1 /* $NetBSD: getnetnamadr.c,v 1.42 2012/03/13 21:13:41 christos 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 1.42 2012/03/13 21:13:41 christos 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 int parse_reversed_addr(const char *, in_addr_t *);
108 static struct netent *getnetanswer(querybuf *, int, int);
109 static int _files_getnetbyaddr(void *, void *, va_list);
110 static int _files_getnetbyname(void *, void *, va_list);
111 static int _dns_getnetbyaddr(void *, void *, va_list);
112 static int _dns_getnetbyname(void *, void *, va_list);
113 #ifdef YP
114 static int _yp_getnetbyaddr(void *, void *, va_list);
115 static int _yp_getnetbyname(void *, void *, va_list);
116 static struct netent *_ypnetent(char *);
117 #endif
118
119 /*
120 * parse_reversed_addr --
121 * parse str, which should be of the form 'd.c.b.a.IN-ADDR.ARPA'
122 * (a PTR as per RFC 1101) and convert into an in_addr_t of the
123 * address 'a.b.c.d'.
124 * returns 0 on success (storing in *result), or -1 on error.
125 */
126 static int
parse_reversed_addr(const char * str,in_addr_t * result)127 parse_reversed_addr(const char *str, in_addr_t *result)
128 {
129 unsigned long octet[4];
130 const char *sp;
131 char *ep;
132 int octidx;
133
134 sp = str;
135 /* find the four octets 'd.b.c.a.' */
136 for (octidx = 0; octidx < 4; octidx++) {
137 /* ensure it's a number */
138 if (!isdigit((unsigned char)*sp))
139 return -1;
140 octet[octidx] = strtoul(sp, &ep, 10);
141 /* with a trailing '.' */
142 if (*ep != '.')
143 return -1;
144 /* and is 0 <= octet <= 255 */
145 if (octet[octidx] > 255)
146 return -1;
147 sp = ep + 1;
148 }
149 /* ensure trailer is correct */
150 if (strcasecmp(sp, "IN-ADDR.ARPA") != 0)
151 return -1;
152 *result = 0;
153 /* build result from octets in reverse */
154 for (octidx = 3; octidx >= 0; octidx--) {
155 *result <<= 8;
156 *result |= (in_addr_t)(octet[octidx] & 0xff);
157 }
158 return 0;
159 }
160
161 static struct netent *
getnetanswer(querybuf * answer,int anslen,int net_i)162 getnetanswer(querybuf *answer, int anslen, int net_i)
163 {
164 static char n_name[MAXDNAME];
165 static char netbuf[PACKETSZ];
166
167 HEADER *hp;
168 u_char *cp;
169 int n;
170 u_char *eom;
171 int type, class, ancount, qdcount, haveanswer;
172 char *in, *bp, **ap, *ep;
173
174 _DIAGASSERT(answer != NULL);
175
176 /*
177 * find first satisfactory answer
178 *
179 * answer --> +------------+ ( MESSAGE )
180 * | Header |
181 * +------------+
182 * | Question | the question for the name server
183 * +------------+
184 * | Answer | RRs answering the question
185 * +------------+
186 * | Authority | RRs pointing toward an authority
187 * | Additional | RRs holding additional information
188 * +------------+
189 */
190 eom = answer->buf + anslen;
191 hp = &answer->hdr;
192 ancount = ntohs(hp->ancount); /* #/records in the answer section */
193 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
194 bp = netbuf;
195 ep = netbuf + sizeof(netbuf);
196 cp = answer->buf + HFIXEDSZ;
197 if (!qdcount) {
198 if (hp->aa)
199 h_errno = HOST_NOT_FOUND;
200 else
201 h_errno = TRY_AGAIN;
202 return NULL;
203 }
204 while (qdcount-- > 0) {
205 n = __dn_skipname(cp, eom);
206 if (n < 0 || (cp + n + QFIXEDSZ) > eom) {
207 h_errno = NO_RECOVERY;
208 return(NULL);
209 }
210 cp += n + QFIXEDSZ;
211 }
212 ap = net_aliases;
213 *ap = NULL;
214 net_entry.n_aliases = net_aliases;
215 haveanswer = 0;
216 n_name[0] = '\0';
217 while (--ancount >= 0 && cp < eom) {
