nes-proj/os/net/app-layer/coap/coap-transactions.c
2018-08-25 22:15:45 -07:00

172 lines
5.7 KiB
C

/*
* Copyright (c) 2013, Institute for Pervasive Computing, ETH Zurich
* 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.
*/
/**
* \file
* CoAP module for reliable transport
* \author
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
*/
/**
* \addtogroup coap
* @{
*/
#include "coap-transactions.h"
#include "coap-observe.h"
#include "coap-timer.h"
#include "lib/memb.h"
#include "lib/list.h"
#include <stdlib.h>
/* Log configuration */
#include "coap-log.h"
#define LOG_MODULE "coap"
#define LOG_LEVEL LOG_LEVEL_COAP
/*---------------------------------------------------------------------------*/
MEMB(transactions_memb, coap_transaction_t, COAP_MAX_OPEN_TRANSACTIONS);
LIST(transactions_list);
/*---------------------------------------------------------------------------*/
static void
coap_retransmit_transaction(coap_timer_t *nt)
{
coap_transaction_t *t = coap_timer_get_user_data(nt);
if(t == NULL) {
LOG_DBG("No retransmission data in coap_timer!\n");
return;
}
++(t->retrans_counter);
LOG_DBG("Retransmitting %u (%u)\n", t->mid, t->retrans_counter);
coap_send_transaction(t);
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/*- Internal API ------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
coap_transaction_t *
coap_new_transaction(uint16_t mid, const coap_endpoint_t *endpoint)
{
coap_transaction_t *t = memb_alloc(&transactions_memb);
if(t) {
t->mid = mid;
t->retrans_counter = 0;
/* save client address */
coap_endpoint_copy(&t->endpoint, endpoint);
list_add(transactions_list, t); /* list itself makes sure same element is not added twice */
}
return t;
}
/*---------------------------------------------------------------------------*/
void
coap_send_transaction(coap_transaction_t *t)
{
LOG_DBG("Sending transaction %u\n", t->mid);
if(COAP_TYPE_CON ==
((COAP_HEADER_TYPE_MASK & t->message[0]) >> COAP_HEADER_TYPE_POSITION)) {
if(t->retrans_counter <= COAP_MAX_RETRANSMIT) {
/* not timed out yet */
coap_sendto(&t->endpoint, t->message, t->message_len);
LOG_DBG("Keeping transaction %u\n", t->mid);
if(t->retrans_counter == 0) {
coap_timer_set_callback(&t->retrans_timer, coap_retransmit_transaction);
coap_timer_set_user_data(&t->retrans_timer, t);
t->retrans_interval =
COAP_RESPONSE_TIMEOUT_TICKS + (rand() %
COAP_RESPONSE_TIMEOUT_BACKOFF_MASK);
LOG_DBG("Initial interval %lu msec\n",
(unsigned long)t->retrans_interval);
} else {
t->retrans_interval <<= 1; /* double */
LOG_DBG("Doubled (%u) interval %lu s\n", t->retrans_counter,
(unsigned long)(t->retrans_interval / 1000));
}
/* interval updated above */
coap_timer_set(&t->retrans_timer, t->retrans_interval);
} else {
/* timed out */
LOG_DBG("Timeout\n");
coap_resource_response_handler_t callback = t->callback;
void *callback_data = t->callback_data;
/* handle observers */
coap_remove_observer_by_client(&t->endpoint);
coap_clear_transaction(t);
if(callback) {
callback(callback_data, NULL);
}
}
} else {
coap_sendto(&t->endpoint, t->message, t->message_len);
coap_clear_transaction(t);
}
}
/*---------------------------------------------------------------------------*/
void
coap_clear_transaction(coap_transaction_t *t)
{
if(t) {
LOG_DBG("Freeing transaction %u: %p\n", t->mid, t);
coap_timer_stop(&t->retrans_timer);
list_remove(transactions_list, t);
memb_free(&transactions_memb, t);
}
}
/*---------------------------------------------------------------------------*/
coap_transaction_t *
coap_get_transaction_by_mid(uint16_t mid)
{
coap_transaction_t *t = NULL;
for(t = (coap_transaction_t *)list_head(transactions_list); t; t = t->next) {
if(t->mid == mid) {
LOG_DBG("Found transaction for MID %u: %p\n", t->mid, t);
return t;
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/** @} */