d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
ffc19cf52d
freebsd-dev/sys/kern/sysv_msg.c
Jamie Gritton f7496dcab0 jail: Change the locking around pr_ref and pr_uref 
Require both the prison mutex and allprison_lock when pr_ref or
pr_uref go to/from zero.  Adding a non-first or removing a non-last
reference remain lock-free.  This means that a shared hold on
allprison_lock is sufficient for prison_isalive() to be useful, which
removes a number of cases of lock/check/unlock on the prison mutex.

Expand the locking in kern_jail_set() to keep allprison_lock held
exclusive until the new prison is valid, thus making invalid prisons
invisible to any thread holding allprison_lock (except of course the
one creating or destroying the prison).  This renders prison_isvalid()
nearly redundant, now used only in asserts.

Differential Revision:	https://reviews.freebsd.org/D28419
Differential Revision:	https://reviews.freebsd.org/D28458
2021-02-21 10:55:44 -08:00

1921 lines
49 KiB
C
Raw Blame History

/*-
* 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.
*/
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003-2005 McAfee, Inc.
* Copyright (c) 2016-2017 Robert N. M. Watson
* 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.
*
* Portions of this software were developed by BAE Systems, the University of
* Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
* contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
* Computing (TC) 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_sysvipc.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/msg.h>
#include <sys/racct.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/jail.h>
#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>
FEATURE(sysv_msg, "System V message queues support");
static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
static int msginit(void);
static int msgunload(void);
static int sysvmsg_modload(struct module *, int, void *);
static void msq_remove(struct msqid_kernel *);
static struct prison *msg_find_prison(struct ucred *);
static int msq_prison_cansee(struct prison *, struct msqid_kernel *);
static int msg_prison_check(void *, void *);
static int msg_prison_set(void *, void *);
static int msg_prison_get(void *, void *);
static int msg_prison_remove(void *, void *);
static void msg_prison_cleanup(struct prison *);
#ifdef MSG_DEBUG
#define DPRINTF(a) printf a
#else
#define DPRINTF(a) (void)0
#endif
static void msg_freehdr(struct msg *msghdr);
#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 unsigned msg_prison_slot;/* prison OSD slot */
static struct syscall_helper_data msg_syscalls[] = {
SYSCALL_INIT_HELPER(msgctl),
SYSCALL_INIT_HELPER(msgget),
SYSCALL_INIT_HELPER(msgsnd),
SYSCALL_INIT_HELPER(msgrcv),
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
SYSCALL_INIT_HELPER(msgsys),
SYSCALL_INIT_HELPER_COMPAT(freebsd7_msgctl),
#endif
SYSCALL_INIT_LAST
};
#ifdef COMPAT_FREEBSD32
#include <compat/freebsd32/freebsd32.h>
#include <compat/freebsd32/freebsd32_ipc.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32_signal.h>
#include <compat/freebsd32/freebsd32_syscall.h>
#include <compat/freebsd32/freebsd32_util.h>
static struct syscall_helper_data msg32_syscalls[] = {
SYSCALL32_INIT_HELPER(freebsd32_msgctl),
SYSCALL32_INIT_HELPER(freebsd32_msgsnd),
SYSCALL32_INIT_HELPER(freebsd32_msgrcv),
SYSCALL32_INIT_HELPER_COMPAT(msgget),
SYSCALL32_INIT_HELPER(freebsd32_msgsys),
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl),
#endif
SYSCALL_INIT_LAST
};
#endif
static int
msginit()
{
struct prison *pr;
void **rsv;
int i, error;
osd_method_t methods[PR_MAXMETHOD] = {
[PR_METHOD_CHECK] = msg_prison_check,
[PR_METHOD_SET] = msg_prison_set,
[PR_METHOD_GET] = msg_prison_get,
[PR_METHOD_REMOVE] = msg_prison_remove,
};
msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
M_WAITOK | M_ZERO);
/*
