chmod/chmod_acl.c

   1 /*
   2  * Copyright (c) 1989, 1993, 1994
   3  *      The Regents of the University of California.  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 #include <err.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <sys/types.h>
  38 #include <unistd.h>
  39 #include <errno.h>
  40 #include <fcntl.h>
  41 #include <sys/stat.h>
  42
  43 #include <membership.h>
  44 #include "chmod_acl.h"
  45
  46 extern void usage(void);
  47
  48 #ifdef __APPLE__
  49 static struct {
  50         acl_perm_t      perm;
  51         char            *name;
  52         int             flags;
  53 #define ACL_PERM_DIR    (1<<0)
  54 #define ACL_PERM_FILE   (1<<1)
  55 } acl_perms[] = {
  56         {ACL_READ_DATA,         "read",         ACL_PERM_FILE},
  57         {ACL_LIST_DIRECTORY,    "list",         ACL_PERM_DIR},
  58         {ACL_WRITE_DATA,        "write",        ACL_PERM_FILE},
  59         {ACL_ADD_FILE,          "add_file",     ACL_PERM_DIR},
  60         {ACL_EXECUTE,           "execute",      ACL_PERM_FILE},
  61         {ACL_SEARCH,            "search",       ACL_PERM_DIR},
  62         {ACL_DELETE,            "delete",       ACL_PERM_FILE | ACL_PERM_DIR},
  63         {ACL_APPEND_DATA,       "append",       ACL_PERM_FILE},
  64         {ACL_ADD_SUBDIRECTORY,  "add_subdirectory", ACL_PERM_DIR},
  65         {ACL_DELETE_CHILD,      "delete_child", ACL_PERM_DIR},
  66         {ACL_READ_ATTRIBUTES,   "readattr",     ACL_PERM_FILE | ACL_PERM_DIR},
  67         {ACL_WRITE_ATTRIBUTES,  "writeattr",    ACL_PERM_FILE | ACL_PERM_DIR},
  68         {ACL_READ_EXTATTRIBUTES, "readextattr", ACL_PERM_FILE | ACL_PERM_DIR},
  69         {ACL_WRITE_EXTATTRIBUTES, "writeextattr", ACL_PERM_FILE | ACL_PERM_DIR},
  70         {ACL_READ_SECURITY,     "readsecurity", ACL_PERM_FILE | ACL_PERM_DIR},
  71         {ACL_WRITE_SECURITY,    "writesecurity", ACL_PERM_FILE | ACL_PERM_DIR},
  72         {ACL_CHANGE_OWNER,      "chown",        ACL_PERM_FILE | ACL_PERM_DIR},
  73         {0, NULL, 0}
  74 };
  75
  76 static struct {
  77         acl_flag_t      flag;
  78         char            *name;
  79         int             flags;
  80 } acl_flags[] = {
  81         {ACL_ENTRY_INHERITED,           "inherited",            ACL_PERM_FILE | ACL_PERM_DIR},
  82         {ACL_ENTRY_FILE_INHERIT,        "file_inherit",         ACL_PERM_DIR},
  83         {ACL_ENTRY_DIRECTORY_INHERIT,   "directory_inherit",    ACL_PERM_DIR},
  84         {ACL_ENTRY_LIMIT_INHERIT,       "limit_inherit",        ACL_PERM_FILE | ACL_PERM_DIR},
  85         {ACL_ENTRY_ONLY_INHERIT,        "only_inherit",         ACL_PERM_DIR},
  86         {0, NULL, 0}
  87 };
  88
  89 /* TBD - Many of these routines could potentially be considered for
  90  * inclusion in a library. If that is done, either avoid use of "err"
  91  * and implement a better fall-through strategy in case of errors,
  92  * or use err_set_exit() and make various structures globals.
