sysv_msg.c revision 192895
1139804Simp/*- 22729Sdfr * Implementation of SVID messages 32729Sdfr * 42729Sdfr * Author: Daniel Boulet 52729Sdfr * 62729Sdfr * Copyright 1993 Daniel Boulet and RTMX Inc. 72729Sdfr * 82729Sdfr * This system call was implemented by Daniel Boulet under contract from RTMX. 92729Sdfr * 102729Sdfr * Redistribution and use in source forms, with and without modification, 112729Sdfr * are permitted provided that this entire comment appears intact. 122729Sdfr * 132729Sdfr * Redistribution in binary form may occur without any restrictions. 142729Sdfr * Obviously, it would be nice if you gave credit where credit is due 152729Sdfr * but requiring it would be too onerous. 162729Sdfr * 172729Sdfr * This software is provided ``AS IS'' without any warranties of any kind. 182729Sdfr */ 19140614Srwatson/*- 20140614Srwatson * Copyright (c) 2003-2005 McAfee, Inc. 21140614Srwatson * All rights reserved. 22140614Srwatson * 23140614Srwatson * This software was developed for the FreeBSD Project in part by McAfee 24140614Srwatson * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR 25140614Srwatson * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research 26140614Srwatson * program. 27140614Srwatson * 28140614Srwatson * Redistribution and use in source and binary forms, with or without 29140614Srwatson * modification, are permitted provided that the following conditions 30140614Srwatson * are met: 31140614Srwatson * 1. Redistributions of source code must retain the above copyright 32140614Srwatson * notice, this list of conditions and the following disclaimer. 33140614Srwatson * 2. Redistributions in binary form must reproduce the above copyright 34140614Srwatson * notice, this list of conditions and the following disclaimer in the 35140614Srwatson * documentation and/or other materials provided with the distribution. 36140614Srwatson * 37140614Srwatson * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 38140614Srwatson * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39140614Srwatson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 40140614Srwatson * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 41140614Srwatson * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 42140614Srwatson * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 43140614Srwatson * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44140614Srwatson * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 45140614Srwatson * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 46140614Srwatson * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 47140614Srwatson * SUCH DAMAGE. 48140614Srwatson */ 492729Sdfr 50116182Sobrien#include <sys/cdefs.h> 51116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/sysv_msg.c 192895 2009-05-27 14:11:23Z jamie $"); 52116182Sobrien 5359839Speter#include "opt_sysvipc.h" 54140614Srwatson#include "opt_mac.h" 5559839Speter 562729Sdfr#include <sys/param.h> 572729Sdfr#include <sys/systm.h> 5811626Sbde#include <sys/sysproto.h> 592729Sdfr#include <sys/kernel.h> 60164033Srwatson#include <sys/priv.h> 612729Sdfr#include <sys/proc.h> 6282607Sdillon#include <sys/lock.h> 6382607Sdillon#include <sys/mutex.h> 64129882Sphk#include <sys/module.h> 652729Sdfr#include <sys/msg.h> 6669449Salfred#include <sys/syscall.h> 67140839Ssobomax#include <sys/syscallsubr.h> 6811626Sbde#include <sys/sysent.h> 6959839Speter#include <sys/sysctl.h> 7059839Speter#include <sys/malloc.h> 7168024Srwatson#include <sys/jail.h> 722729Sdfr 73163606Srwatson#include <security/mac/mac_framework.h> 74163606Srwatson 7559839Speterstatic MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues"); 7659839Speter 7792723Salfredstatic void msginit(void); 7892723Salfredstatic int msgunload(void); 7992723Salfredstatic int sysvmsg_modload(struct module *, int, void *); 8010358Sjulian 81100523Salfred#ifdef MSG_DEBUG 82100523Salfred#define DPRINTF(a) printf a 83100523Salfred#else 84100523Salfred#define DPRINTF(a) 85100523Salfred#endif 862729Sdfr 8792723Salfredstatic void msg_freehdr(struct msg *msghdr); 882729Sdfr 8911626Sbde/* XXX casting to (sy_call_t *) is bogus, as usual. */ 9012819Sphkstatic sy_call_t *msgcalls[] = { 9111626Sbde (sy_call_t *)msgctl, (sy_call_t *)msgget, 9211626Sbde (sy_call_t *)msgsnd, (sy_call_t *)msgrcv 9311626Sbde}; 942729Sdfr 9559839Speter#ifndef MSGSSZ 9659839Speter#define MSGSSZ 8 /* Each segment must be 2^N long */ 9759839Speter#endif 9859839Speter#ifndef MSGSEG 9959839Speter#define MSGSEG 2048 /* must be less than 32767 */ 10059839Speter#endif 10159839Speter#define MSGMAX (MSGSSZ*MSGSEG) 10259839Speter#ifndef MSGMNB 10359839Speter#define MSGMNB 2048 /* max # of bytes in a queue */ 10459839Speter#endif 10559839Speter#ifndef MSGMNI 10659839Speter#define MSGMNI 40 10759839Speter#endif 10859839Speter#ifndef MSGTQL 10959839Speter#define MSGTQL 40 11059839Speter#endif 11159839Speter 11259839Speter/* 11359839Speter * Based on the configuration parameters described in an SVR2 (yes, two) 11459839Speter * config(1m) man page. 11559839Speter * 11659839Speter * Each message is broken up and stored in segments that are msgssz bytes 11759839Speter * long. For efficiency reasons, this should be a power of two. Also, 11859839Speter * it doesn't make sense if it is less than 8 or greater than about 256. 11959839Speter * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 12059839Speter * two between 8 and 1024 inclusive (and panic's if it isn't). 12159839Speter */ 12259839Speterstruct msginfo msginfo = { 12359839Speter MSGMAX, /* max chars in a message */ 12459839Speter MSGMNI, /* # of message queue identifiers */ 12559839Speter MSGMNB, /* max chars in a queue */ 12659839Speter MSGTQL, /* max messages in system */ 12759839Speter MSGSSZ, /* size of a message segment */ 12859839Speter /* (must be small power of 2 greater than 4) */ 12959839Speter MSGSEG /* number of message segments */ 13059839Speter}; 13159839Speter 13259839Speter/* 13359839Speter * macros to convert between msqid_ds's and msqid's. 13459839Speter * (specific to this implementation) 13559839Speter */ 13659839Speter#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000)) 13759839Speter#define MSQID_IX(id) ((id) & 0xffff) 13859839Speter#define MSQID_SEQ(id) (((id) >> 16) & 0xffff) 13959839Speter 14059839Speter/* 14159839Speter * The rest of this file is specific to this particular implementation. 