/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * Based on usr/src/ucblib/libucb/port/gen/scandir.c
 */

/*
 * Scan the directory dirname calling select to make a list of selected
 * directory entries then sort using qsort and compare routine dcomp.
 * Returns the number of entries and a pointer to a list of pointers to
 * struct direct (through namelist). Returns -1 if there were any errors.
 */

#include <sys/feature_tests.h>

#pragma weak _scandir = scandir
#pragma weak _alphasort = alphasort
#if !defined(_LP64)
#pragma weak _scandir64 = scandir64
#pragma weak _alphasort64 = alphasort64
#endif

#include "lint.h"
#include <dirent.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>


#if !defined(_LP64)
int
scandir64(const char *dirname, struct dirent64 *(*namelist[]),
    int (*select)(const struct dirent64 *),
    int (*dcomp)(const struct dirent64 **, const struct dirent64 **))
{
        struct dirent64 *d, *p, **names = NULL;
        size_t  nitems = 0;
        size_t  arraysz, entlen;
        struct stat64   stb;
        DIR     *dirp;
        u_longlong_t    tmp_arraysz;

        if ((dirp = opendir(dirname)) == NULL)
                return (-1);
        if (fstat64(dirp->dd_fd, &stb) < 0)
                goto fail;

        /*
         * estimate the array size by taking the size of the directory file
         * and dividing it by a multiple of the minimum size entry.
         */
        tmp_arraysz = stb.st_size / 24; /* 24 bytes on a 64-bit system */
        if (tmp_arraysz > INT_MAX)
                arraysz = INT_MAX;
        else
                arraysz = (size_t)tmp_arraysz;
        names = malloc(arraysz * sizeof (struct dirent64 *));
        if (names == NULL)
                goto fail;

        while ((d = readdir64(dirp)) != NULL) {
                if (select != NULL && !(*select)(d))
                        continue;       /* just selected names */

                entlen = d->d_reclen;
                /*
                 * Make a minimum size copy of the data
                 */
                p = malloc(entlen);
                if (p == NULL)
                        goto fail;
                (void) memcpy(p, d, entlen);
                /*
                 * Check to make sure the array has space left and
                 * realloc the maximum size.
                 */
                if (nitems >= arraysz) {
                        struct dirent64 **tmp;
                        if (nitems == INT_MAX) {
                                /* overflow */
                                free(p);
                                errno = EOVERFLOW;
                                goto fail;
                        }
                        arraysz += 512;         /* no science here */
                        tmp = realloc(names,
                            arraysz * sizeof (struct dirent64 *));
                        if (tmp == NULL) {
                                free(p);
                                goto fail;
                        }
                        names = tmp;
                }
                names[nitems++] = p;
        }
        (void) closedir(dirp);
        if (nitems && dcomp != NULL)
                qsort(names, nitems, sizeof (struct dirent64 *),
                    (int(*)(const void *, const void *))dcomp);
        *namelist = names;

        return ((int)nitems);

fail:
        while (nitems != 0) {
                free(names[--nitems]);
        }
        if (names)
                free(names);
        (void) closedir(dirp);
        return (-1);
}
#endif


int
scandir(const char *dirname, struct dirent *(*namelist[]),
    int (*select)(const struct dirent *),
    int (*dcomp)(const struct dirent **, const struct dirent **))
{
        struct dirent   *d, *p, **names = NULL;
        size_t  nitems = 0;
        size_t  arraysz, entlen;
        struct stat64   stb;
        DIR     *dirp;
        u_longlong_t    tmp_arraysz;

        if ((dirp = opendir(dirname)) == NULL)
                return (-1);
        if (fstat64(dirp->dd_fd, &stb) < 0)
                goto fail;

        /*
         * estimate the array size by taking the size of the directory file
         * and dividing it by a multiple of the minimum size entry.
         */
        tmp_arraysz = stb.st_size / 24; /* 24 bytes on a 64-bit system */
        if (tmp_arraysz > INT_MAX)
                arraysz = INT_MAX;
        else
                arraysz = (size_t)tmp_arraysz;
        names = malloc(arraysz * sizeof (struct dirent *));
        if (names == NULL)
                goto fail;

        while ((d = readdir(dirp)) != NULL) {
                if (select != NULL && !(*select)(d))
                        continue;       /* just selected names */

                entlen = d->d_reclen;
                /*
                 * Make a minimum size copy of the data
                 */
                p = malloc(entlen);
                if (p == NULL)
                        goto fail;
                (void) memcpy(p, d, entlen);
                /*
                 * Check to make sure the array has space left and
                 * realloc the maximum size.
                 */
                if (nitems >= arraysz) {
                        struct dirent **tmp;
                        if (nitems == INT_MAX) {
                                /* overflow */
                                free(p);
                                errno = EOVERFLOW;
                                goto fail;
                        }
                        arraysz += 512;         /* no science here */
                        tmp = realloc(names,
                            arraysz * sizeof (struct dirent *));
                        if (tmp == NULL) {
                                free(p);
                                goto fail;
                        }
                        names = tmp;
                }
                names[nitems++] = p;
        }
        (void) closedir(dirp);
        if (nitems && dcomp != NULL)
                qsort(names, nitems, sizeof (struct dirent *),
                    (int(*)(const void *, const void *))dcomp);
        *namelist = names;

        return ((int)nitems);

fail:
        while (nitems != 0) {
                free(names[--nitems]);
        }
        if (names)
                free(names);
        (void) closedir(dirp);
        return (-1);
}

/*
 * Alphabetic order comparison routine for those who want it.
 */
int
alphasort(const struct dirent **d1, const struct dirent **d2)
{
        return (strcoll((*d1)->d_name,
            (*d2)->d_name));
}

#if !defined(_LP64)
int
alphasort64(const struct dirent64 **d1, const struct dirent64 **d2)
{
        return (strcoll((*d1)->d_name,
            (*d2)->d_name));
}
#endif