xref: /freebsd/lib/libc/gen/getgrent.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
1 /*-
2  * Copyright (c) 2003 Networks Associates Technology, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by
6  * Jacques A. Vidrine, Safeport Network Services, and Network
7  * Associates Laboratories, the Security Research Division of Network
8  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
9  * ("CBOSS"), as part of the DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "namespace.h"
37 #include <sys/param.h>
38 #ifdef YP
39 #include <rpc/rpc.h>
40 #include <rpcsvc/yp_prot.h>
41 #include <rpcsvc/ypclnt.h>
42 #endif
43 #include <ctype.h>
44 #include <errno.h>
45 #ifdef HESIOD
46 #include <hesiod.h>
47 #endif
48 #include <grp.h>
49 #include <nsswitch.h>
50 #include <pthread.h>
51 #include <pthread_np.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <syslog.h>
56 #include <unistd.h>
57 #include "un-namespace.h"
58 #include "libc_private.h"
59 #include "nss_tls.h"
60 
61 
62 enum constants {
63 	GRP_STORAGE_INITIAL	= 1 << 10, /* 1 KByte */
64 	GRP_STORAGE_MAX		= 1 << 20, /* 1 MByte */
65 	SETGRENT		= 1,
66 	ENDGRENT		= 2,
67 	HESIOD_NAME_MAX		= 256,
68 };
69 
70 static const ns_src defaultsrc[] = {
71 	{ NSSRC_COMPAT, NS_SUCCESS },
72 	{ NULL, 0 }
73 };
74 
75 int	 __gr_match_entry(const char *, size_t, enum nss_lookup_type,
76 	    const char *, gid_t);
77 int	 __gr_parse_entry(char *, size_t, struct group *, char *, size_t,
78 	    int *);
79 
80 static	int	 is_comment_line(const char *, size_t);
81 
82 union key {
83 	const char	*name;
84 	gid_t		 gid;
85 };
86 static	struct group *getgr(int (*)(union key, struct group *, char *, size_t,
87 		    struct group **), union key);
88 static	int	 wrap_getgrnam_r(union key, struct group *, char *, size_t,
89 		    struct group **);
90 static	int	 wrap_getgrgid_r(union key, struct group *, char *, size_t,
91 		    struct group **);
92 static	int	 wrap_getgrent_r(union key, struct group *, char *, size_t,
93 		    struct group **);
94 
95 struct files_state {
96 	FILE	*fp;
97 	int	 stayopen;
98 };
99 static	void	 files_endstate(void *);
100 NSS_TLS_HANDLING(files);
101 static	int	 files_setgrent(void *, void *, va_list);
102 static	int	 files_group(void *, void *, va_list);
103 
104 
105 #ifdef HESIOD
106 struct dns_state {
107 	long	counter;
108 };
109 static	void	 dns_endstate(void *);
110 NSS_TLS_HANDLING(dns);
111 static	int	 dns_setgrent(void *, void *, va_list);
112 static	int	 dns_group(void *, void *, va_list);
113 #endif
114 
115 
116 #ifdef YP
117 struct nis_state {
118 	char	 domain[MAXHOSTNAMELEN];
119 	int	 done;
120 	char	*key;
121 	int	 keylen;
122 };
123 static	void	 nis_endstate(void *);
124 NSS_TLS_HANDLING(nis);
125 static	int	 nis_setgrent(void *, void *, va_list);
126 static	int	 nis_group(void *, void *, va_list);
127 #endif
128 
129 struct compat_state {
130 	FILE	*fp;
131 	int	 stayopen;
132 	char	*name;
133 	enum _compat {
134 		COMPAT_MODE_OFF = 0,
135 		COMPAT_MODE_ALL,
136 		COMPAT_MODE_NAME
137 	}	 compat;
138 };
139 static	void	 compat_endstate(void *);
140 NSS_TLS_HANDLING(compat);
141 static	int	 compat_setgrent(void *, void *, va_list);
142 static	int	 compat_group(void *, void *, va_list);
143 
144 
145 /* XXX IEEE Std 1003.1, 2003 specifies `void setgrent(void)' */
146 int
147 setgrent(void)
148 {
149 	static const ns_dtab dtab[] = {
150 		{ NSSRC_FILES, files_setgrent, (void *)SETGRENT },
151 #ifdef HESIOD
152 		{ NSSRC_DNS, dns_setgrent, (void *)SETGRENT },
153 #endif
154 #ifdef YP
155 		{ NSSRC_NIS, nis_setgrent, (void *)SETGRENT },
156 #endif
157 		{ NSSRC_COMPAT, compat_setgrent, (void *)SETGRENT },
158 		{ NULL, NULL, NULL }
159 	};
160 	(void)_nsdispatch(NULL, dtab, NSDB_GROUP, "setgrent", defaultsrc, 0);
161 	return (1);
162 }
163 
164 
165 int
166 setgroupent(int stayopen)
167 {
168 	static const ns_dtab dtab[] = {
169 		{ NSSRC_FILES, files_setgrent, (void *)SETGRENT },
