sysv_msg.c revision 83366
150477Speter/* $FreeBSD: head/sys/kern/sysv_msg.c 83366 2001-09-12 08:38:13Z julian $ */ 22729Sdfr 32729Sdfr/* 42729Sdfr * Implementation of SVID messages 52729Sdfr * 62729Sdfr * Author: Daniel Boulet 72729Sdfr * 82729Sdfr * Copyright 1993 Daniel Boulet and RTMX Inc. 92729Sdfr * 102729Sdfr * This system call was implemented by Daniel Boulet under contract from RTMX. 112729Sdfr * 122729Sdfr * Redistribution and use in source forms, with and without modification, 132729Sdfr * are permitted provided that this entire comment appears intact. 142729Sdfr * 152729Sdfr * Redistribution in binary form may occur without any restrictions. 162729Sdfr * Obviously, it would be nice if you gave credit where credit is due 172729Sdfr * but requiring it would be too onerous. 182729Sdfr * 192729Sdfr * This software is provided ``AS IS'' without any warranties of any kind. 202729Sdfr */ 212729Sdfr 2259839Speter#include "opt_sysvipc.h" 2359839Speter 242729Sdfr#include <sys/param.h> 252729Sdfr#include <sys/systm.h> 2611626Sbde#include <sys/sysproto.h> 272729Sdfr#include <sys/kernel.h> 282729Sdfr#include <sys/proc.h> 2982607Sdillon#include <sys/lock.h> 3082607Sdillon#include <sys/mutex.h> 312729Sdfr#include <sys/msg.h> 3269449Salfred#include <sys/syscall.h> 3311626Sbde#include <sys/sysent.h> 3459839Speter#include <sys/sysctl.h> 3559839Speter#include <sys/malloc.h> 3668024Srwatson#include <sys/jail.h> 372729Sdfr 3859839Speterstatic MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues"); 3959839Speter 4069449Salfredstatic void msginit __P((void)); 4169449Salfredstatic int msgunload __P((void)); 4269449Salfredstatic int sysvmsg_modload __P((struct module *, int, void *)); 4310358Sjulian 442729Sdfr#define MSG_DEBUG 452729Sdfr#undef MSG_DEBUG_OK 462729Sdfr 4711626Sbdestatic void msg_freehdr __P((struct msg *msghdr)); 482729Sdfr 4911626Sbde/* XXX casting to (sy_call_t *) is bogus, as usual. */ 5012819Sphkstatic sy_call_t *msgcalls[] = { 5111626Sbde (sy_call_t *)msgctl, (sy_call_t *)msgget, 5211626Sbde (sy_call_t *)msgsnd, (sy_call_t *)msgrcv 5311626Sbde}; 542729Sdfr 5559839Speterstruct msg { 5659839Speter struct msg *msg_next; /* next msg in the chain */ 5759839Speter long msg_type; /* type of this message */ 5859839Speter /* >0 -> type of this message */ 5959839Speter /* 0 -> free header */ 6059839Speter u_short msg_ts; /* size of this message */ 6159839Speter short msg_spot; /* location of start of msg in buffer */ 6259839Speter}; 6359839Speter 6459839Speter 6559839Speter#ifndef MSGSSZ 6659839Speter#define MSGSSZ 8 /* Each segment must be 2^N long */ 6759839Speter#endif 6859839Speter#ifndef MSGSEG 6959839Speter#define MSGSEG 2048 /* must be less than 32767 */ 7059839Speter#endif 7159839Speter#define MSGMAX (MSGSSZ*MSGSEG) 7259839Speter#ifndef MSGMNB 7359839Speter#define MSGMNB 2048 /* max # of bytes in a queue */ 7459839Speter#endif 7559839Speter#ifndef MSGMNI 7659839Speter#define MSGMNI 40 7759839Speter#endif 7859839Speter#ifndef MSGTQL 7959839Speter#define MSGTQL 40 8059839Speter#endif 8159839Speter 8259839Speter/* 8359839Speter * Based on the configuration parameters described in an SVR2 (yes, two) 8459839Speter * config(1m) man page. 8559839Speter * 8659839Speter * Each message is broken up and stored in segments that are msgssz bytes 8759839Speter * long. For efficiency reasons, this should be a power of two. Also, 8859839Speter * it doesn't make sense if it is less than 8 or greater than about 256. 8959839Speter * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 9059839Speter * two between 8 and 1024 inclusive (and panic's if it isn't). 9159839Speter */ 9259839Speterstruct msginfo msginfo = { 9359839Speter MSGMAX, /* max chars in a message */ 9459839Speter MSGMNI, /* # of message queue identifiers */ 9559839Speter MSGMNB, /* max chars in a queue */ 9659839Speter MSGTQL, /* max messages in system */ 9759839Speter MSGSSZ, /* size of a message segment */ 9859839Speter /* (must be small power of 2 greater than 4) */ 9959839Speter MSGSEG /* number of message segments */ 10059839Speter}; 10159839Speter 10259839Speter/* 10359839Speter * macros to convert between msqid_ds's and msqid's. 10459839Speter * (specific to this implementation) 10559839Speter */ 10659839Speter#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000)) 10759839Speter#define MSQID_IX(id) ((id) & 0xffff) 10859839Speter#define MSQID_SEQ(id) (((id) >> 16) & 0xffff) 10959839Speter 11059839Speter/* 11159839Speter * The rest of this file is specific to this particular implementation. 11259839Speter */ 11359839Speter 11459839Speterstruct msgmap { 11559839Speter short next; /* next segment in buffer */ 11659839Speter /* -1 -> available */ 11759839Speter /* 0..