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: stable/10/sys/kern/sysv_msg.c 329741 2018-02-21 18:32:57Z brooks $"); 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 TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg); 219 TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz); 220 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz; 221 TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni); 222 TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb); 223 TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql); 224 225 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK); 226 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); 227 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); 228 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG, 229 M_WAITOK); 230 231 /* 232 * msginfo.msgssz should be a power of two for efficiency reasons. 233 * It is also pretty silly if msginfo.msgssz is less than 8 234 * or greater than about 256 so ... 235 */ 236 237 i = 8; 238 while (i < 1024 && i != msginfo.msgssz) 239 i <<= 1; 240 if (i != msginfo.msgssz) { 241 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz, 242 msginfo.msgssz)); 243 panic("msginfo.msgssz not a small power of 2"); 244 } 245 246 if (msginfo.msgseg > 32767) { 247 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg)); 248 panic("msginfo.msgseg > 32767"); 249 } 250 251 for (i = 0; i < msginfo.msgseg; i++) { 252 if (i > 0) 253 msgmaps[i-1].next = i; 254 msgmaps[i].next = -1; /* implies entry is available */ 255 } 256 free_msgmaps = 0; 257 nfree_msgmaps = msginfo.msgseg; 258 259 for (i = 0; i < msginfo.msgtql; i++) { 260 msghdrs[i].msg_type = 0; 261 if (i > 0) 262 msghdrs[i-1].msg_next = &msghdrs[i]; 263 msghdrs[i].msg_next = NULL; 264#ifdef MAC 265 mac_sysvmsg_init(&msghdrs[i]); 266#endif 267 } 268 free_msghdrs = &msghdrs[0]; 269 270 for (i = 0; i < msginfo.msgmni; i++) { 271 msqids[i].u.msg_qbytes = 0; /* implies entry is available */ 272 msqids[i].u.msg_perm.seq = 0; /* reset to a known value */ 273 msqids[i].u.msg_perm.mode = 0; 274#ifdef MAC 275 mac_sysvmsq_init(&msqids[i]); 276#endif 277 } 278 mtx_init(&msq_mtx, "msq", NULL, MTX_DEF); 279 280 /* Set current prisons according to their allow.sysvipc. */ 281 msg_prison_slot = osd_jail_register(NULL, methods); 282 rsv = osd_reserve(msg_prison_slot); 283 prison_lock(&prison0); 284 (void)osd_jail_set_reserved(&prison0, msg_prison_slot, rsv, &prison0); 285 prison_unlock(&prison0); 286 rsv = NULL; 287 sx_slock(&allprison_lock); 288 TAILQ_FOREACH(pr, &allprison, pr_list) { 289 if (rsv == NULL) 290 rsv = osd_reserve(msg_prison_slot); 291 prison_lock(pr); 292 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 293 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv, 294 &prison0); 295 rsv = NULL; 296 } 297 prison_unlock(pr); 298 } 299 if (rsv != NULL) 300 osd_free_reserved(rsv); 301 sx_sunlock(&allprison_lock); 302 303 error = syscall_helper_register(msg_syscalls); 304 if (error != 0) 305 return (error); 306#ifdef COMPAT_FREEBSD32 307 error = syscall32_helper_register(msg32_syscalls); 308 if (error != 0) 309 return (error); 310#endif 311 return (0); 312} 313 314static int 315msgunload() 316{ 317 struct msqid_kernel *msqkptr; 318 int msqid; 319#ifdef MAC 320 int i; 321#endif 322 323 syscall_helper_unregister(msg_syscalls); 324#ifdef COMPAT_FREEBSD32 325 syscall32_helper_unregister(msg32_syscalls); 326#endif 327 328 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 329 msqkptr = &msqids[msqid]; 330 if (msqkptr->u.msg_qbytes != 0 || 331 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 332 break; 333 } 334 if (msqid != msginfo.msgmni) 335 return (EBUSY); 336 337 if (msg_prison_slot != 0) 338 osd_jail_deregister(msg_prison_slot); 339#ifdef MAC 340 for (i = 0; i < msginfo.msgtql; i++) 341 mac_sysvmsg_destroy(&msghdrs[i]); 342 for (msqid = 0; msqid < msginfo.msgmni; msqid++) 343 mac_sysvmsq_destroy(&msqids[msqid]); 344#endif 345 free(msgpool, M_MSG); 346 free(msgmaps, M_MSG); 347 free(msghdrs, M_MSG); 348 free(msqids, M_MSG); 349 mtx_destroy(&msq_mtx); 350 return (0); 351} 352 353 354static int 355sysvmsg_modload(struct module *module, int cmd, void *arg) 356{ 357 int error = 0; 358 359 switch (cmd) { 360 case MOD_LOAD: 361 error = msginit(); 362 if (error != 0) 363 msgunload(); 364 break; 365 case MOD_UNLOAD: 366 error = msgunload(); 367 break; 368 case MOD_SHUTDOWN: 369 break; 370 default: 371 error = EINVAL; 372 break; 373 } 374 return (error); 375} 376 377static moduledata_t sysvmsg_mod = { 378 "sysvmsg", 379 &sysvmsg_modload, 380 NULL 381}; 382 383DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST); 384MODULE_VERSION(sysvmsg, 1); 385 386static void 387msg_freehdr(msghdr) 388 struct msg *msghdr; 389{ 390 while (msghdr->msg_ts > 0) { 391 short next; 392 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg) 393 panic("msghdr->msg_spot out of range"); 394 next = msgmaps[msghdr->msg_spot].next; 395 msgmaps[msghdr->msg_spot].next = free_msgmaps; 396 free_msgmaps = msghdr->msg_spot; 397 nfree_msgmaps++; 398 msghdr->msg_spot = next; 399 if (msghdr->msg_ts >= msginfo.msgssz) 400 msghdr->msg_ts -= msginfo.msgssz; 401 else 402 msghdr->msg_ts = 0; 403 } 404 if (msghdr->msg_spot != -1) 405 panic("msghdr->msg_spot != -1"); 406 msghdr->msg_next = free_msghdrs; 407 free_msghdrs = msghdr; 408#ifdef MAC 409 mac_sysvmsg_cleanup(msghdr); 410#endif 411} 412 413static void 414msq_remove(struct msqid_kernel *msqkptr) 415{ 416 struct msg *msghdr; 417 418 racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1); 419 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum); 420 