[linux-2.6-block.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 <asm/uaccess.h>

int iterate_dir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	int res = -ENOTDIR;
	if (!file->f_op->iterate)
		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)) {
		ctx->pos = file->f_pos;
		res = file->f_op->iterate(file, ctx);
		file->f_pos = ctx->pos;
		fsnotify_access(file);
		file_accessed(file);
	}
	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(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(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 (__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(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(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 (__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(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(f);
	return error;
}
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>
	21
	22	#include <asm/uaccess.h>
	23
5c0ba4e0	24	int iterate_dir(struct file file, struct dir_context ctx)
1da177e4	25	{
496ad9aa	26	struct inode *inode = file_inode(file);
1da177e4	27	int res = -ENOTDIR;
72c2d531	28	if (!file->f_op->iterate)
1da177e4 LT	29	goto out;
	30
	31	res = security_file_permission(file, MAY_READ);
	32	if (res)
	33	goto out;
	34
da784511 LH	35	res = mutex_lock_killable(&inode->i_mutex);
	36	if (res)
	37	goto out;
	38
1da177e4 LT	39	res = -ENOENT;
1da177e4 LT	40	if (!IS_DEADDIR(inode)) {
2233f31a AV	41	ctx->pos = file->f_pos;
	42	res = file->f_op->iterate(file, ctx);
	43	file->f_pos = ctx->pos;
d4c7cf6c	44	fsnotify_access(file);
1da177e4 LT	45	file_accessed(file);
1da177e4 LT	46	}
5955102c	47	inode_unlock(inode);
1da177e4 LT	48	out:
	49	return res;
	50	}
5c0ba4e0	51	EXPORT_SYMBOL(iterate_dir);
1da177e4 LT	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	*/
1da177e4 LT	61
	62	#ifdef __ARCH_WANT_OLD_READDIR
	63
	64	struct 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
	71	struct readdir_callback {
5c0ba4e0	72	struct dir_context ctx;
1da177e4 LT	73	struct old_linux_dirent __user * dirent;
	74	int result;
	75	};
	76
ac7576f4 MS	77	static int fillonedir(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	78	loff_t offset, u64 ino, unsigned int d_type)
1da177e4	79	{
ac7576f4 MS	80	struct readdir_callback *buf =
ac7576f4 MS	81	container_of(ctx, struct readdir_callback, ctx);
1da177e4	82	struct old_linux_dirent __user * dirent;
afefdbb2	83	unsigned long d_ino;
1da177e4 LT	84
	85	if (buf->result)
	86	return -EINVAL;
afefdbb2	87	d_ino = ino;
8f3f655d AV	88	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	89	buf->result = -EOVERFLOW;
afefdbb2	90	return -EOVERFLOW;
8f3f655d	91	}
1da177e4 LT	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;
afefdbb2	98	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	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;
	105	efault:
	106	buf->result = -EFAULT;
	107	return -EFAULT;
	108	}
	109
d4e82042 HC	110	SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
d4e82042 HC	111	struct old_linux_dirent __user *, dirent, unsigned int, count)
1da177e4 LT	112	{
1da177e4 LT	113	int error;
2903ff01	114	struct fd f = fdget(fd);
ac6614b7 AV	115	struct readdir_callback buf = {
	116	.ctx.actor = fillonedir,
	117	.dirent = dirent
	118	};
1da177e4	119
2903ff01	120	if (!f.file)
863ced7f	121	return -EBADF;
1da177e4	122
5c0ba4e0	123	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0	124	if (buf.result)
1da177e4 LT	125	error = buf.result;
1da177e4 LT	126
2903ff01	127	fdput(f);
1da177e4 LT	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	*/
	137	struct linux_dirent {
	138	unsigned long d_ino;
	139	unsigned long d_off;
	140	unsigned short d_reclen;
	141	char d_name[1];
	142	};
	143
	144	struct getdents_callback {
5c0ba4e0	145	struct dir_context ctx;
1da177e4 LT	146	struct linux_dirent __user * current_dir;
	147	struct linux_dirent __user * previous;
	148	int count;
	149	int error;
	150	};
	151
