File content as of revision 17:69ff00ce39f4:

#ifndef SW_HTTPSERVER_H
#define SW_HTTPSERVER_H
#include "mbed.h"
//#include "MODSERIAL.h"    // would like to hook in mod serial for higher performance, less blocking
#include "Wifly.h"
#include "TCPSocketServer.h"
#include "TCPSocketConnection.h"

#ifdef MODSERIAL_H
#define PC MODSERIAL
#else
#define PC Serial
#endif

/// This is the default buffer size used to send files. You might size
/// this to be equal or less than the payload size of 1460 bytes.
/// See User Manual 3.6.1.
#define FILESEND_BUF_SIZE 1460


/// MAX_HEADER_SIZE is the default size to contain the largest header.
/// This is the size of the URL and query string, and also all the
/// other header information about the client. This can be
/// a couple of K, larger if you have big forms as it includes the
/// form data that is submitted.
#define MAX_HEADER_SIZE 1000


/// HTTPServer is a simple web server using the WiFly module.
///
/// While simple, it is a capable, web server. The basic mode
/// of operation is for it to serve static web pages from an available
/// file system.
///
/// The default page is index.htm (compile time defined)
/// standard support to serve a number of standard file types;
/// gif, jpg, jpeg, ico, png, zip, gz, tar, txt, pdf, htm, html
/// (this list is also compile time defined)
///
/// It can also serve dynamically generated pages, and therefore
/// respond to form submission. Through the dynamic interface it is
/// then quite easy to interact with the hardware, reading the inputs
/// or signaling outputs.
///
/// @code
///     HTTPServer svr(&wifly, HTTP_SERVER_PORT, "/local/", 15, 30, 10, &pc);
///     svr.RegisterHandler("/dyn1", SimpleDynamicPage);
///     while (true)
///        {
///        svr.Poll();   // this is non blocking process, but variable execution
///        }
/// @endcode
///
/// This web server used nweb as a starting point, but expanded well beyond there.
///  http://www.ibm.com/developerworks/systems/library/es-nweb/sidefile1.html
///
/// @note This server uses a modified version of the mbed WiflyInterface - there
/// were a number of performance issues identified and resolved in the local version.
///
/// Given: scheme://server:port/path?query_string#fragment_id
/// @li scheme is "http"
/// @li server is whatever IP the server has
/// @li port is the registered port
/// @li /path is the reference to the file (actual or logical) on the server
/// @li query_string is any combination of name=value pairs
/// @li fragment_id is a reference to an anchor on the page
///
/// Features:
/// @li Serves static pages from a file system. Many normal filetypes are
///     supported.
/// @li Compile time configurable for the "default" file, typically index.htm.
/// @li Provides a registration interface for dynamically generated pages that
///     can then interact with other hardware.
/// @li Revised to be Non-blocking, however the execution time is variable
///     depending on the actions being performed and can span hundreds of msec.
///
/// Limitations:
/// @li Supports only a single connection at a time.
/// @li Rapid requests for page objects (e.g. embedded images) are lost. Still
///     working to understand this issue.
///
/// ToDo:
/// @li A web page with served objects (img src=...) is rarely served properly. It
///       might trace to forcing the connection to close, but not yet sure.
///       Explore "Set Uart Rx Data Buffer" in WiFly manual 2.3.65
/// @li hunt down lengthy operations - there seems to be a long timeout somewhere.
/// @li parse the header similar to the query string, and then make
///       those parameters accessible - perhaps like environment vars.
/// @li move part of the POST method handler to the registered handler, so
///       it can decide if it should allocate the needed memory.
/// @li Add password capability to some web pages
/// @li transform the pc serial interface to a log interface, which might
///       be more useful.
/// @li Add ability to put WiFly in AP mode and then configuration pages
///       to find and join a network.
/// @li Add ability to change/update SW in the WiFly module
/// @li Add ability to upload a new application to the mbed
///
/// History:
/// @li 20130530 Initial version
/// @li 20130601 Renamed ip_process to Poll
/// @li 20130617 Cleaned up some of the documentation changes
/// @li 20130623 Make it non-blocking. "Poll" takes a variable amount
///              of time, based on whether it is idle, or how much it
///              has to do.
///
/// @note Copyright © 2013 by Smartware Computing, all rights reserved.
///     Individuals may use this application for evaluation or non-commercial
///     purposes. Within this restriction, changes may be made to this application
///     as long as this copyright notice is retained. The user shall make
///     clear that their work is a derived work, and not the original.
///     Users of this application and sources accept this application "as is" and
///     shall hold harmless Smartware Computing, for any undesired results while
///     using this application - whether real or imagined.
///
/// @author David Smart, Smartware Computing
///
class HTTPServer
{
public:
    /**
    * name-value pairs for parameters
    */
    typedef struct NAMEVALUE {
        char * name;
        char * value;
    } namevalue;

