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.
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36 * @(#)setmode.c 8.2 (Berkeley) 3/25/94
37 * $FreeBSD: src/lib/libc/gen/setmode.c,v 1.5.2.1 2001/03/05 09:34:10 obrien Exp $
38 * $DragonFly: src/lib/libc/gen/setmode.c,v 1.2 2003/06/17 04:26:42 dillon Exp $
41 #include <sys/types.h>
53 #define SET_LEN 6 /* initial # of bitcmd struct to malloc */
54 #define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
56 typedef struct bitcmd {
64 #define CMD2_GBITS 0x04
65 #define CMD2_OBITS 0x08
66 #define CMD2_UBITS 0x10
68 static BITCMD *addcmd __P((BITCMD *, int, int, int, u_int));
69 static void compress_mode __P((BITCMD *));
71 static void dumpmode __P((BITCMD *));
75 * Given the old mode and an array of bitcmd structures, apply the operations
76 * described in the bitcmd structures to the old mode, and return the new mode.
77 * Note that there is no '=' command; a strict assignment is just a '-' (clear
78 * bits) followed by a '+' (set bits).
86 register mode_t clrval, newmode, value;
90 for (value = 0;; set++)
93 * When copying the user, group or other bits around, we "know"
94 * where the bits are in the mode so that we can do shifts to
95 * copy them around. If we don't use shifts, it gets real
96 * grundgy with lots of single bit checks and bit sets.
99 value = (newmode & S_IRWXU) >> 6;
103 value = (newmode & S_IRWXG) >> 3;
107 value = newmode & S_IRWXO;
108 common: if (set->cmd2 & CMD2_CLR) {
110 (set->cmd2 & CMD2_SET) ? S_IRWXO : value;
111 if (set->cmd2 & CMD2_UBITS)
112 newmode &= ~((clrval<<6) & set->bits);
113 if (set->cmd2 & CMD2_GBITS)
114 newmode &= ~((clrval<<3) & set->bits);
115 if (set->cmd2 & CMD2_OBITS)
116 newmode &= ~(clrval & set->bits);
118 if (set->cmd2 & CMD2_SET) {
119 if (set->cmd2 & CMD2_UBITS)
120 newmode |= (value<<6) & set->bits;
121 if (set->cmd2 & CMD2_GBITS)
122 newmode |= (value<<3) & set->bits;
123 if (set->cmd2 & CMD2_OBITS)
124 newmode |= value & set->bits;
129 newmode |= set->bits;
133 newmode &= ~set->bits;
137 if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
138 newmode |= set->bits;
144 (void)printf("getmode:%04o -> %04o\n", omode, newmode);
150 #define ADDCMD(a, b, c, d) \
151 if (set >= endset) { \
152 register BITCMD *newset; \
153 setlen += SET_LEN_INCR; \
154 newset = realloc(saveset, sizeof(BITCMD) * setlen); \
157 set = newset + (set - saveset); \
159 endset = newset + (setlen - 2); \
161 set = addcmd(set, (a), (b), (c), (d))
163 #define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
169 register int perm, who;
171 BITCMD *set, *saveset, *endset;
172 sigset_t sigset, sigoset;
174 int equalopdone=0, permXbits, setlen;
180 * Get a copy of the mask for the permissions that are mask relative.
181 * Flip the bits, we want what's not set. Since it's possible that
182 * the caller is opening files inside a signal handler, protect them
186 (void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
187 (void)umask(mask = umask(0));
189 (void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
191 setlen = SET_LEN + 2;
193 if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
196 endset = set + (setlen - 2);
199 * If an absolute number, get it and return; disallow non-octal digits
202 if (isdigit((unsigned char)*p)) {
203 perm = (mode_t)strtol(p, NULL, 8);
204 if (perm & ~(STANDARD_BITS|S_ISTXT)) {
209 if (*p < '0' || *p > '7') {
213 ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
218 * Build list of structures to set/clear/copy bits as described by
219 * each clause of the symbolic mode.
222 /* First, find out which bits might be modified. */
223 for (who = 0;; ++p) {
226 who |= STANDARD_BITS;
229 who |= S_ISUID|S_IRWXU;
232 who |= S_ISGID|S_IRWXG;
242 getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
250 for (perm = 0, permXbits = 0;; ++p) {
253 perm |= S_IRUSR|S_IRGRP|S_IROTH;
256 /* If only "other" bits ignore set-id. */
257 if (!who || who & ~S_IRWXO)
258 perm |= S_ISUID|S_ISGID;
261 /* If only "other" bits ignore sticky. */
262 if (!who || who & ~S_IRWXO) {
268 perm |= S_IWUSR|S_IWGRP|S_IWOTH;
271 permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
274 perm |= S_IXUSR|S_IXGRP|S_IXOTH;
280 * When ever we hit 'u', 'g', or 'o', we have
281 * to flush out any partial mode that we have,
282 * and then do the copying of the mode bits.
285 ADDCMD(op, who, perm, mask);
290 if (op == '+' && permXbits) {
291 ADDCMD('X', who, permXbits, mask);
294 ADDCMD(*p, who, op, mask);
299 * Add any permissions that we haven't already
302 if (perm || (op == '=' && !equalopdone)) {
305 ADDCMD(op, who, perm, mask);
309 ADDCMD('X', who, permXbits, mask);
324 (void)printf("Before compress_mode()\n");
327 compress_mode(saveset);
329 (void)printf("After compress_mode()\n");
336 addcmd(set, op, who, oparg, mask)
338 register int oparg, who;
345 set->bits = who ? who : STANDARD_BITS;
354 set->bits = (who ? who : mask) & oparg;
362 set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
363 ((who & S_IRGRP) ? CMD2_GBITS : 0) |
364 ((who & S_IROTH) ? CMD2_OBITS : 0);
367 set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
372 set->cmd2 |= CMD2_SET;
373 else if (oparg == '-')
374 set->cmd2 |= CMD2_CLR;
375 else if (oparg == '=')
376 set->cmd2 |= CMD2_SET|CMD2_CLR;
385 register BITCMD *set;
387 for (; set->cmd; ++set)
388 (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
389 set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
390 set->cmd2 & CMD2_CLR ? " CLR" : "",
391 set->cmd2 & CMD2_SET ? " SET" : "",
392 set->cmd2 & CMD2_UBITS ? " UBITS" : "",
393 set->cmd2 & CMD2_GBITS ? " GBITS" : "",
394 set->cmd2 & CMD2_OBITS ? " OBITS" : "");
399 * Given an array of bitcmd structures, compress by compacting consecutive
400 * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
401 * 'g' and 'o' commands continue to be separate. They could probably be
402 * compacted, but it's not worth the effort.
406 register BITCMD *set;
408 register BITCMD *nset;
409 register int setbits, clrbits, Xbits, op;
412 /* Copy over any 'u', 'g' and 'o' commands. */
413 while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
419 for (setbits = clrbits = Xbits = 0;; nset++) {
420 if ((op = nset->cmd) == '-') {
421 clrbits |= nset->bits;
422 setbits &= ~nset->bits;
423 Xbits &= ~nset->bits;
424 } else if (op == '+') {
425 setbits |= nset->bits;
426 clrbits &= ~nset->bits;
427 Xbits &= ~nset->bits;
428 } else if (op == 'X')
429 Xbits |= nset->bits & ~setbits;