1b1241c8eSRitesh Harjani // SPDX-License-Identifier: GPL-2.0
2b1241c8eSRitesh Harjani
3b1241c8eSRitesh Harjani #include <linux/quotaops.h>
472f63f4aSRitesh Harjani #include <linux/uuid.h>
5b1241c8eSRitesh Harjani
6b1241c8eSRitesh Harjani #include "ext4.h"
7b1241c8eSRitesh Harjani #include "xattr.h"
8b1241c8eSRitesh Harjani #include "ext4_jbd2.h"
9b1241c8eSRitesh Harjani
ext4_fname_from_fscrypt_name(struct ext4_filename * dst,const struct fscrypt_name * src)103030b59cSRitesh Harjani static void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
113030b59cSRitesh Harjani const struct fscrypt_name *src)
123030b59cSRitesh Harjani {
133030b59cSRitesh Harjani memset(dst, 0, sizeof(*dst));
143030b59cSRitesh Harjani
153030b59cSRitesh Harjani dst->usr_fname = src->usr_fname;
163030b59cSRitesh Harjani dst->disk_name = src->disk_name;
173030b59cSRitesh Harjani dst->hinfo.hash = src->hash;
183030b59cSRitesh Harjani dst->hinfo.minor_hash = src->minor_hash;
193030b59cSRitesh Harjani dst->crypto_buf = src->crypto_buf;
203030b59cSRitesh Harjani }
213030b59cSRitesh Harjani
ext4_fname_setup_filename(struct inode * dir,const struct qstr * iname,int lookup,struct ext4_filename * fname)223030b59cSRitesh Harjani int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
233030b59cSRitesh Harjani int lookup, struct ext4_filename *fname)
243030b59cSRitesh Harjani {
253030b59cSRitesh Harjani struct fscrypt_name name;
263030b59cSRitesh Harjani int err;
273030b59cSRitesh Harjani
283030b59cSRitesh Harjani err = fscrypt_setup_filename(dir, iname, lookup, &name);
293030b59cSRitesh Harjani if (err)
303030b59cSRitesh Harjani return err;
313030b59cSRitesh Harjani
323030b59cSRitesh Harjani ext4_fname_from_fscrypt_name(fname, &name);
333030b59cSRitesh Harjani
343030b59cSRitesh Harjani #if IS_ENABLED(CONFIG_UNICODE)
353030b59cSRitesh Harjani err = ext4_fname_setup_ci_filename(dir, iname, fname);
367ca4b085SLuís Henriques if (err)
377ca4b085SLuís Henriques ext4_fname_free_filename(fname);
383030b59cSRitesh Harjani #endif
393030b59cSRitesh Harjani return err;
403030b59cSRitesh Harjani }
413030b59cSRitesh Harjani
ext4_fname_prepare_lookup(struct inode * dir,struct dentry * dentry,struct ext4_filename * fname)423030b59cSRitesh Harjani int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
433030b59cSRitesh Harjani struct ext4_filename *fname)
443030b59cSRitesh Harjani {
453030b59cSRitesh Harjani struct fscrypt_name name;
463030b59cSRitesh Harjani int err;
473030b59cSRitesh Harjani
483030b59cSRitesh Harjani err = fscrypt_prepare_lookup(dir, dentry, &name);
493030b59cSRitesh Harjani if (err)
503030b59cSRitesh Harjani return err;
513030b59cSRitesh Harjani
523030b59cSRitesh Harjani ext4_fname_from_fscrypt_name(fname, &name);
533030b59cSRitesh Harjani
543030b59cSRitesh Harjani #if IS_ENABLED(CONFIG_UNICODE)
553030b59cSRitesh Harjani err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
567ca4b085SLuís Henriques if (err)