14259839Speter */ 14359839Speter 14459839Speterstruct msgmap { 14559839Speter short next; /* next segment in buffer */ 14659839Speter /* -1 -> available */ 14759839Speter /* 0..(MSGSEG-1) -> index of next segment */ 14859839Speter}; 14959839Speter 15059839Speter#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */ 15159839Speter 15212819Sphkstatic int nfree_msgmaps; /* # of free map entries */ 15312819Sphkstatic short free_msgmaps; /* head of linked list of free map entries */ 15459839Speterstatic struct msg *free_msghdrs;/* list of free msg headers */ 15559839Speterstatic char *msgpool; /* MSGMAX byte long msg buffer pool */ 15659839Speterstatic struct msgmap *msgmaps; /* MSGSEG msgmap structures */ 15759839Speterstatic struct msg *msghdrs; /* MSGTQL msg headers */ 158137613Srwatsonstatic struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */ 159101772Salfredstatic struct mtx msq_mtx; /* global mutex for message queues. */ 1602729Sdfr 16159839Speterstatic void 16269449Salfredmsginit() 1632729Sdfr{ 1642729Sdfr register int i; 1652729Sdfr 16683765Smr TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg); 16783765Smr TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz); 16883765Smr msginfo.msgmax = msginfo.msgseg * msginfo.msgssz; 16983765Smr TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni); 170139436Srwatson TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb); 171139436Srwatson TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql); 17283765Smr 173111119Simp msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK); 17459839Speter if (msgpool == NULL) 17559839Speter panic("msgpool is NULL"); 176111119Simp msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); 17759839Speter if (msgmaps == NULL) 17859839Speter panic("msgmaps is NULL"); 179111119Simp msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); 18059839Speter if (msghdrs == NULL) 18159839Speter panic("msghdrs is NULL"); 182137613Srwatson msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG, 183137613Srwatson M_WAITOK); 18459839Speter if (msqids == NULL) 18559839Speter panic("msqids is NULL"); 18659839Speter 1872729Sdfr /* 1882729Sdfr * msginfo.msgssz should be a power of two for efficiency reasons. 1892729Sdfr * It is also pretty silly if msginfo.msgssz is less than 8 1902729Sdfr * or greater than about 256 so ... 1912729Sdfr */ 1922729Sdfr 1932729Sdfr i = 8; 1942729Sdfr while (i < 1024 && i != msginfo.msgssz) 1952729Sdfr i <<= 1; 1962729Sdfr if (i != msginfo.msgssz) { 197100523Salfred DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz, 198100523Salfred msginfo.msgssz)); 1992729Sdfr panic("msginfo.msgssz not a small power of 2"); 2002729Sdfr } 2012729Sdfr 2022729Sdfr if (msginfo.msgseg > 32767) { 203100523Salfred DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg)); 2042729Sdfr panic("msginfo.msgseg > 32767"); 2052729Sdfr } 2062729Sdfr 2072729Sdfr if (msgmaps == NULL) 2082729Sdfr panic("msgmaps is NULL"); 2092729Sdfr 2102729Sdfr for (i = 0; i < msginfo.msgseg; i++) { 2112729Sdfr if (i > 0) 2122729Sdfr msgmaps[i-1].next = i; 2132729Sdfr msgmaps[i].next = -1; /* implies entry is available */ 2142729Sdfr } 2152729Sdfr free_msgmaps = 0; 2162729Sdfr nfree_msgmaps = msginfo.msgseg; 2172729Sdfr 2182729Sdfr if (msghdrs == NULL) 2192729Sdfr panic("msghdrs is NULL"); 2202729Sdfr 2212729Sdfr for (i = 0; i < msginfo.msgtql; i++) { 2222729Sdfr msghdrs[i].msg_type = 0; 2232729Sdfr if (i > 0) 2242729Sdfr msghdrs[i-1].msg_next = &msghdrs[i]; 2252729Sdfr msghdrs[i].msg_next = NULL; 226140614Srwatson#ifdef MAC 227172930Srwatson mac_sysvmsg_init(&msghdrs[i]); 228140614Srwatson#endif 2292729Sdfr } 2302729Sdfr free_msghdrs = &msghdrs[0]; 2312729Sdfr 2322729Sdfr if (msqids == NULL) 2332729Sdfr panic("msqids is NULL"); 2342729Sdfr 2352729Sdfr for (i = 0; i < msginfo.msgmni; i++) { 236137613Srwatson msqids[i].u.msg_qbytes = 0; /* implies entry is available */ 237137613Srwatson msqids[i].u.msg_perm.seq = 0; /* reset to a known value */ 238137613Srwatson msqids[i].u.msg_perm.mode = 0; 239140614Srwatson#ifdef MAC 240172930Srwatson mac_sysvmsq_init(&msqids[i]); 241140614Srwatson#endif 2422729Sdfr } 243101772Salfred mtx_init(&msq_mtx, "msq", NULL, MTX_DEF); 2442729Sdfr} 2452729Sdfr 24669449Salfredstatic int 24769449Salfredmsgunload() 24869449Salfred{ 249137613Srwatson struct msqid_kernel *msqkptr; 25069449Salfred int msqid; 251140614Srwatson#ifdef MAC 252140614Srwatson int i; 253140614Srwatson#endif 25469449Salfred 25569449Salfred for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 25669449Salfred /* 25769449Salfred * Look for an unallocated and unlocked msqid_ds. 25869449Salfred * msqid_ds's can be locked by msgsnd or msgrcv while 25969449Salfred * they are copying the message in/out. We can't 26069449Salfred * re-use the entry until they release it. 26169449Salfred */ 262137613Srwatson msqkptr = &msqids[msqid]; 263137613Srwatson if (msqkptr->u.msg_qbytes != 0 || 264137613Srwatson (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 26569449Salfred break; 26669449Salfred } 26769449Salfred if (msqid != msginfo.msgmni) 26869449Salfred return (EBUSY); 26969449Salfred 270140614Srwatson#ifdef MAC 271140614Srwatson for (i = 0; i < msginfo.msgtql; i++) 272172930Srwatson mac_sysvmsg_destroy(&msghdrs[i]); 273140614Srwatson for (msqid = 0; msqid < msginfo.msgmni; msqid++) 274172930Srwatson mac_sysvmsq_destroy(&msqids[msqid]); 275140614Srwatson#endif 27669449Salfred free(msgpool, M_MSG); 27769449Salfred free(msgmaps, M_MSG); 27869449Salfred free(msghdrs, M_MSG); 27969449Salfred free(msqids, M_MSG); 280101772Salfred mtx_destroy(&msq_mtx); 28169449Salfred return (0); 28269449Salfred} 28369449Salfred 28469449Salfred 28569449Salfredstatic int 28669449Salfredsysvmsg_modload(struct module *module, int cmd, void *arg) 28769449Salfred{ 