1/* $NetBSD$ */ 2 3/* 4 * Portions Copyright (C) 2004, 2005, 2007, 2011, 2012 Internet Systems Consortium, Inc. ("ISC") 5 * Portions Copyright (C) 1999-2001, 2003 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20/* Id */ 21 22/*! \file */ 23 24/* 25 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 26 * All rights reserved. 27 * 28 * Redistribution and use in source and binary forms, with or without 29 * modification, are permitted provided that the following conditions 30 * are met: 31 * 1. Redistributions of source code must retain the above copyright 32 * notice, this list of conditions and the following disclaimer. 33 * 2. Redistributions in binary form must reproduce the above copyright 34 * notice, this list of conditions and the following disclaimer in the 35 * documentation and/or other materials provided with the distribution. 36 * 3. Neither the name of the project nor the names of its contributors 37 * may be used to endorse or promote products derived from this software 38 * without specific prior written permission. 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 */ 52 53/* 54 * XXX 55 * Issues to be discussed: 56 * - Return values. There seems to be no standard for return value (RFC2553) 57 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 58 */ 59 60 61/** 62 * This function is equivalent to the getnameinfo(3) function defined in 63 * RFC2133. lwres_getnameinfo() returns the hostname for the struct 64 * sockaddr sa which is salen bytes long. The hostname is of length 65 * hostlen and is returned via *host. The maximum length of the hostname 66 * is 1025 bytes: #NI_MAXHOST. 67 * 68 * The name of the service associated with the port number in sa is 69 * returned in *serv. It is servlen bytes long. The maximum length of the 70 * service name is #NI_MAXSERV - 32 bytes. 71 * 72 * The flags argument sets the following bits: 73 * 74 * \li #NI_NOFQDN: 75 * A fully qualified domain name is not required for local hosts. 76 * The local part of the fully qualified domain name is returned 77 * instead. 78 * 79 * \li #NI_NUMERICHOST 80 * Return the address in numeric form, as if calling inet_ntop(), 81 * instead of a host name. 82 * 83 * \li #NI_NAMEREQD 84 * A name is required. If the hostname cannot be found in the DNS 85 * and this flag is set, a non-zero error code is returned. If the 86 * hostname is not found and the flag is not set, the address is 87 * returned in numeric form. 88 * 89 * \li #NI_NUMERICSERV 90 * The service name is returned as a digit string representing the 91 * port number. 92 * 93 * \li #NI_DGRAM 94 * Specifies that the service being looked up is a datagram 95 * service, and causes getservbyport() to be called with a second 96 * argument of "udp" instead of its default of "tcp". This is 97 * required for the few ports (512-514) that have different 98 * services for UDP and TCP. 99 * 100 * \section getnameinfo_return Return Values 101 * 102 * lwres_getnameinfo() returns 0 on success or a non-zero error code if 103 * an error occurs. 104 * 105 * \section getname_see See Also 106 * 107 * RFC2133, getservbyport(), 108 * lwres_getnamebyaddr(). lwres_net_ntop(). 109 * 110 * \section getnameinfo_bugs Bugs 111 * 112 * RFC2133 fails to define what the nonzero return values of 113 * getnameinfo() are. 114 */ 115 116#include <config.h> 117 118#include <stdio.h> 119#include <string.h> 120 121#include <lwres/lwres.h> 122#include <lwres/net.h> 123#include <lwres/netdb.h> 124#include "print_p.h" 125 126#include "assert_p.h" 127 128#define SUCCESS 0 129 130/*% afd structure definition */ 131static struct afd { 132 int a_af; 133 size_t a_addrlen; 134 size_t a_socklen; 135} afdl [] = { 136 /*! 137 * First entry is linked last... 138 */ 139 { AF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in) }, 140 { AF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6) }, 141 {0, 0, 0}, 142}; 143 144#define ENI_NOSERVNAME 1 145#define ENI_NOHOSTNAME 2 146#define ENI_MEMORY 3 147#define ENI_SYSTEM 4 148#define ENI_FAMILY 5 149#define ENI_SALEN 6 150#define ENI_NOSOCKET 7 151 152/*! 153 * The test against 0 is there to keep the Solaris compiler 154 * from complaining about "end-of-loop code not reached". 