GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libc/gen/setmode.c Lines: 101 162 62.3 %
Date: 2017-11-07 Branches: 51 152 33.6 %

Line Branch Exec Source
1
/*	$OpenBSD: setmode.c,v 1.22 2014/10/11 04:14:35 deraadt Exp $	*/
2
/*	$NetBSD: setmode.c,v 1.15 1997/02/07 22:21:06 christos Exp $	*/
3
4
/*
5
 * Copyright (c) 1989, 1993, 1994
6
 *	The Regents of the University of California.  All rights reserved.
7
 *
8
 * This code is derived from software contributed to Berkeley by
9
 * Dave Borman at Cray Research, Inc.
10
 *
11
 * Redistribution and use in source and binary forms, with or without
12
 * modification, are permitted provided that the following conditions
13
 * are met:
14
 * 1. Redistributions of source code must retain the above copyright
15
 *    notice, this list of conditions and the following disclaimer.
16
 * 2. Redistributions in binary form must reproduce the above copyright
17
 *    notice, this list of conditions and the following disclaimer in the
18
 *    documentation and/or other materials provided with the distribution.
19
 * 3. 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
#include <sys/types.h>
37
#include <sys/stat.h>
38
39
#include <ctype.h>
40
#include <errno.h>
41
#include <signal.h>
42
#include <stdlib.h>
43
#include <unistd.h>
44
45
#ifdef SETMODE_DEBUG
46
#include <stdio.h>
47
#endif
48
49
#define	SET_LEN	6		/* initial # of bitcmd struct to malloc */
50
#define	SET_LEN_INCR 4		/* # of bitcmd structs to add as needed */
51
52
typedef struct bitcmd {
53
	char	cmd;
54
	char	cmd2;
55
	mode_t	bits;
56
} BITCMD;
57
58
#define	CMD2_CLR	0x01
59
#define	CMD2_SET	0x02
60
#define	CMD2_GBITS	0x04
61
#define	CMD2_OBITS	0x08
62
#define	CMD2_UBITS	0x10
63
64
static BITCMD	*addcmd(BITCMD *, int, int, int, u_int);
65
static void	 compress_mode(BITCMD *);
66
#ifdef SETMODE_DEBUG
67
static void	 dumpmode(BITCMD *);
68
#endif
69
70
/*
71
 * Given the old mode and an array of bitcmd structures, apply the operations
72
 * described in the bitcmd structures to the old mode, and return the new mode.
73
 * Note that there is no '=' command; a strict assignment is just a '-' (clear
74
 * bits) followed by a '+' (set bits).
75
 */
76
mode_t
77
getmode(const void *bbox, mode_t omode)
78
{
79
	const BITCMD *set;
80
	mode_t clrval, newmode, value;
81
82
4060
	set = (const BITCMD *)bbox;
83
	newmode = omode;
84
5953
	for (value = 0;; set++)
85

5953
		switch(set->cmd) {
86
		/*
87
		 * When copying the user, group or other bits around, we "know"
88
		 * where the bits are in the mode so that we can do shifts to
89
		 * copy them around.  If we don't use shifts, it gets real
90
		 * grundgy with lots of single bit checks and bit sets.
91
		 */
92
		case 'u':
93
			value = (newmode & S_IRWXU) >> 6;
94
			goto common;
95
96
		case 'g':
97
			value = (newmode & S_IRWXG) >> 3;
98
			goto common;
99
100
		case 'o':
101
			value = newmode & S_IRWXO;
102
common:			if (set->cmd2 & CMD2_CLR) {
103
				clrval =
104
				    (set->cmd2 & CMD2_SET) ?  S_IRWXO : value;
105
				if (set->cmd2 & CMD2_UBITS)
106
					newmode &= ~((clrval<<6) & set->bits);
107
				if (set->cmd2 & CMD2_GBITS)
108
					newmode &= ~((clrval<<3) & set->bits);
109
				if (set->cmd2 & CMD2_OBITS)
110
					newmode &= ~(clrval & set->bits);
111
			}
112
			if (set->cmd2 & CMD2_SET) {
113
				if (set->cmd2 & CMD2_UBITS)
114
					newmode |= (value<<6) & set->bits;
115
				if (set->cmd2 & CMD2_GBITS)
116
					newmode |= (value<<3) & set->bits;
117
				if (set->cmd2 & CMD2_OBITS)
118
					newmode |= value & set->bits;
119
			}
120
			break;
121
122
		case '+':
123
1950
			newmode |= set->bits;
124
1950
			break;
125
126
		case '-':
127
1973
			newmode &= ~set->bits;
128
1973
			break;
129
130
		case 'X':
131
			if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
132
				newmode |= set->bits;
133
			break;
134
135
		case '\0':
136
		default:
137
#ifdef SETMODE_DEBUG
138
			(void)printf("getmode:%04o -> %04o\n", omode, newmode);
139
#endif
140
2030
			return (newmode);
141
		}
142
}
143
144
#define	ADDCMD(a, b, c, d)						\
145
	if (set >= endset) {						\
146
		BITCMD *newset;						\
147
		setlen += SET_LEN_INCR;					\
148
		newset = reallocarray(saveset, setlen, sizeof(BITCMD));	\
149
		if (newset == NULL) {					\
150
			free(saveset);					\
151
			return (NULL);					\
152
		}							\
153
		set = newset + (set - saveset);				\
154
		saveset = newset;					\
155
		endset = newset + (setlen - 2);				\
156
	}								\
157
	set = addcmd(set, (a), (b), (c), (d))
158
159
#define	STANDARD_BITS	(S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
160
161
void *
162
setmode(const char *p)
163
{
164
390
	char op, *ep;
165
	BITCMD *set, *saveset, *endset;
166
195
	sigset_t sigset, sigoset;
167
	mode_t mask, perm, permXbits, who;
168
	int equalopdone, setlen;
169
	u_long perml;
170
171
195
	if (!*p) {
172
		errno = EINVAL;
173
		return (NULL);
174
	}
175
176
	/*
177
	 * Get a copy of the mask for the permissions that are mask relative.
178
	 * Flip the bits, we want what's not set.  Since it's possible that
179
	 * the caller is opening files inside a signal handler, protect them
180
	 * as best we can.
181
	 */
182
195
	sigfillset(&sigset);
183
195
	(void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
184
195
	(void)umask(mask = umask(0));
185
195
	mask = ~mask;
186
195
	(void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
187
188
	setlen = SET_LEN + 2;
189
190
195
	if ((set = calloc((u_int)sizeof(BITCMD), setlen)) == NULL)
191
		return (NULL);
192
	saveset = set;
193
195
	endset = set + (setlen - 2);
194
195
	/*
196
	 * If an absolute number, get it and return; disallow non-octal digits
197
	 * or illegal bits.
198
	 */
199
195
	if (isdigit((unsigned char)*p)) {
200
12
		perml = strtoul(p, &ep, 8);
201
		/* The test on perml will also catch overflow. */
202

