1/* 2 * Copyright (C) 2009, 2011-2013 Internet Systems Consortium, Inc. ("ISC") 3 * 4 * Permission to use, copy, modify, and/or distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 10 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 14 * PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17/* $Id$ */ 18 19/*! \file */ 20 21/* 22 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 23 * All rights reserved. 24 * 25 * Redistribution and use in source and binary forms, with or without 26 * modification, are permitted provided that the following conditions 27 * are met: 28 * 1. Redistributions of source code must retain the above copyright 29 * notice, this list of conditions and the following disclaimer. 30 * 2. Redistributions in binary form must reproduce the above copyright 31 * notice, this list of conditions and the following disclaimer in the 32 * documentation and/or other materials provided with the distribution. 33 * 3. Neither the name of the project nor the names of its contributors 34 * may be used to endorse or promote products derived from this software 35 * without specific prior written permission. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 40 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 47 * SUCH DAMAGE. 48 */ 49 50/** 51 * getnameinfo() returns the hostname for the struct sockaddr sa which is 52 * salen bytes long. The hostname is of length hostlen and is returned via 53 * *host. The maximum length of the hostname is 1025 bytes: #NI_MAXHOST. 54 * 55 * The name of the service associated with the port number in sa is 56 * returned in *serv. It is servlen bytes long. The maximum length of the 57 * service name is #NI_MAXSERV - 32 bytes. 58 * 59 * The flags argument sets the following bits: 60 * 61 * \li #NI_NOFQDN: 62 * A fully qualified domain name is not required for local hosts. 63 * The local part of the fully qualified domain name is returned 64 * instead. 65 * 66 * \li #NI_NUMERICHOST 67 * Return the address in numeric form, as if calling inet_ntop(), 68 * instead of a host name. 69 * 70 * \li #NI_NAMEREQD 71 * A name is required. If the hostname cannot be found in the DNS 72 * and this flag is set, a non-zero error code is returned. If the 73 * hostname is not found and the flag is not set, the address is 74 * returned in numeric form. 75 * 76 * \li #NI_NUMERICSERV 77 * The service name is returned as a digit string representing the 78 * port number. 79 * 80 * \li #NI_DGRAM 81 * Specifies that the service being looked up is a datagram 82 * service, and causes getservbyport() to be called with a second 83 * argument of "udp" instead of its default of "tcp". This is 84 * required for the few ports (512-514) that have different 85 * services for UDP and TCP. 86 * 87 * \section getnameinfo_return Return Values 88 * 89 * getnameinfo() returns 0 on success or a non-zero error code if 90 * an error occurs. 91 * 92 * \section getname_see See Also 93 * 94 * RFC3493, getservbyport(), 95 * getnamebyaddr(). inet_ntop(). 96 */ 97 98#include <config.h> 99 100#include <stdio.h> 101#include <string.h> 102 103#include <isc/netaddr.h> 104#include <isc/print.h> 105#include <isc/sockaddr.h> 106#include <isc/util.h> 107 108#include <dns/byaddr.h> 109#include <dns/client.h> 110#include <dns/fixedname.h> 111#include <dns/name.h> 112#include <dns/rdata.h> 113#include <dns/rdataset.h> 114#include <dns/rdatastruct.h> 115#include <dns/result.h> 116 117#include <irs/context.h> 118#include <irs/netdb.h> 119 120#define SUCCESS 0 121 122/*% afd structure definition */ 123static struct afd { 124 int a_af; 125 size_t a_addrlen; 126 size_t a_socklen; 127} afdl [] = { 128 /*! 