1 /* $NetBSD: getnameinfo.c,v 1.49 2010/01/29 22:26:48 is 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 1.49 2010/01/29 22:26:48 is Exp $"); 51 #endif /* LIBC_SCCS and not lint */ 52 53 #include "namespace.h" 54 #include <sys/types.h> 55 #include <sys/socket.h> 56 #include <net/if.h> 57 #include <net/if_dl.h> 58 #include <net/if_ieee1394.h> 59 #include <net/if_types.h> 60 #include <netatalk/at.h> 61 #include <netinet/in.h> 62 #include <arpa/inet.h> 63 #include <arpa/nameser.h> 64 #include <assert.h> 65 #include <limits.h> 66 #include <netdb.h> 67 #include <resolv.h> 68 #include <stddef.h> 69 #include <string.h> 70 71 #include "servent.h" 72 73 #ifdef __weak_alias 74 __weak_alias(getnameinfo,_getnameinfo) 75 #endif 76 77 static const struct afd { 78 int a_af; 79 socklen_t a_addrlen; 80 socklen_t a_socklen; 81 int a_off; 82 } afdl [] = { 83 #ifdef INET6 84 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 85 offsetof(struct sockaddr_in6, sin6_addr)}, 86 #endif 87 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 88 offsetof(struct sockaddr_in, sin_addr)}, 89 {0, 0, 0, 0}, 90 }; 91 92 struct sockinet { 93 u_char si_len; 94 u_char si_family; 95 u_short si_port; 96 }; 97 98 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *, 99 socklen_t, char *, socklen_t, int)); 100 #ifdef INET6 101 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 102 socklen_t, int)); 103 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, 104 int)); 105 #endif 106 static int getnameinfo_atalk __P((const struct sockaddr *, socklen_t, char *, 107 socklen_t, char *, socklen_t, int)); 108 109 static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *, 110 socklen_t, char *, socklen_t, int)); 111 static int hexname __P((const u_int8_t *, size_t, char *, socklen_t)); 112 113 /* 114 * Top-level getnameinfo() code. Look at the address family, and pick an 115 * appropriate function to call. 116 */ 117 int 118 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 119 const struct sockaddr *sa; 120 socklen_t salen; 121 char *host, *serv; 122 socklen_t hostlen, servlen; 123 int flags; 124 { 125 126 switch (sa->sa_family) { 127 case AF_APPLETALK: 128 return getnameinfo_atalk(sa, salen, host, hostlen, 129 serv, servlen, flags); 130 case AF_INET: 131 case AF_INET6: 132 return getnameinfo_inet(sa, salen, host, hostlen, 133 serv, servlen, flags); 134 case AF_LINK: 135 return getnameinfo_link(sa, salen, host, hostlen, 136 serv, servlen, flags); 137 default: 138 return EAI_FAMILY; 139 } 140 } 141 142 /* 143 * getnameinfo_atalk(): 144 * Format an AppleTalk address into a printable format. 145 */ 146 /* ARGSUSED */ 147 static int 148 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen, 149 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 150 int flags) 151 { 152 char numserv[8]; 153 int n, m=0; 154 155 const struct sockaddr_at *sat = 156 (const struct sockaddr_at *)(const void *)sa; 157 158 if (serv != NULL && servlen > 0) { 159 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port); 160 if (strlen(numserv) + 1 > servlen) 161 return EAI_MEMORY; 162 strlcpy(serv, numserv, servlen); 163 } 164 165 n = snprintf(host, hostlen, "%u.