[linux.git] / fs / readdir.c

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

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/export.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/fsnotify.h>
#include <linux/dirent.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/compat.h>

#include <linux/uaccess.h>

int iterate_dir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	bool shared = false;
	int res = -ENOTDIR;
	if (file->f_op->iterate_shared)
		shared = true;
	else if (!file->f_op->iterate)
		goto out;

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

	if (shared) {
		inode_lock_shared(inode);
	} else {
		res = down_write_killable(&inode->i_rwsem);
		if (res)
			goto out;
	}

	res = -ENOENT;
	if (!IS_DEADDIR(inode)) {
		ctx->pos = file->f_pos;
		if (shared)
			res = file->f_op->iterate_shared(file, ctx);
		else
			res = file->f_op->iterate(file, ctx);
		file->f_pos = ctx->pos;
		fsnotify_access(file);
		file_accessed(file);
	}
	if (shared)
		inode_unlock_shared(inode);
	else
		inode_unlock(inode);
out:
	return res;
}
EXPORT_SYMBOL(iterate_dir);

/*
 * 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).
 */

#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 dir_context ctx;
	struct old_linux_dirent __user * dirent;
	int result;
};

static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
		      loff_t offset, u64 ino, unsigned int d_type)
{
	struct readdir_callback *buf =
		container_of(ctx, struct readdir_callback, ctx);
	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) {
		buf->result = -EOVERFLOW;
		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;
}

SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
		struct old_linux_dirent __user *, dirent, unsigned int, count)
{
	int error;
	struct fd f = fdget_pos(fd);
	struct readdir_callback buf = {
		.ctx.actor = fillonedir,
		.dirent = dirent
	};

	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (buf.result)
		error = buf.result;

	fdput_pos(f);
	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 dir_context ctx;
	struct linux_dirent __user * current_dir;
	struct linux_dirent __user * previous;
	int count;
	int error;
};

static int filldir(struct dir_context *ctx, const char *name, int namlen,
		   loff_t offset, u64 ino, unsigned int d_type)
{
	struct linux_dirent __user * dirent;
	struct getdents_callback *buf =
		container_of(ctx, struct getdents_callback, ctx);
	unsigned long d_ino;
	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + 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) {
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
	}
	dirent = buf->previous;
	if (dirent) {
		if (signal_pending(current))
			return -EINTR;
		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;
}

SYSCALL_DEFINE3(getdents, unsigned int, fd,
		struct linux_dirent __user *, dirent, unsigned int, count)
{
	struct fd f;
	struct linux_dirent __user * lastdirent;
	struct getdents_callback buf = {
		.ctx.actor = filldir,
		.count = count,
		.current_dir = dirent
	};
	int error;

	if (!access_ok(VERIFY_WRITE, dirent, count))
		return -EFAULT;

	f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(buf.ctx.pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fdput_pos(f);
	return error;
}

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

static int filldir64(struct dir_context *ctx, const char *name, int namlen,
		     loff_t offset, u64 ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct getdents_callback64 *buf =
		container_of(ctx, struct getdents_callback64, ctx);
	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
		sizeof(u64));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;
	if (dirent) {
		if (signal_pending(current))
			return -EINTR;
		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;
}

SYSCALL_DEFINE3(getdents64, unsigned int, fd,
		struct linux_dirent64 __user *, dirent, unsigned int, count)
{
	struct fd f;
	struct linux_dirent64 __user * lastdirent;
	struct getdents_callback64 buf = {
		.ctx.actor = filldir64,
		.count = count,
		.current_dir = dirent
	};
	int error;

	if (!access_ok(VERIFY_WRITE, dirent, count))
		return -EFAULT;

	f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = buf.ctx.pos;
		if (__put_user(d_off, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fdput_pos(f);
	return error;
}

