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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * POSIX message queues filesystem for Linux. | |
3 | * | |
4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) | |
f66e928b | 5 | * Michal Wronski (michal.wronski@gmail.com) |
1da177e4 LT |
6 | * |
7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) | |
8 | * Lockless receive & send, fd based notify: | |
9 | * Manfred Spraul (manfred@colorfullife.com) | |
10 | * | |
20ca73bc GW |
11 | * Audit: George Wilson (ltcgcw@us.ibm.com) |
12 | * | |
1da177e4 LT |
13 | * This file is released under the GPL. |
14 | */ | |
15 | ||
c59ede7b | 16 | #include <linux/capability.h> |
1da177e4 LT |
17 | #include <linux/init.h> |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/file.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/namei.h> | |
22 | #include <linux/sysctl.h> | |
23 | #include <linux/poll.h> | |
24 | #include <linux/mqueue.h> | |
25 | #include <linux/msg.h> | |
26 | #include <linux/skbuff.h> | |
5b5c4d1a | 27 | #include <linux/vmalloc.h> |
1da177e4 LT |
28 | #include <linux/netlink.h> |
29 | #include <linux/syscalls.h> | |
20ca73bc | 30 | #include <linux/audit.h> |
7ed20e1a | 31 | #include <linux/signal.h> |
5f921ae9 | 32 | #include <linux/mutex.h> |
b488893a PE |
33 | #include <linux/nsproxy.h> |
34 | #include <linux/pid.h> | |
614b84cf | 35 | #include <linux/ipc_namespace.h> |
6b550f94 | 36 | #include <linux/user_namespace.h> |
5a0e3ad6 | 37 | #include <linux/slab.h> |
5f921ae9 | 38 | |
1da177e4 LT |
39 | #include <net/sock.h> |
40 | #include "util.h" | |
41 | ||
42 | #define MQUEUE_MAGIC 0x19800202 | |
43 | #define DIRENT_SIZE 20 | |
44 | #define FILENT_SIZE 80 | |
45 | ||
46 | #define SEND 0 | |
47 | #define RECV 1 | |
48 | ||
49 | #define STATE_NONE 0 | |
50 | #define STATE_PENDING 1 | |
51 | #define STATE_READY 2 | |
52 | ||
1da177e4 LT |
53 | struct ext_wait_queue { /* queue of sleeping tasks */ |
54 | struct task_struct *task; | |
55 | struct list_head list; | |
56 | struct msg_msg *msg; /* ptr of loaded message */ | |
57 | int state; /* one of STATE_* values */ | |
58 | }; | |
59 | ||
60 | struct mqueue_inode_info { | |
61 | spinlock_t lock; | |
62 | struct inode vfs_inode; | |
63 | wait_queue_head_t wait_q; | |
64 | ||
65 | struct msg_msg **messages; | |
66 | struct mq_attr attr; | |
67 | ||
68 | struct sigevent notify; | |
a03fcb73 | 69 | struct pid* notify_owner; |
6f9ac6d9 | 70 | struct user_namespace *notify_user_ns; |
338cec32 | 71 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
72 | struct sock *notify_sock; |
73 | struct sk_buff *notify_cookie; | |
74 | ||
75 | /* for tasks waiting for free space and messages, respectively */ | |
76 | struct ext_wait_queue e_wait_q[2]; | |
77 | ||
78 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
79 | }; | |
80 | ||
92e1d5be | 81 | static const struct inode_operations mqueue_dir_inode_operations; |
9a32144e | 82 | static const struct file_operations mqueue_file_operations; |
b87221de | 83 | static const struct super_operations mqueue_super_ops; |
1da177e4 LT |
84 | static void remove_notification(struct mqueue_inode_info *info); |
85 | ||
e18b890b | 86 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 LT |
87 | |
88 | static struct ctl_table_header * mq_sysctl_table; | |
89 | ||
90 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
91 | { | |
92 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
93 | } | |
94 | ||
7eafd7c7 SH |
95 | /* |
96 | * This routine should be called with the mq_lock held. | |
97 | */ | |
98 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
614b84cf | 99 | { |
7eafd7c7 | 100 | return get_ipc_ns(inode->i_sb->s_fs_info); |
614b84cf SH |
101 | } |
102 | ||
7eafd7c7 | 103 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
614b84cf | 104 | { |
7eafd7c7 SH |
105 | struct ipc_namespace *ns; |
106 | ||
107 | spin_lock(&mq_lock); | |
108 | ns = __get_ns_from_inode(inode); | |
109 | spin_unlock(&mq_lock); | |
110 | return ns; | |
614b84cf SH |
111 | } |
112 | ||
7eafd7c7 | 113 | static struct inode *mqueue_get_inode(struct super_block *sb, |
1b9d5ff7 | 114 | struct ipc_namespace *ipc_ns, umode_t mode, |
7eafd7c7 | 115 | struct mq_attr *attr) |
1da177e4 | 116 | { |
86a264ab | 117 | struct user_struct *u = current_user(); |
1da177e4 | 118 | struct inode *inode; |
d40dcdb0 | 119 | int ret = -ENOMEM; |
1da177e4 LT |
120 | |
121 | inode = new_inode(sb); | |
04715206 JS |
122 | if (!inode) |
123 | goto err; | |
124 | ||
125 | inode->i_ino = get_next_ino(); | |
126 | inode->i_mode = mode; | |
127 | inode->i_uid = current_fsuid(); | |
128 | inode->i_gid = current_fsgid(); | |
129 | inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; | |
130 | ||
131 | if (S_ISREG(mode)) { | |
132 | struct mqueue_inode_info *info; | |
04715206 JS |
133 | unsigned long mq_bytes, mq_msg_tblsz; |
134 | ||
135 | inode->i_fop = &mqueue_file_operations; | |
136 | inode->i_size = FILENT_SIZE; | |
137 | /* mqueue specific info */ | |
138 | info = MQUEUE_I(inode); | |
139 | spin_lock_init(&info->lock); | |
140 | init_waitqueue_head(&info->wait_q); | |
141 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
142 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
143 | info->notify_owner = NULL; | |
6f9ac6d9 | 144 | info->notify_user_ns = NULL; |
04715206 JS |
145 | info->qsize = 0; |
146 | info->user = NULL; /* set when all is ok */ | |
147 | memset(&info->attr, 0, sizeof(info->attr)); | |
cef0184c KM |
148 | info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, |
149 | ipc_ns->mq_msg_default); | |
150 | info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, | |
151 | ipc_ns->mq_msgsize_default); | |
04715206 JS |
152 | if (attr) { |
153 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
154 | info->attr.mq_msgsize = attr->mq_msgsize; | |
155 | } | |