28869449Salfred int error = 0; 28969449Salfred 29069449Salfred switch (cmd) { 29169449Salfred case MOD_LOAD: 29269449Salfred msginit(); 29369449Salfred break; 29469449Salfred case MOD_UNLOAD: 29569449Salfred error = msgunload(); 29669449Salfred break; 29769449Salfred case MOD_SHUTDOWN: 29869449Salfred break; 29969449Salfred default: 30069449Salfred error = EINVAL; 30169449Salfred break; 30269449Salfred } 30369449Salfred return (error); 30469449Salfred} 30569449Salfred 30671038Sdesstatic moduledata_t sysvmsg_mod = { 30771038Sdes "sysvmsg", 30869449Salfred &sysvmsg_modload, 30969449Salfred NULL 31069449Salfred}; 31169449Salfred 31288633SalfredSYSCALL_MODULE_HELPER(msgsys); 31388633SalfredSYSCALL_MODULE_HELPER(msgctl); 31488633SalfredSYSCALL_MODULE_HELPER(msgget); 31588633SalfredSYSCALL_MODULE_HELPER(msgsnd); 31688633SalfredSYSCALL_MODULE_HELPER(msgrcv); 31769449Salfred 31871038SdesDECLARE_MODULE(sysvmsg, sysvmsg_mod, 31969449Salfred SI_SUB_SYSV_MSG, SI_ORDER_FIRST); 32071038SdesMODULE_VERSION(sysvmsg, 1); 32169449Salfred 3222729Sdfr/* 323167211Srwatson * Entry point for all MSG calls. 3242729Sdfr */ 3252729Sdfrint 32683366Sjulianmsgsys(td, uap) 32783366Sjulian struct thread *td; 32811626Sbde /* XXX actually varargs. */ 32911626Sbde struct msgsys_args /* { 330118615Snectar int which; 33111626Sbde int a2; 33211626Sbde int a3; 33311626Sbde int a4; 33411626Sbde int a5; 33511626Sbde int a6; 33611626Sbde } */ *uap; 3372729Sdfr{ 33882607Sdillon int error; 3392729Sdfr 340192895Sjamie if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) 34191703Sjhb return (ENOSYS); 342118615Snectar if (uap->which < 0 || 343118615Snectar uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0])) 34491703Sjhb return (EINVAL); 34583366Sjulian error = (*msgcalls[uap->which])(td, &uap->a2); 34682607Sdillon return (error); 3472729Sdfr} 3482729Sdfr 3492729Sdfrstatic void 3502729Sdfrmsg_freehdr(msghdr) 3512729Sdfr struct msg *msghdr; 3522729Sdfr{ 3532729Sdfr while (msghdr->msg_ts > 0) { 3542729Sdfr short next; 3552729Sdfr if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg) 3562729Sdfr panic("msghdr->msg_spot out of range"); 3572729Sdfr next = msgmaps[msghdr->msg_spot].next; 3582729Sdfr msgmaps[msghdr->msg_spot].next = free_msgmaps; 3592729Sdfr free_msgmaps = msghdr->msg_spot; 3602729Sdfr nfree_msgmaps++; 3612729Sdfr msghdr->msg_spot = next; 3622729Sdfr if (msghdr->msg_ts >= msginfo.msgssz) 3632729Sdfr msghdr->msg_ts -= msginfo.msgssz; 3642729Sdfr else 3652729Sdfr msghdr->msg_ts = 0; 3662729Sdfr } 3672729Sdfr if (msghdr->msg_spot != -1) 3682729Sdfr panic("msghdr->msg_spot != -1"); 3692729Sdfr msghdr->msg_next = free_msghdrs; 3702729Sdfr free_msghdrs = msghdr; 371140614Srwatson#ifdef MAC 372172930Srwatson mac_sysvmsg_cleanup(msghdr); 373140614Srwatson#endif 3742729Sdfr} 3752729Sdfr 37612866Speter#ifndef _SYS_SYSPROTO_H_ 3772729Sdfrstruct msgctl_args { 3782729Sdfr int msqid; 3792729Sdfr int cmd; 38012866Speter struct msqid_ds *buf; 3812729Sdfr}; 38212866Speter#endif 38312866Speterint 38483366Sjulianmsgctl(td, uap) 38583366Sjulian struct thread *td; 3862729Sdfr register struct msgctl_args *uap; 3872729Sdfr{ 3882729Sdfr int msqid = uap->msqid; 3892729Sdfr int cmd = uap->cmd; 3902729Sdfr struct msqid_ds msqbuf; 391140839Ssobomax int error; 392140839Ssobomax 393165403Sjkim DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf)); 394140839Ssobomax if (cmd == IPC_SET && 395140839Ssobomax (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0) 396140839Ssobomax return (error); 397141471Sjhb error = kern_msgctl(td, msqid, cmd, &msqbuf); 398140839Ssobomax if (cmd == IPC_STAT && error == 0) 399141471Sjhb error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds)); 400140839Ssobomax return (error); 401140839Ssobomax} 402140839Ssobomax 403140839Ssobomaxint 404141471Sjhbkern_msgctl(td, msqid, cmd, msqbuf) 405140839Ssobomax struct thread *td; 406140839Ssobomax int msqid; 407140839Ssobomax int cmd; 408140839Ssobomax struct msqid_ds *msqbuf; 409140839Ssobomax{ 410140839Ssobomax int rval, error, msqix; 411137613Srwatson register struct msqid_kernel *msqkptr; 4122729Sdfr 413192895Sjamie if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) 41491703Sjhb return (ENOSYS); 41591703Sjhb 416140839Ssobomax msqix = IPCID_TO_IX(msqid); 4172729Sdfr 418140839Ssobomax if (msqix < 0 || msqix >= msginfo.msgmni) { 419140839Ssobomax DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 420100523Salfred msginfo.msgmni)); 421101772Salfred return (EINVAL); 4222729Sdfr } 4232729Sdfr 424140839Ssobomax msqkptr = &msqids[msqix]; 4252729Sdfr 426101772Salfred mtx_lock(&msq_mtx); 427137613Srwatson if (msqkptr->u.msg_qbytes == 0) { 428100523Salfred DPRINTF(("no such msqid\n")); 42982607Sdillon error = EINVAL; 43082607Sdillon goto done2; 4312729Sdfr } 432140839Ssobomax if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 433100523Salfred DPRINTF(("wrong sequence number\n")); 43482607Sdillon error = EINVAL; 43582607Sdillon goto done2; 4362729Sdfr } 437140614Srwatson#ifdef MAC 438172930Srwatson error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd); 439162468Srwatson if (error != 0) 440140614Srwatson goto done2; 441140614Srwatson#endif 4422729Sdfr 44382607Sdillon error = 0; 4442729Sdfr rval = 0; 4452729Sdfr 4462729Sdfr switch (cmd) { 4472729Sdfr 4482729Sdfr case IPC_RMID: 4492729Sdfr { 4502729Sdfr struct msg *msghdr; 451137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 45282607Sdillon goto done2; 453137613Srwatson 454140614Srwatson#ifdef MAC 455140614Srwatson /* 456140614Srwatson * Check that the thread has MAC access permissions to 457140614Srwatson * individual msghdrs. Note: We need to do this in a 458140614Srwatson * separate loop because the actual loop alters the 459140614Srwatson * msq/msghdr info as it progresses, and there is no going 460140614Srwatson * back if half the way through we discover that the 461140614Srwatson * thread cannot free a certain msghdr. The msq will get 462140614Srwatson * into an inconsistent state. 