1/* $OpenBSD: scandir.c,v 1.23 2024/04/15 15:47:58 florian Exp $ */ 2/* 3 * Copyright (c) 1983, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31/* 32 * Scan the directory dirname calling select to make a list of selected 33 * directory entries then sort using qsort and compare routine dcomp. 34 * Returns the number of entries and a pointer to a list of pointers to 35 * struct dirent (through namelist). Returns -1 if there were any errors. 36 */ 37 38#include <sys/types.h> 39#include <sys/stat.h> 40#include <dirent.h> 41#include <errno.h> 42#include <fcntl.h> 43#include <stdint.h> 44#include <stdlib.h> 45#include <string.h> 46#include <unistd.h> 47#include "telldir.h" 48 49#define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 50 51/* 52 * The DIRSIZ macro is the minimum record length which will hold the directory 53 * entry. This requires the amount of space in struct dirent without the 54 * d_name field, plus enough space for the name and a terminating nul byte 55 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 56 */ 57#undef DIRSIZ 58#define DIRSIZ(dp) \ 59 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 60 (((dp)->d_namlen + 1 + 3) &~ 3)) 61 62static int 63scandir_dirp(DIR *dirp, struct dirent ***namelist, 64 int (*select)(const struct dirent *), 65 int (*dcomp)(const struct dirent **, const struct dirent **)) 66{ 67 struct dirent *d, *p, **names = NULL; 68 size_t nitems = 0; 69 struct stat stb; 70 long arraysz; 71 72 if (fstat(dirp->dd_fd, &stb) == -1) 73 goto fail; 74 75 /* 76 * estimate the array size by taking the size of the directory file 77 * and dividing it by a multiple of the minimum size entry. 78 */ 79 arraysz = MAXIMUM(stb.st_size / 24, 16); 80 if (arraysz > SIZE_MAX / sizeof(struct dirent *)) { 81 errno = ENOMEM; 82 goto fail; 83 } 84 names = calloc(arraysz, sizeof(struct dirent *)); 85 if (names == NULL) 86 goto fail; 87 88 while ((d = readdir(dirp)) != NULL) { 89 if (select != NULL && !(*select)(d)) 90 continue; /* just selected names */ 91 92 /* 93 * Check to make sure the array has space left and 94 * realloc the maximum size. 95 */ 96 if (nitems >= arraysz) { 97 struct dirent **nnames; 98 99 if (fstat(dirp->dd_fd, &stb) == -1) 100 goto fail; 101 102 arraysz *= 2; 103 if (SIZE_MAX / sizeof(struct dirent *) < arraysz) 104 goto fail; 105 nnames = reallocarray(names, 106 arraysz, sizeof(struct dirent *)); 107 if (nnames == NULL) 108 goto fail; 109 110 names = nnames; 111 } 112 113 /* 114 * Make a minimum size copy of the data 115 */ 116 p = malloc(DIRSIZ(d)); 117 if (p == NULL) 118 goto fail; 119 120 p->d_ino = d->d_ino; 121 p->d_type = d->d_type; 122 p->d_reclen = d->d_reclen; 123 p->d_namlen = d->d_namlen; 124 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 125 names[nitems++] = p; 126 } 127 closedir(dirp); 128 if (nitems && dcomp != NULL) 129 qsort(names, nitems, sizeof(struct dirent *), 130 (int(*)(const void *, const void *))dcomp); 131 *namelist = names; 132 return (nitems); 133 134fail: 135 while (nitems > 0) 136 free(names[--nitems]); 137 free(names); 138 closedir(dirp); 139 return (-1); 140} 141 142int 143scandir(const char *dirname, struct dirent ***namelist, 144 int (*select)(const struct dirent *), 145 int (*dcomp)(const struct dirent **, const struct dirent **)) 146{ 147 DIR *dirp; 148 149 if ((dirp = opendir(dirname)) == NULL) 150 return (-1); 151 152 return (scandir_dirp(dirp, namelist, select, dcomp)); 153} 154 155int 156scandirat(int dirfd, const char *dirname, struct dirent ***namelist, 157 int (*select)(const struct dirent *), 158 int (*dcomp)(const struct dirent **, const struct dirent **)) 159{ 160 DIR *dirp; 161 int fd; 162 163 fd = HIDDEN(openat)(dirfd, dirname, O_RDONLY | O_DIRECTORY | O_CLOEXEC); 164 if (fd == -1) 165 return (-1); 166 dirp = __fdopendir(fd); 167 if (dirp == NULL) { 168 HIDDEN(close)(fd); 169 return (-1); 170 } 171 return (scandir_dirp(dirp, namelist, select, dcomp)); 172} 173 174/* 175 * Alphabetic order comparison routine for those who want it. 176 */ 177int 178alphasort(const struct dirent **d1, const struct dirent **d2) 179{ 180 return(strcmp((*d1)->d_name, (*d2)->d_name)); 181} 182