lib/acl-internal.h

   1 /* Internal implementation of access control lists.  -*- coding: utf-8 -*-
   2
   3    Copyright (C) 2002-2003, 2005-2020 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 and Cygwin >= 2.5, additional ACL related API is available in
  34    <acl/libacl.h>.  */
  35 #ifdef HAVE_ACL_LIBACL_H
  36 # include <acl/libacl.h>
  37 #endif
  38
  39 /* On HP-UX >= 11.11, additional ACL API is available in <aclv.h>.  */
  40 #if HAVE_ACLV_H
  41 # include <sys/types.h>
  42 # include <aclv.h>
  43 /* HP-UX 11.11 lacks these declarations.  */
  44 extern int acl (char *, int, int, struct acl *);
  45 extern int aclsort (int, int, struct acl *);
  46 #endif
  47
  48 #include <errno.h>
  49
  50 #include <limits.h>
  51 #ifndef MIN
  52 # define MIN(a,b) ((a) < (b) ? (a) : (b))
  53 #endif
  54
  55 #ifndef SIZE_MAX
  56 # define SIZE_MAX ((size_t) -1)
  57 #endif
  58
  59 #ifndef HAVE_FCHMOD
  60 # define HAVE_FCHMOD false
  61 # define fchmod(fd, mode) (-1)
  62 #endif
  63
  64 #ifndef _GL_INLINE_HEADER_BEGIN
  65  #error "Please include config.h first."
  66 #endif
  67 _GL_INLINE_HEADER_BEGIN
  68 #ifndef ACL_INTERNAL_INLINE
  69 # define ACL_INTERNAL_INLINE _GL_INLINE
  70 #endif
  71
  72 #if USE_ACL
  73
  74 # if HAVE_ACL_GET_FILE
  75 /* POSIX 1003.1e (draft 17 -- abandoned) specific version.  */
  76 /* Linux, FreeBSD, Mac OS X, IRIX, Tru64, Cygwin >= 2.5 */
  77
  78 #  ifndef MIN_ACL_ENTRIES
  79 #   define MIN_ACL_ENTRIES 4
  80 #  endif
  81
  82 /* POSIX 1003.1e (draft 17) */
  83 #  ifdef HAVE_ACL_GET_FD
  84 /* Most platforms have a 1-argument acl_get_fd, only OSF/1 has a 2-argument
  85    macro(!).  */
  86 #   if HAVE_ACL_FREE_TEXT /* OSF/1 */
  87 ACL_INTERNAL_INLINE acl_t
  88 rpl_acl_get_fd (int fd)
  89 {
  90   return acl_get_fd (fd, ACL_TYPE_ACCESS);
  91 }
  92 #    undef acl_get_fd
  93 #    define acl_get_fd rpl_acl_get_fd
  94 #   endif
  95 #  else
  96 #   define HAVE_ACL_GET_FD false
  97 #   undef acl_get_fd
  98 #   define acl_get_fd(fd) (NULL)
  99 #  endif
 100
 101 /* POSIX 1003.1e (draft 17) */
 102 #  ifdef HAVE_ACL_SET_FD
 103 /* Most platforms have a 2-argument acl_set_fd, only OSF/1 has a 3-argument
 104    macro(!).  */
 105 #   if HAVE_ACL_FREE_TEXT /* OSF/1 */
 106 ACL_INTERNAL_INLINE int
 107 rpl_acl_set_fd (int fd, acl_t acl)
 108 {
 109   return acl_set_fd (fd, ACL_TYPE_ACCESS, acl);
 110 }
 111 #    undef acl_set_fd
 112 #    define acl_set_fd rpl_acl_set_fd
 113 #   endif
 114 #  else
 115 #   define HAVE_ACL_SET_FD false
 116 #   undef acl_set_fd
 117 #   define acl_set_fd(fd, acl) (-1)
 118 #  endif
 119
 120 /* POSIX 1003.1e (draft 13) */
 121 #  if ! HAVE_ACL_FREE_TEXT
 122 #   define acl_free_text(buf) acl_free (buf)
 123 #  endif
 124
 125 /* Linux-specific */
 126 /* Cygwin >= 2.5 implements this function, but it returns 1 for all
 127    directories, thus is unusable.  */
 128 #  if !defined HAVE_ACL_EXTENDED_FILE || defined __CYGWIN__
 129 #   undef HAVE_ACL_EXTENDED_FILE
 130 #   define HAVE_ACL_EXTENDED_FILE false
 131 #   define acl_extended_file(name) (-1)
 132 #  endif
 133
 134 #  if ! defined HAVE_ACL_FROM_MODE && ! defined HAVE_ACL_FROM_TEXT
 135 #   define acl_from_mode (NULL)
 136 #  endif
 137
 138 /* Set to 0 if a file's mode is stored independently from the ACL.  */
 139 #  if (HAVE_ACL_COPY_EXT_NATIVE && HAVE_ACL_CREATE_ENTRY_NP) || defined __sgi /* Mac OS X, IRIX */
 140 #   define MODE_INSIDE_ACL 0
 141 #  endif
 142
 143 /* Return the number of entries in ACL.
