lib/file-has-acl.c

   1 /* Test whether a file has a nontrivial access control list.
   2
   3    Copyright (C) 2002-2003, 2005-2013 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 Grünbacher, and Bruno Haible.  */
  19
  20 /* Without this pragma, gcc 4.7.0 20120126 may suggest that the
  21    file_has_acl function might be candidate for attribute 'const'  */
  22 #if (__GNUC__ == 4 && 6 <= __GNUC_MINOR__) || 4 < __GNUC__
  23 # pragma GCC diagnostic ignored "-Wsuggest-attribute=const"
  24 #endif
  25
  26 #include <config.h>
  27
  28 #include "acl.h"
  29
  30 #include "acl-internal.h"
  31
  32
  33 #if USE_ACL && HAVE_ACL_GET_FILE
  34
  35 # if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
  36
  37 /* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED.
  38    Return 1 if the given ACL is non-trivial.
  39    Return 0 if it is trivial.  */
  40 int
  41 acl_extended_nontrivial (acl_t acl)
  42 {
  43   /* acl is non-trivial if it is non-empty.  */
  44   return (acl_entries (acl) > 0);
  45 }
  46
  47 # else /* Linux, FreeBSD, IRIX, Tru64 */
  48
  49 /* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS.
  50    Return 1 if the given ACL is non-trivial.
  51    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
  52    Return -1 and set errno upon failure to determine it.  */
  53 int
  54 acl_access_nontrivial (acl_t acl)
  55 {
  56   /* acl is non-trivial if it has some entries other than for "user::",
  57      "group::", and "other::".  Normally these three should be present
  58      at least, allowing us to write
  59         return (3 < acl_entries (acl));
  60      but the following code is more robust.  */
  61 #  if HAVE_ACL_FIRST_ENTRY /* Linux, FreeBSD */
  62
  63   acl_entry_t ace;
  64   int got_one;
  65
  66   for (got_one = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace);
  67        got_one > 0;
  68        got_one = acl_get_entry (acl, ACL_NEXT_ENTRY, &ace))
  69     {
  70       acl_tag_t tag;
  71       if (acl_get_tag_type (ace, &tag) < 0)
  72         return -1;
  73       if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
  74         return 1;
  75     }
  76   return got_one;
  77
  78 #  elif HAVE_ACL_TO_SHORT_TEXT /* IRIX */
  79   /* Don't use acl_get_entry: it is undocumented.  */
  80
  81   int count = acl->acl_cnt;
  82   int i;
  83
  84   for (i = 0; i < count; i++)
  85     {
  86       acl_entry_t ace = &acl->acl_entry[i];
  87       acl_tag_t tag = ace->ae_tag;
  88
  89       if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ
  90             || tag == ACL_OTHER_OBJ))
  91         return 1;
  92     }
  93   return 0;
  94
  95 #  elif HAVE_ACL_FREE_TEXT /* Tru64 */
  96   /* Don't use acl_get_entry: it takes only one argument and does not work.  */
  97
  98   int count = acl->acl_num;
  99   acl_entry_t ace;
 100
 101   for (ace = acl->acl_first; count > 0; ace = ace->next, count--)
 102     {
 103       acl_tag_t tag;
 104       acl_perm_t perm;
 105
 106       tag = ace->entry->acl_type;
 107       if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
 108         return 1;
 109
 110       perm = ace->entry->acl_perm;
 111       /* On Tru64, perm can also contain non-standard bits such as
 112          PERM_INSERT, PERM_DELETE, PERM_MODIFY, PERM_LOOKUP, ... */
 113       if ((perm & ~(ACL_READ | ACL_WRITE | ACL_EXECUTE)) != 0)
 114         return 1;
 115     }
 116   return 0;
 117
 118 #  else
 119
 120   errno = ENOSYS;
 121   return -1;
 122 #  endif
 123 }
 124
 125 # endif
 126
 127
 128 #elif USE_ACL && HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
 129
 130 /* Test an ACL retrieved with GETACL.
