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> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
5f921ae9 | 36 | |
1da177e4 LT |
37 | #include <net/sock.h> |
38 | #include "util.h" | |
39 | ||
40 | #define MQUEUE_MAGIC 0x19800202 | |
41 | #define DIRENT_SIZE 20 | |
42 | #define FILENT_SIZE 80 | |
43 | ||
44 | #define SEND 0 | |
45 | #define RECV 1 | |
46 | ||
47 | #define STATE_NONE 0 | |
48 | #define STATE_PENDING 1 | |
49 | #define STATE_READY 2 | |
50 | ||
1da177e4 LT |
51 | struct ext_wait_queue { /* queue of sleeping tasks */ |
52 | struct task_struct *task; | |
53 | struct list_head list; | |
54 | struct msg_msg *msg; /* ptr of loaded message */ | |
55 | int state; /* one of STATE_* values */ | |
56 | }; | |
57 | ||
58 | struct mqueue_inode_info { | |
59 | spinlock_t lock; | |
60 | struct inode vfs_inode; | |
61 | wait_queue_head_t wait_q; | |
62 | ||
63 | struct msg_msg **messages; | |
64 | struct mq_attr attr; | |
65 | ||
66 | struct sigevent notify; | |
a03fcb73 | 67 | struct pid* notify_owner; |
338cec32 | 68 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
69 | struct sock *notify_sock; |
70 | struct sk_buff *notify_cookie; | |
71 | ||
72 | /* for tasks waiting for free space and messages, respectively */ | |
73 | struct ext_wait_queue e_wait_q[2]; | |
74 | ||
75 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
76 | }; | |
77 | ||
92e1d5be | 78 | static const struct inode_operations mqueue_dir_inode_operations; |
9a32144e | 79 | static const struct file_operations mqueue_file_operations; |
b87221de | 80 | static const struct super_operations mqueue_super_ops; |
1da177e4 LT |
81 | static void remove_notification(struct mqueue_inode_info *info); |
82 | ||
e18b890b | 83 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 LT |
84 | |
85 | static struct ctl_table_header * mq_sysctl_table; | |
86 | ||
87 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
88 | { | |
89 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
90 | } | |
91 | ||
7eafd7c7 SH |
92 | /* |
93 | * This routine should be called with the mq_lock held. | |
94 | */ | |
95 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
614b84cf | 96 | { |
7eafd7c7 | 97 | return get_ipc_ns(inode->i_sb->s_fs_info); |
614b84cf SH |
98 | } |
99 | ||
7eafd7c7 | 100 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
614b84cf | 101 | { |
7eafd7c7 SH |
102 | struct ipc_namespace *ns; |
103 | ||
104 | spin_lock(&mq_lock); | |
105 | ns = __get_ns_from_inode(inode); | |
106 | spin_unlock(&mq_lock); | |
107 | return ns; | |
614b84cf SH |
108 | } |
109 | ||
7eafd7c7 SH |
110 | static struct inode *mqueue_get_inode(struct super_block *sb, |
111 | struct ipc_namespace *ipc_ns, int mode, | |
112 | struct mq_attr *attr) | |
1da177e4 | 113 | { |
86a264ab | 114 | struct user_struct *u = current_user(); |
1da177e4 LT |
115 | struct inode *inode; |
116 | ||
117 | inode = new_inode(sb); | |
118 | if (inode) { | |
119 | inode->i_mode = mode; | |
414c0708 DH |
120 | inode->i_uid = current_fsuid(); |
121 | inode->i_gid = current_fsgid(); | |
1da177e4 LT |
122 | inode->i_mtime = inode->i_ctime = inode->i_atime = |
123 | CURRENT_TIME; | |
124 | ||
125 | if (S_ISREG(mode)) { | |
126 | struct mqueue_inode_info *info; | |
127 | struct task_struct *p = current; | |
1da177e4 LT |
128 | unsigned long mq_bytes, mq_msg_tblsz; |
129 | ||
130 | inode->i_fop = &mqueue_file_operations; | |
131 | inode->i_size = FILENT_SIZE; | |
132 | /* mqueue specific info */ | |
133 | info = MQUEUE_I(inode); | |
134 | spin_lock_init(&info->lock); | |
135 | init_waitqueue_head(&info->wait_q); | |
136 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
137 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
a03fcb73 | 138 | info->notify_owner = NULL; |
1da177e4 LT |
139 | info->qsize = 0; |
140 | info->user = NULL; /* set when all is ok */ | |
141 | memset(&info->attr, 0, sizeof(info->attr)); | |
614b84cf SH |
142 | info->attr.mq_maxmsg = ipc_ns->mq_msg_max; |
143 | info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; | |
1da177e4 LT |
144 | if (attr) { |
145 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
146 | info->attr.mq_msgsize = attr->mq_msgsize; | |
147 | } | |
148 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
c8308b1c AGR |
149 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); |
150 | if (!info->messages) | |
151 | goto out_inode; | |
152 | ||
1da177e4 LT |
153 | mq_bytes = (mq_msg_tblsz + |
154 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
155 | ||
156 | spin_lock(&mq_lock); | |
157 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
158 | u->mq_bytes + mq_bytes > | |
f1eb1332 | 159 | task_rlimit(p, RLIMIT_MSGQUEUE)) { |
1da177e4 | 160 | spin_unlock(&mq_lock); |
6d8af64c | 161 | /* mqueue_evict_inode() releases info->messages */ |
1da177e4 LT |
162 | goto out_inode; |
163 | } | |
164 | u->mq_bytes += mq_bytes; | |
165 | spin_unlock(&mq_lock); | |
166 | ||
1da177e4 LT |
167 | /* all is ok */ |
168 | info->user = get_uid(u); | |
169 | } else if (S_ISDIR(mode)) { | |
d8c76e6f | 170 | inc_nlink(inode); |
1da177e4 LT |
171 | /* Some things misbehave if size == 0 on a directory */ |
172 | inode->i_size = 2 * DIRENT_SIZE; | |
173 | inode->i_op = &mqueue_dir_inode_operations; | |
174 | inode->i_fop = &simple_dir_operations; | |
175 | } | |
176 | } | |
177 | return inode; | |
178 | out_inode: | |
1da177e4 LT |
179 | iput(inode); |
180 | return NULL; | |
181 | } | |
182 | ||
