1 /* $NetBSD: lcl_gr.c,v 1.1.1.2 2012/09/09 16:07:57 christos Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1993, 1995
5 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 /*
37 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
38 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
39 *
40 * Permission to use, copy, modify, and distribute this software for any
41 * purpose with or without fee is hereby granted, provided that the above
42 * copyright notice and this permission notice appear in all copies.
43 *
44 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
45 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
46 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
47 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
48 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
49 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
50 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
51 */
52
53 #if defined(LIBC_SCCS) && !defined(lint)
54 static const char rcsid[] = "Id: lcl_gr.c,v 1.3 2005/04/27 04:56:30 sra Exp ";
55 /* from getgrent.c 8.2 (Berkeley) 3/21/94"; */
56 /* from BSDI Id: getgrent.c,v 2.8 1996/05/28 18:15:14 bostic Exp $ */
57 #endif /* LIBC_SCCS and not lint */
58
59 /* extern */
60
61 #include "port_before.h"
62
63 #ifndef WANT_IRS_PW
64 static int __bind_irs_gr_unneeded;
65 #else
66
67 #include <sys/param.h>
68 #include <sys/types.h>
69 #include <netinet/in.h>
70 #include <arpa/nameser.h>
71 #include <resolv.h>
72
73 #include <errno.h>
74 #include <fcntl.h>
75 #include <grp.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <unistd.h>
80
81 #include <irs.h>
82 #include <isc/memcluster.h>
83
84 #include "irs_p.h"
85 #include "lcl_p.h"
86 #include "irp_p.h"
87
88 #include "port_after.h"
89
90
91 /* Types. */
92
93 struct pvt {
94 FILE * fp;
95 /*%<
96 * Need space to store the entries read from the group file.
97 * The members list also needs space per member, and the
98 * strings making up the user names must be allocated
99 * somewhere. Rather than doing lots of small allocations,
100 * we keep one buffer and resize it as needed.
101 */
102 struct group group;
103 size_t nmemb; /*%< Malloc'd max index of gr_mem[]. */
104 char * membuf;
105 size_t membufsize;
106 };
107
108 /* Forward. */
109
110 static void gr_close(struct irs_gr *);
111 static struct group * gr_next(struct irs_gr *);
112 static struct group * gr_byname(struct irs_gr *, const char *);
113 static struct group * gr_bygid(struct irs_gr *, gid_t);
114 static void gr_rewind(struct irs_gr *);
115 static void gr_minimize(struct irs_gr *);
116
117 static int grstart(struct pvt *);
118 static char * grnext(struct pvt *);
119 static struct group * grscan(struct irs_gr *, int, gid_t, const char *);
120
121 /* Portability. */
122
123 #ifndef SEEK_SET
124 # define SEEK_SET 0
125 #endif
126
127 /* Public. */
128
129 struct irs_gr *
irs_lcl_gr(struct irs_acc * this)130 irs_lcl_gr(struct irs_acc *this) {
131 struct irs_gr *gr;
132 struct pvt *pvt;
133
134 UNUSED(this);
135
136 if (!(gr = memget(sizeof *gr))) {
137 errno = ENOMEM;
138 return (NULL);
139 }
140 memset(gr, 0x5e, sizeof *gr);
141 if (!(pvt = memget(sizeof *pvt))) {
142 memput(gr, sizeof *gr);
143 errno = ENOMEM;
144 return (NULL);
145 }
146 memset(pvt, 0, sizeof *pvt);
147 gr->private = pvt;
148 gr->close = gr_close;
149 gr->next = gr_next;
150 gr->byname = gr_byname;
151 gr->bygid = gr_bygid;
152 gr->rewind = gr_rewind;
153 gr->list = make_group_list;
154 gr->minimize = gr_minimize;
155 gr->res_get = NULL;
156 gr->res_set = NULL;
157 return (gr);
158 }
159
160 /* Methods. */
161
162 static void
gr_close(struct irs_gr * this)163 gr_close(struct irs_gr *this) {
164 struct pvt *pvt = (struct pvt *)this->private;
165
166 if (pvt->fp)
167 (void)fclose(pvt->fp);
168 if (pvt->group.gr_mem)
169 free(pvt->group.gr_mem);
170 if (pvt->membuf)
171 free(pvt->membuf);
172 memput(pvt, sizeof *pvt);
173 memput(this, sizeof *this);
174 }
175
176 static struct group *
gr_next(struct irs_gr * this)177 gr_next(struct irs_gr *this) {
178 struct pvt *pvt = (struct pvt *)this->private;
179
180 if (!pvt->fp && !grstart(pvt))
181 return (NULL);
182 return (grscan(this, 0, 0, NULL));
183 }
184
185 static struct group *
gr_byname(struct irs_gr * this,const char * name)186 gr_byname(struct irs_gr *this, const char *name) {
187 if (!grstart((struct pvt *)this->private))
188 return (NULL);
189 return (grscan(this, 1, 0, name));
190 }
191
192 static struct group *