* 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");
}
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;
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];
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);
/* Set current prisons according to their allow.sysvipc. */
msg_prison_slot = osd_jail_register(NULL, methods);
rsv = osd_reserve(msg_prison_slot);
prison_lock(&prison0);
(void)osd_jail_set_reserved(&prison0, msg_prison_slot, rsv, &prison0);
prison_unlock(&prison0);
rsv = NULL;
sx_slock(&allprison_lock);
TAILQ_FOREACH(pr, &allprison, pr_list) {
if (rsv == NULL)
rsv = osd_reserve(msg_prison_slot);
prison_lock(pr);
if (pr->pr_allow & PR_ALLOW_SYSVIPC) {
(void)osd_jail_set_reserved(pr, msg_prison_slot, rsv,
&prison0);
rsv = NULL;
}
prison_unlock(pr);
}
if (rsv != NULL)
osd_free_reserved(rsv);
sx_sunlock(&allprison_lock);
error = syscall_helper_register(msg_syscalls, SY_THR_STATIC_KLD);
if (error != 0)
return (error);
#ifdef COMPAT_FREEBSD32
error = syscall32_helper_register(msg32_syscalls, SY_THR_STATIC_KLD);
if (error != 0)
return (error);
#endif
return (0);
}
static int
msgunload()
{
struct msqid_kernel *msqkptr;
int msqid;
#ifdef MAC
int i;
#endif
syscall_helper_unregister(msg_syscalls);
#ifdef COMPAT_FREEBSD32
syscall32_helper_unregister(msg32_syscalls);
#endif
for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
msqkptr = &msqids[msqid];
if (msqkptr->u.msg_qbytes != 0 ||
(msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
break;
}
if (msqid != msginfo.msgmni)
return (EBUSY);
if (msg_prison_slot != 0)
osd_jail_deregister(msg_prison_slot);
#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:
error = msginit();
if (error != 0)
msgunload();
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
};
DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
MODULE_VERSION(sysvmsg, 1);
static void
msg_freehdr(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
}
static void
msq_remove(struct msqid_kernel *msqkptr)
{
struct msg *msghdr;
racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1);
racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum);
racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes);
crfree(msqkptr->cred);
msqkptr->cred = NULL;
/* 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);
}
static struct prison *
msg_find_prison(struct ucred *cred)
{
struct prison *pr, *rpr;
pr = cred->cr_prison;
prison_lock(pr);
rpr = osd_jail_get(pr, msg_prison_slot);
prison_unlock(pr);
return rpr;
}
static int
msq_prison_cansee(struct prison *rpr, struct msqid_kernel *msqkptr)
{
if (msqkptr->cred == NULL ||
!(rpr == msqkptr->cred->cr_prison ||
prison_ischild(rpr, msqkptr->cred->cr_prison)))
return (EINVAL);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct msgctl_args {
int msqid;
int cmd;
struct msqid_ds *buf;
};
#endif
int
sys_msgctl(struct thread *td, 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(struct thread *td, int msqid, int cmd, struct msqid_ds *msqbuf)
{
int rval, error, msqix;
struct msqid_kernel *msqkptr;
struct prison *rpr;
rpr = msg_find_prison(td->td_ucred);
if (rpr == NULL)
return (ENOSYS);
AUDIT_ARG_SVIPC_CMD(cmd);
AUDIT_ARG_SVIPC_ID(msqid);
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;
}
error = msq_prison_cansee(rpr, msqkptr);
if (error != 0) {
DPRINTF(("requester can't see prison\n"));
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:
{
#ifdef MAC
struct msg *msghdr;
#endif
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
msq_remove(msqkptr);
}
break;
case IPC_SET:
AUDIT_ARG_SVIPC_PERM(&msqbuf->msg_perm);
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;
if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison)
msqbuf->msg_perm.key = IPC_PRIVATE;
/*
* Try to hide the fact that the structure layout is shared by
* both the kernel and userland. These pointers are not useful
* to userspace.
