freebsd-dev/sys/kern/sysv_msg.c

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1999-08-28 01:08:13 +00:00
/* $FreeBSD$ */
/*
* Implementation of SVID messages
*
* Author: Daniel Boulet
*
* Copyright 1993 Daniel Boulet and RTMX Inc.
*
* This system call was implemented by Daniel Boulet under contract from RTMX.
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*/
#include "opt_sysvipc.h"
#include <sys/param.h>
#include <sys/systm.h>
Start including <sys/sysproto.h> to get the correct args structs and prototypes for all syscalls. The args structs are still declared in comments as in VOP implementation functions. I don't like the duplication for this, but several more layers of changes are required to get it right. First we need to catch up with 4.4lite2, which uses macros to handle struct padding. Then we need to catch up with NetBSD, which passes the args correctly (as void *). Then we need to handle varargs functions and struct padding better. I think all the details can be hidden in machine-generated functions so that the args structs and verbose macros to reference them don't have to appear in the core sources. Add prototypes. Add bogus casts to hide the evil type puns exposed by the previous steps. &uap[1] was used to get at the args after the first. This worked because only the first arg in *uap was declared. This broke when the machine- genenerated args struct declared all the args (actually it declares extra args in some cases and depends on the user stack having some accessible junk after the last arg, not to mention the user args being on the stack. It isn't possible to declare a correct args struct for a varargs syscall). The msgsys(), semsys() and shmsys() syscall interfaces are BAD because they multiplex several syscalls that have different types of args. There was no reason to duplicate this sysv braindamage but now we're stuck with it. NetBSD has reimplemented the syscalls properly as separate syscalls #220-231. Declare static functions as static in both their prototype and their implementation (the latter is optional, and this misfeature was used). Remove gratuitous #includes. Continue cleaning up new init stuff.
1995-10-21 19:50:00 +00:00
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/msg.h>
#include <sys/syscall.h>
Start including <sys/sysproto.h> to get the correct args structs and prototypes for all syscalls. The args structs are still declared in comments as in VOP implementation functions. I don't like the duplication for this, but several more layers of changes are required to get it right. First we need to catch up with 4.4lite2, which uses macros to handle struct padding. Then we need to catch up with NetBSD, which passes the args correctly (as void *). Then we need to handle varargs functions and struct padding better. I think all the details can be hidden in machine-generated functions so that the args structs and verbose macros to reference them don't have to appear in the core sources. Add prototypes. Add bogus casts to hide the evil type puns exposed by the previous steps. &uap[1] was used to get at the args after the first. This worked because only the first arg in *uap was declared. This broke when the machine- genenerated args struct declared all the args (actually it declares extra args in some cases and depends on the user stack having some accessible junk after the last arg, not to mention the user args being on the stack. It isn't possible to declare a correct args struct for a varargs syscall). The msgsys(), semsys() and shmsys() syscall interfaces are BAD because they multiplex several syscalls that have different types of args. There was no reason to duplicate this sysv braindamage but now we're stuck with it. NetBSD has reimplemented the syscalls properly as separate syscalls #220-231. Declare static functions as static in both their prototype and their implementation (the latter is optional, and this misfeature was used). Remove gratuitous #includes. Continue cleaning up new init stuff.
1995-10-21 19:50:00 +00:00
#include <sys/sysent.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/jail.h>
static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
static void msginit __P((void));
static int msgunload __P((void));
static int sysvmsg_modload __P((struct module *, int, void *));
#define MSG_DEBUG
#undef MSG_DEBUG_OK
Start including <sys/sysproto.h> to get the correct args structs and prototypes for all syscalls. The args structs are still declared in comments as in VOP implementation functions. I don't like the duplication for this, but several more layers of changes are required to get it right. First we need to catch up with 4.4lite2, which uses macros to handle struct padding. Then we need to catch up with NetBSD, which passes the args correctly (as void *). Then we need to handle varargs functions and struct padding better. I think all the details can be hidden in machine-generated functions so that the args structs and verbose macros to reference them don't have to appear in the core sources. Add prototypes. Add bogus casts to hide the evil type puns exposed by the previous steps. &uap[1] was used to get at the args after the first. This worked because only the first arg in *uap was declared. This broke when the machine- genenerated args struct declared all the args (actually it declares extra args in some cases and depends on the user stack having some accessible junk after the last arg, not to mention the user args being on the stack. It isn't possible to declare a correct args struct for a varargs syscall). The msgsys(), semsys() and shmsys() syscall interfaces are BAD because they multiplex several syscalls that have different types of args. There was no reason to duplicate this sysv braindamage but now we're stuck with it. NetBSD has reimplemented the syscalls properly as separate syscalls #220-231. Declare static functions as static in both their prototype and their implementation (the latter is optional, and this misfeature was used). Remove gratuitous #includes. Continue cleaning up new init stuff.
