getnetnamadr.c revision 1.41.22.1
1 /* $NetBSD: getnetnamadr.c,v 1.41.22.1 2015/11/17 09:25:03 bouyer Exp $ */ 2 3 /* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro 4 * Dep. Matematica Universidade de Coimbra, Portugal, Europe 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 */ 10 /* 11 * Copyright (c) 1983, 1993 12 * The Regents of the University of California. All rights reserved. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)getnetbyaddr.c 8.1 (Berkeley) 6/4/93"; 43 static char sccsid_[] = "from getnetnamadr.c 1.4 (Coimbra) 93/06/03"; 44 static char rcsid[] = "Id: getnetnamadr.c,v 8.8 1997/06/01 20:34:37 vixie Exp "; 45 #else 46 __RCSID("$NetBSD: getnetnamadr.c,v 1.41.22.1 2015/11/17 09:25:03 bouyer Exp $"); 47 #endif 48 #endif /* LIBC_SCCS and not lint */ 49 50 #include "namespace.h" 51 #include <sys/types.h> 52 #include <sys/param.h> 53 #include <sys/socket.h> 54 #include <netinet/in.h> 55 #include <arpa/inet.h> 56 #include <arpa/nameser.h> 57 58 #include <assert.h> 59 #include <ctype.h> 60 #include <errno.h> 61 #include <netdb.h> 62 #include <nsswitch.h> 63 #include <resolv.h> 64 #include <stdarg.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 69 #ifdef YP 70 #include <rpc/rpc.h> 71 #include <rpcsvc/yp_prot.h> 72 #include <rpcsvc/ypclnt.h> 73 #endif 74 75 #ifdef __weak_alias 76 __weak_alias(getnetbyaddr,_getnetbyaddr) 77 __weak_alias(getnetbyname,_getnetbyname) 78 #endif 79 80 #define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \ 81 (ok)(nm) != 0) 82 #define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok) 83 #define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok) 84 85 86 extern int _net_stayopen; 87 88 #define BYADDR 0 89 #define BYNAME 1 90 #define MAXALIASES 35 91 92 #define MAXPACKET (64*1024) 93 94 typedef union { 95 HEADER hdr; 96 u_char buf[MAXPACKET]; 97 } querybuf; 98 99 typedef union { 100 long al; 101 char ac; 102 } align; 103 104 #ifdef YP 105 static char *__ypdomain; 106 static char *__ypcurrent; 107 static int __ypcurrentlen; 108 #endif 109 110 static struct netent net_entry; 111 static char *net_aliases[MAXALIASES]; 112 113 static int parse_reversed_addr(const char *, in_addr_t *); 114 static struct netent *getnetanswer(res_state, querybuf *, int, int); 115 static int _files_getnetbyaddr(void *, void *, va_list); 116 static int _files_getnetbyname(void *, void *, va_list); 117 static int _dns_getnetbyaddr(void *, void *, va_list); 118 static int _dns_getnetbyname(void *, void *, va_list); 119 #ifdef YP 120 static int _yp_getnetbyaddr(void *, void *, va_list); 121 static int _yp_getnetbyname(void *, void *, va_list); 122 static struct netent *_ypnetent(char *); 123 #endif 124 125 /* 126 * parse_reversed_addr -- 127 * parse str, which should be of the form 'd.c.b.a.IN-ADDR.ARPA' 128 * (a PTR as per RFC 1101) and convert into an in_addr_t of the 129 * address 'a.b.c.d'. 130 * returns 0 on success (storing in *result), or -1 on error. 