[linux.git] / fs / readdir.c

/*
 *  linux/fs/readdir.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 */

#include <linux/module.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/dirent.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>

#include <asm/uaccess.h>

int vfs_readdir(struct file *file, filldir_t filler, void *buf)
{
	struct inode *inode = file->f_dentry->d_inode;
	int res = -ENOTDIR;
	if (!file->f_op || !file->f_op->readdir)
		goto out;

	res = security_file_permission(file, MAY_READ);
	if (res)
		goto out;

	mutex_lock(&inode->i_mutex);
	res = -ENOENT;
	if (!IS_DEADDIR(inode)) {
		res = file->f_op->readdir(file, buf, filler);
		file_accessed(file);
	}
	mutex_unlock(&inode->i_mutex);
out:
	return res;
}

EXPORT_SYMBOL(vfs_readdir);

/*
 * Traditional linux readdir() handling..
 *
 * "count=1" is a special case, meaning that the buffer is one
 * dirent-structure in size and that the code can't handle more
 * anyway. Thus the special "fillonedir()" function for that
 * case (the low-level handlers don't need to care about this).
 */
#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))

#ifdef __ARCH_WANT_OLD_READDIR

struct old_linux_dirent {
	unsigned long	d_ino;
	unsigned long	d_offset;
	unsigned short	d_namlen;
	char		d_name[1];
};

struct readdir_callback {
	struct old_linux_dirent __user * dirent;
	int result;
};

static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
		      ino_t ino, unsigned int d_type)
{
	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	struct old_linux_dirent __user * dirent;

	if (buf->result)
		return -EINVAL;
	buf->result++;
	dirent = buf->dirent;
	if (!access_ok(VERIFY_WRITE, dirent,
			(unsigned long)(dirent->d_name + namlen + 1) -
				(unsigned long)dirent))
		goto efault;
	if (	__put_user(ino, &dirent->d_ino) ||
		__put_user(offset, &dirent->d_offset) ||
		__put_user(namlen, &dirent->d_namlen) ||
		__copy_to_user(dirent->d_name, name, namlen) ||
		__put_user(0, dirent->d_name + namlen))
		goto efault;
	return 0;
efault:
	buf->result = -EFAULT;
	return -EFAULT;
}

asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
{
	int error;
	struct file * file;
	struct readdir_callback buf;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.result = 0;
	buf.dirent = dirent;

	error = vfs_readdir(file, fillonedir, &buf);
	if (error >= 0)
		error = buf.result;

	fput(file);
out:
	return error;
}

#endif /* __ARCH_WANT_OLD_READDIR */

/*
 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
 * interface. 
 */
struct linux_dirent {
	unsigned long	d_ino;
	unsigned long	d_off;
	unsigned short	d_reclen;
	char		d_name[1];
};

struct getdents_callback {
	struct linux_dirent __user * current_dir;
	struct linux_dirent __user * previous;
	int count;
	int error;
};

static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
		   ino_t ino, unsigned int d_type)
{
	struct linux_dirent __user * dirent;
	struct getdents_callback * buf = (struct getdents_callback *) __buf;
	int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;
	if (dirent) {
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(ino, &dirent->d_ino))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
{
	struct file * file;
	struct linux_dirent __user * lastdirent;
	struct getdents_callback buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, filldir, &buf);
	if (error < 0)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}

#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))

struct getdents_callback64 {
	struct linux_dirent64 __user * current_dir;
	struct linux_dirent64 __user * previous;
	int count;
	int error;
};

static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
		     ino_t ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
	int reclen = ROUND_UP64(NAME_OFFSET(dirent) + namlen + 1);

