xref: /freebsd/lib/libc/gen/getnetgrent.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
1 /*
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)getnetgrent.c	8.2 (Berkeley) 4/27/95";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "namespace.h"
40 
41 #include <ctype.h>
42 #include <errno.h>
43 #include <netdb.h>
44 #include <nsswitch.h>
45 #include <pthread.h>
46 #include <pthread_np.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 #include "nss_tls.h"
53 
54 #ifdef YP
55 /*
56  * Notes:
57  * We want to be able to use NIS netgroups properly while retaining
58  * the ability to use a local /etc/netgroup file. Unfortunately, you
59  * can't really do both at the same time - at least, not efficiently.
60  * NetBSD deals with this problem by creating a netgroup database
61  * using Berkeley DB (just like the password database) that allows
62  * for lookups using netgroup, netgroup.byuser or netgroup.byhost
63  * searches. This is a neat idea, but I don't have time to implement
64  * something like that now. (I think ultimately it would be nice
65  * if we DB-fied the group and netgroup stuff all in one shot, but
66  * for now I'm satisfied just to have something that works well
67  * without requiring massive code changes.)
68  *
69  * Therefore, to still permit the use of the local file and maintain
70  * optimum NIS performance, we allow for the following conditions:
71  *
72  * - If /etc/netgroup does not exist and NIS is turned on, we use
73  *   NIS netgroups only.
74  *
75  * - If /etc/netgroup exists but is empty, we use NIS netgroups
76  *   only.
77  *
78  * - If /etc/netgroup exists and contains _only_ a '+', we use
79  *   NIS netgroups only.
80  *
81  * - If /etc/netgroup exists, contains locally defined netgroups
82  *   and a '+', we use a mixture of NIS and the local entries.
83  *   This method should return the same NIS data as just using
84  *   NIS alone, but it will be slower if the NIS netgroup database
85  *   is large (innetgr() in particular will suffer since extra
86  *   processing has to be done in order to determine memberships
87  *   using just the raw netgroup data).
88  *
89  * - If /etc/netgroup exists and contains only locally defined
90  *   netgroup entries, we use just those local entries and ignore
91  *   NIS (this is the original, pre-NIS behavior).
92  */
93 
94 #include <rpc/rpc.h>
95 #include <rpcsvc/yp_prot.h>
96 #include <rpcsvc/ypclnt.h>
97 #include <sys/param.h>
98 #include <sys/stat.h>
99 #include <sys/errno.h>
100 static char *_netgr_yp_domain;
101 int _use_only_yp;
102 static int _netgr_yp_enabled;
103 static int _yp_innetgr;
104 #endif
105 
106 #ifndef _PATH_NETGROUP
107 #define _PATH_NETGROUP "/etc/netgroup"
108 #endif
109 
110 enum constants {
111 	NGRP_STORAGE_INITIAL	= 1 << 10, /* 1 KByte */
112 	NGRP_STORAGE_MAX	= 1 << 20, /* 1 MByte */
113 };
114 
115 static const ns_src defaultsrc[] = {
116 	{ NSSRC_COMPAT, NS_SUCCESS },
117 	{ NULL, 0 },
118 };
119 
120 /*
121  * Static Variables and functions used by setnetgrent(), getnetgrent() and
122  * endnetgrent().
123  * There are two linked lists:
124  * - linelist is just used by setnetgrent() to parse the net group file via.
