1/*- 2 * Implementation of SVID messages 3 * 4 * Author: Daniel Boulet 5 * 6 * Copyright 1993 Daniel Boulet and RTMX Inc. 7 * 8 * This system call was implemented by Daniel Boulet under contract from RTMX. 9 * 10 * Redistribution and use in source forms, with and without modification, 11 * are permitted provided that this entire comment appears intact. 12 * 13 * Redistribution in binary form may occur without any restrictions. 14 * Obviously, it would be nice if you gave credit where credit is due 15 * but requiring it would be too onerous. 16 * 17 * This software is provided ``AS IS'' without any warranties of any kind. 18 */ 19/*- 20 * Copyright (c) 2003-2005 McAfee, Inc. 21 * All rights reserved. 22 * 23 * This software was developed for the FreeBSD Project in part by McAfee 24 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR 25 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research 26 * program. 27 * 28 * Redistribution and use in source and binary forms, with or without 29 * modification, are permitted provided that the following conditions 30 * are met: 31 * 1. Redistributions of source code must retain the above copyright 32 * notice, this list of conditions and the following disclaimer. 33 * 2. Redistributions in binary form must reproduce the above copyright 34 * notice, this list of conditions and the following disclaimer in the 35 * documentation and/or other materials provided with the distribution. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 40 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 47 * SUCH DAMAGE. 48 */ 49 50#include <sys/cdefs.h> 51__FBSDID("$FreeBSD: releng/11.0/sys/kern/sysv_msg.c 301737 2016-06-09 15:34:33Z jamie $"); 52 53#include "opt_compat.h" 54#include "opt_sysvipc.h" 55 56#include <sys/param.h> 57#include <sys/systm.h> 58#include <sys/sysproto.h> 59#include <sys/kernel.h> 60#include <sys/priv.h> 61#include <sys/proc.h> 62#include <sys/lock.h> 63#include <sys/mutex.h> 64#include <sys/module.h> 65#include <sys/mount.h> 66#include <sys/msg.h> 67#include <sys/racct.h> 68#include <sys/sx.h> 69#include <sys/syscall.h> 70#include <sys/syscallsubr.h> 71#include <sys/sysent.h> 72#include <sys/sysctl.h> 73#include <sys/malloc.h> 74#include <sys/jail.h> 75 76#include <security/mac/mac_framework.h> 77 78FEATURE(sysv_msg, "System V message queues support"); 79 80static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues"); 81 82static int msginit(void); 83static int msgunload(void); 84static int sysvmsg_modload(struct module *, int, void *); 85static void msq_remove(struct msqid_kernel *); 86static struct prison *msg_find_prison(struct ucred *); 87static int msq_prison_cansee(struct prison *, struct msqid_kernel *); 88static int msg_prison_check(void *, void *); 89static int msg_prison_set(void *, void *); 90static int msg_prison_get(void *, void *); 91static int msg_prison_remove(void *, void *); 92static void msg_prison_cleanup(struct prison *); 93 94 95#ifdef MSG_DEBUG 96#define DPRINTF(a) printf a 97#else 98#define DPRINTF(a) (void)0 99#endif 100 101static void msg_freehdr(struct msg *msghdr); 102 103#ifndef MSGSSZ 104#define MSGSSZ 8 /* Each segment must be 2^N long */ 105#endif 106#ifndef MSGSEG 107#define MSGSEG 2048 /* must be less than 32767 */ 108#endif 109#define MSGMAX (MSGSSZ*MSGSEG) 110#ifndef MSGMNB 111#define MSGMNB 2048 /* max # of bytes in a queue */ 112#endif 113#ifndef MSGMNI 114#define MSGMNI 40 115#endif 116#ifndef MSGTQL 117#define MSGTQL 40 118#endif 119 120/* 121 * Based on the configuration parameters described in an SVR2 (yes, two) 122 * config(1m) man page. 123 * 124 * Each message is broken up and stored in segments that are msgssz bytes 125 * long. For efficiency reasons, this should be a power of two. Also, 126 * it doesn't make sense if it is less than 8 or greater than about 256. 127 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 128 * two between 8 and 1024 inclusive (and panic's if it isn't). 129 */ 130struct msginfo msginfo = { 131 MSGMAX, /* max chars in a message */ 132 MSGMNI, /* # of message queue identifiers */ 133 MSGMNB, /* max chars in a queue */ 134 MSGTQL, /* max messages in system */ 135 MSGSSZ, /* size of a message segment */ 136 /* (must be small power of 2 greater than 4) */ 137 MSGSEG /* number of message segments */ 138}; 139 140/* 141 * macros to convert between msqid_ds's and msqid's. 142 * (specific to this implementation) 143 */ 144#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000)) 145#define MSQID_IX(id) ((id) & 0xffff) 146#define MSQID_SEQ(id) (((id) >> 16) & 0xffff) 147 148/* 149 * The rest of this file is specific to this particular implementation. 150 */ 151 152struct msgmap { 153 short next; /* next segment in buffer */ 154 /* -1 -> available */ 155 /* 0..(MSGSEG-1) -> index of next segment */ 156}; 157 158#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */ 159 160static int nfree_msgmaps; /* # of free map entries */ 161static short free_msgmaps; /* head of linked list of free map entries */ 162static struct msg *free_msghdrs;/* list of free msg headers */ 163static char *msgpool; /* MSGMAX byte long msg buffer pool */ 164static struct msgmap *msgmaps; /* MSGSEG msgmap structures */ 165static struct msg *msghdrs; /* MSGTQL msg headers */ 166static struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */ 167static struct mtx msq_mtx; /* global mutex for message queues. */ 168static unsigned msg_prison_slot;/* prison OSD slot */ 169 170static struct syscall_helper_data msg_syscalls[] = { 171 SYSCALL_INIT_HELPER(msgctl), 172 SYSCALL_INIT_HELPER(msgget), 173 SYSCALL_INIT_HELPER(msgsnd), 174 SYSCALL_INIT_HELPER(msgrcv), 175#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 176 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 177 SYSCALL_INIT_HELPER(msgsys), 178 SYSCALL_INIT_HELPER_COMPAT(freebsd7_msgctl), 179#endif 180 SYSCALL_INIT_LAST 181}; 182 183#ifdef COMPAT_FREEBSD32 184#include <compat/freebsd32/freebsd32.h> 185#include <compat/freebsd32/freebsd32_ipc.h> 186#include <compat/freebsd32/freebsd32_proto.h> 187#include <compat/freebsd32/freebsd32_signal.h> 188#include <compat/freebsd32/freebsd32_syscall.h> 189#include <compat/freebsd32/freebsd32_util.h> 190 191static struct syscall_helper_data msg32_syscalls[] = { 192 SYSCALL32_INIT_HELPER(freebsd32_msgctl), 193 SYSCALL32_INIT_HELPER(freebsd32_msgsnd), 194 SYSCALL32_INIT_HELPER(freebsd32_msgrcv), 195 SYSCALL32_INIT_HELPER_COMPAT(msgget), 