freebsd-dev/sys/kern/sysv_msg.c

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/*-
* 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.
*/
/*-
* Copyright (c) 2003-2005 McAfee, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project in part by McAfee
* Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
* contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
* program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
2003-06-11 00:56:59 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_sysvipc.h"
#include "opt_mac.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/priv.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
2004-05-30 20:34:58 +00:00
#include <sys/module.h>
#include <sys/msg.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.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>
#include <security/mac/mac_framework.h>
static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
2002-03-19 21:25:46 +00:00
static void msginit(void);
static int msgunload(void);
static int sysvmsg_modload(struct module *, int, void *);
#ifdef MSG_DEBUG
#define DPRINTF(a) printf a
#else
#define DPRINTF(a)
#endif
2002-03-19 21:25:46 +00:00
static void msg_freehdr(struct msg *msghdr);
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 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
};
#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_kernel *msqids; /* MSGMNI msqid_kernel struct's */
static struct mtx msq_mtx; /* global mutex for message queues. */
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);
TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
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_kernel) * 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) {
DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
msginfo.msgssz));
panic("msginfo.msgssz not a small power of 2");
}
if (msginfo.msgseg > 32767) {
DPRINTF(("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;
#ifdef MAC
mac_sysvmsg_init(&msghdrs[i]);
#endif
}
free_msghdrs = &msghdrs[0];
if (msqids == NULL)
panic("msqids is NULL");
for (i = 0; i < msginfo.msgmni; i++) {
msqids[i].u.msg_qbytes = 0; /* implies entry is available */
msqids[i].u.msg_perm.seq = 0; /* reset to a known value */
msqids[i].u.msg_perm.mode = 0;
#ifdef MAC
mac_sysvmsq_init(&msqids[i]);
#endif
}
mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
}
static int
msgunload()
{
struct msqid_kernel *msqkptr;
int msqid;
#ifdef MAC
int i;
#endif
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.
*/
msqkptr = &msqids[msqid];
if (msqkptr->u.msg_qbytes != 0 ||
(msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
break;
}
if (msqid != msginfo.msgmni)
return (EBUSY);
#ifdef MAC
for (i = 0; i < msginfo.msgtql; i++)
mac_sysvmsg_destroy(&msghdrs[i]);
for (msqid = 0; msqid < msginfo.msgmni; msqid++)
mac_sysvmsq_destroy(&msqids[msqid]);
#endif
free(msgpool, M_MSG);
free(msgmaps, M_MSG);
free(msghdrs, M_MSG);
free(msqids, M_MSG);
mtx_destroy(&msq_mtx);
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.
*/
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 /* {
int which;
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
int a2;
int a3;
int a4;
int a5;
int a6;
} */ *uap;
{
int error;
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
return (ENOSYS);
if (uap->which < 0 ||
uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
return (EINVAL);
error = (*msgcalls[uap->which])(td, &uap->a2);
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;
#ifdef MAC
mac_sysvmsg_cleanup(msghdr);
#endif
}
#ifndef _SYS_SYSPROTO_H_
struct msgctl_args {
int msqid;
int cmd;
struct msqid_ds *buf;
};
#endif
int
msgctl(td, uap)
struct thread *td;
register struct msgctl_args *uap;
{
int msqid = uap->msqid;
int cmd = uap->cmd;
struct msqid_ds msqbuf;
int error;
DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
if (cmd == IPC_SET &&
(error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
return (error);
error = kern_msgctl(td, msqid, cmd, &msqbuf);
if (cmd == IPC_STAT && error == 0)
error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
return (error);
}
int
kern_msgctl(td, msqid, cmd, msqbuf)
struct thread *td;
int msqid;
int cmd;
struct msqid_ds *msqbuf;
{
int rval, error, msqix;
register struct msqid_kernel *msqkptr;
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
return (ENOSYS);
msqix = IPCID_TO_IX(msqid);
if (msqix < 0 || msqix >= msginfo.msgmni) {
DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
msginfo.msgmni));
return (EINVAL);
}
msqkptr = &msqids[msqix];
mtx_lock(&msq_mtx);
if (msqkptr->u.msg_qbytes == 0) {
DPRINTF(("no such msqid\n"));
error = EINVAL;
goto done2;
}
if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
DPRINTF(("wrong sequence number\n"));
error = EINVAL;
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
if (error != 0)
goto done2;
#endif
error = 0;
rval = 0;
switch (cmd) {
case IPC_RMID:
{
struct msg *msghdr;
if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
goto done2;
#ifdef MAC
/*
* Check that the thread has MAC access permissions to
* individual msghdrs. Note: We need to do this in a
* separate loop because the actual loop alters the
* msq/msghdr info as it progresses, and there is no going
* back if half the way through we discover that the
* thread cannot free a certain msghdr. The msq will get
* into an inconsistent state.
