1 /* $NetBSD: getnetnamadr.c,v 1.44 2015/10/26 19:41:19 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 1.44 2015/10/26 19:41:19 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 #define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \
81 (ok)(nm) != 0)
82 #define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok)
83 #define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok)
84
85
86 extern int _net_stayopen;
87
88 #define BYADDR 0
89 #define BYNAME 1
90 #define MAXALIASES 35
91
92 #define MAXPACKET (64*1024)
93
94 typedef union {
95 HEADER hdr;
96 u_char buf[MAXPACKET];
97 } querybuf;
98
99 typedef union {
100 long al;
101 char ac;
102 } align;
103
104 #ifdef YP
105 static char *__ypdomain;
106 static char *__ypcurrent;
107 static int __ypcurrentlen;
108 #endif
109
110 static struct netent net_entry;
111 static char *net_aliases[MAXALIASES];
112
113 static int parse_reversed_addr(const char *, in_addr_t *);
114 static struct netent *getnetanswer(res_state, querybuf *, int, int);
115 static int _files_getnetbyaddr(void *, void *, va_list);
116 static int _files_getnetbyname(void *, void *, va_list);
117 static int _dns_getnetbyaddr(void *, void *, va_list);
118 static int _dns_getnetbyname(void *, void *, va_list);
119 #ifdef YP
120 static int _yp_getnetbyaddr(void *, void *, va_list);
121 static int _yp_getnetbyname(void *, void *, va_list);
122 static struct netent *_ypnetent(char *);
123 #endif
124
125 /*
126 * parse_reversed_addr --
127 * parse str, which should be of the form 'd.c.b.a.IN-ADDR.ARPA'
128 * (a PTR as per RFC 1101) and convert into an in_addr_t of the
129 * address 'a.b.c.d'.
130 * returns 0 on success (storing in *result), or -1 on error.
131 */
132 static int
parse_reversed_addr(const char * str,in_addr_t * result)133 parse_reversed_addr(const char *str, in_addr_t *result)
134 {
135 unsigned long octet[4];
136 const char *sp;
137 char *ep;
138 int octidx;
139
140 sp = str;
141 /* find the four octets 'd.b.c.a.' */
142 for (octidx = 0; octidx < 4; octidx++) {
143 /* ensure it's a number */
144 if (!isdigit((unsigned char)*sp))
145 return -1;
146 octet[octidx] = strtoul(sp, &ep, 10);
147 /* with a trailing '.' */
148 if (*ep != '.')
149 return -1;
150 /* and is 0 <= octet <= 255 */
151 if (octet[octidx] > 255)
152 return -1;
153 sp = ep + 1;
154 }
155 /* ensure trailer is correct */
156 if (strcasecmp(sp, "IN-ADDR.ARPA") != 0)
157 return -1;
158 *result = 0;
159 /* build result from octets in reverse */
160 for (octidx = 3; octidx >= 0; octidx--) {
161 *result <<= 8;
162 *result |= (in_addr_t)(octet[octidx] & 0xff);
163 }
164 return 0;
165 }
166
167 static struct netent *
getnetanswer(res_state res,querybuf * answer,int anslen,int net_i)168 getnetanswer(res_state res, querybuf *answer, int anslen, int net_i)
169 {
170 static char n_name[MAXDNAME];
171 static char netbuf[PACKETSZ];
172
173 HEADER *hp;
174 u_char *cp;
175 int n;
176 u_char *eom;
177 int type, class, ancount, qdcount, haveanswer;
178 char *in, *bp, **ap, *ep;
179
180 _DIAGASSERT(answer != NULL);
181 _DIAGASSERT(res != NULL);
182
183 /*
184 * find first satisfactory answer
185 *
186 * answer --> +------------+ ( MESSAGE )
187 * | Header |
188 * +------------+
189 * | Question | the question for the name server
190 * +------------+
191 * | Answer | RRs answering the question
192 * +------------+
193 * | Authority | RRs pointing toward an authority
194 * | Additional | RRs holding additional information
195 * +------------+
196 */
197 eom = answer->buf + anslen;
198 hp = &answer->hdr;
199 ancount = ntohs(hp->ancount); /* #/records in the answer section */
200 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
201 bp = netbuf;