1995-10-21 19:50:00 +00:00
static void msg_freehdr __P((struct msg *msghdr));
/* XXX casting to (sy_call_t *) is bogus, as usual. */
static sy_call_t *msgcalls[] = {
Start including <sys/sysproto.h> to get the correct args structs and prototypes for all syscalls. The args structs are still declared in comments as in VOP implementation functions. I don't like the duplication for this, but several more layers of changes are required to get it right. First we need to catch up with 4.4lite2, which uses macros to handle struct padding. Then we need to catch up with NetBSD, which passes the args correctly (as void *). Then we need to handle varargs functions and struct padding better. I think all the details can be hidden in machine-generated functions so that the args structs and verbose macros to reference them don't have to appear in the core sources. Add prototypes. Add bogus casts to hide the evil type puns exposed by the previous steps. &uap[1] was used to get at the args after the first. This worked because only the first arg in *uap was declared. This broke when the machine- genenerated args struct declared all the args (actually it declares extra args in some cases and depends on the user stack having some accessible junk after the last arg, not to mention the user args being on the stack. It isn't possible to declare a correct args struct for a varargs syscall). The msgsys(), semsys() and shmsys() syscall interfaces are BAD because they multiplex several syscalls that have different types of args. There was no reason to duplicate this sysv braindamage but now we're stuck with it. NetBSD has reimplemented the syscalls properly as separate syscalls #220-231. Declare static functions as static in both their prototype and their implementation (the latter is optional, and this misfeature was used). Remove gratuitous #includes. Continue cleaning up new init stuff.
1995-10-21 19:50:00 +00:00
(sy_call_t *)msgctl, (sy_call_t *)msgget,
(sy_call_t *)msgsnd, (sy_call_t *)msgrcv
};
struct msg {
struct msg *msg_next; /* next msg in the chain */
long msg_type; /* type of this message */
/* >0 -> type of this message */
/* 0 -> free header */
u_short msg_ts; /* size of this message */
short msg_spot; /* location of start of msg in buffer */
};
#ifndef MSGSSZ
#define MSGSSZ 8 /* Each segment must be 2^N long */
#endif
#ifndef MSGSEG
#define MSGSEG 2048 /* must be less than 32767 */
#endif
#define MSGMAX (MSGSSZ*MSGSEG)
#ifndef MSGMNB
#define MSGMNB 2048 /* max # of bytes in a queue */
#endif
#ifndef MSGMNI
#define MSGMNI 40
#endif
#ifndef MSGTQL
#define MSGTQL 40
#endif
/*
* Based on the configuration parameters described in an SVR2 (yes, two)
* config(1m) man page.
*
* Each message is broken up and stored in segments that are msgssz bytes
* long. For efficiency reasons, this should be a power of two. Also,
* it doesn't make sense if it is less than 8 or greater than about 256.
* Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
* two between 8 and 1024 inclusive (and panic's if it isn't).
*/
struct msginfo msginfo = {
MSGMAX, /* max chars in a message */
MSGMNI, /* # of message queue identifiers */
MSGMNB, /* max chars in a queue */
MSGTQL, /* max messages in system */
MSGSSZ, /* size of a message segment */
/* (must be small power of 2 greater than 4) */
MSGSEG /* number of message segments */
};
/*
* macros to convert between msqid_ds's and msqid's.
* (specific to this implementation)
*/
#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
#define MSQID_IX(id) ((id) & 0xffff)
#define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
/*
* The rest of this file is specific to this particular implementation.
*/
struct msgmap {
short next; /* next segment in buffer */
/* -1 -> available */
/* 0..(MSGSEG-1) -> index of next segment */
};
#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
static int nfree_msgmaps; /* # of free map entries */
static short free_msgmaps; /* head of linked list of free map entries */
static struct msg *free_msghdrs;/* list of free msg headers */
static char *msgpool; /* MSGMAX byte long msg buffer pool */
static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
static struct msg *msghdrs; /* MSGTQL msg headers */
static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
static void
msginit()
{
register int i;
TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
if (msgpool == NULL)
panic("msgpool is NULL");
msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
if (msgmaps == NULL)
panic("msgmaps is NULL");
msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
if (msghdrs == NULL)
panic("msghdrs is NULL");
msqids = malloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
if (msqids == NULL)
panic("msqids is NULL");
/*
* msginfo.msgssz should be a power of two for efficiency reasons.
* It is also pretty silly if msginfo.msgssz is less than 8
* or greater than about 256 so ...