156 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); | |
fd1f87d2 | 157 | if (mq_msg_tblsz > PAGE_SIZE) |
5b5c4d1a DL |
158 | info->messages = vmalloc(mq_msg_tblsz); |
159 | else | |
160 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); | |
04715206 JS |
161 | if (!info->messages) |
162 | goto out_inode; | |
163 | ||
164 | mq_bytes = (mq_msg_tblsz + | |
165 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); | |
1da177e4 | 166 | |
04715206 JS |
167 | spin_lock(&mq_lock); |
168 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
2a4e64b8 | 169 | u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { |
04715206 JS |
170 | spin_unlock(&mq_lock); |
171 | /* mqueue_evict_inode() releases info->messages */ | |
d40dcdb0 | 172 | ret = -EMFILE; |
04715206 | 173 | goto out_inode; |
1da177e4 | 174 | } |
04715206 JS |
175 | u->mq_bytes += mq_bytes; |
176 | spin_unlock(&mq_lock); | |
177 | ||
178 | /* all is ok */ | |
179 | info->user = get_uid(u); | |
180 | } else if (S_ISDIR(mode)) { | |
181 | inc_nlink(inode); | |
182 | /* Some things misbehave if size == 0 on a directory */ | |
183 | inode->i_size = 2 * DIRENT_SIZE; | |
184 | inode->i_op = &mqueue_dir_inode_operations; | |
185 | inode->i_fop = &simple_dir_operations; | |
1da177e4 | 186 | } |
04715206 | 187 | |
1da177e4 LT |
188 | return inode; |
189 | out_inode: | |
1da177e4 | 190 | iput(inode); |
04715206 | 191 | err: |
d40dcdb0 | 192 | return ERR_PTR(ret); |
1da177e4 LT |
193 | } |
194 | ||
195 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) | |
196 | { | |
197 | struct inode *inode; | |
7eafd7c7 | 198 | struct ipc_namespace *ns = data; |
1da177e4 LT |
199 | |
200 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
201 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
202 | sb->s_magic = MQUEUE_MAGIC; | |
203 | sb->s_op = &mqueue_super_ops; | |
204 | ||
48fde701 AV |
205 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
206 | if (IS_ERR(inode)) | |
207 | return PTR_ERR(inode); | |
1da177e4 | 208 | |
48fde701 AV |
209 | sb->s_root = d_make_root(inode); |
210 | if (!sb->s_root) | |
211 | return -ENOMEM; | |
212 | return 0; | |
1da177e4 LT |
213 | } |
214 | ||
ceefda69 | 215 | static struct dentry *mqueue_mount(struct file_system_type *fs_type, |
454e2398 | 216 | int flags, const char *dev_name, |
ceefda69 | 217 | void *data) |
1da177e4 | 218 | { |
7eafd7c7 SH |
219 | if (!(flags & MS_KERNMOUNT)) |
220 | data = current->nsproxy->ipc_ns; | |
ceefda69 | 221 | return mount_ns(fs_type, flags, data, mqueue_fill_super); |
1da177e4 LT |
222 | } |
223 | ||
51cc5068 | 224 | static void init_once(void *foo) |
1da177e4 LT |
225 | { |
226 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
227 | ||
a35afb83 | 228 | inode_init_once(&p->vfs_inode); |
1da177e4 LT |
229 | } |
230 | ||
231 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
232 | { | |
233 | struct mqueue_inode_info *ei; | |
234 | ||
e94b1766 | 235 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
236 | if (!ei) |
237 | return NULL; | |
238 | return &ei->vfs_inode; | |
239 | } | |
240 | ||
fa0d7e3d | 241 | static void mqueue_i_callback(struct rcu_head *head) |
1da177e4 | 242 | { |
fa0d7e3d | 243 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
244 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); |
245 | } | |
246 | ||
fa0d7e3d NP |
247 | static void mqueue_destroy_inode(struct inode *inode) |
248 | { | |
249 | call_rcu(&inode->i_rcu, mqueue_i_callback); | |
250 | } | |
251 | ||
6d8af64c | 252 | static void mqueue_evict_inode(struct inode *inode) |
1da177e4 LT |
253 | { |
254 | struct mqueue_inode_info *info; | |
255 | struct user_struct *user; | |
256 | unsigned long mq_bytes; | |
257 | int i; | |
7eafd7c7 | 258 | struct ipc_namespace *ipc_ns; |
1da177e4 | 259 | |
dbd5768f | 260 | clear_inode(inode); |
6d8af64c AV |
261 | |
262 | if (S_ISDIR(inode->i_mode)) | |
1da177e4 | 263 | return; |
6d8af64c | 264 | |
7eafd7c7 | 265 | ipc_ns = get_ns_from_inode(inode); |
1da177e4 LT |
266 | info = MQUEUE_I(inode); |
267 | spin_lock(&info->lock); | |
268 | for (i = 0; i < info->attr.mq_curmsgs; i++) | |
269 | free_msg(info->messages[i]); | |
fd1f87d2 | 270 | if (is_vmalloc_addr(info->messages)) |
5b5c4d1a DL |
271 | vfree(info->messages); |
272 | else | |
273 | kfree(info->messages); | |
1da177e4 LT |
274 | spin_unlock(&info->lock); |
275 | ||
8834cf79 AGR |
276 | /* Total amount of bytes accounted for the mqueue */ |
277 | mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *) | |
278 | + info->attr.mq_msgsize); | |
1da177e4 LT |
279 | user = info->user; |
280 | if (user) { | |
281 | spin_lock(&mq_lock); | |
282 | user->mq_bytes -= mq_bytes; | |
7eafd7c7 SH |
283 | /* |
284 | * get_ns_from_inode() ensures that the | |
285 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
286 | * to which we now hold a reference, or it is NULL. | |
287 | * We can't put it here under mq_lock, though. | |
288 | */ | |
289 | if (ipc_ns) | |
290 | ipc_ns->mq_queues_count--; | |
1da177e4 LT |
291 | spin_unlock(&mq_lock); |
292 | free_uid(user); | |
293 | } | |
7eafd7c7 SH |
294 | if (ipc_ns) |
295 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
296 | } |
297 | ||
298 | static int mqueue_create(struct inode *dir, struct dentry *dentry, | |
4acdaf27 | 299 | umode_t mode, struct nameidata *nd) |
1da177e4 LT |
300 | { |
301 | struct inode *inode; | |
302 | struct mq_attr *attr = dentry->d_fsdata; | |
303 | int error; | |
7eafd7c7 | 304 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
305 | |
306 | spin_lock(&mq_lock); | |
7eafd7c7 SH |
307 | ipc_ns = __get_ns_from_inode(dir); |
308 | if (!ipc_ns) { | |
309 | error = -EACCES; | |
310 | goto out_unlock; | |
311 | } | |
02967ea0 DL |
312 | if (ipc_ns->mq_queues_count >= HARD_QUEUESMAX || |
313 | (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && | |
314 | !capable(CAP_SYS_RESOURCE))) { | |
