1 /* $NetBSD: getnameinfo.c,v 1.36 2002/05/14 14:31:06 kleink 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 1.36 2002/05/14 14:31:06 kleink 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 <netinet/in.h> 61 #include <arpa/inet.h> 62 #include <arpa/nameser.h> 63 #include <assert.h> 64 #include <limits.h> 65 #include <netdb.h> 66 #include <resolv.h> 67 #include <stddef.h> 68 #include <string.h> 69 70 #ifdef __weak_alias 71 __weak_alias(getnameinfo,_getnameinfo) 72 #endif 73 74 static const struct afd { 75 int a_af; 76 socklen_t a_addrlen; 77 socklen_t a_socklen; 78 int a_off; 79 } afdl [] = { 80 #ifdef INET6 81 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 82 offsetof(struct sockaddr_in6, sin6_addr)}, 83 #endif 84 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 85 offsetof(struct sockaddr_in, sin_addr)}, 86 {0, 0, 0}, 87 }; 88 89 struct sockinet { 90 u_char si_len; 91 u_char si_family; 92 u_short si_port; 93 }; 94 95 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *, 96 socklen_t, char *, socklen_t, int)); 97 #ifdef INET6 98 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 99 socklen_t, int)); 100 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 101 #endif 102 static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *, 103 socklen_t, char *, socklen_t, int)); 104 static int hexname __P((const u_int8_t *, size_t, char *, socklen_t)); 105 106 /* 107 * Top-level getnameinfo() code. Look at the address family, and pick an 108 * appropriate function to call. 109 */ 110 int 111 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 112 const struct sockaddr *sa; 113 socklen_t salen; 114 char *host, *serv; 115 socklen_t hostlen, servlen; 116 int flags; 117 { 118 119 switch (sa->sa_family) { 120 case AF_INET: 121 case AF_INET6: 122 return getnameinfo_inet(sa, salen, host, hostlen, 123 serv, servlen, flags); 124 case AF_LINK: 125 return getnameinfo_link(sa, salen, host, hostlen, 126 serv, servlen, flags); 127 default: 128 return EAI_FAMILY; 129 } 130 } 131 132 133 /* 134 * getnameinfo_inet(): 135 * Format an IPv4 or IPv6 sockaddr into a printable string. 136 */ 137 static int 138 getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags) 139 const struct sockaddr *sa; 140 socklen_t salen; 141 char *host; 142 socklen_t hostlen; 143 char *serv; 144 socklen_t servlen; 145 int flags; 146 { 147 const struct afd *afd; 148 struct servent *sp; 149 struct hostent *hp; 150 u_short port; 151 int family, i; 152 const char *addr; 153 u_int32_t v4a; 154 char numserv[512]; 155 char numaddr[512]; 156 157 /* sa is checked below */ 158 /* host may be NULL */ 159 /* serv may be NULL */ 160 161 if (sa == NULL) 162 return EAI_FAIL; 163 164 #ifdef BSD4_4 165 if (sa->sa_len != salen) 166 return EAI_FAIL; 167 #endif 168 169 family = sa->sa_family; 170 for (i = 0; afdl[i].a_af; i++) 171 if (afdl[i].a_af == family) { 172 afd = &afdl[i]; 173 goto found; 174 } 175 return EAI_FAMILY; 176 177 found: 178 if (salen != afd->a_socklen) 179 return EAI_FAIL; 180 181 /* network byte order */ 182 port = ((const struct sockinet *)(const void *)sa)->si_port; 183 addr = (const char *)(const void *)sa + afd->a_off; 184 185 if (serv == NULL || servlen == 0) { 186 /* 187 * do nothing in this case. 188 * in case you are wondering if "&&" is more correct than 189 * "||" here: rfc2553bis-03 says that serv == NULL OR 190 * servlen == 0 means that the caller does not want the result. 