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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>
* All rights reserved.
*
* 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/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.
*/
int
ipcperm(td, perm, mode)
struct thread *td;
struct ipc_perm *perm;
int mode;
{
struct ucred *cred = td->td_ucred;
int error;
if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
/*
* For a non-create/owner, we require privilege to
* modify the object protections. Note: some other
* implementations permit IPC_M to be delegated to
* unprivileged non-creator/owner uids/gids.
*/
if (mode & IPC_M) {
error = suser(td);
if (error)
return (error);
}
/*
* Try to match against creator/owner group; if not, fall
* back on other.
*/
mode >>= 3;
if (!groupmember(perm->gid, cred) &&
!groupmember(perm->cgid, cred))
mode >>= 3;
} else {
/*
* Always permit the creator/owner to update the object
* protections regardless of whether the object mode
* permits it.
*/
if (mode & IPC_M)
return (0);
}
if ((mode & perm->mode) != mode) {
if (suser(td) != 0)
return (EACCES);
}
return (0);
}
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