xref: /freebsd/lib/libc/gen/getgrent.c (revision a3d9bf49b57923118c339642594246ef73872ee8)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2003 Networks Associates Technology, Inc.
5  * All rights reserved.
6  *
7  * This software was developed for the FreeBSD Project by
8  * Jacques A. Vidrine, Safeport Network Services, and Network
9  * Associates Laboratories, the Security Research Division of Network
10  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
11  * ("CBOSS"), as part of the DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 __FBSDID("$FreeBSD$");
37 
38 #include "namespace.h"
39 #include <sys/param.h>
40 #ifdef YP
41 #include <rpc/rpc.h>
42 #include <rpcsvc/yp_prot.h>
43 #include <rpcsvc/ypclnt.h>
44 #endif
45 #include <assert.h>
46 #include <ctype.h>
47 #include <errno.h>
48 #ifdef HESIOD
49 #include <hesiod.h>
50 #endif
51 #include <grp.h>
52 #include <nsswitch.h>
53 #include <pthread.h>
54 #include <pthread_np.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <syslog.h>
59 #include <unistd.h>
60 #include "un-namespace.h"
61 #include "libc_private.h"
62 #include "nss_tls.h"
63 #ifdef NS_CACHING
64 #include "nscache.h"
65 #endif
66 
67 enum constants {
68 	GRP_STORAGE_INITIAL	= 1 << 10, /* 1 KByte */
69 	GRP_STORAGE_MAX		= 1 << 20, /* 1 MByte */
70 	SETGRENT		= 1,
71 	ENDGRENT		= 2,
72 	HESIOD_NAME_MAX		= 256,
73 };
74 
75 static const ns_src defaultsrc[] = {
76 	{ NSSRC_COMPAT, NS_SUCCESS },
77 	{ NULL, 0 }
78 };
79 
80 int	 __getgroupmembership(const char *, gid_t, gid_t *, int, int *);
81 int	 __gr_match_entry(const char *, size_t, enum nss_lookup_type,
82 	    const char *, gid_t);
83 int	 __gr_parse_entry(char *, size_t, struct group *, char *, size_t,
84 	    int *);
85 
86 static	int	 is_comment_line(const char *, size_t);
87 
88 union key {
89 	const char	*name;
90 	gid_t		 gid;
91 };
92 static	struct group *getgr(int (*)(union key, struct group *, char *, size_t,
93 		    struct group **), union key);
94 static	int	 wrap_getgrnam_r(union key, struct group *, char *, size_t,
95 		    struct group **);
96 static	int	 wrap_getgrgid_r(union key, struct group *, char *, size_t,
97 		    struct group **);
98 static	int	 wrap_getgrent_r(union key, struct group *, char *, size_t,
99 		    struct group **);
100 
101 struct files_state {
102 	FILE	*fp;
103 	int	 stayopen;
104 };
105 static	void	 files_endstate(void *);
106 NSS_TLS_HANDLING(files);
107 static	int	 files_setgrent(void *, void *, va_list);
108 static	int	 files_group(void *, void *, va_list);
109 
110 
111 #ifdef HESIOD
112 struct dns_state {
113 	long	counter;
114 };
115 static	void	 dns_endstate(void *);
116 NSS_TLS_HANDLING(dns);
117 static	int	 dns_setgrent(void *, void *, va_list);
118 static	int	 dns_group(void *, void *, va_list);
119 #endif
120 
121 
122 #ifdef YP
123 struct nis_state {
124 	char	 domain[MAXHOSTNAMELEN];
125 	int	 done;
126 	char	*key;
127 	int	 keylen;
128 };
129 static	void	 nis_endstate(void *);
130 NSS_TLS_HANDLING(nis);
131 static	int	 nis_setgrent(void *, void *, va_list);
132 static	int	 nis_group(void *, void *, va_list);
133 #endif
134 
135 struct compat_state {
136 	FILE	*fp;
137 	int	 stayopen;
138 	char	*name;
139 	enum _compat {
140 		COMPAT_MODE_OFF = 0,
141 		COMPAT_MODE_ALL,
142 		COMPAT_MODE_NAME
143 	}	 compat;
144 };
145 static	void	 compat_endstate(void *);
146 NSS_TLS_HANDLING(compat);
147 static	int	 compat_setgrent(void *, void *, va_list);
148 static	int	 compat_group(void *, void *, va_list);
149 
150 static	int	gr_addgid(gid_t, gid_t *, int, int *);
151 static	int	getgroupmembership_fallback(void *, void *, va_list);
152 
153 #ifdef NS_CACHING
154 static	int	 grp_id_func(char *, size_t *, va_list, void *);
155 static	int	 grp_marshal_func(char *, size_t *, void *, va_list, void *);
156 static	int	 grp_unmarshal_func(char *, size_t, void *, va_list, void *);
157 
158 static int
159 grp_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata)
160 {
161 	char	*name;
162 	gid_t	gid;
163 
164 	size_t	desired_size, size;
165 	int	res = NS_UNAVAIL;
166 	enum nss_lookup_type lookup_type;
167 
168 
169 	lookup_type = (enum nss_lookup_type)(uintptr_t)cache_mdata;
170 	switch (lookup_type) {
171 	case nss_lt_name:
172 		name = va_arg(ap, char *);
173 		size = strlen(name);
174 		desired_size = sizeof(enum nss_lookup_type) + size + 1;
175 		if (desired_size > *buffer_size) {
176 			res = NS_RETURN;
177 			goto fin;
178 		}
179 
180 		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
181 		memcpy(buffer + sizeof(enum nss_lookup_type), name, size + 1);
182 
183 		res = NS_SUCCESS;
184 		break;
185 	case nss_lt_id:
186 		gid = va_arg(ap, gid_t);
187 		desired_size = sizeof(enum nss_lookup_type) + sizeof(gid_t);
188 		if (desired_size > *buffer_size) {
189 			res = NS_RETURN;
190 			goto fin;
191 		}
192 
193 		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
194 		memcpy(buffer + sizeof(enum nss_lookup_type), &gid,
195 		    sizeof(gid_t));
196 
197 		res = NS_SUCCESS;
198 		break;
199 	default:
200 		/* should be unreachable */
201 		return (NS_UNAVAIL);
202 	}
203 
204 fin:
205 	*buffer_size = desired_size;
206 	return (res);
207 }
208 
209 static int
