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> |
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 | ||
91 | static spinlock_t mq_lock; | |
e18b890b | 92 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 LT |
93 | |
94 | static struct ctl_table_header * mq_sysctl_table; | |
95 | ||
96 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
97 | { | |
98 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
99 | } | |
100 | ||
614b84cf SH |
101 | void mq_init_ns(struct ipc_namespace *ns) |
102 | { | |
103 | ns->mq_queues_count = 0; | |
104 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
105 | ns->mq_msg_max = DFLT_MSGMAX; | |
106 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
107 | ns->mq_mnt = mntget(init_ipc_ns.mq_mnt); | |
108 | } | |
109 | ||
110 | void mq_exit_ns(struct ipc_namespace *ns) | |
111 | { | |
112 | /* will need to clear out ns->mq_mnt->mnt_sb->s_fs_info here */ | |
113 | mntput(ns->mq_mnt); | |
114 | } | |
115 | ||
1da177e4 LT |
116 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, |
117 | struct mq_attr *attr) | |
118 | { | |
86a264ab | 119 | struct user_struct *u = current_user(); |
1da177e4 | 120 | struct inode *inode; |
614b84cf | 121 | struct ipc_namespace *ipc_ns = &init_ipc_ns; |
1da177e4 LT |
122 | |
123 | inode = new_inode(sb); | |
124 | if (inode) { | |
125 | inode->i_mode = mode; | |
414c0708 DH |
126 | inode->i_uid = current_fsuid(); |
127 | inode->i_gid = current_fsgid(); | |
1da177e4 LT |
128 | inode->i_mtime = inode->i_ctime = inode->i_atime = |
129 | CURRENT_TIME; | |
130 | ||
131 | if (S_ISREG(mode)) { | |
132 | struct mqueue_inode_info *info; | |
133 | struct task_struct *p = current; | |
1da177e4 LT |
134 | unsigned long mq_bytes, mq_msg_tblsz; |
135 | ||
136 | inode->i_fop = &mqueue_file_operations; | |
137 | inode->i_size = FILENT_SIZE; | |
138 | /* mqueue specific info */ | |
139 | info = MQUEUE_I(inode); | |
140 | spin_lock_init(&info->lock); | |
141 | init_waitqueue_head(&info->wait_q); | |
142 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
143 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
144 | info->messages = NULL; | |
a03fcb73 | 145 | info->notify_owner = NULL; |
1da177e4 LT |
146 | info->qsize = 0; |
147 | info->user = NULL; /* set when all is ok */ | |
148 | memset(&info->attr, 0, sizeof(info->attr)); | |
614b84cf SH |
149 | info->attr.mq_maxmsg = ipc_ns->mq_msg_max; |
150 | info->attr.mq_msgsize = ipc_ns->mq_msgsize_max; | |
1da177e4 LT |
151 | if (attr) { |
152 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
153 | info->attr.mq_msgsize = attr->mq_msgsize; | |
154 | } | |
155 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
156 | mq_bytes = (mq_msg_tblsz + | |
157 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
158 | ||
159 | spin_lock(&mq_lock); | |
160 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
161 | u->mq_bytes + mq_bytes > | |
162 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { | |
163 | spin_unlock(&mq_lock); | |
164 | goto out_inode; | |
165 | } | |
166 | u->mq_bytes += mq_bytes; | |
167 | spin_unlock(&mq_lock); | |
168 | ||
169 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
170 | if (!info->messages) { | |
171 | spin_lock(&mq_lock); | |
172 | u->mq_bytes -= mq_bytes; | |
173 | spin_unlock(&mq_lock); | |
174 | goto out_inode; | |
175 | } | |
176 | /* all is ok */ | |
177 | info->user = get_uid(u); | |
178 | } else if (S_ISDIR(mode)) { | |
d8c76e6f | 179 | inc_nlink(inode); |
1da177e4 LT |
180 | /* Some things misbehave if size == 0 on a directory */ |
181 | inode->i_size = 2 * DIRENT_SIZE; | |
182 | inode->i_op = &mqueue_dir_inode_operations; | |
183 | inode->i_fop = &simple_dir_operations; | |
184 | } | |
185 | } | |
186 | return inode; | |
187 | out_inode: | |
188 | make_bad_inode(inode); | |
189 | iput(inode); | |
190 | return NULL; | |
191 | } | |
192 | ||
193 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
194 | { | |
195 | struct inode *inode; | |
196 | ||
197 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
198 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
199 | sb->s_magic = MQUEUE_MAGIC; | |
200 | sb->s_op = &mqueue_super_ops; | |
201 | ||
202 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); | |
203 | if (!inode) | |
204 | return -ENOMEM; | |
205 | ||
206 | sb->s_root = d_alloc_root(inode); | |
207 | if (!sb->s_root) { | |
208 | iput(inode); | |
209 | return -ENOMEM; | |
210 | } | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
454e2398 DH |
215 | static int mqueue_get_sb(struct file_system_type *fs_type, |
216 | int flags, const char *dev_name, | |
217 | void *data, struct vfsmount *mnt) | |
1da177e4 | 218 | { |
454e2398 | 219 | return get_sb_single(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 | ||
244 | static void mqueue_delete_inode(struct inode *inode) | |
245 | { | |
246 | struct mqueue_inode_info *info; | |
247 | struct user_struct *user; | |
248 | unsigned long mq_bytes; | |
249 | int i; | |
614b84cf | 250 | struct ipc_namespace *ipc_ns = &init_ipc_ns; |
1da177e4 LT |
251 | |
252 | if (S_ISDIR(inode->i_mode)) { | |
