getnetnamadr.c revision 1.39
1 /* $NetBSD: getnetnamadr.c,v 1.39 2008/05/08 12:26:55 lukem 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 1.39 2008/05/08 12:26:55 lukem 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 extern int _net_stayopen; 81 82 #define BYADDR 0 83 #define BYNAME 1 84 #define MAXALIASES 35 85 86 #define MAXPACKET (64*1024) 87 88 typedef union { 89 HEADER hdr; 90 u_char buf[MAXPACKET]; 91 } querybuf; 92 93 typedef union { 94 long al; 95 char ac; 96 } align; 97 98 #ifdef YP 99 static char *__ypdomain; 100 static char *__ypcurrent; 101 static int __ypcurrentlen; 102 #endif 103 104 static struct netent net_entry; 105 static char *net_aliases[MAXALIASES]; 106 107 static struct netent *getnetanswer(querybuf *, int, int); 108 int _files_getnetbyaddr(void *, void *, va_list); 109 int _files_getnetbyname(void *, void *, va_list); 110 int _dns_getnetbyaddr(void *, void *, va_list); 111 int _dns_getnetbyname(void *, void *, va_list); 112 #ifdef YP 113 int _yp_getnetbyaddr(void *, void *, va_list); 114 int _yp_getnetbyname(void *, void *, va_list); 115 struct netent *_ypnetent(char *); 116 #endif 117 118 /* 119 * parse_reversed_addr -- 120 * parse str, which should be of the form 'd.c.b.a.IN-ADDR.ARPA' 121 * (a PTR as per RFC 1101) and convert into an in_addr_t of the 122 * address 'a.b.c.d'. 123 * returns 0 on success (storing in *result), or -1 on error. 124 */ 125 static int 126 parse_reversed_addr(const char *str, in_addr_t *result) 127 { 128 unsigned long octet[4]; 129 const char *sp; 130 char *ep; 131 int octidx; 132 133 sp = str; 134 /* find the four octets 'd.b.c.a.' */ 135 for (octidx = 0; octidx < 4; octidx++) { 136 /* ensure it's a number */ 137 if (!isdigit((unsigned char)*sp)) 138 return -1; 139 octet[octidx] = strtoul(sp, &ep, 10); 140 /* with a trailing '.' */ 141 if (*ep != '.') 142 return -1; 143 /* and is 0 <= octet <= 255 */ 144 if (octet[octidx] > 255) 145 return -1; 146 sp = ep + 1; 147 } 148 /* ensure trailer is correct */ 149 if (strcasecmp(sp, "IN-ADDR.ARPA") != 0) 150 return -1; 151 *result = 0; 152 /* build result from octets in reverse */ 153 for (octidx = 3; octidx >= 0; octidx--) { 154 *result <<= 8; 155 *result |= (octet[octidx] & 0xff); 156 } 157 return 0; 158 } 159 160 static struct netent * 161 getnetanswer(querybuf *answer, int anslen, int net_i) 162 { 163 HEADER *hp; 164 u_char *cp; 165 int n; 166 u_char *eom; 167 int type, class, ancount, qdcount, haveanswer; 168 char *in, *bp, **ap, *ep; 169 static char n_name[MAXDNAME]; 170 static char netbuf[PACKETSZ]; 171 172 _DIAGASSERT(answer != NULL); 173 174 /* 175 * find first satisfactory answer 176 * 177 * answer --> +------------+ ( MESSAGE ) 178 * | Header | 179 * +------------+ 180 * | Question | the question for the name server 181 * +------------+ 182 * | Answer | RRs answering the question 183 * +------------+ 184 * | Authority | RRs pointing toward an authority 185 * | Additional | RRs holding additional information 186 * +------------+ 187 */ 188 eom = answer->buf + anslen; 189 hp = &answer->hdr; 190 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 191 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 192 bp = netbuf; 193 ep = netbuf + sizeof(netbuf); 194 cp = answer->buf + HFIXEDSZ; 195 if (!qdcount) { 196 if (hp->aa) 197 h_errno = HOST_NOT_FOUND; 198 else 199 h_errno = TRY_AGAIN; 200 return NULL; 201 } 