| 1 | /* $NetBSD: sys_mqueue.c,v 1.39 2015/06/29 15:44:45 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2007-2011 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) is protected by mqlist_lock. |
| 36 | * Each message queue and its members are protected by mqueue::mq_mtx. |
| 37 | * Note that proc_t::p_mqueue_cnt is updated atomically. |
| 38 | * |
| 39 | * Lock order: |
| 40 | * |
| 41 | * mqlist_lock -> |
| 42 | * mqueue::mq_mtx |
| 43 | */ |
| 44 | |
| 45 | #include <sys/cdefs.h> |
| 46 | __KERNEL_RCSID(0, "$NetBSD: sys_mqueue.c,v 1.39 2015/06/29 15:44:45 christos Exp $" ); |
| 47 | |
| 48 | #include <sys/param.h> |
| 49 | #include <sys/types.h> |
| 50 | #include <sys/atomic.h> |
| 51 | |
| 52 | #include <sys/file.h> |
| 53 | #include <sys/filedesc.h> |
| 54 | #include <sys/kauth.h> |
| 55 | #include <sys/lwp.h> |
| 56 | #include <sys/mqueue.h> |
| 57 | #include <sys/module.h> |
| 58 | #include <sys/poll.h> |
| 59 | #include <sys/select.h> |
| 60 | #include <sys/signal.h> |
| 61 | #include <sys/signalvar.h> |
| 62 | #include <sys/stat.h> |
| 63 | #include <sys/sysctl.h> |
| 64 | #include <sys/syscall.h> |
| 65 | #include <sys/syscallvar.h> |
| 66 | #include <sys/syscallargs.h> |
| 67 | |
| 68 | #include <miscfs/genfs/genfs.h> |
| 69 | |
| 70 | MODULE(MODULE_CLASS_MISC, mqueue, NULL); |
| 71 | |
| 72 | /* System-wide limits. */ |
| 73 | static u_int mq_open_max = MQ_OPEN_MAX; |
| 74 | static u_int mq_prio_max = MQ_PRIO_MAX; |
| 75 | static u_int mq_max_msgsize = 16 * MQ_DEF_MSGSIZE; |
| 76 | static u_int mq_def_maxmsg = 32; |
| 77 | static u_int mq_max_maxmsg = 16 * 32; |
| 78 | |
| 79 | static pool_cache_t mqmsg_cache __read_mostly; |
| 80 | static kmutex_t mqlist_lock __cacheline_aligned; |
| 81 | static LIST_HEAD(, mqueue) mqueue_head __cacheline_aligned; |
| 82 | static struct sysctllog * mqsysctl_log; |
| 83 | |
| 84 | static kauth_listener_t mq_listener; |
| 85 | |
| 86 | static int mqueue_sysinit(void); |
| 87 | static int mqueue_sysfini(bool); |
| 88 | static int mqueue_sysctl_init(void); |
| 89 | static int mq_poll_fop(file_t *, int); |
| 90 | static int mq_stat_fop(file_t *, struct stat *); |
| 91 | static int mq_close_fop(file_t *); |
| 92 | |
| 93 | static const struct fileops mqops = { |
| 94 | .fo_read = fbadop_read, |
| 95 | .fo_write = fbadop_write, |
| 96 | .fo_ioctl = fbadop_ioctl, |
| 97 | .fo_fcntl = fnullop_fcntl, |
| 98 | .fo_poll = mq_poll_fop, |
| 99 | .fo_stat = mq_stat_fop, |
| 100 | .fo_close = mq_close_fop, |
| 101 | .fo_kqfilter = fnullop_kqfilter, |
| 102 | .fo_restart = fnullop_restart, |
| 103 | }; |
| 104 | |
| 105 | static const struct syscall_package mqueue_syscalls[] = { |
| 106 | { SYS_mq_open, 0, (sy_call_t *)sys_mq_open }, |
| 107 | { SYS_mq_close, 0, (sy_call_t *)sys_mq_close }, |
| 108 | { SYS_mq_unlink, 0, (sy_call_t *)sys_mq_unlink }, |
| 109 | { SYS_mq_getattr, 0, (sy_call_t *)sys_mq_getattr }, |
| 110 | { SYS_mq_setattr, 0, (sy_call_t *)sys_mq_setattr }, |
| 111 | { SYS_mq_notify, 0, (sy_call_t *)sys_mq_notify }, |
| 112 | { SYS_mq_send, 0, (sy_call_t *)sys_mq_send }, |
| 113 | { SYS_mq_receive, 0, (sy_call_t *)sys_mq_receive }, |
| 114 | { SYS___mq_timedsend50, 0, (sy_call_t *)sys___mq_timedsend50 }, |
| 115 | { SYS___mq_timedreceive50, 0, (sy_call_t *)sys___mq_timedreceive50 }, |
| 116 | { 0, 0, NULL } |
| 117 | }; |
| 118 | |
| 119 | static int |
| 120 | mq_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, |
| 121 | void *arg0, void *arg1, void *arg2, void *arg3) |
| 122 | { |
| 123 | mqueue_t *mq; |
| 124 | int result; |
| 125 | |
| 126 | if (action != KAUTH_SYSTEM_MQUEUE) |
| 127 | return KAUTH_RESULT_DEFER; |
| 128 | |
| 129 | result = KAUTH_RESULT_DEFER; |
| 130 | |
| 131 | mq = arg1; |
| 132 | |
| 133 | if (kauth_cred_geteuid(cred) == mq->mq_euid) |
| 134 | result = KAUTH_RESULT_ALLOW; |
| 135 | |
| 136 | return result; |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Initialisation and unloading of POSIX message queue subsystem. |
| 141 | */ |
| 142 | |
| 143 | static int |
| 144 | mqueue_sysinit(void) |
| 145 | { |
| 146 | int error; |
| 147 | |
| 148 | mqmsg_cache = pool_cache_init(MQ_DEF_MSGSIZE, coherency_unit, |
| 149 | 0, 0, "mqmsgpl" , NULL, IPL_NONE, NULL, NULL, NULL); |
| 150 | mutex_init(&mqlist_lock, MUTEX_DEFAULT, IPL_NONE); |
| 151 | LIST_INIT(&mqueue_head); |
| 152 | |
| 153 | error = mqueue_sysctl_init(); |
| 154 | if (error) { |
| 155 | (void)mqueue_sysfini(false); |
| 156 | return error; |
| 157 | } |
| 158 | error = syscall_establish(NULL, mqueue_syscalls); |
| 159 | if (error) { |
| 160 | (void)mqueue_sysfini(false); |
| 161 | } |
| 162 | mq_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, |
| 163 | mq_listener_cb, NULL); |
| 164 | return error; |
| 165 | } |
