381 lines
11 KiB
C
381 lines
11 KiB
C
/** \addtogroup servreghack
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* @{ */
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/*
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* Copyright (c) 2010, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This file is part of the Contiki operating system.
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*
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*/
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/**
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* \file
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* Implementation of the servreg-hack application
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* \author
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* Adam Dunkels <adam@sics.se>
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*/
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#include "contiki.h"
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#include "contiki-lib.h"
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#include "contiki-net.h"
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#include "net/uip.h"
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#include "net/uip-ds6.h"
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#include "servreg-hack.h"
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#include <stdio.h>
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struct servreg_hack_registration {
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struct servreg_hack_registration *next;
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struct timer timer;
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uip_ipaddr_t addr;
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servreg_hack_id_t id;
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uint8_t seqno;
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};
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#define MAX_REGISTRATIONS 16
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LIST(others_services);
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LIST(own_services);
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MEMB(registrations, struct servreg_hack_registration, MAX_REGISTRATIONS);
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PROCESS(servreg_hack_process, "Service regstry hack");
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#define PERIOD_TIME 120 * CLOCK_SECOND
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#define NEW_REG_TIME 10 * CLOCK_SECOND
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#define MAX_BUFSIZE 2 + 80
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#define UDP_PORT 61616
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#define LIFETIME 10 * 60 * CLOCK_SECOND
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#define SEQNO_LT(a, b) ((signed char)((a) - (b)) < 0)
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static struct etimer sendtimer;
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static uint8_t started = 0;
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/*---------------------------------------------------------------------------*/
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/* Go through the list of registrations and remove those that are too
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old. */
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static void
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purge_registrations(void)
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{
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struct servreg_hack_registration *t;
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for(t = list_head(own_services);
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t != NULL;
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t = list_item_next(t)) {
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if(timer_expired(&t->timer)) {
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t->seqno++;
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timer_set(&t->timer, LIFETIME / 2);
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}
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}
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for(t = list_head(others_services);
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t != NULL;
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t = list_item_next(t)) {
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if(timer_expired(&t->timer)) {
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list_remove(others_services, t);
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memb_free(®istrations, t);
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t = list_head(others_services);
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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void
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servreg_hack_init(void)
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{
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if(started == 0) {
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list_init(others_services);
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list_init(own_services);
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memb_init(®istrations);
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process_start(&servreg_hack_process, NULL);
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started = 1;
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}
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}
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/*---------------------------------------------------------------------------*/
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void
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servreg_hack_register(servreg_hack_id_t id, const uip_ipaddr_t *addr)
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{
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servreg_hack_item_t *t;
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struct servreg_hack_registration *r;
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/* Walk through list, see if we already have a service ID
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registered. If not, allocate a new registration and put it on our
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list. If we cannot allocate a service registration, we reuse one
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from the service registrations made by others. */
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servreg_hack_init();
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for(t = list_head(own_services);
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t != NULL;
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t = list_item_next(t)) {
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if(servreg_hack_item_id(t) == id) {
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return;
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}
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}
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r = memb_alloc(®istrations);
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if(r == NULL) {
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printf("servreg_hack_register: error, could not allocate memory, should reclaim another registration but this has not been implemented yet.\n");
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return;
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}
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r->id = id;
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r->seqno = 1;
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uip_ipaddr_copy(&r->addr, addr);
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timer_set(&r->timer, LIFETIME / 2);
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list_push(own_services, r);
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PROCESS_CONTEXT_BEGIN(&servreg_hack_process);
