1/* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */ 2 3/* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * Copyright (c) 2000 Ben Harris. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33/* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked 36 * - RFC2553 says that we should raise error on short buffer. X/Open says 37 * we need to truncate the result. We obey RFC2553 (and X/Open should be 38 * modified). ipngwg rough consensus seems to follow RFC2553. 39 * - What is "local" in NI_FQDN? 40 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 41 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if 42 * sin6_scope_id is filled - standardization status? 43 * XXX breaks backward compat for code that expects no scopeid. 44 * beware on merge. 45 */ 46 47#include <sys/cdefs.h> 48__FBSDID("$FreeBSD: releng/10.3/lib/libc/net/getnameinfo.c 287736 2015-09-13 03:15:37Z hrs $"); 49 50#include <sys/types.h> 51#include <sys/socket.h> 52#include <net/if.h> 53#include <net/if_dl.h> 54#include <net/if_types.h> 55#include <net/firewire.h> 56#include <netinet/in.h> 57#include <arpa/inet.h> 58#include <arpa/nameser.h> 59#include <netdb.h> 60#include <resolv.h> 61#include <string.h> 62#include <stddef.h> 63#include <errno.h> 64 65static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *, 66 size_t, char *, size_t, int); 67#ifdef INET6 68static int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 69 size_t, int); 70static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 71#endif 72static int getnameinfo_link(const struct sockaddr *, socklen_t, char *, 73 size_t, char *, size_t, int); 74static int hexname(const u_int8_t *, size_t, char *, size_t); 75 76int 77getnameinfo(const struct sockaddr *sa, socklen_t salen, 78 char *host, size_t hostlen, char *serv, size_t servlen, 79 int flags) 80{ 81 if (sa == NULL) 82 return (EAI_FAIL); 83 84 switch (sa->sa_family) { 85 case AF_INET: 86#ifdef INET6 87 case AF_INET6: 88#endif 89 return getnameinfo_inet(sa, salen, host, hostlen, serv, 90 servlen, flags); 91 case AF_LINK: 92 return getnameinfo_link(sa, salen, host, hostlen, serv, 93 servlen, flags); 94 default: 95 return EAI_FAMILY; 96 } 97} 98 99static const struct afd { 100 int a_af; 101 size_t a_addrlen; 102 socklen_t a_socklen; 103 int a_off; 104} afdl [] = { 105#ifdef INET6 106 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 107 offsetof(struct sockaddr_in6, sin6_addr)}, 108#endif 109 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 110 offsetof(struct sockaddr_in, sin_addr)}, 111 {0, 0, 0}, 112}; 113 114struct sockinet { 115 u_char si_len; 116 u_char si_family; 117 u_short si_port; 118}; 119 120static int 121getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, 122 char *host, size_t hostlen, char *serv, size_t servlen, 123 int flags) 124{ 125 const struct afd *afd; 126 struct servent *sp; 127 struct hostent *hp; 128 u_short port; 129 const char *addr; 130 u_int32_t v4a; 131 int h_error; 132 char numserv[512]; 133 char numaddr[512]; 134 135 for (afd = &afdl[0]; afd->a_af > 0; afd++) { 136 if (afd->a_af == sa->sa_family) 137 break; 138 } 139 if (afd->a_af == 0) 140 return (EAI_FAMILY); 141 142 if (salen != afd->a_socklen) 143 return EAI_FAIL; 144 145 /* network byte order */ 146 port = ((const struct sockinet *)sa)->si_port; 147 addr = (const char *)sa + afd->a_off; 148 149 if (serv == NULL || servlen == 0) { 150 /* 151 * do nothing in this case. 152 * in case you are wondering if "&&" is more correct than 153 * "||" here: rfc2553bis-03 says that serv == NULL OR 154 * servlen == 0 means that the caller does not want the result. 