129 * First entry is linked last... 130 */ 131 { AF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in) }, 132 { AF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6) }, 133 {0, 0, 0}, 134}; 135 136/*! 137 * The test against 0 is there to keep the Solaris compiler 138 * from complaining about "end-of-loop code not reached". 139 */ 140#define ERR(code) \ 141 do { result = (code); \ 142 if (result != 0) goto cleanup; \ 143 } while (0) 144 145int 146getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, 147 IRS_GETNAMEINFO_BUFLEN_T hostlen, char *serv, 148 IRS_GETNAMEINFO_BUFLEN_T servlen, IRS_GETNAMEINFO_FLAGS_T flags) 149{ 150 struct afd *afd = NULL; 151 struct servent *sp; 152 unsigned short port = 0; 153#ifdef IRS_PLATFORM_HAVESALEN 154 size_t len; 155#endif 156 int family, i; 157 const void *addr = NULL; 158 char *p; 159#if 0 160 unsigned long v4a; 161 unsigned char pfx; 162#endif 163 char numserv[sizeof("65000")]; 164 char numaddr[sizeof("abcd:abcd:abcd:abcd:abcd:abcd:255.255.255.255") 165 + 1 + sizeof("4294967295")]; 166 const char *proto; 167 int result = SUCCESS; 168 169 if (sa == NULL) 170 ERR(EAI_FAIL); 171 172#ifdef IRS_PLATFORM_HAVESALEN 173 len = sa->sa_len; 174 if (len != salen) 175 ERR(EAI_FAIL); 176#endif 177 178 family = sa->sa_family; 179 for (i = 0; afdl[i].a_af; i++) 180 if (afdl[i].a_af == family) { 181 afd = &afdl[i]; 182 goto found; 183 } 184 ERR(EAI_FAMILY); 185 186 found: 187 if (salen != afd->a_socklen) 188 ERR(EAI_FAIL); 189 190 switch (family) { 191 case AF_INET: 192 port = ((const struct sockaddr_in *)sa)->sin_port; 193 addr = &((const struct sockaddr_in *)sa)->sin_addr.s_addr; 194 break; 195 196 case AF_INET6: 197 port = ((const struct sockaddr_in6 *)sa)->sin6_port; 198 addr = ((const struct sockaddr_in6 *)sa)->sin6_addr.s6_addr; 199 break; 200 201 default: 202 INSIST(0); 203 } 204 proto = (flags & NI_DGRAM) ? "udp" : "tcp"; 205 206 if (serv == NULL || servlen == 0U) { 207 /* 208 * Caller does not want service. 209 */ 210 } else if ((flags & NI_NUMERICSERV) != 0 || 211 (sp = getservbyport(port, proto)) == NULL) { 212 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 213 if ((strlen(numserv) + 1) > servlen) 214 ERR(EAI_OVERFLOW); 215 strcpy(serv, numserv); 216 } else { 217 if ((strlen(sp->s_name) + 1) > servlen) 218 ERR(EAI_OVERFLOW); 219 strcpy(serv, sp->s_name); 220 } 221 222#if 0 223 switch (sa->sa_family) { 224 case AF_INET: 225 v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr; 226 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 227 flags |= NI_NUMERICHOST; 228 v4a >>= IN_CLASSA_NSHIFT; 229 if (v4a == 0 || v4a == IN_LOOPBACKNET) 230 flags |= NI_NUMERICHOST; 231 break; 232 233 case AF_INET6: 234 pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0]; 235 if (pfx == 0 || pfx == 0xfe || pfx == 0xff) 236 flags |= NI_NUMERICHOST; 237 break; 238 } 239#endif 240 241 if (host == NULL || hostlen == 0U) { 242 /* 243 * do nothing in this case. 244 * in case you are wondering if "&&" is more correct than 245 * "||" here: RFC3493 says that host == NULL or hostlen == 0 246 * means that the caller does not want the result. 247 */ 248 } else if ((flags & NI_NUMERICHOST) != 0) { 249 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 250 == NULL) 251 ERR(EAI_SYSTEM); 252#if defined(IRS_HAVE_SIN6_SCOPE_ID) 253 if (afd->a_af == AF_INET6 && 254 ((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 255 char *p = numaddr + strlen(numaddr); 256 const char *stringscope = NULL; 257#ifdef VENDOR_SPECIFIC 258 /* 259 * Vendors may want to add support for 260 * non-numeric scope identifier. 