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f2df0f7c SK |
1 | /* $NetBSD: sys_mqueue.c,v 1.16 2009/04/11 23:05:26 christos Exp $ */ |
2 | ||
3 | /* | |
4 | * Copyright (c) 2007, 2008 Mindaugas Rasiukevicius <rmind at NetBSD org> | |
5 | * All rights reserved. | |
6 | * | |
7 | * Redistribution and use in source and binary forms, with or without | |
8 | * modification, are permitted provided that the following conditions | |
9 | * are met: | |
10 | * 1. Redistributions of source code must retain the above copyright | |
11 | * notice, this list of conditions and the following disclaimer. | |
12 | * 2. Redistributions in binary form must reproduce the above copyright | |
13 | * notice, this list of conditions and the following disclaimer in the | |
14 | * documentation and/or other materials provided with the distribution. | |
15 | * | |
16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
26 | * SUCH DAMAGE. | |
27 | */ | |
28 | ||
29 | /* | |
30 | * Implementation of POSIX message queues. | |
31 | * Defined in the Base Definitions volume of IEEE Std 1003.1-2001. | |
32 | * | |
33 | * Locking | |
34 | * | |
35 | * Global list of message queues (mqueue_head) and proc_t::p_mqueue_cnt | |
36 | * counter are protected by mqlist_mtx lock. The very message queue and | |
37 | * its members are protected by mqueue::mq_mtx. | |
38 | * | |
39 | * Lock order: | |
40 | * mqlist_mtx | |
41 | * -> mqueue::mq_mtx | |
42 | */ | |
43 | ||
f2df0f7c SK |
44 | #include <stdbool.h> |
45 | #include <sys/param.h> | |
46 | #include <sys/types.h> | |
47 | #include <sys/errno.h> | |
48 | #include <sys/fcntl.h> | |
49 | #include <sys/file.h> | |
50 | #include <sys/filedesc.h> | |
51 | #include <sys/ucred.h> | |
52 | #include <sys/priv.h> | |
53 | #include <sys/kernel.h> | |
54 | #include <sys/malloc.h> | |
975523fa | 55 | #include <sys/mplock2.h> |
f2df0f7c | 56 | #include <sys/mqueue.h> |
f2df0f7c SK |
57 | #include <sys/proc.h> |
58 | #include <sys/queue.h> | |
b06aab00 | 59 | #include <sys/event.h> |
f2df0f7c SK |
60 | #include <sys/serialize.h> |
61 | #include <sys/signal.h> | |
62 | #include <sys/signalvar.h> | |
63 | #include <sys/spinlock.h> | |
64 | #include <sys/spinlock2.h> | |
65 | #include <sys/stat.h> | |
66 | #include <sys/sysctl.h> | |
67 | #include <sys/sysproto.h> | |
68 | #include <sys/systm.h> | |
69 | #include <sys/lock.h> | |
70 | #include <sys/unistd.h> | |
71 | #include <sys/vnode.h> | |
72 | ||
73 | /* System-wide limits. */ | |
74 | static u_int mq_open_max = MQ_OPEN_MAX; | |
75 | static u_int mq_prio_max = MQ_PRIO_MAX; | |
76 | static u_int mq_max_msgsize = 16 * MQ_DEF_MSGSIZE; | |
77 | static u_int mq_def_maxmsg = 32; | |
8658b626 | 78 | static u_int mq_max_maxmsg = 16 * 32; |
f2df0f7c SK |
79 | |
80 | struct lock mqlist_mtx; | |
f2df0f7c SK |
81 | static LIST_HEAD(, mqueue) mqueue_head = |
82 | LIST_HEAD_INITIALIZER(mqueue_head); | |
83 | ||
84 | typedef struct file file_t; /* XXX: Should we put this in sys/types.h ? */ | |
85 | ||
86 | /* Function prototypes */ | |
f2df0f7c SK |
87 | static int mq_stat_fop(file_t *, struct stat *, struct ucred *cred); |
88 | static int mq_close_fop(file_t *); | |
b06aab00 SG |
89 | static int mq_kqfilter_fop(struct file *fp, struct knote *kn); |
90 | static void mqfilter_read_detach(struct knote *kn); | |
91 | static void mqfilter_write_detach(struct knote *kn); | |
92 | static int mqfilter_read(struct knote *kn, long hint); | |
93 | static int mqfilter_write(struct knote *kn, long hint); | |
f2df0f7c SK |
94 | |
95 | /* Some time-related utility functions */ | |
96 | static int itimespecfix(struct timespec *ts); | |
97 | static int tstohz(const struct timespec *ts); | |
98 | ||
99 | /* File operations vector */ | |
100 | static struct fileops mqops = { | |
101 | .fo_read = badfo_readwrite, | |
102 | .fo_write = badfo_readwrite, | |
103 | .fo_ioctl = badfo_ioctl, | |
f2df0f7c SK |
104 | .fo_stat = mq_stat_fop, |
105 | .fo_close = mq_close_fop, | |
b06aab00 | 106 | .fo_kqfilter = mq_kqfilter_fop, |
f2df0f7c SK |
107 | .fo_shutdown = badfo_shutdown |
108 | }; | |
109 | ||
110 | /* Define a new malloc type for message queues */ | |
111 | MALLOC_DECLARE(M_MQBUF); | |
112 | MALLOC_DEFINE(M_MQBUF, "mqueues", "Buffers to message queues"); | |
113 | ||
f2df0f7c SK |
114 | /* |
115 | * Initialize POSIX message queue subsystem. | |
116 | */ | |
117 | void | |
118 | mqueue_sysinit(void) | |
119 | { | |
f2df0f7c SK |
120 | lockinit(&mqlist_mtx, "mqlist_mtx", 0, LK_CANRECURSE); |
121 | } | |
122 | ||
123 | /* | |
124 | * Free the message. | |
125 | */ | |
126 | static void | |
127 | mqueue_freemsg(struct mq_msg *msg, const size_t size) | |
128 | { | |
88be9cd1 | 129 | kfree(msg, M_MQBUF); |
f2df0f7c SK |
130 | } |
131 | ||
132 | /* | |
133 | * Destroy the message queue. | |
134 | */ | |
135 | static void | |
