1 /* $OpenBSD: getgrent.c,v 1.50 2022/08/02 17:00:15 deraadt Exp $ */
2 /*
3 * Copyright (c) 1989, 1993
4 * The Regents of the University of California. All rights reserved.
5 * Portions Copyright (c) 1994, Jason Downs. All Rights Reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/types.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <limits.h>
37 #include <unistd.h>
38 #include <grp.h>
39 #include <errno.h>
40 #ifdef YP
41 #include <rpc/rpc.h>
42 #include <rpcsvc/yp.h>
43 #include <rpcsvc/ypclnt.h>
44 #include "ypinternal.h"
45 #include "ypexclude.h"
46 #endif
47 #include "thread_private.h"
48
49 /* This global storage is locked for the non-rentrant functions */
50 _THREAD_PRIVATE_KEY(gr_storage);
51 static struct group_storage {
52 #define MAXGRP 200
53 char *members[MAXGRP];
54 #define MAXLINELENGTH 1024
55 char line[MAXLINELENGTH];
56 } gr_storage;
57 #define GETGR_R_SIZE_MAX _GR_BUF_LEN
58
59 /* File pointers are locked with the 'gr' mutex */
60 _THREAD_PRIVATE_KEY(gr);
61 static FILE *_gr_fp;
62 static struct group _gr_group;
63 static int _gr_stayopen;
64 static int grscan(int, gid_t, const char *, struct group *, struct group_storage *,
65 int *);
66 static int start_gr(void);
67 static void endgrent_basic(void);
68
69 static struct group *getgrnam_gs(const char *, struct group *,
70 struct group_storage *);
71 static struct group *getgrgid_gs(gid_t, struct group *,
72 struct group_storage *);
73
74 #ifdef YP
75 static struct _ypexclude *__ypexhead = NULL;
76 static int __ypmode = 0;
77 static char *__ypcurrent, *__ypdomain;
78 static int __ypcurrentlen;
79 #endif
80
81 struct group *
_getgrent_yp(int * foundyp)82 _getgrent_yp(int *foundyp)
83 {
84 struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr, _gr_group, NULL);
85 struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
86 gr_storage, NULL);
87
88 _THREAD_PRIVATE_MUTEX_LOCK(gr);
89 if ((!_gr_fp && !start_gr()) || !grscan(0, 0, NULL, p_gr, gs, foundyp))
90 p_gr = NULL;
91 _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
92 return (p_gr);
93 }
94
95 struct group *
getgrent(void)96 getgrent(void)
97 {
98 return (_getgrent_yp(NULL));
99 }
100
101 static struct group *
getgrnam_gs(const char * name,struct group * p_gr,struct group_storage * gs)102 getgrnam_gs(const char *name, struct group *p_gr, struct group_storage *gs)
103 {
104 int rval;
105
106 _THREAD_PRIVATE_MUTEX_LOCK(gr);
107 if (!start_gr())
108 rval = 0;
109 else {
110 rval = grscan(1, 0, name, p_gr, gs, NULL);
111 if (!_gr_stayopen)
112 endgrent_basic();
113 }
114 _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
115 return(rval ? p_gr : NULL);
116 }
117
118 struct group *
getgrnam(const char * name)119 getgrnam(const char *name)
120 {
121 struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr,_gr_group,NULL);
122 struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
123 gr_storage, NULL);
124
125 return getgrnam_gs(name, p_gr, gs);
126 }
127
128 int
getgrnam_r(const char * name,struct group * grp,char * buffer,size_t bufsize,struct group ** result)129 getgrnam_r(const char *name, struct group *grp, char *buffer,
130 size_t bufsize, struct group **result)
131 {
132 int errnosave;
133 int ret;
134
135 if (bufsize < GETGR_R_SIZE_MAX)
136 return ERANGE;
137 errnosave = errno;
138 errno = 0;
139 *result = getgrnam_gs(name, grp, (struct group_storage *)buffer);
140 if (*result == NULL)
141 ret = errno;
142 else
143 ret = 0;
144 errno = errnosave;
145 return ret;
146 }
147 DEF_WEAK(getgrnam_r);
148
149 static struct group *