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes); 421 crfree(msqkptr->cred); 422 msqkptr->cred = NULL; 423 424 /* Free the message headers */ 425 msghdr = msqkptr->u.msg_first; 426 while (msghdr != NULL) { 427 struct msg *msghdr_tmp; 428 429 /* Free the segments of each message */ 430 msqkptr->u.msg_cbytes -= msghdr->msg_ts; 431 msqkptr->u.msg_qnum--; 432 msghdr_tmp = msghdr; 433 msghdr = msghdr->msg_next; 434 msg_freehdr(msghdr_tmp); 435 } 436 437 if (msqkptr->u.msg_cbytes != 0) 438 panic("msg_cbytes is screwed up"); 439 if (msqkptr->u.msg_qnum != 0) 440 panic("msg_qnum is screwed up"); 441 442 msqkptr->u.msg_qbytes = 0; /* Mark it as free */ 443 444#ifdef MAC 445 mac_sysvmsq_cleanup(msqkptr); 446#endif 447 448 wakeup(msqkptr); 449} 450 451static struct prison * 452msg_find_prison(struct ucred *cred) 453{ 454 struct prison *pr, *rpr; 455 456 pr = cred->cr_prison; 457 prison_lock(pr); 458 rpr = osd_jail_get(pr, msg_prison_slot); 459 prison_unlock(pr); 460 return rpr; 461} 462 463static int 464msq_prison_cansee(struct prison *rpr, struct msqid_kernel *msqkptr) 465{ 466 467 if (msqkptr->cred == NULL || 468 !(rpr == msqkptr->cred->cr_prison || 469 prison_ischild(rpr, msqkptr->cred->cr_prison))) 470 return (EINVAL); 471 return (0); 472} 473 474#ifndef _SYS_SYSPROTO_H_ 475struct msgctl_args { 476 int msqid; 477 int cmd; 478 struct msqid_ds *buf; 479}; 480#endif 481int 482sys_msgctl(td, uap) 483 struct thread *td; 484 register struct msgctl_args *uap; 485{ 486 int msqid = uap->msqid; 487 int cmd = uap->cmd; 488 struct msqid_ds msqbuf; 489 int error; 490 491 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf)); 492 if (cmd == IPC_SET && 493 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0) 494 return (error); 495 error = kern_msgctl(td, msqid, cmd, &msqbuf); 496 if (cmd == IPC_STAT && error == 0) 497 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds)); 498 return (error); 499} 500 501int 502kern_msgctl(td, msqid, cmd, msqbuf) 503 struct thread *td; 504 int msqid; 505 int cmd; 506 struct msqid_ds *msqbuf; 507{ 508 int rval, error, msqix; 509 register struct msqid_kernel *msqkptr; 510 struct prison *rpr; 511 512 rpr = msg_find_prison(td->td_ucred); 513 if (rpr == NULL) 514 return (ENOSYS); 515 516 msqix = IPCID_TO_IX(msqid); 517 518 if (msqix < 0 || msqix >= msginfo.msgmni) { 519 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 520 msginfo.msgmni)); 521 return (EINVAL); 522 } 523 524 msqkptr = &msqids[msqix]; 525 526 mtx_lock(&msq_mtx); 527 if (msqkptr->u.msg_qbytes == 0) { 528 DPRINTF(("no such msqid\n")); 529 error = EINVAL; 530 goto done2; 531 } 532 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 533 DPRINTF(("wrong sequence number\n")); 534 error = EINVAL; 535 goto done2; 536 } 537 538 error = msq_prison_cansee(rpr, msqkptr); 539 if (error != 0) { 540 DPRINTF(("requester can't see prison\n")); 541 goto done2; 542 } 543 544#ifdef MAC 545 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd); 546 if (error != 0) 547 goto done2; 548#endif 549 550 error = 0; 551 rval = 0; 552 553 switch (cmd) { 554 555 case IPC_RMID: 556 { 557#ifdef MAC 558 struct msg *msghdr; 559#endif 560 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 561 goto done2; 562 563#ifdef MAC 564 /* 565 * Check that the thread has MAC access permissions to 566 * individual msghdrs. Note: We need to do this in a 567 * separate loop because the actual loop alters the 568 * msq/msghdr info as it progresses, and there is no going 569 * back if half the way through we discover that the 570 * thread cannot free a certain msghdr. The msq will get 571 * into an inconsistent state. 572 */ 573 for (msghdr = msqkptr->u.msg_first; msghdr != NULL; 574 msghdr = msghdr->msg_next) { 575 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr); 576 if (error != 0) 577 goto done2; 578 } 579#endif 580 581 msq_remove(msqkptr); 582 } 583 584 break; 585 586 case IPC_SET: 587 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 588 goto done2; 589 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) { 590 error = priv_check(td, PRIV_IPC_MSGSIZE); 591 if (error) 592 goto done2; 593 } 594 if (msqbuf->msg_qbytes > msginfo.msgmnb) { 595 DPRINTF(("can't increase msg_qbytes beyond %d" 596 "(truncating)\n", msginfo.msgmnb)); 597 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ 598 } 599 if (msqbuf->msg_qbytes == 0) { 600 DPRINTF(("can't reduce msg_qbytes to 0\n")); 601 error = EINVAL; /* non-standard errno! */ 602 goto done2; 603 } 604 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */ 605 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */ 606 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) | 607 (msqbuf->msg_perm.mode & 0777); 608 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes; 609 msqkptr->u.msg_ctime = time_second; 610 break; 611 612 case IPC_STAT: 613 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 614 DPRINTF(("requester doesn't have read access\n")); 615 goto done2; 616 } 617 *msqbuf = msqkptr->u; 618 if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison) 619 msqbuf->msg_perm.key = IPC_PRIVATE; 620 break; 621 622 default: 623 DPRINTF(("invalid command %d\n", cmd)); 624 error = EINVAL; 625 goto done2; 626 } 627 628 if (error == 0) 629 td->td_retval[0] = rval; 630done2: 631 mtx_unlock(&msq_mtx); 632 return (error); 633} 634 635#ifndef _SYS_SYSPROTO_H_ 636struct msgget_args { 637 key_t key; 638 int msgflg; 639}; 640#endif 641 642int 643sys_msgget(td, uap) 644 struct thread *td; 645 register struct msgget_args *uap; 646{ 647 int msqid, error = 0; 648 int key = uap->key; 649 int msgflg = uap->msgflg; 650 struct ucred *cred = td->td_ucred; 