136 | mqueue_destroy(struct mqueue *mq) | |
137 | { | |
138 | struct mq_msg *msg; | |
139 | size_t msz; | |
140 | u_int i; | |
141 | ||
142 | /* Note MQ_PQSIZE + 1. */ | |
143 | for (i = 0; i < MQ_PQSIZE + 1; i++) { | |
144 | while ((msg = TAILQ_FIRST(&mq->mq_head[i])) != NULL) { | |
145 | TAILQ_REMOVE(&mq->mq_head[i], msg, msg_queue); | |
146 | msz = sizeof(struct mq_msg) + msg->msg_len; | |
147 | mqueue_freemsg(msg, msz); | |
148 | } | |
149 | } | |
150 | lockuninit(&mq->mq_mtx); | |
151 | kfree(mq, M_MQBUF); | |
152 | } | |
153 | ||
154 | /* | |
155 | * Lookup for file name in general list of message queues. | |
156 | * => locks the message queue | |
157 | */ | |
158 | static void * | |
159 | mqueue_lookup(char *name) | |
160 | { | |
161 | struct mqueue *mq; | |
162 | ||
163 | KKASSERT(lockstatus(&mqlist_mtx, curthread)); | |
164 | ||
165 | LIST_FOREACH(mq, &mqueue_head, mq_list) { | |
166 | if (strncmp(mq->mq_name, name, MQ_NAMELEN) == 0) { | |
167 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
168 | return mq; | |
169 | } | |
170 | } | |
171 | ||
172 | return NULL; | |
173 | } | |
174 | ||
175 | /* | |
176 | * mqueue_get: get the mqueue from the descriptor. | |
177 | * => locks the message queue, if found. | |
d1d64679 | 178 | * => holds a reference on the file descriptor. |
f2df0f7c SK |
179 | */ |
180 | static int | |
181 | mqueue_get(struct lwp *l, mqd_t mqd, file_t **fpr) | |
182 | { | |
183 | struct mqueue *mq; | |
184 | file_t *fp; | |
185 | ||
186 | fp = holdfp(curproc->p_fd, (int)mqd, -1); /* XXX: Why -1 ? */ | |
187 | if (__predict_false(fp == NULL)) | |
188 | return EBADF; | |
189 | ||
190 | if (__predict_false(fp->f_type != DTYPE_MQUEUE)) { | |
191 | fdrop(fp); | |
192 | return EBADF; | |
193 | } | |
194 | mq = fp->f_data; | |
195 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
196 | ||
197 | *fpr = fp; | |
198 | return 0; | |
199 | } | |
200 | ||
201 | /* | |
202 | * mqueue_linear_insert: perform linear insert according to the message | |
203 | * priority into the reserved queue (MQ_PQRESQ). Reserved queue is a | |
204 | * sorted list used only when mq_prio_max is increased via sysctl. | |
205 | */ | |
206 | static inline void | |
207 | mqueue_linear_insert(struct mqueue *mq, struct mq_msg *msg) | |
208 | { | |
209 | struct mq_msg *mit; | |
210 | ||
211 | TAILQ_FOREACH(mit, &mq->mq_head[MQ_PQRESQ], msg_queue) { | |
212 | if (msg->msg_prio > mit->msg_prio) | |
213 | break; | |
214 | } | |
215 | if (mit == NULL) { | |
216 | TAILQ_INSERT_TAIL(&mq->mq_head[MQ_PQRESQ], msg, msg_queue); | |
217 | } else { | |
218 | TAILQ_INSERT_BEFORE(mit, msg, msg_queue); | |
219 | } | |
220 | } | |
221 | ||
222 | /* | |
223 | * Validate input. | |
224 | */ | |
225 | int | |
226 | itimespecfix(struct timespec *ts) | |
227 | { | |
228 | if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000) | |
229 | return (EINVAL); | |
a591f597 MD |
230 | if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < nstick) |
231 | ts->tv_nsec = nstick; | |
f2df0f7c SK |
232 | return (0); |
233 | } | |
234 | ||
235 | /* | |
236 | * Compute number of ticks in the specified amount of time. | |
237 | */ | |
238 | int | |
239 | tstohz(const struct timespec *ts) | |
240 | { | |
241 | struct timeval tv; | |
242 | ||
243 | /* | |
244 | * usec has great enough resolution for hz, so convert to a | |
245 | * timeval and use tvtohz() above. | |
246 | */ | |
247 | TIMESPEC_TO_TIMEVAL(&tv, ts); | |
248 | return tvtohz_high(&tv); /* XXX Why _high() and not _low() ? */ | |
249 | } | |
250 | ||
251 | /* | |
252 | * Converter from struct timespec to the ticks. | |
253 | * Used by mq_timedreceive(), mq_timedsend(). | |
254 | */ | |
255 | int | |
256 | abstimeout2timo(struct timespec *ts, int *timo) | |
257 | { | |
258 | struct timespec tsd; | |
259 | int error; | |
260 | ||
959f863f SK |
261 | error = itimespecfix(ts); |
262 | if (error) { | |
263 | return error; | |
a27ab186 | 264 | } |
f2df0f7c SK |
265 | getnanotime(&tsd); |
266 | timespecsub(ts, &tsd); | |
267 | if (ts->tv_sec < 0 || (ts->tv_sec == 0 && ts->tv_nsec <= 0)) { | |
268 | return ETIMEDOUT; | |
269 | } | |
f2df0f7c SK |
270 | *timo = tstohz(ts); |
271 | KKASSERT(*timo != 0); | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
276 | static int | |
277 | mq_stat_fop(file_t *fp, struct stat *st, struct ucred *cred) | |
278 | { | |
279 | struct mqueue *mq = fp->f_data; | |
280 | ||
281 | (void)memset(st, 0, sizeof(*st)); | |
282 | ||
283 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
284 | st->st_mode = mq->mq_mode; | |
285 | st->st_uid = mq->mq_euid; | |
286 | st->st_gid = mq->mq_egid; | |
287 | st->st_atimespec = mq->mq_atime; | |
288 | st->st_mtimespec = mq->mq_mtime; | |
289 | /*st->st_ctimespec = st->st_birthtimespec = mq->mq_btime;*/ | |
290 | st->st_uid = fp->f_cred->cr_uid; | |
291 | st->st_gid = fp->f_cred->cr_svgid; | |
