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Commit | Line | Data |
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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> |
5f921ae9 | 35 | |
1da177e4 LT |
36 | #include <net/sock.h> |
37 | #include "util.h" | |
38 | ||
39 | #define MQUEUE_MAGIC 0x19800202 | |
40 | #define DIRENT_SIZE 20 | |
41 | #define FILENT_SIZE 80 | |
42 | ||
43 | #define SEND 0 | |
44 | #define RECV 1 | |
45 | ||
46 | #define STATE_NONE 0 | |
47 | #define STATE_PENDING 1 | |
48 | #define STATE_READY 2 | |
49 | ||
b231cca4 JK |
50 | /* |
51 | * Define the ranges various user-specified maximum values can | |
52 | * be set to. | |
53 | */ | |
54 | #define MIN_MSGMAX 1 /* min value for msg_max */ | |
55 | #define MAX_MSGMAX HARD_MSGMAX /* max value for msg_max */ | |
56 | #define MIN_MSGSIZEMAX 128 /* min value for msgsize_max */ | |
57 | #define MAX_MSGSIZEMAX (8192*128) /* max value for msgsize_max */ | |
1da177e4 LT |
58 | |
59 | struct ext_wait_queue { /* queue of sleeping tasks */ | |
60 | struct task_struct *task; | |
61 | struct list_head list; | |
62 | struct msg_msg *msg; /* ptr of loaded message */ | |
63 | int state; /* one of STATE_* values */ | |
64 | }; | |
65 | ||
66 | struct mqueue_inode_info { | |
67 | spinlock_t lock; | |
68 | struct inode vfs_inode; | |
69 | wait_queue_head_t wait_q; | |
70 | ||
71 | struct msg_msg **messages; | |
72 | struct mq_attr attr; | |
73 | ||
74 | struct sigevent notify; | |
a03fcb73 | 75 | struct pid* notify_owner; |
338cec32 | 76 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
77 | struct sock *notify_sock; |
78 | struct sk_buff *notify_cookie; | |
79 | ||
80 | /* for tasks waiting for free space and messages, respectively */ | |
81 | struct ext_wait_queue e_wait_q[2]; | |
82 | ||
83 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
84 | }; | |
85 | ||
92e1d5be | 86 | static const struct inode_operations mqueue_dir_inode_operations; |
9a32144e | 87 | static const struct file_operations mqueue_file_operations; |
1da177e4 LT |
88 | static struct super_operations mqueue_super_ops; |
89 | static void remove_notification(struct mqueue_inode_info *info); | |
90 | ||
e18b890b | 91 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 LT |
92 | |
93 | static struct ctl_table_header * mq_sysctl_table; | |
94 | ||
95 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
96 | { | |
97 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
98 | } | |
99 | ||
7eafd7c7 SH |
100 | /* |
101 | * This routine should be called with the mq_lock held. | |
102 | */ | |
103 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
614b84cf | 104 | { |
7eafd7c7 | 105 | return get_ipc_ns(inode->i_sb->s_fs_info); |
614b84cf SH |
106 | } |
107 | ||
7eafd7c7 | 108 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
614b84cf | 109 | { |
7eafd7c7 SH |
110 | struct ipc_namespace *ns; |
111 | ||
112 | spin_lock(&mq_lock); | |
113 | ns = __get_ns_from_inode(inode); | |
114 | spin_unlock(&mq_lock); | |
115 | return ns; | |
614b84cf SH |
116 | } |
117 | ||
7eafd7c7 SH |
118 | static struct inode *mqueue_get_inode(struct super_block *sb, |
119 | struct ipc_namespace *ipc_ns, int mode, | |
120 | struct mq_attr *attr) | |
1da177e4 | 121 | { |
86a264ab | 122 | struct user_struct *u = current_user(); |
1da177e4 LT |
123 | struct inode *inode; |
124 | ||
125 | inode = new_inode(sb); | |
126 | if (inode) { | |
127 | inode->i_mode = mode; | |
414c0708 DH |
128 | inode->i_uid = current_fsuid(); |
129 | inode->i_gid = current_fsgid(); | |
1da177e4 LT |
130 | inode->i_mtime = inode->i_ctime = inode->i_atime = |
131 | CURRENT_TIME; | |
132 | ||
133 | if (S_ISREG(mode)) { | |
134 | struct mqueue_inode_info *info; | |
135 | struct task_struct *p = current; | |
1da177e4 LT |
136 | unsigned long mq_bytes, mq_msg_tblsz; |
137 | ||
138 | inode->i_fop = &mqueue_file_operations; | |
139 | inode->i_size = FILENT_SIZE; | |
140 | /* mqueue specific info */ | |
141 | info = MQUEUE_I(inode); | |
142 | spin_lock_init(&info->lock); | |
143 | init_waitqueue_head(&info->wait_q); | |
144 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
145 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
146 | info->messages = NULL; | |
a03fcb73 | 147 | info->notify_owner = NULL; |
1da177e4 LT |
148 | info->qsize = 0; |
149 | info->user = NULL; /* set when all is ok */ | |
150 | memset(&info->attr, 0, sizeof(info->attr)); | |
614b84cf SH |
151 | info->attr.mq_maxmsg = ipc_ns->mq_msg_max; |
152 | info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; | |
1da177e4 LT |
153 | if (attr) { |
154 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
155 | info->attr.mq_msgsize = attr->mq_msgsize; | |
156 | } | |
157 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
158 | mq_bytes = (mq_msg_tblsz + | |
159 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
160 | ||
161 | spin_lock(&mq_lock); | |
162 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
163 | u->mq_bytes + mq_bytes > | |
164 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
165 | spin_unlock(&mq_lock); | |
166 | goto out_inode; | |
167 | } | |
168 | u->mq_bytes += mq_bytes; | |
169 | spin_unlock(&mq_lock); | |
170 | ||
171 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
172 | if (!info->messages) { | |
173 | spin_lock(&mq_lock); | |
174 | u->mq_bytes -= mq_bytes; | |
175 | spin_unlock(&mq_lock); | |
176 | goto out_inode; | |
177 | } | |