218 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
219 if ((n < 0) || !res_dnok(bp))
220 break;
221 cp += n;
222 (void)strlcpy(n_name, bp, sizeof(n_name));
223 GETSHORT(type, cp);
224 GETSHORT(class, cp);
225 cp += INT32SZ; /* TTL */
226 GETSHORT(n, cp);
227 if (class == C_IN && type == T_PTR) {
228 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
229 if ((n < 0) || !res_hnok(bp)) {
230 cp += n;
231 return NULL;
232 }
233 cp += n;
234 *ap++ = bp;
235 bp += strlen(bp) + 1;
236 net_entry.n_addrtype =
237 (class == C_IN) ? AF_INET : AF_UNSPEC;
238 haveanswer++;
239 }
240 }
241 if (haveanswer) {
242 *ap = NULL;
243 switch (net_i) {
244 case BYADDR:
245 net_entry.n_name = *net_entry.n_aliases;
246 net_entry.n_net = 0L;
247 break;
248 case BYNAME:
249 ap = net_entry.n_aliases;
250 next_alias:
251 in = *ap++;
252 if (in == NULL) {
253 h_errno = HOST_NOT_FOUND;
254 return NULL;
255 }
256 net_entry.n_name = n_name;
257 if (parse_reversed_addr(in, &net_entry.n_net) == -1)
258 goto next_alias;
259 break;
260 }
261 net_entry.n_aliases++;
262 #if (defined(__sparc__) && defined(_LP64)) || \
263 defined(__alpha__) || \
264 (defined(__i386__) && defined(_LP64)) || \
265 (defined(__sh__) && defined(_LP64))
266 net_entry.__n_pad0 = 0;
267 #endif
268 return &net_entry;
269 }
270 h_errno = TRY_AGAIN;
271 return NULL;
272 }
273
274 /*ARGSUSED*/
275 static int
_files_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)276 _files_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
277 {
278 struct netent **retval = va_arg(ap, struct netent **);
279 uint32_t net = va_arg(ap, uint32_t);
280 int type = va_arg(ap, int);
281
282 struct netent *np;
283
284 setnetent(_net_stayopen);
285 while ((np = getnetent()) != NULL)
286 if (np->n_addrtype == type && np->n_net == net)
287 break;
288 if (!_net_stayopen)
289 endnetent();
290
291 if (np != NULL) {
292 *retval = np;
293 return NS_SUCCESS;
294 } else {
295 h_errno = HOST_NOT_FOUND;
296 return NS_NOTFOUND;
297 }
298 }
299
300 /*ARGSUSED*/
301 static int
_dns_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)302 _dns_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
303 {
304 struct netent **retval = va_arg(ap, struct netent **);
305 uint32_t net = va_arg(ap, uint32_t);
306 int type = va_arg(ap, int);
307
308 unsigned int netbr[4];
309 int nn, anslen;
310 querybuf *buf;
311 char qbuf[MAXDNAME];
312 uint32_t net2;
313 struct netent *np;
314 res_state res;
315
316 if (type != AF_INET)
317 return NS_UNAVAIL;
318
319 for (nn = 4, net2 = net; net2; net2 >>= 8)
320 netbr[--nn] = (unsigned int)(net2 & 0xff);
321 switch (nn) {
322 default:
323 return NS_UNAVAIL;
324 case 3: /* Class A */
325 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]);
326 break;
327 case 2: /* Class B */
328 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa",
329 netbr[3], netbr[2]);
330 break;
331 case 1: /* Class C */
332 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa",
333 netbr[3], netbr[2], netbr[1]);
334 break;
335 case 0: /* Class D - E */
336 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
337 netbr[3], netbr[2], netbr[1], netbr[0]);
338 break;
339 }
340 buf = malloc(sizeof(*buf));
341 if (buf == NULL) {
342 h_errno = NETDB_INTERNAL;
343 return NS_NOTFOUND;
344 }
345 res = __res_get_state();
346 if (res == NULL) {
347 free(buf);
348 return NS_NOTFOUND;
349 }
350 anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf,
351 (int)sizeof(buf->buf));
352 if (anslen < 0) {
353 free(buf);
354 #ifdef DEBUG
355 if (res->options & RES_DEBUG)
