osd-contiki/apps/er-coap-07/er-coap-07-observing.c
2012-03-29 18:56:46 +02:00

255 lines
8.7 KiB
C

/*
* 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-07-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(uip_ipaddr_t *addr, uint16_t port, const uint8_t *token, size_t token_len, const char *url)
{
/* Remove existing observe relationship, if any. */
coap_remove_observer_by_url(addr, port, url);
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);
o->last_mid = 0;
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 client ");
PRINT6ADDR(addr);
PRINTF(":%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 && obs->token_len==token_len && memcmp(obs->token, token, token_len)==0)
{
coap_remove_observer(obs);
removed++;
}
}
return removed;
}
int
coap_remove_observer_by_url(uip_ipaddr_t *addr, uint16_t port, const char *url)
{
int removed = 0;
coap_observer_t* obs = NULL;
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
PRINTF("Remove check URL %p\n", url);
if (uip_ipaddr_cmp(&obs->addr, addr) && obs->port==port && (obs->url==url || memcmp(obs->url, url, strlen(obs->url))==0))
{
coap_remove_observer(obs);
removed++;
}
}
return removed;
}
int
coap_remove_observer_by_mid(uip_ipaddr_t *addr, uint16_t port, uint16_t mid)
{
int removed = 0;
coap_observer_t* obs = NULL;
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
PRINTF("Remove check MID %u\n", mid);
if (uip_ipaddr_cmp(&obs->addr, addr) && obs->port==port && obs->last_mid==mid)
{
coap_remove_observer(obs);
removed++;
}
}
return removed;
}
/*-----------------------------------------------------------------------------------*/
void
coap_notify_observers(resource_t *resource, uint16_t obs_counter, void *notification)
{
coap_packet_t *const coap_res = (coap_packet_t *) notification;
coap_observer_t* obs = NULL;
uint8_t preferred_type = coap_res->type;
PRINTF("Observing: Notification from %s\n", resource->url);
/* Iterate over observers. */
for (obs = (coap_observer_t*)list_head(observers_list); obs; obs = obs->next)
{
if (obs->url==resource->url) /* using RESOURCE url pointer 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_mid(), &obs->addr, obs->port)) )
{
PRINTF(" Observer ");
PRINT6ADDR(&obs->addr);
PRINTF(":%u\n", obs->port);
/* Update last MID for RST matching. */
obs->last_mid = transaction->mid;
/* Prepare response */
coap_res->mid = transaction->mid;
coap_set_header_observe(coap_res, obs_counter);
coap_set_header_token(coap_res, obs->token, obs->token_len);
/* Use CON to check whether client is still there/interested after COAP_OBSERVING_REFRESH_INTERVAL. */
if (stimer_expired(&obs->refresh_timer))
{
PRINTF(" Refreshing with CON\n");
coap_res->type = COAP_TYPE_CON;
stimer_restart(&obs->refresh_timer);
}
else
{
coap_res->type = preferred_type;
}
transaction->packet_len = coap_serialize_message(coap_res, transaction->packet);
coap_send_transaction(transaction);
}
}
}
}
/*-----------------------------------------------------------------------------------*/
void
coap_observe_handler(resource_t *resource, void *request, void *response)
{
coap_packet_t *const coap_req = (coap_packet_t *) request;
coap_packet_t *const coap_res = (coap_packet_t *) response;
static char content[16];
if (coap_req->code==COAP_GET && coap_res->code<128) /* GET request and response without error code */
{
if (IS_OPTION(coap_req, COAP_OPTION_OBSERVE))
{
if (coap_add_observer(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport, coap_req->token, coap_req->token_len, resource->url))
{
coap_set_header_observe(coap_res, 0);
/*
* For demonstration purposes only. A subscription should return the same representation as a normal GET.
* TODO: Comment the following line for any real application.
*/
coap_set_payload(coap_res, content, snprintf(content, sizeof(content), "Added %u/%u", list_length(observers_list), COAP_MAX_OBSERVERS));
}
else
{
coap_res->code = SERVICE_UNAVAILABLE_5_03;
coap_set_payload(coap_res, "TooManyObservers", 16);
} /* if (added observer) */
}
else /* if (observe) */
{
/* Remove client if it is currently observing. */
coap_remove_observer_by_url(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport, resource->url);
} /* if (observe) */
}
}