253 | clear_inode(inode); | |
254 | return; | |
255 | } | |
256 | info = MQUEUE_I(inode); | |
257 | spin_lock(&info->lock); | |
258 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
259 | free_msg(info->messages[i]); | |
260 | kfree(info->messages); | |
261 | spin_unlock(&info->lock); | |
262 | ||
263 | clear_inode(inode); | |
264 | ||
265 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + | |
266 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
267 | user = info->user; | |
268 | if (user) { | |
269 | spin_lock(&mq_lock); | |
270 | user->mq_bytes -= mq_bytes; | |
614b84cf | 271 | ipc_ns->mq_queues_count--; |
1da177e4 LT |
272 | spin_unlock(&mq_lock); |
273 | free_uid(user); | |
274 | } | |
275 | } | |
276 | ||
277 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
278 | int mode, struct nameidata *nd) | |
279 | { | |
280 | struct inode *inode; | |
281 | struct mq_attr *attr = dentry->d_fsdata; | |
282 | int error; | |
614b84cf | 283 | struct ipc_namespace *ipc_ns = &init_ipc_ns; |
1da177e4 LT |
284 | |
285 | spin_lock(&mq_lock); | |
614b84cf SH |
286 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
287 | !capable(CAP_SYS_RESOURCE)) { | |
1da177e4 | 288 | error = -ENOSPC; |
614b84cf | 289 | goto out_unlock; |
1da177e4 | 290 | } |
614b84cf | 291 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
292 | spin_unlock(&mq_lock); |
293 | ||
294 | inode = mqueue_get_inode(dir->i_sb, mode, attr); | |
295 | if (!inode) { | |
296 | error = -ENOMEM; | |
297 | spin_lock(&mq_lock); | |
614b84cf SH |
298 | ipc_ns->mq_queues_count--; |
299 | goto out_unlock; | |
1da177e4 LT |
300 | } |
301 | ||
302 | dir->i_size += DIRENT_SIZE; | |
303 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
304 | ||
305 | d_instantiate(dentry, inode); | |
306 | dget(dentry); | |
307 | return 0; | |
614b84cf | 308 | out_unlock: |
1da177e4 LT |
309 | spin_unlock(&mq_lock); |
310 | return error; | |
311 | } | |
312 | ||
313 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
314 | { | |
315 | struct inode *inode = dentry->d_inode; | |
316 | ||
317 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
318 | dir->i_size -= DIRENT_SIZE; | |
9a53c3a7 | 319 | drop_nlink(inode); |
1da177e4 LT |
320 | dput(dentry); |
321 | return 0; | |
322 | } | |
323 | ||
324 | /* | |
325 | * This is routine for system read from queue file. | |
326 | * To avoid mess with doing here some sort of mq_receive we allow | |
327 | * to read only queue size & notification info (the only values | |
328 | * that are interesting from user point of view and aren't accessible | |
329 | * through std routines) | |
330 | */ | |
331 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 332 | size_t count, loff_t *off) |
1da177e4 | 333 | { |
6d63079a | 334 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 | 335 | char buffer[FILENT_SIZE]; |
f1a43f93 | 336 | ssize_t ret; |
1da177e4 LT |
337 | |
338 | spin_lock(&info->lock); | |
339 | snprintf(buffer, sizeof(buffer), | |
340 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
341 | info->qsize, | |
342 | info->notify_owner ? info->notify.sigev_notify : 0, | |
343 | (info->notify_owner && | |
344 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
345 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 346 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
347 | spin_unlock(&info->lock); |
348 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 349 | |
f1a43f93 AM |
350 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
351 | strlen(buffer)); | |
352 | if (ret <= 0) | |
353 | return ret; | |
1da177e4 | 354 | |
6d63079a | 355 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
f1a43f93 | 356 | return ret; |
1da177e4 LT |
357 | } |
358 | ||
75e1fcc0 | 359 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 360 | { |
6d63079a | 361 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
362 | |
363 | spin_lock(&info->lock); | |
a03fcb73 | 364 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
365 | remove_notification(info); |
366 | ||
367 | spin_unlock(&info->lock); | |
368 | return 0; | |
369 | } | |
370 | ||
371 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
372 | { | |
6d63079a | 373 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
374 | int retval = 0; |
375 | ||
376 | poll_wait(filp, &info->wait_q, poll_tab); | |
377 | ||
378 | spin_lock(&info->lock); | |
379 | if (info->attr.mq_curmsgs) | |
380 | retval = POLLIN | POLLRDNORM; | |
381 | ||
382 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
383 | retval |= POLLOUT | POLLWRNORM; | |
384 | spin_unlock(&info->lock); | |
385 | ||
386 | return retval; | |
387 | } | |
388 | ||
389 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
390 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
391 | struct ext_wait_queue *ewp) | |
392 | { | |
393 | struct ext_wait_queue *walk; | |
394 | ||
395 | ewp->task = current; | |
396 | ||
397 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
398 | if (walk->task->static_prio <= current->static_prio) { | |
399 | list_add_tail(&ewp->list, &walk->list); | |
400 | return; | |
401 | } | |
402 | } | |
