1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /*static char *sccsid = "from: @(#)setmode.c 5.6 (Berkeley) 5/27/91";*/ 36 static char *rcsid = "$Id: setmode.c,v 1.4 1993/12/23 23:14:43 jtc Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 #include <sys/errno.h> 42 #ifdef SETMODE_DEBUG 43 #include <stdio.h> 44 #endif 45 #include <stdlib.h> 46 #include <ctype.h> 47 48 #define SET_LEN 6 /* initial # of bitcmd struct to malloc */ 49 #define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */ 50 51 struct bitcmd { 52 char cmd; 53 char cmd2; 54 mode_t bits; 55 }; 56 57 #define CMD2_CLR 0x01 58 #define CMD2_SET 0x02 59 #define CMD2_GBITS 0x04 60 #define CMD2_OBITS 0x08 61 #define CMD2_UBITS 0x10 62 63 /* 64 * Given the old mode and an array of bitcmd structures, apply the operations 65 * described in the bitcmd structures to the old mode, and return the new mode. 66 * Note that there is no '=' command; a strict assignment is just a '-' (clear 67 * bits) followed by a '+' (set bits). 68 */ 69 mode_t 70 getmode(bbox, omode) 71 void *bbox; 72 mode_t omode; 73 { 74 register struct bitcmd *set; 75 register mode_t newmode, value; 76 77 set = (struct bitcmd *)bbox; 78 newmode = omode; 79 for (value = 0;; set++) 80 switch(set->cmd) { 81 /* 82 * When copying the user, group or other bits around, we "know" 83 * where the bit are in the mode so that we can do shifts to 84 * copy them around. If we don't use shifts, it gets real 85 * grundgy with lots of single bit checks and bit sets. 86 */ 87 case 'u': 88 value = (newmode & S_IRWXU) >> 6; 89 goto common; 90 91 case 'g': 92 value = (newmode & S_IRWXG) >> 3; 93 goto common; 94 95 case 'o': 96 value = newmode & S_IRWXO; 97 common: 98 if (set->cmd2 & CMD2_CLR) { 99 if (set->cmd2 & CMD2_UBITS) 100 newmode &= ~(S_IRWXU & set->bits); 101 if (set->cmd2 & CMD2_GBITS) 102 newmode &= ~(S_IRWXG & set->bits); 103 if (set->cmd2 & CMD2_OBITS) 104 newmode &= ~(S_IRWXO & set->bits); 105 } 106 if (set->cmd2 & CMD2_SET) { 107 if (set->cmd2 & CMD2_UBITS) 108 newmode |= (value<<6) & set->bits; 109 if (set->cmd2 & CMD2_GBITS) 110 newmode |= (value<<3) & set->bits; 111 if (set->cmd2 & CMD2_OBITS) 112 newmode |= value & set->bits; 113 } 114 break; 115 116 case '+': 117 newmode |= set->bits; 118 break; 119 120 case '-': 121 newmode &= ~set->bits; 122 break; 123 124 case 'X': 125 if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH)) 126 newmode |= set->bits; 127 break; 128 129 case '\0': 130 default: 131 #ifdef SETMODE_DEBUG 132 (void)printf("getmode(, %04o) -> %04o\n", 133 omode, newmode); 134 #endif 135 return(newmode); 136 } 137 } 138 139 #define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO) 140 141 static struct bitcmd * 142 addcmd(set, op, who, oparg, mask) 143 struct bitcmd *set; 144 register int oparg, who; 145 register int op; 146 mode_t mask; 147 { 148 switch (op) { 149 case '+': 150 case 'X': 151 set->cmd = op; 152 set->bits = (who ? who : mask) & oparg; 153 break; 154 155 case '-': 156 set->cmd = '-'; 157 set->bits = (who ? who : (S_IRWXU|S_IRWXG|S_IRWXO)) & oparg; 158 break; 159 160 case '=': 161 set->cmd = '-'; 162 if (!who) { 