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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Common NFSv4 ACL handling code. |
3 | * | |
4 | * Copyright (c) 2002, 2003 The Regents of the University of Michigan. | |
5 | * All rights reserved. | |
6 | * | |
7 | * Marius Aamodt Eriksen <marius@umich.edu> | |
8 | * Jeff Sedlak <jsedlak@umich.edu> | |
9 | * J. Bruce Fields <bfields@umich.edu> | |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * | |
15 | * 1. Redistributions of source code must retain the above copyright | |
16 | * notice, this list of conditions and the following disclaimer. | |
17 | * 2. Redistributions in binary form must reproduce the above copyright | |
18 | * notice, this list of conditions and the following disclaimer in the | |
19 | * documentation and/or other materials provided with the distribution. | |
20 | * 3. Neither the name of the University nor the names of its | |
21 | * contributors may be used to endorse or promote products derived | |
22 | * from this software without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
25 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
26 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
27 | * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR | |
31 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | |
32 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | |
33 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | |
34 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
35 | */ | |
36 | ||
5a0e3ad6 | 37 | #include <linux/slab.h> |
1da177e4 | 38 | #include <linux/nfs_fs.h> |
afeacc8c | 39 | #include <linux/export.h> |
4ac7249e | 40 | #include "nfsfh.h" |
3554116d | 41 | #include "nfsd.h" |
2ca72e17 | 42 | #include "acl.h" |
4ac7249e | 43 | #include "vfs.h" |
1da177e4 | 44 | |
4ac7249e CH |
45 | #define NFS4_ACL_TYPE_DEFAULT 0x01 |
46 | #define NFS4_ACL_DIR 0x02 | |
47 | #define NFS4_ACL_OWNER 0x04 | |
1da177e4 LT |
48 | |
49 | /* mode bit translations: */ | |
50 | #define NFS4_READ_MODE (NFS4_ACE_READ_DATA) | |
51 | #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA) | |
52 | #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE | |
53 | #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE) | |
54 | #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL) | |
55 | ||
56 | /* We don't support these bits; insist they be neither allowed nor denied */ | |
57 | #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \ | |
58 | | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS) | |
59 | ||
60 | /* flags used to simulate posix default ACLs */ | |
61 | #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \ | |
7bdfa68c | 62 | | NFS4_ACE_DIRECTORY_INHERIT_ACE) |
1da177e4 | 63 | |
7bdfa68c BF |
64 | #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \ |
65 | | NFS4_ACE_INHERIT_ONLY_ACE \ | |
66 | | NFS4_ACE_IDENTIFIER_GROUP) | |
b548edc2 | 67 | |
1da177e4 LT |
68 | #define MASK_EQUAL(mask1, mask2) \ |
69 | ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) ) | |
70 | ||
71 | static u32 | |
72 | mask_from_posix(unsigned short perm, unsigned int flags) | |
73 | { | |
74 | int mask = NFS4_ANYONE_MODE; | |
75 | ||
76 | if (flags & NFS4_ACL_OWNER) | |
77 | mask |= NFS4_OWNER_MODE; | |
78 | if (perm & ACL_READ) | |
79 | mask |= NFS4_READ_MODE; | |
80 | if (perm & ACL_WRITE) | |
81 | mask |= NFS4_WRITE_MODE; | |
82 | if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) | |
83 | mask |= NFS4_ACE_DELETE_CHILD; | |
84 | if (perm & ACL_EXECUTE) | |
85 | mask |= NFS4_EXECUTE_MODE; | |
86 | return mask; | |
87 | } | |
88 | ||
89 | static u32 | |
bec50c47 | 90 | deny_mask_from_posix(unsigned short perm, u32 flags) |
1da177e4 | 91 | { |
bec50c47 BF |
92 | u32 mask = 0; |
93 | ||
94 | if (perm & ACL_READ) | |
95 | mask |= NFS4_READ_MODE; | |
96 | if (perm & ACL_WRITE) | |
97 | mask |= NFS4_WRITE_MODE; | |
98 | if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) | |
99 | mask |= NFS4_ACE_DELETE_CHILD; | |
100 | if (perm & ACL_EXECUTE) | |
101 | mask |= NFS4_EXECUTE_MODE; | |
102 | return mask; | |
1da177e4 LT |
103 | } |
104 | ||
105 | /* XXX: modify functions to return NFS errors; they're only ever | |
106 | * used by nfs code, after all.... */ | |
107 | ||
09229edb BF |