202 while (qdcount-- > 0) { 203 n = __dn_skipname(cp, eom); 204 if (n < 0 || (cp + n + QFIXEDSZ) > eom) { 205 h_errno = NO_RECOVERY; 206 return(NULL); 207 } 208 cp += n + QFIXEDSZ; 209 } 210 ap = net_aliases; 211 *ap = NULL; 212 net_entry.n_aliases = net_aliases; 213 haveanswer = 0; 214 n_name[0] = '\0'; 215 while (--ancount >= 0 && cp < eom) { 216 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 217 if ((n < 0) || !res_dnok(bp)) 218 break; 219 cp += n; 220 (void)strlcpy(n_name, bp, sizeof(n_name)); 221 GETSHORT(type, cp); 222 GETSHORT(class, cp); 223 cp += INT32SZ; /* TTL */ 224 GETSHORT(n, cp); 225 if (class == C_IN && type == T_PTR) { 226 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 227 if ((n < 0) || !res_hnok(bp)) { 228 cp += n; 229 return NULL; 230 } 231 cp += n; 232 *ap++ = bp; 233 bp += strlen(bp) + 1; 234 net_entry.n_addrtype = 235 (class == C_IN) ? AF_INET : AF_UNSPEC; 236 haveanswer++; 237 } 238 } 239 if (haveanswer) { 240 *ap = NULL; 241 switch (net_i) { 242 case BYADDR: 243 net_entry.n_name = *net_entry.n_aliases; 244 net_entry.n_net = 0L; 245 break; 246 case BYNAME: 247 ap = net_entry.n_aliases; 248 next_alias: 249 in = *ap++; 250 if (in == NULL) { 251 h_errno = HOST_NOT_FOUND; 252 return NULL; 253 } 254 net_entry.n_name = n_name; 255 if (parse_reversed_addr(in, &net_entry.n_net) == -1) 256 goto next_alias; 257 break; 258 } 259 net_entry.n_aliases++; 260 #if (defined(__sparc__) && defined(_LP64)) || \ 261 defined(__alpha__) || \ 262 (defined(__i386__) && defined(_LP64)) || \ 263 (defined(__sh__) && defined(_LP64)) 264 net_entry.__n_pad0 = 0; 265 #endif 266 return &net_entry; 267 } 268 h_errno = TRY_AGAIN; 269 return NULL; 270 } 271 272 /*ARGSUSED*/ 273 int 274 _files_getnetbyaddr(void *rv, void *cb_data, va_list ap) 275 { 276 struct netent *p; 277 uint32_t net; 278 int type; 279 280 _DIAGASSERT(rv != NULL); 281 282 net = va_arg(ap, uint32_t); 283 type = va_arg(ap, int); 284 285 setnetent(_net_stayopen); 286 while ((p = getnetent()) != NULL) 287 if (p->n_addrtype == type && p->n_net == net) 288 break; 289 if (!_net_stayopen) 290 endnetent(); 291 *((struct netent **)rv) = p; 292 if (p==NULL) { 293 h_errno = HOST_NOT_FOUND; 294 return NS_NOTFOUND; 295 } 296 return NS_SUCCESS; 297 } 298 299 /*ARGSUSED*/ 300 int 301 _dns_getnetbyaddr(void *rv, void *cb_data, va_list ap) 302 { 303 unsigned int netbr[4]; 304 int nn, anslen; 305 querybuf *buf; 306 char qbuf[MAXDNAME]; 307 uint32_t net2; 308 struct netent *np; 309 uint32_t net; 310 int type; 311 res_state res; 312 313 _DIAGASSERT(rv != NULL); 314 315 net = va_arg(ap, uint32_t); 316 type = va_arg(ap, int); 317 318 if (type != AF_INET) 319 return NS_UNAVAIL; 320 321 for (nn = 4, net2 = net; net2; net2 >>= 8) 322 netbr[--nn] = (unsigned int)(net2 & 0xff); 323 switch (nn) { 324 default: 325 return NS_UNAVAIL; 326 case 3: /* Class A */ 327 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]); 328 break; 329 case 2: /* Class B */ 330 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa", 331 netbr[3], netbr[2]); 332 break; 333 case 1: /* Class C */ 334 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa", 335 netbr[3], netbr[2], netbr[1]); 336 break; 337 case 0: /* Class D - E */ 338 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", 339 netbr[3], netbr[2], netbr[1], netbr[0]); 340 break; 341 } 342 buf = malloc(sizeof(*buf)); 343 if (buf == NULL) { 