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0fd16957 HG |
1 | // SPDX-License-Identifier: MIT |
2 | /* | |
3 | * VirtualBox Guest Shared Folders support: Utility functions. | |
4 | * Mainly conversion from/to VirtualBox/Linux data structures. | |
5 | * | |
6 | * Copyright (C) 2006-2018 Oracle Corporation | |
7 | */ | |
8 | ||
9 | #include <linux/namei.h> | |
10 | #include <linux/nls.h> | |
11 | #include <linux/sizes.h> | |
cbcc268b | 12 | #include <linux/pagemap.h> |
0fd16957 HG |
13 | #include <linux/vfs.h> |
14 | #include "vfsmod.h" | |
15 | ||
16 | struct inode *vboxsf_new_inode(struct super_block *sb) | |
17 | { | |
18 | struct vboxsf_sbi *sbi = VBOXSF_SBI(sb); | |
19 | struct inode *inode; | |
20 | unsigned long flags; | |
21 | int cursor, ret; | |
22 | u32 gen; | |
23 | ||
24 | inode = new_inode(sb); | |
25 | if (!inode) | |
26 | return ERR_PTR(-ENOMEM); | |
27 | ||
28 | idr_preload(GFP_KERNEL); | |
29 | spin_lock_irqsave(&sbi->ino_idr_lock, flags); | |
30 | cursor = idr_get_cursor(&sbi->ino_idr); | |
31 | ret = idr_alloc_cyclic(&sbi->ino_idr, inode, 1, 0, GFP_ATOMIC); | |
32 | if (ret >= 0 && ret < cursor) | |
33 | sbi->next_generation++; | |
34 | gen = sbi->next_generation; | |
35 | spin_unlock_irqrestore(&sbi->ino_idr_lock, flags); | |
36 | idr_preload_end(); | |
37 | ||
38 | if (ret < 0) { | |
39 | iput(inode); | |
40 | return ERR_PTR(ret); | |
41 | } | |
42 | ||
43 | inode->i_ino = ret; | |
44 | inode->i_generation = gen; | |
45 | return inode; | |
46 | } | |
47 | ||
48 | /* set [inode] attributes based on [info], uid/gid based on [sbi] */ | |
e98f93e7 AV |
49 | int vboxsf_init_inode(struct vboxsf_sbi *sbi, struct inode *inode, |
50 | const struct shfl_fsobjinfo *info, bool reinit) | |
0fd16957 HG |
51 | { |
52 | const struct shfl_fsobjattr *attr; | |
53 | s64 allocated; | |
e98f93e7 | 54 | umode_t mode; |
0fd16957 HG |
55 | |
56 | attr = &info->attr; | |
57 | ||
58 | #define mode_set(r) ((attr->mode & (SHFL_UNIX_##r)) ? (S_##r) : 0) | |
59 | ||
60 | mode = mode_set(IRUSR); | |
61 | mode |= mode_set(IWUSR); | |
62 | mode |= mode_set(IXUSR); | |
63 | ||
64 | mode |= mode_set(IRGRP); | |
65 | mode |= mode_set(IWGRP); | |
66 | mode |= mode_set(IXGRP); | |
67 | ||
68 | mode |= mode_set(IROTH); | |
69 | mode |= mode_set(IWOTH); | |
70 | mode |= mode_set(IXOTH); | |
71 | ||
72 | #undef mode_set | |
73 | ||
74 | /* We use the host-side values for these */ | |
75 | inode->i_flags |= S_NOATIME | S_NOCMTIME; | |
76 | inode->i_mapping->a_ops = &vboxsf_reg_aops; | |
77 | ||
78 | if (SHFL_IS_DIRECTORY(attr->mode)) { | |
e98f93e7 AV |
79 | if (sbi->o.dmode_set) |
80 | mode = sbi->o.dmode; | |
81 | mode &= ~sbi->o.dmask; | |
82 | mode |= S_IFDIR; | |
83 | if (!reinit) { | |
84 | inode->i_op = &vboxsf_dir_iops; | |
85 | inode->i_fop = &vboxsf_dir_fops; | |
86 | /* | |
87 | * XXX: this probably should be set to the number of entries | |
88 | * in the directory plus two (. ..) | |
89 | */ | |
90 | set_nlink(inode, 1); | |
91 | } else if (!S_ISDIR(inode->i_mode)) | |
