1 /* $NetBSD: getnetnamadr.c,v 1.26 2002/11/14 02:14:43 itojun 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. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 */ 42 43 #include <sys/cdefs.h> 44 #if defined(LIBC_SCCS) && !defined(lint) 45 #if 0 46 static char sccsid[] = "@(#)getnetbyaddr.c 8.1 (Berkeley) 6/4/93"; 47 static char sccsid_[] = "from getnetnamadr.c 1.4 (Coimbra) 93/06/03"; 48 static char rcsid[] = "Id: getnetnamadr.c,v 8.8 1997/06/01 20:34:37 vixie Exp "; 49 #else 50 __RCSID("$NetBSD: getnetnamadr.c,v 1.26 2002/11/14 02:14:43 itojun Exp $"); 51 #endif 52 #endif /* LIBC_SCCS and not lint */ 53 54 #include "namespace.h" 55 #include <sys/types.h> 56 #include <sys/param.h> 57 #include <sys/socket.h> 58 #include <netinet/in.h> 59 #include <arpa/inet.h> 60 #include <arpa/nameser.h> 61 62 #include <assert.h> 63 #include <ctype.h> 64 #include <errno.h> 65 #include <netdb.h> 66 #include <nsswitch.h> 67 #include <resolv.h> 68 #include <stdarg.h> 69 #include <stdio.h> 70 #include <stdlib.h> 71 #include <string.h> 72 73 #ifdef YP 74 #include <rpc/rpc.h> 75 #include <rpcsvc/yp_prot.h> 76 #include <rpcsvc/ypclnt.h> 77 #endif 78 79 #ifdef __weak_alias 80 __weak_alias(getnetbyaddr,_getnetbyaddr) 81 __weak_alias(getnetbyname,_getnetbyname) 82 #endif 83 84 extern int _net_stayopen; 85 86 #define BYADDR 0 87 #define BYNAME 1 88 #define MAXALIASES 35 89 90 #define MAXPACKET (64*1024) 91 92 typedef union { 93 HEADER hdr; 94 u_char buf[MAXPACKET]; 95 } querybuf; 96 97 typedef union { 98 long al; 99 char ac; 100 } align; 101 102 #ifdef YP 103 static char *__ypdomain; 104 static char *__ypcurrent; 105 static int __ypcurrentlen; 106 #endif 107 108 static struct netent net_entry; 109 static char *net_aliases[MAXALIASES]; 110 111 static struct netent *getnetanswer __P((querybuf *, int, int)); 112 int _files_getnetbyaddr __P((void *, void *, va_list)); 113 int _files_getnetbyname __P((void *, void *, va_list)); 114 int _dns_getnetbyaddr __P((void *, void *, va_list)); 115 int _dns_getnetbyname __P((void *, void *, va_list)); 116 #ifdef YP 117 int _yp_getnetbyaddr __P((void *, void *, va_list)); 118 int _yp_getnetbyname __P((void *, void *, va_list)); 119 struct netent *_ypnetent __P((char *)); 120 #endif 121 122 static struct netent * 123 getnetanswer(answer, anslen, net_i) 124 querybuf *answer; 125 int anslen; 126 int net_i; 127 { 128 HEADER *hp; 129 u_char *cp; 130 int n; 131 u_char *eom; 132 int type, class, ancount, qdcount, haveanswer, i, nchar; 133 char aux1[MAXDNAME], aux2[MAXDNAME], ans[MAXDNAME]; 134 char *in, *st, *pauxt, *bp, **ap; 135 char *paux1 = &aux1[0], *paux2 = &aux2[0], *ep; 136 static char netbuf[PACKETSZ]; 137 138 _DIAGASSERT(answer != NULL); 139 140 /* 141 * find first satisfactory answer 142 * 143 * answer --> +------------+ ( MESSAGE ) 144 * | Header | 145 * +------------+ 146 * | Question | the question for the name server 147 * +------------+ 148 * | Answer | RRs answering the question 149 * +------------+ 150 * | Authority | RRs pointing toward an authority 151 * | Additional | RRs holding additional information 152 * +------------+ 153 */ 154 eom = answer->buf + anslen; 155 hp = &answer->hdr; 156 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 157 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 158 bp = netbuf; 159 ep = netbuf + sizeof(netbuf); 160 cp = answer->buf + HFIXEDSZ; 161 if (!qdcount) { 162 if (hp->aa) 163 h_errno = HOST_NOT_FOUND; 164 else 165 