577ca4b085SLuís Henriques ext4_fname_free_filename(fname);
583030b59cSRitesh Harjani #endif
593030b59cSRitesh Harjani return err;
603030b59cSRitesh Harjani }
613030b59cSRitesh Harjani
ext4_fname_free_filename(struct ext4_filename * fname)623030b59cSRitesh Harjani void ext4_fname_free_filename(struct ext4_filename *fname)
633030b59cSRitesh Harjani {
643030b59cSRitesh Harjani struct fscrypt_name name;
653030b59cSRitesh Harjani
663030b59cSRitesh Harjani name.crypto_buf = fname->crypto_buf;
673030b59cSRitesh Harjani fscrypt_free_filename(&name);
683030b59cSRitesh Harjani
693030b59cSRitesh Harjani fname->crypto_buf.name = NULL;
703030b59cSRitesh Harjani fname->usr_fname = NULL;
713030b59cSRitesh Harjani fname->disk_name.name = NULL;
723030b59cSRitesh Harjani
733030b59cSRitesh Harjani #if IS_ENABLED(CONFIG_UNICODE)
743030b59cSRitesh Harjani kfree(fname->cf_name.name);
753030b59cSRitesh Harjani fname->cf_name.name = NULL;
763030b59cSRitesh Harjani #endif
773030b59cSRitesh Harjani }
783030b59cSRitesh Harjani
uuid_is_zero(__u8 u[16])7972f63f4aSRitesh Harjani static bool uuid_is_zero(__u8 u[16])
8072f63f4aSRitesh Harjani {
8172f63f4aSRitesh Harjani int i;
8272f63f4aSRitesh Harjani
8372f63f4aSRitesh Harjani for (i = 0; i < 16; i++)
8472f63f4aSRitesh Harjani if (u[i])
8572f63f4aSRitesh Harjani return false;
8672f63f4aSRitesh Harjani return true;
8772f63f4aSRitesh Harjani }
8872f63f4aSRitesh Harjani
ext4_ioctl_get_encryption_pwsalt(struct file * filp,void __user * arg)8972f63f4aSRitesh Harjani int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)
9072f63f4aSRitesh Harjani {
9172f63f4aSRitesh Harjani struct super_block *sb = file_inode(filp)->i_sb;
9272f63f4aSRitesh Harjani struct ext4_sb_info *sbi = EXT4_SB(sb);
9372f63f4aSRitesh Harjani int err, err2;
9472f63f4aSRitesh Harjani handle_t *handle;
9572f63f4aSRitesh Harjani
9672f63f4aSRitesh Harjani if (!ext4_has_feature_encrypt(sb))
9772f63f4aSRitesh Harjani return -EOPNOTSUPP;
9872f63f4aSRitesh Harjani
9972f63f4aSRitesh Harjani if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
10072f63f4aSRitesh Harjani err = mnt_want_write_file(filp);
10172f63f4aSRitesh Harjani if (err)
10272f63f4aSRitesh Harjani return err;
10372f63f4aSRitesh Harjani handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
10472f63f4aSRitesh Harjani if (IS_ERR(handle)) {
10572f63f4aSRitesh Harjani err = PTR_ERR(handle);
10672f63f4aSRitesh Harjani goto pwsalt_err_exit;
10772f63f4aSRitesh Harjani }
10872f63f4aSRitesh Harjani err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
10972f63f4aSRitesh Harjani EXT4_JTR_NONE);
11072f63f4aSRitesh Harjani if (err)
11172f63f4aSRitesh Harjani goto pwsalt_err_journal;
11272f63f4aSRitesh Harjani lock_buffer(sbi->s_sbh);
11372f63f4aSRitesh Harjani generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
11472f63f4aSRitesh Harjani ext4_superblock_csum_set(sb);
11572f63f4aSRitesh Harjani unlock_buffer(sbi->s_sbh);
11672f63f4aSRitesh Harjani err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
