nes-proj/examples/coap/resources/res-hello.c

82 lines
3.5 KiB
C

/*
* 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
* Example resource
* \author
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
*/
#include <stdlib.h>
#include <string.h>
#include "coap-engine.h"
static void res_get_handler(coap_message_t *request, coap_message_t *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
/*
* A handler function named [resource name]_handler must be implemented for each RESOURCE.
* A buffer for the response payload is provided through the buffer pointer. Simple resources can ignore
* preferred_size and offset, but must respect the REST_MAX_CHUNK_SIZE limit for the buffer.
* If a smaller block size is requested for CoAP, the REST framework automatically splits the data.
*/
RESOURCE(res_hello,
"title=\"Hello world: ?len=0..\";rt=\"Text\"",
res_get_handler,
NULL,
NULL,
NULL);
static void
res_get_handler(coap_message_t *request, coap_message_t *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
{
const char *len = NULL;
/* Some data that has the length up to REST_MAX_CHUNK_SIZE. For more, see the chunk resource. */
char const *const message = "Hello World! ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxy";
int length = 12; /* |<-------->| */
/* The query string can be retrieved by rest_get_query() or parsed for its key-value pairs. */
if(coap_get_query_variable(request, "len", &len)) {
length = atoi(len);
if(length < 0) {
length = 0;
}
if(length > REST_MAX_CHUNK_SIZE) {
length = REST_MAX_CHUNK_SIZE;
}
memcpy(buffer, message, length);
} else {
memcpy(buffer, message, length);
} coap_set_header_content_format(response, TEXT_PLAIN); /* text/plain is the default, hence this option could be omitted. */
coap_set_header_etag(response, (uint8_t *)&length, 1);
coap_set_payload(response, buffer, length);
}