blob: d5c15a7c67c3b5cf6a0d26a93e4c63072d8b85dc [file] [log] [blame]
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -07001/*
2 * dev_cgroup.c - device cgroup subsystem
3 *
4 * Copyright 2007 IBM Corp
5 */
6
7#include <linux/device_cgroup.h>
8#include <linux/cgroup.h>
9#include <linux/ctype.h>
10#include <linux/list.h>
11#include <linux/uaccess.h>
Serge E. Hallyn29486df2008-04-29 01:00:14 -070012#include <linux/seq_file.h>
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070013
14#define ACC_MKNOD 1
15#define ACC_READ 2
16#define ACC_WRITE 4
17#define ACC_MASK (ACC_MKNOD | ACC_READ | ACC_WRITE)
18
19#define DEV_BLOCK 1
20#define DEV_CHAR 2
21#define DEV_ALL 4 /* this represents all devices */
22
23/*
24 * whitelist locking rules:
25 * cgroup_lock() cannot be taken under dev_cgroup->lock.
26 * dev_cgroup->lock can be taken with or without cgroup_lock().
27 *
28 * modifications always require cgroup_lock
29 * modifications to a list which is visible require the
30 * dev_cgroup->lock *and* cgroup_lock()
31 * walking the list requires dev_cgroup->lock or cgroup_lock().
32 *
33 * reasoning: dev_whitelist_copy() needs to kmalloc, so needs
34 * a mutex, which the cgroup_lock() is. Since modifying
35 * a visible list requires both locks, either lock can be
36 * taken for walking the list.
37 */
38
39struct dev_whitelist_item {
40 u32 major, minor;
41 short type;
42 short access;
43 struct list_head list;
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -070044 struct rcu_head rcu;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070045};
46
47struct dev_cgroup {
48 struct cgroup_subsys_state css;
49 struct list_head whitelist;
50 spinlock_t lock;
51};
52
Pavel Emelyanovb66862f2008-06-05 22:46:24 -070053static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s)
54{
55 return container_of(s, struct dev_cgroup, css);
56}
57
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070058static inline struct dev_cgroup *cgroup_to_devcgroup(struct cgroup *cgroup)
59{
Pavel Emelyanovb66862f2008-06-05 22:46:24 -070060 return css_to_devcgroup(cgroup_subsys_state(cgroup, devices_subsys_id));
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070061}
62
Paul Menagef92523e2008-07-25 01:47:03 -070063static inline struct dev_cgroup *task_devcgroup(struct task_struct *task)
64{
65 return css_to_devcgroup(task_subsys_state(task, devices_subsys_id));
66}
67
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070068struct cgroup_subsys devices_subsys;
69
70static int devcgroup_can_attach(struct cgroup_subsys *ss,
71 struct cgroup *new_cgroup, struct task_struct *task)
72{
73 if (current != task && !capable(CAP_SYS_ADMIN))
74 return -EPERM;
75
76 return 0;
77}
78
79/*
80 * called under cgroup_lock()
81 */
82static int dev_whitelist_copy(struct list_head *dest, struct list_head *orig)
83{
84 struct dev_whitelist_item *wh, *tmp, *new;
85
86 list_for_each_entry(wh, orig, list) {
Li Zefan2cdc7242008-10-18 20:28:06 -070087 new = kmemdup(wh, sizeof(*wh), GFP_KERNEL);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070088 if (!new)
89 goto free_and_exit;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -070090 list_add_tail(&new->list, dest);
91 }
92
93 return 0;
94
95free_and_exit:
96 list_for_each_entry_safe(wh, tmp, dest, list) {
97 list_del(&wh->list);
98 kfree(wh);
99 }
100 return -ENOMEM;
101}
102
103/* Stupid prototype - don't bother combining existing entries */
104/*
105 * called under cgroup_lock()
106 * since the list is visible to other tasks, we need the spinlock also
107 */
108static int dev_whitelist_add(struct dev_cgroup *dev_cgroup,
109 struct dev_whitelist_item *wh)
110{
Pavel Emelyanovd1ee2972008-06-05 22:46:28 -0700111 struct dev_whitelist_item *whcopy, *walk;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700112
Li Zefan2cdc7242008-10-18 20:28:06 -0700113 whcopy = kmemdup(wh, sizeof(*wh), GFP_KERNEL);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700114 if (!whcopy)
115 return -ENOMEM;
116
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700117 spin_lock(&dev_cgroup->lock);
