#include <linux/init.h>
#include <linux/namei.h>
#include <linux/security.h>
-
-#define SECURITYFS_MAGIC 0x73636673
+#include <linux/magic.h>
static struct vfsmount *mount;
static int mount_count;
-/*
- * TODO:
- * I think I can get rid of these default_file_ops, but not quite sure...
- */
-static ssize_t default_read_file(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
-{
- return 0;
-}
-
-static ssize_t default_write_file(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- return count;
-}
-
-static int default_open(struct inode *inode, struct file *file)
-{
- if (inode->i_private)
- file->private_data = inode->i_private;
-
- return 0;
-}
-
-static const struct file_operations default_file_ops = {
- .read = default_read_file,
- .write = default_write_file,
- .open = default_open,
-};
-
-static struct inode *get_inode(struct super_block *sb, int mode, dev_t dev)
-{
- struct inode *inode = new_inode(sb);
-
- if (inode) {
- inode->i_mode = mode;
- inode->i_uid = 0;
- inode->i_gid = 0;
- inode->i_blocks = 0;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- switch (mode & S_IFMT) {
- default:
- init_special_inode(inode, mode, dev);
- break;
- case S_IFREG:
- inode->i_fop = &default_file_ops;
- break;
- case S_IFDIR:
- inode->i_op = &simple_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
-
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inc_nlink(inode);
- break;
- }
- }
- return inode;
-}
-
-/* SMP-safe */
-static int mknod(struct inode *dir, struct dentry *dentry,
- int mode, dev_t dev)
-{
- struct inode *inode;
- int error = -EPERM;
-
- if (dentry->d_inode)
- return -EEXIST;
-
- inode = get_inode(dir->i_sb, mode, dev);
- if (inode) {
- d_instantiate(dentry, inode);
- dget(dentry);
- error = 0;
- }
- return error;
-}
-
-static int mkdir(struct inode *dir, struct dentry *dentry, int mode)
-{
- int res;
-
- mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
- res = mknod(dir, dentry, mode, 0);
- if (!res)
- inc_nlink(dir);
- return res;
-}
-
-static int create(struct inode *dir, struct dentry *dentry, int mode)
-{
- mode = (mode & S_IALLUGO) | S_IFREG;
- return mknod(dir, dentry, mode, 0);
-}
-
static inline int positive(struct dentry *dentry)
{
return dentry->d_inode && !d_unhashed(dentry);
return simple_fill_super(sb, SECURITYFS_MAGIC, files);
}
-static int get_sb(struct file_system_type *fs_type,
+static struct dentry *get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
- void *data, struct vfsmount *mnt)
+ void *data)
{
- return get_sb_single(fs_type, flags, data, fill_super, mnt);
+ return mount_single(fs_type, flags, data, fill_super);
}
static struct file_system_type fs_type = {
.owner = THIS_MODULE,
.name = "securityfs",
- .get_sb = get_sb,
+ .mount = get_sb,
.kill_sb = kill_litter_super,
};
-static int create_by_name(const char *name, mode_t mode,
- struct dentry *parent,
- struct dentry **dentry)
-{
- int error = 0;
-
- *dentry = NULL;
-
- /* If the parent is not specified, we create it in the root.
- * We need the root dentry to do this, which is in the super
- * block. A pointer to that is in the struct vfsmount that we
- * have around.
- */
- if (!parent ) {
- if (mount && mount->mnt_sb) {
- parent = mount->mnt_sb->s_root;
- }
- }
- if (!parent) {
- pr_debug("securityfs: Ah! can not find a parent!\n");
- return -EFAULT;
- }
-
- mutex_lock(&parent->d_inode->i_mutex);
- *dentry = lookup_one_len(name, parent, strlen(name));
- if (!IS_ERR(dentry)) {
- if ((mode & S_IFMT) == S_IFDIR)
- error = mkdir(parent->d_inode, *dentry, mode);
- else
- error = create(parent->d_inode, *dentry, mode);
- } else
- error = PTR_ERR(dentry);
- mutex_unlock(&parent->d_inode->i_mutex);
-
- return error;
-}
-
/**
* securityfs_create_file - create a file in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the securityfs filesystem.
