[people/ms/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/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_inode(file);
	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).
 */

#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) {
		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;

	if (!f.file)
		return -EBADF;

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

	error = vfs_readdir(f.file, fillonedir, &buf);
	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 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;
	int error;

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

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

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

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

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

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

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

	error = vfs_readdir(f.file, filldir64, &buf);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = f.file->f_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
	23	int vfs_readdir(struct file file, filldir_t filler, void buf)
	24	{
496ad9aa	25	struct inode *inode = file_inode(file);
1da177e4 LT	26	int res = -ENOTDIR;
	27	if (!file->f_op \|\| !file->f_op->readdir)
	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;
	39	if (!IS_DEADDIR(inode)) {
	40	res = file->f_op->readdir(file, buf, filler);
	41	file_accessed(file);
	42	}
1b1dcc1b	43	mutex_unlock(&inode->i_mutex);
1da177e4 LT	44	out:
	45	return res;
	46	}
	47
	48	EXPORT_SYMBOL(vfs_readdir);
	49
	50	/*
	51	* Traditional linux readdir() handling..
	52	*
	53	* "count=1" is a special case, meaning that the buffer is one
	54	* dirent-structure in size and that the code can't handle more
	55	* anyway. Thus the special "fillonedir()" function for that
	56	* case (the low-level handlers don't need to care about this).
	57	*/
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	82	d_ino = ino;
8f3f655d AV	83	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	84	buf->result = -EOVERFLOW;
afefdbb2	85	return -EOVERFLOW;
8f3f655d	86	}
1da177e4 LT	87	buf->result++;
	88	dirent = buf->dirent;
	89	if (!access_ok(VERIFY_WRITE, dirent,
	90	(unsigned long)(dirent->d_name + namlen + 1) -
	91	(unsigned long)dirent))
	92	goto efault;
afefdbb2	93	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	94	__put_user(offset, &dirent->d_offset) \|\|
	95	__put_user(namlen, &dirent->d_namlen) \|\|
	96	__copy_to_user(dirent->d_name, name, namlen) \|\|
	97	__put_user(0, dirent->d_name + namlen))
	98	goto efault;
	99	return 0;
	100	efault:
	101	buf->result = -EFAULT;
	102	return -EFAULT;
	103	}
	104
d4e82042 HC	105	SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
d4e82042 HC	106	struct old_linux_dirent __user *, dirent, unsigned int, count)
1da177e4 LT	107	{
1da177e4 LT	108	int error;
2903ff01	109	struct fd f = fdget(fd);
1da177e4 LT	110	struct readdir_callback buf;
1da177e4 LT	111
2903ff01	112	if (!f.file)
863ced7f	113	return -EBADF;
1da177e4 LT	114
	115	buf.result = 0;
	116	buf.dirent = dirent;
	117
2903ff01	118	error = vfs_readdir(f.file, fillonedir, &buf);
53c9c5c0	119	if (buf.result)
1da177e4 LT	120	error = buf.result;
1da177e4 LT	121
2903ff01	122	fdput(f);
1da177e4 LT	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;
85c9fe8f KW	152	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
85c9fe8f KW	153	sizeof(long));
1da177e4 LT	154
	155	buf->error = -EINVAL; /* only used if we fail.. */
	156	if (reclen > buf->count)
	157	return -EINVAL;
afefdbb2	158	d_ino = ino;
8f3f655d AV	159	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	160	buf->error = -EOVERFLOW;
afefdbb2	161	return -EOVERFLOW;
8f3f655d	162	}
1da177e4 LT	163	dirent = buf->previous;
	164	if (dirent) {
	165	if (__put_user(offset, &dirent->d_off))
	166	goto efault;
	167	}
	168	dirent = buf->current_dir;
afefdbb2	169	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	170	goto efault;
