libexec/mknetid/parse_group.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)getgrent.c       8.2 (Berkeley) 3/21/94
  30  * $FreeBSD: src/libexec/mknetid/parse_group.c,v 1.6 1999/08/28 00:09:42 peter Exp $
  31  * $DragonFly: src/libexec/mknetid/parse_group.c,v 1.3 2006/08/03 16:40:46 swildner Exp $
  32  */
  33
  34 /*
  35  * This is a slightly modified chunk of getgrent(3). All the YP support
  36  * and unneeded functions have been stripped out.
  37  */
  38
  39 #include <sys/types.h>
  40 #include <grp.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 struct group *_getgrent(void);
  46 int _setgrent(void);
  47 void _endgrent(void);
  48 FILE *_gr_fp;
  49
  50 static struct group _gr_group;
  51 static int _gr_stayopen;
  52 static int grscan(int, gid_t, char *), start_gr(void);
  53
  54 #define MAXGRP          200
  55 static char *members[MAXGRP];
  56 #define MAXLINELENGTH   1024
  57 static char line[MAXLINELENGTH];
  58
  59 struct group *
  60 _getgrent(void)
  61 {
  62         if (!_gr_fp && !start_gr()) {
  63                 return NULL;
  64         }
  65
  66
  67         if (!grscan(0, 0, NULL))
  68                 return(NULL);
  69         return(&_gr_group);
  70 }
  71
  72 static int
  73 start_gr(void)
  74 {
  75         return 1;
  76 }
  77
  78 static int
  79 _setgroupent(int stayopen)
  80 {
  81         if (!start_gr())
  82                 return(0);
  83         _gr_stayopen = stayopen;
  84         return(1);
  85 }
  86
  87 int
  88 _setgrent(void)
  89 {
  90         return(_setgroupent(0));
  91 }
  92
  93 void
  94 _endgrent(void)
  95 {
  96         if (_gr_fp) {
  97                 (void)fclose(_gr_fp);
  98                 _gr_fp = NULL;
  99         }
 100 }
 101
 102 static int
 103 grscan(int search, gid_t gid, char *name)
 104 {
 105         char *cp, **m;
 106         char *bp;
 107         for (;;) {
 108                 if (!fgets(line, sizeof(line), _gr_fp))
 109                         return(0);
 110                 bp = line;
 111                 /* skip lines that are too big */
 112                 if (!index(line, '\n')) {
 113                         int ch;
 114
 115                         while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
 116                                 ;
 117                         continue;
 118                 }
 119                 if ((_gr_group.gr_name = strsep(&bp, ":\n")) == NULL)
 120                         break;
 121                 if (_gr_group.gr_name[0] == '+')
 122                         continue;
 123
 124                 if (search && name) {
 125                         if(strcmp(_gr_group.gr_name, name)) {
 126                                 continue;
 127                         }
 128                 }
 129                 if ((_gr_group.gr_passwd = strsep(&bp, ":\n")) == NULL)
 130                         break;
 131                 if (!(cp = strsep(&bp, ":\n")))
 132                         continue;
 133                 _gr_group.gr_gid = atoi(cp);
 134                 if (search && name == NULL && _gr_group.gr_gid != gid)
 135                         continue;
 136                 cp = NULL;
 137                 if (bp == NULL) /* !! Must check for this! */
 138                         break;
 139                 for (m = _gr_group.gr_mem = members;; bp++) {
 140                         if (m == &members[MAXGRP - 1])
 141                                 break;
 142                         if (*bp == ',') {
 143                                 if (cp) {
 144                                         *bp = '\0';
 145                                         *m++ = cp;
 146                                         cp = NULL;
 147                                 }
 148                         } else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
 149                                 if (cp) {
 150                                         *bp = '\0';
 151                                         *m++ = cp;
 152                         }
 153                                 break;
 154                         } else if (cp == NULL)
 155                                 cp = bp;
 156                 }
 157                 *m = NULL;
 158                 return(1);
 159         }
 160         /* NOTREACHED */
 161         return (0);
 162 }