170 #ifdef HESIOD
171 		{ NSSRC_DNS, dns_setgrent, (void *)SETGRENT },
172 #endif
173 #ifdef YP
174 		{ NSSRC_NIS, nis_setgrent, (void *)SETGRENT },
175 #endif
176 		{ NSSRC_COMPAT, compat_setgrent, (void *)SETGRENT },
177 		{ NULL, NULL, NULL }
178 	};
179 	(void)_nsdispatch(NULL, dtab, NSDB_GROUP, "setgrent", defaultsrc,
180 	    stayopen);
181 	return (1);
182 }
183 
184 
185 void
186 endgrent(void)
187 {
188 	static const ns_dtab dtab[] = {
189 		{ NSSRC_FILES, files_setgrent, (void *)ENDGRENT },
190 #ifdef HESIOD
191 		{ NSSRC_DNS, dns_setgrent, (void *)ENDGRENT },
192 #endif
193 #ifdef YP
194 		{ NSSRC_NIS, nis_setgrent, (void *)ENDGRENT },
195 #endif
196 		{ NSSRC_COMPAT, compat_setgrent, (void *)ENDGRENT },
197 		{ NULL, NULL, NULL }
198 	};
199 	(void)_nsdispatch(NULL, dtab, NSDB_GROUP, "endgrent", defaultsrc);
200 }
201 
202 
203 int
204 getgrent_r(struct group *grp, char *buffer, size_t bufsize,
205     struct group **result)
206 {
207 	static const ns_dtab dtab[] = {
208 		{ NSSRC_FILES, files_group, (void *)nss_lt_all },
209 #ifdef HESIOD
210 		{ NSSRC_DNS, dns_group, (void *)nss_lt_all },
211 #endif
212 #ifdef YP
213 		{ NSSRC_NIS, nis_group, (void *)nss_lt_all },
214 #endif
215 		{ NSSRC_COMPAT, compat_group, (void *)nss_lt_all },
216 		{ NULL, NULL, NULL }
217 	};
218 	int	rv, ret_errno;
219 
220 	ret_errno = 0;
221 	*result = NULL;
222 	rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrent_r", defaultsrc,
223 	    grp, buffer, bufsize, &ret_errno);
224 	if (rv == NS_SUCCESS)
225 		return (0);
226 	else
227 		return (ret_errno);
228 }
229 
230 
231 int
232 getgrnam_r(const char *name, struct group *grp, char *buffer, size_t bufsize,
233     struct group **result)
234 {
235 	static const ns_dtab dtab[] = {
236 		{ NSSRC_FILES, files_group, (void *)nss_lt_name },
237 #ifdef HESIOD
238 		{ NSSRC_DNS, dns_group, (void *)nss_lt_name },
239 #endif
240 #ifdef YP
241 		{ NSSRC_NIS, nis_group, (void *)nss_lt_name },
242 #endif
243 		{ NSSRC_COMPAT, compat_group, (void *)nss_lt_name },
244 		{ NULL, NULL, NULL }
245 	};
246 	int	rv, ret_errno;
247 
248 	ret_errno = 0;
249 	*result = NULL;
250 	rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrnam_r", defaultsrc,
251 	    name, grp, buffer, bufsize, &ret_errno);
252 	if (rv == NS_SUCCESS)
253 		return (0);
254 	else
255 		return (ret_errno);
256 }
257 
258 
259 int
260 getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize,
261     struct group **result)
262 {
263 	static const ns_dtab dtab[] = {
264 		{ NSSRC_FILES, files_group, (void *)nss_lt_id },
265 #ifdef HESIOD
266 		{ NSSRC_DNS, dns_group, (void *)nss_lt_id },
267 #endif
268 #ifdef YP
269 		{ NSSRC_NIS, nis_group, (void *)nss_lt_id },
270 #endif
271 		{ NSSRC_COMPAT, compat_group, (void *)nss_lt_id },
272 		{ NULL, NULL, NULL }
273 	};
274 	int	rv, ret_errno;
275 
276 	ret_errno = 0;
277 	*result = NULL;
278 	rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrgid_r", defaultsrc,
279 	    gid, grp, buffer, bufsize, &ret_errno);
280 	if (rv == NS_SUCCESS)
281 		return (0);
282 	else
283 		return (ret_errno);
284 }
285 
286 
287 static struct group	 grp;
288 static char		*grp_storage;
289 static size_t		 grp_storage_size;
290 
291 static struct group *
292 getgr(int (*fn)(union key, struct group *, char *, size_t, struct group **),
293     union key key)
294 {
295 	int		 rv;
296 	struct group	*res;
297 
298 	if (grp_storage == NULL) {
299 		grp_storage = malloc(GRP_STORAGE_INITIAL);
300 		if (grp_storage == NULL)
301 			return (NULL);
302 		grp_storage_size = GRP_STORAGE_INITIAL;
303 	}
304 	do {
305 		rv = fn(key, &grp, grp_storage, grp_storage_size, &res);
306 		if (res == NULL && rv == ERANGE) {
307 			free(grp_storage);
308 			if ((grp_storage_size << 1) > GRP_STORAGE_MAX) {
309 				grp_storage = NULL;
310 				errno = ERANGE;
311 				return (NULL);
312 			}
313 			grp_storage_size <<= 1;
314 			grp_storage = malloc(grp_storage_size);