*/
i = 8;
while (i < 1024 && i != msginfo.msgssz)
i <<= 1;
if (i != msginfo.msgssz) {
printf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
msginfo.msgssz);
panic("msginfo.msgssz not a small power of 2");
}
if (msginfo.msgseg > 32767) {
printf("msginfo.msgseg=%d\n", msginfo.msgseg);
panic("msginfo.msgseg > 32767");
}
if (msgmaps == NULL)
panic("msgmaps is NULL");
for (i = 0; i < msginfo.msgseg; i++) {
if (i > 0)
msgmaps[i-1].next = i;
msgmaps[i].next = -1; /* implies entry is available */
}
free_msgmaps = 0;
nfree_msgmaps = msginfo.msgseg;
if (msghdrs == NULL)
panic("msghdrs is NULL");
for (i = 0; i < msginfo.msgtql; i++) {
msghdrs[i].msg_type = 0;
if (i > 0)
msghdrs[i-1].msg_next = &msghdrs[i];
msghdrs[i].msg_next = NULL;
}
free_msghdrs = &msghdrs[0];
if (msqids == NULL)
panic("msqids is NULL");
for (i = 0; i < msginfo.msgmni; i++) {
msqids[i].msg_qbytes = 0; /* implies entry is available */
msqids[i].msg_perm.seq = 0; /* reset to a known value */
msqids[i].msg_perm.mode = 0;
}
}
static int
msgunload()
{
struct msqid_ds *msqptr;
int msqid;
for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
/*
* Look for an unallocated and unlocked msqid_ds.
* msqid_ds's can be locked by msgsnd or msgrcv while
* they are copying the message in/out. We can't
* re-use the entry until they release it.
*/
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes != 0 ||
(msqptr->msg_perm.mode & MSG_LOCKED) != 0)
break;
}
if (msqid != msginfo.msgmni)
return (EBUSY);
free(msgpool, M_MSG);
free(msgmaps, M_MSG);
free(msghdrs, M_MSG);
free(msqids, M_MSG);
return (0);
}
static int
sysvmsg_modload(struct module *module, int cmd, void *arg)
{
int error = 0;
switch (cmd) {
case MOD_LOAD:
msginit();
break;
case MOD_UNLOAD:
error = msgunload();
break;
case MOD_SHUTDOWN:
break;
default:
error = EINVAL;
break;
}
return (error);
}
static moduledata_t sysvmsg_mod = {
"sysvmsg",
&sysvmsg_modload,
NULL
};
SYSCALL_MODULE_HELPER(msgsys);
SYSCALL_MODULE_HELPER(msgctl);
SYSCALL_MODULE_HELPER(msgget);
SYSCALL_MODULE_HELPER(msgsnd);
SYSCALL_MODULE_HELPER(msgrcv);
DECLARE_MODULE(sysvmsg, sysvmsg_mod,
SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
MODULE_VERSION(sysvmsg, 1);
/*
* Entry point for all MSG calls
*
* MPSAFE
*/
int
msgsys(td, uap)
struct thread *td;
Start including <sys/sysproto.h> to get the correct args structs and prototypes for all syscalls. The args structs are still declared in comments as in VOP implementation functions. I don't like the duplication for this, but several more layers of changes are required to get it right. First we need to catch up with 4.4lite2, which uses macros to handle struct padding. Then we need to catch up with NetBSD, which passes the args correctly (as void *). Then we need to handle varargs functions and struct padding better. I think all the details can be hidden in machine-generated functions so that the args structs and verbose macros to reference them don't have to appear in the core sources. Add prototypes. Add bogus casts to hide the evil type puns exposed by the previous steps. &uap[1] was used to get at the args after the first. This worked because only the first arg in *uap was declared. This broke when the machine- genenerated args struct declared all the args (actually it declares extra args in some cases and depends on the user stack having some accessible junk after the last arg, not to mention the user args being on the stack. It isn't possible to declare a correct args struct for a varargs syscall). The msgsys(), semsys() and shmsys() syscall interfaces are BAD because they multiplex several syscalls that have different types of args. There was no reason to duplicate this sysv braindamage but now we're stuck with it. NetBSD has reimplemented the syscalls properly as separate syscalls #220-231. Declare static functions as static in both their prototype and their implementation (the latter is optional, and this misfeature was used). Remove gratuitous #includes. Continue cleaning up new init stuff.
