4 * Copyright (C) 1995 Linus Torvalds
7 #include <linux/stddef.h>
8 #include <linux/kernel.h>
9 #include <linux/export.h>
10 #include <linux/time.h>
12 #include <linux/errno.h>
13 #include <linux/stat.h>
14 #include <linux/file.h>
16 #include <linux/dirent.h>
17 #include <linux/security.h>
18 #include <linux/syscalls.h>
19 #include <linux/unistd.h>
21 #include <asm/uaccess.h>
23 int iterate_dir(struct file *file, struct dir_context *ctx)
25 struct inode *inode = file_inode(file);
27 if (!file->f_op || (!file->f_op->readdir && !file->f_op->iterate))
30 res = security_file_permission(file, MAY_READ);
34 res = mutex_lock_killable(&inode->i_mutex);
39 if (!IS_DEADDIR(inode)) {
40 if (file->f_op->iterate) {
41 ctx->pos = file->f_pos;
42 res = file->f_op->iterate(file, ctx);
43 file->f_pos = ctx->pos;
45 res = file->f_op->readdir(file, ctx, ctx->actor);
46 ctx->pos = file->f_pos;
50 mutex_unlock(&inode->i_mutex);
54 EXPORT_SYMBOL(iterate_dir);
57 * Traditional linux readdir() handling..
59 * "count=1" is a special case, meaning that the buffer is one
60 * dirent-structure in size and that the code can't handle more
61 * anyway. Thus the special "fillonedir()" function for that
62 * case (the low-level handlers don't need to care about this).
65 #ifdef __ARCH_WANT_OLD_READDIR
67 struct old_linux_dirent {
69 unsigned long d_offset;
70 unsigned short d_namlen;
74 struct readdir_callback {
75 struct dir_context ctx;
76 struct old_linux_dirent __user * dirent;
80 static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
81 u64 ino, unsigned int d_type)
83 struct readdir_callback *buf = (struct readdir_callback *) __buf;
84 struct old_linux_dirent __user * dirent;
90 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
91 buf->result = -EOVERFLOW;
96 if (!access_ok(VERIFY_WRITE, dirent,
97 (unsigned long)(dirent->d_name + namlen + 1) -
98 (unsigned long)dirent))
100 if ( __put_user(d_ino, &dirent->d_ino) ||
101 __put_user(offset, &dirent->d_offset) ||
102 __put_user(namlen, &dirent->d_namlen) ||
103 __copy_to_user(dirent->d_name, name, namlen) ||
104 __put_user(0, dirent->d_name + namlen))
108 buf->result = -EFAULT;
112 SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
113 struct old_linux_dirent __user *, dirent, unsigned int, count)
116 struct fd f = fdget(fd);
117 struct readdir_callback buf = {
118 .ctx.actor = fillonedir,
125 error = iterate_dir(f.file, &buf.ctx);
133 #endif /* __ARCH_WANT_OLD_READDIR */
136 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
139 struct linux_dirent {
142 unsigned short d_reclen;
146 struct getdents_callback {
147 struct dir_context ctx;
148 struct linux_dirent __user * current_dir;
149 struct linux_dirent __user * previous;
154 static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
155 u64 ino, unsigned int d_type)
157 struct linux_dirent __user * dirent;
158 struct getdents_callback * buf = (struct getdents_callback *) __buf;
160 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
163 buf->error = -EINVAL; /* only used if we fail.. */
164 if (reclen > buf->count)
167 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
168 buf->error = -EOVERFLOW;
171 dirent = buf->previous;
173 if (__put_user(offset, &dirent->d_off))
176 dirent = buf->current_dir;
177 if (__put_user(d_ino, &dirent->d_ino))
179 if (__put_user(reclen, &dirent->d_reclen))
181 if (copy_to_user(dirent->d_name, name, namlen))
183 if (__put_user(0, dirent->d_name + namlen))
185 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
187 buf->previous = dirent;
188 dirent = (void __user *)dirent + reclen;
189 buf->current_dir = dirent;
190 buf->count -= reclen;
193 buf->error = -EFAULT;
197 SYSCALL_DEFINE3(getdents, unsigned int, fd,
198 struct linux_dirent __user *, dirent, unsigned int, count)
201 struct linux_dirent __user * lastdirent;
202 struct getdents_callback buf = {
203 .ctx.actor = filldir,
205 .current_dir = dirent
209 if (!access_ok(VERIFY_WRITE, dirent, count))
216 error = iterate_dir(f.file, &buf.ctx);
219 lastdirent = buf.previous;
221 if (put_user(buf.ctx.pos, &lastdirent->d_off))
224 error = count - buf.count;
230 struct getdents_callback64 {
231 struct dir_context ctx;
232 struct linux_dirent64 __user * current_dir;
233 struct linux_dirent64 __user * previous;
238 static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
239 u64 ino, unsigned int d_type)
241 struct linux_dirent64 __user *dirent;
242 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
243 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
246 buf->error = -EINVAL; /* only used if we fail.. */
247 if (reclen > buf->count)
249 dirent = buf->previous;
251 if (__put_user(offset, &dirent->d_off))
254 dirent = buf->current_dir;
255 if (__put_user(ino, &dirent->d_ino))
257 if (__put_user(0, &dirent->d_off))
259 if (__put_user(reclen, &dirent->d_reclen))
261 if (__put_user(d_type, &dirent->d_type))
263 if (copy_to_user(dirent->d_name, name, namlen))
265 if (__put_user(0, dirent->d_name + namlen))
267 buf->previous = dirent;
268 dirent = (void __user *)dirent + reclen;
269 buf->current_dir = dirent;
270 buf->count -= reclen;
273 buf->error = -EFAULT;
277 SYSCALL_DEFINE3(getdents64, unsigned int, fd,
278 struct linux_dirent64 __user *, dirent, unsigned int, count)
281 struct linux_dirent64 __user * lastdirent;
282 struct getdents_callback64 buf = {
283 .ctx.actor = filldir64,
285 .current_dir = dirent
289 if (!access_ok(VERIFY_WRITE, dirent, count))
296 error = iterate_dir(f.file, &buf.ctx);
299 lastdirent = buf.previous;
301 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
302 if (__put_user(d_off, &lastdirent->d_off))
305 error = count - buf.count;