315 			if (grp_storage == NULL)
316 				return (NULL);
317 		}
318 	} while (res == NULL && rv == ERANGE);
319 	if (rv != 0)
320 		errno = rv;
321 	return (res);
322 }
323 
324 
325 static int
326 wrap_getgrnam_r(union key key, struct group *grp, char *buffer, size_t bufsize,
327     struct group **res)
328 {
329 	return (getgrnam_r(key.name, grp, buffer, bufsize, res));
330 }
331 
332 
333 static int
334 wrap_getgrgid_r(union key key, struct group *grp, char *buffer, size_t bufsize,
335     struct group **res)
336 {
337 	return (getgrgid_r(key.gid, grp, buffer, bufsize, res));
338 }
339 
340 
341 static int
342 wrap_getgrent_r(union key key __unused, struct group *grp, char *buffer,
343     size_t bufsize, struct group **res)
344 {
345 	return (getgrent_r(grp, buffer, bufsize, res));
346 }
347 
348 
349 struct group *
350 getgrnam(const char *name)
351 {
352 	union key key;
353 
354 	key.name = name;
355 	return (getgr(wrap_getgrnam_r, key));
356 }
357 
358 
359 struct group *
360 getgrgid(gid_t gid)
361 {
362 	union key key;
363 
364 	key.gid = gid;
365 	return (getgr(wrap_getgrgid_r, key));
366 }
367 
368 
369 struct group *
370 getgrent(void)
371 {
372 	union key key;
373 
374 	key.gid = 0; /* not used */
375 	return (getgr(wrap_getgrent_r, key));
376 }
377 
378 
379 static int
380 is_comment_line(const char *s, size_t n)
381 {
382 	const char	*eom;
383 
384 	eom = &s[n];
385 
386 	for (; s < eom; s++)
387 		if (*s == '#' || !isspace((unsigned char)*s))
388 			break;
389 	return (*s == '#' || s == eom);
390 }
391 
392 
393 /*
394  * files backend
395  */
396 static void
397 files_endstate(void *p)
398 {
399 
400 	if (p == NULL)
401 		return;
402 	if (((struct files_state *)p)->fp != NULL)
403 		fclose(((struct files_state *)p)->fp);
404 	free(p);
405 }
406 
407 
408 static int
409 files_setgrent(void *retval, void *mdata, va_list ap)
410 {
411 	struct files_state *st;
412 	int		 rv, stayopen;
413 
414 	rv = files_getstate(&st);
415 	if (rv != 0)
416 		return (NS_UNAVAIL);
417 	switch ((enum constants)mdata) {
418 	case SETGRENT:
419 		stayopen = va_arg(ap, int);
420 		if (st->fp != NULL)
421 			rewind(st->fp);
422 		else if (stayopen)
423 			st->fp = fopen(_PATH_GROUP, "r");
424 		break;
425 	case ENDGRENT:
426 		if (st->fp != NULL) {
427 			fclose(st->fp);
428 			st->fp = NULL;
429 		}
430 		break;
431 	default:
432 		break;
433 	}
434 	return (NS_UNAVAIL);
435 }
436 
437 
438 static int
439 files_group(void *retval, void *mdata, va_list ap)
440 {
441 	struct files_state	*st;
442 	enum nss_lookup_type	 how;
443 	const char		*name, *line;
444 	struct group		*grp;
445 	gid_t			 gid;
446 	char			*buffer;
447 	size_t			 bufsize, linesize;
448 	int			 rv, stayopen, *errnop;
449 
450 	name = NULL;
451 	gid = (gid_t)-1;
452 	how = (enum nss_lookup_type)mdata;
453 	switch (how) {
454 	case nss_lt_name:
455 		name = va_arg(ap, const char *);
456 		break;
457 	case nss_lt_id:
458 		gid = va_arg(ap, gid_t);
459 		break;
460 	case nss_lt_all:
461 		break;
462 	default:
463 		return (NS_NOTFOUND);
464 	}
465 	grp = va_arg(ap, struct group *);
466 	buffer = va_arg(ap, char *);
467 	bufsize = va_arg(ap, size_t);
468 	errnop = va_arg(ap, int *);
469 	*errnop = files_getstate(&st);
470 	if (*errnop != 0)
471 		return (NS_UNAVAIL);
472 	if (st->fp == NULL &&
473 	    ((st->fp = fopen(_PATH_GROUP, "r")) == NULL)) {
474 		*errnop = errno;
475 		return (NS_UNAVAIL);
476 	}
477 	if (how == nss_lt_all)
478 		stayopen = 1;
479 	else {
480 		rewind(st->fp);
481 		stayopen = st->stayopen;
482 	}
483 	rv = NS_NOTFOUND;
484 	while ((line = fgetln(st->fp, &linesize)) != NULL) {
485 		if (line[linesize-1] == '\n')
486 			linesize--;
487 		rv = __gr_match_entry(line, linesize, how, name, gid);
488 		if (rv != NS_SUCCESS)
489 			continue;
490 		/* We need room at least for the line, a string NUL
491 		 * terminator, alignment padding, and one (char *)
492 		 * pointer for the member list terminator.