125  *   parse_netgrp()
126  * - netgrp is the list of entries for the current netgroup
127  */
128 struct linelist {
129 	struct linelist	*l_next;	/* Chain ptr. */
130 	int		l_parsed;	/* Flag for cycles */
131 	char		*l_groupname;	/* Name of netgroup */
132 	char		*l_line;	/* Netgroup entrie(s) to be parsed */
133 };
134 
135 struct netgrp {
136 	struct netgrp	*ng_next;	/* Chain ptr */
137 	char		*ng_str[3];	/* Field pointers, see below */
138 };
139 
140 struct netgr_state {
141 	FILE		*st_netf;
142 	struct linelist	*st_linehead;
143 	struct netgrp	*st_nextgrp;
144 	struct netgrp	*st_gr;
145 	char		*st_grname;
146 };
147 
148 #define NG_HOST		0	/* Host name */
149 #define NG_USER		1	/* User name */
150 #define NG_DOM		2	/* and Domain name */
151 
152 static void	netgr_endstate(void *);
153 NSS_TLS_HANDLING(netgr);
154 
155 static int	files_endnetgrent(void *, void *, va_list);
156 static int	files_getnetgrent_r(void *, void *, va_list);
157 static int	files_setnetgrent(void *, void *, va_list);
158 
159 static int	compat_endnetgrent(void *, void *, va_list);
160 static int	compat_innetgr(void *, void *, va_list);
161 static int	compat_getnetgrent_r(void *, void *, va_list);
162 static int	compat_setnetgrent(void *, void *, va_list);
163 
164 static void	_compat_clearstate(void);
165 static int	_getnetgrent_r(char **, char **, char **, char *, size_t, int *,
166 		    struct netgr_state *);
167 static int	_innetgr_fallback(void *, void *, const char *, const char *,
168 		    const char *, const char *);
169 static int	innetgr_fallback(void *, void *, va_list);
170 static int	parse_netgrp(const char *, struct netgr_state *, int);
171 static struct linelist *read_for_group(const char *, struct netgr_state *, int);
172 
173 #define	LINSIZ	1024	/* Length of netgroup file line */
174 
175 static const ns_dtab getnetgrent_dtab[] = {
176 	NS_FILES_CB(files_getnetgrent_r, NULL)
177 	NS_COMPAT_CB(compat_getnetgrent_r, NULL)
178 	{ NULL, NULL, NULL },
179 };
180 
181 static const ns_dtab setnetgrent_dtab[] = {
182 	NS_FILES_CB(files_setnetgrent, NULL)
183 	NS_COMPAT_CB(compat_setnetgrent, NULL)
184 	{ NULL, NULL, NULL },
185 };
186 
187 static const ns_dtab endnetgrent_dtab[] = {
188 	NS_FILES_CB(files_endnetgrent, NULL)
189 	NS_COMPAT_CB(compat_endnetgrent, NULL)
190 	{ NULL, NULL, NULL },
191 };
192 
193 static struct netgr_state compat_state;
194 
195 static void
196 netgr_endstate(void *arg)
197 {
198 	struct linelist *lp, *olp;
199 	struct netgrp *gp, *ogp;
200 	struct netgr_state *st;
201 
202 	st = (struct netgr_state *)arg;
203 	lp = st->st_linehead;
204 	while (lp != NULL) {
205 		olp = lp;
206 		lp = lp->l_next;
207 		free(olp->l_groupname);
208 		free(olp->l_line);
209 		free(olp);
210 	}
211 	st->st_linehead = NULL;
212 	if (st->st_grname != NULL) {
213 		free(st->st_grname);
214 		st->st_grname = NULL;
215 	}
216 	gp = st->st_gr;
217 	while (gp != NULL) {
218 		ogp = gp;
219 		gp = gp->ng_next;
220 		free(ogp->ng_str[NG_HOST]);
221 		free(ogp->ng_str[NG_USER]);
222 		free(ogp->ng_str[NG_DOM]);
223 		free(ogp);
224 	}
225 	st->st_gr = NULL;
226 	st->st_nextgrp = NULL;
227 }
228 
229 static int
230 files_getnetgrent_r(void *retval, void *mdata, va_list ap)
231 {
232 	struct netgr_state *st;
233 	char **hostp, **userp, **domp, *buf;
234 	size_t bufsize;
235 	int *errnop;
236 
237 	hostp = va_arg(ap, char **);
238 	userp = va_arg(ap, char **);
239 	domp = va_arg(ap, char **);
240 	buf = va_arg(ap, char *);
241 	bufsize = va_arg(ap, size_t);
242 	errnop = va_arg(ap, int *);
243 
244 	if (netgr_getstate(&st) != 0)
245 		return (NS_UNAVAIL);