Pavel Emelyanovd1ee2972008-06-05 22:46:28 -0700118 list_for_each_entry(walk, &dev_cgroup->whitelist, list) {
119 if (walk->type != wh->type)
120 continue;
121 if (walk->major != wh->major)
122 continue;
123 if (walk->minor != wh->minor)
124 continue;
125
126 walk->access |= wh->access;
127 kfree(whcopy);
128 whcopy = NULL;
129 }
130
131 if (whcopy != NULL)
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700132 list_add_tail_rcu(&whcopy->list, &dev_cgroup->whitelist);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700133 spin_unlock(&dev_cgroup->lock);
134 return 0;
135}
136
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700137static void whitelist_item_free(struct rcu_head *rcu)
138{
139 struct dev_whitelist_item *item;
140
141 item = container_of(rcu, struct dev_whitelist_item, rcu);
142 kfree(item);
143}
144
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700145/*
146 * called under cgroup_lock()
147 * since the list is visible to other tasks, we need the spinlock also
148 */
149static void dev_whitelist_rm(struct dev_cgroup *dev_cgroup,
150 struct dev_whitelist_item *wh)
151{
152 struct dev_whitelist_item *walk, *tmp;
153
154 spin_lock(&dev_cgroup->lock);
155 list_for_each_entry_safe(walk, tmp, &dev_cgroup->whitelist, list) {
156 if (walk->type == DEV_ALL)
157 goto remove;
158 if (walk->type != wh->type)
159 continue;
160 if (walk->major != ~0 && walk->major != wh->major)
161 continue;
162 if (walk->minor != ~0 && walk->minor != wh->minor)
163 continue;
164
165remove:
166 walk->access &= ~wh->access;
167 if (!walk->access) {
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700168 list_del_rcu(&walk->list);
169 call_rcu(&walk->rcu, whitelist_item_free);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700170 }
171 }
172 spin_unlock(&dev_cgroup->lock);
173}
174
175/*
176 * called from kernel/cgroup.c with cgroup_lock() held.
177 */
178static struct cgroup_subsys_state *devcgroup_create(struct cgroup_subsys *ss,
179 struct cgroup *cgroup)
180{
181 struct dev_cgroup *dev_cgroup, *parent_dev_cgroup;
182 struct cgroup *parent_cgroup;
183 int ret;
184
185 dev_cgroup = kzalloc(sizeof(*dev_cgroup), GFP_KERNEL);
186 if (!dev_cgroup)
187 return ERR_PTR(-ENOMEM);
188 INIT_LIST_HEAD(&dev_cgroup->whitelist);
189 parent_cgroup = cgroup->parent;
190
191 if (parent_cgroup == NULL) {
192 struct dev_whitelist_item *wh;
193 wh = kmalloc(sizeof(*wh), GFP_KERNEL);
194 if (!wh) {
195 kfree(dev_cgroup);
196 return ERR_PTR(-ENOMEM);
197 }
198 wh->minor = wh->major = ~0;
199 wh->type = DEV_ALL;
Li Zefan7759fc92008-07-25 01:47:08 -0700200 wh->access = ACC_MASK;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700201 list_add(&wh->list, &dev_cgroup->whitelist);
202 } else {
203 parent_dev_cgroup = cgroup_to_devcgroup(parent_cgroup);
204 ret = dev_whitelist_copy(&dev_cgroup->whitelist,
205 &parent_dev_cgroup->whitelist);
206 if (ret) {
207 kfree(dev_cgroup);
208 return ERR_PTR(ret);
209 }
210 }
211
212 spin_lock_init(&dev_cgroup->lock);
213 return &dev_cgroup->css;
214}
215
216static void devcgroup_destroy(struct cgroup_subsys *ss,
217 struct cgroup *cgroup)
218{
219 struct dev_cgroup *dev_cgroup;
220 struct dev_whitelist_item *wh, *tmp;
221
222 dev_cgroup = cgroup_to_devcgroup(cgroup);
223 list_for_each_entry_safe(wh, tmp, &dev_cgroup->whitelist, list) {
224 list_del(&wh->list);
225 kfree(wh);
226 }
227 kfree(dev_cgroup);
228}
229
230#define DEVCG_ALLOW 1
231#define DEVCG_DENY 2
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700232#define DEVCG_LIST 3
233
Li Zefan17d213f2008-07-13 12:14:02 -0700234#define MAJMINLEN 13
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700235#define ACCLEN 4
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700236
237static void set_access(char *acc, short access)
238{
239 int idx = 0;
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700240 memset(acc, 0, ACCLEN);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700241 if (access & ACC_READ)
242 acc[idx++] = 'r';
243 if (access & ACC_WRITE)