*/
msqbuf->__msg_first = msqbuf->__msg_last = NULL;
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
sys_msgget(struct thread *td, struct msgget_args *uap)
{
int msqid, error = 0;
int key = uap->key;
int msgflg = uap->msgflg;
struct ucred *cred = td->td_ucred;
struct msqid_kernel *msqkptr = NULL;
DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
if (msg_find_prison(cred) == NULL)
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->cred != NULL &&
msqkptr->cred->cr_prison == cred->cr_prison &&
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;
}
AUDIT_ARG_SVIPC_ID(IXSEQ_TO_IPCID(msqid,
msqkptr->u.msg_perm));
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;
}
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(td->td_proc);
error = racct_add(td->td_proc, RACCT_NMSGQ, 1);
PROC_UNLOCK(td->td_proc);
if (error != 0) {
error = ENOSPC;
goto done2;
}
}
#endif
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);
msqkptr->cred = crhold(cred);
/* 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
AUDIT_ARG_SVIPC_PERM(&msqkptr->u.msg_perm);
} 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; /* XXX msgp is actually mtext. */
size_t msgsz;
int msgflg;
};
#endif
int
kern_msgsnd(struct thread *td, int msqid, const void *msgp,
size_t msgsz, int msgflg, long mtype)
{
int msqix, segs_needed, error = 0;
struct msqid_kernel *msqkptr;
struct msg *msghdr;
struct prison *rpr;
short next;
#ifdef RACCT
size_t saved_msgsz = 0;
#endif
rpr = msg_find_prison(td->td_ucred);
if (rpr == NULL)
return (ENOSYS);
mtx_lock(&msq_mtx);
AUDIT_ARG_SVIPC_ID(msqid);
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];
AUDIT_ARG_SVIPC_PERM(&msqkptr->u.msg_perm);
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 = msq_prison_cansee(rpr, msqkptr))) {
DPRINTF(("requester can't see prison\n"));
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
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(td->td_proc);
if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) {
PROC_UNLOCK(td->td_proc);
error = EAGAIN;
goto done2;
}
saved_msgsz = msgsz;
if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) {
racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
PROC_UNLOCK(td->td_proc);
error = EAGAIN;
goto done2;
}
PROC_UNLOCK(td->td_proc);
}
#endif
segs_needed = howmany(msgsz, 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 done3;
}
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 done3;
}
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 done3;
}
/*
* Make sure that the msq queue still exists
*/
if (msqkptr->u.msg_qbytes == 0) {
DPRINTF(("msqid deleted\n"));
error = EIDRM;
goto done3;
}
} 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 done3;
}
/*
* 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 done3;
}
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 done3;
}
#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 done3;
}
#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;
done3:
#ifdef RACCT
if (racct_enable && error != 0) {
PROC_LOCK(td->td_proc);
racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz);
PROC_UNLOCK(td->td_proc);
}
#endif
done2:
mtx_unlock(&msq_mtx);
return (error);
}
int
sys_msgsnd(struct thread *td, 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
/* XXX msgp is actually mtext. */
int
kern_msgrcv(struct thread *td, int msqid, void *msgp, size_t msgsz, long msgtyp,
int msgflg, long *mtype)
{
size_t len;
struct msqid_kernel *msqkptr;
struct msg *msghdr;
struct prison *rpr;
int msqix, error = 0;
short next;
rpr = msg_find_prison(td->td_ucred);
if (rpr == NULL)
return (ENOSYS);
AUDIT_ARG_SVIPC_ID(msqid);
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);
AUDIT_ARG_SVIPC_PERM(&msqkptr->u.msg_perm);
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 = msq_prison_cansee(rpr, msqkptr))) {
DPRINTF(("requester can't see prison\n"));
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;
racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1);
racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts);
/*
* 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
sys_msgrcv(struct thread *td, 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)
{
struct msqid_kernel tmsqk;
#ifdef COMPAT_FREEBSD32
struct msqid_kernel32 tmsqk32;
#endif
struct prison *pr, *rpr;
void *outaddr;
size_t outsize;
int error, i;
pr = req->td->td_ucred->cr_prison;
rpr = msg_find_prison(req->td->td_ucred);
error = 0;
for (i = 0; i < msginfo.msgmni; i++) {
mtx_lock(&msq_mtx);
if (msqids[i].u.msg_qbytes == 0 || rpr == NULL ||
msq_prison_cansee(rpr, &msqids[i]) != 0)
bzero(&tmsqk, sizeof(tmsqk));
else {
tmsqk = msqids[i];
if (tmsqk.cred->cr_prison != pr)
tmsqk.u.msg_perm.key = IPC_PRIVATE;
}
mtx_unlock(&msq_mtx);
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
bzero(&tmsqk32, sizeof(tmsqk32));
freebsd32_ipcperm_out(&tmsqk.u.msg_perm,
&tmsqk32.u.msg_perm);
/* Don't copy u.msg_first or u.msg_last */
CP(tmsqk, tmsqk32, u.msg_cbytes);
CP(tmsqk, tmsqk32, u.msg_qnum);
CP(tmsqk, tmsqk32, u.msg_qbytes);
CP(tmsqk, tmsqk32, u.msg_lspid);
CP(tmsqk, tmsqk32, u.msg_lrpid);
CP(tmsqk, tmsqk32, u.msg_stime);
CP(tmsqk, tmsqk32, u.msg_rtime);
CP(tmsqk, tmsqk32, u.msg_ctime);
/* Don't copy label or cred */
outaddr = &tmsqk32;
outsize = sizeof(tmsqk32);
} else
#endif
{
/* Don't leak kernel pointers */
tmsqk.u.__msg_first = NULL;
tmsqk.u.__msg_last = NULL;
tmsqk.label = NULL;
tmsqk.cred = NULL;
/*
* XXX: some padding also exists, but we take care to
* allocate our pool of msqid_kernel structs with
* zeroed memory so this should be OK.