h_errno = TRY_AGAIN; 166 return (NULL); 167 } 168 while (qdcount-- > 0) { 169 n = __dn_skipname(cp, eom); 170 if (n < 0 || (cp + n + QFIXEDSZ) > eom) { 171 h_errno = NO_RECOVERY; 172 return(NULL); 173 } 174 cp += n + QFIXEDSZ; 175 } 176 ap = net_aliases; 177 *ap = NULL; 178 net_entry.n_aliases = net_aliases; 179 haveanswer = 0; 180 while (--ancount >= 0 && cp < eom) { 181 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 182 if ((n < 0) || !res_dnok(bp)) 183 break; 184 cp += n; 185 ans[0] = '\0'; 186 (void)strlcpy(ans, bp, sizeof(ans)); 187 GETSHORT(type, cp); 188 GETSHORT(class, cp); 189 cp += INT32SZ; /* TTL */ 190 GETSHORT(n, cp); 191 if (class == C_IN && type == T_PTR) { 192 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 193 if ((n < 0) || !res_hnok(bp)) { 194 cp += n; 195 return (NULL); 196 } 197 cp += n; 198 *ap++ = bp; 199 bp += strlen(bp) + 1; 200 net_entry.n_addrtype = 201 (class == C_IN) ? AF_INET : AF_UNSPEC; 202 haveanswer++; 203 } 204 } 205 if (haveanswer) { 206 *ap = NULL; 207 switch (net_i) { 208 case BYADDR: 209 net_entry.n_name = *net_entry.n_aliases; 210 net_entry.n_net = 0L; 211 break; 212 case BYNAME: 213 ap = net_entry.n_aliases; 214 next_alias: 215 in = *ap++; 216 if (in == NULL) { 217 h_errno = HOST_NOT_FOUND; 218 return (NULL); 219 } 220 net_entry.n_name = ans; 221 aux2[0] = '\0'; 222 for (i = 0; i < 4; i++) { 223 for (st = in, nchar = 0; 224 isdigit((unsigned char)*st); 225 st++, nchar++) 226 ; 227 if (*st != '.' || nchar == 0 || nchar > 3) 228 goto next_alias; 229 if (i != 0) 230 nchar++; 231 (void)strlcpy(paux1, in, (size_t)nchar); 232 paux1[nchar] = '\0'; 233 pauxt = paux2; 234 paux2 = strcat(paux1, paux2); 235 paux1 = pauxt; 236 in = ++st; 237 } 238 net_entry.n_net = inet_network(paux2); 239 break; 240 } 241 if (strcasecmp(in, "IN-ADDR.ARPA") != 0) 242 goto next_alias; 243 net_entry.n_aliases++; 244 return (&net_entry); 245 } 246 h_errno = TRY_AGAIN; 247 return (NULL); 248 } 249 250 /*ARGSUSED*/ 251 int 252 _files_getnetbyaddr(rv, cb_data, ap) 253 void *rv; 254 void *cb_data; 255 va_list ap; 256 { 257 struct netent *p; 258 unsigned long net; 259 int type; 260 261 _DIAGASSERT(rv != NULL); 262 263 net = va_arg(ap, unsigned long); 264 type = va_arg(ap, int); 265 266 setnetent(_net_stayopen); 267 while ((p = getnetent()) != NULL) 268 if (p->n_addrtype == type && p->n_net == net) 269 break; 270 if (!_net_stayopen) 271 endnetent(); 272 *((struct netent **)rv) = p; 273 if (p==NULL) { 274 h_errno = HOST_NOT_FOUND; 275 return NS_NOTFOUND; 276 } 277 return NS_SUCCESS; 278 } 279 280 /*ARGSUSED*/ 281 int 282 _dns_getnetbyaddr(rv, cb_data, ap) 283 void *rv; 284 void *cb_data; 285 va_list ap; 286 { 287 unsigned int netbr[4]; 288 int nn, anslen; 289 querybuf *buf; 290 char qbuf[MAXDNAME]; 291 unsigned long net2; 292 struct netent *np; 293 unsigned long net; 294 int type; 295 296 _DIAGASSERT(rv != NULL); 297 298 net = va_arg(ap, unsigned long); 299 type = va_arg(ap, int); 300 301 if (type != AF_INET) 302 return NS_UNAVAIL; 303 304 for (nn = 4, net2 = net; net2; net2 >>= 8) 305 netbr[--nn] = (unsigned int)(net2 & 0xff); 306 switch (nn) { 307 default: 308 return NS_UNAVAIL; 309 case 3: /* Class A */ 310 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]); 311 break; 312 case 2: /* Class B */ 313 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa", 314 netbr[3], netbr[2]); 315 break; 316 case 1: /* Class C */ 317 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa", 