356 printf("res_query failed\n");
357 #endif
358 __res_put_state(res);
359 return NS_NOTFOUND;
360 }
361 __res_put_state(res);
362 np = getnetanswer(buf, anslen, BYADDR);
363 free(buf);
364 if (np) {
365 /* maybe net should be unsigned? */
366 uint32_t u_net = net;
367
368 /* Strip trailing zeros */
369 while ((u_net & 0xff) == 0 && u_net != 0)
370 u_net >>= 8;
371 np->n_net = u_net;
372 }
373
374 if (np != NULL) {
375 *retval = np;
376 return NS_SUCCESS;
377 } else {
378 h_errno = HOST_NOT_FOUND;
379 return NS_NOTFOUND;
380 }
381 }
382
383 struct netent *
getnetbyaddr(uint32_t net,int net_type)384 getnetbyaddr(uint32_t net, int net_type)
385 {
386 int rv;
387 struct netent *retval;
388
389 static const ns_dtab dtab[] = {
390 NS_FILES_CB(_files_getnetbyaddr, NULL)
391 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */
392 NS_NIS_CB(_yp_getnetbyaddr, NULL)
393 NS_NULL_CB
394 };
395
396 retval = NULL;
397 h_errno = NETDB_INTERNAL;
398 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyaddr",
399 __nsdefaultsrc, &retval, net, net_type);
400 if (rv == NS_SUCCESS) {
401 h_errno = NETDB_SUCCESS;
402 return retval;
403 }
404 return NULL;
405 }
406
407 /*ARGSUSED*/
408 static int
_files_getnetbyname(void * cbrv,void * cbdata,va_list ap)409 _files_getnetbyname(void *cbrv, void *cbdata, va_list ap)
410 {
411 struct netent **retval = va_arg(ap, struct netent **);
412 const char *name = va_arg(ap, const char *);
413
414 struct netent *np;
415 char **cp;
416
417 setnetent(_net_stayopen);
418 while ((np = getnetent()) != NULL) {
419 if (strcasecmp(np->n_name, name) == 0)
420 break;
421 for (cp = np->n_aliases; *cp != 0; cp++)
422 if (strcasecmp(*cp, name) == 0)
423 goto found;
424 }
425 found:
426 if (!_net_stayopen)
427 endnetent();
428
429 if (np != NULL) {
430 *retval = np;
431 return NS_SUCCESS;
432 } else {
433 h_errno = HOST_NOT_FOUND;
434 return NS_NOTFOUND;
435 }
436 }
437
438 /*ARGSUSED*/
439 static int
_dns_getnetbyname(void * cbrv,void * cbdata,va_list ap)440 _dns_getnetbyname(void *cbrv, void *cbdata, va_list ap)
441 {
442 struct netent **retval = va_arg(ap, struct netent **);
443 const char *name = va_arg(ap, const char *);
444
445 int anslen;
446 querybuf *buf;
447 char qbuf[MAXDNAME];
448 struct netent *np;
449 res_state res;
450
451 strlcpy(&qbuf[0], name, sizeof(qbuf));
452 buf = malloc(sizeof(*buf));
453 if (buf == NULL) {
454 h_errno = NETDB_INTERNAL;
455 return NS_NOTFOUND;
456 }
457 res = __res_get_state();
458 if (res == NULL) {
459 free(buf);
460 return NS_NOTFOUND;
461 }
462 anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf,
463 (int)sizeof(buf->buf));
464 if (anslen < 0) {
465 free(buf);
466 #ifdef DEBUG
467 if (res->options & RES_DEBUG)
468 printf("res_search failed\n");
469 #endif
470 __res_put_state(res);
471 return NS_NOTFOUND;
472 }
473 __res_put_state(res);
474 np = getnetanswer(buf, anslen, BYNAME);
475 free(buf);
476
477 if (np != NULL) {
478 *retval = np;
479 return NS_SUCCESS;
480 } else {
481 h_errno = HOST_NOT_FOUND;
482 return NS_NOTFOUND;
483 }
484 }
485
486 struct netent *
getnetbyname(const char * name)487 getnetbyname(const char *name)
488 {
489 int rv;
490 struct netent *retval;
491
492 static const ns_dtab dtab[] = {
493 NS_FILES_CB(_files_getnetbyname, NULL)
494 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */
495 NS_NIS_CB(_yp_getnetbyname, NULL)
496 NS_NULL_CB
497 };
498
499 _DIAGASSERT(name != NULL);
500
501 retval = NULL;
502 h_errno = NETDB_INTERNAL;