651 register struct msqid_kernel *msqkptr = NULL; 652 653 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg)); 654 655 if (msg_find_prison(cred) == NULL) 656 return (ENOSYS); 657 658 mtx_lock(&msq_mtx); 659 if (key != IPC_PRIVATE) { 660 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 661 msqkptr = &msqids[msqid]; 662 if (msqkptr->u.msg_qbytes != 0 && 663 msqkptr->cred != NULL && 664 msqkptr->cred->cr_prison == cred->cr_prison && 665 msqkptr->u.msg_perm.key == key) 666 break; 667 } 668 if (msqid < msginfo.msgmni) { 669 DPRINTF(("found public key\n")); 670 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { 671 DPRINTF(("not exclusive\n")); 672 error = EEXIST; 673 goto done2; 674 } 675 if ((error = ipcperm(td, &msqkptr->u.msg_perm, 676 msgflg & 0700))) { 677 DPRINTF(("requester doesn't have 0%o access\n", 678 msgflg & 0700)); 679 goto done2; 680 } 681#ifdef MAC 682 error = mac_sysvmsq_check_msqget(cred, msqkptr); 683 if (error != 0) 684 goto done2; 685#endif 686 goto found; 687 } 688 } 689 690 DPRINTF(("need to allocate the msqid_ds\n")); 691 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { 692 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 693 /* 694 * Look for an unallocated and unlocked msqid_ds. 695 * msqid_ds's can be locked by msgsnd or msgrcv while 696 * they are copying the message in/out. We can't 697 * re-use the entry until they release it. 698 */ 699 msqkptr = &msqids[msqid]; 700 if (msqkptr->u.msg_qbytes == 0 && 701 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0) 702 break; 703 } 704 if (msqid == msginfo.msgmni) { 705 DPRINTF(("no more msqid_ds's available\n")); 706 error = ENOSPC; 707 goto done2; 708 } 709#ifdef RACCT 710 if (racct_enable) { 711 PROC_LOCK(td->td_proc); 712 error = racct_add(td->td_proc, RACCT_NMSGQ, 1); 713 PROC_UNLOCK(td->td_proc); 714 if (error != 0) { 715 error = ENOSPC; 716 goto done2; 717 } 718 } 719#endif 720 DPRINTF(("msqid %d is available\n", msqid)); 721 msqkptr->u.msg_perm.key = key; 722 msqkptr->u.msg_perm.cuid = cred->cr_uid; 723 msqkptr->u.msg_perm.uid = cred->cr_uid; 724 msqkptr->u.msg_perm.cgid = cred->cr_gid; 725 msqkptr->u.msg_perm.gid = cred->cr_gid; 726 msqkptr->u.msg_perm.mode = (msgflg & 0777); 727 msqkptr->cred = crhold(cred); 728 /* Make sure that the returned msqid is unique */ 729 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff; 730 msqkptr->u.msg_first = NULL; 731 msqkptr->u.msg_last = NULL; 732 msqkptr->u.msg_cbytes = 0; 733 msqkptr->u.msg_qnum = 0; 734 msqkptr->u.msg_qbytes = msginfo.msgmnb; 735 msqkptr->u.msg_lspid = 0; 736 msqkptr->u.msg_lrpid = 0; 737 msqkptr->u.msg_stime = 0; 738 msqkptr->u.msg_rtime = 0; 739 msqkptr->u.msg_ctime = time_second; 740#ifdef MAC 741 mac_sysvmsq_create(cred, msqkptr); 742#endif 743 } else { 744 DPRINTF(("didn't find it and wasn't asked to create it\n")); 745 error = ENOENT; 746 goto done2; 747 } 748 749found: 750 /* Construct the unique msqid */ 751 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm); 752done2: 753 mtx_unlock(&msq_mtx); 754 return (error); 755} 756 757#ifndef _SYS_SYSPROTO_H_ 758struct msgsnd_args { 759 int msqid; 760 const void *msgp; 761 size_t msgsz; 762 int msgflg; 763}; 764#endif 765int 766kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype) 767 struct thread *td; 768 int msqid; 769 const void *msgp; /* XXX msgp is actually mtext. */ 770 size_t msgsz; 771 int msgflg; 772 long mtype; 773{ 774 int msqix, segs_needed, error = 0; 775 register struct msqid_kernel *msqkptr; 776 register struct msg *msghdr; 777 struct prison *rpr; 778 short next; 779#ifdef RACCT 780 size_t saved_msgsz; 781#endif 782 783 rpr = msg_find_prison(td->td_ucred); 784 if (rpr == NULL) 785 return (ENOSYS); 786 787 mtx_lock(&msq_mtx); 788 msqix = IPCID_TO_IX(msqid); 789 790 if (msqix < 0 || msqix >= msginfo.msgmni) { 791 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 792 msginfo.msgmni)); 793 error = EINVAL; 794 goto done2; 795 } 796 797 msqkptr = &msqids[msqix]; 798 if (msqkptr->u.msg_qbytes == 0) { 799 DPRINTF(("no such message queue id\n")); 800 error = EINVAL; 801 goto done2; 802 } 803 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 804 DPRINTF(("wrong sequence number\n")); 805 error = EINVAL; 806 goto done2; 807 } 808 809 if ((error = msq_prison_cansee(rpr, msqkptr))) { 810 DPRINTF(("requester can't see prison\n")); 811 goto done2; 812 } 813 814 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) { 815 DPRINTF(("requester doesn't have write access\n")); 816 goto done2; 817 } 818 819#ifdef MAC 820 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr); 821 if (error != 0) 822 goto done2; 823#endif 824 825#ifdef RACCT 826 if (racct_enable) { 827 PROC_LOCK(td->td_proc); 828 if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) { 829 PROC_UNLOCK(td->td_proc); 830 error = EAGAIN; 831 goto done2; 832 } 833 saved_msgsz = msgsz; 834 if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) { 835 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 836 PROC_UNLOCK(td->td_proc); 837 error = EAGAIN; 838 goto done2; 839 } 840 PROC_UNLOCK(td->td_proc); 841 } 842#endif 843 844 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz; 845 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz, 846 msginfo.msgssz, segs_needed)); 847 for (;;) { 848 int need_more_resources = 0; 849 850 /* 851 * check msgsz 852 * (inside this loop in case msg_qbytes changes while we sleep) 853 */ 854 855 if (msgsz > msqkptr->u.msg_qbytes) { 856 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n")); 857 error = EINVAL; 858 goto done3; 859 } 860 861 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) { 862 DPRINTF(("msqid