210 grp_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap,
211     void *cache_mdata)
212 {
213 	char *name;
214 	gid_t gid;
215 	struct group *grp;
216 	char *orig_buf;
217 	size_t orig_buf_size;
218 
219 	struct group new_grp;
220 	size_t desired_size, size, mem_size;
221 	char *p, **mem;
222 
223 	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
224 	case nss_lt_name:
225 		name = va_arg(ap, char *);
226 		break;
227 	case nss_lt_id:
228 		gid = va_arg(ap, gid_t);
229 		break;
230 	case nss_lt_all:
231 		break;
232 	default:
233 		/* should be unreachable */
234 		return (NS_UNAVAIL);
235 	}
236 
237 	grp = va_arg(ap, struct group *);
238 	orig_buf = va_arg(ap, char *);
239 	orig_buf_size = va_arg(ap, size_t);
240 
241 	desired_size = _ALIGNBYTES + sizeof(struct group) + sizeof(char *);
242 
243 	if (grp->gr_name != NULL)
244 		desired_size += strlen(grp->gr_name) + 1;
245 	if (grp->gr_passwd != NULL)
246 		desired_size += strlen(grp->gr_passwd) + 1;
247 
248 	if (grp->gr_mem != NULL) {
249 		mem_size = 0;
250 		for (mem = grp->gr_mem; *mem; ++mem) {
251 			desired_size += strlen(*mem) + 1;
252 			++mem_size;
253 		}
254 
255 		desired_size += _ALIGNBYTES + (mem_size + 1) * sizeof(char *);
256 	}
257 
258 	if (desired_size > *buffer_size) {
259 		/* this assignment is here for future use */
260 		*buffer_size = desired_size;
261 		return (NS_RETURN);
262 	}
263 
264 	memcpy(&new_grp, grp, sizeof(struct group));
265 	memset(buffer, 0, desired_size);
266 
267 	*buffer_size = desired_size;
268 	p = buffer + sizeof(struct group) + sizeof(char *);
269 	memcpy(buffer + sizeof(struct group), &p, sizeof(char *));
270 	p = (char *)_ALIGN(p);
271 
272 	if (new_grp.gr_name != NULL) {
273 		size = strlen(new_grp.gr_name);
274 		memcpy(p, new_grp.gr_name, size);
275 		new_grp.gr_name = p;
276 		p += size + 1;
277 	}
278 
279 	if (new_grp.gr_passwd != NULL) {
280 		size = strlen(new_grp.gr_passwd);
281 		memcpy(p, new_grp.gr_passwd, size);
282 		new_grp.gr_passwd = p;
283 		p += size + 1;
284 	}
285 
286 	if (new_grp.gr_mem != NULL) {
287 		p = (char *)_ALIGN(p);
288 		memcpy(p, new_grp.gr_mem, sizeof(char *) * mem_size);
289 		new_grp.gr_mem = (char **)p;
290 		p += sizeof(char *) * (mem_size + 1);
291 
292 		for (mem = new_grp.gr_mem; *mem; ++mem) {
293 			size = strlen(*mem);
294 			memcpy(p, *mem, size);
295 			*mem = p;
296 			p += size + 1;
297 		}
298 	}
299 
300 	memcpy(buffer, &new_grp, sizeof(struct group));
301 	return (NS_SUCCESS);
302 }
303 
304 static int
305 grp_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap,
306     void *cache_mdata)
307 {
308 	char *name;
309 	gid_t gid;
310 	struct group *grp;
311 	char *orig_buf;
312 	size_t orig_buf_size;
313 	int *ret_errno;
314 
315 	char *p;
316 	char **mem;
317 
318 	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
319 	case nss_lt_name:
320 		name = va_arg(ap, char *);
321 		break;
322 	case nss_lt_id:
323 		gid = va_arg(ap, gid_t);
324 		break;
325 	case nss_lt_all:
326 		break;
327 	default:
328 		/* should be unreachable */
329 		return (NS_UNAVAIL);
330 	}
331 
332 	grp = va_arg(ap, struct group *);
333 	orig_buf = va_arg(ap, char *);
334 	orig_buf_size = va_arg(ap, size_t);
335 	ret_errno = va_arg(ap, int *);
336 
337 	if (orig_buf_size + sizeof(struct group) + sizeof(char *) < buffer_size)
338 	{
339 		*ret_errno = ERANGE;
340 		return (NS_RETURN);
341 	} else if (buffer_size < sizeof(struct group) + sizeof(char *)) {
342 		/*
343 		 * nscd(8) sometimes returns buffer_size=1 for nonexistent
344 		 * entries.
345 		 */
346 		*ret_errno = 0;
347 		return (NS_NOTFOUND);
348 	}
349 
350 	memcpy(grp, buffer, sizeof(struct group));
351 	memcpy(&p, buffer + sizeof(struct group), sizeof(char *));
352 
353 	if (orig_buf_size + sizeof(struct group) + sizeof(char *) +
354 	    _ALIGN(p) - (size_t)p < buffer_size) {
355 		*ret_errno = ERANGE;
356 		return (NS_RETURN);
357 	}
358 
359 	orig_buf = (char *)_ALIGN(orig_buf);
360 	memcpy(orig_buf, buffer + sizeof(struct group) + sizeof(char *) +
361 	    _ALIGN(p) - (size_t)p,
362 	    buffer_size - sizeof(struct group) - sizeof(char *) -
363 	    _ALIGN(p) + (size_t)p);
364 	p = (char *)_ALIGN(p);
365 
366 	NS_APPLY_OFFSET(grp->gr_name, orig_buf, p, char *);
367 	NS_APPLY_OFFSET(grp->gr_passwd, orig_buf, p, char *);
368 	if (grp->gr_mem != NULL) {
369 		NS_APPLY_OFFSET(grp->gr_mem, orig_buf, p, char **);
370 
371 		for (mem = grp->gr_mem; *mem; ++mem)
372 			NS_APPLY_OFFSET(*mem, orig_buf, p, char *);
373 	}
374 
375 	if (retval != NULL)
376 		*((struct group **)retval) = grp;
377 
378 	return (NS_SUCCESS);
379 }
380 
381 NSS_MP_CACHE_HANDLING(group);
382 #endif /* NS_CACHING */
383 
384 #ifdef NS_CACHING
385 static const nss_cache_info setgrent_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
386 	group, (void *)nss_lt_all,
387 	NULL, NULL);
388 #endif
389 
390 static const ns_dtab setgrent_dtab[] = {
391 	{ NSSRC_FILES, files_setgrent, (void *)SETGRENT },
392 #ifdef HESIOD
393 	{ NSSRC_DNS, dns_setgrent, (void *)SETGRENT },
394 #endif
395 #ifdef YP
396 	{ NSSRC_NIS, nis_setgrent, (void *)SETGRENT },
397 #endif
398 	{ NSSRC_COMPAT, compat_setgrent, (void *)SETGRENT },
399 #ifdef NS_CACHING