108 | /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the |
109 | * side of being more restrictive, so the mode bit mapping below is | |
110 | * pessimistic. An optimistic version would be needed to handle DENY's, | |
111 | * but we espect to coalesce all ALLOWs and DENYs before mapping to mode | |
112 | * bits. */ | |
113 | ||
114 | static void | |
115 | low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags) | |
1da177e4 | 116 | { |
09229edb | 117 | u32 write_mode = NFS4_WRITE_MODE; |
1da177e4 | 118 | |
09229edb BF |
119 | if (flags & NFS4_ACL_DIR) |
120 | write_mode |= NFS4_ACE_DELETE_CHILD; | |
1da177e4 LT |
121 | *mode = 0; |
122 | if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE) | |
123 | *mode |= ACL_READ; | |
09229edb | 124 | if ((perm & write_mode) == write_mode) |
1da177e4 LT |
125 | *mode |= ACL_WRITE; |
126 | if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE) | |
127 | *mode |= ACL_EXECUTE; | |
1da177e4 LT |
128 | } |
129 | ||
130 | struct ace_container { | |
131 | struct nfs4_ace *ace; | |
132 | struct list_head ace_l; | |
133 | }; | |
134 | ||
135 | static short ace2type(struct nfs4_ace *); | |
28e05dd8 BF |
136 | static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, |
137 | unsigned int); | |
1da177e4 | 138 | |
4ac7249e CH |
139 | int |
140 | nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, | |
141 | struct nfs4_acl **acl) | |
1da177e4 | 142 | { |
4ac7249e CH |
143 | struct inode *inode = dentry->d_inode; |
144 | int error = 0; | |
145 | struct posix_acl *pacl = NULL, *dpacl = NULL; | |
146 | unsigned int flags = 0; | |
28e05dd8 | 147 | int size = 0; |
1da177e4 | 148 | |
4ac7249e CH |
149 | pacl = get_acl(inode, ACL_TYPE_ACCESS); |
150 | if (!pacl) { | |
151 | pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); | |
152 | if (IS_ERR(pacl)) | |
153 | return PTR_ERR(pacl); | |
1da177e4 | 154 | } |
09bdc2d7 BF |
155 | /* allocate for worst case: one (deny, allow) pair each: */ |
156 | size += 2 * pacl->a_count; | |
4ac7249e CH |
157 | |
158 | if (S_ISDIR(inode->i_mode)) { | |
159 | flags = NFS4_ACL_DIR; | |
160 | dpacl = get_acl(inode, ACL_TYPE_DEFAULT); | |
161 | if (dpacl) | |
162 | size += 2 * dpacl->a_count; | |
1da177e4 LT |
163 | } |
164 | ||
4ac7249e CH |
165 | *acl = nfs4_acl_new(size); |
166 | if (*acl == NULL) { | |
167 | error = -ENOMEM; | |
168 | goto out; | |
169 | } | |
1da177e4 | 170 | |
09bdc2d7 | 171 | _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); |
1da177e4 | 172 | |
28e05dd8 | 173 | if (dpacl) |
4ac7249e | 174 | _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); |
1da177e4 | 175 | |
4ac7249e CH |
176 | out: |
177 | posix_acl_release(pacl); | |
178 | posix_acl_release(dpacl); | |
179 | return error; | |
1da177e4 LT |
180 | } |
181 | ||
bec50c47 BF |
182 | struct posix_acl_summary { |
183 | unsigned short owner; | |
184 | unsigned short users; | |
185 | unsigned short group; | |
186 | unsigned short groups; | |
187 | unsigned short other; | |
188 | unsigned short mask; | |
189 | }; | |
190 | ||
28e05dd8 | 191 | static void |
bec50c47 | 192 | summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) |
1da177e4 | 193 | { |
bec50c47 | 194 | struct posix_acl_entry *pa, *pe; |
f7fede4b BF |
195 | |
196 | /* | |
197 | * Only pas.users and pas.groups need initialization; previous | |
198 | * posix_acl_valid() calls ensure that the other fields will be | |
199 | * initialized in the following loop. But, just to placate gcc: | |
200 | */ | |
201 | memset(pas, 0, sizeof(*pas)); | |
bec50c47 BF |
202 | pas->mask = 07; |
203 | ||
204 | pe = acl->a_entries + acl->a_count; | |
205 | ||
206 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
207 | switch (pa->e_tag) { | |
208 | case ACL_USER_OBJ: | |
209 | pas->owner = pa->e_perm; | |
210 | break; | |
211 | case ACL_GROUP_OBJ: | |
212 | pas->group = pa->e_perm; | |
213 | break; | |
214 | case ACL_USER: | |
215 | pas->users |= pa->e_perm; | |
216 | break; | |
217 | case ACL_GROUP: | |
218 | pas->groups |= pa->e_perm; | |
219 | break; | |
220 | case ACL_OTHER: | |
221 | pas->other = pa->e_perm; | |
222 | break; | |
223 | case ACL_MASK: | |
224 | pas->mask = pa->e_perm; | |
225 | break; | |
226 | } | |
227 | } | |
228 | /* We'll only care about effective permissions: */ | |