292 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
b06aab00 | 297 | static struct filterops mqfiltops_read = |
4c91dbc9 | 298 | { FILTEROP_ISFD, NULL, mqfilter_read_detach, mqfilter_read }; |
b06aab00 | 299 | static struct filterops mqfiltops_write = |
4c91dbc9 | 300 | { FILTEROP_ISFD, NULL, mqfilter_write_detach, mqfilter_write }; |
b06aab00 SG |
301 | |
302 | static int | |
303 | mq_kqfilter_fop(struct file *fp, struct knote *kn) | |
304 | { | |
305 | struct mqueue *mq = fp->f_data; | |
306 | struct klist *klist; | |
307 | ||
308 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
309 | ||
310 | switch (kn->kn_filter) { | |
311 | case EVFILT_READ: | |
312 | kn->kn_fop = &mqfiltops_read; | |
313 | kn->kn_hook = (caddr_t)mq; | |
5b22f1a7 | 314 | klist = &mq->mq_rkq.ki_note; |
b06aab00 SG |
315 | break; |
316 | case EVFILT_WRITE: | |
317 | kn->kn_fop = &mqfiltops_write; | |
318 | kn->kn_hook = (caddr_t)mq; | |
5b22f1a7 | 319 | klist = &mq->mq_wkq.ki_note; |
b06aab00 SG |
320 | break; |
321 | default: | |
322 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
323 | return (EOPNOTSUPP); | |
324 | } | |
325 | ||
5b22f1a7 | 326 | knote_insert(klist, kn); |
b06aab00 SG |
327 | lockmgr(&mq->mq_mtx, LK_RELEASE); |
328 | ||
329 | return (0); | |
330 | } | |
331 | ||
332 | static void | |
333 | mqfilter_read_detach(struct knote *kn) | |
334 | { | |
335 | struct mqueue *mq = (struct mqueue *)kn->kn_hook; | |
336 | ||
337 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
5b22f1a7 SG |
338 | struct klist *klist = &mq->mq_rkq.ki_note; |
339 | knote_remove(klist, kn); | |
b06aab00 SG |
340 | lockmgr(&mq->mq_mtx, LK_RELEASE); |
341 | } | |
342 | ||
343 | static void | |
344 | mqfilter_write_detach(struct knote *kn) | |
345 | { | |
346 | struct mqueue *mq = (struct mqueue *)kn->kn_hook; | |
347 | ||
348 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
5b22f1a7 SG |
349 | struct klist *klist = &mq->mq_wkq.ki_note; |
350 | knote_remove(klist, kn); | |
b06aab00 SG |
351 | lockmgr(&mq->mq_mtx, LK_RELEASE); |
352 | } | |
353 | ||
354 | static int | |
355 | mqfilter_read(struct knote *kn, long hint) | |
356 | { | |
357 | struct mqueue *mq = (struct mqueue *)kn->kn_hook; | |
358 | struct mq_attr *mqattr; | |
359 | int ready = 0; | |
360 | ||
361 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
362 | mqattr = &mq->mq_attrib; | |
363 | /* Ready for receiving, if there are messages in the queue */ | |
364 | if (mqattr->mq_curmsgs) | |
365 | ready = 1; | |
366 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
367 | ||
368 | return (ready); | |
369 | } | |
370 | ||
371 | static int | |
372 | mqfilter_write(struct knote *kn, long hint) | |
373 | { | |
374 | struct mqueue *mq = (struct mqueue *)kn->kn_hook; | |
375 | struct mq_attr *mqattr; | |
376 | int ready = 0; | |
377 | ||
378 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
379 | mqattr = &mq->mq_attrib; | |
380 | /* Ready for sending, if the message queue is not full */ | |
381 | if (mqattr->mq_curmsgs < mqattr->mq_maxmsg) | |
382 | ready = 1; | |
383 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
384 | ||
385 | return (ready); | |
386 | } | |
387 | ||
f2df0f7c SK |
388 | static int |
389 | mq_close_fop(file_t *fp) | |
390 | { | |
391 | struct proc *p = curproc; | |
392 | struct mqueue *mq = fp->f_data; | |
393 | bool destroy; | |
394 | ||
395 | lockmgr(&mqlist_mtx, LK_EXCLUSIVE); | |
396 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
397 | ||
398 | /* Decrease the counters */ | |
399 | p->p_mqueue_cnt--; | |
400 | mq->mq_refcnt--; | |
401 | ||
402 | /* Remove notification if registered for this process */ | |
403 | if (mq->mq_notify_proc == p) | |
404 | mq->mq_notify_proc = NULL; | |
405 | ||
406 | /* | |
407 | * If this is the last reference and mqueue is marked for unlink, | |
408 | * remove and later destroy the message queue. | |
409 | */ | |
410 | if (mq->mq_refcnt == 0 && (mq->mq_attrib.mq_flags & MQ_UNLINK)) { | |
411 | LIST_REMOVE(mq, mq_list); | |
412 | destroy = true; | |
413 | } else | |
414 | destroy = false; | |
415 | ||
416 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
417 | lockmgr(&mqlist_mtx, LK_RELEASE); | |
418 | ||
419 | if (destroy) | |
420 | mqueue_destroy(mq); | |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | /* | |
426 | * General mqueue system calls. | |
427 | */ | |
428 | ||
429 | int | |
430 | sys_mq_open(struct mq_open_args *uap) | |
431 | { | |
432 | /* { | |
433 | syscallarg(const char *) name; | |
434 | syscallarg(int) oflag; | |
435 | syscallarg(mode_t) mode; | |
436 | syscallarg(struct mq_attr) attr; | |
437 | } */ | |
9910d07b MD |
438 | struct thread *td = curthread; |
439 | struct proc *p = td->td_proc; | |
f3a2d8c4 | 440 | struct filedesc *fdp = p->p_fd; |
f2df0f7c SK |
441 | struct mqueue *mq, *mq_new = NULL; |
442 | file_t *fp; | |
