/* * 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 */ #include #include #include "er-coap-12-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 ((addr==NULL || (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, int32_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; if (obs_counter>=0) 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) */ } }