1995-10-21 19:50:00 +00:00
/* XXX actually varargs. */
struct msgsys_args /* {
u_int which;
int a2;
int a3;
int a4;
int a5;
int a6;
} */ *uap;
{
int error;
mtx_lock(&Giant);
if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) {
error = ENOSYS;
goto done2;
}
if (uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0])) {
error = EINVAL;
goto done2;
}
error = (*msgcalls[uap->which])(td, &uap->a2);
done2:
mtx_unlock(&Giant);
return (error);
}
static void
msg_freehdr(msghdr)
struct msg *msghdr;
{
while (msghdr->msg_ts > 0) {
short next;
if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
panic("msghdr->msg_spot out of range");
next = msgmaps[msghdr->msg_spot].next;
msgmaps[msghdr->msg_spot].next = free_msgmaps;
free_msgmaps = msghdr->msg_spot;
nfree_msgmaps++;
msghdr->msg_spot = next;
if (msghdr->msg_ts >= msginfo.msgssz)
msghdr->msg_ts -= msginfo.msgssz;
else
msghdr->msg_ts = 0;
}
if (msghdr->msg_spot != -1)
panic("msghdr->msg_spot != -1");
msghdr->msg_next = free_msghdrs;
free_msghdrs = msghdr;
}
#ifndef _SYS_SYSPROTO_H_
struct msgctl_args {
int msqid;
int cmd;
struct msqid_ds *buf;
};
#endif
/*
* MPSAFE
*/
int
msgctl(td, uap)
struct thread *td;
register struct msgctl_args *uap;
{
int msqid = uap->msqid;
int cmd = uap->cmd;
struct msqid_ds *user_msqptr = uap->buf;
int rval, error;
struct msqid_ds msqbuf;
register struct msqid_ds *msqptr;
#ifdef MSG_DEBUG_OK
printf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
#endif
mtx_lock(&Giant);
if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) {
error = ENOSYS;
goto done2;
}
msqid = IPCID_TO_IX(msqid);
if (msqid < 0 || msqid >= msginfo.msgmni) {
#ifdef MSG_DEBUG_OK
printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
msginfo.msgmni);
#endif
error = EINVAL;
goto done2;
}
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes == 0) {
#ifdef MSG_DEBUG_OK
printf("no such msqid\n");
#endif
error = EINVAL;
goto done2;
}
if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
#ifdef MSG_DEBUG_OK
printf("wrong sequence number\n");
#endif
error = EINVAL;
goto done2;
}
error = 0;
rval = 0;
switch (cmd) {
case IPC_RMID:
{
struct msg *msghdr;
if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M)))
goto done2;
/* Free the message headers */
msghdr = msqptr->msg_first;
while (msghdr != NULL) {
struct msg *msghdr_tmp;
/* Free the segments of each message */
msqptr->msg_cbytes -= msghdr->msg_ts;
msqptr->msg_qnum--;
msghdr_tmp = msghdr;
msghdr = msghdr->msg_next;
msg_freehdr(msghdr_tmp);
}
if (msqptr->msg_cbytes != 0)
panic("msg_cbytes is screwed up");
if (msqptr->msg_qnum != 0)
panic("msg_qnum is screwed up");
msqptr->msg_qbytes = 0; /* Mark it as free */
wakeup((caddr_t)msqptr);
}
break;
case IPC_SET:
if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M)))
goto done2;
if ((error = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
goto done2;
if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
error = suser_td(td);
if (error)
goto done2;
}
if (msqbuf.msg_qbytes > msginfo.msgmnb) {
#ifdef MSG_DEBUG_OK
printf("can't increase msg_qbytes beyond %d (truncating)\n",
msginfo.msgmnb);
#endif
msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
}
if (msqbuf.msg_qbytes == 0) {
#ifdef MSG_DEBUG_OK
printf("can't reduce msg_qbytes to 0\n");
#endif
error = EINVAL; /* non-standard errno! */
goto done2;
}
msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
(msqbuf.msg_perm.mode & 0777);
msqptr->msg_qbytes = msqbuf.msg_qbytes;
msqptr->msg_ctime = time_second;
break;
case IPC_STAT:
if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) {
#ifdef MSG_DEBUG_OK
printf("requester doesn't have read access\n");
#endif
goto done2;
}
error = copyout((caddr_t)msqptr, user_msqptr,
sizeof(struct msqid_ds));
break;
default:
#ifdef MSG_DEBUG_OK
printf("invalid command %d\n", cmd);
#endif
error = EINVAL;
goto done2;
}
if (error == 0)
td->td_retval[0] = rval;
done2:
mtx_unlock(&Giant);
return(error);
}
#ifndef _SYS_SYSPROTO_H_
struct msgget_args {
key_t key;
int msgflg;
};
#endif
/*
* MPSAFE
*/
int
msgget(td, uap)
struct thread *td;
register struct msgget_args *uap;
{
int msqid, error = 0;
int key = uap->key;
int msgflg = uap->msgflg;
struct ucred *cred = td->td_proc->p_ucred;
1994-09-17 13:24:29 +00:00
register struct msqid_ds *msqptr = NULL;
#ifdef MSG_DEBUG_OK
printf("msgget(0x%x, 0%o)\n", key, msgflg);
#endif
mtx_lock(&Giant);
if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) {
error = ENOSYS;
goto done2;
}
if (key != IPC_PRIVATE) {
for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes != 0 &&
msqptr->msg_perm.key == key)
break;
}
if (msqid < msginfo.msgmni) {
#ifdef MSG_DEBUG_OK
printf("found public key\n");
#endif
if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
#ifdef MSG_DEBUG_OK
printf("not exclusive\n");
#endif
error = EEXIST;
goto done2;
}
if ((error = ipcperm(td, &msqptr->msg_perm, msgflg & 0700 ))) {
#ifdef MSG_DEBUG_OK
printf("requester doesn't have 0%o access\n",
msgflg & 0700);
#endif
goto done2;
}
goto found;
}
}
#ifdef MSG_DEBUG_OK
printf("need to allocate the msqid_ds\n");
#endif
if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
/*
* Look for an unallocated and unlocked msqid_ds.
