osd-contiki/apps/er-coap-03/er-coap-03-observing.c

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/*
* Copyright (c) 2011, 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 observing resources
* \author
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
*/
#include <stdio.h>
#include <string.h>
#include "er-coap-03-observing.h"
#define DEBUG 0
#if DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#define PRINT6ADDR(addr) PRINTF("[%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x]", ((uint8_t *)addr)[0], ((uint8_t *)addr)[1], ((uint8_t *)addr)[2], ((uint8_t *)addr)[3], ((uint8_t *)addr)[4], ((uint8_t *)addr)[5], ((uint8_t *)addr)[6], ((uint8_t *)addr)[7], ((uint8_t *)addr)[8], ((uint8_t *)addr)[9], ((uint8_t *)addr)[10], ((uint8_t *)addr)[11], ((uint8_t *)addr)[12], ((uint8_t *)addr)[13], ((uint8_t *)addr)[14], ((uint8_t *)addr)[15])
#define PRINTLLADDR(lladdr) PRINTF("[%02x:%02x:%02x:%02x:%02x:%02x]",(lladdr)->addr[0], (lladdr)->addr[1], (lladdr)->addr[2], (lladdr)->addr[3],(lladdr)->addr[4], (lladdr)->addr[5])
#else
#define PRINTF(...)
#define PRINT6ADDR(addr)
#define PRINTLLADDR(addr)
#endif
MEMB(observers_memb, coap_observer_t, COAP_MAX_OBSERVERS);
LIST(observers_list);
/*-----------------------------------------------------------------------------------*/
coap_observer_t *
coap_add_observer(const char *url, uip_ipaddr_t *addr, uint16_t port, const uint8_t *token, size_t token_len)
{
coap_observer_t *o = memb_alloc(&observers_memb);
if (o)
{
o->url = url;
uip_ipaddr_copy(&o->addr, addr);
o->port = port;
o->token_len = token_len;
memcpy(o->token, token, token_len);
stimer_set(&o->refresh_timer, COAP_OBSERVING_REFRESH_INTERVAL);
PRINTF("Adding observer for /%s [0x%02X%02X]\n", o->url, o->token[0], o->token[1]);
list_add(observers_list, o);
}
return o;
}
/*-----------------------------------------------------------------------------------*/
void
coap_remove_observer(coap_observer_t *o)
{
PRINTF("Removing observer for /%s [0x%02X%02X]\n", o->url, o->token[0], o->token[1]);
memb_free(&observers_memb, o);
list_remove(observers_list, o);
}
int
coap_remove_observer_by_client(uip_ipaddr_t *addr, uint16_t port)
{
int removed = 0;
coap_observer_t* obs = NULL;
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
PRINTF("Remove check Port %u\n", port);
if (uip_ipaddr_cmp(&obs->addr, addr) && obs->port==port)
{
coap_remove_observer(obs);
removed++;
}
}
return removed;
}
int
coap_remove_observer_by_token(uip_ipaddr_t *addr, uint16_t port, uint8_t *token, size_t token_len)
{
int removed = 0;
coap_observer_t* obs = NULL;
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
PRINTF("Remove check Token 0x%02X%02X\n", token[0], token[1]);
if (uip_ipaddr_cmp(&obs->addr, addr) && obs->port==port && memcmp(obs->token, token, token_len)==0)
{
coap_remove_observer(obs);
removed++;
}
}
return removed;
}
/*-----------------------------------------------------------------------------------*/
void
coap_notify_observers(const char *url, int type, uint32_t observe, uint8_t *payload, size_t payload_len)
{
coap_observer_t* obs = NULL;
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
if (obs->url==url) /* using RESOURCE url string as handle */
{
coap_transaction_t *transaction = NULL;
/*TODO implement special transaction for CON, sharing the same buffer to allow for more observers */
if ( (transaction = coap_new_transaction(coap_get_tid(), &obs->addr, obs->port)) )
{
/* Use CON to check whether client is still there/interested after COAP_OBSERVING_REFRESH_INTERVAL. */
if (stimer_expired(&obs->refresh_timer))
{
PRINTF("Observing: Refresh client with CON\n");
type = COAP_TYPE_CON;
stimer_restart(&obs->refresh_timer);
}
/* prepare response */
coap_packet_t push[1]; /* This way the packet can be treated as pointer as usual. */
coap_init_message(push, (coap_message_type_t)type, OK_200, transaction->tid );
coap_set_header_observe(push, observe);
coap_set_header_token(push, obs->token, obs->token_len);
coap_set_payload(push, payload, payload_len);
transaction->packet_len = coap_serialize_message(push, transaction->packet);
PRINTF("Observing: Notify from /%s for ", url);
PRINT6ADDR(&obs->addr);
PRINTF(":%u\n", obs->port);
PRINTF(" %.*s\n", payload_len, payload);
coap_send_transaction(transaction);
}
}
}
}
/*-----------------------------------------------------------------------------------*/
void
coap_observe_handler(resource_t *resource, void *request, void *response)
{
static char content[26];
if (response && ((coap_packet_t *)response)->code<128) /* response without error code */
{
if (IS_OPTION((coap_packet_t *)request, COAP_OPTION_OBSERVE))
{
if (IS_OPTION((coap_packet_t *)request, COAP_OPTION_TOKEN))
{
if (coap_add_observer(resource->url, &UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport, ((coap_packet_t *)request)->token, ((coap_packet_t *)request)->token_len))
{
coap_set_header_observe(response, 0);
coap_set_payload(response, (uint8_t *)content, snprintf(content, sizeof(content), "Added as observer %u/%u", list_length(observers_list), COAP_MAX_OBSERVERS));
}
else
{
((coap_packet_t *)response)->code = SERVICE_UNAVAILABLE_503;
coap_set_payload(response, (uint8_t *)"Too many observers", 18);
} /* if (added observer) */
}
else /* if (token) */
{
((coap_packet_t *)response)->code = TOKEN_OPTION_REQUIRED;
coap_set_payload(response, (uint8_t *)"Observing requires token", 24);
} /* if (token) */
}
else /* if (observe) */
{
/* Remove client if it is currently observing. */
coap_remove_observer_by_client(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport);
} /* if (observe) */
}
}