| 166 | |
| 167 | static int |
| 168 | mqueue_sysfini(bool interface) |
| 169 | { |
| 170 | |
| 171 | if (interface) { |
| 172 | int error; |
| 173 | bool inuse; |
| 174 | |
| 175 | /* Stop syscall activity. */ |
| 176 | error = syscall_disestablish(NULL, mqueue_syscalls); |
| 177 | if (error) |
| 178 | return error; |
| 179 | /* Check if there are any message queues in use. */ |
| 180 | mutex_enter(&mqlist_lock); |
| 181 | inuse = !LIST_EMPTY(&mqueue_head); |
| 182 | mutex_exit(&mqlist_lock); |
| 183 | if (inuse) { |
| 184 | error = syscall_establish(NULL, mqueue_syscalls); |
| 185 | KASSERT(error == 0); |
| 186 | return EBUSY; |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | if (mqsysctl_log != NULL) |
| 191 | sysctl_teardown(&mqsysctl_log); |
| 192 | |
| 193 | kauth_unlisten_scope(mq_listener); |
| 194 | |
| 195 | mutex_destroy(&mqlist_lock); |
| 196 | pool_cache_destroy(mqmsg_cache); |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * Module interface. |
| 202 | */ |
| 203 | static int |
| 204 | mqueue_modcmd(modcmd_t cmd, void *arg) |
| 205 | { |
| 206 | |
| 207 | switch (cmd) { |
| 208 | case MODULE_CMD_INIT: |
| 209 | return mqueue_sysinit(); |
| 210 | case MODULE_CMD_FINI: |
| 211 | return mqueue_sysfini(true); |
| 212 | default: |
| 213 | return ENOTTY; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * Free the message. |
| 219 | */ |
| 220 | static void |
| 221 | mqueue_freemsg(struct mq_msg *msg, const size_t size) |
| 222 | { |
| 223 | |
| 224 | if (size > MQ_DEF_MSGSIZE) { |
| 225 | kmem_free(msg, size); |
| 226 | } else { |
| 227 | pool_cache_put(mqmsg_cache, msg); |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * Destroy the message queue. |
| 233 | */ |
| 234 | static void |
| 235 | mqueue_destroy(struct mqueue *mq) |
| 236 | { |
| 237 | struct mq_msg *msg; |
| 238 | size_t msz; |
| 239 | u_int i; |
| 240 | |
| 241 | /* Note MQ_PQSIZE + 1. */ |
| 242 | for (i = 0; i <= MQ_PQSIZE; i++) { |
| 243 | while ((msg = TAILQ_FIRST(&mq->mq_head[i])) != NULL) { |
| 244 | TAILQ_REMOVE(&mq->mq_head[i], msg, msg_queue); |
| 245 | msz = sizeof(struct mq_msg) + msg->msg_len; |
| 246 | mqueue_freemsg(msg, msz); |
| 247 | } |
| 248 | } |
| 249 | if (mq->mq_name) { |
| 250 | kmem_free(mq->mq_name, MQ_NAMELEN); |
| 251 | } |
| 252 | seldestroy(&mq->mq_rsel); |
| 253 | seldestroy(&mq->mq_wsel); |
| 254 | cv_destroy(&mq->mq_send_cv); |
| 255 | cv_destroy(&mq->mq_recv_cv); |
| 256 | mutex_destroy(&mq->mq_mtx); |
| 257 | kmem_free(mq, sizeof(struct mqueue)); |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | * mqueue_lookup: lookup for file name in general list of message queues. |
| 262 | * |
| 263 | * => locks the message queue on success |
| 264 | */ |
| 265 | static mqueue_t * |
| 266 | mqueue_lookup(const char *name) |
| 267 | { |
| 268 | mqueue_t *mq; |
| 269 | |
| 270 | KASSERT(mutex_owned(&mqlist_lock)); |
| 271 | |
| 272 | LIST_FOREACH(mq, &mqueue_head, mq_list) { |
| 273 | if (strncmp(mq->mq_name, name, MQ_NAMELEN) == 0) { |
| 274 | mutex_enter(&mq->mq_mtx); |
| 275 | return mq; |
| 276 | } |
| 277 | } |
| 278 | return NULL; |
| 279 | } |
| 280 | |
| 281 | /* |
| 282 | * mqueue_get: get the mqueue from the descriptor. |
| 283 | * |
| 284 | * => locks the message queue, if found. |
| 285 | * => holds a reference on the file descriptor. |
| 286 | */ |
| 287 | int |
| 288 | mqueue_get(mqd_t mqd, int fflag, mqueue_t **mqret) |
| 289 | { |
| 290 | const int fd = (int)mqd; |
| 291 | mqueue_t *mq; |
| 292 | file_t *fp; |
| 293 | |
| 294 | fp = fd_getfile(fd); |
| 295 | if (__predict_false(fp == NULL)) { |
| 296 | return EBADF; |
| 297 | } |
| 298 | if (__predict_false(fp->f_type != DTYPE_MQUEUE)) { |
| 299 | fd_putfile(fd); |
| 300 | return EBADF; |
| 301 | } |
| 302 | if (fflag && (fp->f_flag & fflag) == 0) { |
| 303 | fd_putfile(fd); |
| 304 | return EBADF; |
| 305 | } |
| 306 | mq = fp->f_mqueue; |
| 307 | mutex_enter(&mq->mq_mtx); |
| 308 | |
| 309 | *mqret = mq; |
| 310 | return 0; |
| 311 | } |
| 312 | |
| 313 | /* |
| 314 | * mqueue_linear_insert: perform linear insert according to the message |
| 315 | * priority into the reserved queue (MQ_PQRESQ). Reserved queue is a |
| 316 | * sorted list used only when mq_prio_max is increased via sysctl. |
| 317 | */ |
| 318 | static inline void |
| 319 | mqueue_linear_insert(struct mqueue *mq, struct mq_msg *msg) |
| 320 | { |
| 321 | struct mq_msg *mit; |
| 322 | |
| 323 | TAILQ_FOREACH(mit, &mq->mq_head[MQ_PQRESQ], msg_queue) { |
| 324 | if (msg->msg_prio > mit->msg_prio) |
| 325 | break; |
| 326 | } |
| 327 | if (mit == NULL) { |
| 328 | TAILQ_INSERT_TAIL(&mq->mq_head[MQ_PQRESQ], msg, msg_queue); |
| 329 | } else { |
| 330 | TAILQ_INSERT_BEFORE(mit, msg, msg_queue); |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | static int |
