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
11 #include "debug.h"
12 #include "ntfs.h"
13 #include "ntfs_fs.h"
14
15 /*
16 * fill_name_de - Format NTFS_DE in @buf.
17 */
fill_name_de(struct ntfs_sb_info * sbi,void * buf,const struct qstr * name,const struct cpu_str * uni)18 int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
19 const struct cpu_str *uni)
20 {
21 int err;
22 struct NTFS_DE *e = buf;
23 u16 data_size;
24 struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
25
26 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
27 e->ref.high = fname->home.high = 0;
28 #endif
29 if (uni) {
30 #ifdef __BIG_ENDIAN
31 int ulen = uni->len;
32 __le16 *uname = fname->name;
33 const u16 *name_cpu = uni->name;
34
35 while (ulen--)
36 *uname++ = cpu_to_le16(*name_cpu++);
37 #else
38 memcpy(fname->name, uni->name, uni->len * sizeof(u16));
39 #endif
40 fname->name_len = uni->len;
41
42 } else {
43 /* Convert input string to unicode. */
44 err = ntfs_nls_to_utf16(sbi, name->name, name->len,
45 (struct cpu_str *)&fname->name_len,
46 NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
47 if (err < 0)
48 return err;
49 }
50
51 fname->type = FILE_NAME_POSIX;
52 data_size = fname_full_size(fname);
53
54 e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
55 e->key_size = cpu_to_le16(data_size);
56 e->flags = 0;
57 e->res = 0;
58
59 return 0;
60 }
61
62 /*
63 * ntfs_lookup - inode_operations::lookup
64 */
ntfs_lookup(struct inode * dir,struct dentry * dentry,u32 flags)65 static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
66 u32 flags)
67 {
68 struct ntfs_inode *ni = ntfs_i(dir);
69 struct cpu_str *uni = __getname();
70 struct inode *inode;
71 int err;
72
73 if (!uni)
74 inode = ERR_PTR(-ENOMEM);
75 else {
76 err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
77 dentry->d_name.len, uni, NTFS_NAME_LEN,
78 UTF16_HOST_ENDIAN);
79 if (err < 0)
80 inode = ERR_PTR(err);
81 else {
82 ni_lock(ni);
83 inode = dir_search_u(dir, uni, NULL);
84 ni_unlock(ni);
85 }
86 __putname(uni);
87 }
88
89 /*
90 * Check for a null pointer
91 * If the MFT record of ntfs inode is not a base record, inode->i_op can be NULL.
92 * This causes null pointer dereference in d_splice_alias().
93 */
94 if (!IS_ERR_OR_NULL(inode) && !inode->i_op) {
95 iput(inode);
96 inode = ERR_PTR(-EINVAL);
97 }
98
99 return d_splice_alias(inode, dentry);
100 }
101
102 /*
103 * ntfs_create - inode_operations::create
104 */
ntfs_create(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)105 static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
106 struct dentry *dentry, umode_t mode, bool excl)
107 {
108 struct inode *inode;
109
110 inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
111 0, NULL, 0, NULL);
112
113 return IS_ERR(inode) ? PTR_ERR(inode) : 0;
114 }
115
116 /*
117 * ntfs_mknod
118 *
119 * inode_operations::mknod
120 */
ntfs_mknod(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)121 static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
122 struct dentry *dentry, umode_t mode, dev_t rdev)
123 {
124 struct inode *inode;
125
126 inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
127 NULL, 0, NULL);
128
129 return IS_ERR(inode) ? PTR_ERR(inode) : 0;
130 }
131
132 /*
133 * ntfs_link - inode_operations::link
134 */
ntfs_link(struct dentry * ode,struct inode * dir,struct dentry * de)135 static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