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etimer_set(&sendtimer, random_rand() % (NEW_REG_TIME));
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PROCESS_CONTEXT_END(&servreg_hack_process);
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}
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/*---------------------------------------------------------------------------*/
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servreg_hack_item_t *
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servreg_hack_list_head(void)
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{
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purge_registrations();
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return list_head(others_services);
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}
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/*---------------------------------------------------------------------------*/
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servreg_hack_id_t
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servreg_hack_item_id(servreg_hack_item_t *item)
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{
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return ((struct servreg_hack_registration *)item)->id;
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}
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/*---------------------------------------------------------------------------*/
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uip_ipaddr_t *
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servreg_hack_item_address(servreg_hack_item_t *item)
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{
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return &((struct servreg_hack_registration *)item)->addr;
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}
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/*---------------------------------------------------------------------------*/
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uip_ipaddr_t *
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servreg_hack_lookup(servreg_hack_id_t id)
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{
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servreg_hack_item_t *t;
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servreg_hack_init();
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purge_registrations();
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for(t = servreg_hack_list_head(); t != NULL; t = list_item_next(t)) {
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if(servreg_hack_item_id(t) == id) {
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return servreg_hack_item_address(t);
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}
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}
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return NULL;
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}
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/*---------------------------------------------------------------------------*/
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static void
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handle_incoming_reg(const uip_ipaddr_t *owner, servreg_hack_id_t id, uint8_t seqno)
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{
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servreg_hack_item_t *t;
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struct servreg_hack_registration *r;
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/* Walk through list, see if we already have a service ID
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registered. If so, we do different things depending on the seqno
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of the update: if the seqno is older than what we have, we
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discard the incoming registration. If the seqno is newer than
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what we have, we reset the lifetime timer of the current
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registration.
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If we did not have the service registered already, we allocate a
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new registration and put it on our list. If we cannot allocate a
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service registration, we discard the incoming registration (for
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now - we might later choose to discard the oldest registration
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that we have). */
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for(t = servreg_hack_list_head();
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t != NULL;
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t = list_item_next(t)) {
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if(servreg_hack_item_id(t) == id) {
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r = t;
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if(SEQNO_LT(r->seqno, seqno)) {
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r->seqno = seqno;
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timer_set(&r->timer, LIFETIME);
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/* Put item first on list, so that subsequent lookups will
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find this one. */
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list_remove(others_services, r);
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list_push(others_services, r);
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}
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return;
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}
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}
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r = memb_alloc(®istrations);
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if(r == NULL) {
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printf("servreg_hack_register: error, could not allocate memory, should reclaim another registration but this has not been implemented yet.\n");
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return;
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}
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r->id = id;
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r->seqno = 1;
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uip_ipaddr_copy(&r->addr, owner);
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timer_set(&r->timer, LIFETIME);
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list_add(others_services, r);
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}
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/*---------------------------------------------------------------------------*/
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/*
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* The structure of UDP messages:
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*
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* +-------------------+-------------------+
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* | Numregs (1 byte) | Flags (1 byte) |
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* +-------------------+-------------------+-------------------+
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* | IP addr (16 bytes)| 3 regs (3 bytes) | Seqno (1 byte) |
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* +-------------------+-------------------+-------------------+
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* | IP addr (16 bytes)| 3 regs (3 bytes) | Seqno (1 byte) |
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* +-------------------+-------------------+-------------------+
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* | ... | ... | ... |
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* +-------------------+-------------------+-------------------+
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*/
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#define MSG_NUMREGS_OFFSET 0
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#define MSG_FLAGS_OFFSET 1