92 | return -ESTALE; | |
93 | inode->i_mode = mode; | |
0fd16957 | 94 | } else if (SHFL_IS_SYMLINK(attr->mode)) { |
e98f93e7 AV |
95 | if (sbi->o.fmode_set) |
96 | mode = sbi->o.fmode; | |
97 | mode &= ~sbi->o.fmask; | |
98 | mode |= S_IFLNK; | |
99 | if (!reinit) { | |
100 | inode->i_op = &vboxsf_lnk_iops; | |
101 | set_nlink(inode, 1); | |
102 | } else if (!S_ISLNK(inode->i_mode)) | |
103 | return -ESTALE; | |
104 | inode->i_mode = mode; | |
0fd16957 | 105 | } else { |
e98f93e7 AV |
106 | if (sbi->o.fmode_set) |
107 | mode = sbi->o.fmode; | |
108 | mode &= ~sbi->o.fmask; | |
109 | mode |= S_IFREG; | |
110 | if (!reinit) { | |
111 | inode->i_op = &vboxsf_reg_iops; | |
112 | inode->i_fop = &vboxsf_reg_fops; | |
113 | set_nlink(inode, 1); | |
114 | } else if (!S_ISREG(inode->i_mode)) | |
115 | return -ESTALE; | |
116 | inode->i_mode = mode; | |
0fd16957 HG |
117 | } |
118 | ||
119 | inode->i_uid = sbi->o.uid; | |
120 | inode->i_gid = sbi->o.gid; | |
121 | ||
122 | inode->i_size = info->size; | |
123 | inode->i_blkbits = 12; | |
124 | /* i_blocks always in units of 512 bytes! */ | |
125 | allocated = info->allocated + 511; | |
126 | do_div(allocated, 512); | |
127 | inode->i_blocks = allocated; | |
128 | ||
9caef040 JL |
129 | inode_set_atime_to_ts(inode, |
130 | ns_to_timespec64(info->access_time.ns_relative_to_unix_epoch)); | |
0593be0c JL |
131 | inode_set_ctime_to_ts(inode, |
132 | ns_to_timespec64(info->change_time.ns_relative_to_unix_epoch)); | |
9caef040 JL |
133 | inode_set_mtime_to_ts(inode, |
134 | ns_to_timespec64(info->modification_time.ns_relative_to_unix_epoch)); | |
e98f93e7 | 135 | return 0; |
0fd16957 HG |
136 | } |
137 | ||
138 | int vboxsf_create_at_dentry(struct dentry *dentry, | |
139 | struct shfl_createparms *params) | |
140 | { | |
141 | struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); | |
142 | struct shfl_string *path; | |
143 | int err; | |
144 | ||
145 | path = vboxsf_path_from_dentry(sbi, dentry); | |
146 | if (IS_ERR(path)) | |
147 | return PTR_ERR(path); | |
148 | ||
149 | err = vboxsf_create(sbi->root, path, params); | |
150 | __putname(path); | |
151 | ||
152 | return err; | |
153 | } | |
154 | ||
155 | int vboxsf_stat(struct vboxsf_sbi *sbi, struct shfl_string *path, | |
156 | struct shfl_fsobjinfo *info) | |
157 | { | |
158 | struct shfl_createparms params = {}; | |
159 | int err; | |
160 | ||
161 | params.handle = SHFL_HANDLE_NIL; | |
162 | params.create_flags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW; | |
163 | ||
164 | err = vboxsf_create(sbi->root, path, ¶ms); | |
165 | if (err) | |
166 | return err; | |
167 | ||
168 | if (params.result != SHFL_FILE_EXISTS) | |
169 | return -ENOENT; | |
170 | ||
171 | if (info) | |
172 | *info = params.info; | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | int vboxsf_stat_dentry(struct dentry *dentry, struct shfl_fsobjinfo *info) | |
178 | { | |
179 | struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); | |
180 | struct shfl_string *path; | |