229 | pas->users &= pas->mask; | |
230 | pas->group &= pas->mask; | |
231 | pas->groups &= pas->mask; | |
1da177e4 LT |
232 | } |
233 | ||
234 | /* We assume the acl has been verified with posix_acl_valid. */ | |
28e05dd8 | 235 | static void |
1da177e4 LT |
236 | _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, |
237 | unsigned int flags) | |
238 | { | |
bec50c47 BF |
239 | struct posix_acl_entry *pa, *group_owner_entry; |
240 | struct nfs4_ace *ace; | |
241 | struct posix_acl_summary pas; | |
242 | unsigned short deny; | |
1da177e4 | 243 | int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? |
54c04409 | 244 | NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); |
1da177e4 LT |
245 | |
246 | BUG_ON(pacl->a_count < 3); | |
bec50c47 | 247 | summarize_posix_acl(pacl, &pas); |
1da177e4 LT |
248 | |
249 | pa = pacl->a_entries; | |
bec50c47 BF |
250 | ace = acl->aces + acl->naces; |
251 | ||
252 | /* We could deny everything not granted by the owner: */ | |
253 | deny = ~pas.owner; | |
254 | /* | |
255 | * but it is equivalent (and simpler) to deny only what is not | |
256 | * granted by later entries: | |
257 | */ | |
258 | deny &= pas.users | pas.group | pas.groups | pas.other; | |
259 | if (deny) { | |
260 | ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; | |
261 | ace->flag = eflag; | |
262 | ace->access_mask = deny_mask_from_posix(deny, flags); | |
263 | ace->whotype = NFS4_ACL_WHO_OWNER; | |
264 | ace++; | |
265 | acl->naces++; | |
266 | } | |
267 | ||
268 | ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; | |
269 | ace->flag = eflag; | |
270 | ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); | |
271 | ace->whotype = NFS4_ACL_WHO_OWNER; | |
272 | ace++; | |
273 | acl->naces++; | |
1da177e4 LT |
274 | pa++; |
275 | ||
276 | while (pa->e_tag == ACL_USER) { | |
bec50c47 BF |
277 | deny = ~(pa->e_perm & pas.mask); |
278 | deny &= pas.groups | pas.group | pas.other; | |
279 | if (deny) { | |
280 | ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; | |
281 | ace->flag = eflag; | |
282 | ace->access_mask = deny_mask_from_posix(deny, flags); | |
283 | ace->whotype = NFS4_ACL_WHO_NAMED; | |
ab8e4aee | 284 | ace->who_uid = pa->e_uid; |
bec50c47 BF |
285 | ace++; |
286 | acl->naces++; | |
287 | } | |
288 | ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; | |
289 | ace->flag = eflag; | |
290 | ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, | |
291 | flags); | |
292 | ace->whotype = NFS4_ACL_WHO_NAMED; | |
ab8e4aee | 293 | ace->who_uid = pa->e_uid; |
bec50c47 BF |
294 | ace++; |
295 | acl->naces++; | |
1da177e4 LT |
296 | pa++; |
297 | } | |
298 | ||
299 | /* In the case of groups, we apply allow ACEs first, then deny ACEs, | |
300 | * since a user can be in more than one group. */ | |
301 | ||
302 | /* allow ACEs */ | |
303 | ||
1da177e4 | 304 | group_owner_entry = pa; |
bec50c47 BF |
305 | |
306 | ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; | |
307 | ace->flag = eflag; | |
308 | ace->access_mask = mask_from_posix(pas.group, flags); | |
309 | ace->whotype = NFS4_ACL_WHO_GROUP; | |
310 | ace++; | |
311 | acl->naces++; | |
1da177e4 LT |
312 | pa++; |
313 | ||
314 | while (pa->e_tag == ACL_GROUP) { | |
bec50c47 BF |
315 | ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; |
316 | ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; | |
317 | ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, | |
318 | flags); | |
319 | ace->whotype = NFS4_ACL_WHO_NAMED; | |
ab8e4aee | 320 | ace->who_gid = pa->e_gid; |
bec50c47 BF |
321 | ace++; |
322 | acl->naces++; | |
1da177e4 LT |
323 | pa++; |
324 | } | |
325 | ||
326 | /* deny ACEs */ | |
327 | ||
328 | pa = group_owner_entry; | |
bec50c47 BF |
329 | |
330 | deny = ~pas.group & pas.other; | |
331 | if (deny) { | |
332 | ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; | |
d8d0b85b | 333 | ace->flag = eflag; |
bec50c47 BF |
334 | ace->access_mask = deny_mask_from_posix(deny, flags); |
335 | ace->whotype = NFS4_ACL_WHO_GROUP; | |
336 | ace++; | |
337 | acl->naces++; | |
338 | } | |
1da177e4 | 339 | pa++; |
bec50c47 | 340 | |
1da177e4 | 341 | while (pa->e_tag == ACL_GROUP) { |
bec50c47 BF |
342 | deny = ~(pa->e_perm & pas.mask); |
343 | deny &= pas.other; | |
344 | if (deny) { | |
