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-rw-r--r--fs/ecryptfs/inode.c1224
1 files changed, 1224 insertions, 0 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
new file mode 100644
index 0000000000..5ab4b87888
--- /dev/null
+++ b/fs/ecryptfs/inode.c
@@ -0,0 +1,1224 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2004 Erez Zadok
+ * Copyright (C) 2001-2004 Stony Brook University
+ * Copyright (C) 2004-2007 International Business Machines Corp.
+ * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Michael C. Thompsion <mcthomps@us.ibm.com>
+ */
+
+#include <linux/file.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/fs_stack.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/fileattr.h>
+#include <asm/unaligned.h>
+#include "ecryptfs_kernel.h"
+
+static int lock_parent(struct dentry *dentry,
+ struct dentry **lower_dentry,
+ struct inode **lower_dir)
+{
+ struct dentry *lower_dir_dentry;
+
+ lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
+ *lower_dir = d_inode(lower_dir_dentry);
+ *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+ inode_lock_nested(*lower_dir, I_MUTEX_PARENT);
+ return (*lower_dentry)->d_parent == lower_dir_dentry ? 0 : -EINVAL;
+}
+
+static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
+{
+ return ecryptfs_inode_to_lower(inode) == lower_inode;
+}
+
+static int ecryptfs_inode_set(struct inode *inode, void *opaque)
+{
+ struct inode *lower_inode = opaque;
+
+ ecryptfs_set_inode_lower(inode, lower_inode);
+ fsstack_copy_attr_all(inode, lower_inode);
+ /* i_size will be overwritten for encrypted regular files */
+ fsstack_copy_inode_size(inode, lower_inode);
+ inode->i_ino = lower_inode->i_ino;
+ inode->i_mapping->a_ops = &ecryptfs_aops;
+
+ if (S_ISLNK(inode->i_mode))
+ inode->i_op = &ecryptfs_symlink_iops;
+ else if (S_ISDIR(inode->i_mode))
+ inode->i_op = &ecryptfs_dir_iops;
+ else
+ inode->i_op = &ecryptfs_main_iops;
+
+ if (S_ISDIR(inode->i_mode))
+ inode->i_fop = &ecryptfs_dir_fops;
+ else if (special_file(inode->i_mode))
+ init_special_inode(inode, inode->i_mode, inode->i_rdev);
+ else
+ inode->i_fop = &ecryptfs_main_fops;
+
+ return 0;
+}
+
+static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
+ struct super_block *sb)
+{
+ struct inode *inode;
+
+ if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
+ return ERR_PTR(-EXDEV);
+ if (!igrab(lower_inode))
+ return ERR_PTR(-ESTALE);
+ inode = iget5_locked(sb, (unsigned long)lower_inode,
+ ecryptfs_inode_test, ecryptfs_inode_set,
+ lower_inode);
+ if (!inode) {
+ iput(lower_inode);
+ return ERR_PTR(-EACCES);
+ }
+ if (!(inode->i_state & I_NEW))
+ iput(lower_inode);
+
+ return inode;
+}
+
+struct inode *ecryptfs_get_inode(struct inode *lower_inode,
+ struct super_block *sb)
+{
+ struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
+
+ if (!IS_ERR(inode) && (inode->i_state & I_NEW))
+ unlock_new_inode(inode);
+
+ return inode;
+}
+
+/**
+ * ecryptfs_interpose
+ * @lower_dentry: Existing dentry in the lower filesystem
+ * @dentry: ecryptfs' dentry
+ * @sb: ecryptfs's super_block
+ *
+ * Interposes upper and lower dentries.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_interpose(struct dentry *lower_dentry,
+ struct dentry *dentry, struct super_block *sb)
+{
+ struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
+
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ d_instantiate(dentry, inode);
+
+ return 0;
+}
+
+static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+ int rc;
+
+ rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+ dget(lower_dentry); // don't even try to make the lower negative
+ if (!rc) {
+ if (d_unhashed(lower_dentry))
+ rc = -EINVAL;
+ else
+ rc = vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry,
+ NULL);
+ }
+ if (rc) {
+ printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
+ goto out_unlock;
+ }
+ fsstack_copy_attr_times(dir, lower_dir);
+ set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
+ inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
+out_unlock:
+ dput(lower_dentry);
+ inode_unlock(lower_dir);
+ if (!rc)
+ d_drop(dentry);
+ return rc;
+}
+
+/**
+ * ecryptfs_do_create
+ * @directory_inode: inode of the new file's dentry's parent in ecryptfs
+ * @ecryptfs_dentry: New file's dentry in ecryptfs
+ * @mode: The mode of the new file
+ *
+ * Creates the underlying file and the eCryptfs inode which will link to
+ * it. It will also update the eCryptfs directory inode to mimic the
+ * stat of the lower directory inode.