(MSGSEG-1) -> index of next segment */ 11859839Speter}; 11959839Speter 12059839Speter#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */ 12159839Speter 12212819Sphkstatic int nfree_msgmaps; /* # of free map entries */ 12312819Sphkstatic short free_msgmaps; /* head of linked list of free map entries */ 12459839Speterstatic struct msg *free_msghdrs;/* list of free msg headers */ 12559839Speterstatic char *msgpool; /* MSGMAX byte long msg buffer pool */ 12659839Speterstatic struct msgmap *msgmaps; /* MSGSEG msgmap structures */ 12759839Speterstatic struct msg *msghdrs; /* MSGTQL msg headers */ 12859839Speterstatic struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */ 1292729Sdfr 13059839Speterstatic void 13169449Salfredmsginit() 1322729Sdfr{ 1332729Sdfr register int i; 1342729Sdfr 13559839Speter msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK); 13659839Speter if (msgpool == NULL) 13759839Speter panic("msgpool is NULL"); 13859839Speter msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); 13959839Speter if (msgmaps == NULL) 14059839Speter panic("msgmaps is NULL"); 14159839Speter msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); 14259839Speter if (msghdrs == NULL) 14359839Speter panic("msghdrs is NULL"); 14459839Speter msqids = malloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK); 14559839Speter if (msqids == NULL) 14659839Speter panic("msqids is NULL"); 14759839Speter 1482729Sdfr /* 1492729Sdfr * msginfo.msgssz should be a power of two for efficiency reasons. 1502729Sdfr * It is also pretty silly if msginfo.msgssz is less than 8 1512729Sdfr * or greater than about 256 so ... 1522729Sdfr */ 1532729Sdfr 1542729Sdfr i = 8; 1552729Sdfr while (i < 1024 && i != msginfo.msgssz) 1562729Sdfr i <<= 1; 1572729Sdfr if (i != msginfo.msgssz) { 1582729Sdfr printf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz, 1592729Sdfr msginfo.msgssz); 1602729Sdfr panic("msginfo.msgssz not a small power of 2"); 1612729Sdfr } 1622729Sdfr 1632729Sdfr if (msginfo.msgseg > 32767) { 1642729Sdfr printf("msginfo.msgseg=%d\n", msginfo.msgseg); 1652729Sdfr panic("msginfo.msgseg > 32767"); 1662729Sdfr } 1672729Sdfr 1682729Sdfr if (msgmaps == NULL) 1692729Sdfr panic("msgmaps is NULL"); 1702729Sdfr 1712729Sdfr for (i = 0; i < msginfo.msgseg; i++) { 1722729Sdfr if (i > 0) 1732729Sdfr msgmaps[i-1].next = i; 1742729Sdfr msgmaps[i].next = -1; /* implies entry is available */ 1752729Sdfr } 1762729Sdfr free_msgmaps = 0; 1772729Sdfr nfree_msgmaps = msginfo.msgseg; 1782729Sdfr 1792729Sdfr if (msghdrs == NULL) 1802729Sdfr panic("msghdrs is NULL"); 1812729Sdfr 1822729Sdfr for (i = 0; i < msginfo.msgtql; i++) { 1832729Sdfr msghdrs[i].msg_type = 0; 1842729Sdfr if (i > 0) 1852729Sdfr msghdrs[i-1].msg_next = &msghdrs[i]; 1862729Sdfr msghdrs[i].msg_next = NULL; 1872729Sdfr } 1882729Sdfr free_msghdrs = &msghdrs[0]; 1892729Sdfr 1902729Sdfr if (msqids == NULL) 1912729Sdfr panic("msqids is NULL"); 1922729Sdfr 1932729Sdfr for (i = 0; i < msginfo.msgmni; i++) { 1942729Sdfr msqids[i].msg_qbytes = 0; /* implies entry is available */ 1952729Sdfr msqids[i].msg_perm.seq = 0; /* reset to a known value */ 19666085Speter msqids[i].msg_perm.mode = 0; 1972729Sdfr } 1982729Sdfr} 1992729Sdfr 20069449Salfredstatic int 20169449Salfredmsgunload() 20269449Salfred{ 20369449Salfred struct msqid_ds *msqptr; 20469449Salfred int msqid; 20569449Salfred 20669449Salfred for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 20769449Salfred /* 20869449Salfred * Look for an unallocated and unlocked msqid_ds. 20969449Salfred * msqid_ds's can be locked by msgsnd or msgrcv while 21069449Salfred * they are copying the message in/out. We can't 21169449Salfred * re-use the entry until they release it. 21269449Salfred */ 21369449Salfred msqptr = &msqids[msqid]; 21469449Salfred if (msqptr->msg_qbytes != 0 || 21569449Salfred (msqptr->msg_perm.mode & MSG_LOCKED) != 0) 21669449Salfred break; 21769449Salfred } 21869449Salfred if (msqid != msginfo.msgmni) 21969449Salfred return (EBUSY); 22069449Salfred 22169449Salfred free(msgpool, M_MSG); 22269449Salfred free(msgmaps, M_MSG); 22369449Salfred free(msghdrs, M_MSG); 22469449Salfred free(msqids, M_MSG); 22569449Salfred return (0); 22669449Salfred} 22769449Salfred 22869449Salfred 22969449Salfredstatic int 23069449Salfredsysvmsg_modload(struct module *module, int cmd, void *arg) 23169449Salfred{ 23269449Salfred int error = 0; 23369449Salfred 23469449Salfred switch (cmd) { 23569449Salfred case MOD_LOAD: 23669449Salfred msginit(); 23769449Salfred break; 23869449Salfred case MOD_UNLOAD: 23969449Salfred error = msgunload(); 24069449Salfred break; 24169449Salfred case MOD_SHUTDOWN: 24269449Salfred break; 24369449Salfred default: 24469449Salfred error = EINVAL; 24569449Salfred break; 24669449Salfred } 24769449Salfred return (error); 24869449Salfred} 24969449Salfred 25071038Sdesstatic moduledata_t sysvmsg_mod = { 25171038Sdes "sysvmsg", 25269449Salfred &sysvmsg_modload, 25369449Salfred NULL 25469449Salfred}; 25569449Salfred 25669644SalfredSYSCALL_MODULE_HELPER(msgsys, 6); 25769449SalfredSYSCALL_MODULE_HELPER(msgctl, 3); 25869449SalfredSYSCALL_MODULE_HELPER(msgget, 2); 25969449SalfredSYSCALL_MODULE_HELPER(msgsnd, 4); 26069449SalfredSYSCALL_MODULE_HELPER(msgrcv, 5); 26169449Salfred 26271038SdesDECLARE_MODULE(sysvmsg, sysvmsg_mod, 26369449Salfred SI_SUB_SYSV_MSG, SI_ORDER_FIRST); 26471038SdesMODULE_VERSION(sysvmsg, 1); 26569449Salfred 2662729Sdfr/* 2672729Sdfr * Entry point for all MSG calls 26882607Sdillon * 26982607Sdillon * MPSAFE 2702729Sdfr */ 2712729Sdfrint 27283366Sjulianmsgsys(td, uap) 27383366Sjulian struct thread *td; 27411626Sbde /* XXX actually varargs. */ 27511626Sbde struct msgsys_args /* { 27611626Sbde u_int which; 27711626Sbde int a2; 27811626Sbde int a3; 27911626Sbde int a4; 28011626Sbde int a5; 28111626Sbde int a6; 28211626Sbde } */ *uap; 