155 */ 156#define ERR(code) \ 157 do { result = (code); \ 158 if (result != 0) goto cleanup; \ 159 } while (/*CONSTCOND*/0) 160 161/*% lightweight resolver socket address structure to hostname and service name */ 162int 163lwres_getnameinfo(const struct sockaddr *sa, size_t salen, char *host, 164 size_t hostlen, char *serv, size_t servlen, int flags) 165{ 166 struct afd *afd; 167 struct servent *sp; 168 unsigned short port; 169#ifdef LWRES_PLATFORM_HAVESALEN 170 size_t len; 171#endif 172 int family, i; 173 const void *addr; 174 char *p; 175#if 0 176 unsigned long v4a; 177 unsigned char pfx; 178#endif 179 char numserv[sizeof("65000")]; 180 char numaddr[sizeof("abcd:abcd:abcd:abcd:abcd:abcd:255.255.255.255") 181 + 1 + sizeof("4294967295")]; 182 const char *proto; 183 lwres_uint32_t lwf = 0; 184 lwres_context_t *lwrctx = NULL; 185 lwres_gnbaresponse_t *by = NULL; 186 int result = SUCCESS; 187 int n; 188 189 if (sa == NULL) 190 ERR(ENI_NOSOCKET); 191 192#ifdef LWRES_PLATFORM_HAVESALEN 193 len = sa->sa_len; 194 if (len != salen) 195 ERR(ENI_SALEN); 196#endif 197 198 family = sa->sa_family; 199 for (i = 0; afdl[i].a_af; i++) 200 if (afdl[i].a_af == family) { 201 afd = &afdl[i]; 202 goto found; 203 } 204 ERR(ENI_FAMILY); 205 206 found: 207 if (salen != afd->a_socklen) 208 ERR(ENI_SALEN); 209 210 switch (family) { 211 case AF_INET: 212 port = ((const struct sockaddr_in *)sa)->sin_port; 213 addr = &((const struct sockaddr_in *)sa)->sin_addr.s_addr; 214 break; 215 216 case AF_INET6: 217 port = ((const struct sockaddr_in6 *)sa)->sin6_port; 218 addr = ((const struct sockaddr_in6 *)sa)->sin6_addr.s6_addr; 219 break; 220 221 default: 222 port = 0; 223 addr = NULL; 224 POST(port); POST(addr); 225 INSIST(0); 226 } 227 proto = (flags & NI_DGRAM) ? "udp" : "tcp"; 228 229 if (serv == NULL || servlen == 0U) { 230 /* 231 * Caller does not want service. 232 */ 233 } else if ((flags & NI_NUMERICSERV) != 0 || 234 (sp = getservbyport(port, proto)) == NULL) { 235 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 236 if ((strlen(numserv) + 1) > servlen) 237 ERR(ENI_MEMORY); 238 strcpy(serv, numserv); 239 } else { 240 if ((strlen(sp->s_name) + 1) > servlen) 241 ERR(ENI_MEMORY); 242 strcpy(serv, sp->s_name); 243 } 244 245#if 0 246 switch (sa->sa_family) { 247 case AF_INET: 248 v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr; 249 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 250 flags |= NI_NUMERICHOST; 251 v4a >>= IN_CLASSA_NSHIFT; 252 if (v4a == 0 || v4a == IN_LOOPBACKNET) 253 flags |= NI_NUMERICHOST; 254 break; 255 256 case AF_INET6: 257 pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0]; 258 if (pfx == 0 || pfx == 0xfe || pfx == 0xff) 259 flags |= NI_NUMERICHOST; 260 break; 261 } 262#endif 263 264 if (host == NULL || hostlen == 0U) { 265 /* 266 * What should we do? 267 */ 268 } else if (flags & NI_NUMERICHOST) { 269 if (lwres_net_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 270 == NULL) 271 ERR(ENI_SYSTEM); 272#if defined(LWRES_HAVE_SIN6_SCOPE_ID) 273 if (afd->a_af == AF_INET6 && 274 ((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 275 char *p = numaddr + strlen(numaddr); 276 const char *stringscope = NULL; 277#if 0 278 if ((flags & NI_NUMERICSCOPE) == 0) { 279 /* 280 * Vendors may want to add support for 281 * non-numeric scope identifier. 282 */ 283 stringscope = foo; 284 } 285#endif 286 if (stringscope == NULL) { 287 snprintf(p, sizeof(numaddr) - (p - numaddr), 288 "%%%u", 289 ((const struct sockaddr_in6 *)sa)->sin6_scope_id); 290 } else { 291 snprintf(p, sizeof(numaddr) - (p - numaddr), 292 "%%%s", stringscope); 293 } 294 } 295#endif 296 if (strlen(numaddr) + 1 > hostlen) 297 ERR(ENI_MEMORY); 298 strcpy(host, numaddr); 299 } else { 300 switch (family) { 301 case AF_INET: 302 lwf = LWRES_ADDRTYPE_V4; 303 break; 304 case AF_INET6: 305 lwf = LWRES_ADDRTYPE_V6; 306 break; 307 default: 308 INSIST(0); 309 } 310 311 n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0); 312 if (n == 0) 313 (void) lwres_conf_parse(lwrctx, lwres_resolv_conf); 314 315 if (n == 0) 316 n = lwres_getnamebyaddr(lwrctx, lwf, 317 (lwres_uint16_t)afd->a_addrlen, 318 addr, &by); 319 if (n == 0) { 320 if (flags & NI_NOFQDN) { 321 p = strchr(by->realname, '.'); 322 if (p) 323 *p = '\0'; 324 } 325 if ((strlen(by->realname) + 1) > hostlen) 326 ERR(ENI_MEMORY); 327 strcpy(host, by->realname); 328 } else { 329 if (flags & NI_NAMEREQD) 330 ERR(ENI_NOHOSTNAME); 331 if (lwres_net_ntop(afd->a_af, addr, numaddr, 332 sizeof(numaddr)) 333 == NULL) 334 ERR(ENI_NOHOSTNAME); 335 if ((strlen(numaddr) + 1) > hostlen) 336 ERR(ENI_MEMORY); 337 strcpy(host, numaddr); 338 } 339 } 340 result = SUCCESS; 341 cleanup: 342 if (by != NULL) 343 lwres_gnbaresponse_free(lwrctx, &by); 344 if (lwrctx != NULL) { 345 lwres_conf_clear(lwrctx); 346 lwres_context_destroy(&lwrctx); 347 } 348 return (result); 349} 350