dir.c

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/*
 * Copyright (C) 2004, 2005, 2007-2009, 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2001  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.
 */

/* $Id$ */

/*! \file
 * \author  Principal Authors: DCL */

#include <config.h>

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

#include <ctype.h>
#include <errno.h>
#include <unistd.h>

#include <isc/dir.h>
#include <isc/magic.h>
#include <isc/string.h>
#include <isc/util.h>

#include "errno2result.h"

#define ISC_DIR_MAGIC           ISC_MAGIC('D', 'I', 'R', '*')
#define VALID_DIR(dir)          ISC_MAGIC_VALID(dir, ISC_DIR_MAGIC)

void
isc_dir_init(isc_dir_t *dir) {
        REQUIRE(dir != NULL);

        dir->entry.name[0] = '\0';
        dir->entry.length = 0;

        dir->handle = NULL;

        dir->magic = ISC_DIR_MAGIC;
}

/*!
 * \brief Allocate workspace and open directory stream. If either one fails,
 * NULL will be returned.
 */
isc_result_t
isc_dir_open(isc_dir_t *dir, const char *dirname) {
        char *p;
        isc_result_t result = ISC_R_SUCCESS;

        REQUIRE(VALID_DIR(dir));
        REQUIRE(dirname != NULL);

        /*
         * Copy directory name.  Need to have enough space for the name,
         * a possible path separator, the wildcard, and the final NUL.
         */
        if (strlen(dirname) + 3 > sizeof(dir->dirname))
                /* XXXDCL ? */
                return (ISC_R_NOSPACE);
        strcpy(dir->dirname, dirname);

        /*
         * Append path separator, if needed, and "*".
         */
        p = dir->dirname + strlen(dir->dirname);
        if (dir->dirname < p && *(p - 1) != '/')
                *p++ = '/';
        *p++ = '*';
        *p = '\0';

        /*
         * Open stream.
         */
        dir->handle = opendir(dirname);

        if (dir->handle == NULL)
                return isc__errno2result(errno);

        return (result);
}

/*!
 * \brief Return previously retrieved file or get next one.

 * Unix's dirent has
 * separate open and read functions, but the Win32 and DOS interfaces open
 * the dir stream and reads the first file in one operation.
 */
isc_result_t
isc_dir_read(isc_dir_t *dir) {
        struct dirent *entry;

        REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

        /*
         * Fetch next file in directory.
         */
        entry = readdir(dir->handle);

        if (entry == NULL)
                return (ISC_R_NOMORE);

        /*
         * Make sure that the space for the name is long enough.
         */
        if (sizeof(dir->entry.name) <= strlen(entry->d_name))
            return (ISC_R_UNEXPECTED);

        strcpy(dir->entry.name, entry->d_name);

        /*
         * Some dirents have d_namlen, but it is not portable.
         */
        dir->entry.length = strlen(entry->d_name);

        return (ISC_R_SUCCESS);
}

/*!
 * \brief Close directory stream.
 */
void
isc_dir_close(isc_dir_t *dir) {
       REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

       (void)closedir(dir->handle);
       dir->handle = NULL;
}

/*!
 * \brief Reposition directory stream at start.
 */
isc_result_t
isc_dir_reset(isc_dir_t *dir) {
        REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

        rewinddir(dir->handle);

        return (ISC_R_SUCCESS);
}

isc_result_t
isc_dir_chdir(const char *dirname) {
        /*!
         * \brief Change the current directory to 'dirname'.
         */

        REQUIRE(dirname != NULL);

        if (chdir(dirname) < 0)
                return (isc__errno2result(errno));

        return (ISC_R_SUCCESS);
}

isc_result_t
isc_dir_chroot(const char *dirname) {

        REQUIRE(dirname != NULL);

#ifdef HAVE_CHROOT
        if (chroot(dirname) < 0 || chdir("/") < 0)
                return (isc__errno2result(errno));

        return (ISC_R_SUCCESS);
#else
        return (ISC_R_NOTIMPLEMENTED);
#endif
}

isc_result_t
isc_dir_createunique(char *templet) {
        isc_result_t result;
        char *x;
        char *p;
        int i;
        int pid;

        REQUIRE(templet != NULL);

        /*!
         * \brief mkdtemp is not portable, so this emulates it.
         */

        pid = getpid();

        /*
         * Replace trailing Xs with the process-id, zero-filled.
         */
        for (x = templet + strlen(templet) - 1; *x == 'X' && x >= templet;
             x--, pid /= 10)
                *x = pid % 10 + '0';

        x++;                    /* Set x to start of ex-Xs. */

        do {
                i = mkdir(templet, 0700);
                if (i == 0 || errno != EEXIST)
                        break;

                /*
                 * The BSD algorithm.
                 */
                p = x;
                while (*p != '\0') {
                        if (isdigit(*p & 0xff))
                                *p = 'a';
                        else if (*p != 'z')
                                ++*p;
                        else {
                                /*
                                 * Reset character and move to next.
                                 */
                                *p++ = 'a';
                                continue;
                        }

                        break;
                }

                if (*p == '\0') {
                        /*
                         * Tried all combinations.  errno should already
                         * be EEXIST, but ensure it is anyway for
                         * isc__errno2result().
                         */
                        errno = EEXIST;
                        break;
                }
        } while (1);

        if (i == -1)
                result = isc__errno2result(errno);
        else
                result = ISC_R_SUCCESS;

        return (result);
}

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