244 acc[idx++] = 'w';
245 if (access & ACC_MKNOD)
246 acc[idx++] = 'm';
247}
248
249static char type_to_char(short type)
250{
251 if (type == DEV_ALL)
252 return 'a';
253 if (type == DEV_CHAR)
254 return 'c';
255 if (type == DEV_BLOCK)
256 return 'b';
257 return 'X';
258}
259
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700260static void set_majmin(char *str, unsigned m)
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700261{
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700262 if (m == ~0)
Li Zefan7759fc92008-07-25 01:47:08 -0700263 strcpy(str, "*");
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700264 else
Li Zefan7759fc92008-07-25 01:47:08 -0700265 sprintf(str, "%u", m);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700266}
267
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700268static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft,
269 struct seq_file *m)
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700270{
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700271 struct dev_cgroup *devcgroup = cgroup_to_devcgroup(cgroup);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700272 struct dev_whitelist_item *wh;
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700273 char maj[MAJMINLEN], min[MAJMINLEN], acc[ACCLEN];
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700274
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700275 rcu_read_lock();
276 list_for_each_entry_rcu(wh, &devcgroup->whitelist, list) {
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700277 set_access(acc, wh->access);
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700278 set_majmin(maj, wh->major);
279 set_majmin(min, wh->minor);
280 seq_printf(m, "%c %s:%s %s\n", type_to_char(wh->type),
281 maj, min, acc);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700282 }
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700283 rcu_read_unlock();
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700284
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700285 return 0;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700286}
287
288/*
289 * may_access_whitelist:
290 * does the access granted to dev_cgroup c contain the access
291 * requested in whitelist item refwh.
292 * return 1 if yes, 0 if no.
293 * call with c->lock held
294 */
295static int may_access_whitelist(struct dev_cgroup *c,
296 struct dev_whitelist_item *refwh)
297{
298 struct dev_whitelist_item *whitem;
299
300 list_for_each_entry(whitem, &c->whitelist, list) {
301 if (whitem->type & DEV_ALL)
302 return 1;
303 if ((refwh->type & DEV_BLOCK) && !(whitem->type & DEV_BLOCK))
304 continue;
305 if ((refwh->type & DEV_CHAR) && !(whitem->type & DEV_CHAR))
306 continue;
307 if (whitem->major != ~0 && whitem->major != refwh->major)
308 continue;
309 if (whitem->minor != ~0 && whitem->minor != refwh->minor)
310 continue;
Li Zefanec229e82008-07-13 12:14:04 -0700311 if (refwh->access & (~whitem->access))
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700312 continue;
313 return 1;
314 }
315 return 0;
316}
317
318/*
319 * parent_has_perm:
320 * when adding a new allow rule to a device whitelist, the rule
321 * must be allowed in the parent device
322 */
Paul Menagef92523e2008-07-25 01:47:03 -0700323static int parent_has_perm(struct dev_cgroup *childcg,
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700324 struct dev_whitelist_item *wh)
325{
Paul Menagef92523e2008-07-25 01:47:03 -0700326 struct cgroup *pcg = childcg->css.cgroup->parent;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700327 struct dev_cgroup *parent;
328 int ret;
329
330 if (!pcg)
331 return 1;
332 parent = cgroup_to_devcgroup(pcg);
333 spin_lock(&parent->lock);
334 ret = may_access_whitelist(parent, wh);
335 spin_unlock(&parent->lock);
336 return ret;
337}
338
339/*
340 * Modify the whitelist using allow/deny rules.
341 * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD
342 * so we can give a container CAP_MKNOD to let it create devices but not
343 * modify the whitelist.
