1 /* $OpenBSD: scandir.c,v 1.21 2019/06/28 13:32:41 deraadt 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 <stdint.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include "telldir.h" 46 47 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 48 49 /* 50 * The DIRSIZ macro is the minimum record length which will hold the directory 51 * entry. This requires the amount of space in struct dirent without the 52 * d_name field, plus enough space for the name and a terminating nul byte 53 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 54 */ 55 #undef DIRSIZ 56 #define DIRSIZ(dp) \ 57 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 58 (((dp)->d_namlen + 1 + 3) &~ 3)) 59 60 int 61 scandir(const char *dirname, struct dirent ***namelist, 62 int (*select)(const struct dirent *), 63 int (*dcomp)(const struct dirent **, const struct dirent **)) 64 { 65 struct dirent *d, *p, **names = NULL; 66 size_t nitems = 0; 67 struct stat stb; 68 long arraysz; 69 DIR *dirp; 70 71 if ((dirp = opendir(dirname)) == NULL) 72 return (-1); 73 if (fstat(dirp->dd_fd, &stb) == -1) 74 goto fail; 75 76 /* 77 * estimate the array size by taking the size of the directory file 78 * and dividing it by a multiple of the minimum size entry. 79 */ 80 arraysz = MAXIMUM(stb.st_size / 24, 16); 81 if (arraysz > SIZE_MAX / sizeof(struct dirent *)) { 82 errno = ENOMEM; 83 goto fail; 84 } 85 names = calloc(arraysz, sizeof(struct dirent *)); 86 if (names == NULL) 87 goto fail; 88 89 while ((d = readdir(dirp)) != NULL) { 90 if (select != NULL && !(*select)(d)) 91 continue; /* just selected names */ 92 93 /* 94 * Check to make sure the array has space left and 95 * realloc the maximum size. 96 */ 97 if (nitems >= arraysz) { 98 struct dirent **nnames; 99 100 if (fstat(dirp->dd_fd, &stb) == -1) 101 goto fail; 102 103 arraysz *= 2; 104 if (SIZE_MAX / sizeof(struct dirent *) < arraysz) 105 goto fail; 106 nnames = reallocarray(names, 107 arraysz, sizeof(struct dirent *)); 108 if (nnames == NULL) 109 goto fail; 110 111 names = nnames; 112 } 113 114 /* 115 * Make a minimum size copy of the data 116 */ 117 p = malloc(DIRSIZ(d)); 118 if (p == NULL) 119 goto fail; 120 121 p->d_ino = d->d_ino; 122 p->d_type = d->d_type; 123 p->d_reclen = d->d_reclen; 124 p->d_namlen = d->d_namlen; 125 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 126 names[nitems++] = p; 127 } 128 closedir(dirp); 129 if (nitems && dcomp != NULL) 130 qsort(names, nitems, sizeof(struct dirent *), 131 (int(*)(const void *, const void *))dcomp); 132 *namelist = names; 133 return (nitems); 134 135 fail: 136 while (nitems > 0) 137 free(names[--nitems]); 138 free(names); 139 closedir(dirp); 140 return (-1); 141 } 142 143 /* 144 * Alphabetic order comparison routine for those who want it. 145 */ 146 int 147 alphasort(const struct dirent **d1, const struct dirent **d2) 148 { 149 return(strcmp((*d1)->d_name, (*d2)->d_name)); 150 } 151