463140614Srwatson */ 464140614Srwatson for (msghdr = msqkptr->u.msg_first; msghdr != NULL; 465140614Srwatson msghdr = msghdr->msg_next) { 466172930Srwatson error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr); 467162468Srwatson if (error != 0) 468140614Srwatson goto done2; 469140614Srwatson } 470140614Srwatson#endif 471140614Srwatson 4722729Sdfr /* Free the message headers */ 473137613Srwatson msghdr = msqkptr->u.msg_first; 4742729Sdfr while (msghdr != NULL) { 4752729Sdfr struct msg *msghdr_tmp; 4762729Sdfr 4772729Sdfr /* Free the segments of each message */ 478137613Srwatson msqkptr->u.msg_cbytes -= msghdr->msg_ts; 479137613Srwatson msqkptr->u.msg_qnum--; 4802729Sdfr msghdr_tmp = msghdr; 4812729Sdfr msghdr = msghdr->msg_next; 4822729Sdfr msg_freehdr(msghdr_tmp); 4832729Sdfr } 4842729Sdfr 485137613Srwatson if (msqkptr->u.msg_cbytes != 0) 4862729Sdfr panic("msg_cbytes is screwed up"); 487137613Srwatson if (msqkptr->u.msg_qnum != 0) 4882729Sdfr panic("msg_qnum is screwed up"); 4892729Sdfr 490137613Srwatson msqkptr->u.msg_qbytes = 0; /* Mark it as free */ 4912729Sdfr 492140614Srwatson#ifdef MAC 493172930Srwatson mac_sysvmsq_cleanup(msqkptr); 494140614Srwatson#endif 495140614Srwatson 496137613Srwatson wakeup(msqkptr); 4972729Sdfr } 4982729Sdfr 4992729Sdfr break; 5002729Sdfr 5012729Sdfr case IPC_SET: 502137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M))) 50382607Sdillon goto done2; 504140839Ssobomax if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) { 505170587Srwatson error = priv_check(td, PRIV_IPC_MSGSIZE); 50682607Sdillon if (error) 50782607Sdillon goto done2; 50843426Sphk } 509140839Ssobomax if (msqbuf->msg_qbytes > msginfo.msgmnb) { 510100523Salfred DPRINTF(("can't increase msg_qbytes beyond %d" 511100523Salfred "(truncating)\n", msginfo.msgmnb)); 512140839Ssobomax msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ 5132729Sdfr } 514140839Ssobomax if (msqbuf->msg_qbytes == 0) { 515100523Salfred DPRINTF(("can't reduce msg_qbytes to 0\n")); 51682607Sdillon error = EINVAL; /* non-standard errno! */ 51782607Sdillon goto done2; 5182729Sdfr } 519140839Ssobomax msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */ 520140839Ssobomax msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */ 521137613Srwatson msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) | 522140839Ssobomax (msqbuf->msg_perm.mode & 0777); 523140839Ssobomax msqkptr->u.msg_qbytes = msqbuf->msg_qbytes; 524137613Srwatson msqkptr->u.msg_ctime = time_second; 5252729Sdfr break; 5262729Sdfr 5272729Sdfr case IPC_STAT: 528137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 529100523Salfred DPRINTF(("requester doesn't have read access\n")); 53082607Sdillon goto done2; 5312729Sdfr } 532141471Sjhb *msqbuf = msqkptr->u; 5332729Sdfr break; 5342729Sdfr 5352729Sdfr default: 536100523Salfred DPRINTF(("invalid command %d\n", cmd)); 53782607Sdillon error = EINVAL; 53882607Sdillon goto done2; 5392729Sdfr } 5402729Sdfr 54182607Sdillon if (error == 0) 54283366Sjulian td->td_retval[0] = rval; 54382607Sdillondone2: 544101772Salfred mtx_unlock(&msq_mtx); 545141471Sjhb return (error); 5462729Sdfr} 5472729Sdfr 54812866Speter#ifndef _SYS_SYSPROTO_H_ 5492729Sdfrstruct msgget_args { 5502729Sdfr key_t key; 5512729Sdfr int msgflg; 5522729Sdfr}; 55312866Speter#endif 55412866Speterint 55583366Sjulianmsgget(td, uap) 55683366Sjulian struct thread *td; 5572729Sdfr register struct msgget_args *uap; 5582729Sdfr{ 55982607Sdillon int msqid, error = 0; 5602729Sdfr int key = uap->key; 5612729Sdfr int msgflg = uap->msgflg; 56291703Sjhb struct ucred *cred = td->td_ucred; 563137613Srwatson register struct msqid_kernel *msqkptr = NULL; 5642729Sdfr 565100523Salfred DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg)); 5662729Sdfr 567192895Sjamie if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) 56891703Sjhb return (ENOSYS); 56991703Sjhb 570101772Salfred mtx_lock(&msq_mtx); 5712729Sdfr if (key != IPC_PRIVATE) { 5722729Sdfr for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 573137613Srwatson msqkptr = &msqids[msqid]; 574137613Srwatson if (msqkptr->u.msg_qbytes != 0 && 575137613Srwatson msqkptr->u.msg_perm.key == key) 5762729Sdfr break; 5772729Sdfr } 5782729Sdfr if (msqid < msginfo.msgmni) { 579100523Salfred DPRINTF(("found public key\n")); 5802729Sdfr if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { 581100523Salfred DPRINTF(("not exclusive\n")); 58282607Sdillon error = EEXIST; 58382607Sdillon goto done2; 5842729Sdfr } 585137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, 586137613Srwatson msgflg & 0700))) { 587100523Salfred DPRINTF(("requester doesn't have 0%o access\n", 588100523Salfred msgflg & 0700)); 58982607Sdillon goto done2; 5902729Sdfr } 591140614Srwatson#ifdef MAC 592172930Srwatson error = mac_sysvmsq_check_msqget(cred, msqkptr); 593162468Srwatson if (error != 0) 594140614Srwatson goto done2; 595140614Srwatson#endif 5962729Sdfr goto found; 5972729Sdfr } 5982729Sdfr } 5992729Sdfr 600100523Salfred DPRINTF(("need to allocate the msqid_ds\n")); 6012729Sdfr if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { 6022729Sdfr for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 6032729Sdfr /* 6042729Sdfr * Look for an unallocated and unlocked msqid_ds. 6052729Sdfr * msqid_ds's can be locked by msgsnd or msgrcv while 6062729Sdfr * they are copying the message in/out. We can't 6072729Sdfr * re-use the entry until they release it. 6082729Sdfr */ 609137613Srwatson msqkptr = &msqids[msqid]; 610137613Srwatson if (msqkptr->u.msg_qbytes == 0 && 611137613Srwatson (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0) 6122729Sdfr break; 6132729Sdfr } 6142729Sdfr if (msqid == msginfo.msgmni) { 615100523Salfred DPRINTF(("no more msqid_ds's available\n")); 61682607Sdillon error = ENOSPC; 61782607Sdillon goto done2; 6182729Sdfr } 619100523Salfred DPRINTF(("msqid %d is available\n", msqid)); 620137613Srwatson msqkptr->u.msg_perm.key = key; 621137613Srwatson msqkptr->u.msg_perm.cuid = cred->cr_uid; 622137613Srwatson msqkptr->u.msg_perm.uid = cred->cr_uid; 623137613Srwatson msqkptr->u.msg_perm.cgid = cred->cr_gid; 624137613Srwatson msqkptr->u.msg_perm.gid = cred->cr_gid; 625137613Srwatson