lib/acl-internal.h

   1 /* Internal implementation of access control lists.  -*- coding: utf-8 -*-
   2
   3    Copyright (C) 2002-2003, 2005-2018 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 <https://www.gnu.org/licenses/>.
  17
  18    Written by Paul Eggert, Andreas Grünbacher, and Bruno Haible.  */
  19
  20 #include "acl.h"
  21
  22 #include <stdbool.h>
  23 #include <stdlib.h>
  24
  25 /* All systems define the ACL related API in <sys/acl.h>.  */
  26 #if HAVE_SYS_ACL_H
  27 # include <sys/acl.h>
  28 #endif
  29 #if defined HAVE_FACL && ! defined GETACLCNT && defined ACL_CNT
  30 # define GETACLCNT ACL_CNT
  31 #endif
  32
  33 /* On Linux, additional ACL related API is available in <acl/libacl.h>.  */
  34 #ifdef HAVE_ACL_LIBACL_H
  35 # include <acl/libacl.h>
  36 #endif
  37
  38 /* On HP-UX >= 11.11, additional ACL API is available in <aclv.h>.  */
  39 #if HAVE_ACLV_H
  40 # include <sys/types.h>
  41 # include <aclv.h>
  42 /* HP-UX 11.11 lacks these declarations.  */
  43 extern int acl (char *, int, int, struct acl *);
  44 extern int aclsort (int, int, struct acl *);
  45 #endif
  46
  47 #include <errno.h>
  48
  49 #include <limits.h>
  50 #ifndef MIN
  51 # define MIN(a,b) ((a) < (b) ? (a) : (b))
  52 #endif
  53
  54 #ifndef SIZE_MAX
  55 # define SIZE_MAX ((size_t) -1)
  56 #endif
  57
  58 #ifndef HAVE_FCHMOD
  59 # define HAVE_FCHMOD false
  60 # define fchmod(fd, mode) (-1)
  61 #endif
  62
  63 #ifndef _GL_INLINE_HEADER_BEGIN
  64  #error "Please include config.h first."
  65 #endif
  66 _GL_INLINE_HEADER_BEGIN
  67 #ifndef ACL_INTERNAL_INLINE
  68 # define ACL_INTERNAL_INLINE _GL_INLINE
  69 #endif
  70
  71 #if USE_ACL
  72
  73 # if HAVE_ACL_GET_FILE
  74 /* POSIX 1003.1e (draft 17 -- abandoned) specific version.  */
  75 /* Linux, FreeBSD, Mac OS X, IRIX, Tru64 */
  76
  77 #  ifndef MIN_ACL_ENTRIES
  78 #   define MIN_ACL_ENTRIES 4
  79 #  endif
  80
  81 /* POSIX 1003.1e (draft 17) */
  82 #  ifdef HAVE_ACL_GET_FD
  83 /* Most platforms have a 1-argument acl_get_fd, only OSF/1 has a 2-argument
  84    macro(!).  */
  85 #   if HAVE_ACL_FREE_TEXT /* OSF/1 */
  86 ACL_INTERNAL_INLINE acl_t
  87 rpl_acl_get_fd (int fd)
  88 {
  89   return acl_get_fd (fd, ACL_TYPE_ACCESS);
  90 }
  91 #    undef acl_get_fd
  92 #    define acl_get_fd rpl_acl_get_fd
  93 #   endif
  94 #  else
  95 #   define HAVE_ACL_GET_FD false
  96 #   undef acl_get_fd
  97 #   define acl_get_fd(fd) (NULL)
  98 #  endif
  99
 100 /* POSIX 1003.1e (draft 17) */
 101 #  ifdef HAVE_ACL_SET_FD
 102 /* Most platforms have a 2-argument acl_set_fd, only OSF/1 has a 3-argument
 103    macro(!).  */
 104 #   if HAVE_ACL_FREE_TEXT /* OSF/1 */
 105 ACL_INTERNAL_INLINE int
