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.

Revision:
3:d6224049b3bf
Parent:
2:8653bbcf7e58
Child:
4:d065642c32cc
--- a/HTTPConnection.h	Sun May 26 23:22:36 2013 +0000
+++ b/HTTPConnection.h	Tue May 28 01:56:14 2013 +0000
@@ -1,4 +1,25 @@
 /* HTTPConnection.h */
+/*
+Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de)
+ 
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+ 
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
 #ifndef __HTTPConnection_H__
 #define __HTTPConnection_H__
 
@@ -10,60 +31,76 @@
 
 class HTTPServer;
 
-enum HTTPRequestType
+/** Type HTTPRequestType enumerates request types
+*/
+typedef enum 
 {
-    HTTP_RT_GET,
-    HTTP_RT_POST,
-    HTTP_RT_PUT,
-    HTTP_RT_OPTIONS,
-    HTTP_RT_HEAD,
-    HTTP_RT_DELETE,
-    HTTP_RT_TRACE,
-    HTTP_RT_CONNECT
-};
+    HTTP_RT_GET,        /*!< GET request */
+    HTTP_RT_POST,       /*!< POST request */
+    HTTP_RT_PUT,        /*!< PUT request */
+    HTTP_RT_OPTIONS,    /*!< OPTIONS request */
+    HTTP_RT_HEAD,       /*!< HEAD request */
+    HTTP_RT_DELETE,     /*!< DELETE request */
+    HTTP_RT_TRACE,      /*!< TRACE request */
+    HTTP_RT_CONNECT     /*!< CONNECT request */
+} HTTPRequestType;
 
-struct HTTPMessage
-{
-    HTTPRequestType             request;
-    std::string                 uri;
-    std::string                 version;
-    std::map<string, string>    headers;
-};
 
 /** class HTTPConnection, encapsulates one connection being made throught the HTTPServer
  *
  */
 class HTTPConnection {
     public:
-    /** public constructor
-     *
-     */
-    HTTPConnection ();
-    ~HTTPConnection();
-    
-    /** function to close this connection. To be called from internally.
-    */
-    void close();
-    
-    /** query if this connection is closed and can be deleted.
-    @returns true if connection is closed.
-    */
-    bool is_closed();
-    
-    /**
-    Polling function
-    @returns -1 if connection is not required anymore. Can happen if a fault occured or if the connection is not needed anymore.
-    */
-    int poll();
+        
+        /** HTTPMessage contains all the details of the request received by external HTTP client.
+        */
+        typedef struct 
+        {
+            /** Specifies the request type received
+            */
+            HTTPRequestType             request;
+            /** The uri associated with the request.
+            */
+            std::string                 uri;
+            /** Contains the HTTP/1.1 or HTTP/1.0 version requested by client.
+            */
+            std::string                 version;
+            /** Map of headers provided by the client in the form <HeaderName>:<HeaderValue>
+            */
+            std::map<std::string, std::string>    headers;
+        } HTTPMessage;
+        /** Public constructor for HTTPConnection objects.
+         *
+         */
+        HTTPConnection ();
+        
+        /** Destructor for HTTPConnection objects.
+        *
+        */
+        ~HTTPConnection();
+        
+        /** Query if this connection is already closed and can be deleted.
+        @returns true, if connection is closed.
+        */
+        bool is_closed();
+        
+        /** Polling function for the connection.
+        * @returns -1 if connection is not required anymore. In the current version of this library this should be the normal case. This may change in future versions.
+        */
+        int poll();
     
     protected:
+        
+        /** Function to close this connection. To be called from internally.
+        */
+        void close();
+
         friend class HTTPServer;
                         
         TCPSocketConnection m_Tcp;
         HTTPMessage m_Msg;
-        
         int parse(char *buffer);
-        int parseHeader(const char *buffer);
+        int parseHeader(char *buffer);
         int receiveHeaders(const char* buffer, int nBuffSize);
         int receiveLine(char* szLine, int nMaxLen, int nTimeout = -1, char szLineTerm = '\n');