msqkptr->u.msg_perm.mode = (msgflg & 0777); 6262729Sdfr /* Make sure that the returned msqid is unique */ 627137613Srwatson msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff; 628137613Srwatson msqkptr->u.msg_first = NULL; 629137613Srwatson msqkptr->u.msg_last = NULL; 630137613Srwatson msqkptr->u.msg_cbytes = 0; 631137613Srwatson msqkptr->u.msg_qnum = 0; 632137613Srwatson msqkptr->u.msg_qbytes = msginfo.msgmnb; 633137613Srwatson msqkptr->u.msg_lspid = 0; 634137613Srwatson msqkptr->u.msg_lrpid = 0; 635137613Srwatson msqkptr->u.msg_stime = 0; 636137613Srwatson msqkptr->u.msg_rtime = 0; 637137613Srwatson msqkptr->u.msg_ctime = time_second; 638140614Srwatson#ifdef MAC 639172930Srwatson mac_sysvmsq_create(cred, msqkptr); 640140614Srwatson#endif 6412729Sdfr } else { 642100523Salfred DPRINTF(("didn't find it and wasn't asked to create it\n")); 64382607Sdillon error = ENOENT; 64482607Sdillon goto done2; 6452729Sdfr } 6462729Sdfr 6472729Sdfrfound: 6482729Sdfr /* Construct the unique msqid */ 649137613Srwatson td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm); 65082607Sdillondone2: 651101772Salfred mtx_unlock(&msq_mtx); 65282607Sdillon return (error); 6532729Sdfr} 6542729Sdfr 65512866Speter#ifndef _SYS_SYSPROTO_H_ 6562729Sdfrstruct msgsnd_args { 6572729Sdfr int msqid; 658109895Salfred const void *msgp; 6592729Sdfr size_t msgsz; 6602729Sdfr int msgflg; 6612729Sdfr}; 66212866Speter#endif 66312866Speterint 664165403Sjkimkern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype) 66583366Sjulian struct thread *td; 666165403Sjkim int msqid; 667165403Sjkim const void *msgp; /* XXX msgp is actually mtext. */ 668165403Sjkim size_t msgsz; 669165403Sjkim int msgflg; 670165403Sjkim long mtype; 6712729Sdfr{ 672165403Sjkim int msqix, segs_needed, error = 0; 673137613Srwatson register struct msqid_kernel *msqkptr; 6742729Sdfr register struct msg *msghdr; 6752729Sdfr short next; 6762729Sdfr 677192895Sjamie if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) 67891703Sjhb return (ENOSYS); 67991703Sjhb 680101772Salfred mtx_lock(&msq_mtx); 681165403Sjkim msqix = IPCID_TO_IX(msqid); 6822729Sdfr 683165403Sjkim if (msqix < 0 || msqix >= msginfo.msgmni) { 684165403Sjkim DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 685100523Salfred msginfo.msgmni)); 68682607Sdillon error = EINVAL; 68782607Sdillon goto done2; 6882729Sdfr } 6892729Sdfr 690165403Sjkim msqkptr = &msqids[msqix]; 691137613Srwatson if (msqkptr->u.msg_qbytes == 0) { 692100523Salfred DPRINTF(("no such message queue id\n")); 69382607Sdillon error = EINVAL; 69482607Sdillon goto done2; 6952729Sdfr } 696165403Sjkim if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 697100523Salfred DPRINTF(("wrong sequence number\n")); 69882607Sdillon error = EINVAL; 69982607Sdillon goto done2; 7002729Sdfr } 7012729Sdfr 702137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) { 703100523Salfred DPRINTF(("requester doesn't have write access\n")); 70482607Sdillon goto done2; 7052729Sdfr } 7062729Sdfr 707140614Srwatson#ifdef MAC 708172930Srwatson error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr); 709162468Srwatson if (error != 0) 710140614Srwatson goto done2; 711140614Srwatson#endif 712140614Srwatson 7132729Sdfr segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz; 714165403Sjkim DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz, 715165403Sjkim msginfo.msgssz, segs_needed)); 7162729Sdfr for (;;) { 7172729Sdfr int need_more_resources = 0; 7182729Sdfr 7192729Sdfr /* 7202729Sdfr * check msgsz 7212729Sdfr * (inside this loop in case msg_qbytes changes while we sleep) 7222729Sdfr */ 7232729Sdfr 724137613Srwatson if (msgsz > msqkptr->u.msg_qbytes) { 725137613Srwatson DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n")); 72682607Sdillon error = EINVAL; 72782607Sdillon goto done2; 7282729Sdfr } 7292729Sdfr 730137613Srwatson if (msqkptr->u.msg_perm.mode & MSG_LOCKED) { 731100523Salfred DPRINTF(("msqid is locked\n")); 7322729Sdfr need_more_resources = 1; 7332729Sdfr } 734137613Srwatson if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) { 735100523Salfred DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n")); 7362729Sdfr need_more_resources = 1; 7372729Sdfr } 7382729Sdfr if (segs_needed > nfree_msgmaps) { 739100523Salfred DPRINTF(("segs_needed > nfree_msgmaps\n")); 7402729Sdfr need_more_resources = 1; 7412729Sdfr } 7422729Sdfr if (free_msghdrs == NULL) { 743100523Salfred DPRINTF(("no more msghdrs\n")); 7442729Sdfr need_more_resources = 1; 7452729Sdfr } 7462729Sdfr 7472729Sdfr if (need_more_resources) { 7482729Sdfr int we_own_it; 7492729Sdfr 7502729Sdfr if ((msgflg & IPC_NOWAIT) != 0) { 751100523Salfred DPRINTF(("need more resources but caller " 752100523Salfred "doesn't want to wait\n")); 75382607Sdillon error = EAGAIN; 75482607Sdillon goto done2; 7552729Sdfr } 7562729Sdfr 757137613Srwatson if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) { 758100523Salfred DPRINTF(("we don't own the msqid_ds\n")); 7592729Sdfr we_own_it = 0; 7602729Sdfr } else { 7612729Sdfr /* Force later arrivals to wait for our 7622729Sdfr request */ 763100523Salfred DPRINTF(("we own the msqid_ds\n")); 764137613Srwatson msqkptr->u.msg_perm.mode |= MSG_LOCKED; 7652729Sdfr we_own_it = 1; 7662729Sdfr } 767164368Sjkim DPRINTF(("msgsnd: goodnight\n")); 768137613Srwatson error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 769164368Sjkim "msgsnd", hz); 770164368Sjkim DPRINTF(("msgsnd: good morning, error=%d\n", error)); 7712729Sdfr if (we_own_it) 772137613Srwatson msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 773164368Sjkim if (error == EWOULDBLOCK) { 774164368Sjkim DPRINTF(("msgsnd: timed out\n")); 775164368Sjkim continue; 776164368Sjkim } 77782607Sdillon if (error != 0) { 778100523Salfred DPRINTF(("msgsnd: interrupted system call\n")); 77982607Sdillon error = EINTR; 78082607Sdillon goto done2; 7812729Sdfr } 7822729Sdfr 7832729Sdfr /* 7842729Sdfr * Make sure that the msq queue still exists 7852729Sdfr */ 7862729Sdfr 787137613Srwatson if (msqkptr->u.msg_qbytes == 0) { 788100523Salfred DPRINTF(("msqid deleted\n")); 78982607Sdillon