    /**
    * Indicates the purpose of the Handler callback
    *
    * Application code in a dynamic page uses this to determine the state
    * and therefore the needed operation to be performed.
    *
    * @code
    * bool SimpleDynamicPage(HTTPServer *svr, HTTPServer::CallBackType type, 
    *                        const char * path, const HTTPServer::namevalue *queryParams, 
    *                        int queryParamCount) {
    *     char buf[100];
    *     bool ret = false;
    *
    *     switch (type) {
    *         case HTTPServer::SEND_PAGE:
    *             svr->header(200, "OK", "Content-Type: text/html\r\n");
    *             svr->send("<html><head><title>Dynamic Page</title></head>\r\n");
    *             svr->send("<body>\r\n");
    *             svr->send("This page was generated dynamically. Create your own name=value pairs on the URL "
    *                       "which uses the GET method.<br/>\r\n");
    *             sprintf(buf, "%d parameters passed to {%s}:<br/>\r\n", queryParamCount, path);
    *             svr->send(buf);
    *             for (int i=0; i<queryParamCount; i++) {
    *                 sprintf(buf, "%d: %s = %s<br/>\r\n", i, queryParams[i].name, queryParams[i].value);
    *                 svr->send(buf);
    *             }
    *             svr->send("<br/><a href='/'>back to main</a></body></html>\r\n");
    *             ret = true;
    *             break;
    *         case HTTPServer::CONTENT_LENGTH_REQUEST:
    *             ret = true;
    *             break;
    *         case HTTPServer::DATA_TRANSFER:
    *             ret = true;
    *             break;
    *         default:
    *             ret = false;
    *             break;
    *     }
    *     return ret;
    * }
    * @endcode
    */
    typedef enum CALLBACKTYPE {
        CONTENT_LENGTH_REQUEST, ///< ask the client if they wish to accept the data, typically from a POST event
        DATA_TRANSFER,          ///< not currently used, may allow "chunking" the data to the client
        SEND_PAGE,              ///< the activated method should now send the page
    } CallBackType;

    /**
    * This is the prototype for custom handlers that are activated via a callback
    *
    * This callback gets overloaded for a few purposes, which can be identified by the \see CallBackType parameter
    * @li SEND_PAGE - the callback should now send the html page, using as many svr->send() as needed.
    *       When the callback returns, it should always indicate true.
    * @li CONTENT_LENGTH_REQUEST - the server is asking the callback if it wants to receive the message,
    *        which may require significant memory. If the request is accepted, true should be returned.
    *        If the request is denied, false should be returned.
    *
    * @param svr is a handle to this class, so the callback has access to member functions
    * @param queryParams is a pointer to an array of name value pairs
    * @queryParamCount is the number of parameters.
    * @return true if command was accepted
    */
    typedef bool (* Handler)(HTTPServer * svr, CallBackType type, const char *path, const namevalue *queryParams, int queryParamCount);