 106 rpl_acl_set_fd (int fd, acl_t acl)
 107 {
 108   return acl_set_fd (fd, ACL_TYPE_ACCESS, acl);
 109 }
 110 #    undef acl_set_fd
 111 #    define acl_set_fd rpl_acl_set_fd
 112 #   endif
 113 #  else
 114 #   define HAVE_ACL_SET_FD false
 115 #   undef acl_set_fd
 116 #   define acl_set_fd(fd, acl) (-1)
 117 #  endif
 118
 119 /* POSIX 1003.1e (draft 13) */
 120 #  if ! HAVE_ACL_FREE_TEXT
 121 #   define acl_free_text(buf) acl_free (buf)
 122 #  endif
 123
 124 /* Linux-specific */
 125 #  ifndef HAVE_ACL_EXTENDED_FILE
 126 #   define HAVE_ACL_EXTENDED_FILE false
 127 #   define acl_extended_file(name) (-1)
 128 #  endif
 129
 130 #  if ! defined HAVE_ACL_FROM_MODE && ! defined HAVE_ACL_FROM_TEXT
 131 #   define acl_from_mode (NULL)
 132 #  endif
 133
 134 /* Set to 0 if a file's mode is stored independently from the ACL.  */
 135 #  if (HAVE_ACL_COPY_EXT_NATIVE && HAVE_ACL_CREATE_ENTRY_NP) || defined __sgi /* Mac OS X, IRIX */
 136 #   define MODE_INSIDE_ACL 0
 137 #  endif
 138
 139 /* Return the number of entries in ACL.
 140    Return -1 and set errno upon failure to determine it.  */
 141 /* Define a replacement for acl_entries if needed. (Only Linux has it.)  */
 142 #  if !HAVE_ACL_ENTRIES
 143 #   define acl_entries rpl_acl_entries
 144 extern int acl_entries (acl_t);
 145 #  endif
 146
 147 #  if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
 148 /* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED.
 149    Return 1 if the given ACL is non-trivial.
 150    Return 0 if it is trivial.  */
 151 extern int acl_extended_nontrivial (acl_t);
 152 #  else
 153 /* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS.
 154    Return 1 if the given ACL is non-trivial.
 155    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
 156    Return -1 and set errno upon failure to determine it.  */
 157 extern int acl_access_nontrivial (acl_t);
 158
 159 /* ACL is an ACL, from a file, stored as type ACL_TYPE_DEFAULT.
 160    Return 1 if the given ACL is non-trivial.
 161    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
 162    Return -1 and set errno upon failure to determine it.  */
 163 extern int acl_default_nontrivial (acl_t);
 164 #  endif
 165
 166 # elif HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
 167
 168 /* Set to 0 if a file's mode is stored independently from the ACL.  */
 169 #  if defined __CYGWIN__ /* Cygwin */
 170 #   define MODE_INSIDE_ACL 0
 171 #  endif
 172
 173 /* Return 1 if the given ACL is non-trivial.
 174    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 175 extern int acl_nontrivial (int count, aclent_t *entries) _GL_ATTRIBUTE_PURE;
 176
 177 #  ifdef ACE_GETACL /* Solaris 10 */
 178
 179 /* Test an ACL retrieved with ACE_GETACL.