246 
247 	return (_getnetgrent_r(hostp, userp, domp, buf, bufsize, errnop, st));
248 }
249 
250 static int
251 files_setnetgrent(void *retval, void *mdata, va_list ap)
252 {
253 	const ns_src src[] = {
254 		{ NSSRC_FILES, NS_SUCCESS },
255 		{ NULL, 0 },
256 	};
257 	struct netgr_state *st;
258 	const char *group;
259 	int rv;
260 
261 	group = va_arg(ap, const char *);
262 
263 	if (group == NULL || group[0] == '\0')
264 		return (NS_RETURN);
265 
266 	rv = netgr_getstate(&st);
267 	if (rv != 0)
268 		return (NS_UNAVAIL);
269 
270 	if (st->st_gr == NULL || strcmp(group, st->st_grname) != 0) {
271 		(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP,
272 		    "endnetgrent", src);
273 		if ((st->st_netf = fopen(_PATH_NETGROUP, "re")) != NULL) {
274 			if (parse_netgrp(group, st, 0) != 0)
275 				(void)_nsdispatch(NULL, endnetgrent_dtab,
276 				    NSDB_NETGROUP, "endnetgrent", src);
277 			else
278 				st->st_grname = strdup(group);
279 			(void)fclose(st->st_netf);
280 			st->st_netf = NULL;
281 		}
282 	}
283 	st->st_nextgrp = st->st_gr;
284 	return (st->st_grname != NULL ? NS_SUCCESS : NS_NOTFOUND);
285 }
286 
287 static int
288 files_endnetgrent(void *retval, void *mdata, va_list ap)
289 {
290 	struct netgr_state *st;
291 
292 	if (netgr_getstate(&st) != 0)
293 		return (NS_UNAVAIL);
294 	netgr_endstate(st);
295 	return (NS_SUCCESS);
296 }
297 
298 static int
299 compat_getnetgrent_r(void *retval, void *mdata, va_list ap)
300 {
301 	char **hostp, **userp, **domp, *buf;
302 	size_t bufsize;
303 	int *errnop;
304 #ifdef YP
305 	_yp_innetgr = 0;
306 #endif
307 
308 	hostp = va_arg(ap, char **);
309 	userp = va_arg(ap, char **);
310 	domp = va_arg(ap, char **);
311 	buf = va_arg(ap, char *);
312 	bufsize = va_arg(ap, size_t);
313 	errnop = va_arg(ap, int *);
314 
315 	return (_getnetgrent_r(hostp, userp, domp, buf, bufsize, errnop,
316 	    &compat_state));
317 }
318 
319 /*
320  * compat_setnetgrent()
321  * Parse the netgroup file looking for the netgroup and build the list
322  * of netgrp structures. Let parse_netgrp() and read_for_group() do
323  * most of the work.
324  */
325 static int
326 compat_setnetgrent(void *retval, void *mdata, va_list ap)
327 {
328 	FILE *netf;
329 	const char *group;
330 #ifdef YP
331 	struct stat _yp_statp;
332 	char _yp_plus;
333 #endif
334 
335 	group = va_arg(ap, const char *);
336 
337 	/* Sanity check */
338 	if (group == NULL || !strlen(group))
339 		return (NS_RETURN);
340 
341 	if (compat_state.st_gr == NULL ||
342 	    strcmp(group, compat_state.st_grname) != 0) {
343 		_compat_clearstate();
344 
345 #ifdef YP
346 		/* Presumed guilty until proven innocent. */
347 		_use_only_yp = 0;
348 		/*
349 		 * If /etc/netgroup doesn't exist or is empty,
350 		 * use NIS exclusively.
351 		 */
352 		if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) &&
353 		    errno == ENOENT) || _yp_statp.st_size == 0)
354 			_use_only_yp = _netgr_yp_enabled = 1;
355 		if ((netf = fopen(_PATH_NETGROUP,"re")) != NULL ||_use_only_yp){
356 			compat_state.st_netf = netf;
357 		/*
358 		 * Icky: grab the first character of the netgroup file
359 		 * and turn on NIS if it's a '+'. rewind the stream
360 		 * afterwards so we don't goof up read_for_group() later.
361 		 */
362 			if (netf) {
363 				fscanf(netf, "%c", &_yp_plus);
364 				rewind(netf);
365 				if (_yp_plus == '+')
366 					_use_only_yp = _netgr_yp_enabled = 1;
367 			}
368 		/*
369 		 * If we were called specifically for an innetgr()
370 		 * lookup and we're in NIS-only mode, short-circuit
371 		 * parse_netgroup() and cut directly to the chase.