    /**
    * Create the HTTPServer object.
    *
    * @param wifly is the serial port with the wifly interface.
    * @param port is the optional parameter for the port number to use, default is 80.
    * @param webroot is a file system path to the root folder for the web space.
    * @param maxheaderParams defines the maximum number of parameters to extract from a header (Host: 192..\r\nConnection: keep-alive\r\n...)
    * @param maxqueryParams defines the maximum number of query parameters to a dynamic function (and the memory to support them).
    * @param maxdynamicpages defines the maximum number of dynamic pages that can be registered.
    * @param pc is the serial port for debug information (I should transform this to a log interface)
    * @param allocforheader is the memory allocation to support the largest expected header from a client
    * @param allocforfile is the memory allocation to support sending a file to the client. This is typically sized to fit
    *        an ethernet frame.
    */
    HTTPServer(Wifly * wifly, int port = 80, const char * webroot = "/", int maxheaderParams = 15, int maxqueryParams = 30, int maxdynamicpages = 10,
               PC * pc = NULL, int _allocforheader = MAX_HEADER_SIZE, int _allocforfile = FILESEND_BUF_SIZE);

    /**
    * Destructor, which can clean up memory.
    */
    ~HTTPServer();

    /**
    * The process to call whenever there is free time, as this basically does
    * all the work to monitor for connections and handle replies.
    *
    * 20130601 Renamed from ip_process to Poll
    */
    void Poll();

    /**
    * Send typical header data, and some optional data back to the client.
    *
    * This forms and sends the typical header back to the client. It may also send
    * optional data (which must end with "\r\n"). It then sends the second newline
    * sequence that signals the end of the header.
    *
    * @param code is the optional return code; 200 = OK, if not provided then 404 = Not found is returned
    * @param code_text is the text to align with the code (e.g. 404, "Not Found")
    * @param content_type is a pointer to "Content-Type: text/html\r\n" (for example)
    * @param optional_text is a pointer to any other text that is part of the header, which must
    *        have \r\n termination.
    */
    void header(int code = 404, const char * code_text = "Not Found", const char * content_type = NULL, const char * optional_text = NULL);

    /**
    * Send text to the client
    *
    * This sends the specified text to the client. If the number of bytes is not set,
    * then it calculates the number of bytes as a string. For binary transfers, the
    * number of bytes to send is required for proper operation.
    *
    * @param msg is the text string to send
    * @param bytes is the number of bytes to send. If not set, then strlen is calculated.
    */
    void send(const char * msg, int bytes = -1);

    /**
    * Send a referenced file to the client, including the header
    *
    * This sends a file from the filesystem to the client. It must be of a supported type
    * in order to properly create the header.
    *
    * @param filename is the fully qualified path and filename
    * @param filetype is the header information (e.g. "Content-Type: application/pdf")
    * @return true if it thinks it sent ok, false otherwise.
    */
    bool SendFile(const char * filename, const char * filetype);

    /**
    * register a handler for a specific URL.
    *
    * This api lets you register a dynamic handler in the web server. This is
    * most useful for interactive web pages, rather than simply serving static
    * pages.
    *
    * @code
    *
    *   ...
    *   svr.RegisterHandler("/dyn1", SimpleDynamicPage);svr.RegisterHandler("/dyn1", SimpleDynamicPage);
    *   ...
    *
    *   bool SimpleDynamicPage(HTTPServer *svr, HTTPServer::CallBackType type, const char * path, const HTTPServer::namevalue *queryParams, int queryParamCount) {
    *       char buf[100];
    *       bool ret = false;
    *
    *       switch (type) {
    *           case HTTPServer::SEND_PAGE:
    *               svr->header(200, "OK", "Content-Type: text/html\r\n");
    *               svr->send("<html><head><title>Dynamic Page</title></head>\r\n");
    *               svr->send("<body>\r\n");
    *               svr->send("This page was generated dynamically. Create your own name=value pairs on the URL "
    *                         "which uses the GET method.<br/>\r\n");
    *               sprintf(buf, "%d parameters passed to {%s}:<br/>\r\n", queryParamCount, path);
    *               svr->send(buf);
    *               for (int i=0; i<queryParamCount; i++) {
    *                   sprintf(buf, "%d: %s = %s<br/>\r\n", i, queryParams[i].name, queryParams[i].value);
    *                   svr->send(buf);
    *               }
    *               svr->send("Stats:<br/>\r\n");
    *               sprintf(buf,"Free memory space: %d<br/>\r\n", Free());
    *               svr->send(buf);
    *               sprintf(buf,"Max Header size: %d<br/>\r\n", svr->GetMaxHeaderSize());
    *               svr->send(buf);
    *               svr->send("<br/><a href='/'>back to main</a></body></html>\r\n");
    *               ret = true;
    *               break;
    *           case HTTPServer::CONTENT_LENGTH_REQUEST:
    *               ret = true;
    *               break;
    *           case HTTPServer::DATA_TRANSFER:
    *               ret = true;
    *               break;
    *           default:
    *               ret = false;
    *               break;
    *       }
    *       return ret;
    *   }
    * @endcode
    *
    * @param path to register
    * @param callback of type Handler
    * @return true if successfully registered
    */
    bool RegisterHandler(const char * path, Handler callback);