344 * It seems likely we'll want to add a CAP_CONTAINER capability to allow
345 * us to also grant CAP_SYS_ADMIN to containers without giving away the
346 * device whitelist controls, but for now we'll stick with CAP_SYS_ADMIN
347 *
348 * Taking rules away is always allowed (given CAP_SYS_ADMIN). Granting
349 * new access is only allowed if you're in the top-level cgroup, or your
350 * parent cgroup has the access you're asking for.
351 */
Paul Menagef92523e2008-07-25 01:47:03 -0700352static int devcgroup_update_access(struct dev_cgroup *devcgroup,
353 int filetype, const char *buffer)
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700354{
Paul Menagef92523e2008-07-25 01:47:03 -0700355 struct dev_cgroup *cur_devcgroup;
356 const char *b;
Li Zefan7759fc92008-07-25 01:47:08 -0700357 char *endp;
Li Zefanc012a542008-10-18 20:28:07 -0700358 int count;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700359 struct dev_whitelist_item wh;
360
361 if (!capable(CAP_SYS_ADMIN))
362 return -EPERM;
363
Paul Menagef92523e2008-07-25 01:47:03 -0700364 cur_devcgroup = task_devcgroup(current);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700365
366 memset(&wh, 0, sizeof(wh));
367 b = buffer;
368
369 switch (*b) {
370 case 'a':
371 wh.type = DEV_ALL;
372 wh.access = ACC_MASK;
Li Zefand823f6b2008-07-04 10:00:07 -0700373 wh.major = ~0;
374 wh.minor = ~0;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700375 goto handle;
376 case 'b':
377 wh.type = DEV_BLOCK;
378 break;
379 case 'c':
380 wh.type = DEV_CHAR;
381 break;
382 default:
Paul Menagef92523e2008-07-25 01:47:03 -0700383 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700384 }
385 b++;
Paul Menagef92523e2008-07-25 01:47:03 -0700386 if (!isspace(*b))
387 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700388 b++;
389 if (*b == '*') {
390 wh.major = ~0;
391 b++;
392 } else if (isdigit(*b)) {
Li Zefan7759fc92008-07-25 01:47:08 -0700393 wh.major = simple_strtoul(b, &endp, 10);
394 b = endp;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700395 } else {
Paul Menagef92523e2008-07-25 01:47:03 -0700396 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700397 }
Paul Menagef92523e2008-07-25 01:47:03 -0700398 if (*b != ':')
399 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700400 b++;
401
402 /* read minor */
403 if (*b == '*') {
404 wh.minor = ~0;
405 b++;
406 } else if (isdigit(*b)) {
Li Zefan7759fc92008-07-25 01:47:08 -0700407 wh.minor = simple_strtoul(b, &endp, 10);
408 b = endp;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700409 } else {
Paul Menagef92523e2008-07-25 01:47:03 -0700410 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700411 }
Paul Menagef92523e2008-07-25 01:47:03 -0700412 if (!isspace(*b))
413 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700414 for (b++, count = 0; count < 3; count++, b++) {
415 switch (*b) {
416 case 'r':
417 wh.access |= ACC_READ;
418 break;
419 case 'w':
420 wh.access |= ACC_WRITE;
421 break;
422 case 'm':
423 wh.access |= ACC_MKNOD;
424 break;
425 case '\n':
426 case '\0':
427 count = 3;
428 break;
429 default:
Paul Menagef92523e2008-07-25 01:47:03 -0700430 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700431 }
432 }
433
434handle:
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700435 switch (filetype) {
436 case DEVCG_ALLOW:
Paul Menagef92523e2008-07-25 01:47:03 -0700437 if (!parent_has_perm(devcgroup, &wh))
438 return -EPERM;
439 return dev_whitelist_add(devcgroup, &wh);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700440 case DEVCG_DENY:
441 dev_whitelist_rm(devcgroup, &wh);
442 break;
443 default:
Paul Menagef92523e2008-07-25 01:47:03 -0700444 return -EINVAL;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700445 }
Paul Menagef92523e2008-07-25 01:47:03 -0700446 return 0;
447}
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700448
Paul Menagef92523e2008-07-25 01:47:03 -0700449static int devcgroup_access_write(struct cgroup *cgrp, struct cftype *cft,
450 const char *buffer)
451{
452 int retval;
453 if (!cgroup_lock_live_group(cgrp))
454 return -ENODEV;
455 retval = devcgroup_update_access(cgroup_to_devcgroup(cgrp),
