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/11/sys/kern/sysv_msg.c 331643 2018-03-27 18:52:27Z dim $"); 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 | M_ZERO); 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(struct thread *td, struct msgctl_args *uap) 477{ 478 int msqid = uap->msqid; 479 int cmd = uap->cmd; 480 struct msqid_ds msqbuf; 481 int error; 482 483 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf)); 484 if (cmd == IPC_SET && 485 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0) 486 return (error); 487 error = kern_msgctl(td, msqid, cmd, &msqbuf); 488 if (cmd == IPC_STAT && error == 0) 489 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds)); 490 return (error); 491} 492 493int 494kern_msgctl(td, msqid, cmd, msqbuf) 495 struct thread *td; 496 int msqid; 497 int cmd; 498 struct msqid_ds *msqbuf; 499{ 500 int rval, error, msqix; 501 struct msqid_kernel *msqkptr; 502 struct prison *rpr; 503 504 rpr = msg_find_prison(td->td_ucred); 505 if (rpr == NULL) 506 return (ENOSYS); 507 508 msqix = IPCID_TO_IX(msqid); 509 510 if (msqix < 0 || msqix >= msginfo.msgmni) { 511 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 512 msginfo.msgmni)); 513 return (EINVAL); 514 } 515 516 msqkptr = &msqids[msqix]; 517 518 mtx_lock(&msq_mtx); 519 if (msqkptr->u.msg_qbytes == 0) { 520 DPRINTF(("no such msqid\n")); 521 error = EINVAL; 522 goto done2; 523 } 524 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 525 DPRINTF(("wrong sequence number\n")); 526 error = EINVAL; 527 goto done2; 528 } 529 530 error = msq_prison_cansee(rpr, msqkptr); 531 if (error != 0) { 532 DPRINTF(("requester can't see prison\n")); 533 goto done2; 534 } 535 536#ifdef MAC 537 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd); 538 if (error != 0) 539 goto done2; 540#endif 541 542 error = 0; 543 rval = 0; 544 545 switch (cmd) { 546 547 case IPC_RMID: 548 { 549#ifdef MAC 550 struct msg *msghdr; 551#endif 552 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 553 goto done2; 554 555#ifdef MAC 556 /* 557 * Check that the thread has MAC access permissions to 558 * individual msghdrs. Note: We need to do this in a 559 * separate loop because the actual loop alters the 560 * msq/msghdr info as it progresses, and there is no going 561 * back if half the way through we discover that the 562 * thread cannot free a certain msghdr. The msq will get 563 * into an inconsistent state. 564 */ 565 for (msghdr = msqkptr->u.msg_first; msghdr != NULL; 566 msghdr = msghdr->msg_next) { 567 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr); 568 if (error != 0) 569 goto done2; 570 } 571#endif 572 573 msq_remove(msqkptr); 574 } 575 576 break; 577 578 case IPC_SET: 579 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 580 goto done2; 581 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) { 582 error = priv_check(td, PRIV_IPC_MSGSIZE); 583 if (error) 584 goto done2; 585 } 586 if (msqbuf->msg_qbytes > msginfo.msgmnb) { 587 DPRINTF(("can't increase msg_qbytes beyond %d" 588 "(truncating)\n", msginfo.msgmnb)); 589 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ 590 } 591 if (msqbuf->msg_qbytes == 0) { 592 DPRINTF(("can't reduce msg_qbytes to 0\n")); 593 error = EINVAL; /* non-standard errno! */ 594 goto done2; 595 } 596 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */ 597 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */ 598 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) | 599 (msqbuf->msg_perm.mode & 0777); 600 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes; 601 msqkptr->u.msg_ctime = time_second; 602 break; 603 604 case IPC_STAT: 605 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 606 DPRINTF(("requester doesn't have read access\n")); 607 goto done2; 608 } 609 *msqbuf = msqkptr->u; 610 if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison) 611 msqbuf->msg_perm.key = IPC_PRIVATE; 612 break; 613 614 default: 615 DPRINTF(("invalid command %d\n", cmd)); 616 error = EINVAL; 617 goto done2; 618 } 619 620 if (error == 0) 621 td->td_retval[0] = rval; 622done2: 623 mtx_unlock(&msq_mtx); 624 return (error); 625} 626 627#ifndef _SYS_SYSPROTO_H_ 628struct msgget_args { 629 key_t key; 630 int msgflg; 631}; 632#endif 633 634int 635sys_msgget(struct thread *td, struct msgget_args *uap) 636{ 637 int msqid, error = 0; 638 int key = uap->key; 639 int msgflg = uap->msgflg; 640 struct ucred *cred = td->td_ucred; 641 struct msqid_kernel *msqkptr = NULL; 642 643 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg)); 644 645 if (msg_find_prison(cred) == NULL) 646 return (ENOSYS); 647 648 mtx_lock(&msq_mtx); 649 if (key != IPC_PRIVATE) { 650 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 651 msqkptr = &msqids[msqid]; 652 if (msqkptr->u.msg_qbytes != 0 && 653 msqkptr->cred != NULL && 654 msqkptr->cred->cr_prison == cred->cr_prison && 655 msqkptr->u.msg_perm.key == key) 656 break; 657 } 658 if (msqid < msginfo.msgmni) { 659 DPRINTF(("found public key\n")); 660 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { 661 DPRINTF(("not exclusive\n")); 662 error = EEXIST; 663 goto done2; 664 } 665 if ((error = ipcperm(td, &msqkptr->u.msg_perm, 666 msgflg & 0700))) { 667 DPRINTF(("requester doesn't have 0%o access\n", 668 msgflg & 0700)); 669 goto done2; 670 } 671#ifdef MAC 672 error = mac_sysvmsq_check_msqget(cred, msqkptr); 673 if (error != 0) 674 goto done2; 675#endif 676 goto found; 677 } 678 } 679 680 DPRINTF(("need to allocate the msqid_ds\n")); 681 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { 682 for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 683 /* 684 * Look for an unallocated and unlocked msqid_ds. 685 * msqid_ds's can be locked by msgsnd or msgrcv while 686 * they are copying the message in/out. We can't 687 * re-use the entry until they release it. 688 */ 689 msqkptr = &msqids[msqid]; 690 if (msqkptr->u.msg_qbytes == 0 && 691 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0) 692 break; 693 } 694 if (msqid == msginfo.msgmni) { 695 DPRINTF(("no more msqid_ds's available\n")); 696 error = ENOSPC; 697 goto done2; 698 } 699#ifdef RACCT 700 if (racct_enable) { 701 PROC_LOCK(td->td_proc); 702 error = racct_add(td->td_proc, RACCT_NMSGQ, 1); 703 PROC_UNLOCK(td->td_proc); 704 if (error != 0) { 705 error = ENOSPC; 706 goto done2; 707 } 708 } 709#endif 710 DPRINTF(("msqid %d is available\n", msqid)); 711 msqkptr->u.msg_perm.key = key; 712 msqkptr->u.msg_perm.cuid = cred->cr_uid; 713 msqkptr->u.msg_perm.uid = cred->cr_uid; 714 msqkptr->u.msg_perm.cgid = cred->cr_gid; 715 msqkptr->u.msg_perm.gid = cred->cr_gid; 716 msqkptr->u.msg_perm.mode = (msgflg & 0777); 717 msqkptr->cred = crhold(cred); 718 /* Make sure that the returned msqid is unique */ 719 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff; 720 msqkptr->u.msg_first = NULL; 721 msqkptr->u.msg_last = NULL; 722 msqkptr->u.msg_cbytes = 0; 723 msqkptr->u.msg_qnum = 0; 724 msqkptr->u.msg_qbytes = msginfo.msgmnb; 725 msqkptr->u.msg_lspid = 0; 726 msqkptr->u.msg_lrpid = 0; 727 msqkptr->u.msg_stime = 0; 728 msqkptr->u.msg_rtime = 0; 729 msqkptr->u.msg_ctime = time_second; 730#ifdef MAC 731 mac_sysvmsq_create(cred, msqkptr); 732#endif 733 } else { 734 DPRINTF(("didn't find it and wasn't asked to create it\n")); 735 error = ENOENT; 736 goto done2; 737 } 738 739found: 740 /* Construct the unique msqid */ 741 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm); 742done2: 743 mtx_unlock(&msq_mtx); 744 return (error); 745} 746 747#ifndef _SYS_SYSPROTO_H_ 748struct msgsnd_args { 749 int msqid; 750 const void *msgp; /* XXX msgp is actually mtext. */ 751 size_t msgsz; 752 int msgflg; 753}; 754#endif 755int 756kern_msgsnd(struct thread *td, int msqid, const void *msgp, 757 size_t msgsz, int msgflg, long mtype) 758{ 759 int msqix, segs_needed, error = 0; 760 struct msqid_kernel *msqkptr; 761 struct msg *msghdr; 762 struct prison *rpr; 763 short next; 764#ifdef RACCT 765 size_t saved_msgsz; 766#endif 767 768 rpr = msg_find_prison(td->td_ucred); 769 if (rpr == NULL) 770 return (ENOSYS); 771 772 mtx_lock(&msq_mtx); 773 msqix = IPCID_TO_IX(msqid); 774 775 if (msqix < 0 || msqix >= msginfo.msgmni) { 776 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 777 msginfo.msgmni)); 778 error = EINVAL; 779 goto done2; 780 } 781 782 msqkptr = &msqids[msqix]; 783 if (msqkptr->u.msg_qbytes == 0) { 784 DPRINTF(("no such message queue id\n")); 785 error = EINVAL; 786 goto done2; 787 } 788 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 789 DPRINTF(("wrong sequence number\n")); 790 error = EINVAL; 791 goto done2; 792 } 793 794 if ((error = msq_prison_cansee(rpr, msqkptr))) { 795 DPRINTF(("requester can't see prison\n")); 796 goto done2; 797 } 798 799 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) { 800 DPRINTF(("requester doesn't have write access\n")); 801 goto done2; 802 } 803 804#ifdef MAC 805 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr); 806 if (error != 0) 807 goto done2; 808#endif 809 810#ifdef RACCT 811 if (racct_enable) { 812 PROC_LOCK(td->td_proc); 813 if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) { 814 PROC_UNLOCK(td->td_proc); 815 error = EAGAIN; 816 goto done2; 817 } 818 saved_msgsz = msgsz; 819 if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) { 820 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 821 PROC_UNLOCK(td->td_proc); 822 error = EAGAIN; 823 goto done2; 824 } 825 PROC_UNLOCK(td->td_proc); 826 } 827#endif 828 829 segs_needed = howmany(msgsz, msginfo.msgssz); 830 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz, 831 msginfo.msgssz, segs_needed)); 832 for (;;) { 833 int need_more_resources = 0; 834 835 /* 836 * check msgsz 837 * (inside this loop in case msg_qbytes changes while we sleep) 838 */ 839 840 if (msgsz > msqkptr->u.msg_qbytes) { 841 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n")); 842 error = EINVAL; 843 goto done3; 844 } 845 846 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) { 847 DPRINTF(("msqid is locked\n")); 848 need_more_resources = 1; 849 } 850 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) { 851 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n")); 852 need_more_resources = 1; 853 } 854 if (segs_needed > nfree_msgmaps) { 855 DPRINTF(("segs_needed > nfree_msgmaps\n")); 856 need_more_resources = 1; 857 } 858 if (free_msghdrs == NULL) { 859 DPRINTF(("no more msghdrs\n")); 860 need_more_resources = 1; 861 } 862 863 if (need_more_resources) { 864 int we_own_it; 865 866 if ((msgflg & IPC_NOWAIT) != 0) { 867 DPRINTF(("need more resources but caller " 868 "doesn't want to wait\n")); 869 error = EAGAIN; 870 goto done3; 871 } 872 873 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) { 874 DPRINTF(("we don't own the msqid_ds\n")); 875 we_own_it = 0; 876 } else { 877 /* Force later arrivals to wait for our 878 request */ 879 DPRINTF(("we own the msqid_ds\n")); 880 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 881 we_own_it = 1; 882 } 883 DPRINTF(("msgsnd: goodnight\n")); 884 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 885 "msgsnd", hz); 886 DPRINTF(("msgsnd: good morning, error=%d\n", error)); 887 if (we_own_it) 888 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 889 if (error == EWOULDBLOCK) { 890 DPRINTF(("msgsnd: timed out\n")); 891 continue; 892 } 893 if (error != 0) { 894 DPRINTF(("msgsnd: interrupted system call\n")); 895 error = EINTR; 896 goto done3; 897 } 898 899 /* 900 * Make sure that the msq queue still exists 901 */ 902 903 if (msqkptr->u.msg_qbytes == 0) { 904 DPRINTF(("msqid deleted\n")); 905 error = EIDRM; 906 goto done3; 907 } 908 909 } else { 910 DPRINTF(("got all the resources that we need\n")); 911 break; 912 } 913 } 914 915 /* 916 * We have the resources that we need. 917 * Make sure! 918 */ 919 920 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) 921 panic("msg_perm.mode & MSG_LOCKED"); 922 if (segs_needed > nfree_msgmaps) 923 panic("segs_needed > nfree_msgmaps"); 924 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) 925 panic("msgsz + msg_cbytes > msg_qbytes"); 926 if (free_msghdrs == NULL) 927 panic("no more msghdrs"); 928 929 /* 930 * Re-lock the msqid_ds in case we page-fault when copying in the 931 * message 932 */ 933 934 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 935 panic("msqid_ds is already locked"); 936 msqkptr->u.msg_perm.mode |= MSG_LOCKED; 937 938 /* 939 * Allocate a message header 940 */ 941 942 msghdr = free_msghdrs; 943 free_msghdrs = msghdr->msg_next; 944 msghdr->msg_spot = -1; 945 msghdr->msg_ts = msgsz; 946 msghdr->msg_type = mtype; 947#ifdef MAC 948 /* 949 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here 950 * immediately? Or, should it be checked just before the msg is 951 * enqueued in the msgq (as it is done now)? 952 */ 953 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr); 954#endif 955 956 /* 957 * Allocate space for the message 958 */ 959 960 while (segs_needed > 0) { 961 if (nfree_msgmaps <= 0) 962 panic("not enough msgmaps"); 963 if (free_msgmaps == -1) 964 panic("nil free_msgmaps"); 965 next = free_msgmaps; 966 if (next <= -1) 967 panic("next too low #1"); 968 if (next >= msginfo.msgseg) 969 panic("next out of range #1"); 970 DPRINTF(("allocating segment %d to message\n", next)); 971 free_msgmaps = msgmaps[next].next; 972 nfree_msgmaps--; 973 msgmaps[next].next = msghdr->msg_spot; 974 msghdr->msg_spot = next; 975 segs_needed--; 976 } 977 978 /* 979 * Validate the message type 980 */ 981 982 if (msghdr->msg_type < 1) { 983 msg_freehdr(msghdr); 984 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 985 wakeup(msqkptr); 986 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type)); 987 error = EINVAL; 988 goto done3; 989 } 990 991 /* 992 * Copy in the message body 993 */ 994 995 next = msghdr->msg_spot; 996 while (msgsz > 0) { 997 size_t tlen; 998 if (msgsz > msginfo.msgssz) 999 tlen = msginfo.msgssz; 1000 else 1001 tlen = msgsz; 1002 if (next <= -1) 1003 panic("next too low #2"); 1004 if (next >= msginfo.msgseg) 1005 panic("next out of range #2"); 1006 mtx_unlock(&msq_mtx); 1007 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz], 1008 tlen)) != 0) { 1009 mtx_lock(&msq_mtx); 1010 DPRINTF(("error %d copying in message segment\n", 1011 error)); 1012 msg_freehdr(msghdr); 1013 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1014 wakeup(msqkptr); 1015 goto done3; 1016 } 1017 mtx_lock(&msq_mtx); 1018 msgsz -= tlen; 1019 msgp = (const char *)msgp + tlen; 1020 next = msgmaps[next].next; 1021 } 1022 if (next != -1) 1023 panic("didn't use all the msg segments"); 1024 1025 /* 1026 * We've got the message. Unlock the msqid_ds. 1027 */ 1028 1029 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 1030 1031 /* 1032 * Make sure that the msqid_ds is still allocated. 