    /**
    * determine if the named file is a supported type (htm, html, jpg, etc)
    *
    * if you pass in a filename, it will attempt to extract the extension
    * and compare that to the list of supported file types. If it finds a
    * match, then it will return a pointer to the content-type string.
    *
    * @code
    *   fType = GetSupportedType("mypix.jpg");
    *   if (fType) {
    *       ...
    * @endcode
    *
    * @param filename is the filename to test, based on the extension
    * @return pointer to a Content-Type string if supported, or NULL if not.
    */
    const char * GetSupportedType(const char * filename);

    /**
    * search the available parameters for 'name' and if found, return the 'value'
    *
    * After the querystring is parsed, the server maintains an array of
    * name=value pairs. This Get function will search for the passed in name
    * and provide access to the value.
    *
    * @code
    * BusOut leds(LED1,LED2,LED3,LED4);
    * ...
    * leds = atoi(svr->GetParameter("leds"));
    * @endcode
    *
    * @param name is the name to search for
    * @return pointer to the value, or NULL
    */
    const char * GetParameter(const char * name);

    /**
    * Parse the text string into name=value parameters.
    *
    * This will directly modify the referenced string. If there is a
    * #fragment_id on the end of the string, it will be removed.
    *
    * @param pString is a pointer to the string.
    */
    void ParseParameters(char * pString);

    /**
    * Unescape string converts a coded string "in place" into a normal string.
    *
    * A query string will have a number of characters replaced for communication
    * which includes spaces, quotes, question marks and more. Most of them
    * will be replaced with a %xx format, where xx is the hex code for the
    * character. Since the string will only get shorter when this happens
    * the operation is performed in place.
    *
    * this    "This%20is%20a%20question%3F%20and%20an%20answer."
    *
    * becomes "This is a question? and an answer."
    *
    * @note '+' is another form of space, so is converted to a space before the %xx
    *
    * @param encoded string to be converted
    */
    void UnescapeString(char * encoded);

    /**
    * Get the IP address of the remote node to which we are connected.
    *
    * This will get the IP address of the remote node to which we are
    * currently connected. This is written into the buffer in
    * "192.168.100.234" format. If the buffer size is note >= 16 bytes,
    * it will set the buffer to null.
    *
    * @note This switches the module into, and out of, command mode
    *          which has quite a time penalty.
    *
    * @param str is the string to write the address into, which should be at
    *        least as large as "192.168.100.203" (16-bytes).
    * @param strSize of the str buffer must be >=16, so it will not buffer overrun.
    * @returns true if it succeeded, false otherwise
    */
    bool GetRemoteAddr(char * str, int strSize);

    /**
    * This is used to force a connection to close.
    *
    * This switches the module into command mode, performs the close,
    * then switches it back to data mode. So, this is a time-expensive
    * command.
    *
    * @returns true if successful
    */
    bool close_connection();

    /**
    * Diagnostic to get the size of the largest header.
    *
    * This is a diagnostic function, so you can resize the allocated
    * buffer for your application. With proper sizing, more of the
    * system memory is available for your application.
    *
    * @code
    * sprintf(buf,"Max Header size: %d<br/>\r\n", svr->GetMaxHeaderSize());
    * svr->send(buf);
    * @endcode
    *
    * @returns size in bytes of the larger header measured.
    */
    int GetMaxHeaderSize();

