contrib/bind/lib/isc/fsaccess.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: fsaccess.c,v 1.10 2007/06/19 23:47:17 tbox Exp $ */
  19
  20 /*! \file
  21  * \brief
  22  * This file contains the OS-independent functionality of the API.
  23  */
  24 #include <isc/fsaccess.h>
  25 #include <isc/result.h>
  26 #include <isc/util.h>
  27
  28 /*!
  29  * Shorthand.  Maybe ISC__FSACCESS_PERMISSIONBITS should not even be in
  30  * <isc/fsaccess.h>.  Could check consistency with sizeof(isc_fsaccess_t)
  31  * and the number of bits in each function.
  32  */
  33 #define STEP            (ISC__FSACCESS_PERMISSIONBITS)
  34 #define GROUP           (STEP)
  35 #define OTHER           (STEP * 2)
  36
  37 void
  38 isc_fsaccess_add(int trustee, int permission, isc_fsaccess_t *access) {
  39         REQUIRE(trustee <= 0x7);
  40         REQUIRE(permission <= 0xFF);
  41
  42         if ((trustee & ISC_FSACCESS_OWNER) != 0)
  43                 *access |= permission;
  44
  45         if ((trustee & ISC_FSACCESS_GROUP) != 0)
  46                 *access |= (permission << GROUP);
  47
  48         if ((trustee & ISC_FSACCESS_OTHER) != 0)
  49                 *access |= (permission << OTHER);
  50 }
  51
  52 void
  53 isc_fsaccess_remove(int trustee, int permission, isc_fsaccess_t *access) {
  54         REQUIRE(trustee <= 0x7);
  55         REQUIRE(permission <= 0xFF);
  56
  57
  58         if ((trustee & ISC_FSACCESS_OWNER) != 0)
  59                 *access &= ~permission;
  60
  61         if ((trustee & ISC_FSACCESS_GROUP) != 0)
  62                 *access &= ~(permission << GROUP);
  63
  64         if ((trustee & ISC_FSACCESS_OTHER) != 0)
  65                 *access &= ~(permission << OTHER);
  66 }
  67
  68 static isc_result_t
  69 check_bad_bits(isc_fsaccess_t access, isc_boolean_t is_dir) {
  70         isc_fsaccess_t bits;
  71
  72         /*
  73          * Check for disallowed user bits.
  74          */
  75         if (is_dir)
  76                 bits = ISC_FSACCESS_READ |
  77                        ISC_FSACCESS_WRITE |
  78                        ISC_FSACCESS_EXECUTE;
  79         else
  80                 bits = ISC_FSACCESS_CREATECHILD |
  81                        ISC_FSACCESS_ACCESSCHILD |
  82                        ISC_FSACCESS_DELETECHILD |
  83                        ISC_FSACCESS_LISTDIRECTORY;
  84
  85         /*
  86          * Set group bad bits.
  87          */
  88         bits |= bits << STEP;
  89         /*
  90          * Set other bad bits.
  91          */
  92         bits |= bits << STEP;
  93
  94         if ((access & bits) != 0) {
  95                 if (is_dir)
  96                         return (ISC_R_NOTFILE);
  97                 else
  98                         return (ISC_R_NOTDIRECTORY);
  99         }
 100
 101         return (ISC_R_SUCCESS);
 102 }