196 SYSCALL32_INIT_HELPER(freebsd32_msgsys), 197#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 198 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 199 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl), 200#endif 201 SYSCALL_INIT_LAST 202}; 203#endif 204 205static int 206msginit() 207{ 208 struct prison *pr; 209 void **rsv; 210 int i, error; 211 osd_method_t methods[PR_MAXMETHOD] = { 212 [PR_METHOD_CHECK] = msg_prison_check, 213 [PR_METHOD_SET] = msg_prison_set, 214 [PR_METHOD_GET] = msg_prison_get, 215 [PR_METHOD_REMOVE] = msg_prison_remove, 216 }; 217 218 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz; 219 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK); 220 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); 221 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); 222 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG, 223 M_WAITOK); 224 225 /* 226 * msginfo.msgssz should be a power of two for efficiency reasons. 227 * It is also pretty silly if msginfo.msgssz is less than 8 228 * or greater than about 256 so ... 229 */ 230 231 i = 8; 232 while (i < 1024 && i != msginfo.msgssz) 233 i <<= 1; 234 if (i != msginfo.msgssz) { 235 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz, 236 msginfo.msgssz)); 237 panic("msginfo.msgssz not a small power of 2"); 238 } 239 240 if (msginfo.msgseg > 32767) { 241 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg)); 242 panic("msginfo.msgseg > 32767"); 243 } 244 245 for (i = 0; i < msginfo.msgseg; i++) { 246 if (i > 0) 247 msgmaps[i-1].next = i; 248 msgmaps[i].next = -1; /* implies entry is available */ 249 } 250 free_msgmaps = 0; 251 nfree_msgmaps = msginfo.msgseg; 252 253 for (i = 0; i < msginfo.msgtql; i++) { 254 msghdrs[i].msg_type = 0; 255 if (i > 0) 256 msghdrs[i-1].msg_next = &msghdrs[i]; 257 msghdrs[i].msg_next = NULL; 258#ifdef MAC 259 mac_sysvmsg_init(&msghdrs[i]); 260#endif 261 } 262 free_msghdrs = &msghdrs[0]; 263 264 for (i = 0; i < msginfo.msgmni; i++) { 265 msqids[i].u.msg_qbytes = 0; /* implies entry is available */ 266 msqids[i].u.msg_perm.seq = 0; /* reset to a known value */ 267 msqids[i].u.msg_perm.mode = 0; 268#ifdef MAC 269 mac_sysvmsq_init(&msqids[i]); 270#endif 271 } 272 mtx_init(&msq_mtx, "msq", NULL, MTX_DEF); 273 274 /* Set current prisons according to their allow.sysvipc. */ 275 msg_prison_slot = osd_jail_register(NULL, methods); 276 rsv = osd_reserve(msg_prison_slot); 277 prison_lock(&prison0); 278 (void)osd_jail_set_reserved(&prison0, msg_prison_slot, rsv, &prison0); 279 prison_unlock(&prison0); 280 rsv = NULL; 281 sx_slock(&allprison_lock); 282 TAILQ_FOREACH(pr, &allprison, pr_list) { 283 if (rsv == NULL) 284 rsv = osd_reserve(msg_prison_slot); 285 prison_lock(pr); 286 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 287 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv, 288 &prison0); 289 rsv = NULL; 290 } 291 prison_unlock(pr); 292 } 293 if (rsv != NULL) 294 osd_free_reserved(rsv); 295 sx_sunlock(&allprison_lock); 296 297 error = syscall_helper_register(msg_syscalls, SY_THR_STATIC_KLD); 298 if (error != 0) 299 return (error); 300#ifdef COMPAT_FREEBSD32 301 error = syscall32_helper_register(msg32_syscalls, SY_THR_STATIC_KLD); 302 if (error != 0) 303 return (error); 304#endif 305 return (0); 306} 307 308static int 309msgunload() 310{ 311 struct msqid_kernel *msqkptr; 312 int msqid; 313#ifdef MAC 314 int i; 315#endif 316 317 syscall_helper_unregister(msg_syscalls); 318#ifdef COMPAT_FREEBSD32 319 syscall32_helper_unregister(msg32_syscalls); 320#endif 321 322 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 323 msqkptr = &msqids[msqid]; 324 if (msqkptr->u.msg_qbytes != 0 || 325 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 326 break; 327 } 328 if (msqid != msginfo.msgmni) 329 return (EBUSY); 330 331 if (msg_prison_slot != 0) 332 osd_jail_deregister(msg_prison_slot); 333#ifdef MAC 334 for (i = 0; i < msginfo.msgtql; i++) 335 mac_sysvmsg_destroy(&msghdrs[i]); 336 for (msqid = 0; msqid < msginfo.msgmni; msqid++) 337 mac_sysvmsq_destroy(&msqids[msqid]); 338#endif 339 free(msgpool, M_MSG); 340 free(msgmaps, M_MSG); 341 free(msghdrs, M_MSG); 342 free(msqids, M_MSG); 343 mtx_destroy(&msq_mtx); 344 return (0); 345} 346 347 348static int 349sysvmsg_modload(struct module *module, int cmd, void *arg) 350{ 351 int error = 0; 352 353 switch (cmd) { 354 case MOD_LOAD: 355 error = msginit(); 356 if (error != 0) 357 msgunload(); 358 break; 359 case MOD_UNLOAD: 360 error = msgunload(); 361 break; 362 case MOD_SHUTDOWN: 363 break; 364 default: 365 error = EINVAL; 366 break; 367 } 368 return (error); 369} 370 371static moduledata_t sysvmsg_mod = { 372 "sysvmsg", 373 &sysvmsg_modload, 374 NULL 375}; 376 377DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST); 378MODULE_VERSION(sysvmsg, 1); 379 380static void 381msg_freehdr(msghdr) 382 struct msg *msghdr; 383{ 384 while (msghdr->msg_ts > 0) { 385 short next; 386 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg) 387 panic("msghdr->msg_spot out of range"); 388 next = msgmaps[msghdr->msg_spot].next; 389 msgmaps[msghdr->msg_spot].next = free_msgmaps; 390 free_msgmaps = msghdr->msg_spot; 391 nfree_msgmaps++; 392 msghdr->msg_spot = next; 393 if (msghdr->msg_ts >= msginfo.msgssz) 394 msghdr->msg_ts -= msginfo.msgssz; 395 else 396 msghdr->msg_ts = 0; 397 } 398 if (msghdr->msg_spot != -1) 399 panic("msghdr->msg_spot != -1"); 400 msghdr->msg_next = free_msghdrs; 401 free_msghdrs = msghdr; 402#ifdef MAC 403 mac_sysvmsg_cleanup(msghdr); 404#endif 405} 406 407static void 408msq_remove(struct msqid_kernel *msqkptr) 409{ 410 struct msg *msghdr; 411 412 racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1); 413 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum); 414 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes); 415 crfree(msqkptr->cred); 416 msqkptr->cred = NULL; 417 418 /* Free the message headers */ 419 msghdr = msqkptr->u.msg_first; 420 while (msghdr != NULL) { 421 struct msg *msghdr_tmp; 422 423 /* Free the segments of each message */ 424 msqkptr->u.msg_cbytes -= msghdr->msg_ts; 425 msqkptr->u.msg_qnum--; 426 msghdr_tmp = msghdr; 427 msghdr = msghdr->msg_next; 428 msg_freehdr(msghdr_tmp); 429 } 430 431 if (msqkptr->u.msg_cbytes != 0) 432 panic("msg_cbytes is screwed up"); 433 if (msqkptr->u.msg_qnum != 0) 434 panic("msg_qnum is screwed up"); 435 436 msqkptr->u.msg_qbytes = 0; /* Mark it as free */ 437 438#ifdef MAC 439 mac_sysvmsq_cleanup(msqkptr); 440#endif 441 442 wakeup(msqkptr); 443} 444 445static struct prison * 446msg_find_prison(struct ucred *cred) 447{ 448 struct prison *pr, *rpr; 449 450 pr = cred->cr_prison; 451 prison_lock(pr); 452 rpr = osd_jail_get(pr, msg_prison_slot); 453 prison_unlock(pr); 454 return rpr; 455} 456 457static int 458msq_prison_cansee(struct prison *rpr, struct msqid_kernel *msqkptr) 459{ 460 461 if (msqkptr->cred == NULL || 462 !