xref: /freebsd/lib/libc/gen/getnetgrent.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Rick Macklem at The University of Guelph.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __SCCSID("@(#)getnetgrent.c	8.2 (Berkeley) 4/27/95");
37 #include "namespace.h"
38 
39 #include <ctype.h>
40 #include <errno.h>
41 #include <netdb.h>
42 #include <nsswitch.h>
43 #include <pthread.h>
44 #include <pthread_np.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include "nss_tls.h"
51 
52 #ifdef YP
53 /*
54  * Notes:
55  * We want to be able to use NIS netgroups properly while retaining
56  * the ability to use a local /etc/netgroup file. Unfortunately, you
57  * can't really do both at the same time - at least, not efficiently.
58  * NetBSD deals with this problem by creating a netgroup database
59  * using Berkeley DB (just like the password database) that allows
60  * for lookups using netgroup, netgroup.byuser or netgroup.byhost
61  * searches. This is a neat idea, but I don't have time to implement
62  * something like that now. (I think ultimately it would be nice
63  * if we DB-fied the group and netgroup stuff all in one shot, but
64  * for now I'm satisfied just to have something that works well
65  * without requiring massive code changes.)
66  *
67  * Therefore, to still permit the use of the local file and maintain
68  * optimum NIS performance, we allow for the following conditions:
69  *
70  * - If /etc/netgroup does not exist and NIS is turned on, we use
71  *   NIS netgroups only.
72  *
73  * - If /etc/netgroup exists but is empty, we use NIS netgroups
74  *   only.
75  *
76  * - If /etc/netgroup exists and contains _only_ a '+', we use
77  *   NIS netgroups only.
78  *
79  * - If /etc/netgroup exists, contains locally defined netgroups
80  *   and a '+', we use a mixture of NIS and the local entries.
81  *   This method should return the same NIS data as just using
82  *   NIS alone, but it will be slower if the NIS netgroup database
83  *   is large (innetgr() in particular will suffer since extra
84  *   processing has to be done in order to determine memberships
85  *   using just the raw netgroup data).
86  *
87  * - If /etc/netgroup exists and contains only locally defined
88  *   netgroup entries, we use just those local entries and ignore
89  *   NIS (this is the original, pre-NIS behavior).
90  */
91 
92 #include <rpc/rpc.h>
93 #include <rpcsvc/yp_prot.h>
94 #include <rpcsvc/ypclnt.h>
95 #include <sys/param.h>
96 #include <sys/stat.h>
97 #include <sys/errno.h>
98 static char *_netgr_yp_domain;
99 int _use_only_yp;
100 static int _netgr_yp_enabled;
101 static int _yp_innetgr;
102 #endif
103 
104 #ifndef _PATH_NETGROUP
105 #define _PATH_NETGROUP "/etc/netgroup"
106 #endif
107 
108 enum constants {
109 	NGRP_STORAGE_INITIAL	= 1 << 10, /* 1 KByte */
110 	NGRP_STORAGE_MAX	= 1 << 20, /* 1 MByte */
111 };
112 
113 static const ns_src defaultsrc[] = {
114 	{ NSSRC_COMPAT, NS_SUCCESS },
115 	{ NULL, 0 },
116 };
117 
118 /*
119  * Static Variables and functions used by setnetgrent(), getnetgrent() and
120  * endnetgrent().
121  * There are two linked lists:
122  * - linelist is just used by setnetgrent() to parse the net group file via.
