1/* Test whether a file has a nontrivial access control list. 2 3 Copyright (C) 2002-2003, 2005-2010 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 18 Written by Paul Eggert, Andreas Gr��nbacher, and Bruno Haible. */ 19 20#include <config.h> 21 22#include "acl.h" 23 24#include "acl-internal.h" 25 26 27#if USE_ACL && HAVE_ACL_GET_FILE 28 29# if HAVE_ACL_TYPE_EXTENDED /* MacOS X */ 30 31/* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED. 32 Return 1 if the given ACL is non-trivial. 33 Return 0 if it is trivial. */ 34int 35acl_extended_nontrivial (acl_t acl) 36{ 37 /* acl is non-trivial if it is non-empty. */ 38 return (acl_entries (acl) > 0); 39} 40 41# else /* Linux, FreeBSD, IRIX, Tru64 */ 42 43/* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS. 44 Return 1 if the given ACL is non-trivial. 45 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. 46 Return -1 and set errno upon failure to determine it. */ 47int 48acl_access_nontrivial (acl_t acl) 49{ 50 /* acl is non-trivial if it has some entries other than for "user::", 51 "group::", and "other::". Normally these three should be present 52 at least, allowing us to write 53 return (3 < acl_entries (acl)); 54 but the following code is more robust. */ 55# if HAVE_ACL_FIRST_ENTRY /* Linux, FreeBSD */ 56 57 acl_entry_t ace; 58 int got_one; 59 60 for (got_one = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace); 61 got_one > 0; 62 got_one = acl_get_entry (acl, ACL_NEXT_ENTRY, &ace)) 63 { 64 acl_tag_t tag; 65 if (acl_get_tag_type (ace, &tag) < 0) 66 return -1; 67 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER)) 68 return 1; 69 } 70 return got_one; 71 72# else /* IRIX, Tru64 */ 73# if HAVE_ACL_TO_SHORT_TEXT /* IRIX */ 74 /* Don't use acl_get_entry: it is undocumented. */ 75 76 int count = acl->acl_cnt; 77 int i; 78 79 for (i = 0; i < count; i++) 80 { 81 acl_entry_t ace = &acl->acl_entry[i]; 82 acl_tag_t tag = ace->ae_tag; 83 84 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ 85 || tag == ACL_OTHER_OBJ)) 86 return 1; 87 } 88 return 0; 89 90# endif 91# if HAVE_ACL_FREE_TEXT /* Tru64 */ 92 /* Don't use acl_get_entry: it takes only one argument and does not work. */ 93 94 int count = acl->acl_num; 95 acl_entry_t ace; 96 97 for (ace = acl->acl_first; count > 0; ace = ace->next, count--) 98 { 99 acl_tag_t tag; 100 acl_perm_t perm; 101 102 tag = ace->entry->acl_type; 103 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER)) 104 return 1; 105 106 perm = ace->entry->acl_perm; 107 /* On Tru64, perm can also contain non-standard bits such as 108 PERM_INSERT, PERM_DELETE, PERM_MODIFY, PERM_LOOKUP, ... */ 109 if ((perm & ~(ACL_READ | ACL_WRITE | ACL_EXECUTE)) != 0) 110 return 1; 111 } 112 return 0; 113 114# endif 115# endif 116} 117 118# endif 119 120 121#elif USE_ACL && HAVE_ACL && defined GETACL /* Solaris, Cygwin, not HP-UX */ 122 123# if !defined ACL_NO_TRIVIAL /* Solaris <= 10, Cygwin */ 124 125/* Test an ACL retrieved with GETACL. 126 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial. 127 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ 128int 129acl_nontrivial (int count, aclent_t *entries) 130{ 131 int i; 132 133 for (i = 0; i < count; i++) 134 { 135 aclent_t *ace = &entries[i]; 136 137 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat(). 138 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat(). 139 We don't need to check ace->a_id in these cases. */ 140 if (!(ace->a_type == USER_OBJ 141 || ace->a_type == GROUP_OBJ 142 || ace->a_type == OTHER_OBJ 143 /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry 144 sometimes. */ 145 || ace->a_type == CLASS_OBJ)) 146 return 1; 147 } 148 return 0; 149} 150 151# ifdef ACE_GETACL 152 153/* Test an ACL retrieved with ACE_GETACL. 