1 /* $NetBSD: getnameinfo.c,v 1.54 2013/08/16 15:27:12 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 1.54 2013/08/16 15:27:12 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 #include "hostent.h" 74 75 #ifdef __weak_alias 76 __weak_alias(getnameinfo,_getnameinfo) 77 #endif 78 79 static const struct afd { 80 int a_af; 81 socklen_t a_addrlen; 82 socklen_t a_socklen; 83 int a_off; 84 } afdl [] = { 85 #ifdef INET6 86 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 87 offsetof(struct sockaddr_in6, sin6_addr)}, 88 #endif 89 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 90 offsetof(struct sockaddr_in, sin_addr)}, 91 {0, 0, 0, 0}, 92 }; 93 94 struct sockinet { 95 u_char si_len; 96 u_char si_family; 97 u_short si_port; 98 }; 99 100 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *, 101 socklen_t, char *, socklen_t, int); 102 #ifdef INET6 103 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 104 socklen_t, int); 105 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 106 #endif 107 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *, 108 socklen_t, char *, socklen_t, int); 109 static int getnameinfo_local(const struct sockaddr *, socklen_t, char *, 110 socklen_t, char *, socklen_t, int); 111 112 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *, 113 socklen_t, char *, socklen_t, int); 114 static int hexname(const uint8_t *, size_t, char *, socklen_t); 115 116 /* 117 * Top-level getnameinfo() code. Look at the address family, and pick an 118 * appropriate function to call. 119 */ 120 int 121 getnameinfo(const struct sockaddr *sa, socklen_t salen, 122 char *host, socklen_t hostlen, 123 char *serv, socklen_t servlen, 124 int flags) 125 { 126 127 switch (sa->sa_family) { 128 case AF_APPLETALK: 129 return getnameinfo_atalk(sa, salen, host, hostlen, 130 serv, servlen, flags); 131 case AF_INET: 132 case AF_INET6: 133 return getnameinfo_inet(sa, salen, host, hostlen, 134 serv, servlen, flags); 135 case AF_LINK: 136 return getnameinfo_link(sa, salen, host, hostlen, 137 serv, servlen, flags); 138 case AF_LOCAL: 139 return getnameinfo_local(sa, salen, host, hostlen, 140 serv, servlen, flags); 141 default: 142 return EAI_FAMILY; 143 } 144 } 145 146 /* 147 * getnameinfo_atalk(): 148 * Format an AppleTalk address into a printable format. 149 */ 150 /* ARGSUSED */ 151 static int 152 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen, 153 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 154 int flags) 155 { 156 char numserv[8]; 157 int n, m=0; 158 159 const struct sockaddr_at *sat = 160 (const struct sockaddr_at *)(const void *)sa; 161 162 if (serv != NULL && servlen > 0) { 163 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port); 164 if (strlen(numserv) + 1 > servlen) 165 return EAI_MEMORY; 166 strlcpy(serv, numserv, servlen); 167 } 168 169 n = snprintf(host, hostlen, "%u.%u", 170 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node); 171 172 if (n < 0 || (socklen_t)(m+n) >= hostlen) 173 goto errout; 174 175 m += n; 176 177 if (sat->sat_range.r_netrange.nr_phase) { 178 n = snprintf(host+m, hostlen-m, " phase %u", 179 sat->sat_range.r_netrange.nr_phase); 180 181 if (n < 0 || (socklen_t)(m+n) >= hostlen) 182 goto errout; 183 184 m += n; 185 } 186 if (sat->sat_range.r_netrange.nr_firstnet) { 187 n = snprintf(host+m, hostlen-m, " range %u - %u", 188 ntohs(sat->sat_range.r_netrange.nr_firstnet), 189 ntohs(sat->sat_range.r_netrange.nr_lastnet )); 190 191 if (n < 0 || (socklen_t)(m+n) >= hostlen) 192 goto errout; 193 194 m += n; 195 } 196 197 return 0; 198 199 errout: 200 if (host && hostlen>0) 201 host[m] = '\0'; /* XXX ??? */ 202 203 return EAI_MEMORY; 204 } 205 206 /* 207 * getnameinfo_local(): 208 * Format an local address into a printable format. 