123  *   parse_netgrp()
124  * - netgrp is the list of entries for the current netgroup
125  */
126 struct linelist {
127 	struct linelist	*l_next;	/* Chain ptr. */
128 	int		l_parsed;	/* Flag for cycles */
129 	char		*l_groupname;	/* Name of netgroup */
130 	char		*l_line;	/* Netgroup entrie(s) to be parsed */
131 };
132 
133 struct netgrp {
134 	struct netgrp	*ng_next;	/* Chain ptr */
135 	char		*ng_str[3];	/* Field pointers, see below */
136 };
137 
138 struct netgr_state {
139 	FILE		*st_netf;
140 	struct linelist	*st_linehead;
141 	struct netgrp	*st_nextgrp;
142 	struct netgrp	*st_gr;
143 	char		*st_grname;
144 };
145 
146 #define NG_HOST		0	/* Host name */
147 #define NG_USER		1	/* User name */
148 #define NG_DOM		2	/* and Domain name */
149 
150 static void	netgr_endstate(void *);
151 NSS_TLS_HANDLING(netgr);
152 
153 static int	files_endnetgrent(void *, void *, va_list);
154 static int	files_getnetgrent_r(void *, void *, va_list);
155 static int	files_setnetgrent(void *, void *, va_list);
156 
157 static int	compat_endnetgrent(void *, void *, va_list);
158 static int	compat_innetgr(void *, void *, va_list);
159 static int	compat_getnetgrent_r(void *, void *, va_list);
160 static int	compat_setnetgrent(void *, void *, va_list);
161 
162 static void	_compat_clearstate(void);
163 static int	_getnetgrent_r(char **, char **, char **, char *, size_t, int *,
164 		    struct netgr_state *);
165 static int	_innetgr_fallback(void *, void *, const char *, const char *,
166 		    const char *, const char *);
167 static int	innetgr_fallback(void *, void *, va_list);
168 static int	parse_netgrp(const char *, struct netgr_state *, int);
169 static struct linelist *read_for_group(const char *, struct netgr_state *, int);
170 
171 #define	LINSIZ	1024	/* Length of netgroup file line */
172 
173 static const ns_dtab getnetgrent_dtab[] = {
174 	NS_FILES_CB(files_getnetgrent_r, NULL)
175 	NS_COMPAT_CB(compat_getnetgrent_r, NULL)
176 	{ NULL, NULL, NULL },
177 };
178 
179 static const ns_dtab setnetgrent_dtab[] = {
180 	NS_FILES_CB(files_setnetgrent, NULL)
181 	NS_COMPAT_CB(compat_setnetgrent, NULL)
182 	{ NULL, NULL, NULL },
183 };
184 
185 static const ns_dtab endnetgrent_dtab[] = {
186 	NS_FILES_CB(files_endnetgrent, NULL)
187 	NS_COMPAT_CB(compat_endnetgrent, NULL)
188 	{ NULL, NULL, NULL },
189 };
190 
191 static struct netgr_state compat_state;
192 
193 static void
194 netgr_endstate(void *arg)
195 {
196 	struct linelist *lp, *olp;
197 	struct netgrp *gp, *ogp;
198 	struct netgr_state *st;
199 
200 	st = (struct netgr_state *)arg;
201 	lp = st->st_linehead;
202 	while (lp != NULL) {
203 		olp = lp;
204 		lp = lp->l_next;
205 		free(olp->l_groupname);
206 		free(olp->l_line);
207 		free(olp);
208 	}
209 	st->st_linehead = NULL;
210 	if (st->st_grname != NULL) {
211 		free(st->st_grname);
212 		st->st_grname = NULL;
213 	}
214 	gp = st->st_gr;
215 	while (gp != NULL) {
216 		ogp = gp;
217 		gp = gp->ng_next;
218 		free(ogp->ng_str[NG_HOST]);
219 		free(ogp->ng_str[NG_USER]);
220 		free(ogp->ng_str[NG_DOM]);
221 		free(ogp);
222 	}
223 	st->st_gr = NULL;
224 	st->st_nextgrp = NULL;
225 }
226 
227 static int
228 files_getnetgrent_r(void *retval, void *mdata, va_list ap)
229 {
230 	struct netgr_state *st;
231 	char **hostp, **userp, **domp, *buf;
232 	size_t bufsize;
233 	int *errnop;
234 
235 	hostp = va_arg(ap, char **);
236 	userp = va_arg(ap, char **);
237 	domp = va_arg(ap, char **);
238 	buf = va_arg(ap, char *);
239 	bufsize = va_arg(ap, size_t);
240 	errnop = va_arg(ap, int *);
241 
242 	if (netgr_getstate(&st) != 0)
243 		return (NS_UNAVAIL);