ac7576f4 MS	152	static int filldir(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	153	loff_t offset, u64 ino, unsigned int d_type)
1da177e4 LT	154	{
1da177e4 LT	155	struct linux_dirent __user * dirent;
ac7576f4 MS	156	struct getdents_callback *buf =
ac7576f4 MS	157	container_of(ctx, struct getdents_callback, ctx);
afefdbb2	158	unsigned long d_ino;
85c9fe8f KW	159	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
85c9fe8f KW	160	sizeof(long));
1da177e4 LT	161
	162	buf->error = -EINVAL; /* only used if we fail.. */
	163	if (reclen > buf->count)
	164	return -EINVAL;
afefdbb2	165	d_ino = ino;
8f3f655d AV	166	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	167	buf->error = -EOVERFLOW;
afefdbb2	168	return -EOVERFLOW;
8f3f655d	169	}
1da177e4 LT	170	dirent = buf->previous;
	171	if (dirent) {
	172	if (__put_user(offset, &dirent->d_off))
	173	goto efault;
	174	}
	175	dirent = buf->current_dir;
afefdbb2	176	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	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;
	191	efault:
	192	buf->error = -EFAULT;
	193	return -EFAULT;
	194	}
	195
20f37034 HC	196	SYSCALL_DEFINE3(getdents, unsigned int, fd,
20f37034 HC	197	struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4	198	{
2903ff01	199	struct fd f;
1da177e4	200	struct linux_dirent __user * lastdirent;
ac6614b7 AV	201	struct getdents_callback buf = {
	202	.ctx.actor = filldir,
	203	.count = count,
	204	.current_dir = dirent
	205	};
1da177e4 LT	206	int error;
1da177e4 LT	207
1da177e4	208	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	209	return -EFAULT;
1da177e4	210
2903ff01 AV	211	f = fdget(fd);
2903ff01 AV	212	if (!f.file)
863ced7f	213	return -EBADF;
1da177e4	214
5c0ba4e0	215	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	216	if (error >= 0)
53c9c5c0 AV	217	error = buf.error;
1da177e4 LT	218	lastdirent = buf.previous;
1da177e4 LT	219	if (lastdirent) {
bb6f619b	220	if (put_user(buf.ctx.pos, &lastdirent->d_off))
1da177e4 LT	221	error = -EFAULT;
	222	else
	223	error = count - buf.count;
	224	}
2903ff01	225	fdput(f);
1da177e4 LT	226	return error;
	227	}
	228
1da177e4	229	struct getdents_callback64 {
5c0ba4e0	230	struct dir_context ctx;
1da177e4 LT	231	struct linux_dirent64 __user * current_dir;
	232	struct linux_dirent64 __user * previous;
	233	int count;
	234	int error;
	235	};
	236
ac7576f4 MS	237	static int filldir64(struct dir_context ctx, const char name, int namlen,
ac7576f4 MS	238	loff_t offset, u64 ino, unsigned int d_type)
1da177e4 LT	239	{
1da177e4 LT	240	struct linux_dirent64 __user *dirent;
ac7576f4 MS	241	struct getdents_callback64 *buf =
ac7576f4 MS	242	container_of(ctx, struct getdents_callback64, ctx);
85c9fe8f KW	243	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
85c9fe8f KW	244	sizeof(u64));
1da177e4 LT	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;
	272	efault:
	273	buf->error = -EFAULT;
	274	return -EFAULT;
	275	}
	276
20f37034 HC	277	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
20f37034 HC	278	struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4	279	{
2903ff01	280	struct fd f;
1da177e4	281	struct linux_dirent64 __user * lastdirent;
ac6614b7 AV	282	struct getdents_callback64 buf = {
	283	.ctx.actor = filldir64,
	284	.count = count,
	285	.current_dir = dirent
	286	};
1da177e4 LT	287	int error;
1da177e4 LT	288
1da177e4	289	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	290	return -EFAULT;
1da177e4	291
2903ff01 AV	292	f = fdget(fd);
2903ff01 AV	293	if (!f.file)
863ced7f	294	return -EBADF;
1da177e4	295
5c0ba4e0	296	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	297	if (error >= 0)
53c9c5c0 AV	298	error = buf.error;
1da177e4 LT	299	lastdirent = buf.previous;
1da177e4 LT	300	if (lastdirent) {
bb6f619b	301	typeof(lastdirent->d_off) d_off = buf.ctx.pos;
1da177e4	302	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	303	error = -EFAULT;
	304	else
	305	error = count - buf.count;
1da177e4	306	}
2903ff01	307	fdput(f);
1da177e4 LT	308	return error;
1da177e4 LT	309	}