443 | char *name; | |
444 | int mqd, error, oflag; | |
445 | ||
446 | /* Check access mode flags */ | |
447 | oflag = SCARG(uap, oflag); | |
448 | if ((oflag & O_ACCMODE) == (O_WRONLY | O_RDWR)) { | |
449 | return EINVAL; | |
450 | } | |
451 | ||
452 | /* Get the name from the user-space */ | |
d3a2b23d VS |
453 | name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO | M_NULLOK); |
454 | if (name == NULL) | |
455 | return (ENOMEM); | |
f2df0f7c SK |
456 | error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL); |
457 | if (error) { | |
458 | kfree(name, M_MQBUF); | |
459 | return error; | |
460 | } | |
461 | ||
462 | if (oflag & O_CREAT) { | |
463 | struct mq_attr attr; | |
464 | u_int i; | |
465 | ||
466 | /* Check the limit */ | |
467 | if (p->p_mqueue_cnt == mq_open_max) { | |
468 | kfree(name, M_MQBUF); | |
469 | return EMFILE; | |
470 | } | |
471 | ||
472 | /* Empty name is invalid */ | |
473 | if (name[0] == '\0') { | |
474 | kfree(name, M_MQBUF); | |
475 | return EINVAL; | |
476 | } | |
477 | ||
478 | /* Check for mqueue attributes */ | |
479 | if (SCARG(uap, attr)) { | |
480 | error = copyin(SCARG(uap, attr), &attr, | |
481 | sizeof(struct mq_attr)); | |
482 | if (error) { | |
483 | kfree(name, M_MQBUF); | |
484 | return error; | |
485 | } | |
8658b626 SK |
486 | if (attr.mq_maxmsg <= 0 || |
487 | attr.mq_maxmsg > mq_max_maxmsg || | |
488 | attr.mq_msgsize <= 0 || | |
f2df0f7c SK |
489 | attr.mq_msgsize > mq_max_msgsize) { |
490 | kfree(name, M_MQBUF); | |
491 | return EINVAL; | |
492 | } | |
493 | attr.mq_curmsgs = 0; | |
494 | } else { | |
495 | memset(&attr, 0, sizeof(struct mq_attr)); | |
496 | attr.mq_maxmsg = mq_def_maxmsg; | |
497 | attr.mq_msgsize = | |
498 | MQ_DEF_MSGSIZE - sizeof(struct mq_msg); | |
499 | } | |
500 | ||
501 | /* | |
502 | * Allocate new mqueue, initialize data structures, | |
503 | * copy the name, attributes and set the flag. | |
504 | */ | |
d3a2b23d VS |
505 | mq_new = kmalloc(sizeof(struct mqueue), M_MQBUF, |
506 | M_WAITOK | M_ZERO | M_NULLOK); | |
507 | if (mq_new == NULL) { | |
508 | kfree(name, M_MQBUF); | |
509 | return (ENOMEM); | |
510 | } | |
f2df0f7c SK |
511 | |
512 | lockinit(&mq_new->mq_mtx, "mq_new->mq_mtx", 0, LK_CANRECURSE); | |
513 | for (i = 0; i < (MQ_PQSIZE + 1); i++) { | |
514 | TAILQ_INIT(&mq_new->mq_head[i]); | |
515 | } | |
516 | ||
517 | strlcpy(mq_new->mq_name, name, MQ_NAMELEN); | |
518 | memcpy(&mq_new->mq_attrib, &attr, sizeof(struct mq_attr)); | |
519 | ||
520 | /*CTASSERT((O_MASK & (MQ_UNLINK | MQ_RECEIVE)) == 0);*/ | |
521 | /* mq_new->mq_attrib.mq_flags = (O_MASK & oflag); */ | |
522 | mq_new->mq_attrib.mq_flags = oflag; | |
523 | ||
524 | /* Store mode and effective UID with GID */ | |
525 | mq_new->mq_mode = ((SCARG(uap, mode) & | |
526 | ~p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT; | |
9910d07b MD |
527 | mq_new->mq_euid = td->td_ucred->cr_uid; |
528 | mq_new->mq_egid = td->td_ucred->cr_svgid; | |
f2df0f7c SK |
529 | } |
530 | ||
531 | /* Allocate file structure and descriptor */ | |
f3a2d8c4 | 532 | error = falloc(td->td_lwp, &fp, &mqd); |
f2df0f7c SK |
533 | if (error) { |
534 | if (mq_new) | |
535 | mqueue_destroy(mq_new); | |
536 | kfree(name, M_MQBUF); | |
537 | return error; | |
538 | } | |
539 | fp->f_type = DTYPE_MQUEUE; | |
540 | fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE); | |
541 | fp->f_ops = &mqops; | |
542 | ||
543 | /* Look up for mqueue with such name */ | |
544 | lockmgr(&mqlist_mtx, LK_EXCLUSIVE); | |
545 | mq = mqueue_lookup(name); | |
546 | if (mq) { | |
547 | int acc_mode; | |
548 | ||
549 | KKASSERT(lockstatus(&mq->mq_mtx, curthread)); | |
550 | ||
551 | /* Check if mqueue is not marked as unlinking */ | |
552 | if (mq->mq_attrib.mq_flags & MQ_UNLINK) { | |
553 | error = EACCES; | |
554 | goto exit; | |
555 | } | |
556 | /* Fail if O_EXCL is set, and mqueue already exists */ | |
557 | if ((oflag & O_CREAT) && (oflag & O_EXCL)) { | |
558 | error = EEXIST; | |
559 | goto exit; | |
560 | } | |
561 | ||
562 | /* | |
563 | * Check the permissions. Note the difference between | |
564 | * VREAD/VWRITE and FREAD/FWRITE. | |
565 | */ | |
566 | acc_mode = 0; | |
567 | if (fp->f_flag & FREAD) { | |
568 | acc_mode |= VREAD; | |
569 | } | |
570 | if (fp->f_flag & FWRITE) { | |
571 | acc_mode |= VWRITE; | |
572 | } | |
573 | if (vaccess(VNON, mq->mq_mode, mq->mq_euid, mq->mq_egid, | |
9910d07b | 574 | acc_mode, td->td_ucred)) { |
f2df0f7c SK |
575 | |
576 | error = EACCES; | |
577 | goto exit; | |
578 | } | |
579 | } else { | |
580 | /* Fail if mqueue neither exists, nor we create it */ | |
581 | if ((oflag & O_CREAT) == 0) { | |
582 | lockmgr(&mqlist_mtx, LK_RELEASE); | |
583 | KKASSERT(mq_new == NULL); | |
f3a2d8c4 | 584 | fsetfd(fdp, NULL, mqd); |
f2df0f7c SK |
585 | fp->f_ops = &badfileops; |
586 | fdrop(fp); | |
587 | kfree(name, M_MQBUF); | |