178 | /* all is ok */ | |
179 | info->user = get_uid(u); | |
180 | } else if (S_ISDIR(mode)) { | |
d8c76e6f | 181 | inc_nlink(inode); |
1da177e4 LT |
182 | /* Some things misbehave if size == 0 on a directory */ |
183 | inode->i_size = 2 * DIRENT_SIZE; | |
184 | inode->i_op = &mqueue_dir_inode_operations; | |
185 | inode->i_fop = &simple_dir_operations; | |
186 | } | |
187 | } | |
188 | return inode; | |
189 | out_inode: | |
190 | make_bad_inode(inode); | |
191 | iput(inode); | |
192 | return NULL; | |
193 | } | |
194 | ||
195 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
196 | { | |
197 | struct inode *inode; | |
7eafd7c7 SH |
198 | struct ipc_namespace *ns = data; |
199 | int error = 0; | |
1da177e4 LT |
200 | |
201 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
202 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
203 | sb->s_magic = MQUEUE_MAGIC; | |
204 | sb->s_op = &mqueue_super_ops; | |
205 | ||
7eafd7c7 SH |
206 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, |
207 | NULL); | |
208 | if (!inode) { | |
209 | error = -ENOMEM; | |
210 | goto out; | |
211 | } | |
1da177e4 LT |
212 | |
213 | sb->s_root = d_alloc_root(inode); | |
214 | if (!sb->s_root) { | |
215 | iput(inode); | |
7eafd7c7 | 216 | error = -ENOMEM; |
1da177e4 LT |
217 | } |
218 | ||
7eafd7c7 SH |
219 | out: |
220 | return error; | |
1da177e4 LT |
221 | } |
222 | ||
454e2398 DH |
223 | static int mqueue_get_sb(struct file_system_type *fs_type, |
224 | int flags, const char *dev_name, | |
225 | void *data, struct vfsmount *mnt) | |
1da177e4 | 226 | { |
7eafd7c7 SH |
227 | if (!(flags & MS_KERNMOUNT)) |
228 | data = current->nsproxy->ipc_ns; | |
229 | return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt); | |
1da177e4 LT |
230 | } |
231 | ||
51cc5068 | 232 | static void init_once(void *foo) |
1da177e4 LT |
233 | { |
234 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
235 | ||
a35afb83 | 236 | inode_init_once(&p->vfs_inode); |
1da177e4 LT |
237 | } |
238 | ||
239 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
240 | { | |
241 | struct mqueue_inode_info *ei; | |
242 | ||
e94b1766 | 243 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
244 | if (!ei) |
245 | return NULL; | |
246 | return &ei->vfs_inode; | |
247 | } | |
248 | ||
249 | static void mqueue_destroy_inode(struct inode *inode) | |
250 | { | |
251 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
252 | } | |
253 | ||
254 | static void mqueue_delete_inode(struct inode *inode) | |
255 | { | |
256 | struct mqueue_inode_info *info; | |
257 | struct user_struct *user; | |
258 | unsigned long mq_bytes; | |
259 | int i; | |
7eafd7c7 | 260 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
261 | |
262 | if (S_ISDIR(inode->i_mode)) { | |
263 | clear_inode(inode); | |
264 | return; | |
265 | } | |
7eafd7c7 | 266 | ipc_ns = get_ns_from_inode(inode); |
1da177e4 LT |
267 | info = MQUEUE_I(inode); |
268 | spin_lock(&info->lock); | |
269 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
270 | free_msg(info->messages[i]); | |
271 | kfree(info->messages); | |
272 | spin_unlock(&info->lock); | |
273 | ||
274 | clear_inode(inode); | |
275 | ||
276 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + | |
277 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
278 | user = info->user; | |
279 | if (user) { | |
280 | spin_lock(&mq_lock); | |
281 | user->mq_bytes -= mq_bytes; | |
7eafd7c7 SH |
282 | /* |
283 | * get_ns_from_inode() ensures that the | |
284 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
285 | * to which we now hold a reference, or it is NULL. | |
286 | * We can't put it here under mq_lock, though. | |
287 | */ | |
288 | if (ipc_ns) | |
289 | ipc_ns->mq_queues_count--; | |
1da177e4 LT |
290 | spin_unlock(&mq_lock); |
291 | free_uid(user); | |
292 | } | |
7eafd7c7 SH |
293 | if (ipc_ns) |
294 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
295 | } |
296 | ||
297 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
298 | int mode, struct nameidata *nd) | |
299 | { | |
300 | struct inode *inode; | |
301 | struct mq_attr *attr = dentry->d_fsdata; | |
302 | int error; | |
7eafd7c7 | 303 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
304 | |
305 | spin_lock(&mq_lock); | |
7eafd7c7 SH |
306 | ipc_ns = __get_ns_from_inode(dir); |
307 | if (!ipc_ns) { | |
308 | error = -EACCES; | |
309 | goto out_unlock; | |
310 | } | |
614b84cf SH |
311 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
312 | !capable(CAP_SYS_RESOURCE)) { | |
1da177e4 | 313 | error = -ENOSPC; |
614b84cf | 314 | goto out_unlock; |
1da177e4 | 315 | } |
614b84cf | 316 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
317 | spin_unlock(&mq_lock); |
318 | ||
7eafd7c7 | 319 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
1da177e4 LT |
320 | if (!inode) { |
321 | error = -ENOMEM; | |
322 | spin_lock(&mq_lock); | |
614b84cf SH |
323 | ipc_ns->mq_queues_count--; |
324 | goto out_unlock; | |
1da177e4 LT |
325 | } |
326 | ||
7eafd7c7 | 327 | put_ipc_ns(ipc_ns); |
1da177e4 LT |
328 | dir->i_size += DIRENT_SIZE; |
329 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
330 | ||
331 | d_instantiate(dentry, inode); | |
332 | dget(dentry); | |
333 | return 0; | |
614b84cf | 334 | out_unlock: |
1da177e4 | 335 | spin_unlock(&mq_lock); |
7eafd7c7 SH |
336 | if (ipc_ns) |
337 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
338 | return error; |
339 | } | |
340 | ||
