1 /* Copyright (C) 1992-1998, 2000, 2002-2003, 2009-2020 Free Software
2 Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 3, or (at your option) any
8 later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, see <https://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19
20 #include <dirent.h>
21
22 #include <stdlib.h>
23 #include <string.h>
24 #include <errno.h>
25 #if _LIBC
26 # include <bits/libc-lock.h>
27 #endif
28
29 #undef select
30
31 #ifndef _D_EXACT_NAMLEN
32 # define _D_EXACT_NAMLEN(d) strlen ((d)->d_name)
33 #endif
34 #ifndef _D_ALLOC_NAMLEN
35 # ifndef __KLIBC__
36 # define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
37 # else
38 /* On OS/2 kLIBC, d_name is not the last field of struct dirent. See
39 <https://trac.netlabs.org/libc/browser/branches/libc-0.6/src/emx/include/sys/dirent.h#L68>. */
40 # include <stddef.h>
41 # define _D_ALLOC_NAMLEN(d) (sizeof (struct dirent) - \
42 offsetof (struct dirent, d_name))
43 # endif
44 #endif
45
46 #if _LIBC
47 # ifndef SCANDIR
48 # define SCANDIR scandir
49 # define READDIR __readdir
50 # define DIRENT_TYPE struct dirent
51 # endif
52 #else
53 # define SCANDIR scandir
54 # define READDIR readdir
55 # define DIRENT_TYPE struct dirent
56 # define __opendir opendir
57 # define __closedir closedir
58 # define __set_errno(val) errno = (val)
59
60 /* The results of opendir() in this file are not used with dirfd and fchdir,
61 and we do not leak fds to any single-threaded code that could use stdio,
62 therefore save some unnecessary recursion in fchdir.c and opendir_safer.c.
63 FIXME - if the kernel ever adds support for multi-thread safety for
64 avoiding standard fds, then we should use opendir_safer. */
65 # undef opendir
66 # undef closedir
67 #endif
68
69 #ifndef SCANDIR_CANCEL
70 # define SCANDIR_CANCEL
71 struct scandir_cancel_struct
72 {
73 DIR *dp;
74 void *v;
75 size_t cnt;
76 };
77
78 # if _LIBC
79 static void
cancel_handler(void * arg)80 cancel_handler (void *arg)
81 {
82 struct scandir_cancel_struct *cp = arg;
83 size_t i;
84 void **v = cp->v;
85
86 for (i = 0; i < cp->cnt; ++i)
87 free (v[i]);
88 free (v);
89 (void) __closedir (cp->dp);
90 }
91 # endif
92 #endif
93
94
95 int
96 #ifndef __KLIBC__
SCANDIR(const char * dir,DIRENT_TYPE *** namelist,int (* select)(const DIRENT_TYPE *),int (* cmp)(const DIRENT_TYPE **,const DIRENT_TYPE **))97 SCANDIR (const char *dir,
98 DIRENT_TYPE ***namelist,
99 int (*select) (const DIRENT_TYPE *),
100 int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
101 #else
102 /* On OS/2 kLIBC, scandir() declaration is different from POSIX. See
103 <https://trac.netlabs.org/libc/browser/branches/libc-0.6/src/emx/include/dirent.h#L141>. */
104 SCANDIR (const char *dir,
105 DIRENT_TYPE ***namelist,
106 int (*select) (DIRENT_TYPE *),
107 int (*cmp) (const void *, const void *))
108 #endif
109 {
110 DIR *dp = __opendir (dir);
111 DIRENT_TYPE **v = NULL;
112 size_t vsize = 0;
113 struct scandir_cancel_struct c;
114 DIRENT_TYPE *d;
115 int save;
116
117 if (dp == NULL)
118 return -1;
119
120 save = errno;
121 __set_errno (0);
122
123 c.dp = dp;
124 c.v = NULL;
125 c.cnt = 0;
126 #if _LIBC
127 __libc_cleanup_push (cancel_handler, &c);
128 #endif
129
130 while ((d = READDIR (dp)) != NULL)
131 {
132 int use_it = select == NULL;
133
134 if (! use_it)
135 {
136 use_it = select (d);
137 /* The select function might have changed errno. It was
138 zero before and it need to be again to make the latter
139 tests work. */
140 __set_errno (0);
141 }
142
143 if (use_it)
144 {
145 DIRENT_TYPE *vnew;
146 size_t dsize;
147
148 /* Ignore errors from select or readdir */
149 __set_errno (0);
150
151 if (__builtin_expect (c.cnt == vsize, 0))
152 {
153 DIRENT_TYPE **new;
154 if (vsize == 0)
155 vsize = 10;
156 else
157 vsize *= 2;
158 new = (DIRENT_TYPE **) realloc (v, vsize * sizeof (*v));
159 if (new == NULL)
160 break;
161 v = new;
162 c.v = (void *) v;
163 }
164
165 dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
166 vnew = (DIRENT_TYPE *) malloc (dsize);
167 if (vnew == NULL)
168 break;
169
170 v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
171 }
172 }
173
174 if (__builtin_expect (errno, 0) != 0)
175 {
176 save = errno;
177
178 while (c.cnt > 0)
179 free (v[--c.cnt]);
180 free (v);
181 c.cnt = -1;
182 }
183 else
184 {
185 /* Sort the list if we have a comparison function to sort with. */
186 if (cmp != NULL)
187 qsort (v, c.cnt, sizeof (*v), (int (*) (const void *, const void *)) cmp);
188
189 *namelist = v;
190 }
191
192 #if _LIBC
193 __libc_cleanup_pop (0);
194 #endif
195
196 (void) __closedir (dp);
197 __set_errno (save);
198
199 return c.cnt;
200 }
201