261 */ 262 stringscope = foo; 263#endif 264 if (stringscope == NULL) { 265 snprintf(p, sizeof(numaddr) - (p - numaddr), 266 "%%%u", 267 ((const struct sockaddr_in6 *)sa)->sin6_scope_id); 268 } else { 269 snprintf(p, sizeof(numaddr) - (p - numaddr), 270 "%%%s", stringscope); 271 } 272 } 273#endif 274 if (strlen(numaddr) + 1 > hostlen) 275 ERR(EAI_OVERFLOW); 276 strcpy(host, numaddr); 277 } else { 278 isc_netaddr_t netaddr; 279 dns_fixedname_t ptrfname; 280 dns_name_t *ptrname; 281 irs_context_t *irsctx = NULL; 282 dns_client_t *client; 283 isc_boolean_t found = ISC_FALSE; 284 dns_namelist_t answerlist; 285 dns_rdataset_t *rdataset; 286 isc_region_t hostregion; 287 char hoststr[1024]; /* is this enough? */ 288 isc_result_t iresult; 289 290 /* Get IRS context and the associated DNS client object */ 291 iresult = irs_context_get(&irsctx); 292 if (iresult != ISC_R_SUCCESS) 293 ERR(EAI_FAIL); 294 client = irs_context_getdnsclient(irsctx); 295 296 /* Make query name */ 297 isc_netaddr_fromsockaddr(&netaddr, (const isc_sockaddr_t *)sa); 298 dns_fixedname_init(&ptrfname); 299 ptrname = dns_fixedname_name(&ptrfname); 300 iresult = dns_byaddr_createptrname2(&netaddr, 0, ptrname); 301 if (iresult != ISC_R_SUCCESS) 302 ERR(EAI_FAIL); 303 304 /* Get the PTR RRset */ 305 ISC_LIST_INIT(answerlist); 306 iresult = dns_client_resolve(client, ptrname, 307 dns_rdataclass_in, 308 dns_rdatatype_ptr, 309 DNS_CLIENTRESOPT_ALLOWRUN, 310 &answerlist); 311 switch (iresult) { 312 case ISC_R_SUCCESS: 313 /* 314 * a 'non-existent' error is not necessarily fatal for 315 * getnameinfo(). 316 */ 317 case DNS_R_NCACHENXDOMAIN: 318 case DNS_R_NCACHENXRRSET: 319 break; 320 case DNS_R_SIGINVALID: 321 case DNS_R_SIGEXPIRED: 322 case DNS_R_SIGFUTURE: 323 case DNS_R_KEYUNAUTHORIZED: 324 case DNS_R_MUSTBESECURE: 325 case DNS_R_COVERINGNSEC: 326 case DNS_R_NOTAUTHORITATIVE: 327 case DNS_R_NOVALIDKEY: 328 case DNS_R_NOVALIDDS: 329 case DNS_R_NOVALIDSIG: 330 ERR(EAI_INSECUREDATA); 331 break; 332 default: 333 ERR(EAI_FAIL); 334 } 335 336 /* Parse the answer for the hostname */ 337 for (ptrname = ISC_LIST_HEAD(answerlist); ptrname != NULL; 338 ptrname = ISC_LIST_NEXT(ptrname, link)) { 339 for (rdataset = ISC_LIST_HEAD(ptrname->list); 340 rdataset != NULL; 341 rdataset = ISC_LIST_NEXT(rdataset, link)) { 342 if (!dns_rdataset_isassociated(rdataset)) 343 continue; 344 if (rdataset->type != dns_rdatatype_ptr) 345 continue; 346 347 for (iresult = dns_rdataset_first(rdataset); 348 iresult == ISC_R_SUCCESS; 349 iresult = dns_rdataset_next(rdataset)) { 350 dns_rdata_t rdata; 351 dns_rdata_ptr_t rdata_ptr; 352 isc_buffer_t b; 353 354 dns_rdata_init(&rdata); 355 dns_rdataset_current(rdataset, &rdata); 356 dns_rdata_tostruct(&rdata, &rdata_ptr, 357 NULL); 358 359 isc_buffer_init(&b, hoststr, 360 sizeof(hoststr)); 361 iresult = 362 dns_name_totext(&rdata_ptr.ptr, 363 ISC_TRUE, &b); 364 dns_rdata_freestruct(&rdata_ptr); 365 if (iresult == ISC_R_SUCCESS) { 366 /* 367 * We ignore the rest of the 368 * answer. After all, 369 * getnameinfo() can return 370 * at most one hostname. 371 */ 372 found = ISC_TRUE; 373 isc_buffer_usedregion( 374 &b, &hostregion); 375 goto ptrfound; 376 } 377 378 } 379 } 380 } 381 ptrfound: 382 dns_client_freeresanswer(client, &answerlist); 383 if (found) { 384 if ((flags & NI_NOFQDN) != 0) { 385 p = strchr(hoststr, '.'); 386 if (p) 387 *p = '\0'; 388 } 389 if (hostregion.length + 1 > hostlen) 390 ERR(EAI_OVERFLOW); 391 snprintf(host, hostlen, "%.*s", 392 (int)hostregion.length, 393 (char *)hostregion.base); 394 } else { 395 if ((flags & NI_NAMEREQD) != 0) 396 ERR(EAI_NONAME); 397 if (inet_ntop(afd->a_af, addr, numaddr, 398 sizeof(numaddr)) == NULL) 399 ERR(EAI_SYSTEM); 400 if ((strlen(numaddr) + 1) > hostlen) 401 ERR(EAI_OVERFLOW); 402 strcpy(host, numaddr); 403 } 404 } 405 result = SUCCESS; 406 407 cleanup: 408 return (result); 409} 410