Loading...
1/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
7#include <linux/stddef.h>
8#include <linux/kernel.h>
9#include <linux/export.h>
10#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
15#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
23int iterate_dir(struct file *file, struct dir_context *ctx)
24{
25 struct inode *inode = file_inode(file);
26 int res = -ENOTDIR;
27 if (!file->f_op->iterate)
28 goto out;
29
30 res = security_file_permission(file, MAY_READ);
31 if (res)
32 goto out;
33
34 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
38 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
40 ctx->pos = file->f_pos;
41 res = file->f_op->iterate(file, ctx);
42 file->f_pos = ctx->pos;
43 file_accessed(file);
44 }
45 mutex_unlock(&inode->i_mutex);
46out:
47 return res;
48}
49EXPORT_SYMBOL(iterate_dir);
50
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 */
59
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 {
70 struct dir_context ctx;
71 struct old_linux_dirent __user * dirent;
72 int result;
73};
74
75static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
76 u64 ino, unsigned int d_type)
77{
78 struct readdir_callback *buf = (struct readdir_callback *) __buf;
79 struct old_linux_dirent __user * dirent;
80 unsigned long d_ino;
81
82 if (buf->result)
83 return -EINVAL;
84 d_ino = ino;
85 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
86 buf->result = -EOVERFLOW;
87 return -EOVERFLOW;
88 }
89 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;
95 if ( __put_user(d_ino, &dirent->d_ino) ||
96 __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
107SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
108 struct old_linux_dirent __user *, dirent, unsigned int, count)
109{
110 int error;
111 struct fd f = fdget(fd);
112 struct readdir_callback buf = {
113 .ctx.actor = fillonedir,
114 .dirent = dirent
115 };
116
117 if (!f.file)
118 return -EBADF;
119
120 error = iterate_dir(f.file, &buf.ctx);
121 if (buf.result)
122 error = buf.result;
123
124 fdput(f);
125 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 {
142 struct dir_context ctx;
143 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,
150 u64 ino, unsigned int d_type)
151{
152 struct linux_dirent __user * dirent;
153 struct getdents_callback * buf = (struct getdents_callback *) __buf;
154 unsigned long d_ino;
155 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
156 sizeof(long));
157
158 buf->error = -EINVAL; /* only used if we fail.. */
159 if (reclen > buf->count)
160 return -EINVAL;
161 d_ino = ino;
162 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
163 buf->error = -EOVERFLOW;
164 return -EOVERFLOW;
165 }
166 dirent = buf->previous;
167 if (dirent) {
168 if (__put_user(offset, &dirent->d_off))
169 goto efault;
170 }
171 dirent = buf->current_dir;
172 if (__put_user(d_ino, &dirent->d_ino))
173 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
192SYSCALL_DEFINE3(getdents, unsigned int, fd,
193 struct linux_dirent __user *, dirent, unsigned int, count)
194{
195 struct fd f;
196 struct linux_dirent __user * lastdirent;
197 struct getdents_callback buf = {
198 .ctx.actor = filldir,
199 .count = count,
200 .current_dir = dirent
201 };
202 int error;
203
204 if (!access_ok(VERIFY_WRITE, dirent, count))
205 return -EFAULT;
206
207 f = fdget(fd);
208 if (!f.file)
209 return -EBADF;
210
211 error = iterate_dir(f.file, &buf.ctx);
212 if (error >= 0)
213 error = buf.error;
214 lastdirent = buf.previous;
215 if (lastdirent) {
216 if (put_user(buf.ctx.pos, &lastdirent->d_off))
217 error = -EFAULT;
218 else
219 error = count - buf.count;
220 }
221 fdput(f);
222 return error;
223}
224
225struct getdents_callback64 {
226 struct dir_context ctx;
227 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,
234 u64 ino, unsigned int d_type)
235{
236 struct linux_dirent64 __user *dirent;
237 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
238 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
239 sizeof(u64));