2832729Sdfr{ 28482607Sdillon int error; 2852729Sdfr 28682607Sdillon mtx_lock(&Giant); 28783366Sjulian if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) { 28882607Sdillon error = ENOSYS; 28982607Sdillon goto done2; 29082607Sdillon } 29182607Sdillon if (uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0])) { 29282607Sdillon error = EINVAL; 29382607Sdillon goto done2; 29482607Sdillon } 29583366Sjulian error = (*msgcalls[uap->which])(td, &uap->a2); 29682607Sdillondone2: 29782607Sdillon mtx_unlock(&Giant); 29882607Sdillon return (error); 2992729Sdfr} 3002729Sdfr 3012729Sdfrstatic void 3022729Sdfrmsg_freehdr(msghdr) 3032729Sdfr struct msg *msghdr; 3042729Sdfr{ 3052729Sdfr while (msghdr->msg_ts > 0) { 3062729Sdfr short next; 3072729Sdfr if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg) 3082729Sdfr panic("msghdr->msg_spot out of range"); 3092729Sdfr next = msgmaps[msghdr->msg_spot].next; 3102729Sdfr msgmaps[msghdr->msg_spot].next = free_msgmaps; 3112729Sdfr free_msgmaps = msghdr->msg_spot; 3122729Sdfr nfree_msgmaps++; 3132729Sdfr msghdr->msg_spot = next; 3142729Sdfr if (msghdr->msg_ts >= msginfo.msgssz) 3152729Sdfr msghdr->msg_ts -= msginfo.msgssz; 3162729Sdfr else 3172729Sdfr msghdr->msg_ts = 0; 3182729Sdfr } 3192729Sdfr if (msghdr->msg_spot != -1) 3202729Sdfr panic("msghdr->msg_spot != -1"); 3212729Sdfr msghdr->msg_next = free_msghdrs; 3222729Sdfr free_msghdrs = msghdr; 3232729Sdfr} 3242729Sdfr 32512866Speter#ifndef _SYS_SYSPROTO_H_ 3262729Sdfrstruct msgctl_args { 3272729Sdfr int msqid; 3282729Sdfr int cmd; 32912866Speter struct msqid_ds *buf; 3302729Sdfr}; 33112866Speter#endif 3322729Sdfr 33382607Sdillon/* 33482607Sdillon * MPSAFE 33582607Sdillon */ 33612866Speterint 33783366Sjulianmsgctl(td, uap) 33883366Sjulian struct thread *td; 3392729Sdfr register struct msgctl_args *uap; 3402729Sdfr{ 3412729Sdfr int msqid = uap->msqid; 3422729Sdfr int cmd = uap->cmd; 34312866Speter struct msqid_ds *user_msqptr = uap->buf; 34482607Sdillon int rval, error; 3452729Sdfr struct msqid_ds msqbuf; 3462729Sdfr register struct msqid_ds *msqptr; 3472729Sdfr 3482729Sdfr#ifdef MSG_DEBUG_OK 3492729Sdfr printf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr); 3502729Sdfr#endif 35182607Sdillon mtx_lock(&Giant); 35283366Sjulian if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) { 35382607Sdillon error = ENOSYS; 35482607Sdillon goto done2; 35582607Sdillon } 35668024Srwatson 3572729Sdfr msqid = IPCID_TO_IX(msqid); 3582729Sdfr 3592729Sdfr if (msqid < 0 || msqid >= msginfo.msgmni) { 3602729Sdfr#ifdef MSG_DEBUG_OK 3612729Sdfr printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid, 3622729Sdfr msginfo.msgmni); 3632729Sdfr#endif 36482607Sdillon error = EINVAL; 36582607Sdillon goto done2; 3662729Sdfr } 3672729Sdfr 3682729Sdfr msqptr = &msqids[msqid]; 3692729Sdfr 3702729Sdfr if (msqptr->msg_qbytes == 0) { 3712729Sdfr#ifdef MSG_DEBUG_OK 3722729Sdfr printf("no such msqid\n"); 3732729Sdfr#endif 37482607Sdillon error = EINVAL; 37582607Sdillon goto done2; 3762729Sdfr } 3772729Sdfr if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { 3782729Sdfr#ifdef MSG_DEBUG_OK 3792729Sdfr printf("wrong sequence number\n"); 3802729Sdfr#endif 38182607Sdillon error = EINVAL; 38282607Sdillon goto done2; 3832729Sdfr } 3842729Sdfr 38582607Sdillon error = 0; 3862729Sdfr rval = 0; 3872729Sdfr 3882729Sdfr switch (cmd) { 3892729Sdfr 3902729Sdfr case IPC_RMID: 3912729Sdfr { 3922729Sdfr struct msg *msghdr; 39383366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M))) 39482607Sdillon goto done2; 3952729Sdfr /* Free the message headers */ 3962729Sdfr msghdr = msqptr->msg_first; 3972729Sdfr while (msghdr != NULL) { 3982729Sdfr struct msg *msghdr_tmp; 3992729Sdfr 4002729Sdfr /* Free the segments of each message */ 4012729Sdfr msqptr->msg_cbytes -= msghdr->msg_ts; 4022729Sdfr msqptr->msg_qnum--; 4032729Sdfr msghdr_tmp = msghdr; 4042729Sdfr msghdr = msghdr->msg_next; 4052729Sdfr msg_freehdr(msghdr_tmp); 4062729Sdfr } 4072729Sdfr 4082729Sdfr if (msqptr->msg_cbytes != 0) 4092729Sdfr panic("msg_cbytes is screwed up"); 4102729Sdfr if (msqptr->msg_qnum != 0) 4112729Sdfr panic("msg_qnum is screwed up"); 4122729Sdfr 4132729Sdfr msqptr->msg_qbytes = 0; /* Mark it as free */ 4142729Sdfr 4152729Sdfr wakeup((caddr_t)msqptr); 4162729Sdfr } 4172729Sdfr 4182729Sdfr break; 4192729Sdfr 4202729Sdfr case IPC_SET: 42183366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M))) 42282607Sdillon goto done2; 42382607Sdillon if ((error = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0) 42482607Sdillon goto done2; 42543426Sphk if (msqbuf.msg_qbytes > msqptr->msg_qbytes) { 42683366Sjulian error = suser_td(td); 42782607Sdillon if (error) 42882607Sdillon goto done2; 42943426Sphk } 4302729Sdfr if (msqbuf.msg_qbytes > msginfo.msgmnb) { 4312729Sdfr#ifdef MSG_DEBUG_OK 4322729Sdfr printf("can't increase msg_qbytes beyond %d (truncating)\n", 4332729Sdfr msginfo.msgmnb); 4342729Sdfr#endif 4352729Sdfr msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ 4362729Sdfr } 4372729Sdfr if (msqbuf.msg_qbytes == 0) { 4382729Sdfr#ifdef MSG_DEBUG_OK 4392729Sdfr printf("can't reduce msg_qbytes to 0\n"); 4402729Sdfr#endif 44182607Sdillon error = EINVAL; /* non-standard errno! */ 44282607Sdillon goto done2; 4432729Sdfr } 4442729Sdfr msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */ 4452729Sdfr msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */ 4462729Sdfr msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) | 4472729Sdfr (msqbuf.msg_perm.mode & 0777); 4482729Sdfr msqptr->msg_qbytes = msqbuf.msg_qbytes; 44934961Sphk msqptr->msg_ctime = time_second; 4502729Sdfr break; 4512729Sdfr 4522729Sdfr case IPC_STAT: 45383366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) { 4542729Sdfr#ifdef MSG_DEBUG_OK 4552729Sdfr printf("requester doesn't have read access\n"); 4562729Sdfr#endif 45782607Sdillon goto done2; 4582729Sdfr } 45982607Sdillon error = copyout((caddr_t)msqptr, user_msqptr, 4602729Sdfr sizeof(struct msqid_ds)); 4612729Sdfr break; 4622729Sdfr 4632729Sdfr default: 4642729Sdfr#ifdef MSG_DEBUG_OK 4652729Sdfr printf("invalid command %d\n", cmd); 4662729Sdfr#endif 46782607Sdillon error = EINVAL; 46882607Sdillon goto done2; 4692729Sdfr } 4702729Sdfr 47182607Sdillon if (error == 0) 47283366Sjulian td->td_retval[0] = rval; 47382607Sdillondone2: 47482607Sdillon mtx_unlock(&Giant); 47582607Sdillon return(error); 4762729Sdfr} 4772729Sdfr 47812866Speter#ifndef _SYS_SYSPROTO_H_ 4792729Sdfrstruct msgget_args { 4802729Sdfr key_t key; 4812729Sdfr int msgflg; 4822729Sdfr}; 48312866Speter#endif 4842729Sdfr 48582607Sdillon/* 48682607Sdillon * MPSAFE 48782607Sdillon */ 48812866Speterint 48983366Sjulianmsgget(td, uap) 49083366Sjulian struct thread *td; 4912729Sdfr register struct msgget_args *uap; 4922729Sdfr{ 49382607Sdillon int msqid, error = 0; 4942729Sdfr int key = uap->key; 4952729Sdfr int msgflg = uap->msgflg; 49683366Sjulian struct ucred *cred = td->td_proc->p_ucred; 4972836Sdg register struct msqid_ds *msqptr = NULL; 4982729Sdfr 4992729Sdfr#ifdef MSG_DEBUG_OK 5002729Sdfr printf("msgget(0x%x, 0%o)\n", key, msgflg); 5012729Sdfr#endif 5022729Sdfr 50382607Sdillon mtx_lock(&Giant); 50483366Sjulian if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) { 50582607Sdillon error = ENOSYS; 50682607Sdillon goto done2; 50782607Sdillon } 50882607Sdillon 5092729Sdfr if (key != IPC_PRIVATE) { 5102729Sdfr for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 5112729Sdfr msqptr = &msqids[msqid]; 5122729Sdfr if (msqptr->msg_qbytes != 0 && 5132729Sdfr msqptr->msg_perm.key == key) 5142729Sdfr break; 5152729Sdfr } 5162729Sdfr if (msqid < msginfo.msgmni) { 5172729Sdfr#ifdef MSG_DEBUG_OK 5182729Sdfr printf("found public key\n"); 5192729Sdfr#endif 5202729Sdfr if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { 5212729Sdfr#ifdef MSG_DEBUG_OK 5222729Sdfr printf("not exclusive\n"); 5232729Sdfr#endif 52482607Sdillon error = EEXIST; 52582607Sdillon goto done2; 5262729Sdfr } 52783366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, msgflg & 0700 ))) { 5282729Sdfr#ifdef MSG_DEBUG_OK 5292729Sdfr printf("requester doesn't have 0%o access\n", 5302729Sdfr msgflg & 0700); 5312729Sdfr#endif 53282607Sdillon goto done2; 5332729Sdfr } 5342729Sdfr goto found; 5352729Sdfr } 5362729Sdfr } 5372729Sdfr 5382729Sdfr#ifdef MSG_DEBUG_OK 5392729Sdfr printf("need to allocate the msqid_ds\n"); 5402729Sdfr#endif 5412729Sdfr if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { 5422729Sdfr for (msqid = 0; msqid < msginfo.msgmni; msqid++) { 5432729Sdfr /* 5442729Sdfr * Look for an unallocated and unlocked msqid_ds. 5452729Sdfr * msqid_ds's can be locked by msgsnd or msgrcv while 5462729Sdfr * they are copying the message in/out. We can't 5472729Sdfr * re-use the entry until they release it. 5482729Sdfr */ 5492729Sdfr msqptr = &msqids[msqid]; 5502729Sdfr if (msqptr->msg_qbytes == 0 && 5512729Sdfr (msqptr->msg_perm.mode & MSG_LOCKED) == 0) 5522729Sdfr break; 5532729Sdfr } 5542729Sdfr if (msqid == msginfo.msgmni) { 5552729Sdfr#ifdef MSG_DEBUG_OK 5562729Sdfr printf("no more msqid_ds's available\n"); 5572729Sdfr#endif 55882607Sdillon error = ENOSPC; 55982607Sdillon goto done2; 5602729Sdfr } 5612729Sdfr#ifdef MSG_DEBUG_OK 5622729Sdfr printf("msqid %d is available\n", msqid); 5632729Sdfr#endif 5642729Sdfr msqptr->msg_perm.key = key; 5652729Sdfr msqptr->msg_perm.cuid = cred->cr_uid; 5662729Sdfr msqptr->msg_perm.uid = cred->cr_uid; 5672729Sdfr msqptr->msg_perm.cgid = cred->cr_gid; 5682729Sdfr msqptr->msg_perm.gid = cred->cr_gid; 5692729Sdfr msqptr->msg_perm.mode = (msgflg & 0777); 5702729Sdfr /* Make sure that the returned msqid is unique */ 5712729Sdfr msqptr->msg_perm.seq++; 5722729Sdfr msqptr->msg_first = NULL; 5732729Sdfr msqptr->msg_last = NULL; 5742729Sdfr msqptr->msg_cbytes = 0; 5752729Sdfr msqptr->msg_qnum = 0; 5762729Sdfr msqptr->msg_qbytes = msginfo.msgmnb; 5772729Sdfr msqptr->msg_lspid = 0; 5782729Sdfr msqptr->msg_lrpid = 0; 5792729Sdfr msqptr->msg_stime = 0; 5802729Sdfr msqptr->msg_rtime = 0; 58134961Sphk msqptr->msg_ctime = time_second; 5822729Sdfr } else { 5832729Sdfr#ifdef MSG_DEBUG_OK 5842729Sdfr printf("didn't find it and wasn't asked to create it\n"); 5852729Sdfr#endif 58682607Sdillon error = ENOENT; 58782607Sdillon goto done2; 5882729Sdfr } 5892729Sdfr 5902729Sdfrfound: 5912729Sdfr /* Construct the unique msqid */ 59283366Sjulian td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm); 59382607Sdillondone2: 59482607Sdillon mtx_unlock(&Giant); 59582607Sdillon return (error); 5962729Sdfr} 5972729Sdfr 59812866Speter#ifndef _SYS_SYSPROTO_H_ 5992729Sdfrstruct