24
		if (*ep != '\0' || (perml & ~(STANDARD_BITS|S_ISTXT))) {
203
			free(saveset);
204
			errno = ERANGE;
205
			return (NULL);
206
		}
207
12
		perm = (mode_t)perml;
208

24
		ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
209
12
		set->cmd = 0;
210
12
		return (saveset);
211
	}
212
213
	/*
214
	 * Build list of structures to set/clear/copy bits as described by
215
	 * each clause of the symbolic mode.
216
	 */
217
33
	for (;;) {
218
		/* First, find out which bits might be modified. */
219
536
		for (who = 0;; ++p) {
220

536
			switch (*p) {
221
			case 'a':
222
45
				who |= STANDARD_BITS;
223
45
				break;
224
			case 'u':
225
37
				who |= S_ISUID|S_IRWXU;
226
37
				break;
227
			case 'g':
228
119
				who |= S_ISGID|S_IRWXG;
229
119
				break;
230
			case 'o':
231
119
				who |= S_IRWXO;
232
119
				break;
233
			default:
234
				goto getop;
235
			}
236
		}
237
238

454
getop:		if ((op = *p++) != '+' && op != '-' && op != '=') {
239
11
			free(saveset);
240
11
			errno = EINVAL;
241
11
			return (NULL);
242
		}
243
205
		if (op == '=')
244
68
			equalopdone = 0;
245
246
205
		who &= ~S_ISTXT;
247
563
		for (perm = 0, permXbits = 0;; ++p) {
248


563
			switch (*p) {
249
			case 'r':
250
197
				perm |= S_IRUSR|S_IRGRP|S_IROTH;
251
197
				break;
252
			case 's':
253
				/*
254
				 * If specific bits where requested and
255
				 * only "other" bits ignore set-id.
256
				 */
257
				if (who == 0 || (who & ~S_IRWXO))
258
					perm |= S_ISUID|S_ISGID;
259
				break;
260
			case 't':
261
				/*
262
				 * If specific bits where requested and
263
				 * only "other" bits ignore sticky.
264
				 */
265
				if (who == 0 || (who & ~S_IRWXO)) {
266
					who |= S_ISTXT;
267
					perm |= S_ISTXT;
268
				}
269
				break;
270
			case 'w':
271
70
				perm |= S_IWUSR|S_IWGRP|S_IWOTH;
272
70
				break;
273
			case 'X':
274
				permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
275
				break;
276
			case 'x':
277
91
				perm |= S_IXUSR|S_IXGRP|S_IXOTH;
278
91
				break;
279
			case 'u':
280
			case 'g':
281
			case 'o':
282
				/*
283
				 * When ever we hit 'u', 'g', or 'o', we have
284
				 * to flush out any partial mode that we have,
285
				 * and then do the copying of the mode bits.
286
				 */
287
				if (perm) {
288
					ADDCMD(op, who, perm, mask);
289
					perm = 0;
290
				}
291
				if (op == '=')
292
					equalopdone = 1;
293
				if (op == '+' && permXbits) {
294
					ADDCMD('X', who, permXbits, mask);
295
					permXbits = 0;
296
				}
297
				ADDCMD(*p, who, op, mask);
298
				break;
299
300
			default:
301
				/*
302
				 * Add any permissions that we haven't already
303
				 * done.
304
				 */
305