* msqid_ds's can be locked by msgsnd or msgrcv while
* they are copying the message in/out. We can't
* re-use the entry until they release it.
*/
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes == 0 &&
(msqptr->msg_perm.mode & MSG_LOCKED) == 0)
break;
}
if (msqid == msginfo.msgmni) {
#ifdef MSG_DEBUG_OK
printf("no more msqid_ds's available\n");
#endif
error = ENOSPC;
goto done2;
}
#ifdef MSG_DEBUG_OK
printf("msqid %d is available\n", msqid);
#endif
msqptr->msg_perm.key = key;
msqptr->msg_perm.cuid = cred->cr_uid;
msqptr->msg_perm.uid = cred->cr_uid;
msqptr->msg_perm.cgid = cred->cr_gid;
msqptr->msg_perm.gid = cred->cr_gid;
msqptr->msg_perm.mode = (msgflg & 0777);
/* Make sure that the returned msqid is unique */
msqptr->msg_perm.seq++;
msqptr->msg_first = NULL;
msqptr->msg_last = NULL;
msqptr->msg_cbytes = 0;
msqptr->msg_qnum = 0;
msqptr->msg_qbytes = msginfo.msgmnb;
msqptr->msg_lspid = 0;
msqptr->msg_lrpid = 0;
msqptr->msg_stime = 0;
msqptr->msg_rtime = 0;
msqptr->msg_ctime = time_second;
} else {
#ifdef MSG_DEBUG_OK
printf("didn't find it and wasn't asked to create it\n");
#endif
error = ENOENT;
goto done2;
}
found:
/* Construct the unique msqid */
td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
done2:
mtx_unlock(&Giant);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct msgsnd_args {
int msqid;
void *msgp;
size_t msgsz;
int msgflg;
};
#endif
/*
* MPSAFE
*/
int
msgsnd(td, uap)
struct thread *td;
register struct msgsnd_args *uap;
{
int msqid = uap->msqid;
void *user_msgp = uap->msgp;
size_t msgsz = uap->msgsz;
int msgflg = uap->msgflg;
int segs_needed, error = 0;
register struct msqid_ds *msqptr;
register struct msg *msghdr;
short next;
#ifdef MSG_DEBUG_OK
printf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
msgflg);
#endif
mtx_lock(&Giant);
if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) {
error = ENOSYS;
goto done2;
}
msqid = IPCID_TO_IX(msqid);
if (msqid < 0 || msqid >= msginfo.msgmni) {
#ifdef MSG_DEBUG_OK
printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
msginfo.msgmni);
#endif
error = EINVAL;
goto done2;
}
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes == 0) {
#ifdef MSG_DEBUG_OK
printf("no such message queue id\n");
#endif
error = EINVAL;
goto done2;
}
if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
#ifdef MSG_DEBUG_OK
printf("wrong sequence number\n");
#endif
error = EINVAL;
goto done2;
}
if ((error = ipcperm(td, &msqptr->msg_perm, IPC_W))) {
#ifdef MSG_DEBUG_OK
printf("requester doesn't have write access\n");
#endif
goto done2;
}
segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
#ifdef MSG_DEBUG_OK
printf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
segs_needed);
#endif
for (;;) {
int need_more_resources = 0;
/*
* check msgsz
* (inside this loop in case msg_qbytes changes while we sleep)
*/
1994-09-17 13:24:29 +00:00
if (msgsz > msqptr->msg_qbytes) {
#ifdef MSG_DEBUG_OK
printf("msgsz > msqptr->msg_qbytes\n");
#endif
error = EINVAL;
goto done2;
}
if (msqptr->msg_perm.mode & MSG_LOCKED) {
#ifdef MSG_DEBUG_OK
printf("msqid is locked\n");
#endif
need_more_resources = 1;
}
if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
#ifdef MSG_DEBUG_OK
printf("msgsz + msg_cbytes > msg_qbytes\n");
#endif
need_more_resources = 1;
}
if (segs_needed > nfree_msgmaps) {
#ifdef MSG_DEBUG_OK
printf("segs_needed > nfree_msgmaps\n");
#endif
need_more_resources = 1;
}
if (free_msghdrs == NULL) {
#ifdef MSG_DEBUG_OK
printf("no more msghdrs\n");
#endif
need_more_resources = 1;
}
if (need_more_resources) {
int we_own_it;
if ((msgflg & IPC_NOWAIT) != 0) {
