getnetnamadr.c revision 1.19
1 /* $NetBSD: getnetnamadr.c,v 1.19 2000/01/22 22:19:14 mycroft 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 1.19 2000/01/22 22:19:14 mycroft 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 <stdio.h> 69 #include <stdlib.h> 70 #include <string.h> 71 72 #ifdef __STDC__ 73 #include <stdarg.h> 74 #else 75 #include <varargs.h> 76 #endif 77 78 #ifdef YP 79 #include <rpc/rpc.h> 80 #include <rpcsvc/yp_prot.h> 81 #include <rpcsvc/ypclnt.h> 82 #endif 83 84 #ifdef __weak_alias 85 __weak_alias(getnetbyaddr,_getnetbyaddr) 86 __weak_alias(getnetbyname,_getnetbyname) 87 #endif 88 89 extern int h_errno; 90 extern int _net_stayopen; 91 92 #define BYADDR 0 93 #define BYNAME 1 94 #define MAXALIASES 35 95 96 #if PACKETSZ > 1024 97 #define MAXPACKET PACKETSZ 98 #else 99 #define MAXPACKET 1024 100 #endif 101 102 typedef union { 103 HEADER hdr; 104 u_char buf[MAXPACKET]; 105 } querybuf; 106 107 typedef union { 108 long al; 109 char ac; 110 } align; 111 112 #ifdef YP 113 static char *__ypdomain; 114 static char *__ypcurrent; 115 static int __ypcurrentlen; 116 #endif 117 118 static struct netent net_entry; 119 static char *net_aliases[MAXALIASES]; 120 121 static struct netent *getnetanswer __P((querybuf *, int, int)); 122 int _files_getnetbyaddr __P((void *, void *, va_list)); 123 int _files_getnetbyname __P((void *, void *, va_list)); 124 int _dns_getnetbyaddr __P((void *, void *, va_list)); 125 int _dns_getnetbyname __P((void *, void *, va_list)); 126 #ifdef YP 127 int _yp_getnetbyaddr __P((void *, void *, va_list)); 128 int _yp_getnetbyname __P((void *, void *, va_list)); 129 struct netent *_ypnetent __P((char *)); 130 #endif 131 132 static struct netent * 133 getnetanswer(answer, anslen, net_i) 134 querybuf *answer; 135 int anslen; 136 int net_i; 137 { 138 HEADER *hp; 139 u_char *cp; 140 int n; 141 u_char *eom; 142 int type, class, buflen, ancount, qdcount, haveanswer, i, nchar; 143 char aux1[30], aux2[30], ans[30], *in, *st, *pauxt, *bp, **ap, 144 *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0; 145 static char netbuf[PACKETSZ]; 146 147 _DIAGASSERT(answer != NULL); 148 149 /* 150 * find first satisfactory answer 151 * 152 * answer --> +------------+ ( MESSAGE ) 153 * | Header | 154 * +------------+ 155 * | Question | the question for the name server 156 * +------------+ 157 * | Answer | RRs answering the question 158 * +------------+ 159 * | Authority | RRs pointing toward an authority 160 * | Additional | RRs holding additional information 161 * +------------+ 162 */ 163 eom = answer->buf + anslen; 164 hp = &answer->hdr; 165 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 166 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 167 bp = netbuf; 168 buflen = sizeof(netbuf); 169 cp = answer->buf + HFIXEDSZ; 170 if (!qdcount) { 171 if (hp->aa) 172 h_errno = HOST_NOT_FOUND; 173 else 174 h_errno = TRY_AGAIN; 175 return (NULL); 176 } 177 while (qdcount-- > 0) 178 cp += __dn_skipname(cp, eom) + QFIXEDSZ; 179 ap = net_aliases; 180 *ap = NULL; 181 net_entry.n_aliases = net_aliases; 182 haveanswer = 0; 183 while (--ancount >= 0 && cp < eom) { 184 n = dn_expand(answer->buf, eom, cp, bp, buflen); 185 if ((n < 0) || !res_dnok(bp)) 186 break; 187 cp += n; 188 ans[0] = '\0'; 189 (void)strcpy(&ans[0], bp); 190 GETSHORT(type, cp); 191 GETSHORT(class, cp); 192 cp += INT32SZ; /* TTL */ 193 GETSHORT(n, cp); 194 if (class == C_IN && type == T_PTR) { 195 n = dn_expand(answer->buf, eom, cp, bp, buflen); 196 if ((n < 0) || !res_hnok(bp)) { 197 cp += n; 198 return (NULL); 199 } 200 cp += n; 201 *ap++ = bp; 202 bp += strlen(bp) + 1; 203 net_entry.n_addrtype = 204 (class == C_IN) ? AF_INET : AF_UNSPEC; 205 haveanswer++; 206 } 207 } 208 if (haveanswer) { 209 *ap = NULL; 210 switch (net_i) { 211 case BYADDR: 212 net_entry.n_name = *net_entry.n_aliases; 213 net_entry.n_net = 0L; 214 break; 215 case BYNAME: 216 in = *net_entry.n_aliases; 217 net_entry.n_name = &ans[0]; 218 aux2[0] = '\0'; 219 for (i = 0; i < 4; i++) { 220 for (st = in, nchar = 0; 221 *st != '.'; 222 st++, nchar++) 223 ; 224 if (nchar != 1 || *in != '0' || flag) { 225 flag = 1; 226 (void)strncpy(paux1, 227 (i==0) ? in : in-1, 228 (size_t)((i==0) ? nchar : nchar+1)); 229 paux1[(i==0) ? nchar : nchar+1] = '\0'; 230 pauxt = paux2; 231 paux2 = strcat(paux1, paux2); 232 paux1 = pauxt; 233 } 234 in = ++st; 235 } 236 net_entry.n_net = inet_network(paux2); 237 break; 238 } 239 net_entry.n_aliases++; 240 return (&net_entry); 241 } 242 h_errno = TRY_AGAIN; 243 return (NULL); 244 } 245 246 /*ARGSUSED*/ 247 int 248 _files_getnetbyaddr(rv, cb_data, ap) 249 void *rv; 250 void *cb_data; 251 va_list ap; 252 { 253 struct netent *p; 254 unsigned long net; 255 int type; 256 257 _DIAGASSERT(rv != NULL); 258 259 net = va_arg(ap, unsigned long); 260 type = va_arg(ap, int); 261 262 setnetent(_net_stayopen); 263 while ((p = getnetent()) != NULL) 264 if (p->n_addrtype == type && p->n_net == net) 265 break; 266 if (!_net_stayopen) 267 endnetent(); 268 *((struct netent **)rv) = p; 269 if (p==NULL) { 270 h_errno = HOST_NOT_FOUND; 271 return NS_NOTFOUND; 272 } 273 return NS_SUCCESS; 274 } 275 276 /*ARGSUSED*/ 277 int 278 _dns_getnetbyaddr(rv, cb_data, ap) 279 void *rv; 280 void *cb_data; 281 va_list ap; 282 { 283 unsigned int netbr[4]; 284 int nn, anslen; 285 querybuf buf; 286 char qbuf[MAXDNAME]; 287 unsigned long net2; 288 struct netent *np; 289 unsigned long net; 290 int type; 291 292 _DIAGASSERT(rv != NULL); 293 294 net = va_arg(ap, unsigned long); 295 type = va_arg(ap, int); 296 297 if (type != AF_INET) 298 return NS_UNAVAIL; 299 300 for (nn = 4, net2 = net; net2; net2 >>= 8) 301 netbr[--nn] = (unsigned int)(net2 & 0xff); 302 switch (nn) { 303 default: 304 return NS_UNAVAIL; 305 case 3: /* Class A */ 306 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]); 307 break; 308 case 2: /* Class B */ 309 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); 310 break; 311 case 1: /* Class C */ 312 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 313 netbr[1]); 314 break; 315 case 0: /* Class D - E */ 316 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 317 netbr[1], netbr[0]); 318 break; 319 } 320 anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)(void *)&buf, 321 sizeof(buf)); 322 if (anslen < 0) { 