* @data: a pointer to something that the caller will want to get to later
* on. The inode.i_private pointer will point to this value on
* this file.
*
* This is the basic "create a file" function for securityfs. It allows for a
- * wide range of flexibility in createing a file, or a directory (if you
+ * wide range of flexibility in creating a file, or a directory (if you
* want to create a directory, the securityfs_create_dir() function is
- * recommended to be used instead.)
+ * recommended to be used instead).
*
- * This function will return a pointer to a dentry if it succeeds. This
+ * This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here). If an error occurs, the function will return
+ * the erorr value (via ERR_PTR).
*
- * If securityfs is not enabled in the kernel, the value -ENODEV will be
- * returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
- * code.
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
*/
-struct dentry *securityfs_create_file(const char *name, mode_t mode,
+struct dentry *securityfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
- struct dentry *dentry = NULL;
+ struct dentry *dentry;
+ int is_dir = S_ISDIR(mode);
+ struct inode *dir, *inode;
int error;
+ if (!is_dir) {
+ BUG_ON(!fops);
+ mode = (mode & S_IALLUGO) | S_IFREG;
+ }
+
pr_debug("securityfs: creating file '%s'\n",name);
error = simple_pin_fs(&fs_type, &mount, &mount_count);
- if (error) {
- dentry = ERR_PTR(error);
- goto exit;
+ if (error)
+ return ERR_PTR(error);
+
+ if (!parent)
+ parent = mount->mnt_root;
+
+ dir = parent->d_inode;
+
+ mutex_lock(&dir->i_mutex);
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (IS_ERR(dentry))
+ goto out;
+
+ if (dentry->d_inode) {
+ error = -EEXIST;
+ goto out1;
}
- error = create_by_name(name, mode, parent, &dentry);
- if (error) {
- dentry = ERR_PTR(error);
- simple_release_fs(&mount, &mount_count);
- goto exit;
+ inode = new_inode(dir->i_sb);
+ if (!inode) {
+ error = -ENOMEM;
+ goto out1;
}
- if (dentry->d_inode) {
- if (fops)
- dentry->d_inode->i_fop = fops;
- if (data)
- dentry->d_inode->i_private = data;
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_private = data;
+ if (is_dir) {
+ inode->i_op = &simple_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inc_nlink(inode);
+ inc_nlink(dir);
+ } else {
+ inode->i_fop = fops;
}
-exit:
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ mutex_unlock(&dir->i_mutex);
+ return dentry;
+
+out1:
+ dput(dentry);
+ dentry = ERR_PTR(error);
+out:
+ mutex_unlock(&dir->i_mutex);
+ simple_release_fs(&mount, &mount_count);
return dentry;
}
EXPORT_SYMBOL_GPL(securityfs_create_file);
* @name: a pointer to a string containing the name of the directory to
* create.
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* directory will be created in the root of the securityfs filesystem.
*
- * This function creates a directory in securityfs with the given name.
+ * This function creates a directory in securityfs with the given @name.
*
- * This function will return a pointer to a dentry if it succeeds. This
+ * This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here). If an error occurs, %NULL will be returned.
*
- * If securityfs is not enabled in the kernel, the value -ENODEV will be
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
/**
* securityfs_remove - removes a file or directory from the securityfs filesystem
*
- * @dentry: a pointer to a the dentry of the file or directory to be
- * removed.
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
*
* This function removes a file or directory in securityfs that was previously
* created with a call to another securityfs function (like
* securityfs_create_file() or variants thereof.)
*
* This function is required to be called in order for the file to be
- * removed, no automatic cleanup of files will happen when a module is
- * removed, you are responsible here.
+ * removed. No automatic cleanup of files will happen when a module is
+ * removed; you are responsible here.
*/
void securityfs_remove(struct dentry *dentry)
{
struct dentry *parent;
- if (!dentry)
+ if (!dentry || IS_ERR(dentry))
return;
parent = dentry->d_parent;
retval = register_filesystem(&fs_type);
if (retval)
- kobject_unregister(security_kobj);
+ kobject_put(security_kobj);
return retval;
}