154 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial. 155 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ 156int 157acl_ace_nontrivial (int count, ace_t *entries) 158{ 159 int i; 160 161 /* The flags in the ace_t structure changed in a binary incompatible way 162 when ACL_NO_TRIVIAL etc. were introduced in <sys/acl.h> version 1.15. 163 How to distinguish the two conventions at runtime? 164 In the old convention, usually three ACEs have a_flags = ACE_OWNER / 165 ACE_GROUP / ACE_OTHER, in the range 0x0100..0x0400. In the new 166 convention, these values are not used. */ 167 int old_convention = 0; 168 169 for (i = 0; i < count; i++) 170 if (entries[i].a_flags & (ACE_OWNER | ACE_GROUP | ACE_OTHER)) 171 { 172 old_convention = 1; 173 break; 174 } 175 176 if (old_convention) 177 /* Running on Solaris 10. */ 178 for (i = 0; i < count; i++) 179 { 180 ace_t *ace = &entries[i]; 181 182 /* Note: 183 If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from stat(). 184 If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from stat(). 185 We don't need to check ace->a_who in these cases. */ 186 if (!(ace->a_type == ALLOW 187 && (ace->a_flags == ACE_OWNER 188 || ace->a_flags == ACE_GROUP 189 || ace->a_flags == ACE_OTHER))) 190 return 1; 191 } 192 else 193 /* Running on Solaris 10 (newer version) or Solaris 11. */ 194 for (i = 0; i < count; i++) 195 { 196 ace_t *ace = &entries[i]; 197 198 if (!(ace->a_type == ACE_ACCESS_ALLOWED_ACE_TYPE 199 && (ace->a_flags == NEW_ACE_OWNER 200 || ace->a_flags 201 == (NEW_ACE_GROUP | NEW_ACE_IDENTIFIER_GROUP) 202 || ace->a_flags == ACE_EVERYONE) 203 && (ace->a_access_mask 204 & ~(NEW_ACE_READ_DATA | NEW_ACE_WRITE_DATA | NEW_ACE_EXECUTE)) 205 == 0)) 206 return 1; 207 } 208 209 return 0; 210} 211 212# endif 213 214# endif 215 216#elif USE_ACL && HAVE_GETACL /* HP-UX */ 217 218/* Return 1 if the given ACL is non-trivial. 219 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ 220int 221acl_nontrivial (int count, struct acl_entry *entries, struct stat *sb) 222{ 223 int i; 224 225 for (i = 0; i < count; i++) 226 { 227 struct acl_entry *ace = &entries[i]; 228 229 if (!((ace->uid == sb->st_uid && ace->gid == ACL_NSGROUP) 230 || (ace->uid == ACL_NSUSER && ace->gid == sb->st_gid) 231 || (ace->uid == ACL_NSUSER && ace->gid == ACL_NSGROUP))) 232 return 1; 233 } 234 return 0; 235} 236 237#elif USE_ACL && (HAVE_ACLX_GET || HAVE_STATACL) /* AIX */ 238 239/* Return 1 if the given ACL is non-trivial. 240 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ 241int 242acl_nontrivial (struct acl *a) 243{ 244 /* The normal way to iterate through an ACL is like this: 245 struct acl_entry *ace; 246 for (ace = a->acl_ext; ace != acl_last (a); ace = acl_nxt (ace)) 247 { 248 struct ace_id *aei; 249 switch (ace->ace_type) 250 { 251 case ACC_PERMIT: 252 case ACC_DENY: 253 case ACC_SPECIFY: 254 ...; 255 } 256 for (aei = ace->ace_id; aei != id_last (ace); aei = id_nxt (aei)) 257 ... 258 } 259 */ 260 return (acl_last (a) != a->acl_ext ? 1 : 0); 261} 262 263# if HAVE_ACLX_GET && defined ACL_AIX_WIP /* newer AIX */ 264 265/* Return 1 if the given ACL is non-trivial. 266 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ 267int 268acl_nfs4_nontrivial (nfs4_acl_int_t *a) 269{ 270# if 1 /* let's try this first */ 271 return (a->aclEntryN > 0 ? 1 : 0); 272# else 273 int count = a->aclEntryN; 274 int i; 275 276 for (i = 0; i < count; i++) 277 { 278 nfs4_ace_int_t *ace = &a->aclEntry[i]; 279 280 if (!