588 | return ENOENT; | |
589 | } | |
590 | ||
591 | /* Check the limit */ | |
592 | if (p->p_mqueue_cnt == mq_open_max) { | |
593 | error = EMFILE; | |
594 | goto exit; | |
595 | } | |
596 | ||
597 | /* Insert the queue to the list */ | |
598 | mq = mq_new; | |
599 | lockmgr(&mq->mq_mtx, LK_EXCLUSIVE); | |
600 | LIST_INSERT_HEAD(&mqueue_head, mq, mq_list); | |
601 | mq_new = NULL; | |
602 | getnanotime(&mq->mq_btime); | |
603 | mq->mq_atime = mq->mq_mtime = mq->mq_btime; | |
604 | } | |
605 | ||
606 | /* Increase the counters, and make descriptor ready */ | |
607 | p->p_mqueue_cnt++; | |
608 | mq->mq_refcnt++; | |
609 | fp->f_data = mq; | |
610 | exit: | |
611 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
612 | lockmgr(&mqlist_mtx, LK_RELEASE); | |
613 | ||
614 | if (mq_new) | |
615 | mqueue_destroy(mq_new); | |
616 | if (error) { | |
f3a2d8c4 | 617 | fsetfd(fdp, NULL, mqd); |
f2df0f7c SK |
618 | fp->f_ops = &badfileops; |
619 | } else { | |
f3a2d8c4 | 620 | fsetfd(fdp, fp, mqd); |
f2df0f7c SK |
621 | uap->sysmsg_result = mqd; |
622 | } | |
623 | fdrop(fp); | |
624 | kfree(name, M_MQBUF); | |
625 | ||
626 | return error; | |
627 | } | |
628 | ||
629 | int | |
630 | sys_mq_close(struct mq_close_args *uap) | |
631 | { | |
632 | return sys_close((void *)uap); | |
633 | } | |
634 | ||
635 | /* | |
636 | * Primary mq_receive1() function. | |
637 | */ | |
638 | int | |
639 | mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len, | |
640 | unsigned *msg_prio, struct timespec *ts, ssize_t *mlen) | |
641 | { | |
642 | file_t *fp = NULL; | |
643 | struct mqueue *mq; | |
644 | struct mq_msg *msg = NULL; | |
645 | struct mq_attr *mqattr; | |
646 | u_int idx; | |
647 | int error; | |
648 | ||
649 | /* Get the message queue */ | |
650 | error = mqueue_get(l, mqdes, &fp); | |
651 | if (error) { | |
652 | return error; | |
653 | } | |
654 | mq = fp->f_data; | |
655 | if ((fp->f_flag & FREAD) == 0) { | |
656 | error = EBADF; | |
657 | goto error; | |
658 | } | |
659 | getnanotime(&mq->mq_atime); | |
660 | mqattr = &mq->mq_attrib; | |
661 | ||
662 | /* Check the message size limits */ | |
663 | if (msg_len < mqattr->mq_msgsize) { | |
664 | error = EMSGSIZE; | |
665 | goto error; | |
666 | } | |
667 | ||
668 | /* Check if queue is empty */ | |
669 | while (mqattr->mq_curmsgs == 0) { | |
670 | int t; | |
671 | ||
672 | if (mqattr->mq_flags & O_NONBLOCK) { | |
673 | error = EAGAIN; | |
674 | goto error; | |
675 | } | |
c8b16402 SK |
676 | if (ts) { |
677 | error = abstimeout2timo(ts, &t); | |
678 | if (error) | |
679 | goto error; | |
680 | } else | |
681 | t = 0; | |
f2df0f7c SK |
682 | /* |
683 | * Block until someone sends the message. | |
684 | * While doing this, notification should not be sent. | |
685 | */ | |
686 | mqattr->mq_flags |= MQ_RECEIVE; | |
acb0b16f | 687 | error = lksleep(&mq->mq_send_cv, &mq->mq_mtx, PCATCH, "mqsend", t); |
f2df0f7c SK |
688 | mqattr->mq_flags &= ~MQ_RECEIVE; |
689 | if (error || (mqattr->mq_flags & MQ_UNLINK)) { | |
690 | error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR; | |
691 | goto error; | |
692 | } | |
693 | } | |
694 | ||
695 | ||
696 | /* | |
697 | * Find the highest priority message, and remove it from the queue. | |
698 | * At first, reserved queue is checked, bitmap is next. | |
699 | */ | |
700 | msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]); | |
701 | if (__predict_true(msg == NULL)) { | |
702 | idx = ffs(mq->mq_bitmap); | |
703 | msg = TAILQ_FIRST(&mq->mq_head[idx]); | |
704 | KKASSERT(msg != NULL); | |
705 | } else { | |
706 | idx = MQ_PQRESQ; | |
707 | } | |
708 | TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue); | |
709 | ||
710 | /* Unmark the bit, if last message. */ | |
711 | if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) { | |
712 | KKASSERT((MQ_PQSIZE - idx) == msg->msg_prio); | |
713 | mq->mq_bitmap &= ~(1 << --idx); | |
714 | } | |
715 | ||
716 | /* Decrement the counter and signal waiter, if any */ | |
717 | mqattr->mq_curmsgs--; | |
718 | wakeup_one(&mq->mq_recv_cv); | |
719 | ||
720 | /* Ready for sending now */ | |
5b22f1a7 | 721 | KNOTE(&mq->mq_wkq.ki_note, 0); |
f2df0f7c SK |
722 | error: |
723 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
724 | fdrop(fp); | |
725 | if (error) | |
726 | return error; | |
727 | ||
728 | /* | |
729 | * Copy the data to the user-space. | |
730 | * Note: According to POSIX, no message should be removed from the | |
731 | * queue in case of fail - this would be violated. | |
732 | */ | |
733 | *mlen = msg->msg_len; | |
734 | error = copyout(msg->msg_ptr, msg_ptr, msg->msg_len); | |
735 | if (error == 0 && msg_prio) | |
736 | error = copyout(&msg->msg_prio, msg_prio, sizeof(unsigned)); | |
737 | mqueue_freemsg(msg, sizeof(struct mq_msg) + msg->msg_len); | |
738 | ||
739 | return error; | |
740 | } | |
741 | ||
742 | int | |