244 
245 	return (_getnetgrent_r(hostp, userp, domp, buf, bufsize, errnop, st));
246 }
247 
248 static int
249 files_setnetgrent(void *retval, void *mdata, va_list ap)
250 {
251 	const ns_src src[] = {
252 		{ NSSRC_FILES, NS_SUCCESS },
253 		{ NULL, 0 },
254 	};
255 	struct netgr_state *st;
256 	const char *group;
257 	int rv;
258 
259 	group = va_arg(ap, const char *);
260 
261 	if (group == NULL || group[0] == '\0')
262 		return (NS_RETURN);
263 
264 	rv = netgr_getstate(&st);
265 	if (rv != 0)
266 		return (NS_UNAVAIL);
267 
268 	if (st->st_gr == NULL || strcmp(group, st->st_grname) != 0) {
269 		(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP,
270 		    "endnetgrent", src);
271 		if ((st->st_netf = fopen(_PATH_NETGROUP, "re")) != NULL) {
272 			if (parse_netgrp(group, st, 0) != 0)
273 				(void)_nsdispatch(NULL, endnetgrent_dtab,
274 				    NSDB_NETGROUP, "endnetgrent", src);
275 			else
276 				st->st_grname = strdup(group);
277 			(void)fclose(st->st_netf);
278 			st->st_netf = NULL;
279 		}
280 	}
281 	st->st_nextgrp = st->st_gr;
282 	return (st->st_grname != NULL ? NS_SUCCESS : NS_NOTFOUND);
283 }
284 
285 static int
286 files_endnetgrent(void *retval, void *mdata, va_list ap)
287 {
288 	struct netgr_state *st;
289 
290 	if (netgr_getstate(&st) != 0)
291 		return (NS_UNAVAIL);
292 	netgr_endstate(st);
293 	return (NS_SUCCESS);
294 }
295 
296 static int
297 compat_getnetgrent_r(void *retval, void *mdata, va_list ap)
298 {
299 	char **hostp, **userp, **domp, *buf;
300 	size_t bufsize;
301 	int *errnop;
302 #ifdef YP
303 	_yp_innetgr = 0;
304 #endif
305 
306 	hostp = va_arg(ap, char **);
307 	userp = va_arg(ap, char **);
308 	domp = va_arg(ap, char **);
309 	buf = va_arg(ap, char *);
310 	bufsize = va_arg(ap, size_t);
311 	errnop = va_arg(ap, int *);
312 
313 	return (_getnetgrent_r(hostp, userp, domp, buf, bufsize, errnop,
314 	    &compat_state));
315 }
316 
317 /*
318  * compat_setnetgrent()
319  * Parse the netgroup file looking for the netgroup and build the list
320  * of netgrp structures. Let parse_netgrp() and read_for_group() do
321  * most of the work.
322  */
323 static int
324 compat_setnetgrent(void *retval, void *mdata, va_list ap)
325 {
326 	FILE *netf;
327 	const char *group;
328 #ifdef YP
329 	struct stat _yp_statp;
330 	char _yp_plus;
331 #endif
332 
333 	group = va_arg(ap, const char *);
334 
335 	/* Sanity check */
336 	if (group == NULL || !strlen(group))
337 		return (NS_RETURN);
338 
339 	if (compat_state.st_gr == NULL ||
340 	    strcmp(group, compat_state.st_grname) != 0) {
341 		_compat_clearstate();
342 
343 #ifdef YP
344 		/* Presumed guilty until proven innocent. */
345 		_use_only_yp = 0;
346 		/*
347 		 * If /etc/netgroup doesn't exist or is empty,
348 		 * use NIS exclusively.
349 		 */
350 		if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) &&
351 		    errno == ENOENT) || _yp_statp.st_size == 0)
352 			_use_only_yp = _netgr_yp_enabled = 1;
353 		if ((netf = fopen(_PATH_NETGROUP,"re")) != NULL ||_use_only_yp){
354 			compat_state.st_netf = netf;
355 		/*
356 		 * Icky: grab the first character of the netgroup file
357 		 * and turn on NIS if it's a '+'. rewind the stream
358 		 * afterwards so we don't goof up read_for_group() later.
359 		 */
360 			if (netf) {
361 				fscanf(netf, "%c", &_yp_plus);
362 				rewind(netf);
363 				if (_yp_plus == '+')
364 					_use_only_yp = _netgr_yp_enabled = 1;
365 			}
366 		/*
367 		 * If we were called specifically for an innetgr()
368 		 * lookup and we're in NIS-only mode, short-circuit
369 		 * parse_netgroup() and cut directly to the chase.