493 		 */
494 		if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
495 			*errnop = ERANGE;
496 			rv = NS_RETURN;
497 			break;
498 		}
499 		memcpy(buffer, line, linesize);
500 		buffer[linesize] = '\0';
501 		rv = __gr_parse_entry(buffer, linesize, grp,
502 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
503 		if (rv & NS_TERMINATE)
504 			break;
505 	}
506 	if (!stayopen && st->fp != NULL) {
507 		fclose(st->fp);
508 		st->fp = NULL;
509 	}
510 	if (rv == NS_SUCCESS && retval != NULL)
511 		*(struct group **)retval = grp;
512 	return (rv);
513 }
514 
515 
516 #ifdef HESIOD
517 /*
518  * dns backend
519  */
520 static void
521 dns_endstate(void *p)
522 {
523 
524 	free(p);
525 }
526 
527 
528 static int
529 dns_setgrent(void *retval, void *cb_data, va_list ap)
530 {
531 	struct dns_state	*st;
532 	int			 rv;
533 
534 	rv = dns_getstate(&st);
535 	if (rv != 0)
536 		return (NS_UNAVAIL);
537 	st->counter = 0;
538 	return (NS_UNAVAIL);
539 }
540 
541 
542 static int
543 dns_group(void *retval, void *mdata, va_list ap)
544 {
545 	char			 buf[HESIOD_NAME_MAX];
546 	struct dns_state	*st;
547 	struct group		*grp;
548 	const char		*name, *label;
549 	void			*ctx;
550 	char			*buffer, **hes;
551 	size_t			 bufsize, adjsize, linesize;
552 	gid_t			 gid;
553 	enum nss_lookup_type	 how;
554 	int			 rv, *errnop;
555 
556 	ctx = NULL;
557 	hes = NULL;
558 	name = NULL;
559 	gid = (gid_t)-1;
560 	how = (enum nss_lookup_type)mdata;
561 	switch (how) {
562 	case nss_lt_name:
563 		name = va_arg(ap, const char *);
564 		break;
565 	case nss_lt_id:
566 		gid = va_arg(ap, gid_t);
567 		break;
568 	case nss_lt_all:
569 		break;
570 	}
571 	grp     = va_arg(ap, struct group *);
572 	buffer  = va_arg(ap, char *);
573 	bufsize = va_arg(ap, size_t);
574 	errnop  = va_arg(ap, int *);
575 	*errnop = dns_getstate(&st);
576 	if (*errnop != 0)
577 		return (NS_UNAVAIL);
578 	if (hesiod_init(&ctx) != 0) {
579 		*errnop = errno;
580 		rv = NS_UNAVAIL;
581 		goto fin;
582 	}
583 	do {
584 		rv = NS_NOTFOUND;
585 		switch (how) {
586 		case nss_lt_name:
587 			label = name;
588 			break;
589 		case nss_lt_id:
590 			if (snprintf(buf, sizeof(buf), "%lu",
591 			    (unsigned long)gid) >= sizeof(buf))
592 				goto fin;
593 			label = buf;
594 			break;
595 		case nss_lt_all:
596 			if (st->counter < 0)
597 				goto fin;
598 			if (snprintf(buf, sizeof(buf), "group-%ld",
599 			    st->counter++) >= sizeof(buf))
600 				goto fin;
601 			label = buf;
602 			break;
603 		}
604 		hes = hesiod_resolve(ctx, label,
605 		    how == nss_lt_id ? "gid" : "group");
606 		if ((how == nss_lt_id && hes == NULL &&
607 		    (hes = hesiod_resolve(ctx, buf, "group")) == NULL) ||
608 		    hes == NULL) {
609 			if (how == nss_lt_all)
610 				st->counter = -1;
611 			if (errno != ENOENT)
612 				*errnop = errno;
613 			goto fin;
614 		}
615 		rv = __gr_match_entry(hes[0], strlen(hes[0]), how, name, gid);
616 		if (rv != NS_SUCCESS) {
617 			hesiod_free_list(ctx, hes);
618 			hes = NULL;
619 			continue;
620 		}
621 		/* We need room at least for the line, a string NUL
622 		 * terminator, alignment padding, and one (char *)
623 		 * pointer for the member list terminator.