403 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
404 | } | |
405 | ||
406 | /* | |
407 | * Puts current task to sleep. Caller must hold queue lock. After return | |
408 | * lock isn't held. | |
409 | * sr: SEND or RECV | |
410 | */ | |
411 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
412 | long timeout, struct ext_wait_queue *ewp) | |
413 | { | |
414 | int retval; | |
415 | signed long time; | |
416 | ||
417 | wq_add(info, sr, ewp); | |
418 | ||
419 | for (;;) { | |
420 | set_current_state(TASK_INTERRUPTIBLE); | |
421 | ||
422 | spin_unlock(&info->lock); | |
423 | time = schedule_timeout(timeout); | |
424 | ||
425 | while (ewp->state == STATE_PENDING) | |
426 | cpu_relax(); | |
427 | ||
428 | if (ewp->state == STATE_READY) { | |
429 | retval = 0; | |
430 | goto out; | |
431 | } | |
432 | spin_lock(&info->lock); | |
433 | if (ewp->state == STATE_READY) { | |
434 | retval = 0; | |
435 | goto out_unlock; | |
436 | } | |
437 | if (signal_pending(current)) { | |
438 | retval = -ERESTARTSYS; | |
439 | break; | |
440 | } | |
441 | if (time == 0) { | |
442 | retval = -ETIMEDOUT; | |
443 | break; | |
444 | } | |
445 | } | |
446 | list_del(&ewp->list); | |
447 | out_unlock: | |
448 | spin_unlock(&info->lock); | |
449 | out: | |
450 | return retval; | |
451 | } | |
452 | ||
453 | /* | |
454 | * Returns waiting task that should be serviced first or NULL if none exists | |
455 | */ | |
456 | static struct ext_wait_queue *wq_get_first_waiter( | |
457 | struct mqueue_inode_info *info, int sr) | |
458 | { | |
459 | struct list_head *ptr; | |
460 | ||
461 | ptr = info->e_wait_q[sr].list.prev; | |
462 | if (ptr == &info->e_wait_q[sr].list) | |
463 | return NULL; | |
464 | return list_entry(ptr, struct ext_wait_queue, list); | |
465 | } | |
466 | ||
467 | /* Auxiliary functions to manipulate messages' list */ | |
468 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
469 | { | |
470 | int k; | |
471 | ||
472 | k = info->attr.mq_curmsgs - 1; | |
473 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
474 | info->messages[k + 1] = info->messages[k]; | |
475 | k--; | |
476 | } | |
477 | info->attr.mq_curmsgs++; | |
478 | info->qsize += ptr->m_ts; | |
479 | info->messages[k + 1] = ptr; | |
480 | } | |
481 | ||
482 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
483 | { | |
484 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
485 | return info->messages[info->attr.mq_curmsgs]; | |
486 | } | |
487 | ||
488 | static inline void set_cookie(struct sk_buff *skb, char code) | |
489 | { | |
490 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
491 | } | |
492 | ||
493 | /* | |
494 | * The next function is only to split too long sys_mq_timedsend | |
495 | */ | |
496 | static void __do_notify(struct mqueue_inode_info *info) | |
497 | { | |
498 | /* notification | |
499 | * invoked when there is registered process and there isn't process | |
500 | * waiting synchronously for message AND state of queue changed from | |
501 | * empty to not empty. Here we are sure that no one is waiting | |
502 | * synchronously. */ | |
503 | if (info->notify_owner && | |
504 | info->attr.mq_curmsgs == 1) { | |
505 | struct siginfo sig_i; | |
506 | switch (info->notify.sigev_notify) { | |
507 | case SIGEV_NONE: | |
508 | break; | |
509 | case SIGEV_SIGNAL: | |
510 | /* sends signal */ | |
511 | ||
512 | sig_i.si_signo = info->notify.sigev_signo; | |
513 | sig_i.si_errno = 0; | |
514 | sig_i.si_code = SI_MESGQ; | |
515 | sig_i.si_value = info->notify.sigev_value; | |
a6684999 SB |
516 | sig_i.si_pid = task_tgid_nr_ns(current, |
517 | ns_of_pid(info->notify_owner)); | |
414c0708 | 518 | sig_i.si_uid = current_uid(); |
1da177e4 | 519 | |
a03fcb73 CLG |
520 | kill_pid_info(info->notify.sigev_signo, |
521 | &sig_i, info->notify_owner); | |
1da177e4 LT |
522 | break; |
523 | case SIGEV_THREAD: | |
524 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 525 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
526 | break; |
527 | } | |
528 | /* after notification unregisters process */ | |
a03fcb73 CLG |
529 | put_pid(info->notify_owner); |
530 | info->notify_owner = NULL; | |
1da177e4 LT |
531 | } |
532 | wake_up(&info->wait_q); | |
533 | } | |
534 | ||
c32c8af4 | 535 | static long prepare_timeout(struct timespec *p) |
1da177e4 | 536 | { |
c32c8af4 | 537 | struct timespec nowts; |
1da177e4 LT |
538 | long timeout; |
539 | ||
c32c8af4 AV |
540 | if (p) { |
541 | if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0 | |
542 | || p->tv_nsec >= NSEC_PER_SEC)) | |
1da177e4 LT |
543 | return -EINVAL; |
544 | nowts = CURRENT_TIME; | |
545 | /* first subtract as jiffies can't be too big */ | |
c32c8af4 AV |
546 | p->tv_sec -= nowts.tv_sec; |
547 | if (p->tv_nsec < nowts.tv_nsec) { | |
548 | p->tv_nsec += NSEC_PER_SEC; | |
549 | p->tv_sec--; | |
1da177e4 | 550 | } |
c32c8af4 AV |
551 | p->tv_nsec -= nowts.tv_nsec; |
552 | if (p->tv_sec < 0) | |
1da177e4 LT |
553 | return 0; |
554 | ||
c32c8af4 | 555 | timeout = timespec_to_jiffies(p) + 1; |
1da177e4 LT |
556 | } else |
557 | return MAX_SCHEDULE_TIMEOUT; | |
558 | ||
559 | return timeout; | |
560 | } | |