370 		 */
371 			if (_use_only_yp && _yp_innetgr) {
372 				/* dohw! */
373 				if (netf != NULL)
374 					fclose(netf);
375 				return (NS_RETURN);
376 			}
377 #else
378 		if ((netf = fopen(_PATH_NETGROUP, "re"))) {
379 			compat_state.st_netf = netf;
380 #endif
381 			if (parse_netgrp(group, &compat_state, 1)) {
382 				_compat_clearstate();
383 			} else {
384 				compat_state.st_grname = strdup(group);
385 			}
386 			if (netf)
387 				fclose(netf);
388 		}
389 	}
390 	compat_state.st_nextgrp = compat_state.st_gr;
391 	return (NS_SUCCESS);
392 }
393 
394 static void
395 _compat_clearstate(void)
396 {
397 
398 #ifdef YP
399 	_netgr_yp_enabled = 0;
400 #endif
401 	netgr_endstate(&compat_state);
402 }
403 
404 /*
405  * compat_endnetgrent() - cleanup
406  */
407 static int
408 compat_endnetgrent(void *retval, void *mdata, va_list ap)
409 {
410 
411 	_compat_clearstate();
412 	return (NS_SUCCESS);
413 }
414 
415 int
416 _getnetgrent_r(char **hostp, char **userp, char **domp, char *buf,
417     size_t bufsize, int *errnop, struct netgr_state *st)
418 {
419 	char *p, *src;
420 	size_t len;
421 	int rv;
422 
423 #define	COPY_NG_ELEM(dstp, i) do {					\
424 	src = st->st_nextgrp->ng_str[(i)];				\
425 	if (src == NULL)						\
426 		src = "";						\
427 	len = strlcpy(p, src, bufsize);					\
428 	if (len >= bufsize) {						\
429 		*errnop = ERANGE;					\
430 		return (NS_RETURN);					\
431 	}								\
432 	*(dstp) = p;							\
433 	p += len + 1;							\
434 	bufsize -= len + 1;						\
435 } while (0)
436 
437 	p = buf;
438 	if (st->st_nextgrp != NULL) {
439 		COPY_NG_ELEM(hostp, NG_HOST);
440 		COPY_NG_ELEM(userp, NG_USER);
441 		COPY_NG_ELEM(domp, NG_DOM);
442 		st->st_nextgrp = st->st_nextgrp->ng_next;
443 		rv = NS_SUCCESS;
444 	} else {
445 		rv = NS_NOTFOUND;
446 	}
447 #undef COPY_NG_ELEM
448 
449 	return (rv);
450 }
451 
452 #ifdef YP
453 static int
454 _listmatch(const char *list, const char *group, int len)
455 {
456 	const char *ptr = list;
457 	const char *cptr;
458 	int glen = strlen(group);
459 
460 	/* skip possible leading whitespace */
461 	while (isspace((unsigned char)*ptr))
462 		ptr++;
463 
464 	while (ptr < list + len) {
465 		cptr = ptr;
466 		while(*ptr != ','  && *ptr != '\0' && !isspace((unsigned char)*ptr))
467 			ptr++;
468 		if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
469 			return (1);
470 		while (*ptr == ','  || isspace((unsigned char)*ptr))
471 			ptr++;
472 	}
473 
474 	return (0);
475 }
476 
477 static int
478 _revnetgr_lookup(char* lookupdom, char* map, const char* str,
479 		 const char* dom, const char* group)
480 {
481 	int y, rv, rot;
482 	char key[MAXHOSTNAMELEN];
483 	char *result;
484 	int resultlen;
485 
486 	for (rot = 0; ; rot++) {
487 		switch (rot) {
488 		case 0:
489 			snprintf(key, MAXHOSTNAMELEN, "%s.%s", str,
490 			    dom ? dom : lookupdom);
491 			break;
492 		case 1:
493 			snprintf(key, MAXHOSTNAMELEN, "%s.*", str);
494 			break;
495 		case 2:
496 			snprintf(key, MAXHOSTNAMELEN, "*.%s",
497 			    dom ? dom : lookupdom);
498 			break;
499 		case 3:
500 			snprintf(key, MAXHOSTNAMELEN, "*.*");
501 			break;
502 		default:
503 			return (0);
504 		}
505 		y = yp_match(lookupdom, map, key, strlen(key), &result,
506 		    &resultlen);
507 		if (y == 0) {
508 			rv = _listmatch(result, group, resultlen);
509 			free(result);
510 			if (rv)
511 				return (1);
512 		} else if (y != YPERR_KEY) {
513 			/*
514 			 * If we get an error other than 'no
515 			 * such key in map' then something is
516 			 * wrong and we should stop the search.