%u", 166 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node); 167 168 if (n < 0 || (socklen_t)(m+n) >= hostlen) 169 goto errout; 170 171 m += n; 172 173 if (sat->sat_range.r_netrange.nr_phase) { 174 n = snprintf(host+m, hostlen-m, " phase %u", 175 sat->sat_range.r_netrange.nr_phase); 176 177 if (n < 0 || (socklen_t)(m+n) >= hostlen) 178 goto errout; 179 180 m += n; 181 } 182 if (sat->sat_range.r_netrange.nr_firstnet) { 183 n = snprintf(host+m, hostlen-m, " range %u - %u", 184 ntohs(sat->sat_range.r_netrange.nr_firstnet), 185 ntohs(sat->sat_range.r_netrange.nr_lastnet )); 186 187 if (n < 0 || (socklen_t)(m+n) >= hostlen) 188 goto errout; 189 190 m += n; 191 } 192 193 return 0; 194 195 errout: 196 if (host && hostlen>0) 197 host[m] = '\0'; /* XXX ??? */ 198 199 return EAI_MEMORY; 200 } 201 202 /* 203 * getnameinfo_inet(): 204 * Format an IPv4 or IPv6 sockaddr into a printable string. 205 */ 206 static int 207 getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags) 208 const struct sockaddr *sa; 209 socklen_t salen; 210 char *host; 211 socklen_t hostlen; 212 char *serv; 213 socklen_t servlen; 214 int flags; 215 { 216 const struct afd *afd; 217 struct servent *sp; 218 struct hostent *hp; 219 u_short port; 220 int family, i; 221 const char *addr; 222 u_int32_t v4a; 223 char numserv[512]; 224 char numaddr[512]; 225 226 /* sa is checked below */ 227 /* host may be NULL */ 228 /* serv may be NULL */ 229 230 if (sa == NULL) 231 return EAI_FAIL; 232 233 #ifdef BSD4_4 234 if (sa->sa_len != salen) 235 return EAI_FAIL; 236 #endif 237 238 family = sa->sa_family; 239 for (i = 0; afdl[i].a_af; i++) 240 if (afdl[i].a_af == family) { 241 afd = &afdl[i]; 242 goto found; 243 } 244 return EAI_FAMILY; 245 246 found: 247 if (salen != afd->a_socklen) 248 return EAI_FAIL; 249 250 /* network byte order */ 251 port = ((const struct sockinet *)(const void *)sa)->si_port; 252 addr = (const char *)(const void *)sa + afd->a_off; 253 254 if (serv == NULL || servlen == 0) { 255 /* 256 * do nothing in this case. 257 * in case you are wondering if "&&" is more correct than 258 * "||" here: rfc2553bis-03 says that serv == NULL OR 259 * servlen == 0 means that the caller does not want the result. 260 */ 261 } else { 262 struct servent_data svd; 263 struct servent sv; 264 265 if (flags & NI_NUMERICSERV) 266 sp = NULL; 267 else { 268 (void)memset(&svd, 0, sizeof(svd)); 269 sp = getservbyport_r(port, 270 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd); 271 } 272 if (sp) { 273 if (strlen(sp->s_name) + 1 > servlen) { 274 endservent_r(&svd); 275 return EAI_MEMORY; 276 } 277 strlcpy(serv, sp->s_name, servlen); 278 endservent_r(&svd); 279 } else { 280 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 281 if (strlen(numserv) + 1 > servlen) 282 return EAI_MEMORY; 283 strlcpy(serv, numserv, servlen); 284 } 285 } 286 287 switch (sa->sa_family) { 288 case AF_INET: 289 v4a = (u_int32_t) 290 ntohl(((const struct sockaddr_in *) 291 (const void *)sa)->sin_addr.s_addr); 292 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 293 flags |= NI_NUMERICHOST; 294 v4a >>= IN_CLASSA_NSHIFT; 295 if (v4a == 0) 296 flags |= NI_NUMERICHOST; 297 break; 298 #ifdef INET6 299 case AF_INET6: 300 { 301 const struct sockaddr_in6 *sin6; 302 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 303 switch (sin6->sin6_addr.s6_addr[0]) { 304 case 0x00: 305 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 306 ; 307 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 308 ; 309 else 310 flags |= NI_NUMERICHOST; 311 break; 312 default: 313 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 314 flags |= NI_NUMERICHOST; 315 } 316 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 317 flags |= NI_NUMERICHOST; 318 break; 319 } 320 } 321 break; 322 #endif 323 } 324 if (host == NULL || hostlen == 0) { 325 /* 326 * do nothing in this case. 327 * in case you are wondering if "&&" is more correct than 328 * "||" here: rfc2553bis-03 says that host == NULL or 329 * hostlen == 0 means that the caller does not want the result. 