if (salen < afd->a_socklen)
280 return EAI_FAMILY;
281
282 /* network byte order */
283 port = ((const struct sockinet *)(const void *)sa)->si_port;
284 addr = (const char *)(const void *)sa + afd->a_off;
285
286 if (serv == NULL || servlen == 0) {
287 /*
288 * do nothing in this case.
289 * in case you are wondering if "&&" is more correct than
290 * "||" here: rfc2553bis-03 says that serv == NULL OR
291 * servlen == 0 means that the caller does not want the result.
292 */
293 } else {
294 struct servent_data svd;
295 struct servent sv;
296
297 if (flags & NI_NUMERICSERV)
298 sp = NULL;
299 else {
300 (void)memset(&svd, 0, sizeof(svd));
301 sp = getservbyport_r(port,
302 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd);
303 }
304 if (sp) {
305 if (strlen(sp->s_name) + 1 > servlen) {
306 endservent_r(&svd);
307 return EAI_MEMORY;
308 }
309 strlcpy(serv, sp->s_name, servlen);
310 endservent_r(&svd);
311 } else {
312 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
313 if (strlen(numserv) + 1 > servlen)
314 return EAI_MEMORY;
315 strlcpy(serv, numserv, servlen);
316 }
317 }
318
319 switch (sa->sa_family) {
320 case AF_INET:
321 v4a = (uint32_t)
322 ntohl(((const struct sockaddr_in *)
323 (const void *)sa)->sin_addr.s_addr);
324 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
325 flags |= NI_NUMERICHOST;
326 v4a >>= IN_CLASSA_NSHIFT;
327 if (v4a == 0)
328 flags |= NI_NUMERICHOST;
329 break;
330 #ifdef INET6
331 case AF_INET6:
332 {
333 const struct sockaddr_in6 *sin6;
334 sin6 = (const struct sockaddr_in6 *)(const void *)sa;
335 switch (sin6->sin6_addr.s6_addr[0]) {
336 case 0x00:
337 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
338 ;
339 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
340 ;
341 else
342 flags |= NI_NUMERICHOST;
343 break;
344 default:
345 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
346 flags |= NI_NUMERICHOST;
347 }
348 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
349 flags |= NI_NUMERICHOST;
350 break;
351 }
352 }
353 break;
354 #endif
355 }
356 if (host == NULL || hostlen == 0) {
357 /*
358 * do nothing in this case.
359 * in case you are wondering if "&&" is more correct than
360 * "||" here: rfc2553bis-03 says that host == NULL or
361 * hostlen == 0 means that the caller does not want the result.
362 */
363 } else if (flags & NI_NUMERICHOST) {
364 size_t numaddrlen;
365
366 /* NUMERICHOST and NAMEREQD conflicts with each other */
367 if (flags & NI_NAMEREQD)
368 return EAI_NONAME;
369
370 switch(afd->a_af) {
371 #ifdef INET6
372 case AF_INET6:
373 {
374 int error;
375
376 if ((error = ip6_parsenumeric(sa, addr, host,
377 hostlen, flags)) != 0)
378 return(error);
379 break;
380 }
381 #endif
382 default:
383 if (inet_ntop(afd->a_af, addr, numaddr,
384 (socklen_t)sizeof(numaddr)) == NULL)
385 return EAI_SYSTEM;
386 numaddrlen = strlen(numaddr);
387 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
388 return EAI_MEMORY;
389 strlcpy(host, numaddr, hostlen);
390 break;
391 }
392 } else {
393 struct hostent hent;
394 char hbuf[4096];
395 int he;
396 hp = gethostbyaddr_r(addr, afd->a_addrlen, afd->a_af, &hent,
397 hbuf, sizeof(hbuf), &he);
398
399 if (hp) {
400 #if 0
401 /*
402 * commented out, since "for local host" is not
403 * implemented here - see RFC2553 p30
404 */
405 if (flags & NI_NOFQDN) {
406 char *p;
407 p = strchr(hp->h_name, '.');
408 if (p)
409 *p = '\0';
410 }
411 #endif
412 if (strlen(hp->h_name) + 1 > hostlen) {
413 return EAI_MEMORY;
414 }
415 strlcpy(host, hp->h_name, hostlen);
416 } else {
417 switch (he) {
418 case NO_DATA:
419 case HOST_NOT_FOUND:
420 if (flags & NI_NAMEREQD)
421 return EAI_NONAME;
422 break;
423 case TRY_AGAIN:
424 return EAI_AGAIN;
425 case NETDB_SUCCESS:
426 case NETDB_INTERNAL:
427 case NO_RECOVERY:
428 /*FALLTHROUGH*/
429 default:
430 return EAI_SYSTEM;
431 }
432 switch(afd->a_af) {
433 #ifdef INET6
434 case AF_INET6:
435 {
436 int error;
437
438 if ((error = ip6_parsenumeric(sa, addr, host,
439 hostlen,
440 flags)) != 0)
441 return(error);
442 break;
443 }
444 #endif
445 default:
446 if (inet_ntop(afd->a_af, addr, host,
447 hostlen) == NULL)
448 return EAI_SYSTEM;
449 break;
450 }
451 }
452 }
453 return(0);
454 }
455
456 #ifdef INET6
457 static int
ip6_parsenumeric(const struct sockaddr * sa,const char * addr,char * host,socklen_t hostlen,int flags)458 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
459 socklen_t hostlen, int flags)
460 {
461 size_t numaddrlen;
462 char numaddr[512];
463
464 _DIAGASSERT(sa != NULL);
465 _DIAGASSERT(addr != NULL);
466 _DIAGASSERT(host != NULL);
467
468 if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr))
