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

Overview

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() {

    pc.baud(460800);
    HTTPFsRequestHandler::mount("/local/", "/");
    svr.addHandler<HTTPFsRequestHandler>("/");

    if (!svr.start()) {
       error("Server not starting !");
        exit(0);
    }
    
    while(1) {
        svr.poll();
        myled = 1;
        wait(0.2);
        myled = 0;
        wait(0.2);
    }
}

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() {

    pc.baud(460800);
    HTTPFsRequestHandler::mount("/local/", "/");
    svr.addHandler<HTTPFsRequestHandler>("/");

    //  Initialize the EthernetInterface and initiate a connection using DHCP.
    eth.init();
    eth.connect();

    // ***
    // 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 !");
        exit(0);
    }
    
    // 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) {
        svr.poll();
        myled = 1;
        wait(0.2);
        myled = 0;
        wait(0.2);
    }
}

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() {

    pc.baud(460800);
    RPC::add_rpc_class<RpcDigitalOut>();
    svr.addHandler<HTTPRpcRequestHandler>("/RPC");
    
    if (!svr.start()) {
        error("Server not starting !");
        exit(0);
    }
    
    while(1) {
        svr.poll();
        myled = 1;
        wait(0.2);
        myled = 0;
        wait(0.2);
    }
}

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'.

and

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.

Committer:
leihen
Date:
Wed Jun 05 23:39:24 2013 +0000
Revision:
12:ba81cc117fb6
Parent:
11:3943841e1798
Child:
13:aa5338a5e452
Improved throughput of data.
; fixed incorrect Header handling.
; Fixed Support for other FileSystem Handler