372 		 */
373 			if (_use_only_yp && _yp_innetgr) {
374 				/* dohw! */
375 				if (netf != NULL)
376 					fclose(netf);
377 				return (NS_RETURN);
378 			}
379 #else
380 		if ((netf = fopen(_PATH_NETGROUP, "re"))) {
381 			compat_state.st_netf = netf;
382 #endif
383 			if (parse_netgrp(group, &compat_state, 1)) {
384 				_compat_clearstate();
385 			} else {
386 				compat_state.st_grname = strdup(group);
387 			}
388 			if (netf)
389 				fclose(netf);
390 		}
391 	}
392 	compat_state.st_nextgrp = compat_state.st_gr;
393 	return (NS_SUCCESS);
394 }
395 
396 static void
397 _compat_clearstate(void)
398 {
399 
400 #ifdef YP
401 	_netgr_yp_enabled = 0;
402 #endif
403 	netgr_endstate(&compat_state);
404 }
405 
406 /*
407  * compat_endnetgrent() - cleanup
408  */
409 static int
410 compat_endnetgrent(void *retval, void *mdata, va_list ap)
411 {
412 
413 	_compat_clearstate();
414 	return (NS_SUCCESS);
415 }
416 
417 int
418 _getnetgrent_r(char **hostp, char **userp, char **domp, char *buf,
419     size_t bufsize, int *errnop, struct netgr_state *st)
420 {
421 	char *p, *src;
422 	size_t len;
423 	int rv;
424 
425 #define	COPY_NG_ELEM(dstp, i) do {					\
426 	src = st->st_nextgrp->ng_str[(i)];				\
427 	if (src == NULL)						\
428 		src = "";						\
429 	len = strlcpy(p, src, bufsize);					\
430 	if (len >= bufsize) {						\
431 		*errnop = ERANGE;					\
432 		return (NS_RETURN);					\
433 	}								\
434 	*(dstp) = p;							\
435 	p += len + 1;							\
436 	bufsize -= len + 1;						\
437 } while (0)
438 
439 	p = buf;
440 	if (st->st_nextgrp != NULL) {
441 		COPY_NG_ELEM(hostp, NG_HOST);
442 		COPY_NG_ELEM(userp, NG_USER);
443 		COPY_NG_ELEM(domp, NG_DOM);
444 		st->st_nextgrp = st->st_nextgrp->ng_next;
445 		rv = NS_SUCCESS;
446 	} else {
447 		rv = NS_NOTFOUND;
448 	}
449 #undef COPY_NG_ELEM
450 
451 	return (rv);
452 }
453 
454 #ifdef YP
455 static int
456 _listmatch(const char *list, const char *group, int len)
457 {
458 	const char *ptr = list;
459 	const char *cptr;
460 	int glen = strlen(group);
461 
462 	/* skip possible leading whitespace */
463 	while (isspace((unsigned char)*ptr))
464 		ptr++;
465 
466 	while (ptr < list + len) {
467 		cptr = ptr;
468 		while(*ptr != ','  && *ptr != '\0' && !isspace((unsigned char)*ptr))
469 			ptr++;
470 		if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
471 			return (1);
472 		while (*ptr == ','  || isspace((unsigned char)*ptr))
473 			ptr++;
474 	}
475 
476 	return (0);
477 }
478 
479 static int
480 _revnetgr_lookup(char* lookupdom, char* map, const char* str,
481 		 const char* dom, const char* group)
482 {
483 	int y, rv, rot;
484 	char key[MAXHOSTNAMELEN];
485 	char *result;
486 	int resultlen;
487 
488 	for (rot = 0; ; rot++) {
489 		switch (rot) {
490 		case 0:
491 			snprintf(key, MAXHOSTNAMELEN, "%s.%s", str,
492 			    dom ? dom : lookupdom);
493 			break;
494 		case 1:
495 			snprintf(key, MAXHOSTNAMELEN, "%s.*", str);
496 			break;
497 		case 2:
498 			snprintf(key, MAXHOSTNAMELEN, "*.%s",
499 			    dom ? dom : lookupdom);
500 			break;
501 		case 3:
502 			snprintf(key, MAXHOSTNAMELEN, "*.*");
503 			break;
504 		default:
505 			return (0);
506 		}
507 		y = yp_match(lookupdom, map, key, strlen(key), &result,
508 		    &resultlen);
509 		if (y == 0) {
510 			rv = _listmatch(result, group, resultlen);
511 			free(result);
512 			if (rv)
513 				return (1);
514 		} else if (y != YPERR_KEY) {
515 			/*
516 			 * If we get an error other than 'no
517 			 * such key in map' then something is
518 			 * wrong and we should stop the search.
