1 /* $NetBSD: getnameinfo.c,v 1.43 2006/02/17 15:58:26 ginsbach 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 1.43 2006/02/17 15:58:26 ginsbach Exp $"); 51 #endif /* LIBC_SCCS and not lint */ 52 53 #include <sys/types.h> 54 #include <sys/socket.h> 55 #include <net/if.h> 56 #include <net/if_dl.h> 57 #include <net/if_ieee1394.h> 58 #include <net/if_types.h> 59 #include <netinet/in.h> 60 #include <arpa/inet.h> 61 #include "arpa_nameser.h" 62 #include <assert.h> 63 #include <limits.h> 64 #include <netdb.h> 65 #ifdef ANDROID_CHANGES 66 #include "resolv_private.h" 67 #else 68 #include <resolv.h> 69 #endif 70 #include <stddef.h> 71 #include <string.h> 72 73 static const struct afd { 74 int a_af; 75 socklen_t a_addrlen; 76 socklen_t a_socklen; 77 int a_off; 78 } afdl [] = { 79 #ifdef INET6 80 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 81 offsetof(struct sockaddr_in6, sin6_addr)}, 82 #endif 83 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 84 offsetof(struct sockaddr_in, sin_addr)}, 85 {0, 0, 0, 0}, 86 }; 87 88 struct sockinet { 89 u_char si_len; 90 u_char si_family; 91 u_short si_port; 92 }; 93 94 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *, 95 socklen_t, char *, socklen_t, int)); 96 #ifdef INET6 97 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 98 socklen_t, int)); 99 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, 100 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 getnameinfo(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags) 111 { 112 switch (sa->sa_family) { 113 case AF_INET: 114 case AF_INET6: 115 return getnameinfo_inet(sa, salen, host, hostlen, 116 serv, servlen, flags); 117 #if 0 118 case AF_LINK: 119 return getnameinfo_link(sa, salen, host, hostlen, 120 serv, servlen, flags); 121 #endif 122 default: 123 return EAI_FAMILY; 124 } 125 } 126 127 128 /* 129 * getnameinfo_inet(): 130 * Format an IPv4 or IPv6 sockaddr into a printable string. 131 */ 132 static int 133 getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags) 134 const struct sockaddr *sa; 135 socklen_t salen; 136 char *host; 137 socklen_t hostlen; 138 char *serv; 139 socklen_t servlen; 140 int flags; 141 { 142 const struct afd *afd; 143 struct servent *sp; 144 struct hostent *hp; 145 u_short port; 146 int family, i; 147 const char *addr; 148 u_int32_t v4a; 149 char numserv[512]; 150 char numaddr[512]; 151 152 /* sa is checked below */ 153 /* host may be NULL */ 154 /* serv may be NULL */ 155 156 if (sa == NULL) 157 return EAI_FAIL; 158 159 #ifdef BSD4_4 160 if (sa->sa_len != salen) 161 return EAI_FAIL; 162 #endif 163 164 family = sa->sa_family; 165 for (i = 0; afdl[i].a_af; i++) 166 if (afdl[i].a_af == family) { 167 afd = &afdl[i]; 168 goto found; 169 } 170 return EAI_FAMILY; 171 172 found: 173 if (salen != afd->a_socklen) 174 return EAI_FAIL; 175 176 /* network byte order */ 177 port = ((const struct sockinet *)(const void *)sa)->si_port; 178 addr = (const char *)(const void *)sa + afd->a_off; 179 180 if (serv == NULL || servlen == 0) { 181 /* 182 * do nothing in this case. 183 * in case you are wondering if "&&" is more correct than 184 * "||" here: rfc2553bis-03 says that serv == NULL OR 185 * servlen == 0 means that the caller does not want the result. 