345 | ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; | |
346 | ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; | |
55bb55dc | 347 | ace->access_mask = deny_mask_from_posix(deny, flags); |
bec50c47 | 348 | ace->whotype = NFS4_ACL_WHO_NAMED; |
ab8e4aee | 349 | ace->who_gid = pa->e_gid; |
bec50c47 BF |
350 | ace++; |
351 | acl->naces++; | |
352 | } | |
1da177e4 LT |
353 | pa++; |
354 | } | |
355 | ||
356 | if (pa->e_tag == ACL_MASK) | |
357 | pa++; | |
bec50c47 BF |
358 | ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; |
359 | ace->flag = eflag; | |
360 | ace->access_mask = mask_from_posix(pa->e_perm, flags); | |
361 | ace->whotype = NFS4_ACL_WHO_EVERYONE; | |
362 | acl->naces++; | |
1da177e4 LT |
363 | } |
364 | ||
ab8e4aee EB |
365 | static bool |
366 | pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) | |
367 | { | |
368 | if (pace1->e_tag != pace2->e_tag) | |
369 | return pace1->e_tag > pace2->e_tag; | |
370 | if (pace1->e_tag == ACL_USER) | |
371 | return uid_gt(pace1->e_uid, pace2->e_uid); | |
372 | if (pace1->e_tag == ACL_GROUP) | |
373 | return gid_gt(pace1->e_gid, pace2->e_gid); | |
374 | return false; | |
375 | } | |
376 | ||
1da177e4 LT |
377 | static void |
378 | sort_pacl_range(struct posix_acl *pacl, int start, int end) { | |
379 | int sorted = 0, i; | |
380 | struct posix_acl_entry tmp; | |
381 | ||
382 | /* We just do a bubble sort; easy to do in place, and we're not | |
383 | * expecting acl's to be long enough to justify anything more. */ | |
384 | while (!sorted) { | |
385 | sorted = 1; | |
386 | for (i = start; i < end; i++) { | |
ab8e4aee EB |
387 | if (pace_gt(&pacl->a_entries[i], |
388 | &pacl->a_entries[i+1])) { | |
1da177e4 LT |
389 | sorted = 0; |
390 | tmp = pacl->a_entries[i]; | |
391 | pacl->a_entries[i] = pacl->a_entries[i+1]; | |
392 | pacl->a_entries[i+1] = tmp; | |
393 | } | |
394 | } | |
395 | } | |
396 | } | |
397 | ||
398 | static void | |
399 | sort_pacl(struct posix_acl *pacl) | |
400 | { | |
401 | /* posix_acl_valid requires that users and groups be in order | |
402 | * by uid/gid. */ | |
403 | int i, j; | |
404 | ||
405 | if (pacl->a_count <= 4) | |
406 | return; /* no users or groups */ | |
407 | i = 1; | |
408 | while (pacl->a_entries[i].e_tag == ACL_USER) | |
409 | i++; | |
410 | sort_pacl_range(pacl, 1, i-1); | |
411 | ||
412 | BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); | |
aba24d71 | 413 | j = ++i; |
1da177e4 LT |
414 | while (pacl->a_entries[j].e_tag == ACL_GROUP) |
415 | j++; | |
416 | sort_pacl_range(pacl, i, j-1); | |
417 | return; | |
418 | } | |
419 | ||
09229edb BF |
420 | /* |
421 | * While processing the NFSv4 ACE, this maintains bitmasks representing | |
422 | * which permission bits have been allowed and which denied to a given | |
423 | * entity: */ | |
424 | struct posix_ace_state { | |
425 | u32 allow; | |
426 | u32 deny; | |
427 | }; | |
428 | ||
429 | struct posix_user_ace_state { | |
ab8e4aee EB |
430 | union { |
431 | kuid_t uid; | |
432 | kgid_t gid; | |
433 | }; | |
09229edb BF |
434 | struct posix_ace_state perms; |
435 | }; | |
436 | ||
437 | struct posix_ace_state_array { | |
438 | int n; | |
439 | struct posix_user_ace_state aces[]; | |
440 | }; | |
441 | ||
442 | /* | |
443 | * While processing the NFSv4 ACE, this maintains the partial permissions | |
444 | * calculated so far: */ | |
445 | ||
446 | struct posix_acl_state { | |
3160a711 | 447 | int empty; |
09229edb BF |
448 | struct posix_ace_state owner; |
449 | struct posix_ace_state group; | |
450 | struct posix_ace_state other; | |
451 | struct posix_ace_state everyone; | |
452 | struct posix_ace_state mask; /* Deny unused in this case */ | |
453 | struct posix_ace_state_array *users; | |
454 | struct posix_ace_state_array *groups; | |
455 | }; | |
456 | ||
1da177e4 | 457 | static int |
09229edb | 458 | init_state(struct posix_acl_state *state, int cnt) |
1da177e4 | 459 | { |
09229edb BF |
460 | int alloc; |
461 | ||
462 | memset(state, 0, sizeof(struct posix_acl_state)); | |
3160a711 | 463 | state->empty = 1; |
09229edb BF |
464 | /* |
465 | * In the worst case, each individual acl could be for a distinct | |
466 | * named user or group, but we don't no which, so we allocate | |
467 | * enough space for either: | |
468 | */ | |
