251 lines
9.1 KiB
C
251 lines
9.1 KiB
C
/*
|
|
* Copyright (c) 2007, Swedish Institute of 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.
|
|
*
|
|
* $Id: example-multihop.c,v 1.6 2010/01/14 14:32:22 joxe Exp $
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Testing the multihop forwarding layer (multihop) in Rime
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*
|
|
*
|
|
* This example shows how to use the multihop Rime module, how
|
|
* to use the announcement mechanism, how to manage a list
|
|
* with the list module, and how to allocate memory with the
|
|
* memb module.
|
|
*
|
|
* The multihop module provides hooks for forwarding packets
|
|
* in a multi-hop fashion, but does not implement any routing
|
|
* protocol. A routing mechanism must be provided by the
|
|
* application or protocol running on top of the multihop
|
|
* module. In this case, this example program provides the
|
|
* routing mechanism.
|
|
*
|
|
* The routing mechanism implemented by this example program
|
|
* is very simple: it forwards every incoming packet to a
|
|
* random neighbor. The program maintains a list of neighbors,
|
|
* which it populated through the use of the announcement
|
|
* mechanism.
|
|
*
|
|
* The neighbor list is populated by incoming announcements
|
|
* from neighbors. The program maintains a list of neighbors,
|
|
* where each entry is allocated from a MEMB() (memory block
|
|
* pool). Each neighbor has a timeout so that they do not
|
|
* occupy their list entry for too long.
|
|
*
|
|
* When a packet arrives to the node, the function forward()
|
|
* is called by the multihop layer. This function picks a
|
|
* random neighbor to send the packet to. The packet is
|
|
* forwarded by every node in the network until it reaches its
|
|
* final destination (or is discarded in transit due to a
|
|
* transmission error or a collision).
|
|
*
|
|
*/
|
|
|
|
#include "contiki.h"
|
|
#include "net/rime.h"
|
|
#include "lib/list.h"
|
|
#include "lib/memb.h"
|
|
#include "lib/random.h"
|
|
#include "dev/button-sensor.h"
|
|
#include "dev/leds.h"
|
|
|
|
#include <stdio.h>
|
|
|
|
#define CHANNEL 135
|
|
|
|
|
|
struct example_neighbor {
|
|
struct example_neighbor *next;
|
|
rimeaddr_t addr;
|
|
struct ctimer ctimer;
|
|
};
|
|
|
|
#define NEIGHBOR_TIMEOUT 60 * CLOCK_SECOND
|
|
#define MAX_NEIGHBORS 16
|
|
LIST(neighbor_table);
|
|
MEMB(neighbor_mem, struct example_neighbor, MAX_NEIGHBORS);
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS(example_multihop_process, "multihop example");
|
|
AUTOSTART_PROCESSES(&example_multihop_process);
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* This function is called by the ctimer present in each neighbor
|
|
* table entry. The function removes the neighbor from the table
|
|
* because it has become too old.
|
|
*/
|
|
static void
|
|
remove_neighbor(void *n)
|
|
{
|
|
struct example_neighbor *e = n;
|
|
|
|
list_remove(neighbor_table, e);
|
|
memb_free(&neighbor_mem, e);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* This function is called when an incoming announcement arrives. The
|
|
* function checks the neighbor table to see if the neighbor is
|
|
* already present in the list. If the neighbor is not present in the
|
|
* list, a new neighbor table entry is allocated and is added to the
|
|
* neighbor table.
|
|
*/
|
|
static void
|
|
received_announcement(struct announcement *a, rimeaddr_t *from,
|
|
uint16_t id, uint16_t value)
|
|
{
|
|
struct example_neighbor *e;
|
|
|
|
/* printf("Got announcement from %d.%d, id %d, value %d\n",
|
|
from->u8[0], from->u8[1], id, value);*/
|
|
|
|
/* We received an announcement from a neighbor so we need to update
|
|
the neighbor list, or add a new entry to the table. */
|
|
for(e = list_head(neighbor_table); e != NULL; e = e->next) {
|
|
if(rimeaddr_cmp(from, &e->addr)) {
|
|
/* Our neighbor was found, so we update the timeout. */
|
|
ctimer_set(&e->ctimer, NEIGHBOR_TIMEOUT, remove_neighbor, e);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* The neighbor was not found in the list, so we add a new entry by
|
|
allocating memory from the neighbor_mem pool, fill in the
|
|
necessary fields, and add it to the list. */
|
|
e = memb_alloc(&neighbor_mem);
|
|
if(e != NULL) {
|
|
rimeaddr_copy(&e->addr, from);
|
|
list_add(neighbor_table, e);
|
|
ctimer_set(&e->ctimer, NEIGHBOR_TIMEOUT, remove_neighbor, e);
|
|
}
|
|
}
|
|
static struct announcement example_announcement;
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* This function is called at the final recepient of the message.
