Single instance HTTP Server using new Ethernet Interface.

Dependents:   EthHTTPServer if201410_section5 _PE2E_12-04_EthernetInterfaceServer MGAS_GR_Peach ... more

Fork of WiFlyHTTPServer by Henry Leinen

Desciprtion of the library


This is an HTTPServer library using the new MBED EthernetInterface library. It allows you to :

  • serve files from any file System
  • use Remote procedure calls
  • extend the HTTPServer functionality according to your needs, using the provided handler classes or writing new classes. The following sections will give you a brief overview of how to use the library.

Usage description

You can use the library as file server, as RPC server or a combination of both. You can even define your own behaviour by deriving from one of the classes provided.

Use as file server

You may want to look at my sample application which allows you to serve files from the internal local storage of the mbed with no modifcation of the code :

Very simple example application

#include "mbed.h"
#include "HTTPServer.h"
#include "FsHandler.h"
#include "LocalFileSystem.h"

//  Use LED1 to indicate that the main loop is still executing
DigitalOut myled(LED1);
//  Use the serial connection 'pc' to dump debug information
Serial pc(USBTX, USBRX, "pc");
//  Instantiate a HTTPServer to handle incoming requests
HTTPServer  svr;
//  Instantiate a local file system handler named 'local' which will be used later to access files on the mbed.
LocalFileSystem local("local");

int main() {

    HTTPFsRequestHandler::mount("/local/", "/");

    if (!svr.start()) {
       error("Server not starting !");
    while(1) {
        myled = 1;
        myled = 0;

Another alternative is to provide the EthernetInterface library to the HTTPServer library. This may be useful in case you need to perform other tasks with your internet connection. In this case it is necessary that you initialize the EthernetInterface and perform the connection prior to calling the start() method. Here is the example :

Sample application with re-use of existing EthernetInterface object

#include "mbed.h"
#include "HTTPServer.h"
#include "FsHandler.h"
#include "LocalFileSystem.h"
#include "EthernetInterface.h"

//  Use LED1 to indicate that the main loop is still executing
DigitalOut myled(LED1);
//  Use the serial connection 'pc' to dump debug information
Serial pc(USBTX, USBRX, "pc");
//  Instantiate a HTTPServer to handle incoming requests
HTTPServer  svr;
//  Instantiate a local file system handler named 'local' which will be used later to access files on the mbed.
LocalFileSystem local("local");
//  Create the EthernetInterface. This is optional, please see the documentation of HTTP Server's start method.
EthernetInterface eth;

int main() {

    HTTPFsRequestHandler::mount("/local/", "/");

    //  Initialize the EthernetInterface and initiate a connection using DHCP.

    // ***
    // TODO: Perform other Tasks using the ethernet connection here.
    // ****
    // Now start the server on port 80.
    if (!svr.start(80, &eth)) {
        error("Server not starting !");
    // The whole server activity is performed in this Loop. You can also put it into a separate RTOS Task and let it run there all the time.
    while(1) {
        myled = 1;
        myled = 0;

Use as remote procedure call (RPC) server

To access objects or resources via HTTP you can make use of the RPC functionality. Each object that shall be accessible via HTTP needs to be registered before use. Here is an example which Registers the DigitalOut class for use over RPC :

RPC usage over HTTPServer

#include "mbed.h"
#include "HTTPServer.h"
#include "RpcHandler.h"
#include "mbed_rpc.h"

//  Use LED1 to indicate that the main loop is still executing
DigitalOut myled(LED1);
//  Use the serial connection 'pc' to dump debug information
Serial pc(USBTX, USBRX, "pc");
//  Instantiate a HTTPServer to handle incoming requests
HTTPServer  svr;

int main() {

    if (!svr.start()) {
        error("Server not starting !");
    while(1) {
        myled = 1;
        myled = 0;

And using the above code, enter the following in the address field of your browser :

http://<your_mbed_ip>/RPC/DigitalOut/new LED4 myled4 - - > to create a new object of type DigitalOut on pin LED4 which can be referred to as 'myled4'.


http://<your_mbed_ip>/RPC/myled4/write 1 - - > to switch on the LED4.