209 */ 210 /* ARGSUSED */ 211 static int 212 getnameinfo_local(const struct sockaddr *sa, socklen_t salen, 213 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 214 int flags) 215 { 216 const struct sockaddr_un *sun = 217 (const struct sockaddr_un *)(const void *)sa; 218 219 if (serv != NULL && servlen > 0) 220 serv[0] = '\0'; 221 222 if (host && hostlen > 0) 223 strlcpy(host, sun->sun_path, 224 MIN(sizeof(sun->sun_path) + 1, hostlen)); 225 226 return 0; 227 } 228 229 /* 230 * getnameinfo_inet(): 231 * Format an IPv4 or IPv6 sockaddr into a printable string. 232 */ 233 static int 234 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, 235 char *host, socklen_t hostlen, 236 char *serv, socklen_t servlen, 237 int flags) 238 { 239 const struct afd *afd; 240 struct servent *sp; 241 struct hostent *hp; 242 u_short port; 243 int family, i; 244 const char *addr; 245 uint32_t v4a; 246 char numserv[512]; 247 char numaddr[512]; 248 249 /* sa is checked below */ 250 /* host may be NULL */ 251 /* serv may be NULL */ 252 253 if (sa == NULL) 254 return EAI_FAIL; 255 256 family = sa->sa_family; 257 for (i = 0; afdl[i].a_af; i++) 258 if (afdl[i].a_af == family) { 259 afd = &afdl[i]; 260 goto found; 261 } 262 return EAI_FAMILY; 263 264 found: 265 if (salen != afd->a_socklen) 266 return EAI_FAIL; 267 268 /* network byte order */ 269 port = ((const struct sockinet *)(const void *)sa)->si_port; 270 addr = (const char *)(const void *)sa + afd->a_off; 271 272 if (serv == NULL || servlen == 0) { 273 /* 274 * do nothing in this case. 275 * in case you are wondering if "&&" is more correct than 276 * "||" here: rfc2553bis-03 says that serv == NULL OR 277 * servlen == 0 means that the caller does not want the result. 278 */ 279 } else { 280 struct servent_data svd; 281 struct servent sv; 282 283 if (flags & NI_NUMERICSERV) 284 sp = NULL; 285 else { 286 (void)memset(&svd, 0, sizeof(svd)); 287 sp = getservbyport_r(port, 288 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd); 289 } 290 if (sp) { 291 if (strlen(sp->s_name) + 1 > servlen) { 292 endservent_r(&svd); 293 return EAI_MEMORY; 294 } 295 strlcpy(serv, sp->s_name, servlen); 296 endservent_r(&svd); 297 } else { 298 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 299 if (strlen(numserv) + 1 > servlen) 300 return EAI_MEMORY; 301 strlcpy(serv, numserv, servlen); 302 } 303 } 304 305 switch (sa->sa_family) { 306 case AF_INET: 307 v4a = (uint32_t) 308 ntohl(((const struct sockaddr_in *) 309 (const void *)sa)->sin_addr.s_addr); 310 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 311 flags |= NI_NUMERICHOST; 312 v4a >>= IN_CLASSA_NSHIFT; 313 if (v4a == 0) 314 flags |= NI_NUMERICHOST; 315 break; 316 #ifdef INET6 317 case AF_INET6: 318 { 319 const struct sockaddr_in6 *sin6; 320 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 321 switch (sin6->sin6_addr.s6_addr[0]) { 322 case 0x00: 323 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 324 ; 325 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 326 ; 327 else 328 flags |= NI_NUMERICHOST; 329 break; 330 default: 331 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 332 flags |= NI_NUMERICHOST; 333 } 334 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 335 flags |= NI_NUMERICHOST; 336 break; 337 } 338 } 339 break; 340 #endif 341 } 342 if (host == NULL || hostlen == 0) { 343 /* 344 * do nothing in this case. 345 * in case you are wondering if "&&" is more correct than 346 * "||" here: rfc2553bis-03 says that host == NULL or 347 * hostlen == 0 means that the caller does not want the result. 