(rpr == msqkptr->cred->cr_prison || 463 prison_ischild(rpr, msqkptr->cred->cr_prison))) 464 return (EINVAL); 465 return (0); 466} 467 468#ifndef _SYS_SYSPROTO_H_ 469struct msgctl_args { 470 int msqid; 471 int cmd; 472 struct msqid_ds *buf; 473}; 474#endif 475int 476sys_msgctl(td, uap) 477 struct thread *td; 478 register struct msgctl_args *uap; 479{ 480 int msqid = uap->msqid; 481 int cmd = uap->cmd; 482 struct msqid_ds msqbuf; 483 int error; 484 485 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf)); 486 if (cmd == IPC_SET && 487 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0) 488 return (error); 489 error = kern_msgctl(td, msqid, cmd, &msqbuf); 490 if (cmd == IPC_STAT && error == 0) 491 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds)); 492 return (error); 493} 494 495int 496kern_msgctl(td, msqid, cmd, msqbuf) 497 struct thread *td; 498 int msqid; 499 int cmd; 500 struct msqid_ds *msqbuf; 501{ 502 int rval, error, msqix; 503 register struct msqid_kernel *msqkptr; 504 struct prison *rpr; 505 506 rpr = msg_find_prison(td->td_ucred); 507 if (rpr == NULL) 508 return (ENOSYS); 509 510 msqix = IPCID_TO_IX(msqid); 511 512 if (msqix < 0 || msqix >= msginfo.msgmni) { 513 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 514 msginfo.msgmni)); 515 return (EINVAL); 516 } 517 518 msqkptr = &msqids[msqix]; 519 520 mtx_lock(&msq_mtx); 521 if (msqkptr->u.msg_qbytes == 0) { 522 DPRINTF(("no such msqid\n")); 523 error = EINVAL; 524 goto done2; 525 } 526 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 527 DPRINTF(("wrong sequence number\n")); 528 error = EINVAL; 529 goto done2; 530 } 531 532 error = msq_prison_cansee(rpr, msqkptr); 533 if (error != 0) { 534 DPRINTF(("requester can't see prison\n")); 535 goto done2; 536 } 537 538#ifdef MAC 539 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd); 540 if (error != 0) 541 goto done2; 542#endif 543 544 error = 0; 545 rval = 0; 546 547 switch (cmd) { 548 549 case IPC_RMID: 550 { 551#ifdef MAC 552 struct msg *msghdr; 553#endif 554 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 555 goto done2; 556 557#ifdef MAC 558 /* 559 * Check that the thread has MAC access permissions to 560 * individual msghdrs. Note: We need to do this in a 561 * separate loop because the actual loop alters the 562 * msq/msghdr info as it progresses, and there is no going 563 * back if half the way through we discover that the 564 * thread cannot free a certain msghdr. The msq will get 565 * into an inconsistent state. 566 */ 567 for (msghdr = msqkptr->u.msg_first; msghdr != NULL; 568 msghdr = msghdr->msg_next) { 569 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr); 570 if (error != 0) 571 goto done2; 572 } 573#endif 574 575 msq_remove(msqkptr); 576 } 577 578 break; 579 580 case IPC_SET: 581 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 582 goto done2; 583 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) { 584 error = priv_check(td, PRIV_IPC_MSGSIZE); 585 if (error) 586 goto done2; 587 } 588 if (msqbuf->msg_qbytes > msginfo.msgmnb) { 589 DPRINTF(("can't increase msg_qbytes beyond %d" 590 "(truncating)\n", msginfo.msgmnb)); 591 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ 592 } 593 if (msqbuf->msg_qbytes == 0) { 594 DPRINTF(("can't reduce msg_qbytes to 0\n")); 595 error = EINVAL; /* non-standard errno! */ 596 goto done2; 597 } 598 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */ 599 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */ 600 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) | 601 (msqbuf->msg_perm.mode & 0777); 602 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes; 603 msqkptr->u.msg_ctime = time_second; 604 break; 605 606 case IPC_STAT: 607 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 608 DPRINTF(("requester doesn't have read access\n")); 609 goto done2; 610 } 611 *msqbuf = msqkptr->u; 612 if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison) 613 msqbuf->msg_perm.key = IPC_PRIVATE; 614 break; 615 616 default: 617 DPRINTF(("invalid command %d\n", cmd)); 618 error = EINVAL; 619 goto done2; 620 } 621 622 if (error == 0) 623 td->td_retval[0] = rval; 624done2: 625 mtx_unlock(&msq_mtx); 626 return (error); 627} 628 629#ifndef _SYS_SYSPROTO_H_ 630struct msgget_args { 631 key_t key; 632 int msgflg; 633}; 634#endif 635 636int 637sys_msgget(td, uap) 638 struct thread *td; 639 register struct msgget_args *uap; 640{ 641 int msqid, error = 0; 642 int key = uap->key; 643 int msgflg = uap->msgflg; 644 struct ucred *cred = td->td_ucred; 645 register struct msqid_kernel *msqkptr = NULL; 646 647 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg)); 648 649 if (msg_find_prison(cred) == NULL) 650 return (ENOSYS); 651 652 mtx_lock(&msq_mtx); 653 if (key != IPC_PRIVATE) { 654 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 655 msqkptr = &msqids[msqid]; 656 if (msqkptr->u.msg_qbytes != 0 && 657 msqkptr->cred != NULL && 658 msqkptr->cred->cr_prison == cred->cr_prison && 659 msqkptr->u.msg_perm.key == key) 660 break; 661 } 662 if (msqid < msginfo.msgmni) { 663 DPRINTF(("found public key\n")); 664 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { 665 DPRINTF(("not exclusive\n")); 666 error = EEXIST; 667 goto done2; 668 } 669 if ((error = ipcperm(td, &msqkptr->u.msg_perm, 670 msgflg & 0700))) { 671 DPRINTF(("requester doesn't have 0%o access\n", 672 msgflg & 0700)); 673 goto done2; 674 } 675#ifdef MAC 676 error = mac_sysvmsq_check_msqget(cred, msqkptr); 677 if (error != 0) 678 goto done2; 679#endif 680 goto found; 681 } 682 } 683 684 DPRINTF(("need to allocate the msqid_ds\n")); 685 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { 686 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 687 /* 688 * Look for an unallocated and unlocked msqid_ds. 689 * msqid_ds's can be locked by msgsnd or msgrcv while 690 * they are copying the message in/out. We can't 691 * re-use the entry until they release it. 692 */ 693 msqkptr = &msqids[msqid]; 694 if (msqkptr->u.msg_qbytes == 0 && 695 