[linux.git] / fs / readdir.c

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

#include <linux/kernel.h>
#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/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_path.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;

	res = mutex_lock_killable(&inode->i_mutex);
	if (res)
		goto out;

	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)))

#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,
		      u64 ino, unsigned int d_type)
{
	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	struct old_linux_dirent __user * dirent;
	unsigned long d_ino;

	if (buf->result)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
		return -EOVERFLOW;
	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(d_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,
		   u64 ino, unsigned int d_type)
{
	struct linux_dirent __user * dirent;
	struct getdents_callback * buf = (struct getdents_callback *) __buf;
	unsigned long d_ino;
	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
		return -EOVERFLOW;
	dirent = buf->previous;
	if (dirent) {
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(d_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;
}

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,
		     u64 ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));

	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
022a1692	7	#include <linux/kernel.h>
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/time.h>
	10	#include <linux/mm.h>
	11	#include <linux/errno.h>
	12	#include <linux/stat.h>
	13	#include <linux/file.h>
1da177e4 LT	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	{
0f7fc9e4	24	struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 LT	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
da784511 LH	33	res = mutex_lock_killable(&inode->i_mutex);
	34	if (res)
	35	goto out;
	36
1da177e4 LT	37	res = -ENOENT;
	38	if (!IS_DEADDIR(inode)) {
	39	res = file->f_op->readdir(file, buf, filler);
	40	file_accessed(file);
	41	}
1b1dcc1b	42	mutex_unlock(&inode->i_mutex);
1da177e4 LT	43	out:
	44	return res;
	45	}
	46
	47	EXPORT_SYMBOL(vfs_readdir);
	48
	49	/*
	50	* Traditional linux readdir() handling..
	51	*
	52	* "count=1" is a special case, meaning that the buffer is one
	53	* dirent-structure in size and that the code can't handle more
	54	* anyway. Thus the special "fillonedir()" function for that
	55	* case (the low-level handlers don't need to care about this).
	56	*/
	57	#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
1da177e4 LT	58
	59	#ifdef __ARCH_WANT_OLD_READDIR
	60
	61	struct old_linux_dirent {
	62	unsigned long d_ino;
	63	unsigned long d_offset;
	64	unsigned short d_namlen;
	65	char d_name[1];
	66	};
	67
	68	struct readdir_callback {
	69	struct old_linux_dirent __user * dirent;
	70	int result;
	71	};
	72
	73	static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	74	u64 ino, unsigned int d_type)
1da177e4 LT	75	{
	76	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	77	struct old_linux_dirent __user * dirent;
afefdbb2	78	unsigned long d_ino;
1da177e4 LT	79
	80	if (buf->result)
	81	return -EINVAL;
afefdbb2 DH	82	d_ino = ino;
	83	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
	84	return -EOVERFLOW;
1da177e4 LT	85	buf->result++;
	86	dirent = buf->dirent;
	87	if (!access_ok(VERIFY_WRITE, dirent,
	88	(unsigned long)(dirent->d_name + namlen + 1) -
	89	(unsigned long)dirent))
	90	goto efault;
afefdbb2	91	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	92	__put_user(offset, &dirent->d_offset) \|\|
	93	__put_user(namlen, &dirent->d_namlen) \|\|
	94	__copy_to_user(dirent->d_name, name, namlen) \|\|
	95	__put_user(0, dirent->d_name + namlen))
	96	goto efault;
	97	return 0;
	98	efault:
	99	buf->result = -EFAULT;
	100	return -EFAULT;
	101	}
	102
	103	asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
	104	{
	105	int error;
	106	struct file * file;
	107	struct readdir_callback buf;
	108
	109	error = -EBADF;
	110	file = fget(fd);
	111	if (!file)
	112	goto out;
	113
	114	buf.result = 0;
	115	buf.dirent = dirent;
	116
	117	error = vfs_readdir(file, fillonedir, &buf);
	118	if (error >= 0)
	119	error = buf.result;
	120
	121	fput(file);
	122	out:
	123	return error;
	124	}
	125
	126	#endif /* __ARCH_WANT_OLD_READDIR */
	127
	128	/*
	129	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	130	* interface.
	131	*/
	132	struct linux_dirent {
	133	unsigned long d_ino;
	134	unsigned long d_off;
	135	unsigned short d_reclen;
	136	char d_name[1];
	137	};
	138