348 */ 349 } else if (flags & NI_NUMERICHOST) { 350 size_t numaddrlen; 351 352 /* NUMERICHOST and NAMEREQD conflicts with each other */ 353 if (flags & NI_NAMEREQD) 354 return EAI_NONAME; 355 356 switch(afd->a_af) { 357 #ifdef INET6 358 case AF_INET6: 359 { 360 int error; 361 362 if ((error = ip6_parsenumeric(sa, addr, host, 363 hostlen, flags)) != 0) 364 return(error); 365 break; 366 } 367 #endif 368 default: 369 if (inet_ntop(afd->a_af, addr, numaddr, 370 (socklen_t)sizeof(numaddr)) == NULL) 371 return EAI_SYSTEM; 372 numaddrlen = strlen(numaddr); 373 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 374 return EAI_MEMORY; 375 strlcpy(host, numaddr, hostlen); 376 break; 377 } 378 } else { 379 struct hostent hent; 380 char hbuf[4096]; 381 int he; 382 hp = gethostbyaddr_r(addr, afd->a_addrlen, afd->a_af, &hent, 383 hbuf, sizeof(hbuf), &he); 384 385 if (hp) { 386 #if 0 387 /* 388 * commented out, since "for local host" is not 389 * implemented here - see RFC2553 p30 390 */ 391 if (flags & NI_NOFQDN) { 392 char *p; 393 p = strchr(hp->h_name, '.'); 394 if (p) 395 *p = '\0'; 396 } 397 #endif 398 if (strlen(hp->h_name) + 1 > hostlen) { 399 return EAI_MEMORY; 400 } 401 strlcpy(host, hp->h_name, hostlen); 402 } else { 403 if (flags & NI_NAMEREQD) 404 return EAI_NONAME; 405 switch(afd->a_af) { 406 #ifdef INET6 407 case AF_INET6: 408 { 409 int error; 410 411 if ((error = ip6_parsenumeric(sa, addr, host, 412 hostlen, 413 flags)) != 0) 414 return(error); 415 break; 416 } 417 #endif 418 default: 419 if (inet_ntop(afd->a_af, addr, host, 420 hostlen) == NULL) 421 return EAI_SYSTEM; 422 break; 423 } 424 } 425 } 426 return(0); 427 } 428 429 #ifdef INET6 430 static int 431 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host, 432 socklen_t hostlen, int flags) 433 { 434 size_t numaddrlen; 435 char numaddr[512]; 436 437 _DIAGASSERT(sa != NULL); 438 _DIAGASSERT(addr != NULL); 439 _DIAGASSERT(host != NULL); 440 441 if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr)) 442 == NULL) 443 return EAI_SYSTEM; 444 445 numaddrlen = strlen(numaddr); 446 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 447 return EAI_OVERFLOW; 448 strlcpy(host, numaddr, hostlen); 449 450 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 451 char zonebuf[MAXHOSTNAMELEN]; 452 int zonelen; 453 454 zonelen = ip6_sa2str( 455 (const struct sockaddr_in6 *)(const void *)sa, 456 zonebuf, sizeof(zonebuf), flags); 457 if (zonelen < 0) 458 return EAI_OVERFLOW; 459 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 460 return EAI_OVERFLOW; 461 /* construct <numeric-addr><delim><zoneid> */ 462 memcpy(host + numaddrlen + 1, zonebuf, 463 (size_t)zonelen); 464 host[numaddrlen] = SCOPE_DELIMITER; 465 host[numaddrlen + 1 + zonelen] = '\0'; 466 } 467 468 return 0; 469 } 470 471 /* ARGSUSED */ 472 static int 473 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 474 { 475 unsigned int ifindex; 476 const struct in6_addr *a6; 477 int n; 478 479 _DIAGASSERT(sa6 != NULL); 480 _DIAGASSERT(buf != NULL); 481 482 ifindex = (unsigned int)sa6->sin6_scope_id; 483 a6 = &sa6->sin6_addr; 484 485 #ifdef NI_NUMERICSCOPE 486 if ((flags & NI_NUMERICSCOPE) != 0) { 487 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 488 if (n < 0 || (size_t)n >= bufsiz) 489 return -1; 490 else 491 return n; 492 } 493 #endif 494 495 /* if_indextoname() does not take buffer size. not a good api... */ 496 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 497 bufsiz >= IF_NAMESIZE) { 498 char *p = if_indextoname(ifindex, buf); 499 if (p) { 500 return (int)strlen(p); 501 } 502 } 503 504 /* last resort */ 505 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 506 if (n < 0 || (size_t) n >= bufsiz) 507 return -1; 508 else 509 return n; 510 } 511 #endif /* INET6 */ 512 513 514 /* 515 * getnameinfo_link(): 516 * Format a link-layer address into a printable format, paying attention to 517 * the interface type. 518 */ 519 /* ARGSUSED */ 520 static int 521 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 522 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 523 int flags) 524 { 525 const struct sockaddr_dl *sdl = 526 (const struct sockaddr_dl *)(const void *)sa; 527 const struct ieee1394_hwaddr *iha; 528 int n; 529 530 if (serv != NULL && servlen > 0) 531 *serv = '\0'; 532 533 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 534 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 535 if (n < 0 || (socklen_t) n > hostlen) { 536 *host = '\0'; 537 return EAI_MEMORY; 538 } 539 return 0; 540 } 541 542 switch (sdl->sdl_type) { 543 #ifdef IFT_ECONET 544 case IFT_ECONET: 545 if (sdl->sdl_alen < 2) 546 return EAI_FAMILY; 547 if (CLLADDR(sdl)[1] == 0) 548 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 549 else 550 n = snprintf(host, hostlen, "%u.%u", 551 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 552 if (n < 0 || (socklen_t) n >= hostlen) { 553 *host = '\0'; 554 return EAI_MEMORY; 555 } else 556 return 0; 557 #endif 558 case IFT_IEEE1394: 559 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 560 return EAI_FAMILY; 561 iha = 562 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 563 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 564 host, hostlen); 565 /* 566 * The following have zero-length addresses. 567 * IFT_ATM (net/if_atmsubr.c) 568 * IFT_FAITH (net/if_faith.c) 569 * IFT_GIF (net/if_gif.c) 570 * IFT_LOOP (net/if_loop.c) 571 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 572 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 573 * IFT_STF (net/if_stf.c) 574 * IFT_L2VLAN (net/if_vlan.c) 575 * IFT_PROPVIRTUAL (net/if_bridge.h> 576 */ 577 /* 578 * The following use IPv4 addresses as link-layer addresses: 579 * IFT_OTHER (net/if_gre.c) 580 */ 581 case IFT_ARCNET: /* default below is believed correct for all these. */ 582 case IFT_ETHER: 583 case IFT_FDDI: 584 case IFT_HIPPI: 585 case IFT_ISO88025: 586 default: 587 return hexname((const uint8_t *)CLLADDR(sdl), 588 (size_t)sdl->sdl_alen, host, hostlen); 589 } 590 } 591 592 static int 593 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen) 594 { 595 int n; 596 size_t i; 597 char *outp = host; 598 599 *outp = '\0'; 600 for (i = 0; i < len; i++) { 601 n = snprintf(outp, hostlen, "%s%02x", 602 i ? ":" : "", cp[i]); 603 if (n < 0 || (socklen_t) n >= hostlen) { 604 *host = '\0'; 605 return EAI_MEMORY; 606 } 607 outp += n; 608 hostlen -= n; 609 } 610 return 0; 611 } 612