/contrib/bind9/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
 37void
 38isc_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
 52void
 53isc_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
 68static isc_result_t
 69check_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}