Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * POSIX message queues filesystem for Linux. | |
3 | * | |
4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) | |
f66e928b | 5 | * Michal Wronski (michal.wronski@gmail.com) |
1da177e4 LT |
6 | * |
7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) | |
8 | * Lockless receive & send, fd based notify: | |
9 | * Manfred Spraul (manfred@colorfullife.com) | |
10 | * | |
20ca73bc GW |
11 | * Audit: George Wilson (ltcgcw@us.ibm.com) |
12 | * | |
1da177e4 LT |
13 | * This file is released under the GPL. |
14 | */ | |
15 | ||
c59ede7b | 16 | #include <linux/capability.h> |
1da177e4 LT |
17 | #include <linux/init.h> |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/file.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/namei.h> | |
22 | #include <linux/sysctl.h> | |
23 | #include <linux/poll.h> | |
24 | #include <linux/mqueue.h> | |
25 | #include <linux/msg.h> | |
26 | #include <linux/skbuff.h> | |
27 | #include <linux/netlink.h> | |
28 | #include <linux/syscalls.h> | |
20ca73bc | 29 | #include <linux/audit.h> |
7ed20e1a | 30 | #include <linux/signal.h> |
5f921ae9 | 31 | #include <linux/mutex.h> |
b488893a PE |
32 | #include <linux/nsproxy.h> |
33 | #include <linux/pid.h> | |
614b84cf | 34 | #include <linux/ipc_namespace.h> |
6b550f94 | 35 | #include <linux/user_namespace.h> |
5a0e3ad6 | 36 | #include <linux/slab.h> |
5f921ae9 | 37 | |
1da177e4 LT |
38 | #include <net/sock.h> |
39 | #include "util.h" | |
40 | ||
41 | #define MQUEUE_MAGIC 0x19800202 | |
42 | #define DIRENT_SIZE 20 | |
43 | #define FILENT_SIZE 80 | |
44 | ||
45 | #define SEND 0 | |
46 | #define RECV 1 | |
47 | ||
48 | #define STATE_NONE 0 | |
49 | #define STATE_PENDING 1 | |
50 | #define STATE_READY 2 | |
51 | ||
1da177e4 LT |
52 | struct ext_wait_queue { /* queue of sleeping tasks */ |
53 | struct task_struct *task; | |
54 | struct list_head list; | |
55 | struct msg_msg *msg; /* ptr of loaded message */ | |
56 | int state; /* one of STATE_* values */ | |
57 | }; | |
58 | ||
59 | struct mqueue_inode_info { | |
60 | spinlock_t lock; | |
61 | struct inode vfs_inode; | |
62 | wait_queue_head_t wait_q; | |
63 | ||
64 | struct msg_msg **messages; | |
65 | struct mq_attr attr; | |
66 | ||
67 | struct sigevent notify; | |
a03fcb73 | 68 | struct pid* notify_owner; |
6f9ac6d9 | 69 | struct user_namespace *notify_user_ns; |
338cec32 | 70 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
71 | struct sock *notify_sock; |
72 | struct sk_buff *notify_cookie; | |
73 | ||
74 | /* for tasks waiting for free space and messages, respectively */ | |
75 | struct ext_wait_queue e_wait_q[2]; | |
76 | ||
77 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
78 | }; | |
79 | ||
92e1d5be | 80 | static const struct inode_operations mqueue_dir_inode_operations; |
9a32144e | 81 | static const struct file_operations mqueue_file_operations; |
b87221de | 82 | static const struct super_operations mqueue_super_ops; |
1da177e4 LT |
83 | static void remove_notification(struct mqueue_inode_info *info); |
84 | ||
e18b890b | 85 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 LT |
86 | |
87 | static struct ctl_table_header * mq_sysctl_table; | |
88 | ||
89 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
90 | { | |
91 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
92 | } | |
93 | ||
7eafd7c7 SH |
94 | /* |
95 | * This routine should be called with the mq_lock held. | |
96 | */ | |
97 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
614b84cf | 98 | { |
7eafd7c7 | 99 | return get_ipc_ns(inode->i_sb->s_fs_info); |
614b84cf SH |
100 | } |
101 | ||
7eafd7c7 | 102 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
614b84cf | 103 | { |
7eafd7c7 SH |
104 | struct ipc_namespace *ns; |
105 | ||
106 | spin_lock(&mq_lock); | |
107 | ns = __get_ns_from_inode(inode); | |
108 | spin_unlock(&mq_lock); | |
109 | return ns; | |
614b84cf SH |
110 | } |
111 | ||
7eafd7c7 | 112 | static struct inode *mqueue_get_inode(struct super_block *sb, |
1b9d5ff7 | 113 | struct ipc_namespace *ipc_ns, umode_t mode, |
7eafd7c7 | 114 | struct mq_attr *attr) |
1da177e4 | 115 | { |
86a264ab | 116 | struct user_struct *u = current_user(); |
1da177e4 | 117 | struct inode *inode; |
d40dcdb0 | 118 | int ret = -ENOMEM; |
1da177e4 LT |
119 | |
120 | inode = new_inode(sb); | |
04715206 JS |
121 | if (!inode) |
122 | goto err; | |
123 | ||
124 | inode->i_ino = get_next_ino(); | |
125 | inode->i_mode = mode; | |
126 | inode->i_uid = current_fsuid(); | |
127 | inode->i_gid = current_fsgid(); | |
128 | inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; | |
129 | ||
130 | if (S_ISREG(mode)) { | |
131 | struct mqueue_inode_info *info; | |
04715206 JS |
132 | unsigned long mq_bytes, mq_msg_tblsz; |
133 | ||
134 | inode->i_fop = &mqueue_file_operations; | |
135 | inode->i_size = FILENT_SIZE; | |
136 | /* mqueue specific info */ | |
137 | info = MQUEUE_I(inode); | |
138 | spin_lock_init(&info->lock); | |
139 | init_waitqueue_head(&info->wait_q); | |
140 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
141 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
142 | info->notify_owner = NULL; | |
6f9ac6d9 | 143 | info->notify_user_ns = NULL; |
04715206 JS |
144 | info->qsize = 0; |
145 | info->user = NULL; /* set when all is ok */ | |
146 | memset(&info->attr, 0, sizeof(info->attr)); | |
147 | info->attr.mq_maxmsg = ipc_ns->mq_msg_max; | |
148 | info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; | |
149 | if (attr) { | |
150 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
151 | info->attr.mq_msgsize = attr->mq_msgsize; | |
152 | } | |
153 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
154 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