error = EIDRM; 79082607Sdillon goto done2; 7912729Sdfr } 7922729Sdfr 7932729Sdfr } else { 794100523Salfred DPRINTF(("got all the resources that we need\n")); 7952729Sdfr break; 7962729Sdfr } 7972729Sdfr } 7982729Sdfr 7992729Sdfr /* 8002729Sdfr * We have the resources that we need. 8012729Sdfr * Make sure! 8022729Sdfr */ 8032729Sdfr 804137613Srwatson if (msqkptr->u.msg_perm.mode & MSG_LOCKED) 8052729Sdfr panic("msg_perm.mode & MSG_LOCKED"); 8062729Sdfr if (segs_needed > nfree_msgmaps) 8072729Sdfr panic("segs_needed > nfree_msgmaps"); 808137613Srwatson if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) 8092729Sdfr panic("msgsz + msg_cbytes > msg_qbytes"); 8102729Sdfr if (free_msghdrs == NULL) 8112729Sdfr panic("no more msghdrs"); 8122729Sdfr 8132729Sdfr /* 8142729Sdfr * Re-lock the msqid_ds in case we page-fault when copying in the 8152729Sdfr * message 8162729Sdfr */ 8172729Sdfr 818137613Srwatson if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) 8192729Sdfr panic("msqid_ds is already locked"); 820137613Srwatson msqkptr->u.msg_perm.mode |= MSG_LOCKED; 8212729Sdfr 8222729Sdfr /* 8232729Sdfr * Allocate a message header 8242729Sdfr */ 8252729Sdfr 8262729Sdfr msghdr = free_msghdrs; 8272729Sdfr free_msghdrs = msghdr->msg_next; 8282729Sdfr msghdr->msg_spot = -1; 8292729Sdfr msghdr->msg_ts = msgsz; 830165403Sjkim msghdr->msg_type = mtype; 831140614Srwatson#ifdef MAC 832140614Srwatson /* 833172930Srwatson * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here 834140614Srwatson * immediately? Or, should it be checked just before the msg is 835140614Srwatson * enqueued in the msgq (as it is done now)? 836140614Srwatson */ 837172930Srwatson mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr); 838140614Srwatson#endif 8392729Sdfr 8402729Sdfr /* 8412729Sdfr * Allocate space for the message 8422729Sdfr */ 8432729Sdfr 8442729Sdfr while (segs_needed > 0) { 8452729Sdfr if (nfree_msgmaps <= 0) 8462729Sdfr panic("not enough msgmaps"); 8472729Sdfr if (free_msgmaps == -1) 8482729Sdfr panic("nil free_msgmaps"); 8492729Sdfr next = free_msgmaps; 8502729Sdfr if (next <= -1) 8512729Sdfr panic("next too low #1"); 8522729Sdfr if (next >= msginfo.msgseg) 8532729Sdfr panic("next out of range #1"); 854100523Salfred DPRINTF(("allocating segment %d to message\n", next)); 8552729Sdfr free_msgmaps = msgmaps[next].next; 8562729Sdfr nfree_msgmaps--; 8572729Sdfr msgmaps[next].next = msghdr->msg_spot; 8582729Sdfr msghdr->msg_spot = next; 8592729Sdfr segs_needed--; 8602729Sdfr } 8612729Sdfr 8622729Sdfr /* 8632729Sdfr * Validate the message type 8642729Sdfr */ 8652729Sdfr 8662729Sdfr if (msghdr->msg_type < 1) { 8672729Sdfr msg_freehdr(msghdr); 868137613Srwatson msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 869137613Srwatson wakeup(msqkptr); 870165403Sjkim DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type)); 87182607Sdillon error = EINVAL; 87282607Sdillon goto done2; 8732729Sdfr } 8742729Sdfr 8752729Sdfr /* 8762729Sdfr * Copy in the message body 8772729Sdfr */ 8782729Sdfr 8792729Sdfr next = msghdr->msg_spot; 8802729Sdfr while (msgsz > 0) { 8812729Sdfr size_t tlen; 8822729Sdfr if (msgsz > msginfo.msgssz) 8832729Sdfr tlen = msginfo.msgssz; 8842729Sdfr else 8852729Sdfr tlen = msgsz; 8862729Sdfr if (next <= -1) 8872729Sdfr panic("next too low #2"); 8882729Sdfr if (next >= msginfo.msgseg) 8892729Sdfr panic("next out of range #2"); 890101772Salfred mtx_unlock(&msq_mtx); 891165403Sjkim if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz], 8922729Sdfr tlen)) != 0) { 893101772Salfred mtx_lock(&msq_mtx); 894100523Salfred DPRINTF(("error %d copying in message segment\n", 895100523Salfred error)); 8962729Sdfr msg_freehdr(msghdr); 897137613Srwatson msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 898137613Srwatson wakeup(msqkptr); 89982607Sdillon goto done2; 9002729Sdfr } 901101772Salfred mtx_lock(&msq_mtx); 9022729Sdfr msgsz -= tlen; 903165403Sjkim msgp = (const char *)msgp + tlen; 9042729Sdfr next = msgmaps[next].next; 9052729Sdfr } 9062729Sdfr if (next != -1) 9072729Sdfr panic("didn't use all the msg segments"); 9082729Sdfr 9092729Sdfr /* 9102729Sdfr * We've got the message. Unlock the msqid_ds. 9112729Sdfr */ 9122729Sdfr 913137613Srwatson msqkptr->u.msg_perm.mode &= ~MSG_LOCKED; 9142729Sdfr 9152729Sdfr /* 9162729Sdfr * Make sure that the msqid_ds is still allocated. 9172729Sdfr */ 9182729Sdfr 919137613Srwatson if (msqkptr->u.msg_qbytes == 0) { 9202729Sdfr msg_freehdr(msghdr); 921137613Srwatson wakeup(msqkptr); 92282607Sdillon error = EIDRM; 92382607Sdillon goto done2; 9242729Sdfr } 9252729Sdfr 926140614Srwatson#ifdef MAC 9272729Sdfr /* 928140614Srwatson * Note: Since the task/thread allocates the msghdr and usually 929140614Srwatson * primes it with its own MAC label, for a majority of policies, it 930140614Srwatson * won't be necessary to check whether the msghdr has access 931172930Srwatson * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would 932140614Srwatson * suffice in that case. However, this hook may be required where 933140614Srwatson * individual policies derive a non-identical label for the msghdr 934140614Srwatson * from the current thread label and may want to check the msghdr 935140614Srwatson * enqueue permissions, along with read/write permissions to the 936140614Srwatson * msgq. 937140614Srwatson */ 938172930Srwatson error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr); 939140614Srwatson if (error != 0) { 940140614Srwatson msg_freehdr(msghdr); 941140614Srwatson wakeup(msqkptr); 942140614Srwatson goto done2; 943140614Srwatson } 944140614Srwatson#endif 945140614Srwatson 946140614Srwatson /* 9472729Sdfr * Put the message into the queue 9482729Sdfr */ 949137613Srwatson if (msqkptr->u.msg_first == NULL) { 950137613Srwatson msqkptr->u.msg_first = msghdr; 951137613Srwatson msqkptr->u.msg_last = msghdr; 9522729Sdfr } else { 953137613Srwatson msqkptr->u.msg_last->msg_next = msghdr; 954137613Srwatson msqkptr->u.msg_last = msghdr; 9552729Sdfr } 956137613Srwatson msqkptr->u.msg_last->msg_next = NULL; 9572729Sdfr 958137613Srwatson msqkptr->u.msg_cbytes += msghdr->msg_ts; 959137613Srwatson msqkptr->u.msg_qnum++; 960137613Srwatson msqkptr->u.msg_lspid = td->td_proc->p_pid; 961137613Srwatson msqkptr->u.msg_stime = time_second; 9622729Sdfr 963137613Srwatson wakeup(msqkptr); 96483366Sjulian td->td_retval[0] = 0; 96582607Sdillondone2: 966101772Salfred mtx_unlock(&msq_mtx); 96782607Sdillon return (error); 9682729Sdfr} 9692729Sdfr 970165403Sjkimint 971165403Sjkimmsgsnd(td, uap) 972165403Sjkim struct thread *td; 973165403Sjkim register struct msgsnd_args *uap; 974165403Sjkim{ 975165403Sjkim int error; 976165403Sjkim long mtype; 977165403Sjkim 978165403Sjkim DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp, 979165403Sjkim uap->msgsz, uap->msgflg)); 980165403Sjkim 981165403Sjkim if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) { 982165403Sjkim DPRINTF(("error %d copying the message type\n", error)); 983165403Sjkim return (error); 984165403Sjkim } 985165403Sjkim return (kern_msgsnd(td, uap->msqid, 986165403Sjkim (const char *)uap->msgp + sizeof(mtype), 987165403Sjkim uap->msgsz, uap->msgflg, mtype)); 988165403Sjkim} 989165403Sjkim 99012866Speter#ifndef _SYS_SYSPROTO_H_ 9912729Sdfrstruct msgrcv_args { 9922729Sdfr int msqid; 9932729Sdfr void *msgp; 9942729Sdfr size_t msgsz; 9952729Sdfr long msgtyp; 9962729Sdfr int msgflg; 9972729Sdfr}; 99812866Speter#endif 99912866Speterint 1000165403Sjkimkern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype) 100183366Sjulian struct thread *td; 1002165403Sjkim int msqid; 1003165403Sjkim void *msgp; /* XXX msgp is actually mtext. */ 1004165403Sjkim size_t msgsz; 1005165403Sjkim long msgtyp; 1006165403Sjkim int msgflg; 1007165403Sjkim long *mtype; 10082729Sdfr{ 10092729Sdfr size_t len; 1010137613Srwatson register struct msqid_kernel *msqkptr; 10112729Sdfr register struct msg *msghdr; 1012165403Sjkim int msqix, error = 0; 10132729Sdfr short next; 10142729Sdfr 1015192895Sjamie if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) 101691703Sjhb return (ENOSYS); 101791703Sjhb 1018165403Sjkim msqix = IPCID_TO_IX(msqid); 10192729Sdfr 1020165403Sjkim if (msqix < 0 || msqix >= msginfo.msgmni) { 1021165403Sjkim DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix, 1022100523Salfred msginfo.msgmni)); 1023101772Salfred return (EINVAL); 10242729Sdfr } 10252729Sdfr 1026165403Sjkim msqkptr = &msqids[msqix]; 1027101772Salfred mtx_lock(&msq_mtx); 1028137613Srwatson if (msqkptr->u.msg_qbytes == 0) { 1029100523Salfred DPRINTF(("no such message queue id\n")); 103082607Sdillon error = EINVAL; 103182607Sdillon goto done2; 10322729Sdfr } 1033165403Sjkim if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1034100523Salfred DPRINTF(("wrong sequence number\n")); 103582607Sdillon error = EINVAL; 103682607Sdillon goto done2; 10372729Sdfr } 10382729Sdfr 1039137613Srwatson if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) { 1040100523Salfred DPRINTF(("requester doesn't have read access\n")); 104182607Sdillon goto done2; 10422729Sdfr } 10432729Sdfr 1044140614Srwatson#ifdef MAC 1045172930Srwatson error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr); 1046162468Srwatson if (error != 0) 1047140614Srwatson goto done2; 1048140614Srwatson#endif 1049140614Srwatson 10502729Sdfr msghdr = NULL; 10512729Sdfr while (msghdr == NULL) { 10522729Sdfr if (msgtyp == 0) { 1053137613Srwatson msghdr = msqkptr->u.msg_first; 10542729Sdfr if (msghdr != NULL) { 10552729Sdfr if (msgsz < msghdr->msg_ts && 10562729Sdfr (msgflg & MSG_NOERROR) == 0) { 1057100523Salfred DPRINTF(("first message on the queue " 1058165403Sjkim "is too big (want %zu, got %d)\n", 1059100523Salfred msgsz, msghdr->msg_ts)); 106082607Sdillon error = E2BIG; 106182607Sdillon goto done2; 10622729Sdfr } 1063140614Srwatson#ifdef MAC 1064172930Srwatson error = mac_sysvmsq_check_msgrcv(td->td_ucred, 1065140614Srwatson msghdr); 1066162468Srwatson if (error != 0) 1067140614Srwatson goto done2; 1068140614Srwatson#endif 1069137613Srwatson if (msqkptr->u.msg_first == msqkptr->u.msg_last) { 1070137613Srwatson msqkptr->u.msg_first = NULL; 1071137613Srwatson msqkptr->u.msg_last = NULL; 10722729Sdfr } else { 1073137613Srwatson msqkptr->u.msg_first = msghdr->msg_next; 1074137613Srwatson if (msqkptr->u.msg_first == NULL) 10752729Sdfr panic("msg_first/last screwed up #1"); 10762729Sdfr } 10772729Sdfr } 10782729Sdfr } else { 10792729Sdfr struct msg *previous; 10802729Sdfr struct msg **prev; 10812729Sdfr 10822729Sdfr previous = NULL; 1083137613Srwatson prev = &(msqkptr->u.msg_first); 10842729Sdfr while ((msghdr = *prev) != NULL) { 10852729Sdfr /* 10862729Sdfr * Is this message's type an exact match or is 10872729Sdfr * this message's type less than or equal to 10882729Sdfr * the absolute value of a negative msgtyp? 10892729Sdfr * Note that the second half of this test can 10902729Sdfr * NEVER be true if msgtyp is positive since 10912729Sdfr * msg_type is always positive! 10922729Sdfr */ 10932729Sdfr 10942729Sdfr if (msgtyp == msghdr->msg_type || 10952729Sdfr msghdr->msg_type <= -msgtyp) { 1096165403Sjkim DPRINTF(("found message type %ld, " 1097165403Sjkim "requested %ld\n", 1098100523Salfred msghdr->msg_type, msgtyp)); 10992729Sdfr if (msgsz < msghdr->msg_ts && 11002729Sdfr (msgflg & MSG_NOERROR) == 0) { 1101100523Salfred DPRINTF(("requested message " 1102100523Salfred "on the queue is too big " 1103165403Sjkim "(want %zu, got %hu)\n", 1104100523Salfred msgsz, msghdr->msg_ts)); 110582607Sdillon error = E2BIG; 110682607Sdillon goto done2; 11072729Sdfr } 1108140614Srwatson#ifdef MAC 1109172930Srwatson error = mac_sysvmsq_check_msgrcv( 1110140614Srwatson td->td_ucred, msghdr); 1111162468Srwatson if (error != 0) 1112140614Srwatson goto done2; 1113140614Srwatson#endif 11142729Sdfr *prev = msghdr->msg_next; 1115137613Srwatson if (msghdr == msqkptr->u.msg_last) { 11162729Sdfr if (previous == NULL) { 11172729Sdfr if (prev != 1118137613Srwatson &msqkptr->u.msg_first) 11192729Sdfr panic("msg_first/last screwed up #2"); 1120137613Srwatson msqkptr->u.msg_first = 11212729Sdfr NULL; 1122137613Srwatson msqkptr->u.msg_last = 11232729Sdfr NULL; 11242729Sdfr } else { 11252729Sdfr if (prev == 