561 | ||
562 | static void remove_notification(struct mqueue_inode_info *info) | |
563 | { | |
a03fcb73 | 564 | if (info->notify_owner != NULL && |
1da177e4 LT |
565 | info->notify.sigev_notify == SIGEV_THREAD) { |
566 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 567 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 568 | } |
a03fcb73 CLG |
569 | put_pid(info->notify_owner); |
570 | info->notify_owner = NULL; | |
1da177e4 LT |
571 | } |
572 | ||
614b84cf | 573 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4 LT |
574 | { |
575 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
576 | return 0; | |
577 | if (capable(CAP_SYS_RESOURCE)) { | |
578 | if (attr->mq_maxmsg > HARD_MSGMAX) | |
579 | return 0; | |
580 | } else { | |
614b84cf SH |
581 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
582 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) | |
1da177e4 LT |
583 | return 0; |
584 | } | |
585 | /* check for overflow */ | |
586 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
587 | return 0; | |
588 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + | |
589 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < | |
590 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) | |
591 | return 0; | |
592 | return 1; | |
593 | } | |
594 | ||
595 | /* | |
596 | * Invoked when creating a new queue via sys_mq_open | |
597 | */ | |
614b84cf SH |
598 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, |
599 | struct dentry *dentry, int oflag, mode_t mode, | |
600 | struct mq_attr *attr) | |
1da177e4 | 601 | { |
745ca247 | 602 | const struct cred *cred = current_cred(); |
4a3fd211 | 603 | struct file *result; |
1da177e4 LT |
604 | int ret; |
605 | ||
564f6993 | 606 | if (attr) { |
7c7dce92 | 607 | ret = -EINVAL; |
614b84cf | 608 | if (!mq_attr_ok(ipc_ns, attr)) |
7c7dce92 | 609 | goto out; |
1da177e4 | 610 | /* store for use during create */ |
564f6993 | 611 | dentry->d_fsdata = attr; |
1da177e4 LT |
612 | } |
613 | ||
ce3b0f8d | 614 | mode &= ~current_umask(); |
614b84cf | 615 | ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
616 | if (ret) |
617 | goto out; | |
1da177e4 LT |
618 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
619 | dentry->d_fsdata = NULL; | |
620 | if (ret) | |
4a3fd211 DH |
621 | goto out_drop_write; |
622 | ||
614b84cf | 623 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211 DH |
624 | /* |
625 | * dentry_open() took a persistent mnt_want_write(), | |
626 | * so we can now drop this one. | |
627 | */ | |
614b84cf | 628 | mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
629 | return result; |
630 | ||
631 | out_drop_write: | |
614b84cf | 632 | mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce92 AV |
633 | out: |
634 | dput(dentry); | |
614b84cf | 635 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 636 | return ERR_PTR(ret); |
1da177e4 LT |
637 | } |
638 | ||
639 | /* Opens existing queue */ | |
614b84cf SH |
640 | static struct file *do_open(struct ipc_namespace *ipc_ns, |
641 | struct dentry *dentry, int oflag) | |
1da177e4 | 642 | { |
745ca247 DH |
643 | const struct cred *cred = current_cred(); |
644 | ||
645 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
646 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 647 | |
7c7dce92 AV |
648 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
649 | dput(dentry); | |
614b84cf | 650 | mntput(ipc_ns->mq_mnt); |
1da177e4 | 651 | return ERR_PTR(-EINVAL); |
7c7dce92 | 652 | } |
1da177e4 | 653 | |
f419a2e3 | 654 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
7c7dce92 | 655 | dput(dentry); |
614b84cf | 656 | mntput(ipc_ns->mq_mnt); |
1da177e4 | 657 | return ERR_PTR(-EACCES); |
7c7dce92 | 658 | } |
1da177e4 | 659 | |
614b84cf | 660 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
1da177e4 LT |
661 | } |
662 | ||
d5460c99 HC |
663 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode, |
664 | struct mq_attr __user *, u_attr) | |
1da177e4 LT |
665 | { |
666 | struct dentry *dentry; | |
667 | struct file *filp; | |
668 | char *name; | |
564f6993 | 669 | struct mq_attr attr; |
1da177e4 | 670 | int fd, error; |
614b84cf | 671 | struct ipc_namespace *ipc_ns = &init_ipc_ns; |
1da177e4 | 672 | |
564f6993 AV |
673 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
674 | return -EFAULT; | |
675 | ||
676 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
20ca73bc | 677 | |
1da177e4 LT |
678 | if (IS_ERR(name = getname(u_name))) |
679 | return PTR_ERR(name); | |
680 | ||
269f2134 | 681 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
682 | if (fd < 0) |
683 | goto out_putname; | |
684 | ||
614b84cf SH |
685 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
686 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
1da177e4 LT |
687 | if (IS_ERR(dentry)) { |
688 | error = PTR_ERR(dentry); | |
689 | goto out_err; | |
690 | } | |
614b84cf | 691 | mntget(ipc_ns->mq_mnt); |
1da177e4 LT |
692 | |
693 | if (oflag & O_CREAT) { | |
694 | if (dentry->d_inode) { /* entry already exists */ | |
5a190ae6 | 695 | audit_inode(name, dentry); |
7c7dce92 AV |
696 | error = -EEXIST; |