624 		 */
625 		adjsize = bufsize - _ALIGNBYTES - sizeof(char *);
626 		linesize = strlcpy(buffer, hes[0], adjsize);
627 		if (linesize >= adjsize) {
628 			*errnop = ERANGE;
629 			rv = NS_RETURN;
630 			goto fin;
631 		}
632 		hesiod_free_list(ctx, hes);
633 		hes = NULL;
634 		rv = __gr_parse_entry(buffer, linesize, grp,
635 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
636 	} while (how == nss_lt_all && !(rv & NS_TERMINATE));
637 fin:
638 	if (hes != NULL)
639 		hesiod_free_list(ctx, hes);
640 	if (ctx != NULL)
641 		hesiod_end(ctx);
642 	if (rv == NS_SUCCESS && retval != NULL)
643 		*(struct group **)retval = grp;
644 	return (rv);
645 }
646 #endif /* HESIOD */
647 
648 
649 #ifdef YP
650 /*
651  * nis backend
652  */
653 static void
654 nis_endstate(void *p)
655 {
656 
657 	if (p == NULL)
658 		return;
659 	free(((struct nis_state *)p)->key);
660 	free(p);
661 }
662 
663 
664 static int
665 nis_setgrent(void *retval, void *cb_data, va_list ap)
666 {
667 	struct nis_state	*st;
668 	int			 rv;
669 
670 	rv = nis_getstate(&st);
671 	if (rv != 0)
672 		return (NS_UNAVAIL);
673 	st->done = 0;
674 	free(st->key);
675 	st->key = NULL;
676 	return (NS_UNAVAIL);
677 }
678 
679 
680 static int
681 nis_group(void *retval, void *mdata, va_list ap)
682 {
683 	char		 *map;
684 	struct nis_state *st;
685 	struct group	*grp;
686 	const char	*name;
687 	char		*buffer, *key, *result;
688 	size_t		 bufsize;
689 	gid_t		 gid;
690 	enum nss_lookup_type how;
691 	int		*errnop, keylen, resultlen, rv;
692 
693 	name = NULL;
694 	gid = (gid_t)-1;
695 	how = (enum nss_lookup_type)mdata;
696 	switch (how) {
697 	case nss_lt_name:
698 		name = va_arg(ap, const char *);
699 		map = "group.byname";
700 		break;
701 	case nss_lt_id:
702 		gid = va_arg(ap, gid_t);
703 		map = "group.bygid";
704 		break;
705 	case nss_lt_all:
706 		map = "group.byname";
707 		break;
708 	}
709 	grp     = va_arg(ap, struct group *);
710 	buffer  = va_arg(ap, char *);
711 	bufsize = va_arg(ap, size_t);
712 	errnop  = va_arg(ap, int *);
713 	*errnop = nis_getstate(&st);
714 	if (*errnop != 0)
715 		return (NS_UNAVAIL);
716 	if (st->domain[0] == '\0') {
717 		if (getdomainname(st->domain, sizeof(st->domain)) != 0) {
718 			*errnop = errno;
719 			return (NS_UNAVAIL);
720 		}
721 	}
722 	result = NULL;
723 	do {
724 		rv = NS_NOTFOUND;
725 		switch (how) {
726 		case nss_lt_name:
727 			if (strlcpy(buffer, name, bufsize) >= bufsize)
728 				goto erange;
729 			break;
730 		case nss_lt_id:
731 			if (snprintf(buffer, bufsize, "%lu",
732 			    (unsigned long)gid) >= bufsize)
733 				goto erange;
734 			break;
735 		case nss_lt_all:
736 			if (st->done)
737 				goto fin;
738 			break;
739 		}
740 		result = NULL;
741 		if (how == nss_lt_all) {
742 			if (st->key == NULL)
743 				rv = yp_first(st->domain, map, &st->key,
744 				    &st->keylen, &result, &resultlen);
745 			else {
746 				key = st->key;
747 				keylen = st->keylen;
748 				st->key = NULL;
749 				rv = yp_next(st->domain, map, key, keylen,
750 				    &st->key, &st->keylen, &result,
751 				    &resultlen);
752 				free(key);
753 			}
754 			if (rv != 0) {
755 				free(result);
756 				free(st->key);
757 				st->key = NULL;
758 				if (rv == YPERR_NOMORE) {
759 					st->done = 1;
760 					rv = NS_NOTFOUND;
761 				} else
762 					rv = NS_UNAVAIL;
763 				goto fin;
764 			}
765 		} else {
766 			rv = yp_match(st->domain, map, buffer, strlen(buffer),
767 			    &result, &resultlen);
768 			if (rv == YPERR_KEY) {
769 				rv = NS_NOTFOUND;
770 				continue;
771 			} else if (rv != 0) {
772 				free(result);
773 				rv = NS_UNAVAIL;
774 				continue;
775 			}
776 		}
777 		/* We need room at least for the line, a string NUL
778 		 * terminator, alignment padding, and one (char *)
779 		 * pointer for the member list terminator.