155 | if (!info->messages) | |
156 | goto out_inode; | |
157 | ||
158 | mq_bytes = (mq_msg_tblsz + | |
159 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
1da177e4 | 160 | |
04715206 JS |
161 | spin_lock(&mq_lock); |
162 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
2a4e64b8 | 163 | u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { |
04715206 JS |
164 | spin_unlock(&mq_lock); |
165 | /* mqueue_evict_inode() releases info->messages */ | |
d40dcdb0 | 166 | ret = -EMFILE; |
04715206 | 167 | goto out_inode; |
1da177e4 | 168 | } |
04715206 JS |
169 | u->mq_bytes += mq_bytes; |
170 | spin_unlock(&mq_lock); | |
171 | ||
172 | /* all is ok */ | |
173 | info->user = get_uid(u); | |
174 | } else if (S_ISDIR(mode)) { | |
175 | inc_nlink(inode); | |
176 | /* Some things misbehave if size == 0 on a directory */ | |
177 | inode->i_size = 2 * DIRENT_SIZE; | |
178 | inode->i_op = &mqueue_dir_inode_operations; | |
179 | inode->i_fop = &simple_dir_operations; | |
1da177e4 | 180 | } |
04715206 | 181 | |
1da177e4 LT |
182 | return inode; |
183 | out_inode: | |
1da177e4 | 184 | iput(inode); |
04715206 | 185 | err: |
d40dcdb0 | 186 | return ERR_PTR(ret); |
1da177e4 LT |
187 | } |
188 | ||
189 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
190 | { | |
191 | struct inode *inode; | |
7eafd7c7 | 192 | struct ipc_namespace *ns = data; |
1da177e4 LT |
193 | |
194 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
195 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
196 | sb->s_magic = MQUEUE_MAGIC; | |
197 | sb->s_op = &mqueue_super_ops; | |
198 | ||
48fde701 AV |
199 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
200 | if (IS_ERR(inode)) | |
201 | return PTR_ERR(inode); | |
1da177e4 | 202 | |
48fde701 AV |
203 | sb->s_root = d_make_root(inode); |
204 | if (!sb->s_root) | |
205 | return -ENOMEM; | |
206 | return 0; | |
1da177e4 LT |
207 | } |
208 | ||
ceefda69 | 209 | static struct dentry *mqueue_mount(struct file_system_type *fs_type, |
454e2398 | 210 | int flags, const char *dev_name, |
ceefda69 | 211 | void *data) |
1da177e4 | 212 | { |
7eafd7c7 SH |
213 | if (!(flags & MS_KERNMOUNT)) |
214 | data = current->nsproxy->ipc_ns; | |
ceefda69 | 215 | return mount_ns(fs_type, flags, data, mqueue_fill_super); |
1da177e4 LT |
216 | } |
217 | ||
51cc5068 | 218 | static void init_once(void *foo) |
1da177e4 LT |
219 | { |
220 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
221 | ||
a35afb83 | 222 | inode_init_once(&p->vfs_inode); |
1da177e4 LT |
223 | } |
224 | ||
225 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
226 | { | |
227 | struct mqueue_inode_info *ei; | |
228 | ||
e94b1766 | 229 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
230 | if (!ei) |
231 | return NULL; | |
232 | return &ei->vfs_inode; | |
233 | } | |
234 | ||
fa0d7e3d | 235 | static void mqueue_i_callback(struct rcu_head *head) |
1da177e4 | 236 | { |
fa0d7e3d | 237 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
238 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); |
239 | } | |
240 | ||
fa0d7e3d NP |
241 | static void mqueue_destroy_inode(struct inode *inode) |
242 | { | |
243 | call_rcu(&inode->i_rcu, mqueue_i_callback); | |
244 | } | |
245 | ||
6d8af64c | 246 | static void mqueue_evict_inode(struct inode *inode) |
1da177e4 LT |
247 | { |
248 | struct mqueue_inode_info *info; | |
249 | struct user_struct *user; | |
250 | unsigned long mq_bytes; | |
251 | int i; | |
7eafd7c7 | 252 | struct ipc_namespace *ipc_ns; |
1da177e4 | 253 | |
dbd5768f | 254 | clear_inode(inode); |
6d8af64c AV |
255 | |
256 | if (S_ISDIR(inode->i_mode)) | |
1da177e4 | 257 | return; |
6d8af64c | 258 | |
7eafd7c7 | 259 | ipc_ns = get_ns_from_inode(inode); |
1da177e4 LT |
260 | info = MQUEUE_I(inode); |
261 | spin_lock(&info->lock); | |
262 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
263 | free_msg(info->messages[i]); | |
264 | kfree(info->messages); | |
265 | spin_unlock(&info->lock); | |
266 | ||
8834cf79 AGR |
267 | /* Total amount of bytes accounted for the mqueue */ |
268 | mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *) | |
269 | + info->attr.mq_msgsize); | |
1da177e4 LT |
270 | user = info->user; |
271 | if (user) { | |
272 | spin_lock(&mq_lock); | |
273 | user->mq_bytes -= mq_bytes; | |
7eafd7c7 SH |
274 | /* |
275 | * get_ns_from_inode() ensures that the | |
276 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
277 | * to which we now hold a reference, or it is NULL. | |
278 | * We can't put it here under mq_lock, though. | |
279 | */ | |
280 | if (ipc_ns) | |
281 | ipc_ns->mq_queues_count--; | |
1da177e4 LT |
282 | spin_unlock(&mq_lock); |
283 | free_uid(user); | |
284 | } | |
7eafd7c7 SH |
285 | if (ipc_ns) |
286 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
287 | } |
288 | ||
289 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
4acdaf27 | 290 | umode_t mode, struct nameidata *nd) |
1da177e4 LT |
291 | { |
292 | struct inode *inode; | |
293 | struct mq_attr *attr = dentry->d_fsdata; | |
294 | int error; | |
7eafd7c7 | 295 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
296 | |
297 | spin_lock(&mq_lock); | |
7eafd7c7 SH |
298 | ipc_ns = __get_ns_from_inode(dir); |
299 | if (!ipc_ns) { | |
300 | error = -EACCES; | |
301 | goto out_unlock; | |
302 | } | |
614b84cf SH |
303 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
304 | !capable(CAP_SYS_RESOURCE)) { | |
1da177e4 | 305 | error = -ENOSPC; |
614b84cf | 306 | goto out_unlock; |
1da177e4 | 307 | } |
614b84cf | 308 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
309 | spin_unlock(&mq_lock); |
310 | ||
7eafd7c7 | 311 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
d40dcdb0 JS |
312 | if (IS_ERR(inode)) { |
313 | error = PTR_ERR(inode); | |