((ace->flags & ACE4_ID_SPECIAL) != 0 281 && (ace->aceWho.special_whoid == ACE4_WHO_OWNER 282 || ace->aceWho.special_whoid == ACE4_WHO_GROUP 283 || ace->aceWho.special_whoid == ACE4_WHO_EVERYONE) 284 && ace->aceType == ACE4_ACCESS_ALLOWED_ACE_TYPE 285 && ace->aceFlags == 0 286 && (ace->aceMask & ~(ACE4_READ_DATA | ACE4_LIST_DIRECTORY 287 | ACE4_WRITE_DATA | ACE4_ADD_FILE 288 | ACE4_EXECUTE)) == 0)) 289 return 1; 290 } 291 return 0; 292# endif 293} 294 295# endif 296 297#endif 298 299 300/* Return 1 if NAME has a nontrivial access control list, 0 if NAME 301 only has no or a base access control list, and -1 (setting errno) 302 on error. SB must be set to the stat buffer of FILE. */ 303 304int 305file_has_acl (char const *name, struct stat const *sb) 306{ 307#if USE_ACL 308 if (! S_ISLNK (sb->st_mode)) 309 { 310# if HAVE_ACL_GET_FILE 311 312 /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */ 313 /* Linux, FreeBSD, MacOS X, IRIX, Tru64 */ 314 int ret; 315 316 if (HAVE_ACL_EXTENDED_FILE) /* Linux */ 317 { 318 /* On Linux, acl_extended_file is an optimized function: It only 319 makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for 320 ACL_TYPE_DEFAULT. */ 321 ret = acl_extended_file (name); 322 } 323 else /* FreeBSD, MacOS X, IRIX, Tru64 */ 324 { 325# if HAVE_ACL_TYPE_EXTENDED /* MacOS X */ 326 /* On MacOS X, acl_get_file (name, ACL_TYPE_ACCESS) 327 and acl_get_file (name, ACL_TYPE_DEFAULT) 328 always return NULL / EINVAL. There is no point in making 329 these two useless calls. The real ACL is retrieved through 330 acl_get_file (name, ACL_TYPE_EXTENDED). */ 331 acl_t acl = acl_get_file (name, ACL_TYPE_EXTENDED); 332 if (acl) 333 { 334 ret = acl_extended_nontrivial (acl); 335 acl_free (acl); 336 } 337 else 338 ret = -1; 339# else /* FreeBSD, IRIX, Tru64 */ 340 acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS); 341 if (acl) 342 { 343 int saved_errno; 344 345 ret = acl_access_nontrivial (acl); 346 saved_errno = errno; 347 acl_free (acl); 348 errno = saved_errno; 349# if HAVE_ACL_FREE_TEXT /* Tru64 */ 350 /* On OSF/1, acl_get_file (name, ACL_TYPE_DEFAULT) always 351 returns NULL with errno not set. There is no point in 352 making this call. */ 353# else /* FreeBSD, IRIX */ 354 /* On Linux, FreeBSD, IRIX, acl_get_file (name, ACL_TYPE_ACCESS) 355 and acl_get_file (name, ACL_TYPE_DEFAULT) on a directory 356 either both succeed or both fail; it depends on the 357 file system. Therefore there is no point in making the second 358 call if the first one already failed. */ 359 if (ret == 0 && S_ISDIR (sb->st_mode)) 360 { 361 acl = acl_get_file (name, ACL_TYPE_DEFAULT); 362 if (acl) 363 { 364 ret = (0 < acl_entries (acl)); 365 acl_free (acl); 366 } 367 else 368 ret = -1; 369 } 370# endif 371 } 372 else 373 ret = -1; 374# endif 375 } 376 if (ret < 0) 377 return ACL_NOT_WELL_SUPPORTED (errno) ? 0 : -1; 378 return ret; 379 380# elif HAVE_ACL && defined GETACLCNT /* Solaris, Cygwin, not HP-UX */ 381 382# if defined ACL_NO_TRIVIAL 383 384 /* Solaris 10 (newer version), which has additional API declared in 385 <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial, 386 acl_fromtext, ...). */ 387 return acl_trivial (name); 388 389# else /* Solaris, Cygwin, general case */ 390 391 /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions 392 of Unixware. The acl() call returns the access and default ACL both 393 at once. */ 394 int count; 395 { 396 aclent_t *entries; 397 398 for (;;) 399 { 400 count = acl (name, GETACLCNT, 0, NULL); 401 402 if (count < 0) 403 { 404 if (errno == ENOSYS || errno == ENOTSUP) 405 break; 406 else 407 return -1; 408 } 409 410 if (count == 0) 411 break; 412 413 /* Don't use MIN_ACL_ENTRIES: It's set to 4 on Cygwin, but Cygwin 414 returns only 3 entries for files with no ACL. But this is safe: 415 If there are more than 4 entries, there cannot be only the 416 "user::", "group::", "other:", and "mask:" entries. */ 417 if (count > 4) 418 return 1; 419 420 entries = (aclent_t *) malloc (count * sizeof (aclent_t)); 421 if (entries == NULL) 422 { 423 errno = ENOMEM; 424 return -1; 425 } 426 if (acl (name, GETACL, count, entries) == count) 427 { 428 if (acl_nontrivial (count, entries)) 429 { 430 free (entries); 431 return 1; 432 } 433 free (entries); 434 break; 435 } 436 /* Huh? The number of ACL entries changed since the last call. 437 Repeat. */ 438 free (entries); 439 } 440 } 441 442# ifdef ACE_GETACL 443 /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4 444 file systems (whereas the other ones are used in UFS file systems). */ 445 { 446 ace_t *entries; 447 448 for (;;) 449 { 450 count = acl (name, ACE_GETACLCNT, 0, NULL); 451 452 if (count < 0) 453 { 454 if (errno == ENOSYS || errno == EINVAL) 455 break; 456 else 457 return -1; 458 } 459 460 if (count == 0) 461 break; 462 463 /* If there are more than 3 entries, there cannot be only the 464 ACE_OWNER, ACE_GROUP, ACE_OTHER entries. */ 465 if (count > 3) 466 return 1; 467 468 entries = (ace_t *) malloc (count * sizeof (ace_t)); 469 if (entries == NULL) 470 { 471 errno = ENOMEM; 472 return -1; 473 } 474 if (acl (name, ACE_GETACL, count, entries) == count) 475 { 476 if (acl_ace_nontrivial (count, entries)) 477 { 478 free (entries); 479 return 1; 480 } 481 free (entries); 482 break; 483 } 484 /* Huh? The number of ACL entries changed since the last call. 485 Repeat. */ 486 free (entries); 487 } 488 } 489# endif 490 491 return 0; 492# endif 493 494# elif HAVE_GETACL /* HP-UX */ 495 496 int count; 497 struct acl_entry entries[NACLENTRIES]; 498 499 for (;;) 500 { 501 count = getacl (name, 0, NULL); 502 503 if (count < 0) 504 return (errno == ENOSYS || errno == EOPNOTSUPP ? 0 : -1); 505 506 if (count == 0) 507 return 0; 508 509 if (count > NACLENTRIES) 510 /* If NACLENTRIES cannot be trusted, use dynamic memory 511 allocation. */ 512 abort (); 513 514 /* If there are more than 3 entries, there cannot be only the 515 (uid,%), (%,gid), (%,%) entries. */ 516 if (count > 3) 517 return 1; 518 519 if (getacl (name, count, entries) == count) 520 { 521 struct stat statbuf; 522 523 if (stat (name, &statbuf) < 0) 524 return -1; 525 526 return acl_nontrivial (count, entries, &statbuf); 527 } 528 /* Huh? The number of ACL entries changed since the last call. 529 Repeat. */ 530 } 531 532# elif HAVE_ACLX_GET && defined ACL_AIX_WIP /* AIX */ 533 534 acl_type_t type; 535 char aclbuf[1024]; 536 void *acl = aclbuf; 537 size_t aclsize = sizeof (aclbuf); 538 mode_t mode; 539 540 for (;;) 541 { 542 /* The docs say that type being 0 is equivalent to ACL_ANY, but it 543 is not true, in AIX 5.3. */ 544 type.u64 = ACL_ANY; 545 if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0) 546 break; 547 if (errno != ENOSPC) 548 { 549 if (acl != aclbuf) 550 { 551 int saved_errno = errno; 552 free (acl); 553 errno = saved_errno; 554 } 555 return -1; 556 } 557 aclsize = 2 * aclsize; 558 if (acl != aclbuf) 559 free (acl); 560 acl = malloc (aclsize); 561 if (acl == NULL) 562 { 563 errno = ENOMEM; 564 return -1; 565 } 566 } 567 568 if (type.u64 == ACL_AIXC) 569 { 570 int result = acl_nontrivial ((struct acl *) acl); 571 if (acl != aclbuf) 572 free (acl); 573 return result; 574 } 575 else if (type.u64 == ACL_NFS4) 576 { 577 int result = acl_nfs4_nontrivial ((nfs4_acl_int_t *) acl); 578 if (acl != aclbuf) 579 free (acl); 580 return result; 581 } 582 else 583 { 584 /* A newer type of ACL has been introduced in the system. 585 We should better support it. */ 586 if (acl != aclbuf) 587 free (acl); 588 errno = EINVAL; 589 return -1; 590 } 591 592# elif HAVE_STATACL /* older AIX */ 593 594 union { struct acl a; char room[4096]; } u; 595 596 if (statacl (name, STX_NORMAL, &u.a, sizeof (u)) < 0) 597 return -1; 598 599 return acl_nontrivial (&u.a); 600 601# endif 602 } 603#endif 604 605 return 0; 606} 607