344 h_errno = NETDB_INTERNAL; 345 return NS_NOTFOUND; 346 } 347 res = __res_get_state(); 348 if (res == NULL) 349 return NS_NOTFOUND; 350 anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); 351 if (anslen < 0) { 352 free(buf); 353 #ifdef DEBUG 354 if (res->options & RES_DEBUG) 355 printf("res_query failed\n"); 356 #endif 357 __res_put_state(res); 358 return NS_NOTFOUND; 359 } 360 __res_put_state(res); 361 np = getnetanswer(buf, anslen, BYADDR); 362 free(buf); 363 if (np) { 364 /* maybe net should be unsigned? */ 365 uint32_t u_net = net; 366 367 /* Strip trailing zeros */ 368 while ((u_net & 0xff) == 0 && u_net != 0) 369 u_net >>= 8; 370 np->n_net = u_net; 371 } 372 *((struct netent **)rv) = np; 373 if (np == NULL) { 374 h_errno = HOST_NOT_FOUND; 375 return NS_NOTFOUND; 376 } 377 return NS_SUCCESS; 378 } 379 380 381 struct netent * 382 getnetbyaddr(uint32_t net, int net_type) 383 { 384 struct netent *np; 385 static const ns_dtab dtab[] = { 386 NS_FILES_CB(_files_getnetbyaddr, NULL) 387 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */ 388 NS_NIS_CB(_yp_getnetbyaddr, NULL) 389 NS_NULL_CB 390 }; 391 392 np = NULL; 393 h_errno = NETDB_INTERNAL; 394 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyaddr", __nsdefaultsrc, 395 net, net_type) != NS_SUCCESS) 396 return NULL; 397 h_errno = NETDB_SUCCESS; 398 return np; 399 } 400 401 /*ARGSUSED*/ 402 int 403 _files_getnetbyname(void *rv, void *cb_data, va_list ap) 404 { 405 struct netent *p; 406 char **cp; 407 const char *name; 408 409 _DIAGASSERT(rv != NULL); 410 411 name = va_arg(ap, const char *); 412 setnetent(_net_stayopen); 413 while ((p = getnetent()) != NULL) { 414 if (strcasecmp(p->n_name, name) == 0) 415 break; 416 for (cp = p->n_aliases; *cp != 0; cp++) 417 if (strcasecmp(*cp, name) == 0) 418 goto found; 419 } 420 found: 421 if (!_net_stayopen) 422 endnetent(); 423 *((struct netent **)rv) = p; 424 if (p==NULL) { 425 h_errno = HOST_NOT_FOUND; 426 return NS_NOTFOUND; 427 } 428 return NS_SUCCESS; 429 } 430 431 /*ARGSUSED*/ 432 int 433 _dns_getnetbyname(void *rv, void *cb_data, va_list ap) 434 { 435 int anslen; 436 querybuf *buf; 437 char qbuf[MAXDNAME]; 438 struct netent *np; 439 const char *net; 440 res_state res; 441 442 _DIAGASSERT(rv != NULL); 443 444 net = va_arg(ap, const char *); 445 strlcpy(&qbuf[0], net, sizeof(qbuf)); 446 buf = malloc(sizeof(*buf)); 447 if (buf == NULL) { 448 h_errno = NETDB_INTERNAL; 449 return NS_NOTFOUND; 450 } 451 res = __res_get_state(); 452 if (res == NULL) { 453 free(buf); 454 return NS_NOTFOUND; 455 } 456 anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf, 457 sizeof(buf->buf)); 458 if (anslen < 0) { 459 free(buf); 460 #ifdef DEBUG 461 if (res->options & RES_DEBUG) 462 printf("res_search failed\n"); 463 #endif 464 __res_put_state(res); 465 return NS_NOTFOUND; 466 } 467 __res_put_state(res); 468 np = getnetanswer(buf, anslen, BYNAME); 469 free(buf); 470 *((struct netent **)rv) = np; 471 if (np == NULL) { 472 h_errno = HOST_NOT_FOUND; 473 return NS_NOTFOUND; 474 } 475 return NS_SUCCESS; 476 } 477 478 struct netent * 479 getnetbyname(const char *net) 480 { 481 struct netent *np; 482 static const ns_dtab dtab[] = { 483 NS_FILES_CB(_files_getnetbyname, NULL) 484 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */ 485 NS_NIS_CB(_yp_getnetbyname, NULL) 486 NS_NULL_CB 487 }; 488 489 _DIAGASSERT(net != NULL); 490 491 np = NULL; 