 144    Return -1 and set errno upon failure to determine it.  */
 145 /* Define a replacement for acl_entries if needed. (Only Linux has it.)  */
 146 #  if !HAVE_ACL_ENTRIES
 147 #   define acl_entries rpl_acl_entries
 148 extern int acl_entries (acl_t);
 149 #  endif
 150
 151 #  if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
 152 /* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED.
 153    Return 1 if the given ACL is non-trivial.
 154    Return 0 if it is trivial.  */
 155 extern int acl_extended_nontrivial (acl_t);
 156 #  else
 157 /* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS.
 158    Return 1 if the given ACL is non-trivial.
 159    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
 160    Return -1 and set errno upon failure to determine it.  */
 161 extern int acl_access_nontrivial (acl_t);
 162
 163 /* ACL is an ACL, from a file, stored as type ACL_TYPE_DEFAULT.
 164    Return 1 if the given ACL is non-trivial.
 165    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
 166    Return -1 and set errno upon failure to determine it.  */
 167 extern int acl_default_nontrivial (acl_t);
 168 #  endif
 169
 170 # elif HAVE_FACL && defined GETACL /* Solaris, Cygwin < 2.5, not HP-UX */
 171
 172 /* Set to 0 if a file's mode is stored independently from the ACL.  */
 173 #  if defined __CYGWIN__ /* Cygwin */
 174 #   define MODE_INSIDE_ACL 0
 175 #  endif
 176
 177 /* Return 1 if the given ACL is non-trivial.
 178    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 179 extern int acl_nontrivial (int count, aclent_t *entries) _GL_ATTRIBUTE_PURE;
 180
 181 #  ifdef ACE_GETACL /* Solaris 10 */
 182
 183 /* Test an ACL retrieved with ACE_GETACL.