181 | int err; | |
182 | ||
183 | path = vboxsf_path_from_dentry(sbi, dentry); | |
184 | if (IS_ERR(path)) | |
185 | return PTR_ERR(path); | |
186 | ||
187 | err = vboxsf_stat(sbi, path, info); | |
188 | __putname(path); | |
189 | return err; | |
190 | } | |
191 | ||
192 | int vboxsf_inode_revalidate(struct dentry *dentry) | |
193 | { | |
194 | struct vboxsf_sbi *sbi; | |
195 | struct vboxsf_inode *sf_i; | |
196 | struct shfl_fsobjinfo info; | |
9caef040 | 197 | struct timespec64 mtime, prev_mtime; |
0fd16957 HG |
198 | struct inode *inode; |
199 | int err; | |
200 | ||
201 | if (!dentry || !d_really_is_positive(dentry)) | |
202 | return -EINVAL; | |
203 | ||
204 | inode = d_inode(dentry); | |
9caef040 | 205 | prev_mtime = inode_get_mtime(inode); |
0fd16957 HG |
206 | sf_i = VBOXSF_I(inode); |
207 | sbi = VBOXSF_SBI(dentry->d_sb); | |
208 | if (!sf_i->force_restat) { | |
209 | if (time_before(jiffies, dentry->d_time + sbi->o.ttl)) | |
210 | return 0; | |
211 | } | |
212 | ||
213 | err = vboxsf_stat_dentry(dentry, &info); | |
214 | if (err) | |
215 | return err; | |
216 | ||
217 | dentry->d_time = jiffies; | |
218 | sf_i->force_restat = 0; | |
e98f93e7 AV |
219 | err = vboxsf_init_inode(sbi, inode, &info, true); |
220 | if (err) | |
221 | return err; | |
0fd16957 HG |
222 | |
223 | /* | |
224 | * If the file was changed on the host side we need to invalidate the | |
225 | * page-cache for it. Note this also gets triggered by our own writes, | |
226 | * this is unavoidable. | |
227 | */ | |
9caef040 JL |
228 | mtime = inode_get_mtime(inode); |
229 | if (timespec64_compare(&mtime, &prev_mtime) > 0) | |
0fd16957 HG |
230 | invalidate_inode_pages2(inode->i_mapping); |
231 | ||
232 | return 0; | |
233 | } | |
234 | ||
b74d24f7 | 235 | int vboxsf_getattr(struct mnt_idmap *idmap, const struct path *path, |
549c7297 | 236 | struct kstat *kstat, u32 request_mask, unsigned int flags) |
0fd16957 HG |
237 | { |
238 | int err; | |
239 | struct dentry *dentry = path->dentry; | |
240 | struct inode *inode = d_inode(dentry); | |
241 | struct vboxsf_inode *sf_i = VBOXSF_I(inode); | |
242 | ||
243 | switch (flags & AT_STATX_SYNC_TYPE) { | |
244 | case AT_STATX_DONT_SYNC: | |
245 | err = 0; | |
246 | break; | |
247 | case AT_STATX_FORCE_SYNC: | |
248 | sf_i->force_restat = 1; | |
df561f66 | 249 | fallthrough; |
0fd16957 HG |
250 | default: |
251 | err = vboxsf_inode_revalidate(dentry); | |
252 | } | |
253 | if (err) | |
254 | return err; | |
255 | ||
0d72b928 | 256 | generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), kstat); |
0fd16957 HG |
257 | return 0; |
258 | } | |
259 | ||
c1632a0f | 260 | int vboxsf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, |
549c7297 | 261 | struct iattr *iattr) |
0fd16957 HG |
262 | { |
263 | struct vboxsf_inode *sf_i = VBOXSF_I(d_inode(dentry)); | |
264 | struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); | |
265 | struct shfl_createparms params = {}; | |
266 | struct shfl_fsobjinfo info = {}; | |
267 | u32 buf_len; | |
268 | int err; | |