186 */ 187 } else { 188 if (flags & NI_NUMERICSERV) 189 sp = NULL; 190 else { 191 sp = getservbyport(port, 192 (flags & NI_DGRAM) ? "udp" : "tcp"); 193 } 194 if (sp) { 195 if (strlen(sp->s_name) + 1 > (size_t)servlen) 196 return EAI_MEMORY; 197 strlcpy(serv, sp->s_name, servlen); 198 } else { 199 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 200 if (strlen(numserv) + 1 > (size_t)servlen) 201 return EAI_MEMORY; 202 strlcpy(serv, numserv, servlen); 203 } 204 } 205 206 switch (sa->sa_family) { 207 case AF_INET: 208 v4a = (u_int32_t) 209 ntohl(((const struct sockaddr_in *) 210 (const void *)sa)->sin_addr.s_addr); 211 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 212 flags |= NI_NUMERICHOST; 213 v4a >>= IN_CLASSA_NSHIFT; 214 if (v4a == 0) 215 flags |= NI_NUMERICHOST; 216 break; 217 #ifdef INET6 218 case AF_INET6: 219 { 220 const struct sockaddr_in6 *sin6; 221 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 222 switch (sin6->sin6_addr.s6_addr[0]) { 223 case 0x00: 224 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 225 ; 226 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 227 ; 228 else 229 flags |= NI_NUMERICHOST; 230 break; 231 default: 232 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 233 flags |= NI_NUMERICHOST; 234 } 235 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 236 flags |= NI_NUMERICHOST; 237 break; 238 } 239 } 240 break; 241 #endif 242 } 243 if (host == NULL || hostlen == 0) { 244 /* 245 * do nothing in this case. 246 * in case you are wondering if "&&" is more correct than 247 * "||" here: rfc2553bis-03 says that host == NULL or 248 * hostlen == 0 means that the caller does not want the result. 249 */ 250 } else if (flags & NI_NUMERICHOST) { 251 size_t numaddrlen; 252 253 /* NUMERICHOST and NAMEREQD conflicts with each other */ 254 if (flags & NI_NAMEREQD) 255 return EAI_NONAME; 256 257 switch(afd->a_af) { 258 #ifdef INET6 259 case AF_INET6: 260 { 261 int error; 262 263 if ((error = ip6_parsenumeric(sa, addr, host, 264 hostlen, flags)) != 0) 265 return(error); 266 break; 267 } 268 #endif 269 default: 270 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 271 == NULL) 272 return EAI_SYSTEM; 273 numaddrlen = strlen(numaddr); 274 if (numaddrlen + 1 > (size_t)hostlen) /* don't forget terminator */ 275 return EAI_MEMORY; 276 strlcpy(host, numaddr, hostlen); 277 break; 278 } 279 } else { 280 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 281 282 if (hp) { 283 #if 0 284 /* 285 * commented out, since "for local host" is not 286 * implemented here - see RFC2553 p30 287 */ 288 if (flags & NI_NOFQDN) { 289 char *p; 290 p = strchr(hp->h_name, '.'); 291 if (p) 292 *p = '\0'; 293 } 294 #endif 295 if (strlen(hp->h_name) + 1 > (size_t)hostlen) { 296 return EAI_MEMORY; 297 } 298 strlcpy(host, hp->h_name, hostlen); 299 } else { 300 if (flags & NI_NAMEREQD) 301 return EAI_NONAME; 302 switch(afd->a_af) { 303 #ifdef INET6 304 case AF_INET6: 305 { 306 int error; 307 308 if ((error = ip6_parsenumeric(sa, addr, host, 309 hostlen, 310 flags)) != 0) 311 return(error); 312 break; 313 } 314 #endif 315 default: 316 if (inet_ntop(afd->a_af, addr, host, 317 hostlen) == NULL) 318 return EAI_SYSTEM; 319 break; 320 } 321 } 322 } 323 return(0); 324 } 325 326 #ifdef INET6 327 static int 328 ip6_parsenumeric(sa, addr, host, hostlen, flags) 329 const struct sockaddr *sa; 330 const char *addr; 331 char *host; 332 socklen_t hostlen; 333 int flags; 334 { 335 size_t numaddrlen; 336 char numaddr[512]; 337 338 assert(sa != NULL); 339 assert(addr != NULL); 340 assert(host != NULL); 341 342 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 343 return EAI_SYSTEM; 344 345 numaddrlen = strlen(numaddr); 346 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 347 return EAI_OVERFLOW; 348 strlcpy(host, numaddr, hostlen); 349 350 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 351 char zonebuf[MAXHOSTNAMELEN]; 352 int zonelen; 353 354 zonelen = ip6_sa2str( 355 (const struct sockaddr_in6 *)(const void *)sa, 356 zonebuf, sizeof(zonebuf), flags); 357 if (zonelen < 0) 358 return EAI_OVERFLOW; 359 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen) 360 return EAI_OVERFLOW; 361 /* construct <numeric-addr><delim><zoneid> */ 362 memcpy(host + numaddrlen + 1, zonebuf, 363 (size_t)zonelen); 364 host[numaddrlen] = SCOPE_DELIMITER; 365 