1 /* $NetBSD: getnameinfo.c,v 1.43 2006/02/17 15:58:26 ginsbach 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 1.43 2006/02/17 15:58:26 ginsbach Exp $");
51 #endif /* LIBC_SCCS and not lint */
52
53 #include <sys/types.h>
54 #include <sys/socket.h>
55 #include <net/if.h>
56 #include <net/if_dl.h>
57 #include <net/if_ieee1394.h>
58 #include <net/if_types.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
61 #include "arpa_nameser.h"
62 #include <assert.h>
63 #include <limits.h>
64 #include <netdb.h>
65 #ifdef ANDROID_CHANGES
66 #include "resolv_private.h"
67 #else
68 #include <resolv.h>
69 #endif
70 #include <stddef.h>
71 #include <string.h>
72
73 static const struct afd {
74 int a_af;
75 socklen_t a_addrlen;
76 socklen_t a_socklen;
77 int a_off;
78 } afdl [] = {
79 #ifdef INET6
80 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
81 offsetof(struct sockaddr_in6, sin6_addr)},
82 #endif
83 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
84 offsetof(struct sockaddr_in, sin_addr)},
85 {0, 0, 0, 0},
86 };
87
88 struct sockinet {
89 u_char si_len;
90 u_char si_family;
91 u_short si_port;
92 };
93
94 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
95 socklen_t, char *, socklen_t, int));
96 #ifdef INET6
97 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
98 socklen_t, int));
99 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t,
100 int));
101 #endif
102 static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *,
103 socklen_t, char *, socklen_t, int));
104 static int hexname __P((const u_int8_t *, size_t, char *, socklen_t));
105
106 /*
107 * Top-level getnameinfo() code. Look at the address family, and pick an
108 * appropriate function to call.
109 */
getnameinfo(const struct sockaddr * sa,socklen_t salen,char * host,size_t hostlen,char * serv,size_t servlen,int flags)110 int getnameinfo(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags)
111 {
112 switch (sa->sa_family) {
113 case AF_INET:
114 case AF_INET6:
115 return getnameinfo_inet(sa, salen, host, hostlen,
116 serv, servlen, flags);
117 #if 0
118 case AF_LINK:
119 return getnameinfo_link(sa, salen, host, hostlen,
120 serv, servlen, flags);
121 #endif
122 default:
123 return EAI_FAMILY;
124 }
125 }
126
127
128 /*
129 * getnameinfo_inet():
130 * Format an IPv4 or IPv6 sockaddr into a printable string.
131 */
132 static int
getnameinfo_inet(sa,salen,host,hostlen,serv,servlen,flags)133 getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags)
134 const struct sockaddr *sa;
135 socklen_t salen;
136 char *host;
137 socklen_t hostlen;
138 char *serv;
139 socklen_t servlen;
140 int flags;
141 {
142 const struct afd *afd;
143 struct servent *sp;
144 struct hostent *hp;
145 u_short port;
146 int family, i;
147 const char *addr;
148 u_int32_t v4a;
149 char numserv[512];
150 char numaddr[512];
151
152 /* sa is checked below */
153 /* host may be NULL */
154 /* serv may be NULL */
155
156 if (sa == NULL)
157 return EAI_FAIL;
158
159 #ifdef BSD4_4
160 if (sa->sa_len != salen)
161 return EAI_FAIL;
162 #endif
163
164 family = sa->sa_family;
165 for (i = 0; afdl[i].a_af; i++)
166 if (afdl[i].a_af == family) {
167 afd = &afdl[i];
168 goto found;
169 }
170 return EAI_FAMILY;
171
172 found:
173 if (salen != afd->a_socklen)
174 return EAI_FAIL;
175
176 /* network byte order */
177 port = ((const struct sockinet *)(const void *)sa)->si_port;
178 addr = (const char *)(const void *)sa + afd->a_off;
179
180 if (serv == NULL || servlen == 0) {
181 /*
182 * do nothing in this case.
183 * in case you are wondering if "&&" is more correct than
184 * "||" here: rfc2553bis-03 says that serv == NULL OR
185 * servlen == 0 means that the caller does not want the result.
