Sergei G / Mbed OS coap-example

CoAP messages on W5500 used as a NetworkStack. Built for NUCLEO-L476RG that has no built-in networking.

Dependencies:   NetworkServices W5500Interface easy-connect

Fork of coap-example by sandbox

source/main.cpp@0:0681e205d0e9, 2017-02-15 (annotated)

Committer:
Jan Jongboom
Date:
Wed Feb 15 21:18:58 2017 +0100
Revision:
0:0681e205d0e9
Child:
1:b56863927244
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jan Jongboom 0:0681e205d0e9 1 /*
Jan Jongboom 0:0681e205d0e9 2 * PackageLicenseDeclared: Apache-2.0
Jan Jongboom 0:0681e205d0e9 3 * Copyright (c) 2017 ARM Limited
Jan Jongboom 0:0681e205d0e9 4 *
Jan Jongboom 0:0681e205d0e9 5 * Licensed under the Apache License, Version 2.0 (the "License");
Jan Jongboom 0:0681e205d0e9 6 * you may not use this file except in compliance with the License.
Jan Jongboom 0:0681e205d0e9 7 * You may obtain a copy of the License at
Jan Jongboom 0:0681e205d0e9 8 *
Jan Jongboom 0:0681e205d0e9 9 * http://www.apache.org/licenses/LICENSE-2.0
Jan Jongboom 0:0681e205d0e9 10 *
Jan Jongboom 0:0681e205d0e9 11 * Unless required by applicable law or agreed to in writing, software
Jan Jongboom 0:0681e205d0e9 12 * distributed under the License is distributed on an "AS IS" BASIS,
Jan Jongboom 0:0681e205d0e9 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Jan Jongboom 0:0681e205d0e9 14 * See the License for the specific language governing permissions and
Jan Jongboom 0:0681e205d0e9 15 * limitations under the License.
Jan Jongboom 0:0681e205d0e9 16 */
Jan Jongboom 0:0681e205d0e9 17
Jan Jongboom 0:0681e205d0e9 18 #include <string>
Jan Jongboom 0:0681e205d0e9 19 #include "mbed.h"
Jan Jongboom 0:0681e205d0e9 20 #include "easy-connect.h"
Jan Jongboom 0:0681e205d0e9 21 #include "sn_nsdl.h"
Jan Jongboom 0:0681e205d0e9 22 #include "sn_coap_protocol.h"
Jan Jongboom 0:0681e205d0e9 23 #include "sn_coap_header.h"
Jan Jongboom 0:0681e205d0e9 24
Jan Jongboom 0:0681e205d0e9 25 UDPSocket socket; // Socket to talk CoAP over
Jan Jongboom 0:0681e205d0e9 26 Thread recvfromThread; // Thread to receive messages over CoAP
Jan Jongboom 0:0681e205d0e9 27
Jan Jongboom 0:0681e205d0e9 28 struct coap_s* coapHandle;
Jan Jongboom 0:0681e205d0e9 29 coap_version_e coapVersion = COAP_VERSION_1;
Jan Jongboom 0:0681e205d0e9 30
Jan Jongboom 0:0681e205d0e9 31 // CoAP HAL
Jan Jongboom 0:0681e205d0e9 32 void* coap_malloc(uint16_t size) {
Jan Jongboom 0:0681e205d0e9 33 return malloc(size);
Jan Jongboom 0:0681e205d0e9 34 }
Jan Jongboom 0:0681e205d0e9 35
Jan Jongboom 0:0681e205d0e9 36 void coap_free(void* addr) {
Jan Jongboom 0:0681e205d0e9 37 free(addr);
Jan Jongboom 0:0681e205d0e9 38 }
Jan Jongboom 0:0681e205d0e9 39
Jan Jongboom 0:0681e205d0e9 40 // tx_cb and rx_cb are not used in this program
Jan Jongboom 0:0681e205d0e9 41 uint8_t coap_tx_cb(uint8_t *a, uint16_t b, sn_nsdl_addr_s *c, void *d) {
Jan Jongboom 0:0681e205d0e9 42 printf("coap tx cb\n");
Jan Jongboom 0:0681e205d0e9 43 return 0;
Jan Jongboom 0:0681e205d0e9 44 }
Jan Jongboom 0:0681e205d0e9 45