	139	struct getdents_callback {
	140	struct linux_dirent __user * current_dir;
	141	struct linux_dirent __user * previous;
	142	int count;
	143	int error;
	144	};
	145
	146	static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	147	u64 ino, unsigned int d_type)
1da177e4 LT	148	{
	149	struct linux_dirent __user * dirent;
	150	struct getdents_callback * buf = (struct getdents_callback *) __buf;
afefdbb2	151	unsigned long d_ino;
022a1692	152	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
1da177e4 LT	153
	154	buf->error = -EINVAL; /* only used if we fail.. */
	155	if (reclen > buf->count)
	156	return -EINVAL;
afefdbb2 DH	157	d_ino = ino;
	158	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
	159	return -EOVERFLOW;
1da177e4 LT	160	dirent = buf->previous;
	161	if (dirent) {
	162	if (__put_user(offset, &dirent->d_off))
	163	goto efault;
	164	}
	165	dirent = buf->current_dir;
afefdbb2	166	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	167	goto efault;
	168	if (__put_user(reclen, &dirent->d_reclen))
	169	goto efault;
	170	if (copy_to_user(dirent->d_name, name, namlen))
	171	goto efault;
	172	if (__put_user(0, dirent->d_name + namlen))
	173	goto efault;
	174	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	175	goto efault;
	176	buf->previous = dirent;
	177	dirent = (void __user *)dirent + reclen;
	178	buf->current_dir = dirent;
	179	buf->count -= reclen;
	180	return 0;
	181	efault:
	182	buf->error = -EFAULT;
	183	return -EFAULT;
	184	}
	185
	186	asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
	187	{
	188	struct file * file;
	189	struct linux_dirent __user * lastdirent;
	190	struct getdents_callback buf;
	191	int error;
	192
	193	error = -EFAULT;
	194	if (!access_ok(VERIFY_WRITE, dirent, count))
	195	goto out;
	196
	197	error = -EBADF;
	198	file = fget(fd);
	199	if (!file)
	200	goto out;
	201
	202	buf.current_dir = dirent;
	203	buf.previous = NULL;
	204	buf.count = count;
	205	buf.error = 0;
	206
	207	error = vfs_readdir(file, filldir, &buf);
	208	if (error < 0)
	209	goto out_putf;
	210	error = buf.error;
	211	lastdirent = buf.previous;
	212	if (lastdirent) {
	213	if (put_user(file->f_pos, &lastdirent->d_off))
	214	error = -EFAULT;
	215	else
	216	error = count - buf.count;
	217	}
	218
	219	out_putf:
	220	fput(file);
	221	out:
	222	return error;
	223	}
	224
1da177e4 LT	225	struct getdents_callback64 {
	226	struct linux_dirent64 __user * current_dir;
	227	struct linux_dirent64 __user * previous;
	228	int count;
	229	int error;
	230	};
	231
	232	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	233	u64 ino, unsigned int d_type)
1da177e4 LT	234	{
	235	struct linux_dirent64 __user *dirent;
	236	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
022a1692	237	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
1da177e4 LT	238
	239	buf->error = -EINVAL; /* only used if we fail.. */
	240	if (reclen > buf->count)
	241	return -EINVAL;
	242	dirent = buf->previous;
	243	if (dirent) {
	244	if (__put_user(offset, &dirent->d_off))
	245	goto efault;
	246	}
	247	dirent = buf->current_dir;
	248	if (__put_user(ino, &dirent->d_ino))
	249	goto efault;
	250	if (__put_user(0, &dirent->d_off))
	251	goto efault;
	252	if (__put_user(reclen, &dirent->d_reclen))
	253	goto efault;
	254	if (__put_user(d_type, &dirent->d_type))
	255	goto efault;
	256	if (copy_to_user(dirent->d_name, name, namlen))
	257	goto efault;
	258	if (__put_user(0, dirent->d_name + namlen))
	259	goto efault;
	260	buf->previous = dirent;
	261	dirent = (void __user *)dirent + reclen;
	262	buf->current_dir = dirent;
	263	buf->count -= reclen;
	264	return 0;
	265	efault:
	266	buf->error = -EFAULT;
	267	return -EFAULT;
	268	}
	269
	270	asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
	271	{
	272	struct file * file;
	273	struct linux_dirent64 __user * lastdirent;
	274	struct getdents_callback64 buf;
	275	int error;
	276
	277	error = -EFAULT;
	278	if (!access_ok(VERIFY_WRITE, dirent, count))
	279	goto out;
	280
	281	error = -EBADF;
	282	file = fget(fd);
	283	if (!file)
	284	goto out;
	285
	286	buf.current_dir = dirent;
	287	buf.previous = NULL;
	288	buf.count = count;
	289	buf.error = 0;
	290
	291	error = vfs_readdir(file, filldir64, &buf);
	292	if (error < 0)
	293	goto out_putf;
	294	error = buf.error;
	295	lastdirent = buf.previous;
	296	if (lastdirent) {
	297	typeof(lastdirent->d_off) d_off = file->f_pos;
	298	error = -EFAULT;
	299	if (__put_user(d_off, &lastdirent->d_off))
	300	goto out_putf;
	301	error = count - buf.count;
302	}
303
304	out_putf:
305	fput(file);
306	out:
307	return error;
308	}