 131    Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
 132    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 133 int
 134 acl_nontrivial (int count, aclent_t *entries)
 135 {
 136   int i;
 137
 138   for (i = 0; i < count; i++)
 139     {
 140       aclent_t *ace = &entries[i];
 141
 142       /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
 143          If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
 144          We don't need to check ace->a_id in these cases.  */
 145       if (!(ace->a_type == USER_OBJ
 146             || ace->a_type == GROUP_OBJ
 147             || ace->a_type == OTHER_OBJ
 148             /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry
 149                sometimes.  */
 150             || ace->a_type == CLASS_OBJ))
 151         return 1;
 152     }
 153   return 0;
 154 }
 155
 156 # ifdef ACE_GETACL
 157
 158 /* A shortcut for a bitmask.  */
 159 #  define NEW_ACE_WRITEA_DATA (NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA)
 160
 161 /* Test an ACL retrieved with ACE_GETACL.
 162    Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
 163    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 164 int
 165 acl_ace_nontrivial (int count, ace_t *entries)
 166 {
 167   int i;
 168
 169   /* The flags in the ace_t structure changed in a binary incompatible way
 170      when ACL_NO_TRIVIAL etc. were introduced in <sys/acl.h> version 1.15.
 171      How to distinguish the two conventions at runtime?
 172      In the old convention, usually three ACEs have a_flags = ACE_OWNER /
 173      ACE_GROUP / ACE_OTHER, in the range 0x0100..0x0400.  In the new
 174      convention, these values are not used.  */
 175   int old_convention = 0;
 176
 177   for (i = 0; i < count; i++)
 178     if (entries[i].a_flags & (OLD_ACE_OWNER | OLD_ACE_GROUP | OLD_ACE_OTHER))
 179       {
 180         old_convention = 1;
 181         break;
 182       }
 183
 184   if (old_convention)
 185     /* Running on Solaris 10.  */
 186     for (i = 0; i < count; i++)
 187       {
 188         ace_t *ace = &entries[i];
 189
 190         /* Note:
 191            If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from stat().
 192            If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from stat().
 193            We don't need to check ace->a_who in these cases.  */
 194         if (!(ace->a_type == OLD_ALLOW
 195               && (ace->a_flags == OLD_ACE_OWNER
 196                   || ace->a_flags == OLD_ACE_GROUP
 197                   || ace->a_flags == OLD_ACE_OTHER)))
 198           return 1;
 199       }
 200   else
 201     {
 202       /* Running on Solaris 10 (newer version) or Solaris 11.  */
 203       unsigned int access_masks[6] =
 204         {
 205           0, /* owner@ deny */
 206           0, /* owner@ allow */
 207           0, /* group@ deny */
 208           0, /* group@ allow */
 209           0, /* everyone@ deny */
 210           0  /* everyone@ allow */
 211         };
 212
 213       for (i = 0; i < count; i++)
 214         {
 215           ace_t *ace = &entries[i];
 216           unsigned int index1;
 217           unsigned int index2;
 218
 219           if (ace->a_type == NEW_ACE_ACCESS_ALLOWED_ACE_TYPE)
 220             index1 = 1;
 221           else if (ace->a_type == NEW_ACE_ACCESS_DENIED_ACE_TYPE)
 222             index1 = 0;
 223           else
 224             return 1;
 225
 226           if (ace->a_flags == NEW_ACE_OWNER)
 227             index2 = 0;
 228           else if (ace->a_flags == (NEW_ACE_GROUP | NEW_ACE_IDENTIFIER_GROUP))
 229             index2 = 2;
 230           else if (ace->a_flags == NEW_ACE_EVERYONE)
 231             index2 = 4;
 232           else
 233             return 1;
 234
 235           access_masks[index1 + index2] |= ace->a_access_mask;
 236         }
 237
 238       /* The same bit shouldn't be both allowed and denied.  */
 239       if (access_masks[0] & access_masks[1])
 240         return 1;
 241       if (access_masks[2] & access_masks[3])
 242         return 1;
 243       if (access_masks[4] & access_masks[5])
 244         return 1;
 245
 246       /* Check minimum masks.  */