330 */ 331 } else if (flags & NI_NUMERICHOST) { 332 size_t numaddrlen; 333 334 /* NUMERICHOST and NAMEREQD conflicts with each other */ 335 if (flags & NI_NAMEREQD) 336 return EAI_NONAME; 337 338 switch(afd->a_af) { 339 #ifdef INET6 340 case AF_INET6: 341 { 342 int error; 343 344 if ((error = ip6_parsenumeric(sa, addr, host, 345 hostlen, flags)) != 0) 346 return(error); 347 break; 348 } 349 #endif 350 default: 351 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 352 == NULL) 353 return EAI_SYSTEM; 354 numaddrlen = strlen(numaddr); 355 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 356 return EAI_MEMORY; 357 strlcpy(host, numaddr, hostlen); 358 break; 359 } 360 } else { 361 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 362 363 if (hp) { 364 #if 0 365 /* 366 * commented out, since "for local host" is not 367 * implemented here - see RFC2553 p30 368 */ 369 if (flags & NI_NOFQDN) { 370 char *p; 371 p = strchr(hp->h_name, '.'); 372 if (p) 373 *p = '\0'; 374 } 375 #endif 376 if (strlen(hp->h_name) + 1 > hostlen) { 377 return EAI_MEMORY; 378 } 379 strlcpy(host, hp->h_name, hostlen); 380 } else { 381 if (flags & NI_NAMEREQD) 382 return EAI_NONAME; 383 switch(afd->a_af) { 384 #ifdef INET6 385 case AF_INET6: 386 { 387 int error; 388 389 if ((error = ip6_parsenumeric(sa, addr, host, 390 hostlen, 391 flags)) != 0) 392 return(error); 393 break; 394 } 395 #endif 396 default: 397 if (inet_ntop(afd->a_af, addr, host, 398 hostlen) == NULL) 399 return EAI_SYSTEM; 400 break; 401 } 402 } 403 } 404 return(0); 405 } 406 407 #ifdef INET6 408 static int 409 ip6_parsenumeric(sa, addr, host, hostlen, flags) 410 const struct sockaddr *sa; 411 const char *addr; 412 char *host; 413 socklen_t hostlen; 414 int flags; 415 { 416 size_t numaddrlen; 417 char numaddr[512]; 418 419 _DIAGASSERT(sa != NULL); 420 _DIAGASSERT(addr != NULL); 421 _DIAGASSERT(host != NULL); 422 423 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 424 return EAI_SYSTEM; 425 426 numaddrlen = strlen(numaddr); 427 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 428 return EAI_OVERFLOW; 429 strlcpy(host, numaddr, hostlen); 430 431 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 432 char zonebuf[MAXHOSTNAMELEN]; 433 int zonelen; 434 435 zonelen = ip6_sa2str( 436 (const struct sockaddr_in6 *)(const void *)sa, 437 zonebuf, sizeof(zonebuf), flags); 438 if (zonelen < 0) 439 return EAI_OVERFLOW; 440 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 441 return EAI_OVERFLOW; 442 /* construct <numeric-addr><delim><zoneid> */ 443 memcpy(host + numaddrlen + 1, zonebuf, 444 (size_t)zonelen); 445 host[numaddrlen] = SCOPE_DELIMITER; 446 host[numaddrlen + 1 + zonelen] = '\0'; 447 } 448 449 return 0; 450 } 451 452 /* ARGSUSED */ 453 static int 454 ip6_sa2str(sa6, buf, bufsiz, flags) 455 const struct sockaddr_in6 *sa6; 456 char *buf; 457 size_t bufsiz; 458 int flags; 459 { 460 unsigned int ifindex; 461 const struct in6_addr *a6; 462 int n; 463 464 _DIAGASSERT(sa6 != NULL); 465 _DIAGASSERT(buf != NULL); 466 467 ifindex = (unsigned