155 */ 156 } else { 157 if (flags & NI_NUMERICSERV) 158 sp = NULL; 159 else { 160 sp = getservbyport(port, 161 (flags & NI_DGRAM) ? "udp" : "tcp"); 162 } 163 if (sp) { 164 if (strlen(sp->s_name) + 1 > servlen) 165 return EAI_MEMORY; 166 strlcpy(serv, sp->s_name, servlen); 167 } else { 168 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 169 if (strlen(numserv) + 1 > servlen) 170 return EAI_MEMORY; 171 strlcpy(serv, numserv, servlen); 172 } 173 } 174 175 switch (sa->sa_family) { 176 case AF_INET: 177 v4a = (u_int32_t) 178 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 179 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 180 flags |= NI_NUMERICHOST; 181 v4a >>= IN_CLASSA_NSHIFT; 182 if (v4a == 0) 183 flags |= NI_NUMERICHOST; 184 break; 185#ifdef INET6 186 case AF_INET6: 187 { 188 const struct sockaddr_in6 *sin6; 189 sin6 = (const struct sockaddr_in6 *)sa; 190 switch (sin6->sin6_addr.s6_addr[0]) { 191 case 0x00: 192 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 193 ; 194 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 195 ; 196 else 197 flags |= NI_NUMERICHOST; 198 break; 199 default: 200 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 201 flags |= NI_NUMERICHOST; 202 } 203 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 204 flags |= NI_NUMERICHOST; 205 break; 206 } 207 } 208 break; 209#endif 210 } 211 if (host == NULL || hostlen == 0) { 212 /* 213 * do nothing in this case. 214 * in case you are wondering if "&&" is more correct than 215 * "||" here: rfc2553bis-03 says that host == NULL or 216 * hostlen == 0 means that the caller does not want the result. 217 */ 218 } else if (flags & NI_NUMERICHOST) { 219 size_t numaddrlen; 220 221 /* NUMERICHOST and NAMEREQD conflicts with each other */ 222 if (flags & NI_NAMEREQD) 223 return EAI_NONAME; 224 225 switch(afd->a_af) { 226#ifdef INET6 227 case AF_INET6: 228 { 229 int error; 230 231 if ((error = ip6_parsenumeric(sa, addr, host, 232 hostlen, flags)) != 0) 233 return(error); 234 break; 235 } 236#endif 237 default: 238 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 239 == NULL) 240 return EAI_SYSTEM; 241 numaddrlen = strlen(numaddr); 242 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 243 return EAI_MEMORY; 244 strlcpy(host, numaddr, hostlen); 245 break; 246 } 247 } else { 248 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 249 250 if (hp) { 251#if 0 252 /* 253 * commented out, since "for local host" is not 254 * implemented here - see RFC2553 p30 255 */ 256 if (flags & NI_NOFQDN) { 257 char *p; 258 p = strchr(hp->h_name, '.'); 259 if (p) 260 *p = '\0'; 261 } 262#endif 263 if (strlen(hp->h_name) + 1 > hostlen) { 264 freehostent(hp); 265 return EAI_MEMORY; 266 } 267 strlcpy(host, hp->h_name, hostlen); 268 freehostent(hp); 269 } else { 270 if (flags & NI_NAMEREQD) 271 return EAI_NONAME; 272 switch(afd->a_af) { 273#ifdef INET6 274 case AF_INET6: 275 { 276 int error; 277 278 if ((error = ip6_parsenumeric(sa, addr, host, 279 hostlen, 280 flags)) != 0) 281 return(error); 282 break; 283 } 284#endif 285 default: 286 if (inet_ntop(afd->a_af, addr, host, 287 hostlen) == NULL) 288 return EAI_SYSTEM; 289 break; 290 } 291 } 292 } 293 return(0); 294} 295 296#ifdef INET6 297static int 298ip6_parsenumeric(const struct sockaddr *sa, const char *addr, 299 char *host, size_t hostlen, int flags) 300{ 301 size_t numaddrlen; 302 char numaddr[512]; 303 304 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 305 return EAI_SYSTEM; 306 307 numaddrlen = strlen(numaddr); 308 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 309 return EAI_OVERFLOW; 310 strlcpy(host, numaddr, hostlen); 311 312 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 313 char zonebuf[MAXHOSTNAMELEN]; 314 int zonelen; 315 316 zonelen = ip6_sa2str( 317 (const struct sockaddr_in6 *)(const void *)sa, 318 zonebuf, sizeof(zonebuf), flags); 319 if (zonelen < 0) 320 return EAI_OVERFLOW; 321 if (zonelen + 1 + numaddrlen + 1 > hostlen) 322 return EAI_OVERFLOW; 323 324 /* construct <numeric-addr><delim><zoneid> */ 325 memcpy(host + numaddrlen + 1, zonebuf, 326 (size_t)zonelen); 327 host[numaddrlen] = SCOPE_DELIMITER; 328 host[numaddrlen + 1 + zonelen] = '\0'; 329 } 330 331 return 0; 332} 333 334/* ARGSUSED */ 335static int 336ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 337{ 338 unsigned int ifindex; 339 const struct in6_addr *a6; 340 int n; 341 342 ifindex = (unsigned int)sa6->sin6_scope_id; 343 a6 = &sa6->sin6_addr; 344 345#ifdef NI_NUMERICSCOPE 346 if ((flags & NI_NUMERICSCOPE) != 0) { 347 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 348 if (n < 0 || n >= bufsiz) 349 return -1; 350 else 351 return n; 352 } 353#endif 354 355 /* if_indextoname() does not take buffer size. not a good api... */ 356 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 357 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { 358 char *p = if_indextoname(ifindex, buf); 359 if (p) { 360 return(strlen(p)); 361 } 362 } 363 364 /* last resort */ 365 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 366 if (n < 0 || (size_t)n >= bufsiz) 367 return -1; 368 else 369 return n; 370} 371#endif /* INET6 */ 372 373/* 374 * getnameinfo_link(): 375 * Format a link-layer address into a printable format, paying attention to 376 * the interface type. 377 */ 378/* ARGSUSED */ 379static int 380getnameinfo_link(const struct sockaddr *sa, socklen_t salen, 381 char *host, size_t hostlen, char *serv, size_t servlen, int flags) 382{ 383 const struct sockaddr_dl *sdl = 384 (const struct sockaddr_dl *)(const void *)sa; 385 const struct fw_hwaddr *iha; 386 int n; 387 388 if (serv != NULL && servlen > 0) 389 *serv = '\0'; 390 391 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) { 392 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index); 393 if (n >= hostlen) { 394 *host = '\0'; 395 return (EAI_MEMORY); 396 } 397 return (0); 398 } 399 400 if (sdl->sdl_nlen > 0 && sdl->sdl_alen == 0) { 401 n = sdl->sdl_nlen; 402 if (n >= hostlen) { 403 *host = '\0'; 404 return (EAI_MEMORY); 405 } 406 memcpy(host, sdl->sdl_data, sdl->sdl_nlen); 407 host[n] = '\0'; 408 return (0); 409 } 410 411 switch (sdl->sdl_type) { 412 case IFT_IEEE1394: 413 if (sdl->sdl_alen < sizeof(iha->sender_unique_ID_hi) + 414 sizeof(iha->sender_unique_ID_lo)) 415 return EAI_FAMILY; 416 iha = (const struct fw_hwaddr *)(const void *)LLADDR(sdl); 417 return hexname((const u_int8_t *)&iha->sender_unique_ID_hi, 418 sizeof(iha->sender_unique_ID_hi) + 419 sizeof(iha->sender_unique_ID_lo), 420 host, hostlen); 421 /* 422 * The following have zero-length addresses. 423 * IFT_ATM (net/if_atmsubr.c) 424 * IFT_FAITH (net/if_faith.c) 425 * IFT_GIF (net/if_gif.c) 426 * IFT_LOOP (net/if_loop.c) 427 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c) 428 * IFT_SLIP (net/if_sl.c, net/if_strip.c) 429 * IFT_STF (net/if_stf.c) 430 * IFT_L2VLAN (net/if_vlan.c) 431 * IFT_BRIDGE (net/if_bridge.h> 432 */ 433 /* 434 * The following use IPv4 addresses as link-layer addresses: 435 * IFT_OTHER (net/if_gre.c) 436 * IFT_OTHER (netinet/ip_ipip.c) 437 */ 438 /* default below is believed correct for all these. */ 439 case IFT_ARCNET: 440 case IFT_ETHER: 441 case IFT_FDDI: 442 case IFT_HIPPI: 443 case IFT_ISO88025: 444 default: 445 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, 446 host, hostlen); 447 } 448} 449 450static int 451hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen) 452{ 453 int i, n; 454 char *outp = host; 455 456 *outp = '\0'; 457 for (i = 0; i < len; i++) { 458 n = snprintf(outp, hostlen, "%s%02x", 459 i ? ":" : "", cp[i]); 460 if (n < 0 || n >= hostlen) { 461 *host = '\0'; 462 return EAI_MEMORY; 463 } 464 outp += n; 465 hostlen -= n; 466 } 467 return 0; 468} 469