1 /* $NetBSD: getnameinfo.c,v 1.52 2012/03/20 17:44:18 matt 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 1.52 2012/03/20 17:44:18 matt 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(const struct sockaddr *, socklen_t, char *, 99 socklen_t, char *, socklen_t, int); 100 #ifdef INET6 101 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 102 socklen_t, int); 103 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 104 #endif 105 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *, 106 socklen_t, char *, socklen_t, int); 107 108 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *, 109 socklen_t, char *, socklen_t, int); 110 static int hexname(const uint8_t *, size_t, char *, socklen_t); 111 112 /* 113 * Top-level getnameinfo() code. Look at the address family, and pick an 114 * appropriate function to call. 115 */ 116 int 117 getnameinfo(const struct sockaddr *sa, socklen_t salen, 118 char *host, socklen_t hostlen, 119 char *serv, socklen_t servlen, 120 int flags) 121 { 122 123 switch (sa->sa_family) { 124 case AF_APPLETALK: 125 return getnameinfo_atalk(sa, salen, host, hostlen, 126 serv, servlen, flags); 127 case AF_INET: 128 case AF_INET6: 129 return getnameinfo_inet(sa, salen, host, hostlen, 130 serv, servlen, flags); 131 case AF_LINK: 132 return getnameinfo_link(sa, salen, host, hostlen, 133 serv, servlen, flags); 134 default: 135 return EAI_FAMILY; 136 } 137 } 138 139 /* 140 * getnameinfo_atalk(): 141 * Format an AppleTalk address into a printable format. 142 */ 143 /* ARGSUSED */ 144 static int 145 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen, 146 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 147 int flags) 148 { 149 char numserv[8]; 150 int n, m=0; 151 152 const struct sockaddr_at *sat = 153 (const struct sockaddr_at *)(const void *)sa; 154 155 if (serv != NULL && servlen > 0) { 156 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port); 157 if (strlen(numserv) + 1 > servlen) 158 return EAI_MEMORY; 159 strlcpy(serv, numserv, servlen); 160 } 161 162 n = snprintf(host, hostlen, "%u.%u", 163 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node); 164 165 if (n < 0 || (socklen_t)(m+n) >= hostlen) 166 goto errout; 167 168 m += n; 169 170 if (sat->sat_range.r_netrange.nr_phase) { 171 n = snprintf(host+m, hostlen-m, " phase %u", 172 sat->sat_range.r_netrange.nr_phase); 173 174 if (n < 0 || (socklen_t)(m+n) >= hostlen) 175 goto errout; 176 177 m += n; 178 } 179 if (sat->sat_range.r_netrange.nr_firstnet) { 180 n = snprintf(host+m, hostlen-m, " range %u - %u", 181 ntohs(sat->sat_range.r_netrange.nr_firstnet), 182 ntohs(sat->sat_range.r_netrange.nr_lastnet )); 183 184 if (n < 0 || (socklen_t)(m+n) >= hostlen) 185 goto errout; 186 187 m += n; 188 } 189 190 return 0; 191 192 errout: 193 if (host && hostlen>0) 194 host[m] = '\0'; /* XXX ??? */ 195 196 return EAI_MEMORY; 197 } 198 199 /* 200 * getnameinfo_inet(): 201 * Format an IPv4 or IPv6 sockaddr into a printable string. 202 */ 203 static int 204 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, 205 char *host, socklen_t hostlen, 206 char *serv, socklen_t servlen, 207 int flags) 208 { 209 const struct afd *afd; 210 struct servent *sp; 211 struct hostent *hp; 212 u_short port; 213 int family, i; 214 const char *addr; 215 uint32_t v4a; 216 char numserv[512]; 217 char numaddr[512]; 218 219 /* sa is checked below */ 220 /* host may be NULL */ 221 /* serv may be NULL */ 222 223 if (sa == NULL) 224 return EAI_FAIL; 225 226 family = sa->sa_family; 227 for (i = 0; afdl[i].a_af; i++) 228 if (afdl[i].a_af == family) { 229 afd = &afdl[i]; 230 goto found; 231 } 232 return EAI_FAMILY; 233 234 found: 235 if (salen != afd->a_socklen) 236 return EAI_FAIL; 237 238 /* network byte order */ 239 port = ((const struct sockinet *)(const void *)sa)->si_port; 240 addr = (const char *)(const void *)sa + afd->a_off; 241 242 if (serv == NULL || servlen == 0) { 243 /* 244 * do nothing in this case. 245 * in case you are wondering if "&&" is more correct than 246 * "||" here: rfc2553bis-03 says that serv == NULL OR 247 * servlen == 0 means that the caller does not want the result. 