[linux.git] / fs / readdir.c

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

#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;

	mutex_lock(&inode->i_mutex);
	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).
 */
#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))

#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)
		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;
}

asmlinkage long 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 (error >= 0)
		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(NAME_OFFSET(dirent) + 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)
		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;
}

asmlinkage long sys_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)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}

out_putf:
	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(NAME_OFFSET(dirent) + 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;
}

asmlinkage long sys_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)
		goto out_putf;
	error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = file->f_pos;
		error = -EFAULT;
		if (__put_user(d_off, &lastdirent->d_off))
			goto out_putf;
		error = count - buf.count;
	}

out_putf:
	fput(file);
out:
	return error;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/readdir.c
	3	*
	4	* Copyright (C) 1995 Linus Torvalds
	5	*/
	6
022a1692	7	#include <linux/kernel.h>
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/time.h>
	10	#include <linux/mm.h>
	11	#include <linux/errno.h>
	12	#include <linux/stat.h>
	13	#include <linux/file.h>
1da177e4 LT	14	#include <linux/fs.h>
	15	#include <linux/dirent.h>
	16	#include <linux/security.h>
	17	#include <linux/syscalls.h>
	18	#include <linux/unistd.h>
	19
	20	#include <asm/uaccess.h>
	21
	22	int vfs_readdir(struct file file, filldir_t filler, void buf)
	23	{
0f7fc9e4	24	struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 LT	25	int res = -ENOTDIR;
	26	if (!file->f_op \|\| !file->f_op->readdir)
	27	goto out;
	28
	29	res = security_file_permission(file, MAY_READ);
	30	if (res)
	31	goto out;
	32
1b1dcc1b	33	mutex_lock(&inode->i_mutex);
1da177e4 LT	34	res = -ENOENT;
	35	if (!IS_DEADDIR(inode)) {
	36	res = file->f_op->readdir(file, buf, filler);
	37	file_accessed(file);
	38	}
1b1dcc1b	39	mutex_unlock(&inode->i_mutex);
1da177e4 LT	40	out:
	41	return res;
	42	}
	43
	44	EXPORT_SYMBOL(vfs_readdir);
	45
	46	/*
	47	* Traditional linux readdir() handling..
	48	*
	49	* "count=1" is a special case, meaning that the buffer is one
	50	* dirent-structure in size and that the code can't handle more
	51	* anyway. Thus the special "fillonedir()" function for that
	52	* case (the low-level handlers don't need to care about this).
	53	*/
	54	#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
1da177e4 LT	55
	56	#ifdef __ARCH_WANT_OLD_READDIR
	57
	58	struct old_linux_dirent {
	59	unsigned long d_ino;
	60	unsigned long d_offset;
	61	unsigned short d_namlen;
	62	char d_name[1];
	63	};
	64
	65	struct readdir_callback {
	66	struct old_linux_dirent __user * dirent;
	67	int result;
	68	};
	69
	70	static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	71	u64 ino, unsigned int d_type)
1da177e4 LT	72	{
	73	struct readdir_callback * buf = (struct readdir_callback *) __buf;
	74	struct old_linux_dirent __user * dirent;
afefdbb2	75	unsigned long d_ino;
1da177e4 LT	76
	77	if (buf->result)
	78	return -EINVAL;
afefdbb2 DH	79	d_ino = ino;
	80	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
	81	return -EOVERFLOW;
1da177e4 LT	82	buf->result++;
	83	dirent = buf->dirent;
	84	if (!access_ok(VERIFY_WRITE, dirent,
	85	(unsigned long)(dirent->d_name + namlen + 1) -
	86	(unsigned long)dirent))
	87	goto efault;
afefdbb2	88	if ( __put_user(d_ino, &dirent->d_ino) \|\|
1da177e4 LT	89	__put_user(offset, &dirent->d_offset) \|\|
	90	__put_user(namlen, &dirent->d_namlen) \|\|
	91	__copy_to_user(dirent->d_name, name, namlen) \|\|
	92	__put_user(0, dirent->d_name + namlen))
	93	goto efault;
	94	return 0;
	95	efault:
	96	buf->result = -EFAULT;
	97	return -EFAULT;
	98	}
	99
	100	asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
	101	{
	102	int error;
	103	struct file * file;
	104	struct readdir_callback buf;
	105
	106	error = -EBADF;
	107	file = fget(fd);
	108	if (!file)
	109	goto out;
	110
	111	buf.result = 0;
	112	buf.dirent = dirent;
	113
	114	error = vfs_readdir(file, fillonedir, &buf);
	115	if (error >= 0)
	116	error = buf.result;
	117
	118	fput(file);
	119	out:
	120	return error;
	121	}
	122
	123	#endif /* __ARCH_WANT_OLD_READDIR */
	124
	125	/*
	126	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	127	* interface.
	128	*/
	129	struct linux_dirent {
