/*********************************************************************
 *
 *                  FTP ServerModule for Microchip TCP/IP Stack
 *
 *********************************************************************
 * FileName:        FTP.c
 * Dependencies:    StackTsk.h
 *                  TCP.h
 * Processor:       PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F
 * Complier:        Microchip C18 v3.02 or higher
 *					Microchip C30 v2.01 or higher
 * Company:         Microchip Technology, Inc.
 *
 * Software License Agreement
 *
 * This software is owned by Microchip Technology Inc. ("Microchip") 
 * and is supplied to you for use exclusively as described in the 
 * associated software agreement.  This software is protected by 
 * software and other intellectual property laws.  Any use in 
 * violation of the software license may subject the user to criminal 
 * sanctions as well as civil liability.  Copyright 2006 Microchip
 * Technology Inc.  All rights reserved.
 *
 * This software is provided "AS IS."  MICROCHIP DISCLAIMS ALL 
 * WARRANTIES, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, NOT LIMITED 
 * TO MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND 
 * INFRINGEMENT.  Microchip shall in no event be liable for special, 
 * incidental, or consequential damages.
 *
 *
 * Author               Date    Comment
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Nilesh Rajbharti     4/23/01  Original        (Rev 1.0)
 * Nilesh Rajbharti     11/13/02 Fixed FTPServer()
 * Howard Schlunder		07/10/06 Added hash printing to FTP client
 * Howard Schlunder		07/20/06 Added FTP_RESP_DATA_NO_SOCKET error message
  ********************************************************************/
#define THIS_IS_FTP

#include <string.h>
#include <stdlib.h>
#include "..\Include\FTP.h"
#include "..\Include\TCP.h"
#include "..\Include\Tick.h"

#include "..\Include\MPFS.h"

#if defined(STACK_USE_FTP_SERVER)


#define FTP_COMMAND_PORT                (21)
#define FTP_DATA_PORT                   (20)
#define FTP_TIMEOUT                     (TICK)((TICK)180 * TICK_SECOND)
#define MAX_FTP_ARGS                    (7)
#define MAX_FTP_CMD_STRING_LEN          (31)

typedef enum _SM_FTP
{
    SM_FTP_NOT_CONNECTED,
    SM_FTP_CONNECTED,
    SM_FTP_USER_NAME,
    SM_FTP_USER_PASS,
    SM_FTP_RESPOND
} SM_FTP;

typedef enum _SM_FTP_CMD
{
    SM_FTP_CMD_IDLE,
    SM_FTP_CMD_WAIT,
    SM_FTP_CMD_RECEIVE,
    SM_FTP_CMD_WAIT_FOR_DISCONNECT
} SM_FTP_CMD;

typedef enum _FTP_COMMAND
{
    FTP_CMD_USER,
    FTP_CMD_PASS,
    FTP_CMD_QUIT,
    FTP_CMD_STOR,
    FTP_CMD_PORT,
    FTP_CMD_ABORT,
    FTP_CMD_UNKNOWN,
    FTP_CMD_NONE,
} FTP_COMMAND;

// Each entry in following table must match with that of FTP_COMMAND enum.
ROM char *FTPCommandString[] =
{
    "USER",                         // FTP_CMD_USER
    "PASS",                         // FTP_CMD_PASS
    "QUIT",                         // FTP_CMD_QUIT
    "STOR",                         // FTP_CMD_STOR
    "PORT",                         // FTP_CMD_PORT
    "ABOR"                          // FTP_CMD_ABORT
};
#define FTP_COMMAND_TABLE_SIZE  ( sizeof(FTPCommandString)/sizeof(FTPCommandString[0]) )


typedef enum _FTP_RESPONSE
{
    FTP_RESP_BANNER,
    FTP_RESP_USER_OK,
    FTP_RESP_PASS_OK,
    FTP_RESP_QUIT_OK,
    FTP_RESP_STOR_OK,
    FTP_RESP_UNKNOWN,
    FTP_RESP_LOGIN,
    FTP_RESP_DATA_OPEN,
    FTP_RESP_DATA_READY,
    FTP_RESP_DATA_CLOSE,
	FTP_RESP_DATA_NO_SOCKET,
    FTP_RESP_OK,

    FTP_RESP_NONE                       // This must always be the last
                                        // There is no corresponding string.
} FTP_RESPONSE;