Jan Jongboom 0:0681e205d0e9 46 int8_t coap_rx_cb(sn_coap_hdr_s *a, sn_nsdl_addr_s *b, void *c) {
Jan Jongboom 0:0681e205d0e9 47 printf("coap rx cb\n");
Jan Jongboom 0:0681e205d0e9 48 return 0;
Jan Jongboom 0:0681e205d0e9 49 }
Jan Jongboom 0:0681e205d0e9 50
Jan Jongboom 0:0681e205d0e9 51 // Main function for the recvfrom thread
Jan Jongboom 0:0681e205d0e9 52 void recvfromMain() {
Jan Jongboom 0:0681e205d0e9 53 SocketAddress addr;
Jan Jongboom 0:0681e205d0e9 54 uint8_t* recv_buffer = (uint8_t*)malloc(1280); // Suggested is to keep packet size under 1280 bytes
Jan Jongboom 0:0681e205d0e9 55
Jan Jongboom 0:0681e205d0e9 56 nsapi_size_or_error_t ret;
Jan Jongboom 0:0681e205d0e9 57
Jan Jongboom 0:0681e205d0e9 58 while ((ret = socket.recvfrom(&addr, recv_buffer, 1280)) >= 0) {
Jan Jongboom 0:0681e205d0e9 59 // to see where the message came from, inspect addr.get_addr() and addr.get_port()
Jan Jongboom 0:0681e205d0e9 60
Jan Jongboom 0:0681e205d0e9 61 printf("Received a message of length '%d'\n", ret);
Jan Jongboom 0:0681e205d0e9 62
Jan Jongboom 0:0681e205d0e9 63 sn_coap_hdr_s* parsed = sn_coap_parser(coapHandle, ret, recv_buffer, &coapVersion);
Jan Jongboom 0:0681e205d0e9 64
Jan Jongboom 0:0681e205d0e9 65 // We know the payload is going to be a string
Jan Jongboom 0:0681e205d0e9 66 std::string payload((const char*)parsed->payload_ptr, parsed->payload_len);
Jan Jongboom 0:0681e205d0e9 67
Jan Jongboom 0:0681e205d0e9 68 printf("\tmsg_id: %d\n", parsed->msg_id);
Jan Jongboom 0:0681e205d0e9 69 printf("\tmsg_code: %d\n", parsed->msg_code);
Jan Jongboom 0:0681e205d0e9 70 printf("\tcontent_format: %d\n", parsed->content_format);
Jan Jongboom 0:0681e205d0e9 71 printf("\tpayload_len: %d\n", parsed->payload_len);
Jan Jongboom 0:0681e205d0e9 72 printf("\tpayload: %s\n", payload.c_str());
Jan Jongboom 0:0681e205d0e9 73 printf("\toptions_list_ptr: %p\n", parsed->options_list_ptr);
Jan Jongboom 0:0681e205d0e9 74 }
Jan Jongboom 0:0681e205d0e9 75
Jan Jongboom 0:0681e205d0e9 76 free(recv_buffer);
Jan Jongboom 0:0681e205d0e9 77
Jan Jongboom 0:0681e205d0e9 78 printf("UDPSocket::recvfrom failed, error code %d. Shutting down receive thread.\n", ret);
Jan Jongboom 0:0681e205d0e9 79 }
Jan Jongboom 0:0681e205d0e9 80
Jan Jongboom 0:0681e205d0e9 81 int main() {
Jan Jongboom 0:0681e205d0e9 82 NetworkInterface *network = easy_connect(true);
Jan Jongboom 0:0681e205d0e9 83 if (!network) {
Jan Jongboom 0:0681e205d0e9 84 printf("Cannot connect to the network, see serial output");
Jan Jongboom 0:0681e205d0e9 85 return 1;
Jan Jongboom 0:0681e205d0e9 86 }
Jan Jongboom 0:0681e205d0e9 87
Jan Jongboom 0:0681e205d0e9 88 printf("Connected to the network. Opening a socket...\n");
Jan Jongboom 0:0681e205d0e9 89
Jan Jongboom 0:0681e205d0e9 90 // Open a socket on the network interface
Jan Jongboom 0:0681e205d0e9 91 socket.open(network);
Jan Jongboom 0:0681e205d0e9 92
Jan Jongboom 0:0681e205d0e9 93 // Initialize the CoAP protocol handle, pointing to local implementations on malloc/free/tx/rx functions