1033 */ 1034 1035 if (msqkptr->u.msg_qbytes == 0) { 1036 msg_freehdr(msghdr); 1037 wakeup(msqkptr); 1038 error = EIDRM; 1039 goto done3; 1040 } 1041 1042#ifdef MAC 1043 /* 1044 * Note: Since the task/thread allocates the msghdr and usually 1045 * primes it with its own MAC label, for a majority of policies, it 1046 * won't be necessary to check whether the msghdr has access 1047 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would 1048 * suffice in that case. However, this hook may be required where 1049 * individual policies derive a non-identical label for the msghdr 1050 * from the current thread label and may want to check the msghdr 1051 * enqueue permissions, along with read/write permissions to the 1052 * msgq. 1053 */ 1054 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr); 1055 if (error != 0) { 1056 msg_freehdr(msghdr); 1057 wakeup(msqkptr); 1058 goto done3; 1059 } 1060#endif 1061 1062 /* 1063 * Put the message into the queue 1064 */ 1065 if (msqkptr->u.msg_first == NULL) { 1066 msqkptr->u.msg_first = msghdr; 1067 msqkptr->u.msg_last = msghdr; 1068 } else { 1069 msqkptr->u.msg_last->msg_next = msghdr; 1070 msqkptr->u.msg_last = msghdr; 1071 } 1072 msqkptr->u.msg_last->msg_next = NULL; 1073 1074 msqkptr->u.msg_cbytes += msghdr->msg_ts; 1075 msqkptr->u.msg_qnum++; 1076 msqkptr->u.msg_lspid = td->td_proc->p_pid; 1077 msqkptr->u.msg_stime = time_second; 1078 1079 wakeup(msqkptr); 1080 td->td_retval[0] = 0; 1081done3: 1082#ifdef RACCT 1083 if (racct_enable && error != 0) { 1084 PROC_LOCK(td->td_proc); 1085 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1); 1086 racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz); 1087 PROC_UNLOCK(td->td_proc); 1088 } 1089#endif 1090done2: 1091 mtx_unlock(&msq_mtx); 1092 return (error); 1093} 1094 1095int 1096sys_msgsnd(struct thread *td, struct msgsnd_args *uap) 1097{ 1098 int error; 1099 long mtype; 1100 1101 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp, 1102 uap->msgsz, uap->msgflg)); 1103 1104 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) { 1105 DPRINTF(("error %d copying the message type\n", error)); 1106 return (error); 1107 } 1108 return (kern_msgsnd(td, uap->msqid, 1109 (const char *)uap->msgp + sizeof(mtype), 1110 uap->msgsz, uap->msgflg, mtype)); 1111} 1112 1113#ifndef _SYS_SYSPROTO_H_ 1114struct msgrcv_args { 1115 int msqid; 1116 void *msgp; 1117 size_t msgsz; 1118 long msgtyp; 1119 int msgflg; 1120}; 1121#endif 1122/* XXX msgp is actually mtext. */ 1123int 1124kern_msgrcv(struct thread *td, int msqid, void *msgp, size_t msgsz, long msgtyp, 1125 int msgflg, long *mtype) 1126{ 1127 size_t len; 1128 struct msqid_kernel *msqkptr; 1129 struct msg *msghdr; 1130 struct prison *rpr; 1131 int msqix, error = 0; 1132 short next; 1133 1134 rpr = msg_find_prison(td->td_ucred); 1135 if (rpr == NULL) 1136 return (ENOSYS); 1137 1138 msqix = IPCID_TO_IX(msqid); 1139 1140 if (msqix < 0 || msqix >= msginfo.msgmni) { 1141 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 1142 msginfo.msgmni)); 1143 return (EINVAL); 1144 } 1145 1146 msqkptr = &msqids[msqix]; 1147 mtx_lock(&msq_mtx); 1148 if (msqkptr->u.msg_qbytes == 0) { 1149 DPRINTF(("no such message queue id\n")); 1150 error = EINVAL; 1151 goto done2; 1152 } 1153 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1154 DPRINTF(("wrong sequence number\n")); 1155 error = EINVAL; 1156 goto done2; 1157 } 1158 1159 if ((error = msq_prison_cansee(rpr, msqkptr))) { 1160 DPRINTF(("requester can't see prison\n")); 1161 goto done2; 1162 } 1163 1164 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 1165 DPRINTF(("requester doesn't have read access\n")); 1166 goto done2; 1167 } 1168 1169#ifdef MAC 1170 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr); 1171 if (error != 0) 1172 goto done2; 1173#endif 1174 1175 msghdr = NULL; 1176 while (msghdr == NULL) { 1177 if (msgtyp == 0) { 1178 msghdr = msqkptr->u.msg_first; 1179 if (msghdr != NULL) { 1180 if (msgsz < msghdr->msg_ts && 1181 (msgflg & MSG_NOERROR) == 0) { 1182 DPRINTF(("first message on the queue " 1183 "is too big (want %zu, got %d)\n", 1184 msgsz, msghdr->msg_ts)); 1185 error = E2BIG; 1186 goto done2; 1187 } 1188#ifdef MAC 1189 error = mac_sysvmsq_check_msgrcv(td->td_ucred, 1190 msghdr); 1191 if (error != 0) 1192 goto done2; 1193#endif 1194 if (msqkptr->u.msg_first == msqkptr->u.msg_last) { 1195 msqkptr->u.msg_first = NULL; 1196 msqkptr->u.msg_last = NULL; 1197 } else { 1198 msqkptr->u.msg_first = msghdr->msg_next; 1199 if (msqkptr->u.msg_first == NULL) 1200 panic("msg_first/last screwed up #1"); 1201 } 1202 } 1203 } else { 1204 struct msg *previous; 1205 struct msg **prev; 1206 1207 previous = NULL; 1208 prev = &(msqkptr->u.msg_first); 1209 while ((msghdr = *prev) != NULL) { 1210 /* 1211 * Is this message's type an exact match or is 1212 * this message's type less than or equal to 1213 * the absolute value of a negative msgtyp? 