1 /* $NetBSD: getnameinfo.c,v 1.53 2012/09/26 23:13:00 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 1.53 2012/09/26 23:13:00 christos 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 <sys/un.h> 57 #include <net/if.h> 58 #include <net/if_dl.h> 59 #include <net/if_ieee1394.h> 60 #include <net/if_types.h> 61 #include <netatalk/at.h> 62 #include <netinet/in.h> 63 #include <arpa/inet.h> 64 #include <arpa/nameser.h> 65 #include <assert.h> 66 #include <limits.h> 67 #include <netdb.h> 68 #include <resolv.h> 69 #include <stddef.h> 70 #include <string.h> 71 72 #include "servent.h" 73 74 #ifdef __weak_alias 75 __weak_alias(getnameinfo,_getnameinfo) 76 #endif 77 78 static const struct afd { 79 int a_af; 80 socklen_t a_addrlen; 81 socklen_t a_socklen; 82 int a_off; 83 } afdl [] = { 84 #ifdef INET6 85 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 86 offsetof(struct sockaddr_in6, sin6_addr)}, 87 #endif 88 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 89 offsetof(struct sockaddr_in, sin_addr)}, 90 {0, 0, 0, 0}, 91 }; 92 93 struct sockinet { 94 u_char si_len; 95 u_char si_family; 96 u_short si_port; 97 }; 98 99 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *, 100 socklen_t, char *, socklen_t, int); 101 #ifdef INET6 102 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 103 socklen_t, int); 104 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 105 #endif 106 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *, 107 socklen_t, char *, socklen_t, int); 108 static int getnameinfo_local(const struct sockaddr *, socklen_t, char *, 109 socklen_t, char *, socklen_t, int); 110 111 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *, 112 socklen_t, char *, socklen_t, int); 113 static int hexname(const uint8_t *, size_t, char *, socklen_t); 114 115 /* 116 * Top-level getnameinfo() code. Look at the address family, and pick an 117 * appropriate function to call. 118 */ 119 int 120 getnameinfo(const struct sockaddr *sa, socklen_t salen, 121 char *host, socklen_t hostlen, 122 char *serv, socklen_t 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 case AF_LOCAL: 138 return getnameinfo_local(sa, salen, host, hostlen, 139 serv, servlen, flags); 140 default: 141 return EAI_FAMILY; 142 } 143 } 144 145 /* 146 * getnameinfo_atalk(): 147 * Format an AppleTalk address into a printable format. 148 */ 149 /* ARGSUSED */ 150 static int 151 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen, 152 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 153 int flags) 154 { 155 char numserv[8]; 156 int n, m=0; 157 158 const struct sockaddr_at *sat = 159 (const struct sockaddr_at *)(const void *)sa; 160 161 if (serv != NULL && servlen > 0) { 162 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port); 163 if (strlen(numserv) + 1 > servlen) 164 return EAI_MEMORY; 165 strlcpy(serv, numserv, servlen); 166 } 167 168 n = snprintf(host, hostlen, "%u.%u", 169 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node); 170 171 if (n < 0 || (socklen_t)(m+n) >= hostlen) 172 goto errout; 173 174 m += n; 175 176 if (sat->sat_range.r_netrange.nr_phase) { 177 n = snprintf(host+m, hostlen-m, " phase %u", 178 sat->sat_range.r_netrange.nr_phase); 179 180 if (n < 0 || (socklen_t)(m+n) >= hostlen) 181 goto errout; 182 183 m += n; 184 } 185 if (sat->sat_range.r_netrange.nr_firstnet) { 186 n = snprintf(host+m, hostlen-m, " range %u - %u", 187 ntohs(sat->sat_range.r_netrange.nr_firstnet), 188 ntohs(sat->sat_range.r_netrange.nr_lastnet )); 189 190 if (n < 0 || (socklen_t)(m+n) >= hostlen) 191 goto errout; 192 193 m += n; 194 } 195 196 return 0; 197 198 errout: 199 if (host && hostlen>0) 200 host[m] = '\0'; /* XXX ??? */ 201 202 return EAI_MEMORY; 203 } 204 205 /* 206 * getnameinfo_local(): 207 * Format an local address into a printable format. 