183 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
184 | { | |
185 | struct inode *inode; | |
7eafd7c7 | 186 | struct ipc_namespace *ns = data; |
8d8ffefa | 187 | int error; |
1da177e4 LT |
188 | |
189 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
190 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
191 | sb->s_magic = MQUEUE_MAGIC; | |
192 | sb->s_op = &mqueue_super_ops; | |
193 | ||
7eafd7c7 SH |
194 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, |
195 | NULL); | |
196 | if (!inode) { | |
197 | error = -ENOMEM; | |
198 | goto out; | |
199 | } | |
1da177e4 LT |
200 | |
201 | sb->s_root = d_alloc_root(inode); | |
202 | if (!sb->s_root) { | |
203 | iput(inode); | |
7eafd7c7 | 204 | error = -ENOMEM; |
8d8ffefa | 205 | goto out; |
1da177e4 | 206 | } |
8d8ffefa | 207 | error = 0; |
1da177e4 | 208 | |
7eafd7c7 SH |
209 | out: |
210 | return error; | |
1da177e4 LT |
211 | } |
212 | ||
454e2398 DH |
213 | static int mqueue_get_sb(struct file_system_type *fs_type, |
214 | int flags, const char *dev_name, | |
215 | void *data, struct vfsmount *mnt) | |
1da177e4 | 216 | { |
7eafd7c7 SH |
217 | if (!(flags & MS_KERNMOUNT)) |
218 | data = current->nsproxy->ipc_ns; | |
219 | return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt); | |
1da177e4 LT |
220 | } |
221 | ||
51cc5068 | 222 | static void init_once(void *foo) |
1da177e4 LT |
223 | { |
224 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
225 | ||
a35afb83 | 226 | inode_init_once(&p->vfs_inode); |
1da177e4 LT |
227 | } |
228 | ||
229 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
230 | { | |
231 | struct mqueue_inode_info *ei; | |
232 | ||
e94b1766 | 233 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
234 | if (!ei) |
235 | return NULL; | |
236 | return &ei->vfs_inode; | |
237 | } | |
238 | ||
239 | static void mqueue_destroy_inode(struct inode *inode) | |
240 | { | |
241 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
242 | } | |
243 | ||
6d8af64c | 244 | static void mqueue_evict_inode(struct inode *inode) |
1da177e4 LT |
245 | { |
246 | struct mqueue_inode_info *info; | |
247 | struct user_struct *user; | |
248 | unsigned long mq_bytes; | |
249 | int i; | |
7eafd7c7 | 250 | struct ipc_namespace *ipc_ns; |
1da177e4 | 251 | |
6d8af64c AV |
252 | end_writeback(inode); |
253 | ||
254 | if (S_ISDIR(inode->i_mode)) | |
1da177e4 | 255 | return; |
6d8af64c | 256 | |
7eafd7c7 | 257 | ipc_ns = get_ns_from_inode(inode); |
1da177e4 LT |
258 | info = MQUEUE_I(inode); |
259 | spin_lock(&info->lock); | |
260 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
261 | free_msg(info->messages[i]); | |
262 | kfree(info->messages); | |
263 | spin_unlock(&info->lock); | |
264 | ||
8834cf79 AGR |
265 | /* Total amount of bytes accounted for the mqueue */ |
266 | mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *) | |
267 | + info->attr.mq_msgsize); | |
1da177e4 LT |
268 | user = info->user; |
269 | if (user) { | |
270 | spin_lock(&mq_lock); | |
271 | user->mq_bytes -= mq_bytes; | |
7eafd7c7 SH |
272 | /* |
273 | * get_ns_from_inode() ensures that the | |
274 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
275 | * to which we now hold a reference, or it is NULL. | |
276 | * We can't put it here under mq_lock, though. | |
277 | */ | |
278 | if (ipc_ns) | |
279 | ipc_ns->mq_queues_count--; | |
1da177e4 LT |
280 | spin_unlock(&mq_lock); |
281 | free_uid(user); | |
282 | } | |
7eafd7c7 SH |
283 | if (ipc_ns) |
284 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
285 | } |
286 | ||
287 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
288 | int mode, struct nameidata *nd) | |
289 | { | |
290 | struct inode *inode; | |
291 | struct mq_attr *attr = dentry->d_fsdata; | |
292 | int error; | |
7eafd7c7 | 293 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
294 | |
295 | spin_lock(&mq_lock); | |
7eafd7c7 SH |
296 | ipc_ns = __get_ns_from_inode(dir); |
297 | if (!ipc_ns) { | |
298 | error = -EACCES; | |
299 | goto out_unlock; | |
300 | } | |
614b84cf SH |
301 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
302 | !capable(CAP_SYS_RESOURCE)) { | |
1da177e4 | 303 | error = -ENOSPC; |
614b84cf | 304 | goto out_unlock; |
1da177e4 | 305 | } |
614b84cf | 306 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
307 | spin_unlock(&mq_lock); |
308 | ||
7eafd7c7 | 309 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
1da177e4 LT |
310 | if (!inode) { |
311 | error = -ENOMEM; | |
312 | spin_lock(&mq_lock); | |
614b84cf SH |
313 | ipc_ns->mq_queues_count--; |
314 | goto out_unlock; | |
1da177e4 LT |
315 | } |
316 | ||
7eafd7c7 | 317 | put_ipc_ns(ipc_ns); |
1da177e4 LT |
318 | dir->i_size += DIRENT_SIZE; |
319 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
320 | ||
321 | d_instantiate(dentry, inode); | |
322 | dget(dentry); | |
323 | return 0; | |
614b84cf | 324 | out_unlock: |
1da177e4 | 325 | spin_unlock(&mq_lock); |
7eafd7c7 SH |
326 | if (ipc_ns) |
327 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
328 | return error; |
329 | } | |
330 | ||
331 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
332 | { | |
333 | struct inode *inode = dentry->d_inode; | |
334 | ||
335 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
336 | dir->i_size -= DIRENT_SIZE; | |
9a53c3a7 | 337 | drop_nlink(inode); |
1da177e4 LT |
338 | dput(dentry); |
339 | return 0; | |
340 | } | |
341 | ||
342 | /* | |
343 | * This is routine for system read from queue file. | |
