2 * Implement the core of the --chmod option.
4 * Copyright (C) 2002 Scott Howard
5 * Copyright (C) 2005-2020 Wayne Davison
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, visit the http://fsf.org website.
24 extern mode_t orig_umask;
26 #define FLAG_X_KEEP (1<<0)
27 #define FLAG_DIRS_ONLY (1<<1)
28 #define FLAG_FILES_ONLY (1<<2)
30 struct chmod_mode_struct {
31 struct chmod_mode_struct *next;
42 #define STATE_1ST_HALF 1
43 #define STATE_2ND_HALF 2
44 #define STATE_OCTAL_NUM 3
46 /* Parse a chmod-style argument, and break it down into one or more AND/OR
47 * pairs in a linked list. We return a pointer to new items on success
48 * (appending the items to the specified list), or NULL on error. */
49 struct chmod_mode_struct *parse_chmod(const char *modestr,
50 struct chmod_mode_struct **root_mode_ptr)
52 int state = STATE_1ST_HALF;
53 int where = 0, what = 0, op = 0, topbits = 0, topoct = 0, flags = 0;
54 struct chmod_mode_struct *first_mode = NULL, *curr_mode = NULL,
57 while (state != STATE_ERROR) {
58 if (!*modestr || *modestr == ',') {
65 prev_mode = curr_mode;
66 curr_mode = new_array(struct chmod_mode_struct, 1);
68 prev_mode->next = curr_mode;
70 first_mode = curr_mode;
71 curr_mode->next = NULL;
77 bits = (where * what) & ~orig_umask;
82 curr_mode->ModeAND = CHMOD_BITS;
83 curr_mode->ModeOR = bits + topoct;
86 curr_mode->ModeAND = CHMOD_BITS - bits - topoct;
87 curr_mode->ModeOR = 0;
90 curr_mode->ModeAND = CHMOD_BITS - (where * 7) - (topoct ? topbits : 0);
91 curr_mode->ModeOR = bits + topoct;
94 curr_mode->ModeAND = 0;
95 curr_mode->ModeOR = bits;
99 curr_mode->flags = flags;
105 state = STATE_1ST_HALF;
106 where = what = op = topoct = topbits = flags = 0;
113 if (flags & FLAG_FILES_ONLY)
115 flags |= FLAG_DIRS_ONLY;
118 if (flags & FLAG_DIRS_ONLY)
120 flags |= FLAG_FILES_ONLY;
138 state = STATE_2ND_HALF;
142 state = STATE_2ND_HALF;
146 state = STATE_2ND_HALF;
149 if (isDigit(modestr) && *modestr < '8' && !where) {
151 state = STATE_OCTAL_NUM;
153 what = *modestr - '0';
168 flags |= FLAG_X_KEEP;
187 case STATE_OCTAL_NUM:
188 if (isDigit(modestr) && *modestr < '8') {
189 what = what*8 + *modestr - '0';
190 if (what > CHMOD_BITS)
199 if (state == STATE_ERROR) {
200 free_chmod_mode(first_mode);
204 if (!(curr_mode = *root_mode_ptr))
205 *root_mode_ptr = first_mode;
207 while (curr_mode->next)
208 curr_mode = curr_mode->next;
209 curr_mode->next = first_mode;
216 /* Takes an existing file permission and a list of AND/OR changes, and
217 * create a new permissions. */
218 int tweak_mode(int mode, struct chmod_mode_struct *chmod_modes)
220 int IsX = mode & 0111;
221 int NonPerm = mode & ~CHMOD_BITS;
223 for ( ; chmod_modes; chmod_modes = chmod_modes->next) {
224 if ((chmod_modes->flags & FLAG_DIRS_ONLY) && !S_ISDIR(NonPerm))
226 if ((chmod_modes->flags & FLAG_FILES_ONLY) && S_ISDIR(NonPerm))
228 mode &= chmod_modes->ModeAND;
229 if ((chmod_modes->flags & FLAG_X_KEEP) && !IsX && !S_ISDIR(NonPerm))
230 mode |= chmod_modes->ModeOR & ~0111;
232 mode |= chmod_modes->ModeOR;
235 return mode | NonPerm;
238 /* Free the linked list created by parse_chmod. */
239 int free_chmod_mode(struct chmod_mode_struct *chmod_modes)
241 struct chmod_mode_struct *next;
243 while (chmod_modes) {
244 next = chmod_modes->next;