743 | sys_mq_receive(struct mq_receive_args *uap) | |
744 | { | |
745 | /* { | |
746 | syscallarg(mqd_t) mqdes; | |
747 | syscallarg(char *) msg_ptr; | |
748 | syscallarg(size_t) msg_len; | |
749 | syscallarg(unsigned *) msg_prio; | |
750 | } */ | |
751 | ssize_t mlen; | |
752 | int error; | |
753 | ||
754 | error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr), | |
755 | SCARG(uap, msg_len), SCARG(uap, msg_prio), 0, &mlen); | |
756 | if (error == 0) | |
757 | uap->sysmsg_result = mlen; | |
758 | ||
759 | return error; | |
760 | } | |
761 | ||
762 | int | |
763 | sys_mq_timedreceive(struct mq_timedreceive_args *uap) | |
764 | { | |
765 | /* { | |
766 | syscallarg(mqd_t) mqdes; | |
767 | syscallarg(char *) msg_ptr; | |
768 | syscallarg(size_t) msg_len; | |
769 | syscallarg(unsigned *) msg_prio; | |
770 | syscallarg(const struct timespec *) abs_timeout; | |
771 | } */ | |
772 | int error; | |
773 | ssize_t mlen; | |
774 | struct timespec ts, *tsp; | |
775 | ||
776 | /* Get and convert time value */ | |
777 | if (SCARG(uap, abs_timeout)) { | |
778 | error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts)); | |
779 | if (error) | |
780 | return error; | |
781 | tsp = &ts; | |
782 | } else { | |
783 | tsp = NULL; | |
784 | } | |
785 | ||
786 | error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr), | |
787 | SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp, &mlen); | |
788 | if (error == 0) | |
789 | uap->sysmsg_result = mlen; | |
790 | ||
791 | return error; | |
792 | } | |
793 | ||
794 | /* | |
795 | * Primary mq_send1() function. | |
796 | */ | |
797 | int | |
798 | mq_send1(struct lwp *l, mqd_t mqdes, const char *msg_ptr, size_t msg_len, | |
799 | unsigned msg_prio, struct timespec *ts) | |
800 | { | |
801 | file_t *fp = NULL; | |
802 | struct mqueue *mq; | |
803 | struct mq_msg *msg; | |
804 | struct mq_attr *mqattr; | |
805 | struct proc *notify = NULL; | |
806 | /*ksiginfo_t ksi;*/ | |
807 | size_t size; | |
808 | int error; | |
809 | ||
810 | /* Check the priority range */ | |
811 | if (msg_prio >= mq_prio_max) | |
812 | return EINVAL; | |
813 | ||
814 | /* Allocate a new message */ | |
815 | size = sizeof(struct mq_msg) + msg_len; | |
816 | if (size > mq_max_msgsize) | |
817 | return EMSGSIZE; | |
818 | ||
88be9cd1 | 819 | msg = kmalloc(size, M_MQBUF, M_WAITOK | M_NULLOK); |
d3a2b23d VS |
820 | if (msg == NULL) |
821 | return (ENOMEM); | |
822 | ||
f2df0f7c SK |
823 | |
824 | /* Get the data from user-space */ | |
825 | error = copyin(msg_ptr, msg->msg_ptr, msg_len); | |
826 | if (error) { | |
827 | mqueue_freemsg(msg, size); | |
828 | return error; | |
829 | } | |
830 | msg->msg_len = msg_len; | |
831 | msg->msg_prio = msg_prio; | |
832 | ||
833 | /* Get the mqueue */ | |
834 | error = mqueue_get(l, mqdes, &fp); | |
835 | if (error) { | |
836 | mqueue_freemsg(msg, size); | |
837 | return error; | |
838 | } | |
839 | mq = fp->f_data; | |
840 | if ((fp->f_flag & FWRITE) == 0) { | |
841 | error = EBADF; | |
842 | goto error; | |
843 | } | |
844 | getnanotime(&mq->mq_mtime); | |
845 | mqattr = &mq->mq_attrib; | |
846 | ||
847 | /* Check the message size limit */ | |
848 | if (msg_len <= 0 || msg_len > mqattr->mq_msgsize) { | |
849 | error = EMSGSIZE; | |
850 | goto error; | |
851 | } | |
852 | ||
853 | /* Check if queue is full */ | |
854 | while (mqattr->mq_curmsgs >= mqattr->mq_maxmsg) { | |
855 | int t; | |
856 | ||
857 | if (mqattr->mq_flags & O_NONBLOCK) { | |
858 | error = EAGAIN; | |
859 | goto error; | |
860 | } | |
c8b16402 SK |
861 | if (ts) { |
862 | error = abstimeout2timo(ts, &t); | |
863 | if (error) | |
864 | goto error; | |
865 | } else | |
866 | t = 0; | |
f2df0f7c | 867 | /* Block until queue becomes available */ |
acb0b16f | 868 | error = lksleep(&mq->mq_recv_cv, &mq->mq_mtx, PCATCH, "mqrecv", t); |
f2df0f7c SK |
869 | if (error || (mqattr->mq_flags & MQ_UNLINK)) { |
870 | error = (error == EWOULDBLOCK) ? ETIMEDOUT : error; | |
871 | goto error; | |
872 | } | |
873 | } | |
874 | KKASSERT(mq->mq_attrib.mq_curmsgs < mq->mq_attrib.mq_maxmsg); | |
875 | ||
876 | /* | |
877 | * Insert message into the queue, according to the priority. | |
878 | * Note the difference between index and priority. | |
879 | */ | |
880 | if (__predict_true(msg_prio < MQ_PQSIZE)) { | |
881 | u_int idx = MQ_PQSIZE - msg_prio; | |
882 | ||
883 | KKASSERT(idx != MQ_PQRESQ); | |
884 | TAILQ_INSERT_TAIL(&mq->mq_head[idx], msg, msg_queue); | |
885 | mq->mq_bitmap |= (1 << --idx); | |
886 | } else { | |
887 | mqueue_linear_insert(mq, msg); | |
888 | } | |
889 | ||
890 | /* Check for the notify */ | |
891 | if (mqattr->mq_curmsgs == 0 && mq->mq_notify_proc && | |
c8b16402 SK |
892 | (mqattr->mq_flags & MQ_RECEIVE) == 0 && |
893 | mq->mq_sig_notify.sigev_notify == SIGEV_SIGNAL) { | |
f2df0f7c SK |
894 | /* Initialize the signal */ |
895 | /*KSI_INIT(&ksi);*/ | |