269 | ||
270 | params.handle = SHFL_HANDLE_NIL; | |
271 | params.create_flags = SHFL_CF_ACT_OPEN_IF_EXISTS | | |
272 | SHFL_CF_ACT_FAIL_IF_NEW | | |
273 | SHFL_CF_ACCESS_ATTR_WRITE; | |
274 | ||
275 | /* this is at least required for Posix hosts */ | |
276 | if (iattr->ia_valid & ATTR_SIZE) | |
277 | params.create_flags |= SHFL_CF_ACCESS_WRITE; | |
278 | ||
279 | err = vboxsf_create_at_dentry(dentry, ¶ms); | |
280 | if (err || params.result != SHFL_FILE_EXISTS) | |
281 | return err ? err : -ENOENT; | |
282 | ||
283 | #define mode_set(r) ((iattr->ia_mode & (S_##r)) ? SHFL_UNIX_##r : 0) | |
284 | ||
285 | /* | |
286 | * Setting the file size and setting the other attributes has to | |
287 | * be handled separately. | |
288 | */ | |
289 | if (iattr->ia_valid & (ATTR_MODE | ATTR_ATIME | ATTR_MTIME)) { | |
290 | if (iattr->ia_valid & ATTR_MODE) { | |
291 | info.attr.mode = mode_set(IRUSR); | |
292 | info.attr.mode |= mode_set(IWUSR); | |
293 | info.attr.mode |= mode_set(IXUSR); | |
294 | info.attr.mode |= mode_set(IRGRP); | |
295 | info.attr.mode |= mode_set(IWGRP); | |
296 | info.attr.mode |= mode_set(IXGRP); | |
297 | info.attr.mode |= mode_set(IROTH); | |
298 | info.attr.mode |= mode_set(IWOTH); | |
299 | info.attr.mode |= mode_set(IXOTH); | |
300 | ||
301 | if (iattr->ia_mode & S_IFDIR) | |
302 | info.attr.mode |= SHFL_TYPE_DIRECTORY; | |
303 | else | |
304 | info.attr.mode |= SHFL_TYPE_FILE; | |
305 | } | |
306 | ||
307 | if (iattr->ia_valid & ATTR_ATIME) | |
308 | info.access_time.ns_relative_to_unix_epoch = | |
309 | timespec64_to_ns(&iattr->ia_atime); | |
310 | ||
311 | if (iattr->ia_valid & ATTR_MTIME) | |
312 | info.modification_time.ns_relative_to_unix_epoch = | |
313 | timespec64_to_ns(&iattr->ia_mtime); | |
314 | ||
315 | /* | |
316 | * Ignore ctime (inode change time) as it can't be set | |
317 | * from userland anyway. | |
318 | */ | |
319 | ||
320 | buf_len = sizeof(info); | |
321 | err = vboxsf_fsinfo(sbi->root, params.handle, | |
322 | SHFL_INFO_SET | SHFL_INFO_FILE, &buf_len, | |
323 | &info); | |
324 | if (err) { | |
325 | vboxsf_close(sbi->root, params.handle); | |
326 | return err; | |
327 | } | |
328 | ||
329 | /* the host may have given us different attr then requested */ | |
330 | sf_i->force_restat = 1; | |
331 | } | |
332 | ||
333 | #undef mode_set | |
334 | ||
335 | if (iattr->ia_valid & ATTR_SIZE) { | |
336 | memset(&info, 0, sizeof(info)); | |
337 | info.size = iattr->ia_size; | |
338 | buf_len = sizeof(info); | |
339 | err = vboxsf_fsinfo(sbi->root, params.handle, | |
340 | SHFL_INFO_SET | SHFL_INFO_SIZE, &buf_len, | |
341 | &info); | |
342 | if (err) { | |
343 | vboxsf_close(sbi->root, params.handle); | |
344 | return err; | |
345 | } | |
346 | ||
347 | /* the host may have given us different attr then requested */ | |
348 | sf_i->force_restat = 1; | |
349 | } | |
350 | ||
351 | vboxsf_close(sbi->root, params.handle); | |
352 | ||
353 | /* Update the inode with what the host has actually given us. */ | |
354 | if (sf_i->force_restat) | |