1214 * Note that the second half of this test can 1215 * NEVER be true if msgtyp is positive since 1216 * msg_type is always positive! 1217 */ 1218 1219 if (msgtyp == msghdr->msg_type || 1220 msghdr->msg_type <= -msgtyp) { 1221 DPRINTF(("found message type %ld, " 1222 "requested %ld\n", 1223 msghdr->msg_type, msgtyp)); 1224 if (msgsz < msghdr->msg_ts && 1225 (msgflg & MSG_NOERROR) == 0) { 1226 DPRINTF(("requested message " 1227 "on the queue is too big " 1228 "(want %zu, got %hu)\n", 1229 msgsz, msghdr->msg_ts)); 1230 error = E2BIG; 1231 goto done2; 1232 } 1233#ifdef MAC 1234 error = mac_sysvmsq_check_msgrcv( 1235 td->td_ucred, msghdr); 1236 if (error != 0) 1237 goto done2; 1238#endif 1239 *prev = msghdr->msg_next; 1240 if (msghdr == msqkptr->u.msg_last) { 1241 if (previous == NULL) { 1242 if (prev != 1243 &msqkptr->u.msg_first) 1244 panic("msg_first/last screwed up #2"); 1245 msqkptr->u.msg_first = 1246 NULL; 1247 msqkptr->u.msg_last = 1248 NULL; 1249 } else { 1250 if (prev == 1251 &msqkptr->u.msg_first) 1252 panic("msg_first/last screwed up #3"); 1253 msqkptr->u.msg_last = 1254 previous; 1255 } 1256 } 1257 break; 1258 } 1259 previous = msghdr; 1260 prev = &(msghdr->msg_next); 1261 } 1262 } 1263 1264 /* 1265 * We've either extracted the msghdr for the appropriate 1266 * message or there isn't one. 1267 * If there is one then bail out of this loop. 1268 */ 1269 1270 if (msghdr != NULL) 1271 break; 1272 1273 /* 1274 * Hmph! No message found. Does the user want to wait? 1275 */ 1276 1277 if ((msgflg & IPC_NOWAIT) != 0) { 1278 DPRINTF(("no appropriate message found (msgtyp=%ld)\n", 1279 msgtyp)); 1280 /* The SVID says to return ENOMSG. */ 1281 error = ENOMSG; 1282 goto done2; 1283 } 1284 1285 /* 1286 * Wait for something to happen 1287 */ 1288 1289 DPRINTF(("msgrcv: goodnight\n")); 1290 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 1291 "msgrcv", 0); 1292 DPRINTF(("msgrcv: good morning (error=%d)\n", error)); 1293 1294 if (error != 0) { 1295 DPRINTF(("msgrcv: interrupted system call\n")); 1296 error = EINTR; 1297 goto done2; 1298 } 1299 1300 /* 1301 * Make sure that the msq queue still exists 1302 */ 1303 1304 if (msqkptr->u.msg_qbytes == 0 || 1305 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1306 DPRINTF(("msqid deleted\n")); 1307 error = EIDRM; 1308 goto done2; 1309 } 1310 } 1311 1312 /* 1313 * Return the message to the user. 1314 * 1315 * First, do the bookkeeping (before we risk being interrupted). 1316 */ 1317 1318 msqkptr->u.msg_cbytes -= msghdr->msg_ts; 1319 msqkptr->u.msg_qnum--; 1320 msqkptr->u.msg_lrpid = td->td_proc->p_pid; 1321 msqkptr->u.msg_rtime = time_second; 1322 1323 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1); 1324 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts); 1325 1326 /* 1327 * Make msgsz the actual amount that we'll be returning. 1328 * Note that this effectively truncates the message if it is too long 1329 * (since msgsz is never increased). 1330 */ 1331 1332 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz, 1333 msghdr->msg_ts)); 1334 if (msgsz > msghdr->msg_ts) 1335 msgsz = msghdr->msg_ts; 1336 *mtype = msghdr->msg_type; 1337 1338 /* 1339 * Return the segments to the user 1340 */ 1341 1342 next = msghdr->msg_spot; 1343 for (len = 0; len < msgsz; len += msginfo.msgssz) { 1344 size_t tlen; 1345 1346 if (msgsz - len > msginfo.msgssz) 1347 tlen = msginfo.msgssz; 1348 else 1349 tlen = msgsz - len; 1350 if (next <= -1) 1351 panic("next too low #3"); 1352 if (next >= msginfo.msgseg) 1353 panic("next out of range #3"); 1354 mtx_unlock(&msq_mtx); 1355 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen); 1356 mtx_lock(&msq_mtx); 1357 if (error != 0) { 1358 DPRINTF(("error (%d) copying out message segment\n", 1359 error)); 1360 msg_freehdr(msghdr); 1361 wakeup(msqkptr); 1362 goto done2; 1363 } 1364 msgp = (char *)msgp + tlen; 1365 next = msgmaps[next].next; 1366 } 1367 1368 /* 1369 * Done, return the actual number of bytes copied out. 1370 */ 1371 1372 msg_freehdr(msghdr); 1373 wakeup(msqkptr); 1374 td->td_retval[0] = msgsz; 1375done2: 1376 mtx_unlock(&msq_mtx); 1377 return (error); 1378} 1379 1380int 1381sys_msgrcv(struct thread *td, struct msgrcv_args *uap) 1382{ 1383 int error; 1384 long mtype; 1385 1386 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid, 1387 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg)); 1388 1389 if ((error = kern_msgrcv(td, uap->msqid, 1390 (char *)uap->msgp + sizeof(mtype), uap->msgsz, 1391 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1392 return (error); 1393 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0) 1394 DPRINTF(("error %d copying the message type\n", error)); 1395 return (error); 1396} 1397 1398static int 1399sysctl_msqids(SYSCTL_HANDLER_ARGS) 