341 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
342 | { | |
343 | struct inode *inode = dentry->d_inode; | |
344 | ||
345 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
346 | dir->i_size -= DIRENT_SIZE; | |
9a53c3a7 | 347 | drop_nlink(inode); |
1da177e4 LT |
348 | dput(dentry); |
349 | return 0; | |
350 | } | |
351 | ||
352 | /* | |
353 | * This is routine for system read from queue file. | |
354 | * To avoid mess with doing here some sort of mq_receive we allow | |
355 | * to read only queue size & notification info (the only values | |
356 | * that are interesting from user point of view and aren't accessible | |
357 | * through std routines) | |
358 | */ | |
359 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 360 | size_t count, loff_t *off) |
1da177e4 | 361 | { |
6d63079a | 362 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 | 363 | char buffer[FILENT_SIZE]; |
f1a43f93 | 364 | ssize_t ret; |
1da177e4 LT |
365 | |
366 | spin_lock(&info->lock); | |
367 | snprintf(buffer, sizeof(buffer), | |
368 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
369 | info->qsize, | |
370 | info->notify_owner ? info->notify.sigev_notify : 0, | |
371 | (info->notify_owner && | |
372 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
373 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 374 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
375 | spin_unlock(&info->lock); |
376 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 377 | |
f1a43f93 AM |
378 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
379 | strlen(buffer)); | |
380 | if (ret <= 0) | |
381 | return ret; | |
1da177e4 | 382 | |
6d63079a | 383 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
f1a43f93 | 384 | return ret; |
1da177e4 LT |
385 | } |
386 | ||
75e1fcc0 | 387 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 388 | { |
6d63079a | 389 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
390 | |
391 | spin_lock(&info->lock); | |
a03fcb73 | 392 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
393 | remove_notification(info); |
394 | ||
395 | spin_unlock(&info->lock); | |
396 | return 0; | |
397 | } | |
398 | ||
399 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
400 | { | |
6d63079a | 401 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
402 | int retval = 0; |
403 | ||
404 | poll_wait(filp, &info->wait_q, poll_tab); | |
405 | ||
406 | spin_lock(&info->lock); | |
407 | if (info->attr.mq_curmsgs) | |
408 | retval = POLLIN | POLLRDNORM; | |
409 | ||
410 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
411 | retval |= POLLOUT | POLLWRNORM; | |
412 | spin_unlock(&info->lock); | |
413 | ||
414 | return retval; | |
415 | } | |
416 | ||
417 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
418 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
419 | struct ext_wait_queue *ewp) | |
420 | { | |
421 | struct ext_wait_queue *walk; | |
422 | ||
423 | ewp->task = current; | |
424 | ||
425 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
426 | if (walk->task->static_prio <= current->static_prio) { | |
427 | list_add_tail(&ewp->list, &walk->list); | |
428 | return; | |
429 | } | |
430 | } | |
431 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
432 | } | |
433 | ||
434 | /* | |
435 | * Puts current task to sleep. Caller must hold queue lock. After return | |
436 | * lock isn't held. | |
437 | * sr: SEND or RECV | |
438 | */ | |
439 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
440 | long timeout, struct ext_wait_queue *ewp) | |
441 | { | |
442 | int retval; | |
443 | signed long time; | |
444 | ||
445 | wq_add(info, sr, ewp); | |
446 | ||
447 | for (;;) { | |
448 | set_current_state(TASK_INTERRUPTIBLE); | |
449 | ||
450 | spin_unlock(&info->lock); | |
451 | time = schedule_timeout(timeout); | |
452 | ||
453 | while (ewp->state == STATE_PENDING) | |
454 | cpu_relax(); | |
455 | ||
456 | if (ewp->state == STATE_READY) { | |
457 | retval = 0; | |
458 | goto out; | |
459 | } | |
460 | spin_lock(&info->lock); | |
461 | if (ewp->state == STATE_READY) { | |
462 | retval = 0; | |
463 | goto out_unlock; | |
464 | } | |
465 | if (signal_pending(current)) { | |
466 | retval = -ERESTARTSYS; | |
467 | break; | |
468 | } | |
469 | if (time == 0) { | |
470 | retval = -ETIMEDOUT; | |
471 | break; | |
472 | } | |
473 | } | |
474 | list_del(&ewp->list); | |
475 | out_unlock: | |
476 | spin_unlock(&info->lock); | |
477 | out: | |
478 | return retval; | |
479 | } | |
480 | ||
481 | /* | |
482 | * Returns waiting task that should be serviced first or NULL if none exists | |
483 | */ | |
484 | static struct ext_wait_queue *wq_get_first_waiter( | |
485 | struct mqueue_inode_info *info, int sr) | |
486 | { | |
487 | struct list_head *ptr; | |
488 | ||
489 | ptr = info->e_wait_q[sr].list.prev; | |
490 | if (ptr == &info->e_wait_q[sr].list) | |
491 | return NULL; | |
492 | return list_entry(ptr, struct ext_wait_queue, list); | |
493 | } | |
494 | ||
495 | /* Auxiliary functions to manipulate messages' list */ | |
496 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
497 | { | |
498 | int k; | |
499 | ||
500 | k = info->attr.mq_curmsgs - 1; | |
501 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
502 | info->messages[k + 1] = info->messages[k]; | |
503 | k--; | |
504 | } | |
505 | info->attr.mq_curmsgs++; | |
506 | info->qsize += ptr->m_ts; | |
507 | info->messages[k + 1] = ptr; | |
508 | } | |
509 | ||
510 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