| 335 | mq_stat_fop(file_t *fp, struct stat *st) |
| 336 | { |
| 337 | struct mqueue *mq = fp->f_mqueue; |
| 338 | |
| 339 | memset(st, 0, sizeof(*st)); |
| 340 | |
| 341 | mutex_enter(&mq->mq_mtx); |
| 342 | st->st_mode = mq->mq_mode; |
| 343 | st->st_uid = mq->mq_euid; |
| 344 | st->st_gid = mq->mq_egid; |
| 345 | st->st_atimespec = mq->mq_atime; |
| 346 | st->st_mtimespec = mq->mq_mtime; |
| 347 | st->st_ctimespec = st->st_birthtimespec = mq->mq_btime; |
| 348 | st->st_uid = kauth_cred_geteuid(fp->f_cred); |
| 349 | st->st_gid = kauth_cred_getegid(fp->f_cred); |
| 350 | mutex_exit(&mq->mq_mtx); |
| 351 | |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | static int |
| 356 | mq_poll_fop(file_t *fp, int events) |
| 357 | { |
| 358 | struct mqueue *mq = fp->f_mqueue; |
| 359 | struct mq_attr *mqattr; |
| 360 | int revents = 0; |
| 361 | |
| 362 | mutex_enter(&mq->mq_mtx); |
| 363 | mqattr = &mq->mq_attrib; |
| 364 | if (events & (POLLIN | POLLRDNORM)) { |
| 365 | /* Ready for receiving, if there are messages in the queue. */ |
| 366 | if (mqattr->mq_curmsgs) |
| 367 | revents |= events & (POLLIN | POLLRDNORM); |
| 368 | else |
| 369 | selrecord(curlwp, &mq->mq_rsel); |
| 370 | } |
| 371 | if (events & (POLLOUT | POLLWRNORM)) { |
| 372 | /* Ready for sending, if the message queue is not full. */ |
| 373 | if (mqattr->mq_curmsgs < mqattr->mq_maxmsg) |
| 374 | revents |= events & (POLLOUT | POLLWRNORM); |
| 375 | else |
| 376 | selrecord(curlwp, &mq->mq_wsel); |
| 377 | } |
| 378 | mutex_exit(&mq->mq_mtx); |
| 379 | |
| 380 | return revents; |
| 381 | } |
| 382 | |
| 383 | static int |
| 384 | mq_close_fop(file_t *fp) |
| 385 | { |
| 386 | proc_t *p = curproc; |
| 387 | mqueue_t *mq = fp->f_mqueue; |
| 388 | bool destroy = false; |
| 389 | |
| 390 | mutex_enter(&mq->mq_mtx); |
| 391 | KASSERT(mq->mq_refcnt > 0); |
| 392 | if (--mq->mq_refcnt == 0) { |
| 393 | /* Destroy if the last reference and unlinked. */ |
| 394 | destroy = (mq->mq_attrib.mq_flags & MQ_UNLINKED) != 0; |
| 395 | } |
| 396 | mutex_exit(&mq->mq_mtx); |
| 397 | |
| 398 | if (destroy) { |
| 399 | mqueue_destroy(mq); |
| 400 | } |
| 401 | atomic_dec_uint(&p->p_mqueue_cnt); |
| 402 | return 0; |
| 403 | } |
| 404 | |
| 405 | static int |
| 406 | mqueue_access(mqueue_t *mq, int access, kauth_cred_t cred) |
| 407 | { |
| 408 | mode_t acc_mode = 0; |
| 409 | |
| 410 | /* Note the difference between VREAD/VWRITE and FREAD/FWRITE. */ |
| 411 | if (access & FREAD) { |
| 412 | acc_mode |= VREAD; |
| 413 | } |
| 414 | if (access & FWRITE) { |
| 415 | acc_mode |= VWRITE; |
| 416 | } |
| 417 | if (genfs_can_access(VNON, mq->mq_mode, mq->mq_euid, |
| 418 | mq->mq_egid, acc_mode, cred)) { |
| 419 | return EACCES; |
| 420 | } |
| 421 | return 0; |
| 422 | } |
| 423 | |
| 424 | static int |
| 425 | mqueue_create(lwp_t *l, char *name, struct mq_attr *attr, mode_t mode, |
| 426 | int oflag, mqueue_t **mqret) |
| 427 | { |
| 428 | proc_t *p = l->l_proc; |
| 429 | struct cwdinfo *cwdi = p->p_cwdi; |
| 430 | mqueue_t *mq; |
| 431 | u_int i; |
| 432 | |
| 433 | /* Pre-check the limit. */ |
| 434 | if (p->p_mqueue_cnt >= mq_open_max) { |
| 435 | return EMFILE; |
| 436 | } |
| 437 | |
| 438 | /* Empty name is invalid. */ |
| 439 | if (name[0] == '\0') { |
| 440 | return EINVAL; |
| 441 | } |
| 442 | |
| 443 | /* Check for mqueue attributes. */ |
| 444 | if (attr) { |
| 445 | if (attr->mq_maxmsg <= 0 || attr->mq_maxmsg > mq_max_maxmsg || |
| 446 | attr->mq_msgsize <= 0 || |
| 447 | attr->mq_msgsize > mq_max_msgsize) { |
| 448 | return EINVAL; |
| 449 | } |
| 450 | attr->mq_curmsgs = 0; |
| 451 | } |
| 452 | |
| 453 | /* |
| 454 | * Allocate new message queue, initialize data structures, copy the |
| 455 | * name attributes. Note that the initial reference is set here. |
| 456 | */ |
| 457 | mq = kmem_zalloc(sizeof(mqueue_t), KM_SLEEP); |
| 458 | |
| 459 | mutex_init(&mq->mq_mtx, MUTEX_DEFAULT, IPL_NONE); |
| 460 | cv_init(&mq->mq_send_cv, "mqsendcv" ); |
| 461 | cv_init(&mq->mq_recv_cv, "mqrecvcv" ); |
| 462 | for (i = 0; i < (MQ_PQSIZE + 1); i++) { |
| 463 | TAILQ_INIT(&mq->mq_head[i]); |
| 464 | } |
| 465 | selinit(&mq->mq_rsel); |
| 466 | selinit(&mq->mq_wsel); |
| 467 | mq->mq_name = name; |
| 468 | mq->mq_refcnt = 1; |
| 469 | |
| 470 | if (attr != NULL) { |
| 471 | memcpy(&mq->mq_attrib, attr, sizeof(struct mq_attr)); |
| 472 | } else { |
| 473 | memset(&mq->mq_attrib, 0, sizeof(struct mq_attr)); |
| 474 | mq->mq_attrib.mq_maxmsg = mq_def_maxmsg; |
| 475 | mq->mq_attrib.mq_msgsize = MQ_DEF_MSGSIZE - sizeof(struct mq_msg); |
| 476 | } |
| 477 | |
| 478 | CTASSERT((O_MASK & (MQ_UNLINKED | MQ_RECEIVE)) == 0); |
| 479 | mq->mq_attrib.mq_flags = (O_MASK & oflag); |