#ifdef MSG_DEBUG_OK
printf("need more resources but caller doesn't want to wait\n");
#endif
error = EAGAIN;
goto done2;
}
if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
#ifdef MSG_DEBUG_OK
printf("we don't own the msqid_ds\n");
#endif
we_own_it = 0;
} else {
/* Force later arrivals to wait for our
request */
#ifdef MSG_DEBUG_OK
printf("we own the msqid_ds\n");
#endif
msqptr->msg_perm.mode |= MSG_LOCKED;
we_own_it = 1;
}
#ifdef MSG_DEBUG_OK
printf("goodnight\n");
#endif
error = tsleep((caddr_t)msqptr, (PZERO - 4) | PCATCH,
"msgwait", 0);
#ifdef MSG_DEBUG_OK
printf("good morning, error=%d\n", error);
#endif
if (we_own_it)
msqptr->msg_perm.mode &= ~MSG_LOCKED;
if (error != 0) {
#ifdef MSG_DEBUG_OK
printf("msgsnd: interrupted system call\n");
#endif
error = EINTR;
goto done2;
}
/*
* Make sure that the msq queue still exists
*/
if (msqptr->msg_qbytes == 0) {
#ifdef MSG_DEBUG_OK
printf("msqid deleted\n");
#endif
error = EIDRM;
goto done2;
}
} else {
#ifdef MSG_DEBUG_OK
printf("got all the resources that we need\n");
#endif
break;
}
}
/*
* We have the resources that we need.
* Make sure!
*/
if (msqptr->msg_perm.mode & MSG_LOCKED)
panic("msg_perm.mode & MSG_LOCKED");
if (segs_needed > nfree_msgmaps)
panic("segs_needed > nfree_msgmaps");
if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
panic("msgsz + msg_cbytes > msg_qbytes");
if (free_msghdrs == NULL)
panic("no more msghdrs");
/*
* Re-lock the msqid_ds in case we page-fault when copying in the
* message
*/
if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
panic("msqid_ds is already locked");
msqptr->msg_perm.mode |= MSG_LOCKED;
/*
* Allocate a message header
*/
msghdr = free_msghdrs;
free_msghdrs = msghdr->msg_next;
msghdr->msg_spot = -1;
msghdr->msg_ts = msgsz;
/*
* Allocate space for the message
*/
while (segs_needed > 0) {
if (nfree_msgmaps <= 0)
panic("not enough msgmaps");
if (free_msgmaps == -1)
panic("nil free_msgmaps");
next = free_msgmaps;
if (next <= -1)
panic("next too low #1");
if (next >= msginfo.msgseg)
panic("next out of range #1");
#ifdef MSG_DEBUG_OK
printf("allocating segment %d to message\n", next);
#endif
free_msgmaps = msgmaps[next].next;
nfree_msgmaps--;
msgmaps[next].next = msghdr->msg_spot;
msghdr->msg_spot = next;
segs_needed--;
}
/*
* Copy in the message type
*/
if ((error = copyin(user_msgp, &msghdr->msg_type,
sizeof(msghdr->msg_type))) != 0) {
#ifdef MSG_DEBUG_OK
printf("error %d copying the message type\n", error);
#endif
msg_freehdr(msghdr);
msqptr->msg_perm.mode &= ~MSG_LOCKED;
wakeup((caddr_t)msqptr);
goto done2;
}
user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
/*
* Validate the message type
*/
if (msghdr->msg_type < 1) {
msg_freehdr(msghdr);
msqptr->msg_perm.mode &= ~MSG_LOCKED;
wakeup((caddr_t)msqptr);
#ifdef MSG_DEBUG_OK
printf("mtype (%d) < 1\n", msghdr->msg_type);
#endif
error = EINVAL;
goto done2;
}
/*
* Copy in the message body
*/
next = msghdr->msg_spot;
while (msgsz > 0) {
size_t tlen;
if (msgsz > msginfo.msgssz)
tlen = msginfo.msgssz;
else
tlen = msgsz;
if (next <= -1)
panic("next too low #2");
if (next >= msginfo.msgseg)
panic("next out of range #2");
if ((error = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
tlen)) != 0) {
#ifdef MSG_DEBUG_OK
printf("error %d copying in message segment\n", error);
#endif
msg_freehdr(msghdr);
msqptr->msg_perm.mode &= ~MSG_LOCKED;
wakeup((caddr_t)msqptr);
goto done2;
}
msgsz -= tlen;
user_msgp = (char *)user_msgp + tlen;
next = msgmaps[next].next;
}
if (next != -1)
panic("didn't use all the msg segments");
/*
* We've got the message. Unlock the msqid_ds.
