libcoap example server

coap-server.cpp

// g++ -o coap-server coap-server.cpp -lcoap-2-openssl -lPocoNet -lPocoFoundation


#include <Poco/Net/SocketAddress.h>
#include <Poco/Random.h>
#include <Poco/NumberFormatter.h>
#include <Poco/Exception.h>
#include <coap2/coap.h>
#include <iostream>


int main(int argc, char** argv)
{
	coap_context_t* pCoapContext = nullptr;

	coap_startup();

	try
	{
		Poco::Net::SocketAddress sockAddr("localhost", "5683");
		coap_address_t coapAddr;
		coapAddr.size = sockAddr.length();
		std::memcpy(&coapAddr.addr.sin, sockAddr.addr(), sockAddr.length());

		pCoapContext = coap_new_context(nullptr);
		if (!pCoapContext) throw Poco::IOException("cannot create CoAP context");

		coap_endpoint_t* pCoapEndpoint = coap_new_endpoint(pCoapContext, &coapAddr, COAP_PROTO_UDP);
		if (!pCoapEndpoint) throw Poco::IOException("cannot create CoAP endpoint");

		coap_str_const_t uri = { 4, reinterpret_cast<const uint8_t*>("rssi") };
		coap_resource_t* pCoapResource = coap_resource_init(&uri, 0);

		coap_register_handler(pCoapResource, COAP_REQUEST_GET,
			[](auto, auto, auto, auto, auto, auto, coap_pdu_t* pResponse)
			{
				static Poco::Random rnd;

				pResponse->code = COAP_RESPONSE_CODE(205);
				int rssi = -50 - rnd.next(20);
				std::string data = Poco::NumberFormatter::format(rssi);
				coap_add_data(pResponse, data.size(), reinterpret_cast<const uint8_t*>(data.data()));
			});

		coap_add_resource(pCoapContext, pCoapResource);

		for (;;)
		{
			coap_run_once(pCoapContext, 0);
		}
	}
	catch (Poco::Exception& exc)
	{
		std::cerr << exc.displayText() << std::endl;
	}

	if (pCoapContext) coap_free_context(pCoapContext);

	coap_cleanup();

	return 0;
}