344 | * To avoid mess with doing here some sort of mq_receive we allow | |
345 | * to read only queue size & notification info (the only values | |
346 | * that are interesting from user point of view and aren't accessible | |
347 | * through std routines) | |
348 | */ | |
349 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 350 | size_t count, loff_t *off) |
1da177e4 | 351 | { |
6d63079a | 352 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 | 353 | char buffer[FILENT_SIZE]; |
f1a43f93 | 354 | ssize_t ret; |
1da177e4 LT |
355 | |
356 | spin_lock(&info->lock); | |
357 | snprintf(buffer, sizeof(buffer), | |
358 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
359 | info->qsize, | |
360 | info->notify_owner ? info->notify.sigev_notify : 0, | |
361 | (info->notify_owner && | |
362 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
363 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 364 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
365 | spin_unlock(&info->lock); |
366 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 367 | |
f1a43f93 AM |
368 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
369 | strlen(buffer)); | |
370 | if (ret <= 0) | |
371 | return ret; | |
1da177e4 | 372 | |
6d63079a | 373 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
f1a43f93 | 374 | return ret; |
1da177e4 LT |
375 | } |
376 | ||
75e1fcc0 | 377 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 378 | { |
6d63079a | 379 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
380 | |
381 | spin_lock(&info->lock); | |
a03fcb73 | 382 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
383 | remove_notification(info); |
384 | ||
385 | spin_unlock(&info->lock); | |
386 | return 0; | |
387 | } | |
388 | ||
389 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
390 | { | |
6d63079a | 391 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
392 | int retval = 0; |
393 | ||
394 | poll_wait(filp, &info->wait_q, poll_tab); | |
395 | ||
396 | spin_lock(&info->lock); | |
397 | if (info->attr.mq_curmsgs) | |
398 | retval = POLLIN | POLLRDNORM; | |
399 | ||
400 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
401 | retval |= POLLOUT | POLLWRNORM; | |
402 | spin_unlock(&info->lock); | |
403 | ||
404 | return retval; | |
405 | } | |
406 | ||
407 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
408 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
409 | struct ext_wait_queue *ewp) | |
410 | { | |
411 | struct ext_wait_queue *walk; | |
412 | ||
413 | ewp->task = current; | |
414 | ||
415 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
416 | if (walk->task->static_prio <= current->static_prio) { | |
417 | list_add_tail(&ewp->list, &walk->list); | |
418 | return; | |
419 | } | |
420 | } | |
421 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
422 | } | |
423 | ||
424 | /* | |
425 | * Puts current task to sleep. Caller must hold queue lock. After return | |
426 | * lock isn't held. | |
427 | * sr: SEND or RECV | |
428 | */ | |
429 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
9ca7d8e6 | 430 | ktime_t *timeout, struct ext_wait_queue *ewp) |
1da177e4 LT |
431 | { |
432 | int retval; | |
433 | signed long time; | |
434 | ||
435 | wq_add(info, sr, ewp); | |
436 | ||
437 | for (;;) { | |
438 | set_current_state(TASK_INTERRUPTIBLE); | |
439 | ||
440 | spin_unlock(&info->lock); | |
9ca7d8e6 CE |
441 | time = schedule_hrtimeout_range_clock(timeout, |
442 | HRTIMER_MODE_ABS, 0, CLOCK_REALTIME); | |
1da177e4 LT |
443 | |
444 | while (ewp->state == STATE_PENDING) | |
445 | cpu_relax(); | |
446 | ||
447 | if (ewp->state == STATE_READY) { | |
448 | retval = 0; | |
449 | goto out; | |
450 | } | |
451 | spin_lock(&info->lock); | |
452 | if (ewp->state == STATE_READY) { | |
453 | retval = 0; | |
454 | goto out_unlock; | |
455 | } | |
456 | if (signal_pending(current)) { | |
457 | retval = -ERESTARTSYS; | |
458 | break; | |
459 | } | |
460 | if (time == 0) { | |
461 | retval = -ETIMEDOUT; | |
462 | break; | |
463 | } | |
464 | } | |
465 | list_del(&ewp->list); | |
466 | out_unlock: | |
467 | spin_unlock(&info->lock); | |
468 | out: | |
469 | return retval; | |
470 | } | |
471 | ||
472 | /* | |
473 | * Returns waiting task that should be serviced first or NULL if none exists | |
474 | */ | |
475 | static struct ext_wait_queue *wq_get_first_waiter( | |
476 | struct mqueue_inode_info *info, int sr) | |
477 | { | |
478 | struct list_head *ptr; | |
479 | ||
480 | ptr = info->e_wait_q[sr].list.prev; | |
481 | if (ptr == &info->e_wait_q[sr].list) | |
482 | return NULL; | |
483 | return list_entry(ptr, struct ext_wait_queue, list); | |
484 | } | |
485 | ||
486 | /* Auxiliary functions to manipulate messages' list */ | |
487 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
488 | { | |
489 | int k; | |
490 | ||
491 | k = info->attr.mq_curmsgs - 1; | |
492 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
493 | info->messages[k + 1] = info->messages[k]; | |
494 | k--; | |
495 | } | |
496 | info->attr.mq_curmsgs++; | |
497 | info->qsize += ptr->m_ts; | |
498 | info->messages[k + 1] = ptr; | |
499 | } | |
500 | ||
501 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
502 | { | |
503 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
504 | return info->messages[info->attr.mq_curmsgs]; | |
505 | } | |
506 | ||
507 | static inline void set_cookie(struct sk_buff *skb, char code) | |
508 | { | |
509 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
510 | } | |
511 | ||
512 | /* | |
