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:
Sat Jun 01 16:49:17 2013 +0000
Revision:
6:fe661fa9d18a
Parent:
5:dc88012caef1
Child:
9:c2a1462b9b71
Added DEBUG preprocessor constant to each file.
; Added non-blocking polling function.

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 6:fe661fa9d18a 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 0:7a2421e63e74 14 #define INFO(x, ...) if (m_pDbg) m_pDbg->printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__); else printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__);
leihen 0:7a2421e63e74 15 #define WARN(x, ...) if (m_pDbg) m_pDbg->printf("[HttpServer : WARN]"x"\r\n", ##__VA_ARGS__); else printf("[HttpServer : DBG]"x"\r\n", ##__VA_ARGS__);
leihen 0:7a2421e63e74 16 #define ERR(x, ...) if (m_pDbg) m_pDbg->printf("[HttpServer : ERR]"x"\r\n", ##__VA_ARGS__); else 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 3:d6224049b3bf 26 HTTPServer::HTTPServer(Serial *dbg)
leihen 0:7a2421e63e74 27 {
leihen 3:d6224049b3bf 28 m_pDbg = dbg;
leihen 0:7a2421e63e74 29 m_pSvr = NULL;
leihen 2:8653bbcf7e58 30 m_pErrorHandler = StdErrorHandler;
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 2:8653bbcf7e58 48 sprintf(echoHeader,"HTTP/1.1 404 Fail\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 0:7a2421e63e74 61
leihen 0:7a2421e63e74 62 // Create a new server object
leihen 0:7a2421e63e74 63 m_pSvr = new TCPSocketServer();
leihen 0:7a2421e63e74 64
leihen 0:7a2421e63e74 65 // Bind the local server to the given port
leihen 0:7a2421e63e74 66 if (m_pSvr->bind(port) < 0) {
leihen 0:7a2421e63e74 67 ERR("Failed to bind to port %d\n", port);
leihen 0:7a2421e63e74 68 return -1;
leihen 0:7a2421e63e74 69 }
leihen 0:7a2421e63e74 70 else {
leihen 0:7a2421e63e74 71 INFO("Binding succeeded !\n");
leihen 0:7a2421e63e74 72 }
leihen 0:7a2421e63e74 73
leihen 0:7a2421e63e74 74 // Listen to a maximum of 10 concurrent connections
leihen 0:7a2421e63e74 75 if (m_pSvr->listen(1) < 0) {
leihen 0:7a2421e63e74 76 ERR("Faild to listen !\n");
leihen 0:7a2421e63e74 77 delete m_pSvr;
leihen 0:7a2421e63e74 78 m_pSvr = NULL;
leihen 0:7a2421e63e74 79 return -1;
leihen 0:7a2421e63e74 80 }
leihen 0:7a2421e63e74 81 else {
leihen 0:7a2421e63e74 82 INFO("Listening\n");
leihen 0:7a2421e63e74 83 }
leihen 0:7a2421e63e74 84
leihen 0:7a2421e63e74 85 // set into non blocking operation
leihen 0:7a2421e63e74 86 m_pSvr->set_blocking(false, 100);
leihen 0:7a2421e63e74 87
leihen 0:7a2421e63e74 88 return 0;
leihen 0:7a2421e63e74 89 }
leihen 0:7a2421e63e74 90
leihen 0:7a2421e63e74 91
leihen 6:fe661fa9d18a 92 int HTTPServer::poll(bool blocking)
leihen 0:7a2421e63e74 93 {
leihen 5:dc88012caef1 94 int retval = -1;
leihen 0:7a2421e63e74 95 INFO("Listening for new connection requests.");
leihen 0:7a2421e63e74 96
leihen 0:7a2421e63e74 97 // This thread basically checks if there is a new incoming connection.
leihen 0:7a2421e63e74 98 // If so , a new HTTPConnection is created and the connection thread is started.