492 h_errno = NETDB_INTERNAL; 493 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyname", __nsdefaultsrc, 494 net) != NS_SUCCESS) 495 return NULL; 496 h_errno = NETDB_SUCCESS; 497 return np; 498 } 499 500 #ifdef YP 501 /*ARGSUSED*/ 502 int 503 _yp_getnetbyaddr(void *rv, void *cb_data, va_list ap) 504 { 505 struct netent *np; 506 char qbuf[MAXDNAME]; 507 unsigned int netbr[4]; 508 uint32_t net, net2; 509 int type, r; 510 511 _DIAGASSERT(rv != NULL); 512 513 net = va_arg(ap, uint32_t); 514 type = va_arg(ap, int); 515 516 if (type != AF_INET) 517 return NS_UNAVAIL; 518 519 if (!__ypdomain) { 520 if (_yp_check(&__ypdomain) == 0) 521 return NS_UNAVAIL; 522 } 523 np = NULL; 524 if (__ypcurrent) 525 free(__ypcurrent); 526 __ypcurrent = NULL; 527 for (r = 4, net2 = net; net2; net2 >>= 8) 528 netbr[--r] = (unsigned int)(net2 & 0xff); 529 switch (r) { 530 default: 531 return NS_UNAVAIL; 532 case 3: /* Class A */ 533 snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]); 534 break; 535 case 2: /* Class B */ 536 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]); 537 break; 538 case 1: /* Class C */ 539 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2], 540 netbr[3]); 541 break; 542 case 0: /* Class D - E */ 543 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1], 544 netbr[2], netbr[3]); 545 break; 546 } 547 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf), 548 &__ypcurrent, &__ypcurrentlen); 549 if (r == 0) 550 np = _ypnetent(__ypcurrent); 551 552 *((struct netent **)rv) = np; 553 if (np == NULL) { 554 h_errno = HOST_NOT_FOUND; 555 return NS_NOTFOUND; 556 } 557 return NS_SUCCESS; 558 559 } 560 561 int 562 /*ARGSUSED*/ 563 _yp_getnetbyname(void *rv, void *cb_data, va_list ap) 564 { 565 struct netent *np; 566 const char *name; 567 int r; 568 569 _DIAGASSERT(rv != NULL); 570 571 name = va_arg(ap, const char *); 572 573 if (!__ypdomain) { 574 if (_yp_check(&__ypdomain) == 0) 575 return NS_UNAVAIL; 576 } 577 np = NULL; 578 if (__ypcurrent) 579 free(__ypcurrent); 580 __ypcurrent = NULL; 581 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name), 582 &__ypcurrent, &__ypcurrentlen); 583 if (r == 0) 584 np = _ypnetent(__ypcurrent); 585 586 *((struct netent **)rv) = np; 587 if (np == NULL) { 588 h_errno = HOST_NOT_FOUND; 589 return NS_NOTFOUND; 590 } 591 return NS_SUCCESS; 592 } 593 594 struct netent * 595 _ypnetent(char *line) 596 { 597 char *cp, *p, **q; 598 599 _DIAGASSERT(line != NULL); 600 601 net_entry.n_name = line; 602 cp = strpbrk(line, " \t"); 603 if (cp == NULL) 604 return NULL; 605 *cp++ = '\0'; 606 while (*cp == ' ' || *cp == '\t') 607 cp++; 608 p = strpbrk(cp, " \t"); 609 if (p != NULL) 610 *p++ = '\0'; 611 net_entry.n_net = inet_network(cp); 612 #if (defined(__sparc__) && defined(_LP64)) || \ 613 defined(__alpha__) || \ 614 (defined(__i386__) && defined(_LP64)) || \ 615 (defined(__sh__) && defined(_LP64)) 616 net_entry.__n_pad0 = 0; 617 #endif 618 net_entry.n_addrtype = AF_INET; 619 q = net_entry.n_aliases = net_aliases; 620 if (p != NULL) { 621 cp = p; 622 while (cp && *cp) { 623 if (*cp == ' ' || *cp == '\t') { 624 cp++; 625 continue; 626 } 627 if (q < &net_aliases[MAXALIASES - 1]) 628 *q++ = cp; 629 cp = strpbrk(cp, " \t"); 630 if (cp != NULL) 631 *cp++ = '\0'; 632 } 633 } 634 *q = NULL; 635 636 return &net_entry; 637 } 638 #endif 639
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