#ifdef CONFIG_COMPAT
struct compat_old_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_offset;
	unsigned short	d_namlen;
	char		d_name[1];
};

struct compat_readdir_callback {
	struct dir_context ctx;
	struct compat_old_linux_dirent __user *dirent;
	int result;
};

static int compat_fillonedir(struct dir_context *ctx, const char *name,
			     int namlen, loff_t offset, u64 ino,
			     unsigned int d_type)
{
	struct compat_readdir_callback *buf =
		container_of(ctx, struct compat_readdir_callback, ctx);
	struct compat_old_linux_dirent __user *dirent;
	compat_ulong_t d_ino;

	if (buf->result)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->result = -EOVERFLOW;
		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;
}

COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
		struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
{
	int error;
	struct fd f = fdget_pos(fd);
	struct compat_readdir_callback buf = {
		.ctx.actor = compat_fillonedir,
		.dirent = dirent
	};

	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (buf.result)
		error = buf.result;

	fdput_pos(f);
	return error;
}

struct compat_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_off;
	unsigned short	d_reclen;
	char		d_name[1];
};

struct compat_getdents_callback {
	struct dir_context ctx;
	struct compat_linux_dirent __user *current_dir;
	struct compat_linux_dirent __user *previous;
	int count;
	int error;
};

static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
		loff_t offset, u64 ino, unsigned int d_type)
{
	struct compat_linux_dirent __user * dirent;
	struct compat_getdents_callback *buf =
		container_of(ctx, struct compat_getdents_callback, ctx);
	compat_ulong_t d_ino;
	int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
		namlen + 2, sizeof(compat_long_t));

	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) {
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
	}
	dirent = buf->previous;
	if (dirent) {
		if (signal_pending(current))
			return -EINTR;
		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;
}

COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
		struct compat_linux_dirent __user *, dirent, unsigned int, count)
{
	struct fd f;
	struct compat_linux_dirent __user * lastdirent;
	struct compat_getdents_callback buf = {
		.ctx.actor = compat_filldir,
		.current_dir = dirent,
		.count = count
	};
	int error;

	if (!access_ok(VERIFY_WRITE, dirent, count))
		return -EFAULT;