469 == NULL)
470 return EAI_SYSTEM;
471
472 numaddrlen = strlen(numaddr);
473 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
474 return EAI_OVERFLOW;
475 strlcpy(host, numaddr, hostlen);
476
477 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
478 char zonebuf[MAXHOSTNAMELEN];
479 int zonelen;
480
481 zonelen = ip6_sa2str(
482 (const struct sockaddr_in6 *)(const void *)sa,
483 zonebuf, sizeof(zonebuf), flags);
484 if (zonelen < 0)
485 return EAI_OVERFLOW;
486 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen)
487 return EAI_OVERFLOW;
488 /* construct <numeric-addr><delim><zoneid> */
489 memcpy(host + numaddrlen + 1, zonebuf,
490 (size_t)zonelen);
491 host[numaddrlen] = SCOPE_DELIMITER;
492 host[numaddrlen + 1 + zonelen] = '\0';
493 }
494
495 return 0;
496 }
497
498 /* ARGSUSED */
499 static int
ip6_sa2str(const struct sockaddr_in6 * sa6,char * buf,size_t bufsiz,int flags)500 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
501 {
502 unsigned int ifindex;
503 const struct in6_addr *a6;
504 int n;
505
506 _DIAGASSERT(sa6 != NULL);
507 _DIAGASSERT(buf != NULL);
508
509 ifindex = (unsigned int)sa6->sin6_scope_id;
510 a6 = &sa6->sin6_addr;
511
512 #ifdef NI_NUMERICSCOPE
513 if ((flags & NI_NUMERICSCOPE) != 0) {
514 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
515 if (n < 0 || (size_t)n >= bufsiz)
516 return -1;
517 else
518 return n;
519 }
520 #endif
521
522 /* if_indextoname() does not take buffer size. not a good api... */
523 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
524 bufsiz >= IF_NAMESIZE) {
525 char *p = if_indextoname(ifindex, buf);
526 if (p) {
527 return (int)strlen(p);
528 }
529 }
530
531 /* last resort */
532 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
533 if (n < 0 || (size_t) n >= bufsiz)
534 return -1;
535 else
536 return n;
537 }
538 #endif /* INET6 */
539
540
541 /*
542 * getnameinfo_link():
543 * Format a link-layer address into a printable format, paying attention to
544 * the interface type.
545 */
546 /* ARGSUSED */
547 static int
getnameinfo_link(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)548 getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
549 char *host, socklen_t hostlen, char *serv, socklen_t servlen,
550 int flags)
551 {
552 const struct sockaddr_dl *sdl =
553 (const struct sockaddr_dl *)(const void *)sa;
554 const struct ieee1394_hwaddr *iha;
555 int n;
556
557 if (salen <= sizeof(*sdl) - sizeof(sdl->sdl_data))
558 return EAI_FAMILY;
559
560 if (serv != NULL && servlen > 0)
561 *serv = '\0';
562
563 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
564 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
565 goto out;
566 }
567
568 switch (sdl->sdl_type) {
569 #ifdef IFT_ECONET
570 case IFT_ECONET:
571 if (sdl->sdl_alen < 2)
572 return EAI_FAMILY;
573 if (CLLADDR(sdl)[1] == 0)
574 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
575 else
576 n = snprintf(host, hostlen, "%u.%u",
577 CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
578 goto out;
579 #endif
580 case IFT_IEEE1394:
581 if (sdl->sdl_alen < sizeof(iha->iha_uid))
582 return EAI_FAMILY;
583 iha =
584 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
585 return hexname(iha->iha_uid, sizeof(iha->iha_uid),
586 host, hostlen);
587 /*
588 * The following have zero-length addresses.
589 * IFT_ATM (net/if_atmsubr.c)
590 * IFT_FAITH (net/if_faith.c)
591 * IFT_GIF (net/if_gif.c)
592 * IFT_LOOP (net/if_loop.c)
593 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c)
594 * IFT_SLIP (net/if_sl.c, net/if_strip.c)
595 * IFT_STF (net/if_stf.c)
596 * IFT_L2VLAN (net/if_vlan.c)
597 * IFT_PROPVIRTUAL (net/if_bridge.h>
598 */
599 /*
600 * The following use IPv4 addresses as link-layer addresses:
601 * IFT_OTHER (net/if_gre.c)
602 */
603 case IFT_ARCNET: /* default below is believed correct for all these. */
604 case IFT_ETHER:
605 case IFT_FDDI:
606 case IFT_HIPPI:
607 case IFT_ISO88025:
608 default:
609 return hexname((const uint8_t *)CLLADDR(sdl),
610 (size_t)sdl->sdl_alen, host, hostlen);
611 }
612 out:
613 if (n < 0 || (socklen_t) n >= hostlen) {
614 *host = '\0';
615 return EAI_MEMORY;
616 }
617 return 0;
618 }
619
620 static int
hexname(const uint8_t * cp,size_t len,char * host,socklen_t hostlen)621 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen)
622 {
623 int n;
624 size_t i;
625 char *outp = host;
626
627 *outp = '\0';
628 for (i = 0; i < len; i++) {
629 n = snprintf(outp, hostlen, "%s%02x",
630 i ? ":" : "", cp[i]);
631 if (n < 0 || (socklen_t) n >= hostlen) {
632 *host = '\0';
633 return EAI_MEMORY;
634 }
635 outp += n;
636 hostlen -= n;
637 }
638 return 0;
639 }
640