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getgrent.c revision 1.21 
      1 /*	$NetBSD: getgrent.c,v 1.21 1997/07/21 14:07:05 jtc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  * Portions Copyright (c) 1994, Jason Downs. All Rights Reserved.
      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  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #if defined(LIBC_SCCS) && !defined(lint)
     39 #if 0
     40 static char sccsid[] = "@(#)getgrent.c	8.2 (Berkeley) 3/21/94";
     41 #else
     42 __RCSID("$NetBSD: getgrent.c,v 1.21 1997/07/21 14:07:05 jtc Exp $");
     43 #endif
     44 #endif /* LIBC_SCCS and not lint */
     45 
     46 #include "namespace.h"
     47 #include <sys/types.h>
     48 #include <limits.h>
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <string.h>
     52 #include <grp.h>
     53 #ifdef YP
     54 #include <rpc/rpc.h>
     55 #include <rpcsvc/yp_prot.h>
     56 #include <rpcsvc/ypclnt.h>
     57 #endif
     58 
     59 #ifdef __weak_alias
     60 __weak_alias(endgrent,_endgrent);
     61 __weak_alias(getgrent,_getgrent);
     62 __weak_alias(getgrgid,_getgrgid);
     63 __weak_alias(getgrnam,_getgrnam);
     64 __weak_alias(setgrent,_setgrent);
     65 __weak_alias(setgroupent,_setgroupent);
     66 #endif
     67 
     68 static FILE *_gr_fp;
     69 static struct group _gr_group;
     70 static int _gr_stayopen;
     71 static int grscan __P((int, gid_t, const char *));
     72 static int start_gr __P((void));
     73 
     74 #define	MAXGRP		200
     75 static char *members[MAXGRP];
     76 #define	MAXLINELENGTH	1024
     77 static char line[MAXLINELENGTH];
     78 
     79 #ifdef YP
     80 enum _ypmode { YPMODE_NONE, YPMODE_FULL, YPMODE_NAME };
     81 static enum _ypmode __ypmode;
     82 static char	*__ypcurrent, *__ypdomain;
     83 static int	__ypcurrentlen;
     84 #endif
     85 
     86 struct group *
     87 getgrent()
     88 {
     89 	if ((!_gr_fp && !start_gr()) || !grscan(0, 0, NULL))
     90 		return(NULL);
     91 	return(&_gr_group);
     92 }
     93 
     94 struct group *
     95 getgrnam(name)
     96 	const char *name;
     97 {
     98 	int rval;
     99 
    100 	if (!start_gr())
    101 		return(NULL);
    102 	rval = grscan(1, 0, name);
    103 	if (!_gr_stayopen)
    104 		endgrent();
    105 	return(rval ? &_gr_group : NULL);
    106 }
    107 
    108 struct group *
    109 #ifdef __STDC__
    110 getgrgid(gid_t gid)
    111 #else
    112 getgrgid(gid)
    113 	gid_t gid;
    114 #endif
    115 {
    116 	int rval;
    117 
    118 	if (!start_gr())
    119 		return(NULL);
    120 	rval = grscan(1, gid, NULL);
    121 	if (!_gr_stayopen)
    122 		endgrent();
    123 	return(rval ? &_gr_group : NULL);
    124 }
    125 
    126 static int
    127 start_gr()
    128 {
    129 	if (_gr_fp) {
    130 		rewind(_gr_fp);
    131 #ifdef YP
    132 		__ypmode = YPMODE_NONE;
    133 		if (__ypcurrent)
    134 			free(__ypcurrent);
    135 		__ypcurrent = NULL;
    136 #endif
    137 		return(1);
    138 	}
    139 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
    140 }
    141 
    142 void
    143 setgrent()
    144 {
    145 	(void) setgroupent(0);
    146 }
    147 
    148 int
    149 setgroupent(stayopen)
    150 	int stayopen;
    151 {
    152 	if (!start_gr())
    153 		return(0);
    154 	_gr_stayopen = stayopen;
    155 	return(1);
    156 }
    157 
    158 void
    159 endgrent()
    160 {
    161 	if (_gr_fp) {
    162 		(void)fclose(_gr_fp);
    163 		_gr_fp = NULL;
    164 #ifdef YP
    165 		__ypmode = YPMODE_NONE;
    166 		if (__ypcurrent)
    167 			free(__ypcurrent);
    168 		__ypcurrent = NULL;
    169 #endif
    170 	}
    171 }
    172 
    173 static int
    174 grscan(search, gid, name)
    175 	int search;
    176 	gid_t gid;
    177 	const char *name;
    178 {
    179 	char *cp, **m;
    180 	char *bp, *ep;
    181 	unsigned long id;
    182 #ifdef YP
    183 	char *key, *data;
    184 	int keylen, datalen;
    185 	int r;
    186 	char *grname = (char *)NULL;
    187 #endif
    188 
    189 	for (;;) {
    190 #ifdef YP
    191 		if (__ypmode != YPMODE_NONE) {
    192 
    193 			if (!__ypdomain) {
    194 				if (yp_get_default_domain(&__ypdomain)) {
    195 					__ypmode = YPMODE_NONE;
    196 					if (grname != (char *)NULL) {
    197 						free(grname);
    198 						grname = (char *)NULL;
    199 					}
    200 					continue;
    201 				}
    202 			}
    203 			switch(__ypmode) {
    204 			case YPMODE_FULL:
    205 				data = NULL;
    206 				if (__ypcurrent) {
    207 					key = NULL;
    208 					r = yp_next(__ypdomain, "group.byname",
    209 						__ypcurrent, __ypcurrentlen,
    210 						&key, &keylen, &data, &datalen);
    211 					free(__ypcurrent);
    212 					if (r != 0) {
    213 						__ypcurrent = NULL;
    214 						if (key)
    215 							free(key);