1da177e4 | 314 | spin_lock(&mq_lock); |
614b84cf SH |
315 | ipc_ns->mq_queues_count--; |
316 | goto out_unlock; | |
1da177e4 LT |
317 | } |
318 | ||
7eafd7c7 | 319 | put_ipc_ns(ipc_ns); |
1da177e4 LT |
320 | dir->i_size += DIRENT_SIZE; |
321 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
322 | ||
323 | d_instantiate(dentry, inode); | |
324 | dget(dentry); | |
325 | return 0; | |
614b84cf | 326 | out_unlock: |
1da177e4 | 327 | spin_unlock(&mq_lock); |
7eafd7c7 SH |
328 | if (ipc_ns) |
329 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
330 | return error; |
331 | } | |
332 | ||
333 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
334 | { | |
335 | struct inode *inode = dentry->d_inode; | |
336 | ||
337 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
338 | dir->i_size -= DIRENT_SIZE; | |
9a53c3a7 | 339 | drop_nlink(inode); |
1da177e4 LT |
340 | dput(dentry); |
341 | return 0; | |
342 | } | |
343 | ||
344 | /* | |
345 | * This is routine for system read from queue file. | |
346 | * To avoid mess with doing here some sort of mq_receive we allow | |
347 | * to read only queue size & notification info (the only values | |
348 | * that are interesting from user point of view and aren't accessible | |
349 | * through std routines) | |
350 | */ | |
351 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 352 | size_t count, loff_t *off) |
1da177e4 | 353 | { |
6d63079a | 354 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 | 355 | char buffer[FILENT_SIZE]; |
f1a43f93 | 356 | ssize_t ret; |
1da177e4 LT |
357 | |
358 | spin_lock(&info->lock); | |
359 | snprintf(buffer, sizeof(buffer), | |
360 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
361 | info->qsize, | |
362 | info->notify_owner ? info->notify.sigev_notify : 0, | |
363 | (info->notify_owner && | |
364 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
365 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 366 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
367 | spin_unlock(&info->lock); |
368 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 369 | |
f1a43f93 AM |
370 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
371 | strlen(buffer)); | |
372 | if (ret <= 0) | |
373 | return ret; | |
1da177e4 | 374 | |
6d63079a | 375 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
f1a43f93 | 376 | return ret; |
1da177e4 LT |
377 | } |
378 | ||
75e1fcc0 | 379 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 380 | { |
6d63079a | 381 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
382 | |
383 | spin_lock(&info->lock); | |
a03fcb73 | 384 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
385 | remove_notification(info); |
386 | ||
387 | spin_unlock(&info->lock); | |
388 | return 0; | |
389 | } | |
390 | ||
391 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
392 | { | |
6d63079a | 393 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
394 | int retval = 0; |
395 | ||
396 | poll_wait(filp, &info->wait_q, poll_tab); | |
397 | ||
398 | spin_lock(&info->lock); | |
399 | if (info->attr.mq_curmsgs) | |
400 | retval = POLLIN | POLLRDNORM; | |
401 | ||
402 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
403 | retval |= POLLOUT | POLLWRNORM; | |
404 | spin_unlock(&info->lock); | |
405 | ||
406 | return retval; | |
407 | } | |
408 | ||
409 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
410 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
411 | struct ext_wait_queue *ewp) | |
412 | { | |
413 | struct ext_wait_queue *walk; | |
414 | ||
415 | ewp->task = current; | |
416 | ||
417 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
418 | if (walk->task->static_prio <= current->static_prio) { | |
419 | list_add_tail(&ewp->list, &walk->list); | |
420 | return; | |
421 | } | |
422 | } | |
423 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
424 | } | |
425 | ||
426 | /* | |
427 | * Puts current task to sleep. Caller must hold queue lock. After return | |
428 | * lock isn't held. | |
429 | * sr: SEND or RECV | |
430 | */ | |
431 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
9ca7d8e6 | 432 | ktime_t *timeout, struct ext_wait_queue *ewp) |
1da177e4 LT |
433 | { |
434 | int retval; | |
435 | signed long time; | |
436 | ||
437 | wq_add(info, sr, ewp); | |
438 | ||
439 | for (;;) { | |
440 | set_current_state(TASK_INTERRUPTIBLE); | |
441 | ||
442 | spin_unlock(&info->lock); | |
32ea845d WG |
443 | time = schedule_hrtimeout_range_clock(timeout, 0, |
444 | HRTIMER_MODE_ABS, CLOCK_REALTIME); | |
1da177e4 LT |
445 | |
446 | while (ewp->state == STATE_PENDING) | |
447 | cpu_relax(); | |
448 | ||
449 | if (ewp->state == STATE_READY) { | |
450 | retval = 0; | |
451 | goto out; | |
452 | } | |
453 | spin_lock(&info->lock); | |
454 | if (ewp->state == STATE_READY) { | |
455 | retval = 0; | |
456 | goto out_unlock; | |
457 | } | |
458 | if (signal_pending(current)) { | |
459 | retval = -ERESTARTSYS; | |
460 | break; | |
461 | } | |
462 | if (time == 0) { | |
463 | retval = -ETIMEDOUT; | |
464 | break; | |
465 | } | |
466 | } | |
467 | list_del(&ewp->list); | |
468 | out_unlock: | |
469 | spin_unlock(&info->lock); | |
470 | out: | |
471 | return retval; | |
472 | } | |
473 | ||
474 | /* | |
475 | * Returns waiting task that should be serviced first or NULL if none exists | |
476 | */ | |
477 | static struct ext_wait_queue *wq_get_first_waiter( | |
478 | struct mqueue_inode_info *info, int sr) | |
479 | { | |
480 | struct list_head *ptr; | |
481 | ||
482 | ptr = info->e_wait_q[sr].list.prev; | |
483 | if (ptr == &info->e_wait_q[sr].list) | |
484 | return NULL; | |
485 | return list_entry(ptr, struct ext_wait_queue, list); | |
486 | } | |
487 | ||
488 | /* Auxiliary functions to manipulate messages' list */ | |