191 */ 192 } else { 193 if (flags & NI_NUMERICSERV) 194 sp = NULL; 195 else { 196 sp = getservbyport(port, 197 (flags & NI_DGRAM) ? "udp" : "tcp"); 198 } 199 if (sp) { 200 if (strlen(sp->s_name) + 1 > servlen) 201 return EAI_MEMORY; 202 strcpy(serv, sp->s_name); 203 } else { 204 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 205 if (strlen(numserv) + 1 > servlen) 206 return EAI_MEMORY; 207 strcpy(serv, numserv); 208 } 209 } 210 211 switch (sa->sa_family) { 212 case AF_INET: 213 v4a = (u_int32_t) 214 ntohl(((const struct sockaddr_in *) 215 (const void *)sa)->sin_addr.s_addr); 216 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 217 flags |= NI_NUMERICHOST; 218 v4a >>= IN_CLASSA_NSHIFT; 219 if (v4a == 0) 220 flags |= NI_NUMERICHOST; 221 break; 222 #ifdef INET6 223 case AF_INET6: 224 { 225 const struct sockaddr_in6 *sin6; 226 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 227 switch (sin6->sin6_addr.s6_addr[0]) { 228 case 0x00: 229 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 230 ; 231 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 232 ; 233 else 234 flags |= NI_NUMERICHOST; 235 break; 236 default: 237 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 238 flags |= NI_NUMERICHOST; 239 } 240 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 241 flags |= NI_NUMERICHOST; 242 break; 243 } 244 } 245 break; 246 #endif 247 } 248 if (host == NULL || hostlen == 0) { 249 /* 250 * do nothing in this case. 251 * in case you are wondering if "&&" is more correct than 252 * "||" here: rfc2553bis-03 says that host == NULL or 253 * hostlen == 0 means that the caller does not want the result. 254 */ 255 } else if (flags & NI_NUMERICHOST) { 256 int numaddrlen; 257 258 /* NUMERICHOST and NAMEREQD conflicts with each other */ 259 if (flags & NI_NAMEREQD) 260 return EAI_NONAME; 261 262 switch(afd->a_af) { 263 #ifdef INET6 264 case AF_INET6: 265 { 266 int error; 267 268 if ((error = ip6_parsenumeric(sa, addr, host, 269 hostlen, flags)) != 0) 270 return(error); 271 break; 272 } 273 #endif 274 default: 275 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 276 == NULL) 277 return EAI_SYSTEM; 278 numaddrlen = strlen(numaddr); 279 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 280 return EAI_MEMORY; 281 strcpy(host, numaddr); 282 break; 283 } 284 } else { 285 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 286 287 if (hp) { 288 #if 0 289 /* 290 * commented out, since "for local host" is not 291 * implemented here - see RFC2553 p30 292 */ 293 if (flags & NI_NOFQDN) { 294 char *p; 295 p = strchr(hp->h_name, '.'); 296 if (p) 297 *p = '\0'; 298 } 299 #endif 300 if (strlen(hp->h_name) + 1 > hostlen) { 301 return EAI_MEMORY; 302 } 303 strcpy(host, hp->h_name); 304 } else { 305 if (flags & NI_NAMEREQD) 306 return EAI_NONAME; 307 switch(afd->a_af) { 308 #ifdef INET6 309 case AF_INET6: 310 { 311 int error; 312 313 if ((error = ip6_parsenumeric(sa, addr, host, 314 hostlen, 315 flags)) != 0) 316 return(error); 317 break; 318 } 319 #endif 320 default: 321 if (inet_ntop(afd->a_af, addr, host, 322 hostlen) == NULL) 323 return EAI_SYSTEM; 324 break; 325 } 326 } 327 } 328 return(0); 329 } 330 331 #ifdef INET6 332 static int 333 ip6_parsenumeric(sa, addr, host, hostlen, flags) 334 const struct sockaddr *sa; 335 const char *addr; 336 char *host; 337 socklen_t hostlen; 338 int flags; 339 { 340 int numaddrlen; 341 char numaddr[512]; 342 343 _DIAGASSERT(sa != NULL); 344 _DIAGASSERT(addr != NULL); 345 _DIAGASSERT(host != NULL); 346 347 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 348 return EAI_SYSTEM; 349 350 numaddrlen = strlen(numaddr); 351 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 352 return EAI_MEMORY; 353 strcpy(host, numaddr); 354 355 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 356 char zonebuf[MAXHOSTNAMELEN]; 357 int zonelen; 358 359 zonelen = ip6_sa2str( 360 (const struct sockaddr_in6 *)(const void *)sa, 361 zonebuf, sizeof(zonebuf), flags); 362 if (zonelen < 0) 363 return EAI_MEMORY; 364 if (zonelen + 1 + numaddrlen + 1 > hostlen) 365 return EAI_MEMORY; 366 /* construct <numeric-addr><delim><zoneid> */ 367 memcpy(host + numaddrlen + 1, zonebuf, 368 (size_t)zonelen); 369 host[numaddrlen] = SCOPE_DELIMITER; 370 host[numaddrlen + 1 + zonelen] = '\0'; 371 } 372 373 return 0; 374 } 375 376 /* ARGSUSED */ 377 static int 378 ip6_sa2str(sa6, buf, bufsiz, flags) 379 const struct sockaddr_in6 *sa6; 380 char *buf; 381 size_t bufsiz; 382 int flags; 383 { 384 unsigned int ifindex; 385 const struct in6_addr *a6; 386 int n; 387 388 _DIAGASSERT(sa6 != NULL); 389 _DIAGASSERT(buf != NULL); 390 391 ifindex = (unsigned int)sa6->sin6_scope_id; 392 a6 = &sa6->sin6_addr; 393 394 #ifdef NI_NUMERICSCOPE 395 if ((flags & NI_NUMERICSCOPE) != 0) { 396 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 397 if (n < 0 || n >= bufsiz) 398 return -1; 399 else 400 return n; 401 } 402 #endif 403 404 /* if_indextoname() does not take buffer size. not a good api... */ 405 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 406 bufsiz >= IF_NAMESIZE) { 407 char *p = if_indextoname(ifindex, buf); 408 if (p) { 409 return(strlen(p)); 410 } 411 } 412 413 /* last resort */ 414 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 415 if (n < 0 || n >= bufsiz) 416 return -1; 417 else 418 return n; 419 } 420 #endif /* INET6 */ 421 422 423 /* 424 * getnameinfo_link(): 425 * Format a link-layer address into a printable format, paying attention to 426 * the interface type. 427 */ 428 /* ARGSUSED */ 429 static int 430 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 431 char *host, socklen_t hostlen, char *serv, socklen_t servlen, int flags) 432 { 433 const struct sockaddr_dl *sdl = 434 (const struct sockaddr_dl *)(const void *)sa; 435 const struct ieee1394_hwaddr *iha; 436 int n; 437 438 if (serv != NULL && servlen > 0) 439 *serv = '\0'; 440 441 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 442 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index); 443 if (n > hostlen) { 444 *host = '\0'; 445 return EAI_MEMORY; 446 } 447 return 0; 448 } 449 450 switch (sdl->sdl_type) { 451 #ifdef IFT_ECONET 452 case IFT_ECONET: 453 if (sdl->sdl_alen < 2) 454 return EAI_FAMILY; 455 if (LLADDR(sdl)[1] == 0) 456 n = snprintf(host, hostlen, "%d", LLADDR(sdl)[0]); 457 else 458 n = snprintf(host, hostlen, "%d.%d", 459 LLADDR(sdl)[1], LLADDR(sdl)[0]); 460 if (n >= hostlen) { 461 *host = '\0'; 462 return EAI_MEMORY; 463 } else 464 return 0; 465 #endif 466 case IFT_IEEE1394: 467 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 468 return EAI_FAMILY; 469 iha = 470 (const struct ieee1394_hwaddr *)(const void *)LLADDR(sdl); 471 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 472 host, hostlen); 473 /* 474 * The following have zero-length addresses. 475 * IFT_ATM (net/if_atmsubr.c) 476 * IFT_FAITH (net/if_faith.c) 477 * IFT_GIF (net/if_gif.c) 478 * IFT_LOOP (net/if_loop.c) 479 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 480 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 481 * IFT_STF (net/if_stf.c) 482 * IFT_L2VLAN (net/if_vlan.c) 483 * IFT_PROPVIRTUAL (net/if_bridge.h> 484 */ 485 /* 486 * The following use IPv4 addresses as link-layer addresses: 487 * IFT_OTHER (net/if_gre.c) 488 */ 489 case IFT_ARCNET: /* default below is believed correct for all these. */ 490 case IFT_ETHER: 491 case IFT_FDDI: 492 case IFT_HIPPI: 493 case IFT_ISO88025: 494 default: 495 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, 496 host, hostlen); 497 } 498 } 499 500 static int 501 hexname(cp, len, host, hostlen) 502 const u_int8_t *cp; 503 char *host; 504 size_t len; 505 socklen_t hostlen; 506 { 507 int i, n; 508 char *outp = host; 509 510 *outp = '\0'; 511 for (i = 0; i < len; i++) { 512 n = snprintf(outp, hostlen, "%s%02x", 513 i ? ":" : "", cp[i]); 514 if (n < 0 || n >= hostlen) { 515 *host = '\0'; 516 return EAI_MEMORY; 517 } 518 outp += n; 519 hostlen -= n; 520 } 521 return 0; 522 } 523