Yes We Can / yeswecancoap

Coap Client and Server

Dependencies:   DebugLib EthernetInterface cantcoap mbed-rtos

Dependents:   COAP coap

Fork of yeswecancoap by Sille Van Landschoot

YesWeCanCoap

Is a small coap client and server library for mbed based on the cantcoap library.

Import librarycantcoap

This is CoAP library with a focus on simplicity. It offers minimal CoAP PDU construction and decoding to and from byte buffers.

Last commit 30 Jan 2014 by Ashley Mills

yeswecancoap server enables easy implementation of coap resources, each with a dedicated function. When the function is registered by the server, it will do the rest.

Coap server example

Repository: YesWeCanCoap-example

Coap client example

under construction

client.cpp@29:62113a57353b, 2015-11-17 (annotated)

Committer:
sillevl
Date:
Tue Nov 17 16:44:39 2015 +0000
Revision:
29:62113a57353b
Parent:
19:6414961fb98d 
added method to get the ip address

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dwini 8:0169da22e764 1 #include "client.h"
dwini 10:77bd145ec06c 2 #include "response.h"
dwini 10:77bd145ec06c 3 #include "request.h"
dwini 8:0169da22e764 4
dwini 8:0169da22e764 5 // Identifier is some trivial string used for console output
dwini 8:0169da22e764 6 Client::Client(const char * server, const int port, std::string identifier) {
dwini 8:0169da22e764 7 udp_socket.init();
dwini 8:0169da22e764 8 udp_socket.set_blocking(false, 1000);
dwini 8:0169da22e764 9 new_token_id = 0;
dwini 8:0169da22e764 10 coap_server.set_address(server, port);
dwini 8:0169da22e764 11 this->identifier = identifier;
dwini 8:0169da22e764 12 new_message_id = 0;
dwini 8:0169da22e764 13 }
dwini 8:0169da22e764 14
dwini 8:0169da22e764 15 // Respons handler can be left null if no content respons is expected
dwini 19:6414961fb98d 16 void Client::sendRequest(char* uri, void (*response_handler)(Request*, Response*), CoapPDU::Code method) {
dwini 8:0169da22e764 17
dwini 8:0169da22e764 18 CoapPDU *req_pdu = new CoapPDU();
dwini 8:0169da22e764 19
dwini 8:0169da22e764 20 switch (method) {
dwini 19:6414961fb98d 21 case CoapPDU::COAP_GET:
dwini 8:0169da22e764 22 req_pdu->setType(CoapPDU::COAP_CONFIRMABLE);
dwini 19:6414961fb98d 23 break;
dwini 19:6414961fb98d 24 case CoapPDU::COAP_POST:
dwini 19:6414961fb98d 25 req_pdu->setType(CoapPDU::COAP_CONFIRMABLE);
dwini 8:0169da22e764 26 break;
dwini 8:0169da22e764 27 }
dwini 19:6414961fb98d 28 req_pdu->setCode(method);
dwini 8:0169da22e764 29 req_pdu->setMessageID(new_message_id++);
dwini 14:ce76110ecf4d 30 new_token_id++;
dwini 14:ce76110ecf4d 31 req_pdu->setToken((uint8_t *)&new_token_id, sizeof(new_token_id));
dwini 8:0169da22e764 32 req_pdu->setURI(uri, strlen(uri));
dwini 8:0169da22e764 33
dwini 8:0169da22e764 34 unsigned int retries = 5;
dwini 8:0169da22e764 35 while (retries > 0 && udp_socket.sendTo(coap_server, (char *)(req_pdu->getPDUPointer()), req_pdu->getPDULength()) < 0) {
dwini 8:0169da22e764 36 retries--;
dwini 8:0169da22e764 37 }
dwini 8:0169da22e764 38
dwini 8:0169da22e764 39 if (retries == 0) {
dwini 8:0169da22e764 40 printf("UDP socket problem - Could not send PDU\r\n");
dwini 8:0169da22e764 41 return;
dwini 8:0169da22e764 42 } else {
dwini 19:6414961fb98d 43 if (method == CoapPDU::COAP_GET) { // Or confirmable ...
dwini 8:0169da22e764 44 // We need to save request and wait for respons of server