697 | if (oflag & O_EXCL) | |
698 | goto out; | |
614b84cf | 699 | filp = do_open(ipc_ns, dentry, oflag); |
1da177e4 | 700 | } else { |
614b84cf SH |
701 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, |
702 | dentry, oflag, mode, | |
564f6993 | 703 | u_attr ? &attr : NULL); |
1da177e4 | 704 | } |
7c7dce92 AV |
705 | } else { |
706 | error = -ENOENT; | |
707 | if (!dentry->d_inode) | |
708 | goto out; | |
5a190ae6 | 709 | audit_inode(name, dentry); |
614b84cf | 710 | filp = do_open(ipc_ns, dentry, oflag); |
7c7dce92 | 711 | } |
1da177e4 LT |
712 | |
713 | if (IS_ERR(filp)) { | |
714 | error = PTR_ERR(filp); | |
715 | goto out_putfd; | |
716 | } | |
717 | ||
1da177e4 LT |
718 | fd_install(fd, filp); |
719 | goto out_upsem; | |
720 | ||
7c7dce92 AV |
721 | out: |
722 | dput(dentry); | |
614b84cf | 723 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 724 | out_putfd: |
1da177e4 LT |
725 | put_unused_fd(fd); |
726 | out_err: | |
727 | fd = error; | |
728 | out_upsem: | |
614b84cf | 729 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
730 | out_putname: |
731 | putname(name); | |
732 | return fd; | |
733 | } | |
734 | ||
d5460c99 | 735 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
736 | { |
737 | int err; | |
738 | char *name; | |
739 | struct dentry *dentry; | |
740 | struct inode *inode = NULL; | |
614b84cf | 741 | struct ipc_namespace *ipc_ns = &init_ipc_ns; |
1da177e4 LT |
742 | |
743 | name = getname(u_name); | |
744 | if (IS_ERR(name)) | |
745 | return PTR_ERR(name); | |
746 | ||
614b84cf | 747 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814 | 748 | I_MUTEX_PARENT); |
614b84cf | 749 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4 LT |
750 | if (IS_ERR(dentry)) { |
751 | err = PTR_ERR(dentry); | |
752 | goto out_unlock; | |
753 | } | |
754 | ||
755 | if (!dentry->d_inode) { | |
756 | err = -ENOENT; | |
757 | goto out_err; | |
758 | } | |
759 | ||
760 | inode = dentry->d_inode; | |
761 | if (inode) | |
762 | atomic_inc(&inode->i_count); | |
614b84cf | 763 | err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b DH |
764 | if (err) |
765 | goto out_err; | |
1da177e4 | 766 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf | 767 | mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4 LT |
768 | out_err: |
769 | dput(dentry); | |
770 | ||
771 | out_unlock: | |
614b84cf | 772 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
773 | putname(name); |
774 | if (inode) | |
775 | iput(inode); | |
776 | ||
777 | return err; | |
778 | } | |
779 | ||
780 | /* Pipelined send and receive functions. | |
781 | * | |
782 | * If a receiver finds no waiting message, then it registers itself in the | |
783 | * list of waiting receivers. A sender checks that list before adding the new | |
784 | * message into the message array. If there is a waiting receiver, then it | |
785 | * bypasses the message array and directly hands the message over to the | |
786 | * receiver. | |
787 | * The receiver accepts the message and returns without grabbing the queue | |
788 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
789 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 790 | * ipc/sem.c for more details. |
1da177e4 LT |
791 | * |
792 | * The same algorithm is used for senders. | |
793 | */ | |
794 | ||
795 | /* pipelined_send() - send a message directly to the task waiting in | |
796 | * sys_mq_timedreceive() (without inserting message into a queue). | |
797 | */ | |
798 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
799 | struct msg_msg *message, | |
800 | struct ext_wait_queue *receiver) | |
801 | { | |
802 | receiver->msg = message; | |
803 | list_del(&receiver->list); | |
804 | receiver->state = STATE_PENDING; | |
805 | wake_up_process(receiver->task); | |
d59dd462 | 806 | smp_wmb(); |
1da177e4 LT |
807 | receiver->state = STATE_READY; |
808 | } | |
809 | ||
810 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
811 | * gets its message and put to the queue (we have one free place for sure). */ | |
812 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
813 | { | |
814 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
815 | ||
816 | if (!sender) { | |
817 | /* for poll */ | |
818 | wake_up_interruptible(&info->wait_q); | |
819 | return; | |
820 | } | |
821 | msg_insert(sender->msg, info); | |
822 | list_del(&sender->list); | |
823 | sender->state = STATE_PENDING; | |
824 | wake_up_process(sender->task); | |
d59dd462 | 825 | smp_wmb(); |
1da177e4 LT |
826 | sender->state = STATE_READY; |
827 | } | |
828 | ||
c4ea37c2 HC |
829 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
830 | size_t, msg_len, unsigned int, msg_prio, | |
831 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
832 | { |
833 | struct file *filp; | |
834 | struct inode *inode; | |
835 | struct ext_wait_queue wait; | |
836 | struct ext_wait_queue *receiver; | |
837 | struct msg_msg *msg_ptr; | |
838 | struct mqueue_inode_info *info; | |
c32c8af4 | 839 | struct timespec ts, *p = NULL; |
1da177e4 LT |
840 | long timeout; |
841 | int ret; | |
842 | ||
c32c8af4 AV |
843 | if (u_abs_timeout) { |
