summaryrefslogtreecommitdiffstats
path: root/lib/gshadow.c
blob: e5a0f61eeb1f0403063c5ef539bee989b5412d0c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
/*
 * Copyright (c) 1990 - 1994, Julianne Frances Haugh
 * Copyright (c) 1996 - 1998, Marek Michałkiewicz
 * Copyright (c) 2005       , Tomasz Kłoczko
 * Copyright (c) 2008 - 2009, Nicolas François
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the copyright holders or contributors may not be used to
 *    endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <config.h>

/* Newer versions of Linux libc already have shadow support.  */
#if defined(SHADOWGRP) && !defined(HAVE_SHADOWGRP)	/*{ */

#ident "$Id$"

#include <stdio.h>
#include "prototypes.h"
#include "defines.h"
static /*@null@*/FILE *shadow;
static /*@null@*//*@only@*/char **members = NULL;
static size_t nmembers = 0;
static /*@null@*//*@only@*/char **admins = NULL;
static size_t nadmins = 0;
static struct sgrp sgroup;

#define	FIELDS	4

#ifdef	USE_NIS
static bool nis_used;
static bool nis_ignore;
static enum { native, start, middle, native2 } nis_state;
static bool nis_bound;
static char *nis_domain;
static char *nis_key;
static int nis_keylen;
static char *nis_val;
static int nis_vallen;

#define	IS_NISCHAR(c) ((c)=='+')
#endif

#ifdef	USE_NIS
/*
 * bind_nis - bind to NIS server
 */

static int bind_nis (void)
{
	if (yp_get_default_domain (&nis_domain))
		return -1;

	nis_bound = true;
	return 0;
}
#endif

static /*@null@*/char **build_list (char *s, char **list[], size_t * nlist)
{
	char **ptr = *list;
	size_t nelem = *nlist, size;

	while (s != NULL && *s != '\0') {
		size = (nelem + 1) * sizeof (ptr);
		ptr = realloc (*list, size);
		if (NULL != ptr) {
			ptr[nelem] = s;
			nelem++;
			*list = ptr;
			*nlist = nelem;
			s = strchr (s, ',');
			if (NULL != s) {
				*s = '\0';
				s++;
			}
		}
	}
	size = (nelem + 1) * sizeof (ptr);
	ptr = realloc (*list, size);
	if (NULL != ptr) {
		ptr[nelem] = NULL;
		*list = ptr;
	}
	return ptr;
}

void setsgent (void)
{
#ifdef	USE_NIS
	nis_state = native;
#endif
	if (NULL != shadow) {
		rewind (shadow);
	} else {
		shadow = fopen (SGROUP_FILE, "r");
	}
}

void endsgent (void)
{
	if (NULL != shadow) {
		(void) fclose (shadow);
	}

	shadow = (FILE *) 0;
}

/*@observer@*//*@null@*/struct sgrp *sgetsgent (const char *string)
{
	static char *sgrbuf = NULL;
	static size_t sgrbuflen = 0;

	char *fields[FIELDS];
	char *cp;
	int i;
	size_t len = strlen (string) + 1;

	if (len > sgrbuflen) {
		char *buf = (char *) realloc (sgrbuf, sizeof (char) * len);
		if (NULL == buf) {
			return NULL;
		}
		sgrbuf = buf;
		sgrbuflen = len;
	}

	strncpy (sgrbuf, string, len);
	sgrbuf[len-1] = '\0';

	cp = strrchr (sgrbuf, '\n');
	if (NULL != cp) {
		*cp = '\0';
	}

	/*
	 * There should be exactly 4 colon separated fields.  Find
	 * all 4 of them and save the starting addresses in fields[].
	 */

	for (cp = sgrbuf, i = 0; (i < FIELDS) && (NULL != cp); i++) {
		fields[i] = cp;
		cp = strchr (cp, ':');
		if (NULL != cp) {
			*cp++ = '\0';
		}
	}