205
				if (perm || (op == '=' && !equalopdone)) {
306
205
					if (op == '=')
307
68
						equalopdone = 1;
308

410
					ADDCMD(op, who, perm, mask);
309
					perm = 0;
310
205
				}
311
205
				if (permXbits) {
312
					ADDCMD('X', who, permXbits, mask);
313
					permXbits = 0;
314
				}
315
				goto apply;
316
			}
317
		}
318
319
205
apply:		if (!*p)
320
			break;
321
33
		if (*p != ',')
322
			goto getop;
323
33
		++p;
324
	}
325
172
	set->cmd = 0;
326
#ifdef SETMODE_DEBUG
327
	(void)printf("Before compress_mode()\n");
328
	dumpmode(saveset);
329
#endif
330
172
	compress_mode(saveset);
331
#ifdef SETMODE_DEBUG
332
	(void)printf("After compress_mode()\n");
333
	dumpmode(saveset);
334
#endif
335
172
	return (saveset);
336
195
}
337
338
static BITCMD *
339
addcmd(BITCMD *set, int op, int who, int oparg, u_int mask)
340
{
341


731
	switch (op) {
342
	case '=':
343
80
		set->cmd = '-';
344
80
		set->bits = who ? who : STANDARD_BITS;
345
80
		set++;
346
347
80
		op = '+';
348
		/* FALLTHROUGH */
349
	case '+':
350
	case '-':
351
	case 'X':
352
217
		set->cmd = op;
353
217
		set->bits = (who ? who : mask) & oparg;
354
217
		break;
355
356
	case 'u':
357
	case 'g':
358
	case 'o':
359
		set->cmd = op;
360
		if (who) {
361
			set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
362
				    ((who & S_IRGRP) ? CMD2_GBITS : 0) |
363
				    ((who & S_IROTH) ? CMD2_OBITS : 0);
364
			set->bits = (mode_t)~0;
365
		} else {
366
			set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
367
			set->bits = mask;
368
		}
369
370
		if (oparg == '+')
371
			set->cmd2 |= CMD2_SET;
372
		else if (oparg == '-')
373
			set->cmd2 |= CMD2_CLR;
374
		else if (oparg == '=')
375
			set->cmd2 |= CMD2_SET|CMD2_CLR;
376
		break;
377
	}
378
217
	return (set + 1);
379
}
380
381
#ifdef SETMODE_DEBUG
382
static void
383
dumpmode(BITCMD *set)
384
{
385
	for (; set->cmd; ++set)
386
		(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
387
		    set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
388
		    set->cmd2 & CMD2_CLR ? " CLR" : "",
389
		    set->cmd2 & CMD2_SET ? " SET" : "",
390
		    set->cmd2 & CMD2_UBITS ? " UBITS" : "",
391
		    set->cmd2 & CMD2_GBITS ? " GBITS" : "",
392
		    set->cmd2 & CMD2_OBITS ? " OBITS" : "");
393
}
394
#endif
395
396
/*
397
 * Given an array of bitcmd structures, compress by compacting consecutive
398
 * '+', '-' and 'X' commands into at most 3 commands, one of each.  The 'u',
399
 * 'g' and 'o' commands continue to be separate.  They could probably be
400
 * compacted, but it's not worth the effort.
401
 */
402
static void
403
compress_mode(BITCMD *set)
404
{
405
	BITCMD *nset;
406
	int setbits, clrbits, Xbits, op;
407
408
344
	for (nset = set;;) {
409
		/* Copy over any 'u', 'g' and 'o' commands. */
410
688
		while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
411
172
			*set++ = *nset++;
412
172
			if (!op)
413
				return;
414
		}
415
416
445
		for (setbits = clrbits = Xbits = 0;; nset++) {
417
445
			if ((op = nset->cmd) == '-') {
418
148
				clrbits |= nset->bits;
419
148
				setbits &= ~nset->bits;
420
148
				Xbits &= ~nset->bits;
421
445
			} else if (op == '+') {
422
125
				setbits |= nset->bits;
423
125
				clrbits &= ~nset->bits;
424
125
				Xbits &= ~nset->bits;
425
297
			} else if (op == 'X')
426
				Xbits |= nset->bits & ~setbits;
427
			else
428
				break;
429
		}
430
172
		if (clrbits) {
431
115
			set->cmd = '-';
432
115
			set->cmd2 = 0;
433
115
			set->bits = clrbits;
434
115
			set++;
435
115
		}
436
172
		if (setbits) {
437
92
			set->cmd = '+';
438
92
			set->cmd2 = 0;
439
92
			set->bits = setbits;
440
92
			set++;
441
92
		}
442
172
		if (Xbits) {
443
			set->cmd = 'X';
444
			set->cmd2 = 0;
445
			set->bits = Xbits;
446
			set++;
447
		}
448
	}
449
172
}