163 set->bits = STANDARD_BITS; 164 who = mask; 165 } else 166 set->bits = who; 167 set++; 168 169 set->cmd = '+'; 170 set->bits = who & oparg; 171 break; 172 case 'u': 173 case 'g': 174 case 'o': 175 set->cmd = op; 176 if (who) { 177 set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) | 178 ((who & S_IRGRP) ? CMD2_GBITS : 0) | 179 ((who & S_IROTH) ? CMD2_OBITS : 0); 180 set->bits = ~0; 181 } else { 182 set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS; 183 set->bits = mask; 184 } 185 186 if (oparg == '+') 187 set->cmd2 |= CMD2_SET; 188 else if (oparg == '-') 189 set->cmd2 |= CMD2_CLR; 190 else if (oparg == '=') 191 set->cmd2 |= CMD2_SET|CMD2_CLR; 192 break; 193 } 194 return(set+1); 195 } 196 197 #define ADDCMD(a, b, c, d) \ 198 if (set >= endset) { \ 199 register struct bitcmd *newset; \ 200 setlen += SET_LEN_INCR; \ 201 newset = realloc(saveset, sizeof(struct bitcmd) * setlen); \ 202 if (!saveset) \ 203 return(NULL); \ 204 set = newset + (set - saveset); \ 205 saveset = newset; \ 206 endset = newset + (setlen - 2); \ 207 } \ 208 set = addcmd(set, (a), (b), (c), (d)) 209 210 void * 211 setmode(p) 212 register char *p; 213 { 214 register int perm, who; 215 register char op; 216 mode_t mask; 217 struct bitcmd *set, *saveset, *endset; 218 int permXbits, setlen; 219 static void compress_mode(); 220 221 /* 222 * Get a copy of the mask for the permissions that are mask relative. 223 * Flip the bits, we want what's not set. 224 */ 225 (void)umask(mask = umask(0)); 226 mask = ~mask; 227 228 setlen = SET_LEN + 2; 229 230 set = (struct bitcmd *)malloc((u_int)(sizeof(struct bitcmd) * setlen)); 231 if (!set) 232 return(NULL); 233 saveset = set; 234 endset = set + (setlen - 2); 235 236 /* 237 * If an absolute number, get it and return; disallow non-octal digits 238 * or illegal bits. 239 */ 240 if (isdigit(*p)) { 241 perm = (mode_t)strtol(p, (char **)0, 8); 242 if (perm & ~(STANDARD_BITS|S_ISTXT)) { 243 free(saveset); 244 return(NULL); 245 } 246 while (*++p) 247 if (*p < '0' || *p > '7') { 248 free(saveset); 249 return(NULL); 250 } 251 ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask); 252 return((void *)saveset); 253 } 254 255 if (!*p) { 256 free(saveset); 257 return(NULL); 258 } 259 /* 260 * Build list of structures to set/clear/copy bits as described by 261 * each clause of the symbolic mode. 262 */ 263 for (;;) { 264 /* First, find out which bits might be modified. */ 265 for (who = 0;; ++p) { 266 switch (*p) { 267 case 'a': 268 who |= STANDARD_BITS; 269 break; 270 case 'u': 271 who |= S_ISUID|S_IRWXU; 272 break; 273 case 'g': 274 who |= S_ISGID|S_IRWXG; 275 break; 276 case 'o': 277 who |= S_IRWXO; 278 break; 279 default: 280 goto getop; 281 } 282 } 283 getop: 284 285 if ((op = *p++) != '+' && op != '-' && op != '=') { 286 free(saveset); 287 return(NULL); 288 } 289 290 who &= ~S_ISTXT; 291 for (perm = 0, permXbits = 0;; ++p) { 292 switch (*p) { 293 case 'r': 294 perm |= S_IRUSR|S_IRGRP|S_IROTH; 295 break; 296 case 's': 297 /* If only "other" bits ignore set-id. */ 298 if (who & ~S_IRWXO) 299 perm |= S_ISUID|S_ISGID; 300 break; 301 case 't': 302 /* If only "other" bits