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getgrent.c revision 1.5
      1 /*
      2  * Copyright (c) 1989 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if defined(LIBC_SCCS) && !defined(lint)
     35 /*static char *sccsid = "from: @(#)getgrent.c	5.9 (Berkeley) 4/1/91";*/
     36 static char *rcsid = "$Id: getgrent.c,v 1.5 1993/10/25 23:36:53 jtc Exp $";
     37 #endif /* LIBC_SCCS and not lint */
     38 
     39 #include <sys/types.h>
     40 #include <stdio.h>
     41 #include <stdlib.h>
     42 #include <string.h>
     43 #include <grp.h>
     44 #ifdef YP
     45 #include <rpc/rpc.h>
     46 #include <rpcsvc/yp_prot.h>
     47 #include <rpcsvc/ypclnt.h>
     48 #endif
     49 
     50 static FILE *_gr_fp;
     51 static struct group _gr_group;
     52 static int _gr_stayopen;
     53 static int grscan(), start_gr();
     54 
     55 #define	MAXGRP		200
     56 static char *members[MAXGRP];
     57 #define	MAXLINELENGTH	1024
     58 static char line[MAXLINELENGTH];
     59 
     60 #ifdef YP
     61 static char	*__ypcurrent, *__ypdomain;
     62 static int	__ypcurrentlen, __ypmode=0;
     63 #endif
     64 
     65 struct group *
     66 getgrent()
     67 {
     68 	if (!_gr_fp && !start_gr() || !grscan(0, 0, NULL))
     69 		return(NULL);
     70 	return(&_gr_group);
     71 }
     72 
     73 struct group *
     74 getgrnam(name)
     75 	const char *name;
     76 {
     77 	int rval;
     78 
     79 	if (!start_gr())
     80 		return(NULL);
     81 	rval = grscan(1, 0, name);
     82 	if (!_gr_stayopen)
     83 		endgrent();
     84 	return(rval ? &_gr_group : NULL);
     85 }
     86 
     87 struct group *
     88 #ifdef __STDC__
     89 getgrgid(gid_t gid)
     90 #else
     91 getgrgid(gid)
     92 	gid_t gid;
     93 #endif
     94 {
     95 	int rval;
     96 
     97 	if (!start_gr())
     98 		return(NULL);
     99 	rval = grscan(1, gid, NULL);
    100 	if (!_gr_stayopen)
    101 		endgrent();
    102 	return(rval ? &_gr_group : NULL);
    103 }
    104 
    105 static int
    106 start_gr()
    107 {
    108 	if (_gr_fp) {
    109 		rewind(_gr_fp);
    110 		return(1);
    111 	}
    112 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
    113 }
    114 
    115 void
    116 setgrent()
    117 {
    118 	(void) setgroupent(0);
    119 }
    120 
    121 int
    122 setgroupent(stayopen)
    123 	int stayopen;
    124 {
    125 	if (!start_gr())
    126 		return(0);
    127 	_gr_stayopen = stayopen;
    128 	return(1);
    129 }
    130 
    131 void
    132 endgrent()
    133 {
    134 	if (_gr_fp) {
    135 		(void)fclose(_gr_fp);
    136 		_gr_fp = NULL;
    137 	}
    138 }
    139 
    140 static int
    141 grscan(search, gid, name)
    142 	register int search, gid;
    143 	register char *name;
    144 {
    145 	register char *cp, **m;
    146 	char *bp;
    147 	char *fgets(), *strsep(), *index();
    148 
    149 	for (;;) {
    150 #ifdef YP
    151 		if(__ypmode) {
    152 			char *key, *data;
    153 			int keylen, datalen;
    154 			int r;
    155 
    156 			if(!__ypdomain) {
    157 				if(yp_get_default_domain(&__ypdomain)) {
    158 					__ypmode = 0;
    159 					continue;
    160 				}
    161 			}
    162 			if(__ypcurrent) {
    163 				r = yp_next(__ypdomain, "group.byname",
    164 					__ypcurrent, __ypcurrentlen,
    165 					&key, &keylen, &data, &datalen);
    166 				free(__ypcurrent);
    167 				/*printf("yp_next %d\n", r);*/
    168 				switch(r) {
    169 				case 0:
    170 					break;
    171 				default:
    172 					__ypcurrent = NULL;
    173 					__ypmode = 0;
    174 					free(data);
    175 					continue;
    176 				}
    177 				__ypcurrent = key;
    178 				__ypcurrentlen = keylen;
    179 				bcopy(data, line, datalen);
    180 				free(data);
    181 			} else {
    182 				r = yp_first(__ypdomain, "group.byname",
    183 					&__ypcurrent, &__ypcurrentlen,
    184 					&data, &datalen);
    185 				/*printf("yp_first %d\n", r);*/
    186 				switch(r) {
    187 				case 0:
    188 					break;
    189 				default:
    190 					__ypmode = 0;
    191 					free(data);
    192 					continue;
    193 				}
    194 				bcopy(data, line, datalen);
    195 				free(data);
    196 			}
    197 			line[datalen] = '\0';
    198 			/*printf("line = %s\n", line);*/
    199 			bp = line;
    200 			goto parse;
    201 		}
    202 #endif
    203 		if (!fgets(line, sizeof(line), _gr_fp))
    204 			return(0);
    205 		bp = line;
    206 		/* skip lines that are too big */
    207 		if (!index(line, '\n')) {
    208 			int ch;
    209 
    210 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
    211 				;
    212 			continue;
    213 		}
    214 #ifdef YP
    215 		if ((strcmp("+\n", line) == 0) || (strncmp("+:*:0:", line, 5) == 0)) {
    216 			if(_yp_check(NULL)) {
    217 				__ypmode = 1;
    218 				continue;
    219 			}
    220 		}
    221 parse:
    222 #endif
    223 		_gr_group.gr_name = strsep(&bp, ":\n");
    224 		if (search && name && strcmp(_gr_group.gr_name, name))
    225 			continue;
    226 		_gr_group.gr_passwd = strsep(&bp, ":\n");
    227 		if (!(cp = strsep(&bp, ":\n")))
    228 			continue;
    229 		_gr_group.gr_gid = atoi(cp);
    230 		if (search && name == NULL && _gr_group.gr_gid != gid)
    231 			continue;
    232 		for (m = _gr_group.gr_mem = members;; ++m) {
    233 			if (m == &members[MAXGRP - 1]) {
    234 				*m = NULL;
    235 				break;
    236 			}
    237 			if ((*m = strsep(&bp, ", \n")) == NULL)
    238 				break;
    239 		}
    240 		return(1);
    241 	}
    242 	/* NOTREACHED */
    243 }
    244