511 | { | |
512 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
513 | return info->messages[info->attr.mq_curmsgs]; | |
514 | } | |
515 | ||
516 | static inline void set_cookie(struct sk_buff *skb, char code) | |
517 | { | |
518 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
519 | } | |
520 | ||
521 | /* | |
522 | * The next function is only to split too long sys_mq_timedsend | |
523 | */ | |
524 | static void __do_notify(struct mqueue_inode_info *info) | |
525 | { | |
526 | /* notification | |
527 | * invoked when there is registered process and there isn't process | |
528 | * waiting synchronously for message AND state of queue changed from | |
529 | * empty to not empty. Here we are sure that no one is waiting | |
530 | * synchronously. */ | |
531 | if (info->notify_owner && | |
532 | info->attr.mq_curmsgs == 1) { | |
533 | struct siginfo sig_i; | |
534 | switch (info->notify.sigev_notify) { | |
535 | case SIGEV_NONE: | |
536 | break; | |
537 | case SIGEV_SIGNAL: | |
538 | /* sends signal */ | |
539 | ||
540 | sig_i.si_signo = info->notify.sigev_signo; | |
541 | sig_i.si_errno = 0; | |
542 | sig_i.si_code = SI_MESGQ; | |
543 | sig_i.si_value = info->notify.sigev_value; | |
a6684999 SB |
544 | sig_i.si_pid = task_tgid_nr_ns(current, |
545 | ns_of_pid(info->notify_owner)); | |
414c0708 | 546 | sig_i.si_uid = current_uid(); |
1da177e4 | 547 | |
a03fcb73 CLG |
548 | kill_pid_info(info->notify.sigev_signo, |
549 | &sig_i, info->notify_owner); | |
1da177e4 LT |
550 | break; |
551 | case SIGEV_THREAD: | |
552 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 553 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
554 | break; |
555 | } | |
556 | /* after notification unregisters process */ | |
a03fcb73 CLG |
557 | put_pid(info->notify_owner); |
558 | info->notify_owner = NULL; | |
1da177e4 LT |
559 | } |
560 | wake_up(&info->wait_q); | |
561 | } | |
562 | ||
c32c8af4 | 563 | static long prepare_timeout(struct timespec *p) |
1da177e4 | 564 | { |
c32c8af4 | 565 | struct timespec nowts; |
1da177e4 LT |
566 | long timeout; |
567 | ||
c32c8af4 AV |
568 | if (p) { |
569 | if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0 | |
570 | || p->tv_nsec >= NSEC_PER_SEC)) | |
1da177e4 LT |
571 | return -EINVAL; |
572 | nowts = CURRENT_TIME; | |
573 | /* first subtract as jiffies can't be too big */ | |
c32c8af4 AV |
574 | p->tv_sec -= nowts.tv_sec; |
575 | if (p->tv_nsec < nowts.tv_nsec) { | |
576 | p->tv_nsec += NSEC_PER_SEC; | |
577 | p->tv_sec--; | |
1da177e4 | 578 | } |
c32c8af4 AV |
579 | p->tv_nsec -= nowts.tv_nsec; |
580 | if (p->tv_sec < 0) | |
1da177e4 LT |
581 | return 0; |
582 | ||
c32c8af4 | 583 | timeout = timespec_to_jiffies(p) + 1; |
1da177e4 LT |
584 | } else |
585 | return MAX_SCHEDULE_TIMEOUT; | |
586 | ||
587 | return timeout; | |
588 | } | |
589 | ||
590 | static void remove_notification(struct mqueue_inode_info *info) | |
591 | { | |
a03fcb73 | 592 | if (info->notify_owner != NULL && |
1da177e4 LT |
593 | info->notify.sigev_notify == SIGEV_THREAD) { |
594 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 595 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 596 | } |
a03fcb73 CLG |
597 | put_pid(info->notify_owner); |
598 | info->notify_owner = NULL; | |
1da177e4 LT |
599 | } |
600 | ||
614b84cf | 601 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4 LT |
602 | { |
603 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
604 | return 0; | |
605 | if (capable(CAP_SYS_RESOURCE)) { | |
606 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
607 | return 0; | |
608 | } else { | |
614b84cf SH |
609 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
610 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) | |
1da177e4 LT |
611 | return 0; |
612 | } | |
613 | /* check for overflow */ | |
614 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
615 | return 0; | |
616 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
617 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
618 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
619 | return 0; | |
620 | return 1; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Invoked when creating a new queue via sys_mq_open | |
625 | */ | |
614b84cf SH |
626 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, |
627 | struct dentry *dentry, int oflag, mode_t mode, | |
628 | struct mq_attr *attr) | |
1da177e4 | 629 | { |
745ca247 | 630 | const struct cred *cred = current_cred(); |
4a3fd211 | 631 | struct file *result; |
1da177e4 LT |
632 | int ret; |
633 | ||
564f6993 | 634 | if (attr) { |
7c7dce92 | 635 | ret = -EINVAL; |
614b84cf | 636 | if (!mq_attr_ok(ipc_ns, attr)) |
7c7dce92 | 637 | goto out; |
1da177e4 | 638 | /* store for use during create */ |
564f6993 | 639 | dentry->d_fsdata = attr; |
1da177e4 LT |
640 | } |
641 | ||
ce3b0f8d | 642 | mode &= ~current_umask(); |
614b84cf | 643 | ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
644 | if (ret) |
645 | goto out; | |
1da177e4 LT |
646 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
647 | dentry->d_fsdata = NULL; | |
648 | if (ret) | |
4a3fd211 DH |
649 | goto out_drop_write; |
650 | ||
614b84cf | 651 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211 DH |
652 | /* |
653 | * dentry_open() took a persistent mnt_want_write(), | |
654 | * so we can now drop this one. | |
655 | */ | |
614b84cf | 656 | mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