489 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
490 | { | |
491 | int k; | |
492 | ||
493 | k = info->attr.mq_curmsgs - 1; | |
494 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
495 | info->messages[k + 1] = info->messages[k]; | |
496 | k--; | |
497 | } | |
498 | info->attr.mq_curmsgs++; | |
499 | info->qsize += ptr->m_ts; | |
500 | info->messages[k + 1] = ptr; | |
501 | } | |
502 | ||
503 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
504 | { | |
505 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
506 | return info->messages[info->attr.mq_curmsgs]; | |
507 | } | |
508 | ||
509 | static inline void set_cookie(struct sk_buff *skb, char code) | |
510 | { | |
511 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
512 | } | |
513 | ||
514 | /* | |
515 | * The next function is only to split too long sys_mq_timedsend | |
516 | */ | |
517 | static void __do_notify(struct mqueue_inode_info *info) | |
518 | { | |
519 | /* notification | |
520 | * invoked when there is registered process and there isn't process | |
521 | * waiting synchronously for message AND state of queue changed from | |
522 | * empty to not empty. Here we are sure that no one is waiting | |
523 | * synchronously. */ | |
524 | if (info->notify_owner && | |
525 | info->attr.mq_curmsgs == 1) { | |
526 | struct siginfo sig_i; | |
527 | switch (info->notify.sigev_notify) { | |
528 | case SIGEV_NONE: | |
529 | break; | |
530 | case SIGEV_SIGNAL: | |
531 | /* sends signal */ | |
532 | ||
533 | sig_i.si_signo = info->notify.sigev_signo; | |
534 | sig_i.si_errno = 0; | |
535 | sig_i.si_code = SI_MESGQ; | |
536 | sig_i.si_value = info->notify.sigev_value; | |
6b550f94 SH |
537 | /* map current pid/uid into info->owner's namespaces */ |
538 | rcu_read_lock(); | |
a6684999 SB |
539 | sig_i.si_pid = task_tgid_nr_ns(current, |
540 | ns_of_pid(info->notify_owner)); | |
76b6db01 | 541 | sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); |
6b550f94 | 542 | rcu_read_unlock(); |
1da177e4 | 543 | |
a03fcb73 CLG |
544 | kill_pid_info(info->notify.sigev_signo, |
545 | &sig_i, info->notify_owner); | |
1da177e4 LT |
546 | break; |
547 | case SIGEV_THREAD: | |
548 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 549 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
550 | break; |
551 | } | |
552 | /* after notification unregisters process */ | |
a03fcb73 | 553 | put_pid(info->notify_owner); |
6f9ac6d9 | 554 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 555 | info->notify_owner = NULL; |
6f9ac6d9 | 556 | info->notify_user_ns = NULL; |
1da177e4 LT |
557 | } |
558 | wake_up(&info->wait_q); | |
559 | } | |
560 | ||
9ca7d8e6 CE |
561 | static int prepare_timeout(const struct timespec __user *u_abs_timeout, |
562 | ktime_t *expires, struct timespec *ts) | |
1da177e4 | 563 | { |
9ca7d8e6 CE |
564 | if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) |
565 | return -EFAULT; | |
566 | if (!timespec_valid(ts)) | |
567 | return -EINVAL; | |
1da177e4 | 568 | |
9ca7d8e6 CE |
569 | *expires = timespec_to_ktime(*ts); |
570 | return 0; | |
1da177e4 LT |
571 | } |
572 | ||
573 | static void remove_notification(struct mqueue_inode_info *info) | |
574 | { | |
a03fcb73 | 575 | if (info->notify_owner != NULL && |
1da177e4 LT |
576 | info->notify.sigev_notify == SIGEV_THREAD) { |
577 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 578 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 579 | } |
a03fcb73 | 580 | put_pid(info->notify_owner); |
6f9ac6d9 | 581 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 582 | info->notify_owner = NULL; |
6f9ac6d9 | 583 | info->notify_user_ns = NULL; |
1da177e4 LT |
584 | } |
585 | ||
614b84cf | 586 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4 LT |
587 | { |
588 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
589 | return 0; | |
590 | if (capable(CAP_SYS_RESOURCE)) { | |
591 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
592 | return 0; | |
593 | } else { | |
614b84cf SH |
594 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
595 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) | |
1da177e4 LT |
596 | return 0; |
597 | } | |
598 | /* check for overflow */ | |
599 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
600 | return 0; | |
8834cf79 AGR |
601 | if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize |
602 | + sizeof (struct msg_msg *))) < | |
1da177e4 LT |
603 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) |
604 | return 0; | |
605 | return 1; | |
606 | } | |
607 | ||
608 | /* | |
609 | * Invoked when creating a new queue via sys_mq_open | |
610 | */ | |
614b84cf | 611 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, |
4acdaf27 | 612 | struct dentry *dentry, int oflag, umode_t mode, |
614b84cf | 613 | struct mq_attr *attr) |
1da177e4 | 614 | { |
745ca247 | 615 | const struct cred *cred = current_cred(); |
4a3fd211 | 616 | struct file *result; |
1da177e4 LT |
617 | int ret; |
618 | ||
564f6993 | 619 | if (attr) { |
8d8ffefa AGR |
620 | if (!mq_attr_ok(ipc_ns, attr)) { |
621 | ret = -EINVAL; | |
7c7dce92 | 622 | goto out; |
8d8ffefa | 623 | } |
1da177e4 | 624 | /* store for use during create */ |
564f6993 | 625 | dentry->d_fsdata = attr; |
1da177e4 LT |
626 | } |
627 | ||
ce3b0f8d | 628 | mode &= ~current_umask(); |
614b84cf | 629 | ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
630 | if (ret) |
631 | goto out; | |
1da177e4 LT |
632 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
633 | dentry->d_fsdata = NULL; | |
634 | if (ret) | |
4a3fd211 DH |
635 | goto out_drop_write; |
636 | ||
614b84cf | 637 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211 DH |
638 | /* |
639 | * dentry_open() took a persistent mnt_want_write(), | |
