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er-coap: add client-side support for CoAP Observe 

Client-side support for CoAP observe is not compiled by default. To enable it, the COAP_OBSERVE_CLIENT macro must be defined equal to 1.
This commit is contained in:
Daniele Alessandrelli 2015-02-22 17:01:46 +01:00
parent 5e25ca9bf5
commit 799e9350a0
5 changed files with 477 additions and 1 deletions
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4
apps/er-coap/Makefile.er-coap
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@ -1,4 +1,6 @@
er-coap_src = er-coap.c er-coap-engine.c er-coap-transactions.c er-coap-observe.c er-coap-separate.c er-coap-res-well-known-core.c er-coap-block1.c
er-coap_src = er-coap.c er-coap-engine.c er-coap-transactions.c \
er-coap-observe.c er-coap-separate.c er-coap-res-well-known-core.c \
er-coap-block1.c er-coap-observe-client.c
# Erbium will implement the REST Engine
CFLAGS += -DREST=coap_rest_implementation

10
apps/er-coap/er-coap-engine.c
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@ -253,6 +253,16 @@ coap_receive(void)
}
/* if(ACKed transaction) */
transaction = NULL;
#if COAP_OBSERVE_CLIENT
/* if observe notification */
if((message->type == COAP_TYPE_CON || message->type == COAP_TYPE_NON)
&& IS_OPTION(message, COAP_OPTION_OBSERVE)) {
PRINTF("Observe [%u]\n", message->observe);
coap_handle_notification(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport,
message);
}
#endif /* COAP_OBSERVE_CLIENT */
} /* request or response */
} /* parsed correctly */

1
apps/er-coap/er-coap-engine.h
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@ -44,6 +44,7 @@
#include "er-coap-transactions.h"
#include "er-coap-observe.h"
#include "er-coap-separate.h"
#include "er-coap-observe-client.h"
#define SERVER_LISTEN_PORT UIP_HTONS(COAP_SERVER_PORT)

