1/* 2 * Copyright (c) 1989, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Dave Borman at Cray Research, Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94"; 35#endif /* LIBC_SCCS and not lint */ 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: src/lib/libc/gen/setmode.c,v 1.11 2007/01/09 00:27:55 imp Exp $"); 38 39#include "namespace.h" 40#include <sys/types.h> 41#include <sys/stat.h> 42 43#include <ctype.h> 44#include <signal.h> 45#include <stddef.h> 46#include <stdlib.h> 47#include <unistd.h> 48 49#ifdef SETMODE_DEBUG 50#include <stdio.h> 51#endif 52#include "un-namespace.h" 53 54#define SET_LEN 6 /* initial # of bitcmd struct to malloc */ 55#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */ 56 57typedef struct bitcmd { 58 char cmd; 59 char cmd2; 60 mode_t bits; 61} BITCMD; 62 63#define CMD2_CLR 0x01 64#define CMD2_SET 0x02 65#define CMD2_GBITS 0x04 66#define CMD2_OBITS 0x08 67#define CMD2_UBITS 0x10 68 69#define compress_mode _sm_compress_mode 70 71static BITCMD *addcmd(BITCMD *, int, int, int, u_int); 72__private_extern__ void compress_mode(BITCMD *); 73#ifdef SETMODE_DEBUG 74static void dumpmode(BITCMD *); 75#endif 76 77#ifndef BUILDING_VARIANT 78/* 79 * Given the old mode and an array of bitcmd structures, apply the operations 80 * described in the bitcmd structures to the old mode, and return the new mode. 81 * Note that there is no '=' command; a strict assignment is just a '-' (clear 82 * bits) followed by a '+' (set bits). 83 */ 84mode_t 85getmode(const void *bbox, mode_t omode) 86{ 87 const BITCMD *set; 88 mode_t clrval, newmode, value; 89 90 set = (const BITCMD *)bbox; 91 newmode = omode; 92 for (value = 0;; set++) 93 switch(set->cmd) { 94 /* 95 * When copying the user, group or other bits around, we "know" 96 * where the bits are in the mode so that we can do shifts to 97 * copy them around. If we don't use shifts, it gets real 98 * grundgy with lots of single bit checks and bit sets. 99 */ 100 case 'u': 101 value = (newmode & S_IRWXU) >> 6; 102 goto common; 103 104 case 'g': 105 value = (newmode & S_IRWXG) >> 3; 106 goto common; 107 108 case 'o': 109 value = newmode & S_IRWXO; 110common: if (set->cmd2 & CMD2_CLR) { 111 clrval = 112 (set->cmd2 & CMD2_SET) ? S_IRWXO : value; 113 if (set->cmd2 & CMD2_UBITS) 114 newmode &= ~((clrval<<6) & set->bits); 115 if (set->cmd2 & CMD2_GBITS) 116 newmode &= ~((clrval<<3) & set->bits); 117 if (set->cmd2 & CMD2_OBITS) 118 newmode &= ~(clrval & set->bits); 119 } 120 if (set->cmd2 & CMD2_SET) { 121 if (set->cmd2 & CMD2_UBITS) 122 newmode |= (value<<6) & set->bits; 123 if (set->cmd2 & CMD2_GBITS) 124 newmode |= (value<<3) & set->bits; 125 if (set->cmd2 & CMD2_OBITS) 126 newmode |= value & set->bits; 127 } 128 break; 129 130 case '+': 131 newmode |= set->bits; 132 break; 133 134 case '-': 135 newmode &= ~set->bits; 136 break; 137 138 case 'X': 139 if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH)) 140 newmode |= set->bits; 141 break; 142 143 case '\0': 144 default: 145#ifdef SETMODE_DEBUG 146 (void)printf("getmode:%04o -> %04o\n", omode, newmode); 147#endif 148 return (newmode); 149 } 150} 151#endif /* BUILDING_VARIANT */ 152 153#define ADDCMD(a, b, c, d) \ 154 if (set >= endset) { \ 155 BITCMD *newset; \ 156 setlen += SET_LEN_INCR; \ 157 newset = realloc(saveset, sizeof(BITCMD) * setlen); \ 158 if (!newset) { \ 159 if (saveset) \ 160 free(saveset); \ 161 saveset = NULL; \ 162 return (NULL); \ 163 } \ 164 set = newset + (set - saveset); \ 165 saveset = newset; \ 166 endset = newset + (setlen - 2); \ 167 } \ 168 set = addcmd(set, (a), (b), (c), (d)) 169 170#ifndef VARIANT_LEGACY 171#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO|S_ISTXT) 172#else /* VARIANT_LEGACY */ 173#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO) 174#endif /* !VARIANT_LEGACY */ 175 176void * 177setmode(const char *p) 178{ 179 int perm, who; 180 char op, *ep; 181 BITCMD *set, *saveset, *endset; 182 sigset_t sigset, sigoset; 183 mode_t mask; 184 int equalopdone=0, permXbits, setlen; 185 long perml; 186 187 if (!*p) 188 return (NULL); 189 190 /* 191 * Get a copy of the mask for the permissions that are mask relative. 192 * Flip the bits, we want what's not set. Since it's possible that 193 * the caller is opening files inside a signal handler, protect them 194 * as best we can. 195 */ 196 sigfillset(&sigset); 197 (void)_sigprocmask(SIG_BLOCK, &sigset, &sigoset); 198 (void)umask(mask = umask(0)); 199 mask = ~mask; 200 (void)_sigprocmask(SIG_SETMASK, &sigoset, NULL); 201 202 setlen = SET_LEN + 2; 203 204 if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL) 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((unsigned char)*p)) { 214 perml = strtol(p, &ep, 8); 215#ifndef VARIANT_LEGACY 216 if (*ep || perml < 0 || perml & ~STANDARD_BITS) 217#else /* VARIANT_LEGACY */ 218 if (*ep || perml < 0 || perml & ~(STANDARD_BITS|S_ISTXT)) 219#endif /* !VARIANT_LEGACY */ 220 { 221 free(saveset); 222 return (NULL); 223 } 224 perm = (mode_t)perml; 225#ifndef VARIANT_LEGACY 226 ADDCMD('=', STANDARD_BITS, perm, mask); 227#else /* VARIANT_LEGACY */ 228 ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask); 229#endif /* !VARIANT_LEGACY */ 230 set->cmd = 0; 231 return (saveset); 232 } 233 234 /* 235 * Build list of structures to set/clear/copy bits as described by 236 * each clause of the symbolic mode. 237 */ 238 for (;;) { 239 /* First, find out which bits might be modified. */ 240 for (who = 0;; ++p) { 241 switch (*p) { 242 case 'a': 243 who |= STANDARD_BITS; 244 break; 245 case 'u': 246 who |= S_ISUID|S_IRWXU; 247 break; 248 case 'g': 249 who |= S_ISGID|S_IRWXG; 250 break; 251 case 'o': 252 who |= S_IRWXO; 253 break; 254 default: 255 goto getop; 256 } 257 } 258 259getop: if ((op = *p++) != '+' && op != '-' && op != '=') { 260 free(saveset); 261 return (NULL); 262 } 263 if (op == '=') 264 equalopdone = 0; 265 266#ifdef VARIANT_LEGACY 267 who &= ~S_ISTXT; 268#endif /* VARIANT_LEGACY */ 269 for (perm = 0, permXbits = 0;; ++p) { 270 switch (*p) { 271 case 'r': 272 perm |= S_IRUSR|S_IRGRP|S_IROTH; 273 break; 274 case 's': 275 /* If only "other" bits ignore set-id. */ 276 if (!who || who & ~S_IRWXO) 277 perm |= S_ISUID|S_ISGID; 278 break; 279 case 't': 280 /* If only "other" bits ignore sticky. */ 281 if (!who || who & ~S_IRWXO) { 282#ifdef VARIANT_LEGACY 283 who |= S_ISTXT; 284#endif /* VARIANT_LEGACY */ 285 perm |= S_ISTXT; 286 } 287 break; 288 case 'w': 289 perm |= S_IWUSR|S_IWGRP|S_IWOTH; 290 break; 291 case 'X': 292 permXbits = S_IXUSR|S_IXGRP|S_IXOTH; 293 break; 294 case 'x': 295 perm |= S_IXUSR|S_IXGRP|S_IXOTH; 296 break; 297 case 'u': 298 case 'g': 299 case 'o': 300 /* 301 * When ever we hit 'u', 'g', or 'o', we have 302 * to flush out any partial mode that we have, 303 * and then do the copying of the mode bits. 304 */ 305 if (perm) { 306 ADDCMD(op, who, perm, mask); 307 perm = 0; 308 } 309 if (op == '=') 310 equalopdone = 1; 311 if (op == '+' && permXbits) { 312 ADDCMD('X', who, permXbits, mask); 313 permXbits = 0; 314 } 315 ADDCMD(*p, who, op, mask); 316 break; 317 318 default: 319 /* 320 * Add any permissions that we haven't already 321 * done. 322 */ 323 if (perm || (op == '=' && !equalopdone)) { 324 if (op == '=') 325 equalopdone = 1; 326 ADDCMD(op, who, perm, mask); 327 perm = 0; 328 } 329 if (permXbits) { 330 ADDCMD('X', who, permXbits, mask); 331 permXbits = 0; 332 } 333 goto apply; 334 } 335 } 336 337apply: if (!