640 | * so we can now drop this one. | |
641 | */ | |
614b84cf | 642 | mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
643 | return result; |
644 | ||
645 | out_drop_write: | |
614b84cf | 646 | mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce92 AV |
647 | out: |
648 | dput(dentry); | |
614b84cf | 649 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 650 | return ERR_PTR(ret); |
1da177e4 LT |
651 | } |
652 | ||
653 | /* Opens existing queue */ | |
614b84cf SH |
654 | static struct file *do_open(struct ipc_namespace *ipc_ns, |
655 | struct dentry *dentry, int oflag) | |
1da177e4 | 656 | { |
04db0dde | 657 | int ret; |
745ca247 DH |
658 | const struct cred *cred = current_cred(); |
659 | ||
660 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
661 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 662 | |
7c7dce92 | 663 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
04db0dde AGR |
664 | ret = -EINVAL; |
665 | goto err; | |
7c7dce92 | 666 | } |
1da177e4 | 667 | |
f419a2e3 | 668 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
04db0dde AGR |
669 | ret = -EACCES; |
670 | goto err; | |
7c7dce92 | 671 | } |
1da177e4 | 672 | |
614b84cf | 673 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
04db0dde AGR |
674 | |
675 | err: | |
676 | dput(dentry); | |
677 | mntput(ipc_ns->mq_mnt); | |
678 | return ERR_PTR(ret); | |
1da177e4 LT |
679 | } |
680 | ||
df0a4283 | 681 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, |
d5460c99 | 682 | struct mq_attr __user *, u_attr) |
1da177e4 LT |
683 | { |
684 | struct dentry *dentry; | |
685 | struct file *filp; | |
686 | char *name; | |
564f6993 | 687 | struct mq_attr attr; |
1da177e4 | 688 | int fd, error; |
7eafd7c7 | 689 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 | 690 | |
564f6993 AV |
691 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
692 | return -EFAULT; | |
693 | ||
694 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
20ca73bc | 695 | |
1da177e4 LT |
696 | if (IS_ERR(name = getname(u_name))) |
697 | return PTR_ERR(name); | |
698 | ||
269f2134 | 699 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
700 | if (fd < 0) |
701 | goto out_putname; | |
702 | ||
614b84cf SH |
703 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
704 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
1da177e4 LT |
705 | if (IS_ERR(dentry)) { |
706 | error = PTR_ERR(dentry); | |
4294a8ee | 707 | goto out_putfd; |
1da177e4 | 708 | } |
614b84cf | 709 | mntget(ipc_ns->mq_mnt); |
1da177e4 LT |
710 | |
711 | if (oflag & O_CREAT) { | |
712 | if (dentry->d_inode) { /* entry already exists */ | |
5a190ae6 | 713 | audit_inode(name, dentry); |
8d8ffefa AGR |
714 | if (oflag & O_EXCL) { |
715 | error = -EEXIST; | |
7c7dce92 | 716 | goto out; |
8d8ffefa | 717 | } |
614b84cf | 718 | filp = do_open(ipc_ns, dentry, oflag); |
1da177e4 | 719 | } else { |
614b84cf SH |
720 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, |
721 | dentry, oflag, mode, | |
564f6993 | 722 | u_attr ? &attr : NULL); |
1da177e4 | 723 | } |
7c7dce92 | 724 | } else { |
8d8ffefa AGR |
725 | if (!dentry->d_inode) { |
726 | error = -ENOENT; | |
7c7dce92 | 727 | goto out; |
8d8ffefa | 728 | } |
5a190ae6 | 729 | audit_inode(name, dentry); |
614b84cf | 730 | filp = do_open(ipc_ns, dentry, oflag); |
7c7dce92 | 731 | } |
1da177e4 LT |
732 | |
733 | if (IS_ERR(filp)) { | |
734 | error = PTR_ERR(filp); | |
735 | goto out_putfd; | |
736 | } | |
737 | ||
1da177e4 LT |
738 | fd_install(fd, filp); |
739 | goto out_upsem; | |
740 | ||
7c7dce92 AV |
741 | out: |
742 | dput(dentry); | |
614b84cf | 743 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 744 | out_putfd: |
1da177e4 | 745 | put_unused_fd(fd); |
1da177e4 LT |
746 | fd = error; |
747 | out_upsem: | |
614b84cf | 748 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
749 | out_putname: |
750 | putname(name); | |
751 | return fd; | |
752 | } | |
753 | ||
d5460c99 | 754 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
755 | { |
756 | int err; | |
757 | char *name; | |
758 | struct dentry *dentry; | |
759 | struct inode *inode = NULL; | |
7eafd7c7 | 760 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
761 | |
762 | name = getname(u_name); | |
763 | if (IS_ERR(name)) | |
764 | return PTR_ERR(name); | |
765 | ||
614b84cf | 766 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814 | 767 | I_MUTEX_PARENT); |
614b84cf | 768 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4 LT |
769 | if (IS_ERR(dentry)) { |
770 | err = PTR_ERR(dentry); | |
771 | goto out_unlock; | |
772 | } | |
773 | ||
774 | if (!dentry->d_inode) { | |
775 | err = -ENOENT; | |
776 | goto out_err; | |
777 | } | |
778 | ||
779 | inode = dentry->d_inode; | |
780 | if (inode) | |
7de9c6ee | 781 | ihold(inode); |
614b84cf | 782 | err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b DH |
783 | if (err) |
784 | goto out_err; | |
1da177e4 | 785 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf | 786 | mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4 LT |
787 | out_err: |
788 | dput(dentry); | |
789 | ||
790 | out_unlock: | |
614b84cf | 791 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
792 | putname(name); |
793 | if (inode) | |
794 | iput(inode); | |
795 | ||
796 | return err; | |
797 | } | |
798 | ||
799 | /* Pipelined send and receive functions. | |
800 | * | |
801 | * If a receiver finds no waiting message, then it registers itself in the | |
802 | * list of waiting receivers. A sender checks that list before adding the new | |
803 | * message into the message array. If there is a waiting receiver, then it | |
804 | * bypasses the message array and directly hands the message over to the | |
805 | * receiver. | |