131 */ 132 static int 133 parse_reversed_addr(const char *str, in_addr_t *result) 134 { 135 unsigned long octet[4]; 136 const char *sp; 137 char *ep; 138 int octidx; 139 140 sp = str; 141 /* find the four octets 'd.b.c.a.' */ 142 for (octidx = 0; octidx < 4; octidx++) { 143 /* ensure it's a number */ 144 if (!isdigit((unsigned char)*sp)) 145 return -1; 146 octet[octidx] = strtoul(sp, &ep, 10); 147 /* with a trailing '.' */ 148 if (*ep != '.') 149 return -1; 150 /* and is 0 <= octet <= 255 */ 151 if (octet[octidx] > 255) 152 return -1; 153 sp = ep + 1; 154 } 155 /* ensure trailer is correct */ 156 if (strcasecmp(sp, "IN-ADDR.ARPA") != 0) 157 return -1; 158 *result = 0; 159 /* build result from octets in reverse */ 160 for (octidx = 3; octidx >= 0; octidx--) { 161 *result <<= 8; 162 *result |= (octet[octidx] & 0xff); 163 } 164 return 0; 165 } 166 167 static struct netent * 168 getnetanswer(res_state res, querybuf *answer, int anslen, int net_i) 169 { 170 static char n_name[MAXDNAME]; 171 static char netbuf[PACKETSZ]; 172 173 HEADER *hp; 174 u_char *cp; 175 int n; 176 u_char *eom; 177 int type, class, ancount, qdcount, haveanswer; 178 char *in, *bp, **ap, *ep; 179 180 _DIAGASSERT(answer != NULL); 181 _DIAGASSERT(res != NULL); 182 183 /* 184 * find first satisfactory answer 185 * 186 * answer --> +------------+ ( MESSAGE ) 187 * | Header | 188 * +------------+ 189 * | Question | the question for the name server 190 * +------------+ 191 * | Answer | RRs answering the question 192 * +------------+ 193 * | Authority | RRs pointing toward an authority 194 * | Additional | RRs holding additional information 195 * +------------+ 196 */ 197 eom = answer->buf + anslen; 198 hp = &answer->hdr; 199 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 200 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 201 bp = netbuf; 202 ep = netbuf + sizeof(netbuf); 203 cp = answer->buf + HFIXEDSZ; 204 if (!qdcount) { 205 if (hp->aa) 206 h_errno = HOST_NOT_FOUND; 207 else 208 h_errno = TRY_AGAIN; 209 return NULL; 210 } 211 while (qdcount-- > 0) { 212 n = __dn_skipname(cp, eom); 213 if (n < 0 || (cp + n + QFIXEDSZ) > eom) { 214 h_errno = NO_RECOVERY; 215 return(NULL); 216 } 217 cp += n + QFIXEDSZ; 218 } 219 ap = net_aliases; 220 *ap = NULL; 221 net_entry.n_aliases = net_aliases; 222 haveanswer = 0; 223 n_name[0] = '\0'; 224 while (--ancount >= 0 && cp < eom) { 225 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 226 if ((n < 0) || !maybe_dnok(res, bp)) 227 break; 228 cp += n; 229 (void)strlcpy(n_name, bp, sizeof(n_name)); 230 GETSHORT(type, cp); 231 GETSHORT(class, cp); 232 cp += INT32SZ; /* TTL */ 233 GETSHORT(n, cp); 234 if (class == C_IN && type == T_PTR) { 235 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 236 if ((n < 0) || !maybe_hnok(res, bp)) { 237 cp += n; 238 return NULL; 239 } 240 cp += n; 241 *ap++ = bp; 242 bp += strlen(bp) + 1; 243 net_entry.n_addrtype = 244 (class == C_IN) ? AF_INET : AF_UNSPEC; 245 haveanswer++; 246 } 247 } 248 if (haveanswer) { 249 *ap = NULL; 250 switch (net_i) { 251 case BYADDR: 252 net_entry.n_name = *net_entry.n_aliases; 253 net_entry.n_net = 0L; 254 break; 255 case BYNAME: 256 ap = net_entry.n_aliases; 257 next_alias: 258 in = *ap++; 259 if (in == NULL) { 260 h_errno = HOST_NOT_FOUND; 261 return NULL; 262 } 263 net_entry.n_name = n_name; 264 if (parse_reversed_addr(in, &net_entry.n_net) == -1) 265 goto next_alias; 266 break; 267 } 268 net_entry.n_aliases++; 269 #if (defined(__sparc__) && defined(_LP64)) || \ 270 defined(__alpha__) || \ 271 (defined(__i386__) && defined(_LP64)) || \ 272 (defined(__sh__) && defined(_LP64)) 273 net_entry.