|
|
*/
|
|
static void
|
|
recv(struct multihop_conn *c, const rimeaddr_t *sender,
|
|
const rimeaddr_t *prevhop,
|
|
uint8_t hops)
|
|
{
|
|
printf("multihop message received '%s'\n", (char *)packetbuf_dataptr());
|
|
}
|
|
/*
|
|
* This function is called to forward a packet. The function picks a
|
|
* random neighbor from the neighbor list and returns its address. The
|
|
* multihop layer sends the packet to this address. If no neighbor is
|
|
* found, the function returns NULL to signal to the multihop layer
|
|
* that the packet should be dropped.
|
|
*/
|
|
static rimeaddr_t *
|
|
forward(struct multihop_conn *c,
|
|
const rimeaddr_t *originator, const rimeaddr_t *dest,
|
|
const rimeaddr_t *prevhop, uint8_t hops)
|
|
{
|
|
/* Find a random neighbor to send to. */
|
|
int num, i;
|
|
struct example_neighbor *n;
|
|
|
|
if(list_length(neighbor_table) > 0) {
|
|
num = random_rand() % list_length(neighbor_table);
|
|
i = 0;
|
|
for(n = list_head(neighbor_table); n != NULL && i != num; n = n->next) {
|
|
++i;
|
|
}
|
|
if(n != NULL) {
|
|
printf("%d.%d: Forwarding packet to %d.%d (%d in list), hops %d\n",
|
|
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
|
|
n->addr.u8[0], n->addr.u8[1], num,
|
|
packetbuf_attr(PACKETBUF_ATTR_HOPS));
|
|
return &n->addr;
|
|
}
|
|
}
|
|
printf("%d.%d: did not find a neighbor to foward to\n",
|
|
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1]);
|
|
return NULL;
|
|
}
|
|
static const struct multihop_callbacks multihop_call = {recv, forward};
|
|
static struct multihop_conn multihop;
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS_THREAD(example_multihop_process, ev, data)
|
|
{
|
|
PROCESS_EXITHANDLER(multihop_close(&multihop);)
|
|
|
|
PROCESS_BEGIN();
|
|
|
|
/* Initialize the memory for the neighbor table entries. */
|
|
memb_init(&neighbor_mem);
|
|
|
|
/* Initialize the list used for the neighbor table. */
|
|
list_init(neighbor_table);
|
|
|
|
/* Open a multihop connection on Rime channel CHANNEL. */
|
|
multihop_open(&multihop, CHANNEL, &multihop_call);
|
|
|
|
/* Register an announcement with the same announcement ID as the
|
|
Rime channel we use to open the multihop connection above. */
|
|
announcement_register(&example_announcement,
|
|
CHANNEL,
|
|
0,
|
|
received_announcement);
|
|
|
|
/* Activate the button sensor. We use the button to drive traffic -
|
|
when the button is pressed, a packet is sent. */
|
|
button_sensor.configure(SENSORS_ACTIVE, (void *) 1);
|
|
|
|
/* Loop forever, send a packet when the button is pressed. */
|
|
while(1) {
|
|
rimeaddr_t to;
|
|
|
|
/* Wait until we get a sensor event with the button sensor as data. */
|
|
PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event &&
|
|
data == &button_sensor);
|
|
|
|
/* Copy the "Hello" to the packet buffer. */
|
|
packetbuf_copyfrom("Hello", 6);
|
|
|
|
/* Set the Rime address of the final receiver of the packet to
|
|
1.1. This is just a dummy value that happens to work nicely in a
|
|
netsim simulation (because the default simulation setup creates
|
|
one node with address 1.1). */
|
|
to.u8[0] = 1;
|
|
to.u8[1] = 1;
|
|
|
|
/* Send the packet. */
|
|
multihop_send(&multihop, &to);
|
|
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|