leihen 0:7a2421e63e74 99 TCPSocketConnection Clnt;
leihen 0:7a2421e63e74 100
leihen 4:d065642c32cc 101 #ifdef _DEBUG
leihen 0:7a2421e63e74 102 led4 = 1; // Indicate we are waiting for a new connection
leihen 5:dc88012caef1 103 #endif
leihen 6:fe661fa9d18a 104 m_pSvr->set_blocking(blocking);
leihen 5:dc88012caef1 105 retval = m_pSvr->accept(Clnt);
leihen 5:dc88012caef1 106 if (retval > 0) {
leihen 5:dc88012caef1 107 // no connection availale yet, so just return
leihen 5:dc88012caef1 108 #ifdef _DEBUG
leihen 5:dc88012caef1 109 led4 = 0;
leihen 5:dc88012caef1 110 led3 = 0;
leihen 5:dc88012caef1 111 led2 = 0;
leihen 5:dc88012caef1 112 #endif
leihen 5:dc88012caef1 113 return retval;
leihen 5:dc88012caef1 114 }
leihen 5:dc88012caef1 115 if ( retval < 0) {
leihen 0:7a2421e63e74 116 // an error occured
leihen 0:7a2421e63e74 117 ERR("There was an error, Accept returned with an error. Probably the connection to the router was lost. Shutting down server");
leihen 4:d065642c32cc 118 #ifdef _DEBUG
leihen 0:7a2421e63e74 119 led2 = 0;
leihen 4:d065642c32cc 120 #endif
leihen 0:7a2421e63e74 121 m_pSvr->close();
leihen 0:7a2421e63e74 122 delete m_pSvr;
leihen 0:7a2421e63e74 123 m_pSvr = NULL;
leihen 4:d065642c32cc 124 #ifdef _DEBUG
leihen 0:7a2421e63e74 125 led4 = 0;
leihen 0:7a2421e63e74 126 led3 = 1; // ERROR
leihen 0:7a2421e63e74 127 led2 = 0;
leihen 0:7a2421e63e74 128 led1 = 0;
leihen 4:d065642c32cc 129 #endif
leihen 0:7a2421e63e74 130 return -1;
leihen 0:7a2421e63e74 131 }
leihen 0:7a2421e63e74 132 else {
leihen 4:d065642c32cc 133 #ifdef _DEBUG
leihen 0:7a2421e63e74 134 led4 = 0;
leihen 4:d065642c32cc 135 #endif
leihen 0:7a2421e63e74 136 // a new connection was received
leihen 0:7a2421e63e74 137 INFO("Client (IP=%s) is connected !\n", Clnt.get_address());
leihen 0:7a2421e63e74 138 // Start the main connection thread
leihen 4:d065642c32cc 139 #ifdef _DEBUG
leihen 0:7a2421e63e74 140 led3 = 1;
leihen 0:7a2421e63e74 141 led2 = 1;
leihen 4:d065642c32cc 142 #endif
leihen 0:7a2421e63e74 143 HTTPConnection con;
leihen 0:7a2421e63e74 144 int c = con.poll();
leihen 0:7a2421e63e74 145 if (c == 0) {
leihen 1:6b7472d5e9ee 146 // Handle the request
leihen 1:6b7472d5e9ee 147 HandleRequest(con.m_Msg, Clnt);
leihen 0:7a2421e63e74 148 }
leihen 4:d065642c32cc 149 #ifdef _DEBUG
leihen 0:7a2421e63e74 150 led2 = 0;
leihen 0:7a2421e63e74 151 led3 = 0;
leihen 4:d065642c32cc 152 #endif
leihen 0:7a2421e63e74 153 }
leihen 0:7a2421e63e74 154
leihen 0:7a2421e63e74 155 INFO("Leaving polling thread");
leihen 0:7a2421e63e74 156 return 0;
leihen 1:6b7472d5e9ee 157 }
leihen 1:6b7472d5e9ee 158
leihen 3:d6224049b3bf 159 void HTTPServer::HandleRequest(HTTPConnection::HTTPMessage& msg, TCPSocketConnection& tcp)
leihen 3:d6224049b3bf 160 {
leihen 3:d6224049b3bf 161 std::string localPath;
leihen 3:d6224049b3bf 162 std::map<std::string, HTTPRequestHandler*(*)(const char*, const char*, HTTPConnection::HTTPMessage&, TCPSocketConnection&), handlersComp>::const_iterator it;
leihen 3:d6224049b3bf 163
leihen 4:d065642c32cc 164 // Iterate through registered handlers and check if the handler's path is a subset of the requested uri.
leihen 3:d6224049b3bf 165 for (it = m_lpHandlers.begin() ; it != m_lpHandlers.end() ; it++) {
leihen 3:d6224049b3bf 166 // check if this entries' path is fully contained at the beginning of the requested path
leihen 3:d6224049b3bf 167 std::string curpth = it->first;
leihen 3:d6224049b3bf 168
leihen 3:d6224049b3bf 169 if (msg.uri.find(curpth) == 0) {
leihen 4:d065642c32cc 170 // firts matching handler found, we just take it and we'll be happy
leihen 3:d6224049b3bf 171 localPath = msg.uri.substr(curpth.length());
leihen 3:d6224049b3bf 172 break;
leihen 3:d6224049b3bf 173 }
leihen 3:d6224049b3bf 174 }
leihen 3:d6224049b3bf 175
leihen 3:d6224049b3bf 176 if (it == m_lpHandlers.end()) {
leihen 3:d6224049b3bf 177 // There is no such handler, so return invalid
leihen 3:d6224049b3bf 178
leihen 3:d6224049b3bf 179 m_pErrorHandler(msg, tcp);
leihen 3:d6224049b3bf 180 INFO("Webrequest left unhandled.");
leihen 3:d6224049b3bf 181 }
leihen 3:d6224049b3bf 182 else {
leihen 4:d065642c32cc 183 // Valid handler was found
leihen 3:d6224049b3bf 184 INFO("Routing webrequest !");
leihen 4:d065642c32cc 185 // Instantiate the handler object (handling will be done from withing the object's constructor
leihen 3:d6224049b3bf 186 HTTPRequestHandler *phdl = (*it->second)(it->first.c_str(), localPath.c_str(), msg, tcp);
leihen 4:d065642c32cc 187 // now we can delete the object, because handling is completed.
leihen 3:d6224049b3bf 188 if (phdl != NULL)
leihen 3:d6224049b3bf 189 delete phdl;
leihen 3:d6224049b3bf 190 }
leihen 3:d6224049b3bf 191 }