is locked\n")); 863 need_more_resources = 1; 864 } 865 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) { 866 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n")); 867 need_more_resources = 1; 868 } 869 if (segs_needed > nfree_msgmaps) { 870 DPRINTF(("segs_needed > nfree_msgmaps\n")); 871 need_more_resources = 1; 872 } 873 if (free_msghdrs == NULL) { 874 DPRINTF(("no more msghdrs\n")); 875 need_more_resources = 1; 876 } 877 878 if (need_more_resources) { 879 int we_own_it; 880 881 if ((msgflg & IPC_NOWAIT) != 0) { 882 DPRINTF(("need more resources but caller " 883 "doesn't want to wait\n")); 884 error = EAGAIN; 885 goto done3; 886 } 887 888 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) { 889 DPRINTF(("we don't own the msqid_ds\n")); 890 we_own_it = 0; 891 } else { 892 /* Force later arrivals to wait for our 893 request */ 894 DPRINTF(("we own the msqid_ds\n")); 895 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 896 we_own_it = 1; 897 } 898 DPRINTF(("msgsnd: goodnight\n")); 899 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 900 "msgsnd", hz); 901 DPRINTF(("msgsnd: good morning, error=%d\n", error)); 902 if (we_own_it) 903 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 904 if (error == EWOULDBLOCK) { 905 DPRINTF(("msgsnd: timed out\n")); 906 continue; 907 } 908 if (error != 0) { 909 DPRINTF(("msgsnd: interrupted system call\n")); 910 error = EINTR; 911 goto done3; 912 } 913 914 /* 915 * Make sure that the msq queue still exists 916 */ 917 918 if (msqkptr->u.msg_qbytes == 0) { 919 DPRINTF(("msqid deleted\n")); 920 error = EIDRM; 921 goto done3; 922 } 923 924 } else { 925 DPRINTF(("got all the resources that we need\n")); 926 break; 927 } 928 } 929 930 /* 931 * We have the resources that we need. 932 * Make sure! 933 */ 934 935 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) 936 panic("msg_perm.mode & MSG_LOCKED"); 937 if (segs_needed > nfree_msgmaps) 938 panic("segs_needed > nfree_msgmaps"); 939 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) 940 panic("msgsz + msg_cbytes > msg_qbytes"); 941 if (free_msghdrs == NULL) 942 panic("no more msghdrs"); 943 944 /* 945 * Re-lock the msqid_ds in case we page-fault when copying in the 946 * message 947 */ 948 949 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 950 panic("msqid_ds is already locked"); 951 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 952 953 /* 954 * Allocate a message header 955 */ 956 957 msghdr = free_msghdrs; 958 free_msghdrs = msghdr->msg_next; 959 msghdr->msg_spot = -1; 960 msghdr->msg_ts = msgsz; 961 msghdr->msg_type = mtype; 962#ifdef MAC 963 /* 964 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here 965 * immediately? Or, should it be checked just before the msg is 966 * enqueued in the msgq (as it is done now)? 967 */ 968 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr); 969#endif 970 971 /* 972 * Allocate space for the message 973 */ 974 975 while (segs_needed > 0) { 976 if (nfree_msgmaps <= 0) 977 panic("not enough msgmaps"); 978 if (free_msgmaps == -1) 979 panic("nil free_msgmaps"); 980 next = free_msgmaps; 981 if (next <= -1) 982 panic("next too low #1"); 983 if (next >= msginfo.msgseg) 984 panic("next out of range #1"); 985 DPRINTF(("allocating segment %d to message\n", next)); 986 free_msgmaps = msgmaps[next].next; 987 nfree_msgmaps--; 988 msgmaps[next].next = msghdr->msg_spot; 989 msghdr->msg_spot = next; 990 segs_needed--; 991 } 992 993 /* 994 * Validate the message type 995 */ 996 997 if (msghdr->msg_type < 1) { 998 msg_freehdr(msghdr); 999 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1000 wakeup(msqkptr); 1001 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type)); 1002 error = EINVAL; 1003 goto done3; 1004 } 1005 1006 /* 1007 * Copy in the message body 1008 */ 1009 1010 next = msghdr->msg_spot; 1011 while (msgsz > 0) { 1012 size_t tlen; 1013 if (msgsz > msginfo.msgssz) 1014 tlen = msginfo.msgssz; 1015 else 1016 tlen = msgsz; 1017 if (next <= -1) 1018 panic("next too low #2"); 1019 if (next >= msginfo.msgseg) 1020 panic("next out of range #2"); 1021 mtx_unlock(&msq_mtx); 1022 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz], 1023 tlen)) != 0) { 1024 mtx_lock(&msq_mtx); 1025 DPRINTF(("error %d copying in message segment\n", 1026 error)); 1027 msg_freehdr(msghdr); 1028 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1029 wakeup(msqkptr); 1030 goto done3; 1031 } 1032 mtx_lock(&msq_mtx); 1033 msgsz -= tlen; 1034 msgp = (const char *)msgp + tlen; 1035 next = msgmaps[next].next; 1036 } 1037 if (next != -1) 1038 panic("didn't use all the msg segments"); 1039 1040 /* 1041 * We've got the message. Unlock the msqid_ds. 1042 */ 1043 1044 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1045 1046 /* 1047 * Make sure that the msqid_ds is still allocated. 