513 | * The next function is only to split too long sys_mq_timedsend | |
514 | */ | |
515 | static void __do_notify(struct mqueue_inode_info *info) | |
516 | { | |
517 | /* notification | |
518 | * invoked when there is registered process and there isn't process | |
519 | * waiting synchronously for message AND state of queue changed from | |
520 | * empty to not empty. Here we are sure that no one is waiting | |
521 | * synchronously. */ | |
522 | if (info->notify_owner && | |
523 | info->attr.mq_curmsgs == 1) { | |
524 | struct siginfo sig_i; | |
525 | switch (info->notify.sigev_notify) { | |
526 | case SIGEV_NONE: | |
527 | break; | |
528 | case SIGEV_SIGNAL: | |
529 | /* sends signal */ | |
530 | ||
531 | sig_i.si_signo = info->notify.sigev_signo; | |
532 | sig_i.si_errno = 0; | |
533 | sig_i.si_code = SI_MESGQ; | |
534 | sig_i.si_value = info->notify.sigev_value; | |
a6684999 SB |
535 | sig_i.si_pid = task_tgid_nr_ns(current, |
536 | ns_of_pid(info->notify_owner)); | |
414c0708 | 537 | sig_i.si_uid = current_uid(); |
1da177e4 | 538 | |
a03fcb73 CLG |
539 | kill_pid_info(info->notify.sigev_signo, |
540 | &sig_i, info->notify_owner); | |
1da177e4 LT |
541 | break; |
542 | case SIGEV_THREAD: | |
543 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 544 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
545 | break; |
546 | } | |
547 | /* after notification unregisters process */ | |
a03fcb73 CLG |
548 | put_pid(info->notify_owner); |
549 | info->notify_owner = NULL; | |
1da177e4 LT |
550 | } |
551 | wake_up(&info->wait_q); | |
552 | } | |
553 | ||
9ca7d8e6 CE |
554 | static int prepare_timeout(const struct timespec __user *u_abs_timeout, |
555 | ktime_t *expires, struct timespec *ts) | |
1da177e4 | 556 | { |
9ca7d8e6 CE |
557 | if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) |
558 | return -EFAULT; | |
559 | if (!timespec_valid(ts)) | |
560 | return -EINVAL; | |
1da177e4 | 561 | |
9ca7d8e6 CE |
562 | *expires = timespec_to_ktime(*ts); |
563 | return 0; | |
1da177e4 LT |
564 | } |
565 | ||
566 | static void remove_notification(struct mqueue_inode_info *info) | |
567 | { | |
a03fcb73 | 568 | if (info->notify_owner != NULL && |
1da177e4 LT |
569 | info->notify.sigev_notify == SIGEV_THREAD) { |
570 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 571 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 572 | } |
a03fcb73 CLG |
573 | put_pid(info->notify_owner); |
574 | info->notify_owner = NULL; | |
1da177e4 LT |
575 | } |
576 | ||
614b84cf | 577 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4 LT |
578 | { |
579 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
580 | return 0; | |
581 | if (capable(CAP_SYS_RESOURCE)) { | |
582 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
583 | return 0; | |
584 | } else { | |
614b84cf SH |
585 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
586 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) | |
1da177e4 LT |
587 | return 0; |
588 | } | |
589 | /* check for overflow */ | |
590 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
591 | return 0; | |
8834cf79 AGR |
592 | if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize |
593 | + sizeof (struct msg_msg *))) < | |
1da177e4 LT |
594 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) |
595 | return 0; | |
596 | return 1; | |
597 | } | |
598 | ||
599 | /* | |
600 | * Invoked when creating a new queue via sys_mq_open | |
601 | */ | |
614b84cf SH |
602 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, |
603 | struct dentry *dentry, int oflag, mode_t mode, | |
604 | struct mq_attr *attr) | |
1da177e4 | 605 | { |
745ca247 | 606 | const struct cred *cred = current_cred(); |
4a3fd211 | 607 | struct file *result; |
1da177e4 LT |
608 | int ret; |
609 | ||
564f6993 | 610 | if (attr) { |
8d8ffefa AGR |
611 | if (!mq_attr_ok(ipc_ns, attr)) { |
612 | ret = -EINVAL; | |
7c7dce92 | 613 | goto out; |
8d8ffefa | 614 | } |
1da177e4 | 615 | /* store for use during create */ |
564f6993 | 616 | dentry->d_fsdata = attr; |
1da177e4 LT |
617 | } |
618 | ||
ce3b0f8d | 619 | mode &= ~current_umask(); |
614b84cf | 620 | ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
621 | if (ret) |
622 | goto out; | |
1da177e4 LT |
623 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
624 | dentry->d_fsdata = NULL; | |
625 | if (ret) | |
4a3fd211 DH |
626 | goto out_drop_write; |
627 | ||
614b84cf | 628 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211 DH |
629 | /* |
630 | * dentry_open() took a persistent mnt_want_write(), | |
631 | * so we can now drop this one. | |
632 | */ | |
614b84cf | 633 | mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
634 | return result; |
635 | ||
636 | out_drop_write: | |
614b84cf | 637 | mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce92 AV |
638 | out: |
639 | dput(dentry); | |
614b84cf | 640 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 641 | return ERR_PTR(ret); |
1da177e4 LT |
642 | } |
643 | ||
644 | /* Opens existing queue */ | |
614b84cf SH |
645 | static struct file *do_open(struct ipc_namespace *ipc_ns, |
646 | struct dentry *dentry, int oflag) | |
1da177e4 | 647 | { |
04db0dde | 648 | int ret; |
745ca247 DH |
649 | const struct cred *cred = current_cred(); |
650 | ||
651 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
652 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 653 | |
7c7dce92 | 654 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
04db0dde AGR |