msgsnd_args { 6002729Sdfr int msqid; 60112866Speter void *msgp; 6022729Sdfr size_t msgsz; 6032729Sdfr int msgflg; 6042729Sdfr}; 60512866Speter#endif 6062729Sdfr 60782607Sdillon/* 60882607Sdillon * MPSAFE 60982607Sdillon */ 61012866Speterint 61183366Sjulianmsgsnd(td, uap) 61283366Sjulian struct thread *td; 6132729Sdfr register struct msgsnd_args *uap; 6142729Sdfr{ 6152729Sdfr int msqid = uap->msqid; 61612866Speter void *user_msgp = uap->msgp; 6172729Sdfr size_t msgsz = uap->msgsz; 6182729Sdfr int msgflg = uap->msgflg; 61982607Sdillon int segs_needed, error = 0; 6202729Sdfr register struct msqid_ds *msqptr; 6212729Sdfr register struct msg *msghdr; 6222729Sdfr short next; 6232729Sdfr 6242729Sdfr#ifdef MSG_DEBUG_OK 6252729Sdfr printf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz, 6262729Sdfr msgflg); 6272729Sdfr#endif 62882607Sdillon mtx_lock(&Giant); 62983366Sjulian if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) { 63082607Sdillon error = ENOSYS; 63182607Sdillon goto done2; 63282607Sdillon } 63368024Srwatson 6342729Sdfr msqid = IPCID_TO_IX(msqid); 6352729Sdfr 6362729Sdfr if (msqid < 0 || msqid >= msginfo.msgmni) { 6372729Sdfr#ifdef MSG_DEBUG_OK 6382729Sdfr printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid, 6392729Sdfr msginfo.msgmni); 6402729Sdfr#endif 64182607Sdillon error = EINVAL; 64282607Sdillon goto done2; 6432729Sdfr } 6442729Sdfr 6452729Sdfr msqptr = &msqids[msqid]; 6462729Sdfr if (msqptr->msg_qbytes == 0) { 6472729Sdfr#ifdef MSG_DEBUG_OK 6482729Sdfr printf("no such message queue id\n"); 6492729Sdfr#endif 65082607Sdillon error = EINVAL; 65182607Sdillon goto done2; 6522729Sdfr } 6532729Sdfr if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { 6542729Sdfr#ifdef MSG_DEBUG_OK 6552729Sdfr printf("wrong sequence number\n"); 6562729Sdfr#endif 65782607Sdillon error = EINVAL; 65882607Sdillon goto done2; 6592729Sdfr } 6602729Sdfr 66183366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, IPC_W))) { 6622729Sdfr#ifdef MSG_DEBUG_OK 6632729Sdfr printf("requester doesn't have write access\n"); 6642729Sdfr#endif 66582607Sdillon goto done2; 6662729Sdfr } 6672729Sdfr 6682729Sdfr segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz; 6692729Sdfr#ifdef MSG_DEBUG_OK 6702729Sdfr printf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz, 6712729Sdfr segs_needed); 6722729Sdfr#endif 6732729Sdfr for (;;) { 6742729Sdfr int need_more_resources = 0; 6752729Sdfr 6762729Sdfr /* 6772729Sdfr * check msgsz 6782729Sdfr * (inside this loop in case msg_qbytes changes while we sleep) 6792729Sdfr */ 6802729Sdfr 6812836Sdg if (msgsz > msqptr->msg_qbytes) { 6822729Sdfr#ifdef MSG_DEBUG_OK 6832729Sdfr printf("msgsz > msqptr->msg_qbytes\n"); 6842729Sdfr#endif 68582607Sdillon error = EINVAL; 68682607Sdillon goto done2; 6872729Sdfr } 6882729Sdfr 6892729Sdfr if (msqptr->msg_perm.mode & MSG_LOCKED) { 6902729Sdfr#ifdef MSG_DEBUG_OK 6912729Sdfr printf("msqid is locked\n"); 6922729Sdfr#endif 6932729Sdfr need_more_resources = 1; 6942729Sdfr } 6952729Sdfr if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) { 6962729Sdfr#ifdef MSG_DEBUG_OK 6972729Sdfr printf("msgsz + msg_cbytes > msg_qbytes\n"); 6982729Sdfr#endif 6992729Sdfr need_more_resources = 1; 7002729Sdfr } 7012729Sdfr if (segs_needed > nfree_msgmaps) { 7022729Sdfr#ifdef MSG_DEBUG_OK 7032729Sdfr printf("segs_needed > nfree_msgmaps\n"); 7042729Sdfr#endif 7052729Sdfr need_more_resources = 1; 7062729Sdfr } 7072729Sdfr if (free_msghdrs == NULL) { 7082729Sdfr#ifdef MSG_DEBUG_OK 7092729Sdfr printf("no more msghdrs\n"); 7102729Sdfr#endif 7112729Sdfr need_more_resources = 1; 7122729Sdfr } 7132729Sdfr 7142729Sdfr if (need_more_resources) { 7152729Sdfr int we_own_it; 7162729Sdfr 7172729Sdfr if ((msgflg & IPC_NOWAIT) != 0) { 7182729Sdfr#ifdef MSG_DEBUG_OK 7192729Sdfr printf("need more resources but caller doesn't want to wait\n"); 7202729Sdfr#endif 72182607Sdillon error = EAGAIN; 72282607Sdillon goto done2; 7232729Sdfr } 7242729Sdfr 7252729Sdfr if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) { 7262729Sdfr#ifdef MSG_DEBUG_OK 7272729Sdfr printf("we don't own the msqid_ds\n"); 7282729Sdfr#endif 7292729Sdfr we_own_it = 0; 7302729Sdfr } else { 7312729Sdfr /* Force later arrivals to wait for our 7322729Sdfr request */ 7332729Sdfr#ifdef MSG_DEBUG_OK 7342729Sdfr printf("we own the msqid_ds\n"); 7352729Sdfr#endif 7362729Sdfr msqptr->msg_perm.mode |= MSG_LOCKED; 7372729Sdfr we_own_it = 1; 7382729Sdfr } 7392729Sdfr#ifdef MSG_DEBUG_OK 7402729Sdfr printf("goodnight\n"); 7412729Sdfr#endif 74282607Sdillon error = tsleep((caddr_t)msqptr, (PZERO - 4) | PCATCH, 7432729Sdfr "msgwait", 0); 7442729Sdfr#ifdef MSG_DEBUG_OK 74582607Sdillon printf("good morning, error=%d\n", error); 7462729Sdfr#endif 7472729Sdfr if (we_own_it) 7482729Sdfr msqptr->msg_perm.mode &= ~MSG_LOCKED; 74982607Sdillon if (error != 0) { 7502729Sdfr#ifdef MSG_DEBUG_OK 7512729Sdfr printf("msgsnd: interrupted system call\n"); 7522729Sdfr#endif 75382607Sdillon error = EINTR; 75482607Sdillon goto done2; 7552729Sdfr } 7562729Sdfr 7572729Sdfr /* 7582729Sdfr * Make sure that the msq queue still exists 7592729Sdfr */ 7602729Sdfr 7612729Sdfr if (msqptr->msg_qbytes == 0) { 7622729Sdfr#ifdef MSG_DEBUG_OK 7632729Sdfr printf("msqid deleted\n"); 7642729Sdfr#endif 76582607Sdillon error = EIDRM; 