  93  */
  94
  95 #define NAME_USER   (1)
  96 #define NAME_GROUP  (2)
  97 #define NAME_EITHER (NAME_USER | NAME_GROUP)
  98
  99 /* Perform a name to uuid mapping - calls through to memberd */
 100
 101 uuid_t *
 102 name_to_uuid(char *tok, int nametype) {
 103         struct passwd *tpass = NULL;
 104         struct group *tgrp = NULL;
 105         uuid_t *entryg = NULL;
 106
 107         if ((entryg = (uuid_t *) calloc(1,sizeof(uuid_t))) == NULL)
 108                 err(1, "Unable to allocate a uuid");
 109
 110         if (nametype & NAME_USER)
 111                 tpass = getpwnam(tok);
 112
 113         if (NULL == tpass && (nametype & NAME_GROUP))
 114                 tgrp = getgrnam(tok);
 115
 116         if (tpass) {
 117                 if (0 != mbr_uid_to_uuid(tpass->pw_uid, *entryg)) {
 118                         errx(1, "mbr_uid_to_uuid(): Unable to translate uid %d", tpass->pw_uid);
 119                 }
 120         } else if (tgrp) {
 121                 if (0 != mbr_gid_to_uuid(tgrp->gr_gid, *entryg)) {
 122                         errx(1, "mbr_gid_to_uuid(): Unable to translate gid %d", tgrp->gr_gid);
 123                 }
 124         } else {
 125                 errx(1, "Unable to translate '%s' to a UID/GID", tok);
 126         }
 127         return entryg;
 128 }
 129
 130 /* Convert an acl entry in string form to an acl_entry_t */
 131 int
 132 parse_entry(char *entrybuf, acl_entry_t newent) {
 133         char *tok;
 134         char *pebuf;
 135         uuid_t *entryg;
 136
 137         acl_tag_t       tag;
 138         acl_permset_t   perms;
 139         acl_flagset_t   flags;
 140         unsigned permcount = 0;
 141         unsigned pindex = 0;
 142         char *delimiter = " ";
 143         int nametype = NAME_EITHER;
 144
 145         acl_get_permset(newent, &perms);
 146         acl_get_flagset_np(newent, &flags);
 147
 148         pebuf = entrybuf;
 149
 150         if (0 == strncmp(entrybuf, "user:", 5)) {
 151                 nametype = NAME_USER;
 152                 pebuf += 5;
 153         } else if (0 == strncmp(entrybuf, "group:", 6)) {
 154                 nametype = NAME_GROUP;
 155                 pebuf += 6;
 156         }
 157
 158         if (strchr(pebuf, ':')) /* User/Group names can have spaces */
 159                 delimiter = ":";
 160         tok = strsep(&pebuf, delimiter);
 161
 162         if ((tok == NULL) || *tok == '\0') {
 163                 errx(1, "Invalid entry format -- expected user or group name");
 164         }
 165
 166         /* parse the name into a qualifier */
 167         entryg = name_to_uuid(tok, nametype);
 168
 169         tok = strsep(&pebuf, ": "); /* Stick with delimiter? */
 170         if ((tok == NULL) || *tok == '\0') {
 171                 errx(1, "Invalid entry format -- expected allow or deny");
 172         }
 173
 174         /* is the verb 'allow' or 'deny'? */
 175         if (!strcmp(tok, "allow")) {
 176                 tag = ACL_EXTENDED_ALLOW;
 177         } else if (!strcmp(tok, "deny")) {
 178                 tag = ACL_EXTENDED_DENY;
 179         } else {
 180                 errx(1, "Unknown tag type '%s'", tok);
 181         }
 182
 183         /* parse permissions */
 184         for (; (tok = strsep(&pebuf, ",")) != NULL;) {
 185                 if (*tok != '\0') {
 186                         /* is it a permission? */
 187                         for (pindex = 0; acl_perms[pindex].name != NULL; pindex++) {
 188                                 if (!strcmp(acl_perms[pindex].name, tok)) {
 189                                         /* got one */
 190                                         acl_add_perm(perms, acl_perms[pindex].perm);
 191                                         permcount++;
 192                                         goto found;
 193                                 }
 194                         }
 195                         /* is it a flag? */
 196                         for (pindex = 0; acl_flags[pindex].name != NULL; pindex++) {
 197                                 if (!strcmp(acl_flags[pindex].name, tok)) {
 198                                         /* got one */
 199                                         acl_add_flag_np(flags, acl_flags[pindex].flag);