11772f63f4aSRitesh Harjani pwsalt_err_journal:
11872f63f4aSRitesh Harjani err2 = ext4_journal_stop(handle);
11972f63f4aSRitesh Harjani if (err2 && !err)
12072f63f4aSRitesh Harjani err = err2;
12172f63f4aSRitesh Harjani pwsalt_err_exit:
12272f63f4aSRitesh Harjani mnt_drop_write_file(filp);
12372f63f4aSRitesh Harjani if (err)
12472f63f4aSRitesh Harjani return err;
12572f63f4aSRitesh Harjani }
12672f63f4aSRitesh Harjani
12772f63f4aSRitesh Harjani if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))
12872f63f4aSRitesh Harjani return -EFAULT;
12972f63f4aSRitesh Harjani return 0;
13072f63f4aSRitesh Harjani }
13172f63f4aSRitesh Harjani
ext4_get_context(struct inode * inode,void * ctx,size_t len)132b1241c8eSRitesh Harjani static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
133b1241c8eSRitesh Harjani {
134b1241c8eSRitesh Harjani return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
135b1241c8eSRitesh Harjani EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
136b1241c8eSRitesh Harjani }
137b1241c8eSRitesh Harjani
ext4_set_context(struct inode * inode,const void * ctx,size_t len,void * fs_data)138b1241c8eSRitesh Harjani static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
139b1241c8eSRitesh Harjani void *fs_data)
140b1241c8eSRitesh Harjani {
141b1241c8eSRitesh Harjani handle_t *handle = fs_data;
142b1241c8eSRitesh Harjani int res, res2, credits, retries = 0;
143b1241c8eSRitesh Harjani
144b1241c8eSRitesh Harjani /*
145b1241c8eSRitesh Harjani * Encrypting the root directory is not allowed because e2fsck expects
146b1241c8eSRitesh Harjani * lost+found to exist and be unencrypted, and encrypting the root
147b1241c8eSRitesh Harjani * directory would imply encrypting the lost+found directory as well as
148b1241c8eSRitesh Harjani * the filename "lost+found" itself.
149b1241c8eSRitesh Harjani */
150b1241c8eSRitesh Harjani if (inode->i_ino == EXT4_ROOT_INO)
151b1241c8eSRitesh Harjani return -EPERM;
152b1241c8eSRitesh Harjani
153b1241c8eSRitesh Harjani if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
154b1241c8eSRitesh Harjani return -EINVAL;
155b1241c8eSRitesh Harjani
156b1241c8eSRitesh Harjani if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
157b1241c8eSRitesh Harjani return -EOPNOTSUPP;
158b1241c8eSRitesh Harjani
159b1241c8eSRitesh Harjani res = ext4_convert_inline_data(inode);
160b1241c8eSRitesh Harjani if (res)
161b1241c8eSRitesh Harjani return res;
162b1241c8eSRitesh Harjani
163b1241c8eSRitesh Harjani /*
164b1241c8eSRitesh Harjani * If a journal handle was specified, then the encryption context is
165b1241c8eSRitesh Harjani * being set on a new inode via inheritance and is part of a larger
166b1241c8eSRitesh Harjani * transaction to create the inode. Otherwise the encryption context is
167b1241c8eSRitesh Harjani * being set on an existing inode in its own transaction. Only in the
168b1241c8eSRitesh Harjani * latter case should the "retry on ENOSPC" logic be used.