Jan Jongboom 0:0681e205d0e9 94 coapHandle = sn_coap_protocol_init(&coap_malloc, &coap_free, &coap_tx_cb, &coap_rx_cb);
Jan Jongboom 0:0681e205d0e9 95
Jan Jongboom 0:0681e205d0e9 96 // UDPSocket::recvfrom is blocking, so run it in a separate RTOS thread
Jan Jongboom 0:0681e205d0e9 97 recvfromThread.start(&recvfromMain);
Jan Jongboom 0:0681e205d0e9 98
Jan Jongboom 0:0681e205d0e9 99 // Path to the resource we want to retrieve
Jan Jongboom 0:0681e205d0e9 100 const char* coap_uri_path = "/hello";
Jan Jongboom 0:0681e205d0e9 101
Jan Jongboom 0:0681e205d0e9 102 // See ns_coap_header.h
Jan Jongboom 0:0681e205d0e9 103 sn_coap_hdr_s *coap_res_ptr = (sn_coap_hdr_s*)calloc(sizeof(sn_coap_hdr_s), 1);
Jan Jongboom 0:0681e205d0e9 104 coap_res_ptr->uri_path_ptr = (uint8_t*)coap_uri_path; // Path
Jan Jongboom 0:0681e205d0e9 105 coap_res_ptr->uri_path_len = strlen(coap_uri_path);
Jan Jongboom 0:0681e205d0e9 106 coap_res_ptr->msg_code = COAP_MSG_CODE_REQUEST_GET; // CoAP method
Jan Jongboom 0:0681e205d0e9 107 coap_res_ptr->content_format = COAP_CT_TEXT_PLAIN; // CoAP content type
Jan Jongboom 0:0681e205d0e9 108 coap_res_ptr->payload_len = 0; // Body length
Jan Jongboom 0:0681e205d0e9 109 coap_res_ptr->payload_ptr = 0; // Body pointer
Jan Jongboom 0:0681e205d0e9 110 coap_res_ptr->options_list_ptr = 0; // Optional: options list
Jan Jongboom 0:0681e205d0e9 111 // Message ID is used to track request->response patterns, because we're using UDP (so everything is unconfirmed).
Jan Jongboom 0:0681e205d0e9 112 // See the receive code to verify that we get the same message ID back
Jan Jongboom 0:0681e205d0e9 113 coap_res_ptr->msg_id = 7;
Jan Jongboom 0:0681e205d0e9 114
Jan Jongboom 0:0681e205d0e9 115 // Calculate the CoAP message size, allocate the memory and build the message
Jan Jongboom 0:0681e205d0e9 116 uint16_t message_len = sn_coap_builder_calc_needed_packet_data_size(coap_res_ptr);
Jan Jongboom 0:0681e205d0e9 117 printf("Calculated message length: %d bytes\n", message_len);
Jan Jongboom 0:0681e205d0e9 118
Jan Jongboom 0:0681e205d0e9 119 uint8_t* message_ptr = (uint8_t*)malloc(message_len);
Jan Jongboom 0:0681e205d0e9 120 sn_coap_builder(message_ptr, coap_res_ptr);
Jan Jongboom 0:0681e205d0e9 121
Jan Jongboom 0:0681e205d0e9 122 // Uncomment to see the raw buffer that will be sent...
Jan Jongboom 0:0681e205d0e9 123 // printf("Message is: ");
Jan Jongboom 0:0681e205d0e9 124 // for (size_t ix = 0; ix < message_len; ix++) {
Jan Jongboom 0:0681e205d0e9 125 // printf("%02x ", message_ptr[ix]);
Jan Jongboom 0:0681e205d0e9 126 // }
Jan Jongboom 0:0681e205d0e9 127 // printf("\n");
Jan Jongboom 0:0681e205d0e9 128
Jan Jongboom 0:0681e205d0e9 129 int scount = socket.sendto("coap.me", 5683, message_ptr, message_len);
Jan Jongboom 0:0681e205d0e9 130 printf("Sent %d bytes to coap://coap.me:5683\n", scount);
Jan Jongboom 0:0681e205d0e9 131
Jan Jongboom 0:0681e205d0e9 132 free(coap_res_ptr);
Jan Jongboom 0:0681e205d0e9 133 free(message_ptr);
Jan Jongboom 0:0681e205d0e9 134
Jan Jongboom 0:0681e205d0e9 135 Thread::wait(osWaitForever);
Jan Jongboom 0:0681e205d0e9 136 }