469 | alloc = sizeof(struct posix_ace_state_array) | |
91b80969 | 470 | + cnt*sizeof(struct posix_user_ace_state); |
09229edb BF |
471 | state->users = kzalloc(alloc, GFP_KERNEL); |
472 | if (!state->users) | |
473 | return -ENOMEM; | |
474 | state->groups = kzalloc(alloc, GFP_KERNEL); | |
475 | if (!state->groups) { | |
476 | kfree(state->users); | |
477 | return -ENOMEM; | |
478 | } | |
479 | return 0; | |
1da177e4 LT |
480 | } |
481 | ||
09229edb BF |
482 | static void |
483 | free_state(struct posix_acl_state *state) { | |
484 | kfree(state->users); | |
485 | kfree(state->groups); | |
1da177e4 LT |
486 | } |
487 | ||
09229edb | 488 | static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) |
1da177e4 | 489 | { |
09229edb | 490 | state->mask.allow |= astate->allow; |
1da177e4 LT |
491 | } |
492 | ||
09229edb BF |
493 | /* |
494 | * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS, | |
495 | * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate | |
496 | * to traditional read/write/execute permissions. | |
497 | * | |
498 | * It's problematic to reject acls that use certain mode bits, because it | |
499 | * places the burden on users to learn the rules about which bits one | |
500 | * particular server sets, without giving the user a lot of help--we return an | |
501 | * error that could mean any number of different things. To make matters | |
502 | * worse, the problematic bits might be introduced by some application that's | |
503 | * automatically mapping from some other acl model. | |
504 | * | |
505 | * So wherever possible we accept anything, possibly erring on the side of | |
506 | * denying more permissions than necessary. | |
507 | * | |
508 | * However we do reject *explicit* DENY's of a few bits representing | |
509 | * permissions we could never deny: | |
510 | */ | |
1da177e4 | 511 | |
09229edb BF |
512 | static inline int check_deny(u32 mask, int isowner) |
513 | { | |
514 | if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL)) | |
515 | return -EINVAL; | |
516 | if (!isowner) | |
517 | return 0; | |
518 | if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)) | |
519 | return -EINVAL; | |
520 | return 0; | |
1da177e4 LT |
521 | } |
522 | ||
09229edb BF |
523 | static struct posix_acl * |
524 | posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) | |
1da177e4 | 525 | { |
09229edb BF |
526 | struct posix_acl_entry *pace; |
527 | struct posix_acl *pacl; | |
528 | int nace; | |
529 | int i, error = 0; | |
1da177e4 | 530 | |
3160a711 BF |
531 | /* |
532 | * ACLs with no ACEs are treated differently in the inheritable | |
533 | * and effective cases: when there are no inheritable ACEs, we | |
534 | * set a zero-length default posix acl: | |
535 | */ | |
536 | if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) { | |
537 | pacl = posix_acl_alloc(0, GFP_KERNEL); | |
538 | return pacl ? pacl : ERR_PTR(-ENOMEM); | |
539 | } | |
540 | /* | |
541 | * When there are no effective ACEs, the following will end | |
542 | * up setting a 3-element effective posix ACL with all | |
543 | * permissions zero. | |
544 | */ | |
06f9cc12 BF |
545 | if (!state->users->n && !state->groups->n) |
546 | nace = 3; | |
547 | else /* Note we also include a MASK ACE in this case: */ | |
548 | nace = 4 + state->users->n + state->groups->n; | |
09229edb BF |
549 | pacl = posix_acl_alloc(nace, GFP_KERNEL); |
550 | if (!pacl) | |
551 | return ERR_PTR(-ENOMEM); | |
1da177e4 | 552 | |
09229edb BF |
553 | pace = pacl->a_entries; |
554 | pace->e_tag = ACL_USER_OBJ; | |
555 | error = check_deny(state->owner.deny, 1); | |
556 | if (error) | |
557 | goto out_err; | |
558 | low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); | |
09229edb BF |
559 | |
560 | for (i=0; i < state->users->n; i++) { | |
561 | pace++; | |
562 | pace->e_tag = ACL_USER; | |
563 | error = check_deny(state->users->aces[i].perms.deny, 0); | |
564 | if (error) | |
565 | goto out_err; | |
566 | low_mode_from_nfs4(state->users->aces[i].perms.allow, | |
567 | &pace->e_perm, flags); | |
ab8e4aee | 568 | pace->e_uid = state->users->aces[i].uid; |
09229edb | 569 | add_to_mask(state, &state->users->aces[i].perms); |
1da177e4 LT |
570 | } |
571 | ||
09229edb BF |
572 | pace++; |
573 | pace->e_tag = ACL_GROUP_OBJ; | |
