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nes-proj/os/net/app-layer/coap/coap-observe.c

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