 247       if ((NEW_ACE_WRITE_NAMED_ATTRS
 248            | NEW_ACE_WRITE_ATTRIBUTES
 249            | NEW_ACE_WRITE_ACL
 250            | NEW_ACE_WRITE_OWNER)
 251           & ~ access_masks[1])
 252         return 1;
 253       access_masks[1] &= ~(NEW_ACE_WRITE_NAMED_ATTRS
 254                            | NEW_ACE_WRITE_ATTRIBUTES
 255                            | NEW_ACE_WRITE_ACL
 256                            | NEW_ACE_WRITE_OWNER);
 257       if ((NEW_ACE_READ_NAMED_ATTRS
 258            | NEW_ACE_READ_ATTRIBUTES
 259            | NEW_ACE_READ_ACL
 260            | NEW_ACE_SYNCHRONIZE)
 261           & ~ access_masks[5])
 262         return 1;
 263       access_masks[5] &= ~(NEW_ACE_READ_NAMED_ATTRS
 264                            | NEW_ACE_READ_ATTRIBUTES
 265                            | NEW_ACE_READ_ACL
 266                            | NEW_ACE_SYNCHRONIZE);
 267
 268       /* Check the allowed or denied bits.  */
 269       switch ((access_masks[0] | access_masks[1])
 270               & ~(NEW_ACE_READ_NAMED_ATTRS
 271                   | NEW_ACE_READ_ATTRIBUTES
 272                   | NEW_ACE_READ_ACL
 273                   | NEW_ACE_SYNCHRONIZE))
 274         {
 275         case 0:
 276         case NEW_ACE_READ_DATA:
 277         case                     NEW_ACE_WRITEA_DATA:
 278         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
 279         case                                           NEW_ACE_EXECUTE:
 280         case NEW_ACE_READ_DATA |                       NEW_ACE_EXECUTE:
 281         case                     NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 282         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 283           break;
 284         default:
 285           return 1;
 286         }
 287       switch ((access_masks[2] | access_masks[3])
 288               & ~(NEW_ACE_READ_NAMED_ATTRS
 289                   | NEW_ACE_READ_ATTRIBUTES
 290                   | NEW_ACE_READ_ACL
 291                   | NEW_ACE_SYNCHRONIZE))
 292         {
 293         case 0:
 294         case NEW_ACE_READ_DATA:
 295         case                     NEW_ACE_WRITEA_DATA:
 296         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
 297         case                                           NEW_ACE_EXECUTE:
 298         case NEW_ACE_READ_DATA |                       NEW_ACE_EXECUTE:
 299         case                     NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 300         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 301           break;
 302         default:
 303           return 1;
 304         }
 305       switch ((access_masks[4] | access_masks[5])
 306               & ~(NEW_ACE_WRITE_NAMED_ATTRS
 307                   | NEW_ACE_WRITE_ATTRIBUTES
 308                   | NEW_ACE_WRITE_ACL
 309                   | NEW_ACE_WRITE_OWNER))
 310         {
 311         case 0:
 312         case NEW_ACE_READ_DATA:
 313         case                     NEW_ACE_WRITEA_DATA:
 314         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
 315         case                                           NEW_ACE_EXECUTE:
 316         case NEW_ACE_READ_DATA |                       NEW_ACE_EXECUTE:
 317         case                     NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 318         case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
 319           break;
 320         default:
 321           return 1;
 322         }
 323
 324       /* Check that the NEW_ACE_WRITE_DATA and NEW_ACE_APPEND_DATA bits are
 325          either both allowed or both denied.  */
 326       if (((access_masks[0] & NEW_ACE_WRITE_DATA) != 0)
 327           != ((access_masks[0] & NEW_ACE_APPEND_DATA) != 0))
 328         return 1;
 329       if (((access_masks[2] & NEW_ACE_WRITE_DATA) != 0)
 330           != ((access_masks[2] & NEW_ACE_APPEND_DATA) != 0))
 331         return 1;
 332       if (((access_masks[4] & NEW_ACE_WRITE_DATA) != 0)
 333           != ((access_masks[4] & NEW_ACE_APPEND_DATA) != 0))
 334         return 1;
 335     }
 336
 337   return 0;
 338 }
 339
 340 # endif
 341
 342 #elif USE_ACL && HAVE_GETACL /* HP-UX */
 343
 344 /* Return 1 if the given ACL is non-trivial.
