1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *
  4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
  5 *
  6 */
  7
  8#include <linux/fs.h>
  9#include <linux/nls.h>
 10#include <linux/ctype.h>
 11#include <linux/posix_acl.h>
 12
 13#include "debug.h"
 14#include "ntfs.h"
 15#include "ntfs_fs.h"
 16
 17/*
 18 * fill_name_de - Format NTFS_DE in @buf.
 19 */
 20int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
 21		 const struct cpu_str *uni)
 22{
 23	int err;
 24	struct NTFS_DE *e = buf;
 25	u16 data_size;
 26	struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
 27
 28#ifndef CONFIG_NTFS3_64BIT_CLUSTER
 29	e->ref.high = fname->home.high = 0;
 30#endif
 31	if (uni) {
 32#ifdef __BIG_ENDIAN
 33		int ulen = uni->len;
 34		__le16 *uname = fname->name;
 35		const u16 *name_cpu = uni->name;
 36
 37		while (ulen--)
 38			*uname++ = cpu_to_le16(*name_cpu++);
 39#else
 40		memcpy(fname->name, uni->name, uni->len * sizeof(u16));
 41#endif
 42		fname->name_len = uni->len;
 43
 44	} else {
 45		/* Convert input string to unicode. */
 46		err = ntfs_nls_to_utf16(sbi, name->name, name->len,
 47					(struct cpu_str *)&fname->name_len,
 48					NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
 49		if (err < 0)
 50			return err;
 51	}
 52
 53	fname->type = FILE_NAME_POSIX;
 54	data_size = fname_full_size(fname);
 55
 56	e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
 57	e->key_size = cpu_to_le16(data_size);
 58	e->flags = 0;
 59	e->res = 0;
 60
 61	return 0;
 62}
 63
 64/*
 65 * ntfs_lookup - inode_operations::lookup
 66 */
 67static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 68				  u32 flags)
 69{
 70	struct ntfs_inode *ni = ntfs_i(dir);
 71	struct cpu_str *uni = __getname();
 72	struct inode *inode;
 73	int err;
 74
 75	if (!uni)
 76		inode = ERR_PTR(-ENOMEM);
 77	else {
 78		err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
 79					dentry->d_name.len, uni, NTFS_NAME_LEN,
 80					UTF16_HOST_ENDIAN);
 81		if (err < 0)
 82			inode = ERR_PTR(err);
 83		else {
 84			ni_lock(ni);
 85			inode = dir_search_u(dir, uni, NULL);
 86			ni_unlock(ni);
 87		}
 88		__putname(uni);
 89	}
 90
 91	return d_splice_alias(inode, dentry);
 92}
 93
 94/*
 95 * ntfs_create - inode_operations::create
 96 */
 97static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 98		       struct dentry *dentry, umode_t mode, bool excl)
 99{
100	struct inode *inode;
101
102	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
103				  0, NULL, 0, NULL);
104
105	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
106}
107
108/*
109 * ntfs_mknod
110 *
111 * inode_operations::mknod
112 */
113static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
114		      struct dentry *dentry, umode_t mode, dev_t rdev)
115{
116	struct inode *inode;
117
118	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
119				  NULL, 0, NULL);
120
121	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
122}
123
124/*
125 * ntfs_link - inode_operations::link
126 */
127static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
128{
129	int err;
130	struct inode *inode = d_inode(ode);
131	struct ntfs_inode *ni = ntfs_i(inode);
132
133	if (S_ISDIR(inode->i_mode))
134		return -EPERM;
135
136	if (inode->i_nlink >= NTFS_LINK_MAX)
137		return -EMLINK;
138
139	ni_lock_dir(ntfs_i(dir));
140	if (inode != dir)
141		ni_lock(ni);
142
143	inc_nlink(inode);
144	ihold(inode);
145
146	err = ntfs_link_inode(inode, de);
147
148	if (!err) {
149		dir->i_ctime = dir->i_mtime = inode->i_ctime =
150			current_time(dir);
151		mark_inode_dirty(inode);
152		mark_inode_dirty(dir);
153		d_instantiate(de, inode);
154	} else {
155		drop_nlink(inode);