896 | /*ksi.ksi_signo = mq->mq_sig_notify.sigev_signo;*/ | |
897 | /*ksi.ksi_code = SI_MESGQ;*/ | |
898 | /*ksi.ksi_value = mq->mq_sig_notify.sigev_value;*/ | |
899 | /* Unregister the process */ | |
900 | notify = mq->mq_notify_proc; | |
901 | mq->mq_notify_proc = NULL; | |
902 | } | |
903 | ||
904 | /* Increment the counter and signal waiter, if any */ | |
905 | mqattr->mq_curmsgs++; | |
906 | wakeup_one(&mq->mq_send_cv); | |
907 | ||
908 | /* Ready for receiving now */ | |
5b22f1a7 | 909 | KNOTE(&mq->mq_rkq.ki_note, 0); |
f2df0f7c | 910 | error: |
f2df0f7c SK |
911 | lockmgr(&mq->mq_mtx, LK_RELEASE); |
912 | fdrop(fp); | |
913 | ||
914 | if (error) { | |
915 | mqueue_freemsg(msg, size); | |
916 | } else if (notify) { | |
917 | /* Send the notify, if needed */ | |
99ad9bc4 | 918 | lwkt_gettoken(&proc_token); |
f2df0f7c SK |
919 | /*kpsignal(notify, &ksi, NULL);*/ |
920 | ksignal(notify, mq->mq_sig_notify.sigev_signo); | |
99ad9bc4 | 921 | lwkt_reltoken(&proc_token); |
f2df0f7c SK |
922 | } |
923 | ||
924 | return error; | |
925 | } | |
926 | ||
927 | int | |
928 | sys_mq_send(struct mq_send_args *uap) | |
929 | { | |
930 | /* { | |
931 | syscallarg(mqd_t) mqdes; | |
932 | syscallarg(const char *) msg_ptr; | |
933 | syscallarg(size_t) msg_len; | |
934 | syscallarg(unsigned) msg_prio; | |
935 | } */ | |
936 | ||
937 | return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr), | |
938 | SCARG(uap, msg_len), SCARG(uap, msg_prio), 0); | |
939 | } | |
940 | ||
941 | int | |
942 | sys_mq_timedsend(struct mq_timedsend_args *uap) | |
943 | { | |
944 | /* { | |
945 | syscallarg(mqd_t) mqdes; | |
946 | syscallarg(const char *) msg_ptr; | |
947 | syscallarg(size_t) msg_len; | |
948 | syscallarg(unsigned) msg_prio; | |
949 | syscallarg(const struct timespec *) abs_timeout; | |
950 | } */ | |
951 | struct timespec ts, *tsp; | |
952 | int error; | |
953 | ||
954 | /* Get and convert time value */ | |
955 | if (SCARG(uap, abs_timeout)) { | |
956 | error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts)); | |
957 | if (error) | |
958 | return error; | |
959 | tsp = &ts; | |
960 | } else { | |
961 | tsp = NULL; | |
962 | } | |
963 | ||
964 | return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr), | |
965 | SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp); | |
966 | } | |
967 | ||
968 | int | |
969 | sys_mq_notify(struct mq_notify_args *uap) | |
970 | { | |
971 | /* { | |
972 | syscallarg(mqd_t) mqdes; | |
973 | syscallarg(const struct sigevent *) notification; | |
974 | } */ | |
975 | file_t *fp = NULL; | |
976 | struct mqueue *mq; | |
977 | struct sigevent sig; | |
978 | int error; | |
979 | ||
980 | if (SCARG(uap, notification)) { | |
981 | /* Get the signal from user-space */ | |
982 | error = copyin(SCARG(uap, notification), &sig, | |
983 | sizeof(struct sigevent)); | |
984 | if (error) | |
985 | return error; | |
c8b16402 SK |
986 | if (sig.sigev_notify == SIGEV_SIGNAL && |
987 | (sig.sigev_signo <= 0 || sig.sigev_signo >= NSIG)) | |
988 | return EINVAL; | |
f2df0f7c SK |
989 | } |
990 | ||
991 | error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp); | |
992 | if (error) | |
993 | return error; | |
994 | mq = fp->f_data; | |
995 | ||
996 | if (SCARG(uap, notification)) { | |
997 | /* Register notification: set the signal and target process */ | |
998 | if (mq->mq_notify_proc == NULL) { | |
999 | memcpy(&mq->mq_sig_notify, &sig, | |
1000 | sizeof(struct sigevent)); | |
1001 | mq->mq_notify_proc = curproc; | |
1002 | } else { | |
1003 | /* Fail if someone else already registered */ | |
1004 | error = EBUSY; | |
1005 | } | |
1006 | } else { | |
1007 | /* Unregister the notification */ | |
1008 | mq->mq_notify_proc = NULL; | |
1009 | } | |
1010 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
1011 | fdrop(fp); | |
1012 | ||
1013 | return error; | |
1014 | } | |
1015 | ||
1016 | int | |
1017 | sys_mq_getattr(struct mq_getattr_args *uap) | |
1018 | { | |
1019 | /* { | |
1020 | syscallarg(mqd_t) mqdes; | |
1021 | syscallarg(struct mq_attr *) mqstat; | |
1022 | } */ | |
1023 | file_t *fp = NULL; | |
1024 | struct mqueue *mq; | |
1025 | struct mq_attr attr; | |
1026 | int error; | |
1027 | ||
1028 | /* Get the message queue */ | |
766730da | 1029 | error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp); |
f2df0f7c SK |
1030 | if (error) |
1031 | return error; | |
1032 | mq = fp->f_data; | |
1033 | memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr)); | |
1034 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
1035 | fdrop(fp); | |
1036 | ||
1037 | return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr)); | |
1038 | } | |
1039 | ||
1040 | int | |
1041 | sys_mq_setattr(struct mq_setattr_args *uap) | |
1042 | { | |
1043 | /* { | |
1044 | syscallarg(mqd_t) mqdes; | |
1045 | syscallarg(const struct mq_attr *) mqstat; | |