400 	NS_CACHE_CB(&setgrent_cache_info)
401 #endif
402 	{ NULL, NULL, NULL }
403 };
404 
405 #ifdef NS_CACHING
406 static const nss_cache_info endgrent_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
407 	group, (void *)nss_lt_all,
408 	NULL, NULL);
409 #endif
410 
411 static const ns_dtab endgrent_dtab[] = {
412 	{ NSSRC_FILES, files_setgrent, (void *)ENDGRENT },
413 #ifdef HESIOD
414 	{ NSSRC_DNS, dns_setgrent, (void *)ENDGRENT },
415 #endif
416 #ifdef YP
417 	{ NSSRC_NIS, nis_setgrent, (void *)ENDGRENT },
418 #endif
419 	{ NSSRC_COMPAT, compat_setgrent, (void *)ENDGRENT },
420 #ifdef NS_CACHING
421 	NS_CACHE_CB(&endgrent_cache_info)
422 #endif
423 	{ NULL, NULL, NULL }
424 };
425 
426 #ifdef NS_CACHING
427 static const nss_cache_info getgrent_r_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
428 	group, (void *)nss_lt_all,
429 	grp_marshal_func, grp_unmarshal_func);
430 #endif
431 
432 static const ns_dtab getgrent_r_dtab[] = {
433 	{ NSSRC_FILES, files_group, (void *)nss_lt_all },
434 #ifdef HESIOD
435 	{ NSSRC_DNS, dns_group, (void *)nss_lt_all },
436 #endif
437 #ifdef YP
438 	{ NSSRC_NIS, nis_group, (void *)nss_lt_all },
439 #endif
440 	{ NSSRC_COMPAT, compat_group, (void *)nss_lt_all },
441 #ifdef NS_CACHING
442 	NS_CACHE_CB(&getgrent_r_cache_info)
443 #endif
444 	{ NULL, NULL, NULL }
445 };
446 
447 static int
448 gr_addgid(gid_t gid, gid_t *groups, int maxgrp, int *grpcnt)
449 {
450 	int     ret, dupc;
451 
452 	for (dupc = 1; dupc < MIN(maxgrp, *grpcnt); dupc++) {
453 		if (groups[dupc] == gid)
454 			return 1;
455 	}
456 
457 	ret = 1;
458 	if (*grpcnt < maxgrp)
459 		groups[*grpcnt] = gid;
460 	else
461 		ret = 0;
462 
463 	(*grpcnt)++;
464 
465 	return ret;
466 }
467 
468 static int
469 getgroupmembership_fallback(void *retval, void *mdata, va_list ap)
470 {
471 	const ns_src src[] = {
472 		{ mdata, NS_SUCCESS },
473 		{ NULL, 0}
474 	};
475 	struct group	grp;
476 	struct group	*grp_p;
477 	char		*buf;
478 	size_t		bufsize;
479 	const char	*uname;
480 	gid_t		*groups;
481 	gid_t		agroup;
482 	int 		maxgrp, *grpcnt;
483 	int		i, rv, ret_errno;
484 
485 	/*
486 	 * As this is a fallback method, only provided src
487 	 * list will be respected during methods search.
488 	 */
489 	assert(src[0].name != NULL);
490 
491 	uname = va_arg(ap, const char *);
492 	agroup = va_arg(ap, gid_t);
493 	groups = va_arg(ap, gid_t *);
494 	maxgrp = va_arg(ap, int);
495 	grpcnt = va_arg(ap, int *);
496 
497 	rv = NS_UNAVAIL;
498 
499 	buf = malloc(GRP_STORAGE_INITIAL);
500 	if (buf == NULL)
501 		goto out;
502 
503 	bufsize = GRP_STORAGE_INITIAL;
504 
505 	gr_addgid(agroup, groups, maxgrp, grpcnt);
506 
507 	_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", src, 0);
508 	for (;;) {
509 		do {
510 			ret_errno = 0;
511 			grp_p = NULL;
512 			rv = _nsdispatch(&grp_p, getgrent_r_dtab, NSDB_GROUP,
513 			    "getgrent_r", src, &grp, buf, bufsize, &ret_errno);
514 
515 			if (grp_p == NULL && ret_errno == ERANGE) {
516 				free(buf);
517 				if ((bufsize << 1) > GRP_STORAGE_MAX) {
518 					buf = NULL;
519 					errno = ERANGE;
520 					goto out;
521 				}
522 
523 				bufsize <<= 1;
524 				buf = malloc(bufsize);
525 				if (buf == NULL) {
526 					goto out;
527 				}
528 			}
529 		} while (grp_p == NULL && ret_errno == ERANGE);
530 
531 		if (ret_errno != 0) {
532 			errno = ret_errno;
533 			goto out;
534 		}
535 
536 		if (grp_p == NULL)
537 			break;
538 
539 		for (i = 0; grp.gr_mem[i]; i++) {
540 			if (strcmp(grp.gr_mem[i], uname) == 0)
541 			    gr_addgid(grp.gr_gid, groups, maxgrp, grpcnt);
542 		}
543 	}
544 
545 	_nsdispatch(NULL, endgrent_dtab, NSDB_GROUP, "endgrent", src);
546 out:
547 	free(buf);
548 	return (rv);
549 }
550 
551 void
552 setgrent(void)
553 {
554 	(void)_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", defaultsrc, 0);
555 }
556 
557 
558 int
559 setgroupent(int stayopen)
560 {
561 	(void)_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", defaultsrc,
562 	    stayopen);
563 	return (1);
564 }
565 
566 
567 void
568 endgrent(void)
569 {
570 	(void)_nsdispatch(NULL, endgrent_dtab, NSDB_GROUP, "endgrent", defaultsrc);
571 }
572 
573 
574 int
575 getgrent_r(struct group *grp, char *buffer, size_t bufsize,
576     struct group **result)
577 {
578 	int	rv, ret_errno;
579 
580 	ret_errno = 0;
581 	*result = NULL;
582 	rv = _nsdispatch(result, getgrent_r_dtab, NSDB_GROUP, "getgrent_r", defaultsrc,
583 	    grp, buffer, bufsize, &ret_errno);
584 	if (rv == NS_SUCCESS)
585 		return (0);
586 	else
587 		return (ret_errno);
588 }
589 
590 
591 int
592 getgrnam_r(const char *name, struct group *grp, char *buffer, size_t bufsize,
593     struct group **result)
594 {
595 #ifdef NS_CACHING
596 	static const nss_cache_info cache_info =
597     		NS_COMMON_CACHE_INFO_INITIALIZER(
598 		group, (void *)nss_lt_name,
599 		grp_id_func, grp_marshal_func, grp_unmarshal_func);
600 #endif
601 
602 	static const ns_dtab dtab[] = {
603 		{ NSSRC_FILES, files_group, (void *)nss_lt_name },
604 #ifdef HESIOD
605 		{ NSSRC_DNS, dns_group, (void *)nss_lt_name },
606 #endif
607 #ifdef YP
608 		{ NSSRC_NIS, nis_group, (void *)nss_lt_name },
609 #endif
610 		{ NSSRC_COMPAT, compat_group, (void *)nss_lt_name },