 345    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 346 int
 347 acl_nontrivial (int count, struct acl_entry *entries, struct stat *sb)
 348 {
 349   int i;
 350
 351   for (i = 0; i < count; i++)
 352     {
 353       struct acl_entry *ace = &entries[i];
 354
 355       if (!((ace->uid == sb->st_uid && ace->gid == ACL_NSGROUP)
 356             || (ace->uid == ACL_NSUSER && ace->gid == sb->st_gid)
 357             || (ace->uid == ACL_NSUSER && ace->gid == ACL_NSGROUP)))
 358         return 1;
 359     }
 360   return 0;
 361 }
 362
 363 # if HAVE_ACLV_H /* HP-UX >= 11.11 */
 364
 365 /* Return 1 if the given ACL is non-trivial.
 366    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 367 int
 368 aclv_nontrivial (int count, struct acl *entries)
 369 {
 370   int i;
 371
 372   for (i = 0; i < count; i++)
 373     {
 374       struct acl *ace = &entries[i];
 375
 376       /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
 377          If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
 378          We don't need to check ace->a_id in these cases.  */
 379       if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
 380             || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
 381             || ace->a_type == CLASS_OBJ
 382             || ace->a_type == OTHER_OBJ))
 383         return 1;
 384     }
 385   return 0;
 386 }
 387
 388 # endif
 389
 390 #elif USE_ACL && (HAVE_ACLX_GET || HAVE_STATACL) /* AIX */
 391
 392 /* Return 1 if the given ACL is non-trivial.
 393    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 394 int
 395 acl_nontrivial (struct acl *a)
 396 {
 397   /* The normal way to iterate through an ACL is like this:
 398        struct acl_entry *ace;
 399        for (ace = a->acl_ext; ace != acl_last (a); ace = acl_nxt (ace))
 400          {
 401            struct ace_id *aei;
 402            switch (ace->ace_type)
 403              {
 404              case ACC_PERMIT:
 405              case ACC_DENY:
 406              case ACC_SPECIFY:
 407                ...;
 408              }
 409            for (aei = ace->ace_id; aei != id_last (ace); aei = id_nxt (aei))
 410              ...
 411          }
 412    */
 413   return (acl_last (a) != a->acl_ext ? 1 : 0);
 414 }
 415
 416 # if HAVE_ACLX_GET && defined ACL_AIX_WIP /* newer AIX */
 417
 418 /* Return 1 if the given ACL is non-trivial.
 419    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 420 int
 421 acl_nfs4_nontrivial (nfs4_acl_int_t *a)
 422 {
 423 #  if 1 /* let's try this first */
 424   return (a->aclEntryN > 0 ? 1 : 0);
 425 #  else
 426   int count = a->aclEntryN;
 427   int i;
 428
 429   for (i = 0; i < count; i++)
 430     {
 431       nfs4_ace_int_t *ace = &a->aclEntry[i];
 432
 433       if (!((ace->flags & ACE4_ID_SPECIAL) != 0
 434             && (ace->aceWho.special_whoid == ACE4_WHO_OWNER
 435                 || ace->aceWho.special_whoid == ACE4_WHO_GROUP
 436                 || ace->aceWho.special_whoid == ACE4_WHO_EVERYONE)
 437             && ace->aceType == ACE4_ACCESS_ALLOWED_ACE_TYPE
 438             && ace->aceFlags == 0
 439             && (ace->aceMask & ~(ACE4_READ_DATA | ACE4_LIST_DIRECTORY
 440                                  | ACE4_WRITE_DATA | ACE4_ADD_FILE
 441                                  | ACE4_EXECUTE)) == 0))
 442         return 1;
 443     }
 444   return 0;
 445 #  endif
 446 }
 447
 448 # endif
 449
 450 #elif USE_ACL && HAVE_ACLSORT /* NonStop Kernel */
 451
 452 /* Test an ACL retrieved with ACL_GET.