| 480 | |
| 481 | /* Store mode and effective UID with GID. */ |
| 482 | mq->mq_mode = ((mode & ~cwdi->cwdi_cmask) & ALLPERMS) & ~S_ISTXT; |
| 483 | mq->mq_euid = kauth_cred_geteuid(l->l_cred); |
| 484 | mq->mq_egid = kauth_cred_getegid(l->l_cred); |
| 485 | |
| 486 | *mqret = mq; |
| 487 | return 0; |
| 488 | } |
| 489 | |
| 490 | /* |
| 491 | * Helper function for mq_open() - note that "u_name" is a userland pointer, |
| 492 | * while "attr" is a kernel pointer! |
| 493 | */ |
| 494 | int |
| 495 | mq_handle_open(struct lwp *l, const char *u_name, int oflag, mode_t mode, |
| 496 | struct mq_attr *attr, register_t *retval) |
| 497 | { |
| 498 | struct proc *p = l->l_proc; |
| 499 | struct mqueue *mq, *mq_new = NULL; |
| 500 | int mqd, error; |
| 501 | file_t *fp; |
| 502 | char *name; |
| 503 | |
| 504 | /* Get the name from the user-space. */ |
| 505 | name = kmem_alloc(MQ_NAMELEN, KM_SLEEP); |
| 506 | error = copyinstr(u_name, name, MQ_NAMELEN - 1, NULL); |
| 507 | if (error) { |
| 508 | kmem_free(name, MQ_NAMELEN); |
| 509 | return error; |
| 510 | } |
| 511 | |
| 512 | /* Allocate file structure and descriptor. */ |
| 513 | error = fd_allocfile(&fp, &mqd); |
| 514 | if (error) { |
| 515 | kmem_free(name, MQ_NAMELEN); |
| 516 | return error; |
| 517 | } |
| 518 | fp->f_type = DTYPE_MQUEUE; |
| 519 | fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE); |
| 520 | fp->f_ops = &mqops; |
| 521 | |
| 522 | if (oflag & O_CREAT) { |
| 523 | /* Create a new message queue. */ |
| 524 | error = mqueue_create(l, name, attr, mode, oflag, &mq_new); |
| 525 | if (error) { |
| 526 | goto err; |
| 527 | } |
| 528 | KASSERT(mq_new != NULL); |
| 529 | } |
| 530 | |
| 531 | /* Lookup for a message queue with such name. */ |
| 532 | mutex_enter(&mqlist_lock); |
| 533 | mq = mqueue_lookup(name); |
| 534 | if (mq) { |
| 535 | KASSERT(mutex_owned(&mq->mq_mtx)); |
| 536 | mutex_exit(&mqlist_lock); |
| 537 | |
| 538 | /* Check for exclusive create. */ |
| 539 | if (oflag & O_EXCL) { |
| 540 | mutex_exit(&mq->mq_mtx); |
| 541 | error = EEXIST; |
| 542 | goto err; |
| 543 | } |
| 544 | |
| 545 | /* Verify permissions. */ |
| 546 | if (mqueue_access(mq, fp->f_flag, l->l_cred) != 0) { |
| 547 | mutex_exit(&mq->mq_mtx); |
| 548 | error = EACCES; |
| 549 | goto err; |
| 550 | } |
| 551 | |
| 552 | /* If we have the access, add a new reference. */ |
| 553 | mq->mq_refcnt++; |
| 554 | mutex_exit(&mq->mq_mtx); |
| 555 | } else { |
| 556 | /* Fail if not found and not creating. */ |
| 557 | if ((oflag & O_CREAT) == 0) { |
| 558 | mutex_exit(&mqlist_lock); |
| 559 | KASSERT(mq_new == NULL); |
| 560 | error = ENOENT; |
| 561 | goto err; |
| 562 | } |
| 563 | |
| 564 | /* Account and check for the limit. */ |
| 565 | if (atomic_inc_uint_nv(&p->p_mqueue_cnt) > mq_open_max) { |
| 566 | mutex_exit(&mqlist_lock); |
| 567 | atomic_dec_uint(&p->p_mqueue_cnt); |
| 568 | error = EMFILE; |
| 569 | goto err; |
| 570 | } |
| 571 | |
| 572 | /* Initial timestamps. */ |
| 573 | mq = mq_new; |
| 574 | getnanotime(&mq->mq_btime); |
| 575 | mq->mq_atime = mq->mq_mtime = mq->mq_btime; |
| 576 | |
| 577 | /* |
| 578 | * Finally, insert message queue into the list. |
| 579 | * Note: it already has the initial reference. |
| 580 | */ |
| 581 | LIST_INSERT_HEAD(&mqueue_head, mq, mq_list); |
| 582 | mutex_exit(&mqlist_lock); |
| 583 | |
| 584 | mq_new = NULL; |
| 585 | name = NULL; |
| 586 | } |
| 587 | KASSERT(mq != NULL); |
| 588 | fp->f_mqueue = mq; |
| 589 | fd_affix(p, fp, mqd); |
| 590 | *retval = mqd; |
| 591 | err: |
| 592 | if (error) { |
| 593 | fd_abort(p, fp, mqd); |
| 594 | } |
| 595 | if (mq_new) { |
| 596 | /* Note: will free the 'name'. */ |
| 597 | mqueue_destroy(mq_new); |
| 598 | } else if (name) { |
| 599 | kmem_free(name, MQ_NAMELEN); |
| 600 | } |
| 601 | return error; |
| 602 | } |
| 603 | |
| 604 | /* |
| 605 | * General mqueue system calls. |
| 606 | */ |
| 607 | |
| 608 | int |
| 609 | sys_mq_open(struct lwp *l, const struct sys_mq_open_args *uap, |
| 610 | register_t *retval) |
| 611 | { |
| 612 | /* { |
| 613 | syscallarg(const char *) name; |
| 614 | syscallarg(int) oflag; |
| 615 | syscallarg(mode_t) mode; |
| 616 | syscallarg(struct mq_attr) attr; |
| 617 | } */ |
| 618 | struct mq_attr *attr = NULL, a; |
| 619 | int error; |
| 620 | |
| 621 | if ((SCARG(uap, oflag) & O_CREAT) != 0 && SCARG(uap, attr) != NULL) { |
| 622 | error = copyin(SCARG(uap, attr), &a, sizeof(a)); |
| 623 | if (error) |
| 624 | return error; |
| 625 | attr = &a; |
| 626 | } |
| 627 | |
| 628 | return mq_handle_open(l, SCARG(uap, name), SCARG(uap, oflag), |
| 629 | SCARG(uap, mode), attr, retval); |
| 630 | } |
| 631 | |
| 632 | int |
| 633 | sys_mq_close(struct lwp *l, const struct sys_mq_close_args *uap, |