*/
outaddr = &tmsqk;
outsize = sizeof(tmsqk);
}
error = SYSCTL_OUT(req, outaddr, outsize);
if (error != 0)
break;
}
return (error);
}
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,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
NULL, 0, sysctl_msqids, "",
"Array of struct msqid_kernel for each potential message queue");
static int
msg_prison_check(void *obj, void *data)
{
struct prison *pr = obj;
struct prison *prpr;
struct vfsoptlist *opts = data;
int error, jsys;
/*
* sysvmsg is a jailsys integer.
* It must be "disable" if the parent jail is disabled.
*/
error = vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys));
if (error != ENOENT) {
if (error != 0)
return (error);
switch (jsys) {
case JAIL_SYS_DISABLE:
break;
case JAIL_SYS_NEW:
case JAIL_SYS_INHERIT:
prison_lock(pr->pr_parent);
prpr = osd_jail_get(pr->pr_parent, msg_prison_slot);
prison_unlock(pr->pr_parent);
if (prpr == NULL)
return (EPERM);
break;
default:
return (EINVAL);
}
}
return (0);
}
static int
msg_prison_set(void *obj, void *data)
{
struct prison *pr = obj;
struct prison *tpr, *orpr, *nrpr, *trpr;
struct vfsoptlist *opts = data;
void *rsv;
int jsys, descend;
/*
* sysvmsg controls which jail is the root of the associated msgs (this
* jail or same as the parent), or if the feature is available at all.
*/
if (vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)) == ENOENT)
jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
? JAIL_SYS_INHERIT
: vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
? JAIL_SYS_DISABLE
: -1;
if (jsys == JAIL_SYS_DISABLE) {
prison_lock(pr);
orpr = osd_jail_get(pr, msg_prison_slot);
if (orpr != NULL)
osd_jail_del(pr, msg_prison_slot);
prison_unlock(pr);
if (orpr != NULL) {
if (orpr == pr)
msg_prison_cleanup(pr);
/* Disable all child jails as well. */
FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
prison_lock(tpr);
trpr = osd_jail_get(tpr, msg_prison_slot);
if (trpr != NULL) {
osd_jail_del(tpr, msg_prison_slot);
prison_unlock(tpr);
if (trpr == tpr)
msg_prison_cleanup(tpr);
} else {
prison_unlock(tpr);
descend = 0;
}
}
}
} else if (jsys != -1) {
if (jsys == JAIL_SYS_NEW)
nrpr = pr;
else {
prison_lock(pr->pr_parent);
nrpr = osd_jail_get(pr->pr_parent, msg_prison_slot);
prison_unlock(pr->pr_parent);
}
rsv = osd_reserve(msg_prison_slot);
prison_lock(pr);
orpr = osd_jail_get(pr, msg_prison_slot);
if (orpr != nrpr)
(void)osd_jail_set_reserved(pr, msg_prison_slot, rsv,
nrpr);
else
osd_free_reserved(rsv);
prison_unlock(pr);
if (orpr != nrpr) {
if (orpr == pr)
msg_prison_cleanup(pr);
if (orpr != NULL) {
/* Change child jails matching the old root, */
FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
prison_lock(tpr);
trpr = osd_jail_get(tpr,
msg_prison_slot);
if (trpr == orpr) {
(void)osd_jail_set(tpr,
msg_prison_slot, nrpr);
prison_unlock(tpr);
if (trpr == tpr)
msg_prison_cleanup(tpr);
} else {
prison_unlock(tpr);
descend = 0;
}
}
}
}
}
return (0);
}
static int
msg_prison_get(void *obj, void *data)
{
struct prison *pr = obj;
struct prison *rpr;
struct vfsoptlist *opts = data;
int error, jsys;
/* Set sysvmsg based on the jail's root prison. */
prison_lock(pr);
rpr = osd_jail_get(pr, msg_prison_slot);
prison_unlock(pr);
jsys = rpr == NULL ? JAIL_SYS_DISABLE
: rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
error = vfs_setopt(opts, "sysvmsg", &jsys, sizeof(jsys));
if (error == ENOENT)
error = 0;
return (error);
}
static int