	f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(buf.ctx.pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fdput_pos(f);
	return error;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/readdir.c
	3	*
	4	* Copyright (C) 1995 Linus Torvalds
	5	*/
	6
85c9fe8f	7	#include <linux/stddef.h>
022a1692	8	#include <linux/kernel.h>
630d9c47	9	#include <linux/export.h>
1da177e4 LT	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>
1da177e4	15	#include <linux/fs.h>
d4c7cf6c	16	#include <linux/fsnotify.h>
1da177e4 LT	17	#include <linux/dirent.h>
	18	#include <linux/security.h>
	19	#include <linux/syscalls.h>
	20	#include <linux/unistd.h>
0460b2a2	21	#include <linux/compat.h>
1da177e4	22
7c0f6ba6	23	#include <linux/uaccess.h>
1da177e4	24
5c0ba4e0	25	int iterate_dir(struct file file, struct dir_context ctx)
1da177e4	26	{
496ad9aa	27	struct inode *inode = file_inode(file);
61922694	28	bool shared = false;
1da177e4	29	int res = -ENOTDIR;
61922694 AV	30	if (file->f_op->iterate_shared)
	31	shared = true;
	32	else if (!file->f_op->iterate)
1da177e4 LT	33	goto out;
	34
	35	res = security_file_permission(file, MAY_READ);
	36	if (res)
	37	goto out;
	38
00235411	39	if (shared) {
61922694	40	inode_lock_shared(inode);
00235411 AV	41	} else {
	42	res = down_write_killable(&inode->i_rwsem);
	43	if (res)
	44	goto out;
	45	}
da784511	46
1da177e4 LT	47	res = -ENOENT;
1da177e4 LT	48	if (!IS_DEADDIR(inode)) {
2233f31a	49	ctx->pos = file->f_pos;
61922694 AV	50	if (shared)
	51	res = file->f_op->iterate_shared(file, ctx);
	52	else
	53	res = file->f_op->iterate(file, ctx);
2233f31a	54	file->f_pos = ctx->pos;
d4c7cf6c	55	fsnotify_access(file);
1da177e4 LT	56	file_accessed(file);
1da177e4 LT	57	}
61922694 AV	58	if (shared)
	59	inode_unlock_shared(inode);
	60	else
	61	inode_unlock(inode);
1da177e4 LT	62	out:
	63	return res;
	64	}
5c0ba4e0	65	EXPORT_SYMBOL(iterate_dir);
1da177e4 LT	66
	67	/*
	68	* Traditional linux readdir() handling..
	69	*
	70	* "count=1" is a special case, meaning that the buffer is one
	71	* dirent-structure in size and that the code can't handle more
	72	* anyway. Thus the special "fillonedir()" function for that
	73	* case (the low-level handlers don't need to care about this).
	74	*/
1da177e4 LT	75
	76	#ifdef __ARCH_WANT_OLD_READDIR
	77
	78	struct old_linux_dirent {
	79	unsigned long d_ino;
	80	unsigned long d_offset;
	81	unsigned short d_namlen;
	82	char d_name[1];
	83	};
	84
	85	struct readdir_callback {
5c0ba4e0	86	struct dir_context ctx;
1da177e4 LT	87	struct old_linux_dirent __user * dirent;
	88	int result;
	89	};
	90
ac7576f4 MS	91	static int fillonedir(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	92	loff_t offset, u64 ino, unsigned int d_type)
1da177e4	93	{
ac7576f4 MS	94	struct readdir_callback *buf =
ac7576f4 MS	95	container_of(ctx, struct readdir_callback, ctx);
1da177e4	96	struct old_linux_dirent __user * dirent;
afefdbb2	97	unsigned long d_ino;
1da177e4 LT	98
	99	if (buf->result)
	100	return -EINVAL;
afefdbb2	101	d_ino = ino;
8f3f655d AV	102	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	103	buf->result = -EOVERFLOW;
afefdbb2	104	return -EOVERFLOW;
8f3f655d	105	}
1da177e4 LT	106	buf->result++;
	107	dirent = buf->dirent;
	108	if (!access_ok(VERIFY_WRITE, dirent,
	109	(unsigned long)(dirent->d_name + namlen + 1) -
	110	(unsigned long)dirent))
	111	goto efault;
afefdbb2	112	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	113	__put_user(offset, &dirent->d_offset) \|\|
	114	__put_user(namlen, &dirent->d_namlen) \|\|
	115	__copy_to_user(dirent->d_name, name, namlen) \|\|
	116	__put_user(0, dirent->d_name + namlen))
	117	goto efault;
	118	return 0;
	119	efault:
	120	buf->result = -EFAULT;
	121	return -EFAULT;
	122	}
	123
d4e82042 HC	124	SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
d4e82042 HC	125	struct old_linux_dirent __user *, dirent, unsigned int, count)
1da177e4 LT	126	{
1da177e4 LT	127	int error;
63b6df14	128	struct fd f = fdget_pos(fd);
ac6614b7 AV	129	struct readdir_callback buf = {
	130	.ctx.actor = fillonedir,
	131	.dirent = dirent
	132	};
1da177e4	133
2903ff01	134	if (!f.file)
863ced7f	135	return -EBADF;
1da177e4	136
5c0ba4e0	137	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0	138	if (buf.result)
1da177e4 LT	139	error = buf.result;
1da177e4 LT	140
63b6df14	141	fdput_pos(f);
1da177e4 LT	142	return error;
	143	}
	144
	145	#endif /* __ARCH_WANT_OLD_READDIR */
	146
	147	/*
	148	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	149	* interface.
	150	*/
	151	struct linux_dirent {
	152	unsigned long d_ino;
	153	unsigned long d_off;
	154	unsigned short d_reclen;
	155	char d_name[1];
	156	};
	157
	158	struct getdents_callback {
5c0ba4e0	159	struct dir_context ctx;
1da177e4 LT	160	struct linux_dirent __user * current_dir;
	161	struct linux_dirent __user * previous;
	162	int count;
	163	int error;
	164	};
	165
ac7576f4 MS	166	static int filldir(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	167	loff_t offset, u64 ino, unsigned int d_type)
1da177e4 LT	168	{
1da177e4 LT	169	struct linux_dirent __user * dirent;
ac7576f4 MS	170	struct getdents_callback *buf =
ac7576f4 MS	171	container_of(ctx, struct getdents_callback, ctx);
afefdbb2	172	unsigned long d_ino;
85c9fe8f KW	173	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
85c9fe8f KW	174	sizeof(long));
1da177e4 LT	175
	176	buf->error = -EINVAL; /* only used if we fail.. */
	177	if (reclen > buf->count)
	178	return -EINVAL;
afefdbb2	179	d_ino = ino;
8f3f655d AV	180	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	181	buf->error = -EOVERFLOW;
afefdbb2	182	return -EOVERFLOW;
8f3f655d	183	}
1da177e4 LT	184	dirent = buf->previous;
1da177e4 LT	185	if (dirent) {
1f60fbe7 TT	186	if (signal_pending(current))
1f60fbe7 TT	187	return -EINTR;
1da177e4 LT	188	if (__put_user(offset, &dirent->d_off))
	189	goto efault;
	190	}
	191	dirent = buf->current_dir;
afefdbb2	192	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	193	goto efault;
	194	if (__put_user(reclen, &dirent->d_reclen))
	195	goto efault;
	196	if (copy_to_user(dirent->d_name, name, namlen))
	197	goto efault;
	198	if (__put_user(0, dirent->d_name + namlen))
	199	goto efault;
	200	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	201	goto efault;
	202	buf->previous = dirent;
	203	dirent = (void __user *)dirent + reclen;
	204	buf->current_dir = dirent;
	205	buf->count -= reclen;
	206	return 0;
	207	efault:
	208	buf->error = -EFAULT;
	209	return -EFAULT;
	210	}
	211
20f37034 HC	212	SYSCALL_DEFINE3(getdents, unsigned int, fd,
20f37034 HC	213	struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4	214	{
2903ff01	215	struct fd f;
1da177e4	216	struct linux_dirent __user * lastdirent;
ac6614b7 AV	217	struct getdents_callback buf = {
	218	.ctx.actor = filldir,
	219	.count = count,
	220	.current_dir = dirent
	221	};
1da177e4 LT	222	int error;
1da177e4 LT	223
1da177e4	224	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	225	return -EFAULT;
1da177e4	226
63b6df14	227	f = fdget_pos(fd);
2903ff01	228	if (!f.file)
863ced7f	229	return -EBADF;
1da177e4	230
5c0ba4e0	231	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	232	if (error >= 0)
53c9c5c0 AV	233	error = buf.error;
1da177e4 LT	234	lastdirent = buf.previous;
1da177e4 LT	235	if (lastdirent) {
bb6f619b	236	if (put_user(buf.ctx.pos, &lastdirent->d_off))