1048 */ 1049 1050 if (msqkptr->u.msg_qbytes == 0) { 1051 msg_freehdr(msghdr); 1052 wakeup(msqkptr); 1053 error = EIDRM; 1054 goto done3; 1055 } 1056 1057#ifdef MAC 1058 /* 1059 * Note: Since the task/thread allocates the msghdr and usually 1060 * primes it with its own MAC label, for a majority of policies, it 1061 * won't be necessary to check whether the msghdr has access 1062 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would 1063 * suffice in that case. However, this hook may be required where 1064 * individual policies derive a non-identical label for the msghdr 1065 * from the current thread label and may want to check the msghdr 1066 * enqueue permissions, along with read/write permissions to the 1067 * msgq. 1068 */ 1069 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr); 1070 if (error != 0) { 1071 msg_freehdr(msghdr); 1072 wakeup(msqkptr); 1073 goto done3; 1074 } 1075#endif 1076 1077 /* 1078 * Put the message into the queue 1079 */ 1080 if (msqkptr->u.msg_first == NULL) { 1081 msqkptr->u.msg_first = msghdr; 1082 msqkptr->u.msg_last = msghdr; 1083 } else { 1084 msqkptr->u.msg_last->msg_next = msghdr; 1085 msqkptr->u.msg_last = msghdr; 1086 } 1087 msqkptr->u.msg_last->msg_next = NULL; 1088 1089 msqkptr->u.msg_cbytes += msghdr->msg_ts; 1090 msqkptr->u.msg_qnum++; 1091 msqkptr->u.msg_lspid = td->td_proc->p_pid; 1092 msqkptr->u.msg_stime = time_second; 1093 1094 wakeup(msqkptr); 1095 td->td_retval[0] = 0; 1096done3: 1097#ifdef RACCT 1098 if (racct_enable && error != 0) { 1099 PROC_LOCK(td->td_proc); 1100 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 1101 racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz); 1102 PROC_UNLOCK(td->td_proc); 1103 } 1104#endif 1105done2: 1106 mtx_unlock(&msq_mtx); 1107 return (error); 1108} 1109 1110int 1111sys_msgsnd(td, uap) 1112 struct thread *td; 1113 register struct msgsnd_args *uap; 1114{ 1115 int error; 1116 long mtype; 1117 1118 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp, 1119 uap->msgsz, uap->msgflg)); 1120 1121 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) { 1122 DPRINTF(("error %d copying the message type\n", error)); 1123 return (error); 1124 } 1125 return (kern_msgsnd(td, uap->msqid, 1126 (const char *)uap->msgp + sizeof(mtype), 1127 uap->msgsz, uap->msgflg, mtype)); 1128} 1129 1130#ifndef _SYS_SYSPROTO_H_ 1131struct msgrcv_args { 1132 int msqid; 1133 void *msgp; 1134 size_t msgsz; 1135 long msgtyp; 1136 int msgflg; 1137}; 1138#endif 1139int 1140kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype) 1141 struct thread *td; 1142 int msqid; 1143 void *msgp; /* XXX msgp is actually mtext. */ 1144 size_t msgsz; 1145 long msgtyp; 1146 int msgflg; 1147 long *mtype; 1148{ 1149 size_t len; 1150 register struct msqid_kernel *msqkptr; 1151 register struct msg *msghdr; 1152 struct prison *rpr; 1153 int msqix, error = 0; 1154 short next; 1155 1156 rpr = msg_find_prison(td->td_ucred); 1157 if (rpr == NULL) 1158 return (ENOSYS); 1159 1160 msqix = IPCID_TO_IX(msqid); 1161 1162 if (msqix < 0 || msqix >= msginfo.msgmni) { 1163 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 1164 msginfo.msgmni)); 1165 return (EINVAL); 1166 } 1167 1168 msqkptr = &msqids[msqix]; 1169 mtx_lock(&msq_mtx); 1170 if (msqkptr->u.msg_qbytes == 0) { 1171 DPRINTF(("no such message queue id\n")); 1172 error = EINVAL; 1173 goto done2; 1174 } 1175 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1176 DPRINTF(("wrong sequence number\n")); 1177 error = EINVAL; 1178 goto done2; 1179 } 1180 1181 if ((error = msq_prison_cansee(rpr, msqkptr))) { 1182 DPRINTF(("requester can't see prison\n")); 1183 goto done2; 1184 } 1185 1186 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 1187 DPRINTF(("requester doesn't have read access\n")); 1188 goto done2; 1189 } 1190 1191#ifdef MAC 1192 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr); 1193 if (error != 0) 1194 goto done2; 1195#endif 1196 1197 msghdr = NULL; 1198 while (msghdr == NULL) { 1199 if (msgtyp == 0) { 1200 msghdr = msqkptr->u.msg_first; 1201 if (msghdr != NULL) { 1202 if (msgsz < msghdr->msg_ts && 1203 (msgflg & MSG_NOERROR) == 0) { 1204 DPRINTF(("first message on the queue " 1205 "is too big (want %zu, got %d)\n", 1206 msgsz, msghdr->msg_ts)); 1207 error = E2BIG; 1208 goto done2; 1209 } 1210#ifdef MAC 1211 error = mac_sysvmsq_check_msgrcv(td->td_ucred, 1212 msghdr); 1213 if (error != 0) 1214 goto done2; 1215#endif 1216 if (msqkptr->u.msg_first == msqkptr->u.msg_last) { 1217 msqkptr->u.msg_first = NULL; 1218 msqkptr->u.msg_last = NULL; 1219 } else { 1220 msqkptr->u.msg_first = msghdr->msg_next; 1221 if (msqkptr->u.msg_first == NULL) 1222 panic("msg_first/last screwed up #1"); 1223 } 1224 } 1225 } else { 1226 struct msg *previous; 1227 struct msg **prev; 1228 1229 previous = NULL; 1230 prev = &(msqkptr->u.msg_first); 1231 while ((msghdr = *prev) != NULL) { 1232 /* 1233 * Is this message's type an exact match or is 1234 * this message's type less than or equal to 1235 * the absolute value of a negative msgtyp? 1236 * Note that the second half of this test can 1237 * NEVER be true if msgtyp is positive since 1238 * msg_type is always positive! 1239 */ 1240 1241 if (msgtyp == msghdr->msg_type || 1242 msghdr->msg_type <= -msgtyp) { 1243 DPRINTF(("found message type %ld, " 1244 "requested %ld\n", 1245 msghdr->msg_type, msgtyp)); 1246 if (msgsz < msghdr->msg_ts && 1247 (msgflg & MSG_NOERROR) == 0) { 1248 DPRINTF(("requested message " 1249 "on the queue is too big " 1250 "(want %zu, got %hu)\n", 1251 msgsz, msghdr->msg_ts)); 1252 error = E2BIG; 1253 goto done2; 1254 } 1255#ifdef MAC 1256 error = mac_sysvmsq_check_msgrcv( 1257 td->td_ucred, msghdr); 1258 if (error != 0) 1259 goto done2; 1260#endif 1261 *prev = msghdr->msg_next; 1262 if (msghdr == msqkptr->u.msg_last) { 1263 if (previous == NULL) { 1264 if (prev != 1265 &msqkptr->u.msg_first) 1266 panic("msg_first/last screwed up #2"); 1267 msqkptr->u.msg_first = 1268 NULL; 1269 msqkptr->u.msg_last = 1270 NULL; 1271 } else { 1272 if (prev == 1273 &msqkptr->u.msg_first) 1274 panic("msg_first/last screwed up #3"); 1275 msqkptr->u.msg_last = 1276 previous; 1277 } 1278 } 1279 break; 1280 } 1281 previous = msghdr; 1282 prev = &(msghdr->msg_next); 1283 } 1284 } 1285 1286 /* 1287 * We've either extracted the msghdr for the appropriate 1288 * message or there isn't one. 1289 * If there is one then bail out of this loop. 1290 */ 1291 1292 if (msghdr != NULL) 1293 break; 1294 1295 /* 1296 * Hmph! No message found. Does the user want to wait? 1297 */ 1298 1299 if ((msgflg & IPC_NOWAIT) != 0) { 1300 DPRINTF(("no appropriate message found (msgtyp=%ld)\n", 1301 msgtyp)); 1302 /* The SVID says to return ENOMSG. */ 1303 error = ENOMSG; 1304 goto done2; 1305 } 1306 1307 /* 1308 * Wait for something to happen 1309 */ 1310 1311 DPRINTF(("msgrcv: goodnight\n")); 1312 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 1313 "msgrcv", 0); 1314 DPRINTF(("msgrcv: good morning (error=%d)\n", error)); 1315 1316 if (error != 0) { 1317 DPRINTF(("msgrcv: interrupted system call\n")); 1318 error = EINTR; 1319 goto done2; 1320 } 1321 1322 /* 1323 * Make sure that the msq queue still exists 1324 */ 1325 1326 if (msqkptr->u.msg_qbytes == 0 || 1327 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1328 DPRINTF(("msqid deleted\n")); 1329 error = EIDRM; 1330 goto done2; 1331 } 1332 } 1333 1334 /* 1335 * Return the message to the user. 1336 * 1337 * First, do the bookkeeping (before we risk being interrupted). 1338 */ 1339 1340 msqkptr->u.msg_cbytes -= msghdr->msg_ts; 1341 msqkptr->u.msg_qnum--; 1342 msqkptr->u.msg_lrpid = td->td_proc->p_pid; 1343 msqkptr->u.msg_rtime = time_second; 1344 1345 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1); 1346 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts); 1347 1348 /* 1349 * Make msgsz the actual amount that we'll be returning. 1350 * Note that this effectively truncates the message if it is too long 1351 * (since msgsz is never increased). 1352 */ 1353 1354 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz, 1355 msghdr->msg_ts)); 1356 if (msgsz > msghdr->msg_ts) 1357 msgsz = msghdr->msg_ts; 1358 *mtype = msghdr->msg_type; 1359 1360 /* 1361 * Return the segments to the user 1362 */ 1363 1364 next = msghdr->msg_spot; 1365 for (len = 0; len < msgsz; len += msginfo.msgssz) { 1366 size_t tlen; 1367 1368 if (msgsz - len > msginfo.msgssz) 1369 tlen = msginfo.msgssz; 1370 else 1371 tlen = msgsz - len; 1372 if (next <= -1) 1373 panic("next too low #3"); 1374 if (next >= msginfo.msgseg) 1375 panic("next out of range #3"); 1376 mtx_unlock(&msq_mtx); 1377 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen); 1378 mtx_lock(&msq_mtx); 1379 if (error != 0) { 1380 DPRINTF(("error (%d) copying out message segment\n", 1381 error)); 1382 msg_freehdr(msghdr); 1383 wakeup(msqkptr); 1384 goto done2; 1385 } 1386 msgp = (char *)msgp + tlen; 1387 next = msgmaps[next].next; 1388 } 1389 1390 /* 1391 * Done, return the actual number of bytes copied out. 1392 */ 1393 1394 msg_freehdr(msghdr); 1395 wakeup(msqkptr); 1396 td->td_retval[0] = msgsz; 1397done2: 1398 mtx_unlock(&msq_mtx); 1399 return (error); 1400} 1401 1402int 1403sys_msgrcv(td, uap) 1404 struct thread *td; 1405 register struct msgrcv_args *uap; 1406{ 1407 int error; 1408 long mtype; 1409 1410 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid, 1411 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg)); 1412 1413 if ((error = kern_msgrcv(td, uap->msqid, 1414 (char *)uap->msgp + sizeof(mtype), uap->msgsz, 1415 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1416 return (error); 1417 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0) 1418 DPRINTF(("error %d copying the message type\n", error)); 1419 return (error); 1420} 1421 1422static int 1423sysctl_msqids(SYSCTL_HANDLER_ARGS) 1424{ 1425 struct msqid_kernel tmsqk; 1426 struct prison *pr, *rpr; 1427 int error, i; 1428 1429 pr = req->td->td_ucred->cr_prison; 1430 rpr = msg_find_prison(req->td->td_ucred); 1431 error = 0; 1432 for (i = 0; i < msginfo.msgmni; i++) { 1433 mtx_lock(&msq_mtx); 1434 if (msqids[i].u.msg_qbytes == 0 || rpr == NULL || 1435 msq_prison_cansee(rpr, &msqids[i]) != 0) 1436 bzero(&tmsqk, sizeof(tmsqk)); 1437 else { 1438 tmsqk = msqids[i]; 1439 if (tmsqk.cred->cr_prison != pr) 1440 tmsqk.u.msg_perm.key = IPC_PRIVATE; 1441 } 1442 mtx_unlock(&msq_mtx); 1443 error = SYSCTL_OUT(req, &tmsqk, sizeof(tmsqk)); 1444 if (error != 0) 1445 break; 1446 } 1447 return (error); 1448} 1449 1450SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, 1451 "Maximum message size"); 1452SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0, 1453 "Number of message queue identifiers"); 1454SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0, 1455 "Maximum number of bytes in a queue"); 1456SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0, 1457 "Maximum number of messages in the system"); 1458SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0, 1459 "Size of a message segment"); 1460SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0, 1461 "Number of message segments"); 1462SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, 1463 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1464 NULL, 0, sysctl_msqids, "", 1465 "Array of struct msqid_kernel for each potential message queue"); 1466 1467static int 1468msg_prison_check(void *obj, void *data) 1469{ 1470 struct prison *pr = obj; 1471 struct prison *prpr; 1472 struct vfsoptlist *opts = data; 1473 int error, jsys; 1474 1475 /* 1476 * sysvmsg is a jailsys integer. 1477 * It must be "disable" if the parent jail is disabled. 