657 | return result; |
658 | ||
659 | out_drop_write: | |
614b84cf | 660 | mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce92 AV |
661 | out: |
662 | dput(dentry); | |
614b84cf | 663 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 664 | return ERR_PTR(ret); |
1da177e4 LT |
665 | } |
666 | ||
667 | /* Opens existing queue */ | |
614b84cf SH |
668 | static struct file *do_open(struct ipc_namespace *ipc_ns, |
669 | struct dentry *dentry, int oflag) | |
1da177e4 | 670 | { |
745ca247 DH |
671 | const struct cred *cred = current_cred(); |
672 | ||
673 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
674 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 675 | |
7c7dce92 AV |
676 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
677 | dput(dentry); | |
614b84cf | 678 | mntput(ipc_ns->mq_mnt); |
1da177e4 | 679 | return ERR_PTR(-EINVAL); |
7c7dce92 | 680 | } |
1da177e4 | 681 | |
f419a2e3 | 682 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
7c7dce92 | 683 | dput(dentry); |
614b84cf | 684 | mntput(ipc_ns->mq_mnt); |
1da177e4 | 685 | return ERR_PTR(-EACCES); |
7c7dce92 | 686 | } |
1da177e4 | 687 | |
614b84cf | 688 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
1da177e4 LT |
689 | } |
690 | ||
d5460c99 HC |
691 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, |
692 | struct mq_attr __user *, u_attr) | |
1da177e4 LT |
693 | { |
694 | struct dentry *dentry; | |
695 | struct file *filp; | |
696 | char *name; | |
564f6993 | 697 | struct mq_attr attr; |
1da177e4 | 698 | int fd, error; |
7eafd7c7 | 699 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 | 700 | |
564f6993 AV |
701 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
702 | return -EFAULT; | |
703 | ||
704 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
20ca73bc | 705 | |
1da177e4 LT |
706 | if (IS_ERR(name = getname(u_name))) |
707 | return PTR_ERR(name); | |
708 | ||
269f2134 | 709 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
710 | if (fd < 0) |
711 | goto out_putname; | |
712 | ||
614b84cf SH |
713 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
714 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
1da177e4 LT |
715 | if (IS_ERR(dentry)) { |
716 | error = PTR_ERR(dentry); | |
717 | goto out_err; | |
718 | } | |
614b84cf | 719 | mntget(ipc_ns->mq_mnt); |
1da177e4 LT |
720 | |
721 | if (oflag & O_CREAT) { | |
722 | if (dentry->d_inode) { /* entry already exists */ | |
5a190ae6 | 723 | audit_inode(name, dentry); |
7c7dce92 AV |
724 | error = -EEXIST; |
725 | if (oflag & O_EXCL) | |
726 | goto out; | |
614b84cf | 727 | filp = do_open(ipc_ns, dentry, oflag); |
1da177e4 | 728 | } else { |
614b84cf SH |
729 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, |
730 | dentry, oflag, mode, | |
564f6993 | 731 | u_attr ? &attr : NULL); |
1da177e4 | 732 | } |
7c7dce92 AV |
733 | } else { |
734 | error = -ENOENT; | |
735 | if (!dentry->d_inode) | |
736 | goto out; | |
5a190ae6 | 737 | audit_inode(name, dentry); |
614b84cf | 738 | filp = do_open(ipc_ns, dentry, oflag); |
7c7dce92 | 739 | } |
1da177e4 LT |
740 | |
741 | if (IS_ERR(filp)) { | |
742 | error = PTR_ERR(filp); | |
743 | goto out_putfd; | |
744 | } | |
745 | ||
1da177e4 LT |
746 | fd_install(fd, filp); |
747 | goto out_upsem; | |
748 | ||
7c7dce92 AV |
749 | out: |
750 | dput(dentry); | |
614b84cf | 751 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 752 | out_putfd: |
1da177e4 LT |
753 | put_unused_fd(fd); |
754 | out_err: | |
755 | fd = error; | |
756 | out_upsem: | |
614b84cf | 757 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
758 | out_putname: |
759 | putname(name); | |
760 | return fd; | |
761 | } | |
762 | ||
d5460c99 | 763 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
764 | { |
765 | int err; | |
766 | char *name; | |
767 | struct dentry *dentry; | |
768 | struct inode *inode = NULL; | |
7eafd7c7 | 769 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
770 | |
771 | name = getname(u_name); | |
772 | if (IS_ERR(name)) | |
773 | return PTR_ERR(name); | |
774 | ||
614b84cf | 775 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814 | 776 | I_MUTEX_PARENT); |
614b84cf | 777 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4 LT |
778 | if (IS_ERR(dentry)) { |
779 | err = PTR_ERR(dentry); | |
780 | goto out_unlock; | |
781 | } | |
782 | ||
783 | if (!dentry->d_inode) { | |
784 | err = -ENOENT; | |
785 | goto out_err; | |
786 | } | |
787 | ||
788 | inode = dentry->d_inode; | |
789 | if (inode) | |
790 | atomic_inc(&inode->i_count); | |
614b84cf | 791 | err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b DH |
792 | if (err) |
793 | goto out_err; | |
1da177e4 | 794 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf | 795 | mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4 LT |
796 | out_err: |
797 | dput(dentry); | |
798 | ||
799 | out_unlock: | |
614b84cf | 800 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
801 | putname(name); |
802 | if (inode) | |
803 | iput(inode); | |
804 | ||
805 | return err; | |
806 | } | |
807 | ||
808 | /* Pipelined send and receive functions. | |
809 | * | |
810 | * If a receiver finds no waiting message, then it registers itself in the | |
811 | * list of waiting receivers. A sender checks that list before adding the new | |
812 | * message into the message array. If there is a waiting receiver, then it | |
813 | * bypasses the message array and directly hands the message over to the | |