517 			 */
518 			return (-1);
519 		}
520 	}
521 }
522 #endif
523 
524 /*
525  * Search for a match in a netgroup.
526  */
527 static int
528 compat_innetgr(void *retval, void *mdata, va_list ap)
529 {
530 #ifdef YP
531 	const ns_src src[] = {
532 		{ mdata, NS_SUCCESS },
533 		{ NULL, 0 },
534 	};
535 #endif
536 	const char *group, *host, *user, *dom;
537 
538 	group = va_arg(ap, const char *);
539 	host = va_arg(ap, const char *);
540 	user = va_arg(ap, const char *);
541 	dom = va_arg(ap, const char *);
542 
543 	if (group == NULL || !strlen(group))
544 		return (NS_RETURN);
545 
546 #ifdef YP
547 	_yp_innetgr = 1;
548 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
549 	    src, group);
550 	_yp_innetgr = 0;
551 	/*
552 	 * If we're in NIS-only mode, do the search using
553 	 * NIS 'reverse netgroup' lookups.
554 	 *
555 	 * What happens with 'reverse netgroup' lookups:
556 	 *
557 	 * 1) try 'reverse netgroup' lookup
558 	 *    1.a) if host is specified and user is null:
559 	 *         look in netgroup.byhost
560 	 *         (try host.domain, host.*, *.domain or *.*)
561 	 *         if found, return yes
562 	 *    1.b) if user is specified and host is null:
563 	 *         look in netgroup.byuser
564 	 *         (try host.domain, host.*, *.domain or *.*)
565 	 *         if found, return yes
566 	 *    1.c) if both host and user are specified,
567 	 *         don't do 'reverse netgroup' lookup.  It won't work.
568 	 *    1.d) if neither host ane user are specified (why?!?)
569 	 *         don't do 'reverse netgroup' lookup either.
570 	 * 2) if domain is specified and 'reverse lookup' is done:
571 	 *    'reverse lookup' was authoritative.  bye bye.
572 	 * 3) otherwise, too bad, try it the slow way.
573 	 */
574 	if (_use_only_yp && (host == NULL) != (user == NULL)) {
575 		int ret;
576 		if(yp_get_default_domain(&_netgr_yp_domain))
577 			return (NS_NOTFOUND);
578 		ret = _revnetgr_lookup(_netgr_yp_domain,
579 				      host?"netgroup.byhost":"netgroup.byuser",
580 				      host?host:user, dom, group);
581 		if (ret == 1) {
582 			*(int *)retval = 1;
583 			return (NS_SUCCESS);
584 		} else if (ret == 0 && dom != NULL) {
585 			*(int *)retval = 0;
586 			return (NS_SUCCESS);
587 		}
588 	}
589 #endif /* YP */
590 
591 	return (_innetgr_fallback(retval, mdata, group, host, user, dom));
592 }
593 
594 static int
595 _innetgr_fallback(void *retval, void *mdata, const char *group, const char *host,
596     const char *user, const char *dom)
597 {
598 	const ns_src src[] = {
599 		{ mdata, NS_SUCCESS },
600 		{ NULL, 0 },
601 	};
602 	char *h, *u, *d;
603 	char *buf;
604 	size_t bufsize;
605 	int rv, ret_errno;
606 
607 	if (group == NULL || group[0] == '\0')
608 		return (NS_RETURN);
609 
610 	bufsize = NGRP_STORAGE_INITIAL;
611 	buf = malloc(bufsize);
612 	if (buf == NULL)
613 		return (NS_UNAVAIL);
614 
615 	*(int *)retval = 0;
616 
617 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
618 	    src, group);
619 
620 	for (;;) {
621 		do {
622 			ret_errno = 0;
623 			rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP,
624 			    "getnetgrent_r", src, &h, &u, &d, buf, bufsize,
625 			    &ret_errno);
626 			if (rv != NS_SUCCESS && ret_errno == ERANGE) {
627 				bufsize *= 2;
628 				if (bufsize > NGRP_STORAGE_MAX ||
629 				    (buf = reallocf(buf, bufsize)) == NULL)
630 					goto out;
631 			}
632 		} while (rv != NS_SUCCESS && ret_errno == ERANGE);
633 
634 		if (rv != NS_SUCCESS) {