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;
	if (dirent) {
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(ino, &dirent->d_ino))
		goto efault;
	if (__put_user(0, &dirent->d_off))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (__put_user(d_type, &dirent->d_type))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
{
	struct file * file;
	struct linux_dirent64 __user * lastdirent;
	struct getdents_callback64 buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, filldir64, &buf);
	if (error < 0)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = file->f_pos;
		error = -EFAULT;
		if (__put_user(d_off, &lastdirent->d_off))
			goto out_putf;
		error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/readdir.c
	3	*
	4	* Copyright (C) 1995 Linus Torvalds
	5	*/
	6
	7	#include <linux/module.h>
	8	#include <linux/time.h>
	9	#include <linux/mm.h>
	10	#include <linux/errno.h>
	11	#include <linux/stat.h>
	12	#include <linux/file.h>
	13	#include <linux/smp_lock.h>
	14	#include <linux/fs.h>
	15	#include <linux/dirent.h>
	16	#include <linux/security.h>
	17	#include <linux/syscalls.h>
	18	#include <linux/unistd.h>
	19
	20	#include <asm/uaccess.h>
	21
	22	int vfs_readdir(struct file file, filldir_t filler, void buf)
	23	{
	24	struct inode *inode = file->f_dentry->d_inode;
	25	int res = -ENOTDIR;
	26	if (!file->f_op \|\| !file->f_op->readdir)
	27	goto out;
	28
	29	res = security_file_permission(file, MAY_READ);
	30	if (res)
	31	goto out;
	32
1b1dcc1b	33	mutex_lock(&inode->i_mutex);
1da177e4 LT	34	res = -ENOENT;
	35	if (!IS_DEADDIR(inode)) {
	36	res = file->f_op->readdir(file, buf, filler);
	37	file_accessed(file);
	38	}
1b1dcc1b	39	mutex_unlock(&inode->i_mutex);
1da177e4 LT	40	out:
	41	return res;
	42	}
	43
	44	EXPORT_SYMBOL(vfs_readdir);
	45
	46	/*
	47	* Traditional linux readdir() handling..
	48	*
	49	* "count=1" is a special case, meaning that the buffer is one
	50	* dirent-structure in size and that the code can't handle more
	51	* anyway. Thus the special "fillonedir()" function for that
	52	* case (the low-level handlers don't need to care about this).
	53	*/
	54	#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
	55	#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
	56
	57	#ifdef __ARCH_WANT_OLD_READDIR
	58
	59	struct old_linux_dirent {
	60	unsigned long d_ino;
	61	unsigned long d_offset;
	62	unsigned short d_namlen;
	63	char d_name[1];
	64	};
	65
	66	struct readdir_callback {
	67	struct old_linux_dirent __user * dirent;
	68	int result;
	69	};
	70
	71	static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
	72	ino_t ino, unsigned int d_type)
	73	{
	74	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	75	struct old_linux_dirent __user * dirent;
	76
	77	if (buf->result)
	78	return -EINVAL;
	79	buf->result++;
	80	dirent = buf->dirent;
	81	if (!access_ok(VERIFY_WRITE, dirent,
	82	(unsigned long)(dirent->d_name + namlen + 1) -
	83	(unsigned long)dirent))
	84	goto efault;
	85	if ( __put_user(ino, &dirent->d_ino) \|\|
	86	__put_user(offset, &dirent->d_offset) \|\|
	87	__put_user(namlen, &dirent->d_namlen) \|\|
	88	__copy_to_user(dirent->d_name, name, namlen) \|\|
	89	__put_user(0, dirent->d_name + namlen))
	90	goto efault;
	91	return 0;
	92	efault:
	93	buf->result = -EFAULT;
	94	return -EFAULT;
	95	}
	96
	97	asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
	98	{
	99	int error;
	100	struct file * file;
	101	struct readdir_callback buf;
	102
	103	error = -EBADF;
104	file = fget(fd);
105	if (!file)
106	goto out;
107
108	buf.result = 0;
109	buf.dirent = dirent;
110
111	error = vfs_readdir(file, fillonedir, &buf);
112	if (error >= 0)
113	error = buf.result;
114
115	fput(file);
116	out:
117	return error;
118	}
119
120	#endif /* __ARCH_WANT_OLD_READDIR */
121
122	/*
123	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
124	* interface.
125	*/
126	struct linux_dirent {
127	unsigned long d_ino;
128	unsigned long d_off;
129	unsigned short d_reclen;
130	char d_name[1];
131	};
132
133	struct getdents_callback {
134	struct linux_dirent __user * current_dir;
135	struct linux_dirent __user * previous;
