1 /* $NetBSD: getgrent.c,v 1.6 2003/02/19 08:04:29 elric 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 /* 38 * Copied from: lib/libc/gen/getgrent.c 39 * NetBSD: getgrent.c,v 1.46 2003/02/17 00:11:54 simonb Exp 40 * and then gutted, leaving only /etc/group support. 41 */ 42 43 #include <sys/cdefs.h> 44 45 #ifdef __weak_alias 46 #define endgrent _endgrent 47 #define getgrent _getgrent 48 #define getgrgid _getgrgid 49 #define getgrnam _getgrnam 50 #define setgrent _setgrent 51 #define setgroupent _setgroupent 52 53 __weak_alias(endgrent,_endgrent) 54 __weak_alias(getgrent,_getgrent) 55 __weak_alias(getgrgid,_getgrgid) 56 __weak_alias(getgrnam,_getgrnam) 57 __weak_alias(setgrent,_setgrent) 58 __weak_alias(setgroupent,_setgroupent) 59 #endif 60 61 #include <sys/types.h> 62 63 #include <grp.h> 64 #include <limits.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 69 struct group *_getgrent_user(const char *); 70 71 static FILE *_gr_fp; 72 static struct group _gr_group; 73 static int _gr_stayopen; 74 static int _gr_filesdone; 75 76 static int grscan(int, gid_t, const char *, const char *); 77 static int grstart(void); 78 static int grmatchline(int, gid_t, const char *, const char *); 79 80 #define MAXGRP 200 81 #define MAXLINELENGTH 1024 82 83 static __aconst char *members[MAXGRP]; 84 static char grline[MAXLINELENGTH]; 85 86 struct group * 87 getgrent(void) 88 { 89 90 if ((!_gr_fp && !grstart()) || !grscan(0, 0, NULL, NULL)) 91 return (NULL); 92 return &_gr_group; 93 } 94 95 /* 96 * _getgrent_user() is designed only to be called by getgrouplist(3) and 97 * hence makes no guarantees about filling the entire structure that it 98 * returns. It may only fill in the group name and gid fields. 99 */ 100 101 struct group * 102 _getgrent_user(const char *user) 103 { 104 105 if ((!_gr_fp && !grstart()) || !grscan(0, 0, NULL, user)) 106 return (NULL); 107 return &_gr_group; 108 } 109 110 struct group * 111 getgrnam(const char *name) 112 { 113 int rval; 114 115 if (!grstart()) 116 return NULL; 117 rval = grscan(1, 0, name, NULL); 118 if (!_gr_stayopen) 119 endgrent(); 120 return (rval) ? &_gr_group : NULL; 121 } 122 123 struct group * 124 getgrgid(gid_t gid) 125 { 126 int rval; 127 128 if (!grstart()) 129 return NULL; 130 rval = grscan(1, gid, NULL, NULL); 131 if (!_gr_stayopen) 132 endgrent(); 133 return (rval) ? &_gr_group : NULL; 134 } 135 136 static int 137 grstart(void) 138 { 139 140 _gr_filesdone = 0; 141 if (_gr_fp) { 142 rewind(_gr_fp); 143 return 1; 144 } 145 return (_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0; 146 } 147 148 void 149 setgrent(void) 150 { 151 152 (void) setgroupent(0); 153 } 154 155 int 156 setgroupent(int stayopen) 157 { 158 159 if (!grstart()) 160 return 0; 161 _gr_stayopen = stayopen; 162 return 1; 163 } 164 165 void 166 endgrent(void) 167 { 168 169 _gr_filesdone = 0; 170 if (_gr_fp) { 171 (void)fclose(_gr_fp); 172 _gr_fp = NULL; 173 } 174 } 175 176 static int 177 grscan(int search, gid_t gid, const char *name, const char *user) 178 { 179 180 if (_gr_filesdone) 181 return 0; 182 for (;;) { 183 if (!fgets(grline, sizeof(grline), _gr_fp)) { 184 if (!search) 185 _gr_filesdone = 1; 186 return 0; 187 } 188 /* skip lines that are too big */ 189 if (!strchr(grline, '\n')) { 190 int ch; 191 192 while ((ch = getc(_gr_fp)) != '\n' && ch != EOF) 193 ; 194 continue; 195 } 196 if (grmatchline(search, gid, name, user)) 197 return 1; 198 } 199 /* NOTREACHED */ 200 } 201 202 static int 203 grmatchline(int search, gid_t gid, const char *name, const char *user) 204 { 205 unsigned long id; 206 __aconst char **m; 207 char *cp, *bp, *ep; 208 209 /* name may be NULL if search is nonzero */ 210 211 bp = grline; 212 _gr_group.gr_name = strsep(&bp, ":\n"); 213 if (search && name && strcmp(_gr_group.gr_name, name)) 214 return 0; 215 _gr_group.gr_passwd = strsep(&bp, ":\n"); 216 if (!(cp = strsep(&bp, ":\n"))) 217 return 0; 218 id = strtoul(cp, &ep, 10); 219 if (id > GID_MAX || *ep != '\0') 220 return 0; 221 _gr_group.gr_gid = (gid_t)id; 222 if (search && name == NULL && _gr_group.gr_gid != gid) 223 return 0; 224 cp = NULL; 225 if (bp == NULL) 226 return 0; 227 for (_gr_group.gr_mem = m = members;; bp++) { 228 if (m == &members[MAXGRP - 1]) 229 break; 230 if (*bp == ',') { 231 if (cp) { 232 *bp = '\0'; 233 *m++ = cp; 234 cp = NULL; 235 } 236 } else if (*bp == '\0' || *bp == '\n' || *bp == ' ') { 237 if (cp) { 238 *bp = '\0'; 239 *m++ = cp; 240 } 241 break; 242 } else if (cp == NULL) 243 cp = bp; 244 } 245 *m = NULL; 246 if (user) { 247 for (m = members; *m; m++) 248 if (!strcmp(user, *m)) 249 return 1; 250 return 0; 251 } 252 return 1; 253 } 254