780 		 */
781 		if (resultlen >= bufsize - _ALIGNBYTES - sizeof(char *))
782 			goto erange;
783 		memcpy(buffer, result, resultlen);
784 		buffer[resultlen] = '\0';
785 		free(result);
786 		rv = __gr_match_entry(buffer, resultlen, how, name, gid);
787 		if (rv == NS_SUCCESS)
788 			rv = __gr_parse_entry(buffer, resultlen, grp,
789 			    &buffer[resultlen+1], bufsize - resultlen - 1,
790 			    errnop);
791 	} while (how == nss_lt_all && !(rv & NS_TERMINATE));
792 fin:
793 	if (rv == NS_SUCCESS && retval != NULL)
794 		*(struct group **)retval = grp;
795 	return (rv);
796 erange:
797 	*errnop = ERANGE;
798 	return (NS_RETURN);
799 }
800 #endif /* YP */
801 
802 
803 
804 /*
805  * compat backend
806  */
807 static void
808 compat_endstate(void *p)
809 {
810 	struct compat_state *st;
811 
812 	if (p == NULL)
813 		return;
814 	st = (struct compat_state *)p;
815 	free(st->name);
816 	if (st->fp != NULL)
817 		fclose(st->fp);
818 	free(p);
819 }
820 
821 
822 static int
823 compat_setgrent(void *retval, void *mdata, va_list ap)
824 {
825 	static const ns_src compatsrc[] = {
826 #ifdef YP
827 		{ NSSRC_NIS, NS_SUCCESS },
828 #endif
829 		{ NULL, 0 }
830 	};
831 	ns_dtab dtab[] = {
832 #ifdef HESIOD
833 		{ NSSRC_DNS, dns_setgrent, NULL },
834 #endif
835 #ifdef YP
836 		{ NSSRC_NIS, nis_setgrent, NULL },
837 #endif
838 		{ NULL, NULL, NULL }
839 	};
840 	struct compat_state *st;
841 	int		 rv, stayopen;
842 
843 #define set_setent(x, y) do {	 				\
844 	int i;							\
845 								\
846 	for (i = 0; i < (sizeof(x)/sizeof(x[0])) - 1; i++)	\
847 		x[i].mdata = (void *)y;				\
848 } while (0)
849 
850 	rv = compat_getstate(&st);
851 	if (rv != 0)
852 		return (NS_UNAVAIL);
853 	switch ((enum constants)mdata) {
854 	case SETGRENT:
855 		stayopen = va_arg(ap, int);
856 		if (st->fp != NULL)
857 			rewind(st->fp);
858 		else if (stayopen)
859 			st->fp = fopen(_PATH_GROUP, "r");
860 		set_setent(dtab, mdata);
861 		(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "setgrent",
862 		    compatsrc, 0);
863 		break;
864 	case ENDGRENT:
865 		if (st->fp != NULL) {
866 			fclose(st->fp);
867 			st->fp = NULL;
868 		}
869 		set_setent(dtab, mdata);
870 		(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "endgrent",
871 		    compatsrc, 0);
872 		break;
873 	default:
874 		break;
875 	}
876 	st->compat = COMPAT_MODE_OFF;
877 	free(st->name);
878 	st->name = NULL;
879 	return (NS_UNAVAIL);
880 #undef set_setent
881 }
882 
883 
884 static int
885 compat_group(void *retval, void *mdata, va_list ap)
886 {
887 	static const ns_src compatsrc[] = {
888 #ifdef YP
889 		{ NSSRC_NIS, NS_SUCCESS },
890 #endif
891 		{ NULL, 0 }
892 	};
893 	ns_dtab dtab[] = {
894 #ifdef YP
895 		{ NSSRC_NIS, nis_group, NULL },
896 #endif
897 #ifdef HESIOD
898 		{ NSSRC_DNS, dns_group, NULL },
899 #endif
900 		{ NULL, NULL, NULL }
901 	};
902 	struct compat_state	*st;
903 	enum nss_lookup_type	 how;
904 	const char		*name, *line;
905 	struct group		*grp;
906 	gid_t			 gid;
907 	char			*buffer, *p;
908 	void			*discard;
909 	size_t			 bufsize, linesize;
910 	int			 rv, stayopen, *errnop;
911 
912 #define set_lookup_type(x, y) do { 				\
913 	int i;							\
914 								\
915 	for (i = 0; i < (sizeof(x)/sizeof(x[0])) - 1; i++)	\
916 		x[i].mdata = (void *)y;				\
917 } while (0)
918 
919 	name = NULL;
920 	gid = (gid_t)-1;