611 #ifdef NS_CACHING
612 		NS_CACHE_CB(&cache_info)
613 #endif
614 		{ NULL, NULL, NULL }
615 	};
616 	int	rv, ret_errno;
617 
618 	ret_errno = 0;
619 	*result = NULL;
620 	rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrnam_r", defaultsrc,
621 	    name, grp, buffer, bufsize, &ret_errno);
622 	if (rv == NS_SUCCESS)
623 		return (0);
624 	else
625 		return (ret_errno);
626 }
627 
628 
629 int
630 getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize,
631     struct group **result)
632 {
633 #ifdef NS_CACHING
634 	static const nss_cache_info cache_info =
635     		NS_COMMON_CACHE_INFO_INITIALIZER(
636 		group, (void *)nss_lt_id,
637 		grp_id_func, grp_marshal_func, grp_unmarshal_func);
638 #endif
639 
640 	static const ns_dtab dtab[] = {
641 		{ NSSRC_FILES, files_group, (void *)nss_lt_id },
642 #ifdef HESIOD
643 		{ NSSRC_DNS, dns_group, (void *)nss_lt_id },
644 #endif
645 #ifdef YP
646 		{ NSSRC_NIS, nis_group, (void *)nss_lt_id },
647 #endif
648 		{ NSSRC_COMPAT, compat_group, (void *)nss_lt_id },
649 #ifdef NS_CACHING
650 		NS_CACHE_CB(&cache_info)
651 #endif
652 		{ NULL, NULL, NULL }
653 	};
654 	int	rv, ret_errno;
655 
656 	ret_errno = 0;
657 	*result = NULL;
658 	rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrgid_r", defaultsrc,
659 	    gid, grp, buffer, bufsize, &ret_errno);
660 	if (rv == NS_SUCCESS)
661 		return (0);
662 	else
663 		return (ret_errno);
664 }
665 
666 
667 
668 int
669 __getgroupmembership(const char *uname, gid_t agroup, gid_t *groups,
670 	int maxgrp, int *grpcnt)
671 {
672 	static const ns_dtab dtab[] = {
673 		NS_FALLBACK_CB(getgroupmembership_fallback)
674 		{ NULL, NULL, NULL }
675 	};
676 
677 	assert(uname != NULL);
678 	/* groups may be NULL if just sizing when invoked with maxgrp = 0 */
679 	assert(grpcnt != NULL);
680 
681 	*grpcnt = 0;
682 	(void)_nsdispatch(NULL, dtab, NSDB_GROUP, "getgroupmembership",
683 	    defaultsrc, uname, agroup, groups, maxgrp, grpcnt);
684 
685 	/* too many groups found? */
686 	return (*grpcnt > maxgrp ? -1 : 0);
687 }
688 
689 
690 static struct group	 grp;
691 static char		*grp_storage;
692 static size_t		 grp_storage_size;
693 
694 static struct group *
695 getgr(int (*fn)(union key, struct group *, char *, size_t, struct group **),
696     union key key)
697 {
698 	int		 rv;
699 	struct group	*res;
700 
701 	if (grp_storage == NULL) {
702 		grp_storage = malloc(GRP_STORAGE_INITIAL);
703 		if (grp_storage == NULL)
704 			return (NULL);
705 		grp_storage_size = GRP_STORAGE_INITIAL;
706 	}
707 	do {
708 		rv = fn(key, &grp, grp_storage, grp_storage_size, &res);
709 		if (res == NULL && rv == ERANGE) {
710 			free(grp_storage);
711 			if ((grp_storage_size << 1) > GRP_STORAGE_MAX) {
712 				grp_storage = NULL;
713 				errno = ERANGE;
714 				return (NULL);
715 			}
716 			grp_storage_size <<= 1;
717 			grp_storage = malloc(grp_storage_size);
718 			if (grp_storage == NULL)
719 				return (NULL);
720 		}
721 	} while (res == NULL && rv == ERANGE);
722 	if (rv != 0)
723 		errno = rv;
724 	return (res);
725 }
726 
727 
728 static int
729 wrap_getgrnam_r(union key key, struct group *grp, char *buffer, size_t bufsize,
730     struct group **res)
731 {
732 	return (getgrnam_r(key.name, grp, buffer, bufsize, res));
733 }
734 
735 
736 static int
737 wrap_getgrgid_r(union key key, struct group *grp, char *buffer, size_t bufsize,
738     struct group **res)
739 {
740 	return (getgrgid_r(key.gid, grp, buffer, bufsize, res));
741 }
742 
743 
744 static int
745 wrap_getgrent_r(union key key __unused, struct group *grp, char *buffer,
746     size_t bufsize, struct group **res)
747 {
748 	return (getgrent_r(grp, buffer, bufsize, res));
749 }
750 
751 
752 struct group *
753 getgrnam(const char *name)
754 {
755 	union key key;
756 
757 	key.name = name;
758 	return (getgr(wrap_getgrnam_r, key));
759 }
760 
761 
762 struct group *
763 getgrgid(gid_t gid)
764 {
765 	union key key;
766 
767 	key.gid = gid;
768 	return (getgr(wrap_getgrgid_r, key));
769 }
770 
771 
772 struct group *
773 getgrent(void)
774 {
775 	union key key;
776 
777 	key.gid = 0; /* not used */
778 	return (getgr(wrap_getgrent_r, key));
779 }
780 
781 
782 static int
783 is_comment_line(const char *s, size_t n)
784 {
785 	const char	*eom;
786 
787 	eom = &s[n];
788 
789 	for (; s < eom; s++)
790 		if (*s == '#' || !isspace((unsigned char)*s))
791 			break;
792 	return (*s == '#' || s == eom);
793 }
794 
795 
796 /*
797  * files backend
798  */
799 static void
800 files_endstate(void *p)
801 {
802 
803 	if (p == NULL)
804 		return;
805 	if (((struct files_state *)p)->fp != NULL)
806 		fclose(((struct files_state *)p)->fp);
807 	free(p);
808 }
809 
810 
811 static int
812 files_setgrent(void *retval, void *mdata, va_list ap)
813 {
814 	struct files_state *st;
815 	int		 rv, stayopen;
816 
817 	rv = files_getstate(&st);
818 	if (rv != 0)
819 		return (NS_UNAVAIL);
820 	switch ((enum constants)(uintptr_t)mdata) {
821 	case SETGRENT:
822 		stayopen = va_arg(ap, int);
823 		if (st->fp != NULL)
824 			rewind(st->fp);
825 		else if (stayopen)
826 			st->fp = fopen(_PATH_GROUP, "re");
827 		break;
828 	case ENDGRENT:
829 		if (st->fp != NULL) {