136 {
137 int err;
138 struct inode *inode = d_inode(ode);
139 struct ntfs_inode *ni = ntfs_i(inode);
140
141 if (S_ISDIR(inode->i_mode))
142 return -EPERM;
143
144 if (inode->i_nlink >= NTFS_LINK_MAX)
145 return -EMLINK;
146
147 ni_lock_dir(ntfs_i(dir));
148 if (inode != dir)
149 ni_lock(ni);
150
151 inc_nlink(inode);
152 ihold(inode);
153
154 err = ntfs_link_inode(inode, de);
155
156 if (!err) {
157 dir->i_ctime = dir->i_mtime = inode->i_ctime =
158 current_time(dir);
159 mark_inode_dirty(inode);
160 mark_inode_dirty(dir);
161 d_instantiate(de, inode);
162 } else {
163 drop_nlink(inode);
164 iput(inode);
165 }
166
167 if (inode != dir)
168 ni_unlock(ni);
169 ni_unlock(ntfs_i(dir));
170
171 return err;
172 }
173
174 /*
175 * ntfs_unlink - inode_operations::unlink
176 */
ntfs_unlink(struct inode * dir,struct dentry * dentry)177 static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
178 {
179 struct ntfs_inode *ni = ntfs_i(dir);
180 int err;
181
182 ni_lock_dir(ni);
183
184 err = ntfs_unlink_inode(dir, dentry);
185
186 ni_unlock(ni);
187
188 return err;
189 }
190
191 /*
192 * ntfs_symlink - inode_operations::symlink
193 */
ntfs_symlink(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,const char * symname)194 static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
195 struct dentry *dentry, const char *symname)
196 {
197 u32 size = strlen(symname);
198 struct inode *inode;
199
200 inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
201 0, symname, size, NULL);
202
203 return IS_ERR(inode) ? PTR_ERR(inode) : 0;
204 }
205
206 /*
207 * ntfs_mkdir- inode_operations::mkdir
208 */
ntfs_mkdir(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode)209 static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
210 struct dentry *dentry, umode_t mode)
211 {
212 struct inode *inode;
213
214 inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
215 0, NULL, 0, NULL);
216
217 return IS_ERR(inode) ? PTR_ERR(inode) : 0;
218 }
219
220 /*
221 * ntfs_rmdir - inode_operations::rmdir
222 */
ntfs_rmdir(struct inode * dir,struct dentry * dentry)223 static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
224 {
225 struct ntfs_inode *ni = ntfs_i(dir);
226 int err;
227
228 ni_lock_dir(ni);
229
230 err = ntfs_unlink_inode(dir, dentry);
231
232 ni_unlock(ni);
233
234 return err;
235 }
236
237 /*
238 * ntfs_rename - inode_operations::rename
239 */
ntfs_rename(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,struct inode * new_dir,struct dentry * new_dentry,u32 flags)240 static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
241 struct dentry *dentry, struct inode *new_dir,
242 struct dentry *new_dentry, u32 flags)
243 {
244 int err;
245 struct super_block *sb = dir->i_sb;
246 struct ntfs_sb_info *sbi = sb->s_fs_info;
247 struct ntfs_inode *dir_ni = ntfs_i(dir);
248 struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
249 struct inode *inode = d_inode(dentry);
250 struct ntfs_inode *ni = ntfs_i(inode);
251 struct inode *new_inode = d_inode(new_dentry);
252 struct NTFS_DE *de, *new_de;
253 bool is_same, is_bad;
254 /*
255 * de - memory of PATH_MAX bytes:
256 * [0-1024) - original name (dentry->d_name)
257 * [1024-2048) - paired to original name, usually DOS variant of dentry->d_name
258 * [2048-3072) - new name (new_dentry->d_name)
259 */
260 static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