__n_pad0 = 0; 274 #endif 275 return &net_entry; 276 } 277 h_errno = TRY_AGAIN; 278 return NULL; 279 } 280 281 /*ARGSUSED*/ 282 static int 283 _files_getnetbyaddr(void *cbrv, void *cbdata, va_list ap) 284 { 285 struct netent **retval = va_arg(ap, struct netent **); 286 uint32_t net = va_arg(ap, uint32_t); 287 int type = va_arg(ap, int); 288 289 struct netent *np; 290 291 setnetent(_net_stayopen); 292 while ((np = getnetent()) != NULL) 293 if (np->n_addrtype == type && np->n_net == net) 294 break; 295 if (!_net_stayopen) 296 endnetent(); 297 298 if (np != NULL) { 299 *retval = np; 300 return NS_SUCCESS; 301 } else { 302 h_errno = HOST_NOT_FOUND; 303 return NS_NOTFOUND; 304 } 305 } 306 307 /*ARGSUSED*/ 308 static int 309 _dns_getnetbyaddr(void *cbrv, void *cbdata, va_list ap) 310 { 311 struct netent **retval = va_arg(ap, struct netent **); 312 uint32_t net = va_arg(ap, uint32_t); 313 int type = va_arg(ap, int); 314 315 unsigned int netbr[4]; 316 int nn, anslen; 317 querybuf *buf; 318 char qbuf[MAXDNAME]; 319 uint32_t net2; 320 struct netent *np; 321 res_state res; 322 323 if (type != AF_INET) 324 return NS_UNAVAIL; 325 326 for (nn = 4, net2 = net; net2; net2 >>= 8) 327 netbr[--nn] = (unsigned int)(net2 & 0xff); 328 switch (nn) { 329 default: 330 return NS_UNAVAIL; 331 case 3: /* Class A */ 332 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]); 333 break; 334 case 2: /* Class B */ 335 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa", 336 netbr[3], netbr[2]); 337 break; 338 case 1: /* Class C */ 339 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa", 340 netbr[3], netbr[2], netbr[1]); 341 break; 342 case 0: /* Class D - E */ 343 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", 344 netbr[3], netbr[2], netbr[1], netbr[0]); 345 break; 346 } 347 buf = malloc(sizeof(*buf)); 348 if (buf == NULL) { 349 h_errno = NETDB_INTERNAL; 350 return NS_NOTFOUND; 351 } 352 res = __res_get_state(); 353 if (res == NULL) { 354 free(buf); 355 return NS_NOTFOUND; 356 } 357 anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); 358 if (anslen < 0) { 359 free(buf); 360 #ifdef DEBUG 361 if (res->options & RES_DEBUG) 362 printf("res_query failed\n"); 363 #endif 364 __res_put_state(res); 365 return NS_NOTFOUND; 366 } 367 np = getnetanswer(res, buf, anslen, BYADDR); 368 __res_put_state(res); 369 free(buf); 370 if (np) { 371 /* maybe net should be unsigned? */ 372 uint32_t u_net = net; 373 374 /* Strip trailing zeros */ 375 while ((u_net & 0xff) == 0 && u_net != 0) 376 u_net >>= 8; 377 np->n_net = u_net; 378 } 379 380 if (np != NULL) { 381 *retval = np; 382 return NS_SUCCESS; 383 } else { 384 h_errno = HOST_NOT_FOUND; 385 return NS_NOTFOUND; 386 } 387 } 