    216 					}
    217 					else {
    218 						__ypcurrent = key;
    219 						__ypcurrentlen = keylen;
    220 					}
    221 				} else {
    222 					r = yp_first(__ypdomain, "group.byname",
    223 						&__ypcurrent, &__ypcurrentlen,
    224 						&data, &datalen);
    225 				}
    226 				if (r != 0) {
    227 					__ypmode = YPMODE_NONE;
    228 					if (data)
    229 						free(data);
    230 					continue;
    231 				}
    232 				bcopy(data, line, datalen);
    233 				free(data);
    234 				break;
    235 			case YPMODE_NAME:
    236 				if (grname != (char *)NULL) {
    237 					data = NULL;
    238 					r = yp_match(__ypdomain, "group.byname",
    239 						grname, strlen(grname),
    240 						&data, &datalen);
    241 					__ypmode = YPMODE_NONE;
    242 					free(grname);
    243 					grname = (char *)NULL;
    244 					if (r != 0) {
    245 						if (data)
    246 							free(data);
    247 						continue;
    248 					}
    249 					bcopy(data, line, datalen);
    250 					free(data);
    251 				} else {
    252 						/* YP not available? */
    253 					__ypmode = YPMODE_NONE;
    254 					continue;
    255 				}
    256 				break;
    257 			case YPMODE_NONE:
    258 				abort();	/* Cannot happen */
    259 				break;
    260 			}
    261 			line[datalen] = '\0';
    262 			bp = line;
    263 			goto parse;
    264 		}
    265 #endif /* YP */
    266 		if (!fgets(line, sizeof(line), _gr_fp))
    267 			return(0);
    268 		bp = line;
    269 		/* skip lines that are too big */
    270 		if (!strchr(line, '\n')) {
    271 			int ch;
    272 
    273 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
    274 				;
    275 			continue;
    276 		}
    277 #ifdef YP
    278 		if (line[0] == '+') {
    279 			switch(line[1]) {
    280 			case ':':
    281 			case '\0':
    282 			case '\n':
    283 				if (_yp_check(NULL)) {
    284 					if (!search) {
    285 						__ypmode = YPMODE_FULL;
    286 						continue;
    287 					}
    288 					if (!__ypdomain &&
    289 					   yp_get_default_domain(&__ypdomain))
    290 						continue;
    291 					data = NULL;
    292 					if (name) {
    293 						r = yp_match(__ypdomain,
    294 							     "group.byname",
    295 							     name, strlen(name),
    296 							     &data, &datalen);
    297 					} else {
    298 						char buf[20];
    299 						snprintf(buf, sizeof(buf),
    300 						    "%u", gid);
    301 						r = yp_match(__ypdomain,
    302 							     "group.bygid",
    303 							     buf, strlen(buf),
    304 							     &data, &datalen);
    305 					}
    306 					if (r != 0) {
    307 						if (data)
    308 							free(data);
    309 						continue;
    310 					}
    311 					bcopy(data, line, datalen);
    312 					free(data);
    313 					line[datalen] = '\0';
    314 					bp = line;
    315 					_gr_group.gr_name = strsep(&bp, ":\n");
    316 					_gr_group.gr_passwd =
    317 					    strsep(&bp, ":\n");
    318 					if (!(cp = strsep(&bp, ":\n")))
    319 						continue;
    320 					if (name) {
    321 						id = strtoul(cp, &ep, 10);
    322 						if (id > GID_MAX || *ep != '\0')
    323 							continue;
    324 						_gr_group.gr_gid = (gid_t)id;
    325 					} else
    326 						_gr_group.gr_gid = gid;
    327 					goto found_it;
    328 				}
    329 				break;
    330 			default:
    331 				if (_yp_check(NULL)) {
    332 					char *tptr;
    333 
    334 					tptr = strsep(&bp, ":\n");
    335 					if (search && name &&
    336 					    strcmp(tptr, name))
    337 						continue;
    338 					__ypmode = YPMODE_NAME;
    339 					grname = strdup(tptr + 1);
    340 					continue;
    341 				}
    342 				break;
    343 			}
    344 		}
    345 parse:
    346 #endif /* YP */
    347 		_gr_group.gr_name = strsep(&bp, ":\n");
    348 		if (search && name && strcmp(_gr_group.gr_name, name))
    349 			continue;
    350 		_gr_group.gr_passwd = strsep(&bp, ":\n");
    351 		if (!(cp = strsep(&bp, ":\n")))
    352 			continue;
    353 		id = strtoul(cp, &ep, 10);
    354 		if (id > GID_MAX || *ep != '\0')
    355 			continue;
    356 		_gr_group.gr_gid = (gid_t)id;
    357 		if (search && name == NULL && _gr_group.gr_gid != gid)
    358 			continue;
    359 	found_it:
    360 		cp = NULL;
    361 		if (bp == NULL)
    362 			continue;
    363 		for (m = _gr_group.gr_mem = members;; bp++) {
    364 			if (m == &members[MAXGRP - 1])
    365 				break;
    366 			if (*bp == ',') {
    367 				if (cp) {
    368 					*bp = '\0';
    369 					*m++ = cp;
    370 					cp = NULL;
    371 				}
    372 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
    373 				if (cp) {
    374 					*bp = '\0';
    375 					*m++ = cp;
    376 				}
    377 				break;
    378 			} else if (cp == NULL)
    379 				cp = bp;
    380 		}
    381 		*m = NULL;
    382 		return(1);
    383 	}
    384 	/* NOTREACHED */
    385 }
    386