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 IN_ZERONET(v4a)) 229 flags |= NI_NUMERICHOST; 230 break; 231 #ifdef INET6 232 case AF_INET6: 233 { 234 const struct sockaddr_in6 *sin6; 235 sin6 = (const struct sockaddr_in6 *)sa; 236 switch (sin6->sin6_addr.s6_addr[0]) { 237 case 0x00: 238 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 239 ; 240 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 241 ; 242 else 243 flags |= NI_NUMERICHOST; 244 break; 245 default: 246 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 247 flags |= NI_NUMERICHOST; 248 } 249 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 250 flags |= NI_NUMERICHOST; 251 break; 252 } 253 } 254 break; 255 #endif 256 } 257 if (host == NULL || hostlen == 0) { 258 /* 259 * do nothing in this case. 260 * in case you are wondering if "&&" is more correct than 261 * "||" here: rfc2553bis-03 says that host == NULL or 262 * hostlen == 0 means that the caller does not want the result. 263 */ 264 } else if (flags & NI_NUMERICHOST) { 265 size_t numaddrlen; 266 267 /* NUMERICHOST and NAMEREQD conflicts with each other */ 268 if (flags & NI_NAMEREQD) 269 return EAI_NONAME; 270 271 switch(afd->a_af) { 272 #ifdef INET6 273 case AF_INET6: 274 { 275 int error; 276 277 if ((error = ip6_parsenumeric(sa, addr, host, 278 hostlen, flags)) != 0) 279 return(error); 280 break; 281 } 282 #endif 283 default: 284 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 285 == NULL) 286 return EAI_SYSTEM; 287 numaddrlen = strlen(numaddr); 288 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 289 return EAI_MEMORY; 290 strlcpy(host, numaddr, hostlen); 291 break; 292 } 293 } else { 294 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 295 296 if (hp) { 297 #if 0 298 /* 299 * commented out, since "for local host" is not 300 * implemented here - see RFC2553 p30 301 */ 302 if (flags & NI_NOFQDN) { 303 char *p; 304 p = strchr(hp->h_name, '.'); 305 if (p) 306 *p = '\0'; 307 } 308 #endif 309 if (strlen(hp->h_name) + 1 > hostlen) { 310 freehostent(hp); 311 return EAI_MEMORY; 312 } 313 strlcpy(host, hp->h_name, hostlen); 314 freehostent(hp); 315 } else { 316 if (flags & NI_NAMEREQD) 317 return EAI_NONAME; 318 switch(afd->a_af) { 319 #ifdef INET6 320 case AF_INET6: 321 { 322 int error; 323 324 if ((error = ip6_parsenumeric(sa, addr, host, 325 hostlen, 326 flags)) != 0) 327 return(error); 328 break; 329 } 330 #endif 331 default: 332 if (inet_ntop(afd->a_af, addr, host, 333 hostlen) == NULL) 334 return EAI_SYSTEM; 335 break; 336 } 337 } 338 } 339 return(0); 340 } 341 342 #ifdef INET6 343 static int 344 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, 345 char *host, size_t hostlen, int flags) 346 { 347 size_t numaddrlen; 348 char numaddr[512]; 349 350 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 351 return EAI_SYSTEM; 352 353 numaddrlen = strlen(numaddr); 354 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 355 return EAI_OVERFLOW; 356 strlcpy(host, numaddr, hostlen); 357 358 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 359 char zonebuf[MAXHOSTNAMELEN]; 360 int zonelen; 361 362 zonelen = ip6_sa2str( 363 (const struct sockaddr_in6 *)(const void *)sa, 364 zonebuf, sizeof(zonebuf), flags); 365 if (zonelen < 0) 366 return EAI_OVERFLOW; 367 if (zonelen + 1 + numaddrlen + 1 > hostlen) 368 return EAI_OVERFLOW; 369 370 /* construct <numeric-addr><delim><zoneid> */ 371 memcpy(host + numaddrlen + 1, zonebuf, 372 (size_t)zonelen); 373 host[numaddrlen] = SCOPE_DELIMITER; 374 host[numaddrlen + 1 + zonelen] = '\0'; 375 } 376 377 return 0; 378 } 379 380 /* ARGSUSED */ 381 static int 382 