574 | error = check_deny(state->group.deny, 0); | |
575 | if (error) | |
576 | goto out_err; | |
577 | low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); | |
09229edb BF |
578 | add_to_mask(state, &state->group); |
579 | ||
580 | for (i=0; i < state->groups->n; i++) { | |
581 | pace++; | |
582 | pace->e_tag = ACL_GROUP; | |
583 | error = check_deny(state->groups->aces[i].perms.deny, 0); | |
584 | if (error) | |
585 | goto out_err; | |
586 | low_mode_from_nfs4(state->groups->aces[i].perms.allow, | |
587 | &pace->e_perm, flags); | |
ab8e4aee | 588 | pace->e_gid = state->groups->aces[i].gid; |
09229edb BF |
589 | add_to_mask(state, &state->groups->aces[i].perms); |
590 | } | |
1da177e4 | 591 | |
06f9cc12 BF |
592 | if (!state->users->n && !state->groups->n) { |
593 | pace++; | |
594 | pace->e_tag = ACL_MASK; | |
595 | low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); | |
596 | } | |
1da177e4 | 597 | |
09229edb BF |
598 | pace++; |
599 | pace->e_tag = ACL_OTHER; | |
600 | error = check_deny(state->other.deny, 0); | |
601 | if (error) | |
602 | goto out_err; | |
603 | low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); | |
1da177e4 | 604 | |
09229edb BF |
605 | return pacl; |
606 | out_err: | |
607 | posix_acl_release(pacl); | |
608 | return ERR_PTR(error); | |
609 | } | |
1da177e4 | 610 | |
09229edb BF |
611 | static inline void allow_bits(struct posix_ace_state *astate, u32 mask) |
612 | { | |
613 | /* Allow all bits in the mask not already denied: */ | |
614 | astate->allow |= mask & ~astate->deny; | |
615 | } | |
1da177e4 | 616 | |
09229edb BF |
617 | static inline void deny_bits(struct posix_ace_state *astate, u32 mask) |
618 | { | |
619 | /* Deny all bits in the mask not already allowed: */ | |
620 | astate->deny |= mask & ~astate->allow; | |
621 | } | |
1da177e4 | 622 | |
ab8e4aee | 623 | static int find_uid(struct posix_acl_state *state, kuid_t uid) |
09229edb | 624 | { |
ab8e4aee | 625 | struct posix_ace_state_array *a = state->users; |
09229edb | 626 | int i; |
1da177e4 | 627 | |
09229edb | 628 | for (i = 0; i < a->n; i++) |
ab8e4aee | 629 | if (uid_eq(a->aces[i].uid, uid)) |
09229edb BF |
630 | return i; |
631 | /* Not found: */ | |
632 | a->n++; | |
633 | a->aces[i].uid = uid; | |
634 | a->aces[i].perms.allow = state->everyone.allow; | |
635 | a->aces[i].perms.deny = state->everyone.deny; | |
1da177e4 | 636 | |
09229edb | 637 | return i; |
1da177e4 LT |
638 | } |
639 | ||
ab8e4aee EB |
640 | static int find_gid(struct posix_acl_state *state, kgid_t gid) |
641 | { | |
642 | struct posix_ace_state_array *a = state->groups; | |
643 | int i; | |
644 | ||
645 | for (i = 0; i < a->n; i++) | |
646 | if (gid_eq(a->aces[i].gid, gid)) | |
647 | return i; | |
648 | /* Not found: */ | |
649 | a->n++; | |
650 | a->aces[i].gid = gid; | |
651 | a->aces[i].perms.allow = state->everyone.allow; | |
652 | a->aces[i].perms.deny = state->everyone.deny; | |
653 | ||
654 | return i; | |
655 | } | |
656 | ||
09229edb | 657 | static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) |
1da177e4 | 658 | { |
09229edb | 659 | int i; |
1da177e4 | 660 | |
09229edb BF |
661 | for (i=0; i < a->n; i++) |
662 | deny_bits(&a->aces[i].perms, mask); | |
1da177e4 LT |
663 | } |
664 | ||
09229edb | 665 | static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) |
1da177e4 | 666 | { |
09229edb | 667 | int i; |
1da177e4 | 668 | |
09229edb BF |
669 | for (i=0; i < a->n; i++) |
670 | allow_bits(&a->aces[i].perms, mask); | |
1da177e4 LT |
671 | } |
672 | ||
09229edb BF |
673 | static void process_one_v4_ace(struct posix_acl_state *state, |
674 | struct nfs4_ace *ace) | |
1da177e4 | 675 | { |
09229edb BF |
676 | u32 mask = ace->access_mask; |
677 | int i; | |
678 | ||
3160a711 BF |
679 | state->empty = 0; |
680 | ||
09229edb BF |
681 | switch (ace2type(ace)) { |
682 | case ACL_USER_OBJ: | |
683 | if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { | |
684 | allow_bits(&state->owner, mask); | |
685 | } else { | |
686 | deny_bits(&state->owner, mask); | |
687 | } | |
688 | break; | |
689 | case ACL_USER: | |
ab8e4aee | 690 | i = find_uid(state, ace->who_uid); |
09229edb BF |
691 | if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { |
692 | allow_bits(&state->users->aces[i].perms, mask); | |
693 | } else { | |