	171	if (__put_user(reclen, &dirent->d_reclen))
	172	goto efault;
	173	if (copy_to_user(dirent->d_name, name, namlen))
	174	goto efault;
	175	if (__put_user(0, dirent->d_name + namlen))
	176	goto efault;
	177	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	178	goto efault;
	179	buf->previous = dirent;
	180	dirent = (void __user *)dirent + reclen;
	181	buf->current_dir = dirent;
	182	buf->count -= reclen;
	183	return 0;
	184	efault:
	185	buf->error = -EFAULT;
	186	return -EFAULT;
	187	}
	188
20f37034 HC	189	SYSCALL_DEFINE3(getdents, unsigned int, fd,
20f37034 HC	190	struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4	191	{
2903ff01	192	struct fd f;
1da177e4 LT	193	struct linux_dirent __user * lastdirent;
	194	struct getdents_callback buf;
	195	int error;
	196
1da177e4	197	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	198	return -EFAULT;
1da177e4	199
2903ff01 AV	200	f = fdget(fd);
2903ff01 AV	201	if (!f.file)
863ced7f	202	return -EBADF;
1da177e4 LT	203
	204	buf.current_dir = dirent;
	205	buf.previous = NULL;
	206	buf.count = count;
	207	buf.error = 0;
	208
2903ff01	209	error = vfs_readdir(f.file, filldir, &buf);
53c9c5c0 AV	210	if (error >= 0)
53c9c5c0 AV	211	error = buf.error;
1da177e4 LT	212	lastdirent = buf.previous;
1da177e4 LT	213	if (lastdirent) {
2903ff01	214	if (put_user(f.file->f_pos, &lastdirent->d_off))
1da177e4 LT	215	error = -EFAULT;
	216	else
	217	error = count - buf.count;
	218	}
2903ff01	219	fdput(f);
1da177e4 LT	220	return error;
	221	}
	222
1da177e4 LT	223	struct getdents_callback64 {
	224	struct linux_dirent64 __user * current_dir;
	225	struct linux_dirent64 __user * previous;
	226	int count;
	227	int error;
	228	};
	229
	230	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	231	u64 ino, unsigned int d_type)
1da177e4 LT	232	{
	233	struct linux_dirent64 __user *dirent;
	234	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
85c9fe8f KW	235	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
85c9fe8f KW	236	sizeof(u64));
1da177e4 LT	237
	238	buf->error = -EINVAL; /* only used if we fail.. */
	239	if (reclen > buf->count)
	240	return -EINVAL;
	241	dirent = buf->previous;
	242	if (dirent) {
	243	if (__put_user(offset, &dirent->d_off))
	244	goto efault;
	245	}
	246	dirent = buf->current_dir;
	247	if (__put_user(ino, &dirent->d_ino))
	248	goto efault;
	249	if (__put_user(0, &dirent->d_off))
	250	goto efault;
	251	if (__put_user(reclen, &dirent->d_reclen))
	252	goto efault;
	253	if (__put_user(d_type, &dirent->d_type))
	254	goto efault;
	255	if (copy_to_user(dirent->d_name, name, namlen))
	256	goto efault;
	257	if (__put_user(0, dirent->d_name + namlen))
	258	goto efault;
	259	buf->previous = dirent;
	260	dirent = (void __user *)dirent + reclen;
	261	buf->current_dir = dirent;
	262	buf->count -= reclen;
	263	return 0;
	264	efault:
	265	buf->error = -EFAULT;
	266	return -EFAULT;
	267	}
	268
20f37034 HC	269	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
20f37034 HC	270	struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4	271	{
2903ff01	272	struct fd f;
1da177e4 LT	273	struct linux_dirent64 __user * lastdirent;
	274	struct getdents_callback64 buf;
	275	int error;
	276
1da177e4	277	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	278	return -EFAULT;
1da177e4	279
2903ff01 AV	280	f = fdget(fd);
2903ff01 AV	281	if (!f.file)
863ced7f	282	return -EBADF;
1da177e4 LT	283
	284	buf.current_dir = dirent;
	285	buf.previous = NULL;
	286	buf.count = count;
	287	buf.error = 0;
	288
2903ff01	289	error = vfs_readdir(f.file, filldir64, &buf);
53c9c5c0 AV	290	if (error >= 0)
53c9c5c0 AV	291	error = buf.error;
1da177e4 LT	292	lastdirent = buf.previous;
1da177e4 LT	293	if (lastdirent) {
2903ff01	294	typeof(lastdirent->d_off) d_off = f.file->f_pos;
1da177e4	295	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	296	error = -EFAULT;
	297	else
	298	error = count - buf.count;
1da177e4	299	}
2903ff01	300	fdput(f);
1da177e4 LT	301	return error;
1da177e4 LT	302	}