int)sa6->sin6_scope_id; 468 a6 = &sa6->sin6_addr; 469 470 #ifdef NI_NUMERICSCOPE 471 if ((flags & NI_NUMERICSCOPE) != 0) { 472 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 473 if (n < 0 || (size_t)n >= bufsiz) 474 return -1; 475 else 476 return n; 477 } 478 #endif 479 480 /* if_indextoname() does not take buffer size. not a good api... */ 481 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 482 bufsiz >= IF_NAMESIZE) { 483 char *p = if_indextoname(ifindex, buf); 484 if (p) { 485 return(strlen(p)); 486 } 487 } 488 489 /* last resort */ 490 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 491 if (n < 0 || (size_t) n >= bufsiz) 492 return -1; 493 else 494 return n; 495 } 496 #endif /* INET6 */ 497 498 499 /* 500 * getnameinfo_link(): 501 * Format a link-layer address into a printable format, paying attention to 502 * the interface type. 503 */ 504 /* ARGSUSED */ 505 static int 506 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 507 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 508 int flags) 509 { 510 const struct sockaddr_dl *sdl = 511 (const struct sockaddr_dl *)(const void *)sa; 512 const struct ieee1394_hwaddr *iha; 513 int n; 514 515 if (serv != NULL && servlen > 0) 516 *serv = '\0'; 517 518 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 519 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 520 if (n < 0 || (socklen_t) n > hostlen) { 521 *host = '\0'; 522 return EAI_MEMORY; 523 } 524 return 0; 525 } 526 527 switch (sdl->sdl_type) { 528 #ifdef IFT_ECONET 529 case IFT_ECONET: 530 if (sdl->sdl_alen < 2) 531 return EAI_FAMILY; 532 if (CLLADDR(sdl)[1] == 0) 533 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 534 else 535 n = snprintf(host, hostlen, "%u.%u", 536 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 537 if (n < 0 || (socklen_t) n >= hostlen) { 538 *host = '\0'; 539 return EAI_MEMORY; 540 } else 541 return 0; 542 #endif 543 case IFT_IEEE1394: 544 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 545 return EAI_FAMILY; 546 iha = 547 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 548 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 549 host, hostlen); 550 /* 551 * The following have zero-length addresses. 552 * IFT_ATM (net/if_atmsubr.c) 553 * IFT_FAITH (net/if_faith.c) 554 * IFT_GIF (net/if_gif.c) 555 * IFT_LOOP (net/if_loop.c) 556 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 557 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 558 * IFT_STF (net/if_stf.c) 559 * IFT_L2VLAN (net/if_vlan.c) 560 * IFT_PROPVIRTUAL (net/if_bridge.h> 561 */ 562 /* 563 * The following use IPv4 addresses as link-layer addresses: 564 * IFT_OTHER (net/if_gre.c) 565 */ 566 case IFT_ARCNET: /* default below is believed correct for all these. */ 567 case IFT_ETHER: 568 case IFT_FDDI: 569 case IFT_HIPPI: 570 case IFT_ISO88025: 571 default: 572 return hexname((const u_int8_t *)CLLADDR(sdl), 573 (size_t)sdl->sdl_alen, host, hostlen); 574 } 575 } 576 577 static int 578 hexname(cp, len, host, hostlen) 579 const u_int8_t *cp; 580 char *host; 581 size_t len; 582 socklen_t hostlen; 583 { 584 int n; 585 size_t i; 586 char *outp = host; 587 588 *outp = '\0'; 589 for (i = 0; i < len; i++) { 590 n = snprintf(outp, hostlen, "%s%02x", 591 i ? ":" : "", cp[i]); 592 if (n < 0 || (socklen_t) n >= hostlen) { 593 *host = '\0'; 594 return EAI_MEMORY; 595 } 596 outp += n; 597 hostlen -= n; 598 } 599 return 0; 600 } 601