814 | * receiver. | |
815 | * The receiver accepts the message and returns without grabbing the queue | |
816 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
817 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 818 | * ipc/sem.c for more details. |
1da177e4 LT |
819 | * |
820 | * The same algorithm is used for senders. | |
821 | */ | |
822 | ||
823 | /* pipelined_send() - send a message directly to the task waiting in | |
824 | * sys_mq_timedreceive() (without inserting message into a queue). | |
825 | */ | |
826 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
827 | struct msg_msg *message, | |
828 | struct ext_wait_queue *receiver) | |
829 | { | |
830 | receiver->msg = message; | |
831 | list_del(&receiver->list); | |
832 | receiver->state = STATE_PENDING; | |
833 | wake_up_process(receiver->task); | |
d59dd462 | 834 | smp_wmb(); |
1da177e4 LT |
835 | receiver->state = STATE_READY; |
836 | } | |
837 | ||
838 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
839 | * gets its message and put to the queue (we have one free place for sure). */ | |
840 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
841 | { | |
842 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
843 | ||
844 | if (!sender) { | |
845 | /* for poll */ | |
846 | wake_up_interruptible(&info->wait_q); | |
847 | return; | |
848 | } | |
849 | msg_insert(sender->msg, info); | |
850 | list_del(&sender->list); | |
851 | sender->state = STATE_PENDING; | |
852 | wake_up_process(sender->task); | |
d59dd462 | 853 | smp_wmb(); |
1da177e4 LT |
854 | sender->state = STATE_READY; |
855 | } | |
856 | ||
c4ea37c2 HC |
857 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
858 | size_t, msg_len, unsigned int, msg_prio, | |
859 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
860 | { |
861 | struct file *filp; | |
862 | struct inode *inode; | |
863 | struct ext_wait_queue wait; | |
864 | struct ext_wait_queue *receiver; | |
865 | struct msg_msg *msg_ptr; | |
866 | struct mqueue_inode_info *info; | |
c32c8af4 | 867 | struct timespec ts, *p = NULL; |
1da177e4 LT |
868 | long timeout; |
869 | int ret; | |
870 | ||
c32c8af4 AV |
871 | if (u_abs_timeout) { |
872 | if (copy_from_user(&ts, u_abs_timeout, | |
873 | sizeof(struct timespec))) | |
874 | return -EFAULT; | |
875 | p = &ts; | |
876 | } | |
20ca73bc | 877 | |
1da177e4 LT |
878 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
879 | return -EINVAL; | |
880 | ||
c32c8af4 AV |
881 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, p); |
882 | timeout = prepare_timeout(p); | |
1da177e4 LT |
883 | |
884 | ret = -EBADF; | |
885 | filp = fget(mqdes); | |
886 | if (unlikely(!filp)) | |
887 | goto out; | |
888 | ||
6d63079a | 889 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
890 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
891 | goto out_fput; | |
892 | info = MQUEUE_I(inode); | |
5a190ae6 | 893 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 LT |
894 | |
895 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
896 | goto out_fput; | |
897 | ||
898 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
899 | ret = -EMSGSIZE; | |
900 | goto out_fput; | |
901 | } | |
902 | ||
903 | /* First try to allocate memory, before doing anything with | |
904 | * existing queues. */ | |
905 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
906 | if (IS_ERR(msg_ptr)) { | |
907 | ret = PTR_ERR(msg_ptr); | |
908 | goto out_fput; | |
909 | } | |
910 | msg_ptr->m_ts = msg_len; | |
911 | msg_ptr->m_type = msg_prio; | |
912 | ||
913 | spin_lock(&info->lock); | |
914 | ||
915 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
916 | if (filp->f_flags & O_NONBLOCK) { | |
917 | spin_unlock(&info->lock); | |
918 | ret = -EAGAIN; | |
919 | } else if (unlikely(timeout < 0)) { | |
920 | spin_unlock(&info->lock); | |
921 | ret = timeout; | |
922 | } else { | |
923 | wait.task = current; | |
924 | wait.msg = (void *) msg_ptr; | |
925 | wait.state = STATE_NONE; | |
926 | ret = wq_sleep(info, SEND, timeout, &wait); | |
927 | } | |
928 | if (ret < 0) | |
929 | free_msg(msg_ptr); | |
930 | } else { | |
931 | receiver = wq_get_first_waiter(info, RECV); | |
932 | if (receiver) { | |
933 | pipelined_send(info, msg_ptr, receiver); | |
934 | } else { | |
935 | /* adds message to the queue */ | |
936 | msg_insert(msg_ptr, info); | |
937 | __do_notify(info); | |
938 | } | |
939 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
940 | CURRENT_TIME; | |
941 | spin_unlock(&info->lock); | |
942 | ret = 0; | |
943 | } | |
944 | out_fput: | |
945 | fput(filp); | |
946 | out: | |
947 | return ret; | |
948 | } | |
949 | ||
c4ea37c2 HC |
950 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
951 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
952 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
953 | { |
954 | long timeout; | |
955 | ssize_t ret; | |
956 | struct msg_msg *msg_ptr; | |
957 | struct file *filp; | |
958 | struct inode *inode; | |
959 | struct mqueue_inode_info *info; | |
960 | struct ext_wait_queue wait; | |
c32c8af4 | 961 | struct timespec ts, *p = NULL; |
1da177e4 | 962 | |
c32c8af4 AV |
963 | if (u_abs_timeout) { |
964 | if (copy_from_user(&ts, u_abs_timeout, | |
965 | sizeof(struct timespec))) | |
966 | return -EFAULT; | |
967 | p = &ts; | |
968 | } | |
20ca73bc | 969 | |
c32c8af4 AV |
970 | audit_mq_sendrecv(mqdes, msg_len, 0, p); |
971 | timeout = prepare_timeout(p); | |
1da177e4 LT |
972 | |