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0) 696 break; 697 } 698 if (msqid == msginfo.msgmni) { 699 DPRINTF(("no more msqid_ds's available\n")); 700 error = ENOSPC; 701 goto done2; 702 } 703#ifdef RACCT 704 if (racct_enable) { 705 PROC_LOCK(td->td_proc); 706 error = racct_add(td->td_proc, RACCT_NMSGQ, 1); 707 PROC_UNLOCK(td->td_proc); 708 if (error != 0) { 709 error = ENOSPC; 710 goto done2; 711 } 712 } 713#endif 714 DPRINTF(("msqid %d is available\n", msqid)); 715 msqkptr->u.msg_perm.key = key; 716 msqkptr->u.msg_perm.cuid = cred->cr_uid; 717 msqkptr->u.msg_perm.uid = cred->cr_uid; 718 msqkptr->u.msg_perm.cgid = cred->cr_gid; 719 msqkptr->u.msg_perm.gid = cred->cr_gid; 720 msqkptr->u.msg_perm.mode = (msgflg & 0777); 721 msqkptr->cred = crhold(cred); 722 /* Make sure that the returned msqid is unique */ 723 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff; 724 msqkptr->u.msg_first = NULL; 725 msqkptr->u.msg_last = NULL; 726 msqkptr->u.msg_cbytes = 0; 727 msqkptr->u.msg_qnum = 0; 728 msqkptr->u.msg_qbytes = msginfo.msgmnb; 729 msqkptr->u.msg_lspid = 0; 730 msqkptr->u.msg_lrpid = 0; 731 msqkptr->u.msg_stime = 0; 732 msqkptr->u.msg_rtime = 0; 733 msqkptr->u.msg_ctime = time_second; 734#ifdef MAC 735 mac_sysvmsq_create(cred, msqkptr); 736#endif 737 } else { 738 DPRINTF(("didn't find it and wasn't asked to create it\n")); 739 error = ENOENT; 740 goto done2; 741 } 742 743found: 744 /* Construct the unique msqid */ 745 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm); 746done2: 747 mtx_unlock(&msq_mtx); 748 return (error); 749} 750 751#ifndef _SYS_SYSPROTO_H_ 752struct msgsnd_args { 753 int msqid; 754 const void *msgp; 755 size_t msgsz; 756 int msgflg; 757}; 758#endif 759int 760kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype) 761 struct thread *td; 762 int msqid; 763 const void *msgp; /* XXX msgp is actually mtext. */ 764 size_t msgsz; 765 int msgflg; 766 long mtype; 767{ 768 int msqix, segs_needed, error = 0; 769 register struct msqid_kernel *msqkptr; 770 register struct msg *msghdr; 771 struct prison *rpr; 772 short next; 773#ifdef RACCT 774 size_t saved_msgsz; 775#endif 776 777 rpr = msg_find_prison(td->td_ucred); 778 if (rpr == NULL) 779 return (ENOSYS); 780 781 mtx_lock(&msq_mtx); 782 msqix = IPCID_TO_IX(msqid); 783 784 if (msqix < 0 || msqix >= msginfo.msgmni) { 785 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 786 msginfo.msgmni)); 787 error = EINVAL; 788 goto done2; 789 } 790 791 msqkptr = &msqids[msqix]; 792 if (msqkptr->u.msg_qbytes == 0) { 793 DPRINTF(("no such message queue id\n")); 794 error = EINVAL; 795 goto done2; 796 } 797 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 798 DPRINTF(("wrong sequence number\n")); 799 error = EINVAL; 800 goto done2; 801 } 802 803 if ((error = msq_prison_cansee(rpr, msqkptr))) { 804 DPRINTF(("requester can't see prison\n")); 805 goto done2; 806 } 807 808 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) { 809 DPRINTF(("requester doesn't have write access\n")); 810 goto done2; 811 } 812 813#ifdef MAC 814 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr); 815 if (error != 0) 816 goto done2; 817#endif 818 819#ifdef RACCT 820 if (racct_enable) { 821 PROC_LOCK(td->td_proc); 822 if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) { 823 PROC_UNLOCK(td->td_proc); 824 error = EAGAIN; 825 goto done2; 826 } 827 saved_msgsz = msgsz; 828 if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) { 829 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 830 PROC_UNLOCK(td->td_proc); 831 error = EAGAIN; 832 goto done2; 833 } 834 PROC_UNLOCK(td->td_proc); 835 } 836#endif 837 838 segs_needed = howmany(msgsz, msginfo.msgssz); 839 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz, 840 msginfo.msgssz, segs_needed)); 841 for (;;) { 842 int need_more_resources = 0; 843 844 /* 845 * check msgsz 846 * (inside this loop in case msg_qbytes changes while we sleep) 847 */ 848 849 if (msgsz > msqkptr->u.msg_qbytes) { 850 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n")); 851 error = EINVAL; 852 goto done3; 853 } 854 855 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) { 856 DPRINTF(("msqid is locked\n")); 857 need_more_resources = 1; 858 } 859 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) { 860 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n")); 861 need_more_resources = 1; 862 } 863 if (segs_needed > nfree_msgmaps) { 864 DPRINTF(("segs_needed > nfree_msgmaps\n")); 865 need_more_resources = 1; 866 } 867 if (free_msghdrs == NULL) { 868 DPRINTF(("no more msghdrs\n")); 869 need_more_resources = 1; 870 } 871 872 if (need_more_resources) { 873 int we_own_it; 874 875 if ((msgflg & IPC_NOWAIT) != 0) { 876 DPRINTF(("need more resources but caller " 877 "doesn't want to wait\n")); 878 error = EAGAIN; 879 goto done3; 880 } 881 882 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) { 883 DPRINTF(("we don't own the msqid_ds\n")); 884 we_own_it = 0; 885 } else { 886 /* Force later arrivals to wait for our 887 request */ 888 DPRINTF(("we own the msqid_ds\n")); 889 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 890 we_own_it = 1; 891 } 892 DPRINTF(("msgsnd: goodnight\n")); 893 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 894 "msgsnd", hz); 895 DPRINTF(("msgsnd: good morning, error=%d\n", error)); 896 if (we_own_it) 897 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 898 if (error == EWOULDBLOCK) { 899 DPRINTF(("msgsnd: timed out\n")); 900 continue; 901 } 902 if (error != 0) { 903 DPRINTF(("msgsnd: interrupted system call\n")); 904 error = EINTR; 905 goto done3; 906 } 907 908 /* 909 * Make sure that the msq queue still exists 910 */ 911 912 if (msqkptr->u.msg_qbytes == 0) { 913 DPRINTF(("msqid deleted\n")); 914 error = EIDRM; 915 goto done3; 916 } 917 918 } else { 919 DPRINTF(("got all the resources that we need\n")); 920 break; 921 } 922 } 923 924 /* 925 * We have the resources that we need. 926 * Make sure! 927 */ 928 929 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) 930 panic("msg_perm.mode & MSG_LOCKED"); 931 if (segs_needed > nfree_msgmaps) 932 panic("segs_needed > nfree_msgmaps"); 933 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) 934 panic("msgsz + msg_cbytes > msg_qbytes"); 935 if (free_msghdrs == NULL) 936 panic("no more msghdrs"); 937 938 /* 939 * Re-lock the msqid_ds in case we page-fault when copying in the 940 * message 941 */ 942 943 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 944 panic("msqid_ds is already locked"); 945 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 946 947 /* 948 * Allocate a message header 949 */ 950 951 msghdr = free_msghdrs; 952 free_msghdrs = msghdr->msg_next; 953 msghdr->msg_spot = -1; 954 msghdr->msg_ts = msgsz; 955 msghdr->msg_type = mtype; 956#ifdef MAC 957 /* 958 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here 959 * immediately? Or, should it be checked just before the msg is 960 * enqueued in the msgq (as it is done now)? 