844 | if (copy_from_user(&ts, u_abs_timeout, | |
845 | sizeof(struct timespec))) | |
846 | return -EFAULT; | |
847 | p = &ts; | |
848 | } | |
20ca73bc | 849 | |
1da177e4 LT |
850 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
851 | return -EINVAL; | |
852 | ||
c32c8af4 AV |
853 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, p); |
854 | timeout = prepare_timeout(p); | |
1da177e4 LT |
855 | |
856 | ret = -EBADF; | |
857 | filp = fget(mqdes); | |
858 | if (unlikely(!filp)) | |
859 | goto out; | |
860 | ||
6d63079a | 861 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
862 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
863 | goto out_fput; | |
864 | info = MQUEUE_I(inode); | |
5a190ae6 | 865 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 LT |
866 | |
867 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) | |
868 | goto out_fput; | |
869 | ||
870 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
871 | ret = -EMSGSIZE; | |
872 | goto out_fput; | |
873 | } | |
874 | ||
875 | /* First try to allocate memory, before doing anything with | |
876 | * existing queues. */ | |
877 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
878 | if (IS_ERR(msg_ptr)) { | |
879 | ret = PTR_ERR(msg_ptr); | |
880 | goto out_fput; | |
881 | } | |
882 | msg_ptr->m_ts = msg_len; | |
883 | msg_ptr->m_type = msg_prio; | |
884 | ||
885 | spin_lock(&info->lock); | |
886 | ||
887 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
888 | if (filp->f_flags & O_NONBLOCK) { | |
889 | spin_unlock(&info->lock); | |
890 | ret = -EAGAIN; | |
891 | } else if (unlikely(timeout < 0)) { | |
892 | spin_unlock(&info->lock); | |
893 | ret = timeout; | |
894 | } else { | |
895 | wait.task = current; | |
896 | wait.msg = (void *) msg_ptr; | |
897 | wait.state = STATE_NONE; | |
898 | ret = wq_sleep(info, SEND, timeout, &wait); | |
899 | } | |
900 | if (ret < 0) | |
901 | free_msg(msg_ptr); | |
902 | } else { | |
903 | receiver = wq_get_first_waiter(info, RECV); | |
904 | if (receiver) { | |
905 | pipelined_send(info, msg_ptr, receiver); | |
906 | } else { | |
907 | /* adds message to the queue */ | |
908 | msg_insert(msg_ptr, info); | |
909 | __do_notify(info); | |
910 | } | |
911 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
912 | CURRENT_TIME; | |
913 | spin_unlock(&info->lock); | |
914 | ret = 0; | |
915 | } | |
916 | out_fput: | |
917 | fput(filp); | |
918 | out: | |
919 | return ret; | |
920 | } | |
921 | ||
c4ea37c2 HC |
922 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
923 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
924 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
925 | { |
926 | long timeout; | |
927 | ssize_t ret; | |
928 | struct msg_msg *msg_ptr; | |
929 | struct file *filp; | |
930 | struct inode *inode; | |
931 | struct mqueue_inode_info *info; | |
932 | struct ext_wait_queue wait; | |
c32c8af4 | 933 | struct timespec ts, *p = NULL; |
1da177e4 | 934 | |
c32c8af4 AV |
935 | if (u_abs_timeout) { |
936 | if (copy_from_user(&ts, u_abs_timeout, | |
937 | sizeof(struct timespec))) | |
938 | return -EFAULT; | |
939 | p = &ts; | |
940 | } | |
20ca73bc | 941 | |
c32c8af4 AV |
942 | audit_mq_sendrecv(mqdes, msg_len, 0, p); |
943 | timeout = prepare_timeout(p); | |
1da177e4 LT |
944 | |
945 | ret = -EBADF; | |
946 | filp = fget(mqdes); | |
947 | if (unlikely(!filp)) | |
948 | goto out; | |
949 | ||
6d63079a | 950 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
951 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
952 | goto out_fput; | |
953 | info = MQUEUE_I(inode); | |
5a190ae6 | 954 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 LT |
955 | |
956 | if (unlikely(!(filp->f_mode & FMODE_READ))) | |
957 | goto out_fput; | |
958 | ||
959 | /* checks if buffer is big enough */ | |
960 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
961 | ret = -EMSGSIZE; | |
962 | goto out_fput; | |
963 | } | |
964 | ||
965 | spin_lock(&info->lock); | |
966 | if (info->attr.mq_curmsgs == 0) { | |
967 | if (filp->f_flags & O_NONBLOCK) { | |
968 | spin_unlock(&info->lock); | |
969 | ret = -EAGAIN; | |
970 | msg_ptr = NULL; | |
971 | } else if (unlikely(timeout < 0)) { | |
972 | spin_unlock(&info->lock); | |
973 | ret = timeout; | |
974 | msg_ptr = NULL; | |
975 | } else { | |
976 | wait.task = current; | |
977 | wait.state = STATE_NONE; | |
978 | ret = wq_sleep(info, RECV, timeout, &wait); | |
979 | msg_ptr = wait.msg; | |
980 | } | |
981 | } else { | |
982 | msg_ptr = msg_get(info); | |
983 | ||
984 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
985 | CURRENT_TIME; | |
986 | ||
987 | /* There is now free space in queue. */ | |
988 | pipelined_receive(info); | |
989 | spin_unlock(&info->lock); | |
990 | ret = 0; | |
991 | } | |
992 | if (ret == 0) { | |
993 | ret = msg_ptr->m_ts; | |
994 | ||
995 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
996 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
997 | ret = -EFAULT; | |
998 | } | |
999 | free_msg(msg_ptr); | |
1000 | } | |
1001 | out_fput: | |
1002 | fput(filp); | |
1003 | out: | |
