[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 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->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, ctx, ctx->actor);
		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;

	if (!f.file)
		return -EBADF;

	buf.ctx.actor = fillonedir;
	buf.result = 0;
	buf.dirent = dirent;

	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;
	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;
	buf.ctx.actor = filldir;

	error = iterate_dir(f.file, &buf.ctx);
	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 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;
	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;
	buf.ctx.actor = filldir64;

	error = iterate_dir(f.file, &buf.ctx);
	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
5c0ba4e0	23	int iterate_dir(struct file file, struct dir_context ctx)
1da177e4	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;
1da177e4 LT	39	if (!IS_DEADDIR(inode)) {
5c0ba4e0	40	res = file->f_op->readdir(file, ctx, ctx->actor);
1da177e4 LT	41	file_accessed(file);
1da177e4 LT	42	}
1b1dcc1b	43	mutex_unlock(&inode->i_mutex);
1da177e4 LT	44	out:
	45	return res;
	46	}
5c0ba4e0	47	EXPORT_SYMBOL(iterate_dir);
1da177e4 LT	48
	49	/*
	50	* Traditional linux readdir() handling..
	51	*
	52	* "count=1" is a special case, meaning that the buffer is one
	53	* dirent-structure in size and that the code can't handle more
	54	* anyway. Thus the special "fillonedir()" function for that
	55	* case (the low-level handlers don't need to care about this).
	56	*/
1da177e4 LT	57
	58	#ifdef __ARCH_WANT_OLD_READDIR
	59
	60	struct old_linux_dirent {
	61	unsigned long d_ino;
	62	unsigned long d_offset;
	63	unsigned short d_namlen;
	64	char d_name[1];
	65	};
	66
	67	struct readdir_callback {
5c0ba4e0	68	struct dir_context ctx;
1da177e4 LT	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	75	{
5c0ba4e0	76	struct readdir_callback buf = (struct readdir_callback ) __buf;
1da177e4	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	114
5c0ba4e0	115	buf.ctx.actor = fillonedir;
1da177e4 LT	116	buf.result = 0;
	117	buf.dirent = dirent;
	118
5c0ba4e0	119	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0	120	if (buf.result)
1da177e4 LT	121	error = buf.result;
1da177e4 LT	122
2903ff01	123	fdput(f);
1da177e4 LT	124	return error;
	125	}
	126
	127	#endif /* __ARCH_WANT_OLD_READDIR */
	128
	129	/*
	130	* New, all-improved, singing, dancing, iBCS2-compliant getdents()
	131	* interface.
	132	*/
	133	struct linux_dirent {
	134	unsigned long d_ino;
	135	unsigned long d_off;
	136	unsigned short d_reclen;
	137	char d_name[1];
	138	};
	139
	140	struct getdents_callback {
5c0ba4e0	141	struct dir_context ctx;
1da177e4 LT	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	193	{
2903ff01	194	struct fd f;
1da177e4 LT	195	struct linux_dirent __user * lastdirent;
	196	struct getdents_callback buf;
	197	int error;
	198
1da177e4	199	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	200	return -EFAULT;
1da177e4	201
2903ff01 AV	202	f = fdget(fd);
2903ff01 AV	203	if (!f.file)
863ced7f	204	return -EBADF;
1da177e4 LT	205
	206	buf.current_dir = dirent;
	207	buf.previous = NULL;
	208	buf.count = count;
	209	buf.error = 0;
5c0ba4e0	210	buf.ctx.actor = filldir;
1da177e4	211
5c0ba4e0	212	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	213	if (error >= 0)
53c9c5c0 AV	214	error = buf.error;
1da177e4 LT	215	lastdirent = buf.previous;
1da177e4 LT	216	if (lastdirent) {
2903ff01	217	if (put_user(f.file->f_pos, &lastdirent->d_off))
1da177e4 LT	218	error = -EFAULT;
	219	else
	220	error = count - buf.count;
	221	}
2903ff01	222	fdput(f);
1da177e4 LT	223	return error;
	224	}
	225
1da177e4	226	struct getdents_callback64 {
5c0ba4e0	227	struct dir_context ctx;
1da177e4 LT	228	struct linux_dirent64 __user * current_dir;
	229	struct linux_dirent64 __user * previous;
	230	int count;
	231	int error;
	232	};
	233
	234	static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2	235	u64 ino, unsigned int d_type)
1da177e4 LT	236	{
	237	struct linux_dirent64 __user *dirent;
	238	struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
85c9fe8f KW	239	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
85c9fe8f KW	240	sizeof(u64));
1da177e4 LT	241
	242	buf->error = -EINVAL; /* only used if we fail.. */
	243	if (reclen > buf->count)
	244	return -EINVAL;
	245	dirent = buf->previous;
	246	if (dirent) {
	247	if (__put_user(offset, &dirent->d_off))
	248	goto efault;
	249	}
	250	dirent = buf->current_dir;
	251	if (__put_user(ino, &dirent->d_ino))
	252	goto efault;
	253	if (__put_user(0, &dirent->d_off))
	254	goto efault;
	255	if (__put_user(reclen, &dirent->d_reclen))
	256	goto efault;
	257	if (__put_user(d_type, &dirent->d_type))
	258	goto efault;
	259	if (copy_to_user(dirent->d_name, name, namlen))
	260	goto efault;
	261	if (__put_user(0, dirent->d_name + namlen))
	262	goto efault;
	263	buf->previous = dirent;
	264	dirent = (void __user *)dirent + reclen;
	265	buf->current_dir = dirent;
	266	buf->count -= reclen;
	267	return 0;
	268	efault:
	269	buf->error = -EFAULT;
	270	return -EFAULT;
	271	}
	272
20f37034 HC	273	SYSCALL_DEFINE3(getdents64, unsigned int, fd,
20f37034 HC	274	struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4	275	{
2903ff01	276	struct fd f;
1da177e4 LT	277	struct linux_dirent64 __user * lastdirent;
	278	struct getdents_callback64 buf;
	279	int error;
	280
1da177e4	281	if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f	282	return -EFAULT;
1da177e4	283
2903ff01 AV	284	f = fdget(fd);
2903ff01 AV	285	if (!f.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;
5c0ba4e0	292	buf.ctx.actor = filldir64;
1da177e4	293
5c0ba4e0	294	error = iterate_dir(f.file, &buf.ctx);
53c9c5c0 AV	295	if (error >= 0)
53c9c5c0 AV	296	error = buf.error;
1da177e4 LT	297	lastdirent = buf.previous;
1da177e4 LT	298	if (lastdirent) {
2903ff01	299	typeof(lastdirent->d_off) d_off = f.file->f_pos;
1da177e4	300	if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0 AV	301	error = -EFAULT;
	302	else
	303	error = count - buf.count;
1da177e4	304	}
2903ff01	305	fdput(f);
1da177e4 LT	306	return error;
1da177e4 LT	307	}