| File: | src/lib/libc/gen/setmode.c |
| Warning: | line 313, column 6 Value stored to 'permXbits' is never read |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
| 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(*__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_LEN6 6 /* initial # of bitcmd struct to malloc */ |
| 50 | #define SET_LEN_INCR4 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_CLR0x01 0x01 |
| 59 | #define CMD2_SET0x02 0x02 |
| 60 | #define CMD2_GBITS0x04 0x04 |
| 61 | #define CMD2_OBITS0x08 0x08 |
| 62 | #define CMD2_UBITS0x10 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 | set = (const BITCMD *)bbox; |
| 83 | newmode = omode; |
| 84 | for (value = 0;; set++) |
| 85 | 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_IRWXU0000700) >> 6; |
| 94 | goto common; |
| 95 | |
| 96 | case 'g': |
| 97 | value = (newmode & S_IRWXG0000070) >> 3; |
| 98 | goto common; |
| 99 | |
| 100 | case 'o': |
| 101 | value = newmode & S_IRWXO0000007; |
| 102 | common: if (set->cmd2 & CMD2_CLR0x01) { |
| 103 | clrval = |
| 104 | (set->cmd2 & CMD2_SET0x02) ? S_IRWXO0000007 : value; |
| 105 | if (set->cmd2 & CMD2_UBITS0x10) |
| 106 | newmode &= ~((clrval<<6) & set->bits); |
| 107 | if (set->cmd2 & CMD2_GBITS0x04) |
| 108 | newmode &= ~((clrval<<3) & set->bits); |
| 109 | if (set->cmd2 & CMD2_OBITS0x08) |
| 110 | newmode &= ~(clrval & set->bits); |
| 111 | } |
| 112 | if (set->cmd2 & CMD2_SET0x02) { |
| 113 | if (set->cmd2 & CMD2_UBITS0x10) |
| 114 | newmode |= (value<<6) & set->bits; |
| 115 | if (set->cmd2 & CMD2_GBITS0x04) |
| 116 | newmode |= (value<<3) & set->bits; |
| 117 | if (set->cmd2 & CMD2_OBITS0x08) |
| 118 | newmode |= value & set->bits; |
| 119 | } |
| 120 | break; |
| 121 | |
| 122 | case '+': |
| 123 | newmode |= set->bits; |
| 124 | break; |
| 125 | |
| 126 | case '-': |
| 127 | newmode &= ~set->bits; |
| 128 | break; |
| 129 | |
| 130 | case 'X': |
| 131 | if (omode & (S_IFDIR0040000|S_IXUSR0000100|S_IXGRP0000010|S_IXOTH0000001)) |
| 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 | return (newmode); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | #define ADDCMD(a, b, c, d)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, (a), (b), (c), (d)) \ |
| 145 | if (set >= endset) { \ |
| 146 | BITCMD *newset; \ |
| 147 | setlen += SET_LEN_INCR4; \ |
| 148 | newset = reallocarray(saveset, setlen, sizeof(BITCMD)); \ |
| 149 | if (newset == NULL((void *)0)) { \ |
| 150 | free(saveset); \ |
| 151 | return (NULL((void *)0)); \ |
| 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(0004000|0002000|0000700|0000070|0000007) (S_ISUID0004000|S_ISGID0002000|S_IRWXU0000700|S_IRWXG0000070|S_IRWXO0000007) |
| 160 | |
| 161 | void * |
| 162 | setmode(const char *p) |
| 163 | { |
| 164 | char op, *ep; |
| 165 | BITCMD *set, *saveset, *endset; |
| 166 | sigset_t sigset, sigoset; |
| 167 | mode_t mask, perm, permXbits, who; |
| 168 | int equalopdone, setlen; |
| 169 | u_long perml; |
| 170 | |
| 171 | if (!*p) { |
| 172 | errno(*__errno()) = EINVAL22; |
| 173 | return (NULL((void *)0)); |
| 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 | sigfillset(&sigset); |
| 183 | (void)sigprocmask(SIG_BLOCK1, &sigset, &sigoset); |
| 184 | (void)umask(mask = umask(0)); |
| 185 | mask = ~mask; |
| 186 | (void)sigprocmask(SIG_SETMASK3, &sigoset, NULL((void *)0)); |
| 187 | |
| 188 | setlen = SET_LEN6 + 2; |
| 189 | |
| 190 | if ((set = calloc((u_int)sizeof(BITCMD), setlen)) == NULL((void *)0)) |