355 | vboxsf_inode_revalidate(dentry); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | ||
360 | /* | |
361 | * [dentry] contains string encoded in coding system that corresponds | |
362 | * to [sbi]->nls, we must convert it to UTF8 here. | |
363 | * Returns a shfl_string allocated through __getname (must be freed using | |
364 | * __putname), or an ERR_PTR on error. | |
365 | */ | |
366 | struct shfl_string *vboxsf_path_from_dentry(struct vboxsf_sbi *sbi, | |
367 | struct dentry *dentry) | |
368 | { | |
369 | struct shfl_string *shfl_path; | |
370 | int path_len, out_len, nb; | |
371 | char *buf, *path; | |
372 | wchar_t uni; | |
373 | u8 *out; | |
374 | ||
375 | buf = __getname(); | |
376 | if (!buf) | |
377 | return ERR_PTR(-ENOMEM); | |
378 | ||
379 | path = dentry_path_raw(dentry, buf, PATH_MAX); | |
380 | if (IS_ERR(path)) { | |
381 | __putname(buf); | |
382 | return ERR_CAST(path); | |
383 | } | |
384 | path_len = strlen(path); | |
385 | ||
386 | if (sbi->nls) { | |
387 | shfl_path = __getname(); | |
388 | if (!shfl_path) { | |
389 | __putname(buf); | |
390 | return ERR_PTR(-ENOMEM); | |
391 | } | |
392 | ||
393 | out = shfl_path->string.utf8; | |
394 | out_len = PATH_MAX - SHFLSTRING_HEADER_SIZE - 1; | |
395 | ||
396 | while (path_len) { | |
397 | nb = sbi->nls->char2uni(path, path_len, &uni); | |
398 | if (nb < 0) { | |
399 | __putname(shfl_path); | |
400 | __putname(buf); | |
401 | return ERR_PTR(-EINVAL); | |
402 | } | |
403 | path += nb; | |
404 | path_len -= nb; | |
405 | ||
406 | nb = utf32_to_utf8(uni, out, out_len); | |
407 | if (nb < 0) { | |
408 | __putname(shfl_path); | |
409 | __putname(buf); | |
410 | return ERR_PTR(-ENAMETOOLONG); | |
411 | } | |
412 | out += nb; | |
413 | out_len -= nb; | |
414 | } | |
415 | *out = 0; | |
416 | shfl_path->length = out - shfl_path->string.utf8; | |
417 | shfl_path->size = shfl_path->length + 1; | |
418 | __putname(buf); | |
419 | } else { | |
420 | if ((SHFLSTRING_HEADER_SIZE + path_len + 1) > PATH_MAX) { | |
421 | __putname(buf); | |
422 | return ERR_PTR(-ENAMETOOLONG); | |
423 | } | |
424 | /* | |
425 | * dentry_path stores the name at the end of buf, but the | |
426 | * shfl_string string we return must be properly aligned. | |
427 | */ | |
428 | shfl_path = (struct shfl_string *)buf; | |
429 | memmove(shfl_path->string.utf8, path, path_len); | |
430 | shfl_path->string.utf8[path_len] = 0; | |
431 | shfl_path->length = path_len; | |
432 | shfl_path->size = path_len + 1; | |
433 | } | |
434 | ||
435 | return shfl_path; | |
436 | } | |
437 | ||
438 | int vboxsf_nlscpy(struct vboxsf_sbi *sbi, char *name, size_t name_bound_len, | |
439 | const unsigned char *utf8_name, size_t utf8_len) | |
440 | { | |
441 | const char *in; | |
442 | char *out; | |
0fd16957 HG |
443 | size_t out_bound_len; |
444 | size_t in_bound_len; | |
445 | ||
446 | in = utf8_name; | |
447 | in_bound_len = utf8_len; | |
448 | ||
449 | out = name; | |
0fd16957 HG |
450 | /* Reserve space for terminating 0 */ |
