/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010-2011 Monthadar Al Jaberi, TerraNet AB
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * 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 NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

#include <sys/param.h>
#include <sys/jail.h>

#include <sys/socket.h>

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

#include "visibility.h"

/* Function prototypes */
static d_ioctl_t        vis_ioctl;

static struct cdevsw vis_cdevsw = {
        .d_version =    D_VERSION,
        .d_flags =      0,
        .d_ioctl =      vis_ioctl,
        .d_name =       "visctl",
};

void
visibility_init(struct wtap_plugin *plugin)
{
        struct visibility_plugin *vis_plugin;

        vis_plugin = (struct visibility_plugin *) plugin;
        plugin->wp_sdev = make_dev(&vis_cdevsw,0,UID_ROOT,GID_WHEEL,0600,
            (const char *)"visctl");
        plugin->wp_sdev->si_drv1 = vis_plugin;
        mtx_init(&vis_plugin->pl_mtx, "visibility_plugin mtx",
            NULL, MTX_DEF | MTX_RECURSE);
        printf("Using visibility wtap plugin...\n");
}

void
visibility_deinit(struct wtap_plugin *plugin)
{
        struct visibility_plugin *vis_plugin;

        vis_plugin = (struct visibility_plugin *) plugin;
        destroy_dev(plugin->wp_sdev);
        mtx_destroy(&vis_plugin->pl_mtx);
        free(vis_plugin, M_WTAP_PLUGIN);
        printf("Removing visibility wtap plugin...\n");
}

/* We need to use a mutex lock when we read out a visibility map
 * and when we change visibility map from user space through IOCTL
 */
void
visibility_work(struct wtap_plugin *plugin, struct packet *p)
{
        struct visibility_plugin *vis_plugin =
            (struct visibility_plugin *) plugin;
        struct wtap_hal *hal = (struct wtap_hal *)vis_plugin->base.wp_hal;
        struct vis_map *map;

        KASSERT(mtod(p->m, const char *) != (const char *) 0xdeadc0de ||
            mtod(p->m, const char *) != NULL,
            ("[%s] got a corrupt packet from master queue, p->m=%p, p->id=%d\n",
            __func__, p->m, p->id));
        DWTAP_PRINTF("[%d] BROADCASTING m=%p\n", p->id, p->m);
        mtx_lock(&vis_plugin->pl_mtx);
        map = &vis_plugin->pl_node[p->id];
        mtx_unlock(&vis_plugin->pl_mtx);

        /* This is O(n*n) which is not optimal for large
         * number of nodes. Another way of doing it is
         * creating groups of nodes that hear each other.
         * Atleast for this simple static node plugin.
         */
        for(int i=0; i<ARRAY_SIZE; ++i){
                uint32_t index = map->map[i];
                for(int j=0; j<32; ++j){
                        int vis = index & 0x01;
                        if(vis){
                                int k = i*ARRAY_SIZE + j;
                                if(hal->hal_devs[k] != NULL
                                    && hal->hal_devs[k]->up == 1){
                                        struct wtap_softc *sc =
                                            hal->hal_devs[k];
                                        struct mbuf *m =
                                            m_dup(p->m, M_NOWAIT);
                                        DWTAP_PRINTF("[%d] duplicated old_m=%p"
                                            "to new_m=%p\n", p->id, p->m, m);
#if 0
                                        printf("[%d] sending to %d\n",
                                            p->id, k);
#endif
                                        wtap_inject(sc, m);
                                }
                        }
                        index = index >> 1;
                }
        }
}

static void
add_link(struct visibility_plugin *vis_plugin, struct link *l)
{

        mtx_lock(&vis_plugin->pl_mtx);
        struct vis_map *map = &vis_plugin->pl_node[l->id1];
        int index = l->id2/ARRAY_SIZE;
        int bit = l->id2 % ARRAY_SIZE;
        uint32_t value = 1 << bit;
        map->map[index] = map->map[index] | value;
        mtx_unlock(&vis_plugin->pl_mtx);
#if 0
        printf("l->id1=%d, l->id2=%d, map->map[%d] = %u, bit=%d\n",
            l->id1, l->id2, index, map->map[index], bit);
#endif
}

static void
del_link(struct visibility_plugin *vis_plugin, struct link *l)
{

        mtx_lock(&vis_plugin->pl_mtx);
        struct vis_map *map = &vis_plugin->pl_node[l->id1];
        int index = l->id2/ARRAY_SIZE;
        int bit = l->id2 % ARRAY_SIZE;
        uint32_t value = 1 << bit;
        map->map[index] = map->map[index] & ~value;
        mtx_unlock(&vis_plugin->pl_mtx);
#if 0
        printf("map->map[index] = %u\n", map->map[index]);
#endif
}

int
vis_ioctl(struct cdev *sdev, u_long cmd, caddr_t data,
    int fflag, struct thread *td)
{
        struct visibility_plugin *vis_plugin =
            (struct visibility_plugin *) sdev->si_drv1;
        struct wtap_hal *hal = vis_plugin->base.wp_hal;
        struct link l;
        int op;
        int error = 0;

        CURVNET_SET(CRED_TO_VNET(curthread->td_ucred));
        switch(cmd) {
        case VISIOCTLOPEN:
                op =  *(int *)data; 
                if(op == 0)
                        medium_close(hal->hal_md);
                else
                        medium_open(hal->hal_md);
                break;
        case VISIOCTLLINK:
                l = *(struct link *)data;
                if(l.op == 0)
                        del_link(vis_plugin, &l);
                else
                        add_link(vis_plugin, &l);
#if 0
                printf("op=%d, id1=%d, id2=%d\n", l.op, l.id1, l.id2);
#endif
                break;
        default:
                DWTAP_PRINTF("Unknown WTAP IOCTL\n");
                error = EINVAL;
        }

        CURVNET_RESTORE();
        return error;
}