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 #if !defined(__minix) 59 #include <net/if_dl.h> 60 #include <net/if_ieee1394.h> 61 #include <net/if_types.h> 62 #include <netatalk/at.h> 63 #endif /* !defined(__minix) */ 64 #include <netinet/in.h> 65 #include <arpa/inet.h> 66 #include <arpa/nameser.h> 67 #include <assert.h> 68 #include <limits.h> 69 #include <netdb.h> 70 #include <resolv.h> 71 #include <stddef.h> 72 #include <string.h> 73 74 #include "servent.h" 75 #include "hostent.h" 76 77 #ifdef __weak_alias 78 __weak_alias(getnameinfo,_getnameinfo) 79 #endif 80 81 static const struct afd { 82 int a_af; 83 socklen_t a_addrlen; 84 socklen_t a_socklen; 85 int a_off; 86 } afdl [] = { 87 #ifdef INET6 88 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 89 offsetof(struct sockaddr_in6, sin6_addr)}, 90 #endif 91 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 92 offsetof(struct sockaddr_in, sin_addr)}, 93 {0, 0, 0, 0}, 94 }; 95 96 struct sockinet { 97 u_char si_len; 98 u_char si_family; 99 u_short si_port; 100 }; 101 102 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *, 103 socklen_t, char *, socklen_t, int); 104 #ifdef INET6 105 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 106 socklen_t, int); 107 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 108 #endif 109 #if !defined(__minix) 110 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *, 111 socklen_t, char *, socklen_t, int); 112 static int getnameinfo_local(const struct sockaddr *, socklen_t, char *, 113 socklen_t, char *, socklen_t, int); 114 115 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *, 116 socklen_t, char *, socklen_t, int); 117 static int hexname(const uint8_t *, size_t, char *, socklen_t); 118 #endif /* !defined(__minix) */ 119 120 /* 121 * Top-level getnameinfo() code. Look at the address family, and pick an 122 * appropriate function to call. 123 */ 124 int 125 getnameinfo(const struct sockaddr *sa, socklen_t salen, 126 char *host, socklen_t hostlen, 127 char *serv, socklen_t servlen, 128 int flags) 129 { 130 131 switch (sa->sa_family) { 132 #if !defined(__minix) 133 case AF_APPLETALK: 134 return getnameinfo_atalk(sa, salen, host, hostlen, 135 serv, servlen, flags); 136 #endif /* !defined(__minix) */ 137 case AF_INET: 138 case AF_INET6: 139 return getnameinfo_inet(sa, salen, host, hostlen, 140 serv, servlen, flags); 141 #if !defined(__minix) 142 case AF_LINK: 143 return getnameinfo_link(sa, salen, host, hostlen, 144 serv, servlen, flags); 145 case AF_LOCAL: 146 return getnameinfo_local(sa, salen, host, hostlen, 147 serv, servlen, flags); 148 #endif /* !defined(__minix) */ 149 default: 150 return EAI_FAMILY; 151 } 152 } 153 154 #if !defined(__minix) 155 /* 156 * getnameinfo_atalk(): 157 * Format an AppleTalk address into a printable format. 158 */ 159 /* ARGSUSED */ 160 static int 161 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen, 162 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 163 int flags) 164 { 165 char numserv[8]; 166 int n, m=0; 167 168 const struct sockaddr_at *sat = 169 (const struct sockaddr_at *)(const void *)sa; 170 171 if (serv != NULL && servlen > 0) { 172 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port); 173 if (strlen(numserv) + 1 > servlen) 174 return EAI_MEMORY; 175 strlcpy(serv, numserv, servlen); 176 } 177 178 n = snprintf(host, hostlen, "%u.