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 0:7a2421e63e74 3
leihen 11:3943841e1798 4 #define _DEBUG 0
leihen 4:d065642c32cc 5
leihen 4:d065642c32cc 6 #ifdef _DEBUG
leihen 0:7a2421e63e74 7 DigitalOut led1(LED1);
leihen 0:7a2421e63e74 8 DigitalOut led2(LED2);
leihen 0:7a2421e63e74 9 DigitalOut led3(LED3);
leihen 0:7a2421e63e74 10 DigitalOut led4(LED4);
leihen 4:d065642c32cc 11 #endif
leihen 0:7a2421e63e74 12
leihen 4:d065642c32cc 13 #if (_DEBUG && !defined(TARGET_LPC11U24))
leihen 9:c2a1462b9b71 14 #define INFO(x, ...) std::printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__);
leihen 9:c2a1462b9b71 15 #define WARN(x, ...) std::printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__);
leihen 9:c2a1462b9b71 16 #define ERR(x, ...) std::printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__);
leihen 0:7a2421e63e74 17 #else
leihen 0:7a2421e63e74 18 #define INFO(x, ...)
leihen 0:7a2421e63e74 19 #define WARN(x, ...)
leihen 0:7a2421e63e74 20 #define ERR(x, ...)
leihen 0:7a2421e63e74 21 #endif
leihen 0:7a2421e63e74 22
leihen 4:d065642c32cc 23
leihen 4:d065642c32cc 24 /* Constructor */
leihen 4:d065642c32cc 25 /* initialize all members and set the standard error handler. */
leihen 9:c2a1462b9b71 26 HTTPServer::HTTPServer(PinName tx, PinName rx, PinName reset, PinName tcp_status, const char * ssid, const char * phrase, Security sec)
leihen 9:c2a1462b9b71 27 : m_wifly(tx, rx, reset, tcp_status, ssid, phrase, sec)
leihen 0:7a2421e63e74 28 {
leihen 9:c2a1462b9b71 29 m_pErrorHandler = StdErrorHandler;
leihen 0:7a2421e63e74 30 m_pSvr = NULL;
leihen 0:7a2421e63e74 31 }
leihen 0:7a2421e63e74 32
leihen 0:7a2421e63e74 33 HTTPServer::~HTTPServer()
leihen 0:7a2421e63e74 34 {
leihen 0:7a2421e63e74 35 if (m_pSvr) {
leihen 0:7a2421e63e74 36 delete m_pSvr;
leihen 0:7a2421e63e74 37 m_pSvr = NULL;
leihen 0:7a2421e63e74 38 }
leihen 0:7a2421e63e74 39 }
leihen 0:7a2421e63e74 40
leihen 2:8653bbcf7e58 41
leihen 4:d065642c32cc 42 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 43
leihen 3:d6224049b3bf 44 void HTTPServer::StdErrorHandler(HTTPConnection::HTTPMessage& msg, TCPSocketConnection& tcp)
leihen 2:8653bbcf7e58 45 {
leihen 4:d065642c32cc 46 char echoHeader[256];
leihen 2:8653bbcf7e58 47 tcp.set_blocking(true, 1500);
leihen 11:3943841e1798 48 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 49 tcp.send(echoHeader, strlen(echoHeader));
leihen 2:8653bbcf7e58 50 tcp.send((char*)szStdErrorPage, strlen(szStdErrorPage));
leihen 2:8653bbcf7e58 51 }
leihen 2:8653bbcf7e58 52
leihen 2:8653bbcf7e58 53
leihen 0:7a2421e63e74 54 int HTTPServer::start(int port)
leihen 0:7a2421e63e74 55 {
leihen 0:7a2421e63e74 56 // check if the start member was called already once
leihen 0:7a2421e63e74 57 if (m_pSvr != NULL) {
leihen 0:7a2421e63e74 58 ERR("start function was already called, server is already in listening state.");
leihen 0:7a2421e63e74 59 return -1;
leihen 0:7a2421e63e74 60 }
leihen 9:c2a1462b9b71 61 INFO("Initializing wifly\n");
leihen 9:c2a1462b9b71 62 // Initialize the wifly wlan device
leihen 9:c2a1462b9b71 63 m_wifly.init();
leihen 9:c2a1462b9b71 64
leihen 9:c2a1462b9b71 65 INFO("Connecting to network...");
leihen 9:c2a1462b9b71 66 // Try join the network
leihen 11:3943841e1798 67 while(!m_wifly.connect()) {
leihen 11:3943841e1798 68 INFO("Failed to connect. Trying again\n");
leihen 11:3943841e1798 69 m_wifly.reset();
leihen 11:3943841e1798 70 }
leihen 9:c2a1462b9b71 71 INFO("connected\n");
leihen 9:c2a1462b9b71 72
leihen 9:c2a1462b9b71 73 // check if the start member was called already once