 200                                         permcount++;
 201                                         goto found;
 202                                 }
 203                         }
 204                         errx(1,"Invalid permission type '%s'", tok);
 205                 found:
 206                         continue;
 207                 }
 208         }
 209         if (0 == permcount) {
 210                 errx(1, "No permissions specified");
 211         }
 212         acl_set_tag_type(newent, tag);
 213         acl_set_qualifier(newent, entryg);
 214         acl_set_permset(newent, perms);
 215         acl_set_flagset_np(newent, flags);
 216         free(entryg);
 217
 218         return(0);
 219 }
 220
 221 /* Convert one or more acl entries in string form to an acl_t */
 222 acl_t
 223 parse_acl_entries(const char *input) {
 224         acl_t acl_input;
 225         acl_entry_t newent;
 226         char *inbuf;
 227         char *oinbuf;
 228
 229         char **bufp, *entryv[ACL_MAX_ENTRIES];
 230 #if 0
 231 /* XXX acl_from_text(), when implemented, will presumably use the canonical
 232  * text representation format, which is what chmod should be using
 233  * We may need to add an entry number to the input
 234  */
 235         /* Translate the user supplied ACL entry */
 236         /* acl_input = acl_from_text(input); */
 237 #else
 238         inbuf = malloc(MAX_ACL_TEXT_SIZE);
 239
 240         if (inbuf == NULL)
 241                 err(1, "malloc() failed");
 242         strncpy(inbuf, input, MAX_ACL_TEXT_SIZE);
 243         inbuf[MAX_ACL_TEXT_SIZE - 1] = '\0';
 244
 245         if ((acl_input = acl_init(1)) == NULL)
 246                 err(1, "acl_init() failed");
 247
 248         oinbuf = inbuf;
 249
 250         for (bufp = entryv; (*bufp = strsep(&oinbuf, "\n")) != NULL;)
 251                 if (**bufp != '\0') {
 252                         if (0 != acl_create_entry(&acl_input, &newent))
 253                                 err(1, "acl_create_entry() failed");
 254                         if (0 != parse_entry(*bufp, newent)) {
 255                                 errx(1, "Failed parsing entry '%s'", *bufp);
 256                         }
 257                         if (++bufp >= &entryv[ACL_MAX_ENTRIES - 1]) {
 258                                 errx(1, "Too many entries");
 259                         }
 260                 }
 261
 262         free(inbuf);
 263         return acl_input;
 264 #endif  /* #if 0 */
 265 }
 266
 267 /* XXX No Libc support for inherited entries and generation determination yet */
 268 unsigned
 269 get_inheritance_level(acl_entry_t entry) {
 270 /* XXX to be implemented */
 271         return 1;
 272 }
 273
 274 /* Determine a "score" for an acl entry. The entry scores higher if it's
 275  * tagged ACL_EXTENDED_DENY, and non-inherited entries are ranked higher
 276  * than inherited entries.
 277  */
 278
 279 int
 280 score_acl_entry(acl_entry_t entry) {
 281
 282         acl_tag_t       tag;
 283         acl_flagset_t   flags;
 284         acl_permset_t   perms;
 285
 286         int score = 0;
 287
 288         if (entry == NULL)
 289                 return (MINIMUM_TIER);
 290
 291         if (acl_get_tag_type(entry, &tag) != 0) {
 292                 err(1, "Malformed ACL entry, no tag present");
 293         }
 294         if (acl_get_flagset_np(entry, &flags) != 0){
 295                 err(1, "Unable to obtain flagset");
 296         }
 297         if (acl_get_permset(entry, &perms) != 0)
 298                 err(1, "Malformed ACL entry, no permset present");
 299
 300         switch(tag) {
 301         case ACL_EXTENDED_ALLOW:
 302                 break;
 303         case ACL_EXTENDED_DENY:
 304                 score++;
 305                 break;
 306         default:
 307                 errx(1, "Unknown tag type %d present in ACL entry", tag);
 308                 /* NOTREACHED */
 309         }
 310
 311         if (acl_get_flag_np(flags, ACL_ENTRY_INHERITED))
 312                 score += get_inheritance_level(entry) * INHERITANCE_TIER;
 313
 314         return score;
 315 }
 316
 317 int
 318 compare_acl_qualifiers(uuid_t *qa, uuid_t *qb) {
 319         return bcmp(qa, qb, sizeof(uuid_t));
 320 }
 321
 322 /* Compare two ACL permsets.
