122 lines
3.5 KiB
C
122 lines
3.5 KiB
C
/* $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
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/*-
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* Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Herb Peyerl.
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* 4. The name of Herb Peyerl may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_sysvipc.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/sem.h>
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#include <sys/shm.h>
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#include <sys/ipc.h>
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#include <sys/proc.h>
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#include <sys/ucred.h>
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void (*shmfork_hook)(struct proc *, struct proc *) = NULL;
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void (*shmexit_hook)(struct vmspace *) = NULL;
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/* called from kern_fork.c */
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void
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shmfork(p1, p2)
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struct proc *p1, *p2;
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{
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if (shmfork_hook != NULL)
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shmfork_hook(p1, p2);
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return;
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}
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/* called from kern_exit.c */
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void
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shmexit(struct vmspace *vm)
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{
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if (shmexit_hook != NULL)
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shmexit_hook(vm);
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return;
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}
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/*
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* Check for IPC permission.
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*
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* Note: The MAC Framework does not require any modifications to the
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* ipcperm() function, as access control checks are performed throughout the
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* implementation of each primitive. Those entry point calls complement the
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* ipcperm() discertionary checks.
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*/
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int
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ipcperm(td, perm, mode)
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struct thread *td;
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struct ipc_perm *perm;
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int mode;
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{
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struct ucred *cred = td->td_ucred;
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int error;
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if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
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/*
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* For a non-create/owner, we require privilege to
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* modify the object protections. Note: some other
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* implementations permit IPC_M to be delegated to
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* unprivileged non-creator/owner uids/gids.
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*/
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if (mode & IPC_M) {
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error = suser(td);
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if (error)
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return (error);
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}
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/*
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* Try to match against creator/owner group; if not, fall
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* back on other.
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*/
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mode >>= 3;
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if (!groupmember(perm->gid, cred) &&
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!groupmember(perm->cgid, cred))
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mode >>= 3;
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} else {
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/*
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* Always permit the creator/owner to update the object
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* protections regardless of whether the object mode
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* permits it.
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*/
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if (mode & IPC_M)
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return (0);
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}
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if ((mode & perm->mode) != mode) {
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if (suser(td) != 0)
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return (EACCES);
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}
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return (0);
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}
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