961 */ 962 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr); 963#endif 964 965 /* 966 * Allocate space for the message 967 */ 968 969 while (segs_needed > 0) { 970 if (nfree_msgmaps <= 0) 971 panic("not enough msgmaps"); 972 if (free_msgmaps == -1) 973 panic("nil free_msgmaps"); 974 next = free_msgmaps; 975 if (next <= -1) 976 panic("next too low #1"); 977 if (next >= msginfo.msgseg) 978 panic("next out of range #1"); 979 DPRINTF(("allocating segment %d to message\n", next)); 980 free_msgmaps = msgmaps[next].next; 981 nfree_msgmaps--; 982 msgmaps[next].next = msghdr->msg_spot; 983 msghdr->msg_spot = next; 984 segs_needed--; 985 } 986 987 /* 988 * Validate the message type 989 */ 990 991 if (msghdr->msg_type < 1) { 992 msg_freehdr(msghdr); 993 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 994 wakeup(msqkptr); 995 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type)); 996 error = EINVAL; 997 goto done3; 998 } 999 1000 /* 1001 * Copy in the message body 1002 */ 1003 1004 next = msghdr->msg_spot; 1005 while (msgsz > 0) { 1006 size_t tlen; 1007 if (msgsz > msginfo.msgssz) 1008 tlen = msginfo.msgssz; 1009 else 1010 tlen = msgsz; 1011 if (next <= -1) 1012 panic("next too low #2"); 1013 if (next >= msginfo.msgseg) 1014 panic("next out of range #2"); 1015 mtx_unlock(&msq_mtx); 1016 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz], 1017 tlen)) != 0) { 1018 mtx_lock(&msq_mtx); 1019 DPRINTF(("error %d copying in message segment\n", 1020 error)); 1021 msg_freehdr(msghdr); 1022 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1023 wakeup(msqkptr); 1024 goto done3; 1025 } 1026 mtx_lock(&msq_mtx); 1027 msgsz -= tlen; 1028 msgp = (const char *)msgp + tlen; 1029 next = msgmaps[next].next; 1030 } 1031 if (next != -1) 1032 panic("didn't use all the msg segments"); 1033 1034 /* 1035 * We've got the message. Unlock the msqid_ds. 1036 */ 1037 1038 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1039 1040 /* 1041 * Make sure that the msqid_ds is still allocated. 1042 */ 1043 1044 if (msqkptr->u.msg_qbytes == 0) { 1045 msg_freehdr(msghdr); 1046 wakeup(msqkptr); 1047 error = EIDRM; 1048 goto done3; 1049 } 1050 1051#ifdef MAC 1052 /* 1053 * Note: Since the task/thread allocates the msghdr and usually 1054 * primes it with its own MAC label, for a majority of policies, it 1055 * won't be necessary to check whether the msghdr has access 1056 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would 1057 * suffice in that case. However, this hook may be required where 1058 * individual policies derive a non-identical label for the msghdr 1059 * from the current thread label and may want to check the msghdr 1060 * enqueue permissions, along with read/write permissions to the 1061 * msgq. 1062 */ 1063 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr); 1064 if (error != 0) { 1065 msg_freehdr(msghdr); 1066 wakeup(msqkptr); 1067 goto done3; 1068 } 1069#endif 1070 1071 /* 1072 * Put the message into the queue 1073 */ 1074 if (msqkptr->u.msg_first == NULL) { 1075 msqkptr->u.msg_first = msghdr; 1076 msqkptr->u.msg_last = msghdr; 1077 } else { 1078 msqkptr->u.msg_last->msg_next = msghdr; 1079 msqkptr->u.msg_last = msghdr; 1080 } 1081 msqkptr->u.msg_last->msg_next = NULL; 1082 1083 msqkptr->u.msg_cbytes += msghdr->msg_ts; 1084 msqkptr->u.msg_qnum++; 1085 msqkptr->u.msg_lspid = td->td_proc->p_pid; 1086 msqkptr->u.msg_stime = time_second; 1087 1088 wakeup(msqkptr); 1089 td->td_retval[0] = 0; 1090done3: 1091#ifdef RACCT 1092 if (racct_enable && error != 0) { 1093 PROC_LOCK(td->td_proc); 1094 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 1095 racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz); 1096 PROC_UNLOCK(td->td_proc); 1097 } 1098#endif 1099done2: 1100 mtx_unlock(&msq_mtx); 1101 return (error); 1102} 1103 1104int 1105sys_msgsnd(td, uap) 1106 struct thread *td; 1107 register struct msgsnd_args *uap; 1108{ 1109 int error; 1110 long mtype; 1111 1112 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp, 1113 uap->msgsz, uap->msgflg)); 1114 1115 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) { 1116 DPRINTF(("error %d copying the message type\n", error)); 1117 return (error); 1118 } 1119 return (kern_msgsnd(td, uap->msqid, 1120 (const char *)uap->msgp + sizeof(mtype), 1121 uap->msgsz, uap->msgflg, mtype)); 1122} 1123 1124#ifndef _SYS_SYSPROTO_H_ 1125struct msgrcv_args { 1126 int msqid; 1127 void *msgp; 1128 size_t msgsz; 1129 long msgtyp; 1130 int msgflg; 1131}; 1132#endif 1133int 1134kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype) 1135 struct thread *td; 1136 int msqid; 1137 void *msgp; /* XXX msgp is actually mtext. */ 1138 size_t msgsz; 1139 long msgtyp; 1140 int msgflg; 1141 long *mtype; 1142{ 1143 size_t len; 1144 register struct msqid_kernel *msqkptr; 1145 register struct msg *msghdr; 1146 struct prison *rpr; 1147 int msqix, error = 0; 1148 short next; 1149 1150 rpr = msg_find_prison(td->td_ucred); 1151 if (rpr == NULL) 1152 return (ENOSYS); 1153 1154 msqix = IPCID_TO_IX(msqid); 1155 1156 if (msqix < 0 || msqix >= msginfo.msgmni) { 1157 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 1158 msginfo.msgmni)); 1159 return (EINVAL); 1160 } 1161 1162 msqkptr = &msqids[msqix]; 1163 mtx_lock(&msq_mtx); 1164 if (msqkptr->u.msg_qbytes == 0) { 1165 DPRINTF(("no such message queue id\n")); 1166 error = EINVAL; 1167 goto done2; 1168 } 1169 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1170 DPRINTF(("wrong sequence number\n")); 1171 error = EINVAL; 1172 goto done2; 1173 } 1174 1175 if ((error = msq_prison_cansee(rpr, msqkptr))) { 1176 DPRINTF(("requester can't see prison\n")); 1177 goto done2; 1178 } 1179 1180 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 1181 DPRINTF(("requester doesn't have read access\n")); 1182 goto done2; 1183 } 1184 1185#ifdef MAC 1186 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr); 1187 if (error != 0) 1188 goto done2; 1189#endif 1190 1191 msghdr = NULL; 1192 while (msghdr == NULL) { 1193 if (msgtyp == 0) { 1194 msghdr = msqkptr->u.msg_first; 1195 if (msghdr != NULL) { 1196 if (msgsz < msghdr->msg_ts && 1197 (msgflg & MSG_NOERROR) == 0) { 1198 DPRINTF(("first message on the queue " 1199 "is too big (want %zu, got %d)\n", 1200 msgsz, msghdr->msg_ts)); 1201 error = E2BIG; 1202 goto done2; 1203 } 1204#ifdef MAC 1205 error = mac_sysvmsq_check_msgrcv(td->td_ucred, 1206 msghdr); 1207 if (error != 0) 1208 goto done2; 1209#endif 1210 if (msqkptr->u.msg_first == msqkptr->u.msg_last) { 1211 msqkptr->u.msg_first = NULL; 1212 msqkptr->u.msg_last = NULL; 1213 } else { 1214 msqkptr->u.msg_first = msghdr->msg_next; 1215 if (msqkptr->u.msg_first == NULL) 1216 panic("msg_first/last screwed up #1"); 1217 } 1218 } 1219 } else { 1220 struct msg *previous; 1221 struct msg **prev; 1222 1223 previous = NULL; 1224 prev = &(msqkptr->u.msg_first); 1225 while ((msghdr = *prev) != NULL) { 1226 /* 1227 * Is this message's type an exact match or is 1228 * this message's type less than or equal to 1229 * the absolute value of a negative msgtyp? 1230 * Note that the second half of this test can 1231 * NEVER be true if msgtyp is positive since 1232 * msg_type is always positive! 1233 */ 1234 1235 if (msgtyp == msghdr->msg_type || 1236 msghdr->msg_type <= -msgtyp) { 1237 DPRINTF(("found message type %ld, " 1238 "requested %ld\n", 1239 msghdr->msg_type, msgtyp)); 1240 if (msgsz < msghdr->msg_ts && 1241 (msgflg & MSG_NOERROR) == 0) { 1242 DPRINTF(("requested message " 1243 "on the queue is too big " 1244 "(want %zu, got %hu)\n", 1245 msgsz, msghdr->msg_ts)); 1246 error = E2BIG; 1247 goto done2; 1248 } 1249#ifdef MAC 1250 error = mac_sysvmsq_check_msgrcv( 1251 td->td_ucred, msghdr); 1252 if (error != 0) 1253 goto done2; 1254#endif 1255 *prev = msghdr->msg_next; 1256 if (msghdr == msqkptr->u.msg_last) { 1257 if (previous == NULL) { 1258 if (prev != 1259 &msqkptr->u.msg_first) 1260 panic("msg_first/last screwed up #2"); 1261 msqkptr->u.msg_first = 1262 NULL; 1263 msqkptr->u.msg_last = 1264 NULL; 1265 } else { 1266 if (prev == 1267 &msqkptr->u.msg_first) 1268 panic("msg_first/last screwed up #3"); 1269 msqkptr->u.msg_last = 1270 previous; 1271 } 1272 } 1273 break; 1274 } 1275 previous = msghdr; 1276 prev = &(msghdr->msg_next); 1277 } 1278 } 1279 1280 /* 1281 * We've either extracted the msghdr for the appropriate 1282 * message or there isn't one. 1283 * If there is one then bail out of this loop. 1284 */ 1285 1286 if (msghdr != NULL) 1287 break; 1288 1289 /* 1290 * Hmph! No message found. Does the user want to wait? 1291 */ 1292 1293 if ((msgflg & IPC_NOWAIT) != 0) { 1294 DPRINTF(("no appropriate message found (msgtyp=%ld)\n", 1295 msgtyp)); 1296 /* The SVID says to return ENOMSG. */ 1297 error = ENOMSG; 1298 goto done2; 1299 } 1300 1301 /* 1302 * Wait for something to happen 1303 */ 1304 1305 DPRINTF(("msgrcv: goodnight\n")); 1306 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 1307 "msgrcv", 0); 1308 DPRINTF(("msgrcv: good morning (error=%d)\n", error)); 1309 1310 if (error != 0) { 1311 DPRINTF(("msgrcv: interrupted system call\n")); 1312 error = EINTR; 1313 goto done2; 1314 } 1315 1316 /* 1317 * Make sure that the msq queue still exists 1318 */ 1319 1320 if (msqkptr->u.msg_qbytes == 0 || 1321 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1322 DPRINTF(("msqid deleted\n")); 1323 error = EIDRM; 1324 goto done2; 1325 } 1326 } 1327 1328 /* 1329 * Return the message to the user. 1330 * 1331 * First, do the bookkeeping (before we risk being interrupted). 1332 */ 1333 1334 msqkptr->u.msg_cbytes -= msghdr->msg_ts; 1335 msqkptr->u.msg_qnum--; 1336 msqkptr->u.msg_lrpid = td->td_proc->p_pid; 1337 msqkptr->u.msg_rtime = time_second; 1338 1339 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1); 1340 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts); 1341 1342 /* 1343 * Make msgsz the actual amount that we'll be returning. 1344 * Note that this effectively truncates the message if it is too long 1345 * (since msgsz is never increased). 1346 */ 1347 1348 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz, 1349 msghdr->msg_ts)); 1350 if (msgsz > msghdr->msg_ts) 1351 msgsz = msghdr->msg_ts; 1352 *mtype = msghdr->msg_type; 1353 1354 /* 1355 * Return the segments to the user 1356 */ 1357 1358 next = msghdr->msg_spot; 1359 for (len = 0; len < msgsz; len += msginfo.msgssz) { 1360 size_t tlen; 1361 1362 if (msgsz - len > msginfo.msgssz) 1363 tlen = msginfo.msgssz; 1364 else 1365 tlen = msgsz - len; 1366 if (next <= -1) 1367 panic("next too low #3"); 1368 if (next >= msginfo.msgseg) 1369 panic("next out of range #3"); 1370 mtx_unlock(&msq_mtx); 1371 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen); 1372 mtx_lock(&msq_mtx); 1373 if (error != 0) { 1374 DPRINTF(("error (%d) copying out message segment\n", 1375 error)); 1376 msg_freehdr(msghdr); 1377 wakeup(msqkptr); 1378 goto done2; 1379 } 1380 msgp = (char *)msgp + tlen; 1381 next = msgmaps[next].next; 1382 } 1383 1384 /* 1385 * Done, return the actual number of bytes copied out. 1386 */ 1387 1388 msg_freehdr(msghdr); 1389 wakeup(msqkptr); 1390 td->td_retval[0] = msgsz; 1391done2: 1392 mtx_unlock(&msq_mtx); 1393 return (error); 1394} 1395 1396int 1397sys_msgrcv(td, uap) 1398 struct thread *td; 1399 register struct msgrcv_args *uap; 1400{ 1401 int error; 1402 long mtype; 1403 1404 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid, 1405 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg)); 1406 1407 if ((error = kern_msgrcv(td, uap->msqid, 1408 (char *)uap->msgp + sizeof(mtype), uap->msgsz, 1409 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1410 return (error); 1411 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0) 1412 DPRINTF(("error %d copying the message type\n", error)); 1413 return (error); 1414} 1415 1416static int 1417sysctl_msqids(SYSCTL_HANDLER_ARGS) 1418{ 1419 struct msqid_kernel tmsqk; 1420 struct prison *pr, *rpr; 1421 int error, i; 1422 1423 pr = req->td->td_ucred->cr_prison; 1424 rpr = msg_find_prison(req->td->td_ucred); 1425 error = 0; 1426 for (i = 0; i < msginfo.msgmni; i++) { 1427 mtx_lock(&msq_mtx); 1428 if (msqids[i].u.msg_qbytes == 0 || rpr == NULL || 1429 msq_prison_cansee(rpr, &msqids[i]) != 0) 1430 bzero(&tmsqk, sizeof(tmsqk)); 1431 else { 1432 tmsqk = msqids[i]; 1433 if (tmsqk.cred->cr_prison != pr) 1434 tmsqk.u.msg_perm.key = IPC_PRIVATE; 1435 } 1436 mtx_unlock(&msq_mtx); 1437 error = SYSCTL_OUT(req, &tmsqk, sizeof(tmsqk)); 