248 */ 249 } else { 250 struct servent_data svd; 251 struct servent sv; 252 253 if (flags & NI_NUMERICSERV) 254 sp = NULL; 255 else { 256 (void)memset(&svd, 0, sizeof(svd)); 257 sp = getservbyport_r(port, 258 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd); 259 } 260 if (sp) { 261 if (strlen(sp->s_name) + 1 > servlen) { 262 endservent_r(&svd); 263 return EAI_MEMORY; 264 } 265 strlcpy(serv, sp->s_name, servlen); 266 endservent_r(&svd); 267 } else { 268 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 269 if (strlen(numserv) + 1 > servlen) 270 return EAI_MEMORY; 271 strlcpy(serv, numserv, servlen); 272 } 273 } 274 275 switch (sa->sa_family) { 276 case AF_INET: 277 v4a = (uint32_t) 278 ntohl(((const struct sockaddr_in *) 279 (const void *)sa)->sin_addr.s_addr); 280 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 281 flags |= NI_NUMERICHOST; 282 v4a >>= IN_CLASSA_NSHIFT; 283 if (v4a == 0) 284 flags |= NI_NUMERICHOST; 285 break; 286 #ifdef INET6 287 case AF_INET6: 288 { 289 const struct sockaddr_in6 *sin6; 290 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 291 switch (sin6->sin6_addr.s6_addr[0]) { 292 case 0x00: 293 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 294 ; 295 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 296 ; 297 else 298 flags |= NI_NUMERICHOST; 299 break; 300 default: 301 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 302 flags |= NI_NUMERICHOST; 303 } 304 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 305 flags |= NI_NUMERICHOST; 306 break; 307 } 308 } 309 break; 310 #endif 311 } 312 if (host == NULL || hostlen == 0) { 313 /* 314 * do nothing in this case. 315 * in case you are wondering if "&&" is more correct than 316 * "||" here: rfc2553bis-03 says that host == NULL or 317 * hostlen == 0 means that the caller does not want the result. 318 */ 319 } else if (flags & NI_NUMERICHOST) { 320 size_t numaddrlen; 321 322 /* NUMERICHOST and NAMEREQD conflicts with each other */ 323 if (flags & NI_NAMEREQD) 324 return EAI_NONAME; 325 326 switch(afd->a_af) { 327 #ifdef INET6 328 case AF_INET6: 329 { 330 int error; 331 332 if ((error = ip6_parsenumeric(sa, addr, host, 333 hostlen, flags)) != 0) 334 return(error); 335 break; 336 } 337 #endif 338 default: 339 if (inet_ntop(afd->a_af, addr, numaddr, 340 (socklen_t)sizeof(numaddr)) == NULL) 341 return EAI_SYSTEM; 342 numaddrlen = strlen(numaddr); 343 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 344 return EAI_MEMORY; 345 strlcpy(host, numaddr, hostlen); 346 break; 347 } 348 } else { 349 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 350 351 if (hp) { 352 #if 0 353 /* 354 * commented out, since "for local host" is not 355 * implemented here - see RFC2553 p30 356 */ 357 if (flags & NI_NOFQDN) { 358 char *p; 359 p = strchr(hp->h_name, '.'); 360 if (p) 361 *p = '\0'; 362 } 363 #endif 364 if (strlen(hp->h_name) + 1 > hostlen) { 365 return EAI_MEMORY; 366 } 367 strlcpy(host, hp->h_name, hostlen); 368 } else { 369 if (flags & NI_NAMEREQD) 370 return EAI_NONAME; 371 switch(afd->a_af) { 372 #ifdef INET6 373 case AF_INET6: 374 { 375 int error; 376 377 if ((error = ip6_parsenumeric(sa, addr, host, 378 hostlen, 379 flags)) != 0) 380 return(error); 381 break; 382 } 383 #endif 384 default: 385 if (inet_ntop(afd->a_af, addr, host, 386 hostlen) == NULL) 387 return EAI_SYSTEM; 388 break; 389 } 390 } 391 } 392 return(0); 393 } 394 395 #ifdef INET6 396 static int 397 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host, 398 socklen_t hostlen, int flags) 399 { 400 size_t numaddrlen; 401 char numaddr[512]; 402 403 _DIAGASSERT(sa != NULL); 404 _DIAGASSERT(addr != NULL); 405 _DIAGASSERT(host != NULL); 406 407 if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr)) 408 == NULL) 409 return EAI_SYSTEM; 410 411 numaddrlen = strlen(numaddr); 412 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 413 return EAI_OVERFLOW; 414 strlcpy(host, numaddr, hostlen); 415 416 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 417 char zonebuf[MAXHOSTNAMELEN]; 418 int zonelen; 419 420 zonelen = ip6_sa2str( 421 (const struct sockaddr_in6 *)(const void *)sa, 422 zonebuf, sizeof(zonebuf), flags); 423 if (zonelen < 0) 424 return EAI_OVERFLOW; 425 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 426 return EAI_OVERFLOW; 427 /* construct <numeric-addr><delim><zoneid> */ 428 memcpy(host + numaddrlen + 1, zonebuf, 429 (size_t)zonelen); 430 host[numaddrlen] = SCOPE_DELIMITER; 431 host[numaddrlen + 1 + zonelen] = '\0'; 432 } 433 434 return 0; 435 } 436 437 /* ARGSUSED */ 438 static int 439 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 440 { 441 unsigned int ifindex; 442 const struct in6_addr *a6; 443 int n; 444 445 _DIAGASSERT(sa6 != NULL); 446 _DIAGASSERT(buf != NULL); 447 448 ifindex = (unsigned int)sa6->sin6_scope_id; 449 a6 = &sa6->sin6_addr; 450 451 #ifdef NI_NUMERICSCOPE 452 if ((flags & NI_NUMERICSCOPE) != 0) { 453 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 454 if (n < 0 || (size_t)n >= bufsiz) 455 return -1; 456 else 457 return n; 458 } 459 #endif 460 461 /* if_indextoname() does not take buffer size. not a good api... */ 462 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 463 bufsiz >= IF_NAMESIZE) { 464 char *p = if_indextoname(ifindex, buf); 465 if (p) { 466 return (int)strlen(p); 467 } 468 } 469 470 /* last resort */ 471 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 472 if (n < 0 || (size_t) n >= bufsiz) 473 return -1; 474 else 475 return n; 476 } 477 #endif /* INET6 */ 478 479 480 /* 481 * getnameinfo_link(): 482 * Format a link-layer address into a printable format, paying attention to 483 * the interface type. 484 */ 485 /* ARGSUSED */ 486 static int 487 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 488 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 489 int flags) 490 { 491 const struct sockaddr_dl *sdl = 492 (const struct sockaddr_dl *)(const void *)sa; 493 const struct ieee1394_hwaddr *iha; 494 int n; 495 496 if (serv != NULL && servlen > 0) 497 *serv = '\0'; 498 499 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 500 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 501 if (n < 0 || (socklen_t) n > hostlen) { 502 *host = '\0'; 503 return EAI_MEMORY; 504 } 505 return 0; 506 } 507 508 switch (sdl->sdl_type) { 509 #ifdef IFT_ECONET 510 case IFT_ECONET: 511 if (sdl->sdl_alen < 2) 512 return EAI_FAMILY; 513 if (CLLADDR(sdl)[1] == 0) 514 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 515 else 516 n = snprintf(host, hostlen, "%u.%u", 517 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 518 if (n < 0 || (socklen_t) n >= hostlen) { 519 *host = '\0'; 520 return EAI_MEMORY; 521 } else 522 return 0; 523 #endif 524 case IFT_IEEE1394: 525 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 526 return EAI_FAMILY; 527 iha = 528 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 529 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 530 host, hostlen); 531 /* 532 * The following have zero-length addresses. 533 * IFT_ATM (net/if_atmsubr.c) 534 * IFT_FAITH (net/if_faith.c) 535 * IFT_GIF (net/if_gif.c) 536 * IFT_LOOP (net/if_loop.c) 537 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 538 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 539 * IFT_STF (net/if_stf.c) 540 * IFT_L2VLAN (net/if_vlan.c) 541 * IFT_PROPVIRTUAL (net/if_bridge.h> 542 */ 543 /* 544 * The following use IPv4 addresses as link-layer addresses: 545 * IFT_OTHER (net/if_gre.c) 546 */ 547 case IFT_ARCNET: /* default below is believed correct for all these. */ 548 case IFT_ETHER: 549 case IFT_FDDI: 550 case IFT_HIPPI: 551 case IFT_ISO88025: 552 default: 553 return hexname((const uint8_t *)CLLADDR(sdl), 554 (size_t)sdl->sdl_alen, host, hostlen); 555 } 556 } 557 558 static int 559 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen) 560 { 561 int n; 562 size_t i; 563 char *outp = host; 564 565 *outp = '\0'; 566 for (i = 0; i < len; i++) { 567 n = snprintf(outp, hostlen, "%s%02x", 568 i ? ":" : "", cp[i]); 569 if (n < 0 || (socklen_t) n >= hostlen) { 570 *host = '\0'; 571 return EAI_MEMORY; 572 } 573 outp += n; 574 hostlen -= n; 575 } 576 return 0; 577 } 578