1da177e4 LT	237	error = -EFAULT;
	238	else
	239	error = count - buf.count;
	240	}
63b6df14	241	fdput_pos(f);
1da177e4 LT	242	return error;
	243	}
	244
1da177e4	245	struct getdents_callback64 {
5c0ba4e0	246	struct dir_context ctx;
1da177e4 LT	247	struct linux_dirent64 __user * current_dir;
	248	struct linux_dirent64 __user * previous;
	249	int count;
	250	int error;
	251	};
	252
ac7576f4 MS	253	static int filldir64(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	254	loff_t offset, u64 ino, unsigned int d_type)
1da177e4 LT	255	{
1da177e4 LT	256	struct linux_dirent64 __user *dirent;
ac7576f4 MS	257	struct getdents_callback64 *buf =
ac7576f4 MS	258	container_of(ctx, struct getdents_callback64, ctx);
85c9fe8f KW	259	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
85c9fe8f KW	260	sizeof(u64));
1da177e4 LT	261
	262	buf->error = -EINVAL; /* only used if we fail.. */
	263	if (reclen > buf->count)
	264	return -EINVAL;
	265	dirent = buf->previous;
	266	if (dirent) {
1f60fbe7 TT	267	if (signal_pending(current))
1f60fbe7 TT	268	return -EINTR;
1da177e4 LT	269	if (__put_user(offset, &dirent->d_off))
	270	goto efault;
	271	}
	272	dirent = buf->current_dir;
	273	if (__put_user(ino, &dirent->d_ino))
	274	goto efault;
	275	if (__put_user(0, &dirent->d_off))
	276	goto efault;
	277	if (__put_user(reclen, &dirent->d_reclen))
	278	goto efault;
	279	if (__put_user(d_type, &dirent->d_type))
	280	goto efault;
	281	if (copy_to_user(dirent->d_name, name, namlen))
	282	goto efault;
	283	if (__put_user(0, dirent->d_name + namlen))
	284	goto efault;
	285	buf->previous = dirent;
	286	dirent = (void __user *)dirent + reclen;
	287	buf->current_dir = dirent;
	288	buf->count -= reclen;
	289	return 0;
	290	efault:
	291	buf->error = -EFAULT;
	292	return -EFAULT;
	293	}
	294
20f37034 HC	295	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
20f37034 HC	296	struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4	297	{
2903ff01	298	struct fd f;
1da177e4	299	struct linux_dirent64 __user * lastdirent;
ac6614b7 AV	300	struct getdents_callback64 buf = {
	301	.ctx.actor = filldir64,
	302	.count = count,
	303	.current_dir = dirent
	304	};
1da177e4 LT	305	int error;
1da177e4 LT	306
1da177e4	307	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	308	return -EFAULT;
1da177e4	309
63b6df14	310	f = fdget_pos(fd);
2903ff01	311	if (!f.file)
863ced7f	312	return -EBADF;
1da177e4	313
5c0ba4e0	314	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	315	if (error >= 0)
53c9c5c0 AV	316	error = buf.error;
1da177e4 LT	317	lastdirent = buf.previous;
1da177e4 LT	318	if (lastdirent) {
bb6f619b	319	typeof(lastdirent->d_off) d_off = buf.ctx.pos;
1da177e4	320	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	321	error = -EFAULT;
	322	else
	323	error = count - buf.count;
1da177e4	324	}
63b6df14	325	fdput_pos(f);
1da177e4 LT	326	return error;
1da177e4 LT	327	}
0460b2a2 AV	328
	329	#ifdef CONFIG_COMPAT
	330	struct compat_old_linux_dirent {
	331	compat_ulong_t d_ino;
	332	compat_ulong_t d_offset;
	333	unsigned short d_namlen;
	334	char d_name[1];
	335	};
	336
	337	struct compat_readdir_callback {
	338	struct dir_context ctx;
	339	struct compat_old_linux_dirent __user *dirent;
	340	int result;
	341	};
	342
	343	static int compat_fillonedir(struct dir_context ctx, const char name,
	344	int namlen, loff_t offset, u64 ino,
	345	unsigned int d_type)
	346	{
	347	struct compat_readdir_callback *buf =
	348	container_of(ctx, struct compat_readdir_callback, ctx);
	349	struct compat_old_linux_dirent __user *dirent;
	350	compat_ulong_t d_ino;
	351
	352	if (buf->result)
	353	return -EINVAL;
	354	d_ino = ino;
	355	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