+ *
+ * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
+ */
+static struct inode *
+ecryptfs_do_create(struct inode *directory_inode,
+ struct dentry *ecryptfs_dentry, umode_t mode)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+ struct inode *inode;
+
+ rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
+ if (!rc)
+ rc = vfs_create(&nop_mnt_idmap, lower_dir,
+ lower_dentry, mode, true);
+ if (rc) {
+ printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
+ "rc = [%d]\n", __func__, rc);
+ inode = ERR_PTR(rc);
+ goto out_lock;
+ }
+ inode = __ecryptfs_get_inode(d_inode(lower_dentry),
+ directory_inode->i_sb);
+ if (IS_ERR(inode)) {
+ vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry, NULL);
+ goto out_lock;
+ }
+ fsstack_copy_attr_times(directory_inode, lower_dir);
+ fsstack_copy_inode_size(directory_inode, lower_dir);
+out_lock:
+ inode_unlock(lower_dir);
+ return inode;
+}
+
+/*
+ * ecryptfs_initialize_file
+ *
+ * Cause the file to be changed from a basic empty file to an ecryptfs
+ * file with a header and first data page.
+ *
+ * Returns zero on success
+ */
+int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
+ struct inode *ecryptfs_inode)
+{
+ struct ecryptfs_crypt_stat *crypt_stat =
+ &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+ int rc = 0;
+
+ if (S_ISDIR(ecryptfs_inode->i_mode)) {
+ ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
+ crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+ goto out;
+ }
+ ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
+ rc = ecryptfs_new_file_context(ecryptfs_inode);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error creating new file "
+ "context; rc = [%d]\n", rc);
+ goto out;
+ }
+ rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to initialize "
+ "the lower file for the dentry with name "
+ "[%pd]; rc = [%d]\n", __func__,
+ ecryptfs_dentry, rc);
+ goto out;
+ }
+ rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
+ if (rc)
+ printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
+ ecryptfs_put_lower_file(ecryptfs_inode);
+out:
+ return rc;
+}
+
+/*
+ * ecryptfs_create
+ * @mode: The mode of the new file.
+ *
+ * Creates a new file.
+ *
+ * Returns zero on success; non-zero on error condition
+ */
+static int
+ecryptfs_create(struct mnt_idmap *idmap,
+ struct inode *directory_inode, struct dentry *ecryptfs_dentry,
+ umode_t mode, bool excl)
+{
+ struct inode *ecryptfs_inode;
+ int rc;
+
+ ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
+ mode);
+ if (IS_ERR(ecryptfs_inode)) {
+ ecryptfs_printk(KERN_WARNING, "Failed to create file in"
+ "lower filesystem\n");
+ rc = PTR_ERR(ecryptfs_inode);
+ goto out;
+ }
+ /* At this point, a file exists on "disk"; we need to make sure
+ * that this on disk file is prepared to be an ecryptfs file */
+ rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
+ if (rc) {
+ ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
+ ecryptfs_inode);
+ iget_failed(ecryptfs_inode);
+ goto out;
+ }
+ d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
+out:
+ return rc;
+}
+
+static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
+{
+ struct ecryptfs_crypt_stat *crypt_stat;
+ int rc;
+
+ rc = ecryptfs_get_lower_file(dentry, inode);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to initialize "
+ "the lower file for the dentry with name "
+ "[%pd]; rc = [%d]\n", __func__,
+ dentry, rc);
+ return rc;
+ }
+
+ crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ /* TODO: lock for crypt_stat comparison */
+ if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
+ ecryptfs_set_default_sizes(crypt_stat);
+
+ rc = ecryptfs_read_and_validate_header_region(inode);
+ ecryptfs_put_lower_file(inode);
+ if (rc) {
+ rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
+ if (!rc)
+ crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+ }
+
+ /* Must return 0 to allow non-eCryptfs files to be looked up, too */
+ return 0;
+}
+
+/*
+ * ecryptfs_lookup_interpose - Dentry interposition for a lookup
+ */
+static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
+ struct dentry *lower_dentry)
+{
+ const struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
+ struct inode *inode, *lower_inode;
+ struct ecryptfs_dentry_info *dentry_info;
+ int rc = 0;
+
+ dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
+ if (!dentry_info) {
+ dput(lower_dentry);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ fsstack_copy_attr_atime(d_inode(dentry->d_parent),
+ d_inode(path->dentry));
+ BUG_ON(!d_count(lower_dentry));
+
+ ecryptfs_set_dentry_private(dentry, dentry_info);
+ dentry_info->lower_path.mnt = mntget(path->mnt);
+ dentry_info->lower_path.dentry = lower_dentry;
+
+ /*
+ * negative dentry can go positive under us here - its parent is not
+ * locked. That's OK and that could happen just as we return from
+ * ecryptfs_lookup() anyway. Just need to be careful and fetch
+ * ->d_inode only once - it's not stable here.