318 netbr[3], netbr[2], netbr[1]); 319 break; 320 case 0: /* Class D - E */ 321 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", 322 netbr[3], netbr[2], netbr[1], netbr[0]); 323 break; 324 } 325 buf = malloc(sizeof(*buf)); 326 if (buf == NULL) { 327 h_errno = NETDB_INTERNAL; 328 return NS_NOTFOUND; 329 } 330 anslen = res_query(qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); 331 if (anslen < 0) { 332 free(buf); 333 #ifdef DEBUG 334 if (_res.options & RES_DEBUG) 335 printf("res_query failed\n"); 336 #endif 337 return NS_NOTFOUND; 338 } 339 np = getnetanswer(buf, anslen, BYADDR); 340 free(buf); 341 if (np) { 342 /* maybe net should be unsigned? */ 343 unsigned long u_net = net; 344 345 /* Strip trailing zeros */ 346 while ((u_net & 0xff) == 0 && u_net != 0) 347 u_net >>= 8; 348 np->n_net = u_net; 349 } 350 *((struct netent **)rv) = np; 351 if (np == NULL) { 352 h_errno = HOST_NOT_FOUND; 353 return NS_NOTFOUND; 354 } 355 return NS_SUCCESS; 356 } 357 358 359 struct netent * 360 getnetbyaddr(net, net_type) 361 u_long net; 362 int net_type; 363 { 364 struct netent *np; 365 static const ns_dtab dtab[] = { 366 NS_FILES_CB(_files_getnetbyaddr, NULL) 367 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */ 368 NS_NIS_CB(_yp_getnetbyaddr, NULL) 369 { 0 } 370 }; 371 372 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 373 h_errno = NETDB_INTERNAL; 374 return (NULL); 375 } 376 377 np = NULL; 378 h_errno = NETDB_INTERNAL; 379 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyaddr", __nsdefaultsrc, 380 net, net_type) != NS_SUCCESS) 381 return (NULL); 382 h_errno = NETDB_SUCCESS; 383 return (np); 384 } 385 386 /*ARGSUSED*/ 387 int 388 _files_getnetbyname(rv, cb_data, ap) 389 void *rv; 390 void *cb_data; 391 va_list ap; 392 { 393 struct netent *p; 394 char **cp; 395 const char *name; 396 397 _DIAGASSERT(rv != NULL); 398 399 name = va_arg(ap, const char *); 400 setnetent(_net_stayopen); 401 while ((p = getnetent()) != NULL) { 402 if (strcasecmp(p->n_name, name) == 0) 403 break; 404 for (cp = p->n_aliases; *cp != 0; cp++) 405 if (strcasecmp(*cp, name) == 0) 406 goto found; 407 } 408 found: 409 if (!_net_stayopen) 410 endnetent(); 411 *((struct netent **)rv) = p; 412 if (p==NULL) { 413 h_errno = HOST_NOT_FOUND; 414 return NS_NOTFOUND; 415 } 416 return NS_SUCCESS; 417 } 418 419 /*ARGSUSED*/ 420 int 421 _dns_getnetbyname(rv, cb_data, ap) 422 void *rv; 423 void *cb_data; 424 va_list ap; 425 { 426 int anslen; 427 querybuf *buf; 428 char qbuf[MAXDNAME]; 429 struct netent *np; 430 const char *net; 431 432 _DIAGASSERT(rv != NULL); 433 434 net = va_arg(ap, const char *); 435 strlcpy(&qbuf[0], net, sizeof(qbuf)); 436 buf = malloc(sizeof(*buf)); 437 if (buf == NULL) { 438 h_errno = NETDB_INTERNAL; 439 return NS_NOTFOUND; 440 } 441 anslen = res_search(qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); 442 if (anslen < 0) { 443 free(buf); 444 #ifdef DEBUG 445 if (_res.options & RES_DEBUG) 446 printf("res_search failed\n"); 447 #endif 448 return NS_NOTFOUND; 449 } 450 np = getnetanswer(buf, anslen, BYNAME); 451 free(buf); 452 *((struct netent **)rv) = np; 453 if (np == NULL) { 454 h_errno = HOST_NOT_FOUND; 455 return NS_NOTFOUND; 456 } 457 return NS_SUCCESS; 458 } 459 460 struct netent * 461 getnetbyname(net) 462 const char *net; 463 { 464 struct netent *np; 465 static const ns_dtab dtab[] = { 466 NS_FILES_CB(_files_getnetbyname, NULL) 467 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */ 468 NS_NIS_CB(_yp_getnetbyname, NULL) 469 { 0 } 470 }; 471 472 _DIAGASSERT(net != NULL); 473 474 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 475 h_errno = NETDB_INTERNAL; 476 return (NULL); 477 } 478 479 np = NULL; 480 h_errno = NETDB_INTERNAL; 481 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyname", __nsdefaultsrc, 482 net) != NS_SUCCESS) 483 return (NULL); 484 h_errno = NETDB_SUCCESS; 485 return (np); 486 } 487 488 #ifdef YP 489 /*ARGSUSED*/ 490 int 491 _yp_getnetbyaddr(rv, cb_data, ap) 492 void *rv; 493 void *cb_data; 494 va_list ap; 495 { 496 struct netent *np; 497 char qbuf[MAXDNAME]; 498 unsigned int netbr[4]; 499 unsigned long net, net2; 500 int type, r; 501 502 _DIAGASSERT(rv != NULL); 503 504 net = va_arg(ap, unsigned long); 505 type = va_arg(ap, int); 506 507 if (type != AF_INET) 508 return NS_UNAVAIL; 509 510 if (!__ypdomain) { 511 if (_yp_check(&__ypdomain) == 0) 512 return NS_UNAVAIL; 513 } 514 np = NULL; 515 if (__ypcurrent) 516 free(__ypcurrent); 517 __ypcurrent = NULL; 518 for (r = 4, net2 = net; net2; net2 >>= 8) 519 netbr[--r] = (unsigned int)(net2 & 0xff); 520 switch (r) { 521 default: 522 return NS_UNAVAIL; 523 case 3: /* Class A */ 524 snprintf(qbuf, sizeof(qbuf), "%u", netbr[0]); 525 break; 526 case 2: /* Class B */ 527 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[0], netbr[1]); 528 break; 529 case 1: /* Class C */ 530 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[0], netbr[1], 531 netbr[2]); 532 break; 533 case 0: /* Class D - E */ 534 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1], 535 netbr[2], netbr[3]); 536 break; 537 } 538 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf), 539 &__ypcurrent, &__ypcurrentlen); 540 if (r == 0) 541 np = _ypnetent(__ypcurrent); 542 543 *((struct netent **)rv) = np; 544 if (np == NULL) { 545 h_errno = HOST_NOT_FOUND; 546 return NS_NOTFOUND; 547 } 548 return NS_SUCCESS; 549 550 } 551 552 int 553 /*ARGSUSED*/ 554 _yp_getnetbyname(rv, cb_data, ap) 555 void *rv; 556 void *cb_data; 557 va_list ap; 558 { 559 struct netent *np; 560 const char *name; 561 int r; 562 563 _DIAGASSERT(rv != NULL); 564 565 name = va_arg(ap, const char *); 566 567 if (!__ypdomain) { 568 if (_yp_check(&__ypdomain) == 0) 569 return NS_UNAVAIL; 570 } 571 np = NULL; 572 if (__ypcurrent) 573 free(__ypcurrent); 574 __ypcurrent = NULL; 575 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name), 576 &__ypcurrent, &__ypcurrentlen); 577 if (r == 0) 578 np = _ypnetent(__ypcurrent); 579 580 *((struct netent **)rv) = np; 581 if (np == NULL) { 582 h_errno = HOST_NOT_FOUND; 583 return NS_NOTFOUND; 584 } 585 return NS_SUCCESS; 586 } 587 588 struct netent * 589 _ypnetent(line) 590 char *line; 591 { 592 char *cp, *p, **q; 593 594 _DIAGASSERT(line != NULL); 595 596 net_entry.n_name = line; 597 cp = strpbrk(line, " \t"); 598 if (cp == NULL) 599 return (NULL); 600 *cp++ = '\0'; 601 while (*cp == ' ' || *cp == '\t') 602 cp++; 603 p = strpbrk(cp, " \t"); 604 if (p != NULL) 605 *p++ = '\0'; 606 net_entry.n_net = inet_network(cp); 607 net_entry.n_addrtype = AF_INET; 608 q = net_entry.n_aliases = net_aliases; 609 if (p != NULL) { 610 cp = p; 611 while (cp && *cp) { 612 if (*cp == ' ' || *cp == '\t') { 613 cp++; 614 continue; 615 } 616 if (q < &net_aliases[MAXALIASES - 1]) 617 *q++ = cp; 618 cp = strpbrk(cp, " \t"); 619 if (cp != NULL) 620 *cp++ = '\0'; 621 } 622 } 623 *q = NULL; 624 625 return (&net_entry); 626 } 627 #endif 628