921 	how = (enum nss_lookup_type)mdata;
922 	switch (how) {
923 	case nss_lt_name:
924 		name = va_arg(ap, const char *);
925 		break;
926 	case nss_lt_id:
927 		gid = va_arg(ap, gid_t);
928 		break;
929 	case nss_lt_all:
930 		break;
931 	default:
932 		return (NS_NOTFOUND);
933 	}
934 	grp = va_arg(ap, struct group *);
935 	buffer = va_arg(ap, char *);
936 	bufsize = va_arg(ap, size_t);
937 	errnop = va_arg(ap, int *);
938 	*errnop = compat_getstate(&st);
939 	if (*errnop != 0)
940 		return (NS_UNAVAIL);
941 	if (st->fp == NULL &&
942 	    ((st->fp = fopen(_PATH_GROUP, "r")) == NULL)) {
943 		*errnop = errno;
944 		rv = NS_UNAVAIL;
945 		goto fin;
946 	}
947 	if (how == nss_lt_all)
948 		stayopen = 1;
949 	else {
950 		rewind(st->fp);
951 		stayopen = st->stayopen;
952 	}
953 docompat:
954 	switch (st->compat) {
955 	case COMPAT_MODE_ALL:
956 		set_lookup_type(dtab, how);
957 		switch (how) {
958 		case nss_lt_all:
959 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
960 			    "getgrent_r", compatsrc, grp, buffer, bufsize,
961 			    errnop);
962 			break;
963 		case nss_lt_id:
964 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
965 			    "getgrgid_r", compatsrc, gid, grp, buffer, bufsize,
966 			    errnop);
967 			break;
968 		case nss_lt_name:
969 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
970 			    "getgrnam_r", compatsrc, name, grp, buffer,
971 			    bufsize, errnop);
972 			break;
973 		}
974 		if (rv & NS_TERMINATE)
975 			goto fin;
976 		st->compat = COMPAT_MODE_OFF;
977 		break;
978 	case COMPAT_MODE_NAME:
979 		set_lookup_type(dtab, nss_lt_name);
980 		rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
981 		    "getgrnam_r", compatsrc, st->name, grp, buffer, bufsize,
982 		    errnop);
983 		switch (rv) {
984 		case NS_SUCCESS:
985 			switch (how) {
986 			case nss_lt_name:
987 				if (strcmp(name, grp->gr_name) != 0)
988 					rv = NS_NOTFOUND;
989 				break;
990 			case nss_lt_id:
991 				if (gid != grp->gr_gid)
992 					rv = NS_NOTFOUND;
993 				break;
994 			default:
995 				break;
996 			}
997 			break;
998 		case NS_RETURN:
999 			goto fin;
1000 		default:
1001 			break;
1002 		}
1003 		free(st->name);
1004 		st->name = NULL;
1005 		st->compat = COMPAT_MODE_OFF;
1006 		if (rv == NS_SUCCESS)
1007 			goto fin;
1008 		break;
1009 	default:
1010 		break;
1011 	}
1012 	rv = NS_NOTFOUND;
1013 	while ((line = fgetln(st->fp, &linesize)) != NULL) {
1014 		if (line[linesize-1] == '\n')
1015 			linesize--;
1016 		if (linesize > 2 && line[0] == '+') {
1017 			p = memchr(&line[1], ':', linesize);
1018 			if (p == NULL || p == &line[1])
1019 				st->compat = COMPAT_MODE_ALL;
1020 			else {
1021 				st->name = malloc(p - line);
1022 				if (st->name == NULL) {
1023 					syslog(LOG_ERR,
1024 					 "getgrent memory allocation failure");
1025 					*errnop = ENOMEM;
1026 					rv = NS_UNAVAIL;
1027 					break;
1028 				}
1029 				memcpy(st->name, &line[1], p - line - 1);
1030 				st->name[p - line - 1] = '\0';
1031 				st->compat = COMPAT_MODE_NAME;
1032 			}
1033 			goto docompat;
1034 		}
1035 		rv = __gr_match_entry(line, linesize, how, name, gid);
1036 		if (rv != NS_SUCCESS)
1037 			continue;
1038 		/* We need room at least for the line, a string NUL
1039 		 * terminator, alignment padding, and one (char *)
1040 		 * pointer for the member list terminator.