323 #ifdef DEBUG 324 if (_res.options & RES_DEBUG) 325 printf("res_query failed\n"); 326 #endif 327 return NS_NOTFOUND; 328 } 329 np = getnetanswer(&buf, anslen, BYADDR); 330 if (np) { 331 /* maybe net should be unsigned? */ 332 unsigned long u_net = net; 333 334 /* Strip trailing zeros */ 335 while ((u_net & 0xff) == 0 && u_net != 0) 336 u_net >>= 8; 337 np->n_net = u_net; 338 } 339 *((struct netent **)rv) = np; 340 if (np == NULL) { 341 h_errno = HOST_NOT_FOUND; 342 return NS_NOTFOUND; 343 } 344 return NS_SUCCESS; 345 } 346 347 348 struct netent * 349 getnetbyaddr(net, net_type) 350 u_long net; 351 int net_type; 352 { 353 struct netent *np; 354 static const ns_dtab dtab[] = { 355 NS_FILES_CB(_files_getnetbyaddr, NULL) 356 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */ 357 NS_NIS_CB(_yp_getnetbyaddr, NULL) 358 { 0 } 359 }; 360 361 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 362 h_errno = NETDB_INTERNAL; 363 return (NULL); 364 } 365 366 np = NULL; 367 h_errno = NETDB_INTERNAL; 368 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyaddr", __nsdefaultsrc, 369 net, net_type) != NS_SUCCESS) 370 return (NULL); 371 h_errno = NETDB_SUCCESS; 372 return (np); 373 } 374 375 /*ARGSUSED*/ 376 int 377 _files_getnetbyname(rv, cb_data, ap) 378 void *rv; 379 void *cb_data; 380 va_list ap; 381 { 382 struct netent *p; 383 char **cp; 384 const char *name; 385 386 _DIAGASSERT(rv != NULL); 387 388 name = va_arg(ap, const char *); 389 setnetent(_net_stayopen); 390 while ((p = getnetent()) != NULL) { 391 if (strcasecmp(p->n_name, name) == 0) 392 break; 393 for (cp = p->n_aliases; *cp != 0; cp++) 394 if (strcasecmp(*cp, name) == 0) 395 goto found; 396 } 397 found: 398 if (!_net_stayopen) 399 endnetent(); 400 *((struct netent **)rv) = p; 401 if (p==NULL) { 402 h_errno = HOST_NOT_FOUND; 403 return NS_NOTFOUND; 404 } 405 return NS_SUCCESS; 406 } 407 408 /*ARGSUSED*/ 409 int 410 _dns_getnetbyname(rv, cb_data, ap) 411 void *rv; 412 void *cb_data; 413 va_list ap; 414 { 415 int anslen; 416 querybuf buf; 417 char qbuf[MAXDNAME]; 418 struct netent *np; 419 const char *net; 420 421 _DIAGASSERT(rv != NULL); 422 423 net = va_arg(ap, const char *); 424 strcpy(&qbuf[0], net); 425 anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)(void *)&buf, 426 sizeof(buf)); 427 if (anslen < 0) { 428 #ifdef DEBUG 429 if (_res.options & RES_DEBUG) 430 printf("res_query failed\n"); 431 #endif 432 return NS_NOTFOUND; 433 } 434 np = getnetanswer(&buf, anslen, BYNAME); 435 436 *((struct netent **)rv) = np; 437 if (np == NULL) { 438 h_errno = HOST_NOT_FOUND; 439 return NS_NOTFOUND; 440 } 441 return NS_SUCCESS; 442 } 443 444 struct netent * 445 getnetbyname(net) 446 const char *net; 447 { 448 struct netent *np; 449 static const ns_dtab dtab[] = { 450 NS_FILES_CB(_files_getnetbyname, NULL) 451 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */ 452 NS_NIS_CB(_yp_getnetbyname, NULL) 453 { 0 } 454 }; 455 456 _DIAGASSERT(net != NULL); 457 458 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 459 h_errno = NETDB_INTERNAL; 460 return (NULL); 461 } 462 463 np = NULL; 464 h_errno = NETDB_INTERNAL; 465 if (nsdispatch(&np, dtab, NSDB_NETWORKS, "getnetbyname", __nsdefaultsrc, 466 net) != NS_SUCCESS) 467 return (NULL); 468 h_errno = NETDB_SUCCESS; 469 return (np); 470 } 471 472 #ifdef YP 473 /*ARGSUSED*/ 474 int 475 _yp_getnetbyaddr(rv, cb_data, ap) 476 void *rv; 477 void *cb_data; 478 va_list ap; 479 { 480 struct netent *np; 481 char qbuf[MAXDNAME]; 482 unsigned int netbr[4]; 483 unsigned long net, net2; 484 int type, r; 485 486 _DIAGASSERT(rv != NULL); 487 488 net = va_arg(ap, unsigned long); 489 type = va_arg(ap, int); 490 491 if (type != AF_INET) 492 return NS_UNAVAIL; 493 494 if (!__ypdomain) { 495 if (_yp_check(&__ypdomain) == 0) 496 return NS_UNAVAIL; 497 } 498 np = NULL; 499 if (__ypcurrent) 500 free(__ypcurrent); 501 __ypcurrent = NULL; 502 for (r = 4, net2 = net; net2; net2 >>= 8) 503 netbr[--r] = (unsigned int)(net2 & 0xff); 504 switch (r) { 505 default: 506 return NS_UNAVAIL; 507 case 3: /* Class A */ 508 sprintf(qbuf, "%u", netbr[0]); 509 break; 510 case 2: /* Class B */ 511 sprintf(qbuf, "%u.%u", netbr[0], netbr[1]); 512 break; 513 case 1: /* Class C */ 514 sprintf(qbuf, "%u.%u.%u", netbr[0], netbr[1], netbr[2]); 515 break; 516 case 0: /* Class D - E */ 517 sprintf(qbuf, "%u.%u.%u.%u", netbr[0], netbr[1], netbr[2], 518 netbr[3]); 519 break; 520 } 521 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf), 522 &__ypcurrent, &__ypcurrentlen); 523 if (r == 0) 524 np = _ypnetent(__ypcurrent); 525 526 *((struct netent **)rv) = np; 527 if (np == NULL) { 528 h_errno = HOST_NOT_FOUND; 529 return NS_NOTFOUND; 530 } 531 return NS_SUCCESS; 532 533 } 534 535 int 536 /*ARGSUSED*/ 537 _yp_getnetbyname(rv, cb_data, ap) 538 void *rv; 539 void *cb_data; 540 va_list ap; 541 { 542 struct netent *np; 543 const char *name; 544 int r; 545 546 _DIAGASSERT(rv != NULL); 547 548 name = va_arg(ap, const char *); 549 550 if (!__ypdomain) { 551 if (_yp_check(&__ypdomain) == 0) 552 return NS_UNAVAIL; 553 } 554 np = NULL; 555 if (__ypcurrent) 556 free(__ypcurrent); 557 __ypcurrent = NULL; 558 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name), 559 &__ypcurrent, &__ypcurrentlen); 560 if (r == 0) 561 np = _ypnetent(__ypcurrent); 562 563 *((struct netent **)rv) = np; 564 if (np == NULL) { 565 h_errno = HOST_NOT_FOUND; 566 return NS_NOTFOUND; 567 } 568 return NS_SUCCESS; 569 } 570 571 struct netent * 572 _ypnetent(line) 573 char *line; 574 { 575 char *cp, *p, **q; 576 577 _DIAGASSERT(line != NULL); 578 579 net_entry.n_name = line; 580 cp = strpbrk(line, " \t"); 581 if (cp == NULL) 582 return (NULL); 583 *cp++ = '\0'; 584 while (*cp == ' ' || *cp == '\t') 585 cp++; 586 p = strpbrk(cp, " \t"); 587 if (p != NULL) 588 *p++ = '\0'; 589 net_entry.n_net = inet_network(cp); 590 net_entry.n_addrtype = AF_INET; 591 q = net_entry.n_aliases = net_aliases; 592 if (p != NULL) { 593 cp = p; 594 while (cp && *cp) { 595 if (*cp == ' ' || *cp == '\t') { 596 cp++; 597 continue; 598 } 599 if (q < &net_aliases[MAXALIASES - 1]) 600 *q++ = cp; 601 cp = strpbrk(cp, " \t"); 602 if (cp != NULL) 603 *cp++ = '\0'; 604 } 605 } 606 *q = NULL; 607 608 return (&net_entry); 609 } 610 #endif 611
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