655 | ret = -EINVAL; |
656 | goto err; | |
7c7dce92 | 657 | } |
1da177e4 | 658 | |
f419a2e3 | 659 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
04db0dde AGR |
660 | ret = -EACCES; |
661 | goto err; | |
7c7dce92 | 662 | } |
1da177e4 | 663 | |
614b84cf | 664 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
04db0dde AGR |
665 | |
666 | err: | |
667 | dput(dentry); | |
668 | mntput(ipc_ns->mq_mnt); | |
669 | return ERR_PTR(ret); | |
1da177e4 LT |
670 | } |
671 | ||
d5460c99 HC |
672 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, |
673 | struct mq_attr __user *, u_attr) | |
1da177e4 LT |
674 | { |
675 | struct dentry *dentry; | |
676 | struct file *filp; | |
677 | char *name; | |
564f6993 | 678 | struct mq_attr attr; |
1da177e4 | 679 | int fd, error; |
7eafd7c7 | 680 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 | 681 | |
564f6993 AV |
682 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
683 | return -EFAULT; | |
684 | ||
685 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
20ca73bc | 686 | |
1da177e4 LT |
687 | if (IS_ERR(name = getname(u_name))) |
688 | return PTR_ERR(name); | |
689 | ||
269f2134 | 690 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
691 | if (fd < 0) |
692 | goto out_putname; | |
693 | ||
614b84cf SH |
694 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
695 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
1da177e4 LT |
696 | if (IS_ERR(dentry)) { |
697 | error = PTR_ERR(dentry); | |
4294a8ee | 698 | goto out_putfd; |
1da177e4 | 699 | } |
614b84cf | 700 | mntget(ipc_ns->mq_mnt); |
1da177e4 LT |
701 | |
702 | if (oflag & O_CREAT) { | |
703 | if (dentry->d_inode) { /* entry already exists */ | |
5a190ae6 | 704 | audit_inode(name, dentry); |
8d8ffefa AGR |
705 | if (oflag & O_EXCL) { |
706 | error = -EEXIST; | |
7c7dce92 | 707 | goto out; |
8d8ffefa | 708 | } |
614b84cf | 709 | filp = do_open(ipc_ns, dentry, oflag); |
1da177e4 | 710 | } else { |
614b84cf SH |
711 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, |
712 | dentry, oflag, mode, | |
564f6993 | 713 | u_attr ? &attr : NULL); |
1da177e4 | 714 | } |
7c7dce92 | 715 | } else { |
8d8ffefa AGR |
716 | if (!dentry->d_inode) { |
717 | error = -ENOENT; | |
7c7dce92 | 718 | goto out; |
8d8ffefa | 719 | } |
5a190ae6 | 720 | audit_inode(name, dentry); |
614b84cf | 721 | filp = do_open(ipc_ns, dentry, oflag); |
7c7dce92 | 722 | } |
1da177e4 LT |
723 | |
724 | if (IS_ERR(filp)) { | |
725 | error = PTR_ERR(filp); | |
726 | goto out_putfd; | |
727 | } | |
728 | ||
1da177e4 LT |
729 | fd_install(fd, filp); |
730 | goto out_upsem; | |
731 | ||
7c7dce92 AV |
732 | out: |
733 | dput(dentry); | |
614b84cf | 734 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 735 | out_putfd: |
1da177e4 | 736 | put_unused_fd(fd); |
1da177e4 LT |
737 | fd = error; |
738 | out_upsem: | |
614b84cf | 739 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
740 | out_putname: |
741 | putname(name); | |
742 | return fd; | |
743 | } | |
744 | ||
d5460c99 | 745 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
746 | { |
747 | int err; | |
748 | char *name; | |
749 | struct dentry *dentry; | |
750 | struct inode *inode = NULL; | |
7eafd7c7 | 751 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
752 | |
753 | name = getname(u_name); | |
754 | if (IS_ERR(name)) | |
755 | return PTR_ERR(name); | |
756 | ||
614b84cf | 757 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814 | 758 | I_MUTEX_PARENT); |
614b84cf | 759 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4 LT |
760 | if (IS_ERR(dentry)) { |
761 | err = PTR_ERR(dentry); | |
762 | goto out_unlock; | |
763 | } | |
764 | ||
765 | if (!dentry->d_inode) { | |
766 | err = -ENOENT; | |
767 | goto out_err; | |
768 | } | |
769 | ||
770 | inode = dentry->d_inode; | |
771 | if (inode) | |
772 | atomic_inc(&inode->i_count); | |
614b84cf | 773 | err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b DH |
774 | if (err) |
775 | goto out_err; | |
1da177e4 | 776 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf | 777 | mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4 LT |
778 | out_err: |
779 | dput(dentry); | |
780 | ||
781 | out_unlock: | |
614b84cf | 782 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
783 | putname(name); |
784 | if (inode) | |
785 | iput(inode); | |
786 | ||
787 | return err; | |
788 | } | |
789 | ||
790 | /* Pipelined send and receive functions. | |
791 | * | |
792 | * If a receiver finds no waiting message, then it registers itself in the | |
793 | * list of waiting receivers. A sender checks that list before adding the new | |
794 | * message into the message array. If there is a waiting receiver, then it | |
795 | * bypasses the message array and directly hands the message over to the | |
796 | * receiver. | |
797 | * The receiver accepts the message and returns without grabbing the queue | |
798 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
799 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 800 | * ipc/sem.c for more details. |
1da177e4 LT |
801 | * |
802 | * The same algorithm is used for senders. | |
803 | */ | |
804 | ||
805 | /* pipelined_send() - send a message directly to the task waiting in | |
806 | * sys_mq_timedreceive() (without inserting message into a queue). | |
807 | */ | |
808 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
809 | struct msg_msg *message, | |
810 | struct ext_wait_queue *receiver) | |
811 | { | |
812 | receiver->msg = message; | |