208 */ 209 /* ARGSUSED */ 210 static int 211 getnameinfo_local(const struct sockaddr *sa, socklen_t salen, 212 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 213 int flags) 214 { 215 const struct sockaddr_un *sun = 216 (const struct sockaddr_un *)(const void *)sa; 217 218 if (serv != NULL && servlen > 0) 219 serv[0] = '\0'; 220 221 if (host && hostlen > 0) 222 strlcpy(host, sun->sun_path, 223 MIN(sizeof(sun->sun_path) + 1, hostlen)); 224 225 return 0; 226 } 227 228 /* 229 * getnameinfo_inet(): 230 * Format an IPv4 or IPv6 sockaddr into a printable string. 231 */ 232 static int 233 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, 234 char *host, socklen_t hostlen, 235 char *serv, socklen_t servlen, 236 int flags) 237 { 238 const struct afd *afd; 239 struct servent *sp; 240 struct hostent *hp; 241 u_short port; 242 int family, i; 243 const char *addr; 244 uint32_t v4a; 245 char numserv[512]; 246 char numaddr[512]; 247 248 /* sa is checked below */ 249 /* host may be NULL */ 250 /* serv may be NULL */ 251 252 if (sa == NULL) 253 return EAI_FAIL; 254 255 family = sa->sa_family; 256 for (i = 0; afdl[i].a_af; i++) 257 if (afdl[i].a_af == family) { 258 afd = &afdl[i]; 259 goto found; 260 } 261 return EAI_FAMILY; 262 263 found: 264 if (salen != afd->a_socklen) 265 return EAI_FAIL; 266 267 /* network byte order */ 268 port = ((const struct sockinet *)(const void *)sa)->si_port; 269 addr = (const char *)(const void *)sa + afd->a_off; 270 271 if (serv == NULL || servlen == 0) { 272 /* 273 * do nothing in this case. 274 * in case you are wondering if "&&" is more correct than 275 * "||" here: rfc2553bis-03 says that serv == NULL OR 276 * servlen == 0 means that the caller does not want the result. 277 */ 278 } else { 279 struct servent_data svd; 280 struct servent sv; 281 282 if (flags & NI_NUMERICSERV) 283 sp = NULL; 284 else { 285 (void)memset(&svd, 0, sizeof(svd)); 286 sp = getservbyport_r(port, 287 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd); 288 } 289 if (sp) { 290 if (strlen(sp->s_name) + 1 > servlen) { 291 endservent_r(&svd); 292 return EAI_MEMORY; 293 } 294 strlcpy(serv, sp->s_name, servlen); 295 endservent_r(&svd); 296 } else { 297 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 298 if (strlen(numserv) + 1 > servlen) 299 return EAI_MEMORY; 300 strlcpy(serv, numserv, servlen); 301 } 302 } 303 304 switch (sa->sa_family) { 305 case AF_INET: 306 v4a = (uint32_t) 307 ntohl(((const struct sockaddr_in *) 308 (const void *)sa)->sin_addr.s_addr); 309 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 310 flags |= NI_NUMERICHOST; 311 v4a >>= IN_CLASSA_NSHIFT; 312 if (v4a == 0) 313 flags |= NI_NUMERICHOST; 314 break; 315 #ifdef INET6 316 case AF_INET6: 317 { 318 const struct sockaddr_in6 *sin6; 319 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 320 switch (sin6->sin6_addr.s6_addr[0]) { 321 case 0x00: 322 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 323 ; 324 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 325 ; 326 else 327 flags |= NI_NUMERICHOST; 