830 			fclose(st->fp);
831 			st->fp = NULL;
832 		}
833 		break;
834 	default:
835 		break;
836 	}
837 	return (NS_UNAVAIL);
838 }
839 
840 
841 static int
842 files_group(void *retval, void *mdata, va_list ap)
843 {
844 	struct files_state	*st;
845 	enum nss_lookup_type	 how;
846 	const char		*name, *line;
847 	struct group		*grp;
848 	gid_t			 gid;
849 	char			*buffer;
850 	size_t			 bufsize, linesize;
851 	off_t			 pos;
852 	int			 fresh, rv, stayopen, *errnop;
853 
854 	fresh = 0;
855 	name = NULL;
856 	gid = (gid_t)-1;
857 	how = (enum nss_lookup_type)(uintptr_t)mdata;
858 	switch (how) {
859 	case nss_lt_name:
860 		name = va_arg(ap, const char *);
861 		break;
862 	case nss_lt_id:
863 		gid = va_arg(ap, gid_t);
864 		break;
865 	case nss_lt_all:
866 		break;
867 	default:
868 		return (NS_NOTFOUND);
869 	}
870 	grp = va_arg(ap, struct group *);
871 	buffer = va_arg(ap, char *);
872 	bufsize = va_arg(ap, size_t);
873 	errnop = va_arg(ap, int *);
874 	*errnop = files_getstate(&st);
875 	if (*errnop != 0)
876 		return (NS_UNAVAIL);
877 	if (st->fp == NULL) {
878 		st->fp = fopen(_PATH_GROUP, "re");
879 		if (st->fp == NULL) {
880 			*errnop = errno;
881 			return (NS_UNAVAIL);
882 		}
883 		fresh = 1;
884 	}
885 	if (how == nss_lt_all)
886 		stayopen = 1;
887 	else {
888 		if (!fresh)
889 			rewind(st->fp);
890 		stayopen = st->stayopen;
891 	}
892 	rv = NS_NOTFOUND;
893 	if (stayopen)
894 		pos = ftello(st->fp);
895 	while ((line = fgetln(st->fp, &linesize)) != NULL) {
896 		if (line[linesize-1] == '\n')
897 			linesize--;
898 		rv = __gr_match_entry(line, linesize, how, name, gid);
899 		if (rv != NS_SUCCESS)
900 			continue;
901 		/* We need room at least for the line, a string NUL
902 		 * terminator, alignment padding, and one (char *)
903 		 * pointer for the member list terminator.
904 		 */
905 		if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
906 			*errnop = ERANGE;
907 			rv = NS_RETURN;
908 			break;
909 		}
910 		memcpy(buffer, line, linesize);
911 		buffer[linesize] = '\0';
912 		rv = __gr_parse_entry(buffer, linesize, grp,
913 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
914 		if (rv & NS_TERMINATE)
915 			break;
916 		if (stayopen)
917 			pos = ftello(st->fp);
918 	}
919 	if (st->fp != NULL && !stayopen) {
920 		fclose(st->fp);
921 		st->fp = NULL;
922 	}
923 	if (rv == NS_SUCCESS && retval != NULL)
924 		*(struct group **)retval = grp;
925 	else if (rv == NS_RETURN && *errnop == ERANGE && st->fp != NULL)
926 		fseeko(st->fp, pos, SEEK_SET);
927 	return (rv);
928 }
929 
930 
931 #ifdef HESIOD
932 /*
933  * dns backend
934  */
935 static void
936 dns_endstate(void *p)
937 {
938 
939 	free(p);
940 }
941 
942 
943 static int
944 dns_setgrent(void *retval, void *cb_data, va_list ap)
945 {
946 	struct dns_state	*st;
947 	int			 rv;
948 
949 	rv = dns_getstate(&st);
950 	if (rv != 0)
951 		return (NS_UNAVAIL);
952 	st->counter = 0;
953 	return (NS_UNAVAIL);
954 }
955 
956 
957 static int
958 dns_group(void *retval, void *mdata, va_list ap)
959 {
960 	char			 buf[HESIOD_NAME_MAX];
961 	struct dns_state	*st;
962 	struct group		*grp;
963 	const char		*name, *label;
964 	void			*ctx;
965 	char			*buffer, **hes;
966 	size_t			 bufsize, adjsize, linesize;
967 	gid_t			 gid;
968 	enum nss_lookup_type	 how;
969 	int			 rv, *errnop;
970 
971 	ctx = NULL;
972 	hes = NULL;
973 	name = NULL;
974 	gid = (gid_t)-1;
975 	how = (enum nss_lookup_type)mdata;
976 	switch (how) {
977 	case nss_lt_name:
978 		name = va_arg(ap, const char *);
979 		break;
980 	case nss_lt_id:
981 		gid = va_arg(ap, gid_t);
982 		break;
983 	case nss_lt_all:
984 		break;
985 	}
986 	grp     = va_arg(ap, struct group *);
987 	buffer  = va_arg(ap, char *);
988 	bufsize = va_arg(ap, size_t);
989 	errnop  = va_arg(ap, int *);
990 	*errnop = dns_getstate(&st);
991 	if (*errnop != 0)
992 		return (NS_UNAVAIL);
993 	if (hesiod_init(&ctx) != 0) {
994 		*errnop = errno;
995 		rv = NS_UNAVAIL;
996 		goto fin;
997 	}
998 	do {
999 		rv = NS_NOTFOUND;
1000 		switch (how) {
1001 		case nss_lt_name:
1002 			label = name;
1003 			break;
1004 		case nss_lt_id:
1005 			if (snprintf(buf, sizeof(buf), "%lu",
1006 			    (unsigned long)gid) >= sizeof(buf))
1007 				goto fin;
1008 			label = buf;
1009 			break;
1010 		case nss_lt_all:
1011 			if (st->counter < 0)
1012 				goto fin;
1013 			if (snprintf(buf, sizeof(buf), "group-%ld",
1014 			    st->counter++) >= sizeof(buf))
1015 				goto fin;
1016 			label = buf;
1017 			break;
1018 		}
1019 		hes = hesiod_resolve(ctx, label,
1020 		    how == nss_lt_id ? "gid" : "group");
1021 		if ((how == nss_lt_id && hes == NULL &&
1022 		    (hes = hesiod_resolve(ctx, buf, "group")) == NULL) ||
1023 		    hes == NULL) {
1024 			if (how == nss_lt_all)
1025 				st->counter = -1;
1026 			if (errno != ENOENT)
1027 				*errnop = errno;
1028 			goto fin;
1029 		}
1030 		rv = __gr_match_entry(hes[0], strlen(hes[0]), how, name, gid);
1031 		if (rv != NS_SUCCESS) {
1032 			hesiod_free_list(ctx, hes);
1033 			hes = NULL;
1034 			continue;
1035 		}
1036 		/* We need room at least for the line, a string NUL
1037 		 * terminator, alignment padding, and one (char *)
1038 		 * pointer for the member list terminator.
