1 /* $NetBSD: getnetnamadr.c,v 1.45 2020/06/05 11:16:15 nia 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 1.45 2020/06/05 11:16:15 nia 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 net_entry.__n_pad0 = 0;
272 #endif
273 return &net_entry;
274 }
275 h_errno = TRY_AGAIN;
276 return NULL;
277 }
278
279 /*ARGSUSED*/
280 static int
_files_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)281 _files_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
282 {
283 struct netent **retval = va_arg(ap, struct netent **);
284 uint32_t net = va_arg(ap, uint32_t);
285 int type = va_arg(ap, int);
286
287 struct netent *np;
288
289 setnetent(_net_stayopen);
290 while ((np = getnetent()) != NULL)
291 if (np->n_addrtype == type && np->n_net == net)
292 break;
293 if (!_net_stayopen)
294 endnetent();
295
296 if (np != NULL) {
297 *retval = np;
298 return NS_SUCCESS;
299 } else {
300 h_errno = HOST_NOT_FOUND;
301 return NS_NOTFOUND;
302 }
303 }
304
305 /*ARGSUSED*/
306 static int
_dns_getnetbyaddr(void * cbrv,void * cbdata,va_list ap)307 _dns_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
308 {
309 struct netent **retval = va_arg(ap, struct netent **);
310 uint32_t net = va_arg(ap, uint32_t);
311 int type = va_arg(ap, int);
312
313 unsigned int netbr[4];
314 int nn, anslen;
315 querybuf *buf;
316 char qbuf[MAXDNAME];
317 uint32_t net2;
318 struct netent *np;
319 res_state res;
320
321 if (type != AF_INET)
322 return NS_UNAVAIL;
323
324 for (nn = 4, net2 = net; net2; net2 >>= 8)
325 netbr[--nn] = (unsigned int)(net2 & 0xff);
326 switch (nn) {
327 default:
328 return NS_UNAVAIL;
329 case 3: /* Class A */
330 snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]);
331 break;
332 case 2: /* Class B */
333 snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa",
334 netbr[3], netbr[2]);
335 break;
336 case 1: /* Class C */
337 snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa",
338 netbr[3], netbr[2], netbr[1]);
339 break;
340 case 0: /* Class D - E */
341 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
342 netbr[3], netbr[2], netbr[1], netbr[0]);
343 break;
344 }
345 buf = malloc(sizeof(*buf));
346 if (buf == NULL) {
347 h_errno = NETDB_INTERNAL;
348 return NS_NOTFOUND;
349 }
350 res = __res_get_state();
351 if (res == NULL) {
352 free(buf);
353 return NS_NOTFOUND;
354 }
355 anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf,
356 (int)sizeof(buf->buf));
357 if (anslen < 0) {
358 free(buf);
359 #ifdef DEBUG
360 if (res->options & RES_DEBUG)
361 printf("res_query failed\n");
362 #endif
363 __res_put_state(res);
364 return NS_NOTFOUND;
365 }
366 np = getnetanswer(res, buf, anslen, BYADDR);
367 __res_put_state(res);
368 free(buf);
369 if (np) {
370 /* maybe net should be unsigned? */
371 uint32_t u_net = net;
372
373 /* Strip trailing zeros */
374 while ((u_net & 0xff) == 0 && u_net != 0)
375 u_net >>= 8;
376 np->n_net = u_net;
377 }
378
379 if (np != NULL) {
380 *retval = np;
381 return NS_SUCCESS;
382 } else {
383 h_errno = HOST_NOT_FOUND;
384 return NS_NOTFOUND;
385 }
386 }
387
388 struct netent *
getnetbyaddr(uint32_t net,int net_type)389 getnetbyaddr(uint32_t net, int net_type)