202 ep = netbuf + sizeof(netbuf);
203 cp = answer->buf + HFIXEDSZ;
204 if (!qdcount) {
205 if (hp->aa)
206 h_errno = HOST_NOT_FOUND;
207 else
208 h_errno = TRY_AGAIN;
209 return NULL;
210 }
211 while (qdcount-- > 0) {
212 n = __dn_skipname(cp, eom);
213 if (n < 0 || (cp + n + QFIXEDSZ) > eom) {
214 h_errno = NO_RECOVERY;
215 return(NULL);
216 }
217 cp += n + QFIXEDSZ;
218 }
219 ap = net_aliases;
220 *ap = NULL;
221 net_entry.n_aliases = net_aliases;
222 haveanswer = 0;
223 n_name[0] = '\0';
224 while (--ancount >= 0 && cp < eom) {
225 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
226 if ((n < 0) || !maybe_dnok(res, bp))
227 break;
228 cp += n;
229 (void)strlcpy(n_name, bp, sizeof(n_name));
230 GETSHORT(type, cp);
231 GETSHORT(class, cp);
232 cp += INT32SZ; /* TTL */
233 GETSHORT(n, cp);
234 if (class == C_IN && type == T_PTR) {
235 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
236 if ((n < 0) || !maybe_hnok(res, bp)) {
237 cp += n;
238 return NULL;
239 }
240 cp += n;
241 *ap++ = bp;
242 bp += strlen(bp) + 1;
243 net_entry.n_addrtype =
244 (class == C_IN) ? AF_INET : AF_UNSPEC;
245 haveanswer++;
246 }
247 }
248 if (haveanswer) {
249 *ap = NULL;
250 switch (net_i) {
251 case BYADDR:
252 net_entry.n_name = *net_entry.n_aliases;
253 net_entry.n_net = 0L;
254 break;
255 case BYNAME:
256 ap = net_entry.n_aliases;
257 next_alias:
258 in = *ap++;
259 if (in == NULL) {
260 h_errno = HOST_NOT_FOUND;
261 return NULL;
262 }
263 net_entry.n_name = n_name;
264 if (parse_reversed_addr(in, &net_entry.n_net) == -1)
265 goto next_alias;
266 break;
267 }
268 net_entry.n_aliases++;
269 #if (defined(__sparc__) && defined(_LP64)) || \
270 defined(__alpha__) || \
271 (defined(__i386__) && defined(_LP64)) || \
272 (defined(__sh__) && defined(_LP64))
273 net_entry.__n_pad0 = 0;
274 #endif
275 return &net_entry;
276 }
277 h_errno = TRY_AGAIN;
278 return NULL;
279 }
280
281 /*ARGSUSED*/
282 static int
_files_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)283 _files_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
284 {
285 struct netent **retval = va_arg(ap, struct netent **);
286 uint32_t net = va_arg(ap, uint32_t);
287 int type = va_arg(ap, int);
288
289 struct netent *np;
290
291 setnetent(_net_stayopen);
292 while ((np = getnetent()) != NULL)
293 if (np->n_addrtype == type && np->n_net == net)
294 break;
295 if (!_net_stayopen)
296 endnetent();
297
298 if (np != NULL) {
299 *retval = np;
300 return NS_SUCCESS;
301 } else {
302 h_errno = HOST_NOT_FOUND;
303 return NS_NOTFOUND;
304 }
305 }
306
307 /*ARGSUSED*/
308 static int
_dns_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)309 _dns_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
310 {
311 struct netent **retval = va_arg(ap, struct netent **);
312 uint32_t net = va_arg(ap, uint32_t);
313 int type = va_arg(ap, int);
314
315 unsigned int netbr[4];
316 int nn, anslen;
317 querybuf *buf;
318 char qbuf[MAXDNAME];
319 uint32_t net2;
320 struct netent *np;
321 res_state res;
322
323 if (type != AF_INET)
324 return NS_UNAVAIL;
325
326 for (nn = 4, net2 = net; net2; net2 >>= 8)
327 netbr[--nn] = (unsigned int)(net2 & 0xff);
328 switch (nn) {
329 default:
330 return NS_UNAVAIL;
331 case 3: /* Class A */
332 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]);
333 break;
334 case 2: /* Class B */
335 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa",
336 netbr[3], netbr[2]);
337 break;
338 case 1: /* Class C */
339 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa",
340 netbr[3], netbr[2], netbr[1]);
341 break;
342 case 0: /* Class D - E */
343 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
344 netbr[3], netbr[2], netbr[1], netbr[0]);
345 break;