813 | list_del(&receiver->list); | |
814 | receiver->state = STATE_PENDING; | |
815 | wake_up_process(receiver->task); | |
d59dd462 | 816 | smp_wmb(); |
1da177e4 LT |
817 | receiver->state = STATE_READY; |
818 | } | |
819 | ||
820 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
821 | * gets its message and put to the queue (we have one free place for sure). */ | |
822 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
823 | { | |
824 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
825 | ||
826 | if (!sender) { | |
827 | /* for poll */ | |
828 | wake_up_interruptible(&info->wait_q); | |
829 | return; | |
830 | } | |
831 | msg_insert(sender->msg, info); | |
832 | list_del(&sender->list); | |
833 | sender->state = STATE_PENDING; | |
834 | wake_up_process(sender->task); | |
d59dd462 | 835 | smp_wmb(); |
1da177e4 LT |
836 | sender->state = STATE_READY; |
837 | } | |
838 | ||
c4ea37c2 HC |
839 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
840 | size_t, msg_len, unsigned int, msg_prio, | |
841 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
842 | { |
843 | struct file *filp; | |
844 | struct inode *inode; | |
845 | struct ext_wait_queue wait; | |
846 | struct ext_wait_queue *receiver; | |
847 | struct msg_msg *msg_ptr; | |
848 | struct mqueue_inode_info *info; | |
9ca7d8e6 CE |
849 | ktime_t expires, *timeout = NULL; |
850 | struct timespec ts; | |
1da177e4 LT |
851 | int ret; |
852 | ||
c32c8af4 | 853 | if (u_abs_timeout) { |
9ca7d8e6 CE |
854 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
855 | if (res) | |
856 | return res; | |
857 | timeout = &expires; | |
c32c8af4 | 858 | } |
20ca73bc | 859 | |
1da177e4 LT |
860 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
861 | return -EINVAL; | |
862 | ||
9ca7d8e6 | 863 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); |
1da177e4 | 864 | |
1da177e4 | 865 | filp = fget(mqdes); |
8d8ffefa AGR |
866 | if (unlikely(!filp)) { |
867 | ret = -EBADF; | |
1da177e4 | 868 | goto out; |
8d8ffefa | 869 | } |
1da177e4 | 870 | |
6d63079a | 871 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
872 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
873 | ret = -EBADF; | |
1da177e4 | 874 | goto out_fput; |
8d8ffefa | 875 | } |
1da177e4 | 876 | info = MQUEUE_I(inode); |
5a190ae6 | 877 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 878 | |
8d8ffefa AGR |
879 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) { |
880 | ret = -EBADF; | |
1da177e4 | 881 | goto out_fput; |
8d8ffefa | 882 | } |
1da177e4 LT |
883 | |
884 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
885 | ret = -EMSGSIZE; | |
886 | goto out_fput; | |
887 | } | |
888 | ||
889 | /* First try to allocate memory, before doing anything with | |
890 | * existing queues. */ | |
891 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
892 | if (IS_ERR(msg_ptr)) { | |
893 | ret = PTR_ERR(msg_ptr); | |
894 | goto out_fput; | |
895 | } | |
896 | msg_ptr->m_ts = msg_len; | |
897 | msg_ptr->m_type = msg_prio; | |
898 | ||
899 | spin_lock(&info->lock); | |
900 | ||
901 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
902 | if (filp->f_flags & O_NONBLOCK) { | |
903 | spin_unlock(&info->lock); | |
904 | ret = -EAGAIN; | |
1da177e4 LT |
905 | } else { |
906 | wait.task = current; | |
907 | wait.msg = (void *) msg_ptr; | |
908 | wait.state = STATE_NONE; | |
909 | ret = wq_sleep(info, SEND, timeout, &wait); | |
910 | } | |
911 | if (ret < 0) | |
912 | free_msg(msg_ptr); | |
913 | } else { | |
914 | receiver = wq_get_first_waiter(info, RECV); | |
915 | if (receiver) { | |
916 | pipelined_send(info, msg_ptr, receiver); | |
917 | } else { | |
918 | /* adds message to the queue */ | |
919 | msg_insert(msg_ptr, info); | |
920 | __do_notify(info); | |
921 | } | |
922 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
923 | CURRENT_TIME; | |
924 | spin_unlock(&info->lock); | |
925 | ret = 0; | |
926 | } | |
927 | out_fput: | |
928 | fput(filp); | |
929 | out: | |
930 | return ret; | |
931 | } | |
932 | ||
c4ea37c2 HC |
933 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
934 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
935 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 | 936 | { |
1da177e4 LT |
937 | ssize_t ret; |
938 | struct msg_msg *msg_ptr; | |
939 | struct file *filp; | |
940 | struct inode *inode; | |
941 | struct mqueue_inode_info *info; | |
942 | struct ext_wait_queue wait; | |
9ca7d8e6 CE |
943 | ktime_t expires, *timeout = NULL; |
944 | struct timespec ts; | |
1da177e4 | 945 | |
c32c8af4 | 946 | if (u_abs_timeout) { |
9ca7d8e6 CE |
947 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
948 | if (res) | |
949 | return res; | |
950 | timeout = &expires; | |
c32c8af4 | 951 | } |
20ca73bc | 952 | |
9ca7d8e6 | 953 | audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); |
1da177e4 | 954 | |
1da177e4 | 955 | filp = fget(mqdes); |
8d8ffefa AGR |
956 | if (unlikely(!filp)) { |
957 | ret = -EBADF; | |
1da177e4 | 958 | goto out; |
8d8ffefa | 959 | } |
1da177e4 | 960 | |
6d63079a | 961 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
962 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
963 | ret = -EBADF; | |
1da177e4 | 964 | goto out_fput; |
8d8ffefa | 965 | } |
1da177e4 | 966 | info = MQUEUE_I(inode); |
5a190ae6 | 967 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 968 | |
8d8ffefa AGR |
969 | if (unlikely(!(filp->f_mode & FMODE_READ))) { |
970 | ret = -EBADF; | |
1da177e4 | 971 | goto out_fput; |