694 | deny_bits(&state->users->aces[i].perms, mask); | |
695 | mask = state->users->aces[i].perms.deny; | |
696 | deny_bits(&state->owner, mask); | |
697 | } | |
698 | break; | |
699 | case ACL_GROUP_OBJ: | |
700 | if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { | |
701 | allow_bits(&state->group, mask); | |
702 | } else { | |
703 | deny_bits(&state->group, mask); | |
704 | mask = state->group.deny; | |
705 | deny_bits(&state->owner, mask); | |
706 | deny_bits(&state->everyone, mask); | |
707 | deny_bits_array(state->users, mask); | |
708 | deny_bits_array(state->groups, mask); | |
709 | } | |
710 | break; | |
711 | case ACL_GROUP: | |
ab8e4aee | 712 | i = find_gid(state, ace->who_gid); |
09229edb BF |
713 | if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { |
714 | allow_bits(&state->groups->aces[i].perms, mask); | |
715 | } else { | |
716 | deny_bits(&state->groups->aces[i].perms, mask); | |
717 | mask = state->groups->aces[i].perms.deny; | |
718 | deny_bits(&state->owner, mask); | |
719 | deny_bits(&state->group, mask); | |
720 | deny_bits(&state->everyone, mask); | |
721 | deny_bits_array(state->users, mask); | |
722 | deny_bits_array(state->groups, mask); | |
723 | } | |
724 | break; | |
725 | case ACL_OTHER: | |
726 | if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { | |
727 | allow_bits(&state->owner, mask); | |
728 | allow_bits(&state->group, mask); | |
729 | allow_bits(&state->other, mask); | |
730 | allow_bits(&state->everyone, mask); | |
731 | allow_bits_array(state->users, mask); | |
732 | allow_bits_array(state->groups, mask); | |
733 | } else { | |
734 | deny_bits(&state->owner, mask); | |
735 | deny_bits(&state->group, mask); | |
736 | deny_bits(&state->other, mask); | |
737 | deny_bits(&state->everyone, mask); | |
738 | deny_bits_array(state->users, mask); | |
739 | deny_bits_array(state->groups, mask); | |
740 | } | |
1da177e4 LT |
741 | } |
742 | } | |
743 | ||
4ac7249e CH |
744 | static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, |
745 | struct posix_acl **pacl, struct posix_acl **dpacl, | |
746 | unsigned int flags) | |
1da177e4 | 747 | { |
575a6290 | 748 | struct posix_acl_state effective_acl_state, default_acl_state; |
09229edb BF |
749 | struct nfs4_ace *ace; |
750 | int ret; | |
1da177e4 | 751 | |
575a6290 | 752 | ret = init_state(&effective_acl_state, acl->naces); |
09229edb | 753 | if (ret) |
575a6290 BF |
754 | return ret; |
755 | ret = init_state(&default_acl_state, acl->naces); | |
756 | if (ret) | |
757 | goto out_estate; | |
758 | ret = -EINVAL; | |
28e05dd8 | 759 | for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { |
09229edb BF |
760 | if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && |
761 | ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) | |
575a6290 | 762 | goto out_dstate; |
b548edc2 | 763 | if (ace->flag & ~NFS4_SUPPORTED_FLAGS) |
575a6290 | 764 | goto out_dstate; |
7bdfa68c | 765 | if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { |
575a6290 | 766 | process_one_v4_ace(&effective_acl_state, ace); |
b548edc2 | 767 | continue; |
7bdfa68c | 768 | } |
575a6290 BF |
769 | if (!(flags & NFS4_ACL_DIR)) |
770 | goto out_dstate; | |
7bdfa68c BF |
771 | /* |
772 | * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT | |
773 | * is set, we're effectively turning on the other. That's OK, | |
774 | * according to rfc 3530. | |
775 | */ | |
575a6290 BF |
776 | process_one_v4_ace(&default_acl_state, ace); |
777 | ||
778 | if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) | |
779 | process_one_v4_ace(&effective_acl_state, ace); | |
1da177e4 | 780 | } |
575a6290 BF |
781 | *pacl = posix_state_to_acl(&effective_acl_state, flags); |
782 | if (IS_ERR(*pacl)) { | |
783 | ret = PTR_ERR(*pacl); | |
4b2ca38a | 784 | *pacl = NULL; |
575a6290 BF |
785 | goto out_dstate; |
786 | } | |
3160a711 BF |
787 | *dpacl = posix_state_to_acl(&default_acl_state, |
788 | flags | NFS4_ACL_TYPE_DEFAULT); | |
575a6290 BF |
789 | if (IS_ERR(*dpacl)) { |
790 | ret = PTR_ERR(*dpacl); | |
4b2ca38a | 791 | *dpacl = NULL; |
575a6290 | 792 | posix_acl_release(*pacl); |
4b2ca38a | 793 | *pacl = NULL; |
575a6290 BF |
794 | goto out_dstate; |
795 | } | |
796 | sort_pacl(*pacl); | |
797 | sort_pacl(*dpacl); | |
798 | ret = 0; | |