240
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
272SYSCALL_DEFINE3(getdents64, unsigned int, fd,
273 struct linux_dirent64 __user *, dirent, unsigned int, count)
274{
275 struct fd f;
276 struct linux_dirent64 __user * lastdirent;
277 struct getdents_callback64 buf = {
278 .ctx.actor = filldir64,
279 .count = count,
280 .current_dir = dirent
281 };
282 int error;
283
284 if (!access_ok(VERIFY_WRITE, dirent, count))
285 return -EFAULT;
286
287 f = fdget(fd);
288 if (!f.file)
289 return -EBADF;
290
291 error = iterate_dir(f.file, &buf.ctx);
292 if (error >= 0)
293 error = buf.error;
294 lastdirent = buf.previous;
295 if (lastdirent) {
296 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
297 if (__put_user(d_off, &lastdirent->d_off))
298 error = -EFAULT;
299 else
300 error = count - buf.count;
301 }
302 fdput(f);
303 return error;
304}
1/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
7#include <linux/stddef.h>
8#include <linux/kernel.h>
9#include <linux/export.h>
10#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
15#include <linux/fs.h>
16#include <linux/fsnotify.h>
17#include <linux/dirent.h>
18#include <linux/security.h>
19#include <linux/syscalls.h>
20#include <linux/unistd.h>
21
22#include <asm/uaccess.h>
23
24int iterate_dir(struct file *file, struct dir_context *ctx)
25{
26 struct inode *inode = file_inode(file);
27 int res = -ENOTDIR;
28 if (!file->f_op->iterate)
29 goto out;
30
31 res = security_file_permission(file, MAY_READ);
32 if (res)
33 goto out;
34
35 res = mutex_lock_killable(&inode->i_mutex);
36 if (res)
37 goto out;
38
39 res = -ENOENT;
40 if (!IS_DEADDIR(inode)) {
41 ctx->pos = file->f_pos;
42 res = file->f_op->iterate(file, ctx);
43 file->f_pos = ctx->pos;
44 fsnotify_access(file);
45 file_accessed(file);
46 }
47 inode_unlock(inode);
48out:
49 return res;
50}
51EXPORT_SYMBOL(iterate_dir);
52
53/*
54 * Traditional linux readdir() handling..
55 *
56 * "count=1" is a special case, meaning that the buffer is one
57 * dirent-structure in size and that the code can't handle more
58 * anyway. Thus the special "fillonedir()" function for that
59 * case (the low-level handlers don't need to care about this).
60 */
61
62#ifdef __ARCH_WANT_OLD_READDIR
63
64struct old_linux_dirent {
65 unsigned long d_ino;
66 unsigned long d_offset;
67 unsigned short d_namlen;
68 char d_name[1];
69};
70
71struct readdir_callback {
72 struct dir_context ctx;
73 struct old_linux_dirent __user * dirent;
74 int result;
75};
76
77static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
78 loff_t offset, u64 ino, unsigned int d_type)
79{
80 struct readdir_callback *buf =
81 container_of(ctx, struct readdir_callback, ctx);
82 struct old_linux_dirent __user * dirent;
83 unsigned long d_ino;
84
85 if (buf->result)
86 return -EINVAL;
87 d_ino = ino;
88 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
89 buf->result = -EOVERFLOW;
90 return -EOVERFLOW;
91 }
92 buf->result++;
93 dirent = buf->dirent;
94 if (!access_ok(VERIFY_WRITE, dirent,
95 (unsigned long)(dirent->d_name + namlen + 1) -
96 (unsigned long)dirent))
97 goto efault;
98 if ( __put_user(d_ino, &dirent->d_ino) ||
99 __put_user(offset, &dirent->d_offset) ||
100 __put_user(namlen, &dirent->d_namlen) ||
101 __copy_to_user(dirent->d_name, name, namlen) ||
102 __put_user(0, dirent->d_name + namlen))
103 goto efault;
104 return 0;
105efault:
106 buf->result = -EFAULT;
107 return -EFAULT;
108}
109
110SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
111 struct old_linux_dirent __user *, dirent, unsigned int, count)
112{
113 int error;
114 struct fd f = fdget(fd);
115 struct readdir_callback buf = {
116 .ctx.actor = fillonedir,
117 .dirent = dirent
118 };
119
120 if (!f.file)
121 return -EBADF;
122
123 error = iterate_dir(f.file, &buf.ctx);
124 if (buf.result)
125 error = buf.result;
126
127 fdput(f);
128 return error;
129}
130
131#endif /* __ARCH_WANT_OLD_READDIR */
132
133/*
134 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
135 * interface.