156		iput(inode);
157	}
158
159	if (inode != dir)
160		ni_unlock(ni);
161	ni_unlock(ntfs_i(dir));
162
163	return err;
164}
165
166/*
167 * ntfs_unlink - inode_operations::unlink
168 */
169static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
170{
171	struct ntfs_inode *ni = ntfs_i(dir);
172	int err;
173
174	ni_lock_dir(ni);
175
176	err = ntfs_unlink_inode(dir, dentry);
177
178	ni_unlock(ni);
179
180	return err;
181}
182
183/*
184 * ntfs_symlink - inode_operations::symlink
185 */
186static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
187			struct dentry *dentry, const char *symname)
188{
189	u32 size = strlen(symname);
190	struct inode *inode;
191
192	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
193				  0, symname, size, NULL);
194
195	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
196}
197
198/*
199 * ntfs_mkdir- inode_operations::mkdir
200 */
201static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
202		      struct dentry *dentry, umode_t mode)
203{
204	struct inode *inode;
205
206	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
207				  0, NULL, 0, NULL);
208
209	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
210}
211
212/*
213 * ntfs_rmdir - inode_operations::rmdir
214 */
215static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
216{
217	struct ntfs_inode *ni = ntfs_i(dir);
218	int err;
219
220	ni_lock_dir(ni);
221
222	err = ntfs_unlink_inode(dir, dentry);
223
224	ni_unlock(ni);
225
226	return err;
227}
228
229/*
230 * ntfs_rename - inode_operations::rename
231 */
232static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
233		       struct dentry *dentry, struct inode *new_dir,
234		       struct dentry *new_dentry, u32 flags)
235{
236	int err;
237	struct super_block *sb = dir->i_sb;
238	struct ntfs_sb_info *sbi = sb->s_fs_info;
239	struct ntfs_inode *dir_ni = ntfs_i(dir);
240	struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
241	struct inode *inode = d_inode(dentry);
242	struct ntfs_inode *ni = ntfs_i(inode);
243	struct inode *new_inode = d_inode(new_dentry);
244	struct NTFS_DE *de, *new_de;
245	bool is_same, is_bad;
246	/*
247	 * de		- memory of PATH_MAX bytes:
248	 * [0-1024)	- original name (dentry->d_name)
249	 * [1024-2048)	- paired to original name, usually DOS variant of dentry->d_name
250	 * [2048-3072)	- new name (new_dentry->d_name)
251	 */
252	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
253	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
254		      1024);
255	static_assert(PATH_MAX >= 4 * 1024);
256
257	if (flags & ~RENAME_NOREPLACE)
258		return -EINVAL;
259
260	is_same = dentry->d_name.len == new_dentry->d_name.len &&
261		  !memcmp(dentry->d_name.name, new_dentry->d_name.name,
262			  dentry->d_name.len);
263
264	if (is_same && dir == new_dir) {
265		/* Nothing to do. */
266		return 0;
267	}
268
269	if (ntfs_is_meta_file(sbi, inode->i_ino)) {
270		/* Should we print an error? */
271		return -EINVAL;
272	}
273
274	if (new_inode) {
275		/* Target name exists. Unlink it. */
276		dget(new_dentry);
277		ni_lock_dir(new_dir_ni);
278		err = ntfs_unlink_inode(new_dir, new_dentry);
279		ni_unlock(new_dir_ni);
280		dput(new_dentry);
281		if (err)
282			return err;
283	}
284
285	/* Allocate PATH_MAX bytes. */
286	de = __getname();
287	if (!de)
288		return -ENOMEM;
289
290	/* Translate dentry->d_name into unicode form. */
291	err = fill_name_de(sbi, de, &dentry->d_name, NULL);
292	if (err < 0)
293		goto out;
294
295	if (is_same) {
296		/* Reuse 'de'. */
297		new_de = de;
298	} else {
299		/* Translate new_dentry->d_name into unicode form. */
300		new_de = Add2Ptr(de, 2048);
301		err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
