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/* $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
/*-
* Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
* Copyright (c) 2006 nCircle Network Security, Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson for the TrustedBSD
* Project under contract to nCircle Network Security, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Herb Peyerl.
* 4. The name of Herb Peyerl may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/sem.h>
#include <sys/shm.h>
#include <sys/ipc.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/ucred.h>
void (*shmfork_hook)(struct proc *, struct proc *) = NULL;
void (*shmexit_hook)(struct vmspace *) = NULL;
/* called from kern_fork.c */
void
shmfork(p1, p2)
struct proc *p1, *p2;
{
if (shmfork_hook != NULL)
shmfork_hook(p1, p2);
return;
}
/* called from kern_exit.c */
void
shmexit(struct vmspace *vm)
{
if (shmexit_hook != NULL)
shmexit_hook(vm);
return;
}
/*
* Check for IPC permission.
*
* Note: The MAC Framework does not require any modifications to the
* ipcperm() function, as access control checks are performed throughout the
* implementation of each primitive. Those entry point calls complement the
* ipcperm() discertionary checks. Unlike file system discretionary access
* control, the original create of an object is given the same rights as the
* current owner.
*/
int
ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode)
{
struct ucred *cred = td->td_ucred;
int error, obj_mode, dac_granted, priv_granted;
dac_granted = 0;
if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) {
obj_mode = perm->mode;
dac_granted |= IPC_M;
} else if (groupmember(perm->gid, cred) ||
groupmember(perm->cgid, cred)) {
obj_mode = perm->mode;
obj_mode <<= 3;
} else {
obj_mode = perm->mode;
obj_mode <<= 6;
}
/*
* While the System V IPC permission model allows IPC_M to be
* granted, as part of the mode, our implementation requires
* privilege to adminster the object if not the owner or creator.
*/
#if 0
if (obj_mode & IPC_M)
dac_granted |= IPC_M;
#endif
if (obj_mode & IPC_R)
dac_granted |= IPC_R;
if (obj_mode & IPC_W)
dac_granted |= IPC_W;
/*
* Simple case: all required rights are granted by DAC.
*/
if ((dac_granted & acc_mode) == acc_mode)
return (0);
/*
* Privilege is required to satisfy the request.
*/
priv_granted = 0;
if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) {
error = priv_check(td, PRIV_IPC_ADMIN);
if (error == 0)
priv_granted |= IPC_M;
}
if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) {
error = priv_check(td, PRIV_IPC_READ);
if (error == 0)
priv_granted |= IPC_R;
}
if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) {
error = priv_check(td, PRIV_IPC_WRITE);
if (error == 0)
priv_granted |= IPC_W;
}
if (((dac_granted | priv_granted) & acc_mode) == acc_mode)
return (0);
else
return (EACCES);
}
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