| 634 | register_t *retval) |
| 635 | { |
| 636 | |
| 637 | return sys_close(l, (const void *)uap, retval); |
| 638 | } |
| 639 | |
| 640 | /* |
| 641 | * Primary mq_recv1() function. |
| 642 | */ |
| 643 | int |
| 644 | mq_recv1(mqd_t mqdes, void *msg_ptr, size_t msg_len, u_int *msg_prio, |
| 645 | struct timespec *ts, ssize_t *mlen) |
| 646 | { |
| 647 | struct mqueue *mq; |
| 648 | struct mq_msg *msg = NULL; |
| 649 | struct mq_attr *mqattr; |
| 650 | u_int idx; |
| 651 | int error; |
| 652 | |
| 653 | error = mqueue_get(mqdes, FREAD, &mq); |
| 654 | if (error) { |
| 655 | return error; |
| 656 | } |
| 657 | getnanotime(&mq->mq_atime); |
| 658 | mqattr = &mq->mq_attrib; |
| 659 | |
| 660 | /* Check the message size limits */ |
| 661 | if (msg_len < mqattr->mq_msgsize) { |
| 662 | error = EMSGSIZE; |
| 663 | goto error; |
| 664 | } |
| 665 | |
| 666 | /* Check if queue is empty */ |
| 667 | while (mqattr->mq_curmsgs == 0) { |
| 668 | int t; |
| 669 | |
| 670 | if (mqattr->mq_flags & O_NONBLOCK) { |
| 671 | error = EAGAIN; |
| 672 | goto error; |
| 673 | } |
| 674 | if (ts) { |
| 675 | error = ts2timo(CLOCK_REALTIME, TIMER_ABSTIME, ts, &t, |
| 676 | NULL); |
| 677 | if (error) |
| 678 | goto error; |
| 679 | } else |
| 680 | t = 0; |
| 681 | /* |
| 682 | * Block until someone sends the message. |
| 683 | * While doing this, notification should not be sent. |
| 684 | */ |
| 685 | mqattr->mq_flags |= MQ_RECEIVE; |
| 686 | error = cv_timedwait_sig(&mq->mq_send_cv, &mq->mq_mtx, t); |
| 687 | mqattr->mq_flags &= ~MQ_RECEIVE; |
| 688 | if (error || (mqattr->mq_flags & MQ_UNLINKED)) { |
| 689 | error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR; |
| 690 | goto error; |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | /* |
| 695 | * Find the highest priority message, and remove it from the queue. |
| 696 | * At first, reserved queue is checked, bitmap is next. |
| 697 | */ |
| 698 | msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]); |
| 699 | if (__predict_true(msg == NULL)) { |
| 700 | idx = ffs(mq->mq_bitmap); |
| 701 | msg = TAILQ_FIRST(&mq->mq_head[idx]); |
| 702 | KASSERT(msg != NULL); |
| 703 | } else { |
| 704 | idx = MQ_PQRESQ; |
| 705 | } |
| 706 | TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue); |
| 707 | |
| 708 | /* Unmark the bit, if last message. */ |
| 709 | if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) { |
| 710 | KASSERT((MQ_PQSIZE - idx) == msg->msg_prio); |
| 711 | mq->mq_bitmap &= ~(1 << --idx); |
| 712 | } |
| 713 | |
| 714 | /* Decrement the counter and signal waiter, if any */ |
| 715 | mqattr->mq_curmsgs--; |
| 716 | cv_signal(&mq->mq_recv_cv); |
| 717 | |
| 718 | /* Ready for sending now */ |
| 719 | selnotify(&mq->mq_wsel, POLLOUT | POLLWRNORM, 0); |
| 720 | error: |
| 721 | mutex_exit(&mq->mq_mtx); |
| 722 | fd_putfile((int)mqdes); |
| 723 | if (error) |
| 724 | return error; |
| 725 | |
| 726 | /* |
| 727 | * Copy the data to the user-space. |
| 728 | * Note: According to POSIX, no message should be removed from the |
| 729 | * queue in case of fail - this would be violated. |
| 730 | */ |
| 731 | *mlen = msg->msg_len; |
| 732 | error = copyout(msg->msg_ptr, msg_ptr, msg->msg_len); |
| 733 | if (error == 0 && msg_prio) |
| 734 | error = copyout(&msg->msg_prio, msg_prio, sizeof(unsigned)); |
| 735 | mqueue_freemsg(msg, sizeof(struct mq_msg) + msg->msg_len); |
| 736 | |
| 737 | return error; |
| 738 | } |
| 739 | |
| 740 | int |
| 741 | sys_mq_receive(struct lwp *l, const struct sys_mq_receive_args *uap, |
| 742 | register_t *retval) |
| 743 | { |
| 744 | /* { |
| 745 | syscallarg(mqd_t) mqdes; |
| 746 | syscallarg(char *) msg_ptr; |
| 747 | syscallarg(size_t) msg_len; |
| 748 | syscallarg(unsigned *) msg_prio; |
| 749 | } */ |
| 750 | ssize_t mlen; |
| 751 | int error; |
| 752 | |
| 753 | error = mq_recv1(SCARG(uap, mqdes), SCARG(uap, msg_ptr), |
| 754 | SCARG(uap, msg_len), SCARG(uap, msg_prio), NULL, &mlen); |
| 755 | if (error == 0) |
| 756 | *retval = mlen; |
| 757 | |
| 758 | return error; |
| 759 | } |
| 760 | |
| 761 | int |
| 762 | sys___mq_timedreceive50(struct lwp *l, |
| 763 | const struct sys___mq_timedreceive50_args *uap, register_t *retval) |
| 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 | struct timespec ts, *tsp; |
| 773 | ssize_t mlen; |
| 774 | int error; |
| 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_recv1(SCARG(uap, mqdes), SCARG(uap, msg_ptr), |
| 787 | SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp, &mlen); |
| 788 | if (error == 0) |
| 789 | *retval = mlen; |
| 790 | |
| 791 | return error; |
| 792 | } |
| 793 | |
| 794 | /* |
| 795 | * Primary mq_send1() function. |
| 796 | */ |
| 797 | int |
| 798 | mq_send1(mqd_t mqdes, const char *msg_ptr, size_t msg_len, u_int msg_prio, |