519 			 */
520 			return (-1);
521 		}
522 	}
523 }
524 #endif
525 
526 /*
527  * Search for a match in a netgroup.
528  */
529 static int
530 compat_innetgr(void *retval, void *mdata, va_list ap)
531 {
532 #ifdef YP
533 	const ns_src src[] = {
534 		{ mdata, NS_SUCCESS },
535 		{ NULL, 0 },
536 	};
537 #endif
538 	const char *group, *host, *user, *dom;
539 
540 	group = va_arg(ap, const char *);
541 	host = va_arg(ap, const char *);
542 	user = va_arg(ap, const char *);
543 	dom = va_arg(ap, const char *);
544 
545 	if (group == NULL || !strlen(group))
546 		return (NS_RETURN);
547 
548 #ifdef YP
549 	_yp_innetgr = 1;
550 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
551 	    src, group);
552 	_yp_innetgr = 0;
553 	/*
554 	 * If we're in NIS-only mode, do the search using
555 	 * NIS 'reverse netgroup' lookups.
556 	 *
557 	 * What happens with 'reverse netgroup' lookups:
558 	 *
559 	 * 1) try 'reverse netgroup' lookup
560 	 *    1.a) if host is specified and user is null:
561 	 *         look in netgroup.byhost
562 	 *         (try host.domain, host.*, *.domain or *.*)
563 	 *         if found, return yes
564 	 *    1.b) if user is specified and host is null:
565 	 *         look in netgroup.byuser
566 	 *         (try host.domain, host.*, *.domain or *.*)
567 	 *         if found, return yes
568 	 *    1.c) if both host and user are specified,
569 	 *         don't do 'reverse netgroup' lookup.  It won't work.
570 	 *    1.d) if neither host ane user are specified (why?!?)
571 	 *         don't do 'reverse netgroup' lookup either.
572 	 * 2) if domain is specified and 'reverse lookup' is done:
573 	 *    'reverse lookup' was authoritative.  bye bye.
574 	 * 3) otherwise, too bad, try it the slow way.
575 	 */
576 	if (_use_only_yp && (host == NULL) != (user == NULL)) {
577 		int ret;
578 		if(yp_get_default_domain(&_netgr_yp_domain))
579 			return (NS_NOTFOUND);
580 		ret = _revnetgr_lookup(_netgr_yp_domain,
581 				      host?"netgroup.byhost":"netgroup.byuser",
582 				      host?host:user, dom, group);
583 		if (ret == 1) {
584 			*(int *)retval = 1;
585 			return (NS_SUCCESS);
586 		} else if (ret == 0 && dom != NULL) {
587 			*(int *)retval = 0;
588 			return (NS_SUCCESS);
589 		}
590 	}
591 #endif /* YP */
592 
593 	return (_innetgr_fallback(retval, mdata, group, host, user, dom));
594 }
595 
596 static int
597 _innetgr_fallback(void *retval, void *mdata, const char *group, const char *host,
598     const char *user, const char *dom)
599 {
600 	const ns_src src[] = {
601 		{ mdata, NS_SUCCESS },
602 		{ NULL, 0 },
603 	};
604 	char *h, *u, *d;
605 	char *buf;
606 	size_t bufsize;
607 	int rv, ret_errno;
608 
609 	if (group == NULL || group[0] == '\0')
610 		return (NS_RETURN);
611 
612 	bufsize = NGRP_STORAGE_INITIAL;
613 	buf = malloc(bufsize);
614 	if (buf == NULL)
615 		return (NS_UNAVAIL);
616 
617 	*(int *)retval = 0;
618 
619 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
620 	    src, group);
621 
622 	for (;;) {
623 		do {
624 			ret_errno = 0;
625 			rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP,
626 			    "getnetgrent_r", src, &h, &u, &d, buf, bufsize,
627 			    &ret_errno);
628 			if (rv != NS_SUCCESS && ret_errno == ERANGE) {
629 				bufsize *= 2;
630 				if (bufsize > NGRP_STORAGE_MAX ||
631 				    (buf = reallocf(buf, bufsize)) == NULL)
632 					goto out;
633 			}
634 		} while (rv != NS_SUCCESS && ret_errno == ERANGE);
635 
636 		if (rv != NS_SUCCESS) {
637 			if (rv == NS_NOTFOUND && ret_errno == 0)
638 				rv = NS_SUCCESS;
639 			break;
640 		}
641 
642 		if ((host == NULL || h == NULL || strcmp(host, h) == 0) &&
643 		    (user == NULL || u == NULL || strcmp(user, u) == 0) &&
644 		    (dom == NULL || d == NULL || strcmp(dom, d) == 0)) {
645 			*(int *)retval = 1;
646 			break;
647 		}
648 	}
649 
650 out:
651 	free(buf);
652 	(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP, "endnetgrent",
653 	    src);
654 	return (rv);
655 }
656 
657 static int
658 innetgr_fallback(void *retval, void *mdata, va_list ap)
659 {
660 	const char *group, *host, *user, *dom;
661 
662 	group = va_arg(ap, const char *);
663 	host = va_arg(ap, const char *);
664 	user = va_arg(ap, const char *);
665 	dom = va_arg(ap, const char *);
666 
667 	return (_innetgr_fallback(retval, mdata, group, host, user, dom));
668 }
669 
670 /*
671  * Parse the netgroup file setting up the linked lists.
