getnetnamadr.c revision 1.9
1 /* $NetBSD: getnetnamadr.c,v 1.9 1999/01/16 11:43:08 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. 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 1.9 1999/01/16 11:43:08 lukem 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 <ctype.h> 63 #include <errno.h> 64 #include <netdb.h> 65 #include <nsswitch.h> 66 #include <resolv.h> 67 #include <stdio.h> 68 #include <string.h> 69 70 #ifdef __weak_alias 71 __weak_alias(getnetbyaddr,_getnetbyaddr); 72 __weak_alias(getnetbyname,_getnetbyname); 73 #endif 74 75 extern int h_errno; 76 extern int _net_stayopen; 77 78 #if defined(mips) && defined(SYSTYPE_BSD43) 79 extern int errno; 80 #endif 81 82 int _getnetbyaddr __P((void *, void *, va_list)); 83 int _getnetbyname __P((void *, void *, va_list)); 84 int _dns_getnetbyaddr __P((void *, void *, va_list)); 85 int _dns_getnetbyname __P((void *, void *, va_list)); 86 87 #define BYADDR 0 88 #define BYNAME 1 89 #define MAXALIASES 35 90 91 #if PACKETSZ > 1024 92 #define MAXPACKET PACKETSZ 93 #else 94 #define MAXPACKET 1024 95 #endif 96 97 typedef union { 98 HEADER hdr; 99 u_char buf[MAXPACKET]; 100 } querybuf; 101 102 typedef union { 103 long al; 104 char ac; 105 } align; 106 107 static struct netent *getnetanswer __P((querybuf *, int, int)); 108 static struct netent * 109 getnetanswer(answer, anslen, net_i) 110 querybuf *answer; 111 int anslen; 112 int net_i; 113 { 114 115 HEADER *hp; 116 u_char *cp; 117 int n; 118 u_char *eom; 119 int type, class, buflen, ancount, qdcount, haveanswer, i, nchar; 120 char aux1[30], aux2[30], ans[30], *in, *st, *pauxt, *bp, **ap, 121 *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0; 122 static struct netent net_entry; 123 static char *net_aliases[MAXALIASES], netbuf[PACKETSZ]; 124 125 /* 126 * find first satisfactory answer 127 * 128 * answer --> +------------+ ( MESSAGE ) 129 * | Header | 130 * +------------+ 131 * | Question | the question for the name server 132 * +------------+ 133 * | Answer | RRs answering the question 134 * +------------+ 135 * | Authority | RRs pointing toward an authority 136 * | Additional | RRs holding additional information 137 * +------------+ 138 */ 139 eom = answer->buf + anslen; 140 hp = &answer->hdr; 141 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 142 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 143 bp = netbuf; 144 buflen = sizeof(netbuf); 145 cp = answer->buf + HFIXEDSZ; 146 if (!qdcount) { 147 if (hp->aa) 148 h_errno = HOST_NOT_FOUND; 149 else 150 h_errno = TRY_AGAIN; 151 return (NULL); 152 } 153 while (qdcount-- > 0) 154 cp += __dn_skipname(cp, eom) + QFIXEDSZ; 155 ap = net_aliases; 156 *ap = NULL; 157 net_entry.n_aliases = net_aliases; 158 haveanswer = 0; 159 while (--ancount >= 0 && cp < eom) { 160 n = dn_expand(answer->buf, eom, cp, bp, buflen); 161 if ((n < 0) || !res_dnok(bp)) 162 break; 163 cp += n; 164 ans[0] = '\0'; 165 (void)strcpy(&ans[0], bp); 166 GETSHORT(type, cp); 167 GETSHORT(class, cp); 168 cp += INT32SZ; /* TTL */ 169 GETSHORT(n, cp); 170 if (class == C_IN && type == T_PTR) { 171 n = dn_expand(answer->buf, eom, cp, bp, buflen); 172 if ((n < 0) || !res_hnok(bp)) { 173 cp += n; 174 return (NULL); 175 } 176 cp += n; 177 *ap++ = bp; 178 bp += strlen(bp) + 1; 179 net_entry.n_addrtype = 180 (class == C_IN) ? AF_INET : AF_UNSPEC; 181 haveanswer++; 182 } 183 } 184 if (haveanswer) { 185 *ap = NULL; 186 switch (net_i) { 187 case BYADDR: 188 net_entry.n_name = *net_entry.n_aliases; 189 net_entry.n_net = 0L; 190 break; 191 case BYNAME: 192 in = *net_entry.n_aliases; 193 net_entry.n_name = &ans[0]; 194 aux2[0] = '\0'; 195 for (i = 0; i < 4; i++) { 196 for (st = in, nchar = 0; 197 *st != '.'; 198 st++, nchar++) 199 ; 200 if (nchar != 1 || *in != '0' || flag) { 201 flag = 1; 202 (void)strncpy(paux1, 203 (i==0) ? in : in-1, 204 (size_t)((i==0) ? nchar : nchar+1)); 205 paux1[(i==0) ? nchar : nchar+1] = '\0'; 206 pauxt = paux2; 207 paux2 = strcat(paux1, paux2); 208 paux1 = pauxt; 209 } 210 in = ++st; 211 } 212 net_entry.n_net = inet_network(paux2); 213 break; 214 } 215 net_entry.n_aliases++; 216 return (&net_entry); 217 } 218 h_errno = TRY_AGAIN; 219 return (NULL); 220 } 221 222 int 223 _getnetbyaddr(rv, cb_data, ap) 224 void *rv; 225 void *cb_data; 226 va_list ap; 227 { 228 struct netent *p; 229 unsigned long net; 230 int type; 231 232 net = va_arg(ap, unsigned long); 233 type = va_arg(ap, int); 234 235 setnetent(_net_stayopen); 236 while ((p = getnetent()) != NULL) 237 if (p->n_addrtype == type && p->n_net == net) 238 break; 239 if (!