1400{ 1401 struct msqid_kernel tmsqk; 1402#ifdef COMPAT_FREEBSD32 1403 struct msqid_kernel32 tmsqk32; 1404#endif 1405 struct prison *pr, *rpr; 1406 void *outaddr; 1407 size_t outsize; 1408 int error, i; 1409 1410 pr = req->td->td_ucred->cr_prison; 1411 rpr = msg_find_prison(req->td->td_ucred); 1412 error = 0; 1413 for (i = 0; i < msginfo.msgmni; i++) { 1414 mtx_lock(&msq_mtx); 1415 if (msqids[i].u.msg_qbytes == 0 || rpr == NULL || 1416 msq_prison_cansee(rpr, &msqids[i]) != 0) 1417 bzero(&tmsqk, sizeof(tmsqk)); 1418 else { 1419 tmsqk = msqids[i]; 1420 if (tmsqk.cred->cr_prison != pr) 1421 tmsqk.u.msg_perm.key = IPC_PRIVATE; 1422 } 1423 mtx_unlock(&msq_mtx); 1424#ifdef COMPAT_FREEBSD32 1425 if (SV_CURPROC_FLAG(SV_ILP32)) { 1426 bzero(&tmsqk32, sizeof(tmsqk32)); 1427 freebsd32_ipcperm_out(&tmsqk.u.msg_perm, 1428 &tmsqk32.u.msg_perm); 1429 /* Don't copy u.msg_first or u.msg_last */ 1430 CP(tmsqk, tmsqk32, u.msg_cbytes); 1431 CP(tmsqk, tmsqk32, u.msg_qnum); 1432 CP(tmsqk, tmsqk32, u.msg_qbytes); 1433 CP(tmsqk, tmsqk32, u.msg_lspid); 1434 CP(tmsqk, tmsqk32, u.msg_lrpid); 1435 CP(tmsqk, tmsqk32, u.msg_stime); 1436 CP(tmsqk, tmsqk32, u.msg_rtime); 1437 CP(tmsqk, tmsqk32, u.msg_ctime); 1438 /* Don't copy label or cred */ 1439 outaddr = &tmsqk32; 1440 outsize = sizeof(tmsqk32); 1441 } else 1442#endif 1443 { 1444 /* Don't leak kernel pointers */ 1445 tmsqk.u.msg_first = NULL; 1446 tmsqk.u.msg_last = NULL; 1447 tmsqk.label = NULL; 1448 tmsqk.cred = NULL; 1449 /* 1450 * XXX: some padding also exists, but we take care to 1451 * allocate our pool of msqid_kernel structs with 1452 * zeroed memory so this should be OK. 1453 */ 1454 outaddr = &tmsqk; 1455 outsize = sizeof(tmsqk); 1456 } 1457 error = SYSCTL_OUT(req, outaddr, outsize); 1458 if (error != 0) 1459 break; 1460 } 1461 return (error); 1462} 1463 1464SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, 1465 "Maximum message size"); 1466SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0, 1467 "Number of message queue identifiers"); 1468SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0, 1469 "Maximum number of bytes in a queue"); 1470SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0, 1471 "Maximum number of messages in the system"); 1472SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0, 1473 "Size of a message segment"); 1474SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0, 1475 "Number of message segments"); 1476SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, 1477 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1478 NULL, 0, sysctl_msqids, "", 1479 "Array of struct msqid_kernel for each potential message queue"); 1480 1481static int 1482msg_prison_check(void *obj, void *data) 1483{ 1484 struct prison *pr = obj; 1485 struct prison *prpr; 1486 struct vfsoptlist *opts = data; 1487 int error, jsys; 1488 1489 /* 1490 * sysvmsg is a jailsys integer. 1491 * It must be "disable" if the parent jail is disabled. 1492 */ 1493 error = vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1494 if (error != ENOENT) { 1495 if (error != 0) 1496 return (error); 1497 switch (jsys) { 1498 case JAIL_SYS_DISABLE: 1499 break; 1500 case JAIL_SYS_NEW: 1501 case JAIL_SYS_INHERIT: 1502 prison_lock(pr->pr_parent); 1503 prpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1504 prison_unlock(pr->pr_parent); 1505 if (prpr == NULL) 1506 return (EPERM); 1507 break; 1508 default: 1509 return (EINVAL); 1510 } 1511 } 1512 1513 return (0); 1514} 1515 1516static int 1517msg_prison_set(void *obj, void *data) 1518{ 1519 struct prison *pr = obj; 1520 struct prison *tpr, *orpr, *nrpr, *trpr; 1521 struct vfsoptlist *opts = data; 1522 void *rsv; 1523 int jsys, descend; 1524 1525 /* 1526 * sysvmsg controls which jail is the root of the associated msgs (this 1527 * jail or same as the parent), or if the feature is available at all. 1528 */ 1529 if (vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)) == ENOENT) 1530 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1531 ? JAIL_SYS_INHERIT 1532 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1533 ? JAIL_SYS_DISABLE 1534 : -1; 1535 if (jsys == JAIL_SYS_DISABLE) { 1536 prison_lock(pr); 1537 orpr = osd_jail_get(pr, msg_prison_slot); 1538 if (orpr != NULL) 1539 osd_jail_del(pr, msg_prison_slot); 1540 prison_unlock(pr); 1541 if (orpr != NULL) { 1542 if (orpr == pr) 1543 msg_prison_cleanup(pr); 1544 /* Disable all child jails as well. */ 1545 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1546 prison_lock(tpr); 1547 trpr = osd_jail_get(tpr, msg_prison_slot); 1548 if (trpr != NULL) { 1549 osd_jail_del(tpr, msg_prison_slot); 1550 prison_unlock(tpr); 1551 if (trpr == tpr) 1552 msg_prison_cleanup(tpr); 1553 } else { 1554 prison_unlock(tpr); 1555 descend = 0; 1556 } 1557 } 1558 } 1559 } else if (jsys != -1) { 1560 if (jsys == JAIL_SYS_NEW) 1561 nrpr = pr; 1562 else { 1563 