1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)setmode.c 5.6 (Berkeley) 05/27/91"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <sys/stat.h> 14 #include <sys/errno.h> 15 #ifdef SETMODE_DEBUG 16 #include <stdio.h> 17 #endif 18 #include <stdlib.h> 19 #include <ctype.h> 20 21 #define SET_LEN 6 /* initial # of bitcmd struct to malloc */ 22 #define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */ 23 24 struct bitcmd { 25 char cmd; 26 char cmd2; 27 mode_t bits; 28 }; 29 30 #define CMD2_CLR 0x01 31 #define CMD2_SET 0x02 32 #define CMD2_GBITS 0x04 33 #define CMD2_OBITS 0x08 34 #define CMD2_UBITS 0x10 35 36 /* 37 * Given the old mode and an array of bitcmd structures, apply the operations 38 * described in the bitcmd structures to the old mode, and return the new mode. 39 * Note that there is no '=' command; a strict assignment is just a '-' (clear 40 * bits) followed by a '+' (set bits). 41 */ 42 mode_t 43 getmode(bbox, omode) 44 void *bbox; 45 mode_t omode; 46 { 47 register struct bitcmd *set; 48 register mode_t newmode, value; 49 50 set = (struct bitcmd *)bbox; 51 newmode = omode; 52 for (value = 0;; set++) 53 switch(set->cmd) { 54 /* 55 * When copying the user, group or other bits around, we "know" 56 * where the bit are in the mode so that we can do shifts to 57 * copy them around. If we don't use shifts, it gets real 58 * grundgy with lots of single bit checks and bit sets. 59 */ 60 case 'u': 61 value = (newmode & S_IRWXU) >> 6; 62 goto common; 63 64 case 'g': 65 value = (newmode & S_IRWXG) >> 3; 66 goto common; 67 68 case 'o': 69 value = newmode & S_IRWXO; 70 common: 71 if (set->cmd2 & CMD2_CLR) { 72 if (set->cmd2 & CMD2_UBITS) 73 newmode &= ~(S_IRWXU & set->bits); 74 if (set->cmd2 & CMD2_GBITS) 75 newmode &= ~(S_IRWXG & set->bits); 76 if (set->cmd2 & CMD2_OBITS) 77 newmode &= ~(S_IRWXO & set->bits); 78 } 79 if (set->cmd2 & CMD2_SET) { 80 if (set->cmd2 & CMD2_UBITS) 81 newmode |= (value<<6) & set->bits; 82 if (set->cmd2 & CMD2_GBITS) 83 newmode |= (value<<3) & set->bits; 84 if (set->cmd2 & CMD2_OBITS) 85 newmode |= value & set->bits; 86 } 87 break; 88 89 case '+': 90 newmode |= set->bits; 91 break; 92 93 case '-': 94 newmode &= ~set->bits; 95 break; 96 97 case 'X': 98 if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH)) 99 newmode |= set->bits; 100 break; 101 102 case '\0': 103 default: 104 #ifdef SETMODE_DEBUG 105 (void)printf("getmode(, %04o) -> %04o\n", 106 omode, newmode); 107 #endif 108 return(newmode); 109 } 110 } 111 112 #define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO) 113 114 static struct bitcmd * 115 addcmd(set, op, who, oparg, mask) 116 struct bitcmd *set; 117 register int oparg, who; 118 register int op; 119 mode_t mask; 120 { 121 switch (op) { 122 case '+': 123 case 'X': 124 set->cmd = op; 125 set->bits = (who ? who : mask) & oparg; 126 break; 127 128 case '-': 129 set->cmd = '-'; 130 set->bits = (who ? who : (S_IRWXU|S_IRWXG|S_IRWXO)) & oparg; 131 break; 132 133 case '=': 134 set->cmd = '-'; 135 if (!who) { 136 set->bits = STANDARD_BITS; 137 who = mask; 138 } else 139 set->bits = who; 