net/mld/mld_mcastmac.c

/****************************************************************************
 * net/mld/mld_mcastmac.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <assert.h>
#include <debug.h>

#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/mld.h>

#include "devif/devif.h"
#include "mld/mld.h"

#ifdef CONFIG_NET_MLD

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name:  mld_mcastmac
 *
 * Description:
 *   Given an IP address (in network order), create a MLD multicast MAC
 *   address.
 *
 ****************************************************************************/

static void mld_mcastmac(FAR const net_ipv6addr_t ipaddr, FAR uint8_t *mac)
{
  FAR uint8_t *ipaddr8 = (FAR uint8_t *)ipaddr;

  mldinfo("Mcast IP: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
          NTOHS(ipaddr[0]), NTOHS(ipaddr[1]), NTOHS(ipaddr[2]),
          NTOHS(ipaddr[3]), NTOHS(ipaddr[4]), NTOHS(ipaddr[5]),
          NTOHS(ipaddr[6]), NTOHS(ipaddr[7]));

  /* For the MAC address by insert the low 32 Bits of the multicast IPv6
   * Address into the Ethernet Address .  This mapping is from the IETF
   * RFC 7042.
   */

  mac[0] = 0x33;
  mac[1] = 0x33;
  mac[2] = ipaddr8[12];  /* Bits: 96-103 */
  mac[3] = ipaddr8[13];  /* Bits: 104-111 */
  mac[4] = ipaddr8[14];  /* Bits: 112-119 */
  mac[5] = ipaddr8[15];  /* Bits: 120-127 */

  mldinfo("Mcast MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
          mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name:  mld_addmcastmac
 *
 * Description:
 *   Add an MLD MAC address to the device's MAC filter table.
 *
 ****************************************************************************/

void mld_addmcastmac(FAR struct net_driver_s *dev,
                     FAR const net_ipv6addr_t ipaddr)
{
  uint8_t mcastmac[6];

  mldinfo("Adding MAC address filter\n");

  if (dev->d_addmac != NULL)
    {
      mld_mcastmac(ipaddr, mcastmac);
      dev->d_addmac(dev, mcastmac);
    }
}

/****************************************************************************
 * Name:  mld_removemcastmac
 *
 * Description:
 *   Remove an MLD MAC address from the device's MAC filter table.
 *
 ****************************************************************************/

void mld_removemcastmac(FAR struct net_driver_s *dev,
                        FAR const net_ipv6addr_t ipaddr)
{
  uint8_t mcastmac[6];

  mldinfo("Removing MAC address filter\n");

  if (dev->d_rmmac != NULL)
    {
      mld_mcastmac(ipaddr, mcastmac);
      dev->d_rmmac(dev, mcastmac);
    }
}

#endif /* CONFIG_NET_MLD */