302		if (err < 0)
303			goto out;
304	}
305
306	ni_lock_dir(dir_ni);
307	ni_lock(ni);
308	if (dir_ni != new_dir_ni)
309		ni_lock_dir2(new_dir_ni);
310
311	is_bad = false;
312	err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
313	if (is_bad) {
314		/* Restore after failed rename failed too. */
315		_ntfs_bad_inode(inode);
316	} else if (!err) {
317		inode->i_ctime = dir->i_ctime = dir->i_mtime =
318			current_time(dir);
319		mark_inode_dirty(inode);
320		mark_inode_dirty(dir);
321		if (dir != new_dir) {
322			new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
323			mark_inode_dirty(new_dir);
324		}
325
326		if (IS_DIRSYNC(dir))
327			ntfs_sync_inode(dir);
328
329		if (IS_DIRSYNC(new_dir))
330			ntfs_sync_inode(inode);
331	}
332
333	if (dir_ni != new_dir_ni)
334		ni_unlock(new_dir_ni);
335	ni_unlock(ni);
336	ni_unlock(dir_ni);
337out:
338	__putname(de);
339	return err;
340}
341
342/*
343 * ntfs_atomic_open
344 *
345 * inode_operations::atomic_open
346 */
347static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry,
348			    struct file *file, u32 flags, umode_t mode)
349{
350	int err;
351	struct inode *inode;
352	struct ntfs_fnd *fnd = NULL;
353	struct ntfs_inode *ni = ntfs_i(dir);
354	struct dentry *d = NULL;
355	struct cpu_str *uni = __getname();
356	bool locked = false;
357
358	if (!uni)
359		return -ENOMEM;
360
361	err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
362				dentry->d_name.len, uni, NTFS_NAME_LEN,
363				UTF16_HOST_ENDIAN);
364	if (err < 0)
365		goto out;
366
367#ifdef CONFIG_NTFS3_FS_POSIX_ACL
368	if (IS_POSIXACL(dir)) {
369		/* 
370		 * Load in cache current acl to avoid ni_lock(dir):
371		 * ntfs_create_inode -> ntfs_init_acl -> posix_acl_create ->
372		 * ntfs_get_acl -> ntfs_get_acl_ex -> ni_lock
373		 */
374		struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);
375
376		if (IS_ERR(p)) {
377			err = PTR_ERR(p);
378			goto out;
379		}
380		posix_acl_release(p);
381	}
382#endif
383
384	if (d_in_lookup(dentry)) {
385		ni_lock_dir(ni);
386		locked = true;
387		fnd = fnd_get();
388		if (!fnd) {
389			err = -ENOMEM;
390			goto out1;
391		}
392
393		d = d_splice_alias(dir_search_u(dir, uni, fnd), dentry);
394		if (IS_ERR(d)) {
395			err = PTR_ERR(d);
396			d = NULL;
397			goto out2;
398		}
399
400		if (d)
401			dentry = d;
402	}
403
404	if (!(flags & O_CREAT) || d_really_is_positive(dentry)) {
405		err = finish_no_open(file, d);
406		goto out2;
407	}
408
409	file->f_mode |= FMODE_CREATED;
410
411	/*
412	 * fnd contains tree's path to insert to.
413	 * If fnd is not NULL then dir is locked.
414	 */
415
416	/*
417	 * Unfortunately I don't know how to get here correct 'struct nameidata *nd'
418	 * or 'struct user_namespace *mnt_userns'.
419	 * See atomic_open in fs/namei.c.
420	 * This is why xfstest/633 failed.
421	 * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument.
422	 */
423
424	inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0,
425				  NULL, 0, fnd);
426	err = IS_ERR(inode) ? PTR_ERR(inode)
427			    : finish_open(file, dentry, ntfs_file_open);
428	dput(d);
429
430out2:
431	fnd_put(fnd);
432out1:
433	if (locked)
434		ni_unlock(ni);
435out:
436	__putname(uni);
437	return err;
438}
439
440struct dentry *ntfs3_get_parent(struct dentry *child)
441{
442	struct inode *inode = d_inode(child);
443	struct ntfs_inode *ni = ntfs_i(inode);
444
445	struct ATTR_LIST_ENTRY *le = NULL;
446	struct ATTRIB *attr = NULL;
447	struct ATTR_FILE_NAME *fname;
448
449	while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
450				    NULL))) {
451		fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
452		if (!fname)
453			continue;
454
455		return d_obtain_alias(