1478 */ 1479 error = vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1480 if (error != ENOENT) { 1481 if (error != 0) 1482 return (error); 1483 switch (jsys) { 1484 case JAIL_SYS_DISABLE: 1485 break; 1486 case JAIL_SYS_NEW: 1487 case JAIL_SYS_INHERIT: 1488 prison_lock(pr->pr_parent); 1489 prpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1490 prison_unlock(pr->pr_parent); 1491 if (prpr == NULL) 1492 return (EPERM); 1493 break; 1494 default: 1495 return (EINVAL); 1496 } 1497 } 1498 1499 return (0); 1500} 1501 1502static int 1503msg_prison_set(void *obj, void *data) 1504{ 1505 struct prison *pr = obj; 1506 struct prison *tpr, *orpr, *nrpr, *trpr; 1507 struct vfsoptlist *opts = data; 1508 void *rsv; 1509 int jsys, descend; 1510 1511 /* 1512 * sysvmsg controls which jail is the root of the associated msgs (this 1513 * jail or same as the parent), or if the feature is available at all. 1514 */ 1515 if (vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)) == ENOENT) 1516 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1517 ? JAIL_SYS_INHERIT 1518 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1519 ? JAIL_SYS_DISABLE 1520 : -1; 1521 if (jsys == JAIL_SYS_DISABLE) { 1522 prison_lock(pr); 1523 orpr = osd_jail_get(pr, msg_prison_slot); 1524 if (orpr != NULL) 1525 osd_jail_del(pr, msg_prison_slot); 1526 prison_unlock(pr); 1527 if (orpr != NULL) { 1528 if (orpr == pr) 1529 msg_prison_cleanup(pr); 1530 /* Disable all child jails as well. */ 1531 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1532 prison_lock(tpr); 1533 trpr = osd_jail_get(tpr, msg_prison_slot); 1534 if (trpr != NULL) { 1535 osd_jail_del(tpr, msg_prison_slot); 1536 prison_unlock(tpr); 1537 if (trpr == tpr) 1538 msg_prison_cleanup(tpr); 1539 } else { 1540 prison_unlock(tpr); 1541 descend = 0; 1542 } 1543 } 1544 } 1545 } else if (jsys != -1) { 1546 if (jsys == JAIL_SYS_NEW) 1547 nrpr = pr; 1548 else { 1549 prison_lock(pr->pr_parent); 1550 nrpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1551 prison_unlock(pr->pr_parent); 1552 } 1553 rsv = osd_reserve(msg_prison_slot); 1554 prison_lock(pr); 1555 orpr = osd_jail_get(pr, msg_prison_slot); 1556 if (orpr != nrpr) 1557 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv, 1558 nrpr); 1559 else 1560 osd_free_reserved(rsv); 1561 prison_unlock(pr); 1562 if (orpr != nrpr) { 1563 if (orpr == pr) 1564 msg_prison_cleanup(pr); 1565 if (orpr != NULL) { 1566 /* Change child jails matching the old root, */ 1567 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1568 prison_lock(tpr); 1569 trpr = osd_jail_get(tpr, 1570 msg_prison_slot); 1571 if (trpr == orpr) { 1572 (void)osd_jail_set(tpr, 1573 msg_prison_slot, nrpr); 1574 prison_unlock(tpr); 1575 if (trpr == tpr) 1576 msg_prison_cleanup(tpr); 1577 } else { 1578 prison_unlock(tpr); 1579 descend = 0; 1580 } 1581 } 1582 } 1583 } 1584 } 1585 1586 return (0); 1587} 1588 1589static int 1590msg_prison_get(void *obj, void *data) 1591{ 1592 struct prison *pr = obj; 1593 struct prison *rpr; 1594 struct vfsoptlist *opts = data; 1595 int error, jsys; 1596 1597 /* Set sysvmsg based on the jail's root prison. */ 1598 prison_lock(pr); 1599 rpr = osd_jail_get(pr, msg_prison_slot); 1600 prison_unlock(pr); 1601 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1602 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1603 error = vfs_setopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1604 if (error == ENOENT) 1605 error = 0; 1606 return (error); 1607} 1608 1609static int 1610msg_prison_remove(void *obj, void *data __unused) 1611{ 1612 struct prison *pr = obj; 1613 struct prison *rpr; 1614 1615 prison_lock(pr); 1616 rpr = osd_jail_get(pr, msg_prison_slot); 1617 prison_unlock(pr); 1618 if (rpr == pr) 1619 msg_prison_cleanup(pr); 1620 return (0); 1621} 1622 1623static void 1624msg_prison_cleanup(struct prison *pr) 1625{ 1626 struct msqid_kernel *msqkptr; 1627 int i; 1628 1629 /* Remove any msqs that belong to this jail. */ 1630 mtx_lock(&msq_mtx); 1631 for (i = 0; i < msginfo.msgmni; i++) { 1632 msqkptr = &msqids[i]; 1633 if (msqkptr->u.msg_qbytes != 0 && 1634 msqkptr->cred != NULL && msqkptr->cred->cr_prison == pr) 1635 msq_remove(msqkptr); 1636 } 1637 mtx_unlock(&msq_mtx); 1638} 1639 1640SYSCTL_JAIL_PARAM_SYS_NODE(sysvmsg, CTLFLAG_RW, "SYSV message queues"); 1641 1642#ifdef COMPAT_FREEBSD32 1643int 1644freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap) 1645{ 1646 1647#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1648 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1649 switch (uap->which) { 1650 case 0: 1651 return (freebsd7_freebsd32_msgctl(td, 1652 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2)); 1653 case 2: 1654 return (freebsd32_msgsnd(td, 1655 (struct freebsd32_msgsnd_args *)&uap->a2)); 1656 case 3: 1657 return (freebsd32_msgrcv(td, 1658 (struct freebsd32_msgrcv_args *)&uap->a2)); 1659 default: 1660 return (sys_msgsys(td, (struct msgsys_args *)uap)); 1661 } 1662#else 1663 return (nosys(td, NULL)); 1664#endif 1665} 1666 1667#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1668 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1669int 1670freebsd7_freebsd32_msgctl(struct thread *td, 1671 struct freebsd7_freebsd32_msgctl_args *uap) 1672{ 1673 struct msqid_ds msqbuf; 1674 struct msqid_ds32_old msqbuf32; 1675 int error; 1676 1677 if (uap->cmd == IPC_SET) { 1678 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1679 if (error) 1680 return (error); 1681 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1682 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1683 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1684 CP(msqbuf32, msqbuf, msg_cbytes); 1685 CP(msqbuf32, msqbuf, msg_qnum); 1686 CP(msqbuf32, msqbuf, msg_qbytes); 1687 CP(msqbuf32, msqbuf, msg_lspid); 1688 CP(msqbuf32, msqbuf, msg_lrpid); 1689 CP(msqbuf32, msqbuf, msg_stime); 1690 CP(msqbuf32, msqbuf, msg_rtime); 1691 CP(msqbuf32, msqbuf, msg_ctime); 1692 } 1693 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1694 if (error) 1695 return (error); 1696 if (uap->cmd == IPC_STAT) { 1697 bzero(&msqbuf32, sizeof(msqbuf32)); 1698 