%u", 179 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node); 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_phase) { 187 n = snprintf(host+m, hostlen-m, " phase %u", 188 sat->sat_range.r_netrange.nr_phase); 189 190 if (n < 0 || (socklen_t)(m+n) >= hostlen) 191 goto errout; 192 193 m += n; 194 } 195 if (sat->sat_range.r_netrange.nr_firstnet) { 196 n = snprintf(host+m, hostlen-m, " range %u - %u", 197 ntohs(sat->sat_range.r_netrange.nr_firstnet), 198 ntohs(sat->sat_range.r_netrange.nr_lastnet )); 199 200 if (n < 0 || (socklen_t)(m+n) >= hostlen) 201 goto errout; 202 203 m += n; 204 } 205 206 return 0; 207 208 errout: 209 if (host && hostlen>0) 210 host[m] = '\0'; /* XXX ??? */ 211 212 return EAI_MEMORY; 213 } 214 215 /* 216 * getnameinfo_local(): 217 * Format an local address into a printable format. 218 */ 219 /* ARGSUSED */ 220 static int 221 getnameinfo_local(const struct sockaddr *sa, socklen_t salen, 222 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 223 int flags) 224 { 225 const struct sockaddr_un *sun = 226 (const struct sockaddr_un *)(const void *)sa; 227 228 if (serv != NULL && servlen > 0) 229 serv[0] = '\0'; 230 231 if (host && hostlen > 0) 232 strlcpy(host, sun->sun_path, 233 MIN(sizeof(sun->sun_path) + 1, hostlen)); 234 235 return 0; 236 } 237 #endif /* !defined(__minix) */ 238 239 /* 240 * getnameinfo_inet(): 241 * Format an IPv4 or IPv6 sockaddr into a printable string. 242 */ 243 static int 244 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, 245 char *host, socklen_t hostlen, 246 char *serv, socklen_t servlen, 247 int flags) 248 { 249 const struct afd *afd; 250 struct servent *sp; 251 struct hostent *hp; 252 u_short port; 253 int family, i; 254 const char *addr; 255 uint32_t v4a; 256 char numserv[512]; 257 char numaddr[512]; 258 259 /* sa is checked below */ 260 /* host may be NULL */ 261 /* serv may be NULL */ 262 263 if (sa == NULL) 264 return EAI_FAIL; 265 266 family = sa->sa_family; 267 for (i = 0; afdl[i].a_af; i++) 268 if (afdl[i].a_af == family) { 269 afd = &afdl[i]; 270 goto found; 271 } 272 return EAI_FAMILY; 273 274 found: 275 if (salen != afd->a_socklen) 276 return EAI_FAIL; 277 278 /* network byte order */ 279 port = ((const struct sockinet *)(const void *)sa)->si_port; 280 addr = (const char *)(const void *)sa + afd->a_off; 281 282 if (serv == NULL || servlen == 0) { 283 /* 284 * do nothing in this case. 285 * in case you are wondering if "&&" is more correct than 286 * "||" here: rfc2553bis-03 says that serv == NULL OR 287 * servlen == 0 means that the caller does not want the result. 288 */ 289 } else { 290 struct servent_data svd; 291 struct servent sv; 292 293 if (flags & NI_NUMERICSERV) 294 sp = NULL; 295 else { 296 (void)memset(&svd, 0, sizeof(svd)); 297 sp = getservbyport_r(port, 298 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd); 299 } 300 if (sp) { 301 if (strlen(sp->s_name) + 1 > servlen) { 302 endservent_r(&svd); 303 return EAI_MEMORY; 304 } 305 strlcpy(serv, sp->s_name, servlen); 306 endservent_r(&svd); 307 } else { 308 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 309 if (strlen(numserv) + 1 > servlen) 310 return EAI_MEMORY; 311 strlcpy(serv, numserv, servlen); 312 } 313 } 314 315 switch (sa->sa_family) { 316 case AF_INET: 317 v4a = (uint32_t) 318 ntohl(((const struct sockaddr_in *) 319 (const void *)sa)->sin_addr.s_addr); 320 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 321 flags |= NI_NUMERICHOST; 322 v4a >>= IN_CLASSA_NSHIFT; 323 if (v4a == 0) 324 flags |= NI_NUMERICHOST; 325 break; 326 #ifdef INET6 327 case AF_INET6: 328 { 329 const struct sockaddr_in6 *sin6; 330 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 331 switch (sin6->sin6_addr.s6_addr[0]) { 332 case 0x00: 333 