*/
for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
msghdr = msghdr->msg_next) {
error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
if (error != 0)
goto done2;
}
#endif
/* Free the message headers */
msghdr = msqkptr->u.msg_first;
while (msghdr != NULL) {
struct msg *msghdr_tmp;
/* Free the segments of each message */
msqkptr->u.msg_cbytes -= msghdr->msg_ts;
msqkptr->u.msg_qnum--;
msghdr_tmp = msghdr;
msghdr = msghdr->msg_next;
msg_freehdr(msghdr_tmp);
}
if (msqkptr->u.msg_cbytes != 0)
panic("msg_cbytes is screwed up");
if (msqkptr->u.msg_qnum != 0)
panic("msg_qnum is screwed up");
msqkptr->u.msg_qbytes = 0; /* Mark it as free */
#ifdef MAC
mac_sysvmsq_cleanup(msqkptr);
#endif
wakeup(msqkptr);
}
break;
case IPC_SET:
if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
goto done2;
if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
error = priv_check(td, PRIV_IPC_MSGSIZE);
if (error)
goto done2;
}
if (msqbuf->msg_qbytes > msginfo.msgmnb) {
DPRINTF(("can't increase msg_qbytes beyond %d"
"(truncating)\n", msginfo.msgmnb));
msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
}
if (msqbuf->msg_qbytes == 0) {
DPRINTF(("can't reduce msg_qbytes to 0\n"));
error = EINVAL; /* non-standard errno! */
goto done2;
}
msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */
msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */
msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
(msqbuf->msg_perm.mode & 0777);
msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
msqkptr->u.msg_ctime = time_second;
break;
case IPC_STAT:
if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
DPRINTF(("requester doesn't have read access\n"));
goto done2;
}
*msqbuf = msqkptr->u;
break;
default:
DPRINTF(("invalid command %d\n", cmd));
error = EINVAL;
goto done2;
}
if (error == 0)
td->td_retval[0] = rval;
done2:
mtx_unlock(&msq_mtx);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct msgget_args {
key_t key;
int msgflg;
};
#endif
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_ucred;
register struct msqid_kernel *msqkptr = NULL;
DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
return (ENOSYS);
mtx_lock(&msq_mtx);
if (key != IPC_PRIVATE) {
for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
msqkptr = &msqids[msqid];
if (msqkptr->u.msg_qbytes != 0 &&
msqkptr->u.msg_perm.key == key)
break;
}
if (msqid < msginfo.msgmni) {
DPRINTF(("found public key\n"));
if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
DPRINTF(("not exclusive\n"));
error = EEXIST;
goto done2;
}
if ((error = ipcperm(td, &msqkptr->u.msg_perm,
msgflg & 0700))) {
DPRINTF(("requester doesn't have 0%o access\n",
msgflg & 0700));
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msqget(cred, msqkptr);
if (error != 0)
goto done2;
#endif
goto found;
}
}
DPRINTF(("need to allocate the msqid_ds\n"));
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.