186 */
187 } else {
188 if (flags & NI_NUMERICSERV)
189 sp = NULL;
190 else {
191 sp = getservbyport(port,
192 (flags & NI_DGRAM) ? "udp" : "tcp");
193 }
194 if (sp) {
195 if (strlen(sp->s_name) + 1 > (size_t)servlen)
196 return EAI_MEMORY;
197 strlcpy(serv, sp->s_name, servlen);
198 } else {
199 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
200 if (strlen(numserv) + 1 > (size_t)servlen)
201 return EAI_MEMORY;
202 strlcpy(serv, numserv, servlen);
203 }
204 }
205
206 switch (sa->sa_family) {
207 case AF_INET:
208 v4a = (u_int32_t)
209 ntohl(((const struct sockaddr_in *)
210 (const void *)sa)->sin_addr.s_addr);
211 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
212 flags |= NI_NUMERICHOST;
213 v4a >>= IN_CLASSA_NSHIFT;
214 if (v4a == 0)
215 flags |= NI_NUMERICHOST;
216 break;
217 #ifdef INET6
218 case AF_INET6:
219 {
220 const struct sockaddr_in6 *sin6;
221 sin6 = (const struct sockaddr_in6 *)(const void *)sa;
222 switch (sin6->sin6_addr.s6_addr[0]) {
223 case 0x00:
224 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
225 ;
226 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
227 ;
228 else
229 flags |= NI_NUMERICHOST;
230 break;
231 default:
232 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
233 flags |= NI_NUMERICHOST;
234 }
235 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
236 flags |= NI_NUMERICHOST;
237 break;
238 }
239 }
240 break;
241 #endif
242 }
243 if (host == NULL || hostlen == 0) {
244 /*
245 * do nothing in this case.
246 * in case you are wondering if "&&" is more correct than
247 * "||" here: rfc2553bis-03 says that host == NULL or
248 * hostlen == 0 means that the caller does not want the result.
249 */
250 } else if (flags & NI_NUMERICHOST) {
251 size_t numaddrlen;
252
253 /* NUMERICHOST and NAMEREQD conflicts with each other */
254 if (flags & NI_NAMEREQD)
255 return EAI_NONAME;
256
257 switch(afd->a_af) {
258 #ifdef INET6
259 case AF_INET6:
260 {
261 int error;
262
263 if ((error = ip6_parsenumeric(sa, addr, host,
264 hostlen, flags)) != 0)
265 return(error);
266 break;
267 }
268 #endif
269 default:
270 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
271 == NULL)
272 return EAI_SYSTEM;
273 numaddrlen = strlen(numaddr);
274 if (numaddrlen + 1 > (size_t)hostlen) /* don't forget terminator */
275 return EAI_MEMORY;
276 strlcpy(host, numaddr, hostlen);
277 break;
278 }
279 } else {
280 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
281
282 if (hp) {
283 #if 0
284 /*
285 * commented out, since "for local host" is not
286 * implemented here - see RFC2553 p30
287 */
288 if (flags & NI_NOFQDN) {
289 char *p;
290 p = strchr(hp->h_name, '.');
291 if (p)
292 *p = '\0';
293 }
294 #endif
295 if (strlen(hp->h_name) + 1 > (size_t)hostlen) {
296 return EAI_MEMORY;
297 }
298 strlcpy(host, hp->h_name, hostlen);
299 } else {
300 if (flags & NI_NAMEREQD)
301 return EAI_NONAME;
302 switch(afd->a_af) {
303 #ifdef INET6
304 case AF_INET6:
305 {
306 int error;
307
308 if ((error = ip6_parsenumeric(sa, addr, host,
309 hostlen,
310 flags)) != 0)
311 return(error);
312 break;
313 }
314 #endif
315 default:
316 if (inet_ntop(afd->a_af, addr, host,
317 hostlen) == NULL)
318 return EAI_SYSTEM;
319 break;
320 }
321 }
322 }
323 return(0);
324 }
325
326 #ifdef INET6
327 static int
ip6_parsenumeric(sa,addr,host,hostlen,flags)328 ip6_parsenumeric(sa, addr, host, hostlen, flags)
329 const struct sockaddr *sa;
330 const char *addr;
331 char *host;
332 socklen_t hostlen;
333 int flags;
334 {
335 size_t numaddrlen;
336 char numaddr[512];
337
338 assert(sa != NULL);
339 assert(addr != NULL);
340 assert(host != NULL);
341
342 if (hostlen < 0)
343 return EAI_OVERFLOW;
344
345 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
346 return EAI_SYSTEM;
347
348 numaddrlen = strlen(numaddr);
349 if (numaddrlen + 1 > (size_t)hostlen) /* don't forget terminator */
350 return EAI_OVERFLOW;
351 strlcpy(host, numaddr, hostlen);
352
353 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
354 char zonebuf[MAXHOSTNAMELEN];
355 int zonelen;
356
357 zonelen = ip6_sa2str(
358 (const struct sockaddr_in6 *)(const void *)sa,
359 zonebuf, sizeof(zonebuf), flags);
360 if (zonelen < 0)
361 return EAI_OVERFLOW;