+ */
+ lower_inode = READ_ONCE(lower_dentry->d_inode);
+
+ if (!lower_inode) {
+ /* We want to add because we couldn't find in lower */
+ d_add(dentry, NULL);
+ return NULL;
+ }
+ inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
+ if (IS_ERR(inode)) {
+ printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
+ __func__, PTR_ERR(inode));
+ return ERR_CAST(inode);
+ }
+ if (S_ISREG(inode->i_mode)) {
+ rc = ecryptfs_i_size_read(dentry, inode);
+ if (rc) {
+ make_bad_inode(inode);
+ return ERR_PTR(rc);
+ }
+ }
+
+ if (inode->i_state & I_NEW)
+ unlock_new_inode(inode);
+ return d_splice_alias(inode, dentry);
+}
+
+/**
+ * ecryptfs_lookup
+ * @ecryptfs_dir_inode: The eCryptfs directory inode
+ * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
+ * @flags: lookup flags
+ *
+ * Find a file on disk. If the file does not exist, then we'll add it to the
+ * dentry cache and continue on to read it from the disk.
+ */
+static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
+ struct dentry *ecryptfs_dentry,
+ unsigned int flags)
+{
+ char *encrypted_and_encoded_name = NULL;
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+ struct dentry *lower_dir_dentry, *lower_dentry;
+ const char *name = ecryptfs_dentry->d_name.name;
+ size_t len = ecryptfs_dentry->d_name.len;
+ struct dentry *res;
+ int rc = 0;
+
+ lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
+
+ mount_crypt_stat = &ecryptfs_superblock_to_private(
+ ecryptfs_dentry->d_sb)->mount_crypt_stat;
+ if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+ rc = ecryptfs_encrypt_and_encode_filename(
+ &encrypted_and_encoded_name, &len,
+ mount_crypt_stat, name, len);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to encrypt and encode "
+ "filename; rc = [%d]\n", __func__, rc);
+ return ERR_PTR(rc);
+ }
+ name = encrypted_and_encoded_name;
+ }
+
+ lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
+ if (IS_ERR(lower_dentry)) {
+ ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+ "[%ld] on lower_dentry = [%s]\n", __func__,
+ PTR_ERR(lower_dentry),
+ name);
+ res = ERR_CAST(lower_dentry);
+ } else {
+ res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
+ }
+ kfree(encrypted_and_encoded_name);
+ return res;
+}
+
+static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *new_dentry)
+{
+ struct dentry *lower_old_dentry;
+ struct dentry *lower_new_dentry;
+ struct inode *lower_dir;
+ u64 file_size_save;
+ int rc;
+
+ file_size_save = i_size_read(d_inode(old_dentry));
+ lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
+ rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
+ if (!rc)
+ rc = vfs_link(lower_old_dentry, &nop_mnt_idmap, lower_dir,
+ lower_new_dentry, NULL);
+ if (rc || d_really_is_negative(lower_new_dentry))
+ goto out_lock;
+ rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
+ if (rc)
+ goto out_lock;
+ fsstack_copy_attr_times(dir, lower_dir);
+ fsstack_copy_inode_size(dir, lower_dir);
+ set_nlink(d_inode(old_dentry),
+ ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
+ i_size_write(d_inode(new_dentry), file_size_save);
+out_lock:
+ inode_unlock(lower_dir);
+ return rc;
+}
+
+static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
+}
+
+static int ecryptfs_symlink(struct mnt_idmap *idmap,
+ struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+ char *encoded_symname;
+ size_t encoded_symlen;
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
+
+ rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+ if (rc)
+ goto out_lock;
+ mount_crypt_stat = &ecryptfs_superblock_to_private(
+ dir->i_sb)->mount_crypt_stat;
+ rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
+ &encoded_symlen,
+ mount_crypt_stat, symname,
+ strlen(symname));
+ if (rc)
