[net-next-2.6.git] / fs / readdir.c

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

#include <linux/stddef.h>
#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).
 */

#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 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 (buf.result)
		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(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 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)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	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(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 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)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = file->f_pos;
		if (__put_user(d_off, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fput(file);
out:
	return error;
}
Commit	Line	Data
	1	/*
	2	* linux/fs/readdir.c
	3	*
	4	* Copyright (C) 1995 Linus Torvalds
	5	*/
	6
	7	#include <linux/stddef.h>
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	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>
	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	{
	25	struct inode *inode = file->f_path.dentry->d_inode;
	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
	34	res = mutex_lock_killable(&inode->i_mutex);
	35	if (res)
	36	goto out;
	37
	38	res = -ENOENT;
	39	if (!IS_DEADDIR(inode)) {
	40	res = file->f_op->readdir(file, buf, filler);
	41	file_accessed(file);
	42	}
	43	mutex_unlock(&inode->i_mutex);
	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	*/
	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,
	74	u64 ino, unsigned int d_type)
	75	{
	76	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	77	struct old_linux_dirent __user * dirent;
	78	unsigned long d_ino;
	79
	80	if (buf->result)
	81	return -EINVAL;
	82	d_ino = ino;
	83	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
	84	buf->result = -EOVERFLOW;
	85	return -EOVERFLOW;
	86	}
	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;
	93	if ( __put_user(d_ino, &dirent->d_ino) \|\|
	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
	105	SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
	106	struct old_linux_dirent __user *, dirent, unsigned int, count)
	107	{
	108	int error;
	109	struct file * file;
	110	struct readdir_callback buf;
	111
	112	error = -EBADF;
	113	file = fget(fd);
	114	if (!file)
	115	goto out;
	116
	117	buf.result = 0;
	118	buf.dirent = dirent;
	119
	120	error = vfs_readdir(file, fillonedir, &buf);
	121	if (buf.result)
	122	error = buf.result;
	123
	124	fput(file);
	125	out:
	126	return error;
	127	}
	128
	129	#endif /* __ARCH_WANT_OLD_READDIR */
	130
	131	/*
	132	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	133	* interface.
	134	*/
	135	struct linux_dirent {
	136	unsigned long d_ino;
	137	unsigned long d_off;
	138	unsigned short d_reclen;
	139	char d_name[1];
	140	};
	141
	142	struct getdents_callback {
	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,
	150	u64 ino, unsigned int d_type)
	151	{
	152	struct linux_dirent __user * dirent;
	153	struct getdents_callback * buf = (struct getdents_callback *) __buf;
	154	unsigned long d_ino;
	155	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
	156	sizeof(long));
	157
	158	buf->error = -EINVAL; /* only used if we fail.. */
	159	if (reclen > buf->count)
	160	return -EINVAL;
	161	d_ino = ino;
	162	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
	163	buf->error = -EOVERFLOW;
	164	return -EOVERFLOW;
	165	}
	166	dirent = buf->previous;
	167	if (dirent) {
	168	if (__put_user(offset, &dirent->d_off))
	169	goto efault;
	170	}
	171	dirent = buf->current_dir;
	172	if (__put_user(d_ino, &dirent->d_ino))
	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
	192	SYSCALL_DEFINE3(getdents, unsigned int, fd,
	193	struct linux_dirent __user *, dirent, unsigned int, count)
	194	{
	195	struct file * file;
	196	struct linux_dirent __user * lastdirent;
	197	struct getdents_callback buf;
	198	int error;
	199
	200	error = -EFAULT;
	201	if (!access_ok(VERIFY_WRITE, dirent, count))
	202	goto out;
	203
	204	error = -EBADF;
	205	file = fget(fd);
	206	if (!file)
	207	goto out;
	208
	209	buf.current_dir = dirent;
	210	buf.previous = NULL;
	211	buf.count = count;
	212	buf.error = 0;
	213
	214	error = vfs_readdir(file, filldir, &buf);
	215	if (error >= 0)
	216	error = buf.error;
	217	lastdirent = buf.previous;
	218	if (lastdirent) {
	219	if (put_user(file->f_pos, &lastdirent->d_off))
	220	error = -EFAULT;
	221	else
	222	error = count - buf.count;
	223	}
	224	fput(file);
	225	out:
	226	return error;
	227	}
	228
	229	struct getdents_callback64 {
	230	struct linux_dirent64 __user * current_dir;
	231	struct linux_dirent64 __user * previous;
	232	int count;
	233	int error;
	234	};
	235
	236	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
	237	u64 ino, unsigned int d_type)
	238	{
	239	struct linux_dirent64 __user *dirent;
	240	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
	241	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
	242	sizeof(u64));
	243
	244	buf->error = -EINVAL; /* only used if we fail.. */
	245	if (reclen > buf->count)
	246	return -EINVAL;
	247	dirent = buf->previous;
	248	if (dirent) {
	249	if (__put_user(offset, &dirent->d_off))
	250	goto efault;
	251	}
	252	dirent = buf->current_dir;
	253	if (__put_user(ino, &dirent->d_ino))
	254	goto efault;
	255	if (__put_user(0, &dirent->d_off))
	256	goto efault;
	257	if (__put_user(reclen, &dirent->d_reclen))
	258	goto efault;
	259	if (__put_user(d_type, &dirent->d_type))
	260	goto efault;
	261	if (copy_to_user(dirent->d_name, name, namlen))
	262	goto efault;
	263	if (__put_user(0, dirent->d_name + namlen))
	264	goto efault;
	265	buf->previous = dirent;
	266	dirent = (void __user *)dirent + reclen;
	267	buf->current_dir = dirent;
	268	buf->count -= reclen;
	269	return 0;
	270	efault:
	271	buf->error = -EFAULT;
	272	return -EFAULT;
	273	}
	274
	275	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
	276	struct linux_dirent64 __user *, dirent, unsigned int, count)
	277	{
	278	struct file * file;
	279	struct linux_dirent64 __user * lastdirent;
	280	struct getdents_callback64 buf;
	281	int error;
	282
	283	error = -EFAULT;
	284	if (!access_ok(VERIFY_WRITE, dirent, count))
	285	goto out;
	286
	287	error = -EBADF;
	288	file = fget(fd);
	289	if (!file)
	290	goto out;
	291
	292	buf.current_dir = dirent;
	293	buf.previous = NULL;
	294	buf.count = count;
	295	buf.error = 0;
	296
	297	error = vfs_readdir(file, filldir64, &buf);
	298	if (error >= 0)
	299	error = buf.error;
	300	lastdirent = buf.previous;
	301	if (lastdirent) {
	302	typeof(lastdirent->d_off) d_off = file->f_pos;
	303	if (__put_user(d_off, &lastdirent->d_off))
	304	error = -EFAULT;
	305	else
	306	error = count - buf.count;
	307	}
	308	fput(file);
	309	out:
	310	return error;
	311	}