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getgrent.c revision 1.20 
      1 /*	$NetBSD: getgrent.c,v 1.20 1997/07/13 19:01:22 christos 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 1.20 1997/07/13 19:01:22 christos Exp $");
     43 #endif
     44 #endif /* LIBC_SCCS and not lint */
     45 
     46 #include <sys/types.h>
     47 #include <limits.h>
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <grp.h>
     52 #ifdef YP
     53 #include <rpc/rpc.h>
     54 #include <rpcsvc/yp_prot.h>
     55 #include <rpcsvc/ypclnt.h>
     56 #endif
     57 
     58 static FILE *_gr_fp;
     59 static struct group _gr_group;
     60 static int _gr_stayopen;
     61 static int grscan __P((int, gid_t, const char *));
     62 static int start_gr __P((void));
     63 
     64 #define	MAXGRP		200
     65 static char *members[MAXGRP];
     66 #define	MAXLINELENGTH	1024
     67 static char line[MAXLINELENGTH];
     68 
     69 #ifdef YP
     70 enum _ypmode { YPMODE_NONE, YPMODE_FULL, YPMODE_NAME };
     71 static enum _ypmode __ypmode;
     72 static char	*__ypcurrent, *__ypdomain;
     73 static int	__ypcurrentlen;
     74 #endif
     75 
     76 struct group *
     77 getgrent()
     78 {
     79 	if ((!_gr_fp && !start_gr()) || !grscan(0, 0, NULL))
     80 		return(NULL);
     81 	return(&_gr_group);
     82 }
     83 
     84 struct group *
     85 getgrnam(name)
     86 	const char *name;
     87 {
     88 	int rval;
     89 
     90 	if (!start_gr())
     91 		return(NULL);
     92 	rval = grscan(1, 0, name);
     93 	if (!_gr_stayopen)
     94 		endgrent();
     95 	return(rval ? &_gr_group : NULL);
     96 }
     97 
     98 struct group *
     99 #ifdef __STDC__
    100 getgrgid(gid_t gid)
    101 #else
    102 getgrgid(gid)
    103 	gid_t gid;
    104 #endif
    105 {
    106 	int rval;
    107 
    108 	if (!start_gr())
    109 		return(NULL);
    110 	rval = grscan(1, gid, NULL);
    111 	if (!_gr_stayopen)
    112 		endgrent();
    113 	return(rval ? &_gr_group : NULL);
    114 }
    115 
    116 static int
    117 start_gr()
    118 {
    119 	if (_gr_fp) {
    120 		rewind(_gr_fp);
    121 #ifdef YP
    122 		__ypmode = YPMODE_NONE;
    123 		if (__ypcurrent)
    124 			free(__ypcurrent);
    125 		__ypcurrent = NULL;
    126 #endif
    127 		return(1);
    128 	}
    129 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
    130 }
    131 
    132 void
    133 setgrent()
    134 {
    135 	(void) setgroupent(0);
    136 }
    137 
    138 int
    139 setgroupent(stayopen)
    140 	int stayopen;
    141 {
    142 	if (!start_gr())
    143 		return(0);
    144 	_gr_stayopen = stayopen;
    145 	return(1);
    146 }
    147 
    148 void
    149 endgrent()
    150 {
    151 	if (_gr_fp) {
    152 		(void)fclose(_gr_fp);
    153 		_gr_fp = NULL;
    154 #ifdef YP
    155 		__ypmode = YPMODE_NONE;
    156 		if (__ypcurrent)
    157 			free(__ypcurrent);
    158 		__ypcurrent = NULL;
    159 #endif
    160 	}
    161 }
    162 
    163 static int
    164 grscan(search, gid, name)
    165 	int search;
    166 	gid_t gid;
    167 	const char *name;
    168 {
    169 	char *cp, **m;
    170 	char *bp, *ep;
    171 	unsigned long id;
    172 #ifdef YP
    173 	char *key, *data;
    174 	int keylen, datalen;
    175 	int r;
    176 	char *grname = (char *)NULL;
    177 #endif
    178 
    179 	for (;;) {
    180 #ifdef YP
    181 		if (__ypmode != YPMODE_NONE) {
    182 
    183 			if (!__ypdomain) {
    184 				if (yp_get_default_domain(&__ypdomain)) {
    185 					__ypmode = YPMODE_NONE;
    186 					if (grname != (char *)NULL) {
    187 						free(grname);
    188 						grname = (char *)NULL;
    189 					}
    190 					continue;
    191 				}
    192 			}
    193 			switch(__ypmode) {
    194 			case YPMODE_FULL:
    195 				data = NULL;
    196 				if (__ypcurrent) {
    197 					key = NULL;
    198 					r = yp_next(__ypdomain, "group.byname",
    199 						__ypcurrent, __ypcurrentlen,
    200 						&key, &keylen, &data, &datalen);
    201 					free(__ypcurrent);
    202 					if (r != 0) {
    203 						__ypcurrent = NULL;
    204 						if (key)
    205 							free(key);
    206 					}
    207 					else {
    208 						__ypcurrent = key;
    209 						__ypcurrentlen = keylen;
    210 					}
    211 				} else {
    212 					r = yp_first(__ypdomain, "group.byname",
    213 						&__ypcurrent, &__ypcurrentlen,
    214 						&data, &datalen);
    215 				}
    216 				if (r != 0) {
    217 					__ypmode = YPMODE_NONE;
    218 					if (data)
