xref: /netbsd-src/lib/libc/gen/getgrent.c (revision 76c3314d9b71ad2543a439f351d4a71b80af644f)
1 /*	$NetBSD: getgrent.c,v 1.19 1997/05/22 10:38:07 lukem 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 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)getgrent.c	8.2 (Berkeley) 3/21/94";
40 #else
41 static char rcsid[] = "$NetBSD: getgrent.c,v 1.19 1997/05/22 10:38:07 lukem Exp $";
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include <sys/types.h>
46 #include <limits.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <grp.h>
51 #ifdef YP
52 #include <rpc/rpc.h>
53 #include <rpcsvc/yp_prot.h>
54 #include <rpcsvc/ypclnt.h>
55 #endif
56 
57 static FILE *_gr_fp;
58 static struct group _gr_group;
59 static int _gr_stayopen;
60 static int grscan(), start_gr();
61 
62 #define	MAXGRP		200
63 static char *members[MAXGRP];
64 #define	MAXLINELENGTH	1024
65 static char line[MAXLINELENGTH];
66 
67 #ifdef YP
68 enum _ypmode { YPMODE_NONE, YPMODE_FULL, YPMODE_NAME };
69 static enum _ypmode __ypmode;
70 static char	*__ypcurrent, *__ypdomain;
71 static int	__ypcurrentlen;
72 #endif
73 
74 struct group *
75 getgrent()
76 {
77 	if (!_gr_fp && !start_gr() || !grscan(0, 0, NULL))
78 		return(NULL);
79 	return(&_gr_group);
80 }
81 
82 struct group *
83 getgrnam(name)
84 	const char *name;
85 {
86 	int rval;
87 
88 	if (!start_gr())
89 		return(NULL);
90 	rval = grscan(1, 0, name);
91 	if (!_gr_stayopen)
92 		endgrent();
93 	return(rval ? &_gr_group : NULL);
94 }
95 
96 struct group *
97 #ifdef __STDC__
98 getgrgid(gid_t gid)
99 #else
100 getgrgid(gid)
101 	gid_t gid;
102 #endif
103 {
104 	int rval;
105 
106 	if (!start_gr())
107 		return(NULL);
108 	rval = grscan(1, gid, NULL);
109 	if (!_gr_stayopen)
110 		endgrent();
111 	return(rval ? &_gr_group : NULL);
112 }
113 
114 static int
115 start_gr()
116 {
117 	if (_gr_fp) {
118 		rewind(_gr_fp);
119 #ifdef YP
120 		__ypmode = YPMODE_NONE;
121 		if (__ypcurrent)
122 			free(__ypcurrent);
123 		__ypcurrent = NULL;
124 #endif
125 		return(1);
126 	}
127 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
128 }
129 
130 void
131 setgrent()
132 {
133 	(void) setgroupent(0);
134 }
135 
136 int
137 setgroupent(stayopen)
138 	int stayopen;
139 {
140 	if (!start_gr())
141 		return(0);
142 	_gr_stayopen = stayopen;
143 	return(1);
144 }
145 
146 void
147 endgrent()
148 {
149 	if (_gr_fp) {
150 		(void)fclose(_gr_fp);
151 		_gr_fp = NULL;
152 #ifdef YP
153 		__ypmode = YPMODE_NONE;
154 		if (__ypcurrent)
155 			free(__ypcurrent);
156 		__ypcurrent = NULL;
157 #endif
158 	}
159 }
160 
161 static int
162 grscan(search, gid, name)
163 	int search;
164 	gid_t gid;
165 	const char *name;
166 {
167 	char *cp, **m;
168 	char *bp, *ep;
169 	unsigned long id;
170 #ifdef YP
171 	char *key, *data;
172 	int keylen, datalen;
173 	int r;
174 	char *grname = (char *)NULL;
175 #endif
176 
177 	for (;;) {
178 #ifdef YP
179 		if (__ypmode != YPMODE_NONE) {
180 
181 			if (!__ypdomain) {
182 				if (yp_get_default_domain(&__ypdomain)) {
183 					__ypmode = YPMODE_NONE;
184 					if (grname != (char *)NULL) {
185 						free(grname);
186 						grname = (char *)NULL;
187 					}
188 					continue;
189 				}
190 			}
191 			switch(__ypmode) {
192 			case YPMODE_FULL:
193 				data = NULL;
194 				if (__ypcurrent) {
195 					key = NULL;
196 					r = yp_next(__ypdomain, "group.byname",
197 						__ypcurrent, __ypcurrentlen,
198 						&key, &keylen, &data, &datalen);
199 					free(__ypcurrent);
200 					if (r != 0) {
201 						__ypcurrent = NULL;
202 						if (key)
203 							free(key);
204 					}
205 					else {
206 						__ypcurrent = key;
207 						__ypcurrentlen = keylen;
208 					}
209 				} else {
210 					r = yp_first(__ypdomain, "group.byname",
211 						&__ypcurrent, &__ypcurrentlen,
212 						&data, &datalen);
213 				}
214 				if (r != 0) {
215 					__ypmode = YPMODE_NONE;