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 334 ; 335 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 336 ; 337 else 338 flags |= NI_NUMERICHOST; 339 break; 340 default: 341 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 342 flags |= NI_NUMERICHOST; 343 } 344 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 345 flags |= NI_NUMERICHOST; 346 break; 347 } 348 } 349 break; 350 #endif 351 } 352 if (host == NULL || hostlen == 0) { 353 /* 354 * do nothing in this case. 355 * in case you are wondering if "&&" is more correct than 356 * "||" here: rfc2553bis-03 says that host == NULL or 357 * hostlen == 0 means that the caller does not want the result. 358 */ 359 } else if (flags & NI_NUMERICHOST) { 360 size_t numaddrlen; 361 362 /* NUMERICHOST and NAMEREQD conflicts with each other */ 363 if (flags & NI_NAMEREQD) 364 return EAI_NONAME; 365 366 switch(afd->a_af) { 367 #ifdef INET6 368 case AF_INET6: 369 { 370 int error; 371 372 if ((error = ip6_parsenumeric(sa, addr, host, 373 hostlen, flags)) != 0) 374 return(error); 375 break; 376 } 377 #endif 378 default: 379 if (inet_ntop(afd->a_af, addr, numaddr, 380 (socklen_t)sizeof(numaddr)) == NULL) 381 return EAI_SYSTEM; 382 numaddrlen = strlen(numaddr); 383 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 384 return EAI_MEMORY; 385 strlcpy(host, numaddr, hostlen); 386 break; 387 } 388 } else { 389 struct hostent hent; 390 char hbuf[4096]; 391 int he; 392 hp = gethostbyaddr_r(addr, afd->a_addrlen, afd->a_af, &hent, 393 hbuf, sizeof(hbuf), &he); 394 395 if (hp) { 396 #if 0 397 /* 398 * commented out, since "for local host" is not 399 * implemented here - see RFC2553 p30 400 */ 401 if (flags & NI_NOFQDN) { 402 char *p; 403 p = strchr(hp->h_name, '.'); 404 if (p) 405 *p = '\0'; 406 } 407 #endif 408 if (strlen(hp->h_name) + 1 > hostlen) { 409 return EAI_MEMORY; 410 } 411 strlcpy(host, hp->h_name, hostlen); 412 } else { 413 if (flags & NI_NAMEREQD) 414 return EAI_NONAME; 415 switch(afd->a_af) { 416 #ifdef INET6 417 case AF_INET6: 418 { 419 int error; 420 421 if ((error = ip6_parsenumeric(sa, addr, host, 422 hostlen, 423 flags)) != 0) 424 return(error); 425 break; 426 } 427 #endif 428 default: 429 if (inet_ntop(afd->a_af, addr, host, 430 hostlen) == NULL) 431 return EAI_SYSTEM; 432 break; 433 } 434 } 435 } 436 return(0); 437 } 438 439 #ifdef INET6 440 static int 441 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host, 442 socklen_t hostlen, int flags) 443 { 444 size_t numaddrlen; 445 char numaddr[512]; 446 447 _DIAGASSERT(sa != NULL); 448 _DIAGASSERT(addr != NULL); 449 _DIAGASSERT(host != NULL); 450 451 if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr)) 452 == NULL) 453 return EAI_SYSTEM; 454 455 numaddrlen = strlen(numaddr); 456 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 457 return EAI_OVERFLOW; 458 strlcpy(host, numaddr, hostlen); 459 460 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 461 char zonebuf[MAXHOSTNAMELEN]; 462 int zonelen; 463 464 zonelen = ip6_sa2str( 465 (const struct sockaddr_in6 *)(const void *)sa, 466 zonebuf, sizeof(zonebuf), flags); 467 if (zonelen < 0) 468 return EAI_OVERFLOW; 469 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 470 return EAI_OVERFLOW; 471 /* construct <numeric-addr><delim><zoneid> */ 472 memcpy(host + numaddrlen + 1, zonebuf, 473 (size_t)zonelen); 474 host[numaddrlen] = SCOPE_DELIMITER; 475 host[numaddrlen + 1 + zonelen] = '\0'; 476 } 477 478 return 0; 479 } 480 481 /* ARGSUSED */ 482 static int 483 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 484 { 485 unsigned int ifindex; 