xref: /src/sys/kern/sysv_ipc.c

/*
 * Copyright (c) 1994 Herb Peyerl <hpeyerl (at) 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. 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.
 *
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/ipc.h>
#include <sys/systm.h>

/*
 * Check for ipc permission
 */

int
ipcperm(uc, perm, mode)
	struct ucred *uc;
	struct ipc_perm *perm;
	int mode;
{
	int i = 0;

	if (uc->cr_uid == 0)
		return(0);

	/*
	 * Does the user have permission?
	 */
	if (uc->cr_uid != perm->cuid && uc->cr_uid != perm->uid) {
		i = 3;
		/*
		 * Does the group have permission?
		 */
		if (!groupmember(perm->gid, uc) && !groupmember(perm->cgid, uc))
			i += 3;
	}

	if (((mode&0700) & (perm->mode << i)) != mode)
		return(EACCES);
}