*/
msqkptr = &msqids[msqid];
if (msqkptr->u.msg_qbytes == 0 &&
(msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
break;
}
if (msqid == msginfo.msgmni) {
DPRINTF(("no more msqid_ds's available\n"));
error = ENOSPC;
goto done2;
}
DPRINTF(("msqid %d is available\n", msqid));
msqkptr->u.msg_perm.key = key;
msqkptr->u.msg_perm.cuid = cred->cr_uid;
msqkptr->u.msg_perm.uid = cred->cr_uid;
msqkptr->u.msg_perm.cgid = cred->cr_gid;
msqkptr->u.msg_perm.gid = cred->cr_gid;
msqkptr->u.msg_perm.mode = (msgflg & 0777);
/* Make sure that the returned msqid is unique */
msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
msqkptr->u.msg_first = NULL;
msqkptr->u.msg_last = NULL;
msqkptr->u.msg_cbytes = 0;
msqkptr->u.msg_qnum = 0;
msqkptr->u.msg_qbytes = msginfo.msgmnb;
msqkptr->u.msg_lspid = 0;
msqkptr->u.msg_lrpid = 0;
msqkptr->u.msg_stime = 0;
msqkptr->u.msg_rtime = 0;
msqkptr->u.msg_ctime = time_second;
#ifdef MAC
mac_sysvmsq_create(cred, msqkptr);
#endif
} else {
DPRINTF(("didn't find it and wasn't asked to create it\n"));
error = ENOENT;
goto done2;
}
found:
/* Construct the unique msqid */
td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
done2:
mtx_unlock(&msq_mtx);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct msgsnd_args {
int msqid;
const void *msgp;
size_t msgsz;
int msgflg;
};
#endif
int
kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
struct thread *td;
int msqid;
const void *msgp; /* XXX msgp is actually mtext. */
size_t msgsz;
int msgflg;
long mtype;
{
int msqix, segs_needed, error = 0;
register struct msqid_kernel *msqkptr;
register struct msg *msghdr;
short next;
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
return (ENOSYS);
mtx_lock(&msq_mtx);
msqix = IPCID_TO_IX(msqid);
if (msqix < 0 || msqix >= msginfo.msgmni) {
DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
msginfo.msgmni));
error = EINVAL;
goto done2;
}
msqkptr = &msqids[msqix];
if (msqkptr->u.msg_qbytes == 0) {
DPRINTF(("no such message queue id\n"));
error = EINVAL;
goto done2;
}
if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
DPRINTF(("wrong sequence number\n"));
error = EINVAL;
goto done2;
}
if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
DPRINTF(("requester doesn't have write access\n"));
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
if (error != 0)
goto done2;
#endif
segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
msginfo.msgssz, segs_needed));
for (;;) {
int need_more_resources = 0;
/*
* check msgsz
* (inside this loop in case msg_qbytes changes while we sleep)
*/
if (msgsz > msqkptr->u.msg_qbytes) {
DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
error = EINVAL;
goto done2;
}
if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
DPRINTF(("msqid is locked\n"));
need_more_resources = 1;
}
if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
need_more_resources = 1;
}
if (segs_needed > nfree_msgmaps) {
DPRINTF(("segs_needed > nfree_msgmaps\n"));
need_more_resources = 1;
}
if (free_msghdrs == NULL) {
DPRINTF(("no more msghdrs\n"));
need_more_resources = 1;
}
if (need_more_resources) {
int we_own_it;
if ((msgflg & IPC_NOWAIT) != 0) {
DPRINTF(("need more resources but caller "
"doesn't want to wait\n"));
error = EAGAIN;
goto done2;
}
if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
DPRINTF(("we don't own the msqid_ds\n"));
we_own_it = 0;
} else {
/* Force later arrivals to wait for our
request */
DPRINTF(("we own the msqid_ds\n"));
msqkptr->u.msg_perm.mode |= MSG_LOCKED;
we_own_it = 1;
}
DPRINTF(("msgsnd: goodnight\n"));
error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
"msgsnd", hz);
DPRINTF(("msgsnd: good morning, error=%d\n", error));
if (we_own_it)
msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
if (error == EWOULDBLOCK) {
DPRINTF(("msgsnd: timed out\n"));
continue;
}
if (error != 0) {
DPRINTF(("msgsnd: interrupted system call\n"));
error = EINTR;
goto done2;
}
/*
* Make sure that the msq queue still exists
*/
if (msqkptr->u.msg_qbytes == 0) {
DPRINTF(("msqid deleted\n"));
error = EIDRM;
goto done2;
}
} else {
DPRINTF(("got all the resources that we need\n"));
break;
}
}
/*
* We have the resources that we need.
* Make sure!
*/
if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
panic("msg_perm.mode & MSG_LOCKED");
if (segs_needed > nfree_msgmaps)
panic("segs_needed > nfree_msgmaps");
if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.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 ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
panic("msqid_ds is already locked");
msqkptr->u.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;
msghdr->msg_type = mtype;
#ifdef MAC
/*
* XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
* immediately? Or, should it be checked just before the msg is
* enqueued in the msgq (as it is done now)?