prison_lock(pr->pr_parent); 1564 nrpr = osd_jail_get(pr->pr_parent, msg_prison_slot); 1565 prison_unlock(pr->pr_parent); 1566 } 1567 rsv = osd_reserve(msg_prison_slot); 1568 prison_lock(pr); 1569 orpr = osd_jail_get(pr, msg_prison_slot); 1570 if (orpr != nrpr) 1571 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv, 1572 nrpr); 1573 else 1574 osd_free_reserved(rsv); 1575 prison_unlock(pr); 1576 if (orpr != nrpr) { 1577 if (orpr == pr) 1578 msg_prison_cleanup(pr); 1579 if (orpr != NULL) { 1580 /* Change child jails matching the old root, */ 1581 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1582 prison_lock(tpr); 1583 trpr = osd_jail_get(tpr, 1584 msg_prison_slot); 1585 if (trpr == orpr) { 1586 (void)osd_jail_set(tpr, 1587 msg_prison_slot, nrpr); 1588 prison_unlock(tpr); 1589 if (trpr == tpr) 1590 msg_prison_cleanup(tpr); 1591 } else { 1592 prison_unlock(tpr); 1593 descend = 0; 1594 } 1595 } 1596 } 1597 } 1598 } 1599 1600 return (0); 1601} 1602 1603static int 1604msg_prison_get(void *obj, void *data) 1605{ 1606 struct prison *pr = obj; 1607 struct prison *rpr; 1608 struct vfsoptlist *opts = data; 1609 int error, jsys; 1610 1611 /* Set sysvmsg based on the jail's root prison. */ 1612 prison_lock(pr); 1613 rpr = osd_jail_get(pr, msg_prison_slot); 1614 prison_unlock(pr); 1615 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1616 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1617 error = vfs_setopt(opts, "sysvmsg", &jsys, sizeof(jsys)); 1618 if (error == ENOENT) 1619 error = 0; 1620 return (error); 1621} 1622 1623static int 1624msg_prison_remove(void *obj, void *data __unused) 1625{ 1626 struct prison *pr = obj; 1627 struct prison *rpr; 1628 1629 prison_lock(pr); 1630 rpr = osd_jail_get(pr, msg_prison_slot); 1631 prison_unlock(pr); 1632 if (rpr == pr) 1633 msg_prison_cleanup(pr); 1634 return (0); 1635} 1636 1637static void 1638msg_prison_cleanup(struct prison *pr) 1639{ 1640 struct msqid_kernel *msqkptr; 1641 int i; 1642 1643 /* Remove any msqs that belong to this jail. */ 1644 mtx_lock(&msq_mtx); 1645 for (i = 0; i < msginfo.msgmni; i++) { 1646 msqkptr = &msqids[i]; 1647 if (msqkptr->u.msg_qbytes != 0 && 1648 msqkptr->cred != NULL && msqkptr->cred->cr_prison == pr) 1649 msq_remove(msqkptr); 1650 } 1651 mtx_unlock(&msq_mtx); 1652} 1653 1654SYSCTL_JAIL_PARAM_SYS_NODE(sysvmsg, CTLFLAG_RW, "SYSV message queues"); 1655 1656#ifdef COMPAT_FREEBSD32 1657int 1658freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap) 1659{ 1660 1661#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1662 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1663 switch (uap->which) { 1664 case 0: 1665 return (freebsd7_freebsd32_msgctl(td, 1666 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2)); 1667 case 2: 1668 return (freebsd32_msgsnd(td, 1669 (struct freebsd32_msgsnd_args *)&uap->a2)); 1670 case 3: 1671 return (freebsd32_msgrcv(td, 1672 (struct freebsd32_msgrcv_args *)&uap->a2)); 1673 default: 1674 return (sys_msgsys(td, (struct msgsys_args *)uap)); 1675 } 1676#else 1677 return (nosys(td, NULL)); 1678#endif 1679} 1680 1681#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1682 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1683int 1684freebsd7_freebsd32_msgctl(struct thread *td, 1685 struct freebsd7_freebsd32_msgctl_args *uap) 1686{ 1687 struct msqid_ds msqbuf; 1688 struct msqid_ds32_old msqbuf32; 1689 int error; 1690 1691 if (uap->cmd == IPC_SET) { 1692 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1693 if (error) 1694 return (error); 1695 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1696 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1697 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1698 CP(msqbuf32, msqbuf, msg_cbytes); 1699 CP(msqbuf32, msqbuf, msg_qnum); 1700 CP(msqbuf32, msqbuf, msg_qbytes); 1701 CP(msqbuf32, msqbuf, msg_lspid); 1702 CP(msqbuf32, msqbuf, msg_lrpid); 1703 CP(msqbuf32, msqbuf, msg_stime); 1704 CP(msqbuf32, msqbuf, msg_rtime); 1705 CP(msqbuf32, msqbuf, msg_ctime); 1706 } 1707 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1708 if (error) 1709 return (error); 1710 if (uap->cmd == IPC_STAT) { 1711 bzero(&msqbuf32, sizeof(msqbuf32)); 1712 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1713 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1714 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1715 CP(msqbuf, msqbuf32, msg_cbytes); 1716 CP(msqbuf, msqbuf32, msg_qnum); 1717 CP(msqbuf, msqbuf32, msg_qbytes); 1718 CP(msqbuf, msqbuf32, msg_lspid); 1719 CP(msqbuf, msqbuf32, msg_lrpid); 1720 CP(msqbuf, msqbuf32, msg_stime); 1721 CP(msqbuf, msqbuf32, msg_rtime); 1722 CP(msqbuf, msqbuf32, msg_ctime); 1723 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1724 } 1725 return (error); 1726} 1727#endif 1728 1729int 1730freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap) 1731{ 1732 struct msqid_ds msqbuf; 1733 struct msqid_ds32 