1041 		 */
1042 		if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
1043 			*errnop = ERANGE;
1044 			rv = NS_RETURN;
1045 			break;
1046 		}
1047 		memcpy(buffer, line, linesize);
1048 		buffer[linesize] = '\0';
1049 		rv = __gr_parse_entry(buffer, linesize, grp,
1050 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
1051 		if (rv & NS_TERMINATE)
1052 			break;
1053 	}
1054 fin:
1055 	if (!stayopen && st->fp != NULL) {
1056 		fclose(st->fp);
1057 		st->fp = NULL;
1058 	}
1059 	if (rv == NS_SUCCESS && retval != NULL)
1060 		*(struct group **)retval = grp;
1061 	return (rv);
1062 #undef set_lookup_type
1063 }
1064 
1065 
1066 /*
1067  * common group line matching and parsing
1068  */
1069 int
1070 __gr_match_entry(const char *line, size_t linesize, enum nss_lookup_type how,
1071     const char *name, gid_t gid)
1072 {
1073 	size_t		 namesize;
1074 	const char	*p, *eol;
1075 	char		*q;
1076 	unsigned long	 n;
1077 	int		 i, needed;
1078 
1079 	if (linesize == 0 || is_comment_line(line, linesize))
1080 		return (NS_NOTFOUND);
1081 	switch (how) {
1082 	case nss_lt_name:	needed = 1; break;
1083 	case nss_lt_id:		needed = 2; break;
1084 	default:		needed = 2; break;
1085 	}
1086 	eol = &line[linesize];
1087 	for (p = line, i = 0; i < needed && p < eol; p++)
1088 		if (*p == ':')
1089 			i++;
1090 	if (i < needed)
1091 		return (NS_NOTFOUND);
1092 	switch (how) {
1093 	case nss_lt_name:
1094 		namesize = strlen(name);
1095 		if (namesize + 1 == (size_t)(p - line) &&
1096 		    memcmp(line, name, namesize) == 0)
1097 			return (NS_SUCCESS);
1098 		break;
1099 	case nss_lt_id:
1100 		n = strtoul(p, &q, 10);
1101 		if (q < eol && *q == ':' && gid == (gid_t)n)
1102 			return (NS_SUCCESS);
1103 		break;
1104 	case nss_lt_all:
1105 		return (NS_SUCCESS);
1106 	default:
1107 		break;
1108 	}
1109 	return (NS_NOTFOUND);
1110 }
1111 
1112 
1113 int
1114 __gr_parse_entry(char *line, size_t linesize, struct group *grp, char *membuf,
1115     size_t membufsize, int *errnop)
1116 {
1117 	char	       *s_gid, *s_mem, *p, **members;
1118 	unsigned long	n;
1119 	int		maxmembers;
1120 
1121 	memset(grp, 0, sizeof(*grp));
1122 	members = (char **)_ALIGN(membuf);
1123 	membufsize -= (char *)members - membuf;
1124 	maxmembers = membufsize / sizeof(*members);
1125 	if (maxmembers <= 0 ||
1126 	    (grp->gr_name = strsep(&line, ":")) == NULL ||
1127 	    grp->gr_name[0] == '\0' ||
1128 	    (grp->gr_passwd = strsep(&line, ":")) == NULL ||
1129 	    (s_gid = strsep(&line, ":")) == NULL ||
1130 	    s_gid[0] == '\0')
1131 		return (NS_NOTFOUND);
1132 	s_mem = line;
1133 	n = strtoul(s_gid, &s_gid, 10);
1134 	if (s_gid[0] != '\0')
1135 		return (NS_NOTFOUND);
1136 	grp->gr_gid = (gid_t)n;
1137 	grp->gr_mem = members;
1138 	while (maxmembers > 1 && s_mem != NULL) {
1139 		p = strsep(&s_mem, ",");
1140 		if (p != NULL && *p != '\0') {
1141 			*members++ = p;
1142 			maxmembers--;
1143 		}
1144 	}
1145 	*members = NULL;
1146 	if (s_mem == NULL)
1147 		return (NS_SUCCESS);
1148 	else {
1149 		*errnop = ERANGE;
1150 		return (NS_RETURN);
1151 	}
1152 }
1153