Of course it is possible to Register your own objects with the standard MBED RPC functionality.

All the above Scenarios are implemented in a sample application, which will allow you to try out the functionality with basically no changes. If you want to try out the HTTP file Server, it is of course helpful to upload an html file to your MBED local storage.

Here is the sample application :

Import programEthHTTPServer

Working sample implementation for the EthernetInterface HTTPServer.

Future plans

Currently I am not considering to further extend this library. However, if someone needs extensions to this library, I will consider implementing them. Of course I will be taking care of bugfixes.

Known issues

Please note that the current implementation of the EthernetInterface seems to have an issue which results in unresponsive behaviour of the Sockets in some situations. This odd behaviour has not only been reported on my HTTPServer but also on other components using the EthernetInterface library.

Sat Aug 17 16:17:55 2013 +0000
- Removed old Debug message helper macros and replaced them with new hl_debug.h macros.
; - Renamed debug.h file to hl_debug.h to avoid conflict with EthernetInterface.
; - Fixed incorrectly used debug macro where an ERR was used instead of an INFO

Who changed what in which revision?

UserRevisionLine numberNew contents of line
leihen 0:7a2421e63e74 1 #include "mbed.h"
leihen 0:7a2421e63e74 2 #include "HTTPServer.h"
leihen 13:aa5338a5e452 3 #define DEBUG
leihen 16:cc3f5c53d0d5 4 #include "hl_debug.h"
leihen 4:d065642c32cc 5
leihen 0:7a2421e63e74 6
leihen 4:d065642c32cc 7
leihen 4:d065642c32cc 8 /* Constructor */
leihen 4:d065642c32cc 9 /* initialize all members and set the standard error handler. */
leihen 13:aa5338a5e452 10 HTTPServer::HTTPServer()
leihen 14:011edcd33e86 11 : m_pEthernet(NULL)
leihen 0:7a2421e63e74 12 {
leihen 9:c2a1462b9b71 13 m_pErrorHandler = StdErrorHandler;
leihen 0:7a2421e63e74 14 }
leihen 0:7a2421e63e74 15
leihen 0:7a2421e63e74 16 HTTPServer::~HTTPServer()
leihen 0:7a2421e63e74 17 {
leihen 14:011edcd33e86 18 if (m_pEthernet == NULL) {
leihen 14:011edcd33e86 19 INFO("Deleting EthernetInterface Object.\n");
leihen 14:011edcd33e86 20 delete m_pEthernet;
leihen 14:011edcd33e86 21 }
leihen 0:7a2421e63e74 22 }
leihen 0:7a2421e63e74 23
leihen 4:d065642c32cc 24 static const char* szStdErrorPage = "<HTML><HEAD><META content=\"text/html\" http-equiv=Content-Type></HEAD><BODY><h1>Error 404</h1><P>This resource is not available<P></BODY></HTML>\r\n\r\n";
leihen 2:8653bbcf7e58 25
leihen 3:d6224049b3bf 26 void HTTPServer::StdErrorHandler(HTTPConnection::HTTPMessage& msg, TCPSocketConnection& tcp)
leihen 2:8653bbcf7e58 27 {
leihen 4:d065642c32cc 28 char echoHeader[256];
leihen 2:8653bbcf7e58 29 tcp.set_blocking(true, 1500);
leihen 11:3943841e1798 30 sprintf(echoHeader,"HTTP/1.0 404 Fail\r\nConnection: close\r\nContent-Length: %d\r\nContent-Type: text/html\r\nServer: mbed embedded\r\n\n\r",strlen(szStdErrorPage));
leihen 2:8653bbcf7e58 31 tcp.send(echoHeader, strlen(echoHeader));
leihen 2:8653bbcf7e58 32 tcp.send((char*)szStdErrorPage, strlen(szStdErrorPage));
leihen 2:8653bbcf7e58 33 }
leihen 2:8653bbcf7e58 34