 323  *  Returns :
 324  *  MATCH_SUBSET if bperms is a subset of aperms
 325  *  MATCH_SUPERSET if bperms is a superset of aperms
 326  *  MATCH_PARTIAL if the two permsets have a common subset
 327  *  MATCH_EXACT if the two permsets are identical
 328  *  MATCH_NONE if they are disjoint
 329  */
 330
 331 int
 332 compare_acl_permsets(acl_permset_t aperms, acl_permset_t bperms)
 333 {
 334         int i;
 335 /* TBD Implement other match levels as needed */
 336         for (i = 0; acl_perms[i].name != NULL; i++) {
 337                 if (acl_get_perm_np(aperms, acl_perms[i].perm) !=
 338                     acl_get_perm_np(bperms, acl_perms[i].perm))
 339                         return MATCH_NONE;
 340         }
 341         return MATCH_EXACT;
 342 }
 343
 344 int
 345 compare_acl_flagsets(acl_flagset_t aflags, acl_flagset_t bflags)
 346 {
 347         int i;
 348 /* TBD Implement other match levels as needed */
 349         for (i = 0; acl_flags[i].name != NULL; i++) {
 350                 if (acl_get_flag_np(aflags, acl_flags[i].flag) !=
 351                     acl_get_flag_np(bflags, acl_flags[i].flag))
 352                         return MATCH_NONE;
 353         }
 354         return MATCH_EXACT;
 355 }
 356
 357 /* Compares two ACL entries for equality */
 358 int
 359 compare_acl_entries(acl_entry_t a, acl_entry_t b)
 360 {
 361         acl_tag_t atag, btag;
 362         acl_permset_t aperms, bperms;
 363         acl_flagset_t aflags, bflags;
 364         int pcmp = 0, fcmp = 0;
 365
 366         if (0 != compare_acl_qualifiers(acl_get_qualifier(a),
 367                                         acl_get_qualifier(b)))
 368                 return MATCH_NONE;
 369
 370         if (0 != acl_get_tag_type(a, &atag))
 371                 err(1, "No tag type present in entry");
 372         if (0!= acl_get_tag_type(b, &btag))
 373                 err(1, "No tag type present in entry");
 374
 375         if (atag != btag)
 376                 return MATCH_NONE;
 377
 378         if ((acl_get_permset(a, &aperms) != 0) ||
 379             (acl_get_flagset_np(a, &aflags) != 0) ||
 380             (acl_get_permset(b, &bperms) != 0) ||
 381             (acl_get_flagset_np(b, &bflags) != 0))
 382                 err(1, "error fetching permissions");
 383
 384         pcmp = compare_acl_permsets(aperms, bperms);
 385         fcmp = compare_acl_flagsets(aflags, bflags);
 386
 387         if ((pcmp == MATCH_NONE) || (fcmp == MATCH_NONE))
 388                 return(MATCH_PARTIAL);
 389         else
 390                 return(MATCH_EXACT);
 391 }
 392
 393 /* Verify that an ACL is in canonical order. Currently, the canonical
 394  * form is:
 395  * local deny
 396  * local allow
 397  * inherited deny (parent)
 398  * inherited allow (parent)
 399  * inherited deny (grandparent)
 400  * inherited allow (grandparent)
 401  * ...
 402  */
 403 unsigned int
 404 is_canonical(acl_t acl) {
 405
 406         unsigned aindex;
 407         acl_entry_t entry;
 408         int score = 0, next_score = 0;
 409
 410 /* XXX - is a zero entry ACL in canonical form? */
 411         if (0 != acl_get_entry(acl, ACL_FIRST_ENTRY, &entry))
 412                 return 1;
 413
 414         score = score_acl_entry(entry);
 415
 416         for (aindex = 0; acl_get_entry(acl, ACL_NEXT_ENTRY, &entry) == 0;
 417              aindex++)  {
 418                 if (score < (next_score = score_acl_entry(entry)))
 419                         return 0;
 420                 score = next_score;
 421         }
 422         return 1;
 423 }
 424
 425
 426 /* Iterate through an ACL, and find the canonical position for the
 427  * specified entry
 428  */
 429 unsigned int
 430 find_canonical_position(acl_t acl, acl_entry_t modifier) {
 431
 432         acl_entry_t entry;
 433         int mscore = 0;
 434         unsigned mpos = 0;
 435
 436         /* Check if there's an entry with the same qualifier
 437          * and tag type; if not, find the appropriate slot
 438          * for the score.
