373 lines
13 KiB
C
373 lines
13 KiB
C
/*
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* Copyright (c) 2013, Institute for Pervasive Computing, ETH Zurich
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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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* \file
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* CoAP module for observing resources (draft-ietf-core-observe-11).
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* \author
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* Matthias Kovatsch <kovatsch@inf.ethz.ch>
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*/
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/**
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* \addtogroup coap
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* @{
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*/
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#include <stdio.h>
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#include <string.h>
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#include "coap-observe.h"
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#include "coap-engine.h"
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#include "lib/memb.h"
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#include "lib/list.h"
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/* Log configuration */
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#include "coap-log.h"
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#define LOG_MODULE "coap"
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#define LOG_LEVEL LOG_LEVEL_COAP
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/*---------------------------------------------------------------------------*/
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MEMB(observers_memb, coap_observer_t, COAP_MAX_OBSERVERS);
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LIST(observers_list);
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/*---------------------------------------------------------------------------*/
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/*- Internal API ------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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static coap_observer_t *
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add_observer(const coap_endpoint_t *endpoint, const uint8_t *token,
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size_t token_len, const char *uri, int uri_len)
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{
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/* Remove existing observe relationship, if any. */
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coap_remove_observer_by_uri(endpoint, uri);
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coap_observer_t *o = memb_alloc(&observers_memb);
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if(o) {
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int max = sizeof(o->url) - 1;
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if(max > uri_len) {
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max = uri_len;
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}
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memcpy(o->url, uri, max);
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o->url[max] = 0;
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coap_endpoint_copy(&o->endpoint, endpoint);
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o->token_len = token_len;
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memcpy(o->token, token, token_len);
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o->last_mid = 0;
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LOG_INFO("Adding observer (%u/%u) for /%s [0x%02X%02X]\n",
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list_length(observers_list) + 1, COAP_MAX_OBSERVERS,
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o->url, o->token[0], o->token[1]);
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list_add(observers_list, o);
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}
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return o;
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}
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/*---------------------------------------------------------------------------*/
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/*- Removal -----------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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void
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coap_remove_observer(coap_observer_t *o)
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{
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LOG_INFO("Removing observer for /%s [0x%02X%02X]\n", o->url, o->token[0],
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o->token[1]);
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memb_free(&observers_memb, o);
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list_remove(observers_list, o);
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}
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/*---------------------------------------------------------------------------*/
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int
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coap_remove_observer_by_client(const coap_endpoint_t *endpoint)
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{
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int removed = 0;
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coap_observer_t *obs = NULL;
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LOG_DBG("Remove check client ");
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LOG_DBG_COAP_EP(endpoint);
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LOG_DBG_("\n");
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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if(coap_endpoint_cmp(&obs->endpoint, endpoint)) {
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coap_remove_observer(obs);
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removed++;
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}
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}
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return removed;
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}
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/*---------------------------------------------------------------------------*/
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int
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coap_remove_observer_by_token(const coap_endpoint_t *endpoint,
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uint8_t *token, size_t token_len)
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{
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int removed = 0;
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coap_observer_t *obs = NULL;
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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LOG_DBG("Remove check Token 0x%02X%02X\n", token[0], token[1]);
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if(coap_endpoint_cmp(&obs->endpoint, endpoint)
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&& obs->token_len == token_len
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&& memcmp(obs->token, token, token_len) == 0) {
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coap_remove_observer(obs);
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removed++;
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}
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}
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return removed;
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}
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/*---------------------------------------------------------------------------*/
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int
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coap_remove_observer_by_uri(const coap_endpoint_t *endpoint,
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const char *uri)
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{
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int removed = 0;
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coap_observer_t *obs = NULL;
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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LOG_DBG("Remove check URL %p\n", uri);
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if((endpoint == NULL
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|| (coap_endpoint_cmp(&obs->endpoint, endpoint)))
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&& (obs->url == uri || memcmp(obs->url, uri, strlen(obs->url)) == 0)) {
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coap_remove_observer(obs);
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removed++;
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}
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}
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return removed;
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}
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/*---------------------------------------------------------------------------*/
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int
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coap_remove_observer_by_mid(const coap_endpoint_t *endpoint, uint16_t mid)
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{
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int removed = 0;
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coap_observer_t *obs = NULL;
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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LOG_DBG("Remove check MID %u\n", mid);
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if(coap_endpoint_cmp(&obs->endpoint, endpoint)
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&& obs->last_mid == mid) {
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coap_remove_observer(obs);
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removed++;
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}
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}
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return removed;
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}
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/*---------------------------------------------------------------------------*/
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/*- Notification ------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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void
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coap_notify_observers(coap_resource_t *resource)
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{
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coap_notify_observers_sub(resource, NULL);
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}
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/* Can be used either for sub - or when there is not resource - just
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a handler */
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void
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coap_notify_observers_sub(coap_resource_t *resource, const char *subpath)
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{
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/* build notification */
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coap_message_t notification[1]; /* this way the message can be treated as pointer as usual */
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coap_message_t request[1]; /* this way the message can be treated as pointer as usual */
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coap_observer_t *obs = NULL;
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int url_len, obs_url_len;
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char url[COAP_OBSERVER_URL_LEN];
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uint8_t sub_ok = 0;
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if(resource != NULL) {