1126137613Srwatson &msqkptr->u.msg_first) 11272729Sdfr panic("msg_first/last screwed up #3"); 1128137613Srwatson msqkptr->u.msg_last = 11292729Sdfr previous; 11302729Sdfr } 11312729Sdfr } 11322729Sdfr break; 11332729Sdfr } 11342729Sdfr previous = msghdr; 11352729Sdfr prev = &(msghdr->msg_next); 11362729Sdfr } 11372729Sdfr } 11382729Sdfr 11392729Sdfr /* 11402729Sdfr * We've either extracted the msghdr for the appropriate 11412729Sdfr * message or there isn't one. 11422729Sdfr * If there is one then bail out of this loop. 11432729Sdfr */ 11442729Sdfr 11452729Sdfr if (msghdr != NULL) 11462729Sdfr break; 11472729Sdfr 11482729Sdfr /* 11492729Sdfr * Hmph! No message found. Does the user want to wait? 11502729Sdfr */ 11512729Sdfr 11522729Sdfr if ((msgflg & IPC_NOWAIT) != 0) { 1153165403Sjkim DPRINTF(("no appropriate message found (msgtyp=%ld)\n", 1154100523Salfred msgtyp)); 11552729Sdfr /* The SVID says to return ENOMSG. */ 115682607Sdillon error = ENOMSG; 115782607Sdillon goto done2; 11582729Sdfr } 11592729Sdfr 11602729Sdfr /* 11612729Sdfr * Wait for something to happen 11622729Sdfr */ 11632729Sdfr 1164100523Salfred DPRINTF(("msgrcv: goodnight\n")); 1165137613Srwatson error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH, 1166164368Sjkim "msgrcv", 0); 1167100523Salfred DPRINTF(("msgrcv: good morning (error=%d)\n", error)); 11682729Sdfr 116982607Sdillon if (error != 0) { 1170164368Sjkim DPRINTF(("msgrcv: interrupted system call\n")); 117182607Sdillon error = EINTR; 117282607Sdillon goto done2; 11732729Sdfr } 11742729Sdfr 11752729Sdfr /* 11762729Sdfr * Make sure that the msq queue still exists 11772729Sdfr */ 11782729Sdfr 1179137613Srwatson if (msqkptr->u.msg_qbytes == 0 || 1180165403Sjkim msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) { 1181100523Salfred DPRINTF(("msqid deleted\n")); 118282607Sdillon error = EIDRM; 118382607Sdillon goto done2; 11842729Sdfr } 11852729Sdfr } 11862729Sdfr 11872729Sdfr /* 11882729Sdfr * Return the message to the user. 11892729Sdfr * 11902729Sdfr * First, do the bookkeeping (before we risk being interrupted). 11912729Sdfr */ 11922729Sdfr 1193137613Srwatson msqkptr->u.msg_cbytes -= msghdr->msg_ts; 1194137613Srwatson msqkptr->u.msg_qnum--; 1195137613Srwatson msqkptr->u.msg_lrpid = td->td_proc->p_pid; 1196137613Srwatson msqkptr->u.msg_rtime = time_second; 11972729Sdfr 11982729Sdfr /* 11992729Sdfr * Make msgsz the actual amount that we'll be returning. 12002729Sdfr * Note that this effectively truncates the message if it is too long 12012729Sdfr * (since msgsz is never increased). 12022729Sdfr */ 12032729Sdfr 1204165403Sjkim DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz, 1205100523Salfred msghdr->msg_ts)); 12062729Sdfr if (msgsz > msghdr->msg_ts) 12072729Sdfr msgsz = msghdr->msg_ts; 1208165403Sjkim *mtype = msghdr->msg_type; 12092729Sdfr 12102729Sdfr /* 12112729Sdfr * Return the segments to the user 12122729Sdfr */ 12132729Sdfr 12142729Sdfr next = msghdr->msg_spot; 12152729Sdfr for (len = 0; len < msgsz; len += msginfo.msgssz) { 12162729Sdfr size_t tlen; 12172729Sdfr 121845921Ssada if (msgsz - len > msginfo.msgssz) 12192729Sdfr tlen = msginfo.msgssz; 12202729Sdfr else 122145921Ssada tlen = msgsz - len; 12222729Sdfr if (next <= -1) 12232729Sdfr panic("next too low #3"); 12242729Sdfr if (next >= msginfo.msgseg) 12252729Sdfr panic("next out of range #3"); 1226101772Salfred mtx_unlock(&msq_mtx); 1227165403Sjkim error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen); 1228101772Salfred mtx_lock(&msq_mtx); 122982607Sdillon if (error != 0) { 1230100523Salfred DPRINTF(("error (%d) copying out message segment\n", 1231100523Salfred error)); 12322729Sdfr msg_freehdr(msghdr); 1233137613Srwatson wakeup(msqkptr); 123482607Sdillon goto done2; 12352729Sdfr } 1236165403Sjkim msgp = (char *)msgp + tlen; 12372729Sdfr next = msgmaps[next].next; 12382729Sdfr } 12392729Sdfr 12402729Sdfr /* 12412729Sdfr * Done, return the actual number of bytes copied out. 12422729Sdfr */ 12432729Sdfr 12442729Sdfr msg_freehdr(msghdr); 1245137613Srwatson wakeup(msqkptr); 124683366Sjulian td->td_retval[0] = msgsz; 124782607Sdillondone2: 1248101772Salfred mtx_unlock(&msq_mtx); 124982607Sdillon return (error); 12502729Sdfr} 125177461Sdd 1252165403Sjkimint 1253165403Sjkimmsgrcv(td, uap) 1254165403Sjkim struct thread *td; 1255165403Sjkim register struct msgrcv_args *uap; 1256165403Sjkim{ 1257165403Sjkim int error; 1258165403Sjkim long mtype; 1259165403Sjkim 1260165403Sjkim DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid, 1261165403Sjkim uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg)); 1262165403Sjkim 1263165403Sjkim if ((error = kern_msgrcv(td, uap->msqid, 1264165403Sjkim (char *)uap->msgp + sizeof(mtype), uap->msgsz, 1265165403Sjkim uap->msgtyp, uap->msgflg, &mtype)) != 0) 1266165403Sjkim return (error); 1267165403Sjkim if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0) 1268165403Sjkim DPRINTF(("error %d copying the message type\n", error)); 1269165403Sjkim return (error); 1270165403Sjkim} 1271165403Sjkim 127277461Sddstatic int 127377461Sddsysctl_msqids(SYSCTL_HANDLER_ARGS) 127477461Sdd{ 127577461Sdd 127677461Sdd return (SYSCTL_OUT(req, msqids, 1277137613Srwatson sizeof(struct msqid_kernel) * msginfo.msgmni)); 127877461Sdd} 127977461Sdd 1280141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, 1281141710Scsjp "Maximum message size"); 1282141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0, 1283141710Scsjp "Number of message queue identifiers"); 1284141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0, 1285141710Scsjp "Maximum number of bytes in a queue"); 1286141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0, 1287141710Scsjp "Maximum number of messages in the system"); 1288141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0, 1289141710Scsjp "Size of a message segment"); 1290141710ScsjpSYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0, 1291141710Scsjp "Number of message segments"); 129277461SddSYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD, 129377461Sdd NULL, 0, sysctl_msqids, "", "Message queue IDs"); 1294