[mirror_ubuntu-zesty-kernel.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->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;
	int fput_needed;

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;

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

	error = vfs_readdir(file, fillonedir, &buf);
	if (buf.result)
		error = buf.result;

	fput_light(file, fput_needed);
	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 fput_needed;
	int error;

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

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;

	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_light(file, fput_needed);
	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 fput_needed;
	int error;

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

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;

	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_light(file, fput_needed);
	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	{
0f7fc9e4	25	struct inode *inode = file->f_path.dentry->d_inode;
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	{
	108	int error;
	109	struct file * file;
	110	struct readdir_callback buf;
863ced7f	111	int fput_needed;
1da177e4	112
863ced7f	113	file = fget_light(fd, &fput_needed);
1da177e4	114	if (!file)
863ced7f	115	return -EBADF;
1da177e4 LT	116
	117	buf.result = 0;
	118	buf.dirent = dirent;
	119
	120	error = vfs_readdir(file, fillonedir, &buf);
53c9c5c0	121	if (buf.result)
1da177e4 LT	122	error = buf.result;
1da177e4 LT	123
863ced7f	124	fput_light(file, fput_needed);
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 {
	142	struct linux_dirent __user * current_dir;
	143	struct linux_dirent __user * previous;
	144	int count;
	145	int error;
	146	};
	147
	148	static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	149	u64 ino, unsigned int d_type)
1da177e4 LT	150	{
	151	struct linux_dirent __user * dirent;
	152	struct getdents_callback * buf = (struct getdents_callback *) __buf;
afefdbb2	153	unsigned long d_ino;
85c9fe8f KW	154	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
85c9fe8f KW	155	sizeof(long));
1da177e4 LT	156
	157	buf->error = -EINVAL; /* only used if we fail.. */
	158	if (reclen > buf->count)
	159	return -EINVAL;
afefdbb2	160	d_ino = ino;
8f3f655d AV	161	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
8f3f655d AV	162	buf->error = -EOVERFLOW;
afefdbb2	163	return -EOVERFLOW;
8f3f655d	164	}
1da177e4 LT	165	dirent = buf->previous;
	166	if (dirent) {
	167	if (__put_user(offset, &dirent->d_off))
	168	goto efault;
	169	}
	170	dirent = buf->current_dir;
afefdbb2	171	if (__put_user(d_ino, &dirent->d_ino))
1da177e4 LT	172	goto efault;
	173	if (__put_user(reclen, &dirent->d_reclen))
	174	goto efault;
	175	if (copy_to_user(dirent->d_name, name, namlen))
	176	goto efault;
	177	if (__put_user(0, dirent->d_name + namlen))
	178	goto efault;
	179	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
	180	goto efault;
	181	buf->previous = dirent;
	182	dirent = (void __user *)dirent + reclen;
	183	buf->current_dir = dirent;
	184	buf->count -= reclen;
	185	return 0;
	186	efault:
	187	buf->error = -EFAULT;
	188	return -EFAULT;
	189	}
	190
20f37034 HC	191	SYSCALL_DEFINE3(getdents, unsigned int, fd,
20f37034 HC	192	struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4 LT	193	{
	194	struct file * file;
	195	struct linux_dirent __user * lastdirent;
	196	struct getdents_callback buf;
863ced7f	197	int fput_needed;
1da177e4 LT	198	int error;
1da177e4 LT	199
1da177e4	200	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	201	return -EFAULT;
1da177e4	202
863ced7f	203	file = fget_light(fd, &fput_needed);
1da177e4	204	if (!file)
863ced7f	205	return -EBADF;
1da177e4 LT	206
	207	buf.current_dir = dirent;
	208	buf.previous = NULL;
	209	buf.count = count;
	210	buf.error = 0;
	211
	212	error = vfs_readdir(file, filldir, &buf);
53c9c5c0 AV	213	if (error >= 0)
53c9c5c0 AV	214	error = buf.error;
1da177e4 LT	215	lastdirent = buf.previous;
	216	if (lastdirent) {
	217	if (put_user(file->f_pos, &lastdirent->d_off))
	218	error = -EFAULT;
	219	else
	220	error = count - buf.count;
	221	}
863ced7f	222	fput_light(file, fput_needed);
1da177e4 LT	223	return error;
	224	}
	225
1da177e4 LT	226	struct getdents_callback64 {
	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 LT	274	{
	275	struct file * file;
	276	struct linux_dirent64 __user * lastdirent;
	277	struct getdents_callback64 buf;
863ced7f	278	int fput_needed;
1da177e4 LT	279	int error;
1da177e4 LT	280
1da177e4	281	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	282	return -EFAULT;
1da177e4	283
863ced7f	284	file = fget_light(fd, &fput_needed);
1da177e4	285	if (!file)
863ced7f	286	return -EBADF;
1da177e4 LT	287
	288	buf.current_dir = dirent;
	289	buf.previous = NULL;
	290	buf.count = count;
	291	buf.error = 0;
	292
	293	error = vfs_readdir(file, filldir64, &buf);
53c9c5c0 AV	294	if (error >= 0)
53c9c5c0 AV	295	error = buf.error;
1da177e4 LT	296	lastdirent = buf.previous;
	297	if (lastdirent) {
	298	typeof(lastdirent->d_off) d_off = file->f_pos;
1da177e4	299	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	300	error = -EFAULT;
	301	else
	302	error = count - buf.count;
1da177e4	303	}
863ced7f	304	fput_light(file, fput_needed);
1da177e4 LT	305	return error;
1da177e4 LT	306	}