216 					if (data)
217 						free(data);
218 					continue;
219 				}
220 				bcopy(data, line, datalen);
221 				free(data);
222 				break;
223 			case YPMODE_NAME:
224 				if (grname != (char *)NULL) {
225 					data = NULL;
226 					r = yp_match(__ypdomain, "group.byname",
227 						grname, strlen(grname),
228 						&data, &datalen);
229 					__ypmode = YPMODE_NONE;
230 					free(grname);
231 					grname = (char *)NULL;
232 					if (r != 0) {
233 						if (data)
234 							free(data);
235 						continue;
236 					}
237 					bcopy(data, line, datalen);
238 					free(data);
239 				} else {
240 						/* YP not available? */
241 					__ypmode = YPMODE_NONE;
242 					continue;
243 				}
244 				break;
245 			}
246 			line[datalen] = '\0';
247 			bp = line;
248 			goto parse;
249 		}
250 #endif /* YP */
251 		if (!fgets(line, sizeof(line), _gr_fp))
252 			return(0);
253 		bp = line;
254 		/* skip lines that are too big */
255 		if (!strchr(line, '\n')) {
256 			int ch;
257 
258 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
259 				;
260 			continue;
261 		}
262 #ifdef YP
263 		if (line[0] == '+') {
264 			switch(line[1]) {
265 			case ':':
266 			case '\0':
267 			case '\n':
268 				if (_yp_check(NULL)) {
269 					if (!search) {
270 						__ypmode = YPMODE_FULL;
271 						continue;
272 					}
273 					if (!__ypdomain &&
274 					   yp_get_default_domain(&__ypdomain))
275 						continue;
276 					data = NULL;
277 					if (name) {
278 						r = yp_match(__ypdomain,
279 							     "group.byname",
280 							     name, strlen(name),
281 							     &data, &datalen);
282 					} else {
283 						char buf[20];
284 						snprintf(buf, sizeof(buf),
285 						    "%u", gid);
286 						r = yp_match(__ypdomain,
287 							     "group.bygid",
288 							     buf, strlen(buf),
289 							     &data, &datalen);
290 					}
291 					if (r != 0) {
292 						if (data)
293 							free(data);
294 						continue;
295 					}
296 					bcopy(data, line, datalen);
297 					free(data);
298 					line[datalen] = '\0';
299 					bp = line;
300 					_gr_group.gr_name = strsep(&bp, ":\n");
301 					_gr_group.gr_passwd =
302 					    strsep(&bp, ":\n");
303 					if (!(cp = strsep(&bp, ":\n")))
304 						continue;
305 					if (name) {
306 						id = strtoul(cp, &ep, 10);
307 						if (id > GID_MAX || *ep != '\0')
308 							continue;
309 						_gr_group.gr_gid = (gid_t)id;
310 					} else
311 						_gr_group.gr_gid = gid;
312 					goto found_it;
313 				}
314 				break;
315 			default:
316 				if (_yp_check(NULL)) {
317 					char *tptr;
318 
319 					tptr = strsep(&bp, ":\n");
320 					if (search && name &&
321 					    strcmp(tptr, name))
322 						continue;
323 					__ypmode = YPMODE_NAME;
324 					grname = strdup(tptr + 1);
325 					continue;
326 				}
327 				break;
328 			}
329 		}
330 parse:
331 #endif /* YP */
332 		_gr_group.gr_name = strsep(&bp, ":\n");
333 		if (search && name && strcmp(_gr_group.gr_name, name))
334 			continue;
335 		_gr_group.gr_passwd = strsep(&bp, ":\n");
336 		if (!(cp = strsep(&bp, ":\n")))
337 			continue;
338 		id = strtoul(cp, &ep, 10);
339 		if (id > GID_MAX || *ep != '\0')
340 			continue;
341 		_gr_group.gr_gid = (gid_t)id;
342 		if (search && name == NULL && _gr_group.gr_gid != gid)
343 			continue;
344 	found_it:
345 		cp = NULL;
346 		if (bp == NULL)
347 			continue;
348 		for (m = _gr_group.gr_mem = members;; bp++) {
349 			if (m == &members[MAXGRP - 1])
350 				break;
351 			if (*bp == ',') {
352 				if (cp) {
353 					*bp = '\0';
354 					*m++ = cp;
355 					cp = NULL;
356 				}
357 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
358 				if (cp) {
359 					*bp = '\0';
360 					*m++ = cp;
361 				}
362 				break;
363 			} else if (cp == NULL)
364 				cp = bp;
365 		}
366 		*m = NULL;
367 		return(1);
368 	}
369 	/* NOTREACHED */
370 }
371