806 | * The receiver accepts the message and returns without grabbing the queue | |
807 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
808 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 809 | * ipc/sem.c for more details. |
1da177e4 LT |
810 | * |
811 | * The same algorithm is used for senders. | |
812 | */ | |
813 | ||
814 | /* pipelined_send() - send a message directly to the task waiting in | |
815 | * sys_mq_timedreceive() (without inserting message into a queue). | |
816 | */ | |
817 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
818 | struct msg_msg *message, | |
819 | struct ext_wait_queue *receiver) | |
820 | { | |
821 | receiver->msg = message; | |
822 | list_del(&receiver->list); | |
823 | receiver->state = STATE_PENDING; | |
824 | wake_up_process(receiver->task); | |
d59dd462 | 825 | smp_wmb(); |
1da177e4 LT |
826 | receiver->state = STATE_READY; |
827 | } | |
828 | ||
829 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
830 | * gets its message and put to the queue (we have one free place for sure). */ | |
831 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
832 | { | |
833 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
834 | ||
835 | if (!sender) { | |
836 | /* for poll */ | |
837 | wake_up_interruptible(&info->wait_q); | |
838 | return; | |
839 | } | |
840 | msg_insert(sender->msg, info); | |
841 | list_del(&sender->list); | |
842 | sender->state = STATE_PENDING; | |
843 | wake_up_process(sender->task); | |
d59dd462 | 844 | smp_wmb(); |
1da177e4 LT |
845 | sender->state = STATE_READY; |
846 | } | |
847 | ||
c4ea37c2 HC |
848 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
849 | size_t, msg_len, unsigned int, msg_prio, | |
850 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
851 | { |
852 | struct file *filp; | |
853 | struct inode *inode; | |
854 | struct ext_wait_queue wait; | |
855 | struct ext_wait_queue *receiver; | |
856 | struct msg_msg *msg_ptr; | |
857 | struct mqueue_inode_info *info; | |
9ca7d8e6 CE |
858 | ktime_t expires, *timeout = NULL; |
859 | struct timespec ts; | |
1da177e4 LT |
860 | int ret; |
861 | ||
c32c8af4 | 862 | if (u_abs_timeout) { |
9ca7d8e6 CE |
863 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
864 | if (res) | |
865 | return res; | |
866 | timeout = &expires; | |
c32c8af4 | 867 | } |
20ca73bc | 868 | |
1da177e4 LT |
869 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
870 | return -EINVAL; | |
871 | ||
9ca7d8e6 | 872 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); |
1da177e4 | 873 | |
1da177e4 | 874 | filp = fget(mqdes); |
8d8ffefa AGR |
875 | if (unlikely(!filp)) { |
876 | ret = -EBADF; | |
1da177e4 | 877 | goto out; |
8d8ffefa | 878 | } |
1da177e4 | 879 | |
6d63079a | 880 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
881 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
882 | ret = -EBADF; | |
1da177e4 | 883 | goto out_fput; |
8d8ffefa | 884 | } |
1da177e4 | 885 | info = MQUEUE_I(inode); |
5a190ae6 | 886 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 887 | |
8d8ffefa AGR |
888 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) { |
889 | ret = -EBADF; | |
1da177e4 | 890 | goto out_fput; |
8d8ffefa | 891 | } |
1da177e4 LT |
892 | |
893 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
894 | ret = -EMSGSIZE; | |
895 | goto out_fput; | |
896 | } | |
897 | ||
898 | /* First try to allocate memory, before doing anything with | |
899 | * existing queues. */ | |
900 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
901 | if (IS_ERR(msg_ptr)) { | |
902 | ret = PTR_ERR(msg_ptr); | |
903 | goto out_fput; | |
904 | } | |
905 | msg_ptr->m_ts = msg_len; | |
906 | msg_ptr->m_type = msg_prio; | |
907 | ||
908 | spin_lock(&info->lock); | |
909 | ||
910 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
911 | if (filp->f_flags & O_NONBLOCK) { | |
912 | spin_unlock(&info->lock); | |
913 | ret = -EAGAIN; | |
1da177e4 LT |
914 | } else { |
915 | wait.task = current; | |
916 | wait.msg = (void *) msg_ptr; | |
917 | wait.state = STATE_NONE; | |
918 | ret = wq_sleep(info, SEND, timeout, &wait); | |
919 | } | |
920 | if (ret < 0) | |
921 | free_msg(msg_ptr); | |
922 | } else { | |
923 | receiver = wq_get_first_waiter(info, RECV); | |
924 | if (receiver) { | |
925 | pipelined_send(info, msg_ptr, receiver); | |
926 | } else { | |
927 | /* adds message to the queue */ | |
928 | msg_insert(msg_ptr, info); | |
929 | __do_notify(info); | |
930 | } | |
931 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
932 | CURRENT_TIME; | |
933 | spin_unlock(&info->lock); | |
934 | ret = 0; | |
935 | } | |
936 | out_fput: | |
937 | fput(filp); | |
938 | out: | |
939 | return ret; | |
940 | } | |
941 | ||
c4ea37c2 HC |
942 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
943 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
944 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 | 945 | { |
1da177e4 LT |
946 | ssize_t ret; |
947 | struct msg_msg *msg_ptr; | |
948 | struct file *filp; | |
949 | struct inode *inode; | |
950 | struct mqueue_inode_info *info; | |
951 | struct ext_wait_queue wait; | |
9ca7d8e6 CE |
952 | ktime_t expires, *timeout = NULL; |
953 | struct timespec ts; | |
1da177e4 | 954 | |
c32c8af4 | 955 | if (u_abs_timeout) { |
9ca7d8e6 CE |
956 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
957 | if (res) | |
958 | return res; | |
959 | timeout = &expires; | |
c32c8af4 | 960 | } |
20ca73bc | 961 | |
9ca7d8e6 | 962 | audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); |
1da177e4 | 963 | |
1da177e4 | 964 | filp = fget(mqdes); |
8d8ffefa AGR |
965 | if (unlikely(!filp)) { |
966 | ret = -EBADF; | |
1da177e4 | 967 | goto out; |
8d8ffefa | 968 | } |
1da177e4 | 969 | |
6d63079a | 970 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