140 set++; 141 142 set->cmd = '+'; 143 set->bits = who & oparg; 144 break; 145 case 'u': 146 case 'g': 147 case 'o': 148 set->cmd = op; 149 if (who) { 150 set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) | 151 ((who & S_IRGRP) ? CMD2_GBITS : 0) | 152 ((who & S_IROTH) ? CMD2_OBITS : 0); 153 set->bits = ~0; 154 } else { 155 set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS; 156 set->bits = mask; 157 } 158 159 if (oparg == '+') 160 set->cmd2 |= CMD2_SET; 161 else if (oparg == '-') 162 set->cmd2 |= CMD2_CLR; 163 else if (oparg == '=') 164 set->cmd2 |= CMD2_SET|CMD2_CLR; 165 break; 166 } 167 return(set+1); 168 } 169 170 #define ADDCMD(a, b, c, d) \ 171 if (set >= endset) { \ 172 register struct bitcmd *newset; \ 173 setlen += SET_LEN_INCR; \ 174 newset = realloc(saveset, sizeof(struct bitcmd) * setlen); \ 175 if (!saveset) \ 176 return(NULL); \ 177 set = newset + (set - saveset); \ 178 saveset = newset; \ 179 endset = newset + (setlen - 2); \ 180 } \ 181 set = addcmd(set, (a), (b), (c), (d)) 182 183 void * 184 setmode(p) 185 register char *p; 186 { 187 register int perm, who; 188 register char op; 189 mode_t mask; 190 struct bitcmd *set, *saveset, *endset; 191 int permXbits, setlen; 192 static int compress_mode(); 193 194 /* 195 * Get a copy of the mask for the permissions that are mask relative. 196 * Flip the bits, we want what's not set. 197 */ 198 (void)umask(mask = umask(0)); 199 mask = ~mask; 200 201 setlen = SET_LEN + 2; 202 203 set = (struct bitcmd *)malloc((u_int)(sizeof(struct bitcmd) * setlen)); 204 if (!set) 205 return(NULL); 206 saveset = set; 207 endset = set + (setlen - 2); 208 209 /* 210 * If an absolute number, get it and return; disallow non-octal digits 211 * or illegal bits. 212 */ 213 if (isdigit(*p)) { 214 perm = (mode_t)strtol(p, (char **)0, 8); 215 if (perm & ~(STANDARD_BITS|S_ISTXT)) { 216 free(saveset); 217 return(NULL); 218 } 219 while (*++p) 220 if (*p < '0' || *p > '7') { 221 free(saveset); 222 return(NULL); 223 } 224 ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask); 225 return((void *)saveset); 226 } 227 228 if (!*p) { 229 free(saveset); 230 return(NULL); 231 } 232 /* 233 * Build list of structures to set/clear/copy bits as described by 234 * each clause of the symbolic mode. 235 */ 236 for (;;) { 237 /* First, find out which bits might be modified. */ 238 for (who = 0;; ++p) { 239 switch (*p) { 240 case 'a': 241 who |= STANDARD_BITS; 242 break; 243 case 'u': 244 who |= S_ISUID|S_IRWXU; 245 break; 246 case 'g': 247 who |= S_ISGID|S_IRWXG; 248 break; 249 case 'o': 250 who |= S_IRWXO; 251 break; 252 default: 253 goto getop; 254 } 255 } 256 getop: 257 258 if ((op = *p++) != '+' && op != '-' && op != '=') { 259 free(saveset); 260 return(NULL); 261 } 262 263 who &= ~S_ISTXT; 264 for (perm = 0, permXbits = 0;; ++p) { 265 switch (*p) { 266 case 'r': 267 perm |= S_IRUSR|S_IRGRP|S_IROTH; 268 break; 269 case 's': 270 /* If only "other" bits ignore set-id. */ 271 if (who & ~S_IRWXO) 272 perm |= S_ISUID|S_ISGID; 273 break; 274 case 't': 275 /* If only "other" bits ignore sticky. */ 276 if (who & ~S_IRWXO) { 277 who |= S_ISTXT; 278 perm |= S_ISTXT; 279 } 280 break; 281 case 'w': 282 perm |= S_IWUSR|S_IWGRP|S_IWOTH; 283 break; 284 case 'X': 285 permXbits = S_IXUSR|S_IXGRP|S_IXOTH; 286 break; 287 case 'x': 288 perm |= S_IXUSR|S_IXGRP|S_IXOTH; 289 break; 290 case 'u': 291 case 'g': 292 case 'o': 293 /* 294 * When ever we hit 'u', 'g', or 'o', we have 295 * to flush out any partial mode that we have, 296 * and then do the copying of the mode bits. 297 */ 298 if (perm) { 299 ADDCMD(op, who, perm, mask); 300 perm = 0; 301 } 302 if (op == '+' && permXbits) { 303 ADDCMD('X', who, permXbits, mask); 304 permXbits = 0; 305 } 306 ADDCMD(*p, who, op, mask); 307 break; 308 309 default: 310 /* 311 * Add any permissions that we haven't already 312 * done. 313 */ 314 if (perm) { 315 ADDCMD(op, who, perm, mask); 316 perm = 0; 317 } 318 if (permXbits) { 319 ADDCMD('X', who, permXbits, mask); 320 permXbits = 0; 321 } 322 goto apply; 323 } 324 } 325 326 apply: if (!*p) 327 break; 328 if (*p != ',') 329 goto getop; 330 ++p; 331 } 332 set->cmd = 0; 333 #ifdef SETMODE_DEBUG 334 (void)printf("Before compress_mode()\n"); 335 dumpmode(saveset); 336 #endif 337 compress_mode(saveset); 338 #ifdef SETMODE_DEBUG 339 (void)printf("After compress_mode()\n"); 340 dumpmode(saveset); 341 #endif 342 return((void *)saveset); 343 } 344 345 #ifdef SETMODE_DEBUG 346 dumpmode(set) 347 register struct bitcmd *set; 348 { 349 for (; set->cmd; ++set) 350 (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n", 351 set->cmd, set->bits, set->cmd2 ? " cmd2:" : "", 352 set->cmd2 & CMD2_CLR ? " CLR" : "", 353 set->cmd2 & CMD2_SET ? " SET" : "", 354 set->cmd2 & CMD2_UBITS ? " UBITS" : "", 355 set->cmd2 & CMD2_GBITS ? " GBITS" : "", 356 set->cmd2 & CMD2_OBITS ? " OBITS" : ""); 357 } 358 #endif 359 360 /* 361 * Given an array of bitcmd structures, compress by compacting consecutive 362 * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u', 363 * 'g' and 'o' commands continue to be separate. They could probably be 364 * compacted, but it's not worth the effort. 365 */ 366 static 367 compress_mode(set) 368 register struct bitcmd *set; 369 { 370 register struct bitcmd *nset; 371 register int setbits, clrbits, Xbits, op; 372 373 for (nset = set;;) { 374 /* Copy over any 'u', 'g' and 'o' commands. */ 375 while ((op = nset->cmd) != '+' && op != '-' && op != 'X') { 376 *set++ = *nset++; 377 if (!op) 378 return; 379 } 380 381 for (setbits = clrbits = Xbits = 0;; nset++) { 382 if ((op = nset->cmd) == '-') { 383 clrbits |= nset->bits; 384 setbits &= ~nset->bits; 385 Xbits &= ~nset->bits; 386 } else if (op == '+') { 387 setbits |= nset->bits; 388 clrbits &= ~nset->bits; 389 Xbits &= ~nset->bits; 390 } else if (op == 'X') 391 Xbits |= nset->bits & ~setbits; 392 else 393 break; 394 } 395 if (clrbits) { 396 set->cmd = '-'; 397 set->cmd2 = 0; 398 set->bits = clrbits; 399 set++; 400 } 401 if (setbits) { 402 set->cmd = '+'; 403 set->cmd2 = 0; 404 set->bits = setbits; 405 set++; 406 } 407 if (Xbits) { 408 set->cmd = 'X'; 409 set->cmd2 = 0; 410 set->bits = Xbits; 411 set++; 412 } 413 } 414 } 415