 453    Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
 454    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 455 int
 456 acl_nontrivial (int count, struct acl *entries)
 457 {
 458   int i;
 459
 460   for (i = 0; i < count; i++)
 461     {
 462       struct acl *ace = &entries[i];
 463
 464       /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
 465          If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
 466          We don't need to check ace->a_id in these cases.  */
 467       if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
 468             || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
 469             || ace->a_type == CLASS_OBJ
 470             || ace->a_type == OTHER_OBJ))
 471         return 1;
 472     }
 473   return 0;
 474 }
 475
 476 #endif
 477
 478
 479 /* Return 1 if NAME has a nontrivial access control list, 0 if NAME
 480    only has no or a base access control list, and -1 (setting errno)
 481    on error.  SB must be set to the stat buffer of NAME, obtained
 482    through stat() or lstat().  */
 483
 484 int
 485 file_has_acl (char const *name, struct stat const *sb)
 486 {
 487 #if USE_ACL
 488   if (! S_ISLNK (sb->st_mode))
 489     {
 490 # if HAVE_ACL_GET_FILE
 491
 492       /* POSIX 1003.1e (draft 17 -- abandoned) specific version.  */
 493       /* Linux, FreeBSD, Mac OS X, IRIX, Tru64 */
 494       int ret;
 495
 496       if (HAVE_ACL_EXTENDED_FILE) /* Linux */
 497         {
 498           /* On Linux, acl_extended_file is an optimized function: It only
 499              makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
 500              ACL_TYPE_DEFAULT.  */
 501           ret = acl_extended_file (name);
 502         }
 503       else /* FreeBSD, Mac OS X, IRIX, Tru64 */
 504         {
 505 #  if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
 506           /* On Mac OS X, acl_get_file (name, ACL_TYPE_ACCESS)
 507              and acl_get_file (name, ACL_TYPE_DEFAULT)
 508              always return NULL / EINVAL.  There is no point in making
 509              these two useless calls.  The real ACL is retrieved through
 510              acl_get_file (name, ACL_TYPE_EXTENDED).  */
 511           acl_t acl = acl_get_file (name, ACL_TYPE_EXTENDED);
 512           if (acl)
 513             {
 514               ret = acl_extended_nontrivial (acl);
 515               acl_free (acl);
 516             }
 517           else
 518             ret = -1;
 519 #  else /* FreeBSD, IRIX, Tru64 */
 520           acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS);
 521           if (acl)
 522             {
 523               int saved_errno;
 524
 525               ret = acl_access_nontrivial (acl);
 526               saved_errno = errno;
 527               acl_free (acl);
 528               errno = saved_errno;
 529 #   if HAVE_ACL_FREE_TEXT /* Tru64 */
 530               /* On OSF/1, acl_get_file (name, ACL_TYPE_DEFAULT) always
 531                  returns NULL with errno not set.  There is no point in
 532                  making this call.  */
 533 #   else /* FreeBSD, IRIX */
 534               /* On Linux, FreeBSD, IRIX, acl_get_file (name, ACL_TYPE_ACCESS)
 535                  and acl_get_file (name, ACL_TYPE_DEFAULT) on a directory
 536                  either both succeed or both fail; it depends on the
 537                  file system.  Therefore there is no point in making the second
 538                  call if the first one already failed.  */
 539               if (ret == 0 && S_ISDIR (sb->st_mode))
 540                 {
 541                   acl = acl_get_file (name, ACL_TYPE_DEFAULT);
 542                   if (acl)
 543                     {
 544                       ret = (0 < acl_entries (acl));