136 */
137struct linux_dirent {
138 unsigned long d_ino;
139 unsigned long d_off;
140 unsigned short d_reclen;
141 char d_name[1];
142};
143
144struct getdents_callback {
145 struct dir_context ctx;
146 struct linux_dirent __user * current_dir;
147 struct linux_dirent __user * previous;
148 int count;
149 int error;
150};
151
152static int filldir(struct dir_context *ctx, const char *name, int namlen,
153 loff_t offset, u64 ino, unsigned int d_type)
154{
155 struct linux_dirent __user * dirent;
156 struct getdents_callback *buf =
157 container_of(ctx, struct getdents_callback, ctx);
158 unsigned long d_ino;
159 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
160 sizeof(long));
161
162 buf->error = -EINVAL; /* only used if we fail.. */
163 if (reclen > buf->count)
164 return -EINVAL;
165 d_ino = ino;
166 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
167 buf->error = -EOVERFLOW;
168 return -EOVERFLOW;
169 }
170 dirent = buf->previous;
171 if (dirent) {
172 if (__put_user(offset, &dirent->d_off))
173 goto efault;
174 }
175 dirent = buf->current_dir;
176 if (__put_user(d_ino, &dirent->d_ino))
177 goto efault;
178 if (__put_user(reclen, &dirent->d_reclen))
179 goto efault;
180 if (copy_to_user(dirent->d_name, name, namlen))
181 goto efault;
182 if (__put_user(0, dirent->d_name + namlen))
183 goto efault;
184 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
185 goto efault;
186 buf->previous = dirent;
187 dirent = (void __user *)dirent + reclen;
188 buf->current_dir = dirent;
189 buf->count -= reclen;
190 return 0;
191efault:
192 buf->error = -EFAULT;
193 return -EFAULT;
194}
195
196SYSCALL_DEFINE3(getdents, unsigned int, fd,
197 struct linux_dirent __user *, dirent, unsigned int, count)
198{
199 struct fd f;
200 struct linux_dirent __user * lastdirent;
201 struct getdents_callback buf = {
202 .ctx.actor = filldir,
203 .count = count,
204 .current_dir = dirent
205 };
206 int error;
207
208 if (!access_ok(VERIFY_WRITE, dirent, count))
209 return -EFAULT;
210
211 f = fdget(fd);
212 if (!f.file)
213 return -EBADF;
214
215 error = iterate_dir(f.file, &buf.ctx);
216 if (error >= 0)
217 error = buf.error;
218 lastdirent = buf.previous;
219 if (lastdirent) {
220 if (put_user(buf.ctx.pos, &lastdirent->d_off))
221 error = -EFAULT;
222 else
223 error = count - buf.count;
224 }
225 fdput(f);
226 return error;
227}
228
229struct getdents_callback64 {
230 struct dir_context ctx;
231 struct linux_dirent64 __user * current_dir;
232 struct linux_dirent64 __user * previous;
233 int count;
234 int error;
235};
236
237static int filldir64(struct dir_context *ctx, const char *name, int namlen,
238 loff_t offset, u64 ino, unsigned int d_type)
239{
240 struct linux_dirent64 __user *dirent;
241 struct getdents_callback64 *buf =
242 container_of(ctx, struct getdents_callback64, ctx);
243 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
244 sizeof(u64));
245
246 buf->error = -EINVAL; /* only used if we fail.. */
247 if (reclen > buf->count)
248 return -EINVAL;
249 dirent = buf->previous;
250 if (dirent) {
251 if (__put_user(offset, &dirent->d_off))
252 goto efault;
253 }
254 dirent = buf->current_dir;
255 if (__put_user(ino, &dirent->d_ino))
256 goto efault;
257 if (__put_user(0, &dirent->d_off))
258 goto efault;
259 if (__put_user(reclen, &dirent->d_reclen))
260 goto efault;
261 if (__put_user(d_type, &dirent->d_type))
262 goto efault;
263 if (copy_to_user(dirent->d_name, name, namlen))
264 goto efault;
265 if (__put_user(0, dirent->d_name + namlen))
266 goto efault;
267 buf->previous = dirent;
268 dirent = (void __user *)dirent + reclen;
269 buf->current_dir = dirent;
270 buf->count -= reclen;
271 return 0;
272efault:
273 buf->error = -EFAULT;
274 return -EFAULT;
275}
276
277SYSCALL_DEFINE3(getdents64, unsigned int, fd,
278 struct linux_dirent64 __user *, dirent, unsigned int, count)
279{
280 struct fd f;
281 struct linux_dirent64 __user * lastdirent;
282 struct getdents_callback64 buf = {
283 .ctx.actor = filldir64,
284 .count = count,
285 .current_dir = dirent
286 };
287 int error;
288
289 if (!access_ok(VERIFY_WRITE, dirent, count))
290 return -EFAULT;
291
292 f = fdget(fd);
293 if (!f.file)
294 return -EBADF;
295
296 error = iterate_dir(f.file, &buf.ctx);
297 if (error >= 0)
298 error = buf.error;
299 lastdirent = buf.previous;
300 if (lastdirent) {
301 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
302 if (__put_user(d_off, &lastdirent->d_off))
303 error = -EFAULT;
304 else
305 error = count - buf.count;
306 }
307 fdput(f);
308 return error;
309}