1004 | return ret; | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1009 | * and he isn't currently owner of notification, will be silently discarded. | |
1010 | * It isn't explicitly defined in the POSIX. | |
1011 | */ | |
c4ea37c2 HC |
1012 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1013 | const struct sigevent __user *, u_notification) | |
1da177e4 LT |
1014 | { |
1015 | int ret; | |
1016 | struct file *filp; | |
1017 | struct sock *sock; | |
1018 | struct inode *inode; | |
1019 | struct sigevent notification; | |
1020 | struct mqueue_inode_info *info; | |
1021 | struct sk_buff *nc; | |
1022 | ||
20114f71 | 1023 | if (u_notification) { |
1da177e4 LT |
1024 | if (copy_from_user(¬ification, u_notification, |
1025 | sizeof(struct sigevent))) | |
1026 | return -EFAULT; | |
20114f71 AV |
1027 | } |
1028 | ||
1029 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1da177e4 | 1030 | |
20114f71 AV |
1031 | nc = NULL; |
1032 | sock = NULL; | |
1033 | if (u_notification != NULL) { | |
1da177e4 LT |
1034 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1035 | notification.sigev_notify != SIGEV_SIGNAL && | |
1036 | notification.sigev_notify != SIGEV_THREAD)) | |
1037 | return -EINVAL; | |
1038 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1039 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1040 | return -EINVAL; |
1041 | } | |
1042 | if (notification.sigev_notify == SIGEV_THREAD) { | |
c3d8d1e3 PM |
1043 | long timeo; |
1044 | ||
1da177e4 LT |
1045 | /* create the notify skb */ |
1046 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
1047 | ret = -ENOMEM; | |
1048 | if (!nc) | |
1049 | goto out; | |
1050 | ret = -EFAULT; | |
1051 | if (copy_from_user(nc->data, | |
1052 | notification.sigev_value.sival_ptr, | |
1053 | NOTIFY_COOKIE_LEN)) { | |
1054 | goto out; | |
1055 | } | |
1056 | ||
1057 | /* TODO: add a header? */ | |
1058 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1059 | /* and attach it to the socket */ | |
1060 | retry: | |
1061 | filp = fget(notification.sigev_signo); | |
1062 | ret = -EBADF; | |
1063 | if (!filp) | |
1064 | goto out; | |
1065 | sock = netlink_getsockbyfilp(filp); | |
1066 | fput(filp); | |
1067 | if (IS_ERR(sock)) { | |
1068 | ret = PTR_ERR(sock); | |
1069 | sock = NULL; | |
1070 | goto out; | |
1071 | } | |
1072 | ||
c3d8d1e3 | 1073 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1074 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4 LT |
1075 | if (ret == 1) |
1076 | goto retry; | |
1077 | if (ret) { | |
1078 | sock = NULL; | |
1079 | nc = NULL; | |
1080 | goto out; | |
1081 | } | |
1082 | } | |
1083 | } | |
1084 | ||
1085 | ret = -EBADF; | |
1086 | filp = fget(mqdes); | |
1087 | if (!filp) | |
1088 | goto out; | |
1089 | ||
6d63079a | 1090 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
1091 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
1092 | goto out_fput; | |
1093 | info = MQUEUE_I(inode); | |
1094 | ||
1095 | ret = 0; | |
1096 | spin_lock(&info->lock); | |
1097 | if (u_notification == NULL) { | |
a03fcb73 | 1098 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 LT |
1099 | remove_notification(info); |
1100 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1101 | } | |
a03fcb73 | 1102 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1103 | ret = -EBUSY; |
1104 | } else { | |
1105 | switch (notification.sigev_notify) { | |
1106 | case SIGEV_NONE: | |
1107 | info->notify.sigev_notify = SIGEV_NONE; | |
1108 | break; | |
1109 | case SIGEV_THREAD: | |
1110 | info->notify_sock = sock; | |
1111 | info->notify_cookie = nc; | |
1112 | sock = NULL; | |
1113 | nc = NULL; | |
1114 | info->notify.sigev_notify = SIGEV_THREAD; | |
1115 | break; | |
1116 | case SIGEV_SIGNAL: | |
1117 | info->notify.sigev_signo = notification.sigev_signo; | |
1118 | info->notify.sigev_value = notification.sigev_value; | |
1119 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1120 | break; | |
1121 | } | |
a03fcb73 CLG |
1122 | |
1123 | info->notify_owner = get_pid(task_tgid(current)); | |
1da177e4 LT |
1124 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1125 | } | |
1126 | spin_unlock(&info->lock); | |
1127 | out_fput: | |
1128 | fput(filp); | |
1129 | out: | |
1130 | if (sock) { | |
1131 | netlink_detachskb(sock, nc); | |
1132 | } else if (nc) { | |
1133 | dev_kfree_skb(nc); | |
1134 | } | |
1135 | return ret; | |
1136 | } | |
1137 | ||
c4ea37c2 HC |
1138 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1139 | const struct mq_attr __user *, u_mqstat, | |
1140 | struct mq_attr __user *, u_omqstat) | |
1da177e4 LT |
1141 | { |
1142 | int ret; | |
1143 | struct mq_attr mqstat, omqstat; | |
1144 | struct file *filp; | |
1145 | struct inode *inode; | |
1146 | struct mqueue_inode_info *info; | |
1147 | ||
1148 | if (u_mqstat != NULL) { | |
1149 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1150 | return -EFAULT; | |
1151 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1152 | return -EINVAL; | |
1153 | } | |
1154 | ||
1155 | ret = -EBADF; | |
1156 | filp = fget(mqdes); | |
1157 | if (!filp) | |
1158 | goto out; | |
1159 | ||
6d63079a | 1160 | inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