1438 if (error != 0) 1439 break; 1440 } 1441 return (error); 1442} 1443 1444SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, 1445 "Maximum message size"); 1446SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0, 1447 "Number of message queue identifiers"); 1448SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0, 1449 "Maximum number of bytes in a queue"); 1450SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0, 1451 "Maximum number of messages in the system"); 1452SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0, 1453 "Size of a message segment"); 1454SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0, 1455 "Number of message segments"); 1456SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, 1457 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1458 NULL, 0, sysctl_msqids, "", "Message queue IDs"); 1459 1460static int 1461msg_prison_check(void *obj, void *data) 1462{ 1463 struct prison *pr = obj; 1464 struct prison *prpr; 1465 struct vfsoptlist *opts = data; 1466 int error, jsys; 1467 1468 /* 1469 * sysvmsg is a jailsys integer. 1470 * It must be "disable" if the parent jail is disabled. 1471 */ 1472 error = vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1473 if (error != ENOENT) { 1474 if (error != 0) 1475 return (error); 1476 switch (jsys) { 1477 case JAIL_SYS_DISABLE: 1478 break; 1479 case JAIL_SYS_NEW: 1480 case JAIL_SYS_INHERIT: 1481 prison_lock(pr->pr_parent); 1482 prpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1483 prison_unlock(pr->pr_parent); 1484 if (prpr == NULL) 1485 return (EPERM); 1486 break; 1487 default: 1488 return (EINVAL); 1489 } 1490 } 1491 1492 return (0); 1493} 1494 1495static int 1496msg_prison_set(void *obj, void *data) 1497{ 1498 struct prison *pr = obj; 1499 struct prison *tpr, *orpr, *nrpr, *trpr; 1500 struct vfsoptlist *opts = data; 1501 void *rsv; 1502 int jsys, descend; 1503 1504 /* 1505 * sysvmsg controls which jail is the root of the associated msgs (this 1506 * jail or same as the parent), or if the feature is available at all. 1507 */ 1508 if (vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)) == ENOENT) 1509 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1510 ? JAIL_SYS_INHERIT 1511 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1512 ? JAIL_SYS_DISABLE 1513 : -1; 1514 if (jsys == JAIL_SYS_DISABLE) { 1515 prison_lock(pr); 1516 orpr = osd_jail_get(pr, msg_prison_slot); 1517 if (orpr != NULL) 1518 osd_jail_del(pr, msg_prison_slot); 1519 prison_unlock(pr); 1520 if (orpr != NULL) { 1521 if (orpr == pr) 1522 msg_prison_cleanup(pr); 1523 /* Disable all child jails as well. */ 1524 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1525 prison_lock(tpr); 1526 trpr = osd_jail_get(tpr, msg_prison_slot); 1527 if (trpr != NULL) { 1528 osd_jail_del(tpr, msg_prison_slot); 1529 prison_unlock(tpr); 1530 if (trpr == tpr) 1531 msg_prison_cleanup(tpr); 1532 } else { 1533 prison_unlock(tpr); 1534 descend = 0; 1535 } 1536 } 1537 } 1538 } else if (jsys != -1) { 1539 if (jsys == JAIL_SYS_NEW) 1540 nrpr = pr; 1541 else { 1542 prison_lock(pr->pr_parent); 1543 nrpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1544 prison_unlock(pr->pr_parent); 1545 } 1546 rsv = osd_reserve(msg_prison_slot); 1547 prison_lock(pr); 1548 orpr = osd_jail_get(pr, msg_prison_slot); 1549 if (orpr != nrpr) 1550 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv, 1551 nrpr); 1552 else 1553 osd_free_reserved(rsv); 1554 prison_unlock(pr); 1555 if (orpr != nrpr) { 1556 if (orpr == pr) 1557 msg_prison_cleanup(pr); 1558 if (orpr != NULL) { 1559 /* Change child jails matching the old root, */ 1560 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1561 prison_lock(tpr); 1562 trpr = osd_jail_get(tpr, 1563 msg_prison_slot); 1564 if (trpr == orpr) { 1565 (void)osd_jail_set(tpr, 1566 msg_prison_slot, nrpr); 1567 prison_unlock(tpr); 1568 if (trpr == tpr) 1569 msg_prison_cleanup(tpr); 1570 } else { 1571 prison_unlock(tpr); 1572 descend = 0; 1573 } 1574 } 1575 } 1576 } 1577 } 1578 1579 return (0); 1580} 1581 1582static int 1583msg_prison_get(void *obj, void *data) 1584{ 1585 struct prison *pr = obj; 1586 struct prison *rpr; 1587 struct vfsoptlist *opts = data; 1588 int error, jsys; 1589 1590 /* Set sysvmsg based on the jail's root prison. */ 1591 prison_lock(pr); 1592 rpr = osd_jail_get(pr, msg_prison_slot); 1593 prison_unlock(pr); 1594 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1595 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1596 error = vfs_setopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1597 if (error == ENOENT) 1598 error = 0; 1599 return (error); 1600} 1601 1602static int 1603msg_prison_remove(void *obj, void *data __unused) 1604{ 1605 struct prison *pr = obj; 1606 struct prison *rpr; 1607 1608 prison_lock(pr); 1609 rpr = osd_jail_get(pr, msg_prison_slot); 1610 prison_unlock(pr); 1611 if (rpr == pr) 1612 msg_prison_cleanup(pr); 1613 return (0); 1614} 1615 1616static void 1617msg_prison_cleanup(struct prison *pr) 1618{ 1619 struct msqid_kernel *msqkptr; 1620 int i; 1621 1622 /* Remove any msqs that belong to this jail. */ 1623 mtx_lock(&msq_mtx); 1624 for (i = 0; i < msginfo.msgmni; i++) { 1625 msqkptr = &msqids[i]; 1626 if (msqkptr->u.msg_qbytes != 0 && 1627 msqkptr->cred != NULL && msqkptr->cred->cr_prison == pr) 1628 msq_remove(msqkptr); 1629 } 1630 mtx_unlock(&msq_mtx); 1631} 1632 1633SYSCTL_JAIL_PARAM_SYS_NODE(sysvmsg, CTLFLAG_RW, "SYSV message queues"); 1634 1635#ifdef COMPAT_FREEBSD32 1636int 1637freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap) 1638{ 1639 1640#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1641 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1642 switch (uap->which) { 1643 case 0: 1644 return (freebsd7_freebsd32_msgctl(td, 1645 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2)); 1646 case 2: 1647 return (freebsd32_msgsnd(td, 1648 (struct freebsd32_msgsnd_args *)&uap->a2)); 1649 case 3: 1650 return (freebsd32_msgrcv(td, 1651 (struct freebsd32_msgrcv_args *)&uap->a2)); 1652 default: 1653 return (sys_msgsys(td, (struct msgsys_args *)uap)); 1654 } 1655#else 1656 return (nosys(td, NULL)); 1657#endif 1658} 1659 1660#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1661 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1662int 1663freebsd7_freebsd32_msgctl(struct thread *td, 1664 struct freebsd7_freebsd32_msgctl_args *uap) 1665{ 1666 struct msqid_ds msqbuf; 1667 struct msqid_ds32_old