 184    Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
 185    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 186 extern int acl_ace_nontrivial (int count, ace_t *entries) _GL_ATTRIBUTE_PURE;
 187
 188 /* Definitions for when the built executable is executed on Solaris 10
 189    (newer version) or Solaris 11.  */
 190 /* For a_type.  */
 191 #   define OLD_ALLOW 0
 192 #   define OLD_DENY  1
 193 #   define NEW_ACE_ACCESS_ALLOWED_ACE_TYPE 0 /* replaces ALLOW */
 194 #   define NEW_ACE_ACCESS_DENIED_ACE_TYPE  1 /* replaces DENY */
 195 /* For a_flags.  */
 196 #   define OLD_ACE_OWNER            0x0100
 197 #   define OLD_ACE_GROUP            0x0200
 198 #   define OLD_ACE_OTHER            0x0400
 199 #   define NEW_ACE_OWNER            0x1000
 200 #   define NEW_ACE_GROUP            0x2000
 201 #   define NEW_ACE_IDENTIFIER_GROUP 0x0040
 202 #   define NEW_ACE_EVERYONE         0x4000
 203 /* For a_access_mask.  */
 204 #   define NEW_ACE_READ_DATA         0x001 /* corresponds to 'r' */
 205 #   define NEW_ACE_WRITE_DATA        0x002 /* corresponds to 'w' */
 206 #   define NEW_ACE_APPEND_DATA       0x004
 207 #   define NEW_ACE_READ_NAMED_ATTRS  0x008
 208 #   define NEW_ACE_WRITE_NAMED_ATTRS 0x010
 209 #   define NEW_ACE_EXECUTE           0x020
 210 #   define NEW_ACE_DELETE_CHILD      0x040
 211 #   define NEW_ACE_READ_ATTRIBUTES   0x080
 212 #   define NEW_ACE_WRITE_ATTRIBUTES  0x100
 213 #   define NEW_ACE_DELETE          0x10000
 214 #   define NEW_ACE_READ_ACL        0x20000
 215 #   define NEW_ACE_WRITE_ACL       0x40000
 216 #   define NEW_ACE_WRITE_OWNER     0x80000
 217 #   define NEW_ACE_SYNCHRONIZE    0x100000
 218
 219 #  endif
 220
 221 # elif HAVE_GETACL /* HP-UX */
 222
 223 /* Return 1 if the given ACL is non-trivial.
 224    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 225 extern int acl_nontrivial (int count, struct acl_entry *entries);
 226
 227 #  if HAVE_ACLV_H /* HP-UX >= 11.11 */
 228
 229 /* Return 1 if the given ACL is non-trivial.
 230    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 231 extern int aclv_nontrivial (int count, struct acl *entries);
 232
 233 #  endif
 234
 235 # elif HAVE_ACLX_GET && 0 /* AIX */
 236
 237 /* TODO */
 238
 239 # elif HAVE_STATACL /* older AIX */
 240
 241 /* Return 1 if the given ACL is non-trivial.
 242    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 243 extern int acl_nontrivial (struct acl *a);
 244
 245 # elif HAVE_ACLSORT /* NonStop Kernel */
 246
 247 /* Return 1 if the given ACL is non-trivial.
 248    Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.  */
 249 extern int acl_nontrivial (int count, struct acl *entries);
 250
 251 # endif
 252
 253 /* Set to 1 if a file's mode is implicit by the ACL.  */
 254 # ifndef MODE_INSIDE_ACL
 255 #  define MODE_INSIDE_ACL 1
 256 # endif
 257
 258 #endif
 259
 260 struct permission_context {
 261   mode_t mode;
 262 #if USE_ACL
 263 # if HAVE_ACL_GET_FILE /* Linux, FreeBSD, Mac OS X, IRIX, Tru64, Cygwin >= 2.5 */
 264   acl_t acl;
 265 #  if !HAVE_ACL_TYPE_EXTENDED
 266   acl_t default_acl;
 267 #  endif
 268   bool acls_not_supported;
 269
 270 # elif defined GETACL /* Solaris, Cygwin < 2.5 */
 271   int count;
 272   aclent_t *entries;
 273 #  ifdef ACE_GETACL
 274   int ace_count;
 275   ace_t *ace_entries;
 276 #  endif
 277
 278 # elif HAVE_GETACL /* HP-UX */
 279   struct acl_entry entries[NACLENTRIES];
 280   int count;
 281 #  if HAVE_ACLV_H
 282   struct acl aclv_entries[NACLVENTRIES];
 283   int aclv_count;
 284 #  endif
 285
 286 # elif HAVE_STATACL /* older AIX */
 287   union { struct acl a; char room[4096]; } u;
 288   bool have_u;
 289
 290 # elif HAVE_ACLSORT /* NonStop Kernel */
 291   struct acl entries[NACLENTRIES];
 292   int count;
 293
 294 # endif
 295 #endif
 296 };
 297
 298 int get_permissions (const char *, int, mode_t, struct permission_context *);
 299 int set_permissions (struct permission_context *, const char *, int);
 300 void free_permission_context (struct permission_context *);
 301
 302 _GL_INLINE_HEADER_END