342
apps/er-coap/er-coap-observe-client.c Normal file
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@ -0,0 +1,342 @@
/*
* Copyright (c) 2014, Daniele Alessandrelli.
* 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
* Extension to Erbium for enabling CoAP observe clients
* \author
* Daniele Alessandrelli <daniele.alessandrelli@gmail.com>
*/
#include <stdio.h>
#include <string.h>
#include "er-coap.h"
#include "er-coap-observe-client.h"
/* Compile this code only if client-side support for CoAP Observe is required */
#if COAP_OBSERVE_CLIENT
#define DEBUG 1
#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(obs_subjects_memb, coap_observee_t, COAP_MAX_OBSERVEES);
LIST(obs_subjects_list);
/*----------------------------------------------------------------------------*/
static size_t
get_token(void *packet, const uint8_t **token)
{
coap_packet_t *const coap_pkt = (coap_packet_t *)packet;
*token = coap_pkt->token;
return coap_pkt->token_len;
}
/*----------------------------------------------------------------------------*/
static int
set_token(void *packet, const uint8_t *token, size_t token_len)
{
coap_packet_t *const coap_pkt = (coap_packet_t *)packet;
coap_pkt->token_len = MIN(COAP_TOKEN_LEN, token_len);
memcpy(coap_pkt->token, token, coap_pkt->token_len);
return coap_pkt->token_len;
}
/*----------------------------------------------------------------------------*/
coap_observee_t *
coap_obs_add_observee(uip_ipaddr_t *addr, uint16_t port,
const uint8_t *token, size_t token_len, const char *url,
notification_callback_t notification_callback,
void *data)
{
coap_observee_t *o;
/* Remove existing observe relationship, if any. */
coap_obs_remove_observee_by_url(addr, port, url);
o = memb_alloc(&obs_subjects_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; */
o->notification_callback = notification_callback;
o->data = data;
/* stimer_set(&o->refresh_timer, COAP_OBSERVING_REFRESH_INTERVAL); */
PRINTF("Adding obs_subject for /%s [0x%02X%02X]\n", o->url, o->token[0],
o->token[1]);
list_add(obs_subjects_list, o);
}
return o;
}
/*----------------------------------------------------------------------------*/
void
coap_obs_remove_observee(coap_observee_t *o)
{
PRINTF("Removing obs_subject for /%s [0x%02X%02X]\n", o->url, o->token[0],
o->token[1]);
memb_free(&obs_subjects_memb, o);
list_remove(obs_subjects_list, o);
}
/*----------------------------------------------------------------------------*/
coap_observee_t *
coap_get_obs_subject_by_token(const uint8_t *token, size_t token_len)
{
coap_observee_t *obs = NULL;
for(obs = (coap_observee_t *)list_head(obs_subjects_list); obs;
obs = obs->next) {
PRINTF("Looking for token 0x%02X%02X\n", token[0], token[1]);
if(obs->token_len == token_len
&& memcmp(obs->token, token, token_len) == 0) {
return obs;
}
}
return NULL;
}
/*----------------------------------------------------------------------------*/
int
coap_obs_remove_observee_by_token(uip_ipaddr_t *addr, uint16_t port,
uint8_t *token, size_t token_len)
{
int removed = 0;
coap_observee_t *obs = NULL;
for(obs = (coap_observee_t *)list_head(obs_subjects_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_obs_remove_observee(obs);
removed++;
}
}
return removed;
}
/*----------------------------------------------------------------------------*/
int
coap_obs_remove_observee_by_url(uip_ipaddr_t *addr, uint16_t port,
const char *url)
{
int removed = 0;
coap_observee_t *obs = NULL;
for(obs = (coap_observee_t *)list_head(obs_subjects_list); obs;
obs = obs->next) {
PRINTF("Remove check URL %s\n", url);
if(uip_ipaddr_cmp(&obs->addr, addr)
&& obs->port == port
&& (obs->url == url || memcmp(obs->url, url, strlen(obs->url)) == 0)) {
coap_obs_remove_observee(obs);
removed++;
}
}
return removed;
}
/*----------------------------------------------------------------------------*/
static void
simple_reply(coap_message_type_t type, uip_ip6addr_t *addr, uint16_t port,
coap_packet_t *notification)
{
static coap_packet_t response[1];
size_t len;
coap_init_message(response, type, NO_ERROR, notification->mid);
len = coap_serialize_message(response, uip_appdata);
coap_send_message(addr, port, uip_appdata, len);
}
/*----------------------------------------------------------------------------*/
static coap_notification_flag_t
classify_notification(void *response, int first)
{
coap_packet_t *pkt;
pkt = (coap_packet_t *)response;
if(!pkt) {
PRINTF("no response\n");
return NO_REPLY_FROM_SERVER;
}
PRINTF("server replied\n");
if(!IS_RESPONSE_CODE_2_XX(pkt)) {
PRINTF("error response code\n");
return ERROR_RESPONSE_CODE;
}
if(!IS_OPTION(pkt, COAP_OPTION_OBSERVE)) {
PRINTF("server does not support observe\n");
return OBSERVE_NOT_SUPPORTED;
}
if(first) {
return OBSERVE_OK;
}
return NOTIFICATION_OK;
}
/*----------------------------------------------------------------------------*/
void
coap_handle_notification(uip_ipaddr_t *addr, uint16_t port,
coap_packet_t *notification)
{
coap_packet_t *pkt;
const uint8_t *token;
int token_len;
coap_observee_t *obs;
coap_notification_flag_t flag;
uint32_t observe;
PRINTF("coap_handle_notification()\n");
pkt = (coap_packet_t *)notification;
token_len = get_token(pkt, &token);
PRINTF("Getting token\n");
if(0 == token_len) {
PRINTF("Error while handling coap observe notification: "
"no token in message\n");
return;
}
PRINTF("Getting observee info\n");
obs = coap_get_obs_subject_by_token(token, token_len);
if(NULL == obs) {
PRINTF("Error while handling coap observe notification: "
"no matching token found\n");
simple_reply(COAP_TYPE_RST, addr, port, notification);
return;
}
if(notification->type == COAP_TYPE_CON) {
simple_reply(COAP_TYPE_ACK, addr, port, notification);
}
if(obs->notification_callback != NULL) {
flag = classify_notification(notification, 0);
/* TODO: the following mechanism for discarding duplicates is too trivial */
/* refer to Observe RFC for a better solution */
if(flag == NOTIFICATION_OK) {
coap_get_header_observe(notification, &observe);
if(observe == obs->last_observe) {
PRINTF("Discarding duplicate\n");
return;
}
obs->last_observe = observe;
}
obs->notification_callback(obs, notification, flag);
}
}
/*----------------------------------------------------------------------------*/
static void
handle_obs_registration_response(void *data, void *response)
{
coap_observee_t *obs;
notification_callback_t notification_callback;
coap_notification_flag_t flag;
PRINTF("handle_obs_registration_response(): ");
obs = (coap_observee_t *)data;
notification_callback = obs->notification_callback;
flag = classify_notification(response, 1);
if(notification_callback) {
notification_callback(obs, response, flag);
}
if(flag != OBSERVE_OK) {
coap_obs_remove_observee(obs);
}
}
/*----------------------------------------------------------------------------*/
uint8_t
coap_generate_token(uint8_t **token_ptr)
{
static uint8_t token = 0;
token++;
/* FIXME: we should check that this token is not already used */
*token_ptr = (uint8_t *)&token;
return sizeof(token);
}
/*----------------------------------------------------------------------------*/
coap_observee_t *
coap_obs_request_registration(uip_ipaddr_t *addr, uint16_t port, char *uri,
notification_callback_t notification_callback,
void *data)
{
coap_packet_t request[1];
coap_transaction_t *t;
uint8_t *token;
uint8_t token_len;
coap_observee_t *obs;
obs = NULL;
coap_init_message(request, COAP_TYPE_CON, COAP_GET, coap_get_mid());
coap_set_header_uri_path(request, uri);
coap_set_header_observe(request, 0);
token_len = coap_generate_token(&token);
set_token(request, token, token_len);
t = coap_new_transaction(request->mid, addr, port);
if(t) {
obs = coap_obs_add_observee(addr, port, (uint8_t *)token, token_len, uri,
notification_callback, data);
if(obs) {
t->callback = handle_obs_registration_response;
t->callback_data = obs;
t->packet_len = coap_serialize_message(request, t->packet);
coap_send_transaction(t);
} else {
PRINTF("Could not allocate obs_subject resource buffer");
coap_clear_transaction(t);
}
} else {
PRINTF("Could not allocate transaction buffer");
}
return obs;
}
#endif /* COAP_OBSERVE_CLIENT */