host[numaddrlen + 1 + zonelen] = '\0'; 366 } 367 368 return 0; 369 } 370 371 /* ARGSUSED */ 372 static int 373 ip6_sa2str(sa6, buf, bufsiz, flags) 374 const struct sockaddr_in6 *sa6; 375 char *buf; 376 size_t bufsiz; 377 int flags; 378 { 379 unsigned int ifindex; 380 const struct in6_addr *a6; 381 int n; 382 383 assert(sa6 != NULL); 384 assert(buf != NULL); 385 386 ifindex = (unsigned int)sa6->sin6_scope_id; 387 a6 = &sa6->sin6_addr; 388 389 #ifdef NI_NUMERICSCOPE 390 if ((flags & NI_NUMERICSCOPE) != 0) { 391 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 392 if (n < 0 || n >= bufsiz) 393 return -1; 394 else 395 return n; 396 } 397 #endif 398 399 /* if_indextoname() does not take buffer size. not a good api... */ 400 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 401 bufsiz >= IF_NAMESIZE) { 402 char *p = if_indextoname(ifindex, buf); 403 if (p) { 404 return(strlen(p)); 405 } 406 } 407 408 /* last resort */ 409 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 410 if (n < 0 || (size_t) n >= bufsiz) 411 return -1; 412 else 413 return n; 414 } 415 #endif /* INET6 */ 416 417 418 /* 419 * getnameinfo_link(): 420 * Format a link-layer address into a printable format, paying attention to 421 * the interface type. 422 */ 423 /* ARGSUSED */ 424 static int 425 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 426 char *host, socklen_t hostlen, char *serv, socklen_t servlen, 427 int flags) 428 { 429 const struct sockaddr_dl *sdl = 430 (const struct sockaddr_dl *)(const void *)sa; 431 const struct ieee1394_hwaddr *iha; 432 int n; 433 434 if (serv != NULL && servlen > 0) 435 *serv = '\0'; 436 437 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 438 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index); 439 if (n < 0 || (socklen_t) n > hostlen) { 440 *host = '\0'; 441 return EAI_MEMORY; 442 } 443 return 0; 444 } 445 446 switch (sdl->sdl_type) { 447 #ifdef IFT_ECONET 448 case IFT_ECONET: 449 if (sdl->sdl_alen < 2) 450 return EAI_FAMILY; 451 if (CLLADDR(sdl)[1] == 0) 452 n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]); 453 else 454 n = snprintf(host, hostlen, "%u.%u", 455 CLLADDR(sdl)[1], CLLADDR(sdl)[0]); 456 if (n < 0 || (socklen_t) n >= hostlen) { 457 *host = '\0'; 458 return EAI_MEMORY; 459 } else 460 return 0; 461 #endif 462 case IFT_IEEE1394: 463 if (sdl->sdl_alen < sizeof(iha->iha_uid)) 464 return EAI_FAMILY; 465 iha = 466 (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl); 467 return hexname(iha->iha_uid, sizeof(iha->iha_uid), 468 host, hostlen); 469 /* 470 * The following have zero-length addresses. 471 * IFT_ATM (net/if_atmsubr.c) 472 * IFT_FAITH (net/if_faith.c) 473 * IFT_GIF (net/if_gif.c) 474 * IFT_LOOP (net/if_loop.c) 475 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 476 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 477 * IFT_STF (net/if_stf.c) 478 * IFT_L2VLAN (net/if_vlan.c) 479 * IFT_PROPVIRTUAL (net/if_bridge.h> 480 */ 481 /* 482 * The following use IPv4 addresses as link-layer addresses: 483 * IFT_OTHER (net/if_gre.c) 484 */ 485 case IFT_ARCNET: /* default below is believed correct for all these. */ 486 case IFT_ETHER: 487 case IFT_FDDI: 488 case IFT_HIPPI: 489 case IFT_ISO88025: 490 default: 491 return hexname((const u_int8_t *)CLLADDR(sdl), 492 (size_t)sdl->sdl_alen, host, hostlen); 493 } 494 } 495 496 static int 497 hexname(cp, len, host, hostlen) 498 const u_int8_t *cp; 499 char *host; 500 size_t len; 501 socklen_t hostlen; 502 { 503 int n; 504 size_t i; 505 char *outp = host; 506 507 *outp = '\0'; 508 for (i = 0; i < len; i++) { 509 n = snprintf(outp, hostlen, "%s%02x", 510 i ? ":" : "", cp[i]); 511 if (n < 0 || (socklen_t) n >= hostlen) { 512 *host = '\0'; 513 return EAI_MEMORY; 514 } 515 outp += n; 516 hostlen -= n; 517 } 518 return 0; 519 } 520