362 if ((size_t) zonelen + 1 + numaddrlen + 1 > (size_t)hostlen)
363 return EAI_OVERFLOW;
364 /* construct <numeric-addr><delim><zoneid> */
365 memcpy(host + numaddrlen + 1, zonebuf,
366 (size_t)zonelen);
367 host[numaddrlen] = SCOPE_DELIMITER;
368 host[numaddrlen + 1 + zonelen] = '\0';
369 }
370
371 return 0;
372 }
373
374 /* ARGSUSED */
375 static int
ip6_sa2str(sa6,buf,bufsiz,flags)376 ip6_sa2str(sa6, buf, bufsiz, flags)
377 const struct sockaddr_in6 *sa6;
378 char *buf;
379 size_t bufsiz;
380 int flags;
381 {
382 unsigned int ifindex;
383 const struct in6_addr *a6;
384 int n;
385
386 assert(sa6 != NULL);
387 assert(buf != NULL);
388
389 ifindex = (unsigned int)sa6->sin6_scope_id;
390 a6 = &sa6->sin6_addr;
391
392 #ifdef NI_NUMERICSCOPE
393 if ((flags & NI_NUMERICSCOPE) != 0) {
394 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
395 if (n < 0 || n >= bufsiz)
396 return -1;
397 else
398 return n;
399 }
400 #endif
401
402 /* if_indextoname() does not take buffer size. not a good api... */
403 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
404 bufsiz >= IF_NAMESIZE) {
405 char *p = if_indextoname(ifindex, buf);
406 if (p) {
407 return(strlen(p));
408 }
409 }
410
411 /* last resort */
412 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
413 if (n < 0 || (size_t) n >= bufsiz)
414 return -1;
415 else
416 return n;
417 }
418 #endif /* INET6 */
419
420
421 /*
422 * getnameinfo_link():
423 * Format a link-layer address into a printable format, paying attention to
424 * the interface type.
425 */
426 /* ARGSUSED */
427 static int
getnameinfo_link(const struct sockaddr * sa,socklen_t salen,char * host,socklen_t hostlen,char * serv,socklen_t servlen,int flags)428 getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
429 char *host, socklen_t hostlen, char *serv, socklen_t servlen,
430 int flags)
431 {
432 const struct sockaddr_dl *sdl =
433 (const struct sockaddr_dl *)(const void *)sa;
434 const struct ieee1394_hwaddr *iha;
435 int n;
436
437 if (serv != NULL && servlen > 0)
438 *serv = '\0';
439
440 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
441 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
442 if (n < 0 || (socklen_t) n > hostlen) {
443 *host = '\0';
444 return EAI_MEMORY;
445 }
446 return 0;
447 }
448
449 switch (sdl->sdl_type) {
450 #ifdef IFT_ECONET
451 case IFT_ECONET:
452 if (sdl->sdl_alen < 2)
453 return EAI_FAMILY;
454 if (CLLADDR(sdl)[1] == 0)
455 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
456 else
457 n = snprintf(host, hostlen, "%u.%u",
458 CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
459 if (n < 0 || (socklen_t) n >= hostlen) {
460 *host = '\0';
461 return EAI_MEMORY;
462 } else
463 return 0;
464 #endif
465 case IFT_IEEE1394:
466 if (sdl->sdl_alen < sizeof(iha->iha_uid))
467 return EAI_FAMILY;
468 iha =
469 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
470 return hexname(iha->iha_uid, sizeof(iha->iha_uid),
471 host, hostlen);
472 /*
473 * The following have zero-length addresses.
474 * IFT_ATM (net/if_atmsubr.c)
475 * IFT_FAITH (net/if_faith.c)
476 * IFT_GIF (net/if_gif.c)
477 * IFT_LOOP (net/if_loop.c)
478 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c)
479 * IFT_SLIP (net/if_sl.c, net/if_strip.c)
480 * IFT_STF (net/if_stf.c)
481 * IFT_L2VLAN (net/if_vlan.c)
482 * IFT_PROPVIRTUAL (net/if_bridge.h>
483 */
484 /*
485 * The following use IPv4 addresses as link-layer addresses:
486 * IFT_OTHER (net/if_gre.c)
487 */
488 case IFT_ARCNET: /* default below is believed correct for all these. */
489 case IFT_ETHER:
490 case IFT_FDDI:
491 case IFT_HIPPI:
492 case IFT_ISO88025:
493 default:
494 return hexname((const u_int8_t *)CLLADDR(sdl),
495 (size_t)sdl->sdl_alen, host, hostlen);
496 }
497 }
498
499 static int
hexname(cp,len,host,hostlen)500 hexname(cp, len, host, hostlen)
501 const u_int8_t *cp;
502 char *host;
503 size_t len;
504 socklen_t hostlen;
505 {
506 int n;
507 size_t i;
508 char *outp = host;
509
510 *outp = '\0';
511 for (i = 0; i < len; i++) {
512 n = snprintf(outp, hostlen, "%s%02x",
513 i ? ":" : "", cp[i]);
514 if (n < 0 || (socklen_t) n >= hostlen) {
515 *host = '\0';
516 return EAI_MEMORY;
517 }
518 outp += n;
519 hostlen -= n;
520 }
521 return 0;
522 }
523