blob: 5b53d995cae6a06a4b7087ab5850d020490114a3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
Kevin Winchester85c9fe82010-08-09 17:20:22 -07007#include <linux/stddef.h>
Milind Arun Choudhary022a1692007-05-08 00:29:02 -07008#include <linux/kernel.h>
Paul Gortmaker630d9c42011-11-16 23:57:37 -05009#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/fs.h>
16#include <linux/dirent.h>
17#include <linux/security.h>
18#include <linux/syscalls.h>
19#include <linux/unistd.h>
20
21#include <asm/uaccess.h>
22
Al Viro5c0ba4e2013-05-15 13:52:59 -040023int iterate_dir(struct file *file, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024{
Al Viro496ad9a2013-01-23 17:07:38 -050025 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 int res = -ENOTDIR;
Al Viro72c2d532013-09-22 16:27:52 -040027 if (!file->f_op->iterate)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 goto out;
29
30 res = security_file_permission(file, MAY_READ);
31 if (res)
32 goto out;
33
Liam R. Howlettda784512007-12-06 17:39:54 -050034 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
Al Viro2233f312013-05-22 21:44:23 -040040 ctx->pos = file->f_pos;
41 res = file->f_op->iterate(file, ctx);
42 file->f_pos = ctx->pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 file_accessed(file);
44 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080045 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046out:
47 return res;
48}
Al Viro5c0ba4e2013-05-15 13:52:59 -040049EXPORT_SYMBOL(iterate_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51/*
52 * Traditional linux readdir() handling..
53 *
54 * "count=1" is a special case, meaning that the buffer is one
55 * dirent-structure in size and that the code can't handle more
56 * anyway. Thus the special "fillonedir()" function for that
57 * case (the low-level handlers don't need to care about this).
58 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#ifdef __ARCH_WANT_OLD_READDIR
61
62struct old_linux_dirent {
63 unsigned long d_ino;
64 unsigned long d_offset;
65 unsigned short d_namlen;
66 char d_name[1];
67};
68
69struct readdir_callback {
Al Viro5c0ba4e2013-05-15 13:52:59 -040070 struct dir_context ctx;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 struct old_linux_dirent __user * dirent;
72 int result;
73};
74
75static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -070076 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
Al Viro5c0ba4e2013-05-15 13:52:59 -040078 struct readdir_callback *buf = (struct readdir_callback *) __buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 struct old_linux_dirent __user * dirent;
David Howellsafefdbb2006-10-03 01:13:46 -070080 unsigned long d_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 if (buf->result)
83 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -070084 d_ino = ino;
Al Viro8f3f6552008-08-12 00:28:24 -040085 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
86 buf->result = -EOVERFLOW;
David Howellsafefdbb2006-10-03 01:13:46 -070087 return -EOVERFLOW;
Al Viro8f3f6552008-08-12 00:28:24 -040088 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 buf->result++;
90 dirent = buf->dirent;
91 if (!access_ok(VERIFY_WRITE, dirent,
92 (unsigned long)(dirent->d_name + namlen + 1) -
93 (unsigned long)dirent))
94 goto efault;
David Howellsafefdbb2006-10-03 01:13:46 -070095 if ( __put_user(d_ino, &dirent->d_ino) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 __put_user(offset, &dirent->d_offset) ||
97 __put_user(namlen, &dirent->d_namlen) ||
98 __copy_to_user(dirent->d_name, name, namlen) ||
99 __put_user(0, dirent->d_name + namlen))
100 goto efault;
101 return 0;
102efault:
103 buf->result = -EFAULT;
104 return -EFAULT;
105}
106
Heiko Carstensd4e82042009-01-14 14:14:34 +0100107SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
108 struct old_linux_dirent __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
110 int error;
Al Viro2903ff02012-08-28 12:52:22 -0400111 struct fd f = fdget(fd);
Al Viroac6614b2013-05-22 22:22:04 -0400112 struct readdir_callback buf = {
113 .ctx.actor = fillonedir,
114 .dirent = dirent
115 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Al Viro2903ff02012-08-28 12:52:22 -0400117 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400118 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Al Viro5c0ba4e2013-05-15 13:52:59 -0400120 error = iterate_dir(f.file, &buf.ctx);
Al Viro53c9c5c2008-08-24 07:29:52 -0400121 if (buf.result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 error = buf.result;
123
Al Viro2903ff02012-08-28 12:52:22 -0400124 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 return error;
126}
127
128#endif /* __ARCH_WANT_OLD_READDIR */
129
130/*
131 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
132 * interface.