 180    Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
 181    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 182 extern int acl_ace_nontrivial (int count, ace_t *entries) _GL_ATTRIBUTE_PURE;
 183
 184 /* Definitions for when the built executable is executed on Solaris 10
 185    (newer version) or Solaris 11.  */
 186 /* For a_type.  */
 187 #   define OLD_ALLOW 0
 188 #   define OLD_DENY  1
 189 #   define NEW_ACE_ACCESS_ALLOWED_ACE_TYPE 0 /* replaces ALLOW */
 190 #   define NEW_ACE_ACCESS_DENIED_ACE_TYPE  1 /* replaces DENY */
 191 /* For a_flags.  */
 192 #   define OLD_ACE_OWNER            0x0100
 193 #   define OLD_ACE_GROUP            0x0200
 194 #   define OLD_ACE_OTHER            0x0400
 195 #   define NEW_ACE_OWNER            0x1000
 196 #   define NEW_ACE_GROUP            0x2000
 197 #   define NEW_ACE_IDENTIFIER_GROUP 0x0040
 198 #   define NEW_ACE_EVERYONE         0x4000
 199 /* For a_access_mask.  */
 200 #   define NEW_ACE_READ_DATA         0x001 /* corresponds to 'r' */
 201 #   define NEW_ACE_WRITE_DATA        0x002 /* corresponds to 'w' */
 202 #   define NEW_ACE_APPEND_DATA       0x004
 203 #   define NEW_ACE_READ_NAMED_ATTRS  0x008
 204 #   define NEW_ACE_WRITE_NAMED_ATTRS 0x010
 205 #   define NEW_ACE_EXECUTE           0x020
 206 #   define NEW_ACE_DELETE_CHILD      0x040
 207 #   define NEW_ACE_READ_ATTRIBUTES   0x080
 208 #   define NEW_ACE_WRITE_ATTRIBUTES  0x100
 209 #   define NEW_ACE_DELETE          0x10000
 210 #   define NEW_ACE_READ_ACL        0x20000
 211 #   define NEW_ACE_WRITE_ACL       0x40000
 212 #   define NEW_ACE_WRITE_OWNER     0x80000
 213 #   define NEW_ACE_SYNCHRONIZE    0x100000
 214
 215 #  endif
 216
 217 # elif HAVE_GETACL /* HP-UX */
 218
 219 /* Return 1 if the given ACL is non-trivial.
 220    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 221 extern int acl_nontrivial (int count, struct acl_entry *entries);
 222
 223 #  if HAVE_ACLV_H /* HP-UX >= 11.11 */
 224
 225 /* Return 1 if the given ACL is non-trivial.
 226    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 227 extern int aclv_nontrivial (int count, struct acl *entries);
 228
 229 #  endif
 230
 231 # elif HAVE_ACLX_GET && 0 /* AIX */
 232
 233 /* TODO */
 234
 235 # elif HAVE_STATACL /* older AIX */
 236
 237 /* Return 1 if the given ACL is non-trivial.
 238    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 239 extern int acl_nontrivial (struct acl *a);
 240
 241 # elif HAVE_ACLSORT /* NonStop Kernel */
 242
 243 /* Return 1 if the given ACL is non-trivial.
 244    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 245 extern int acl_nontrivial (int count, struct acl *entries);
 246
 247 # endif
 248
 249 /* Set to 1 if a file's mode is implicit by the ACL.  */
 250 # ifndef MODE_INSIDE_ACL
 251 #  define MODE_INSIDE_ACL 1
 252 # endif
 253
 254 #endif
 255
 256 struct permission_context {
 257   mode_t mode;
 258 #if USE_ACL
 259 # if HAVE_ACL_GET_FILE /* Linux, FreeBSD, Mac OS X, IRIX, Tru64 */
 260   acl_t acl;
 261 #  if !HAVE_ACL_TYPE_EXTENDED
 262   acl_t default_acl;
 263 #  endif
 264   bool acls_not_supported;
 265
 266 # elif defined GETACL /* Solaris, Cygwin */
 267   int count;
 268   aclent_t *entries;
 269 #  ifdef ACE_GETACL
 270   int ace_count;
 271   ace_t *ace_entries;
 272 #  endif
 273
 274 # elif HAVE_GETACL /* HP-UX */
 275   struct acl_entry entries[NACLENTRIES];
 276   int count;
 277 #  if HAVE_ACLV_H
 278   struct acl aclv_entries[NACLVENTRIES];
 279   int aclv_count;
 280 #  endif
 281
 282 # elif HAVE_STATACL /* older AIX */
 283   union { struct acl a; char room[4096]; } u;
 284   bool have_u;
 285
 286 # elif HAVE_ACLSORT /* NonStop Kernel */
 287   struct acl entries[NACLENTRIES];
 288   int count;
 289
 290 # endif
 291 #endif
 292 };
 293
 294 int get_permissions (const char *, int, mode_t, struct permission_context *);
 295 int set_permissions (struct permission_context *, const char *, int);
 296 void free_permission_context (struct permission_context *)
 297 #if ! (defined USE_ACL && (HAVE_ACL_GET_FILE || defined GETACL))
 298     _GL_ATTRIBUTE_CONST
 299 #endif
 300   ;
 301
 302 _GL_INLINE_HEADER_END