*/
msqptr->msg_perm.mode &= ~MSG_LOCKED;
/*
* Make sure that the msqid_ds is still allocated.
*/
if (msqptr->msg_qbytes == 0) {
msg_freehdr(msghdr);
wakeup((caddr_t)msqptr);
error = EIDRM;
goto done2;
}
/*
* Put the message into the queue
*/
if (msqptr->msg_first == NULL) {
msqptr->msg_first = msghdr;
msqptr->msg_last = msghdr;
} else {
msqptr->msg_last->msg_next = msghdr;
msqptr->msg_last = msghdr;
}
msqptr->msg_last->msg_next = NULL;
msqptr->msg_cbytes += msghdr->msg_ts;
msqptr->msg_qnum++;
msqptr->msg_lspid = td->td_proc->p_pid;
msqptr->msg_stime = time_second;
wakeup((caddr_t)msqptr);
td->td_retval[0] = 0;
done2:
mtx_unlock(&Giant);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct msgrcv_args {
int msqid;
void *msgp;
size_t msgsz;
long msgtyp;
int msgflg;
};
#endif
/*
* MPSAFE
*/
int
msgrcv(td, uap)
struct thread *td;
register struct msgrcv_args *uap;
{
int msqid = uap->msqid;
void *user_msgp = uap->msgp;
size_t msgsz = uap->msgsz;
long msgtyp = uap->msgtyp;
int msgflg = uap->msgflg;
size_t len;
register struct msqid_ds *msqptr;
register struct msg *msghdr;
int error = 0;
short next;
#ifdef MSG_DEBUG_OK
printf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
msgsz, msgtyp, msgflg);
#endif
mtx_lock(&Giant);
if (!jail_sysvipc_allowed && jailed(td->td_proc->p_ucred)) {
error = ENOSYS;
goto done2;
}
msqid = IPCID_TO_IX(msqid);
if (msqid < 0 || msqid >= msginfo.msgmni) {
#ifdef MSG_DEBUG_OK
printf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
msginfo.msgmni);
#endif
error = EINVAL;
goto done2;
}
msqptr = &msqids[msqid];
if (msqptr->msg_qbytes == 0) {
#ifdef MSG_DEBUG_OK
printf("no such message queue id\n");
#endif
error = EINVAL;
goto done2;
}
if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
#ifdef MSG_DEBUG_OK
printf("wrong sequence number\n");
#endif
error = EINVAL;
goto done2;
}
if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) {
#ifdef MSG_DEBUG_OK
printf("requester doesn't have read access\n");
#endif
goto done2;
}
msghdr = NULL;
while (msghdr == NULL) {
if (msgtyp == 0) {
msghdr = msqptr->msg_first;
if (msghdr != NULL) {
if (msgsz < msghdr->msg_ts &&
(msgflg & MSG_NOERROR) == 0) {
#ifdef MSG_DEBUG_OK
printf("first message on the queue is too big (want %d, got %d)\n",
msgsz, msghdr->msg_ts);
#endif
error = E2BIG;
goto done2;
}
if (msqptr->msg_first == msqptr->msg_last) {
msqptr->msg_first = NULL;
msqptr->msg_last = NULL;
} else {
msqptr->msg_first = msghdr->msg_next;
if (msqptr->msg_first == NULL)
panic("msg_first/last screwed up #1");
}
}
} else {
struct msg *previous;
struct msg **prev;
previous = NULL;
prev = &(msqptr->msg_first);
while ((msghdr = *prev) != NULL) {
/*
* Is this message's type an exact match or is
* this message's type less than or equal to
* the absolute value of a negative msgtyp?
* Note that the second half of this test can
* NEVER be true if msgtyp is positive since
* msg_type is always positive!