| 191 | return (NULL((void *)0)); |
| 192 | saveset = set; |
| 193 | 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 | if (isdigit((unsigned char)*p)) { |
| 200 | perml = strtoul(p, &ep, 8); |
| 201 | /* The test on perml will also catch overflow. */ |
| 202 | if (*ep != '\0' || (perml & ~(STANDARD_BITS(0004000|0002000|0000700|0000070|0000007)|S_ISTXT0001000))) { |
| 203 | free(saveset); |
| 204 | errno(*__errno()) = ERANGE34; |
| 205 | return (NULL((void *)0)); |
| 206 | } |
| 207 | perm = (mode_t)perml; |
| 208 | ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, ('='), (((0004000|0002000|0000700| 0000070|0000007)|0001000)), (perm), (mask)); |
| 209 | set->cmd = 0; |
| 210 | 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 | for (;;) { |
| 218 | /* First, find out which bits might be modified. */ |
| 219 | for (who = 0;; ++p) { |
| 220 | switch (*p) { |
| 221 | case 'a': |
| 222 | who |= STANDARD_BITS(0004000|0002000|0000700|0000070|0000007); |
| 223 | break; |
| 224 | case 'u': |
| 225 | who |= S_ISUID0004000|S_IRWXU0000700; |
| 226 | break; |
| 227 | case 'g': |
| 228 | who |= S_ISGID0002000|S_IRWXG0000070; |
| 229 | break; |
| 230 | case 'o': |
| 231 | who |= S_IRWXO0000007; |
| 232 | break; |
| 233 | default: |
| 234 | goto getop; |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | getop: if ((op = *p++) != '+' && op != '-' && op != '=') { |
| 239 | free(saveset); |
| 240 | errno(*__errno()) = EINVAL22; |
| 241 | return (NULL((void *)0)); |
| 242 | } |
| 243 | if (op == '=') |
| 244 | equalopdone = 0; |
| 245 | |
| 246 | who &= ~S_ISTXT0001000; |
| 247 | for (perm = 0, permXbits = 0;; ++p) { |
| 248 | switch (*p) { |
| 249 | case 'r': |
| 250 | perm |= S_IRUSR0000400|S_IRGRP0000040|S_IROTH0000004; |
| 251 | 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_IRWXO0000007)) |
| 258 | perm |= S_ISUID0004000|S_ISGID0002000; |
| 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_IRWXO0000007)) { |
| 266 | who |= S_ISTXT0001000; |
| 267 | perm |= S_ISTXT0001000; |
| 268 | } |
| 269 | break; |
| 270 | case 'w': |
| 271 | perm |= S_IWUSR0000200|S_IWGRP0000020|S_IWOTH0000002; |
| 272 | break; |
| 273 | case 'X': |
| 274 | permXbits = S_IXUSR0000100|S_IXGRP0000010|S_IXOTH0000001; |
| 275 | break; |
| 276 | case 'x': |
| 277 | perm |= S_IXUSR0000100|S_IXGRP0000010|S_IXOTH0000001; |
| 278 | 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)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, (op), (who), (perm), (mask)); |
| 289 | perm = 0; |
| 290 | } |
| 291 | if (op == '=') |
| 292 | equalopdone = 1; |
| 293 | if (op == '+' && permXbits) { |
| 294 | ADDCMD('X', who, permXbits, mask)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, ('X'), (who), (permXbits), (mask)); |
| 295 | permXbits = 0; |
| 296 | } |
| 297 | ADDCMD(*p, who, op, mask)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, (*p), (who), (op), (mask)); |
| 298 | break; |
| 299 | |
| 300 | default: |
| 301 | /* |
| 302 | * Add any permissions that we haven't already |
| 303 | * done. |
| 304 | */ |
| 305 | if (perm || (op == '=' && !equalopdone)) { |
| 306 | if (op == '=') |
| 307 | equalopdone = 1; |
| 308 | ADDCMD(op, who, perm, mask)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, (op), (who), (perm), (mask)); |
| 309 | perm = 0; |
| 310 | } |
| 311 | if (permXbits) { |
