// SPDX-License-Identifier: GPL-2.0-or-later/* * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University * Copyright (C) 2004-2006 International Business Machines Corp. *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> *              Michael C. Thompson <mcthomps@us.ibm.com> */ #include <linux/fs.h>#include <linux/mount.h>#include <linux/key.h>#include <linux/slab.h>#include <linux/seq_file.h>#include <linux/file.h>#include <linux/statfs.h>#include <linux/magic.h>#include "ecryptfs_kernel.h" struct kmem_cache *ecryptfs_inode_info_cache; /** * ecryptfs_alloc_inode - allocate an ecryptfs inode * @sb: Pointer to the ecryptfs super block * * Called to bring an inode into existence. * * Only handle allocation, setting up structures should be done in * ecryptfs_read_inode. This is because the kernel, between now and * then, will 0 out the private data pointer. * * Returns a pointer to a newly allocated inode, NULL otherwise */static struct inode *ecryptfs_alloc_inode(struct super_block *sb){	struct ecryptfs_inode_info *inode_info;	struct inode *inode = NULL; 	inode_info = alloc_inode_sb(sb, ecryptfs_inode_info_cache, GFP_KERNEL);	if (unlikely(!inode_info))		goto out;	ecryptfs_init_crypt_stat(&inode_info->crypt_stat);	mutex_init(&inode_info->lower_file_mutex);	atomic_set(&inode_info->lower_file_count, 0);	inode_info->lower_file = NULL;	inode = &inode_info->vfs_inode;out:	return inode;} static void ecryptfs_free_inode(struct inode *inode){	struct ecryptfs_inode_info *inode_info;	inode_info = ecryptfs_inode_to_private(inode); 	kmem_cache_free(ecryptfs_inode_info_cache, inode_info);} /** * ecryptfs_destroy_inode * @inode: The ecryptfs inode * * This is used during the final destruction of the inode.  All * allocation of memory related to the inode, including allocated * memory in the crypt_stat struct, will be released here. * There should be no chance that this deallocation will be missed. */static void ecryptfs_destroy_inode(struct inode *inode){	struct ecryptfs_inode_info *inode_info; 	inode_info = ecryptfs_inode_to_private(inode);	BUG_ON(inode_info->lower_file);	ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);} /** * ecryptfs_statfs * @dentry: The ecryptfs dentry * @buf: The struct kstatfs to fill in with stats * * Get the filesystem statistics. Currently, we let this pass right through * to the lower filesystem and take no action ourselves. */static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf){	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);	int rc; 	if (!lower_dentry->d_sb->s_op->statfs)		return -ENOSYS; 	rc = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);	if (rc)		return rc; 	buf->f_type = ECRYPTFS_SUPER_MAGIC;	rc = ecryptfs_set_f_namelen(&buf->f_namelen, buf->f_namelen,	       &ecryptfs_superblock_to_private(dentry->d_sb)->mount_crypt_stat); 	return rc;} /** * ecryptfs_evict_inode * @inode: The ecryptfs inode * * Called by iput() when the inode reference count reached zero * and the inode is not hashed anywhere.  Used to clear anything * that needs to be, before the inode is completely destroyed and put * on the inode free list. We use this to drop out reference to the * lower inode. */static void ecryptfs_evict_inode(struct inode *inode){	truncate_inode_pages_final(&inode->i_data);	clear_inode(inode);	iput(ecryptfs_inode_to_lower(inode));} /* * ecryptfs_show_options * * Prints the mount options for a given superblock. * Returns zero; does not fail. */static int ecryptfs_show_options(struct seq_file *m, struct dentry *root){	struct super_block *sb = root->d_sb;	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =		&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;	struct ecryptfs_global_auth_tok *walker; 	mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);	list_for_each_entry(walker,			    &mount_crypt_stat->global_auth_tok_list,			    mount_crypt_stat_list) {		if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)			seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);		else			seq_printf(m, ",ecryptfs_sig=%s", walker->sig);	}	mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); 	seq_printf(m, ",ecryptfs_cipher=%s",		mount_crypt_stat->global_default_cipher_name); 	if (mount_crypt_stat->global_default_cipher_key_size)		seq_printf(m, ",ecryptfs_key_bytes=%zd",			   mount_crypt_stat->global_default_cipher_key_size);	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {		seq_printf(m, ",ecryptfs_fn_cipher=%s",			   mount_crypt_stat->global_default_fn_cipher_name);		if (mount_crypt_stat->global_default_fn_cipher_key_bytes)			seq_printf(m, ",ecryptfs_fn_key_bytes=%zd",				   mount_crypt_stat->global_default_fn_cipher_key_bytes);	}	if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)		seq_printf(m, ",ecryptfs_passthrough");	if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)		seq_printf(m, ",ecryptfs_xattr_metadata");	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)		seq_printf(m, ",ecryptfs_encrypted_view");	if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)		seq_printf(m, ",ecryptfs_unlink_sigs");	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)		seq_printf(m, ",ecryptfs_mount_auth_tok_only"); 	return 0;} const struct super_operations ecryptfs_sops = {	.alloc_inode = ecryptfs_alloc_inode,	.destroy_inode = ecryptfs_destroy_inode,	.free_inode = ecryptfs_free_inode,	.statfs = ecryptfs_statfs,	.evict_inode = ecryptfs_evict_inode,	.show_options = ecryptfs_show_options};