leihen 2:8653bbcf7e58 35
leihen 14:011edcd33e86 36 bool HTTPServer::start(int port, EthernetInterface* pEthernet)
leihen 0:7a2421e63e74 37 {
leihen 14:011edcd33e86 38 // If no ethernet interface is provided, instantiate own on the heap. This has to be deleted later in the destructor.
leihen 14:011edcd33e86 39 // If a valid pointer to an thernet interface is proveded, we can simply use it.
leihen 14:011edcd33e86 40 if (pEthernet == NULL) {
leihen 14:011edcd33e86 41 INFO("Creating EthernetInterface object\n");
leihen 14:011edcd33e86 42 m_pEthernet = new EthernetInterface();
leihen 14:011edcd33e86 43
leihen 14:011edcd33e86 44 if (m_pEthernet == NULL) {
leihen 14:011edcd33e86 45 ERR("Out of memory, unable to instantiate an EthernetInterface object.");
leihen 14:011edcd33e86 46 return false;
leihen 14:011edcd33e86 47 }
leihen 9:c2a1462b9b71 48
leihen 14:011edcd33e86 49 // Initiaize the network
leihen 14:011edcd33e86 50 INFO("Initializing network\n");
leihen 14:011edcd33e86 51 if (m_pEthernet->init() != 0) {
leihen 14:011edcd33e86 52 ERR("Failed to initialize the ethernet interface !");
leihen 14:011edcd33e86 53 delete m_pEthernet;
leihen 14:011edcd33e86 54 m_pEthernet = NULL;
leihen 14:011edcd33e86 55 return false;
leihen 14:011edcd33e86 56 }
leihen 14:011edcd33e86 57
leihen 14:011edcd33e86 58 // Connect to the network using DHCP
leihen 14:011edcd33e86 59 INFO("Connecting to the network using DHCP...");
leihen 14:011edcd33e86 60 if (m_pEthernet->connect() != 0) {
leihen 14:011edcd33e86 61 ERR("Failed to connect to the ethernet !");
leihen 14:011edcd33e86 62 delete m_pEthernet;
leihen 14:011edcd33e86 63 m_pEthernet = NULL;
leihen 14:011edcd33e86 64 return false;
leihen 14:011edcd33e86 65 }
leihen 14:011edcd33e86 66
leihen 14:011edcd33e86 67 INFO("Connected IP %s", m_pEthernet->getIPAddress());
leihen 14:011edcd33e86 68
leihen 14:011edcd33e86 69 } else {
leihen 14:011edcd33e86 70 // In the case that the ethernet interface is provided, it is assumed that a connection has already been created.
leihen 14:011edcd33e86 71 INFO("Using connection IP %s", pEthernet->getIPAddress());
leihen 14:011edcd33e86 72 }
leihen 14:011edcd33e86 73
leihen 13:aa5338a5e452 74 INFO("Binding to port %d...", port);
leihen 13:aa5338a5e452 75 if (m_Svr.bind(port) < 0) {
leihen 13:aa5338a5e452 76 ERR("Failed to bind to port !\n");
leihen 13:aa5338a5e452 77 error("Binding");
leihen 13:aa5338a5e452 78 return false;
leihen 0:7a2421e63e74 79 }
leihen 0:7a2421e63e74 80
leihen 13:aa5338a5e452 81 INFO("Listening ...");
leihen 13:aa5338a5e452 82 if (m_Svr.listen(1) < 0) {
leihen 13:aa5338a5e452 83 ERR("Failed to listen !\n");
leihen 13:aa5338a5e452 84 error("Listening");
leihen 13:aa5338a5e452 85 return false;
leihen 0:7a2421e63e74 86 }
leihen 0:7a2421e63e74 87
leihen 16:cc3f5c53d0d5 88 INFO("Connected !");
leihen 0:7a2421e63e74 89 // set into non blocking operation
leihen 13:aa5338a5e452 90 m_Svr.set_blocking(false, 100);
leihen 13:aa5338a5e452 91
leihen 13:aa5338a5e452 92 return true;
leihen 0:7a2421e63e74 93 }
leihen 0:7a2421e63e74 94
leihen 0:7a2421e63e74 95
leihen 6:fe661fa9d18a 96 int HTTPServer::poll(bool blocking)
leihen 13:aa5338a5e452 97 {