    /**
    * Get a value from the http header, if it exists.
    *
    * @param hdr is the string to search for (e.g. "Content-Length")
    *
    * @returns pointer to the value associated with that header.
    * @returns NULL if the header is not found.
    */
    const char * GetHeaderValue(const char * hdr);

    /**
    * Performance parameter
    */
    typedef struct SW_PERFPARAM {
        unsigned long long TotalTime_us;
        unsigned long Samples;
        unsigned long MaxTime_us;
    } SW_PerformanceParam;

    /**
    * Performance metrics
    */
    typedef struct SW_PERFDATA {
        SW_PerformanceParam ConnectionAccepted;
        SW_PerformanceParam HeaderParsed;
        SW_PerformanceParam ResponseSent;
        SW_PerformanceParam ConnectionClosed;
        //SW_PerformanceParam SendFile;
    } SW_PerformanceData;

    /**
    * Get performance metrics from the web server.
    *
    * This is a diagnostic function, and gathers data on the internal
    * performance of the server, as it works various actions.
    *
    * @param p is a pointer to a SW_PerformanceData structure to be populated
    */
    void GetPerformanceData(SW_PerformanceData * p);

    /**
    * Reset performance metrics.
    */
    void ResetPerformanceData();
    
    /**
    * Get performance clock
    */
    unsigned int GetPerformanceClock();

    /**
    * Get the underlying wifly object.
    *
    * This lets you get to the underlying wifly object in order to
    * interact with it.
    *
    * @code
    * HTTPServer svr(&wifly, HTTP_SERVER_PORT, "/local/", 15, 30, 10, &pc);
    * ...
    * svr->GetWifly()->getWiflyVerString()
    * @endcode
    *
    * returns the wifly option.
    */
    Wifly * GetWifly() {
        return wifly;
    };

private:
    Wifly * wifly;
    char * webroot;
    PC * pc;
    TCPSocketServer * server;
    TCPSocketConnection client;
    char * rewriteWithDefaultFile(char * queryString);
    char * rewritePrependWebroot(char * queryString);
    
    namevalue *queryParams;          // Query Parameters from the URL this=that&sky=blue&...
    int maxqueryParams;
    int queryParamCount;
    
    namevalue *headerParams;    // Header params Host: 192.168...\r\nConnection: keep-alive\r\n...
    int maxheaderParams;
    int headerParamCount;
    
    int maxheaderbytes;
    char * headerbuffer;
    int headerbuffersize;

    Timer PerformanceTimer;
    /**
    * Records performance data
    *
    * This will take a pointer to a SW_PerformanceParam, and it will
    * take the time when the performance measurement started. It locally
    * accesses the current time to measure the elapsed.
    *
    * @param param is the performance parameter to update
    * @param value is the reference time.
    * @returns the current time which may be used as the reference time
    *          for further measurements.
    */
    unsigned int RecordPerformanceData(SW_PerformanceParam * param, unsigned int value);
    SW_PerformanceData perfData;

    typedef struct HANDLER {
        char * path;
        Handler callback;
    } handler;
    int maxdynamicpages;
    handler *handlers;
    int handlercount;

    char * queryType;
    char * queryString;
//    char * hostString;
//    char * contentLength;
//    char * contentType;
//    char * authorization;
    char * postQueryString;

    /**
    *  Extract the parameter from the record, by searching for the needle in the haystack.
    *
    *  The parameter of interest follows the needle, and may be ' ' delimited
    *  Can damage haystack while processing it.
    *
    * @param haystack is the record to search
    * @param needle is the text to search for, which precedes the text to return
    * @param string is the text following the needle
    * @return true if it extracted something successfully
    */
    bool Extract(char * rec, char * needle, char ** string);

    void SendResponse();
    bool ParseHeader(char * bPtr);
    bool CheckDynamicHandlers();

    int HexCharToInt(char c);
    char HexPairToChar(char * p);
};
#endif //SW_HTTPSERVER_H