	/*
	 * If there was an extra field somehow, or perhaps not enough,
	 * the line is invalid.
	 */

	if ((NULL != cp) || (i != FIELDS)) {
#ifdef	USE_NIS
		if (!IS_NISCHAR (fields[0][0])) {
			return 0;
		} else {
			nis_used = true;
		}
#else
		return 0;
#endif
	}

	sgroup.sg_name = fields[0];
	sgroup.sg_passwd = fields[1];
	if (0 != nadmins) {
		nadmins = 0;
		free (admins);
		admins = NULL;
	}
	if (0 != nmembers) {
		nmembers = 0;
		free (members);
		members = NULL;
	}
	sgroup.sg_adm = build_list (fields[2], &admins, &nadmins);
	sgroup.sg_mem = build_list (fields[3], &members, &nmembers);

	return &sgroup;
}

/*
 * fgetsgent - convert next line in stream to (struct sgrp)
 *
 * fgetsgent() reads the next line from the provided stream and
 * converts it to a (struct sgrp).  NULL is returned on EOF.
 */

/*@observer@*//*@null@*/struct sgrp *fgetsgent (/*@null@*/FILE * fp)
{
	static size_t buflen = 0;
	static char *buf = NULL;

	char *cp;

	if (0 == buflen) {
		buf = (char *) malloc (BUFSIZ);
		if (NULL == buf) {
			return NULL;
		}
		buflen = BUFSIZ;
	}

	if (NULL == fp) {
		return NULL;
	}

#ifdef	USE_NIS
	while (fgetsx (buf, (int) buflen, fp) == buf)
#else
	if (fgetsx (buf, (int) buflen, fp) == buf)
#endif
	{
		while (   ((cp = strrchr (buf, '\n')) == NULL)
		       && (feof (fp) == 0)) {
			size_t len;

			cp = (char *) realloc (buf, buflen*2);
			if (NULL == cp) {
				return NULL;
			}
			buf = cp;
			buflen *= 2;

			len = strlen (buf);
			if (fgetsx (&buf[len],
			            (int) (buflen - len),
			            fp) != &buf[len]) {
				return NULL;
			}
		}
		cp = strrchr (buf, '\n');
		if (NULL != cp) {
			*cp = '\0';
		}
#ifdef	USE_NIS
		if (nis_ignore && IS_NISCHAR (buf[0])) {
			continue;
		}
#endif
		return (sgetsgent (buf));
	}
	return NULL;
}

/*
 * getsgent - get a single shadow group entry
 */

/*@observer@*//*@null@*/struct sgrp *getsgent (void)
{
#ifdef	USE_NIS
	bool nis_1_group = false;
	struct sgrp *val;
#endif
	if (NULL == shadow) {
		setsgent ();
	}

#ifdef	USE_NIS
      again:
	/*
	 * See if we are reading from the local file.
	 */

	if (nis_state == native || nis_state == native2) {

		/*
		 * Get the next entry from the shadow group file.  Return
		 * NULL right away if there is none.
		 */

		val = fgetsgent (shadow);
		if (NULL == val) {
			return 0;
		}

		/*
		 * If this entry began with a NIS escape character, we have
		 * to see if this is just a single group, or if the entire
		 * map is being asked for.
		 */

		if (IS_NISCHAR (val->sg_name[0])) {
			if ('\0' != val->sg_name[1]) {
				nis_1_group = true;
			} else {
				nis_state = start;
			}
		}

		/*
		 * If this isn't a NIS group and this isn't an escape to go
		 * use a NIS map, it must be a regular local group.
		 */

		if (!nis_1_group && (nis_state != start)) {
			return val;
		}

		/*
		 * If this is an escape to use an NIS map, switch over to
		 * that bunch of code.
		 */

		if (nis_state == start) {
			goto again;
		}

		/*
		 * NEEDSWORK.  Here we substitute pieces-parts of this entry.
		 */

		return 0;
	} else {
		if (!nis_bound) {
			if (bind_nis ()) {
				nis_state = native2;
				goto again;
			}
		}
		if (nis_state == start) {
			if (yp_first (nis_domain, "gshadow.byname", &nis_key,
				      &nis_keylen, &nis_val, &nis_vallen)) {
				nis_state = native2;
				goto again;
			}
			nis_state = middle;
		} else if (nis_state == middle) {
			if (yp_next (nis_domain, "gshadow.byname", nis_key,
				     nis_keylen, &nis_key, &nis_keylen,
				     &nis_val, &nis_vallen)) {
				nis_state = native2;
				goto again;
			}
		}
		return sgetsgent (nis_val);
	}
#else
	return (fgetsgent (shadow));
#endif
}