328 break; 329 default: 330 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 331 flags |= NI_NUMERICHOST; 332 } 333 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 334 flags |= NI_NUMERICHOST; 335 break; 336 } 337 } 338 break; 339 #endif 340 } 341 if (host == NULL || hostlen == 0) { 342 /* 343 * do nothing in this case. 344 * in case you are wondering if "&&" is more correct than 345 * "||" here: rfc2553bis-03 says that host == NULL or 346 * hostlen == 0 means that the caller does not want the result. 347 */ 348 } else if (flags & NI_NUMERICHOST) { 349 size_t numaddrlen; 350 351 /* NUMERICHOST and NAMEREQD conflicts with each other */ 352 if (flags & NI_NAMEREQD) 353 return EAI_NONAME; 354 355 switch(afd->a_af) { 356 #ifdef INET6 357 case AF_INET6: 358 { 359 int error; 360 361 if ((error = ip6_parsenumeric(sa, addr, host, 362 hostlen, flags)) != 0) 363 return(error); 364 break; 365 } 366 #endif 367 default: 368 if (inet_ntop(afd->a_af, addr, numaddr, 369 (socklen_t)sizeof(numaddr)) == NULL) 370 return EAI_SYSTEM; 371 numaddrlen = strlen(numaddr); 372 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 373 return EAI_MEMORY; 374 strlcpy(host, numaddr, hostlen); 375 break; 376 } 377 } else { 378 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 379 380 if (hp) { 381 #if 0 382 /* 383 * commented out, since "for local host" is not 384 * implemented here - see RFC2553 p30 385 */ 386 if (flags & NI_NOFQDN) { 387 char *p; 388 p = strchr(hp->h_name, '.'); 389 if (p) 390 *p = '\0'; 391 } 392 #endif 393 if (strlen(hp->h_name) + 1 > hostlen) { 394 return EAI_MEMORY; 395 } 396 strlcpy(host, hp->h_name, hostlen); 397 } else { 398 if (flags & NI_NAMEREQD) 399 return EAI_NONAME; 400 switch(afd->a_af) { 401 #ifdef INET6 402 case AF_INET6: 403 { 404 int error; 405 406 if ((error = ip6_parsenumeric(sa, addr, host, 407 hostlen, 408 flags)) != 0) 409 return(error); 410 break; 411 } 412 #endif 413 default: 414 if (inet_ntop(afd->a_af, addr, host, 415 hostlen) == NULL) 416 return EAI_SYSTEM; 417 break; 418 } 419 } 420 } 421 return(0); 422 } 423 424 #ifdef INET6 425 static int 426 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host, 427 socklen_t hostlen, int flags) 428 { 429 size_t numaddrlen; 430 char numaddr[512]; 431 432 _DIAGASSERT(sa != NULL); 433 _DIAGASSERT(addr != NULL); 434 _DIAGASSERT(host != NULL); 435 436 if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr)) 437 == NULL) 438 return EAI_SYSTEM; 439 440 numaddrlen = strlen(numaddr); 441 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 442 return EAI_OVERFLOW; 443 strlcpy(host, numaddr, hostlen); 444 445 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 446 char zonebuf[MAXHOSTNAMELEN]; 447 int zonelen; 448 449 zonelen = ip6_sa2str( 450 (const struct sockaddr_in6 *)(const void *)sa, 451 zonebuf, sizeof(zonebuf), flags); 452 if (zonelen < 0) 453 return EAI_OVERFLOW; 454 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 455 return EAI_OVERFLOW; 456 /* construct <numeric-addr><delim><zoneid> */ 457 memcpy(host + numaddrlen + 1, zonebuf, 458 (size_t)zonelen); 459 host[numaddrlen] = SCOPE_DELIMITER; 460 host[numaddrlen + 1 + zonelen] = '\0'; 461 } 462 463 return 0; 464 } 465 466 /* ARGSUSED */ 467 static int 468 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 469 { 470 unsigned int ifindex; 471 const struct in6_addr *a6; 472 int n; 473 474 _DIAGASSERT(sa6 != NULL); 475 _DIAGASSERT(buf != NULL); 476 477 ifindex = (unsigned int)sa6->sin6_scope_id; 478 a6 = &sa6->sin6_addr; 479 480 #ifdef NI_NUMERICSCOPE 481 if ((flags & NI_NUMERICSCOPE) != 0) { 482 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 483 if (n < 0 || (size_t)n >= bufsiz) 484 return -1; 485 else 486 return n; 487 } 488 #endif 489 490 /* if_indextoname() does not take buffer size. not a good api... */ 491 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 492 bufsiz >= IF_NAMESIZE) { 493 char *p = if_indextoname(ifindex, buf); 494 if (p) { 495 return (int)strlen(p); 496 } 497 } 498 499 /* last resort */ 500 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 501 if (n < 0 || (size_t) n >= bufsiz) 502 return -1; 503 else 504 return n; 505 } 506 #endif /* INET6 */ 507 508 509 /* 510 * getnameinfo_link(): 511 * Format a link-layer address into a printable format, paying attention to 512 * the interface type. 513 */ 514 /* ARGSUSED */ 515 static int 516 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 517 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 518 int flags) 519 { 520 const struct sockaddr_dl *sdl = 521 (const struct sockaddr_dl *)(const void *)sa; 522 const struct ieee1394_hwaddr *iha; 523 int n; 524 525 if (serv != NULL && servlen > 0) 526 *serv = '\0'; 527 528 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 529 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 530 if (n < 0 || (socklen_t) n > hostlen) { 531 *host = '\0'; 532 return EAI_MEMORY; 533 } 534 return 0; 535 } 536 537 switch (sdl->sdl_type) { 538 #ifdef IFT_ECONET 539 case IFT_ECONET: 540 if (sdl->sdl_alen < 2) 541 return EAI_FAMILY; 542 if (CLLADDR(sdl)[1] == 0) 543 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 544 else 545 n = snprintf(host, hostlen, "%u.%u", 546 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 547 if (n < 0 || (socklen_t) n >= hostlen) { 548 *host = '\0'; 549 return EAI_MEMORY; 550 } else 551 return 0; 552 #endif 553 case IFT_IEEE1394: 554 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 555 return EAI_FAMILY; 556 iha = 557 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 558 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 559 host, hostlen); 560 /* 561 * The following have zero-length addresses. 562 * IFT_ATM (net/if_atmsubr.c) 563 * IFT_FAITH (net/if_faith.c) 564 * IFT_GIF (net/if_gif.c) 565 * IFT_LOOP (net/if_loop.c) 566 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 567 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 568 * IFT_STF (net/if_stf.c) 569 * IFT_L2VLAN (net/if_vlan.c) 570 * IFT_PROPVIRTUAL (net/if_bridge.h> 571 */ 572 /* 573 * The following use IPv4 addresses as link-layer addresses: 574 * IFT_OTHER (net/if_gre.c) 575 */ 576 case IFT_ARCNET: /* default below is believed correct for all these. */ 577 case IFT_ETHER: 578 case IFT_FDDI: 579 case IFT_HIPPI: 580 case IFT_ISO88025: 581 default: 582 return hexname((const uint8_t *)CLLADDR(sdl), 583 (size_t)sdl->sdl_alen, host, hostlen); 584 } 585 } 586 587 static int 588 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen) 589 { 590 int n; 591 size_t i; 592 char *outp = host; 593 594 *outp = '\0'; 595 for (i = 0; i < len; i++) { 596 n = snprintf(outp, hostlen, "%s%02x", 597 i ? ":" : "", cp[i]); 598 if (n < 0 || (socklen_t) n >= hostlen) { 599 *host = '\0'; 600 return EAI_MEMORY; 601 } 602 outp += n; 603 hostlen -= n; 604 } 605 return 0; 606 } 607