+ goto out_lock;
+ rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,
+ encoded_symname);
+ kfree(encoded_symname);
+ if (rc || d_really_is_negative(lower_dentry))
+ goto out_lock;
+ rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+ if (rc)
+ goto out_lock;
+ fsstack_copy_attr_times(dir, lower_dir);
+ fsstack_copy_inode_size(dir, lower_dir);
+out_lock:
+ inode_unlock(lower_dir);
+ if (d_really_is_negative(dentry))
+ d_drop(dentry);
+ return rc;
+}
+
+static int ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+
+ rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+ if (!rc)
+ rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
+ lower_dentry, mode);
+ if (rc || d_really_is_negative(lower_dentry))
+ goto out;
+ rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+ if (rc)
+ goto out;
+ fsstack_copy_attr_times(dir, lower_dir);
+ fsstack_copy_inode_size(dir, lower_dir);
+ set_nlink(dir, lower_dir->i_nlink);
+out:
+ inode_unlock(lower_dir);
+ if (d_really_is_negative(dentry))
+ d_drop(dentry);
+ return rc;
+}
+
+static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+ int rc;
+
+ rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+ dget(lower_dentry); // don't even try to make the lower negative
+ if (!rc) {
+ if (d_unhashed(lower_dentry))
+ rc = -EINVAL;
+ else
+ rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry);
+ }
+ if (!rc) {
+ clear_nlink(d_inode(dentry));
+ fsstack_copy_attr_times(dir, lower_dir);
+ set_nlink(dir, lower_dir->i_nlink);
+ }
+ dput(lower_dentry);
+ inode_unlock(lower_dir);
+ if (!rc)
+ d_drop(dentry);
+ return rc;
+}
+
+static int
+ecryptfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode, dev_t dev)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_dir;
+
+ rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+ if (!rc)
+ rc = vfs_mknod(&nop_mnt_idmap, lower_dir,
+ lower_dentry, mode, dev);
+ if (rc || d_really_is_negative(lower_dentry))
+ goto out;
+ rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+ if (rc)
+ goto out;
+ fsstack_copy_attr_times(dir, lower_dir);
+ fsstack_copy_inode_size(dir, lower_dir);
+out:
+ inode_unlock(lower_dir);
+ if (d_really_is_negative(dentry))
+ d_drop(dentry);
+ return rc;
+}
+
+static int
+ecryptfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
+ struct dentry *old_dentry, struct inode *new_dir,
+ struct dentry *new_dentry, unsigned int flags)
+{
+ int rc;
+ struct dentry *lower_old_dentry;
+ struct dentry *lower_new_dentry;
+ struct dentry *lower_old_dir_dentry;
+ struct dentry *lower_new_dir_dentry;
+ struct dentry *trap;
+ struct inode *target_inode;
+ struct renamedata rd = {};
+
+ if (flags)
+ return -EINVAL;
+
+ lower_old_dir_dentry = ecryptfs_dentry_to_lower(old_dentry->d_parent);
+ lower_new_dir_dentry = ecryptfs_dentry_to_lower(new_dentry->d_parent);
+
+ lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
+ lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
+
+ target_inode = d_inode(new_dentry);
+
+ trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ dget(lower_new_dentry);
+ rc = -EINVAL;
+ if (lower_old_dentry->d_parent != lower_old_dir_dentry)
+ goto out_lock;
+ if (lower_new_dentry->d_parent != lower_new_dir_dentry)
+ goto out_lock;
+ if (d_unhashed(lower_old_dentry) || d_unhashed(lower_new_dentry))
+ goto out_lock;
+ /* source should not be ancestor of target */
+ if (trap == lower_old_dentry)
+ goto out_lock;
+ /* target should not be ancestor of source */
+ if (trap == lower_new_dentry) {
+ rc = -ENOTEMPTY;
+ goto out_lock;
+ }
+
+ rd.old_mnt_idmap = &nop_mnt_idmap;
+ rd.old_dir = d_inode(lower_old_dir_dentry);
+ rd.old_dentry = lower_old_dentry;
+ rd.new_mnt_idmap = &nop_mnt_idmap;
+ rd.new_dir = d_inode(lower_new_dir_dentry);