799 | out_dstate: | |
800 | free_state(&default_acl_state); | |
801 | out_estate: | |
802 | free_state(&effective_acl_state); | |
803 | return ret; | |
1da177e4 LT |
804 | } |
805 | ||
4ac7249e CH |
806 | __be32 |
807 | nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, | |
808 | struct nfs4_acl *acl) | |
809 | { | |
810 | __be32 error; | |
811 | int host_error; | |
812 | struct dentry *dentry; | |
813 | struct inode *inode; | |
814 | struct posix_acl *pacl = NULL, *dpacl = NULL; | |
815 | unsigned int flags = 0; | |
816 | ||
817 | /* Get inode */ | |
818 | error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR); | |
819 | if (error) | |
820 | return error; | |
821 | ||
822 | dentry = fhp->fh_dentry; | |
823 | inode = dentry->d_inode; | |
824 | ||
825 | if (!inode->i_op->set_acl || !IS_POSIXACL(inode)) | |
826 | return nfserr_attrnotsupp; | |
827 | ||
828 | if (S_ISDIR(inode->i_mode)) | |
829 | flags = NFS4_ACL_DIR; | |
830 | ||
831 | host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); | |
832 | if (host_error == -EINVAL) | |
833 | return nfserr_attrnotsupp; | |
834 | if (host_error < 0) | |
835 | goto out_nfserr; | |
836 | ||
837 | host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS); | |
838 | if (host_error < 0) | |
839 | goto out_release; | |
840 | ||
841 | if (S_ISDIR(inode->i_mode)) { | |
842 | host_error = inode->i_op->set_acl(inode, dpacl, | |
843 | ACL_TYPE_DEFAULT); | |
844 | } | |
845 | ||
846 | out_release: | |
847 | posix_acl_release(pacl); | |
848 | posix_acl_release(dpacl); | |
849 | out_nfserr: | |
850 | if (host_error == -EOPNOTSUPP) | |
851 | return nfserr_attrnotsupp; | |
852 | else | |
853 | return nfserrno(host_error); | |
854 | } | |
855 | ||
856 | ||
1da177e4 LT |
857 | static short |
858 | ace2type(struct nfs4_ace *ace) | |
859 | { | |
860 | switch (ace->whotype) { | |
861 | case NFS4_ACL_WHO_NAMED: | |
862 | return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? | |
863 | ACL_GROUP : ACL_USER); | |
864 | case NFS4_ACL_WHO_OWNER: | |
865 | return ACL_USER_OBJ; | |
866 | case NFS4_ACL_WHO_GROUP: | |
867 | return ACL_GROUP_OBJ; | |
868 | case NFS4_ACL_WHO_EVERYONE: | |
869 | return ACL_OTHER; | |
870 | } | |
871 | BUG(); | |
872 | return -1; | |
873 | } | |
874 | ||
1da177e4 | 875 | struct nfs4_acl * |
28e05dd8 | 876 | nfs4_acl_new(int n) |
1da177e4 LT |
877 | { |
878 | struct nfs4_acl *acl; | |
879 | ||
28e05dd8 BF |
880 | acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL); |
881 | if (acl == NULL) | |
1da177e4 | 882 | return NULL; |
1da177e4 | 883 | acl->naces = 0; |
1da177e4 LT |
884 | return acl; |
885 | } | |
886 | ||
1da177e4 LT |
887 | static struct { |
888 | char *string; | |
889 | int stringlen; | |
890 | int type; | |
891 | } s2t_map[] = { | |
892 | { | |
893 | .string = "OWNER@", | |
894 | .stringlen = sizeof("OWNER@") - 1, | |
895 | .type = NFS4_ACL_WHO_OWNER, | |
896 | }, | |
897 | { | |
898 | .string = "GROUP@", | |
899 | .stringlen = sizeof("GROUP@") - 1, | |
900 | .type = NFS4_ACL_WHO_GROUP, | |
901 | }, | |
902 | { | |
903 | .string = "EVERYONE@", | |
904 | .stringlen = sizeof("EVERYONE@") - 1, | |
905 | .type = NFS4_ACL_WHO_EVERYONE, | |
906 | }, | |
907 | }; | |
908 | ||
909 | int | |
910 | nfs4_acl_get_whotype(char *p, u32 len) | |
911 | { | |
912 | int i; | |
913 | ||
e8c96f8c | 914 | for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { |
1da177e4 LT |
915 | if (s2t_map[i].stringlen == len && |
916 | 0 == memcmp(s2t_map[i].string, p, len)) | |
917 | return s2t_map[i].type; | |
918 | } | |
919 | return NFS4_ACL_WHO_NAMED; | |
920 | } | |
921 | ||
3554116d | 922 | __be32 nfs4_acl_write_who(int who, __be32 **p, int *len) |
1da177e4 LT |
923 | { |
924 | int i; | |
3554116d | 925 | int bytes; |
1da177e4 | 926 | |
e8c96f8c | 927 | for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { |
3554116d BF |
928 | if (s2t_map[i].type != who) |
929 | continue; | |
930 | bytes = 4 + (XDR_QUADLEN(s2t_map[i].stringlen) << 2); | |
931 | if (bytes > *len) | |
932 | return nfserr_resource; | |
933 | *p = xdr_encode_opaque(*p, s2t_map[i].string, | |
934 | s2t_map[i].stringlen); | |
935 | *len -= bytes; | |
936 | return 0; | |
1da177e4 | 937 | } |
3554116d | 938 | WARN_ON_ONCE(1); |
1da177e4 LT |
939 | return -1; |
940 | } |