/*
 * getsgnam - get a shadow group entry by name
 */

/*@observer@*//*@null@*/struct sgrp *getsgnam (const char *name)
{
	struct sgrp *sgrp;

#ifdef	USE_NIS
	static char save_name[16];
	int nis_disabled = 0;
#endif

	setsgent ();

#ifdef	USE_NIS
	if (nis_used) {
	      again:

		/*
		 * Search the gshadow.byname map for this group.
		 */

		if (!nis_bound) {
			bind_nis ();
		}

		if (nis_bound) {
			char *cp;

			if (yp_match (nis_domain, "gshadow.byname", name,
				      strlen (name), &nis_val,
				      &nis_vallen) == 0) {
				cp = strchr (nis_val, '\n');
				if (NULL != cp) {
					*cp = '\0';
				}

				nis_state = middle;
				sgrp = sgetsgent (nis_val);
				if (NULL != sgrp) {
					strcpy (save_name, sgrp->sg_name);
					nis_key = save_name;
					nis_keylen = strlen (save_name);
				}
				return sgrp;
			}
		}
		nis_state = native2;
	}
#endif
#ifdef	USE_NIS
	if (nis_used) {
		nis_ignore = true;
		nis_disabled = true;
	}
#endif
	while ((sgrp = getsgent ()) != (struct sgrp *) 0) {
		if (strcmp (name, sgrp->sg_name) == 0) {
			break;
		}
	}
#ifdef	USE_NIS
	nis_ignore = false;
#endif
	return sgrp;
}

/*
 * putsgent - output shadow group entry in text form
 *
 * putsgent() converts the contents of a (struct sgrp) to text and
 * writes the result to the given stream.  This is the logical
 * opposite of fgetsgent.
 */

int putsgent (const struct sgrp *sgrp, FILE * fp)
{
	char *buf, *cp;
	int i;
	size_t size;

	if ((NULL == fp) || (NULL == sgrp)) {
		return -1;
	}

	/* calculate the required buffer size */
	size = strlen (sgrp->sg_name) + strlen (sgrp->sg_passwd) + 10;
	for (i = 0; (NULL != sgrp->sg_adm) && (NULL != sgrp->sg_adm[i]); i++) {
		size += strlen (sgrp->sg_adm[i]) + 1;
	}
	for (i = 0; (NULL != sgrp->sg_mem) && (NULL != sgrp->sg_mem[i]); i++) {
		size += strlen (sgrp->sg_mem[i]) + 1;
	}

	buf = malloc (size);
	if (NULL == buf) {
		return -1;
	}
	cp = buf;

	/*
	 * Copy the group name and passwd.
	 */

	strcpy (cp, sgrp->sg_name);
	cp += strlen (cp);
	*cp++ = ':';

	strcpy (cp, sgrp->sg_passwd);
	cp += strlen (cp);
	*cp++ = ':';

	/*
	 * Copy the administrators, separating each from the other
	 * with a ",".
	 */

	for (i = 0; NULL != sgrp->sg_adm[i]; i++) {
		if (i > 0) {
			*cp++ = ',';
		}

		strcpy (cp, sgrp->sg_adm[i]);
		cp += strlen (cp);
	}
	*cp = ':';
	cp++;

	/*
	 * Now do likewise with the group members.
	 */

	for (i = 0; NULL != sgrp->sg_mem[i]; i++) {
		if (i > 0) {
			*cp = ',';
			cp++;
		}

		strcpy (cp, sgrp->sg_mem[i]);
		cp += strlen (cp);
	}
	*cp = '\n';
	cp++;
	*cp = '\0';

	/*
	 * Output using the function which understands the line
	 * continuation conventions.
	 */

	if (fputsx (buf, fp) == EOF) {
		free (buf);
		return -1;
	}

	free (buf);
	return 0;
}
#else
extern int errno;		/* warning: ANSI C forbids an empty source file */
#endif				/*} SHADOWGRP */