msqbuf32; 1734 int error; 1735 1736 if (uap->cmd == IPC_SET) { 1737 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32)); 1738 if (error) 1739 return (error); 1740 freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm); 1741 PTRIN_CP(msqbuf32, msqbuf, msg_first); 1742 PTRIN_CP(msqbuf32, msqbuf, msg_last); 1743 CP(msqbuf32, msqbuf, msg_cbytes); 1744 CP(msqbuf32, msqbuf, msg_qnum); 1745 CP(msqbuf32, msqbuf, msg_qbytes); 1746 CP(msqbuf32, msqbuf, msg_lspid); 1747 CP(msqbuf32, msqbuf, msg_lrpid); 1748 CP(msqbuf32, msqbuf, msg_stime); 1749 CP(msqbuf32, msqbuf, msg_rtime); 1750 CP(msqbuf32, msqbuf, msg_ctime); 1751 } 1752 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1753 if (error) 1754 return (error); 1755 if (uap->cmd == IPC_STAT) { 1756 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm); 1757 PTROUT_CP(msqbuf, msqbuf32, msg_first); 1758 PTROUT_CP(msqbuf, msqbuf32, msg_last); 1759 CP(msqbuf, msqbuf32, msg_cbytes); 1760 CP(msqbuf, msqbuf32, msg_qnum); 1761 CP(msqbuf, msqbuf32, msg_qbytes); 1762 CP(msqbuf, msqbuf32, msg_lspid); 1763 CP(msqbuf, msqbuf32, msg_lrpid); 1764 CP(msqbuf, msqbuf32, msg_stime); 1765 CP(msqbuf, msqbuf32, msg_rtime); 1766 CP(msqbuf, msqbuf32, msg_ctime); 1767 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32)); 1768 } 1769 return (error); 1770} 1771 1772int 1773freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap) 1774{ 1775 const void *msgp; 1776 long mtype; 1777 int32_t mtype32; 1778 int error; 1779 1780 msgp = PTRIN(uap->msgp); 1781 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0) 1782 return (error); 1783 mtype = mtype32; 1784 return (kern_msgsnd(td, uap->msqid, 1785 (const char *)msgp + sizeof(mtype32), 1786 uap->msgsz, uap->msgflg, mtype)); 1787} 1788 1789int 1790freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap) 1791{ 1792 void *msgp; 1793 long mtype; 1794 int32_t mtype32; 1795 int error; 1796 1797 msgp = PTRIN(uap->msgp); 1798 if ((error = kern_msgrcv(td, uap->msqid, 1799 (char *)msgp + sizeof(mtype32), uap->msgsz, 1800 uap->msgtyp, uap->msgflg, &mtype)) != 0) 1801 return (error); 1802 mtype32 = (int32_t)mtype; 1803 return (copyout(&mtype32, msgp, sizeof(mtype32))); 1804} 1805#endif 1806 1807#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1808 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1809 1810/* XXX casting to (sy_call_t *) is bogus, as usual. */ 1811static sy_call_t *msgcalls[] = { 1812 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget, 1813 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv 1814}; 1815 1816/* 1817 * Entry point for all MSG calls. 1818 * 1819 * XXX actually varargs. 1820 * struct msgsys_args { 1821 * int which; 1822 * int a2; 1823 * int a3; 1824 * int a4; 1825 * int a5; 1826 * int a6; 1827 * } *uap; 1828 */ 1829int 1830sys_msgsys(struct thread *td, struct msgsys_args *uap) 1831{ 1832 int error; 1833 1834 if (uap->which < 0 || uap->which >= nitems(msgcalls)) 1835 return (EINVAL); 1836 error = (*msgcalls[uap->which])(td, &uap->a2); 1837 return (error); 1838} 1839 1840#ifndef CP 1841#define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1842#endif 1843 1844#ifndef _SYS_SYSPROTO_H_ 1845struct freebsd7_msgctl_args { 1846 int msqid; 1847 int cmd; 1848 struct msqid_ds_old *buf; 1849}; 1850#endif 1851int 1852freebsd7_msgctl(struct thread *td, struct freebsd7_msgctl_args *uap) 1853{ 1854 struct msqid_ds_old msqold; 1855 struct msqid_ds msqbuf; 1856 int error; 1857 1858 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd, 1859 uap->buf)); 1860 if (uap->cmd == IPC_SET) { 1861 error = copyin(uap->buf, &msqold, sizeof(msqold)); 1862 if (error) 1863 return (error); 1864 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm); 1865 CP(msqold, msqbuf, msg_first); 1866 CP(msqold, msqbuf, msg_last); 1867 CP(msqold, msqbuf, msg_cbytes); 1868 CP(msqold, msqbuf, msg_qnum); 1869 CP(msqold, msqbuf, msg_qbytes); 1870 CP(msqold, msqbuf, msg_lspid); 1871 CP(msqold, msqbuf, msg_lrpid); 1872 CP(msqold, msqbuf, msg_stime); 1873 CP(msqold, msqbuf, msg_rtime); 1874 CP(msqold, msqbuf, msg_ctime); 1875 } 1876 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf); 1877 if (error) 1878 return (error); 1879 if (uap->cmd == IPC_STAT) { 1880 bzero(&msqold, sizeof(msqold)); 1881 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm); 1882 CP(msqbuf, msqold, msg_first); 1883 CP(msqbuf, msqold, msg_last); 1884 CP(msqbuf, msqold, msg_cbytes); 1885 CP(msqbuf, msqold, msg_qnum); 1886 CP(msqbuf, msqold, msg_qbytes); 1887 CP(msqbuf, msqold, msg_lspid); 1888 CP(msqbuf, msqold, msg_lrpid); 1889 CP(msqbuf, msqold, msg_stime); 1890 CP(msqbuf, msqold, msg_rtime); 1891 CP(msqbuf, msqold, msg_ctime); 1892 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old)); 1893 } 1894 return (error); 1895} 1896 1897#undef CP 1898 1899#endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1900 COMPAT_FREEBSD7 */ 1901