76682607Sdillon goto done2; 7672729Sdfr } 7682729Sdfr 7692729Sdfr } else { 7702729Sdfr#ifdef MSG_DEBUG_OK 7712729Sdfr printf("got all the resources that we need\n"); 7722729Sdfr#endif 7732729Sdfr break; 7742729Sdfr } 7752729Sdfr } 7762729Sdfr 7772729Sdfr /* 7782729Sdfr * We have the resources that we need. 7792729Sdfr * Make sure! 7802729Sdfr */ 7812729Sdfr 7822729Sdfr if (msqptr->msg_perm.mode & MSG_LOCKED) 7832729Sdfr panic("msg_perm.mode & MSG_LOCKED"); 7842729Sdfr if (segs_needed > nfree_msgmaps) 7852729Sdfr panic("segs_needed > nfree_msgmaps"); 7862729Sdfr if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) 7872729Sdfr panic("msgsz + msg_cbytes > msg_qbytes"); 7882729Sdfr if (free_msghdrs == NULL) 7892729Sdfr panic("no more msghdrs"); 7902729Sdfr 7912729Sdfr /* 7922729Sdfr * Re-lock the msqid_ds in case we page-fault when copying in the 7932729Sdfr * message 7942729Sdfr */ 7952729Sdfr 7962729Sdfr if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) 7972729Sdfr panic("msqid_ds is already locked"); 7982729Sdfr msqptr->msg_perm.mode |= MSG_LOCKED; 7992729Sdfr 8002729Sdfr /* 8012729Sdfr * Allocate a message header 8022729Sdfr */ 8032729Sdfr 8042729Sdfr msghdr = free_msghdrs; 8052729Sdfr free_msghdrs = msghdr->msg_next; 8062729Sdfr msghdr->msg_spot = -1; 8072729Sdfr msghdr->msg_ts = msgsz; 8082729Sdfr 8092729Sdfr /* 8102729Sdfr * Allocate space for the message 8112729Sdfr */ 8122729Sdfr 8132729Sdfr while (segs_needed > 0) { 8142729Sdfr if (nfree_msgmaps <= 0) 8152729Sdfr panic("not enough msgmaps"); 8162729Sdfr if (free_msgmaps == -1) 8172729Sdfr panic("nil free_msgmaps"); 8182729Sdfr next = free_msgmaps; 8192729Sdfr if (next <= -1) 8202729Sdfr panic("next too low #1"); 8212729Sdfr if (next >= msginfo.msgseg) 8222729Sdfr panic("next out of range #1"); 8232729Sdfr#ifdef MSG_DEBUG_OK 8242729Sdfr printf("allocating segment %d to message\n", next); 8252729Sdfr#endif 8262729Sdfr free_msgmaps = msgmaps[next].next; 8272729Sdfr nfree_msgmaps--; 8282729Sdfr msgmaps[next].next = msghdr->msg_spot; 8292729Sdfr msghdr->msg_spot = next; 8302729Sdfr segs_needed--; 8312729Sdfr } 8322729Sdfr 8332729Sdfr /* 8342729Sdfr * Copy in the message type 8352729Sdfr */ 8362729Sdfr 83782607Sdillon if ((error = copyin(user_msgp, &msghdr->msg_type, 8382729Sdfr sizeof(msghdr->msg_type))) != 0) { 8392729Sdfr#ifdef MSG_DEBUG_OK 84082607Sdillon printf("error %d copying the message type\n", error); 8412729Sdfr#endif 8422729Sdfr msg_freehdr(msghdr); 8432729Sdfr msqptr->msg_perm.mode &= ~MSG_LOCKED; 8442729Sdfr wakeup((caddr_t)msqptr); 84582607Sdillon goto done2; 8462729Sdfr } 84717971Sbde user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type); 8482729Sdfr 8492729Sdfr /* 8502729Sdfr * Validate the message type 8512729Sdfr */ 8522729Sdfr 8532729Sdfr if (msghdr->msg_type < 1) { 8542729Sdfr msg_freehdr(msghdr); 8552729Sdfr msqptr->msg_perm.mode &= ~MSG_LOCKED; 8562729Sdfr wakeup((caddr_t)msqptr); 8572729Sdfr#ifdef MSG_DEBUG_OK 8582729Sdfr printf("mtype (%d) < 1\n", msghdr->msg_type); 8592729Sdfr#endif 86082607Sdillon error = EINVAL; 86182607Sdillon goto done2; 8622729Sdfr } 8632729Sdfr 8642729Sdfr /* 8652729Sdfr * Copy in the message body 8662729Sdfr */ 8672729Sdfr 8682729Sdfr next = msghdr->msg_spot; 8692729Sdfr while (msgsz > 0) { 8702729Sdfr size_t tlen; 8712729Sdfr if (msgsz > msginfo.msgssz) 8722729Sdfr tlen = msginfo.msgssz; 8732729Sdfr else 8742729Sdfr tlen = msgsz; 8752729Sdfr if (next <= -1) 8762729Sdfr panic("next too low #2"); 8772729Sdfr if (next >= msginfo.msgseg) 8782729Sdfr panic("next out of range #2"); 87982607Sdillon if ((error = copyin(user_msgp, &msgpool[next * msginfo.msgssz], 8802729Sdfr tlen)) != 0) { 8812729Sdfr#ifdef MSG_DEBUG_OK 88282607Sdillon printf("error %d copying in message segment\n", error); 8832729Sdfr#endif 8842729Sdfr msg_freehdr(msghdr); 8852729Sdfr msqptr->msg_perm.mode &= ~MSG_LOCKED; 8862729Sdfr wakeup((caddr_t)msqptr); 88782607Sdillon goto done2; 8882729Sdfr } 8892729Sdfr msgsz -= tlen; 89017971Sbde user_msgp = (char *)user_msgp + tlen; 8912729Sdfr next = msgmaps[next].next; 8922729Sdfr } 8932729Sdfr if (next != -1) 8942729Sdfr panic("didn't use all the msg segments"); 8952729Sdfr 8962729Sdfr /* 8972729Sdfr * We've got the message. Unlock the msqid_ds. 8982729Sdfr */ 8992729Sdfr 9002729Sdfr msqptr->msg_perm.mode &= ~MSG_LOCKED; 9012729Sdfr 9022729Sdfr /* 9032729Sdfr * Make sure that the msqid_ds is still allocated. 9042729Sdfr */ 9052729Sdfr 9062729Sdfr if (msqptr->msg_qbytes == 0) { 9072729Sdfr msg_freehdr(msghdr); 9082729Sdfr wakeup((caddr_t)msqptr); 90982607Sdillon error = EIDRM; 91082607Sdillon goto done2; 9112729Sdfr } 9122729Sdfr 9132729Sdfr /* 9142729Sdfr * Put the message into the queue 9152729Sdfr */ 9162729Sdfr 9172729Sdfr if (msqptr->msg_first == NULL) { 9182729Sdfr msqptr->msg_first = msghdr; 9192729Sdfr msqptr->msg_last = msghdr; 9202729Sdfr } else { 9212729Sdfr msqptr->msg_last->msg_next = msghdr; 9222729Sdfr msqptr->msg_last = msghdr; 9232729Sdfr } 9242729Sdfr msqptr->msg_last->msg_next = NULL; 9252729Sdfr 9262729Sdfr msqptr->msg_cbytes += msghdr->msg_ts; 9272729Sdfr msqptr->msg_qnum++; 92883366Sjulian msqptr->msg_lspid = td->td_proc->p_pid; 92934961Sphk msqptr->msg_stime = time_second; 9302729Sdfr 9312729Sdfr wakeup((caddr_t)msqptr); 93283366Sjulian