456 cft->private, buffer);
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700457 cgroup_unlock();
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700458 return retval;
459}
460
461static struct cftype dev_cgroup_files[] = {
462 {
463 .name = "allow",
Paul Menagef92523e2008-07-25 01:47:03 -0700464 .write_string = devcgroup_access_write,
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700465 .private = DEVCG_ALLOW,
466 },
467 {
468 .name = "deny",
Paul Menagef92523e2008-07-25 01:47:03 -0700469 .write_string = devcgroup_access_write,
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700470 .private = DEVCG_DENY,
471 },
Serge E. Hallyn29486df2008-04-29 01:00:14 -0700472 {
473 .name = "list",
474 .read_seq_string = devcgroup_seq_read,
475 .private = DEVCG_LIST,
476 },
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700477};
478
479static int devcgroup_populate(struct cgroup_subsys *ss,
480 struct cgroup *cgroup)
481{
482 return cgroup_add_files(cgroup, ss, dev_cgroup_files,
483 ARRAY_SIZE(dev_cgroup_files));
484}
485
486struct cgroup_subsys devices_subsys = {
487 .name = "devices",
488 .can_attach = devcgroup_can_attach,
489 .create = devcgroup_create,
490 .destroy = devcgroup_destroy,
491 .populate = devcgroup_populate,
492 .subsys_id = devices_subsys_id,
493};
494
495int devcgroup_inode_permission(struct inode *inode, int mask)
496{
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700497 struct dev_cgroup *dev_cgroup;
498 struct dev_whitelist_item *wh;
499
500 dev_t device = inode->i_rdev;
501 if (!device)
502 return 0;
503 if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode))
504 return 0;
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700505
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700506 rcu_read_lock();
Li Zefan36fd71d2008-09-02 14:35:52 -0700507
508 dev_cgroup = task_devcgroup(current);
509
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700510 list_for_each_entry_rcu(wh, &dev_cgroup->whitelist, list) {
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700511 if (wh->type & DEV_ALL)
512 goto acc_check;
513 if ((wh->type & DEV_BLOCK) && !S_ISBLK(inode->i_mode))
514 continue;
515 if ((wh->type & DEV_CHAR) && !S_ISCHR(inode->i_mode))
516 continue;
517 if (wh->major != ~0 && wh->major != imajor(inode))
518 continue;
519 if (wh->minor != ~0 && wh->minor != iminor(inode))
520 continue;
521acc_check:
522 if ((mask & MAY_WRITE) && !(wh->access & ACC_WRITE))
523 continue;
524 if ((mask & MAY_READ) && !(wh->access & ACC_READ))
525 continue;
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700526 rcu_read_unlock();
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700527 return 0;
528 }
Li Zefan36fd71d2008-09-02 14:35:52 -0700529
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700530 rcu_read_unlock();
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700531
532 return -EPERM;
533}
534
535int devcgroup_inode_mknod(int mode, dev_t dev)
536{
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700537 struct dev_cgroup *dev_cgroup;
538 struct dev_whitelist_item *wh;
539
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700540 rcu_read_lock();
Li Zefan36fd71d2008-09-02 14:35:52 -0700541
542 dev_cgroup = task_devcgroup(current);
543
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700544 list_for_each_entry(wh, &dev_cgroup->whitelist, list) {
545 if (wh->type & DEV_ALL)
546 goto acc_check;
547 if ((wh->type & DEV_BLOCK) && !S_ISBLK(mode))
548 continue;
549 if ((wh->type & DEV_CHAR) && !S_ISCHR(mode))
550 continue;
551 if (wh->major != ~0 && wh->major != MAJOR(dev))
552 continue;
553 if (wh->minor != ~0 && wh->minor != MINOR(dev))
554 continue;
555acc_check:
556 if (!(wh->access & ACC_MKNOD))
557 continue;
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700558 rcu_read_unlock();
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700559 return 0;
560 }
Li Zefan36fd71d2008-09-02 14:35:52 -0700561
Pavel Emelyanov4efd1a12008-07-25 01:47:07 -0700562 rcu_read_unlock();
Li Zefan36fd71d2008-09-02 14:35:52 -0700563
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700564 return -EPERM;
565}