msg_prison_remove(void *obj, void *data __unused)
{
struct prison *pr = obj;
struct prison *rpr;
prison_lock(pr);
rpr = osd_jail_get(pr, msg_prison_slot);
prison_unlock(pr);
if (rpr == pr)
msg_prison_cleanup(pr);
return (0);
}
static void
msg_prison_cleanup(struct prison *pr)
{
struct msqid_kernel *msqkptr;
int i;
/* Remove any msqs that belong to this jail. */
mtx_lock(&msq_mtx);
for (i = 0; i < msginfo.msgmni; i++) {
msqkptr = &msqids[i];
if (msqkptr->u.msg_qbytes != 0 &&
msqkptr->cred != NULL && msqkptr->cred->cr_prison == pr)
msq_remove(msqkptr);
}
mtx_unlock(&msq_mtx);
}
SYSCTL_JAIL_PARAM_SYS_NODE(sysvmsg, CTLFLAG_RW, "SYSV message queues");
#ifdef COMPAT_FREEBSD32
int
freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
{
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
AUDIT_ARG_SVIPC_WHICH(uap->which);
switch (uap->which) {
case 0:
return (freebsd7_freebsd32_msgctl(td,
(struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
case 2:
return (freebsd32_msgsnd(td,
(struct freebsd32_msgsnd_args *)&uap->a2));
case 3:
return (freebsd32_msgrcv(td,
(struct freebsd32_msgrcv_args *)&uap->a2));
default:
return (sys_msgsys(td, (struct msgsys_args *)uap));
}
#else
return (nosys(td, NULL));
#endif
}
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
int
freebsd7_freebsd32_msgctl(struct thread *td,
struct freebsd7_freebsd32_msgctl_args *uap)
{
struct msqid_ds msqbuf;
struct msqid_ds32_old msqbuf32;
int error;
if (uap->cmd == IPC_SET) {
error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
if (error)
return (error);
freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
PTRIN_CP(msqbuf32, msqbuf, __msg_first);
PTRIN_CP(msqbuf32, msqbuf, __msg_last);
CP(msqbuf32, msqbuf, msg_cbytes);
CP(msqbuf32, msqbuf, msg_qnum);
CP(msqbuf32, msqbuf, msg_qbytes);
CP(msqbuf32, msqbuf, msg_lspid);
CP(msqbuf32, msqbuf, msg_lrpid);
CP(msqbuf32, msqbuf, msg_stime);
CP(msqbuf32, msqbuf, msg_rtime);
CP(msqbuf32, msqbuf, msg_ctime);
}
error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
if (error)
return (error);
if (uap->cmd == IPC_STAT) {
bzero(&msqbuf32, sizeof(msqbuf32));
freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
PTROUT_CP(msqbuf, msqbuf32, __msg_first);
PTROUT_CP(msqbuf, msqbuf32, __msg_last);
CP(msqbuf, msqbuf32, msg_cbytes);
CP(msqbuf, msqbuf32, msg_qnum);
CP(msqbuf, msqbuf32, msg_qbytes);
CP(msqbuf, msqbuf32, msg_lspid);
CP(msqbuf, msqbuf32, msg_lrpid);
CP(msqbuf, msqbuf32, msg_stime);
CP(msqbuf, msqbuf32, msg_rtime);
CP(msqbuf, msqbuf32, msg_ctime);
error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
}
return (error);
}
#endif
int
freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
{
struct msqid_ds msqbuf;
struct msqid_ds32 msqbuf32;
int error;
if (uap->cmd == IPC_SET) {
error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
if (error)
return (error);
freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
PTRIN_CP(msqbuf32, msqbuf, __msg_first);
PTRIN_CP(msqbuf32, msqbuf, __msg_last);
CP(msqbuf32, msqbuf, msg_cbytes);
CP(msqbuf32, msqbuf, msg_qnum);
CP(msqbuf32, msqbuf, msg_qbytes);
CP(msqbuf32, msqbuf, msg_lspid);
CP(msqbuf32, msqbuf, msg_lrpid);
CP(msqbuf32, msqbuf, msg_stime);
CP(msqbuf32, msqbuf, msg_rtime);
CP(msqbuf32, msqbuf, msg_ctime);
}
error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
if (error)
return (error);
if (uap->cmd == IPC_STAT) {
freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
