/*---------------------------------------------------------------------------*/
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;
coap_observer_t * obs;
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_req->observe == 0) {
obs = coap_add_observer(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport,
coap_req->token, coap_req->token_len,
resource->url);
if(obs) {
coap_set_header_observe(coap_res, (obs->obs_counter)++);
/*
* 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(&UIP_IP_BUF->srcipaddr,
UIP_UDP_BUF->srcport, coap_req->token,
coap_req->token_len);
}
}
}
}
/*-----------------------------------------------------------------------------------*/
static
int
handle_incoming_data(void)
{
int error = NO_ERROR;
PRINTF("handle_incoming_data(): received uip_datalen=%u \n",(uint16_t)uip_datalen());
if (uip_newdata()) {
PRINTF("receiving UDP datagram from: ");
PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
PRINTF(":%u\n Length: %u\n Data: ", uip_ntohs(UIP_UDP_BUF->srcport), uip_datalen() );
PRINTBITS(uip_appdata, uip_datalen());
PRINTF("\n");
coap_packet_t message[1];
coap_transaction_t *transaction = NULL;
error = coap_parse_message(message, uip_appdata, uip_datalen());
if (error==NO_ERROR)
{
/*TODO duplicates suppression, if required */
PRINTF(" Parsed: v %u, t %u, oc %u, c %u, tid %u\n", message->version, message->type, message->option_count, message->code, message->tid);
PRINTF(" URL: %.*s\n", message->uri_path_len, message->uri_path);
PRINTF(" Payload: %.*s\n", message->payload_len, message->payload);
/* Handle requests. */
if (message->code >= COAP_GET && message->code <= COAP_DELETE)
{
/* Use transaction buffer for response to confirmable request. */
if ( (transaction = coap_new_transaction(message->tid, &UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport)) )
{
uint32_t block_num = 0;
uint16_t block_size = REST_MAX_CHUNK_SIZE;
uint32_t block_offset = 0;
int32_t new_offset = 0;
/* prepare response */
coap_packet_t response[1]; /* This way the packet can be treated as pointer as usual. */
if (message->type==COAP_TYPE_CON)
{
/* Reliable CON requests are answered with an ACK. */
coap_init_message(response, COAP_TYPE_ACK, OK_200, message->tid);
}
else
{
/* Unreliable NON requests are answered with a NON as well. */
coap_init_message(response, COAP_TYPE_NON, OK_200, coap_get_tid());
}
/* resource handlers must take care of different handling (e.g., TOKEN_OPTION_REQUIRED_240) */
if (IS_OPTION(message, COAP_OPTION_TOKEN))
{
coap_set_header_token(response, message->token, message->token_len);
SET_OPTION(response, COAP_OPTION_TOKEN);
}
/* get offset for blockwise transfers */
if (coap_get_header_block(message, &block_num, NULL, &block_size, &block_offset))
{
PRINTF("Blockwise: block request %lu (%u/%u) @ %lu bytes\n", block_num, block_size, REST_MAX_CHUNK_SIZE, block_offset);
block_size = MIN(block_size, REST_MAX_CHUNK_SIZE);
new_offset = block_offset;
}
/*------------------------------------------*/
/* call application-specific handler */
/*------------------------------------------*/
if (service_cbk) {
service_cbk(message, response, transaction->packet+COAP_MAX_HEADER_SIZE, block_size, &new_offset);
}
/*------------------------------------------*/
/* apply blockwise transfers */
if ( IS_OPTION(message, COAP_OPTION_BLOCK) )
{
/* unchanged new_offset indicates that resource is unaware of blockwise transfer */
if (new_offset==block_offset)
{
PRINTF("Blockwise: unaware resource with payload length %u/%u\n", response->payload_len, block_size);
if (block_offset >= response->payload_len)
{
response->code = BAD_REQUEST_400;
coap_set_payload(response, (uint8_t*)"Block out of scope", 18);
}
else
{
coap_set_header_block(response, block_num, response->payload_len - block_offset > block_size, block_size);
coap_set_payload(response, response->payload+block_offset, MIN(response->payload_len - block_offset, block_size));
} /* if (valid offset) */
}
else
{
/* resource provides chunk-wise data */
PRINTF("Blockwise: blockwise resource, new offset %ld\n", new_offset);
coap_set_header_block(response, block_num, new_offset!=-1 || response->payload_len > block_size, block_size);
if (response->payload_len > block_size) coap_set_payload(response, response->payload, block_size);
} /* if (resource aware of blockwise) */
}
else if (new_offset!=0)
{
PRINTF("Blockwise: no block option for blockwise resource, using block size %u\n", REST_MAX_CHUNK_SIZE);
coap_set_header_block(response, 0, new_offset!=-1, REST_MAX_CHUNK_SIZE);
coap_set_payload(response, response->payload, MIN(response->payload_len, REST_MAX_CHUNK_SIZE));
} /* if (blockwise request) */
if ((transaction->packet_len = coap_serialize_message(response, transaction->packet))==0)
{
error = PACKET_SERIALIZATION_ERROR;
}
} else {
error = MEMORY_ALLOCATION_ERROR;
}
}
else
{
/* Responses */
coap_transaction_t *t;
if (message->type==COAP_TYPE_ACK)
{
PRINTF("Received ACK\n");
}
else if (message->type==COAP_TYPE_RST)
{
PRINTF("Received RST\n");
/* Cancel possible subscriptions. */
if (IS_OPTION(message, COAP_OPTION_TOKEN))
{
PRINTF(" Token 0x%02X%02X\n", message->token[0], message->token[1]);
coap_remove_observer_by_token(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport, message->token, message->token_len);
}
}
if ( (t = coap_get_transaction_by_tid(message->tid)) )
{
/* Free transaction memory before callback, as it may create a new transaction. */
restful_response_handler callback = t->callback;
void *callback_data = t->callback_data;
coap_clear_transaction(t);
/* Check if someone registered for the response */
if (callback) {
callback(callback_data, message);
}
} /* if (transaction) */
}
} /* if (parsed correctly) */
if (error==NO_ERROR) {
if (transaction) coap_send_transaction(transaction);
}
else
{
PRINTF("ERROR %u: %s\n", error, error_messages[error]);
/* reuse input buffer */
coap_init_message(message, COAP_TYPE_ACK, INTERNAL_SERVER_ERROR_500, message->tid);
coap_set_payload(message, (uint8_t *) error_messages[error], strlen(error_messages[error]));
coap_send_message(&UIP_IP_BUF->srcipaddr, UIP_UDP_BUF->srcport, uip_appdata, coap_serialize_message(message, uip_appdata));
}
} /* if (new data) */
return error;
}
