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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 2013 RackTop Systems.
*/
#include <errno.h>
#include <sys/types.h>
#include <stdio.h>
#include <userdefs.h>
#include <grp.h>
#include <libcmdutils.h>
static int findunusedgid(gid_t start, gid_t stop, gid_t *ret);
static boolean_t isreservedgid(gid_t gid);
/*
* Find the highest unused uid. If the highest unused gid is "stop",
* then attempt to find a hole in the range. Returns 0 on success.
*/
int
findnextgid(gid_t start, gid_t stop, gid_t *ret)
{
gid_t gid = start;
struct group *grp;
boolean_t overflow = B_FALSE;
setgrent();
for (grp = getgrent(); grp != NULL; grp = getgrent()) {
if (isreservedgid(grp->gr_gid)) /* Skip reserved IDs */
continue;
if (grp->gr_gid >= gid) {
if (grp->gr_gid == stop) { /* Overflow check */
overflow = B_TRUE;
break;
}
gid = grp->gr_gid + 1;
}
}
if (grp == NULL && errno != 0) {
endgrent();
return (-1);
}
endgrent();
if (overflow == B_TRUE) /* Find a hole */
return (findunusedgid(start, stop, ret));
while (isreservedgid(gid) && gid < stop) /* Skip reserved IDs */
gid++;
*ret = gid;
return (0);
}
/*
* Check to see whether the gid is a reserved gid
* -- nobody, noaccess or nogroup
*/
static boolean_t
isreservedgid(gid_t gid)
{
return (gid == 60001 || gid == 60002 || gid == 65534);
}
/*
* findunusedgid() attempts to return the next valid usable id between the
* supplied upper and lower limits. Returns 0 on success.
*/
static int
findunusedgid(gid_t start, gid_t stop, gid_t *ret)
{
gid_t gid;
for (gid = start; gid <= stop; gid++) {
if (isreservedgid(gid))
continue;
if (getgrgid(gid) == NULL) {
if (errno != 0)
return (-1);
break;
}
}
if (gid > stop)
return (-1);
*ret = gid;
return (0);
}
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