| 312 | ADDCMD('X', who, permXbits, mask)if (set >= endset) { BITCMD *newset; setlen += 4; newset = reallocarray(saveset, setlen, sizeof(BITCMD)); if (newset == ((void *)0)) { free(saveset); return (((void *)0)); } set = newset + (set - saveset); saveset = newset; endset = newset + (setlen - 2); } set = addcmd(set, ('X'), (who), (permXbits), (mask)); |
| 313 | permXbits = 0; |
Value stored to 'permXbits' is never read | |
| 314 | } |
| 315 | goto apply; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | apply: if (!*p) |
| 320 | break; |
| 321 | if (*p != ',') |
| 322 | goto getop; |
| 323 | ++p; |
| 324 | } |
| 325 | set->cmd = 0; |
| 326 | #ifdef SETMODE_DEBUG |
| 327 | (void)printf("Before compress_mode()\n"); |
| 328 | dumpmode(saveset); |
| 329 | #endif |
| 330 | compress_mode(saveset); |
| 331 | #ifdef SETMODE_DEBUG |
| 332 | (void)printf("After compress_mode()\n"); |
| 333 | dumpmode(saveset); |
| 334 | #endif |
| 335 | return (saveset); |
| 336 | } |
| 337 | |
| 338 | static BITCMD * |
| 339 | addcmd(BITCMD *set, int op, int who, int oparg, u_int mask) |
| 340 | { |
| 341 | switch (op) { |
| 342 | case '=': |
| 343 | set->cmd = '-'; |
| 344 | set->bits = who ? who : STANDARD_BITS(0004000|0002000|0000700|0000070|0000007); |
| 345 | set++; |
| 346 | |
| 347 | op = '+'; |
| 348 | /* FALLTHROUGH */ |
| 349 | case '+': |
| 350 | case '-': |
| 351 | case 'X': |
| 352 | set->cmd = op; |
| 353 | set->bits = (who ? who : mask) & oparg; |
| 354 | break; |
| 355 | |
| 356 | case 'u': |
| 357 | case 'g': |
| 358 | case 'o': |
| 359 | set->cmd = op; |
| 360 | if (who) { |
| 361 | set->cmd2 = ((who & S_IRUSR0000400) ? CMD2_UBITS0x10 : 0) | |
| 362 | ((who & S_IRGRP0000040) ? CMD2_GBITS0x04 : 0) | |
| 363 | ((who & S_IROTH0000004) ? CMD2_OBITS0x08 : 0); |
| 364 | set->bits = (mode_t)~0; |
| 365 | } else { |
| 366 | set->cmd2 = CMD2_UBITS0x10 | CMD2_GBITS0x04 | CMD2_OBITS0x08; |
| 367 | set->bits = mask; |
| 368 | } |
| 369 | |
| 370 | if (oparg == '+') |
| 371 | set->cmd2 |= CMD2_SET0x02; |
| 372 | else if (oparg == '-') |
| 373 | set->cmd2 |= CMD2_CLR0x01; |
| 374 | else if (oparg == '=') |
| 375 | set->cmd2 |= CMD2_SET0x02|CMD2_CLR0x01; |
| 376 | break; |
| 377 | } |
| 378 | 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_CLR0x01 ? " CLR" : "", |
| 389 | set->cmd2 & CMD2_SET0x02 ? " SET" : "", |
| 390 | set->cmd2 & CMD2_UBITS0x10 ? " UBITS" : "", |
| 391 | set->cmd2 & CMD2_GBITS0x04 ? " GBITS" : "", |
| 392 | set->cmd2 & CMD2_OBITS0x08 ? " 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 | for (nset = set;;) { |
| 409 | /* Copy over any 'u', 'g' and 'o' commands. */ |
| 410 | while ((op = nset->cmd) != '+' && op != '-' && op != 'X') { |
| 411 | *set++ = *nset++; |
| 412 | if (!op) |
| 413 | return; |
| 414 | } |
| 415 | |
| 416 | for (setbits = clrbits = Xbits = 0;; nset++) { |
| 417 | if ((op = nset->cmd) == '-') { |
| 418 | clrbits |= nset->bits; |
| 419 | setbits &= ~nset->bits; |
| 420 | Xbits &= ~nset->bits; |
| 421 | } else if (op == '+') { |
| 422 | setbits |= nset->bits; |
| 423 | clrbits &= ~nset->bits; |
| 424 | Xbits &= ~nset->bits; |
| 425 | } else if (op == 'X') |
| 426 | Xbits |= nset->bits & ~setbits; |
| 427 | else |
| 428 | break; |
| 429 | } |
| 430 | if (clrbits) { |
| 431 | set->cmd = '-'; |
| 432 | set->cmd2 = 0; |
| 433 | set->bits = clrbits; |
| 434 | set++; |
| 435 | } |
| 436 | if (setbits) { |
| 437 | set->cmd = '+'; |
| 438 | set->cmd2 = 0; |
| 439 | set->bits = setbits; |
| 440 | set++; |
| 441 | } |
| 442 | if (Xbits) { |
| 443 | set->cmd = 'X'; |
| 444 | set->cmd2 = 0; |
| 445 | set->bits = Xbits; |
| 446 | set++; |
| 447 | } |
| 448 | } |
| 449 | } |