+ rd.new_dentry = lower_new_dentry;
+ rc = vfs_rename(&rd);
+ if (rc)
+ goto out_lock;
+ if (target_inode)
+ fsstack_copy_attr_all(target_inode,
+ ecryptfs_inode_to_lower(target_inode));
+ fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
+ if (new_dir != old_dir)
+ fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
+out_lock:
+ dput(lower_new_dentry);
+ unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ return rc;
+}
+
+static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
+{
+ DEFINE_DELAYED_CALL(done);
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ const char *link;
+ char *buf;
+ int rc;
+
+ link = vfs_get_link(lower_dentry, &done);
+ if (IS_ERR(link))
+ return ERR_CAST(link);
+
+ rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
+ link, strlen(link));
+ do_delayed_call(&done);
+ if (rc)
+ return ERR_PTR(rc);
+
+ return buf;
+}
+
+static const char *ecryptfs_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
+{
+ size_t len;
+ char *buf;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ buf = ecryptfs_readlink_lower(dentry, &len);
+ if (IS_ERR(buf))
+ return buf;
+ fsstack_copy_attr_atime(d_inode(dentry),
+ d_inode(ecryptfs_dentry_to_lower(dentry)));
+ buf[len] = '\0';
+ set_delayed_call(done, kfree_link, buf);
+ return buf;
+}
+
+/**
+ * upper_size_to_lower_size
+ * @crypt_stat: Crypt_stat associated with file
+ * @upper_size: Size of the upper file
+ *
+ * Calculate the required size of the lower file based on the
+ * specified size of the upper file. This calculation is based on the
+ * number of headers in the underlying file and the extent size.
+ *
+ * Returns Calculated size of the lower file.
+ */
+static loff_t
+upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
+ loff_t upper_size)
+{
+ loff_t lower_size;
+
+ lower_size = ecryptfs_lower_header_size(crypt_stat);
+ if (upper_size != 0) {
+ loff_t num_extents;
+
+ num_extents = upper_size >> crypt_stat->extent_shift;
+ if (upper_size & ~crypt_stat->extent_mask)
+ num_extents++;
+ lower_size += (num_extents * crypt_stat->extent_size);
+ }
+ return lower_size;
+}
+
+/**
+ * truncate_upper
+ * @dentry: The ecryptfs layer dentry
+ * @ia: Address of the ecryptfs inode's attributes
+ * @lower_ia: Address of the lower inode's attributes
+ *
+ * Function to handle truncations modifying the size of the file. Note
+ * that the file sizes are interpolated. When expanding, we are simply
+ * writing strings of 0's out. When truncating, we truncate the upper
+ * inode and update the lower_ia according to the page index
+ * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
+ * the caller must use lower_ia in a call to notify_change() to perform
+ * the truncation of the lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int truncate_upper(struct dentry *dentry, struct iattr *ia,
+ struct iattr *lower_ia)
+{
+ int rc = 0;
+ struct inode *inode = d_inode(dentry);
+ struct ecryptfs_crypt_stat *crypt_stat;
+ loff_t i_size = i_size_read(inode);
+ loff_t lower_size_before_truncate;
+ loff_t lower_size_after_truncate;
+
+ if (unlikely((ia->ia_size == i_size))) {
+ lower_ia->ia_valid &= ~ATTR_SIZE;
+ return 0;
+ }
+ rc = ecryptfs_get_lower_file(dentry, inode);
+ if (rc)
+ return rc;
+ crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
+ /* Switch on growing or shrinking file */
+ if (ia->ia_size > i_size) {
+ char zero[] = { 0x00 };
+
+ lower_ia->ia_valid &= ~ATTR_SIZE;
+ /* Write a single 0 at the last position of the file;
+ * this triggers code that will fill in 0's throughout
+ * the intermediate portion of the previous end of the
+ * file and the new and of the file */
+ rc = ecryptfs_write(inode, zero,
+ (ia->ia_size - 1), 1);
+ } else { /* ia->ia_size < i_size_read(inode) */
