1 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * Copyright (c) 2000 Ben Harris. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the project nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * Issues to be discussed: 37 * - Thread safe-ness must be checked 38 * - RFC2553 says that we should raise error on short buffer. X/Open says 39 * we need to truncate the result. We obey RFC2553 (and X/Open should be 40 * modified). ipngwg rough consensus seems to follow RFC2553. 41 * - What is "local" in NI_FQDN? 42 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 43 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if 44 * sin6_scope_id is filled - standardization status? 45 * XXX breaks backward compat for code that expects no scopeid. 46 * beware on merge. 47 */ 48 49 #include <sys/cdefs.h> 50 __FBSDID("$FreeBSD$"); 51 52 #include <sys/types.h> 53 #include <sys/socket.h> 54 #include <sys/un.h> 55 #include <net/if.h> 56 #include <net/if_dl.h> 57 #include <net/if_types.h> 58 #include <net/firewire.h> 59 #include <netinet/in.h> 60 #include <arpa/inet.h> 61 #include <arpa/nameser.h> 62 #include <netdb.h> 63 #include <resolv.h> 64 #include <string.h> 65 #include <stddef.h> 66 #include <errno.h> 67 68 static const struct afd *find_afd(int); 69 static int getnameinfo_inet(const struct afd *, 70 const struct sockaddr *, socklen_t, char *, 71 size_t, char *, size_t, int); 72 #ifdef INET6 73 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 74 size_t, int); 75 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 76 #endif 77 static int getnameinfo_link(const struct afd *, 78 const struct sockaddr *, socklen_t, char *, 79 size_t, char *, size_t, int); 80 static int hexname(const u_int8_t *, size_t, char *, size_t); 81 static int getnameinfo_un(const struct afd *, 82 const struct sockaddr *, socklen_t, char *, 83 size_t, char *, size_t, int); 84 85 static const struct afd { 86 int a_af; 87 size_t a_addrlen; 88 socklen_t a_socklen; 89 int a_off; 90 int (*a_func)(const struct afd *, 91 const struct sockaddr *, socklen_t, char *, 92 size_t, char *, size_t, int); 93 } afdl [] = { 94 #ifdef INET6 95 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 96 offsetof(struct sockaddr_in6, sin6_addr), 97 getnameinfo_inet}, 98 #endif 99 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 100 offsetof(struct sockaddr_in, sin_addr), 101 getnameinfo_inet}, 102 #define sizeofmember(type, member) (sizeof(((type *)0)->member)) 103 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 104 sizeof(struct sockaddr_un), 105 offsetof(struct sockaddr_un, sun_path), 106 getnameinfo_un}, 107 {PF_LINK, sizeofmember(struct sockaddr_dl, sdl_data), 108 sizeof(struct sockaddr_dl), 109 offsetof(struct sockaddr_dl, sdl_data), 110 getnameinfo_link}, 111 {0, 0, 0}, 112 }; 113 114 int 115 getnameinfo(const struct sockaddr *sa, socklen_t salen, 116 char *host, size_t hostlen, char *serv, size_t servlen, 117 int flags) 118 { 119 const struct afd *afd; 120 121 if (sa == NULL) 122 return (EAI_FAIL); 123 124 afd = find_afd(sa->sa_family); 125 if (afd == NULL) 126 return (EAI_FAMILY); 127 /* 128 * getnameinfo() accepts an salen of sizeof(struct sockaddr_storage) 129 * at maximum as shown in RFC 4038 Sec.6.2.3. 