PTROUT_CP(msqbuf, msqbuf32, __msg_first);
PTROUT_CP(msqbuf, msqbuf32, __msg_last);
CP(msqbuf, msqbuf32, msg_cbytes);
CP(msqbuf, msqbuf32, msg_qnum);
CP(msqbuf, msqbuf32, msg_qbytes);
CP(msqbuf, msqbuf32, msg_lspid);
CP(msqbuf, msqbuf32, msg_lrpid);
CP(msqbuf, msqbuf32, msg_stime);
CP(msqbuf, msqbuf32, msg_rtime);
CP(msqbuf, msqbuf32, msg_ctime);
error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
}
return (error);
}
int
freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
{
const void *msgp;
long mtype;
int32_t mtype32;
int error;
msgp = PTRIN(uap->msgp);
if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
return (error);
mtype = mtype32;
return (kern_msgsnd(td, uap->msqid,
(const char *)msgp + sizeof(mtype32),
uap->msgsz, uap->msgflg, mtype));
}
int
freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
{
void *msgp;
long mtype;
int32_t mtype32;
int error;
msgp = PTRIN(uap->msgp);
if ((error = kern_msgrcv(td, uap->msqid,
(char *)msgp + sizeof(mtype32), uap->msgsz,
uap->msgtyp, uap->msgflg, &mtype)) != 0)
return (error);
mtype32 = (int32_t)mtype;
return (copyout(&mtype32, msgp, sizeof(mtype32)));
}
#endif
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
/* XXX casting to (sy_call_t *) is bogus, as usual. */
static sy_call_t *msgcalls[] = {
(sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget,
(sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
};
/*
* Entry point for all MSG calls.
*
* XXX actually varargs.
* struct msgsys_args {
* int which;
* int a2;
* int a3;
* int a4;
* int a5;
* int a6;
* } *uap;
*/
int
sys_msgsys(struct thread *td, struct msgsys_args *uap)
{
int error;
AUDIT_ARG_SVIPC_WHICH(uap->which);
if (uap->which < 0 || uap->which >= nitems(msgcalls))
return (EINVAL);
error = (*msgcalls[uap->which])(td, &uap->a2);
return (error);
}
#ifndef CP
#define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0)
#endif
#ifndef _SYS_SYSPROTO_H_
struct freebsd7_msgctl_args {
int msqid;
int cmd;
struct msqid_ds_old *buf;
};
#endif
int
freebsd7_msgctl(struct thread *td, struct freebsd7_msgctl_args *uap)
{
struct msqid_ds_old msqold;
struct msqid_ds msqbuf;
int error;
DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
uap->buf));
if (uap->cmd == IPC_SET) {
error = copyin(uap->buf, &msqold, sizeof(msqold));
if (error)
return (error);
ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
CP(msqold, msqbuf, __msg_first);
CP(msqold, msqbuf, __msg_last);
CP(msqold, msqbuf, msg_cbytes);
CP(msqold, msqbuf, msg_qnum);
CP(msqold, msqbuf, msg_qbytes);
CP(msqold, msqbuf, msg_lspid);
CP(msqold, msqbuf, msg_lrpid);
CP(msqold, msqbuf, msg_stime);
CP(msqold, msqbuf, msg_rtime);
CP(msqold, msqbuf, msg_ctime);
}
error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
if (error)
return (error);
if (uap->cmd == IPC_STAT) {
bzero(&msqold, sizeof(msqold));
ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
CP(msqbuf, msqold, __msg_first);
CP(msqbuf, msqold, __msg_last);
CP(msqbuf, msqold, msg_cbytes);
CP(msqbuf, msqold, msg_qnum);
CP(msqbuf, msqold, msg_qbytes);
CP(msqbuf, msqold, msg_lspid);
CP(msqbuf, msqold, msg_lrpid);
CP(msqbuf, msqold, msg_stime);
CP(msqbuf, msqold, msg_rtime);
CP(msqbuf, msqold, msg_ctime);
error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
}
return (error);
}
#undef CP
#endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
COMPAT_FREEBSD7 */
Reference in New Issue View Git Blame Copy Permalink