971 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
972 | ret = -EBADF; | |
1da177e4 | 973 | goto out_fput; |
8d8ffefa | 974 | } |
1da177e4 | 975 | info = MQUEUE_I(inode); |
5a190ae6 | 976 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 977 | |
8d8ffefa AGR |
978 | if (unlikely(!(filp->f_mode & FMODE_READ))) { |
979 | ret = -EBADF; | |
1da177e4 | 980 | goto out_fput; |
8d8ffefa | 981 | } |
1da177e4 LT |
982 | |
983 | /* checks if buffer is big enough */ | |
984 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
985 | ret = -EMSGSIZE; | |
986 | goto out_fput; | |
987 | } | |
988 | ||
989 | spin_lock(&info->lock); | |
990 | if (info->attr.mq_curmsgs == 0) { | |
991 | if (filp->f_flags & O_NONBLOCK) { | |
992 | spin_unlock(&info->lock); | |
993 | ret = -EAGAIN; | |
1da177e4 LT |
994 | } else { |
995 | wait.task = current; | |
996 | wait.state = STATE_NONE; | |
997 | ret = wq_sleep(info, RECV, timeout, &wait); | |
998 | msg_ptr = wait.msg; | |
999 | } | |
1000 | } else { | |
1001 | msg_ptr = msg_get(info); | |
1002 | ||
1003 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
1004 | CURRENT_TIME; | |
1005 | ||
1006 | /* There is now free space in queue. */ | |
1007 | pipelined_receive(info); | |
1008 | spin_unlock(&info->lock); | |
1009 | ret = 0; | |
1010 | } | |
1011 | if (ret == 0) { | |
1012 | ret = msg_ptr->m_ts; | |
1013 | ||
1014 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1015 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1016 | ret = -EFAULT; | |
1017 | } | |
1018 | free_msg(msg_ptr); | |
1019 | } | |
1020 | out_fput: | |
1021 | fput(filp); | |
1022 | out: | |
1023 | return ret; | |
1024 | } | |
1025 | ||
1026 | /* | |
1027 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1028 | * and he isn't currently owner of notification, will be silently discarded. | |
1029 | * It isn't explicitly defined in the POSIX. | |
1030 | */ | |
c4ea37c2 HC |
1031 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1032 | const struct sigevent __user *, u_notification) | |
1da177e4 LT |
1033 | { |
1034 | int ret; | |
1035 | struct file *filp; | |
1036 | struct sock *sock; | |
1037 | struct inode *inode; | |
1038 | struct sigevent notification; | |
1039 | struct mqueue_inode_info *info; | |
1040 | struct sk_buff *nc; | |
1041 | ||
20114f71 | 1042 | if (u_notification) { |
1da177e4 LT |
1043 | if (copy_from_user(¬ification, u_notification, |
1044 | sizeof(struct sigevent))) | |
1045 | return -EFAULT; | |
20114f71 AV |
1046 | } |
1047 | ||
1048 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1da177e4 | 1049 | |
20114f71 AV |
1050 | nc = NULL; |
1051 | sock = NULL; | |
1052 | if (u_notification != NULL) { | |
1da177e4 LT |
1053 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1054 | notification.sigev_notify != SIGEV_SIGNAL && | |
1055 | notification.sigev_notify != SIGEV_THREAD)) | |
1056 | return -EINVAL; | |
1057 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1058 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1059 | return -EINVAL; |
1060 | } | |
1061 | if (notification.sigev_notify == SIGEV_THREAD) { | |
c3d8d1e3 PM |
1062 | long timeo; |
1063 | ||
1da177e4 LT |
1064 | /* create the notify skb */ |
1065 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
8d8ffefa AGR |
1066 | if (!nc) { |
1067 | ret = -ENOMEM; | |
1da177e4 | 1068 | goto out; |
8d8ffefa | 1069 | } |
1da177e4 LT |
1070 | if (copy_from_user(nc->data, |
1071 | notification.sigev_value.sival_ptr, | |
1072 | NOTIFY_COOKIE_LEN)) { | |
8d8ffefa | 1073 | ret = -EFAULT; |
1da177e4 LT |
1074 | goto out; |
1075 | } | |
1076 | ||
1077 | /* TODO: add a header? */ | |
1078 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1079 | /* and attach it to the socket */ | |
1080 | retry: | |
1081 | filp = fget(notification.sigev_signo); | |
8d8ffefa AGR |
1082 | if (!filp) { |
1083 | ret = -EBADF; | |
1da177e4 | 1084 | goto out; |
8d8ffefa | 1085 | } |
1da177e4 LT |
1086 | sock = netlink_getsockbyfilp(filp); |
1087 | fput(filp); | |
1088 | if (IS_ERR(sock)) { | |
1089 | ret = PTR_ERR(sock); | |
1090 | sock = NULL; | |
1091 | goto out; | |
1092 | } | |
1093 | ||
c3d8d1e3 | 1094 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1095 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4 | 1096 | if (ret == 1) |
8d8ffefa | 1097 | goto retry; |
1da177e4 LT |
1098 | if (ret) { |
1099 | sock = NULL; | |
1100 | nc = NULL; | |
1101 | goto out; | |
1102 | } | |
1103 | } | |
1104 | } | |
1105 | ||
1da177e4 | 1106 | filp = fget(mqdes); |
8d8ffefa AGR |
1107 | if (!filp) { |
1108 | ret = -EBADF; | |
1da177e4 | 1109 | goto out; |
8d8ffefa | 1110 | } |
1da177e4 | 1111 | |
6d63079a | 1112 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1113 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1114 | ret = -EBADF; | |
1da177e4 | 1115 | goto out_fput; |
8d8ffefa | 1116 | } |
1da177e4 LT |
1117 | info = MQUEUE_I(inode); |
1118 | ||
1119 | ret = 0; | |
1120 | spin_lock(&info->lock); | |
1121 | if (u_notification == NULL) { | |
a03fcb73 | 1122 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 LT |
1123 | remove_notification(info); |
1124 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1125 | } | |
a03fcb73 | 1126 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1127 | ret = -EBUSY; |
1128 | } else { | |
1129 | switch (notification.sigev_notify) { | |
1130 | case SIGEV_NONE: | |
1131 | info->notify.sigev_notify = SIGEV_NONE; | |
1132 | break; | |
1133 | case SIGEV_THREAD: | |
1134 | info->notify_sock = sock; | |
1135 | info->notify_cookie = nc; | |
1136 | sock = NULL; | |
1137 | nc = NULL; | |
1138 | info->notify.sigev_notify = SIGEV_THREAD; | |
1139 | break; | |
1140 | case SIGEV_SIGNAL: | |