    219 						free(data);
    220 					continue;
    221 				}
    222 				bcopy(data, line, datalen);
    223 				free(data);
    224 				break;
    225 			case YPMODE_NAME:
    226 				if (grname != (char *)NULL) {
    227 					data = NULL;
    228 					r = yp_match(__ypdomain, "group.byname",
    229 						grname, strlen(grname),
    230 						&data, &datalen);
    231 					__ypmode = YPMODE_NONE;
    232 					free(grname);
    233 					grname = (char *)NULL;
    234 					if (r != 0) {
    235 						if (data)
    236 							free(data);
    237 						continue;
    238 					}
    239 					bcopy(data, line, datalen);
    240 					free(data);
    241 				} else {
    242 						/* YP not available? */
    243 					__ypmode = YPMODE_NONE;
    244 					continue;
    245 				}
    246 				break;
    247 			case YPMODE_NONE:
    248 				abort();	/* Cannot happen */
    249 				break;
    250 			}
    251 			line[datalen] = '\0';
    252 			bp = line;
    253 			goto parse;
    254 		}
    255 #endif /* YP */
    256 		if (!fgets(line, sizeof(line), _gr_fp))
    257 			return(0);
    258 		bp = line;
    259 		/* skip lines that are too big */
    260 		if (!strchr(line, '\n')) {
    261 			int ch;
    262 
    263 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
    264 				;
    265 			continue;
    266 		}
    267 #ifdef YP
    268 		if (line[0] == '+') {
    269 			switch(line[1]) {
    270 			case ':':
    271 			case '\0':
    272 			case '\n':
    273 				if (_yp_check(NULL)) {
    274 					if (!search) {
    275 						__ypmode = YPMODE_FULL;
    276 						continue;
    277 					}
    278 					if (!__ypdomain &&
    279 					   yp_get_default_domain(&__ypdomain))
    280 						continue;
    281 					data = NULL;
    282 					if (name) {
    283 						r = yp_match(__ypdomain,
    284 							     "group.byname",
    285 							     name, strlen(name),
    286 							     &data, &datalen);
    287 					} else {
    288 						char buf[20];
    289 						snprintf(buf, sizeof(buf),
    290 						    "%u", gid);
    291 						r = yp_match(__ypdomain,
    292 							     "group.bygid",
    293 							     buf, strlen(buf),
    294 							     &data, &datalen);
    295 					}
    296 					if (r != 0) {
    297 						if (data)
    298 							free(data);
    299 						continue;
    300 					}
    301 					bcopy(data, line, datalen);
    302 					free(data);
    303 					line[datalen] = '\0';
    304 					bp = line;
    305 					_gr_group.gr_name = strsep(&bp, ":\n");
    306 					_gr_group.gr_passwd =
    307 					    strsep(&bp, ":\n");
    308 					if (!(cp = strsep(&bp, ":\n")))
    309 						continue;
    310 					if (name) {
    311 						id = strtoul(cp, &ep, 10);
    312 						if (id > GID_MAX || *ep != '\0')
    313 							continue;
    314 						_gr_group.gr_gid = (gid_t)id;
    315 					} else
    316 						_gr_group.gr_gid = gid;
    317 					goto found_it;
    318 				}
    319 				break;
    320 			default:
    321 				if (_yp_check(NULL)) {
    322 					char *tptr;
    323 
    324 					tptr = strsep(&bp, ":\n");
    325 					if (search && name &&
    326 					    strcmp(tptr, name))
    327 						continue;
    328 					__ypmode = YPMODE_NAME;
    329 					grname = strdup(tptr + 1);
    330 					continue;
    331 				}
    332 				break;
    333 			}
    334 		}
    335 parse:
    336 #endif /* YP */
    337 		_gr_group.gr_name = strsep(&bp, ":\n");
    338 		if (search && name && strcmp(_gr_group.gr_name, name))
    339 			continue;
    340 		_gr_group.gr_passwd = strsep(&bp, ":\n");
    341 		if (!(cp = strsep(&bp, ":\n")))
    342 			continue;
    343 		id = strtoul(cp, &ep, 10);
    344 		if (id > GID_MAX || *ep != '\0')
    345 			continue;
    346 		_gr_group.gr_gid = (gid_t)id;
    347 		if (search && name == NULL && _gr_group.gr_gid != gid)
    348 			continue;
    349 	found_it:
    350 		cp = NULL;
    351 		if (bp == NULL)
    352 			continue;
    353 		for (m = _gr_group.gr_mem = members;; bp++) {
    354 			if (m == &members[MAXGRP - 1])
    355 				break;
    356 			if (*bp == ',') {
    357 				if (cp) {
    358 					*bp = '\0';
    359 					*m++ = cp;
    360 					cp = NULL;
    361 				}
    362 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
    363 				if (cp) {
    364 					*bp = '\0';
    365 					*m++ = cp;
    366 				}
    367 				break;
    368 			} else if (cp == NULL)
    369 				cp = bp;
    370 		}
    371 		*m = NULL;
    372 		return(1);
    373 	}
    374 	/* NOTREACHED */
    375 }
    376