leihen 9:c2a1462b9b71 74 if (m_pSvr != NULL) {
leihen 9:c2a1462b9b71 75 ERR("start function was already called, server is already in listening state.");
leihen 9:c2a1462b9b71 76 return -1;
leihen 9:c2a1462b9b71 77 }
leihen 0:7a2421e63e74 78
leihen 0:7a2421e63e74 79 // Create a new server object
leihen 0:7a2421e63e74 80 m_pSvr = new TCPSocketServer();
leihen 0:7a2421e63e74 81
leihen 0:7a2421e63e74 82 // Bind the local server to the given port
leihen 0:7a2421e63e74 83 if (m_pSvr->bind(port) < 0) {
leihen 0:7a2421e63e74 84 ERR("Failed to bind to port %d\n", port);
leihen 0:7a2421e63e74 85 return -1;
leihen 0:7a2421e63e74 86 }
leihen 0:7a2421e63e74 87 else {
leihen 0:7a2421e63e74 88 INFO("Binding succeeded !\n");
leihen 0:7a2421e63e74 89 }
leihen 0:7a2421e63e74 90
leihen 0:7a2421e63e74 91 // Listen to a maximum of 10 concurrent connections
leihen 0:7a2421e63e74 92 if (m_pSvr->listen(1) < 0) {
leihen 0:7a2421e63e74 93 ERR("Faild to listen !\n");
leihen 0:7a2421e63e74 94 delete m_pSvr;
leihen 0:7a2421e63e74 95 m_pSvr = NULL;
leihen 0:7a2421e63e74 96 return -1;
leihen 0:7a2421e63e74 97 }
leihen 0:7a2421e63e74 98 else {
leihen 0:7a2421e63e74 99 INFO("Listening\n");
leihen 0:7a2421e63e74 100 }
leihen 0:7a2421e63e74 101
leihen 0:7a2421e63e74 102 // set into non blocking operation
leihen 0:7a2421e63e74 103 m_pSvr->set_blocking(false, 100);
leihen 0:7a2421e63e74 104
leihen 0:7a2421e63e74 105 return 0;
leihen 0:7a2421e63e74 106 }
leihen 0:7a2421e63e74 107
leihen 0:7a2421e63e74 108
leihen 6:fe661fa9d18a 109 int HTTPServer::poll(bool blocking)
leihen 0:7a2421e63e74 110 {
leihen 5:dc88012caef1 111 int retval = -1;
leihen 0:7a2421e63e74 112 INFO("Listening for new connection requests.");
leihen 0:7a2421e63e74 113
leihen 0:7a2421e63e74 114 // This thread basically checks if there is a new incoming connection.
leihen 0:7a2421e63e74 115 // If so , a new HTTPConnection is created and the connection thread is started.
leihen 0:7a2421e63e74 116 TCPSocketConnection Clnt;
leihen 0:7a2421e63e74 117
leihen 4:d065642c32cc 118 #ifdef _DEBUG
leihen 0:7a2421e63e74 119 led4 = 1; // Indicate we are waiting for a new connection
leihen 5:dc88012caef1 120 #endif
leihen 6:fe661fa9d18a 121 m_pSvr->set_blocking(blocking);
leihen 5:dc88012caef1 122 retval = m_pSvr->accept(Clnt);
leihen 5:dc88012caef1 123 if (retval > 0) {
leihen 5:dc88012caef1 124 // no connection availale yet, so just return
leihen 5:dc88012caef1 125 #ifdef _DEBUG
leihen 5:dc88012caef1 126 led4 = 0;
leihen 5:dc88012caef1 127 led3 = 0;
leihen 5:dc88012caef1 128 led2 = 0;
leihen 5:dc88012caef1 129 #endif
leihen 5:dc88012caef1 130 return retval;
leihen 5:dc88012caef1 131 }
leihen 5:dc88012caef1 132 if ( retval < 0) {
leihen 0:7a2421e63e74 133 // an error occured
leihen 0:7a2421e63e74 134 ERR("There was an error, Accept returned with an error. Probably the connection to the router was lost. Shutting down server");
leihen 4:d065642c32cc 135 #ifdef _DEBUG
leihen 0:7a2421e63e74 136 led2 = 0;
leihen 4:d065642c32cc 137 #endif
leihen 0:7a2421e63e74 138 m_pSvr->close();
leihen 0:7a2421e63e74 139 delete m_pSvr;
leihen 0:7a2421e63e74 140 m_pSvr = NULL;
leihen 4:d065642c32cc 141 #ifdef _DEBUG
leihen 0:7a2421e63e74 142 led4 = 0;
leihen 0:7a2421e63e74 143 led3 = 1; // ERROR
leihen 0:7a2421e63e74 144 led2 = 0;
leihen 0:7a2421e63e74 145 led1 = 0;
leihen 4:d065642c32cc 146 #endif
leihen 0:7a2421e63e74 147 return -1;
leihen 0:7a2421e63e74 148 }
leihen 0:7a2421e63e74 149 else {
leihen 4:d065642c32cc 150 #ifdef _DEBUG
leihen 0:7a2421e63e74 151 led4 = 0;
leihen 4:d065642c32cc 152 #endif