1da177e4 | 315 | error = -ENOSPC; |
614b84cf | 316 | goto out_unlock; |
1da177e4 | 317 | } |
614b84cf | 318 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
319 | spin_unlock(&mq_lock); |
320 | ||
7eafd7c7 | 321 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
d40dcdb0 JS |
322 | if (IS_ERR(inode)) { |
323 | error = PTR_ERR(inode); | |
1da177e4 | 324 | spin_lock(&mq_lock); |
614b84cf SH |
325 | ipc_ns->mq_queues_count--; |
326 | goto out_unlock; | |
1da177e4 LT |
327 | } |
328 | ||
7eafd7c7 | 329 | put_ipc_ns(ipc_ns); |
1da177e4 LT |
330 | dir->i_size += DIRENT_SIZE; |
331 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
332 | ||
333 | d_instantiate(dentry, inode); | |
334 | dget(dentry); | |
335 | return 0; | |
614b84cf | 336 | out_unlock: |
1da177e4 | 337 | spin_unlock(&mq_lock); |
7eafd7c7 SH |
338 | if (ipc_ns) |
339 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
340 | return error; |
341 | } | |
342 | ||
343 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) | |
344 | { | |
345 | struct inode *inode = dentry->d_inode; | |
346 | ||
347 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; | |
348 | dir->i_size -= DIRENT_SIZE; | |
9a53c3a7 | 349 | drop_nlink(inode); |
1da177e4 LT |
350 | dput(dentry); |
351 | return 0; | |
352 | } | |
353 | ||
354 | /* | |
355 | * This is routine for system read from queue file. | |
356 | * To avoid mess with doing here some sort of mq_receive we allow | |
357 | * to read only queue size & notification info (the only values | |
358 | * that are interesting from user point of view and aren't accessible | |
359 | * through std routines) | |
360 | */ | |
361 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 362 | size_t count, loff_t *off) |
1da177e4 | 363 | { |
6d63079a | 364 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 | 365 | char buffer[FILENT_SIZE]; |
f1a43f93 | 366 | ssize_t ret; |
1da177e4 LT |
367 | |
368 | spin_lock(&info->lock); | |
369 | snprintf(buffer, sizeof(buffer), | |
370 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
371 | info->qsize, | |
372 | info->notify_owner ? info->notify.sigev_notify : 0, | |
373 | (info->notify_owner && | |
374 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
375 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 376 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
377 | spin_unlock(&info->lock); |
378 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 379 | |
f1a43f93 AM |
380 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
381 | strlen(buffer)); | |
382 | if (ret <= 0) | |
383 | return ret; | |
1da177e4 | 384 | |
6d63079a | 385 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
f1a43f93 | 386 | return ret; |
1da177e4 LT |
387 | } |
388 | ||
75e1fcc0 | 389 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 390 | { |
6d63079a | 391 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
392 | |
393 | spin_lock(&info->lock); | |
a03fcb73 | 394 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
395 | remove_notification(info); |
396 | ||
397 | spin_unlock(&info->lock); | |
398 | return 0; | |
399 | } | |
400 | ||
401 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) | |
402 | { | |
6d63079a | 403 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
1da177e4 LT |
404 | int retval = 0; |
405 | ||
406 | poll_wait(filp, &info->wait_q, poll_tab); | |
407 | ||
408 | spin_lock(&info->lock); | |
409 | if (info->attr.mq_curmsgs) | |
410 | retval = POLLIN | POLLRDNORM; | |
411 | ||
412 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
413 | retval |= POLLOUT | POLLWRNORM; | |
414 | spin_unlock(&info->lock); | |
415 | ||
416 | return retval; | |
417 | } | |
418 | ||
419 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
420 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
421 | struct ext_wait_queue *ewp) | |
422 | { | |
423 | struct ext_wait_queue *walk; | |
424 | ||
425 | ewp->task = current; | |
426 | ||
427 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { | |
428 | if (walk->task->static_prio <= current->static_prio) { | |
429 | list_add_tail(&ewp->list, &walk->list); | |
430 | return; | |
431 | } | |
432 | } | |
433 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
434 | } | |
435 | ||
436 | /* | |
437 | * Puts current task to sleep. Caller must hold queue lock. After return | |
438 | * lock isn't held. | |
439 | * sr: SEND or RECV | |
440 | */ | |
441 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
9ca7d8e6 | 442 | ktime_t *timeout, struct ext_wait_queue *ewp) |
1da177e4 LT |
443 | { |
444 | int retval; | |
445 | signed long time; | |
446 | ||
447 | wq_add(info, sr, ewp); | |
448 | ||
449 | for (;;) { | |
450 | set_current_state(TASK_INTERRUPTIBLE); | |
451 | ||
452 | spin_unlock(&info->lock); | |
32ea845d WG |
453 | time = schedule_hrtimeout_range_clock(timeout, 0, |
454 | HRTIMER_MODE_ABS, CLOCK_REALTIME); | |
1da177e4 LT |
455 | |
456 | while (ewp->state == STATE_PENDING) | |
457 | cpu_relax(); | |
458 | ||
459 | if (ewp->state == STATE_READY) { | |
460 | retval = 0; | |
461 | goto out; | |
462 | } | |
463 | spin_lock(&info->lock); | |
464 | if (ewp->state == STATE_READY) { | |
465 | retval = 0; | |
466 | goto out_unlock; | |
467 | } | |
468 | if (signal_pending(current)) { | |
469 | retval = -ERESTARTSYS; | |
470 | break; | |
471 | } | |
472 | if (time == 0) { | |
473 | retval = -ETIMEDOUT; | |
474 | break; | |
475 | } | |
476 | } | |
477 | list_del(&ewp->list); | |
478 | out_unlock: | |
479 | spin_unlock(&info->lock); | |
480 | out: | |
481 | return retval; | |
482 | } | |
483 | ||
484 | /* | |
485 | * Returns waiting task that should be serviced first or NULL if none exists | |
486 | */ | |
487 | static struct ext_wait_queue *wq_get_first_waiter( | |
488 | struct mqueue_inode_info *info, int sr) | |
489 | { | |
490 | struct list_head *ptr; | |
491 | ||
492 | ptr = info->e_wait_q[sr].list.prev; | |