973 | ret = -EBADF; | |
974 | filp = fget(mqdes); | |
975 | if (unlikely(!filp)) | |
976 | goto out; | |
977 | ||
6d63079a | 978 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
979 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
980 | goto out_fput; | |
981 | info = MQUEUE_I(inode); | |
5a190ae6 | 982 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 LT |
983 | |
984 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
985 | goto out_fput; | |
986 | ||
987 | /* checks if buffer is big enough */ | |
988 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
989 | ret = -EMSGSIZE; | |
990 | goto out_fput; | |
991 | } | |
992 | ||
993 | spin_lock(&info->lock); | |
994 | if (info->attr.mq_curmsgs == 0) { | |
995 | if (filp->f_flags & O_NONBLOCK) { | |
996 | spin_unlock(&info->lock); | |
997 | ret = -EAGAIN; | |
998 | msg_ptr = NULL; | |
999 | } else if (unlikely(timeout < 0)) { | |
1000 | spin_unlock(&info->lock); | |
1001 | ret = timeout; | |
1002 | msg_ptr = NULL; | |
1003 | } else { | |
1004 | wait.task = current; | |
1005 | wait.state = STATE_NONE; | |
1006 | ret = wq_sleep(info, RECV, timeout, &wait); | |
1007 | msg_ptr = wait.msg; | |
1008 | } | |
1009 | } else { | |
1010 | msg_ptr = msg_get(info); | |
1011 | ||
1012 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
1013 | CURRENT_TIME; | |
1014 | ||
1015 | /* There is now free space in queue. */ | |
1016 | pipelined_receive(info); | |
1017 | spin_unlock(&info->lock); | |
1018 | ret = 0; | |
1019 | } | |
1020 | if (ret == 0) { | |
1021 | ret = msg_ptr->m_ts; | |
1022 | ||
1023 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1024 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1025 | ret = -EFAULT; | |
1026 | } | |
1027 | free_msg(msg_ptr); | |
1028 | } | |
1029 | out_fput: | |
1030 | fput(filp); | |
1031 | out: | |
1032 | return ret; | |
1033 | } | |
1034 | ||
1035 | /* | |
1036 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1037 | * and he isn't currently owner of notification, will be silently discarded. | |
1038 | * It isn't explicitly defined in the POSIX. | |
1039 | */ | |
c4ea37c2 HC |
1040 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1041 | const struct sigevent __user *, u_notification) | |
1da177e4 LT |
1042 | { |
1043 | int ret; | |
1044 | struct file *filp; | |
1045 | struct sock *sock; | |
1046 | struct inode *inode; | |
1047 | struct sigevent notification; | |
1048 | struct mqueue_inode_info *info; | |
1049 | struct sk_buff *nc; | |
1050 | ||
20114f71 | 1051 | if (u_notification) { |
1da177e4 LT |
1052 | if (copy_from_user(¬ification, u_notification, |
1053 | sizeof(struct sigevent))) | |
1054 | return -EFAULT; | |
20114f71 AV |
1055 | } |
1056 | ||
1057 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1da177e4 | 1058 | |
20114f71 AV |
1059 | nc = NULL; |
1060 | sock = NULL; | |
1061 | if (u_notification != NULL) { | |
1da177e4 LT |
1062 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1063 | notification.sigev_notify != SIGEV_SIGNAL && | |
1064 | notification.sigev_notify != SIGEV_THREAD)) | |
1065 | return -EINVAL; | |
1066 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1067 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1068 | return -EINVAL; |
1069 | } | |
1070 | if (notification.sigev_notify == SIGEV_THREAD) { | |
c3d8d1e3 PM |
1071 | long timeo; |
1072 | ||
1da177e4 LT |
1073 | /* create the notify skb */ |
1074 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
1075 | ret = -ENOMEM; | |
1076 | if (!nc) | |
1077 | goto out; | |
1078 | ret = -EFAULT; | |
1079 | if (copy_from_user(nc->data, | |
1080 | notification.sigev_value.sival_ptr, | |
1081 | NOTIFY_COOKIE_LEN)) { | |
1082 | goto out; | |
1083 | } | |
1084 | ||
1085 | /* TODO: add a header? */ | |
1086 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1087 | /* and attach it to the socket */ | |
1088 | retry: | |
1089 | filp = fget(notification.sigev_signo); | |
1090 | ret = -EBADF; | |
1091 | if (!filp) | |
1092 | goto out; | |
1093 | sock = netlink_getsockbyfilp(filp); | |
1094 | fput(filp); | |
1095 | if (IS_ERR(sock)) { | |
1096 | ret = PTR_ERR(sock); | |
1097 | sock = NULL; | |
1098 | goto out; | |
1099 | } | |
1100 | ||
c3d8d1e3 | 1101 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1102 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4 LT |
1103 | if (ret == 1) |
1104 | goto retry; | |
1105 | if (ret) { | |
1106 | sock = NULL; | |
1107 | nc = NULL; | |
1108 | goto out; | |
1109 | } | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | ret = -EBADF; | |
1114 | filp = fget(mqdes); | |
1115 | if (!filp) | |
1116 | goto out; | |
1117 | ||
6d63079a | 1118 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
1119 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
1120 | goto out_fput; | |
1121 | info = MQUEUE_I(inode); | |
1122 | ||
1123 | ret = 0; | |
1124 | spin_lock(&info->lock); | |
1125 | if (u_notification == NULL) { | |
a03fcb73 | 1126 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 LT |
1127 | remove_notification(info); |
1128 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1129 | } | |
a03fcb73 | 1130 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1131 | ret = -EBUSY; |
1132 | } else { | |
1133 | switch (notification.sigev_notify) { | |
1134 | case SIGEV_NONE: | |
1135 | info->notify.sigev_notify = SIGEV_NONE; | |
1136 | break; | |
1137 | case SIGEV_THREAD: | |
1138 | info->notify_sock = sock; | |