 439          */
 440
 441         if (0 != acl_get_entry(acl, ACL_FIRST_ENTRY, &entry))
 442                 return 0;
 443
 444         mscore = score_acl_entry(modifier);
 445
 446         while (mscore < score_acl_entry(entry)) {
 447
 448                 mpos++;
 449
 450                if (0 != acl_get_entry(acl, ACL_NEXT_ENTRY, &entry))
 451                        break;
 452
 453                }
 454         return mpos;
 455 }
 456
 457 int canonicalize_acl_entries(acl_t acl);
 458
 459 /* For a given acl_entry_t "modifier", find the first exact or
 460  * partially matching entry from the specified acl_t acl
 461  */
 462
 463 int
 464 find_matching_entry (acl_t acl, acl_entry_t modifier, acl_entry_t *rentryp,
 465                      unsigned match_inherited) {
 466
 467         acl_entry_t entry = NULL;
 468
 469         unsigned aindex;
 470         int cmp, fcmp = MATCH_NONE;
 471
 472         for (aindex = 0;
 473              acl_get_entry(acl, entry == NULL ? ACL_FIRST_ENTRY :
 474                            ACL_NEXT_ENTRY, &entry) == 0;
 475              aindex++)  {
 476                 cmp = compare_acl_entries(entry, modifier);
 477                 if ((cmp == MATCH_EXACT) || (cmp == MATCH_PARTIAL)) {
 478                         if (match_inherited) {
 479                                 acl_flagset_t eflags, mflags;
 480
 481                                 if (0 != acl_get_flagset_np(modifier, &mflags))
 482                                         err(1, "Unable to get flagset");
 483
 484                                 if (0 != acl_get_flagset_np(entry, &eflags))
 485                                         err(1, "Unable to get flagset");
 486
 487                                 if (compare_acl_flagsets(mflags, eflags) == MATCH_EXACT) {
 488                                         *rentryp = entry;
 489                                         fcmp = cmp;
 490                                 }
 491                         }
 492                         else {
 493                                 *rentryp = entry;
 494                                 fcmp = cmp;
 495                         }
 496                 }
 497                 if (fcmp == MATCH_EXACT)
 498                         break;
 499         }
 500         return fcmp;
 501 }
 502
 503 /* Remove all perms specified in modifier from rentry*/
 504 int
 505 subtract_from_entry(acl_entry_t rentry, acl_entry_t  modifier, int* valid_perms)
 506 {
 507         acl_permset_t rperms, mperms;
 508         acl_flagset_t rflags, mflags;
 509         if (valid_perms)
 510                 *valid_perms = 0;
 511         int i;
 512
 513         if ((acl_get_permset(rentry, &rperms) != 0) ||
 514             (acl_get_flagset_np(rentry, &rflags) != 0) ||
 515             (acl_get_permset(modifier, &mperms) != 0) ||
 516             (acl_get_flagset_np(modifier, &mflags) != 0))
 517                 err(1, "error computing ACL modification");
 518
 519         for (i = 0; acl_perms[i].name != NULL; i++) {
 520                 if (acl_get_perm_np(mperms, acl_perms[i].perm))
 521                         acl_delete_perm(rperms, acl_perms[i].perm);
 522                 else if (valid_perms && acl_get_perm_np(rperms, acl_perms[i].perm))
 523                         (*valid_perms)++;
 524         }
 525         for (i = 0; acl_flags[i].name != NULL; i++) {
 526                 if (acl_get_flag_np(mflags, acl_flags[i].flag))
 527                         acl_delete_flag_np(rflags, acl_flags[i].flag);
 528         }
 529         acl_set_permset(rentry, rperms);
 530         acl_set_flagset_np(rentry, rflags);
 531         return 0;
 532 }
 533 /* Add the perms specified in modifier to rentry */
 534 int
 535 merge_entry_perms(acl_entry_t rentry, acl_entry_t  modifier)
 536 {
 537         acl_permset_t rperms, mperms;
 538         acl_flagset_t rflags, mflags;
 539         int i;
 540