*/
mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
#endif
/*
* 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");
DPRINTF(("allocating segment %d to message\n", next));
free_msgmaps = msgmaps[next].next;
nfree_msgmaps--;
msgmaps[next].next = msghdr->msg_spot;
msghdr->msg_spot = next;
segs_needed--;
}
/*
* Validate the message type
*/
if (msghdr->msg_type < 1) {
msg_freehdr(msghdr);
msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
wakeup(msqkptr);
DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
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");
mtx_unlock(&msq_mtx);
if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
tlen)) != 0) {
mtx_lock(&msq_mtx);
DPRINTF(("error %d copying in message segment\n",
error));
msg_freehdr(msghdr);
msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
wakeup(msqkptr);
goto done2;
}
mtx_lock(&msq_mtx);
msgsz -= tlen;
msgp = (const char *)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.
*/
msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
/*
* Make sure that the msqid_ds is still allocated.
*/
if (msqkptr->u.msg_qbytes == 0) {
msg_freehdr(msghdr);
wakeup(msqkptr);
error = EIDRM;
goto done2;
}
#ifdef MAC
/*
* Note: Since the task/thread allocates the msghdr and usually
* primes it with its own MAC label, for a majority of policies, it
* won't be necessary to check whether the msghdr has access
* permissions to the msgq. The mac_sysvmsq_check_msqsnd check would
* suffice in that case. However, this hook may be required where
* individual policies derive a non-identical label for the msghdr
* from the current thread label and may want to check the msghdr
* enqueue permissions, along with read/write permissions to the
* msgq.
*/
error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
if (error != 0) {
msg_freehdr(msghdr);
wakeup(msqkptr);
goto done2;
}
#endif
/*
* Put the message into the queue
*/
if (msqkptr->u.msg_first == NULL) {
msqkptr->u.msg_first = msghdr;
msqkptr->u.msg_last = msghdr;
} else {
msqkptr->u.msg_last->msg_next = msghdr;
msqkptr->u.msg_last = msghdr;
}
msqkptr->u.msg_last->msg_next = NULL;
msqkptr->u.msg_cbytes += msghdr->msg_ts;
msqkptr->u.msg_qnum++;
msqkptr->u.msg_lspid = td->td_proc->p_pid;
msqkptr->u.msg_stime = time_second;
wakeup(msqkptr);
td->td_retval[0] = 0;
done2:
mtx_unlock(&msq_mtx);
return (error);
}
int
msgsnd(td, uap)
struct thread *td;
register struct msgsnd_args *uap;
{
int error;
long mtype;
DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
uap->msgsz, uap->msgflg));
if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
DPRINTF(("error %d copying the message type\n", error));
return (error);
}
return (kern_msgsnd(td, uap->msqid,
(const char *)uap->msgp + sizeof(mtype),
uap->msgsz, uap->msgflg, mtype));
}
#ifndef _SYS_SYSPROTO_H_
struct msgrcv_args {
int msqid;
void *msgp;
size_t msgsz;
long msgtyp;
int msgflg;
};
#endif
int
kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
struct thread *td;
int msqid;
void *msgp; /* XXX msgp is actually mtext. */
size_t msgsz;
long msgtyp;
int msgflg;
long *mtype;
{
size_t len;
register struct msqid_kernel *msqkptr;
register struct msg *msghdr;
int msqix, error = 0;
short next;
if (!jail_sysvipc_allowed && jailed(td->td_ucred))
return (ENOSYS);
msqix = IPCID_TO_IX(msqid);
if (msqix < 0 || msqix >= msginfo.msgmni) {
DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
msginfo.msgmni));
return (EINVAL);
}
msqkptr = &msqids[msqix];
mtx_lock(&msq_mtx);
if (msqkptr->u.msg_qbytes == 0) {
DPRINTF(("no such message queue id\n"));
error = EINVAL;
goto done2;
}
if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
DPRINTF(("wrong sequence number\n"));
error = EINVAL;
goto done2;
}
if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
DPRINTF(("requester doesn't have read access\n"));
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
if (error != 0)
goto done2;
#endif
msghdr = NULL;
while (msghdr == NULL) {
if (msgtyp == 0) {
msghdr = msqkptr->u.msg_first;
if (msghdr != NULL) {
if (msgsz < msghdr->msg_ts &&
(msgflg & MSG_NOERROR) == 0) {
DPRINTF(("first message on the queue "