	356	buf->result = -EOVERFLOW;
	357	return -EOVERFLOW;
	358	}
	359	buf->result++;
	360	dirent = buf->dirent;
	361	if (!access_ok(VERIFY_WRITE, dirent,
	362	(unsigned long)(dirent->d_name + namlen + 1) -
	363	(unsigned long)dirent))
	364	goto efault;
	365	if ( __put_user(d_ino, &dirent->d_ino) \|\|
	366	__put_user(offset, &dirent->d_offset) \|\|
	367	__put_user(namlen, &dirent->d_namlen) \|\|
	368	__copy_to_user(dirent->d_name, name, namlen) \|\|
	369	__put_user(0, dirent->d_name + namlen))
	370	goto efault;
	371	return 0;
	372	efault:
	373	buf->result = -EFAULT;
	374	return -EFAULT;
	375	}
	376
	377	COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
	378	struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
	379	{
	380	int error;
	381	struct fd f = fdget_pos(fd);
	382	struct compat_readdir_callback buf = {
	383	.ctx.actor = compat_fillonedir,
	384	.dirent = dirent
	385	};
	386
	387	if (!f.file)
	388	return -EBADF;
	389
	390	error = iterate_dir(f.file, &buf.ctx);
	391	if (buf.result)
392	error = buf.result;
393
394	fdput_pos(f);
395	return error;
396	}
397
398	struct compat_linux_dirent {
399	compat_ulong_t d_ino;
400	compat_ulong_t d_off;
401	unsigned short d_reclen;
402	char d_name[1];
403	};
404
405	struct compat_getdents_callback {
406	struct dir_context ctx;
407	struct compat_linux_dirent __user *current_dir;
408	struct compat_linux_dirent __user *previous;
409	int count;
410	int error;
411	};
412
413	static int compat_filldir(struct dir_context ctx, const char name, int namlen,
414	loff_t offset, u64 ino, unsigned int d_type)
415	{
416	struct compat_linux_dirent __user * dirent;
417	struct compat_getdents_callback *buf =
418	container_of(ctx, struct compat_getdents_callback, ctx);
419	compat_ulong_t d_ino;
420	int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
421	namlen + 2, sizeof(compat_long_t));
422
423	buf->error = -EINVAL; /* only used if we fail.. */
424	if (reclen > buf->count)
425	return -EINVAL;
426	d_ino = ino;
427	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
428	buf->error = -EOVERFLOW;
429	return -EOVERFLOW;
430	}
431	dirent = buf->previous;
432	if (dirent) {
433	if (signal_pending(current))
434	return -EINTR;
435	if (__put_user(offset, &dirent->d_off))
436	goto efault;
437	}
438	dirent = buf->current_dir;
439	if (__put_user(d_ino, &dirent->d_ino))
440	goto efault;
441	if (__put_user(reclen, &dirent->d_reclen))
442	goto efault;
443	if (copy_to_user(dirent->d_name, name, namlen))
444	goto efault;
445	if (__put_user(0, dirent->d_name + namlen))
446	goto efault;
447	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
448	goto efault;
449	buf->previous = dirent;
450	dirent = (void __user *)dirent + reclen;
451	buf->current_dir = dirent;
452	buf->count -= reclen;
453	return 0;
454	efault:
455	buf->error = -EFAULT;
456	return -EFAULT;
457	}
458
459	COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
460	struct compat_linux_dirent __user *, dirent, unsigned int, count)
461	{
462	struct fd f;
463	struct compat_linux_dirent __user * lastdirent;
464	struct compat_getdents_callback buf = {
465	.ctx.actor = compat_filldir,
466	.current_dir = dirent,
467	.count = count
468	};
469	int error;
470
471	if (!access_ok(VERIFY_WRITE, dirent, count))
472	return -EFAULT;
473
474	f = fdget_pos(fd);
475	if (!f.file)
476	return -EBADF;
477
478	error = iterate_dir(f.file, &buf.ctx);
479	if (error >= 0)
480	error = buf.error;
481	lastdirent = buf.previous;
482	if (lastdirent) {
483	if (put_user(buf.ctx.pos, &lastdirent->d_off))
484	error = -EFAULT;
485	else
486	error = count - buf.count;
487	}
488	fdput_pos(f);
489	return error;
490	}
491	#endif