*/
if (msgtyp == msghdr->msg_type ||
msghdr->msg_type <= -msgtyp) {
#ifdef MSG_DEBUG_OK
printf("found message type %d, requested %d\n",
msghdr->msg_type, msgtyp);
#endif
if (msgsz < msghdr->msg_ts &&
(msgflg & MSG_NOERROR) == 0) {
#ifdef MSG_DEBUG_OK
printf("requested message on the queue is too big (want %d, got %d)\n",
msgsz, msghdr->msg_ts);
#endif
error = E2BIG;
goto done2;
}
*prev = msghdr->msg_next;
if (msghdr == msqptr->msg_last) {
if (previous == NULL) {
if (prev !=
&msqptr->msg_first)
panic("msg_first/last screwed up #2");
msqptr->msg_first =
NULL;
msqptr->msg_last =
NULL;
} else {
if (prev ==
&msqptr->msg_first)
panic("msg_first/last screwed up #3");
msqptr->msg_last =
previous;
}
}
break;
}
previous = msghdr;
prev = &(msghdr->msg_next);
}
}
/*
* We've either extracted the msghdr for the appropriate
* message or there isn't one.
* If there is one then bail out of this loop.
*/
if (msghdr != NULL)
break;
/*
* Hmph! No message found. Does the user want to wait?
*/
if ((msgflg & IPC_NOWAIT) != 0) {
#ifdef MSG_DEBUG_OK
printf("no appropriate message found (msgtyp=%d)\n",
msgtyp);
#endif
/* The SVID says to return ENOMSG. */
error = ENOMSG;
goto done2;
}
/*
* Wait for something to happen
*/
#ifdef MSG_DEBUG_OK
printf("msgrcv: goodnight\n");
#endif
error = tsleep((caddr_t)msqptr, (PZERO - 4) | PCATCH, "msgwait",
0);
#ifdef MSG_DEBUG_OK
printf("msgrcv: good morning (error=%d)\n", error);
#endif
if (error != 0) {
#ifdef MSG_DEBUG_OK
printf("msgsnd: interrupted system call\n");
#endif
error = EINTR;
goto done2;
}
/*
* Make sure that the msq queue still exists
*/
if (msqptr->msg_qbytes == 0 ||
msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
#ifdef MSG_DEBUG_OK
printf("msqid deleted\n");
#endif
error = EIDRM;
goto done2;
}
}
/*
* Return the message to the user.
*
* First, do the bookkeeping (before we risk being interrupted).
*/
msqptr->msg_cbytes -= msghdr->msg_ts;
msqptr->msg_qnum--;
msqptr->msg_lrpid = td->td_proc->p_pid;
msqptr->msg_rtime = time_second;
/*
* Make msgsz the actual amount that we'll be returning.
* Note that this effectively truncates the message if it is too long
* (since msgsz is never increased).
*/
#ifdef MSG_DEBUG_OK
printf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
msghdr->msg_ts);
#endif
if (msgsz > msghdr->msg_ts)
msgsz = msghdr->msg_ts;
/*
* Return the type to the user.
*/
error = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
sizeof(msghdr->msg_type));
if (error != 0) {
#ifdef MSG_DEBUG_OK
printf("error (%d) copying out message type\n", error);
#endif
msg_freehdr(msghdr);
wakeup((caddr_t)msqptr);
goto done2;
}
user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
/*
* Return the segments to the user
*/
next = msghdr->msg_spot;
for (len = 0; len < msgsz; len += msginfo.msgssz) {
size_t tlen;
if (msgsz - len > msginfo.msgssz)
tlen = msginfo.msgssz;
else
tlen = msgsz - len;
if (next <= -1)
panic("next too low #3");
if (next >= msginfo.msgseg)
panic("next out of range #3");
error = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
user_msgp, tlen);
if (error != 0) {
#ifdef MSG_DEBUG_OK
printf("error (%d) copying out message segment\n",
error);
#endif
msg_freehdr(msghdr);
wakeup((caddr_t)msqptr);
goto done2;
}
user_msgp = (char *)user_msgp + tlen;
next = msgmaps[next].next;
}
/*
* Done, return the actual number of bytes copied out.
*/
msg_freehdr(msghdr);
wakeup((caddr_t)msqptr);
td->td_retval[0] = msgsz;
done2:
mtx_unlock(&Giant);
return (error);
}
static int
sysctl_msqids(SYSCTL_HANDLER_ARGS)
{
return (SYSCTL_OUT(req, msqids,
sizeof(struct msqid_ds) * msginfo.msgmni));
}
SYSCTL_DECL(_kern_ipc);
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, "");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, "");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, "");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, "");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, "");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "")
SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
NULL, 0, sysctl_msqids, "", "Message queue IDs");