493 | if (ptr == &info->e_wait_q[sr].list) | |
494 | return NULL; | |
495 | return list_entry(ptr, struct ext_wait_queue, list); | |
496 | } | |
497 | ||
498 | /* Auxiliary functions to manipulate messages' list */ | |
499 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) | |
500 | { | |
501 | int k; | |
502 | ||
503 | k = info->attr.mq_curmsgs - 1; | |
504 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { | |
505 | info->messages[k + 1] = info->messages[k]; | |
506 | k--; | |
507 | } | |
508 | info->attr.mq_curmsgs++; | |
509 | info->qsize += ptr->m_ts; | |
510 | info->messages[k + 1] = ptr; | |
511 | } | |
512 | ||
513 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) | |
514 | { | |
515 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; | |
516 | return info->messages[info->attr.mq_curmsgs]; | |
517 | } | |
518 | ||
519 | static inline void set_cookie(struct sk_buff *skb, char code) | |
520 | { | |
521 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; | |
522 | } | |
523 | ||
524 | /* | |
525 | * The next function is only to split too long sys_mq_timedsend | |
526 | */ | |
527 | static void __do_notify(struct mqueue_inode_info *info) | |
528 | { | |
529 | /* notification | |
530 | * invoked when there is registered process and there isn't process | |
531 | * waiting synchronously for message AND state of queue changed from | |
532 | * empty to not empty. Here we are sure that no one is waiting | |
533 | * synchronously. */ | |
534 | if (info->notify_owner && | |
535 | info->attr.mq_curmsgs == 1) { | |
536 | struct siginfo sig_i; | |
537 | switch (info->notify.sigev_notify) { | |
538 | case SIGEV_NONE: | |
539 | break; | |
540 | case SIGEV_SIGNAL: | |
541 | /* sends signal */ | |
542 | ||
543 | sig_i.si_signo = info->notify.sigev_signo; | |
544 | sig_i.si_errno = 0; | |
545 | sig_i.si_code = SI_MESGQ; | |
546 | sig_i.si_value = info->notify.sigev_value; | |
6b550f94 SH |
547 | /* map current pid/uid into info->owner's namespaces */ |
548 | rcu_read_lock(); | |
a6684999 SB |
549 | sig_i.si_pid = task_tgid_nr_ns(current, |
550 | ns_of_pid(info->notify_owner)); | |
76b6db01 | 551 | sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); |
6b550f94 | 552 | rcu_read_unlock(); |
1da177e4 | 553 | |
a03fcb73 CLG |
554 | kill_pid_info(info->notify.sigev_signo, |
555 | &sig_i, info->notify_owner); | |
1da177e4 LT |
556 | break; |
557 | case SIGEV_THREAD: | |
558 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 559 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
560 | break; |
561 | } | |
562 | /* after notification unregisters process */ | |
a03fcb73 | 563 | put_pid(info->notify_owner); |
6f9ac6d9 | 564 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 565 | info->notify_owner = NULL; |
6f9ac6d9 | 566 | info->notify_user_ns = NULL; |
1da177e4 LT |
567 | } |
568 | wake_up(&info->wait_q); | |
569 | } | |
570 | ||
9ca7d8e6 CE |
571 | static int prepare_timeout(const struct timespec __user *u_abs_timeout, |
572 | ktime_t *expires, struct timespec *ts) | |
1da177e4 | 573 | { |
9ca7d8e6 CE |
574 | if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) |
575 | return -EFAULT; | |
576 | if (!timespec_valid(ts)) | |
577 | return -EINVAL; | |
1da177e4 | 578 | |
9ca7d8e6 CE |
579 | *expires = timespec_to_ktime(*ts); |
580 | return 0; | |
1da177e4 LT |
581 | } |
582 | ||
583 | static void remove_notification(struct mqueue_inode_info *info) | |
584 | { | |
a03fcb73 | 585 | if (info->notify_owner != NULL && |
1da177e4 LT |
586 | info->notify.sigev_notify == SIGEV_THREAD) { |
587 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 588 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 589 | } |
a03fcb73 | 590 | put_pid(info->notify_owner); |
6f9ac6d9 | 591 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 592 | info->notify_owner = NULL; |
6f9ac6d9 | 593 | info->notify_user_ns = NULL; |
1da177e4 LT |
594 | } |
595 | ||
614b84cf | 596 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
1da177e4 LT |
597 | { |
598 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
599 | return 0; | |
600 | if (capable(CAP_SYS_RESOURCE)) { | |
02967ea0 DL |
601 | if (attr->mq_maxmsg > HARD_MSGMAX || |
602 | attr->mq_msgsize > HARD_MSGSIZEMAX) | |
1da177e4 LT |
603 | return 0; |
604 | } else { | |
614b84cf SH |
605 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
606 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) | |
1da177e4 LT |
607 | return 0; |
608 | } | |
609 | /* check for overflow */ | |
610 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) | |
611 | return 0; | |
8834cf79 AGR |
612 | if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize |
613 | + sizeof (struct msg_msg *))) < | |
1da177e4 LT |
614 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) |
615 | return 0; | |
616 | return 1; | |
617 | } | |
618 | ||
619 | /* | |
620 | * Invoked when creating a new queue via sys_mq_open | |
621 | */ | |
614b84cf | 622 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, |
4acdaf27 | 623 | struct dentry *dentry, int oflag, umode_t mode, |
614b84cf | 624 | struct mq_attr *attr) |
1da177e4 | 625 | { |
745ca247 | 626 | const struct cred *cred = current_cred(); |
4a3fd211 | 627 | struct file *result; |
1da177e4 LT |
628 | int ret; |
629 | ||
564f6993 | 630 | if (attr) { |
8d8ffefa AGR |
631 | if (!mq_attr_ok(ipc_ns, attr)) { |
632 | ret = -EINVAL; | |
7c7dce92 | 633 | goto out; |
8d8ffefa | 634 | } |
1da177e4 | 635 | /* store for use during create */ |
564f6993 | 636 | dentry->d_fsdata = attr; |
1da177e4 LT |
637 | } |
638 | ||
ce3b0f8d | 639 | mode &= ~current_umask(); |
614b84cf | 640 | ret = mnt_want_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
641 | if (ret) |
642 | goto out; | |
1da177e4 LT |
643 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
644 | dentry->d_fsdata = NULL; | |