 541         if ((acl_get_permset(rentry, &rperms) != 0) ||
 542             (acl_get_flagset_np(rentry, &rflags) != 0) ||
 543             (acl_get_permset(modifier, &mperms) != 0) ||
 544             (acl_get_flagset_np(modifier, &mflags) != 0))
 545                 err(1, "error computing ACL modification");
 546
 547         for (i = 0; acl_perms[i].name != NULL; i++) {
 548                 if (acl_get_perm_np(mperms, acl_perms[i].perm))
 549                         acl_add_perm(rperms, acl_perms[i].perm);
 550         }
 551         for (i = 0; acl_flags[i].name != NULL; i++) {
 552                 if (acl_get_flag_np(mflags, acl_flags[i].flag))
 553                         acl_add_flag_np(rflags, acl_flags[i].flag);
 554         }
 555         acl_set_permset(rentry, rperms);
 556         acl_set_flagset_np(rentry, rflags);
 557         return 0;
 558 }
 559
 560 int
 561 modify_acl(acl_t *oaclp, acl_entry_t modifier, unsigned int optflags,
 562            int position, int inheritance_level,
 563            unsigned flag_new_acl, const char* path) {
 564
 565         unsigned cpos = 0;
 566         acl_entry_t newent = NULL;
 567         int dmatch = 0;
 568         acl_entry_t rentry = NULL;
 569         unsigned retval = 0;
 570         acl_t oacl = *oaclp;
 571
 572 /* Add the inherited flag if requested by the user*/
 573         if (modifier && (optflags & ACL_INHERIT_FLAG)) {
 574                 acl_flagset_t mflags;
 575
 576                 acl_get_flagset_np(modifier, &mflags);
 577                 acl_add_flag_np(mflags, ACL_ENTRY_INHERITED);
 578                 acl_set_flagset_np(modifier, mflags);
 579         }
 580
 581         if (optflags & ACL_SET_FLAG) {
 582                 if (position != -1) {
 583                         if (0 != acl_create_entry_np(&oacl, &newent, position))
 584                                 err(1, "acl_create_entry() failed");
 585                         acl_copy_entry(newent, modifier);
 586                 } else {
 587 /* If an entry exists, add the new permissions to it, else add an
 588  * entry in the canonical position.
 589  */
 590
 591 /* First, check for a matching entry - if one exists, merge flags */
 592                         dmatch = find_matching_entry(oacl, modifier, &rentry, 1);
 593
 594                         if (dmatch != MATCH_NONE) {
 595                                 if (dmatch == MATCH_EXACT)
 596 /* Nothing to be done */
 597                                         goto ma_exit;
 598
 599                                 if (dmatch == MATCH_PARTIAL) {
 600                                         merge_entry_perms(rentry, modifier);
 601                                         goto ma_exit;
 602                                 }
 603                         }
 604 /* Insert the entry in canonical order */
 605                         cpos = find_canonical_position(oacl, modifier);
 606                         if (0!= acl_create_entry_np(&oacl, &newent, cpos))
 607                                 err(1, "acl_create_entry() failed");
 608                         acl_copy_entry(newent, modifier);
 609                 }
 610         } else if (optflags & ACL_DELETE_FLAG) {
 611                 if (flag_new_acl) {
 612                         warnx("No ACL present '%s'", path);
 613                         retval = 1;
 614                 } else if (position != -1 ) {
 615                         if (0 != acl_get_entry(oacl, position, &rentry)) {
 616                                 warnx("Invalid entry number '%s'", path);
 617                                 retval = 1;
 618                         } else {
 619                                 acl_delete_entry(oacl, rentry);
 620                         }
 621                 } else {
 622                         unsigned match_found = 0, aindex;
 623                         for (aindex = 0;
 624                              acl_get_entry(oacl, rentry == NULL ?