sillevl 13:6667e331c719 45 ResourceRequest req = { new_token_id, uri, response_handler, method, req_pdu };
dwini 8:0169da22e764 46 requests.push_back(req);
dwini 8:0169da22e764 47 }
dwini 8:0169da22e764 48 }
dwini 8:0169da22e764 49 }
dwini 8:0169da22e764 50
dwini 8:0169da22e764 51 void Client::checkForResponse(void) {
dwini 8:0169da22e764 52
dwini 8:0169da22e764 53 if (requests.size() > 0) { // responses still need to be received
dwini 8:0169da22e764 54
dwini 8:0169da22e764 55 char buffer[256];
dwini 8:0169da22e764 56 // printf("\r\nChecking for response UDP packet...\r\n");
dwini 8:0169da22e764 57
dwini 8:0169da22e764 58 // Check for udp packet from endpoint
dwini 8:0169da22e764 59 int size = udp_socket.receiveFrom(coap_server, buffer, sizeof(buffer)-1);
dwini 8:0169da22e764 60 if (size > 0) {
dwini 8:0169da22e764 61 buffer[size] = '\0';
dwini 8:0169da22e764 62
dwini 8:0169da22e764 63 char uriBuffer[32];
dwini 8:0169da22e764 64 int recvURILen;
dwini 8:0169da22e764 65 int msgId;
dwini 8:0169da22e764 66 uint32_t token;
dwini 8:0169da22e764 67
dwini 8:0169da22e764 68 // Lets coap
dwini 8:0169da22e764 69 CoapPDU *recvPDU = new CoapPDU((uint8_t*)buffer, 256, size);
dwini 8:0169da22e764 70 if(recvPDU->validate()) {
dwini 8:0169da22e764 71 recvPDU->getURI(uriBuffer, 32, &recvURILen);
dwini 8:0169da22e764 72 msgId = recvPDU->getMessageID();
dwini 8:0169da22e764 73
dwini 8:0169da22e764 74 // Parse token
dwini 8:0169da22e764 75 if (recvPDU->getTokenLength() == sizeof(new_token_id)) {
dwini 8:0169da22e764 76 token = *((uint32_t*)recvPDU->getTokenPointer());
dwini 8:0169da22e764 77 } else if (recvPDU->getTokenLength() == 0) { // Server does not care about tokens ?
dwini 8:0169da22e764 78 // Then we force to match with first request
dwini 8:0169da22e764 79 token = requests[0].token_id;
dwini 8:0169da22e764 80 } else {
dwini 8:0169da22e764 81 printf("Invalid token length\r\n");
dwini 8:0169da22e764 82 delete recvPDU;
dwini 8:0169da22e764 83 return;
dwini 8:0169da22e764 84 }
dwini 8:0169da22e764 85 } else {
dwini 8:0169da22e764 86 printf("Invalid Coap PDU received\r\n");
dwini 8:0169da22e764 87 recvPDU->printHuman();
dwini 8:0169da22e764 88 delete recvPDU;
dwini 8:0169da22e764 89 return;
dwini 8:0169da22e764 90 }
dwini 8:0169da22e764 91
dwini 8:0169da22e764 92 // Check for which request the response is meant
dwini 8:0169da22e764 93 int i = 0;
dwini 8:0169da22e764 94 while (i < requests.size() && requests[i].token_id != token) {
dwini 8:0169da22e764 95 i++;
dwini 8:0169da22e764 96 }
dwini 8:0169da22e764 97
dwini 8:0169da22e764 98 if (i < requests.size()) { // Found
dwini 8:0169da22e764 99 // [TODO] Here we should check if it's not a premature ACK !!!!!!
dwini 8:0169da22e764 100
dwini 8:0169da22e764 101 // Call handler if one exists
dwini 8:0169da22e764 102 if (requests[i].response_handler) {
dwini 10:77bd145ec06c 103 requests[i].response_handler((Request*)(requests[i].req_pdu), (Response*)recvPDU);
dwini 8:0169da22e764 104 }
dwini 8:0169da22e764 105
dwini 8:0169da22e764 106 delete requests[i].req_pdu;
dwini 8:0169da22e764 107 requests.erase(requests.begin() + i);
dwini 8:0169da22e764 108 } else {
dwini 8:0169da22e764 109 printf("Respons for unknown request\r\n");
dwini 8:0169da22e764 110 recvPDU->printHuman();
dwini 8:0169da22e764 111 }
dwini 8:0169da22e764 112
dwini 8:0169da22e764 113 delete recvPDU;
dwini 8:0169da22e764 114 }
dwini 8:0169da22e764 115 }
dwini 8:0169da22e764 116 }