 545                       acl_free (acl);
 546                     }
 547                   else
 548                     ret = -1;
 549                 }
 550 #   endif
 551             }
 552           else
 553             ret = -1;
 554 #  endif
 555         }
 556       if (ret < 0)
 557         return - acl_errno_valid (errno);
 558       return ret;
 559
 560 # elif HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
 561
 562 #  if defined ACL_NO_TRIVIAL
 563
 564       /* Solaris 10 (newer version), which has additional API declared in
 565          <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial,
 566          acl_fromtext, ...).  */
 567       return acl_trivial (name);
 568
 569 #  else /* Solaris, Cygwin, general case */
 570
 571       /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions
 572          of Unixware.  The acl() call returns the access and default ACL both
 573          at once.  */
 574       {
 575         /* Initially, try to read the entries into a stack-allocated buffer.
 576            Use malloc if it does not fit.  */
 577         enum
 578           {
 579             alloc_init = 4000 / sizeof (aclent_t), /* >= 3 */
 580             alloc_max = MIN (INT_MAX, SIZE_MAX / sizeof (aclent_t))
 581           };
 582         aclent_t buf[alloc_init];
 583         size_t alloc = alloc_init;
 584         aclent_t *entries = buf;
 585         aclent_t *malloced = NULL;
 586         int count;
 587
 588         for (;;)
 589           {
 590             count = acl (name, GETACL, alloc, entries);
 591             if (count < 0 && errno == ENOSPC)
 592               {
 593                 /* Increase the size of the buffer.  */
 594                 free (malloced);
 595                 if (alloc > alloc_max / 2)
 596                   {
 597                     errno = ENOMEM;
 598                     return -1;
 599                   }
 600                 alloc = 2 * alloc; /* <= alloc_max */
 601                 entries = malloced =
 602                   (aclent_t *) malloc (alloc * sizeof (aclent_t));
 603                 if (entries == NULL)
 604                   {
 605                     errno = ENOMEM;
 606                     return -1;
 607                   }
 608                 continue;
 609               }
 610             break;
 611           }
 612         if (count < 0)
 613           {
 614             if (errno == ENOSYS || errno == ENOTSUP)
 615               ;
 616             else
 617               {
 618                 int saved_errno = errno;
 619                 free (malloced);
 620                 errno = saved_errno;
 621                 return -1;
 622               }
 623           }
 624         else if (count == 0)
 625           ;
 626         else
 627           {
 628             /* Don't use MIN_ACL_ENTRIES:  It's set to 4 on Cygwin, but Cygwin
 629                returns only 3 entries for files with no ACL.  But this is safe:
 630                If there are more than 4 entries, there cannot be only the
 631                "user::", "group::", "other:", and "mask:" entries.  */
 632             if (count > 4)
 633               {
 634                 free (malloced);
 635                 return 1;
 636               }
 637
 638             if (acl_nontrivial (count, entries))
 639               {
 640                 free (malloced);
 641                 return 1;
 642               }
 643           }
 644         free (malloced);
 645       }
 646
 647 #   ifdef ACE_GETACL
 648       /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4
 649          file systems (whereas the other ones are used in UFS file systems).  */
 650       {
 651         /* Initially, try to read the entries into a stack-allocated buffer.