getgrgid_gs(gid_t gid,struct group * p_gr,struct group_storage * gs)150 getgrgid_gs(gid_t gid, struct group *p_gr, struct group_storage *gs)
151 {
152 int rval;
153
154 _THREAD_PRIVATE_MUTEX_LOCK(gr);
155 if (!start_gr())
156 rval = 0;
157 else {
158 rval = grscan(1, gid, NULL, p_gr, gs, NULL);
159 if (!_gr_stayopen)
160 endgrent_basic();
161 }
162 _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
163 return(rval ? p_gr : NULL);
164 }
165
166 struct group *
getgrgid(gid_t gid)167 getgrgid(gid_t gid)
168 {
169 struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr, _gr_group, NULL);
170 struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
171 gr_storage, NULL);
172
173 return getgrgid_gs(gid, p_gr, gs);
174 }
175
176 int
getgrgid_r(gid_t gid,struct group * grp,char * buffer,size_t bufsize,struct group ** result)177 getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize,
178 struct group **result)
179 {
180 int errnosave;
181 int ret;
182
183 if (bufsize < GETGR_R_SIZE_MAX)
184 return ERANGE;
185 errnosave = errno;
186 errno = 0;
187 *result = getgrgid_gs(gid, grp, (struct group_storage *)buffer);
188 if (*result == NULL)
189 ret = errno;
190 else
191 ret = 0;
192 errno = errnosave;
193 return ret;
194 }
195 DEF_WEAK(getgrgid_r);
196
197 static int
start_gr(void)198 start_gr(void)
199 {
200 if (_gr_fp) {
201 rewind(_gr_fp);
202 #ifdef YP
203 __ypmode = 0;
204 free(__ypcurrent);
205 __ypcurrent = NULL;
206 if (__ypexhead)
207 __ypexclude_free(&__ypexhead);
208 __ypexhead = NULL;
209 #endif
210 return(1);
211 }
212
213 return((_gr_fp = fopen(_PATH_GROUP, "re")) ? 1 : 0);
214 }
215
216 void
setgrent(void)217 setgrent(void)
218 {
219 int saved_errno;
220
221 saved_errno = errno;
222 setgroupent(0);
223 errno = saved_errno;
224 }
225 DEF_WEAK(setgrent);
226
227 int
setgroupent(int stayopen)228 setgroupent(int stayopen)
229 {
230 int retval;
231
232 _THREAD_PRIVATE_MUTEX_LOCK(gr);
233 if (!start_gr())
234 retval = 0;
235 else {
236 _gr_stayopen = stayopen;
237 retval = 1;
238 }
239 _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
240 return (retval);
241 }
242 DEF_WEAK(setgroupent);
243
244 static
245 void
endgrent_basic(void)246 endgrent_basic(void)
247 {
248 int saved_errno;
249
250 if (_gr_fp) {
251 saved_errno = errno;
252 fclose(_gr_fp);
253 _gr_fp = NULL;
254 #ifdef YP
255 __ypmode = 0;
256 free(__ypcurrent);
257 __ypcurrent = NULL;
258 if (__ypexhead)
259 __ypexclude_free(&__ypexhead);
260 __ypexhead = NULL;
261 #endif
262 errno = saved_errno;
263 }
264 }
265
266 void
endgrent(void)267 endgrent(void)
268 {
269 _THREAD_PRIVATE_MUTEX_LOCK(gr);
270 endgrent_basic();
271 _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
272 }
273 DEF_WEAK(endgrent);
274
275 static int
grscan(int search,gid_t gid,const char * name,struct group * p_gr,struct group_storage * gs,int * foundyp)276 grscan(int search, gid_t gid, const char *name, struct group *p_gr,
277 struct group_storage *gs, int *foundyp)
278 {
279 char *cp, **m;
280 char *bp, *endp;
281 u_long ul;
282 #ifdef YP
283 char *key, *data;
284 int keylen, datalen;
285 int r;
286 #endif
287 char **members;
288 char *line;
289 int saved_errno;
290
291 if (gs == NULL)
292 return 0;
293 members = gs->members;
294 line = gs->line;
295 saved_errno = errno;
296
297 for (;;) {
298 #ifdef YP
299 if (__ypmode) {
300 if (__ypcurrent) {
301 r = yp_next(__ypdomain, "group.byname",
302 __ypcurrent, __ypcurrentlen,
303 &key, &keylen, &data, &datalen);
304 free(__ypcurrent);
305 __ypcurrent = key;
306 __ypcurrentlen = keylen;
307 } else {
308 r = yp_first(__ypdomain, "group.byname",
