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/*
File: fs/xattr.c
Extended attribute handling.
Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/file.h>
#include <linux/xattr.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <asm/uaccess.h>
/*
* Extended attribute SET operations
*/
static long
setxattr(struct dentry *d, char __user *name, void __user *value,
size_t size, int flags)
{
int error;
void *kvalue = NULL;
char kname[XATTR_NAME_MAX + 1];
if (flags & ~(XATTR_CREATE|XATTR_REPLACE))
return -EINVAL;
error = strncpy_from_user(kname, name, sizeof(kname));
if (error == 0 || error == sizeof(kname))
error = -ERANGE;
if (error < 0)
return error;
if (size) {
if (size > XATTR_SIZE_MAX)
return -E2BIG;
kvalue = kmalloc(size, GFP_KERNEL);
if (!kvalue)
return -ENOMEM;
if (copy_from_user(kvalue, value, size)) {
kfree(kvalue);
return -EFAULT;
}
}
error = -EOPNOTSUPP;
if (d->d_inode->i_op && d->d_inode->i_op->setxattr) {
down(&d->d_inode->i_sem);
error = security_inode_setxattr(d, kname, kvalue, size, flags);
if (error)
goto out;
error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags);
if (!error)
security_inode_post_setxattr(d, kname, kvalue, size, flags);
out:
up(&d->d_inode->i_sem);
}
if (kvalue)
kfree(kvalue);
return error;
}
asmlinkage long
sys_setxattr(char __user *path, char __user *name, void __user *value,
size_t size, int flags)
{
struct nameidata nd;
int error;
error = user_path_walk(path, &nd);
if (error)
return error;
error = setxattr(nd.dentry, name, value, size, flags);
path_release(&nd);
return error;
}
asmlinkage long
sys_lsetxattr(char __user *path, char __user *name, void __user *value,
size_t size, int flags)
{
struct nameidata nd;
int error;
error = user_path_walk_link(path, &nd);
if (error)
return error;
error = setxattr(nd.dentry, name, value, size, flags);
path_release(&nd);
return error;
}
asmlinkage long
sys_fsetxattr(int fd, char __user *name, void __user *value,
size_t size, int flags)
{
struct file *f;
int error = -EBADF;
f = fget(fd);
if (!f)
return error;
error = setxattr(f->f_dentry, name, value, size, flags);
fput(f);
return error;
}
/*
* Extended attribute GET operations
*/
static ssize_t
getxattr(struct dentry *d, char __user *name, void __user *value, size_t size)
{
ssize_t error;
void *kvalue = NULL;
char kname[XATTR_NAME_MAX + 1];
error = strncpy_from_user(kname, name, sizeof(kname));
if (error == 0 || error == sizeof(kname))
error = -ERANGE;
if (error < 0)
return error;
if (size) {
if (size > XATTR_SIZE_MAX)
size = XATTR_SIZE_MAX;
kvalue = kmalloc(size, GFP_KERNEL);
if (!kvalue)
return -ENOMEM;
}
error = -EOPNOTSUPP;
if (d->d_inode->i_op && d->d_inode->i_op->getxattr) {
error = security_inode_getxattr(d, kname);
if (error)
goto out;
error = d->d_inode->i_op->getxattr(d, kname, kvalue, size);
if (error > 0) {
if (size && copy_to_user(value, kvalue, error))
error = -EFAULT;
} else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
/* The file system tried to returned a value bigger
than XATTR_SIZE_MAX bytes. Not possible. */
error = -E2BIG;
}
}
out:
if (kvalue)
kfree(kvalue);
return error;
}
asmlinkage ssize_t
sys_getxattr(char __user *path, char __user *name, void __user *value,
size_t size)
{
struct nameidata nd;
ssize_t error;
error = user_path_walk(path, &nd);
if (error)
return error;
error = getxattr(nd.dentry, name, value, size);
path_release(&nd);