133 */
134struct linux_dirent {
135 unsigned long d_ino;
136 unsigned long d_off;
137 unsigned short d_reclen;
138 char d_name[1];
139};
140
141struct getdents_callback {
Al Viro5c0ba4e2013-05-15 13:52:59 -0400142 struct dir_context ctx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 struct linux_dirent __user * current_dir;
144 struct linux_dirent __user * previous;
145 int count;
146 int error;
147};
148
149static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700150 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
152 struct linux_dirent __user * dirent;
153 struct getdents_callback * buf = (struct getdents_callback *) __buf;
David Howellsafefdbb2006-10-03 01:13:46 -0700154 unsigned long d_ino;
Kevin Winchester85c9fe82010-08-09 17:20:22 -0700155 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
156 sizeof(long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158 buf->error = -EINVAL; /* only used if we fail.. */
159 if (reclen > buf->count)
160 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -0700161 d_ino = ino;
Al Viro8f3f6552008-08-12 00:28:24 -0400162 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
163 buf->error = -EOVERFLOW;
David Howellsafefdbb2006-10-03 01:13:46 -0700164 return -EOVERFLOW;
Al Viro8f3f6552008-08-12 00:28:24 -0400165 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 dirent = buf->previous;
167 if (dirent) {
168 if (__put_user(offset, &dirent->d_off))
169 goto efault;
170 }
171 dirent = buf->current_dir;
David Howellsafefdbb2006-10-03 01:13:46 -0700172 if (__put_user(d_ino, &dirent->d_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 goto efault;
174 if (__put_user(reclen, &dirent->d_reclen))
175 goto efault;
176 if (copy_to_user(dirent->d_name, name, namlen))
177 goto efault;
178 if (__put_user(0, dirent->d_name + namlen))
179 goto efault;
180 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
181 goto efault;
182 buf->previous = dirent;
183 dirent = (void __user *)dirent + reclen;
184 buf->current_dir = dirent;
185 buf->count -= reclen;
186 return 0;
187efault:
188 buf->error = -EFAULT;
189 return -EFAULT;
190}
191
Heiko Carstens20f37032009-01-14 14:14:23 +0100192SYSCALL_DEFINE3(getdents, unsigned int, fd,
193 struct linux_dirent __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
Al Viro2903ff02012-08-28 12:52:22 -0400195 struct fd f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 struct linux_dirent __user * lastdirent;
Al Viroac6614b2013-05-22 22:22:04 -0400197 struct getdents_callback buf = {
198 .ctx.actor = filldir,
199 .count = count,
200 .current_dir = dirent
201 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 int error;
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (!access_ok(VERIFY_WRITE, dirent, count))
Al Viro863ced72012-04-21 18:40:32 -0400205 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
Al Viro2903ff02012-08-28 12:52:22 -0400207 f = fdget(fd);
208 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400209 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
Al Viro5c0ba4e2013-05-15 13:52:59 -0400211 error = iterate_dir(f.file, &buf.ctx);
Al Viro53c9c5c2008-08-24 07:29:52 -0400212 if (error >= 0)
213 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 lastdirent = buf.previous;
215 if (lastdirent) {
Al Virobb6f6192013-05-15 18:49:12 -0400216 if (put_user(buf.ctx.pos, &lastdirent->d_off))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 error = -EFAULT;
218 else
219 error = count - buf.count;
220 }
Al Viro2903ff02012-08-28 12:52:22 -0400221 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return error;
223}
224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225struct getdents_callback64 {
Al Viro5c0ba4e2013-05-15 13:52:59 -0400226 struct dir_context ctx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 struct linux_dirent64 __user * current_dir;
228 struct linux_dirent64 __user * previous;
229 int count;
230 int error;
231};
232
233static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700234 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
236 struct linux_dirent64 __user *dirent;
237 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
Kevin Winchester85c9fe82010-08-09 17:20:22 -0700238 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
239 sizeof(u64));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241 buf->error = -EINVAL; /* only used if we fail.. */
242 if (reclen > buf->count)
243 return -EINVAL;
244 dirent = buf->previous;
245 if (dirent) {
246 if (__put_user(offset, &dirent->d_off))
247 goto efault;
248 }
249 dirent = buf->current_dir;
250 if (__put_user(ino, &dirent->d_ino))
251 goto efault;
252 if (__put_user(0, &dirent->d_off))
253 goto efault;
254 if (__put_user(reclen, &dirent->d_reclen))
255 goto efault;
256 if (__put_user(d_type, &dirent->d_type))
257 goto efault;
258 if (copy_to_user(dirent->d_name, name, namlen))
259 goto efault;
260 if (__put_user(0, dirent->d_name + namlen))
261 goto efault;
262 buf->previous = dirent;
263 dirent = (void __user *)dirent + reclen;
264 buf->current_dir = dirent;
265 buf->count -= reclen;
266 return 0;
267efault:
268 buf->error = -EFAULT;
269 return -EFAULT;
270}
271
Heiko Carstens20f37032009-01-14 14:14:23 +0100272SYSCALL_DEFINE3(getdents64, unsigned int, fd,
273 struct linux_dirent64 __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274{
Al Viro2903ff02012-08-28 12:52:22 -0400275 struct fd f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 struct linux_dirent64 __user * lastdirent;
Al Viroac6614b2013-05-22 22:22:04 -0400277 struct getdents_callback64 buf = {
278 .ctx.actor = filldir64,
279 .count = count,
280 .current_dir = dirent
281 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 int error;
283
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 if (!access_ok(VERIFY_WRITE, dirent, count))
Al Viro863ced72012-04-21 18:40:32 -0400285 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Al Viro2903ff02012-08-28 12:52:22 -0400287 f = fdget(fd);
288 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400289 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
Al Viro5c0ba4e2013-05-15 13:52:59 -0400291 error = iterate_dir(f.file, &buf.ctx);
Al Viro53c9c5c2008-08-24 07:29:52 -0400292 if (error >= 0)
293 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 lastdirent = buf.previous;
295 if (lastdirent) {
Al Virobb6f6192013-05-15 18:49:12 -0400296 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 if (__put_user(d_off, &lastdirent->d_off))
Al Viro53c9c5c2008-08-24 07:29:52 -0400298 error = -EFAULT;
299 else
300 error = count - buf.count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 }
Al Viro2903ff02012-08-28 12:52:22 -0400302 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return error;
304}