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 383 { 384 unsigned int ifindex; 385 const struct in6_addr *a6; 386 int n; 387 388 ifindex = (unsigned int)sa6->sin6_scope_id; 389 a6 = &sa6->sin6_addr; 390 391 if ((flags & NI_NUMERICSCOPE) != 0) { 392 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 393 if (n < 0 || n >= bufsiz) 394 return -1; 395 else 396 return n; 397 } 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 IN6_IS_ADDR_MC_NODELOCAL(a6)) && 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 * getnameinfo_link(): 419 * Format a link-layer address into a printable format, paying attention to 420 * the interface type. 421 */ 422 /* ARGSUSED */ 423 static int 424 getnameinfo_link(const struct afd *afd, 425 const struct sockaddr *sa, socklen_t salen, 426 char *host, size_t hostlen, char *serv, size_t servlen, int flags) 427 { 428 const struct sockaddr_dl *sdl = 429 (const struct sockaddr_dl *)(const void *)sa; 430 const struct fw_hwaddr *iha; 431 int n; 432 433 if (serv != NULL && servlen > 0) 434 *serv = '\0'; 435 436 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 437 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index); 438 if (n >= hostlen) { 439 *host = '\0'; 440 return (EAI_MEMORY); 441 } 442 return (0); 443 } 444 445 if (sdl->sdl_nlen > 0 && sdl->sdl_alen == 0) { 446 n = sdl->sdl_nlen; 447 if (n >= hostlen) { 448 *host = '\0'; 449 return (EAI_MEMORY); 450 } 451 memcpy(host, sdl->sdl_data, sdl->sdl_nlen); 452 host[n] = '\0'; 453 return (0); 454 } 455 456 switch (sdl->sdl_type) { 457 case IFT_IEEE1394: 458 if (sdl->sdl_alen < sizeof(iha->sender_unique_ID_hi) + 459 sizeof(iha->sender_unique_ID_lo)) 460 return EAI_FAMILY; 461 iha = (const struct fw_hwaddr *)(const void *)LLADDR(sdl); 462 return hexname((const u_int8_t *)&iha->sender_unique_ID_hi, 463 sizeof(iha->sender_unique_ID_hi) + 464 sizeof(iha->sender_unique_ID_lo), 465 host, hostlen); 466 /* 467 * The following have zero-length addresses. 468 * IFT_GIF (net/if_gif.c) 469 * IFT_LOOP (net/if_loop.c) 470 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 471 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 472 * IFT_STF (net/if_stf.c) 473 * IFT_L2VLAN (net/if_vlan.c) 474 * IFT_BRIDGE (net/if_bridge.h> 475 */ 476 /* 477 * The following use IPv4 addresses as link-layer addresses: 478 * IFT_OTHER (net/if_gre.c) 479 * IFT_OTHER (netinet/ip_ipip.c) 480 */ 481 /* default below is believed correct for all these. */ 482 case IFT_ETHER: 483 case IFT_FDDI: 484 case IFT_HIPPI: 485 case IFT_ISO88025: 486 default: 487 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, 488 host, hostlen); 489 } 490 } 491 492 static int 493 hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen) 494 { 495 int i, n; 496 char *outp = host; 497 498 *outp = '\0'; 499 for (i = 0; i < len; i++) { 500 n = snprintf(outp, hostlen, "%s%02x", 501 i ? ":" : "", cp[i]); 502 if (n < 0 || n >= hostlen) { 503 *host = '\0'; 504 return EAI_MEMORY; 505 } 506 outp += n; 507 hostlen -= n; 508 } 509 return 0; 510 } 511 512 /* 513 * getnameinfo_un(): 514 * Format a UNIX IPC domain address (pathname). 515 */ 516 /* ARGSUSED */ 517 static int 518 getnameinfo_un(const struct afd *afd, 519 const struct sockaddr *sa, socklen_t salen, 520 char *host, size_t hostlen, char *serv, size_t servlen, int flags) 521 { 522 size_t pathlen; 523 524 if (serv != NULL && servlen > 0) 525 *serv = '\0'; 526 if (host != NULL && hostlen > 0) { 527 pathlen = salen - afd->a_off; 528 529 if (pathlen + 1 > hostlen) { 530 *host = '\0'; 531 return (EAI_MEMORY); 532 } 533 strlcpy(host, (const char *)sa + afd->a_off, pathlen + 1); 534 } 535 536 return (0); 537 } 538