2 * Copyright (c) 1989, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Dave Borman at Cray Research, Inc.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
39 #include "namespace.h"
40 #include <sys/types.h>
54 #include "un-namespace.h"
55 #include "libc_private.h"
57 #define SET_LEN 6 /* initial # of bitcmd struct to malloc */
58 #define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
60 typedef struct bitcmd {
68 #define CMD2_GBITS 0x04
69 #define CMD2_OBITS 0x08
70 #define CMD2_UBITS 0x10
72 static BITCMD *addcmd(BITCMD *, mode_t, mode_t, mode_t, mode_t);
73 static void compress_mode(BITCMD *);
75 static void dumpmode(BITCMD *);
79 * Given the old mode and an array of bitcmd structures, apply the operations
80 * described in the bitcmd structures to the old mode, and return the new mode.
81 * Note that there is no '=' command; a strict assignment is just a '-' (clear
82 * bits) followed by a '+' (set bits).
85 getmode(const void *bbox, mode_t omode)
88 mode_t clrval, newmode, value;
90 set = (const BITCMD *)bbox;
92 for (value = 0;; set++)
95 * When copying the user, group or other bits around, we "know"
96 * where the bits are in the mode so that we can do shifts to
97 * copy them around. If we don't use shifts, it gets real
98 * grundgy with lots of single bit checks and bit sets.
101 value = (newmode & S_IRWXU) >> 6;
105 value = (newmode & S_IRWXG) >> 3;
109 value = newmode & S_IRWXO;
110 common: if (set->cmd2 & CMD2_CLR) {
112 (set->cmd2 & CMD2_SET) ? S_IRWXO : value;
113 if (set->cmd2 & CMD2_UBITS)
114 newmode &= ~((clrval<<6) & set->bits);
115 if (set->cmd2 & CMD2_GBITS)
116 newmode &= ~((clrval<<3) & set->bits);
117 if (set->cmd2 & CMD2_OBITS)
118 newmode &= ~(clrval & set->bits);
120 if (set->cmd2 & CMD2_SET) {
121 if (set->cmd2 & CMD2_UBITS)
122 newmode |= (value<<6) & set->bits;
123 if (set->cmd2 & CMD2_GBITS)
124 newmode |= (value<<3) & set->bits;
125 if (set->cmd2 & CMD2_OBITS)
126 newmode |= value & set->bits;
131 newmode |= set->bits;
135 newmode &= ~set->bits;
139 if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
140 newmode |= set->bits;
146 (void)printf("getmode:%04o -> %04o\n", omode, newmode);
152 #define ADDCMD(a, b, c, d) \
153 if (set >= endset) { \
155 setlen += SET_LEN_INCR; \
156 newset = realloc(saveset, sizeof(BITCMD) * setlen); \
157 if (newset == NULL) \
159 set = newset + (set - saveset); \
161 endset = newset + (setlen - 2); \
163 set = addcmd(set, (mode_t)(a), (mode_t)(b), (mode_t)(c), (d))
165 #define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
168 setmode(const char *p)
172 BITCMD *set, *saveset, *endset;
173 sigset_t sigset, sigoset;
174 mode_t mask, perm, permXbits, who;
185 * Get a copy of the mask for the permissions that are mask relative.
186 * Flip the bits, we want what's not set. Since it's possible that
187 * the caller is opening files inside a signal handler, protect them
191 (void)__libc_sigprocmask(SIG_BLOCK, &sigset, &sigoset);
192 (void)umask(mask = umask(0));
194 (void)__libc_sigprocmask(SIG_SETMASK, &sigoset, NULL);
196 setlen = SET_LEN + 2;
198 if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
201 endset = set + (setlen - 2);
204 * If an absolute number, get it and return; disallow non-octal digits
207 if (isdigit((unsigned char)*p)) {
209 perml = strtol(p, &ep, 8);
214 if (errno == ERANGE && (perml == LONG_MAX || perml == LONG_MIN))
216 if (perml & ~(STANDARD_BITS|S_ISTXT)) {
220 perm = (mode_t)perml;
221 ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
227 * Build list of structures to set/clear/copy bits as described by
228 * each clause of the symbolic mode.
232 /* First, find out which bits might be modified. */
233 for (who = 0;; ++p) {
236 who |= STANDARD_BITS;
239 who |= S_ISUID|S_IRWXU;
242 who |= S_ISGID|S_IRWXG;
252 getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
260 for (perm = 0, permXbits = 0;; ++p) {
263 perm |= S_IRUSR|S_IRGRP|S_IROTH;
266 /* If only "other" bits ignore set-id. */
267 if (!who || who & ~S_IRWXO)
268 perm |= S_ISUID|S_ISGID;
271 /* If only "other" bits ignore sticky. */
272 if (!who || who & ~S_IRWXO) {
278 perm |= S_IWUSR|S_IWGRP|S_IWOTH;
281 permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
284 perm |= S_IXUSR|S_IXGRP|S_IXOTH;
290 * When ever we hit 'u', 'g', or 'o', we have
291 * to flush out any partial mode that we have,
292 * and then do the copying of the mode bits.
295 ADDCMD(op, who, perm, mask);
300 if (op == '+' && permXbits) {
301 ADDCMD('X', who, permXbits, mask);
304 ADDCMD(*p, who, op, mask);
309 * Add any permissions that we haven't already
312 if (perm || (op == '=' && !equalopdone)) {
315 ADDCMD(op, who, perm, mask);
319 ADDCMD('X', who, permXbits, mask);
334 (void)printf("Before compress_mode()\n");
337 compress_mode(saveset);
339 (void)printf("After compress_mode()\n");
351 addcmd(BITCMD *set, mode_t op, mode_t who, mode_t oparg, mode_t mask)
356 set->bits = who ? who : STANDARD_BITS;
365 set->bits = (who ? who : mask) & oparg;
373 set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
374 ((who & S_IRGRP) ? CMD2_GBITS : 0) |
375 ((who & S_IROTH) ? CMD2_OBITS : 0);
376 set->bits = (mode_t)~0;
378 set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
383 set->cmd2 |= CMD2_SET;
384 else if (oparg == '-')
385 set->cmd2 |= CMD2_CLR;
386 else if (oparg == '=')
387 set->cmd2 |= CMD2_SET|CMD2_CLR;
395 dumpmode(BITCMD *set)
397 for (; set->cmd; ++set)
398 (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
399 set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
400 set->cmd2 & CMD2_CLR ? " CLR" : "",
401 set->cmd2 & CMD2_SET ? " SET" : "",
402 set->cmd2 & CMD2_UBITS ? " UBITS" : "",
403 set->cmd2 & CMD2_GBITS ? " GBITS" : "",
404 set->cmd2 & CMD2_OBITS ? " OBITS" : "");
409 * Given an array of bitcmd structures, compress by compacting consecutive
410 * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
411 * 'g' and 'o' commands continue to be separate. They could probably be
412 * compacted, but it's not worth the effort.
415 compress_mode(BITCMD *set)
418 int setbits, clrbits, Xbits, op;
421 /* Copy over any 'u', 'g' and 'o' commands. */
422 while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
428 for (setbits = clrbits = Xbits = 0;; nset++) {
429 if ((op = nset->cmd) == '-') {
430 clrbits |= nset->bits;
431 setbits &= ~nset->bits;
432 Xbits &= ~nset->bits;
433 } else if (op == '+') {
434 setbits |= nset->bits;
435 clrbits &= ~nset->bits;
436 Xbits &= ~nset->bits;
437 } else if (op == 'X')
438 Xbits |= nset->bits & ~setbits;