gr_bygid(struct irs_gr * this,gid_t gid)193 gr_bygid(struct irs_gr *this, gid_t gid) {
194 if (!grstart((struct pvt *)this->private))
195 return (NULL);
196 return (grscan(this, 1, gid, NULL));
197 }
198
199 static void
gr_rewind(struct irs_gr * this)200 gr_rewind(struct irs_gr *this) {
201 (void) grstart((struct pvt *)this->private);
202 }
203
204 static void
gr_minimize(struct irs_gr * this)205 gr_minimize(struct irs_gr *this) {
206 struct pvt *pvt = (struct pvt *)this->private;
207
208 if (pvt->fp != NULL) {
209 (void)fclose(pvt->fp);
210 pvt->fp = NULL;
211 }
212 }
213
214 /* Private. */
215
216 static int
grstart(struct pvt * pvt)217 grstart(struct pvt *pvt) {
218 if (pvt->fp) {
219 if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
220 return (1);
221 (void)fclose(pvt->fp);
222 }
223 if (!(pvt->fp = fopen(_PATH_GROUP, "r")))
224 return (0);
225 if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
226 fclose(pvt->fp);
227 return (0);
228 }
229 return (1);
230 }
231
232 #define INITIAL_NMEMB 30 /*%< about 120 bytes */
233 #define INITIAL_BUFSIZ (INITIAL_NMEMB * 8) /*%< about 240 bytes */
234 static char *
grnext(struct pvt * pvt)235 grnext(struct pvt *pvt) {
236 char *w, *e;
237 int ch;
238
239 /* Make sure we have a buffer. */
240 if (pvt->membuf == NULL) {
241 pvt->membuf = malloc(INITIAL_BUFSIZ);
242 if (pvt->membuf == NULL) {
243 enomem:
244 errno = ENOMEM;
245 return (NULL);
246 }
247 pvt->membufsize = INITIAL_BUFSIZ;
248 }
249
250 /* Read until EOF or EOL. */
251 w = pvt->membuf;
252 e = pvt->membuf + pvt->membufsize;
253 while ((ch = fgetc(pvt->fp)) != EOF && ch != '\n') {
254 /* Make sure we have room for this character and a \0. */
255 if (w + 1 == e) {
256 size_t o = w - pvt->membuf;
257 size_t n = pvt->membufsize * 2;
258 char *t = realloc(pvt->membuf, n);
259
260 if (t == NULL)
261 goto enomem;
262 pvt->membuf = t;
263 pvt->membufsize = n;
264 w = pvt->membuf + o;
265 e = pvt->membuf + pvt->membufsize;
266 }
267 /* Store it. */
268 *w++ = (char)ch;
269 }
270
271 /* Hitting EOF on the first character really does mean EOF. */
272 if (w == pvt->membuf && ch == EOF) {
273 errno = ENOENT;
274 return (NULL);
275 }
276
277 /* Last line of /etc/group need not end with \n; we don't care. */
278 *w = '\0';
279 return (pvt->membuf);
280 }
281
282 static struct group *
grscan(struct irs_gr * this,int search,gid_t gid,const char * name)283 grscan(struct irs_gr *this, int search, gid_t gid, const char *name) {
284 struct pvt *pvt = (struct pvt *)this->private;
285 size_t n;
286 char *bp, **m, *p;
287
288 /* Read lines until we find one that matches our search criteria. */
289 for (;;) {
290 if ((bp = grnext(pvt)) == NULL)
291 return (NULL);
292
293 /* Optimize the usual case of searching for a name. */
294 pvt->group.gr_name = strsep(&bp, ":");
295 if (search && name != NULL &&
296 strcmp(pvt->group.gr_name, name) != 0)
297 continue;
298 if (bp == NULL || *bp == '\0')
299 goto corrupt;
300
301 /* Skip past the password field. */
302 pvt->group.gr_passwd = strsep(&bp, ":");
303 if (bp == NULL || *bp == '\0')
304 goto corrupt;
305
306 /* Checking for a gid. */
307 if ((p = strsep(&bp, ":")) == NULL)
308 continue;
309 /*
310 * Unlike the tests above, the test below is supposed to be
311 * testing 'p' and not 'bp', in case you think it's a typo.
312 */
313 if (p == NULL || *p == '\0') {
314 corrupt:
315 /* warning: corrupted %s file!", _PATH_GROUP */
316 continue;
317 }
318 pvt->group.gr_gid = atoi(p);
319 if (search && name == NULL && (gid_t)pvt->group.gr_gid != gid)
320 continue;
321
322 /* We want this record. */
323 break;
324 }
325
326 /*
327 * Count commas to find out how many members there might be.
328 * Note that commas separate, so if there is one comma there
329 * can be two members (group:*:id:user1,user2). Add another
330 * to account for the NULL terminator. As above, allocate
331 * largest of INITIAL_NMEMB, or 2*n.
332 */
333 n = 1;
334 if (bp != NULL)
335 for (n = 2, p = bp; (p = strpbrk(p, ", ")) != NULL; ++n)
336 p += strspn(p, ", ");
337 if (n > pvt->nmemb || pvt->group.gr_mem == NULL) {
338 if ((n *= 2) < INITIAL_NMEMB)
339 n = INITIAL_NMEMB;
340 if ((m = realloc(pvt->group.gr_mem, n * sizeof *m)) == NULL)
341 return (NULL);
342 pvt->group.gr_mem = m;
343 pvt->nmemb = n;
344 }
345
346 /* Set the name pointers. */
347 for (m = pvt->group.gr_mem; (p = strsep(&bp, ", ")) != NULL;)
348 if (p[0] != '\0')
349 *m++ = p;
350 *m = NULL;
351
352 return (&pvt->group);
353 }
354
355 #endif /* WANT_IRS_GR */
356 /*! \file */
357