msqbuf32; 1668 int error; 1669 1670 if (uap->cmd == IPC_SET) { 1671 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1672 if (error) 1673 return (error); 1674 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1675 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1676 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1677 CP(msqbuf32, msqbuf, msg_cbytes); 1678 CP(msqbuf32, msqbuf, msg_qnum); 1679 CP(msqbuf32, msqbuf, msg_qbytes); 1680 CP(msqbuf32, msqbuf, msg_lspid); 1681 CP(msqbuf32, msqbuf, msg_lrpid); 1682 CP(msqbuf32, msqbuf, msg_stime); 1683 CP(msqbuf32, msqbuf, msg_rtime); 1684 CP(msqbuf32, msqbuf, msg_ctime); 1685 } 1686 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1687 if (error) 1688 return (error); 1689 if (uap->cmd == IPC_STAT) { 1690 bzero(&msqbuf32, sizeof(msqbuf32)); 1691 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1692 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1693 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1694 CP(msqbuf, msqbuf32, msg_cbytes); 1695 CP(msqbuf, msqbuf32, msg_qnum); 1696 CP(msqbuf, msqbuf32, msg_qbytes); 1697 CP(msqbuf, msqbuf32, msg_lspid); 1698 CP(msqbuf, msqbuf32, msg_lrpid); 1699 CP(msqbuf, msqbuf32, msg_stime); 1700 CP(msqbuf, msqbuf32, msg_rtime); 1701 CP(msqbuf, msqbuf32, msg_ctime); 1702 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1703 } 1704 return (error); 1705} 1706#endif 1707 1708int 1709freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap) 1710{ 1711 struct msqid_ds msqbuf; 1712 struct msqid_ds32 msqbuf32; 1713 int error; 1714 1715 if (uap->cmd == IPC_SET) { 1716 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1717 if (error) 1718 return (error); 1719 freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1720 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1721 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1722 CP(msqbuf32, msqbuf, msg_cbytes); 1723 CP(msqbuf32, msqbuf, msg_qnum); 1724 CP(msqbuf32, msqbuf, msg_qbytes); 1725 CP(msqbuf32, msqbuf, msg_lspid); 1726 CP(msqbuf32, msqbuf, msg_lrpid); 1727 CP(msqbuf32, msqbuf, msg_stime); 1728 CP(msqbuf32, msqbuf, msg_rtime); 1729 CP(msqbuf32, msqbuf, msg_ctime); 1730 } 1731 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1732 if (error) 1733 return (error); 1734 if (uap->cmd == IPC_STAT) { 1735 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1736 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1737 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1738 CP(msqbuf, msqbuf32, msg_cbytes); 1739 CP(msqbuf, msqbuf32, msg_qnum); 1740 CP(msqbuf, msqbuf32, msg_qbytes); 1741 CP(msqbuf, msqbuf32, msg_lspid); 1742 CP(msqbuf, msqbuf32, msg_lrpid); 1743 CP(msqbuf, msqbuf32, msg_stime); 1744 CP(msqbuf, msqbuf32, msg_rtime); 1745 CP(msqbuf, msqbuf32, msg_ctime); 1746 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1747 } 1748 return (error); 1749} 1750 1751int 1752freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap) 1753{ 1754 const void *msgp; 1755 long mtype; 1756 int32_t mtype32; 1757 int error; 1758 1759 msgp = PTRIN(uap->msgp); 1760 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0) 1761 return (error); 1762 mtype = mtype32; 1763 return (kern_msgsnd(td, uap->msqid, 1764 (const char *)msgp + sizeof(mtype32), 1765 uap->msgsz, uap->msgflg, mtype)); 1766} 1767 1768int 1769freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap) 1770{ 1771 void *msgp; 1772 long mtype; 1773 int32_t mtype32; 1774 int error; 1775 1776 msgp = PTRIN(uap->msgp); 1777 if ((error = kern_msgrcv(td, uap->msqid, 1778 (char *)msgp + sizeof(mtype32), uap->msgsz, 1779 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1780 return (error); 1781 mtype32 = (int32_t)mtype; 1782 return (copyout(&mtype32, msgp, sizeof(mtype32))); 1783} 1784#endif 1785 1786#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1787 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1788 1789/* XXX casting to (sy_call_t *) is bogus, as usual. */ 1790static sy_call_t *msgcalls[] = { 1791 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget, 1792 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv 1793}; 1794 1795/* 1796 * Entry point for all MSG calls. 1797 */ 1798int 1799sys_msgsys(td, uap) 1800 struct thread *td; 1801 /* XXX actually varargs. */ 1802 struct msgsys_args /* { 1803 int which; 1804 int a2; 1805 int a3; 1806 int a4; 1807 int a5; 1808 int a6; 1809 } */ *uap; 1810{ 1811 int error; 1812 1813 if (uap->which < 0 || uap->which >= nitems(msgcalls)) 1814 return (EINVAL); 1815 error = (*msgcalls[uap->which])(td, &uap->a2); 1816 return (error); 1817} 1818 1819#ifndef CP 1820#define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1821#endif 1822 1823#ifndef _SYS_SYSPROTO_H_ 1824struct freebsd7_msgctl_args { 1825 int msqid; 1826 int cmd; 1827 struct msqid_ds_old *buf; 1828}; 1829#endif 1830int 1831freebsd7_msgctl(td, uap) 1832 struct thread *td; 1833 struct freebsd7_msgctl_args *uap; 1834{ 1835 struct msqid_ds_old msqold; 1836 struct msqid_ds msqbuf; 1837 int error; 1838 1839 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd, 1840 uap->buf)); 1841 if (uap->cmd == IPC_SET) { 1842 error = copyin(uap->buf, &msqold, sizeof(msqold)); 1843 if (error) 1844 return (error); 1845 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm); 1846 CP(msqold, msqbuf, msg_first); 1847 CP(msqold, msqbuf, msg_last); 1848 CP(msqold, msqbuf, msg_cbytes); 1849 CP(msqold, msqbuf, msg_qnum); 1850 CP(msqold, msqbuf, msg_qbytes); 1851 CP(msqold, msqbuf, msg_lspid); 1852 CP(msqold, msqbuf, msg_lrpid); 1853 CP(msqold, msqbuf, msg_stime); 1854 CP(msqold, msqbuf, msg_rtime); 1855 CP(msqold, msqbuf, msg_ctime); 1856 } 1857 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1858 if (error) 1859 return (error); 1860 if (uap->cmd == IPC_STAT) { 1861 bzero(&msqold, sizeof(msqold)); 1862 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm); 1863 CP(msqbuf, msqold, msg_first); 1864 CP(msqbuf, msqold, msg_last); 1865 CP(msqbuf, msqold, msg_cbytes); 1866 CP(msqbuf, msqold, msg_qnum); 1867 CP(msqbuf, msqold, msg_qbytes); 1868 CP(msqbuf, msqold, msg_lspid); 1869 CP(msqbuf, msqold, msg_lrpid); 1870 CP(msqbuf, msqold, msg_stime); 1871 CP(msqbuf, msqold, msg_rtime); 1872 CP(msqbuf, msqold, msg_ctime); 1873 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old)); 1874 } 1875 return (error); 1876} 1877 1878#undef CP 1879 1880#endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1881 COMPAT_FREEBSD7 */ 1882