/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright 2021 Lutz Donnerhacke
 *
 * 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. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS
 * 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 <atf-c.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>

#include <net/ethernet.h>
#include <netinet/in.h>

#include "util.h"
#include <netgraph/ng_bridge.h>

struct vlan
{
        uint16_t        proto;
        uint16_t        tag;
}               __packed;

struct frame
{
        u_char          dst[ETHER_ADDR_LEN];
        u_char          src[ETHER_ADDR_LEN];
        struct vlan     vlan[10];
}               __packed;

static struct frame msg = {
        .src = {2, 4, 6, 1, 3, 5},
        .dst = {2, 4, 6, 1, 3, 7},
        .vlan[0] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(1, 0, 0))},
        .vlan[1] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(2, 0, 0))},
        .vlan[2] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(3, 0, 0))},
        .vlan[3] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(4, 0, 0))},
        .vlan[4] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(5, 0, 0))},
        .vlan[5] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(6, 0, 0))},
        .vlan[6] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(7, 0, 0))},
        .vlan[7] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(8, 0, 0))},
        .vlan[8] = {htons(ETHERTYPE_VLAN), htons(EVL_MAKETAG(9, 0, 0))},
        .vlan[9] = {0}
};

static void     _basic(int);
static void     get_vlan(void *data, size_t len, void *ctx);

static void
get_vlan(void *data, size_t len, void *ctx)
{
        int            *v = ctx, i;
        struct frame   *f = data;

        (void)len;
        for (i = 0; i < 10; i++)
                v[i] = EVL_VLANOFTAG(ntohs(f->vlan[i].tag));
}

static void
_basic(int direction)
{
        int             r[10];
        int             i, rot, len;

        ng_init();
        ng_errors(PASS);
        ng_shutdown("vr:");
        ng_errors(FAIL);

        ng_mkpeer(".", "a", "vlan_rotate", direction > 0 ? "original" : "ordered");
        ng_name("a", "vr");
        ng_connect(".", "b", "vr:", direction > 0 ? "ordered" : "original");
        ng_register_data("b", get_vlan);

        for (len = 9; len > 0; len--)
        {
                /* reduce the number of vlans */
                msg.vlan[len].proto = htons(ETHERTYPE_IP);

                for (rot = -len + 1; rot < len; rot++)
                {
                        char            cmd[40];

                        /* set rotation offset */
                        snprintf(cmd, sizeof(cmd), "setconf { min=0 max=9 rot=%d }", rot);
                        ng_send_msg("vr:", cmd);

                        ng_send_data("a", &msg, sizeof(msg));
                        ng_handle_events(50, &r);

                        /* check rotation */
                        for (i = 0; i < len; i++)
                        {
                                int             expect = (2 * len + i - direction * rot) % len + 1;
                                int             vlan = r[i];

                                ATF_CHECK_MSG(vlan == expect,
                                 "len=%d rot=%d i=%d -> vlan=%d, expect=%d",
                                              len, rot, i, r[i], expect);
                        }
                }
        }

        ng_shutdown("vr:");
}

ATF_TC(basic);
ATF_TC_HEAD(basic, conf)
{
        atf_tc_set_md_var(conf, "require.user", "root");
}

ATF_TC_BODY(basic, dummy)
{
        _basic(1);
}

ATF_TC(reverse);
ATF_TC_HEAD(reverse, conf)
{
        atf_tc_set_md_var(conf, "require.user", "root");
}

ATF_TC_BODY(reverse, dummy)
{
        _basic(-1);
}

static void     _ethertype(int);
static void     get_ethertype(void *data, size_t len, void *ctx);

static void
get_ethertype(void *data, size_t len, void *ctx)
{
        int            *v = ctx, i;
        struct frame   *f = data;

        (void)len;
        for (i = 0; i < 10; i++)
                v[i] = ntohs(f->vlan[i].proto);
}

static void
_ethertype(int direction)
{
        int             r[10];
        int             i, rounds = 20;

        ng_init();
        ng_errors(PASS);
        ng_shutdown("vr:");
        ng_errors(FAIL);

        ng_mkpeer(".", "a", "vlan_rotate", direction > 0 ? "original" : "ordered");
        ng_name("a", "vr");
        ng_connect(".", "b", "vr:", direction > 0 ? "ordered" : "original");
        ng_register_data("b", get_ethertype);

        while (rounds-- > 0)
        {
                char            cmd[40];
                int             len = 9;
                int             rot = rand() % (2 * len - 1) - len + 1;
                int             vlan[10];

                for (i = 0; i < len; i++)
                {
                        switch (rand() % 3)
                        {
                        default:
                                msg.vlan[i].proto = htons(ETHERTYPE_VLAN);
                                break;
                        case 1:
                                msg.vlan[i].proto = htons(ETHERTYPE_QINQ);
                                break;
                        case 2:
                                msg.vlan[i].proto = htons(ETHERTYPE_8021Q9100);
                                break;
                        }
                }
                msg.vlan[i].proto = htons(ETHERTYPE_IP);

                for (i = 0; i < len; i++)
                        vlan[i] = msg.vlan[i].proto;

                snprintf(cmd, sizeof(cmd), "setconf { min=0 max=9 rot=%d }", rot);
                ng_send_msg("vr:", cmd);

                bzero(r, sizeof(r));
                ng_send_data("a", &msg, sizeof(msg));
                ng_handle_events(50, &r);