309 &__ypcurrent, &__ypcurrentlen,
310 &data, &datalen);
311 }
312 if (r) {
313 __ypmode = 0;
314 __ypcurrent = NULL;
315 if (r == YPERR_NOMORE)
316 continue;
317 else
318 return 0;
319 }
320 bcopy(data, line, datalen);
321 free(data);
322 line[datalen] = '\0';
323 bp = line;
324 goto parse;
325 }
326 #endif
327 if (!fgets(line, sizeof(gs->line), _gr_fp)) {
328 if (feof(_gr_fp) && !ferror(_gr_fp))
329 errno = saved_errno;
330 return 0;
331 }
332 bp = line;
333 /* skip lines that are too big */
334 if (!strchr(line, '\n')) {
335 int ch;
336
337 while ((ch = getc_unlocked(_gr_fp)) != '\n' &&
338 ch != EOF)
339 ;
340 continue;
341 }
342 #ifdef YP
343 if (line[0] == '+' || line[0] == '-') {
344 if (!__ypdomain)
345 yp_get_default_domain(&__ypdomain);
346 }
347 if (line[0] == '+') {
348 switch (line[1]) {
349 case ':':
350 case '\0':
351 case '\n':
352 if (foundyp) {
353 *foundyp = 1;
354 errno = saved_errno;
355 return 0;
356 }
357 if (!search) {
358 __ypmode = 1;
359 continue;
360 }
361 if (name) {
362 r = yp_match(__ypdomain,
363 "group.byname", name, strlen(name),
364 &data, &datalen);
365 } else {
366 char buf[20];
367 snprintf(buf, sizeof buf, "%u", gid);
368 r = yp_match(__ypdomain, "group.bygid",
369 buf, strlen(buf), &data, &datalen);
370 }
371 switch (r) {
372 case 0:
373 break;
374 case YPERR_KEY:
375 continue;
376 default:
377 return 0;
378 }
379 bcopy(data, line, datalen);
380 free(data);
381 line[datalen] = '\0';
382 bp = line;
383 p_gr->gr_name = strsep(&bp, ":\n");
384 if (__ypexclude_is(&__ypexhead, p_gr->gr_name))
385 continue;
386 p_gr->gr_passwd = strsep(&bp, ":\n");
387 if (!(cp = strsep(&bp, ":\n")))
388 continue;
389 if (name) {
390 ul = strtoul(cp, &endp, 10);
391 if (*endp != '\0' || endp == cp ||
392 ul >= GID_MAX)
393 continue;
394 p_gr->gr_gid = ul;
395 } else
396 p_gr->gr_gid = gid;
397 goto found_it;
398 default:
399 bp = strsep(&bp, ":\n") + 1;
400 if ((search && name && strcmp(bp, name)) ||
401 __ypexclude_is(&__ypexhead, bp))
402 continue;
403 r = yp_match(__ypdomain, "group.byname",
404 bp, strlen(bp), &data, &datalen);
405 switch (r) {
406 case 0:
407 break;
408 case YPERR_KEY:
409 continue;
410 default:
411 return 0;
412 }
413 bcopy(data, line, datalen);
414 free(data);
415 line[datalen] = '\0';
416 bp = line;
417 }
418 } else if (line[0] == '-') {
419 if (__ypexclude_add(&__ypexhead,
420 strsep(&line, ":\n") + 1))
421 return 0;
422 if (foundyp) {
423 *foundyp = -1;
424 errno = saved_errno;
425 return 0;
426 }
427 continue;
428 }
429 parse:
430 #endif
431 p_gr->gr_name = strsep(&bp, ":\n");
432 if (search && name && strcmp(p_gr->gr_name, name))
433 continue;
434 #ifdef YP
435 if (__ypmode && __ypexclude_is(&__ypexhead, p_gr->gr_name))
436 continue;
437 #endif
438 p_gr->gr_passwd = strsep(&bp, ":\n");
439 if (!(cp = strsep(&bp, ":\n")))
440 continue;
441 ul = strtoul(cp, &endp, 10);
442 if (endp == cp || *endp != '\0' || ul >= GID_MAX)
443 continue;
444 p_gr->gr_gid = ul;
445 if (search && name == NULL && p_gr->gr_gid != gid)
446 continue;
447 #ifdef YP
448 found_it:
449 #endif
450 cp = NULL;
451 if (bp == NULL)
452 continue;
453 for (m = p_gr->gr_mem = members;; bp++) {
454 if (m == &members[MAXGRP - 1])
455 break;
456 if (*bp == ',') {
457 if (cp) {
458 *bp = '\0';
459 *m++ = cp;
460 cp = NULL;
461 }
462 } else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
463 if (cp) {
464 *bp = '\0';
465 *m++ = cp;
466 }
467 break;
468 } else if (cp == NULL)
469 cp = bp;
470 }
471 *m = NULL;
472 errno = saved_errno;
473 return 1;
474 }
475 /* NOTREACHED */
476 }
477