| 799 | struct timespec *ts) |
| 800 | { |
| 801 | struct mqueue *mq; |
| 802 | struct mq_msg *msg; |
| 803 | struct mq_attr *mqattr; |
| 804 | struct proc *notify = NULL; |
| 805 | ksiginfo_t ksi; |
| 806 | size_t size; |
| 807 | int error; |
| 808 | |
| 809 | /* Check the priority range */ |
| 810 | if (msg_prio >= mq_prio_max) |
| 811 | return EINVAL; |
| 812 | |
| 813 | /* Allocate a new message */ |
| 814 | size = sizeof(struct mq_msg) + msg_len; |
| 815 | if (size > mq_max_msgsize) |
| 816 | return EMSGSIZE; |
| 817 | |
| 818 | if (size > MQ_DEF_MSGSIZE) { |
| 819 | msg = kmem_alloc(size, KM_SLEEP); |
| 820 | } else { |
| 821 | msg = pool_cache_get(mqmsg_cache, PR_WAITOK); |
| 822 | } |
| 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 | error = mqueue_get(mqdes, FWRITE, &mq); |
| 834 | if (error) { |
| 835 | mqueue_freemsg(msg, size); |
| 836 | return error; |
| 837 | } |
| 838 | getnanotime(&mq->mq_mtime); |
| 839 | mqattr = &mq->mq_attrib; |
| 840 | |
| 841 | /* Check the message size limit */ |
| 842 | if (msg_len <= 0 || msg_len > mqattr->mq_msgsize) { |
| 843 | error = EMSGSIZE; |
| 844 | goto error; |
| 845 | } |
| 846 | |
| 847 | /* Check if queue is full */ |
| 848 | while (mqattr->mq_curmsgs >= mqattr->mq_maxmsg) { |
| 849 | int t; |
| 850 | |
| 851 | if (mqattr->mq_flags & O_NONBLOCK) { |
| 852 | error = EAGAIN; |
| 853 | goto error; |
| 854 | } |
| 855 | if (ts) { |
| 856 | error = ts2timo(CLOCK_REALTIME, TIMER_ABSTIME, ts, &t, |
| 857 | NULL); |
| 858 | if (error) |
| 859 | goto error; |
| 860 | } else |
| 861 | t = 0; |
| 862 | /* Block until queue becomes available */ |
| 863 | error = cv_timedwait_sig(&mq->mq_recv_cv, &mq->mq_mtx, t); |
| 864 | if (error || (mqattr->mq_flags & MQ_UNLINKED)) { |
| 865 | error = (error == EWOULDBLOCK) ? ETIMEDOUT : error; |
| 866 | goto error; |
| 867 | } |
| 868 | } |
| 869 | KASSERT(mqattr->mq_curmsgs < mqattr->mq_maxmsg); |
| 870 | |
| 871 | /* |
| 872 | * Insert message into the queue, according to the priority. |
| 873 | * Note the difference between index and priority. |
| 874 | */ |
| 875 | if (__predict_true(msg_prio < MQ_PQSIZE)) { |
| 876 | u_int idx = MQ_PQSIZE - msg_prio; |
| 877 | |
| 878 | KASSERT(idx != MQ_PQRESQ); |
| 879 | TAILQ_INSERT_TAIL(&mq->mq_head[idx], msg, msg_queue); |
| 880 | mq->mq_bitmap |= (1 << --idx); |
| 881 | } else { |
| 882 | mqueue_linear_insert(mq, msg); |
| 883 | } |
| 884 | |
| 885 | /* Check for the notify */ |
| 886 | if (mqattr->mq_curmsgs == 0 && mq->mq_notify_proc && |
| 887 | (mqattr->mq_flags & MQ_RECEIVE) == 0 && |
| 888 | mq->mq_sig_notify.sigev_notify == SIGEV_SIGNAL) { |
| 889 | /* Initialize the signal */ |
| 890 | KSI_INIT(&ksi); |
| 891 | ksi.ksi_signo = mq->mq_sig_notify.sigev_signo; |
| 892 | ksi.ksi_code = SI_MESGQ; |
| 893 | ksi.ksi_value = mq->mq_sig_notify.sigev_value; |
| 894 | /* Unregister the process */ |
| 895 | notify = mq->mq_notify_proc; |
| 896 | mq->mq_notify_proc = NULL; |
| 897 | } |
| 898 | |
| 899 | /* Increment the counter and signal waiter, if any */ |
| 900 | mqattr->mq_curmsgs++; |
| 901 | cv_signal(&mq->mq_send_cv); |
| 902 | |
| 903 | /* Ready for receiving now */ |
| 904 | selnotify(&mq->mq_rsel, POLLIN | POLLRDNORM, 0); |
| 905 | error: |
| 906 | mutex_exit(&mq->mq_mtx); |
| 907 | fd_putfile((int)mqdes); |
| 908 | |
| 909 | if (error) { |
| 910 | mqueue_freemsg(msg, size); |
| 911 | } else if (notify) { |
| 912 | /* Send the notify, if needed */ |
| 913 | mutex_enter(proc_lock); |
| 914 | kpsignal(notify, &ksi, NULL); |
| 915 | mutex_exit(proc_lock); |
| 916 | } |
| 917 | return error; |
| 918 | } |
| 919 | |
| 920 | int |
| 921 | sys_mq_send(struct lwp *l, const struct sys_mq_send_args *uap, |
| 922 | register_t *retval) |
| 923 | { |
| 924 | /* { |
| 925 | syscallarg(mqd_t) mqdes; |
| 926 | syscallarg(const char *) msg_ptr; |
| 927 | syscallarg(size_t) msg_len; |
| 928 | syscallarg(unsigned) msg_prio; |
| 929 | } */ |
| 930 | |
| 931 | return mq_send1(SCARG(uap, mqdes), SCARG(uap, msg_ptr), |
| 932 | SCARG(uap, msg_len), SCARG(uap, msg_prio), NULL); |
| 933 | } |
| 934 | |
| 935 | int |
| 936 | sys___mq_timedsend50(struct lwp *l, const struct sys___mq_timedsend50_args *uap, |
| 937 | register_t *retval) |
| 938 | { |
| 939 | /* { |
| 940 | syscallarg(mqd_t) mqdes; |
| 941 | syscallarg(const char *) msg_ptr; |
| 942 | syscallarg(size_t) msg_len; |
| 943 | syscallarg(unsigned) msg_prio; |
| 944 | syscallarg(const struct timespec *) abs_timeout; |
| 945 | } */ |
| 946 | struct timespec ts, *tsp; |
| 947 | int error; |
| 948 | |
| 949 | /* Get and convert time value */ |
| 950 | if (SCARG(uap, abs_timeout)) { |
| 951 | error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts)); |