645 | if (ret) | |
4a3fd211 DH |
646 | goto out_drop_write; |
647 | ||
614b84cf | 648 | result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
4a3fd211 DH |
649 | /* |
650 | * dentry_open() took a persistent mnt_want_write(), | |
651 | * so we can now drop this one. | |
652 | */ | |
614b84cf | 653 | mnt_drop_write(ipc_ns->mq_mnt); |
4a3fd211 DH |
654 | return result; |
655 | ||
656 | out_drop_write: | |
614b84cf | 657 | mnt_drop_write(ipc_ns->mq_mnt); |
7c7dce92 AV |
658 | out: |
659 | dput(dentry); | |
614b84cf | 660 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 661 | return ERR_PTR(ret); |
1da177e4 LT |
662 | } |
663 | ||
664 | /* Opens existing queue */ | |
614b84cf SH |
665 | static struct file *do_open(struct ipc_namespace *ipc_ns, |
666 | struct dentry *dentry, int oflag) | |
1da177e4 | 667 | { |
04db0dde | 668 | int ret; |
745ca247 DH |
669 | const struct cred *cred = current_cred(); |
670 | ||
671 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, | |
672 | MAY_READ | MAY_WRITE }; | |
1da177e4 | 673 | |
7c7dce92 | 674 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
04db0dde AGR |
675 | ret = -EINVAL; |
676 | goto err; | |
7c7dce92 | 677 | } |
1da177e4 | 678 | |
f419a2e3 | 679 | if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { |
04db0dde AGR |
680 | ret = -EACCES; |
681 | goto err; | |
7c7dce92 | 682 | } |
1da177e4 | 683 | |
614b84cf | 684 | return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); |
04db0dde AGR |
685 | |
686 | err: | |
687 | dput(dentry); | |
688 | mntput(ipc_ns->mq_mnt); | |
689 | return ERR_PTR(ret); | |
1da177e4 LT |
690 | } |
691 | ||
df0a4283 | 692 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, |
d5460c99 | 693 | struct mq_attr __user *, u_attr) |
1da177e4 LT |
694 | { |
695 | struct dentry *dentry; | |
696 | struct file *filp; | |
697 | char *name; | |
564f6993 | 698 | struct mq_attr attr; |
1da177e4 | 699 | int fd, error; |
7eafd7c7 | 700 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 | 701 | |
564f6993 AV |
702 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
703 | return -EFAULT; | |
704 | ||
705 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); | |
20ca73bc | 706 | |
1da177e4 LT |
707 | if (IS_ERR(name = getname(u_name))) |
708 | return PTR_ERR(name); | |
709 | ||
269f2134 | 710 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
711 | if (fd < 0) |
712 | goto out_putname; | |
713 | ||
614b84cf SH |
714 | mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
715 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); | |
1da177e4 LT |
716 | if (IS_ERR(dentry)) { |
717 | error = PTR_ERR(dentry); | |
4294a8ee | 718 | goto out_putfd; |
1da177e4 | 719 | } |
614b84cf | 720 | mntget(ipc_ns->mq_mnt); |
1da177e4 LT |
721 | |
722 | if (oflag & O_CREAT) { | |
723 | if (dentry->d_inode) { /* entry already exists */ | |
5a190ae6 | 724 | audit_inode(name, dentry); |
8d8ffefa AGR |
725 | if (oflag & O_EXCL) { |
726 | error = -EEXIST; | |
7c7dce92 | 727 | goto out; |
8d8ffefa | 728 | } |
614b84cf | 729 | filp = do_open(ipc_ns, dentry, oflag); |
1da177e4 | 730 | } else { |
614b84cf SH |
731 | filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, |
732 | dentry, oflag, mode, | |
564f6993 | 733 | u_attr ? &attr : NULL); |
1da177e4 | 734 | } |
7c7dce92 | 735 | } else { |
8d8ffefa AGR |
736 | if (!dentry->d_inode) { |
737 | error = -ENOENT; | |
7c7dce92 | 738 | goto out; |
8d8ffefa | 739 | } |
5a190ae6 | 740 | audit_inode(name, dentry); |
614b84cf | 741 | filp = do_open(ipc_ns, dentry, oflag); |
7c7dce92 | 742 | } |
1da177e4 LT |
743 | |
744 | if (IS_ERR(filp)) { | |
745 | error = PTR_ERR(filp); | |
746 | goto out_putfd; | |
747 | } | |
748 | ||
1da177e4 LT |
749 | fd_install(fd, filp); |
750 | goto out_upsem; | |
751 | ||
7c7dce92 AV |
752 | out: |
753 | dput(dentry); | |
614b84cf | 754 | mntput(ipc_ns->mq_mnt); |
7c7dce92 | 755 | out_putfd: |
1da177e4 | 756 | put_unused_fd(fd); |
1da177e4 LT |
757 | fd = error; |
758 | out_upsem: | |
614b84cf | 759 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
760 | out_putname: |
761 | putname(name); | |
762 | return fd; | |
763 | } | |
764 | ||
d5460c99 | 765 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
766 | { |
767 | int err; | |
768 | char *name; | |
769 | struct dentry *dentry; | |
770 | struct inode *inode = NULL; | |
7eafd7c7 | 771 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
772 | |
773 | name = getname(u_name); | |
774 | if (IS_ERR(name)) | |
775 | return PTR_ERR(name); | |
776 | ||
614b84cf | 777 | mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, |
7a434814 | 778 | I_MUTEX_PARENT); |
614b84cf | 779 | dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); |
1da177e4 LT |
780 | if (IS_ERR(dentry)) { |
781 | err = PTR_ERR(dentry); | |
782 | goto out_unlock; | |
783 | } | |
784 | ||
785 | if (!dentry->d_inode) { | |
786 | err = -ENOENT; | |
787 | goto out_err; | |
788 | } | |
789 | ||
790 | inode = dentry->d_inode; | |
791 | if (inode) | |
7de9c6ee | 792 | ihold(inode); |
614b84cf | 793 | err = mnt_want_write(ipc_ns->mq_mnt); |
0622753b DH |
794 | if (err) |
795 | goto out_err; | |
1da177e4 | 796 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
614b84cf | 797 | mnt_drop_write(ipc_ns->mq_mnt); |
1da177e4 LT |
798 | out_err: |
799 | dput(dentry); | |
800 | ||
801 | out_unlock: | |
614b84cf | 802 | mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); |
1da177e4 LT |
803 | putname(name); |
804 | if (inode) | |
805 | iput(inode); | |
806 | ||
807 | return err; | |
808 | } | |
809 | ||
810 | /* Pipelined send and receive functions. | |
811 | * | |
812 | * If a receiver finds no waiting message, then it registers itself in the | |
813 | * list of waiting receivers. A sender checks that list before adding the new | |
814 | * message into the message array. If there is a waiting receiver, then it | |