388 389 struct netent * 390 getnetbyaddr(uint32_t net, int net_type) 391 { 392 int rv; 393 struct netent *retval; 394 395 static const ns_dtab dtab[] = { 396 NS_FILES_CB(_files_getnetbyaddr, NULL) 397 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */ 398 NS_NIS_CB(_yp_getnetbyaddr, NULL) 399 NS_NULL_CB 400 }; 401 402 retval = NULL; 403 h_errno = NETDB_INTERNAL; 404 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyaddr", 405 __nsdefaultsrc, &retval, net, net_type); 406 if (rv == NS_SUCCESS) { 407 h_errno = NETDB_SUCCESS; 408 return retval; 409 } 410 return NULL; 411 } 412 413 /*ARGSUSED*/ 414 static int 415 _files_getnetbyname(void *cbrv, void *cbdata, va_list ap) 416 { 417 struct netent **retval = va_arg(ap, struct netent **); 418 const char *name = va_arg(ap, const char *); 419 420 struct netent *np; 421 char **cp; 422 423 setnetent(_net_stayopen); 424 while ((np = getnetent()) != NULL) { 425 if (strcasecmp(np->n_name, name) == 0) 426 break; 427 for (cp = np->n_aliases; *cp != 0; cp++) 428 if (strcasecmp(*cp, name) == 0) 429 goto found; 430 } 431 found: 432 if (!_net_stayopen) 433 endnetent(); 434 435 if (np != NULL) { 436 *retval = np; 437 return NS_SUCCESS; 438 } else { 439 h_errno = HOST_NOT_FOUND; 440 return NS_NOTFOUND; 441 } 442 } 443 444 /*ARGSUSED*/ 445 static int 446 _dns_getnetbyname(void *cbrv, void *cbdata, va_list ap) 447 { 448 struct netent **retval = va_arg(ap, struct netent **); 449 const char *name = va_arg(ap, const char *); 450 451 int anslen; 452 querybuf *buf; 453 char qbuf[MAXDNAME]; 454 struct netent *np; 455 res_state res; 456 457 strlcpy(&qbuf[0], name, sizeof(qbuf)); 458 buf = malloc(sizeof(*buf)); 459 if (buf == NULL) { 460 h_errno = NETDB_INTERNAL; 461 return NS_NOTFOUND; 462 } 463 res = __res_get_state(); 464 if (res == NULL) { 465 free(buf); 466 return NS_NOTFOUND; 467 } 468 anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf, 469 sizeof(buf->buf)); 470 if (anslen < 0) { 471 free(buf); 472 #ifdef DEBUG 473 if (res->options & RES_DEBUG) 474 printf("res_search failed\n"); 475 #endif 476 __res_put_state(res); 477 return NS_NOTFOUND; 478 } 479 np = getnetanswer(res, buf, anslen, BYNAME); 480 __res_put_state(res); 481 free(buf); 482 483 if (np != NULL) { 484 *retval = np; 485 return NS_SUCCESS; 486 } else { 487 h_errno = HOST_NOT_FOUND; 488 return NS_NOTFOUND; 489 } 490 } 491 492 struct netent * 493 getnetbyname(const char *name) 494 { 495 int rv; 496 struct netent *retval; 497 498 static const ns_dtab dtab[] = { 499 NS_FILES_CB(_files_getnetbyname, NULL) 500 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */ 501 NS_NIS_CB(_yp_getnetbyname, NULL) 502 NS_NULL_CB 503 }; 504 505 _DIAGASSERT(name != NULL); 506 507 retval = NULL; 508 h_errno = NETDB_INTERNAL; 509 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyname", 510 __nsdefaultsrc, &retval, name); 511 if (rv == NS_SUCCESS) { 512 h_errno = NETDB_SUCCESS; 513 return retval; 514 } 515 return NULL; 516 } 517 518 #ifdef YP 519 /*ARGSUSED*/ 520 static int 521 _yp_getnetbyaddr(void *cbrv, void *cb_data, va_list ap) 522 { 523 struct netent **retval = va_arg(ap, struct netent **); 524 uint32_t net = va_arg(ap, uint32_t); 525 int type = va_arg(ap, int); 526 527 struct netent *np; 528 char qbuf[MAXDNAME]; 529 unsigned int netbr[4]; 530 uint32_t net2; 531 int r; 532 533 if (type != AF_INET) 534 return NS_UNAVAIL; 535 536 if (!