1139 | info->notify_cookie = nc; | |
1140 | sock = NULL; | |
1141 | nc = NULL; | |
1142 | info->notify.sigev_notify = SIGEV_THREAD; | |
1143 | break; | |
1144 | case SIGEV_SIGNAL: | |
1145 | info->notify.sigev_signo = notification.sigev_signo; | |
1146 | info->notify.sigev_value = notification.sigev_value; | |
1147 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1148 | break; | |
1149 | } | |
a03fcb73 CLG |
1150 | |
1151 | info->notify_owner = get_pid(task_tgid(current)); | |
1da177e4 LT |
1152 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1153 | } | |
1154 | spin_unlock(&info->lock); | |
1155 | out_fput: | |
1156 | fput(filp); | |
1157 | out: | |
1158 | if (sock) { | |
1159 | netlink_detachskb(sock, nc); | |
1160 | } else if (nc) { | |
1161 | dev_kfree_skb(nc); | |
1162 | } | |
1163 | return ret; | |
1164 | } | |
1165 | ||
c4ea37c2 HC |
1166 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1167 | const struct mq_attr __user *, u_mqstat, | |
1168 | struct mq_attr __user *, u_omqstat) | |
1da177e4 LT |
1169 | { |
1170 | int ret; | |
1171 | struct mq_attr mqstat, omqstat; | |
1172 | struct file *filp; | |
1173 | struct inode *inode; | |
1174 | struct mqueue_inode_info *info; | |
1175 | ||
1176 | if (u_mqstat != NULL) { | |
1177 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1178 | return -EFAULT; | |
1179 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1180 | return -EINVAL; | |
1181 | } | |
1182 | ||
1183 | ret = -EBADF; | |
1184 | filp = fget(mqdes); | |
1185 | if (!filp) | |
1186 | goto out; | |
1187 | ||
6d63079a | 1188 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
1189 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
1190 | goto out_fput; | |
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, | |
1232 | }; | |
1233 | ||
1234 | static struct super_operations mqueue_super_ops = { | |
1235 | .alloc_inode = mqueue_alloc_inode, | |
1236 | .destroy_inode = mqueue_destroy_inode, | |
1237 | .statfs = simple_statfs, | |
1238 | .delete_inode = mqueue_delete_inode, | |
1239 | .drop_inode = generic_delete_inode, | |
1240 | }; | |
1241 | ||
1242 | static struct file_system_type mqueue_fs_type = { | |
1243 | .name = "mqueue", | |
1244 | .get_sb = mqueue_get_sb, | |
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 | { | |
1271 | mntput(ns->mq_mnt); | |
1272 | } | |
1273 | ||
b231cca4 JK |
1274 | static int msg_max_limit_min = MIN_MSGMAX; |
1275 | static int msg_max_limit_max = MAX_MSGMAX; | |
1da177e4 | 1276 | |
b231cca4 JK |
1277 | static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; |
1278 | static int msg_maxsize_limit_max = MAX_MSGSIZEMAX; | |
1da177e4 LT |
1279 | |
1280 | static ctl_table mq_sysctls[] = { | |
1281 | { | |
1da177e4 | 1282 | .procname = "queues_max", |
614b84cf | 1283 | .data = &init_ipc_ns.mq_queues_max, |
1da177e4 LT |
1284 | .maxlen = sizeof(int), |
1285 | .mode = 0644, | |
1286 | .proc_handler = &proc_dointvec, | |
1287 | }, | |
1288 | { | |
1da177e4 | 1289 | .procname = "msg_max", |
614b84cf | 1290 | .data = &init_ipc_ns.mq_msg_max, |
1da177e4 LT |
1291 | .maxlen = sizeof(int), |
1292 | .mode = 0644, | |
1293 | .proc_handler = &proc_dointvec_minmax, | |
1294 | .extra1 = &msg_max_limit_min, | |
1295 | .extra2 = &msg_max_limit_max, | |
1296 | }, | |
1297 | { | |
1da177e4 | 1298 | .procname = "msgsize_max", |
614b84cf | 1299 | .data = &init_ipc_ns.mq_msgsize_max, |
1da177e4 LT |
1300 | .maxlen = sizeof(int), |
1301 | .mode = 0644, | |
1302 | .proc_handler = &proc_dointvec_minmax, | |
1303 | .extra1 = &msg_maxsize_limit_min, | |
1304 | .extra2 = &msg_maxsize_limit_max, | |
1305 | }, | |
1306 | { .ctl_name = 0 } | |
1307 | }; | |
1308 | ||
1309 | static ctl_table mq_sysctl_dir[] = { | |
1310 | { | |
1da177e4 LT |
1311 | .procname = "mqueue", |
1312 | .mode = 0555, | |
1313 | .child = mq_sysctls, | |
1314 | }, | |
1315 | { .ctl_name = 0 } | |
1316 | }; | |
1317 | ||
1318 | static ctl_table mq_sysctl_root[] = { | |
1319 | { | |
1320 | .ctl_name = CTL_FS, | |
1321 | .procname = "fs", | |
1322 | .mode = 0555, | |
1323 | .child = mq_sysctl_dir, | |
1324 | }, | |
1325 | { .ctl_name = 0 } | |
1326 | }; | |
1327 | ||
1328 | static int __init init_mqueue_fs(void) | |
1329 | { | |
1330 | int error; | |
1331 | ||
1332 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1333 | sizeof(struct mqueue_inode_info), 0, | |
20c2df83 | 1334 | SLAB_HWCACHE_ALIGN, init_once); |
1da177e4 LT |
1335 | if (mqueue_inode_cachep == NULL) |
1336 | return -ENOMEM; | |
1337 | ||
1338 | /* ignore failues - they are not fatal */ | |
0b4d4147 | 1339 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root); |
1da177e4 LT |
1340 | |
1341 | error = register_filesystem(&mqueue_fs_type); | |
1342 | if (error) | |
1343 | goto out_sysctl; | |
1344 | ||
7eafd7c7 SH |
1345 | spin_lock_init(&mq_lock); |
1346 | ||
1347 | init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns); | |
614b84cf SH |
1348 | if (IS_ERR(init_ipc_ns.mq_mnt)) { |
1349 | error = PTR_ERR(init_ipc_ns.mq_mnt); | |
1da177e4 LT |
1350 | goto out_filesystem; |
1351 | } | |
1352 | ||
1da177e4 LT |
1353 | return 0; |
1354 | ||
1355 | out_filesystem: | |
1356 | unregister_filesystem(&mqueue_fs_type); | |
1357 | out_sysctl: | |
1358 | if (mq_sysctl_table) | |
1359 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1360 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1361 | return error; |
1362 | } | |
1363 | ||
1364 | __initcall(init_mqueue_fs); |