672  */
673 static int
674 parse_netgrp(const char *group, struct netgr_state *st, int niscompat)
675 {
676 	struct netgrp *grp;
677 	struct linelist *lp = st->st_linehead;
678 	char **ng;
679 	char *epos, *gpos, *pos, *spos;
680 	int freepos, len, strpos;
681 #ifdef DEBUG
682 	int fields;
683 #endif
684 
685 	/*
686 	 * First, see if the line has already been read in.
687 	 */
688 	while (lp) {
689 		if (!strcmp(group, lp->l_groupname))
690 			break;
691 		lp = lp->l_next;
692 	}
693 	if (lp == NULL && (lp = read_for_group(group, st, niscompat)) == NULL)
694 		return (1);
695 	if (lp->l_parsed) {
696 #ifdef DEBUG
697 		/*
698 		 * This error message is largely superflous since the
699 		 * code handles the error condition sucessfully, and
700 		 * spewing it out from inside libc can actually hose
701 		 * certain programs.
702 		 */
703 		fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
704 #endif
705 		return (1);
706 	} else
707 		lp->l_parsed = 1;
708 	pos = lp->l_line;
709 	/* Watch for null pointer dereferences, dammit! */
710 	while (pos != NULL && *pos != '\0') {
711 		if (*pos == '(') {
712 			grp = malloc(sizeof(*grp));
713 			if (grp == NULL)
714 				return (1);
715 			ng = grp->ng_str;
716 			bzero(grp, sizeof(*grp));
717 			pos++;
718 			gpos = strsep(&pos, ")");
719 #ifdef DEBUG
720 			fields = 0;
721 #endif
722 			for (strpos = 0; strpos < 3; strpos++) {
723 				if ((spos = strsep(&gpos, ",")) == NULL) {
724 					/*
725 					 * All other systems I've tested
726 					 * return NULL for empty netgroup
727 					 * fields. It's up to user programs
728 					 * to handle the NULLs appropriately.
729 					 */
730 					ng[strpos] = NULL;
731 					continue;
732 				}
733 #ifdef DEBUG
734 				fields++;
735 #endif
736 				while (*spos == ' ' || *spos == '\t')
737 					spos++;
738 				if ((epos = strpbrk(spos, " \t"))) {
739 					*epos = '\0';
740 					len = epos - spos;
741 				} else
742 					len = strlen(spos);
743 				if (len <= 0)
744 					continue;
745 				ng[strpos] = malloc(len + 1);
746 				if (ng[strpos] == NULL) {
747 					for (freepos = 0; freepos < strpos;
748 					    freepos++)
749 						free(ng[freepos]);
750 					free(grp);
751 					return (1);
752 				}
753 				bcopy(spos, ng[strpos], len + 1);
754 			}
755 			grp->ng_next = st->st_gr;
756 			st->st_gr = grp;
757 #ifdef DEBUG
758 			/*
759 			 * Note: on other platforms, malformed netgroup
760 			 * entries are not normally flagged. While we
761 			 * can catch bad entries and report them, we should
762 			 * stay silent by default for compatibility's sake.