486 const struct in6_addr *a6; 487 int n; 488 489 _DIAGASSERT(sa6 != NULL); 490 _DIAGASSERT(buf != NULL); 491 492 ifindex = (unsigned int)sa6->sin6_scope_id; 493 a6 = &sa6->sin6_addr; 494 495 #ifdef NI_NUMERICSCOPE 496 if ((flags & NI_NUMERICSCOPE) != 0) { 497 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 498 if (n < 0 || (size_t)n >= bufsiz) 499 return -1; 500 else 501 return n; 502 } 503 #endif 504 505 /* if_indextoname() does not take buffer size. not a good api... */ 506 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 507 bufsiz >= IF_NAMESIZE) { 508 char *p = if_indextoname(ifindex, buf); 509 if (p) { 510 return (int)strlen(p); 511 } 512 } 513 514 /* last resort */ 515 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 516 if (n < 0 || (size_t) n >= bufsiz) 517 return -1; 518 else 519 return n; 520 } 521 #endif /* INET6 */ 522 523 524 #if !defined(__minix) 525 /* 526 * getnameinfo_link(): 527 * Format a link-layer address into a printable format, paying attention to 528 * the interface type. 529 */ 530 /* ARGSUSED */ 531 static int 532 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 533 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 534 int flags) 535 { 536 const struct sockaddr_dl *sdl = 537 (const struct sockaddr_dl *)(const void *)sa; 538 const struct ieee1394_hwaddr *iha; 539 int n; 540 541 if (serv != NULL && servlen > 0) 542 *serv = '\0'; 543 544 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 545 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 546 if (n < 0 || (socklen_t) n > hostlen) { 547 *host = '\0'; 548 return EAI_MEMORY; 549 } 550 return 0; 551 } 552 553 switch (sdl->sdl_type) { 554 #ifdef IFT_ECONET 555 case IFT_ECONET: 556 if (sdl->sdl_alen < 2) 557 return EAI_FAMILY; 558 if (CLLADDR(sdl)[1] == 0) 559 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 560 else 561 n = snprintf(host, hostlen, "%u.%u", 562 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 563 if (n < 0 || (socklen_t) n >= hostlen) { 564 *host = '\0'; 565 return EAI_MEMORY; 566 } else 567 return 0; 568 #endif 569 case IFT_IEEE1394: 570 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 571 return EAI_FAMILY; 572 iha = 573 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 574 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 575 host, hostlen); 576 /* 577 * The following have zero-length addresses. 578 * IFT_ATM (net/if_atmsubr.c) 579 * IFT_FAITH (net/if_faith.c) 580 * IFT_GIF (net/if_gif.c) 581 * IFT_LOOP (net/if_loop.c) 582 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 583 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 584 * IFT_STF (net/if_stf.c) 585 * IFT_L2VLAN (net/if_vlan.c) 586 * IFT_PROPVIRTUAL (net/if_bridge.h> 587 */ 588 /* 589 * The following use IPv4 addresses as link-layer addresses: 590 * IFT_OTHER (net/if_gre.c) 591 */ 592 case IFT_ARCNET: /* default below is believed correct for all these. */ 593 case IFT_ETHER: 594 case IFT_FDDI: 595 case IFT_HIPPI: 596 case IFT_ISO88025: 597 default: 598 return hexname((const uint8_t *)CLLADDR(sdl), 599 (size_t)sdl->sdl_alen, host, hostlen); 600 } 601 } 602 603 static int 604 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen) 605 { 606 int n; 607 size_t i; 608 char *outp = host; 609 610 *outp = '\0'; 611 for (i = 0; i < len; i++) { 612 n = snprintf(outp, hostlen, "%s%02x", 613 i ? ":" : "", cp[i]); 614 if (n < 0 || (socklen_t) n >= hostlen) { 615 *host = '\0'; 616 return EAI_MEMORY; 617 } 618 outp += n; 619 hostlen -= n; 620 } 621 return 0; 622 } 623 #endif /* !defined(__minix) */ 624