130 */ 131 if (salen > sizeof(struct sockaddr_storage)) 132 return (EAI_FAMILY); 133 134 switch (sa->sa_family) { 135 case PF_LOCAL: 136 /* 137 * PF_LOCAL uses variable salen depending on the 138 * content length of sun_path. Require 1 byte in 139 * sun_path at least. 140 */ 141 if (salen <= afd->a_socklen - 142 sizeofmember(struct sockaddr_un, sun_path)) 143 return (EAI_FAMILY); 144 else if (salen > afd->a_socklen) 145 salen = afd->a_socklen; 146 break; 147 case PF_LINK: 148 if (salen <= afd->a_socklen - 149 sizeofmember(struct sockaddr_dl, sdl_data)) 150 return (EAI_FAMILY); 151 break; 152 default: 153 if (salen < afd->a_socklen) 154 return (EAI_FAMILY); 155 else 156 salen = afd->a_socklen; 157 break; 158 } 159 160 return ((*afd->a_func)(afd, sa, salen, host, hostlen, 161 serv, servlen, flags)); 162 } 163 164 static const struct afd * 165 find_afd(int af) 166 { 167 const struct afd *afd; 168 169 if (af == PF_UNSPEC) 170 return (NULL); 171 for (afd = &afdl[0]; afd->a_af > 0; afd++) { 172 if (afd->a_af == af) 173 return (afd); 174 } 175 return (NULL); 176 } 177 178 static int 179 getnameinfo_inet(const struct afd *afd, 180 const struct sockaddr *sa, socklen_t salen, 181 char *host, size_t hostlen, char *serv, size_t servlen, 182 int flags) 183 { 184 struct servent *sp; 185 struct hostent *hp; 186 u_short port; 187 const char *addr; 188 u_int32_t v4a; 189 int h_error; 190 char numserv[512]; 191 char numaddr[512]; 192 193 /* network byte order */ 194 port = ((const struct sockaddr_in *)sa)->sin_port; 195 addr = (const char *)sa + afd->a_off; 196 197 if (serv == NULL || servlen == 0) { 198 /* 199 * do nothing in this case. 200 * in case you are wondering if "&&" is more correct than 201 * "||" here: rfc2553bis-03 says that serv == NULL OR 202 * servlen == 0 means that the caller does not want the result. 203 */ 204 } else { 205 if (flags & NI_NUMERICSERV) 206 sp = NULL; 207 else { 208 sp = getservbyport(port, 209 (flags & NI_DGRAM) ? "udp" : "tcp"); 210 } 211 if (sp) { 212 if (strlen(sp->s_name) + 1 > servlen) 213 return EAI_MEMORY; 214 strlcpy(serv, sp->s_name, servlen); 215 } else { 216 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 217 if (strlen(numserv) + 1 > servlen) 218 return EAI_MEMORY; 219 strlcpy(serv, numserv, servlen); 220 } 221 } 222 223 switch (sa->sa_family) { 224 case AF_INET: 225 v4a = (u_int32_t) 226 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 227 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 228 flags |= NI_NUMERICHOST; 229 v4a >>= IN_CLASSA_NSHIFT; 230 if (v4a == 0) 231 flags |= NI_NUMERICHOST; 232 break; 233 #ifdef INET6 234 case AF_INET6: 235 { 236 const struct sockaddr_in6 *sin6; 237 sin6 = (const struct sockaddr_in6 *)sa; 238 switch (sin6->sin6_addr.s6_addr[0]) { 239 case 0x00: 240 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 241 ; 242 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 243 ; 244 else 245 flags |= NI_NUMERICHOST; 246 break; 247 default: 248 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 249 flags |= NI_NUMERICHOST; 250 } 251 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 252 flags |= NI_NUMERICHOST; 253 break; 254 } 255 } 256 break; 257 #endif 258 } 259 if (host == NULL || hostlen == 0) { 260 /* 261 * do nothing in this case. 262 * in case you are wondering if "&&" is more correct than 263 * "||" here: rfc2553bis-03 says that host == NULL or 264 * hostlen == 0 means that the caller does not want the result. 