ignore sticky. */ 303 if (who & ~S_IRWXO) { 304 who |= S_ISTXT; 305 perm |= S_ISTXT; 306 } 307 break; 308 case 'w': 309 perm |= S_IWUSR|S_IWGRP|S_IWOTH; 310 break; 311 case 'X': 312 permXbits = S_IXUSR|S_IXGRP|S_IXOTH; 313 break; 314 case 'x': 315 perm |= S_IXUSR|S_IXGRP|S_IXOTH; 316 break; 317 case 'u': 318 case 'g': 319 case 'o': 320 /* 321 * When ever we hit 'u', 'g', or 'o', we have 322 * to flush out any partial mode that we have, 323 * and then do the copying of the mode bits. 324 */ 325 if (perm) { 326 ADDCMD(op, who, perm, mask); 327 perm = 0; 328 } 329 if (op == '+' && permXbits) { 330 ADDCMD('X', who, permXbits, mask); 331 permXbits = 0; 332 } 333 ADDCMD(*p, who, op, mask); 334 break; 335 336 default: 337 /* 338 * Add any permissions that we haven't already 339 * done. 340 */ 341 if (perm) { 342 ADDCMD(op, who, perm, mask); 343 perm = 0; 344 } 345 if (permXbits) { 346 ADDCMD('X', who, permXbits, mask); 347 permXbits = 0; 348 } 349 goto apply; 350 } 351 } 352 353 apply: if (!*p) 354 break; 355 if (*p != ',') 356 goto getop; 357 ++p; 358 } 359 set->cmd = 0; 360 #ifdef SETMODE_DEBUG 361 (void)printf("Before compress_mode()\n"); 362 dumpmode(saveset); 363 #endif 364 compress_mode(saveset); 365 #ifdef SETMODE_DEBUG 366 (void)printf("After compress_mode()\n"); 367 dumpmode(saveset); 368 #endif 369 return((void *)saveset); 370 } 371 372 #ifdef SETMODE_DEBUG 373 dumpmode(set) 374 register struct bitcmd *set; 375 { 376 for (; set->cmd; ++set) 377 (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n", 378 set->cmd, set->bits, set->cmd2 ? " cmd2:" : "", 379 set->cmd2 & CMD2_CLR ? " CLR" : "", 380 set->cmd2 & CMD2_SET ? " SET" : "", 381 set->cmd2 & CMD2_UBITS ? " UBITS" : "", 382 set->cmd2 & CMD2_GBITS ? " GBITS" : "", 383 set->cmd2 & CMD2_OBITS ? " OBITS" : ""); 384 } 385 #endif 386 387 /* 388 * Given an array of bitcmd structures, compress by compacting consecutive 389 * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u', 390 * 'g' and 'o' commands continue to be separate. They could probably be 391 * compacted, but it's not worth the effort. 392 */ 393 static void 394 compress_mode(set) 395 register struct bitcmd *set; 396 { 397 register struct bitcmd *nset; 398 register int setbits, clrbits, Xbits, op; 399 400 for (nset = set;;) { 401 /* Copy over any 'u', 'g' and 'o' commands. */ 402 while ((op = nset->cmd) != '+' && op != '-' && op != 'X') { 403 *set++ = *nset++; 404 if (!op) 405 return; 406 } 407 408 for (setbits = clrbits = Xbits = 0;; nset++) { 409 if ((op = nset->cmd) == '-') { 410 clrbits |= nset->bits; 411 setbits &= ~nset->bits; 412 Xbits &= ~nset->bits; 413 } else if (op == '+') { 414 setbits |= nset->bits; 415 clrbits &= ~nset->bits; 416 Xbits &= ~nset->bits; 417 } else if (op == 'X') 418 Xbits |= nset->bits & ~setbits; 419 else 420 break; 421 } 422 if (clrbits) { 423 set->cmd = '-'; 424 set->cmd2 = 0; 425 set->bits = clrbits; 426 set++; 427 } 428 if (setbits) { 429 set->cmd = '+'; 430 set->cmd2 = 0; 431 set->bits = setbits; 432 set++; 433 } 434 if (Xbits) { 435 set->cmd = 'X'; 436 set->cmd2 = 0; 437 set->bits = Xbits; 438 set++; 439 } 440 } 441 } 442