 652            Use malloc if it does not fit.  */
 653         enum
 654           {
 655             alloc_init = 4000 / sizeof (ace_t), /* >= 3 */
 656             alloc_max = MIN (INT_MAX, SIZE_MAX / sizeof (ace_t))
 657           };
 658         ace_t buf[alloc_init];
 659         size_t alloc = alloc_init;
 660         ace_t *entries = buf;
 661         ace_t *malloced = NULL;
 662         int count;
 663
 664         for (;;)
 665           {
 666             count = acl (name, ACE_GETACL, alloc, entries);
 667             if (count < 0 && errno == ENOSPC)
 668               {
 669                 /* Increase the size of the buffer.  */
 670                 free (malloced);
 671                 if (alloc > alloc_max / 2)
 672                   {
 673                     errno = ENOMEM;
 674                     return -1;
 675                   }
 676                 alloc = 2 * alloc; /* <= alloc_max */
 677                 entries = malloced = (ace_t *) malloc (alloc * sizeof (ace_t));
 678                 if (entries == NULL)
 679                   {
 680                     errno = ENOMEM;
 681                     return -1;
 682                   }
 683                 continue;
 684               }
 685             break;
 686           }
 687         if (count < 0)
 688           {
 689             if (errno == ENOSYS || errno == EINVAL)
 690               ;
 691             else
 692               {
 693                 int saved_errno = errno;
 694                 free (malloced);
 695                 errno = saved_errno;
 696                 return -1;
 697               }
 698           }
 699         else if (count == 0)
 700           ;
 701         else
 702           {
 703             /* In the old (original Solaris 10) convention:
 704                If there are more than 3 entries, there cannot be only the
 705                ACE_OWNER, ACE_GROUP, ACE_OTHER entries.
 706                In the newer Solaris 10 and Solaris 11 convention:
 707                If there are more than 6 entries, there cannot be only the
 708                ACE_OWNER, ACE_GROUP, ACE_EVERYONE entries, each once with
 709                NEW_ACE_ACCESS_ALLOWED_ACE_TYPE and once with
 710                NEW_ACE_ACCESS_DENIED_ACE_TYPE.  */
 711             if (count > 6)
 712               {
 713                 free (malloced);
 714                 return 1;
 715               }
 716
 717             if (acl_ace_nontrivial (count, entries))
 718               {
 719                 free (malloced);
 720                 return 1;
 721               }
 722           }
 723         free (malloced);
 724       }
 725 #   endif
 726
 727       return 0;
 728 #  endif
 729
 730 # elif HAVE_GETACL /* HP-UX */
 731
 732       {
 733         struct acl_entry entries[NACLENTRIES];
 734         int count;
 735
 736         count = getacl (name, NACLENTRIES, entries);
 737
 738         if (count < 0)
 739           {
 740             /* ENOSYS is seen on newer HP-UX versions.
 741                EOPNOTSUPP is typically seen on NFS mounts.
 742                ENOTSUP was seen on Quantum StorNext file systems (cvfs).  */
 743             if (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTSUP)
 744               ;
 745             else
 746               return -1;
 747           }
 748         else if (count == 0)
 749           return 0;
 750         else /* count > 0 */
 751           {
 752             if (count > NACLENTRIES)
 753               /* If NACLENTRIES cannot be trusted, use dynamic memory
 754                  allocation.  */
 755               abort ();
 756
 757             /* If there are more than 3 entries, there cannot be only the
 758                (uid,%), (%,gid), (%,%) entries.  */
 759             if (count > 3)
 760               return 1;
 761
 762             {
 763               struct stat statbuf;
 764
 765               if (stat (name, &statbuf) < 0)
 766                 return -1;
 767
 768               return acl_nontrivial (count, entries, &statbuf);
 769             }
 770           }
 771       }
 772
 773 #  if HAVE_ACLV_H /* HP-UX >= 11.11 */
 774
 775       {
 776         struct acl entries[NACLVENTRIES];
 777         int count;
 778
 779         count = acl ((char *) name, ACL_GET, NACLVENTRIES, entries);
 780
 781         if (count < 0)
 782           {
 783             /* EOPNOTSUPP is seen on NFS in HP-UX 11.11, 11.23.
