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