| 1 | /* |
| 2 | * Implement the core of the --chmod option. |
| 3 | * |
| 4 | * Copyright (C) 2002 Scott Howard |
| 5 | * Copyright (C) 2005-2009 Wayne Davison |
| 6 | * |
| 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. |
| 11 | * |
| 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. |
| 16 | * |
| 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. |
| 19 | */ |
| 20 | |
| 21 | #include "rsync.h" |
| 22 | #include "itypes.h" |
| 23 | |
| 24 | extern mode_t orig_umask; |
| 25 | |
| 26 | #define FLAG_X_KEEP (1<<0) |
| 27 | #define FLAG_DIRS_ONLY (1<<1) |
| 28 | #define FLAG_FILES_ONLY (1<<2) |
| 29 | |
| 30 | struct chmod_mode_struct { |
| 31 | struct chmod_mode_struct *next; |
| 32 | int ModeAND, ModeOR; |
| 33 | char flags; |
| 34 | }; |
| 35 | |
| 36 | #define CHMOD_ADD 1 |
| 37 | #define CHMOD_SUB 2 |
| 38 | #define CHMOD_EQ 3 |
| 39 | #define CHMOD_SET 4 |
| 40 | |
| 41 | #define STATE_ERROR 0 |
| 42 | #define STATE_1ST_HALF 1 |
| 43 | #define STATE_2ND_HALF 2 |
| 44 | #define STATE_OCTAL_NUM 3 |
| 45 | |
| 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 succcess |
| 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) |
| 51 | { |
| 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, |
| 55 | *prev_mode = NULL; |
| 56 | |
| 57 | while (state != STATE_ERROR) { |
| 58 | if (!*modestr || *modestr == ',') { |
| 59 | int bits; |
| 60 | |
| 61 | if (!op) { |
| 62 | state = STATE_ERROR; |
| 63 | break; |
| 64 | } |
| 65 | prev_mode = curr_mode; |
| 66 | curr_mode = new_array(struct chmod_mode_struct, 1); |
| 67 | if (prev_mode) |
| 68 | prev_mode->next = curr_mode; |
| 69 | else |
| 70 | first_mode = curr_mode; |
| 71 | curr_mode->next = NULL; |
| 72 | |
| 73 | if (where) |
| 74 | bits = where * what; |
| 75 | else { |
| 76 | where = 0111; |
| 77 | bits = (where * what) & ~orig_umask; |
| 78 | } |
| 79 | |
| 80 | switch (op) { |
| 81 | case CHMOD_ADD: |
| 82 | curr_mode->ModeAND = CHMOD_BITS; |
| 83 | curr_mode->ModeOR = bits + topoct; |
| 84 | break; |
| 85 | case CHMOD_SUB: |
| 86 | curr_mode->ModeAND = CHMOD_BITS - bits - topoct; |
| 87 | curr_mode->ModeOR = 0; |
| 88 | break; |
| 89 | case CHMOD_EQ: |
| 90 | curr_mode->ModeAND = CHMOD_BITS - (where * 7) - (topoct ? topbits : 0); |
| 91 | curr_mode->ModeOR = bits + topoct; |
| 92 | break; |
| 93 | case CHMOD_SET: |
| 94 | curr_mode->ModeAND = 0; |
| 95 | curr_mode->ModeOR = bits; |
| 96 | break; |
| 97 | } |
| 98 | |
| 99 | curr_mode->flags = flags; |
| 100 | |
| 101 | if (!*modestr) |
| 102 | break; |
| 103 | modestr++; |
| 104 | |
| 105 | state = STATE_1ST_HALF; |
| 106 | where = what = op = topoct = topbits = flags = 0; |
| 107 | } |
| 108 | |
| 109 | switch (state) { |
| 110 | case STATE_1ST_HALF: |
| 111 | switch (*modestr) { |
| 112 | case 'D': |
| 113 | if (flags & FLAG_FILES_ONLY) |
| 114 | state = STATE_ERROR; |
| 115 | flags |= FLAG_DIRS_ONLY; |
| 116 | break; |
| 117 | case 'F': |
| 118 | if (flags & FLAG_DIRS_ONLY) |
| 119 | state = STATE_ERROR; |
| 120 | flags |= FLAG_FILES_ONLY; |
| 121 | break; |
| 122 | case 'u': |
| 123 | where |= 0100; |
| 124 | topbits |= 04000; |
| 125 | break; |
| 126 | case 'g': |
| 127 | where |= 0010; |
