[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/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 || !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;
		file_accessed(file);
	}
	mutex_unlock(&inode->i_mutex);
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(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) {
		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(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(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(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(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 LT	15	#include <linux/fs.h>
	16	#include <linux/dirent.h>
	17	#include <linux/security.h>
	18	#include <linux/syscalls.h>
	19	#include <linux/unistd.h>
	20
	21	#include <asm/uaccess.h>
	22
5c0ba4e0	23	int iterate_dir(struct file file, struct dir_context ctx)
1da177e4	24	{
496ad9aa	25	struct inode *inode = file_inode(file);
1da177e4	26	int res = -ENOTDIR;
2233f31a	27	if (!file->f_op \|\| !file->f_op->iterate)
1da177e4 LT	28	goto out;
	29
	30	res = security_file_permission(file, MAY_READ);
	31	if (res)
	32	goto out;
	33
da784511 LH	34	res = mutex_lock_killable(&inode->i_mutex);
	35	if (res)
	36	goto out;
	37
1da177e4 LT	38	res = -ENOENT;
1da177e4 LT	39	if (!IS_DEADDIR(inode)) {
2233f31a AV	40	ctx->pos = file->f_pos;
	41	res = file->f_op->iterate(file, ctx);
	42	file->f_pos = ctx->pos;
1da177e4 LT	43	file_accessed(file);
1da177e4 LT	44	}
1b1dcc1b	45	mutex_unlock(&inode->i_mutex);
1da177e4 LT	46	out:
	47	return res;
	48	}
5c0ba4e0	49	EXPORT_SYMBOL(iterate_dir);
1da177e4 LT	50
	51	/*
	52	* Traditional linux readdir() handling..
	53	*
	54	* "count=1" is a special case, meaning that the buffer is one
	55	* dirent-structure in size and that the code can't handle more
	56	* anyway. Thus the special "fillonedir()" function for that
	57	* case (the low-level handlers don't need to care about this).
	58	*/
1da177e4 LT	59
	60	#ifdef __ARCH_WANT_OLD_READDIR
	61
	62	struct old_linux_dirent {
	63	unsigned long d_ino;
	64	unsigned long d_offset;
	65	unsigned short d_namlen;
	66	char d_name[1];
	67	};
	68
	69	struct readdir_callback {
5c0ba4e0	70	struct dir_context ctx;
1da177e4 LT	71	struct old_linux_dirent __user * dirent;
	72	int result;
	73	};
	74
	75	static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	76	u64 ino, unsigned int d_type)
1da177e4	77	{
5c0ba4e0	78	struct readdir_callback buf = (struct readdir_callback ) __buf;
1da177e4	79	struct old_linux_dirent __user * dirent;
afefdbb2	80	unsigned long d_ino;
1da177e4 LT	81
	82	if (buf->result)
	83	return -EINVAL;
afefdbb2	84	d_ino = ino;
8f3f655d AV	85	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	86	buf->result = -EOVERFLOW;
afefdbb2	87	return -EOVERFLOW;
8f3f655d	88	}
1da177e4 LT	89	buf->result++;
	90	dirent = buf->dirent;
	91	if (!access_ok(VERIFY_WRITE, dirent,
	92	(unsigned long)(dirent->d_name + namlen + 1) -
	93	(unsigned long)dirent))
	94	goto efault;
afefdbb2	95	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	96	__put_user(offset, &dirent->d_offset) \|\|
	97	__put_user(namlen, &dirent->d_namlen) \|\|
	98	__copy_to_user(dirent->d_name, name, namlen) \|\|
	99	__put_user(0, dirent->d_name + namlen))
	100	goto efault;
	101	return 0;
	102	efault:
	103	buf->result = -EFAULT;
	104	return -EFAULT;
	105	}
	106
d4e82042 HC	107	SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
d4e82042 HC	108	struct old_linux_dirent __user *, dirent, unsigned int, count)
1da177e4 LT	109	{
1da177e4 LT	110	int error;
2903ff01	111	struct fd f = fdget(fd);
ac6614b7 AV	112	struct readdir_callback buf = {
	113	.ctx.actor = fillonedir,
	114	.dirent = dirent
	115	};
1da177e4	116
2903ff01	117	if (!f.file)
863ced7f	118	return -EBADF;
1da177e4	119
5c0ba4e0	120	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0	121	if (buf.result)
1da177e4 LT	122	error = buf.result;
1da177e4 LT	123
2903ff01	124	fdput(f);
1da177e4 LT	125	return error;
	126	}
	127
	128	#endif /* __ARCH_WANT_OLD_READDIR */
	129
	130	/*
	131	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	132	* interface.