451 | out_bound_len = name_bound_len - 1; | |
452 | ||
453 | while (in_bound_len) { | |
454 | int nb; | |
455 | unicode_t uni; | |
456 | ||
457 | nb = utf8_to_utf32(in, in_bound_len, &uni); | |
458 | if (nb < 0) | |
459 | return -EINVAL; | |
460 | ||
461 | in += nb; | |
462 | in_bound_len -= nb; | |
463 | ||
464 | nb = sbi->nls->uni2char(uni, out, out_bound_len); | |
465 | if (nb < 0) | |
466 | return nb; | |
467 | ||
468 | out += nb; | |
469 | out_bound_len -= nb; | |
0fd16957 HG |
470 | } |
471 | ||
472 | *out = 0; | |
473 | ||
474 | return 0; | |
475 | } | |
476 | ||
477 | static struct vboxsf_dir_buf *vboxsf_dir_buf_alloc(struct list_head *list) | |
478 | { | |
479 | struct vboxsf_dir_buf *b; | |
480 | ||
481 | b = kmalloc(sizeof(*b), GFP_KERNEL); | |
482 | if (!b) | |
483 | return NULL; | |
484 | ||
485 | b->buf = kmalloc(DIR_BUFFER_SIZE, GFP_KERNEL); | |
486 | if (!b->buf) { | |
487 | kfree(b); | |
488 | return NULL; | |
489 | } | |
490 | ||
491 | b->entries = 0; | |
492 | b->used = 0; | |
493 | b->free = DIR_BUFFER_SIZE; | |
494 | list_add(&b->head, list); | |
495 | ||
496 | return b; | |
497 | } | |
498 | ||
499 | static void vboxsf_dir_buf_free(struct vboxsf_dir_buf *b) | |
500 | { | |
501 | list_del(&b->head); | |
502 | kfree(b->buf); | |
503 | kfree(b); | |
504 | } | |
505 | ||
506 | struct vboxsf_dir_info *vboxsf_dir_info_alloc(void) | |
507 | { | |
508 | struct vboxsf_dir_info *p; | |
509 | ||
510 | p = kmalloc(sizeof(*p), GFP_KERNEL); | |
511 | if (!p) | |
512 | return NULL; | |
513 | ||
514 | INIT_LIST_HEAD(&p->info_list); | |
515 | return p; | |
516 | } | |
517 | ||
518 | void vboxsf_dir_info_free(struct vboxsf_dir_info *p) | |
519 | { | |
520 | struct list_head *list, *pos, *tmp; | |
521 | ||
522 | list = &p->info_list; | |
523 | list_for_each_safe(pos, tmp, list) { | |
524 | struct vboxsf_dir_buf *b; | |
525 | ||
526 | b = list_entry(pos, struct vboxsf_dir_buf, head); | |
527 | vboxsf_dir_buf_free(b); | |
528 | } | |
529 | kfree(p); | |
530 | } | |
531 | ||
532 | int vboxsf_dir_read_all(struct vboxsf_sbi *sbi, struct vboxsf_dir_info *sf_d, | |
533 | u64 handle) | |
534 | { | |
535 | struct vboxsf_dir_buf *b; | |
536 | u32 entries, size; | |
537 | int err = 0; | |
538 | void *buf; | |
539 | ||
540 | /* vboxsf_dirinfo returns 1 on end of dir */ | |
541 | while (err == 0) { | |
542 | b = vboxsf_dir_buf_alloc(&sf_d->info_list); | |
543 | if (!b) { | |
544 | err = -ENOMEM; | |
545 | break; | |
546 | } | |
547 | ||
548 | buf = b->buf; | |
549 | size = b->free; | |
550 | ||
551 | err = vboxsf_dirinfo(sbi->root, handle, NULL, 0, 0, | |
552 | &size, buf, &entries); | |
553 | if (err < 0) | |
554 | break; | |
555 | ||
556 | b->entries += entries; | |
557 | b->free -= size; | |
558 | b->used += size; | |
559 | } | |
560 | ||
561 | if (b && b->used == 0) | |
562 | vboxsf_dir_buf_free(b); | |
563 | ||
564 | /* -EILSEQ means the host could not translate a filename, ignore */ | |
565 | if (err > 0 || err == -EILSEQ) | |
566 | err = 0; | |
567 | ||
568 | return err; | |
569 | } |