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url_len = strlen(resource->url);
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strncpy(url, resource->url, COAP_OBSERVER_URL_LEN - 1);
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if(url_len < COAP_OBSERVER_URL_LEN - 1 && subpath != NULL) {
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strncpy(&url[url_len], subpath, COAP_OBSERVER_URL_LEN - url_len - 1);
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}
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} else if(subpath != NULL) {
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strncpy(url, subpath, COAP_OBSERVER_URL_LEN - 1);
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} else {
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/* No resource, no subpath */
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return;
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}
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/* Ensure url is null terminated because strncpy does not guarantee this */
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url[COAP_OBSERVER_URL_LEN - 1] = '\0';
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/* url now contains the notify URL that needs to match the observer */
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LOG_INFO("Notification from %s\n", url);
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coap_init_message(notification, COAP_TYPE_NON, CONTENT_2_05, 0);
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/* create a "fake" request for the URI */
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coap_init_message(request, COAP_TYPE_CON, COAP_GET, 0);
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coap_set_header_uri_path(request, url);
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/* iterate over observers */
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url_len = strlen(url);
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/* Assumes lazy evaluation... */
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sub_ok = (resource == NULL) || (resource->flags & HAS_SUB_RESOURCES);
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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obs_url_len = strlen(obs->url);
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/* Do a match based on the parent/sub-resource match so that it is
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possible to do parent-node observe */
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/***** TODO fix here so that we handle the notofication correctly ******/
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/* All the new-style ... is assuming that the URL might be within */
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if((obs_url_len == url_len
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|| (obs_url_len > url_len
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&& sub_ok
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&& obs->url[url_len] == '/'))
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&& strncmp(url, obs->url, url_len) == 0) {
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coap_transaction_t *transaction = NULL;
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/*TODO implement special transaction for CON, sharing the same buffer to allow for more observers */
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if((transaction = coap_new_transaction(coap_get_mid(), &obs->endpoint))) {
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/* if COAP_OBSERVE_REFRESH_INTERVAL is zero, never send observations as confirmable messages */
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if(COAP_OBSERVE_REFRESH_INTERVAL != 0
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&& (obs->obs_counter % COAP_OBSERVE_REFRESH_INTERVAL == 0)) {
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LOG_DBG(" Force Confirmable for\n");
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notification->type = COAP_TYPE_CON;
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}
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LOG_DBG(" Observer ");
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LOG_DBG_COAP_EP(&obs->endpoint);
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LOG_DBG_("\n");
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/* update last MID for RST matching */
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obs->last_mid = transaction->mid;
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/* prepare response */
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notification->mid = transaction->mid;
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int32_t new_offset = 0;
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/* Either old style get_handler or the full handler */
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if(coap_call_handlers(request, notification, transaction->message +
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COAP_MAX_HEADER_SIZE, COAP_MAX_CHUNK_SIZE,
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&new_offset) > 0) {
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LOG_DBG("Notification on new handlers\n");
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} else {
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if(resource != NULL) {
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resource->get_handler(request, notification,
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transaction->message + COAP_MAX_HEADER_SIZE,
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COAP_MAX_CHUNK_SIZE, &new_offset);
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} else {
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/* What to do here? */
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notification->code = BAD_REQUEST_4_00;
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}
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}
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if(notification->code < BAD_REQUEST_4_00) {
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coap_set_header_observe(notification, (obs->obs_counter)++);
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/* mask out to keep the CoAP observe option length <= 3 bytes */
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obs->obs_counter &= 0xffffff;
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}
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coap_set_token(notification, obs->token, obs->token_len);
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if(new_offset != 0) {
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coap_set_header_block2(notification,
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0,
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new_offset != -1,
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COAP_MAX_BLOCK_SIZE);
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coap_set_payload(notification,
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notification->payload,
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MIN(notification->payload_len,
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COAP_MAX_BLOCK_SIZE));
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}
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transaction->message_len =
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coap_serialize_message(notification, transaction->message);
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coap_send_transaction(transaction);
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}
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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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coap_observe_handler(coap_resource_t *resource, coap_message_t *coap_req,
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coap_message_t *coap_res)
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{
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const coap_endpoint_t *src_ep;
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coap_observer_t *obs;
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LOG_DBG("CoAP observer handler rsc: %d\n", resource != NULL);
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if(coap_req->code == COAP_GET && coap_res->code < 128) { /* GET request and response without error code */
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if(coap_is_option(coap_req, COAP_OPTION_OBSERVE)) {
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src_ep = coap_get_src_endpoint(coap_req);
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if(src_ep == NULL) {
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/* No source endpoint, can not add */
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} else if(coap_req->observe == 0) {
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obs = add_observer(src_ep,
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coap_req->token, coap_req->token_len,
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coap_req->uri_path, coap_req->uri_path_len);
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if(obs) {
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coap_set_header_observe(coap_res, (obs->obs_counter)++);
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/* mask out to keep the CoAP observe option length <= 3 bytes */
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obs->obs_counter &= 0xffffff;
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/*
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* Following payload is for demonstration purposes only.
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* A subscription should return the same representation as a normal GET.
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* Uncomment if you want an information about the avaiable observers.
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*/
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#if 0
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static char content[16];
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coap_set_payload(coap_res,
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content,
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snprintf(content, sizeof(content), "Added %u/%u",
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list_length(observers_list),
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COAP_MAX_OBSERVERS));
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#endif
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} else {
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coap_res->code = SERVICE_UNAVAILABLE_5_03;
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coap_set_payload(coap_res, "TooManyObservers", 16);
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}
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} else if(coap_req->observe == 1) {
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/* remove client if it is currently observe */
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coap_remove_observer_by_token(src_ep,
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coap_req->token, coap_req->token_len);
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}
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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uint8_t
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coap_has_observers(char *path)
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{
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coap_observer_t *obs = NULL;
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for(obs = (coap_observer_t *)list_head(observers_list); obs;
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obs = obs->next) {
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if((strncmp(obs->url, path, strlen(path))) == 0) {
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return 1;
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}
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}
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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/** @} */
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