8d8ffefa | 972 | } |
1da177e4 LT |
973 | |
974 | /* checks if buffer is big enough */ | |
975 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
976 | ret = -EMSGSIZE; | |
977 | goto out_fput; | |
978 | } | |
979 | ||
980 | spin_lock(&info->lock); | |
981 | if (info->attr.mq_curmsgs == 0) { | |
982 | if (filp->f_flags & O_NONBLOCK) { | |
983 | spin_unlock(&info->lock); | |
984 | ret = -EAGAIN; | |
1da177e4 LT |
985 | } else { |
986 | wait.task = current; | |
987 | wait.state = STATE_NONE; | |
988 | ret = wq_sleep(info, RECV, timeout, &wait); | |
989 | msg_ptr = wait.msg; | |
990 | } | |
991 | } else { | |
992 | msg_ptr = msg_get(info); | |
993 | ||
994 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
995 | CURRENT_TIME; | |
996 | ||
997 | /* There is now free space in queue. */ | |
998 | pipelined_receive(info); | |
999 | spin_unlock(&info->lock); | |
1000 | ret = 0; | |
1001 | } | |
1002 | if (ret == 0) { | |
1003 | ret = msg_ptr->m_ts; | |
1004 | ||
1005 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1006 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1007 | ret = -EFAULT; | |
1008 | } | |
1009 | free_msg(msg_ptr); | |
1010 | } | |
1011 | out_fput: | |
1012 | fput(filp); | |
1013 | out: | |
1014 | return ret; | |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1019 | * and he isn't currently owner of notification, will be silently discarded. | |
1020 | * It isn't explicitly defined in the POSIX. | |
1021 | */ | |
c4ea37c2 HC |
1022 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1023 | const struct sigevent __user *, u_notification) | |
1da177e4 LT |
1024 | { |
1025 | int ret; | |
1026 | struct file *filp; | |
1027 | struct sock *sock; | |
1028 | struct inode *inode; | |
1029 | struct sigevent notification; | |
1030 | struct mqueue_inode_info *info; | |
1031 | struct sk_buff *nc; | |
1032 | ||
20114f71 | 1033 | if (u_notification) { |
1da177e4 LT |
1034 | if (copy_from_user(¬ification, u_notification, |
1035 | sizeof(struct sigevent))) | |
1036 | return -EFAULT; | |
20114f71 AV |
1037 | } |
1038 | ||
1039 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1da177e4 | 1040 | |
20114f71 AV |
1041 | nc = NULL; |
1042 | sock = NULL; | |
1043 | if (u_notification != NULL) { | |
1da177e4 LT |
1044 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1045 | notification.sigev_notify != SIGEV_SIGNAL && | |
1046 | notification.sigev_notify != SIGEV_THREAD)) | |
1047 | return -EINVAL; | |
1048 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1049 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1050 | return -EINVAL; |
1051 | } | |
1052 | if (notification.sigev_notify == SIGEV_THREAD) { | |
c3d8d1e3 PM |
1053 | long timeo; |
1054 | ||
1da177e4 LT |
1055 | /* create the notify skb */ |
1056 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
8d8ffefa AGR |
1057 | if (!nc) { |
1058 | ret = -ENOMEM; | |
1da177e4 | 1059 | goto out; |
8d8ffefa | 1060 | } |
1da177e4 LT |
1061 | if (copy_from_user(nc->data, |
1062 | notification.sigev_value.sival_ptr, | |
1063 | NOTIFY_COOKIE_LEN)) { | |
8d8ffefa | 1064 | ret = -EFAULT; |
1da177e4 LT |
1065 | goto out; |
1066 | } | |
1067 | ||
1068 | /* TODO: add a header? */ | |
1069 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1070 | /* and attach it to the socket */ | |
1071 | retry: | |
1072 | filp = fget(notification.sigev_signo); | |
8d8ffefa AGR |
1073 | if (!filp) { |
1074 | ret = -EBADF; | |
1da177e4 | 1075 | goto out; |
8d8ffefa | 1076 | } |
1da177e4 LT |
1077 | sock = netlink_getsockbyfilp(filp); |
1078 | fput(filp); | |
1079 | if (IS_ERR(sock)) { | |
1080 | ret = PTR_ERR(sock); | |
1081 | sock = NULL; | |
1082 | goto out; | |
1083 | } | |
1084 | ||
c3d8d1e3 | 1085 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1086 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4 | 1087 | if (ret == 1) |
8d8ffefa | 1088 | goto retry; |
1da177e4 LT |
1089 | if (ret) { |
1090 | sock = NULL; | |
1091 | nc = NULL; | |
1092 | goto out; | |
1093 | } | |
1094 | } | |
1095 | } | |
1096 | ||
1da177e4 | 1097 | filp = fget(mqdes); |
8d8ffefa AGR |
1098 | if (!filp) { |
1099 | ret = -EBADF; | |
1da177e4 | 1100 | goto out; |
8d8ffefa | 1101 | } |
1da177e4 | 1102 | |
6d63079a | 1103 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1104 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1105 | ret = -EBADF; | |
1da177e4 | 1106 | goto out_fput; |
8d8ffefa | 1107 | } |
1da177e4 LT |
1108 | info = MQUEUE_I(inode); |
1109 | ||
1110 | ret = 0; | |
1111 | spin_lock(&info->lock); | |
1112 | if (u_notification == NULL) { | |
a03fcb73 | 1113 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 LT |
1114 | remove_notification(info); |
1115 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1116 | } | |
a03fcb73 | 1117 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1118 | ret = -EBUSY; |
1119 | } else { | |
1120 | switch (notification.sigev_notify) { | |
1121 | case SIGEV_NONE: | |
1122 | info->notify.sigev_notify = SIGEV_NONE; | |
1123 | break; | |
1124 | case SIGEV_THREAD: | |
1125 | info->notify_sock = sock; | |
1126 | info->notify_cookie = nc; | |
1127 | sock = NULL; | |
1128 | nc = NULL; | |
1129 | info->notify.sigev_notify = SIGEV_THREAD; | |
1130 | break; | |
1131 | case SIGEV_SIGNAL: | |
1132 | info->notify.sigev_signo = notification.sigev_signo; | |
1133 | info->notify.sigev_value = notification.sigev_value; | |
1134 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1135 | break; | |