td->td_retval[0] = 0; 93382607Sdillondone2: 93482607Sdillon mtx_unlock(&Giant); 93582607Sdillon return (error); 9362729Sdfr} 9372729Sdfr 93812866Speter#ifndef _SYS_SYSPROTO_H_ 9392729Sdfrstruct msgrcv_args { 9402729Sdfr int msqid; 9412729Sdfr void *msgp; 9422729Sdfr size_t msgsz; 9432729Sdfr long msgtyp; 9442729Sdfr int msgflg; 9452729Sdfr}; 94612866Speter#endif 9472729Sdfr 94882607Sdillon/* 94982607Sdillon * MPSAFE 95082607Sdillon */ 95112866Speterint 95283366Sjulianmsgrcv(td, uap) 95383366Sjulian struct thread *td; 9542729Sdfr register struct msgrcv_args *uap; 9552729Sdfr{ 9562729Sdfr int msqid = uap->msqid; 9572729Sdfr void *user_msgp = uap->msgp; 9582729Sdfr size_t msgsz = uap->msgsz; 9592729Sdfr long msgtyp = uap->msgtyp; 9602729Sdfr int msgflg = uap->msgflg; 9612729Sdfr size_t len; 9622729Sdfr register struct msqid_ds *msqptr; 9632729Sdfr register struct msg *msghdr; 96482607Sdillon int error = 0; 9652729Sdfr short next; 9662729Sdfr 9672729Sdfr#ifdef MSG_DEBUG_OK 9682729Sdfr printf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp, 9692729Sdfr msgsz, msgtyp, msgflg); 9702729Sdfr#endif 9712729Sdfr 97282607Sdillon mtx_lock(&Giant); 97383366Sjulian if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) { 97482607Sdillon error = ENOSYS; 97582607Sdillon goto done2; 97682607Sdillon } 97782607Sdillon 9782729Sdfr msqid = IPCID_TO_IX(msqid); 9792729Sdfr 9802729Sdfr if (msqid < 0 || msqid >= msginfo.msgmni) { 9812729Sdfr#ifdef MSG_DEBUG_OK 9822729Sdfr printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid, 9832729Sdfr msginfo.msgmni); 9842729Sdfr#endif 98582607Sdillon error = EINVAL; 98682607Sdillon goto done2; 9872729Sdfr } 9882729Sdfr 9892729Sdfr msqptr = &msqids[msqid]; 9902729Sdfr if (msqptr->msg_qbytes == 0) { 9912729Sdfr#ifdef MSG_DEBUG_OK 9922729Sdfr printf("no such message queue id\n"); 9932729Sdfr#endif 99482607Sdillon error = EINVAL; 99582607Sdillon goto done2; 9962729Sdfr } 9972729Sdfr if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { 9982729Sdfr#ifdef MSG_DEBUG_OK 9992729Sdfr printf("wrong sequence number\n"); 10002729Sdfr#endif 100182607Sdillon error = EINVAL; 100282607Sdillon goto done2; 10032729Sdfr } 10042729Sdfr 100583366Sjulian if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) { 10062729Sdfr#ifdef MSG_DEBUG_OK 10072729Sdfr printf("requester doesn't have read access\n"); 10082729Sdfr#endif 100982607Sdillon goto done2; 10102729Sdfr } 10112729Sdfr 10122729Sdfr msghdr = NULL; 10132729Sdfr while (msghdr == NULL) { 10142729Sdfr if (msgtyp == 0) { 10152729Sdfr msghdr = msqptr->msg_first; 10162729Sdfr if (msghdr != NULL) { 10172729Sdfr if (msgsz < msghdr->msg_ts && 10182729Sdfr (msgflg & MSG_NOERROR) == 0) { 10192729Sdfr#ifdef MSG_DEBUG_OK 10202729Sdfr printf("first message on the queue is too big (want %d, got %d)\n", 10212729Sdfr msgsz, msghdr->msg_ts); 10222729Sdfr#endif 102382607Sdillon error = E2BIG; 102482607Sdillon goto done2; 10252729Sdfr } 10262729Sdfr if (msqptr->msg_first == msqptr->msg_last) { 10272729Sdfr msqptr->msg_first = NULL; 10282729Sdfr msqptr->msg_last = NULL; 10292729Sdfr } else { 10302729Sdfr msqptr->msg_first = msghdr->msg_next; 10312729Sdfr if (msqptr->msg_first == NULL) 10322729Sdfr panic("msg_first/last screwed up #1"); 10332729Sdfr } 10342729Sdfr } 10352729Sdfr } else { 10362729Sdfr struct msg *previous; 10372729Sdfr struct msg **prev; 10382729Sdfr 10392729Sdfr previous = NULL; 10402729Sdfr prev = &(msqptr->msg_first); 10412729Sdfr while ((msghdr = *prev) != NULL) { 10422729Sdfr /* 10432729Sdfr * Is this message's type an exact match or is 10442729Sdfr * this message's type less than or equal to 10452729Sdfr * the absolute value of a negative msgtyp? 10462729Sdfr * Note that the second half of this test can 10472729Sdfr * NEVER be true if msgtyp is positive since 10482729Sdfr * msg_type is always positive! 10492729Sdfr */ 10502729Sdfr 10512729Sdfr if (msgtyp == msghdr->msg_type || 10522729Sdfr msghdr->msg_type <= -msgtyp) { 10532729Sdfr#ifdef MSG_DEBUG_OK 10542729Sdfr printf("found message type %d, requested %d\n", 10552729Sdfr msghdr->msg_type, msgtyp); 10562729Sdfr#endif 10572729Sdfr if (msgsz < msghdr->msg_ts && 10582729Sdfr (msgflg & MSG_NOERROR) == 0) { 10592729Sdfr#ifdef MSG_DEBUG_OK 10602729Sdfr printf("requested message on the queue is too big (want %d, got %d)\n", 10612729Sdfr msgsz, msghdr->msg_ts); 10622729Sdfr#endif 106382607Sdillon error = E2BIG; 106482607Sdillon goto done2; 10652729Sdfr } 10662729Sdfr *prev = msghdr->msg_next; 10672729Sdfr if (msghdr == msqptr->msg_last) { 10682729Sdfr if (previous == NULL) { 10692729Sdfr if (prev != 10702729Sdfr &msqptr->msg_first) 10712729Sdfr panic("msg_first/last screwed up #2"); 10722729Sdfr msqptr->msg_first = 10732729Sdfr NULL; 10742729Sdfr msqptr->msg_last = 10752729Sdfr NULL; 10762729Sdfr } else { 10772729Sdfr if (prev == 10782729Sdfr &msqptr->msg_first) 10792729Sdfr panic("msg_first/last screwed up #3"); 10802729Sdfr msqptr->msg_last = 10812729Sdfr previous; 10822729Sdfr } 10832729Sdfr } 10842729Sdfr break; 10852729Sdfr } 10862729Sdfr previous = msghdr; 10872729Sdfr prev = &(msghdr->msg_next); 10882729Sdfr } 10892729Sdfr } 10902729Sdfr 10912729Sdfr /* 10922729Sdfr * We've either extracted the msghdr for the appropriate 10932729Sdfr * message or there isn't one. 10942729Sdfr * If there is one then bail out of this loop. 10952729Sdfr */ 10962729Sdfr 10972729Sdfr if (msghdr != NULL) 10982729Sdfr break; 10992729Sdfr 11002729Sdfr /* 11012729Sdfr * Hmph! No message found. Does the user want to wait? 11022729Sdfr */ 11032729Sdfr 11042729Sdfr if ((msgflg & IPC_NOWAIT) != 0) { 11052729Sdfr#ifdef MSG_DEBUG_OK 11062729Sdfr printf("no appropriate message found (msgtyp=%d)\n", 11072729Sdfr msgtyp); 11082729Sdfr#endif 11092729Sdfr /* The SVID says to return ENOMSG. */ 111082607Sdillon error = ENOMSG; 111182607Sdillon goto done2; 11122729Sdfr } 11132729Sdfr 11142729Sdfr /* 11152729Sdfr * Wait for something to happen 11162729Sdfr */ 11172729Sdfr 11182729Sdfr#ifdef MSG_DEBUG_OK 11192729Sdfr printf("msgrcv: goodnight\n"); 11202729Sdfr#endif 112182607Sdillon error = tsleep((caddr_t)msqptr, (PZERO - 4) | PCATCH, "msgwait", 11222729Sdfr 0); 11232729Sdfr#ifdef MSG_DEBUG_OK 112482607Sdillon printf("msgrcv: good morning (error=%d)\n", error); 11252729Sdfr#endif 11262729Sdfr 112782607Sdillon if (error != 0) { 11282729Sdfr#ifdef MSG_DEBUG_OK 11292729Sdfr printf("msgsnd: interrupted system call\n"); 11302729Sdfr#endif 113182607Sdillon error = EINTR; 113282607Sdillon goto done2; 11332729Sdfr } 11342729Sdfr 11352729Sdfr /* 11362729Sdfr * Make sure that the msq queue still exists 11372729Sdfr */ 11382729Sdfr 11392729Sdfr if (msqptr->msg_qbytes == 0 || 11402729Sdfr msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { 11412729Sdfr#ifdef MSG_DEBUG_OK 11422729Sdfr printf("msqid deleted\n"); 11432729Sdfr#endif 114482607Sdillon error = EIDRM; 114582607Sdillon goto done2; 11462729Sdfr } 11472729Sdfr } 11482729Sdfr 11492729Sdfr /* 11502729Sdfr * Return the message to the user. 11512729Sdfr * 11522729Sdfr * First, do the bookkeeping (before we risk being interrupted). 11532729Sdfr */ 11542729Sdfr 11552729Sdfr msqptr->msg_cbytes -= msghdr->msg_ts; 11562729Sdfr msqptr->msg_qnum--; 115783366Sjulian msqptr->msg_lrpid = td->td_proc->p_pid; 115834961Sphk msqptr->msg_rtime = time_second; 11592729Sdfr 11602729Sdfr /* 11612729Sdfr * Make msgsz the actual amount that we'll be returning. 11622729Sdfr * Note that this effectively truncates the message if it is too long 11632729Sdfr * (since msgsz is never increased). 11642729Sdfr */ 11652729Sdfr 11662729Sdfr#ifdef MSG_DEBUG_OK 11672729Sdfr printf("found a message, msgsz=%d, msg_ts=%d\n", msgsz, 11682729Sdfr msghdr->msg_ts); 11692729Sdfr#endif 11702729Sdfr if (msgsz > msghdr->msg_ts) 11712729Sdfr msgsz = msghdr->msg_ts; 11722729Sdfr 11732729Sdfr /* 11742729Sdfr * Return the type to the user. 11752729Sdfr */ 11762729Sdfr 117782607Sdillon error = copyout((caddr_t)&(msghdr->msg_type), user_msgp, 11782729Sdfr sizeof(msghdr->msg_type)); 117982607Sdillon if (error != 0) { 11802729Sdfr#ifdef MSG_DEBUG_OK 118182607Sdillon printf("error (%d) copying out message type\n", error); 11822729Sdfr#endif 11832729Sdfr msg_freehdr(msghdr); 11842729Sdfr wakeup((caddr_t)msqptr); 118582607Sdillon goto done2; 11862729Sdfr } 118717971Sbde user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type); 11882729Sdfr 11892729Sdfr /* 11902729Sdfr * Return the segments to the user 11912729Sdfr */ 11922729Sdfr 11932729Sdfr next = msghdr->msg_spot; 11942729Sdfr for (len = 0; len < msgsz; len += msginfo.msgssz) { 11952729Sdfr size_t tlen; 11962729Sdfr 119745921Ssada if (msgsz - len > msginfo.msgssz) 11982729Sdfr tlen = msginfo.msgssz; 11992729Sdfr else 120045921Ssada tlen = msgsz - len; 12012729Sdfr if (next <= -1) 12022729Sdfr panic("next too low #3"); 12032729Sdfr if (next >= msginfo.msgseg) 12042729Sdfr panic("next out of range #3"); 120582607Sdillon error = copyout((caddr_t)&msgpool[next * msginfo.msgssz], 12062729Sdfr user_msgp, tlen); 120782607Sdillon if (error != 0) { 12082729Sdfr#ifdef MSG_DEBUG_OK 12092729Sdfr printf("error (%d) copying out message segment\n", 121082607Sdillon error); 12112729Sdfr#endif 12122729Sdfr msg_freehdr(msghdr); 12132729Sdfr wakeup((caddr_t)msqptr); 121482607Sdillon goto done2; 12152729Sdfr } 121617971Sbde user_msgp = (char *)user_msgp + tlen; 12172729Sdfr next = msgmaps[next].next; 12182729Sdfr } 12192729Sdfr 12202729Sdfr /* 12212729Sdfr * Done, return the actual number of bytes copied out. 12222729Sdfr */ 12232729Sdfr 12242729Sdfr msg_freehdr(msghdr); 12252729Sdfr wakeup((caddr_t)msqptr); 122683366Sjulian td->td_retval[0] = msgsz; 122782607Sdillondone2: 122882607Sdillon mtx_unlock(&Giant); 122982607Sdillon return (error); 12302729Sdfr} 123177461Sdd 123277461Sddstatic int 123377461Sddsysctl_msqids(SYSCTL_HANDLER_ARGS) 123477461Sdd{ 123577461Sdd 123677461Sdd return (SYSCTL_OUT(req, msqids, 123777461Sdd sizeof(struct msqid_ds) * msginfo.msgmni)); 123877461Sdd} 123977461Sdd 124077461SddSYSCTL_DECL(_kern_ipc); 124177461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, ""); 124277461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, ""); 124377461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, ""); 124477461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, ""); 124577461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, ""); 124677461SddSYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "") 124777461SddSYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD, 124877461Sdd NULL, 0, sysctl_msqids, "", "Message queue IDs"); 1249