 784                EINVAL is seen on NFS in HP-UX 11.31.  */
 785             if (errno == ENOSYS || errno == EOPNOTSUPP || errno == EINVAL)
 786               ;
 787             else
 788               return -1;
 789           }
 790         else if (count == 0)
 791           return 0;
 792         else /* count > 0 */
 793           {
 794             if (count > NACLVENTRIES)
 795               /* If NACLVENTRIES cannot be trusted, use dynamic memory
 796                  allocation.  */
 797               abort ();
 798
 799             /* If there are more than 4 entries, there cannot be only the
 800                four base ACL entries.  */
 801             if (count > 4)
 802               return 1;
 803
 804             return aclv_nontrivial (count, entries);
 805           }
 806       }
 807
 808 #  endif
 809
 810 # elif HAVE_ACLX_GET && defined ACL_AIX_WIP /* AIX */
 811
 812       acl_type_t type;
 813       char aclbuf[1024];
 814       void *acl = aclbuf;
 815       size_t aclsize = sizeof (aclbuf);
 816       mode_t mode;
 817
 818       for (;;)
 819         {
 820           /* The docs say that type being 0 is equivalent to ACL_ANY, but it
 821              is not true, in AIX 5.3.  */
 822           type.u64 = ACL_ANY;
 823           if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0)
 824             break;
 825           if (errno == ENOSYS)
 826             return 0;
 827           if (errno != ENOSPC)
 828             {
 829               if (acl != aclbuf)
 830                 {
 831                   int saved_errno = errno;
 832                   free (acl);
 833                   errno = saved_errno;
 834                 }
 835               return -1;
 836             }
 837           aclsize = 2 * aclsize;
 838           if (acl != aclbuf)
 839             free (acl);
 840           acl = malloc (aclsize);
 841           if (acl == NULL)
 842             {
 843               errno = ENOMEM;
 844               return -1;
 845             }
 846         }
 847
 848       if (type.u64 == ACL_AIXC)
 849         {
 850           int result = acl_nontrivial ((struct acl *) acl);
 851           if (acl != aclbuf)
 852             free (acl);
 853           return result;
 854         }
 855       else if (type.u64 == ACL_NFS4)
 856         {
 857           int result = acl_nfs4_nontrivial ((nfs4_acl_int_t *) acl);
 858           if (acl != aclbuf)
 859             free (acl);
 860           return result;
 861         }
 862       else
 863         {
 864           /* A newer type of ACL has been introduced in the system.
 865              We should better support it.  */
 866           if (acl != aclbuf)
 867             free (acl);
 868           errno = EINVAL;
 869           return -1;
 870         }
 871
 872 # elif HAVE_STATACL /* older AIX */
 873
 874       union { struct acl a; char room[4096]; } u;
 875
 876       if (statacl (name, STX_NORMAL, &u.a, sizeof (u)) < 0)
 877         return -1;
 878
 879       return acl_nontrivial (&u.a);
 880
 881 # elif HAVE_ACLSORT /* NonStop Kernel */
 882
 883       {
 884         struct acl entries[NACLENTRIES];
 885         int count;
 886
 887         count = acl ((char *) name, ACL_GET, NACLENTRIES, entries);
 888
 889         if (count < 0)
 890           {
 891             if (errno == ENOSYS || errno == ENOTSUP)
 892               ;
 893             else
 894               return -1;
 895           }
 896         else if (count == 0)
 897           return 0;
 898         else /* count > 0 */
 899           {
 900             if (count > NACLENTRIES)
 901               /* If NACLENTRIES cannot be trusted, use dynamic memory
 902                  allocation.  */
 903               abort ();
 904
 905             /* If there are more than 4 entries, there cannot be only the
 906                four base ACL entries.  */
 907             if (count > 4)
 908               return 1;
 909
 910             return acl_nontrivial (count, entries);
 911           }
 912       }
 913
 914 # endif
 915     }
 916 #endif
 917
 918   return 0;
 919 }