1141 | info->notify.sigev_signo = notification.sigev_signo; | |
1142 | info->notify.sigev_value = notification.sigev_value; | |
1143 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1144 | break; | |
1145 | } | |
a03fcb73 CLG |
1146 | |
1147 | info->notify_owner = get_pid(task_tgid(current)); | |
6f9ac6d9 | 1148 | info->notify_user_ns = get_user_ns(current_user_ns()); |
1da177e4 LT |
1149 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1150 | } | |
1151 | spin_unlock(&info->lock); | |
1152 | out_fput: | |
1153 | fput(filp); | |
1154 | out: | |
1155 | if (sock) { | |
1156 | netlink_detachskb(sock, nc); | |
1157 | } else if (nc) { | |
1158 | dev_kfree_skb(nc); | |
1159 | } | |
1160 | return ret; | |
1161 | } | |
1162 | ||
c4ea37c2 HC |
1163 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1164 | const struct mq_attr __user *, u_mqstat, | |
1165 | struct mq_attr __user *, u_omqstat) | |
1da177e4 LT |
1166 | { |
1167 | int ret; | |
1168 | struct mq_attr mqstat, omqstat; | |
1169 | struct file *filp; | |
1170 | struct inode *inode; | |
1171 | struct mqueue_inode_info *info; | |
1172 | ||
1173 | if (u_mqstat != NULL) { | |
1174 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1175 | return -EFAULT; | |
1176 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1177 | return -EINVAL; | |
1178 | } | |
1179 | ||
1da177e4 | 1180 | filp = fget(mqdes); |
8d8ffefa AGR |
1181 | if (!filp) { |
1182 | ret = -EBADF; | |
1da177e4 | 1183 | goto out; |
8d8ffefa | 1184 | } |
1da177e4 | 1185 | |
6d63079a | 1186 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1187 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1188 | ret = -EBADF; | |
1da177e4 | 1189 | goto out_fput; |
8d8ffefa | 1190 | } |
1da177e4 LT |
1191 | info = MQUEUE_I(inode); |
1192 | ||
1193 | spin_lock(&info->lock); | |
1194 | ||
1195 | omqstat = info->attr; | |
1196 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1197 | if (u_mqstat) { | |
7392906e | 1198 | audit_mq_getsetattr(mqdes, &mqstat); |
db1dd4d3 | 1199 | spin_lock(&filp->f_lock); |
1da177e4 LT |
1200 | if (mqstat.mq_flags & O_NONBLOCK) |
1201 | filp->f_flags |= O_NONBLOCK; | |
1202 | else | |
1203 | filp->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 1204 | spin_unlock(&filp->f_lock); |
1da177e4 LT |
1205 | |
1206 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1207 | } | |
1208 | ||
1209 | spin_unlock(&info->lock); | |
1210 | ||
1211 | ret = 0; | |
1212 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1213 | sizeof(struct mq_attr))) | |
1214 | ret = -EFAULT; | |
1215 | ||
1216 | out_fput: | |
1217 | fput(filp); | |
1218 | out: | |
1219 | return ret; | |
1220 | } | |
1221 | ||
92e1d5be | 1222 | static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4 LT |
1223 | .lookup = simple_lookup, |
1224 | .create = mqueue_create, | |
1225 | .unlink = mqueue_unlink, | |
1226 | }; | |
1227 | ||
9a32144e | 1228 | static const struct file_operations mqueue_file_operations = { |
1da177e4 LT |
1229 | .flush = mqueue_flush_file, |
1230 | .poll = mqueue_poll_file, | |
1231 | .read = mqueue_read_file, | |
6038f373 | 1232 | .llseek = default_llseek, |
1da177e4 LT |
1233 | }; |
1234 | ||
b87221de | 1235 | static const struct super_operations mqueue_super_ops = { |
1da177e4 LT |
1236 | .alloc_inode = mqueue_alloc_inode, |
1237 | .destroy_inode = mqueue_destroy_inode, | |
6d8af64c | 1238 | .evict_inode = mqueue_evict_inode, |
1da177e4 | 1239 | .statfs = simple_statfs, |
1da177e4 LT |
1240 | }; |
1241 | ||
1242 | static struct file_system_type mqueue_fs_type = { | |
1243 | .name = "mqueue", | |
ceefda69 | 1244 | .mount = mqueue_mount, |
1da177e4 LT |
1245 | .kill_sb = kill_litter_super, |
1246 | }; | |
1247 | ||
7eafd7c7 SH |
1248 | int mq_init_ns(struct ipc_namespace *ns) |
1249 | { | |
1250 | ns->mq_queues_count = 0; | |
1251 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
1252 | ns->mq_msg_max = DFLT_MSGMAX; | |
1253 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
1254 | ||
1255 | ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); | |
1256 | if (IS_ERR(ns->mq_mnt)) { | |
1257 | int err = PTR_ERR(ns->mq_mnt); | |
1258 | ns->mq_mnt = NULL; | |
1259 | return err; | |
1260 | } | |
1261 | return 0; | |
1262 | } | |
1263 | ||
1264 | void mq_clear_sbinfo(struct ipc_namespace *ns) | |
1265 | { | |
1266 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; | |
1267 | } | |
1268 | ||
1269 | void mq_put_mnt(struct ipc_namespace *ns) | |
1270 | { | |
6f686574 | 1271 | kern_unmount(ns->mq_mnt); |
7eafd7c7 SH |
1272 | } |
1273 | ||
1da177e4 LT |
1274 | static int __init init_mqueue_fs(void) |
1275 | { | |
1276 | int error; | |
1277 | ||
1278 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1279 | sizeof(struct mqueue_inode_info), 0, | |
20c2df83 | 1280 | SLAB_HWCACHE_ALIGN, init_once); |
1da177e4 LT |
1281 | if (mqueue_inode_cachep == NULL) |
1282 | return -ENOMEM; | |
1283 | ||
2329e392 | 1284 | /* ignore failures - they are not fatal */ |
bdc8e5f8 | 1285 | mq_sysctl_table = mq_register_sysctl_table(); |
1da177e4 LT |
1286 | |
1287 | error = register_filesystem(&mqueue_fs_type); | |
1288 | if (error) | |
1289 | goto out_sysctl; | |
1290 | ||
7eafd7c7 SH |
1291 | spin_lock_init(&mq_lock); |
1292 | ||
6f686574 AV |
1293 | error = mq_init_ns(&init_ipc_ns); |
1294 | if (error) | |
1da177e4 | 1295 | goto out_filesystem; |
1da177e4 | 1296 | |
1da177e4 LT |
1297 | return 0; |
1298 | ||
1299 | out_filesystem: | |
1300 | unregister_filesystem(&mqueue_fs_type); | |
1301 | out_sysctl: | |
1302 | if (mq_sysctl_table) | |
1303 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1304 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1305 | return error; |
1306 | } | |
1307 | ||
1308 | __initcall(init_mqueue_fs); |