leihen 0:7a2421e63e74 98 // This thread basically checks if there is a new incoming connection.
leihen 0:7a2421e63e74 99 // If so , a new HTTPConnection is created and the connection thread is started.
leihen 0:7a2421e63e74 100 TCPSocketConnection Clnt;
leihen 13:aa5338a5e452 101 if (m_Svr.accept(Clnt) < 0) {
leihen 0:7a2421e63e74 102 return -1;
leihen 0:7a2421e63e74 103 }
leihen 13:aa5338a5e452 104
leihen 13:aa5338a5e452 105 // a new connection was received
leihen 13:aa5338a5e452 106 INFO("Client (IP=%s) is connected !\n", Clnt.get_address());
leihen 13:aa5338a5e452 107 HTTPConnection con(Clnt);
leihen 13:aa5338a5e452 108 int c = con.poll();
leihen 13:aa5338a5e452 109 if (c == 0) {
leihen 13:aa5338a5e452 110 // Handle the request
leihen 13:aa5338a5e452 111 INFO("Handling request !");
leihen 13:aa5338a5e452 112 HandleRequest(con.m_Msg, Clnt);
leihen 0:7a2421e63e74 113 }
leihen 13:aa5338a5e452 114 if (c == -1) {
leihen 13:aa5338a5e452 115 // break;
leihen 13:aa5338a5e452 116 }
leihen 13:aa5338a5e452 117
leihen 0:7a2421e63e74 118 INFO("Leaving polling thread");
leihen 0:7a2421e63e74 119 return 0;
leihen 1:6b7472d5e9ee 120 }
leihen 1:6b7472d5e9ee 121
leihen 3:d6224049b3bf 122 void HTTPServer::HandleRequest(HTTPConnection::HTTPMessage& msg, TCPSocketConnection& tcp)
leihen 3:d6224049b3bf 123 {
leihen 3:d6224049b3bf 124 std::string localPath;
leihen 3:d6224049b3bf 125 std::map<std::string, HTTPRequestHandler*(*)(const char*, const char*, HTTPConnection::HTTPMessage&, TCPSocketConnection&), handlersComp>::const_iterator it;
leihen 3:d6224049b3bf 126
leihen 4:d065642c32cc 127 // Iterate through registered handlers and check if the handler's path is a subset of the requested uri.
leihen 3:d6224049b3bf 128 for (it = m_lpHandlers.begin() ; it != m_lpHandlers.end() ; it++) {
leihen 3:d6224049b3bf 129 // check if this entries' path is fully contained at the beginning of the requested path
leihen 3:d6224049b3bf 130 std::string curpth = it->first;
leihen 3:d6224049b3bf 131
leihen 3:d6224049b3bf 132 if (msg.uri.find(curpth) == 0) {
leihen 4:d065642c32cc 133 // firts matching handler found, we just take it and we'll be happy
leihen 3:d6224049b3bf 134 localPath = msg.uri.substr(curpth.length());
leihen 3:d6224049b3bf 135 break;
leihen 3:d6224049b3bf 136 }
leihen 3:d6224049b3bf 137 }
leihen 13:aa5338a5e452 138
leihen 3:d6224049b3bf 139 if (it == m_lpHandlers.end()) {
leihen 3:d6224049b3bf 140 // There is no such handler, so return invalid
leihen 3:d6224049b3bf 141
leihen 13:aa5338a5e452 142 m_pErrorHandler(msg, tcp);
leihen 3:d6224049b3bf 143 INFO("Webrequest left unhandled.");
leihen 13:aa5338a5e452 144 } else {
leihen 4:d065642c32cc 145 // Valid handler was found
leihen 3:d6224049b3bf 146 INFO("Routing webrequest !");
leihen 4:d065642c32cc 147 // Instantiate the handler object (handling will be done from withing the object's constructor
leihen 3:d6224049b3bf 148 HTTPRequestHandler *phdl = (*it->second)(it->first.c_str(), localPath.c_str(), msg, tcp);
leihen 4:d065642c32cc 149 // now we can delete the object, because handling is completed.
leihen 3:d6224049b3bf 150 if (phdl != NULL)
leihen 3:d6224049b3bf 151 delete phdl;
leihen 3:d6224049b3bf 152 }
leihen 3:d6224049b3bf 153 }