261 static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
262 1024);
263 static_assert(PATH_MAX >= 4 * 1024);
264
265 if (flags & ~RENAME_NOREPLACE)
266 return -EINVAL;
267
268 is_same = dentry->d_name.len == new_dentry->d_name.len &&
269 !memcmp(dentry->d_name.name, new_dentry->d_name.name,
270 dentry->d_name.len);
271
272 if (is_same && dir == new_dir) {
273 /* Nothing to do. */
274 return 0;
275 }
276
277 if (ntfs_is_meta_file(sbi, inode->i_ino)) {
278 /* Should we print an error? */
279 return -EINVAL;
280 }
281
282 if (new_inode) {
283 /* Target name exists. Unlink it. */
284 dget(new_dentry);
285 ni_lock_dir(new_dir_ni);
286 err = ntfs_unlink_inode(new_dir, new_dentry);
287 ni_unlock(new_dir_ni);
288 dput(new_dentry);
289 if (err)
290 return err;
291 }
292
293 /* Allocate PATH_MAX bytes. */
294 de = __getname();
295 if (!de)
296 return -ENOMEM;
297
298 /* Translate dentry->d_name into unicode form. */
299 err = fill_name_de(sbi, de, &dentry->d_name, NULL);
300 if (err < 0)
301 goto out;
302
303 if (is_same) {
304 /* Reuse 'de'. */
305 new_de = de;
306 } else {
307 /* Translate new_dentry->d_name into unicode form. */
308 new_de = Add2Ptr(de, 2048);
309 err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
310 if (err < 0)
311 goto out;
312 }
313
314 ni_lock_dir(dir_ni);
315 ni_lock(ni);
316
317 is_bad = false;
318 err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
319 if (is_bad) {
320 /* Restore after failed rename failed too. */
321 _ntfs_bad_inode(inode);
322 } else if (!err) {
323 inode->i_ctime = dir->i_ctime = dir->i_mtime =
324 current_time(dir);
325 mark_inode_dirty(inode);
326 mark_inode_dirty(dir);
327 if (dir != new_dir) {
328 new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
329 mark_inode_dirty(new_dir);
330 }
331
332 if (IS_DIRSYNC(dir))
333 ntfs_sync_inode(dir);
334
335 if (IS_DIRSYNC(new_dir))
336 ntfs_sync_inode(inode);
337 }
338
339 ni_unlock(ni);
340 ni_unlock(dir_ni);
341 out:
342 __putname(de);
343 return err;
344 }
345
ntfs3_get_parent(struct dentry * child)346 struct dentry *ntfs3_get_parent(struct dentry *child)
347 {
348 struct inode *inode = d_inode(child);
349 struct ntfs_inode *ni = ntfs_i(inode);
350
351 struct ATTR_LIST_ENTRY *le = NULL;
352 struct ATTRIB *attr = NULL;
353 struct ATTR_FILE_NAME *fname;
354
355 while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
356 NULL))) {
357 fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
358 if (!fname)
359 continue;
360
361 return d_obtain_alias(
362 ntfs_iget5(inode->i_sb, &fname->home, NULL));
363 }
364
365 return ERR_PTR(-ENOENT);
366 }
367
368 // clang-format off
369 const struct inode_operations ntfs_dir_inode_operations = {
370 .lookup = ntfs_lookup,
371 .create = ntfs_create,
372 .link = ntfs_link,
373 .unlink = ntfs_unlink,
374 .symlink = ntfs_symlink,
375 .mkdir = ntfs_mkdir,
376 .rmdir = ntfs_rmdir,
377 .mknod = ntfs_mknod,
378 .rename = ntfs_rename,
379 .permission = ntfs_permission,
380 .get_acl = ntfs_get_acl,
381 .set_acl = ntfs_set_acl,
382 .setattr = ntfs3_setattr,
383 .getattr = ntfs_getattr,
384 .listxattr = ntfs_listxattr,
385 .fiemap = ntfs_fiemap,
386 };
387
388 const struct inode_operations ntfs_special_inode_operations = {
389 .setattr = ntfs3_setattr,
390 .getattr = ntfs_getattr,
391 .listxattr = ntfs_listxattr,
392 .get_acl = ntfs_get_acl,
393 .set_acl = ntfs_set_acl,
394 };
395 // clang-format on
396