/* Copyright (C) 2018 Open Information Security Foundation
 *
 * You can copy, redistribute or modify this Program under the terms of
 * the GNU General Public License version 2 as published by the Free
 * Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <stddef.h>
#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#define LINUX_VERSION_CODE 263682

int SEC("filter") hashfilter(struct __sk_buff *skb) {
    __u16 vlan_id = skb->vlan_tci & 0x0fff;
    /* accept VLAN 2 and 4 and drop the rest */
    switch (vlan_id) {
        case 2:
        case 4:
            return -1;
        default:
            return 0;
    }
    return 0;
}

char __license[] SEC("license") = "GPL";

__u32 __version SEC("version") = LINUX_VERSION_CODE;