456			ntfs_iget5(inode->i_sb, &fname->home, NULL));
457	}
458
459	return ERR_PTR(-ENOENT);
460}
461
462/*
463 * dentry_operations::d_hash
464 */
465static int ntfs_d_hash(const struct dentry *dentry, struct qstr *name)
466{
467	struct ntfs_sb_info *sbi;
468	const char *n = name->name;
469	unsigned int len = name->len;
470	unsigned long hash;
471	struct cpu_str *uni;
472	unsigned int c;
473	int err;
474
475	/* First try fast implementation. */
476	hash = init_name_hash(dentry);
477
478	for (;;) {
479		if (!len--) {
480			name->hash = end_name_hash(hash);
481			return 0;
482		}
483
484		c = *n++;
485		if (c >= 0x80)
486			break;
487
488		hash = partial_name_hash(toupper(c), hash);
489	}
490
491	/*
492	 * Try slow way with current upcase table
493	 */
494	uni = __getname();
495	if (!uni)
496		return -ENOMEM;
497
498	sbi = dentry->d_sb->s_fs_info;
499
500	err = ntfs_nls_to_utf16(sbi, name->name, name->len, uni, NTFS_NAME_LEN,
501				UTF16_HOST_ENDIAN);
502	if (err < 0)
503		goto out;
504
505	if (!err) {
506		err = -EINVAL;
507		goto out;
508	}
509
510	hash = ntfs_names_hash(uni->name, uni->len, sbi->upcase,
511			       init_name_hash(dentry));
512	name->hash = end_name_hash(hash);
513	err = 0;
514
515out:
516	__putname(uni);
517	return err;
518}
519
520/*
521 * dentry_operations::d_compare
522 */
523static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
524			  const char *str, const struct qstr *name)
525{
526	struct ntfs_sb_info *sbi;
527	int ret;
528	const char *n1 = str;
529	const char *n2 = name->name;
530	unsigned int len2 = name->len;
531	unsigned int lm = min(len1, len2);
532	unsigned char c1, c2;
533	struct cpu_str *uni1;
534	struct le_str *uni2;
535
536	/* First try fast implementation. */
537	for (;;) {
538		if (!lm--)
539			return len1 != len2;
540
541		if ((c1 = *n1++) == (c2 = *n2++))
542			continue;
543
544		if (c1 >= 0x80 || c2 >= 0x80)
545			break;
546
547		if (toupper(c1) != toupper(c2))
548			return 1;
549	}
550
551	/*
552	 * Try slow way with current upcase table
553	 */
554	sbi = dentry->d_sb->s_fs_info;
555	uni1 = __getname();
556	if (!uni1)
557		return -ENOMEM;
558
559	ret = ntfs_nls_to_utf16(sbi, str, len1, uni1, NTFS_NAME_LEN,
560				UTF16_HOST_ENDIAN);
561	if (ret < 0)
562		goto out;
563
564	if (!ret) {
565		ret = -EINVAL;
566		goto out;
567	}
568
569	uni2 = Add2Ptr(uni1, 2048);
570
571	ret = ntfs_nls_to_utf16(sbi, name->name, name->len,
572				(struct cpu_str *)uni2, NTFS_NAME_LEN,
573				UTF16_LITTLE_ENDIAN);
574	if (ret < 0)
575		goto out;
576
577	if (!ret) {
578		ret = -EINVAL;
579		goto out;
580	}
581
582	ret = !ntfs_cmp_names_cpu(uni1, uni2, sbi->upcase, false) ? 0 : 1;
583
584out:
585	__putname(uni1);
586	return ret;
587}
588
589// clang-format off
590const struct inode_operations ntfs_dir_inode_operations = {
591	.lookup		= ntfs_lookup,
592	.create		= ntfs_create,
593	.link		= ntfs_link,
594	.unlink		= ntfs_unlink,
595	.symlink	= ntfs_symlink,
596	.mkdir		= ntfs_mkdir,
597	.rmdir		= ntfs_rmdir,
598	.mknod		= ntfs_mknod,
599	.rename		= ntfs_rename,
600	.permission	= ntfs_permission,
601	.get_inode_acl	= ntfs_get_acl,
602	.set_acl	= ntfs_set_acl,
603	.setattr	= ntfs3_setattr,
604	.getattr	= ntfs_getattr,
605	.listxattr	= ntfs_listxattr,
606	.atomic_open	= ntfs_atomic_open,
607	.fiemap		= ntfs_fiemap,
608};
609
610const struct inode_operations ntfs_special_inode_operations = {
611	.setattr	= ntfs3_setattr,
612	.getattr	= ntfs_getattr,
613	.listxattr	= ntfs_listxattr,
614	.get_inode_acl	= ntfs_get_acl,
615	.set_acl	= ntfs_set_acl,
616};
617
618const struct dentry_operations ntfs_dentry_ops = {
619	.d_hash		= ntfs_d_hash,
620	.d_compare	= ntfs_d_compare,
621};
622
623// clang-format on