169b1241c8eSRitesh Harjani */
170b1241c8eSRitesh Harjani
171b1241c8eSRitesh Harjani if (handle) {
172b1241c8eSRitesh Harjani res = ext4_xattr_set_handle(handle, inode,
173b1241c8eSRitesh Harjani EXT4_XATTR_INDEX_ENCRYPTION,
174b1241c8eSRitesh Harjani EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
175b1241c8eSRitesh Harjani ctx, len, 0);
176b1241c8eSRitesh Harjani if (!res) {
177b1241c8eSRitesh Harjani ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
178b1241c8eSRitesh Harjani ext4_clear_inode_state(inode,
179b1241c8eSRitesh Harjani EXT4_STATE_MAY_INLINE_DATA);
180b1241c8eSRitesh Harjani /*
181b1241c8eSRitesh Harjani * Update inode->i_flags - S_ENCRYPTED will be enabled,
182b1241c8eSRitesh Harjani * S_DAX may be disabled
183b1241c8eSRitesh Harjani */
184b1241c8eSRitesh Harjani ext4_set_inode_flags(inode, false);
185b1241c8eSRitesh Harjani }
186b1241c8eSRitesh Harjani return res;
187b1241c8eSRitesh Harjani }
188b1241c8eSRitesh Harjani
189b1241c8eSRitesh Harjani res = dquot_initialize(inode);
190b1241c8eSRitesh Harjani if (res)
191b1241c8eSRitesh Harjani return res;
192b1241c8eSRitesh Harjani retry:
193b1241c8eSRitesh Harjani res = ext4_xattr_set_credits(inode, len, false /* is_create */,
194b1241c8eSRitesh Harjani &credits);
195b1241c8eSRitesh Harjani if (res)
196b1241c8eSRitesh Harjani return res;
197b1241c8eSRitesh Harjani
198b1241c8eSRitesh Harjani handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
199b1241c8eSRitesh Harjani if (IS_ERR(handle))
200b1241c8eSRitesh Harjani return PTR_ERR(handle);
201b1241c8eSRitesh Harjani
202b1241c8eSRitesh Harjani res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
203b1241c8eSRitesh Harjani EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
204b1241c8eSRitesh Harjani ctx, len, 0);
205b1241c8eSRitesh Harjani if (!res) {
206b1241c8eSRitesh Harjani ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
207b1241c8eSRitesh Harjani /*
208b1241c8eSRitesh Harjani * Update inode->i_flags - S_ENCRYPTED will be enabled,
209b1241c8eSRitesh Harjani * S_DAX may be disabled
210b1241c8eSRitesh Harjani */
211b1241c8eSRitesh Harjani ext4_set_inode_flags(inode, false);
212b1241c8eSRitesh Harjani res = ext4_mark_inode_dirty(handle, inode);
213b1241c8eSRitesh Harjani if (res)
214b1241c8eSRitesh Harjani EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
215b1241c8eSRitesh Harjani }
216b1241c8eSRitesh Harjani res2 = ext4_journal_stop(handle);
217b1241c8eSRitesh Harjani
218b1241c8eSRitesh Harjani if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
219b1241c8eSRitesh Harjani goto retry;
220b1241c8eSRitesh Harjani if (!res)
221b1241c8eSRitesh Harjani res = res2;
222b1241c8eSRitesh Harjani return res;
223b1241c8eSRitesh Harjani }
224b1241c8eSRitesh Harjani
ext4_get_dummy_policy(struct super_block * sb)225b1241c8eSRitesh Harjani static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
226b1241c8eSRitesh Harjani {
227b1241c8eSRitesh Harjani return EXT4_SB(sb)->s_dummy_enc_policy.policy;
228b1241c8eSRitesh Harjani }
229b1241c8eSRitesh Harjani
ext4_has_stable_inodes(struct super_block * sb)230b1241c8eSRitesh Harjani static bool ext4_has_stable_inodes(struct super_block *sb)
231b1241c8eSRitesh Harjani {
232b1241c8eSRitesh Harjani return ext4_has_feature_stable_inodes(sb);
233b1241c8eSRitesh Harjani }
234b1241c8eSRitesh Harjani
235b1241c8eSRitesh Harjani const struct fscrypt_operations ext4_cryptops = {
23640e13e18SEric Biggers .needs_bounce_pages = 1,
2377a0263dcSEric Biggers .has_32bit_inodes = 1,
238*5b118884SEric Biggers .supports_subblock_data_units = 1,
2395970fbadSEric Biggers .legacy_key_prefix = "ext4:",
240b1241c8eSRitesh Harjani .get_context = ext4_get_context,
241b1241c8eSRitesh Harjani .set_context = ext4_set_context,
242b1241c8eSRitesh Harjani .get_dummy_policy = ext4_get_dummy_policy,
243b1241c8eSRitesh Harjani .empty_dir = ext4_empty_dir,
244b1241c8eSRitesh Harjani .has_stable_inodes = ext4_has_stable_inodes,
245b1241c8eSRitesh Harjani };
246