121
apps/er-coap/er-coap-observe-client.h Normal file
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@ -0,0 +1,121 @@
/*
* Copyright (c) 2014, Daniele Alessandrelli.
* 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
* Extension to Erbium for enabling CoAP observe clients
* \author
* Daniele Alessandrelli <daniele.alessandrelli@gmail.com>
*/
#ifndef COAP_OBSERVING_CLIENT_H_
#define COAP_OBSERVING_CLIENT_H_
#include "er-coap.h"
#include "er-coap-transactions.h"
#ifndef COAP_OBSERVE_CLIENT
#define COAP_OBSERVE_CLIENT 0
#endif
#ifdef COAP_CONF_MAX_OBSERVEES
#define COAP_MAX_OBSERVEES COAP_CONF_MAX_OBSERVEES
#else
#define COAP_MAX_OBSERVEES 4
#endif /* COAP_CONF_MAX_OBSERVEES */
#if COAP_MAX_OPEN_TRANSACTIONS < COAP_MAX_OBSERVEES
#warning "COAP_MAX_OPEN_TRANSACTIONS smaller than COAP_MAX_OBSERVEES: " \
"this may be a problem"
#endif
#define IS_RESPONSE_CODE_2_XX(message) (64 < message->code \
&& message->code < 128)
/*----------------------------------------------------------------------------*/
typedef enum {
OBSERVE_OK,
NOTIFICATION_OK,
OBSERVE_NOT_SUPPORTED,
ERROR_RESPONSE_CODE,
NO_REPLY_FROM_SERVER,
} coap_notification_flag_t;
/*----------------------------------------------------------------------------*/
typedef struct coap_observee_s coap_observee_t;
typedef void (*notification_callback_t)(coap_observee_t *subject,
void *notification,
coap_notification_flag_t);
struct coap_observee_s {
coap_observee_t *next; /* for LIST */
uip_ipaddr_t addr;
uint16_t port;
const char *url;
uint8_t token_len;
uint8_t token[COAP_TOKEN_LEN];
void *data; /* generic pointer for storing user data */
notification_callback_t notification_callback;
uint32_t last_observe;
};
/*----------------------------------------------------------------------------*/
coap_observee_t *coap_obs_add_observee(uip_ipaddr_t *addr, uint16_t port,
const uint8_t *token, size_t token_len,
const char *url,
notification_callback_t
notification_callback, void *data);
void coap_obs_remove_observee(coap_observee_t *o);
coap_observee_t *coap_obs_get_observee_by_token(const uint8_t *token,
size_t token_len);
int coap_obs_remove_observee_by_token(uip_ipaddr_t *addr, uint16_t port,
uint8_t *token, size_t token_len);
int coap_obs_remove_observee_by_url(uip_ipaddr_t *addr, uint16_t port,
const char *url);
void coap_handle_notification(uip_ipaddr_t *, uint16_t port,
coap_packet_t *notification);
coap_observee_t *coap_obs_request_registration(uip_ipaddr_t *addr,
uint16_t port, char *uri,
notification_callback_t
notification_callback,
void *data);
/* TODO: this function may be moved to er-coap.c */
uint8_t coap_generate_token(uint8_t **token_ptr);
#endif /* COAP_OBSERVING_CLIENT_H_ */