1039 		 */
1040 		adjsize = bufsize - _ALIGNBYTES - sizeof(char *);
1041 		linesize = strlcpy(buffer, hes[0], adjsize);
1042 		if (linesize >= adjsize) {
1043 			*errnop = ERANGE;
1044 			rv = NS_RETURN;
1045 			goto fin;
1046 		}
1047 		hesiod_free_list(ctx, hes);
1048 		hes = NULL;
1049 		rv = __gr_parse_entry(buffer, linesize, grp,
1050 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
1051 	} while (how == nss_lt_all && !(rv & NS_TERMINATE));
1052 fin:
1053 	if (hes != NULL)
1054 		hesiod_free_list(ctx, hes);
1055 	if (ctx != NULL)
1056 		hesiod_end(ctx);
1057 	if (rv == NS_SUCCESS && retval != NULL)
1058 		*(struct group **)retval = grp;
1059 	return (rv);
1060 }
1061 #endif /* HESIOD */
1062 
1063 
1064 #ifdef YP
1065 /*
1066  * nis backend
1067  */
1068 static void
1069 nis_endstate(void *p)
1070 {
1071 
1072 	if (p == NULL)
1073 		return;
1074 	free(((struct nis_state *)p)->key);
1075 	free(p);
1076 }
1077 
1078 
1079 static int
1080 nis_setgrent(void *retval, void *cb_data, va_list ap)
1081 {
1082 	struct nis_state	*st;
1083 	int			 rv;
1084 
1085 	rv = nis_getstate(&st);
1086 	if (rv != 0)
1087 		return (NS_UNAVAIL);
1088 	st->done = 0;
1089 	free(st->key);
1090 	st->key = NULL;
1091 	return (NS_UNAVAIL);
1092 }
1093 
1094 
1095 static int
1096 nis_group(void *retval, void *mdata, va_list ap)
1097 {
1098 	char		 *map;
1099 	struct nis_state *st;
1100 	struct group	*grp;
1101 	const char	*name;
1102 	char		*buffer, *key, *result;
1103 	size_t		 bufsize;
1104 	gid_t		 gid;
1105 	enum nss_lookup_type how;
1106 	int		*errnop, keylen, resultlen, rv;
1107 
1108 	name = NULL;
1109 	gid = (gid_t)-1;
1110 	how = (enum nss_lookup_type)(uintptr_t)mdata;
1111 	switch (how) {
1112 	case nss_lt_name:
1113 		name = va_arg(ap, const char *);
1114 		map = "group.byname";
1115 		break;
1116 	case nss_lt_id:
1117 		gid = va_arg(ap, gid_t);
1118 		map = "group.bygid";
1119 		break;
1120 	case nss_lt_all:
1121 		map = "group.byname";
1122 		break;
1123 	}
1124 	grp     = va_arg(ap, struct group *);
1125 	buffer  = va_arg(ap, char *);
1126 	bufsize = va_arg(ap, size_t);
1127 	errnop  = va_arg(ap, int *);
1128 	*errnop = nis_getstate(&st);
1129 	if (*errnop != 0)
1130 		return (NS_UNAVAIL);
1131 	if (st->domain[0] == '\0') {
1132 		if (getdomainname(st->domain, sizeof(st->domain)) != 0) {
1133 			*errnop = errno;
1134 			return (NS_UNAVAIL);
1135 		}
1136 	}
1137 	result = NULL;
1138 	do {
1139 		rv = NS_NOTFOUND;
1140 		switch (how) {
1141 		case nss_lt_name:
1142 			if (strlcpy(buffer, name, bufsize) >= bufsize)
1143 				goto erange;
1144 			break;
1145 		case nss_lt_id:
1146 			if (snprintf(buffer, bufsize, "%lu",
1147 			    (unsigned long)gid) >= bufsize)
1148 				goto erange;
1149 			break;
1150 		case nss_lt_all:
1151 			if (st->done)
1152 				goto fin;
1153 			break;
1154 		}
1155 		result = NULL;
1156 		if (how == nss_lt_all) {
1157 			if (st->key == NULL)
1158 				rv = yp_first(st->domain, map, &st->key,
1159 				    &st->keylen, &result, &resultlen);
1160 			else {
1161 				key = st->key;
1162 				keylen = st->keylen;
1163 				st->key = NULL;
1164 				rv = yp_next(st->domain, map, key, keylen,
1165 				    &st->key, &st->keylen, &result,
1166 				    &resultlen);
1167 				free(key);
1168 			}
1169 			if (rv != 0) {
1170 				free(result);
1171 				free(st->key);
1172 				st->key = NULL;
1173 				if (rv == YPERR_NOMORE) {
1174 					st->done = 1;
1175 					rv = NS_NOTFOUND;
1176 				} else
1177 					rv = NS_UNAVAIL;
1178 				goto fin;
1179 			}
1180 		} else {
1181 			rv = yp_match(st->domain, map, buffer, strlen(buffer),
1182 			    &result, &resultlen);
1183 			if (rv == YPERR_KEY) {
1184 				rv = NS_NOTFOUND;
1185 				continue;
1186 			} else if (rv != 0) {
1187 				free(result);
1188 				rv = NS_UNAVAIL;
1189 				continue;
1190 			}
1191 		}
1192 		/* We need room at least for the line, a string NUL
1193 		 * terminator, alignment padding, and one (char *)
1194 		 * pointer for the member list terminator.