	133	*/
	134	struct linux_dirent {
	135	unsigned long d_ino;
	136	unsigned long d_off;
	137	unsigned short d_reclen;
	138	char d_name[1];
	139	};
	140
	141	struct getdents_callback {
5c0ba4e0	142	struct dir_context ctx;
1da177e4 LT	143	struct linux_dirent __user * current_dir;
	144	struct linux_dirent __user * previous;
	145	int count;
	146	int error;
	147	};
	148
	149	static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	150	u64 ino, unsigned int d_type)
1da177e4 LT	151	{
	152	struct linux_dirent __user * dirent;
	153	struct getdents_callback * buf = (struct getdents_callback *) __buf;
afefdbb2	154	unsigned long d_ino;
85c9fe8f KW	155	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
85c9fe8f KW	156	sizeof(long));
1da177e4 LT	157
	158	buf->error = -EINVAL; /* only used if we fail.. */
	159	if (reclen > buf->count)
	160	return -EINVAL;
afefdbb2	161	d_ino = ino;
8f3f655d AV	162	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	163	buf->error = -EOVERFLOW;
afefdbb2	164	return -EOVERFLOW;
8f3f655d	165	}
1da177e4 LT	166	dirent = buf->previous;
	167	if (dirent) {
	168	if (__put_user(offset, &dirent->d_off))
	169	goto efault;
	170	}
	171	dirent = buf->current_dir;
afefdbb2	172	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	173	goto efault;
	174	if (__put_user(reclen, &dirent->d_reclen))
	175	goto efault;
	176	if (copy_to_user(dirent->d_name, name, namlen))
	177	goto efault;
	178	if (__put_user(0, dirent->d_name + namlen))
	179	goto efault;
	180	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	181	goto efault;
	182	buf->previous = dirent;
	183	dirent = (void __user *)dirent + reclen;
	184	buf->current_dir = dirent;
	185	buf->count -= reclen;
	186	return 0;
	187	efault:
	188	buf->error = -EFAULT;
	189	return -EFAULT;
	190	}
	191
20f37034 HC	192	SYSCALL_DEFINE3(getdents, unsigned int, fd,
20f37034 HC	193	struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4	194	{
2903ff01	195	struct fd f;
1da177e4	196	struct linux_dirent __user * lastdirent;
ac6614b7 AV	197	struct getdents_callback buf = {
	198	.ctx.actor = filldir,
	199	.count = count,
	200	.current_dir = dirent
	201	};
1da177e4 LT	202	int error;
1da177e4 LT	203
1da177e4	204	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	205	return -EFAULT;
1da177e4	206
2903ff01 AV	207	f = fdget(fd);
2903ff01 AV	208	if (!f.file)
863ced7f	209	return -EBADF;
1da177e4	210
5c0ba4e0	211	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	212	if (error >= 0)
53c9c5c0 AV	213	error = buf.error;
1da177e4 LT	214	lastdirent = buf.previous;
1da177e4 LT	215	if (lastdirent) {
bb6f619b	216	if (put_user(buf.ctx.pos, &lastdirent->d_off))
1da177e4 LT	217	error = -EFAULT;
	218	else
	219	error = count - buf.count;
	220	}
2903ff01	221	fdput(f);
1da177e4 LT	222	return error;
	223	}
	224
1da177e4	225	struct getdents_callback64 {
5c0ba4e0	226	struct dir_context ctx;
1da177e4 LT	227	struct linux_dirent64 __user * current_dir;
	228	struct linux_dirent64 __user * previous;
	229	int count;
	230	int error;
	231	};
	232
	233	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	234	u64 ino, unsigned int d_type)
1da177e4 LT	235	{
	236	struct linux_dirent64 __user *dirent;
	237	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
85c9fe8f KW	238	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
85c9fe8f KW	239	sizeof(u64));
1da177e4 LT	240
	241	buf->error = -EINVAL; /* only used if we fail.. */
	242	if (reclen > buf->count)
	243	return -EINVAL;
	244	dirent = buf->previous;
	245	if (dirent) {
	246	if (__put_user(offset, &dirent->d_off))
	247	goto efault;
	248	}
	249	dirent = buf->current_dir;
	250	if (__put_user(ino, &dirent->d_ino))
	251	goto efault;
	252	if (__put_user(0, &dirent->d_off))
	253	goto efault;
	254	if (__put_user(reclen, &dirent->d_reclen))
	255	goto efault;
	256	if (__put_user(d_type, &dirent->d_type))
	257	goto efault;
	258	if (copy_to_user(dirent->d_name, name, namlen))
	259	goto efault;
	260	if (__put_user(0, dirent->d_name + namlen))
	261	goto efault;
	262	buf->previous = dirent;
	263	dirent = (void __user *)dirent + reclen;
	264	buf->current_dir = dirent;
	265	buf->count -= reclen;
	266	return 0;
	267	efault:
	268	buf->error = -EFAULT;
	269	return -EFAULT;
	270	}
	271
20f37034 HC	272	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
20f37034 HC	273	struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4	274	{
2903ff01	275	struct fd f;
1da177e4	276	struct linux_dirent64 __user * lastdirent;
ac6614b7 AV	277	struct getdents_callback64 buf = {
	278	.ctx.actor = filldir64,
	279	.count = count,
	280	.current_dir = dirent
	281	};
1da177e4 LT	282	int error;
1da177e4 LT	283
1da177e4	284	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	285	return -EFAULT;
1da177e4	286
2903ff01 AV	287	f = fdget(fd);
2903ff01 AV	288	if (!f.file)
863ced7f	289	return -EBADF;
1da177e4	290
5c0ba4e0	291	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	292	if (error >= 0)
53c9c5c0 AV	293	error = buf.error;
1da177e4 LT	294	lastdirent = buf.previous;
1da177e4 LT	295	if (lastdirent) {
bb6f619b	296	typeof(lastdirent->d_off) d_off = buf.ctx.pos;
1da177e4	297	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	298	error = -EFAULT;
	299	else
	300	error = count - buf.count;
1da177e4	301	}
2903ff01	302	fdput(f);
1da177e4 LT	303	return error;
1da177e4 LT	304	}