isc/unix/fsaccess.c

/*
 * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: fsaccess.c,v 1.13 2007/06/19 23:47:18 tbox Exp $ */

#include <config.h>

#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>

#include "errno2result.h"

/*! \file
 * \brief
 * The OS-independent part of the API is in lib/isc.
 */
#include "../fsaccess.c"

isc_result_t
isc_fsaccess_set(const char *path, isc_fsaccess_t access) {
    struct stat statb;
    mode_t mode;
    isc_boolean_t is_dir = ISC_FALSE;
    isc_fsaccess_t bits;
    isc_result_t result;

    if (stat(path, &statb) != 0)
        return (isc__errno2result(errno));

    if ((statb.st_mode & S_IFDIR) != 0)
        is_dir = ISC_TRUE;
    else if ((statb.st_mode & S_IFREG) == 0)
        return (ISC_R_INVALIDFILE);

    result = check_bad_bits(access, is_dir);
    if (result != ISC_R_SUCCESS)
        return (result);

    /*
     * Done with checking bad bits.  Set mode_t.
     */
    mode = 0;

#define SET_AND_CLEAR1(modebit) \
    if ((access & bits) != 0) { \
        mode |= modebit; \
        access &= ~bits; \
    }
#define SET_AND_CLEAR(user, group, other) \
    SET_AND_CLEAR1(user); \
    bits <<= STEP; \
    SET_AND_CLEAR1(group); \
    bits <<= STEP; \
    SET_AND_CLEAR1(other);

    bits = ISC_FSACCESS_READ | ISC_FSACCESS_LISTDIRECTORY;

    SET_AND_CLEAR(S_IRUSR, S_IRGRP, S_IROTH);

    bits = ISC_FSACCESS_WRITE |
           ISC_FSACCESS_CREATECHILD |
           ISC_FSACCESS_DELETECHILD;

    SET_AND_CLEAR(S_IWUSR, S_IWGRP, S_IWOTH);

    bits = ISC_FSACCESS_EXECUTE |
           ISC_FSACCESS_ACCESSCHILD;

    SET_AND_CLEAR(S_IXUSR, S_IXGRP, S_IXOTH);

    INSIST(access == 0);

    if (chmod(path, mode) < 0)
        return (isc__errno2result(errno));

    return (ISC_R_SUCCESS);
}