635 			if (rv == NS_NOTFOUND && ret_errno == 0)
636 				rv = NS_SUCCESS;
637 			break;
638 		}
639 
640 		if ((host == NULL || h == NULL || strcmp(host, h) == 0) &&
641 		    (user == NULL || u == NULL || strcmp(user, u) == 0) &&
642 		    (dom == NULL || d == NULL || strcmp(dom, d) == 0)) {
643 			*(int *)retval = 1;
644 			break;
645 		}
646 	}
647 
648 out:
649 	free(buf);
650 	(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP, "endnetgrent",
651 	    src);
652 	return (rv);
653 }
654 
655 static int
656 innetgr_fallback(void *retval, void *mdata, va_list ap)
657 {
658 	const char *group, *host, *user, *dom;
659 
660 	group = va_arg(ap, const char *);
661 	host = va_arg(ap, const char *);
662 	user = va_arg(ap, const char *);
663 	dom = va_arg(ap, const char *);
664 
665 	return (_innetgr_fallback(retval, mdata, group, host, user, dom));
666 }
667 
668 /*
669  * Parse the netgroup file setting up the linked lists.
670  */
671 static int
672 parse_netgrp(const char *group, struct netgr_state *st, int niscompat)
673 {
674 	struct netgrp *grp;
675 	struct linelist *lp = st->st_linehead;
676 	char **ng;
677 	char *epos, *gpos, *pos, *spos;
678 	int freepos, len, strpos;
679 #ifdef DEBUG
680 	int fields;
681 #endif
682 
683 	/*
684 	 * First, see if the line has already been read in.
685 	 */
686 	while (lp) {
687 		if (!strcmp(group, lp->l_groupname))
688 			break;
689 		lp = lp->l_next;
690 	}
691 	if (lp == NULL && (lp = read_for_group(group, st, niscompat)) == NULL)
692 		return (1);
693 	if (lp->l_parsed) {
694 #ifdef DEBUG
695 		/*
696 		 * This error message is largely superflous since the
697 		 * code handles the error condition sucessfully, and
698 		 * spewing it out from inside libc can actually hose
699 		 * certain programs.
700 		 */
701 		fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
702 #endif
703 		return (1);
704 	} else
705 		lp->l_parsed = 1;
706 	pos = lp->l_line;
707 	/* Watch for null pointer dereferences, dammit! */
708 	while (pos != NULL && *pos != '\0') {
709 		if (*pos == '(') {
710 			grp = malloc(sizeof(*grp));
711 			if (grp == NULL)
712 				return (1);
713 			ng = grp->ng_str;
714 			bzero(grp, sizeof(*grp));
715 			pos++;
716 			gpos = strsep(&pos, ")");
717 #ifdef DEBUG
718 			fields = 0;
719 #endif
720 			for (strpos = 0; strpos < 3; strpos++) {
721 				if ((spos = strsep(&gpos, ",")) == NULL) {
722 					/*
723 					 * All other systems I've tested
724 					 * return NULL for empty netgroup
725 					 * fields. It's up to user programs
726 					 * to handle the NULLs appropriately.
727 					 */
728 					ng[strpos] = NULL;
729 					continue;
730 				}
731 #ifdef DEBUG
732 				fields++;
733 #endif
734 				while (*spos == ' ' || *spos == '\t')
735 					spos++;
736 				if ((epos = strpbrk(spos, " \t"))) {
737 					*epos = '\0';
738 					len = epos - spos;
739 				} else
740 					len = strlen(spos);
741 				if (len <= 0)
742 					continue;
743 				ng[strpos] = malloc(len + 1);
744 				if (ng[strpos] == NULL) {
745 					for (freepos = 0; freepos < strpos;
746 					    freepos++)
747 						free(ng[freepos]);
748 					free(grp);
749 					return (1);
750 				}
751 				bcopy(spos, ng[strpos], len + 1);
752 			}
753 			grp->ng_next = st->st_gr;
754 			st->st_gr = grp;
755 #ifdef DEBUG
756 			/*
757 			 * Note: on other platforms, malformed netgroup
758 			 * entries are not normally flagged. While we
759 			 * can catch bad entries and report them, we should
760 			 * stay silent by default for compatibility's sake.