815 | * bypasses the message array and directly hands the message over to the | |
816 | * receiver. | |
817 | * The receiver accepts the message and returns without grabbing the queue | |
818 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers | |
819 | * are necessary. The same algorithm is used for sysv semaphores, see | |
7b7a317c | 820 | * ipc/sem.c for more details. |
1da177e4 LT |
821 | * |
822 | * The same algorithm is used for senders. | |
823 | */ | |
824 | ||
825 | /* pipelined_send() - send a message directly to the task waiting in | |
826 | * sys_mq_timedreceive() (without inserting message into a queue). | |
827 | */ | |
828 | static inline void pipelined_send(struct mqueue_inode_info *info, | |
829 | struct msg_msg *message, | |
830 | struct ext_wait_queue *receiver) | |
831 | { | |
832 | receiver->msg = message; | |
833 | list_del(&receiver->list); | |
834 | receiver->state = STATE_PENDING; | |
835 | wake_up_process(receiver->task); | |
d59dd462 | 836 | smp_wmb(); |
1da177e4 LT |
837 | receiver->state = STATE_READY; |
838 | } | |
839 | ||
840 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
841 | * gets its message and put to the queue (we have one free place for sure). */ | |
842 | static inline void pipelined_receive(struct mqueue_inode_info *info) | |
843 | { | |
844 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
845 | ||
846 | if (!sender) { | |
847 | /* for poll */ | |
848 | wake_up_interruptible(&info->wait_q); | |
849 | return; | |
850 | } | |
851 | msg_insert(sender->msg, info); | |
852 | list_del(&sender->list); | |
853 | sender->state = STATE_PENDING; | |
854 | wake_up_process(sender->task); | |
d59dd462 | 855 | smp_wmb(); |
1da177e4 LT |
856 | sender->state = STATE_READY; |
857 | } | |
858 | ||
c4ea37c2 HC |
859 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
860 | size_t, msg_len, unsigned int, msg_prio, | |
861 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 LT |
862 | { |
863 | struct file *filp; | |
864 | struct inode *inode; | |
865 | struct ext_wait_queue wait; | |
866 | struct ext_wait_queue *receiver; | |
867 | struct msg_msg *msg_ptr; | |
868 | struct mqueue_inode_info *info; | |
9ca7d8e6 CE |
869 | ktime_t expires, *timeout = NULL; |
870 | struct timespec ts; | |
1da177e4 LT |
871 | int ret; |
872 | ||
c32c8af4 | 873 | if (u_abs_timeout) { |
9ca7d8e6 CE |
874 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
875 | if (res) | |
876 | return res; | |
877 | timeout = &expires; | |
c32c8af4 | 878 | } |
20ca73bc | 879 | |
1da177e4 LT |
880 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
881 | return -EINVAL; | |
882 | ||
9ca7d8e6 | 883 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); |
1da177e4 | 884 | |
1da177e4 | 885 | filp = fget(mqdes); |
8d8ffefa AGR |
886 | if (unlikely(!filp)) { |
887 | ret = -EBADF; | |
1da177e4 | 888 | goto out; |
8d8ffefa | 889 | } |
1da177e4 | 890 | |
6d63079a | 891 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
892 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
893 | ret = -EBADF; | |
1da177e4 | 894 | goto out_fput; |
8d8ffefa | 895 | } |
1da177e4 | 896 | info = MQUEUE_I(inode); |
5a190ae6 | 897 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 898 | |
8d8ffefa AGR |
899 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) { |
900 | ret = -EBADF; | |
1da177e4 | 901 | goto out_fput; |
8d8ffefa | 902 | } |
1da177e4 LT |
903 | |
904 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
905 | ret = -EMSGSIZE; | |
906 | goto out_fput; | |
907 | } | |
908 | ||
909 | /* First try to allocate memory, before doing anything with | |
910 | * existing queues. */ | |
911 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
912 | if (IS_ERR(msg_ptr)) { | |
913 | ret = PTR_ERR(msg_ptr); | |
914 | goto out_fput; | |
915 | } | |
916 | msg_ptr->m_ts = msg_len; | |
917 | msg_ptr->m_type = msg_prio; | |
918 | ||
919 | spin_lock(&info->lock); | |
920 | ||
921 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { | |
922 | if (filp->f_flags & O_NONBLOCK) { | |
923 | spin_unlock(&info->lock); | |
924 | ret = -EAGAIN; | |
1da177e4 LT |
925 | } else { |
926 | wait.task = current; | |
927 | wait.msg = (void *) msg_ptr; | |
928 | wait.state = STATE_NONE; | |
929 | ret = wq_sleep(info, SEND, timeout, &wait); | |
930 | } | |
931 | if (ret < 0) | |
932 | free_msg(msg_ptr); | |
933 | } else { | |
934 | receiver = wq_get_first_waiter(info, RECV); | |
935 | if (receiver) { | |
936 | pipelined_send(info, msg_ptr, receiver); | |
937 | } else { | |
938 | /* adds message to the queue */ | |
939 | msg_insert(msg_ptr, info); | |
940 | __do_notify(info); | |
941 | } | |
942 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
943 | CURRENT_TIME; | |
944 | spin_unlock(&info->lock); | |
945 | ret = 0; | |
946 | } | |
947 | out_fput: | |
948 | fput(filp); | |
949 | out: | |
950 | return ret; | |
951 | } | |
952 | ||
c4ea37c2 HC |
953 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
954 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
955 | const struct timespec __user *, u_abs_timeout) | |
1da177e4 | 956 | { |
1da177e4 LT |
957 | ssize_t ret; |
958 | struct msg_msg *msg_ptr; | |
959 | struct file *filp; | |
960 | struct inode *inode; | |
961 | struct mqueue_inode_info *info; | |
962 | struct ext_wait_queue wait; | |
9ca7d8e6 CE |
963 | ktime_t expires, *timeout = NULL; |
964 | struct timespec ts; | |
1da177e4 | 965 | |
c32c8af4 | 966 | if (u_abs_timeout) { |
9ca7d8e6 CE |
967 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
968 | if (res) | |
969 | return res; | |
970 | timeout = &expires; | |
c32c8af4 | 971 | } |
20ca73bc | 972 | |
9ca7d8e6 | 973 | audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); |
1da177e4 | 974 | |
1da177e4 | 975 | filp = fget(mqdes); |
8d8ffefa AGR |
976 | if (unlikely(!filp)) { |
977 | ret = -EBADF; | |
1da177e4 | 978 | goto out; |