1195 		 */
1196 		if (resultlen >= bufsize - _ALIGNBYTES - sizeof(char *)) {
1197 			free(result);
1198 			goto erange;
1199 		}
1200 		memcpy(buffer, result, resultlen);
1201 		buffer[resultlen] = '\0';
1202 		free(result);
1203 		rv = __gr_match_entry(buffer, resultlen, how, name, gid);
1204 		if (rv == NS_SUCCESS)
1205 			rv = __gr_parse_entry(buffer, resultlen, grp,
1206 			    &buffer[resultlen+1], bufsize - resultlen - 1,
1207 			    errnop);
1208 	} while (how == nss_lt_all && !(rv & NS_TERMINATE));
1209 fin:
1210 	if (rv == NS_SUCCESS && retval != NULL)
1211 		*(struct group **)retval = grp;
1212 	return (rv);
1213 erange:
1214 	*errnop = ERANGE;
1215 	return (NS_RETURN);
1216 }
1217 #endif /* YP */
1218 
1219 
1220 
1221 /*
1222  * compat backend
1223  */
1224 static void
1225 compat_endstate(void *p)
1226 {
1227 	struct compat_state *st;
1228 
1229 	if (p == NULL)
1230 		return;
1231 	st = (struct compat_state *)p;
1232 	free(st->name);
1233 	if (st->fp != NULL)
1234 		fclose(st->fp);
1235 	free(p);
1236 }
1237 
1238 
1239 static int
1240 compat_setgrent(void *retval, void *mdata, va_list ap)
1241 {
1242 	static const ns_src compatsrc[] = {
1243 #ifdef YP
1244 		{ NSSRC_NIS, NS_SUCCESS },
1245 #endif
1246 		{ NULL, 0 }
1247 	};
1248 	ns_dtab dtab[] = {
1249 #ifdef HESIOD
1250 		{ NSSRC_DNS, dns_setgrent, NULL },
1251 #endif
1252 #ifdef YP
1253 		{ NSSRC_NIS, nis_setgrent, NULL },
1254 #endif
1255 		{ NULL, NULL, NULL }
1256 	};
1257 	struct compat_state *st;
1258 	int		 rv, stayopen;
1259 
1260 #define set_setent(x, y) do {	 				\
1261 	int i;							\
1262 	for (i = 0; i < (int)(nitems(x) - 1); i++)		\
1263 		x[i].mdata = (void *)y;				\
1264 } while (0)
1265 
1266 	rv = compat_getstate(&st);
1267 	if (rv != 0)
1268 		return (NS_UNAVAIL);
1269 	switch ((enum constants)(uintptr_t)mdata) {
1270 	case SETGRENT:
1271 		stayopen = va_arg(ap, int);
1272 		if (st->fp != NULL)
1273 			rewind(st->fp);
1274 		else if (stayopen)
1275 			st->fp = fopen(_PATH_GROUP, "re");
1276 		set_setent(dtab, mdata);
1277 		(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "setgrent",
1278 		    compatsrc, 0);
1279 		break;
1280 	case ENDGRENT:
1281 		if (st->fp != NULL) {
1282 			fclose(st->fp);
1283 			st->fp = NULL;
1284 		}
1285 		set_setent(dtab, mdata);
1286 		(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "endgrent",
1287 		    compatsrc, 0);
1288 		break;
1289 	default:
1290 		break;
1291 	}
1292 	st->compat = COMPAT_MODE_OFF;
1293 	free(st->name);
1294 	st->name = NULL;
1295 	return (NS_UNAVAIL);
1296 #undef set_setent
1297 }
1298 
1299 
1300 static int
1301 compat_group(void *retval, void *mdata, va_list ap)
1302 {
1303 	static const ns_src compatsrc[] = {
1304 #ifdef YP
1305 		{ NSSRC_NIS, NS_SUCCESS },
1306 #endif
1307 		{ NULL, 0 }
1308 	};
1309 	ns_dtab dtab[] = {
1310 #ifdef YP
1311 		{ NSSRC_NIS, nis_group, NULL },
1312 #endif
1313 #ifdef HESIOD
1314 		{ NSSRC_DNS, dns_group, NULL },
1315 #endif
1316 		{ NULL, NULL, NULL }
1317 	};
1318 	struct compat_state	*st;
1319 	enum nss_lookup_type	 how;
1320 	const char		*name, *line;
1321 	struct group		*grp;
1322 	gid_t			 gid;
1323 	char			*buffer, *p;
1324 	void			*discard;
1325 	size_t			 bufsize, linesize;
1326 	off_t			 pos;
1327 	int			 fresh, rv, stayopen, *errnop;
1328 
1329 #define set_lookup_type(x, y) do { 				\
1330 	int i;							\
1331 	for (i = 0; i < (int)(nitems(x) - 1); i++)		\
1332 		x[i].mdata = (void *)y;				\
1333 } while (0)
1334 
1335 	fresh = 0;
1336 	name = NULL;
1337 	gid = (gid_t)-1;
1338 	how = (enum nss_lookup_type)(uintptr_t)mdata;
1339 	switch (how) {
1340 	case nss_lt_name:
1341 		name = va_arg(ap, const char *);
1342 		break;
1343 	case nss_lt_id:
1344 		gid = va_arg(ap, gid_t);
1345 		break;
1346 	case nss_lt_all:
1347 		break;
1348 	default:
1349 		return (NS_NOTFOUND);
1350 	}
1351 	grp = va_arg(ap, struct group *);
1352 	buffer = va_arg(ap, char *);
1353 	bufsize = va_arg(ap, size_t);
1354 	errnop = va_arg(ap, int *);
1355 	*errnop = compat_getstate(&st);
1356 	if (*errnop != 0)
1357 		return (NS_UNAVAIL);
1358 	if (st->fp == NULL) {
1359 		st->fp = fopen(_PATH_GROUP, "re");
1360 		if (st->fp == NULL) {
1361 			*errnop = errno;
1362 			rv = NS_UNAVAIL;
1363 			goto fin;
1364 		}
1365 		fresh = 1;
1366 	}
1367 	if (how == nss_lt_all)
1368 		stayopen = 1;
1369 	else {
1370 		if (!fresh)
1371 			rewind(st->fp);
1372 		stayopen = st->stayopen;
1373 	}
1374 docompat:
1375 	switch (st->compat) {
1376 	case COMPAT_MODE_ALL:
1377 		set_lookup_type(dtab, how);
1378 		switch (how) {
1379 		case nss_lt_all:
1380 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
1381 			    "getgrent_r", compatsrc, grp, buffer, bufsize,
1382 			    errnop);
1383 			break;
1384 		case nss_lt_id:
1385 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
1386 			    "getgrgid_r", compatsrc, gid, grp, buffer, bufsize,
1387 			    errnop);
1388 			break;
1389 		case nss_lt_name:
1390 			rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
1391 			    "getgrnam_r", compatsrc, name, grp, buffer,
1392 			    bufsize, errnop);
1393 			break;
1394 		}
1395 		if (rv & NS_TERMINATE)
1396 			goto fin;
1397 		st->compat = COMPAT_MODE_OFF;