346 }
347 buf = malloc(sizeof(*buf));
348 if (buf == NULL) {
349 h_errno = NETDB_INTERNAL;
350 return NS_NOTFOUND;
351 }
352 res = __res_get_state();
353 if (res == NULL) {
354 free(buf);
355 return NS_NOTFOUND;
356 }
357 anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf,
358 (int)sizeof(buf->buf));
359 if (anslen < 0) {
360 free(buf);
361 #ifdef DEBUG
362 if (res->options & RES_DEBUG)
363 printf("res_query failed\n");
364 #endif
365 __res_put_state(res);
366 return NS_NOTFOUND;
367 }
368 np = getnetanswer(res, buf, anslen, BYADDR);
369 __res_put_state(res);
370 free(buf);
371 if (np) {
372 /* maybe net should be unsigned? */
373 uint32_t u_net = net;
374
375 /* Strip trailing zeros */
376 while ((u_net & 0xff) == 0 && u_net != 0)
377 u_net >>= 8;
378 np->n_net = u_net;
379 }
380
381 if (np != NULL) {
382 *retval = np;
383 return NS_SUCCESS;
384 } else {
385 h_errno = HOST_NOT_FOUND;
386 return NS_NOTFOUND;
387 }
388 }
389
390 struct netent *
getnetbyaddr(uint32_t net,int net_type)391 getnetbyaddr(uint32_t net, int net_type)
392 {
393 int rv;
394 struct netent *retval;
395
396 static const ns_dtab dtab[] = {
397 NS_FILES_CB(_files_getnetbyaddr, NULL)
398 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */
399 NS_NIS_CB(_yp_getnetbyaddr, NULL)
400 NS_NULL_CB
401 };
402
403 retval = NULL;
404 h_errno = NETDB_INTERNAL;
405 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyaddr",
406 __nsdefaultsrc, &retval, net, net_type);
407 if (rv == NS_SUCCESS) {
408 h_errno = NETDB_SUCCESS;
409 return retval;
410 }
411 return NULL;
412 }
413
414 /*ARGSUSED*/
415 static int
_files_getnetbyname(void * cbrv,void * cbdata,va_list ap)416 _files_getnetbyname(void *cbrv, void *cbdata, va_list ap)
417 {
418 struct netent **retval = va_arg(ap, struct netent **);
419 const char *name = va_arg(ap, const char *);
420
421 struct netent *np;
422 char **cp;
423
424 setnetent(_net_stayopen);
425 while ((np = getnetent()) != NULL) {
426 if (strcasecmp(np->n_name, name) == 0)
427 break;
428 for (cp = np->n_aliases; *cp != 0; cp++)
429 if (strcasecmp(*cp, name) == 0)
430 goto found;
431 }
432 found:
433 if (!_net_stayopen)
434 endnetent();
435
436 if (np != NULL) {
437 *retval = np;
438 return NS_SUCCESS;
439 } else {
440 h_errno = HOST_NOT_FOUND;
441 return NS_NOTFOUND;
442 }
443 }
444
445 /*ARGSUSED*/
446 static int
_dns_getnetbyname(void * cbrv,void * cbdata,va_list ap)447 _dns_getnetbyname(void *cbrv, void *cbdata, va_list ap)
448 {
449 struct netent **retval = va_arg(ap, struct netent **);
450 const char *name = va_arg(ap, const char *);
451
452 int anslen;
453 querybuf *buf;
454 char qbuf[MAXDNAME];
455 struct netent *np;
456 res_state res;
457
458 strlcpy(&qbuf[0], name, sizeof(qbuf));
459 buf = malloc(sizeof(*buf));
460 if (buf == NULL) {
461 h_errno = NETDB_INTERNAL;
462 return NS_NOTFOUND;
463 }
464 res = __res_get_state();
465 if (res == NULL) {
466 free(buf);
467 return NS_NOTFOUND;
468 }
469 anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf,
470 (int)sizeof(buf->buf));
471 if (anslen < 0) {
472 free(buf);
473 #ifdef DEBUG
474 if (res->options & RES_DEBUG)
475 printf("res_search failed\n");
476 #endif
477 __res_put_state(res);
478 return NS_NOTFOUND;
479 }
480 np = getnetanswer(res, buf, anslen, BYNAME);
481 __res_put_state(res);
482 free(buf);
483
484 if (np != NULL) {
485 *retval = np;
486 return NS_SUCCESS;
487 } else {
488 h_errno = HOST_NOT_FOUND;
489 return NS_NOTFOUND;
490 }
491 }
492
493 struct netent *
getnetbyname(const char * name)494 getnetbyname(const char *name)
495 {
496 int rv;
497 struct netent *retval;
498
499 static const ns_dtab dtab[] = {
500 NS_FILES_CB(_files_getnetbyname, NULL)
501 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */
502 NS_NIS_CB(_yp_getnetbyname, NULL)
503 NS_NULL_CB
504 };
505
506 _DIAGASSERT(name != NULL);
507
508 retval = NULL;
509 h_errno = NETDB_INTERNAL;
510 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyname",
511 __nsdefaultsrc, &retval, name);
512 if (rv == NS_SUCCESS) {
513 h_errno = NETDB_SUCCESS;
514 return retval;
515 }
516 return NULL;
517 }
518
519 #ifdef YP
520 /*ARGSUSED*/
521 static int
_yp_getnetbyaddr(void * cbrv,void * cb_data,va_list ap)522 _yp_getnetbyaddr(void *cbrv, void *cb_data, va_list ap)
523 {
524 struct netent **retval = va_arg(ap, struct netent **);
525 uint32_t net = va_arg(ap, uint32_t);
526 int type = va_arg(ap, int);
527
528 struct netent *np;
529 char qbuf[MAXDNAME];
530 unsigned int netbr[4];
531 uint32_t net2;
532 int r;
533
534 if (type != AF_INET)
535 return NS_UNAVAIL;
536
537 if (!__ypdomain) {
538 if (_yp_check(&__ypdomain) == 0)
539 return NS_UNAVAIL;
540 }
541 np = NULL;
542 if (__ypcurrent)
543 free(__ypcurrent);
544 __ypcurrent = NULL;
545 for (r = 4, net2 = net; net2; net2 >>= 8)
546 netbr[--r] = (unsigned int)(net2 & 0xff);
547 switch (r) {
548 default:
549 return NS_UNAVAIL;
550 case 3: /* Class A */
551 snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]);
552 break;
553 case 2: /* Class B */
554 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]);
555 break;
556 case 1: /* Class C */
557 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2],
558 netbr[3]);
559 break;
560 case 0: /* Class D - E */
561 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1],
562 netbr[2], netbr[3]);
563 break;
564 }
565 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf),
566 &__ypcurrent, &__ypcurrentlen);
567 if (r == 0)
568 np = _ypnetent(__ypcurrent);
569
570 if (np != NULL) {
571 *retval = np;
572 return NS_SUCCESS;
573 } else {
574 h_errno = HOST_NOT_FOUND;
575 return NS_NOTFOUND;
576 }
577 }
578
579 /*ARGSUSED*/
580 static int
_yp_getnetbyname(void * cbrv,void * cbdata,va_list ap)581 _yp_getnetbyname(void *cbrv, void *cbdata, va_list ap)
582 {
583 struct netent **retval = va_arg(ap, struct netent **);
584 const char *name = va_arg(ap, const char *);
585
586 struct netent *np;
587 int r;
588
589 if (!__ypdomain) {
590 if (_yp_check(&__ypdomain) == 0)
591 return NS_UNAVAIL;
592 }
593 np = NULL;
594 if (__ypcurrent)
595 free(__ypcurrent);
596 __ypcurrent = NULL;
597 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name),
598 &__ypcurrent, &__ypcurrentlen);
599 if (r == 0)
600 np = _ypnetent(__ypcurrent);
601
602 if (np != NULL) {
603 *retval = np;
604 return NS_SUCCESS;
605 } else {
606 h_errno = HOST_NOT_FOUND;
607 return NS_NOTFOUND;
608 }
609 }
610
611 static struct netent *
_ypnetent(char * line)612 _ypnetent(char *line)
613 {
614 char *cp, *p, **q;
615
616 _DIAGASSERT(line != NULL);
617
618 net_entry.n_name = line;
619 cp = strpbrk(line, " \t");
620 if (cp == NULL)
621 return NULL;
622 *cp++ = '\0';
623 while (*cp == ' ' || *cp == '\t')
624 cp++;
625 p = strpbrk(cp, " \t");
626 if (p != NULL)
627 *p++ = '\0';
628 net_entry.n_net = inet_network(cp);
629 #if (defined(__sparc__) && defined(_LP64)) || \
630 defined(__alpha__) || \
631 (defined(__i386__) && defined(_LP64)) || \
632 (defined(__sh__) && defined(_LP64))
633 net_entry.__n_pad0 = 0;
634 #endif
635 net_entry.n_addrtype = AF_INET;
636 q = net_entry.n_aliases = net_aliases;
637 if (p != NULL) {
638 cp = p;
639 while (cp && *cp) {
640 if (*cp == ' ' || *cp == '\t') {
641 cp++;
642 continue;
643 }
644 if (q < &net_aliases[MAXALIASES - 1])
645 *q++ = cp;
646 cp = strpbrk(cp, " \t");
647 if (cp != NULL)
648 *cp++ = '\0';
649 }
650 }
651 *q = NULL;
652
653 return &net_entry;
654 }
655 #endif
656