390 {
391 int rv;
392 struct netent *retval;
393
394 static const ns_dtab dtab[] = {
395 NS_FILES_CB(_files_getnetbyaddr, NULL)
396 { NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */
397 NS_NIS_CB(_yp_getnetbyaddr, NULL)
398 NS_NULL_CB
399 };
400
401 retval = NULL;
402 h_errno = NETDB_INTERNAL;
403 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyaddr",
404 __nsdefaultsrc, &retval, net, net_type);
405 if (rv == NS_SUCCESS) {
406 h_errno = NETDB_SUCCESS;
407 return retval;
408 }
409 return NULL;
410 }
411
412 /*ARGSUSED*/
413 static int
_files_getnetbyname(void * cbrv,void * cbdata,va_list ap)414 _files_getnetbyname(void *cbrv, void *cbdata, va_list ap)
415 {
416 struct netent **retval = va_arg(ap, struct netent **);
417 const char *name = va_arg(ap, const char *);
418
419 struct netent *np;
420 char **cp;
421
422 setnetent(_net_stayopen);
423 while ((np = getnetent()) != NULL) {
424 if (strcasecmp(np->n_name, name) == 0)
425 break;
426 for (cp = np->n_aliases; *cp != 0; cp++)
427 if (strcasecmp(*cp, name) == 0)
428 goto found;
429 }
430 found:
431 if (!_net_stayopen)
432 endnetent();
433
434 if (np != NULL) {
435 *retval = np;
436 return NS_SUCCESS;
437 } else {
438 h_errno = HOST_NOT_FOUND;
439 return NS_NOTFOUND;
440 }
441 }
442
443 /*ARGSUSED*/
444 static int
_dns_getnetbyname(void * cbrv,void * cbdata,va_list ap)445 _dns_getnetbyname(void *cbrv, void *cbdata, va_list ap)
446 {
447 struct netent **retval = va_arg(ap, struct netent **);
448 const char *name = va_arg(ap, const char *);
449
450 int anslen;
451 querybuf *buf;
452 char qbuf[MAXDNAME];
453 struct netent *np;
454 res_state res;
455
456 strlcpy(&qbuf[0], name, sizeof(qbuf));
457 buf = malloc(sizeof(*buf));
458 if (buf == NULL) {
459 h_errno = NETDB_INTERNAL;
460 return NS_NOTFOUND;
461 }
462 res = __res_get_state();
463 if (res == NULL) {
464 free(buf);
465 return NS_NOTFOUND;
466 }
467 anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf,
468 (int)sizeof(buf->buf));
469 if (anslen < 0) {
470 free(buf);
471 #ifdef DEBUG
472 if (res->options & RES_DEBUG)
473 printf("res_search failed\n");
474 #endif
475 __res_put_state(res);
476 return NS_NOTFOUND;
477 }
478 np = getnetanswer(res, buf, anslen, BYNAME);
479 __res_put_state(res);
480 free(buf);
481
482 if (np != NULL) {
483 *retval = np;
484 return NS_SUCCESS;
485 } else {
486 h_errno = HOST_NOT_FOUND;
487 return NS_NOTFOUND;
488 }
489 }
490
491 struct netent *
getnetbyname(const char * name)492 getnetbyname(const char *name)
493 {
494 int rv;
495 struct netent *retval;
496
497 static const ns_dtab dtab[] = {
498 NS_FILES_CB(_files_getnetbyname, NULL)
499 { NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */
500 NS_NIS_CB(_yp_getnetbyname, NULL)
501 NS_NULL_CB
502 };
503
504 _DIAGASSERT(name != NULL);
505
506 retval = NULL;
507 h_errno = NETDB_INTERNAL;
508 rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyname",
509 __nsdefaultsrc, &retval, name);
510 if (rv == NS_SUCCESS) {
511 h_errno = NETDB_SUCCESS;
512 return retval;
513 }
514 return NULL;
515 }
516
517 #ifdef YP
518 /*ARGSUSED*/
519 static int