	130	unsigned long d_ino;
	131	unsigned long d_off;
	132	unsigned short d_reclen;
	133	char d_name[1];
	134	};
	135
	136	struct getdents_callback {
	137	struct linux_dirent __user * current_dir;
	138	struct linux_dirent __user * previous;
	139	int count;
	140	int error;
	141	};
	142
	143	static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	144	u64 ino, unsigned int d_type)
1da177e4 LT	145	{
	146	struct linux_dirent __user * dirent;
	147	struct getdents_callback * buf = (struct getdents_callback *) __buf;
afefdbb2	148	unsigned long d_ino;
022a1692	149	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
1da177e4 LT	150
	151	buf->error = -EINVAL; /* only used if we fail.. */
	152	if (reclen > buf->count)
	153	return -EINVAL;
afefdbb2 DH	154	d_ino = ino;
	155	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
	156	return -EOVERFLOW;
1da177e4 LT	157	dirent = buf->previous;
	158	if (dirent) {
	159	if (__put_user(offset, &dirent->d_off))
	160	goto efault;
	161	}
	162	dirent = buf->current_dir;
afefdbb2	163	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	164	goto efault;
	165	if (__put_user(reclen, &dirent->d_reclen))
	166	goto efault;
	167	if (copy_to_user(dirent->d_name, name, namlen))
	168	goto efault;
	169	if (__put_user(0, dirent->d_name + namlen))
	170	goto efault;
	171	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	172	goto efault;
	173	buf->previous = dirent;
	174	dirent = (void __user *)dirent + reclen;
	175	buf->current_dir = dirent;
	176	buf->count -= reclen;
	177	return 0;
	178	efault:
	179	buf->error = -EFAULT;
	180	return -EFAULT;
	181	}
	182
	183	asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
	184	{
	185	struct file * file;
	186	struct linux_dirent __user * lastdirent;
	187	struct getdents_callback buf;
	188	int error;
	189
	190	error = -EFAULT;
	191	if (!access_ok(VERIFY_WRITE, dirent, count))
	192	goto out;
	193
	194	error = -EBADF;
	195	file = fget(fd);
	196	if (!file)
	197	goto out;
	198
	199	buf.current_dir = dirent;
	200	buf.previous = NULL;
	201	buf.count = count;
	202	buf.error = 0;
	203
	204	error = vfs_readdir(file, filldir, &buf);
	205	if (error < 0)
	206	goto out_putf;
	207	error = buf.error;
	208	lastdirent = buf.previous;
	209	if (lastdirent) {
	210	if (put_user(file->f_pos, &lastdirent->d_off))
	211	error = -EFAULT;
	212	else
	213	error = count - buf.count;
	214	}
	215
	216	out_putf:
	217	fput(file);
	218	out:
	219	return error;
	220	}
	221
1da177e4 LT	222	struct getdents_callback64 {
	223	struct linux_dirent64 __user * current_dir;
	224	struct linux_dirent64 __user * previous;
	225	int count;
	226	int error;
	227	};
	228
	229	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	230	u64 ino, unsigned int d_type)
1da177e4 LT	231	{
	232	struct linux_dirent64 __user *dirent;
	233	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
022a1692	234	int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
1da177e4 LT	235
	236	buf->error = -EINVAL; /* only used if we fail.. */
	237	if (reclen > buf->count)
	238	return -EINVAL;
	239	dirent = buf->previous;
	240	if (dirent) {
	241	if (__put_user(offset, &dirent->d_off))
	242	goto efault;
	243	}
	244	dirent = buf->current_dir;
	245	if (__put_user(ino, &dirent->d_ino))
	246	goto efault;
	247	if (__put_user(0, &dirent->d_off))
	248	goto efault;
	249	if (__put_user(reclen, &dirent->d_reclen))
	250	goto efault;
	251	if (__put_user(d_type, &dirent->d_type))
	252	goto efault;
	253	if (copy_to_user(dirent->d_name, name, namlen))
	254	goto efault;
	255	if (__put_user(0, dirent->d_name + namlen))
	256	goto efault;
	257	buf->previous = dirent;
	258	dirent = (void __user *)dirent + reclen;
	259	buf->current_dir = dirent;
	260	buf->count -= reclen;
	261	return 0;
	262	efault:
	263	buf->error = -EFAULT;
	264	return -EFAULT;
	265	}
	266
	267	asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
	268	{
	269	struct file * file;
	270	struct linux_dirent64 __user * lastdirent;
	271	struct getdents_callback64 buf;
	272	int error;
	273
	274	error = -EFAULT;
	275	if (!access_ok(VERIFY_WRITE, dirent, count))
	276	goto out;
	277
	278	error = -EBADF;
	279	file = fget(fd);
	280	if (!file)
	281	goto out;
	282
	283	buf.current_dir = dirent;
	284	buf.previous = NULL;
	285	buf.count = count;
	286	buf.error = 0;
	287
	288	error = vfs_readdir(file, filldir64, &buf);
	289	if (error < 0)
	290	goto out_putf;
	291	error = buf.error;
	292	lastdirent = buf.previous;
	293	if (lastdirent) {
	294	typeof(lastdirent->d_off) d_off = file->f_pos;
	295	error = -EFAULT;
	296	if (__put_user(d_off, &lastdirent->d_off))
	297	goto out_putf;
	298	error = count - buf.count;
299	}
300
301	out_putf:
302	fput(file);
303	out:
304	return error;
305	}