mbed-os-examples / Mbed OS mbed-os-example-mbed5-sockets

This is a quick example of a simple HTTP client program using the network-socket API that is provided as a part of mbed-os. The program brings up an underlying network interface, and uses it to perform an HTTP transaction over a TCPSocket.

main.cpp@75:1e3673a86f39, 2019-09-12 (annotated)

Committer:
mbed_official
Date:
Thu Sep 12 16:00:11 2019 +0100
Revision:
75:1e3673a86f39
Parent:
72:47ae7d8d7321 
README.md: remove the External address line form sample output



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Commit copied from https://github.com/ARMmbed/mbed-os-example-sockets

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:17bd84fc5087 1 #include "mbed.h"
mbed_official 0:17bd84fc5087 2
mbed_official 5:3e952c60d705 3 // Network interface
mbed_official 49:1923a727df5b 4 NetworkInterface *net;
mbed_official 0:17bd84fc5087 5
mbed_official 0:17bd84fc5087 6 // Socket demo
mbed_official 5:3e952c60d705 7 int main() {
mbed_official 47:08787ef063cb 8 int remaining;
mbed_official 47:08787ef063cb 9 int rcount;
mbed_official 47:08787ef063cb 10 char *p;
mbed_official 47:08787ef063cb 11 char *buffer = new char[256];
mbed_official 64:a3dc04daaa2a 12 nsapi_size_or_error_t result;
mbed_official 47:08787ef063cb 13
mbed_official 5:3e952c60d705 14 // Bring up the ethernet interface
mbed_official 49:1923a727df5b 15 printf("Mbed OS Socket example\n");
mbed_official 48:f2739ac5cb01 16
mbed_official 48:f2739ac5cb01 17 #ifdef MBED_MAJOR_VERSION
mbed_official 49:1923a727df5b 18 printf("Mbed OS version: %d.%d.%d\n\n", MBED_MAJOR_VERSION, MBED_MINOR_VERSION, MBED_PATCH_VERSION);
mbed_official 48:f2739ac5cb01 19 #endif
mbed_official 48:f2739ac5cb01 20
mbed_official 49:1923a727df5b 21 net = NetworkInterface::get_default_instance();
mbed_official 49:1923a727df5b 22
mbed_official 49:1923a727df5b 23 if (!net) {
mbed_official 49:1923a727df5b 24 printf("Error! No network inteface found.\n");
mbed_official 49:1923a727df5b 25 return 0;
mbed_official 49:1923a727df5b 26 }
mbed_official 49:1923a727df5b 27
mbed_official 64:a3dc04daaa2a 28 result = net->connect();
mbed_official 64:a3dc04daaa2a 29 if (result != 0) {
mbed_official 64:a3dc04daaa2a 30 printf("Error! net->connect() returned: %d\n", result);
mbed_official 64:a3dc04daaa2a 31 return result;
mbed_official 47:08787ef063cb 32 }
mbed_official 0:17bd84fc5087 33
mbed_official 0:17bd84fc5087 34 // Show the network address
mbed_official 49:1923a727df5b 35 const char *ip = net->get_ip_address();
mbed_official 49:1923a727df5b 36 const char *netmask = net->get_netmask();
mbed_official 49:1923a727df5b 37 const char *gateway = net->get_gateway();
mbed_official 13:ed9e4aa00044 38 printf("IP address: %s\n", ip ? ip : "None");
mbed_official 13:ed9e4aa00044 39 printf("Netmask: %s\n", netmask ? netmask : "None");
mbed_official 13:ed9e4aa00044 40 printf("Gateway: %s\n", gateway ? gateway : "None");
mbed_official 0:17bd84fc5087 41
mbed_official 72:47ae7d8d7321 42 // Open a socket on the network interface, and create a TCP connection to ifconfig.io