leihen 0:7a2421e63e74 153 // a new connection was received
leihen 0:7a2421e63e74 154 INFO("Client (IP=%s) is connected !\n", Clnt.get_address());
leihen 0:7a2421e63e74 155 // Start the main connection thread
leihen 11:3943841e1798 156 // while(1) {
leihen 11:3943841e1798 157
leihen 11:3943841e1798 158 #ifdef _DEBUG
leihen 11:3943841e1798 159 led3 = 1;
leihen 11:3943841e1798 160 led2 = 1;
leihen 11:3943841e1798 161 #endif
leihen 11:3943841e1798 162 HTTPConnection con;
leihen 11:3943841e1798 163 int c = con.poll();
leihen 11:3943841e1798 164 if (c == 0) {
leihen 11:3943841e1798 165 // Handle the request
leihen 11:3943841e1798 166 HandleRequest(con.m_Msg, Clnt);
leihen 12:ba81cc117fb6 167 // INFO("Closing connection.\n");
leihen 11:3943841e1798 168 // if (!m_wifly.close()) {
leihen 11:3943841e1798 169 // ERR("Failed to close connection !\n");
leihen 11:3943841e1798 170 // }
leihen 11:3943841e1798 171 }
leihen 11:3943841e1798 172 if (c == -1) {
leihen 11:3943841e1798 173 // No more data available or error
leihen 11:3943841e1798 174 // break;
leihen 11:3943841e1798 175 }
leihen 11:3943841e1798 176 #ifdef _DEBUG
leihen 11:3943841e1798 177 led2 = 0;
leihen 11:3943841e1798 178 led3 = 0;
leihen 11:3943841e1798 179 #endif
leihen 11:3943841e1798 180 // }
leihen 0:7a2421e63e74 181 }
leihen 0:7a2421e63e74 182
leihen 0:7a2421e63e74 183 INFO("Leaving polling thread");
leihen 0:7a2421e63e74 184 return 0;
leihen 1:6b7472d5e9ee 185 }
leihen 1:6b7472d5e9ee 186
leihen 3:d6224049b3bf 187 void HTTPServer::HandleRequest(HTTPConnection::HTTPMessage& msg, TCPSocketConnection& tcp)
leihen 3:d6224049b3bf 188 {
leihen 3:d6224049b3bf 189 std::string localPath;
leihen 3:d6224049b3bf 190 std::map<std::string, HTTPRequestHandler*(*)(const char*, const char*, HTTPConnection::HTTPMessage&, TCPSocketConnection&), handlersComp>::const_iterator it;
leihen 3:d6224049b3bf 191
leihen 4:d065642c32cc 192 // Iterate through registered handlers and check if the handler's path is a subset of the requested uri.
leihen 3:d6224049b3bf 193 for (it = m_lpHandlers.begin() ; it != m_lpHandlers.end() ; it++) {
leihen 3:d6224049b3bf 194 // check if this entries' path is fully contained at the beginning of the requested path
leihen 3:d6224049b3bf 195 std::string curpth = it->first;
leihen 3:d6224049b3bf 196
leihen 3:d6224049b3bf 197 if (msg.uri.find(curpth) == 0) {
leihen 4:d065642c32cc 198 // firts matching handler found, we just take it and we'll be happy
leihen 3:d6224049b3bf 199 localPath = msg.uri.substr(curpth.length());
leihen 3:d6224049b3bf 200 break;
leihen 3:d6224049b3bf 201 }
leihen 3:d6224049b3bf 202 }
leihen 3:d6224049b3bf 203
leihen 3:d6224049b3bf 204 if (it == m_lpHandlers.end()) {
leihen 3:d6224049b3bf 205 // There is no such handler, so return invalid
leihen 3:d6224049b3bf 206
leihen 3:d6224049b3bf 207 m_pErrorHandler(msg, tcp);
leihen 3:d6224049b3bf 208 INFO("Webrequest left unhandled.");
leihen 3:d6224049b3bf 209 }
leihen 3:d6224049b3bf 210 else {
leihen 4:d065642c32cc 211 // Valid handler was found
leihen 3:d6224049b3bf 212 INFO("Routing webrequest !");
leihen 4:d065642c32cc 213 // Instantiate the handler object (handling will be done from withing the object's constructor
leihen 3:d6224049b3bf 214 HTTPRequestHandler *phdl = (*it->second)(it->first.c_str(), localPath.c_str(), msg, tcp);
leihen 4:d065642c32cc 215 // now we can delete the object, because handling is completed.
leihen 3:d6224049b3bf 216 if (phdl != NULL)
leihen 3:d6224049b3bf 217 delete phdl;
leihen 3:d6224049b3bf 218 }
leihen 3:d6224049b3bf 219 }