761 			 */
762 			if (fields < 3) {
763 				fprintf(stderr,
764 				"Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
765 				    ng[NG_HOST] == NULL ? "" : ng[NG_HOST],
766 				    ng[NG_USER] == NULL ? "" : ",",
767 				    ng[NG_USER] == NULL ? "" : ng[NG_USER],
768 				    ng[NG_DOM] == NULL ? "" : ",",
769 				    ng[NG_DOM] == NULL ? "" : ng[NG_DOM],
770 				    lp->l_groupname);
771 			}
772 #endif
773 		} else {
774 			spos = strsep(&pos, ", \t");
775 			if (parse_netgrp(spos, st, niscompat))
776 				continue;
777 		}
778 		if (pos == NULL)
779 			break;
780 		while (*pos == ' ' || *pos == ',' || *pos == '\t')
781 			pos++;
782 	}
783 	return (0);
784 }
785 
786 /*
787  * Read the netgroup file and save lines until the line for the netgroup
788  * is found. Return 1 if eof is encountered.
789  */
790 static struct linelist *
791 read_for_group(const char *group, struct netgr_state *st, int niscompat)
792 {
793 	char *linep, *olinep, *pos, *spos;
794 	int len, olen;
795 	int cont;
796 	struct linelist *lp;
797 	char line[LINSIZ + 2];
798 	FILE *netf;
799 #ifdef YP
800 	char *result;
801 	int resultlen;
802 	linep = NULL;
803 
804 	netf = st->st_netf;
805 	while ((_netgr_yp_enabled && niscompat) ||
806 	    fgets(line, LINSIZ, netf) != NULL) {
807 		if (_netgr_yp_enabled) {
808 			if(!_netgr_yp_domain)
809 				if(yp_get_default_domain(&_netgr_yp_domain))
810 					continue;
811 			if (yp_match(_netgr_yp_domain, "netgroup", group,
812 			    strlen(group), &result, &resultlen)) {
813 				free(result);
814 				if (_use_only_yp)
815 					return ((struct linelist *)0);
816 				else {
817 					_netgr_yp_enabled = 0;
818 					continue;
819 				}
820 			}
821 			if (strlen(result) == 0) {
822 				free(result);
823 				return (NULL);
824 			}
825 			snprintf(line, LINSIZ, "%s %s", group, result);
826 			free(result);
827 		}
828 #else
829 	linep = NULL;
830 	while (fgets(line, LINSIZ, netf) != NULL) {
831 #endif
832 		pos = (char *)&line;
833 #ifdef YP
834 		if (niscompat && *pos == '+') {
835 			_netgr_yp_enabled = 1;
836 			continue;
837 		}
838 #endif
839 		if (*pos == '#')
840 			continue;
841 		while (*pos == ' ' || *pos == '\t')
842 			pos++;
843 		spos = pos;
844 		while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
845 			*pos != '\0')
846 			pos++;
847 		len = pos - spos;
848 		while (*pos == ' ' || *pos == '\t')
849 			pos++;
850 		if (*pos != '\n' && *pos != '\0') {
851 			lp = malloc(sizeof (*lp));
852 			if (lp == NULL)
853 				return (NULL);
854 			lp->l_parsed = 0;
855 			lp->l_groupname = malloc(len + 1);
856 			if (lp->l_groupname == NULL) {
857 				free(lp);
858 				return (NULL);
859 			}
860 			bcopy(spos, lp->l_groupname, len);
861 			*(lp->l_groupname + len) = '\0';
862 			len = strlen(pos);
863 			olen = 0;
864 
865 			/*
866 			 * Loop around handling line continuations.