503 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyname",
504 __nsdefaultsrc, &retval, name);
505 if (rv == NS_SUCCESS) {
506 h_errno = NETDB_SUCCESS;
507 return retval;
508 }
509 return NULL;
510 }
511
512 #ifdef YP
513 /*ARGSUSED*/
514 static int
_yp_getnetbyaddr(void * cbrv,void * cb_data,va_list ap)515 _yp_getnetbyaddr(void *cbrv, void *cb_data, va_list ap)
516 {
517 struct netent **retval = va_arg(ap, struct netent **);
518 uint32_t net = va_arg(ap, uint32_t);
519 int type = va_arg(ap, int);
520
521 struct netent *np;
522 char qbuf[MAXDNAME];
523 unsigned int netbr[4];
524 uint32_t net2;
525 int r;
526
527 if (type != AF_INET)
528 return NS_UNAVAIL;
529
530 if (!__ypdomain) {
531 if (_yp_check(&__ypdomain) == 0)
532 return NS_UNAVAIL;
533 }
534 np = NULL;
535 if (__ypcurrent)
536 free(__ypcurrent);
537 __ypcurrent = NULL;
538 for (r = 4, net2 = net; net2; net2 >>= 8)
539 netbr[--r] = (unsigned int)(net2 & 0xff);
540 switch (r) {
541 default:
542 return NS_UNAVAIL;
543 case 3: /* Class A */
544 snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]);
545 break;
546 case 2: /* Class B */
547 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]);
548 break;
549 case 1: /* Class C */
550 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2],
551 netbr[3]);
552 break;
553 case 0: /* Class D - E */
554 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1],
555 netbr[2], netbr[3]);
556 break;
557 }
558 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf),
559 &__ypcurrent, &__ypcurrentlen);
560 if (r == 0)
561 np = _ypnetent(__ypcurrent);
562
563 if (np != NULL) {
564 *retval = np;
565 return NS_SUCCESS;
566 } else {
567 h_errno = HOST_NOT_FOUND;
568 return NS_NOTFOUND;
569 }
570 }
571
572 /*ARGSUSED*/
573 static int
_yp_getnetbyname(void * cbrv,void * cbdata,va_list ap)574 _yp_getnetbyname(void *cbrv, void *cbdata, va_list ap)
575 {
576 struct netent **retval = va_arg(ap, struct netent **);
577 const char *name = va_arg(ap, const char *);
578
579 struct netent *np;
580 int r;
581
582 if (!__ypdomain) {
583 if (_yp_check(&__ypdomain) == 0)
584 return NS_UNAVAIL;
585 }
586 np = NULL;
587 if (__ypcurrent)
588 free(__ypcurrent);
589 __ypcurrent = NULL;
590 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name),
591 &__ypcurrent, &__ypcurrentlen);
592 if (r == 0)
593 np = _ypnetent(__ypcurrent);
594
595 if (np != NULL) {
596 *retval = np;
597 return NS_SUCCESS;
598 } else {
599 h_errno = HOST_NOT_FOUND;
600 return NS_NOTFOUND;
601 }
602 }
603
604 static struct netent *
_ypnetent(char * line)605 _ypnetent(char *line)
606 {
607 char *cp, *p, **q;
608
609 _DIAGASSERT(line != NULL);
610
611 net_entry.n_name = line;
612 cp = strpbrk(line, " \t");
613 if (cp == NULL)
614 return NULL;
615 *cp++ = '\0';
616 while (*cp == ' ' || *cp == '\t')
617 cp++;
618 p = strpbrk(cp, " \t");
619 if (p != NULL)
620 *p++ = '\0';
621 net_entry.n_net = inet_network(cp);
622 #if (defined(__sparc__) && defined(_LP64)) || \
623 defined(__alpha__) || \
624 (defined(__i386__) && defined(_LP64)) || \
625 (defined(__sh__) && defined(_LP64))
626 net_entry.__n_pad0 = 0;
627 #endif
628 net_entry.n_addrtype = AF_INET;
629 q = net_entry.n_aliases = net_aliases;
630 if (p != NULL) {
631 cp = p;
632 while (cp && *cp) {
633 if (*cp == ' ' || *cp == '\t') {
634 cp++;
635 continue;
636 }
637 if (q < &net_aliases[MAXALIASES - 1])
638 *q++ = cp;
639 cp = strpbrk(cp, " \t");
640 if (cp != NULL)
641 *cp++ = '\0';
642 }
643 }
644 *q = NULL;
645
646 return &net_entry;
647 }
648 #endif
649