*p) 338 break; 339 if (*p != ',') 340 goto getop; 341 ++p; 342 } 343 set->cmd = 0; 344#ifdef SETMODE_DEBUG 345 (void)printf("Before compress_mode()\n"); 346 dumpmode(saveset); 347#endif 348 compress_mode(saveset); 349#ifdef SETMODE_DEBUG 350 (void)printf("After compress_mode()\n"); 351 dumpmode(saveset); 352#endif 353 return (saveset); 354} 355 356static BITCMD * 357addcmd(BITCMD *set, int op, int who, int oparg, u_int mask) 358{ 359 switch (op) { 360 case '=': 361 set->cmd = '-'; 362 set->bits = who ? who : STANDARD_BITS; 363 set++; 364 365 op = '+'; 366 /* FALLTHROUGH */ 367 case '+': 368 case '-': 369 case 'X': 370 set->cmd = op; 371 set->bits = (who ? who : mask) & oparg; 372 break; 373 374 case 'u': 375 case 'g': 376 case 'o': 377 set->cmd = op; 378 if (who) { 379 set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) | 380 ((who & S_IRGRP) ? CMD2_GBITS : 0) | 381 ((who & S_IROTH) ? CMD2_OBITS : 0); 382 set->bits = (mode_t)~0; 383 } else { 384 set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS; 385 set->bits = mask; 386 } 387 388 if (oparg == '+') 389 set->cmd2 |= CMD2_SET; 390 else if (oparg == '-') 391 set->cmd2 |= CMD2_CLR; 392 else if (oparg == '=') 393 set->cmd2 |= CMD2_SET|CMD2_CLR; 394 break; 395 } 396 return (set + 1); 397} 398 399#ifdef SETMODE_DEBUG 400static void 401dumpmode(BITCMD *set) 402{ 403 for (; set->cmd; ++set) 404 (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n", 405 set->cmd, set->bits, set->cmd2 ? " cmd2:" : "", 406 set->cmd2 & CMD2_CLR ? " CLR" : "", 407 set->cmd2 & CMD2_SET ? " SET" : "", 408 set->cmd2 & CMD2_UBITS ? " UBITS" : "", 409 set->cmd2 & CMD2_GBITS ? " GBITS" : "", 410 set->cmd2 & CMD2_OBITS ? " OBITS" : ""); 411} 412#endif 413 414#ifndef BUILDING_VARIANT 415/* 416 * Given an array of bitcmd structures, compress by compacting consecutive 417 * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u', 418 * 'g' and 'o' commands continue to be separate. They could probably be 419 * compacted, but it's not worth the effort. 420 */ 421__private_extern__ void 422compress_mode(BITCMD *set) 423{ 424 BITCMD *nset; 425 int setbits, clrbits, Xbits, op; 426 427 for (nset = set;;) { 428 /* Copy over any 'u', 'g' and 'o' commands. */ 429 while ((op = nset->cmd) != '+' && op != '-' && op != 'X') { 430 *set++ = *nset++; 431 if (!op) 432 return; 433 } 434 435 for (setbits = clrbits = Xbits = 0;; nset++) { 436 if ((op = nset->cmd) == '-') { 437 clrbits |= nset->bits; 438 setbits &= ~nset->bits; 439 Xbits &= ~nset->bits; 440 } else if (op == '+') { 441 setbits |= nset->bits; 442 clrbits &= ~nset->bits; 443 Xbits &= ~nset->bits; 444 } else if (op == 'X') 445 Xbits |= nset->bits & ~setbits; 446 else 447 break; 448 } 449 if (clrbits) { 450 set->cmd = '-'; 451 set->cmd2 = 0; 452 set->bits = clrbits; 453 set++; 454 } 455 if (setbits) { 456 set->cmd = '+'; 457 set->cmd2 = 0; 458 set->bits = setbits; 459 set++; 460 } 461 if (Xbits) { 462 set->cmd = 'X'; 463 set->cmd2 = 0; 464 set->bits = Xbits; 465 set++; 466 } 467 } 468} 469#endif /* BUILDING_VARIANT */ 470