 625                                            ACL_FIRST_ENTRY :
 626                                            ACL_NEXT_ENTRY, &rentry) == 0;
 627                              aindex++)  {
 628                                 unsigned cmp;
 629                                 cmp = compare_acl_entries(rentry, modifier);
 630                                 if ((cmp == MATCH_EXACT) ||
 631                                     (cmp == MATCH_PARTIAL)) {
 632                                         match_found++;
 633                                         if (cmp == MATCH_EXACT)
 634                                                 acl_delete_entry(oacl, rentry);
 635                                         else {
 636                                                 int valid_perms;
 637 /* In the event of a partial match, remove the specified perms from the
 638  * entry */
 639                                                 subtract_from_entry(rentry, modifier, &valid_perms);
 640                                                 /* if no perms survived then delete the entry */
 641                                                 if (valid_perms == 0)
 642                                                         acl_delete_entry(oacl, rentry);
 643                                         }
 644                                 }
 645                         }
 646                         if (0 == match_found) {
 647                                 warnx("Entry not found when attempting delete '%s'",path);
 648                                 retval = 1;
 649                         }
 650                 }
 651         } else if (optflags & ACL_REWRITE_FLAG) {
 652                 acl_entry_t rentry;
 653
 654                 if (-1 == position) {
 655                         usage();
 656                 }
 657                 if (0 == flag_new_acl) {
 658                         if (0 != acl_get_entry(oacl, position,
 659                                                &rentry))
 660                                 err(1, "Invalid entry number '%s'", path);
 661
 662                         if (0 != acl_delete_entry(oacl, rentry))
 663                                 err(1, "Unable to delete entry '%s'", path);
 664                 }
 665                 if (0!= acl_create_entry_np(&oacl, &newent, position))
 666                         err(1, "acl_create_entry() failed");
 667                 acl_copy_entry(newent, modifier);
 668         }
 669 ma_exit:
 670         *oaclp = oacl;
 671         return retval;
 672 }
 673
 674 int
 675 modify_file_acl(unsigned int optflags, const char *path, acl_t modifier, int position, int inheritance_level) {
 676
 677         acl_t oacl = NULL;
 678         unsigned aindex  = 0, flag_new_acl = 0;
 679         acl_entry_t newent = NULL;
 680         acl_entry_t entry = NULL;
 681         unsigned retval = 0 ;
 682
 683         extern int fflag;
 684
 685 /* XXX acl_get_file() returns a zero entry ACL if an ACL was previously
 686  * associated with the file, and has had its entries removed.
 687  * However, POSIX 1003.1e states that a zero entry ACL should be
 688  * returned if the caller asks for ACL_TYPE_DEFAULT, and no ACL is
 689  * associated with the path; it
 690  * does not specifically state that a request for ACL_TYPE_EXTENDED
 691  * should not return a zero entry ACL, however.
 692  */
 693
 694 /* Determine if we've been given a zero entry ACL, or create an ACL if
 695  * none exists. There are some issues to consider here: Should we create
 696  * a zero-entry ACL for a delete or check canonicity operation?
 697  */
 698
 699         if (path == NULL)
 700                 usage();
 701
 702         if (optflags & ACL_CLEAR_FLAG) {
 703                 filesec_t fsec = filesec_init();
 704                 if (fsec == NULL)
 705                         err(1, "filesec_init() failed");
 706                 if (filesec_set_property(fsec, FILESEC_ACL,
 707                                          _FILESEC_REMOVE_ACL) != 0)
 708                         err(1, "filesec_set_property() failed");
 709                 if (chmodx_np(path, fsec) != 0) {
 710                         if (!fflag)
 711                                 warn("Failed to clear ACL on file %s", path);
 712                         retval = 1;
 713                 } else
 714                         retval = 0;
 715                 filesec_free(fsec);
 716                 return (retval);
 717         }
 718
 719         if (optflags & ACL_FROM_STDIN)
 720                 oacl = acl_dup(modifier);
 721         else {
 722                 oacl = acl_get_file(path, ACL_TYPE_EXTENDED);
 723
 724                 if ((oacl == NULL) ||
 725                     (acl_get_entry(oacl,ACL_FIRST_ENTRY, &newent) != 0)) {
 726                         if ((oacl = acl_init(1)) == NULL)
 727                                 err(1, "acl_init() failed");
 728                         flag_new_acl = 1;
 729                         position = 0;
 730                 }
 731
 732                 if ((0 == flag_new_acl) && (optflags & (ACL_REMOVE_INHERIT_FLAG |
