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2015-04-16 09:16:48 +02:00

124 lines
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C

/* $NetBSD: sysv_ipc.c,v 1.10 1995/06/03 05:53:28 mycroft Exp $ */
/*
* Copyright (c) 1995 Charles M. Hannum. 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 Charles M. Hannum.
* 4. The name of the author 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.
*/
#define _KERNEL
#include "ixemul.h"
#include <sys/vnode.h>
#include <sys/ipc.h>
#include <sys/ucred.h>
#define IPC_PERM_ALWAYS_SUCCEED
#ifndef IPC_PERM_ALWAYS_SUCCEED
/*
* Do the usual access checking.
* file_mode, uid and gid are from the vnode in question,
* while acc_mode and cred are from the VOP_ACCESS parameter list
*/
int
vaccess(file_mode, uid, gid, acc_mode, cred)
mode_t file_mode;
uid_t uid;
gid_t gid;
mode_t acc_mode;
struct ucred *cred;
{
mode_t mask;
/* User id 0 always gets access. */
if (cred->cr_uid == 0)
return 0;
mask = 0;
/* Otherwise, check the owner. */
if (cred->cr_uid == uid) {
if (acc_mode & VEXEC)
mask |= S_IXUSR;
if (acc_mode & VREAD)
mask |= S_IRUSR;
if (acc_mode & VWRITE)
mask |= S_IWUSR;
return (file_mode & mask) == mask ? 0 : EACCES;
}
/* Otherwise, check the groups. */
if (cred->cr_gid == gid/* || groupmember(gid, cred)*/) {
if (acc_mode & VEXEC)
mask |= S_IXGRP;
if (acc_mode & VREAD)
mask |= S_IRGRP;
if (acc_mode & VWRITE)
mask |= S_IWGRP;
return (file_mode & mask) == mask ? 0 : EACCES;
}
/* Otherwise, check everyone else. */
if (acc_mode & VEXEC)
mask |= S_IXOTH;
if (acc_mode & VREAD)
mask |= S_IROTH;
if (acc_mode & VWRITE)
mask |= S_IWOTH;
return (file_mode & mask) == mask ? 0 : EACCES;
}
#endif
/*
* Check for ipc permission
*/
int
ipcperm(cred, perm, mode)
struct ucred *cred;
struct ipc_perm *perm;
int mode;
{
#ifdef IPC_PERM_ALWAYS_SUCCEED
return 0;
// Always succeed for now :-(
#else
if (mode == IPC_M) {
if (cred->cr_uid == 0 ||
cred->cr_uid == perm->uid ||
cred->cr_uid == perm->cuid)
return (0);
return (EPERM);
}
if (vaccess(perm->mode, perm->uid, perm->gid, mode, cred) == 0 ||
vaccess(perm->mode, perm->cuid, perm->cgid, mode, cred) == 0)
return (0);
return (EACCES);
#endif
}