_net_stayopen) 240 endnetent(); 241 *((struct netent **)rv) = p; 242 if (p==NULL) { 243 h_errno = HOST_NOT_FOUND; 244 return NS_NOTFOUND; 245 } 246 return NS_SUCCESS; 247 } 248 249 int 250 _dns_getnetbyaddr(rv, cb_data, ap) 251 void *rv; 252 void *cb_data; 253 va_list ap; 254 { 255 unsigned int netbr[4]; 256 int nn, anslen; 257 querybuf buf; 258 char qbuf[MAXDNAME]; 259 unsigned long net2; 260 struct netent *net_entry; 261 unsigned long net; 262 int type; 263 264 net = va_arg(ap, unsigned long); 265 type = va_arg(ap, int); 266 267 if (type != AF_INET) 268 return NS_UNAVAIL; 269 270 for (nn = 4, net2 = net; net2; net2 >>= 8) 271 netbr[--nn] = (unsigned int)(net2 & 0xff); 272 switch (nn) { 273 default: 274 return NS_UNAVAIL; 275 case 3: /* Class A */ 276 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]); 277 break; 278 case 2: /* Class B */ 279 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); 280 break; 281 case 1: /* Class C */ 282 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 283 netbr[1]); 284 break; 285 case 0: /* Class D - E */ 286 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 287 netbr[1], netbr[0]); 288 break; 289 } 290 anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)(void *)&buf, 291 sizeof(buf)); 292 if (anslen < 0) { 293 #ifdef DEBUG 294 if (_res.options & RES_DEBUG) 295 printf("res_query failed\n"); 296 #endif 297 return NS_NOTFOUND; 298 } 299 net_entry = getnetanswer(&buf, anslen, BYADDR); 300 if (net_entry) { 301 /* maybe net should be unsigned? */ 302 unsigned long u_net = net; 303 304 /* Strip trailing zeros */ 305 while ((u_net & 0xff) == 0 && u_net != 0) 306 u_net >>= 8; 307 net_entry->n_net = u_net; 308 } 309 *((struct netent **)rv) = net_entry; 310 if (net_entry == NULL) { 311 h_errno = HOST_NOT_FOUND; 312 return NS_NOTFOUND; 313 } 314 return NS_SUCCESS; 315 } 316 317 struct netent * 318 getnetbyaddr(net, net_type) 319 u_long net; 320 int net_type; 321 { 322 struct netent *net_entry; 323 static ns_dtab dtab[] = { 324 NS_FILES_CB(_getnetbyaddr, NULL), 325 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */ 326 { NULL, NULL, NULL } 327 }; 328 329 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 330 h_errno = NETDB_INTERNAL; 331 return (NULL); 332 } 333 334 net_entry = NULL; 335 if (nsdispatch(&net_entry, dtab, NSDB_NETWORKS, net, net_type) != 336 NS_SUCCESS) { 337 h_errno = NETDB_INTERNAL; 338 return (NULL); 339 } 340 return (net_entry); 341 } 342 343 int 344 _getnetbyname(rv, cb_data, ap) 345 void *rv; 346 void *cb_data; 347 va_list ap; 348 { 349 struct netent *p; 350 char **cp; 351 const char *name; 352 353 name = va_arg(ap, const char *); 354 setnetent(_net_stayopen); 355 while ((p = getnetent()) != NULL) { 356 if (strcasecmp(p->n_name, name) == 0) 357 break; 358 for (cp = p->n_aliases; *cp != 0; cp++) 359 if (strcasecmp(*cp, name) == 0) 360 goto found; 361 } 362 found: 363 if (!_net_stayopen) 364 endnetent(); 365 *((struct netent **)rv) = p; 366 if (p==NULL) { 367 h_errno = HOST_NOT_FOUND; 368 return NS_NOTFOUND; 369 } 370 return NS_SUCCESS; 371 } 372 373 int 374 _dns_getnetbyname(rv, cb_data, ap) 375 void *rv; 376 void *cb_data; 377 va_list ap; 378 { 379 int anslen; 380 querybuf buf; 381 char qbuf[MAXDNAME]; 382 struct netent *net_entry; 383 const char *net; 384 385 net = va_arg(ap, const char *); 386 strcpy(&qbuf[0], net); 387 anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)(void *)&buf, 388 sizeof(buf)); 389 if (anslen < 0) { 390 #ifdef DEBUG 391 if (_res.options & RES_DEBUG) 392 printf("res_query failed\n"); 393 #endif 394 return NS_NOTFOUND; 395 } 396 net_entry = getnetanswer(&buf, anslen, BYNAME); 397 398 *((struct netent **)rv) = net_entry; 399 if (net_entry == NULL) { 400 h_errno = HOST_NOT_FOUND; 401 return NS_NOTFOUND; 402 } 403 return NS_SUCCESS; 404 } 405 406 struct netent * 407 getnetbyname(net) 408 const char *net; 409 { 410 struct netent *net_entry; 411 static ns_dtab dtab[] = { 412 NS_FILES_CB(_getnetbyname, NULL), 413 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */ 414 { NULL, NULL, NULL } 415 }; 416 417 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 418 h_errno = NETDB_INTERNAL; 419 return (NULL); 420 } 421 422 net_entry = NULL; 423 if (nsdispatch(&net_entry, dtab, NSDB_NETWORKS, net) != NS_SUCCESS) { 424 h_errno = NETDB_INTERNAL; 425 return (NULL); 426 } 427 return (net_entry); 428 } 429
Indexes created Wed Sep 24 05:09:52 GMT 2025