1161 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
1162 | goto out_fput; | |
1163 | info = MQUEUE_I(inode); | |
1164 | ||
1165 | spin_lock(&info->lock); | |
1166 | ||
1167 | omqstat = info->attr; | |
1168 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1169 | if (u_mqstat) { | |
7392906e | 1170 | audit_mq_getsetattr(mqdes, &mqstat); |
db1dd4d3 | 1171 | spin_lock(&filp->f_lock); |
1da177e4 LT |
1172 | if (mqstat.mq_flags & O_NONBLOCK) |
1173 | filp->f_flags |= O_NONBLOCK; | |
1174 | else | |
1175 | filp->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 1176 | spin_unlock(&filp->f_lock); |
1da177e4 LT |
1177 | |
1178 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1179 | } | |
1180 | ||
1181 | spin_unlock(&info->lock); | |
1182 | ||
1183 | ret = 0; | |
1184 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1185 | sizeof(struct mq_attr))) | |
1186 | ret = -EFAULT; | |
1187 | ||
1188 | out_fput: | |
1189 | fput(filp); | |
1190 | out: | |
1191 | return ret; | |
1192 | } | |
1193 | ||
92e1d5be | 1194 | static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4 LT |
1195 | .lookup = simple_lookup, |
1196 | .create = mqueue_create, | |
1197 | .unlink = mqueue_unlink, | |
1198 | }; | |
1199 | ||
9a32144e | 1200 | static const struct file_operations mqueue_file_operations = { |
1da177e4 LT |
1201 | .flush = mqueue_flush_file, |
1202 | .poll = mqueue_poll_file, | |
1203 | .read = mqueue_read_file, | |
1204 | }; | |
1205 | ||
1206 | static struct super_operations mqueue_super_ops = { | |
1207 | .alloc_inode = mqueue_alloc_inode, | |
1208 | .destroy_inode = mqueue_destroy_inode, | |
1209 | .statfs = simple_statfs, | |
1210 | .delete_inode = mqueue_delete_inode, | |
1211 | .drop_inode = generic_delete_inode, | |
1212 | }; | |
1213 | ||
1214 | static struct file_system_type mqueue_fs_type = { | |
1215 | .name = "mqueue", | |
1216 | .get_sb = mqueue_get_sb, | |
1217 | .kill_sb = kill_litter_super, | |
1218 | }; | |
1219 | ||
b231cca4 JK |
1220 | static int msg_max_limit_min = MIN_MSGMAX; |
1221 | static int msg_max_limit_max = MAX_MSGMAX; | |
1da177e4 | 1222 | |
b231cca4 JK |
1223 | static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; |
1224 | static int msg_maxsize_limit_max = MAX_MSGSIZEMAX; | |
1da177e4 LT |
1225 | |
1226 | static ctl_table mq_sysctls[] = { | |
1227 | { | |
1da177e4 | 1228 | .procname = "queues_max", |
614b84cf | 1229 | .data = &init_ipc_ns.mq_queues_max, |
1da177e4 LT |
1230 | .maxlen = sizeof(int), |
1231 | .mode = 0644, | |
1232 | .proc_handler = &proc_dointvec, | |
1233 | }, | |
1234 | { | |
1da177e4 | 1235 | .procname = "msg_max", |
614b84cf | 1236 | .data = &init_ipc_ns.mq_msg_max, |
1da177e4 LT |
1237 | .maxlen = sizeof(int), |
1238 | .mode = 0644, | |
1239 | .proc_handler = &proc_dointvec_minmax, | |
1240 | .extra1 = &msg_max_limit_min, | |
1241 | .extra2 = &msg_max_limit_max, | |
1242 | }, | |
1243 | { | |
1da177e4 | 1244 | .procname = "msgsize_max", |
614b84cf | 1245 | .data = &init_ipc_ns.mq_msgsize_max, |
1da177e4 LT |
1246 | .maxlen = sizeof(int), |
1247 | .mode = 0644, | |
1248 | .proc_handler = &proc_dointvec_minmax, | |
1249 | .extra1 = &msg_maxsize_limit_min, | |
1250 | .extra2 = &msg_maxsize_limit_max, | |
1251 | }, | |
1252 | { .ctl_name = 0 } | |
1253 | }; | |
1254 | ||
1255 | static ctl_table mq_sysctl_dir[] = { | |
1256 | { | |
1da177e4 LT |
1257 | .procname = "mqueue", |
1258 | .mode = 0555, | |
1259 | .child = mq_sysctls, | |
1260 | }, | |
1261 | { .ctl_name = 0 } | |
1262 | }; | |
1263 | ||
1264 | static ctl_table mq_sysctl_root[] = { | |
1265 | { | |
1266 | .ctl_name = CTL_FS, | |
1267 | .procname = "fs", | |
1268 | .mode = 0555, | |
1269 | .child = mq_sysctl_dir, | |
1270 | }, | |
1271 | { .ctl_name = 0 } | |
1272 | }; | |
1273 | ||
1274 | static int __init init_mqueue_fs(void) | |
1275 | { | |
1276 | int error; | |
1277 | ||
1278 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1279 | sizeof(struct mqueue_inode_info), 0, | |
20c2df83 | 1280 | SLAB_HWCACHE_ALIGN, init_once); |
1da177e4 LT |
1281 | if (mqueue_inode_cachep == NULL) |
1282 | return -ENOMEM; | |
1283 | ||
1284 | /* ignore failues - they are not fatal */ | |
0b4d4147 | 1285 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root); |
1da177e4 LT |
1286 | |
1287 | error = register_filesystem(&mqueue_fs_type); | |
1288 | if (error) | |
1289 | goto out_sysctl; | |
1290 | ||
614b84cf SH |
1291 | init_ipc_ns.mq_mnt = kern_mount(&mqueue_fs_type); |
1292 | if (IS_ERR(init_ipc_ns.mq_mnt)) { | |
1293 | error = PTR_ERR(init_ipc_ns.mq_mnt); | |
1da177e4 LT |
1294 | goto out_filesystem; |
1295 | } | |
1296 | ||
1297 | /* internal initialization - not common for vfs */ | |
1da177e4 LT |
1298 | spin_lock_init(&mq_lock); |
1299 | ||
1300 | return 0; | |
1301 | ||
1302 | out_filesystem: | |
1303 | unregister_filesystem(&mqueue_fs_type); | |
1304 | out_sysctl: | |
1305 | if (mq_sysctl_table) | |
1306 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1307 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1308 | return error; |
1309 | } | |
1310 | ||
1311 | __initcall(init_mqueue_fs); |