+ /* We're chopping off all the pages down to the page
+ * in which ia->ia_size is located. Fill in the end of
+ * that page from (ia->ia_size & ~PAGE_MASK) to
+ * PAGE_SIZE with zeros. */
+ size_t num_zeros = (PAGE_SIZE
+ - (ia->ia_size & ~PAGE_MASK));
+
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ truncate_setsize(inode, ia->ia_size);
+ lower_ia->ia_size = ia->ia_size;
+ lower_ia->ia_valid |= ATTR_SIZE;
+ goto out;
+ }
+ if (num_zeros) {
+ char *zeros_virt;
+
+ zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
+ if (!zeros_virt) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ rc = ecryptfs_write(inode, zeros_virt,
+ ia->ia_size, num_zeros);
+ kfree(zeros_virt);
+ if (rc) {
+ printk(KERN_ERR "Error attempting to zero out "
+ "the remainder of the end page on "
+ "reducing truncate; rc = [%d]\n", rc);
+ goto out;
+ }
+ }
+ truncate_setsize(inode, ia->ia_size);
+ rc = ecryptfs_write_inode_size_to_metadata(inode);
+ if (rc) {
+ printk(KERN_ERR "Problem with "
+ "ecryptfs_write_inode_size_to_metadata; "
+ "rc = [%d]\n", rc);
+ goto out;
+ }
+ /* We are reducing the size of the ecryptfs file, and need to
+ * know if we need to reduce the size of the lower file. */
+ lower_size_before_truncate =
+ upper_size_to_lower_size(crypt_stat, i_size);
+ lower_size_after_truncate =
+ upper_size_to_lower_size(crypt_stat, ia->ia_size);
+ if (lower_size_after_truncate < lower_size_before_truncate) {
+ lower_ia->ia_size = lower_size_after_truncate;
+ lower_ia->ia_valid |= ATTR_SIZE;
+ } else
+ lower_ia->ia_valid &= ~ATTR_SIZE;
+ }
+out:
+ ecryptfs_put_lower_file(inode);
+ return rc;
+}
+
+static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
+{
+ struct ecryptfs_crypt_stat *crypt_stat;
+ loff_t lower_oldsize, lower_newsize;
+
+ crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ lower_oldsize = upper_size_to_lower_size(crypt_stat,
+ i_size_read(inode));
+ lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
+ if (lower_newsize > lower_oldsize) {
+ /*
+ * The eCryptfs inode and the new *lower* size are mixed here
+ * because we may not have the lower i_mutex held and/or it may
+ * not be appropriate to call inode_newsize_ok() with inodes
+ * from other filesystems.
+ */
+ return inode_newsize_ok(inode, lower_newsize);
+ }
+
+ return 0;
+}
+
+/**
+ * ecryptfs_truncate
+ * @dentry: The ecryptfs layer dentry
+ * @new_length: The length to expand the file to
+ *
+ * Simple function that handles the truncation of an eCryptfs inode and
+ * its corresponding lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+{
+ struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
+ struct iattr lower_ia = { .ia_valid = 0 };
+ int rc;
+
+ rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
+ if (rc)
+ return rc;
+
+ rc = truncate_upper(dentry, &ia, &lower_ia);
+ if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+ inode_lock(d_inode(lower_dentry));
+ rc = notify_change(&nop_mnt_idmap, lower_dentry,
+ &lower_ia, NULL);
+ inode_unlock(d_inode(lower_dentry));
+ }
+ return rc;
+}
+
+static int
+ecryptfs_permission(struct mnt_idmap *idmap, struct inode *inode,
+ int mask)
+{
+ return inode_permission(&nop_mnt_idmap,
+ ecryptfs_inode_to_lower(inode), mask);
+}
+
+/**
+ * ecryptfs_setattr
+ * @idmap: idmap of the target mount
+ * @dentry: dentry handle to the inode to modify
+ * @ia: Structure with flags of what to change and values
+ *
+ * Updates the metadata of an inode. If the update is to the size
+ * i.e. truncation, then ecryptfs_truncate will handle the size modification
+ * of both the ecryptfs inode and the lower inode.
+ *
+ * All other metadata changes will be passed right to the lower filesystem,
+ * and we will just update our inode to look like the lower.