__ypdomain) { 537 if (_yp_check(&__ypdomain) == 0) 538 return NS_UNAVAIL; 539 } 540 np = NULL; 541 if (__ypcurrent) 542 free(__ypcurrent); 543 __ypcurrent = NULL; 544 for (r = 4, net2 = net; net2; net2 >>= 8) 545 netbr[--r] = (unsigned int)(net2 & 0xff); 546 switch (r) { 547 default: 548 return NS_UNAVAIL; 549 case 3: /* Class A */ 550 snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]); 551 break; 552 case 2: /* Class B */ 553 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]); 554 break; 555 case 1: /* Class C */ 556 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2], 557 netbr[3]); 558 break; 559 case 0: /* Class D - E */ 560 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1], 561 netbr[2], netbr[3]); 562 break; 563 } 564 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf), 565 &__ypcurrent, &__ypcurrentlen); 566 if (r == 0) 567 np = _ypnetent(__ypcurrent); 568 569 if (np != NULL) { 570 *retval = np; 571 return NS_SUCCESS; 572 } else { 573 h_errno = HOST_NOT_FOUND; 574 return NS_NOTFOUND; 575 } 576 } 577 578 /*ARGSUSED*/ 579 static int 580 _yp_getnetbyname(void *cbrv, void *cbdata, va_list ap) 581 { 582 struct netent **retval = va_arg(ap, struct netent **); 583 const char *name = va_arg(ap, const char *); 584 585 struct netent *np; 586 int r; 587 588 if (!__ypdomain) { 589 if (_yp_check(&__ypdomain) == 0) 590 return NS_UNAVAIL; 591 } 592 np = NULL; 593 if (__ypcurrent) 594 free(__ypcurrent); 595 __ypcurrent = NULL; 596 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name), 597 &__ypcurrent, &__ypcurrentlen); 598 if (r == 0) 599 np = _ypnetent(__ypcurrent); 600 601 if (np != NULL) { 602 *retval = np; 603 return NS_SUCCESS; 604 } else { 605 h_errno = HOST_NOT_FOUND; 606 return NS_NOTFOUND; 607 } 608 } 609 610 static struct netent * 611 _ypnetent(char *line) 612 { 613 char *cp, *p, **q; 614 615 _DIAGASSERT(line != NULL); 616 617 net_entry.n_name = line; 618 cp = strpbrk(line, " \t"); 619 if (cp == NULL) 620 return NULL; 621 *cp++ = '\0'; 622 while (*cp == ' ' || *cp == '\t') 623 cp++; 624 p = strpbrk(cp, " \t"); 625 if (p != NULL) 626 *p++ = '\0'; 627 net_entry.n_net = inet_network(cp); 628 #if (defined(__sparc__) && defined(_LP64)) || \ 629 defined(__alpha__) || \ 630 (defined(__i386__) && defined(_LP64)) || \ 631 (defined(__sh__) && defined(_LP64)) 632 net_entry.__n_pad0 = 0; 633 #endif 634 net_entry.n_addrtype = AF_INET; 635 q = net_entry.n_aliases = net_aliases; 636 if (p != NULL) { 637 cp = p; 638 while (cp && *cp) { 639 if (*cp == ' ' || *cp == '\t') { 640 cp++; 641 continue; 642 } 643 if (q < &net_aliases[MAXALIASES - 1]) 644 *q++ = cp; 645 cp = strpbrk(cp, " \t"); 646 if (cp != NULL) 647 *cp++ = '\0'; 648 } 649 } 650 *q = NULL; 651 652 return &net_entry; 653 } 654 #endif 655
Indexes created Tue Sep 30 17:09:57 GMT 2025