867 			 */
868 			do {
869 				if (*(pos + len - 1) == '\n')
870 					len--;
871 				if (*(pos + len - 1) == '\\') {
872 					len--;
873 					cont = 1;
874 				} else
875 					cont = 0;
876 				if (len > 0) {
877 					linep = malloc(olen + len + 1);
878 					if (linep == NULL) {
879 						free(lp->l_groupname);
880 						free(lp);
881 						if (olen > 0)
882 							free(olinep);
883 						return (NULL);
884 					}
885 					if (olen > 0) {
886 						bcopy(olinep, linep, olen);
887 						free(olinep);
888 					}
889 					bcopy(pos, linep + olen, len);
890 					olen += len;
891 					*(linep + olen) = '\0';
892 					olinep = linep;
893 				}
894 				if (cont) {
895 					if (fgets(line, LINSIZ, netf)) {
896 						pos = line;
897 						len = strlen(pos);
898 					} else
899 						cont = 0;
900 				}
901 			} while (cont);
902 			lp->l_line = linep;
903 			lp->l_next = st->st_linehead;
904 			st->st_linehead = lp;
905 
906 			/*
907 			 * If this is the one we wanted, we are done.
908 			 */
909 			if (!strcmp(lp->l_groupname, group))
910 				return (lp);
911 		}
912 	}
913 #ifdef YP
914 	/*
915 	 * Yucky. The recursive nature of this whole mess might require
916 	 * us to make more than one pass through the netgroup file.
917 	 * This might be best left outside the #ifdef YP, but YP is
918 	 * defined by default anyway, so I'll leave it like this
919 	 * until I know better.
920 	 */
921 	rewind(netf);
922 #endif
923 	return (NULL);
924 }
925 
926 int
927 getnetgrent_r(char **hostp, char **userp, char **domp, char *buf, size_t bufsize)
928 {
929 	int rv, ret_errno;
930 
931 	ret_errno = 0;
932 	rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP, "getnetgrent_r",
933 	    defaultsrc, hostp, userp, domp, buf, bufsize, &ret_errno);
934 	if (rv == NS_SUCCESS) {
935 		return (1);
936 	} else {
937 		errno = ret_errno;
938 		return (0);
939 	}
940 }
941 
942 int
943 getnetgrent(char **hostp, char **userp, char **domp)
944 {
945 	static char *ngrp_storage;
946 	static size_t ngrp_storage_size;
947 	int ret_errno, rv;
948 
949 	if (ngrp_storage == NULL) {
950 		ngrp_storage_size = NGRP_STORAGE_INITIAL;
951 		ngrp_storage = malloc(ngrp_storage_size);
952 		if (ngrp_storage == NULL)
953 			return (0);
954 	}
955 
956 	do {
957 		ret_errno = 0;
958 		rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP,
959 		    "getnetgrent_r", defaultsrc, hostp, userp, domp,
960 		    ngrp_storage, ngrp_storage_size, &ret_errno);
961 		if (rv != NS_SUCCESS && ret_errno == ERANGE) {
962 			ngrp_storage_size *= 2;
963 			if (ngrp_storage_size > NGRP_STORAGE_MAX) {
964 				free(ngrp_storage);
965 				ngrp_storage = NULL;
966 				errno = ERANGE;
967 				return (0);
968 			}
969 			ngrp_storage = reallocf(ngrp_storage,
970 			    ngrp_storage_size);
971 			if (ngrp_storage == NULL)
972 				return (0);
973 		}
974 	} while (rv != NS_SUCCESS && ret_errno == ERANGE);
975 
976 	if (rv == NS_SUCCESS) {
977 		return (1);
978 	} else {
979 		errno = ret_errno;
980 		return (0);
981 	}
982 }
983 
984 void
985 setnetgrent(const char *netgroup)
986 {
987 
988 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
989 	    defaultsrc, netgroup);
990 }
991 
992 void
993 endnetgrent(void)
994 {
995 
996 	(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP, "endnetgrent",
997 	    defaultsrc);
998 }
999 
1000 int
1001 innetgr(const char *netgroup, const char *host, const char *user,
1002     const char *domain)
1003 {
1004 	static const ns_dtab dtab[] = {
1005 		NS_COMPAT_CB(compat_innetgr, NULL)
1006 		NS_FALLBACK_CB(innetgr_fallback)
1007 		{ NULL, NULL, NULL },
1008 	};
1009 	int result, rv;
1010 
1011 	rv = _nsdispatch(&result, dtab, NSDB_NETGROUP, "innetgr", defaultsrc,
1012 	    netgroup, host, user, domain);
1013 	return (rv == NS_SUCCESS ? result : 0);
1014 }
1015