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#define MSG_ADDRS_OFFSET 2
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#define MSG_IPADDR_SUBOFFSET 0
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#define MSG_REGS_SUBOFFSET 16
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#define MSG_SEQNO_SUBOFFSET 19
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#define MSG_ADDRS_LEN 20
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/*---------------------------------------------------------------------------*/
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static void
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send_udp_packet(struct uip_udp_conn *conn)
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{
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int numregs;
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uint8_t buf[MAX_BUFSIZE];
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int bufptr;
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servreg_hack_item_t *t;
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buf[MSG_FLAGS_OFFSET] = 0;
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numregs = 0;
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bufptr = MSG_ADDRS_OFFSET;
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for(t = list_head(own_services);
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(bufptr + MSG_ADDRS_LEN <= MAX_BUFSIZE) && t != NULL;
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t = list_item_next(t)) {
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uip_ipaddr_copy((uip_ipaddr_t *)&buf[bufptr + MSG_IPADDR_SUBOFFSET],
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servreg_hack_item_address(t));
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buf[bufptr + MSG_REGS_SUBOFFSET] =
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servreg_hack_item_id(t);
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buf[bufptr + MSG_REGS_SUBOFFSET + 1] =
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buf[bufptr + MSG_REGS_SUBOFFSET + 2] = 0;
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buf[bufptr + MSG_SEQNO_SUBOFFSET] = ((struct servreg_hack_registration *)t)->seqno;
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bufptr += MSG_ADDRS_LEN;
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++numregs;
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}
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for(t = servreg_hack_list_head();
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(bufptr + MSG_ADDRS_LEN <= MAX_BUFSIZE) && t != NULL;
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t = list_item_next(t)) {
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uip_ipaddr_copy((uip_ipaddr_t *)&buf[bufptr + MSG_IPADDR_SUBOFFSET],
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servreg_hack_item_address(t));
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buf[bufptr + MSG_REGS_SUBOFFSET] =
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servreg_hack_item_id(t);
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buf[bufptr + MSG_REGS_SUBOFFSET + 1] =
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buf[bufptr + MSG_REGS_SUBOFFSET + 2] = 0;
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buf[bufptr + MSG_SEQNO_SUBOFFSET] = ((struct servreg_hack_registration *)t)->seqno;
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bufptr += MSG_ADDRS_LEN;
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++numregs;
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}
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/* printf("send_udp_packet numregs %d\n", numregs);*/
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buf[MSG_NUMREGS_OFFSET] = numregs;
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if(numregs > 0) {
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/* printf("Sending buffer len %d\n", bufptr);*/
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uip_udp_packet_send(conn, buf, bufptr);
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}
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}
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/*---------------------------------------------------------------------------*/
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static void
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parse_incoming_packet(const uint8_t *buf, int len)
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{
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int numregs;
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int flags;
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int i;
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int bufptr;
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numregs = buf[MSG_NUMREGS_OFFSET];
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flags = buf[MSG_FLAGS_OFFSET];
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/* printf("parse_incoming_packet Numregs %d flags %d\n", numregs, flags);*/
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bufptr = MSG_ADDRS_OFFSET;
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for(i = 0; i < numregs; ++i) {
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handle_incoming_reg((uip_ipaddr_t *)&buf[bufptr + MSG_IPADDR_SUBOFFSET],
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buf[bufptr + MSG_REGS_SUBOFFSET],
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buf[bufptr + MSG_SEQNO_SUBOFFSET]);
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}
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}
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/*---------------------------------------------------------------------------*/
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PROCESS_THREAD(servreg_hack_process, ev, data)
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{
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static struct etimer periodic;
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static struct uip_udp_conn *outconn, *inconn;
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PROCESS_BEGIN();
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/* Create outbound UDP connection. */
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outconn = udp_broadcast_new(UIP_HTONS(UDP_PORT), NULL);
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udp_bind(outconn, UIP_HTONS(UDP_PORT));
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/* Create inbound UDP connection. */
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inconn = udp_new(NULL, UIP_HTONS(UDP_PORT), NULL);
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udp_bind(inconn, UIP_HTONS(UDP_PORT));
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etimer_set(&periodic, PERIOD_TIME);
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etimer_set(&sendtimer, random_rand() % (PERIOD_TIME));
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while(1) {
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PROCESS_WAIT_EVENT();
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if(ev == PROCESS_EVENT_TIMER && data == &periodic) {
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etimer_reset(&periodic);
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etimer_set(&sendtimer, random_rand() % (PERIOD_TIME));
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} else if(ev == PROCESS_EVENT_TIMER && data == &sendtimer) {
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send_udp_packet(outconn);
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} else if(ev == tcpip_event) {
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parse_incoming_packet(uip_appdata, uip_datalen());
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}
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}
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PROCESS_END();
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}
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/*---------------------------------------------------------------------------*/
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