// Each entry in following table must match with FTP_RESPONE enum
ROM char *FTPResponseString[] =
{
    "220 Ready\r\n",                    // FTP_RESP_BANNER
    "331 Password required\r\n",        // FTP_RESP_USER_OK
    "230 Logged in\r\n",                // FTP_RESP_PASS_OK
    "221 Bye\r\n",                      // FTP_RESP_QUIT_OK
    "500 \r\n",                         // FTP_RESP_STOR_OK
    "502 Not implemented\r\n",          // FTP_RESP_UNKNOWN
    "530 Login required\r\n",           // FTP_RESP_LOGIN
    "150 Transferring data...\r\n",     // FTP_RESP_DATA_OPEN
    "125 Done\r\n",                    	// FTP_RESP_DATA_READY
    "\r\n226 Transfer Complete\r\n",    // FTP_RESP_DATA_CLOSE
	"425 Can't create data socket.  Increase MAX_SOCKETS.\r\n",	//FTP_RESP_DATA_NO_SOCKET
    "200 Ok\r\n"                        // FTP_RESP_OK
};


static union
{
    struct
    {
        unsigned char bUserSupplied : 1;
        unsigned char bLoggedIn: 1;
    } Bits;
    BYTE Val;
} FTPFlags;


static TCP_SOCKET       FTPSocket;      // Main ftp command socket.
static TCP_SOCKET       FTPDataSocket;  // ftp data socket.
static WORD_VAL         FTPDataPort;    // ftp data port number as supplied by client

static SM_FTP           smFTP;          // ftp server FSM state
static SM_FTP_CMD       smFTPCommand;   // ftp command FSM state

static FTP_COMMAND      FTPCommand;
static FTP_RESPONSE     FTPResponse;

static char             FTPUser[FTP_USER_NAME_LEN];
static char             FTPString[MAX_FTP_CMD_STRING_LEN+2];
static BYTE             FTPStringLen;
static char             *FTP_argv[MAX_FTP_ARGS];    // Parameters for a ftp command
static BYTE             FTP_argc;       // Total number of params for a ftp command
static TICK             lastActivity;   // Timeout keeper.


static MPFS             FTPFileHandle;

// Private helper functions.
static void ParseFTPString(void);
static FTP_COMMAND ParseFTPCommand(char *cmd);
static void ParseFTPString(void);
static BOOL ExecuteFTPCommand(FTP_COMMAND cmd);
static BOOL PutFile(void);
static BOOL Quit(void);


// Uncomment following line if ftp transactions are to be displayed on
// RS-232 - for debug purpose only.

//#define FTP_SERVER_DEBUG_MODE
#define FTP_PUT_ENABLED

#if defined(FTP_SERVER_DEBUG_MODE)
static USARTPut(BYTE c)
{
    while( !TXSTA_TRMT);
    TXREG = c;
}
#else

#define USARTPut(a)

#endif


/*********************************************************************
 * Function:        void FTPInit(void)
 *
 * PreCondition:    TCP module is already initialized.
 *
 * Input:           None
 *
 * Output:          None
 *
 * Side Effects:    None
 *
 * Overview:        Initializes internal variables of FTP
 *
 * Note:
 ********************************************************************/
void FTPInit(void)
{
    FTPSocket       = TCPListen(FTP_COMMAND_PORT);
    smFTP           = SM_FTP_NOT_CONNECTED;
    FTPStringLen    = 0;
    FTPFlags.Val    = 0;
    FTPDataPort.Val = FTP_DATA_PORT;
}


/*********************************************************************
 * Function:        void FTPServer(void)
 *
 * PreCondition:    FTPInit() must already be called.
 *
 * Input:           None
 *
 * Output:          Opened FTP connections are served.
 *
 * Side Effects:    None
 *
 * Overview:
 *
 * Note:            This function acts as a task (similar to one in
 *                  RTOS).  This function performs its task in
 *                  co-operative manner.  Main application must call
 *                  this function repeatdly to ensure all open
 *                  or new connections are served on time.
 ********************************************************************/
BOOL FTPServer(void)
{
    BYTE v;
    TICK currentTick;

    if ( !TCPIsConnected(FTPSocket) )
    {
        FTPStringLen    = 0;
        FTPCommand      = FTP_CMD_NONE;
        smFTP           = SM_FTP_NOT_CONNECTED;
        FTPFlags.Val    = 0;
        smFTPCommand    = SM_FTP_CMD_IDLE;
        return TRUE;
    }

    if ( TCPIsGetReady(FTPSocket) )
    {
        lastActivity    = TickGet();

        while( TCPGet(FTPSocket, &v ) )
        {
            USARTPut(v);
            FTPString[FTPStringLen++]   = v;
            if ( FTPStringLen == MAX_FTP_CMD_STRING_LEN )
                FTPStringLen            = 0;
        }
        TCPDiscard(FTPSocket);


        if ( v == '\n' )
        {
            FTPString[FTPStringLen]     = '\0';
            FTPStringLen                = 0;
            ParseFTPString();
            FTPCommand                  = ParseFTPCommand(FTP_argv[0]);
        }
    }
    else if ( smFTP != SM_FTP_NOT_CONNECTED )
    {
        currentTick = TickGet();
        currentTick = TickGetDiff(currentTick, lastActivity);
        if ( currentTick >= FTP_TIMEOUT )
        {
            lastActivity                = TickGet();
            FTPCommand                  = FTP_CMD_QUIT;
            smFTP                       = SM_FTP_CONNECTED;
        }
    }

    switch(smFTP)
    {
    case SM_FTP_NOT_CONNECTED:
        FTPResponse = FTP_RESP_BANNER;
        lastActivity = TickGet();
        /* No break - Continue... */