763 			 */
764 			if (fields < 3) {
765 				fprintf(stderr,
766 				"Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
767 				    ng[NG_HOST] == NULL ? "" : ng[NG_HOST],
768 				    ng[NG_USER] == NULL ? "" : ",",
769 				    ng[NG_USER] == NULL ? "" : ng[NG_USER],
770 				    ng[NG_DOM] == NULL ? "" : ",",
771 				    ng[NG_DOM] == NULL ? "" : ng[NG_DOM],
772 				    lp->l_groupname);
773 			}
774 #endif
775 		} else {
776 			spos = strsep(&pos, ", \t");
777 			if (parse_netgrp(spos, st, niscompat))
778 				continue;
779 		}
780 		if (pos == NULL)
781 			break;
782 		while (*pos == ' ' || *pos == ',' || *pos == '\t')
783 			pos++;
784 	}
785 	return (0);
786 }
787 
788 /*
789  * Read the netgroup file and save lines until the line for the netgroup
790  * is found. Return 1 if eof is encountered.
791  */
792 static struct linelist *
793 read_for_group(const char *group, struct netgr_state *st, int niscompat)
794 {
795 	char *linep, *olinep, *pos, *spos;
796 	int len, olen;
797 	int cont;
798 	struct linelist *lp;
799 	char line[LINSIZ + 2];
800 	FILE *netf;
801 #ifdef YP
802 	char *result;
803 	int resultlen;
804 	linep = NULL;
805 
806 	netf = st->st_netf;
807 	while ((_netgr_yp_enabled && niscompat) ||
808 	    fgets(line, LINSIZ, netf) != NULL) {
809 		if (_netgr_yp_enabled) {
810 			if(!_netgr_yp_domain)
811 				if(yp_get_default_domain(&_netgr_yp_domain))
812 					continue;
813 			if (yp_match(_netgr_yp_domain, "netgroup", group,
814 			    strlen(group), &result, &resultlen)) {
815 				free(result);
816 				if (_use_only_yp)
817 					return ((struct linelist *)0);
818 				else {
819 					_netgr_yp_enabled = 0;
820 					continue;
821 				}
822 			}
823 			if (strlen(result) == 0) {
824 				free(result);
825 				return (NULL);
826 			}
827 			snprintf(line, LINSIZ, "%s %s", group, result);
828 			free(result);
829 		}
830 #else
831 	linep = NULL;
832 	while (fgets(line, LINSIZ, netf) != NULL) {
833 #endif
834 		pos = (char *)&line;
835 #ifdef YP
836 		if (niscompat && *pos == '+') {
837 			_netgr_yp_enabled = 1;
838 			continue;
839 		}
840 #endif
841 		if (*pos == '#')
842 			continue;
843 		while (*pos == ' ' || *pos == '\t')
844 			pos++;
845 		spos = pos;
846 		while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
847 			*pos != '\0')
848 			pos++;
849 		len = pos - spos;
850 		while (*pos == ' ' || *pos == '\t')
851 			pos++;
852 		if (*pos != '\n' && *pos != '\0') {
853 			lp = malloc(sizeof (*lp));
854 			if (lp == NULL)
855 				return (NULL);
856 			lp->l_parsed = 0;
857 			lp->l_groupname = malloc(len + 1);
858 			if (lp->l_groupname == NULL) {
859 				free(lp);
860 				return (NULL);
861 			}
862 			bcopy(spos, lp->l_groupname, len);
863 			*(lp->l_groupname + len) = '\0';
864 			len = strlen(pos);
865 			olen = 0;
866 
867 			/*
868 			 * Loop around handling line continuations.
869 			 */
870 			do {
871 				if (*(pos + len - 1) == '\n')
872 					len--;
873 				if (*(pos + len - 1) == '\\') {
874 					len--;
875 					cont = 1;
876 				} else
877 					cont = 0;
878 				if (len > 0) {
879 					linep = malloc(olen + len + 1);
880 					if (linep == NULL) {
881 						free(lp->l_groupname);
882 						free(lp);
883 						if (olen > 0)
884 							free(olinep);
885 						return (NULL);
886 					}
887 					if (olen > 0) {
888 						bcopy(olinep, linep, olen);
889 						free(olinep);
890 					}
891 					bcopy(pos, linep + olen, len);
892 					olen += len;
893 					*(linep + olen) = '\0';
894 					olinep = linep;
895 				}
896 				if (cont) {
897 					if (fgets(line, LINSIZ, netf)) {
898 						pos = line;
899 						len = strlen(pos);
900 					} else
901 						cont = 0;
902 				}
903 			} while (cont);
904 			lp->l_line = linep;
905 			lp->l_next = st->st_linehead;
906 			st->st_linehead = lp;
907 
908 			/*
909 			 * If this is the one we wanted, we are done.