| 952 | if (error) |
| 953 | return error; |
| 954 | tsp = &ts; |
| 955 | } else { |
| 956 | tsp = NULL; |
| 957 | } |
| 958 | |
| 959 | return mq_send1(SCARG(uap, mqdes), SCARG(uap, msg_ptr), |
| 960 | SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp); |
| 961 | } |
| 962 | |
| 963 | int |
| 964 | sys_mq_notify(struct lwp *l, const struct sys_mq_notify_args *uap, |
| 965 | register_t *retval) |
| 966 | { |
| 967 | /* { |
| 968 | syscallarg(mqd_t) mqdes; |
| 969 | syscallarg(const struct sigevent *) notification; |
| 970 | } */ |
| 971 | struct mqueue *mq; |
| 972 | struct sigevent sig; |
| 973 | int error; |
| 974 | |
| 975 | if (SCARG(uap, notification)) { |
| 976 | /* Get the signal from user-space */ |
| 977 | error = copyin(SCARG(uap, notification), &sig, |
| 978 | sizeof(struct sigevent)); |
| 979 | if (error) |
| 980 | return error; |
| 981 | if (sig.sigev_notify == SIGEV_SIGNAL && |
| 982 | (sig.sigev_signo <=0 || sig.sigev_signo >= NSIG)) |
| 983 | return EINVAL; |
| 984 | } |
| 985 | |
| 986 | error = mqueue_get(SCARG(uap, mqdes), 0, &mq); |
| 987 | if (error) { |
| 988 | return error; |
| 989 | } |
| 990 | if (SCARG(uap, notification)) { |
| 991 | /* Register notification: set the signal and target process */ |
| 992 | if (mq->mq_notify_proc == NULL) { |
| 993 | memcpy(&mq->mq_sig_notify, &sig, |
| 994 | sizeof(struct sigevent)); |
| 995 | mq->mq_notify_proc = l->l_proc; |
| 996 | } else { |
| 997 | /* Fail if someone else already registered */ |
| 998 | error = EBUSY; |
| 999 | } |
| 1000 | } else { |
| 1001 | /* Unregister the notification */ |
| 1002 | mq->mq_notify_proc = NULL; |
| 1003 | } |
| 1004 | mutex_exit(&mq->mq_mtx); |
| 1005 | fd_putfile((int)SCARG(uap, mqdes)); |
| 1006 | |
| 1007 | return error; |
| 1008 | } |
| 1009 | |
| 1010 | int |
| 1011 | sys_mq_getattr(struct lwp *l, const struct sys_mq_getattr_args *uap, |
| 1012 | register_t *retval) |
| 1013 | { |
| 1014 | /* { |
| 1015 | syscallarg(mqd_t) mqdes; |
| 1016 | syscallarg(struct mq_attr *) mqstat; |
| 1017 | } */ |
| 1018 | struct mqueue *mq; |
| 1019 | struct mq_attr attr; |
| 1020 | int error; |
| 1021 | |
| 1022 | error = mqueue_get(SCARG(uap, mqdes), 0, &mq); |
| 1023 | if (error) { |
| 1024 | return error; |
| 1025 | } |
| 1026 | memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr)); |
| 1027 | mutex_exit(&mq->mq_mtx); |
| 1028 | fd_putfile((int)SCARG(uap, mqdes)); |
| 1029 | |
| 1030 | return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr)); |
| 1031 | } |
| 1032 | |
| 1033 | int |
| 1034 | sys_mq_setattr(struct lwp *l, const struct sys_mq_setattr_args *uap, |
| 1035 | register_t *retval) |
| 1036 | { |
| 1037 | /* { |
| 1038 | syscallarg(mqd_t) mqdes; |
| 1039 | syscallarg(const struct mq_attr *) mqstat; |
| 1040 | syscallarg(struct mq_attr *) omqstat; |
| 1041 | } */ |
| 1042 | struct mqueue *mq; |
| 1043 | struct mq_attr attr; |
| 1044 | int error, nonblock; |
| 1045 | |
| 1046 | error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr)); |
| 1047 | if (error) |
| 1048 | return error; |
| 1049 | nonblock = (attr.mq_flags & O_NONBLOCK); |
| 1050 | |
| 1051 | error = mqueue_get(SCARG(uap, mqdes), 0, &mq); |
| 1052 | if (error) { |
| 1053 | return error; |
| 1054 | } |
| 1055 | |
| 1056 | /* Copy the old attributes, if needed */ |
| 1057 | if (SCARG(uap, omqstat)) { |
| 1058 | memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr)); |
| 1059 | } |
| 1060 | |
| 1061 | /* Ignore everything, except O_NONBLOCK */ |
| 1062 | if (nonblock) |
| 1063 | mq->mq_attrib.mq_flags |= O_NONBLOCK; |
| 1064 | else |
| 1065 | mq->mq_attrib.mq_flags &= ~O_NONBLOCK; |
| 1066 | |
| 1067 | mutex_exit(&mq->mq_mtx); |
| 1068 | fd_putfile((int)SCARG(uap, mqdes)); |
| 1069 | |
| 1070 | /* |
| 1071 | * Copy the data to the user-space. |
| 1072 | * Note: According to POSIX, the new attributes should not be set in |
| 1073 | * case of fail - this would be violated. |
| 1074 | */ |
| 1075 | if (SCARG(uap, omqstat)) |
| 1076 | error = copyout(&attr, SCARG(uap, omqstat), |
| 1077 | sizeof(struct mq_attr)); |
| 1078 | |
| 1079 | return error; |
| 1080 | } |
| 1081 | |
| 1082 | int |
| 1083 | sys_mq_unlink(struct lwp *l, const struct sys_mq_unlink_args *uap, |
| 1084 | register_t *retval) |
| 1085 | { |
| 1086 | /* { |
| 1087 | syscallarg(const char *) name; |
| 1088 | } */ |
| 1089 | mqueue_t *mq; |
| 1090 | char *name; |
| 1091 | int error, refcnt = 0; |
| 1092 | |
| 1093 | /* Get the name from the user-space */ |
| 1094 | name = kmem_alloc(MQ_NAMELEN, KM_SLEEP); |
| 1095 | error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL); |
| 1096 | if (error) { |
| 1097 | kmem_free(name, MQ_NAMELEN); |
| 1098 | return error; |
| 1099 | } |
| 1100 | |
| 1101 | mutex_enter(&mqlist_lock); |