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1699 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1700 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1701 CP(msqbuf, msqbuf32, msg_cbytes); 1702 CP(msqbuf, msqbuf32, msg_qnum); 1703 CP(msqbuf, msqbuf32, msg_qbytes); 1704 CP(msqbuf, msqbuf32, msg_lspid); 1705 CP(msqbuf, msqbuf32, msg_lrpid); 1706 CP(msqbuf, msqbuf32, msg_stime); 1707 CP(msqbuf, msqbuf32, msg_rtime); 1708 CP(msqbuf, msqbuf32, msg_ctime); 1709 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1710 } 1711 return (error); 1712} 1713#endif 1714 1715int 1716freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap) 1717{ 1718 struct msqid_ds msqbuf; 1719 struct msqid_ds32 msqbuf32; 1720 int error; 1721 1722 if (uap->cmd == IPC_SET) { 1723 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1724 if (error) 1725 return (error); 1726 freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1727 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1728 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1729 CP(msqbuf32, msqbuf, msg_cbytes); 1730 CP(msqbuf32, msqbuf, msg_qnum); 1731 CP(msqbuf32, msqbuf, msg_qbytes); 1732 CP(msqbuf32, msqbuf, msg_lspid); 1733 CP(msqbuf32, msqbuf, msg_lrpid); 1734 CP(msqbuf32, msqbuf, msg_stime); 1735 CP(msqbuf32, msqbuf, msg_rtime); 1736 CP(msqbuf32, msqbuf, msg_ctime); 1737 } 1738 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1739 if (error) 1740 return (error); 1741 if (uap->cmd == IPC_STAT) { 1742 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1743 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1744 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1745 CP(msqbuf, msqbuf32, msg_cbytes); 1746 CP(msqbuf, msqbuf32, msg_qnum); 1747 CP(msqbuf, msqbuf32, msg_qbytes); 1748 CP(msqbuf, msqbuf32, msg_lspid); 1749 CP(msqbuf, msqbuf32, msg_lrpid); 1750 CP(msqbuf, msqbuf32, msg_stime); 1751 CP(msqbuf, msqbuf32, msg_rtime); 1752 CP(msqbuf, msqbuf32, msg_ctime); 1753 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1754 } 1755 return (error); 1756} 1757 1758int 1759freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap) 1760{ 1761 const void *msgp; 1762 long mtype; 1763 int32_t mtype32; 1764 int error; 1765 1766 msgp = PTRIN(uap->msgp); 1767 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0) 1768 return (error); 1769 mtype = mtype32; 1770 return (kern_msgsnd(td, uap->msqid, 1771 (const char *)msgp + sizeof(mtype32), 1772 uap->msgsz, uap->msgflg, mtype)); 1773} 1774 1775int 1776freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap) 1777{ 1778 void *msgp; 1779 long mtype; 1780 int32_t mtype32; 1781 int error; 1782 1783 msgp = PTRIN(uap->msgp); 1784 if ((error = kern_msgrcv(td, uap->msqid, 1785 (char *)msgp + sizeof(mtype32), uap->msgsz, 1786 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1787 return (error); 1788 mtype32 = (int32_t)mtype; 1789 return (copyout(&mtype32, msgp, sizeof(mtype32))); 1790} 1791#endif 1792 1793#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1794 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1795 1796/* XXX casting to (sy_call_t *) is bogus, as usual. */ 1797static sy_call_t *msgcalls[] = { 1798 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget, 1799 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv 1800}; 1801 1802/* 1803 * Entry point for all MSG calls. 1804 */ 1805int 1806sys_msgsys(td, uap) 1807 struct thread *td; 1808 /* XXX actually varargs. */ 1809 struct msgsys_args /* { 1810 int which; 1811 int a2; 1812 int a3; 1813 int a4; 1814 int a5; 1815 int a6; 1816 } */ *uap; 1817{ 1818 int error; 1819 1820 if (uap->which < 0 || 1821 uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0])) 1822 return (EINVAL); 1823 error = (*msgcalls[uap->which])(td, &uap->a2); 1824 return (error); 1825} 1826 1827#ifndef CP 1828#define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1829#endif 1830 1831#ifndef _SYS_SYSPROTO_H_ 1832struct freebsd7_msgctl_args { 1833 int msqid; 1834 int cmd; 1835 struct msqid_ds_old *buf; 1836}; 1837#endif 1838int 1839freebsd7_msgctl(td, uap) 1840 struct thread *td; 1841 struct freebsd7_msgctl_args *uap; 1842{ 1843 struct msqid_ds_old msqold; 1844 struct msqid_ds msqbuf; 1845 int error; 1846 1847 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd, 1848 uap->buf)); 1849 if (uap->cmd == IPC_SET) { 1850 error = copyin(uap->buf, &msqold, sizeof(msqold)); 1851 if (error) 1852 return (error); 1853 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm); 1854 CP(msqold, msqbuf, msg_first); 1855 CP(msqold, msqbuf, msg_last); 1856 CP(msqold, msqbuf, msg_cbytes); 1857 CP(msqold, msqbuf, msg_qnum); 1858 CP(msqold, msqbuf, msg_qbytes); 1859 CP(msqold, msqbuf, msg_lspid); 1860 CP(msqold, msqbuf, msg_lrpid); 1861 CP(msqold, msqbuf, msg_stime); 1862 CP(msqold, msqbuf, msg_rtime); 1863 CP(msqold, msqbuf, msg_ctime); 1864 } 1865 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1866 if (error) 1867 return (error); 1868 if (uap->cmd == IPC_STAT) { 1869 bzero(&msqold, sizeof(msqold)); 1870 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm); 1871 CP(msqbuf, msqold, msg_first); 1872 CP(msqbuf, msqold, msg_last); 1873 CP(msqbuf, msqold, msg_cbytes); 1874 CP(msqbuf, msqold, msg_qnum); 1875 CP(msqbuf, msqold, msg_qbytes); 1876 CP(msqbuf, msqold, msg_lspid); 1877 CP(msqbuf, msqold, msg_lrpid); 1878 CP(msqbuf, msqold, msg_stime); 1879 CP(msqbuf, msqold, msg_rtime); 1880 CP(msqbuf, msqold, msg_ctime); 1881 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old)); 1882 } 1883 return (error); 1884} 1885 1886#undef CP 1887 1888#endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1889 COMPAT_FREEBSD7 */ 1890