| 128 | topbits |= 02000; |
| 129 | break; |
| 130 | case 'o': |
| 131 | where |= 0001; |
| 132 | break; |
| 133 | case 'a': |
| 134 | where |= 0111; |
| 135 | break; |
| 136 | case '+': |
| 137 | op = CHMOD_ADD; |
| 138 | state = STATE_2ND_HALF; |
| 139 | break; |
| 140 | case '-': |
| 141 | op = CHMOD_SUB; |
| 142 | state = STATE_2ND_HALF; |
| 143 | break; |
| 144 | case '=': |
| 145 | op = CHMOD_EQ; |
| 146 | state = STATE_2ND_HALF; |
| 147 | break; |
| 148 | default: |
| 149 | if (isDigit(modestr) && *modestr < '8' && !where) { |
| 150 | op = CHMOD_SET; |
| 151 | state = STATE_OCTAL_NUM; |
| 152 | where = 1; |
| 153 | what = *modestr - '0'; |
| 154 | } else |
| 155 | state = STATE_ERROR; |
| 156 | break; |
| 157 | } |
| 158 | break; |
| 159 | case STATE_2ND_HALF: |
| 160 | switch (*modestr) { |
| 161 | case 'r': |
| 162 | what |= 4; |
| 163 | break; |
| 164 | case 'w': |
| 165 | what |= 2; |
| 166 | break; |
| 167 | case 'X': |
| 168 | flags |= FLAG_X_KEEP; |
| 169 | /* FALL THROUGH */ |
| 170 | case 'x': |
| 171 | what |= 1; |
| 172 | break; |
| 173 | case 's': |
| 174 | if (topbits) |
| 175 | topoct |= topbits; |
| 176 | else |
| 177 | topoct = 04000; |
| 178 | break; |
| 179 | case 't': |
| 180 | topoct |= 01000; |
| 181 | break; |
| 182 | default: |
| 183 | state = STATE_ERROR; |
| 184 | break; |
| 185 | } |
| 186 | break; |
| 187 | case STATE_OCTAL_NUM: |
| 188 | if (isDigit(modestr) && *modestr < '8') { |
| 189 | what = what*8 + *modestr - '0'; |
| 190 | if (what > CHMOD_BITS) |
| 191 | state = STATE_ERROR; |
| 192 | } else |
| 193 | state = STATE_ERROR; |
| 194 | break; |
| 195 | } |
| 196 | modestr++; |
| 197 | } |
| 198 | |
| 199 | if (state == STATE_ERROR) { |
| 200 | free_chmod_mode(first_mode); |
| 201 | return NULL; |
| 202 | } |
| 203 | |
| 204 | if (!(curr_mode = *root_mode_ptr)) |
| 205 | *root_mode_ptr = first_mode; |
| 206 | else { |
| 207 | while (curr_mode->next) |
| 208 | curr_mode = curr_mode->next; |
| 209 | curr_mode->next = first_mode; |
| 210 | } |
| 211 | |
| 212 | return first_mode; |
| 213 | } |
| 214 | |
| 215 | |
| 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) |
| 219 | { |
| 220 | int IsX = mode & 0111; |
| 221 | int NonPerm = mode & ~CHMOD_BITS; |
| 222 | |
| 223 | for ( ; chmod_modes; chmod_modes = chmod_modes->next) { |
| 224 | if ((chmod_modes->flags & FLAG_DIRS_ONLY) && !S_ISDIR(NonPerm)) |
| 225 | continue; |
| 226 | if ((chmod_modes->flags & FLAG_FILES_ONLY) && S_ISDIR(NonPerm)) |
| 227 | continue; |
| 228 | mode &= chmod_modes->ModeAND; |
| 229 | if ((chmod_modes->flags & FLAG_X_KEEP) && !IsX && !S_ISDIR(NonPerm)) |
| 230 | mode |= chmod_modes->ModeOR & ~0111; |
| 231 | else |
| 232 | mode |= chmod_modes->ModeOR; |
| 233 | } |
| 234 | |
| 235 | return mode | NonPerm; |
| 236 | } |
| 237 | |
| 238 | /* Free the linked list created by parse_chmod. */ |
| 239 | int free_chmod_mode(struct chmod_mode_struct *chmod_modes) |
| 240 | { |
| 241 | struct chmod_mode_struct *next; |
| 242 | |
| 243 | while (chmod_modes) { |
| 244 | next = chmod_modes->next; |
| 245 | free(chmod_modes); |
| 246 | chmod_modes = next; |
| 247 | } |
| 248 | return 0; |
| 249 | } |