8d8ffefa | 979 | } |
1da177e4 | 980 | |
6d63079a | 981 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
982 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
983 | ret = -EBADF; | |
1da177e4 | 984 | goto out_fput; |
8d8ffefa | 985 | } |
1da177e4 | 986 | info = MQUEUE_I(inode); |
5a190ae6 | 987 | audit_inode(NULL, filp->f_path.dentry); |
1da177e4 | 988 | |
8d8ffefa AGR |
989 | if (unlikely(!(filp->f_mode & FMODE_READ))) { |
990 | ret = -EBADF; | |
1da177e4 | 991 | goto out_fput; |
8d8ffefa | 992 | } |
1da177e4 LT |
993 | |
994 | /* checks if buffer is big enough */ | |
995 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
996 | ret = -EMSGSIZE; | |
997 | goto out_fput; | |
998 | } | |
999 | ||
1000 | spin_lock(&info->lock); | |
1001 | if (info->attr.mq_curmsgs == 0) { | |
1002 | if (filp->f_flags & O_NONBLOCK) { | |
1003 | spin_unlock(&info->lock); | |
1004 | ret = -EAGAIN; | |
1da177e4 LT |
1005 | } else { |
1006 | wait.task = current; | |
1007 | wait.state = STATE_NONE; | |
1008 | ret = wq_sleep(info, RECV, timeout, &wait); | |
1009 | msg_ptr = wait.msg; | |
1010 | } | |
1011 | } else { | |
1012 | msg_ptr = msg_get(info); | |
1013 | ||
1014 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
1015 | CURRENT_TIME; | |
1016 | ||
1017 | /* There is now free space in queue. */ | |
1018 | pipelined_receive(info); | |
1019 | spin_unlock(&info->lock); | |
1020 | ret = 0; | |
1021 | } | |
1022 | if (ret == 0) { | |
1023 | ret = msg_ptr->m_ts; | |
1024 | ||
1025 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1026 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1027 | ret = -EFAULT; | |
1028 | } | |
1029 | free_msg(msg_ptr); | |
1030 | } | |
1031 | out_fput: | |
1032 | fput(filp); | |
1033 | out: | |
1034 | return ret; | |
1035 | } | |
1036 | ||
1037 | /* | |
1038 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1039 | * and he isn't currently owner of notification, will be silently discarded. | |
1040 | * It isn't explicitly defined in the POSIX. | |
1041 | */ | |
c4ea37c2 HC |
1042 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1043 | const struct sigevent __user *, u_notification) | |
1da177e4 LT |
1044 | { |
1045 | int ret; | |
1046 | struct file *filp; | |
1047 | struct sock *sock; | |
1048 | struct inode *inode; | |
1049 | struct sigevent notification; | |
1050 | struct mqueue_inode_info *info; | |
1051 | struct sk_buff *nc; | |
1052 | ||
20114f71 | 1053 | if (u_notification) { |
1da177e4 LT |
1054 | if (copy_from_user(¬ification, u_notification, |
1055 | sizeof(struct sigevent))) | |
1056 | return -EFAULT; | |
20114f71 AV |
1057 | } |
1058 | ||
1059 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); | |
1da177e4 | 1060 | |
20114f71 AV |
1061 | nc = NULL; |
1062 | sock = NULL; | |
1063 | if (u_notification != NULL) { | |
1da177e4 LT |
1064 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1065 | notification.sigev_notify != SIGEV_SIGNAL && | |
1066 | notification.sigev_notify != SIGEV_THREAD)) | |
1067 | return -EINVAL; | |
1068 | if (notification.sigev_notify == SIGEV_SIGNAL && | |
7ed20e1a | 1069 | !valid_signal(notification.sigev_signo)) { |
1da177e4 LT |
1070 | return -EINVAL; |
1071 | } | |
1072 | if (notification.sigev_notify == SIGEV_THREAD) { | |
c3d8d1e3 PM |
1073 | long timeo; |
1074 | ||
1da177e4 LT |
1075 | /* create the notify skb */ |
1076 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
8d8ffefa AGR |
1077 | if (!nc) { |
1078 | ret = -ENOMEM; | |
1da177e4 | 1079 | goto out; |
8d8ffefa | 1080 | } |
1da177e4 LT |
1081 | if (copy_from_user(nc->data, |
1082 | notification.sigev_value.sival_ptr, | |
1083 | NOTIFY_COOKIE_LEN)) { | |
8d8ffefa | 1084 | ret = -EFAULT; |
1da177e4 LT |
1085 | goto out; |
1086 | } | |
1087 | ||
1088 | /* TODO: add a header? */ | |
1089 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1090 | /* and attach it to the socket */ | |
1091 | retry: | |
1092 | filp = fget(notification.sigev_signo); | |
8d8ffefa AGR |
1093 | if (!filp) { |
1094 | ret = -EBADF; | |
1da177e4 | 1095 | goto out; |
8d8ffefa | 1096 | } |
1da177e4 LT |
1097 | sock = netlink_getsockbyfilp(filp); |
1098 | fput(filp); | |
1099 | if (IS_ERR(sock)) { | |
1100 | ret = PTR_ERR(sock); | |
1101 | sock = NULL; | |
1102 | goto out; | |
1103 | } | |
1104 | ||
c3d8d1e3 | 1105 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1106 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1da177e4 | 1107 | if (ret == 1) |
8d8ffefa | 1108 | goto retry; |
1da177e4 LT |
1109 | if (ret) { |
1110 | sock = NULL; | |
1111 | nc = NULL; | |
1112 | goto out; | |
1113 | } | |
1114 | } | |
1115 | } | |
1116 | ||
1da177e4 | 1117 | filp = fget(mqdes); |
8d8ffefa AGR |
1118 | if (!filp) { |
1119 | ret = -EBADF; | |
1da177e4 | 1120 | goto out; |
8d8ffefa | 1121 | } |
1da177e4 | 1122 | |
6d63079a | 1123 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1124 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1125 | ret = -EBADF; | |
1da177e4 | 1126 | goto out_fput; |
8d8ffefa | 1127 | } |
1da177e4 LT |
1128 | info = MQUEUE_I(inode); |
1129 | ||
1130 | ret = 0; | |
1131 | spin_lock(&info->lock); | |
1132 | if (u_notification == NULL) { | |
a03fcb73 | 1133 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 LT |
1134 | remove_notification(info); |
1135 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1136 | } | |
a03fcb73 | 1137 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1138 | ret = -EBUSY; |
1139 | } else { | |
1140 | switch (notification.sigev_notify) { | |
1141 | case SIGEV_NONE: | |
1142 | info->notify.sigev_notify = SIGEV_NONE; | |
1143 | break; | |
1144 | case SIGEV_THREAD: | |
1145 | info->notify_sock = sock; | |
1146 | info->notify_cookie = nc; | |
1147 | sock = NULL; | |
1148 | nc = NULL; | |
1149 | info->notify.sigev_notify = SIGEV_THREAD; | |
1150 | break; | |
1151 | case SIGEV_SIGNAL: | |