910 			 */
911 			if (!strcmp(lp->l_groupname, group))
912 				return (lp);
913 		}
914 	}
915 #ifdef YP
916 	/*
917 	 * Yucky. The recursive nature of this whole mess might require
918 	 * us to make more than one pass through the netgroup file.
919 	 * This might be best left outside the #ifdef YP, but YP is
920 	 * defined by default anyway, so I'll leave it like this
921 	 * until I know better.
922 	 */
923 	rewind(netf);
924 #endif
925 	return (NULL);
926 }
927 
928 int
929 getnetgrent_r(char **hostp, char **userp, char **domp, char *buf, size_t bufsize)
930 {
931 	int rv, ret_errno;
932 
933 	ret_errno = 0;
934 	rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP, "getnetgrent_r",
935 	    defaultsrc, hostp, userp, domp, buf, bufsize, &ret_errno);
936 	if (rv == NS_SUCCESS) {
937 		return (1);
938 	} else {
939 		errno = ret_errno;
940 		return (0);
941 	}
942 }
943 
944 int
945 getnetgrent(char **hostp, char **userp, char **domp)
946 {
947 	static char *ngrp_storage;
948 	static size_t ngrp_storage_size;
949 	int ret_errno, rv;
950 
951 	if (ngrp_storage == NULL) {
952 		ngrp_storage_size = NGRP_STORAGE_INITIAL;
953 		ngrp_storage = malloc(ngrp_storage_size);
954 		if (ngrp_storage == NULL)
955 			return (0);
956 	}
957 
958 	do {
959 		ret_errno = 0;
960 		rv = _nsdispatch(NULL, getnetgrent_dtab, NSDB_NETGROUP,
961 		    "getnetgrent_r", defaultsrc, hostp, userp, domp,
962 		    ngrp_storage, ngrp_storage_size, &ret_errno);
963 		if (rv != NS_SUCCESS && ret_errno == ERANGE) {
964 			ngrp_storage_size *= 2;
965 			if (ngrp_storage_size > NGRP_STORAGE_MAX) {
966 				free(ngrp_storage);
967 				ngrp_storage = NULL;
968 				errno = ERANGE;
969 				return (0);
970 			}
971 			ngrp_storage = reallocf(ngrp_storage,
972 			    ngrp_storage_size);
973 			if (ngrp_storage == NULL)
974 				return (0);
975 		}
976 	} while (rv != NS_SUCCESS && ret_errno == ERANGE);
977 
978 	if (rv == NS_SUCCESS) {
979 		return (1);
980 	} else {
981 		errno = ret_errno;
982 		return (0);
983 	}
984 }
985 
986 void
987 setnetgrent(const char *netgroup)
988 {
989 
990 	(void)_nsdispatch(NULL, setnetgrent_dtab, NSDB_NETGROUP, "setnetgrent",
991 	    defaultsrc, netgroup);
992 }
993 
994 void
995 endnetgrent(void)
996 {
997 
998 	(void)_nsdispatch(NULL, endnetgrent_dtab, NSDB_NETGROUP, "endnetgrent",
999 	    defaultsrc);
1000 }
1001 
1002 int
1003 innetgr(const char *netgroup, const char *host, const char *user,
1004     const char *domain)
1005 {
1006 	static const ns_dtab dtab[] = {
1007 		NS_COMPAT_CB(compat_innetgr, NULL)
1008 		NS_FALLBACK_CB(innetgr_fallback)
1009 		{ NULL, NULL, NULL },
1010 	};
1011 	int result, rv;
1012 
1013 	rv = _nsdispatch(&result, dtab, NSDB_NETGROUP, "innetgr", defaultsrc,
1014 	    netgroup, host, user, domain);
1015 	return (rv == NS_SUCCESS ? result : 0);
1016 }
1017