1046 | syscallarg(struct mq_attr *) omqstat; | |
1047 | } */ | |
1048 | file_t *fp = NULL; | |
1049 | struct mqueue *mq; | |
1050 | struct mq_attr attr; | |
1051 | int error, nonblock; | |
1052 | ||
1053 | error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr)); | |
1054 | if (error) | |
1055 | return error; | |
1056 | nonblock = (attr.mq_flags & O_NONBLOCK); | |
1057 | ||
1058 | /* Get the message queue */ | |
766730da | 1059 | error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp); |
f2df0f7c SK |
1060 | if (error) |
1061 | return error; | |
1062 | mq = fp->f_data; | |
1063 | ||
1064 | /* Copy the old attributes, if needed */ | |
d1d64679 | 1065 | if (SCARG(uap, omqstat)) { |
f2df0f7c | 1066 | memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr)); |
d1d64679 | 1067 | } |
f2df0f7c SK |
1068 | |
1069 | /* Ignore everything, except O_NONBLOCK */ | |
1070 | if (nonblock) | |
1071 | mq->mq_attrib.mq_flags |= O_NONBLOCK; | |
1072 | else | |
1073 | mq->mq_attrib.mq_flags &= ~O_NONBLOCK; | |
1074 | ||
1075 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
1076 | fdrop(fp); | |
1077 | ||
1078 | /* | |
1079 | * Copy the data to the user-space. | |
1080 | * Note: According to POSIX, the new attributes should not be set in | |
1081 | * case of fail - this would be violated. | |
1082 | */ | |
1083 | if (SCARG(uap, omqstat)) | |
1084 | error = copyout(&attr, SCARG(uap, omqstat), | |
1085 | sizeof(struct mq_attr)); | |
1086 | ||
1087 | return error; | |
1088 | } | |
1089 | ||
1090 | int | |
1091 | sys_mq_unlink(struct mq_unlink_args *uap) | |
1092 | { | |
1093 | /* { | |
1094 | syscallarg(const char *) name; | |
1095 | } */ | |
9910d07b | 1096 | struct thread *td = curthread; |
f2df0f7c SK |
1097 | struct mqueue *mq; |
1098 | char *name; | |
1099 | int error, refcnt = 0; | |
1100 | ||
1101 | /* Get the name from the user-space */ | |
d3a2b23d VS |
1102 | name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO | M_NULLOK); |
1103 | if (name == NULL) | |
1104 | return (ENOMEM); | |
f2df0f7c SK |
1105 | error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL); |
1106 | if (error) { | |
1107 | kfree(name, M_MQBUF); | |
1108 | return error; | |
1109 | } | |
1110 | ||
1111 | /* Lookup for this file */ | |
1112 | lockmgr(&mqlist_mtx, LK_EXCLUSIVE); | |
1113 | mq = mqueue_lookup(name); | |
1114 | if (mq == NULL) { | |
1115 | error = ENOENT; | |
1116 | goto error; | |
1117 | } | |
1118 | ||
1119 | /* Check the permissions */ | |
9910d07b MD |
1120 | if (td->td_ucred->cr_uid != mq->mq_euid && |
1121 | priv_check(td, PRIV_ROOT) != 0) { | |
f2df0f7c SK |
1122 | lockmgr(&mq->mq_mtx, LK_RELEASE); |
1123 | error = EACCES; | |
1124 | goto error; | |
1125 | } | |
1126 | ||
1127 | /* Mark message queue as unlinking, before leaving the window */ | |
1128 | mq->mq_attrib.mq_flags |= MQ_UNLINK; | |
1129 | ||
1130 | /* Wake up all waiters, if there are such */ | |
1131 | wakeup(&mq->mq_send_cv); | |
1132 | wakeup(&mq->mq_recv_cv); | |
1133 | ||
5b22f1a7 SG |
1134 | KNOTE(&mq->mq_rkq.ki_note, 0); |
1135 | KNOTE(&mq->mq_wkq.ki_note, 0); | |
f2df0f7c SK |
1136 | |
1137 | refcnt = mq->mq_refcnt; | |
1138 | if (refcnt == 0) | |
1139 | LIST_REMOVE(mq, mq_list); | |
1140 | ||
1141 | lockmgr(&mq->mq_mtx, LK_RELEASE); | |
1142 | error: | |
1143 | lockmgr(&mqlist_mtx, LK_RELEASE); | |
1144 | ||
1145 | /* | |
1146 | * If there are no references - destroy the message | |
1147 | * queue, otherwise, the last mq_close() will do that. | |
1148 | */ | |
1149 | if (error == 0 && refcnt == 0) | |
1150 | mqueue_destroy(mq); | |
1151 | ||
1152 | kfree(name, M_MQBUF); | |
1153 | return error; | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * SysCtl. | |
1158 | */ | |
1159 | SYSCTL_NODE(_kern, OID_AUTO, mqueue, | |
1160 | CTLFLAG_RW, 0, "Message queue options"); | |
1161 | ||
1162 | SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_open_max, | |
1163 | CTLFLAG_RW, &mq_open_max, 0, | |
1164 | "Maximal number of message queue descriptors per process"); | |
1165 | ||
1166 | SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_prio_max, | |
1167 | CTLFLAG_RW, &mq_prio_max, 0, | |
1168 | "Maximal priority of the message"); | |
1169 | ||
1170 | SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_msgsize, | |
1171 | CTLFLAG_RW, &mq_max_msgsize, 0, | |
1172 | "Maximal allowed size of the message"); | |
1173 | ||
1174 | SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_def_maxmsg, | |
1175 | CTLFLAG_RW, &mq_def_maxmsg, 0, | |
1176 | "Default maximal message count"); | |
1177 | ||
8658b626 SK |
1178 | SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_maxmsg, |
1179 | CTLFLAG_RW, &mq_max_maxmsg, 0, | |
1180 | "Maximal allowed message count"); | |
1181 | ||
f2df0f7c | 1182 | SYSINIT(sys_mqueue_init, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, mqueue_sysinit, NULL); |