 733                                                         ACL_REMOVE_INHERITED_ENTRIES))) {
 734                         acl_t facl = NULL;
 735                         if ((facl = acl_init(1)) == NULL)
 736                                 err(1, "acl_init() failed");
 737                         for (aindex = 0;
 738                              acl_get_entry(oacl,
 739                                            (entry == NULL ? ACL_FIRST_ENTRY :
 740                                             ACL_NEXT_ENTRY), &entry) == 0;
 741                              aindex++) {
 742                                 acl_flagset_t eflags;
 743                                 acl_entry_t fent = NULL;
 744                                 if (acl_get_flagset_np(entry, &eflags) != 0) {
 745                                         err(1, "Unable to obtain flagset");
 746                                 }
 747
 748                                 if (acl_get_flag_np(eflags, ACL_ENTRY_INHERITED)) {
 749                                         if (optflags & ACL_REMOVE_INHERIT_FLAG) {
 750                                                 acl_delete_flag_np(eflags, ACL_ENTRY_INHERITED);
 751                                                 acl_set_flagset_np(entry, eflags);
 752                                                 acl_create_entry(&facl, &fent);
 753                                                 acl_copy_entry(fent, entry);
 754                                         }
 755                                 }
 756                                 else {
 757                                         acl_create_entry(&facl, &fent);
 758                                         acl_copy_entry(fent, entry);
 759                                 }
 760                         }
 761                         if (oacl)
 762                                 acl_free(oacl);
 763                         oacl = facl;
 764                 } else if (optflags & ACL_TO_STDOUT) {
 765                         ssize_t len; /* need to get printacl() from ls(1) */
 766                         char *text = acl_to_text(oacl, &len);
 767                         puts(text);
 768                         acl_free(text);
 769                 } else if (optflags & ACL_CHECK_CANONICITY) {
 770                         if (flag_new_acl) {
 771                                 warnx("No ACL currently associated with file '%s'", path);
 772                         }
 773                         retval = is_canonical(oacl);
 774                 } else if ((optflags & ACL_SET_FLAG) && (position == -1) &&
 775                     (!is_canonical(oacl))) {
 776                         warnx("The specified file '%s' does not have an ACL in canonical order, please specify a position with +a# ", path);
 777                         retval = 1;
 778                 } else if (((optflags & ACL_DELETE_FLAG) && (position != -1))
 779                     || (optflags & ACL_CHECK_CANONICITY)) {
 780                         retval = modify_acl(&oacl, NULL, optflags, position,
 781                                             inheritance_level, flag_new_acl, path);
 782                 } else if ((optflags & (ACL_REMOVE_INHERIT_FLAG|ACL_REMOVE_INHERITED_ENTRIES)) && flag_new_acl) {
 783                         warnx("No ACL currently associated with file '%s'", path);
 784                         retval = 1;
 785                 } else {
 786                         if (!modifier) { /* avoid bus error in acl_get_entry */
 787                                 errx(1, "Internal error: modifier should not be NULL");
 788                         }
 789                         for (aindex = 0;
 790                              acl_get_entry(modifier,
 791                                            (entry == NULL ? ACL_FIRST_ENTRY :
 792                                             ACL_NEXT_ENTRY), &entry) == 0;
 793                              aindex++) {
 794
 795                                 retval += modify_acl(&oacl, entry, optflags,
 796                                                      position, inheritance_level,
 797                                                      flag_new_acl, path);
 798                         }
 799                 }
 800         }
 801
 802 /* XXX Potential race here, since someone else could've modified or
 803  * read the ACL on this file (with the intention of modifying it) in
 804  * the interval from acl_get_file() to acl_set_file(); we can
 805  * minimize one aspect of this  window by comparing the original acl
 806  * to a fresh one from acl_get_file() but we could consider a
 807  * "changeset" mechanism, common locking  strategy, or kernel
 808  * supplied reservation mechanism to prevent this race.
 809  */
 810         if (!(optflags & (ACL_TO_STDOUT|ACL_CHECK_CANONICITY)) &&
 811             (0 != acl_set_file(path, ACL_TYPE_EXTENDED, oacl))){
 812                 if (!fflag)
 813                         warn("Failed to set ACL on file '%s'", path);
 814                 retval = 1;
 815         }
 816
 817         if (oacl)
 818                 acl_free(oacl);
 819
 820         return retval;
 821 }
 822
 823 #endif /*__APPLE__*/