/core/net/ipv6/multicast/smrf.c
C | 214 lines | 110 code | 17 blank | 87 comment | 14 complexity | 97f0fb06b2257725de5cb31db8239b33 MD5 | raw file
- /*
- * Copyright (c) 2010, Loughborough University - Computer Science
- * 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.
- * 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
- *
- * This file is part of the Contiki operating system.
- */
- /**
- * \addtogroup smrf-multicast
- * @{
- */
- /**
- * \file
- * This file implements 'Stateless Multicast RPL Forwarding' (SMRF)
- *
- * \author
- * George Oikonomou - <oikonomou@users.sourceforge.net>
- */
- #include "contiki.h"
- #include "contiki-net.h"
- #include "net/ipv6/multicast/uip-mcast6.h"
- #include "net/ipv6/multicast/uip-mcast6-route.h"
- #include "net/ipv6/multicast/uip-mcast6-stats.h"
- #include "net/ipv6/multicast/smrf.h"
- #include "net/rpl/rpl.h"
- #include "net/netstack.h"
- #include <string.h>
- #define DEBUG DEBUG_NONE
- #include "net/ip/uip-debug.h"
- /*---------------------------------------------------------------------------*/
- /* Macros */
- /*---------------------------------------------------------------------------*/
- /* CCI */
- #define SMRF_FWD_DELAY() NETSTACK_RDC.channel_check_interval()
- /* Number of slots in the next 500ms */
- #define SMRF_INTERVAL_COUNT ((CLOCK_SECOND >> 2) / fwd_delay)
- /*---------------------------------------------------------------------------*/
- /* Internal Data */
- /*---------------------------------------------------------------------------*/
- static struct ctimer mcast_periodic;
- static uint8_t mcast_len;
- static uip_buf_t mcast_buf;
- static uint8_t fwd_delay;
- static uint8_t fwd_spread;
- /*---------------------------------------------------------------------------*/
- /* uIPv6 Pointers */
- /*---------------------------------------------------------------------------*/
- #define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
- /*---------------------------------------------------------------------------*/
- static void
- mcast_fwd(void *p)
- {
- memcpy(uip_buf, &mcast_buf, mcast_len);
- uip_len = mcast_len;
- UIP_IP_BUF->ttl--;
- tcpip_output(NULL);
- uip_clear_buf();
- }
- /*---------------------------------------------------------------------------*/
- static uint8_t
- in()
- {
- rpl_dag_t *d; /* Our DODAG */
- uip_ipaddr_t *parent_ipaddr; /* Our pref. parent's IPv6 address */
- const uip_lladdr_t *parent_lladdr; /* Our pref. parent's LL address */
- /*
- * Fetch a pointer to the LL address of our preferred parent
- *
- * ToDo: This rpl_get_any_dag() call is a dirty replacement of the previous
- * rpl_get_dag(RPL_DEFAULT_INSTANCE);
- * so that things can compile with the new RPL code. This needs updated to
- * read instance ID from the RPL HBHO and use the correct parent accordingly
- */
- d = rpl_get_any_dag();
- if(!d) {
- UIP_MCAST6_STATS_ADD(mcast_dropped);
- return UIP_MCAST6_DROP;
- }
- /* Retrieve our preferred parent's LL address */
- parent_ipaddr = rpl_get_parent_ipaddr(d->preferred_parent);
- parent_lladdr = uip_ds6_nbr_lladdr_from_ipaddr(parent_ipaddr);
- if(parent_lladdr == NULL) {
- UIP_MCAST6_STATS_ADD(mcast_dropped);
- return UIP_MCAST6_DROP;
- }
- /*
- * We accept a datagram if it arrived from our preferred parent, discard
- * otherwise.
- */
- if(memcmp(parent_lladdr, packetbuf_addr(PACKETBUF_ADDR_SENDER),
- UIP_LLADDR_LEN)) {
- PRINTF("SMRF: Routable in but SMRF ignored it\n");
- UIP_MCAST6_STATS_ADD(mcast_dropped);
- return UIP_MCAST6_DROP;
- }
- if(UIP_IP_BUF->ttl <= 1) {
- UIP_MCAST6_STATS_ADD(mcast_dropped);
- return UIP_MCAST6_DROP;
- }
- UIP_MCAST6_STATS_ADD(mcast_in_all);
- UIP_MCAST6_STATS_ADD(mcast_in_unique);
- /* If we have an entry in the mcast routing table, something with
- * a higher RPL rank (somewhere down the tree) is a group member */
- if(uip_mcast6_route_lookup(&UIP_IP_BUF->destipaddr)) {
- /* If we enter here, we will definitely forward */
- UIP_MCAST6_STATS_ADD(mcast_fwd);
- /*
- * Add a delay (D) of at least SMRF_FWD_DELAY() to compensate for how
- * contikimac handles broadcasts. We can't start our TX before the sender
- * has finished its own.
- */
- fwd_delay = SMRF_FWD_DELAY();
- /* Finalise D: D = min(SMRF_FWD_DELAY(), SMRF_MIN_FWD_DELAY) */
- #if SMRF_MIN_FWD_DELAY
- if(fwd_delay < SMRF_MIN_FWD_DELAY) {
- fwd_delay = SMRF_MIN_FWD_DELAY;
- }
- #endif
- if(fwd_delay == 0) {
- /* No delay required, send it, do it now, why wait? */
- UIP_IP_BUF->ttl--;
- tcpip_output(NULL);
- UIP_IP_BUF->ttl++; /* Restore before potential upstack delivery */
- } else {
- /* Randomise final delay in [D , D*Spread], step D */
- fwd_spread = SMRF_INTERVAL_COUNT;
- if(fwd_spread > SMRF_MAX_SPREAD) {
- fwd_spread = SMRF_MAX_SPREAD;
- }
- if(fwd_spread) {
- fwd_delay = fwd_delay * (1 + ((random_rand() >> 11) % fwd_spread));
- }
- memcpy(&mcast_buf, uip_buf, uip_len);
- mcast_len = uip_len;
- ctimer_set(&mcast_periodic, fwd_delay, mcast_fwd, NULL);
- }
- PRINTF("SMRF: %u bytes: fwd in %u [%u]\n",
- uip_len, fwd_delay, fwd_spread);
- }
- /* Done with this packet unless we are a member of the mcast group */
- if(!uip_ds6_is_my_maddr(&UIP_IP_BUF->destipaddr)) {
- PRINTF("SMRF: Not a group member. No further processing\n");
- return UIP_MCAST6_DROP;
- } else {
- PRINTF("SMRF: Ours. Deliver to upper layers\n");
- UIP_MCAST6_STATS_ADD(mcast_in_ours);
- return UIP_MCAST6_ACCEPT;
- }
- }
- /*---------------------------------------------------------------------------*/
- static void
- init()
- {
- UIP_MCAST6_STATS_INIT(NULL);
- uip_mcast6_route_init();
- }
- /*---------------------------------------------------------------------------*/
- static void
- out()
- {
- return;
- }
- /*---------------------------------------------------------------------------*/
- /**
- * \brief The SMRF engine driver
- */
- const struct uip_mcast6_driver smrf_driver = {
- "SMRF",
- init,
- out,
- in,
- };
- /*---------------------------------------------------------------------------*/
- /** @} */