+ */
+static int ecryptfs_setattr(struct mnt_idmap *idmap,
+ struct dentry *dentry, struct iattr *ia)
+{
+ int rc = 0;
+ struct dentry *lower_dentry;
+ struct iattr lower_ia;
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct ecryptfs_crypt_stat *crypt_stat;
+
+ crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
+ if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
+ rc = ecryptfs_init_crypt_stat(crypt_stat);
+ if (rc)
+ return rc;
+ }
+ inode = d_inode(dentry);
+ lower_inode = ecryptfs_inode_to_lower(inode);
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ mutex_lock(&crypt_stat->cs_mutex);
+ if (d_is_dir(dentry))
+ crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+ else if (d_is_reg(dentry)
+ && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
+ || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+
+ mount_crypt_stat = &ecryptfs_superblock_to_private(
+ dentry->d_sb)->mount_crypt_stat;
+ rc = ecryptfs_get_lower_file(dentry, inode);
+ if (rc) {
+ mutex_unlock(&crypt_stat->cs_mutex);
+ goto out;
+ }
+ rc = ecryptfs_read_metadata(dentry);
+ ecryptfs_put_lower_file(inode);
+ if (rc) {
+ if (!(mount_crypt_stat->flags
+ & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
+ rc = -EIO;
+ printk(KERN_WARNING "Either the lower file "
+ "is not in a valid eCryptfs format, "
+ "or the key could not be retrieved. "
+ "Plaintext passthrough mode is not "
+ "enabled; returning -EIO\n");
+ mutex_unlock(&crypt_stat->cs_mutex);
+ goto out;
+ }
+ rc = 0;
+ crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+ | ECRYPTFS_ENCRYPTED);
+ }
+ }
+ mutex_unlock(&crypt_stat->cs_mutex);
+
+ rc = setattr_prepare(&nop_mnt_idmap, dentry, ia);
+ if (rc)
+ goto out;
+ if (ia->ia_valid & ATTR_SIZE) {
+ rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
+ if (rc)
+ goto out;
+ }
+
+ memcpy(&lower_ia, ia, sizeof(lower_ia));
+ if (ia->ia_valid & ATTR_FILE)
+ lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
+ if (ia->ia_valid & ATTR_SIZE) {
+ rc = truncate_upper(dentry, ia, &lower_ia);
+ if (rc < 0)
+ goto out;
+ }
+
+ /*
+ * mode change is for clearing setuid/setgid bits. Allow lower fs
+ * to interpret this in its own way.
+ */
+ if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ lower_ia.ia_valid &= ~ATTR_MODE;
+
+ inode_lock(d_inode(lower_dentry));
+ rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL);
+ inode_unlock(d_inode(lower_dentry));
+out:
+ fsstack_copy_attr_all(inode, lower_inode);
+ return rc;
+}
+
+static int ecryptfs_getattr_link(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct dentry *dentry = path->dentry;
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+ int rc = 0;
+
+ mount_crypt_stat = &ecryptfs_superblock_to_private(
+ dentry->d_sb)->mount_crypt_stat;
+ generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
+ if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+ char *target;
+ size_t targetsiz;
+
+ target = ecryptfs_readlink_lower(dentry, &targetsiz);
+ if (!IS_ERR(target)) {
+ kfree(target);
+ stat->size = targetsiz;
+ } else {
+ rc = PTR_ERR(target);
+ }
+ }
+ return rc;
+}
+
+static int ecryptfs_do_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ if (flags & AT_GETATTR_NOSEC)
+ return vfs_getattr_nosec(path, stat, request_mask, flags);
+ return vfs_getattr(path, stat, request_mask, flags);
+}
+
+static int ecryptfs_getattr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct dentry *dentry = path->dentry;
+ struct kstat lower_stat;
+ int rc;
+
+ rc = ecryptfs_do_getattr(ecryptfs_dentry_to_lower_path(dentry),
+ &lower_stat, request_mask, flags);
+ if (!rc) {
+ fsstack_copy_attr_all(d_inode(dentry),
+ ecryptfs_inode_to_lower(d_inode(dentry)));
+ generic_fillattr(&nop_mnt_idmap, request_mask,
+ d_inode(dentry), stat);
+ stat->blocks = lower_stat.blocks;
+ }
+ return rc;
+}
+
+int
+ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_inode;
+
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ lower_inode = d_inode(lower_dentry);
+ if (!(lower_inode->i_opflags & IOP_XATTR)) {
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+ inode_lock(lower_inode);
+ rc = __vfs_setxattr_locked(&nop_mnt_idmap, lower_dentry, name, value, size, flags, NULL);
+ inode_unlock(lower_inode);
+ if (!rc && inode)
+ fsstack_copy_attr_all(inode, lower_inode);
+out:
+ return rc;
+}
+
+ssize_t
+ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
+ const char *name, void *value, size_t size)
+{
+ int rc;
+