| 1102 | mq = mqueue_lookup(name); |
| 1103 | if (mq == NULL) { |
| 1104 | error = ENOENT; |
| 1105 | goto err; |
| 1106 | } |
| 1107 | KASSERT(mutex_owned(&mq->mq_mtx)); |
| 1108 | |
| 1109 | /* Verify permissions. */ |
| 1110 | if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MQUEUE, 0, mq, |
| 1111 | NULL, NULL)) { |
| 1112 | mutex_exit(&mq->mq_mtx); |
| 1113 | error = EACCES; |
| 1114 | goto err; |
| 1115 | } |
| 1116 | |
| 1117 | /* Remove and destroy if no references. */ |
| 1118 | LIST_REMOVE(mq, mq_list); |
| 1119 | refcnt = mq->mq_refcnt; |
| 1120 | if (refcnt) { |
| 1121 | /* Mark as unlinked, if there are references. */ |
| 1122 | mq->mq_attrib.mq_flags |= MQ_UNLINKED; |
| 1123 | } |
| 1124 | |
| 1125 | /* Wake up waiters, if there are any. */ |
| 1126 | cv_broadcast(&mq->mq_send_cv); |
| 1127 | cv_broadcast(&mq->mq_recv_cv); |
| 1128 | |
| 1129 | selnotify(&mq->mq_rsel, POLLHUP, 0); |
| 1130 | selnotify(&mq->mq_wsel, POLLHUP, 0); |
| 1131 | |
| 1132 | mutex_exit(&mq->mq_mtx); |
| 1133 | err: |
| 1134 | mutex_exit(&mqlist_lock); |
| 1135 | /* |
| 1136 | * If last reference - destroy the message queue. Otherwise, |
| 1137 | * the last mq_close() call will do that. |
| 1138 | */ |
| 1139 | if (!error && refcnt == 0) { |
| 1140 | mqueue_destroy(mq); |
| 1141 | } |
| 1142 | kmem_free(name, MQ_NAMELEN); |
| 1143 | |
| 1144 | return error; |
| 1145 | } |
| 1146 | |
| 1147 | /* |
| 1148 | * System control nodes. |
| 1149 | */ |
| 1150 | static int |
| 1151 | mqueue_sysctl_init(void) |
| 1152 | { |
| 1153 | const struct sysctlnode *node = NULL; |
| 1154 | |
| 1155 | mqsysctl_log = NULL; |
| 1156 | |
| 1157 | sysctl_createv(&mqsysctl_log, 0, NULL, NULL, |
| 1158 | CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, |
| 1159 | CTLTYPE_INT, "posix_msg" , |
| 1160 | SYSCTL_DESCR("Version of IEEE Std 1003.1 and its " |
| 1161 | "Message Passing option to which the " |
| 1162 | "system attempts to conform" ), |
| 1163 | NULL, _POSIX_MESSAGE_PASSING, NULL, 0, |
| 1164 | CTL_KERN, CTL_CREATE, CTL_EOL); |
| 1165 | sysctl_createv(&mqsysctl_log, 0, NULL, &node, |
| 1166 | CTLFLAG_PERMANENT, |
| 1167 | CTLTYPE_NODE, "mqueue" , |
| 1168 | SYSCTL_DESCR("Message queue options" ), |
| 1169 | NULL, 0, NULL, 0, |
| 1170 | CTL_KERN, CTL_CREATE, CTL_EOL); |
| 1171 | |
| 1172 | if (node == NULL) |
| 1173 | return ENXIO; |
| 1174 | |
| 1175 | sysctl_createv(&mqsysctl_log, 0, &node, NULL, |
| 1176 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1177 | CTLTYPE_INT, "mq_open_max" , |
| 1178 | SYSCTL_DESCR("Maximal number of message queue descriptors " |
| 1179 | "that process could open" ), |
| 1180 | NULL, 0, &mq_open_max, 0, |
| 1181 | CTL_CREATE, CTL_EOL); |
| 1182 | sysctl_createv(&mqsysctl_log, 0, &node, NULL, |
| 1183 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1184 | CTLTYPE_INT, "mq_prio_max" , |
| 1185 | SYSCTL_DESCR("Maximal priority of the message" ), |
| 1186 | NULL, 0, &mq_prio_max, 0, |
| 1187 | CTL_CREATE, CTL_EOL); |
| 1188 | sysctl_createv(&mqsysctl_log, 0, &node, NULL, |
| 1189 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1190 | CTLTYPE_INT, "mq_max_msgsize" , |
| 1191 | SYSCTL_DESCR("Maximal allowed size of the message" ), |
| 1192 | NULL, 0, &mq_max_msgsize, 0, |
| 1193 | CTL_CREATE, CTL_EOL); |
| 1194 | sysctl_createv(&mqsysctl_log, 0, &node, NULL, |
| 1195 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1196 | CTLTYPE_INT, "mq_def_maxmsg" , |
| 1197 | SYSCTL_DESCR("Default maximal message count" ), |
| 1198 | NULL, 0, &mq_def_maxmsg, 0, |
| 1199 | CTL_CREATE, CTL_EOL); |
| 1200 | sysctl_createv(&mqsysctl_log, 0, &node, NULL, |
| 1201 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1202 | CTLTYPE_INT, "mq_max_maxmsg" , |
| 1203 | SYSCTL_DESCR("Maximal allowed message count" ), |
| 1204 | NULL, 0, &mq_max_maxmsg, 0, |
| 1205 | CTL_CREATE, CTL_EOL); |
| 1206 | |
| 1207 | return 0; |
| 1208 | } |
| 1209 | |
| 1210 | /* |
| 1211 | * Debugging. |
| 1212 | */ |
| 1213 | #if defined(DDB) |
| 1214 | |
| 1215 | void |
| 1216 | mqueue_print_list(void (*pr)(const char *, ...)) |
| 1217 | { |
| 1218 | struct mqueue *mq; |
| 1219 | |
| 1220 | (*pr)("Global list of the message queues:\n" ); |
| 1221 | (*pr)("%20s %10s %8s %8s %3s %4s %4s %4s\n" , |
| 1222 | "Name" , "Ptr" , "Mode" , "Flags" , "Ref" , |
| 1223 | "MaxMsg" , "MsgSze" , "CurMsg" ); |
| 1224 | LIST_FOREACH(mq, &mqueue_head, mq_list) { |
| 1225 | (*pr)("%20s %10p %8x %8x %3u %6lu %6lu %6lu\n" , |
| 1226 | mq->mq_name, mq, mq->mq_mode, |
| 1227 | mq->mq_attrib.mq_flags, mq->mq_refcnt, |
| 1228 | mq->mq_attrib.mq_maxmsg, mq->mq_attrib.mq_msgsize, |
| 1229 | mq->mq_attrib.mq_curmsgs); |
| 1230 | } |
| 1231 | } |
| 1232 | |
| 1233 | #endif /* defined(DDB) */ |
| 1234 | |