_yp_getnetbyaddr(void * cbrv,void * cb_data,va_list ap)520 _yp_getnetbyaddr(void *cbrv, void *cb_data, va_list ap)
521 {
522 struct netent **retval = va_arg(ap, struct netent **);
523 uint32_t net = va_arg(ap, uint32_t);
524 int type = va_arg(ap, int);
525
526 struct netent *np;
527 char qbuf[MAXDNAME];
528 unsigned int netbr[4];
529 uint32_t net2;
530 int r;
531
532 if (type != AF_INET)
533 return NS_UNAVAIL;
534
535 if (!__ypdomain) {
536 if (_yp_check(&__ypdomain) == 0)
537 return NS_UNAVAIL;
538 }
539 np = NULL;
540 if (__ypcurrent)
541 free(__ypcurrent);
542 __ypcurrent = NULL;
543 for (r = 4, net2 = net; net2; net2 >>= 8)
544 netbr[--r] = (unsigned int)(net2 & 0xff);
545 switch (r) {
546 default:
547 return NS_UNAVAIL;
548 case 3: /* Class A */
549 snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]);
550 break;
551 case 2: /* Class B */
552 snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]);
553 break;
554 case 1: /* Class C */
555 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2],
556 netbr[3]);
557 break;
558 case 0: /* Class D - E */
559 snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1],
560 netbr[2], netbr[3]);
561 break;
562 }
563 r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf),
564 &__ypcurrent, &__ypcurrentlen);
565 if (r == 0)
566 np = _ypnetent(__ypcurrent);
567
568 if (np != NULL) {
569 *retval = np;
570 return NS_SUCCESS;
571 } else {
572 h_errno = HOST_NOT_FOUND;
573 return NS_NOTFOUND;
574 }
575 }
576
577 /*ARGSUSED*/
578 static int
_yp_getnetbyname(void * cbrv,void * cbdata,va_list ap)579 _yp_getnetbyname(void *cbrv, void *cbdata, va_list ap)
580 {
581 struct netent **retval = va_arg(ap, struct netent **);
582 const char *name = va_arg(ap, const char *);
583
584 struct netent *np;
585 int r;
586
587 if (!__ypdomain) {
588 if (_yp_check(&__ypdomain) == 0)
589 return NS_UNAVAIL;
590 }
591 np = NULL;
592 if (__ypcurrent)
593 free(__ypcurrent);
594 __ypcurrent = NULL;
595 r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name),
596 &__ypcurrent, &__ypcurrentlen);
597 if (r == 0)
598 np = _ypnetent(__ypcurrent);
599
600 if (np != NULL) {
601 *retval = np;
602 return NS_SUCCESS;
603 } else {
604 h_errno = HOST_NOT_FOUND;
605 return NS_NOTFOUND;
606 }
607 }
608
609 static struct netent *
_ypnetent(char * line)610 _ypnetent(char *line)
611 {
612 char *cp, *p, **q;
613
614 _DIAGASSERT(line != NULL);
615
616 net_entry.n_name = line;
617 cp = strpbrk(line, " \t");
618 if (cp == NULL)
619 return NULL;
620 *cp++ = '\0';
621 while (*cp == ' ' || *cp == '\t')
622 cp++;
623 p = strpbrk(cp, " \t");
624 if (p != NULL)
625 *p++ = '\0';
626 net_entry.n_net = inet_network(cp);
627 #if (defined(__sparc__) && defined(_LP64)) || \
628 defined(__alpha__)
629 net_entry.__n_pad0 = 0;
630 #endif
631 net_entry.n_addrtype = AF_INET;
632 q = net_entry.n_aliases = net_aliases;
633 if (p != NULL) {
634 cp = p;
635 while (cp && *cp) {
636 if (*cp == ' ' || *cp == '\t') {
637 cp++;
638 continue;
639 }
640 if (q < &net_aliases[MAXALIASES - 1])
641 *q++ = cp;
642 cp = strpbrk(cp, " \t");
643 if (cp != NULL)
644 *cp++ = '\0';
645 }
646 }
647 *q = NULL;
648
649 return &net_entry;
650 }
651 #endif
652