return error;
}
asmlinkage ssize_t
sys_lgetxattr(char __user *path, char __user *name, void __user *value,
size_t size)
{
struct nameidata nd;
ssize_t error;
error = user_path_walk_link(path, &nd);
if (error)
return error;
error = getxattr(nd.dentry, name, value, size);
path_release(&nd);
return error;
}
asmlinkage ssize_t
sys_fgetxattr(int fd, char __user *name, void __user *value, size_t size)
{
struct file *f;
ssize_t error = -EBADF;
f = fget(fd);
if (!f)
return error;
error = getxattr(f->f_dentry, name, value, size);
fput(f);
return error;
}
/*
* Extended attribute LIST operations
*/
static ssize_t
listxattr(struct dentry *d, char __user *list, size_t size)
{
ssize_t error;
char *klist = NULL;
if (size) {
if (size > XATTR_LIST_MAX)
size = XATTR_LIST_MAX;
klist = kmalloc(size, GFP_KERNEL);
if (!klist)
return -ENOMEM;
}
error = -EOPNOTSUPP;
if (d->d_inode->i_op && d->d_inode->i_op->listxattr) {
error = security_inode_listxattr(d);
if (error)
goto out;
error = d->d_inode->i_op->listxattr(d, klist, size);
if (error > 0) {
if (size && copy_to_user(list, klist, error))
error = -EFAULT;
} else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
/* The file system tried to returned a list bigger
than XATTR_LIST_MAX bytes. Not possible. */
error = -E2BIG;
}
}
out:
if (klist)
kfree(klist);
return error;
}
asmlinkage ssize_t
sys_listxattr(char __user *path, char __user *list, size_t size)
{
struct nameidata nd;
ssize_t error;
error = user_path_walk(path, &nd);
if (error)
return error;
error = listxattr(nd.dentry, list, size);
path_release(&nd);
return error;
}
asmlinkage ssize_t
sys_llistxattr(char __user *path, char __user *list, size_t size)
{
struct nameidata nd;
ssize_t error;
error = user_path_walk_link(path, &nd);
if (error)
return error;
error = listxattr(nd.dentry, list, size);
path_release(&nd);
return error;
}
asmlinkage ssize_t
sys_flistxattr(int fd, char __user *list, size_t size)
{
struct file *f;
ssize_t error = -EBADF;
f = fget(fd);
if (!f)
return error;
error = listxattr(f->f_dentry, list, size);
fput(f);
return error;
}
/*
* Extended attribute REMOVE operations
*/
static long
removexattr(struct dentry *d, char __user *name)
{
int error;
char kname[XATTR_NAME_MAX + 1];
error = strncpy_from_user(kname, name, sizeof(kname));
if (error == 0 || error == sizeof(kname))
error = -ERANGE;
if (error < 0)
return error;
error = -EOPNOTSUPP;
if (d->d_inode->i_op && d->d_inode->i_op->removexattr) {
error = security_inode_removexattr(d, kname);
if (error)
goto out;
down(&d->d_inode->i_sem);
error = d->d_inode->i_op->removexattr(d, kname);
up(&d->d_inode->i_sem);
}
out:
return error;
}
asmlinkage long
sys_removexattr(char __user *path, char __user *name)
{
struct nameidata nd;
int error;
error = user_path_walk(path, &nd);
if (error)
return error;
error = removexattr(nd.dentry, name);
path_release(&nd);
return error;
}
asmlinkage long
sys_lremovexattr(char __user *path, char __user *name)
{
struct nameidata nd;
int error;
error = user_path_walk_link(path, &nd);
if (error)
return error;
error = removexattr(nd.dentry, name);
path_release(&nd);
return error;
}
asmlinkage long
sys_fremovexattr(int fd, char __user *name)
{
struct file *f;
int error = -EBADF;
f = fget(fd);
if (!f)
return error;
error = removexattr(f->f_dentry, name);
fput(f);
return error;
}
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