+ if (!(lower_inode->i_opflags & IOP_XATTR)) {
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+ inode_lock(lower_inode);
+ rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
+ inode_unlock(lower_inode);
+out:
+ return rc;
+}
+
+static ssize_t
+ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
+ const char *name, void *value, size_t size)
+{
+ return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
+ ecryptfs_inode_to_lower(inode),
+ name, value, size);
+}
+
+static ssize_t
+ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
+{
+ int rc = 0;
+ struct dentry *lower_dentry;
+
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ if (!d_inode(lower_dentry)->i_op->listxattr) {
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+ inode_lock(d_inode(lower_dentry));
+ rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
+ inode_unlock(d_inode(lower_dentry));
+out:
+ return rc;
+}
+
+static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
+ const char *name)
+{
+ int rc;
+ struct dentry *lower_dentry;
+ struct inode *lower_inode;
+
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ lower_inode = ecryptfs_inode_to_lower(inode);
+ if (!(lower_inode->i_opflags & IOP_XATTR)) {
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+ inode_lock(lower_inode);
+ rc = __vfs_removexattr(&nop_mnt_idmap, lower_dentry, name);
+ inode_unlock(lower_inode);
+out:
+ return rc;
+}
+
+static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
+{
+ return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
+}
+
+static int ecryptfs_fileattr_set(struct mnt_idmap *idmap,
+ struct dentry *dentry, struct fileattr *fa)
+{
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ int rc;
+
+ rc = vfs_fileattr_set(&nop_mnt_idmap, lower_dentry, fa);
+ fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
+
+ return rc;
+}
+
+static struct posix_acl *ecryptfs_get_acl(struct mnt_idmap *idmap,
+ struct dentry *dentry, int type)
+{
+ return vfs_get_acl(idmap, ecryptfs_dentry_to_lower(dentry),
+ posix_acl_xattr_name(type));
+}
+
+static int ecryptfs_set_acl(struct mnt_idmap *idmap,
+ struct dentry *dentry, struct posix_acl *acl,
+ int type)
+{
+ int rc;
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ struct inode *lower_inode = d_inode(lower_dentry);
+
+ rc = vfs_set_acl(&nop_mnt_idmap, lower_dentry,
+ posix_acl_xattr_name(type), acl);
+ if (!rc)
+ fsstack_copy_attr_all(d_inode(dentry), lower_inode);
+ return rc;
+}
+
+const struct inode_operations ecryptfs_symlink_iops = {
+ .get_link = ecryptfs_get_link,
+ .permission = ecryptfs_permission,
+ .setattr = ecryptfs_setattr,
+ .getattr = ecryptfs_getattr_link,
+ .listxattr = ecryptfs_listxattr,
+};
+
+const struct inode_operations ecryptfs_dir_iops = {
+ .create = ecryptfs_create,
+ .lookup = ecryptfs_lookup,
+ .link = ecryptfs_link,
+ .unlink = ecryptfs_unlink,
+ .symlink = ecryptfs_symlink,
+ .mkdir = ecryptfs_mkdir,
+ .rmdir = ecryptfs_rmdir,
+ .mknod = ecryptfs_mknod,
+ .rename = ecryptfs_rename,
+ .permission = ecryptfs_permission,
+ .setattr = ecryptfs_setattr,
+ .listxattr = ecryptfs_listxattr,
+ .fileattr_get = ecryptfs_fileattr_get,
+ .fileattr_set = ecryptfs_fileattr_set,
+ .get_acl = ecryptfs_get_acl,
+ .set_acl = ecryptfs_set_acl,
+};
+
+const struct inode_operations ecryptfs_main_iops = {
+ .permission = ecryptfs_permission,
+ .setattr = ecryptfs_setattr,
+ .getattr = ecryptfs_getattr,
+ .listxattr = ecryptfs_listxattr,
+ .fileattr_get = ecryptfs_fileattr_get,
+ .fileattr_set = ecryptfs_fileattr_set,
+ .get_acl = ecryptfs_get_acl,
+ .set_acl = ecryptfs_set_acl,
+};
+
+static int ecryptfs_xattr_get(const struct xattr_handler *handler,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ return ecryptfs_getxattr(dentry, inode, name, buffer, size);
+}
+
+static int ecryptfs_xattr_set(const struct xattr_handler *handler,
+ struct mnt_idmap *idmap,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, const void *value, size_t size,
+ int flags)
+{
+ if (value)
+ return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
+ else {
+ BUG_ON(flags != XATTR_REPLACE);
+ return ecryptfs_removexattr(dentry, inode, name);
+ }
+}
+
+static const struct xattr_handler ecryptfs_xattr_handler = {
+ .prefix = "", /* match anything */
+ .get = ecryptfs_xattr_get,
+ .set = ecryptfs_xattr_set,
+};
+
+const struct xattr_handler *ecryptfs_xattr_handlers[] = {
+ &ecryptfs_xattr_handler,
+ NULL
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 01:08:14 +0000