1398 		break;
1399 	case COMPAT_MODE_NAME:
1400 		set_lookup_type(dtab, nss_lt_name);
1401 		rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
1402 		    "getgrnam_r", compatsrc, st->name, grp, buffer, bufsize,
1403 		    errnop);
1404 		switch (rv) {
1405 		case NS_SUCCESS:
1406 			switch (how) {
1407 			case nss_lt_name:
1408 				if (strcmp(name, grp->gr_name) != 0)
1409 					rv = NS_NOTFOUND;
1410 				break;
1411 			case nss_lt_id:
1412 				if (gid != grp->gr_gid)
1413 					rv = NS_NOTFOUND;
1414 				break;
1415 			default:
1416 				break;
1417 			}
1418 			break;
1419 		case NS_RETURN:
1420 			goto fin;
1421 		default:
1422 			break;
1423 		}
1424 		free(st->name);
1425 		st->name = NULL;
1426 		st->compat = COMPAT_MODE_OFF;
1427 		if (rv == NS_SUCCESS)
1428 			goto fin;
1429 		break;
1430 	default:
1431 		break;
1432 	}
1433 	rv = NS_NOTFOUND;
1434 	if (stayopen)
1435 		pos = ftello(st->fp);
1436 	while ((line = fgetln(st->fp, &linesize)) != NULL) {
1437 		if (line[linesize-1] == '\n')
1438 			linesize--;
1439 		if (linesize > 2 && line[0] == '+') {
1440 			p = memchr(&line[1], ':', linesize);
1441 			if (p == NULL || p == &line[1])
1442 				st->compat = COMPAT_MODE_ALL;
1443 			else {
1444 				st->name = malloc(p - line);
1445 				if (st->name == NULL) {
1446 					syslog(LOG_ERR,
1447 					 "getgrent memory allocation failure");
1448 					*errnop = ENOMEM;
1449 					rv = NS_UNAVAIL;
1450 					break;
1451 				}
1452 				memcpy(st->name, &line[1], p - line - 1);
1453 				st->name[p - line - 1] = '\0';
1454 				st->compat = COMPAT_MODE_NAME;
1455 			}
1456 			goto docompat;
1457 		}
1458 		rv = __gr_match_entry(line, linesize, how, name, gid);
1459 		if (rv != NS_SUCCESS)
1460 			continue;
1461 		/* We need room at least for the line, a string NUL
1462 		 * terminator, alignment padding, and one (char *)
1463 		 * pointer for the member list terminator.
1464 		 */
1465 		if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
1466 			*errnop = ERANGE;
1467 			rv = NS_RETURN;
1468 			break;
1469 		}
1470 		memcpy(buffer, line, linesize);
1471 		buffer[linesize] = '\0';
1472 		rv = __gr_parse_entry(buffer, linesize, grp,
1473 		    &buffer[linesize + 1], bufsize - linesize - 1, errnop);
1474 		if (rv & NS_TERMINATE)
1475 			break;
1476 		if (stayopen)
1477 			pos = ftello(st->fp);
1478 	}
1479 fin:
1480 	if (st->fp != NULL && !stayopen) {
1481 		fclose(st->fp);
1482 		st->fp = NULL;
1483 	}
1484 	if (rv == NS_SUCCESS && retval != NULL)
1485 		*(struct group **)retval = grp;
1486 	else if (rv == NS_RETURN && *errnop == ERANGE && st->fp != NULL)
1487 		fseeko(st->fp, pos, SEEK_SET);
1488 	return (rv);
1489 #undef set_lookup_type
1490 }
1491 
1492 
1493 /*
1494  * common group line matching and parsing
1495  */
1496 int
1497 __gr_match_entry(const char *line, size_t linesize, enum nss_lookup_type how,
1498     const char *name, gid_t gid)
1499 {
1500 	size_t		 namesize;
1501 	const char	*p, *eol;
1502 	char		*q;
1503 	unsigned long	 n;
1504 	int		 i, needed;
1505 
1506 	if (linesize == 0 || is_comment_line(line, linesize))
1507 		return (NS_NOTFOUND);
1508 	switch (how) {
1509 	case nss_lt_name:	needed = 1; break;
1510 	case nss_lt_id:		needed = 2; break;
1511 	default:		needed = 2; break;
1512 	}
1513 	eol = &line[linesize];
1514 	for (p = line, i = 0; i < needed && p < eol; p++)
1515 		if (*p == ':')
1516 			i++;
1517 	if (i < needed)
1518 		return (NS_NOTFOUND);
1519 	switch (how) {
1520 	case nss_lt_name:
1521 		namesize = strlen(name);
1522 		if (namesize + 1 == (size_t)(p - line) &&
1523 		    memcmp(line, name, namesize) == 0)
1524 			return (NS_SUCCESS);
1525 		break;
1526 	case nss_lt_id:
1527 		n = strtoul(p, &q, 10);
1528 		if (q < eol && *q == ':' && gid == (gid_t)n)
1529 			return (NS_SUCCESS);
1530 		break;
1531 	case nss_lt_all:
1532 		return (NS_SUCCESS);
1533 	default:
1534 		break;
1535 	}
1536 	return (NS_NOTFOUND);
1537 }
1538 
1539 
1540 int
1541 __gr_parse_entry(char *line, size_t linesize, struct group *grp, char *membuf,
1542     size_t membufsize, int *errnop)
1543 {
1544 	char	       *s_gid, *s_mem, *p, **members;
1545 	unsigned long	n;
1546 	int		maxmembers;
1547 
1548 	memset(grp, 0, sizeof(*grp));
1549 	members = (char **)_ALIGN(membuf);
1550 	membufsize -= (char *)members - membuf;
1551 	maxmembers = membufsize / sizeof(*members);
1552 	if (maxmembers <= 0 ||
1553 	    (grp->gr_name = strsep(&line, ":")) == NULL ||
1554 	    grp->gr_name[0] == '\0' ||
1555 	    (grp->gr_passwd = strsep(&line, ":")) == NULL ||
1556 	    (s_gid = strsep(&line, ":")) == NULL ||
1557 	    s_gid[0] == '\0')
1558 		return (NS_NOTFOUND);
1559 	s_mem = line;
1560 	n = strtoul(s_gid, &s_gid, 10);
1561 	if (s_gid[0] != '\0')
1562 		return (NS_NOTFOUND);
1563 	grp->gr_gid = (gid_t)n;
1564 	grp->gr_mem = members;
1565 	while (maxmembers > 1 && s_mem != NULL) {
1566 		p = strsep(&s_mem, ",");
1567 		if (p != NULL && *p != '\0') {
1568 			*members++ = p;
1569 			maxmembers--;
1570 		}
1571 	}
1572 	*members = NULL;
1573 	if (s_mem == NULL)
1574 		return (NS_SUCCESS);
1575 	else {
1576 		*errnop = ERANGE;
1577 		return (NS_RETURN);
1578 	}
1579 }
1580 
1581 
1582