"is too big (want %zu, got %d)\n",
msgsz, msghdr->msg_ts));
error = E2BIG;
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msgrcv(td->td_ucred,
msghdr);
if (error != 0)
goto done2;
#endif
if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
msqkptr->u.msg_first = NULL;
msqkptr->u.msg_last = NULL;
} else {
msqkptr->u.msg_first = msghdr->msg_next;
if (msqkptr->u.msg_first == NULL)
panic("msg_first/last screwed up #1");
}
}
} else {
struct msg *previous;
struct msg **prev;
previous = NULL;
prev = &(msqkptr->u.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) {
DPRINTF(("found message type %ld, "
"requested %ld\n",
msghdr->msg_type, msgtyp));
if (msgsz < msghdr->msg_ts &&
(msgflg & MSG_NOERROR) == 0) {
DPRINTF(("requested message "
"on the queue is too big "
"(want %zu, got %hu)\n",
msgsz, msghdr->msg_ts));
error = E2BIG;
goto done2;
}
#ifdef MAC
error = mac_sysvmsq_check_msgrcv(
td->td_ucred, msghdr);
if (error != 0)
goto done2;
#endif
*prev = msghdr->msg_next;
if (msghdr == msqkptr->u.msg_last) {
if (previous == NULL) {
if (prev !=
&msqkptr->u.msg_first)
panic("msg_first/last screwed up #2");
msqkptr->u.msg_first =
NULL;
msqkptr->u.msg_last =
NULL;
} else {
if (prev ==
&msqkptr->u.msg_first)
panic("msg_first/last screwed up #3");
msqkptr->u.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) {
DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
msgtyp));
/* The SVID says to return ENOMSG. */
error = ENOMSG;
goto done2;
}
/*
* Wait for something to happen
*/
DPRINTF(("msgrcv: goodnight\n"));
error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
"msgrcv", 0);
DPRINTF(("msgrcv: good morning (error=%d)\n", error));
if (error != 0) {
DPRINTF(("msgrcv: interrupted system call\n"));
error = EINTR;
goto done2;
}
/*
* Make sure that the msq queue still exists
*/
if (msqkptr->u.msg_qbytes == 0 ||
msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
DPRINTF(("msqid deleted\n"));
error = EIDRM;
goto done2;
}
}
/*
* Return the message to the user.
*
* First, do the bookkeeping (before we risk being interrupted).
*/
msqkptr->u.msg_cbytes -= msghdr->msg_ts;
msqkptr->u.msg_qnum--;
msqkptr->u.msg_lrpid = td->td_proc->p_pid;
msqkptr->u.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).
*/
DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
msghdr->msg_ts));
if (msgsz > msghdr->msg_ts)
msgsz = msghdr->msg_ts;
*mtype = 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");
mtx_unlock(&msq_mtx);
error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
mtx_lock(&msq_mtx);
if (error != 0) {
DPRINTF(("error (%d) copying out message segment\n",
error));
msg_freehdr(msghdr);
wakeup(msqkptr);
goto done2;
}
msgp = (char *)msgp + tlen;
next = msgmaps[next].next;
}
/*
* Done, return the actual number of bytes copied out.
*/
msg_freehdr(msghdr);
wakeup(msqkptr);
td->td_retval[0] = msgsz;
done2:
mtx_unlock(&msq_mtx);
return (error);
}
int
msgrcv(td, uap)
struct thread *td;
register struct msgrcv_args *uap;
{
int error;
long mtype;
DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
if ((error = kern_msgrcv(td, uap->msqid,
(char *)uap->msgp + sizeof(mtype), uap->msgsz,
uap->msgtyp, uap->msgflg, &mtype)) != 0)
return (error);
if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
DPRINTF(("error %d copying the message type\n", error));
return (error);
}
static int
sysctl_msqids(SYSCTL_HANDLER_ARGS)
{
return (SYSCTL_OUT(req, msqids,
sizeof(struct msqid_kernel) * msginfo.msgmni));
}
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
"Maximum message size");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
"Number of message queue identifiers");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
"Maximum number of bytes in a queue");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
"Maximum number of messages in the system");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
"Size of a message segment");
SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
"Number of message segments");
SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
NULL, 0, sysctl_msqids, "", "Message queue IDs");