/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <grp.h>
#include <sys/stat.h>
#include <unistd.h>
#include <userdefs.h>
#include <strings.h>
#include <stdlib.h>
#include "users.h"
#include "messages.h"

/* lint error-killers: */
void errmsg(int, int);

/* Modify group to new gid and/or new name */
int
mod_group(char *group, gid_t gid, char *newgroup)
{
        int modified = 0;
        int fd;
        char tname[] = "/etc/gtmp.XXXXXX";
        FILE *e_fptr, *t_fptr;
        struct group *g_ptr;
        struct stat sbuf;
        boolean_t haserr;
        int line = 1;

        if ((e_fptr = fopen(GROUP, "r")) == NULL)
                return (EX_UPDATE);

        if (fstat(fileno(e_fptr), &sbuf) != 0)
                return (EX_UPDATE);

        if ((fd = mkstemp(tname)) == -1)
                return (EX_UPDATE);

        if ((t_fptr = fdopen(fd, "w")) == NULL) {
                (void) close(fd);
                (void) unlink(tname);
                return (EX_UPDATE);
        }

        /*
         * Get ownership and permissions correct
         */

        if (fchmod(fd, sbuf.st_mode) != 0 ||
            fchown(fd, sbuf.st_uid, sbuf.st_gid) != 0) {
                (void) fclose(t_fptr);
                (void) unlink(tname);
                return (EX_UPDATE);
        }

        while ((g_ptr = fgetgrent(e_fptr)) != NULL) {

                /* check to see if group is one to modify */
                if (strcmp(g_ptr->gr_name, group) == 0) {
                        if (newgroup != NULL)
                                g_ptr->gr_name = newgroup;
                        if (gid != -1)
                                g_ptr->gr_gid = gid;
                        modified++;
                }
                putgrent(g_ptr, t_fptr);
                line++;
        }

        haserr = !feof(e_fptr);
        if (haserr)
                errmsg(M_SYNTAX, line);

        (void) fclose(e_fptr);

        if (fclose(t_fptr) != 0 || haserr) {
                /* GROUP file contains bad entries or write failed. */
                (void) unlink(tname);
                return (EX_UPDATE);
        }

        if (modified) {
                if (rename(tname, GROUP) != 0) {
                        (void) unlink(tname);
                        return (EX_UPDATE);
                }
                return (EX_SUCCESS);
        } else {
                (void) unlink(tname);
                return (EX_NAME_NOT_EXIST);
        }
}