136	int count;
137	int error;
138	};
139
140	static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
141	ino_t ino, unsigned int d_type)
142	{
143	struct linux_dirent __user * dirent;
144	struct getdents_callback * buf = (struct getdents_callback *) __buf;
145	int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);
146
147	buf->error = -EINVAL; /* only used if we fail.. */
148	if (reclen > buf->count)
149	return -EINVAL;
150	dirent = buf->previous;
151	if (dirent) {
152	if (__put_user(offset, &dirent->d_off))
153	goto efault;
154	}
155	dirent = buf->current_dir;
156	if (__put_user(ino, &dirent->d_ino))
157	goto efault;
158	if (__put_user(reclen, &dirent->d_reclen))
159	goto efault;
160	if (copy_to_user(dirent->d_name, name, namlen))
161	goto efault;
162	if (__put_user(0, dirent->d_name + namlen))
163	goto efault;
164	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
165	goto efault;
166	buf->previous = dirent;
167	dirent = (void __user *)dirent + reclen;
168	buf->current_dir = dirent;
169	buf->count -= reclen;
170	return 0;
171	efault:
172	buf->error = -EFAULT;
173	return -EFAULT;
174	}
175
176	asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
177	{
178	struct file * file;
179	struct linux_dirent __user * lastdirent;
180	struct getdents_callback buf;
181	int error;
182
183	error = -EFAULT;
184	if (!access_ok(VERIFY_WRITE, dirent, count))
185	goto out;
186
187	error = -EBADF;
188	file = fget(fd);
189	if (!file)
190	goto out;
191
192	buf.current_dir = dirent;
193	buf.previous = NULL;
194	buf.count = count;
195	buf.error = 0;
196
197	error = vfs_readdir(file, filldir, &buf);
198	if (error < 0)
199	goto out_putf;
200	error = buf.error;
201	lastdirent = buf.previous;
202	if (lastdirent) {
203	if (put_user(file->f_pos, &lastdirent->d_off))
204	error = -EFAULT;
205	else
206	error = count - buf.count;
207	}
208
209	out_putf:
210	fput(file);
211	out:
212	return error;
213	}
214
215	#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))
216
217	struct getdents_callback64 {
218	struct linux_dirent64 __user * current_dir;
219	struct linux_dirent64 __user * previous;
220	int count;
221	int error;
222	};
223
224	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
225	ino_t ino, unsigned int d_type)
226	{
227	struct linux_dirent64 __user *dirent;
228	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
229	int reclen = ROUND_UP64(NAME_OFFSET(dirent) + namlen + 1);
230
231	buf->error = -EINVAL; /* only used if we fail.. */
232	if (reclen > buf->count)
233	return -EINVAL;
234	dirent = buf->previous;
235	if (dirent) {
236	if (__put_user(offset, &dirent->d_off))
237	goto efault;
238	}
239	dirent = buf->current_dir;
240	if (__put_user(ino, &dirent->d_ino))
241	goto efault;
242	if (__put_user(0, &dirent->d_off))
243	goto efault;
244	if (__put_user(reclen, &dirent->d_reclen))
245	goto efault;
246	if (__put_user(d_type, &dirent->d_type))
247	goto efault;
248	if (copy_to_user(dirent->d_name, name, namlen))
249	goto efault;
250	if (__put_user(0, dirent->d_name + namlen))
251	goto efault;
252	buf->previous = dirent;
253	dirent = (void __user *)dirent + reclen;
254	buf->current_dir = dirent;
255	buf->count -= reclen;
256	return 0;
257	efault:
258	buf->error = -EFAULT;
259	return -EFAULT;
260	}
261
262	asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
263	{
264	struct file * file;
265	struct linux_dirent64 __user * lastdirent;
266	struct getdents_callback64 buf;
267	int error;
268
269	error = -EFAULT;
270	if (!access_ok(VERIFY_WRITE, dirent, count))
271	goto out;
272
273	error = -EBADF;
274	file = fget(fd);
275	if (!file)
276	goto out;
277
278	buf.current_dir = dirent;
279	buf.previous = NULL;
280	buf.count = count;
281	buf.error = 0;
282
283	error = vfs_readdir(file, filldir64, &buf);
284	if (error < 0)
285	goto out_putf;
286	error = buf.error;
287	lastdirent = buf.previous;
288	if (lastdirent) {
289	typeof(lastdirent->d_off) d_off = file->f_pos;
290	error = -EFAULT;
291	if (__put_user(d_off, &lastdirent->d_off))
292	goto out_putf;
293	error = count - buf.count;
294	}
295
296	out_putf:
297	fput(file);
298	out:
299	return error;
300	}