                /* check rotation */
                for (i = 0; i < len; i++)
                {
                        int             expect = (2 * len + i - direction * rot) % len;

                        ATF_CHECK_MSG(r[i] == ntohs(vlan[expect]),
                         "len=%d rot=%d i=%d -> vlan=%04x, expect(%d)=%04x",
                            len, rot, i, ntohs(r[i]), expect, vlan[expect]);
                }
        }

        ng_shutdown("vr:");
}

ATF_TC(ethertype);
ATF_TC_HEAD(ethertype, conf)
{
        atf_tc_set_md_var(conf, "require.user", "root");
}

ATF_TC_BODY(ethertype, dummy)
{
        _ethertype(1);
}

ATF_TC(typeether);
ATF_TC_HEAD(typeether, conf)
{
        atf_tc_set_md_var(conf, "require.user", "root");
}

ATF_TC_BODY(typeether, dummy)
{
        _ethertype(-1);
}

ATF_TC(minmax);
ATF_TC_HEAD(minmax, conf)
{
        atf_tc_set_md_var(conf, "require.user", "root");
}

ATF_TC_BODY(minmax, dummy)
{
        ng_counter_t    r;
        int             len;

        ng_init();
        ng_errors(PASS);
        ng_shutdown("vr:");
        ng_errors(FAIL);

        ng_mkpeer(".", "a", "vlan_rotate", "original");
        ng_name("a", "vr");
        ng_connect(".", "b", "vr:", "ordered");
        ng_connect(".", "c", "vr:", "excessive");
        ng_connect(".", "d", "vr:", "incomplete");
        ng_register_data("a", get_data0);
        ng_register_data("b", get_data1);
        ng_register_data("c", get_data2);
        ng_register_data("d", get_data3);

        ng_send_msg("vr:", "setconf { min=3 max=7 rot=0 }");
        for (len = 9; len > 0; len--)
        {
                /* reduce the number of vlans */
                msg.vlan[len].proto = htons(ETHERTYPE_IP);

                ng_counter_clear(r);
                ng_send_data("a", &msg, sizeof(msg));
                ng_handle_events(50, &r);
                if (len < 3)
                        ATF_CHECK(r[0] == 0 && r[1] == 0 && r[2] == 0 && r[3] == 1);
                else if (len > 7)
                        ATF_CHECK(r[0] == 0 && r[1] == 0 && r[2] == 1 && r[3] == 0);
                else
                        ATF_CHECK(r[0] == 0 && r[1] == 1 && r[2] == 0 && r[3] == 0);

                ng_counter_clear(r);
                ng_send_data("b", &msg, sizeof(msg));
                ng_handle_events(50, &r);
                if (len < 3)
                        ATF_CHECK(r[0] == 0 && r[1] == 0 && r[2] == 0 && r[3] == 1);
                else if (len > 7)
                        ATF_CHECK(r[0] == 0 && r[1] == 0 && r[2] == 1 && r[3] == 0);
                else
                        ATF_CHECK(r[0] == 1 && r[1] == 0 && r[2] == 0 && r[3] == 0);

                ng_counter_clear(r);
                ng_send_data("c", &msg, sizeof(msg));
                ng_handle_events(50, &r);
                ATF_CHECK(r[0] == 1 && r[1] == 0 && r[2] == 0 && r[3] == 0);

                ng_counter_clear(r);
                ng_send_data("d", &msg, sizeof(msg));
                ng_handle_events(50, &r);
                ATF_CHECK(r[0] == 1 && r[1] == 0 && r[2] == 0 && r[3] == 0);
        }

        ng_shutdown("vr:");
}

ATF_TP_ADD_TCS(vlan_rotate)
{
        /* Use "dd if=/dev/random bs=2 count=1 | od -x" to reproduce */
        srand(0xb93b);

        ATF_TP_ADD_TC(vlan_rotate, basic);
        ATF_TP_ADD_TC(vlan_rotate, ethertype);
        ATF_TP_ADD_TC(vlan_rotate, reverse);
        ATF_TP_ADD_TC(vlan_rotate, typeether);
        ATF_TP_ADD_TC(vlan_rotate, minmax);

        return atf_no_error();
}