mbed_official 5:3e952c60d705 43 TCPSocket socket;
mbed_official 56:02a6401ec508 44 // Send a simple http request
mbed_official 72:47ae7d8d7321 45 char sbuffer[] = "GET / HTTP/1.1\r\nHost: ifconfig.io\r\nConnection: close\r\n\r\n";
mbed_official 56:02a6401ec508 46 nsapi_size_t size = strlen(sbuffer);
mbed_official 56:02a6401ec508 47
mbed_official 64:a3dc04daaa2a 48 result = socket.open(net);
mbed_official 64:a3dc04daaa2a 49 if (result != 0) {
mbed_official 64:a3dc04daaa2a 50 printf("Error! socket.open() returned: %d\n", result);
mbed_official 47:08787ef063cb 51 }
mbed_official 0:17bd84fc5087 52
mbed_official 72:47ae7d8d7321 53 result = socket.connect("ifconfig.io", 80);
mbed_official 64:a3dc04daaa2a 54 if (result != 0) {
mbed_official 64:a3dc04daaa2a 55 printf("Error! socket.connect() returned: %d\n", result);
mbed_official 56:02a6401ec508 56 goto DISCONNECT;
mbed_official 47:08787ef063cb 57 }
mbed_official 47:08787ef063cb 58
mbed_official 64:a3dc04daaa2a 59 // Loop until whole request sent
mbed_official 47:08787ef063cb 60 while(size) {
mbed_official 64:a3dc04daaa2a 61 result = socket.send(sbuffer+result, size);
mbed_official 64:a3dc04daaa2a 62 if (result < 0) {
mbed_official 64:a3dc04daaa2a 63 printf("Error! socket.send() returned: %d\n", result);
mbed_official 56:02a6401ec508 64 goto DISCONNECT;
mbed_official 47:08787ef063cb 65 }
mbed_official 64:a3dc04daaa2a 66 size -= result;
mbed_official 64:a3dc04daaa2a 67 printf("sent %d [%.*s]\n", result, strstr(sbuffer, "\r\n")-sbuffer, sbuffer);
mbed_official 40:afef93b6d854 68 }
mbed_official 47:08787ef063cb 69
mbed_official 47:08787ef063cb 70 // Receieve an HTTP response and print out the response line
mbed_official 47:08787ef063cb 71 remaining = 256;
mbed_official 47:08787ef063cb 72 rcount = 0;
mbed_official 47:08787ef063cb 73 p = buffer;
mbed_official 72:47ae7d8d7321 74 while (remaining > 0 && 0 < (result = socket.recv(p, remaining))) {
mbed_official 64:a3dc04daaa2a 75 p += result;
mbed_official 64:a3dc04daaa2a 76 rcount += result;
mbed_official 64:a3dc04daaa2a 77 remaining -= result;
mbed_official 47:08787ef063cb 78 }
mbed_official 64:a3dc04daaa2a 79 if (result < 0) {
mbed_official 64:a3dc04daaa2a 80 printf("Error! socket.recv() returned: %d\n", result);
mbed_official 56:02a6401ec508 81 goto DISCONNECT;
mbed_official 47:08787ef063cb 82 }
mbed_official 64:a3dc04daaa2a 83 // the HTTP response code
mbed_official 13:ed9e4aa00044 84 printf("recv %d [%.*s]\n", rcount, strstr(buffer, "\r\n")-buffer, buffer);
mbed_official 13:ed9e4aa00044 85
mbed_official 47:08787ef063cb 86 delete[] buffer;
mbed_official 0:17bd84fc5087 87
mbed_official 56:02a6401ec508 88 DISCONNECT:
mbed_official 0:17bd84fc5087 89 // Close the socket to return its memory and bring down the network interface
mbed_official 0:17bd84fc5087 90 socket.close();
mbed_official 0:17bd84fc5087 91
mbed_official 5:3e952c60d705 92 // Bring down the ethernet interface
mbed_official 49:1923a727df5b 93 net->disconnect();
mbed_official 0:17bd84fc5087 94 printf("Done\n");
mbed_official 0:17bd84fc5087 95 }