1136 | } | |
a03fcb73 CLG |
1137 | |
1138 | info->notify_owner = get_pid(task_tgid(current)); | |
1da177e4 LT |
1139 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1140 | } | |
1141 | spin_unlock(&info->lock); | |
1142 | out_fput: | |
1143 | fput(filp); | |
1144 | out: | |
1145 | if (sock) { | |
1146 | netlink_detachskb(sock, nc); | |
1147 | } else if (nc) { | |
1148 | dev_kfree_skb(nc); | |
1149 | } | |
1150 | return ret; | |
1151 | } | |
1152 | ||
c4ea37c2 HC |
1153 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1154 | const struct mq_attr __user *, u_mqstat, | |
1155 | struct mq_attr __user *, u_omqstat) | |
1da177e4 LT |
1156 | { |
1157 | int ret; | |
1158 | struct mq_attr mqstat, omqstat; | |
1159 | struct file *filp; | |
1160 | struct inode *inode; | |
1161 | struct mqueue_inode_info *info; | |
1162 | ||
1163 | if (u_mqstat != NULL) { | |
1164 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1165 | return -EFAULT; | |
1166 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1167 | return -EINVAL; | |
1168 | } | |
1169 | ||
1da177e4 | 1170 | filp = fget(mqdes); |
8d8ffefa AGR |
1171 | if (!filp) { |
1172 | ret = -EBADF; | |
1da177e4 | 1173 | goto out; |
8d8ffefa | 1174 | } |
1da177e4 | 1175 | |
6d63079a | 1176 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1177 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1178 | ret = -EBADF; | |
1da177e4 | 1179 | goto out_fput; |
8d8ffefa | 1180 | } |
1da177e4 LT |
1181 | info = MQUEUE_I(inode); |
1182 | ||
1183 | spin_lock(&info->lock); | |
1184 | ||
1185 | omqstat = info->attr; | |
1186 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1187 | if (u_mqstat) { | |
7392906e | 1188 | audit_mq_getsetattr(mqdes, &mqstat); |
db1dd4d3 | 1189 | spin_lock(&filp->f_lock); |
1da177e4 LT |
1190 | if (mqstat.mq_flags & O_NONBLOCK) |
1191 | filp->f_flags |= O_NONBLOCK; | |
1192 | else | |
1193 | filp->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 1194 | spin_unlock(&filp->f_lock); |
1da177e4 LT |
1195 | |
1196 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1197 | } | |
1198 | ||
1199 | spin_unlock(&info->lock); | |
1200 | ||
1201 | ret = 0; | |
1202 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1203 | sizeof(struct mq_attr))) | |
1204 | ret = -EFAULT; | |
1205 | ||
1206 | out_fput: | |
1207 | fput(filp); | |
1208 | out: | |
1209 | return ret; | |
1210 | } | |
1211 | ||
92e1d5be | 1212 | static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4 LT |
1213 | .lookup = simple_lookup, |
1214 | .create = mqueue_create, | |
1215 | .unlink = mqueue_unlink, | |
1216 | }; | |
1217 | ||
9a32144e | 1218 | static const struct file_operations mqueue_file_operations = { |
1da177e4 LT |
1219 | .flush = mqueue_flush_file, |
1220 | .poll = mqueue_poll_file, | |
1221 | .read = mqueue_read_file, | |
1222 | }; | |
1223 | ||
b87221de | 1224 | static const struct super_operations mqueue_super_ops = { |
1da177e4 LT |
1225 | .alloc_inode = mqueue_alloc_inode, |
1226 | .destroy_inode = mqueue_destroy_inode, | |
6d8af64c | 1227 | .evict_inode = mqueue_evict_inode, |
1da177e4 | 1228 | .statfs = simple_statfs, |
1da177e4 LT |
1229 | }; |
1230 | ||
1231 | static struct file_system_type mqueue_fs_type = { | |
1232 | .name = "mqueue", | |
1233 | .get_sb = mqueue_get_sb, | |
1234 | .kill_sb = kill_litter_super, | |
1235 | }; | |
1236 | ||
7eafd7c7 SH |
1237 | int mq_init_ns(struct ipc_namespace *ns) |
1238 | { | |
1239 | ns->mq_queues_count = 0; | |
1240 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
1241 | ns->mq_msg_max = DFLT_MSGMAX; | |
1242 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
1243 | ||
1244 | ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); | |
1245 | if (IS_ERR(ns->mq_mnt)) { | |
1246 | int err = PTR_ERR(ns->mq_mnt); | |
1247 | ns->mq_mnt = NULL; | |
1248 | return err; | |
1249 | } | |
1250 | return 0; | |
1251 | } | |
1252 | ||
1253 | void mq_clear_sbinfo(struct ipc_namespace *ns) | |
1254 | { | |
1255 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; | |
1256 | } | |
1257 | ||
1258 | void mq_put_mnt(struct ipc_namespace *ns) | |
1259 | { | |
1260 | mntput(ns->mq_mnt); | |
1261 | } | |
1262 | ||
1da177e4 LT |
1263 | static int __init init_mqueue_fs(void) |
1264 | { | |
1265 | int error; | |
1266 | ||
1267 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1268 | sizeof(struct mqueue_inode_info), 0, | |
20c2df83 | 1269 | SLAB_HWCACHE_ALIGN, init_once); |
1da177e4 LT |
1270 | if (mqueue_inode_cachep == NULL) |
1271 | return -ENOMEM; | |
1272 | ||
2329e392 | 1273 | /* ignore failures - they are not fatal */ |
bdc8e5f8 | 1274 | mq_sysctl_table = mq_register_sysctl_table(); |
1da177e4 LT |
1275 | |
1276 | error = register_filesystem(&mqueue_fs_type); | |
1277 | if (error) | |
1278 | goto out_sysctl; | |
1279 | ||
7eafd7c7 SH |
1280 | spin_lock_init(&mq_lock); |
1281 | ||
1282 | init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns); | |
614b84cf SH |
1283 | if (IS_ERR(init_ipc_ns.mq_mnt)) { |
1284 | error = PTR_ERR(init_ipc_ns.mq_mnt); | |
1da177e4 LT |
1285 | goto out_filesystem; |
1286 | } | |
1287 | ||
1da177e4 LT |
1288 | return 0; |
1289 | ||
1290 | out_filesystem: | |
1291 | unregister_filesystem(&mqueue_fs_type); | |
1292 | out_sysctl: | |
1293 | if (mq_sysctl_table) | |
1294 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1295 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1296 | return error; |
1297 | } | |
1298 | ||
1299 | __initcall(init_mqueue_fs); |