265 */ 266 } else if (flags & NI_NUMERICHOST) { 267 size_t numaddrlen; 268 269 /* NUMERICHOST and NAMEREQD conflicts with each other */ 270 if (flags & NI_NAMEREQD) 271 return EAI_NONAME; 272 273 switch(afd->a_af) { 274 #ifdef INET6 275 case AF_INET6: 276 { 277 int error; 278 279 if ((error = ip6_parsenumeric(sa, addr, host, 280 hostlen, flags)) != 0) 281 return(error); 282 break; 283 } 284 #endif 285 default: 286 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 287 == NULL) 288 return EAI_SYSTEM; 289 numaddrlen = strlen(numaddr); 290 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 291 return EAI_MEMORY; 292 strlcpy(host, numaddr, hostlen); 293 break; 294 } 295 } else { 296 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 297 298 if (hp) { 299 #if 0 300 /* 301 * commented out, since "for local host" is not 302 * implemented here - see RFC2553 p30 303 */ 304 if (flags & NI_NOFQDN) { 305 char *p; 306 p = strchr(hp->h_name, '.'); 307 if (p) 308 *p = '\0'; 309 } 310 #endif 311 if (strlen(hp->h_name) + 1 > hostlen) { 312 freehostent(hp); 313 return EAI_MEMORY; 314 } 315 strlcpy(host, hp->h_name, hostlen); 316 freehostent(hp); 317 } else { 318 if (flags & NI_NAMEREQD) 319 return EAI_NONAME; 320 switch(afd->a_af) { 321 #ifdef INET6 322 case AF_INET6: 323 { 324 int error; 325 326 if ((error = ip6_parsenumeric(sa, addr, host, 327 hostlen, 328 flags)) != 0) 329 return(error); 330 break; 331 } 332 #endif 333 default: 334 if (inet_ntop(afd->a_af, addr, host, 335 hostlen) == NULL) 336 return EAI_SYSTEM; 337 break; 338 } 339 } 340 } 341 return(0); 342 } 343 344 #ifdef INET6 345 static int 346 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, 347 char *host, size_t hostlen, int flags) 348 { 349 size_t numaddrlen; 350 char numaddr[512]; 351 352 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 353 return EAI_SYSTEM; 354 355 numaddrlen = strlen(numaddr); 356 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 357 return EAI_OVERFLOW; 358 strlcpy(host, numaddr, hostlen); 359 360 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 361 char zonebuf[MAXHOSTNAMELEN]; 362 int zonelen; 363 364 zonelen = ip6_sa2str( 365 (const struct sockaddr_in6 *)(const void *)sa, 366 zonebuf, sizeof(zonebuf), flags); 367 if (zonelen < 0) 368 return EAI_OVERFLOW; 369 if (zonelen + 1 + numaddrlen + 1 > hostlen) 370 return EAI_OVERFLOW; 371 372 /* construct <numeric-addr><delim><zoneid> */ 373 memcpy(host + numaddrlen + 1, zonebuf, 374 (size_t)zonelen); 375 host[numaddrlen] = SCOPE_DELIMITER; 376 host[numaddrlen + 1 + zonelen] = '\0'; 377 } 378 379 return 0; 380 } 381 382 /* ARGSUSED */ 383 static int 384 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 385 { 386 unsigned int ifindex; 387 const struct in6_addr *a6; 388 int n; 389 390 ifindex = (unsigned int)sa6->sin6_scope_id; 391 a6 = &sa6->sin6_addr; 392 393 if ((flags & NI_NUMERICSCOPE) != 0) { 394 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 395 if (n < 0 || n >= bufsiz) 396 return -1; 397 else 398 return n; 399 } 400 401 /* if_indextoname() does not take buffer size. not a good api... */ 402 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 403 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { 404 char *p = if_indextoname(ifindex, buf); 405 if (p) { 406 return(strlen(p)); 407 } 408 } 409 410 /* last resort */ 411 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 412 if (n < 0 || (size_t)n >= bufsiz) 413 return -1; 414 else 415 return n; 416 } 417 #endif /* INET6 */ 418 419 /* 420 * getnameinfo_link(): 421 * Format a link-layer address into a printable format, paying attention to 422 * the interface type. 423 */ 424 /* ARGSUSED */ 425 static int 426 getnameinfo_link(const struct afd *afd, 427 const struct sockaddr *sa, socklen_t salen, 428 char *host, size_t hostlen, char *serv, size_t servlen, int flags) 429 { 430 const struct sockaddr_dl *sdl = 431 (const struct sockaddr_dl *)(const void *)sa; 432 const struct fw_hwaddr *iha; 433 int n; 434 435 if (serv != NULL && servlen > 0) 436 *serv = '\0'; 437 438 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 439 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index); 440 if (n >= hostlen) { 441 *host = '\0'; 442 return (EAI_MEMORY); 443 } 444 return (0); 445 } 446 447 if (sdl->sdl_nlen > 0 && sdl->sdl_alen == 0) { 448 n = sdl->sdl_nlen; 449 if (n >= hostlen) { 450 *host = '\0'; 451 return (EAI_MEMORY); 452 } 453 memcpy(host, sdl->sdl_data, sdl->sdl_nlen); 454 host[n] = '\0'; 455 return (0); 456 } 457 458 switch (sdl->sdl_type) { 459 case IFT_IEEE1394: 460 if (sdl->sdl_alen < sizeof(iha->sender_unique_ID_hi) + 461 sizeof(iha->sender_unique_ID_lo)) 462 return EAI_FAMILY; 463 iha = (const struct fw_hwaddr *)(const void *)LLADDR(sdl); 464 return hexname((const u_int8_t *)&iha->sender_unique_ID_hi, 465 sizeof(iha->sender_unique_ID_hi) + 466 sizeof(iha->sender_unique_ID_lo), 467 host, hostlen); 468 /* 469 * The following have zero-length addresses. 470 * IFT_GIF (net/if_gif.c) 471 * IFT_LOOP (net/if_loop.c) 472 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 473 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 474 * IFT_STF (net/if_stf.c) 475 * IFT_L2VLAN (net/if_vlan.c) 476 * IFT_BRIDGE (net/if_bridge.h> 477 */ 478 /* 479 * The following use IPv4 addresses as link-layer addresses: 480 * IFT_OTHER (net/if_gre.c) 481 * IFT_OTHER (netinet/ip_ipip.c) 482 */ 483 /* default below is believed correct for all these. */ 484 case IFT_ETHER: 485 case IFT_FDDI: 486 case IFT_HIPPI: 487 case IFT_ISO88025: 488 default: 489 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, 490 host, hostlen); 491 } 492 } 493 494 static int 495 hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen) 496 { 497 int i, n; 498 char *outp = host; 499 500 *outp = '\0'; 501 for (i = 0; i < len; i++) { 502 n = snprintf(outp, hostlen, "%s%02x", 503 i ? ":" : "", cp[i]); 504 if (n < 0 || n >= hostlen) { 505 *host = '\0'; 506 return EAI_MEMORY; 507 } 508 outp += n; 509 hostlen -= n; 510 } 511 return 0; 512 } 513 514 /* 515 * getnameinfo_un(): 516 * Format a UNIX IPC domain address (pathname). 517 */ 518 /* ARGSUSED */ 519 static int 520 getnameinfo_un(const struct afd *afd, 521 const struct sockaddr *sa, socklen_t salen, 522 char *host, size_t hostlen, char *serv, size_t servlen, int flags) 523 { 524 size_t pathlen; 525 526 if (serv != NULL && servlen > 0) 527 *serv = '\0'; 528 if (host != NULL && hostlen > 0) { 529 pathlen = salen - afd->a_off; 530 531 if (pathlen + 1 > hostlen) { 532 *host = '\0'; 533 return (EAI_MEMORY); 534 } 535 strlcpy(host, (const char *)sa + afd->a_off, pathlen + 1); 536 } 537 538 return (0); 539 } 540