1152 | info->notify.sigev_signo = notification.sigev_signo; | |
1153 | info->notify.sigev_value = notification.sigev_value; | |
1154 | info->notify.sigev_notify = SIGEV_SIGNAL; | |
1155 | break; | |
1156 | } | |
a03fcb73 CLG |
1157 | |
1158 | info->notify_owner = get_pid(task_tgid(current)); | |
6f9ac6d9 | 1159 | info->notify_user_ns = get_user_ns(current_user_ns()); |
1da177e4 LT |
1160 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1161 | } | |
1162 | spin_unlock(&info->lock); | |
1163 | out_fput: | |
1164 | fput(filp); | |
1165 | out: | |
1166 | if (sock) { | |
1167 | netlink_detachskb(sock, nc); | |
1168 | } else if (nc) { | |
1169 | dev_kfree_skb(nc); | |
1170 | } | |
1171 | return ret; | |
1172 | } | |
1173 | ||
c4ea37c2 HC |
1174 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1175 | const struct mq_attr __user *, u_mqstat, | |
1176 | struct mq_attr __user *, u_omqstat) | |
1da177e4 LT |
1177 | { |
1178 | int ret; | |
1179 | struct mq_attr mqstat, omqstat; | |
1180 | struct file *filp; | |
1181 | struct inode *inode; | |
1182 | struct mqueue_inode_info *info; | |
1183 | ||
1184 | if (u_mqstat != NULL) { | |
1185 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) | |
1186 | return -EFAULT; | |
1187 | if (mqstat.mq_flags & (~O_NONBLOCK)) | |
1188 | return -EINVAL; | |
1189 | } | |
1190 | ||
1da177e4 | 1191 | filp = fget(mqdes); |
8d8ffefa AGR |
1192 | if (!filp) { |
1193 | ret = -EBADF; | |
1da177e4 | 1194 | goto out; |
8d8ffefa | 1195 | } |
1da177e4 | 1196 | |
6d63079a | 1197 | inode = filp->f_path.dentry->d_inode; |
8d8ffefa AGR |
1198 | if (unlikely(filp->f_op != &mqueue_file_operations)) { |
1199 | ret = -EBADF; | |
1da177e4 | 1200 | goto out_fput; |
8d8ffefa | 1201 | } |
1da177e4 LT |
1202 | info = MQUEUE_I(inode); |
1203 | ||
1204 | spin_lock(&info->lock); | |
1205 | ||
1206 | omqstat = info->attr; | |
1207 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; | |
1208 | if (u_mqstat) { | |
7392906e | 1209 | audit_mq_getsetattr(mqdes, &mqstat); |
db1dd4d3 | 1210 | spin_lock(&filp->f_lock); |
1da177e4 LT |
1211 | if (mqstat.mq_flags & O_NONBLOCK) |
1212 | filp->f_flags |= O_NONBLOCK; | |
1213 | else | |
1214 | filp->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 1215 | spin_unlock(&filp->f_lock); |
1da177e4 LT |
1216 | |
1217 | inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
1218 | } | |
1219 | ||
1220 | spin_unlock(&info->lock); | |
1221 | ||
1222 | ret = 0; | |
1223 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, | |
1224 | sizeof(struct mq_attr))) | |
1225 | ret = -EFAULT; | |
1226 | ||
1227 | out_fput: | |
1228 | fput(filp); | |
1229 | out: | |
1230 | return ret; | |
1231 | } | |
1232 | ||
92e1d5be | 1233 | static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4 LT |
1234 | .lookup = simple_lookup, |
1235 | .create = mqueue_create, | |
1236 | .unlink = mqueue_unlink, | |
1237 | }; | |
1238 | ||
9a32144e | 1239 | static const struct file_operations mqueue_file_operations = { |
1da177e4 LT |
1240 | .flush = mqueue_flush_file, |
1241 | .poll = mqueue_poll_file, | |
1242 | .read = mqueue_read_file, | |
6038f373 | 1243 | .llseek = default_llseek, |
1da177e4 LT |
1244 | }; |
1245 | ||
b87221de | 1246 | static const struct super_operations mqueue_super_ops = { |
1da177e4 LT |
1247 | .alloc_inode = mqueue_alloc_inode, |
1248 | .destroy_inode = mqueue_destroy_inode, | |
6d8af64c | 1249 | .evict_inode = mqueue_evict_inode, |
1da177e4 | 1250 | .statfs = simple_statfs, |
1da177e4 LT |
1251 | }; |
1252 | ||
1253 | static struct file_system_type mqueue_fs_type = { | |
1254 | .name = "mqueue", | |
ceefda69 | 1255 | .mount = mqueue_mount, |
1da177e4 LT |
1256 | .kill_sb = kill_litter_super, |
1257 | }; | |
1258 | ||
7eafd7c7 SH |
1259 | int mq_init_ns(struct ipc_namespace *ns) |
1260 | { | |
1261 | ns->mq_queues_count = 0; | |
1262 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
1263 | ns->mq_msg_max = DFLT_MSGMAX; | |
1264 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
cef0184c KM |
1265 | ns->mq_msg_default = DFLT_MSG; |
1266 | ns->mq_msgsize_default = DFLT_MSGSIZE; | |
7eafd7c7 SH |
1267 | |
1268 | ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); | |
1269 | if (IS_ERR(ns->mq_mnt)) { | |
1270 | int err = PTR_ERR(ns->mq_mnt); | |
1271 | ns->mq_mnt = NULL; | |
1272 | return err; | |
1273 | } | |
1274 | return 0; | |
1275 | } | |
1276 | ||
1277 | void mq_clear_sbinfo(struct ipc_namespace *ns) | |
1278 | { | |
1279 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; | |
1280 | } | |
1281 | ||
1282 | void mq_put_mnt(struct ipc_namespace *ns) | |
1283 | { | |
6f686574 | 1284 | kern_unmount(ns->mq_mnt); |
7eafd7c7 SH |
1285 | } |
1286 | ||
1da177e4 LT |
1287 | static int __init init_mqueue_fs(void) |
1288 | { | |
1289 | int error; | |
1290 | ||
1291 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1292 | sizeof(struct mqueue_inode_info), 0, | |
20c2df83 | 1293 | SLAB_HWCACHE_ALIGN, init_once); |
1da177e4 LT |
1294 | if (mqueue_inode_cachep == NULL) |
1295 | return -ENOMEM; | |
1296 | ||
2329e392 | 1297 | /* ignore failures - they are not fatal */ |
bdc8e5f8 | 1298 | mq_sysctl_table = mq_register_sysctl_table(); |
1da177e4 LT |
1299 | |
1300 | error = register_filesystem(&mqueue_fs_type); | |
1301 | if (error) | |
1302 | goto out_sysctl; | |
1303 | ||
7eafd7c7 SH |
1304 | spin_lock_init(&mq_lock); |
1305 | ||
6f686574 AV |
1306 | error = mq_init_ns(&init_ipc_ns); |
1307 | if (error) | |
1da177e4 | 1308 | goto out_filesystem; |
1da177e4 | 1309 | |
1da177e4 LT |
1310 | return 0; |
1311 | ||
1312 | out_filesystem: | |
1313 | unregister_filesystem(&mqueue_fs_type); | |
1314 | out_sysctl: | |
1315 | if (mq_sysctl_table) | |
1316 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1317 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1318 | return error; |
1319 | } | |
1320 | ||
1321 | __initcall(init_mqueue_fs); |