This is myftp 0.2.0 - Circa 1998

Author     : c9811014 - Vikas. Desai 

Contents   :
	This package contains the myftp client and server a subset of the ftp
 protocol.

Compiling  :
		a makefile is included in the package. just running make builds 	both the 'server' and the 'client' for MYFTP.

		just the "server" could be built by running make server.

		just the "client" could be built by running make client.

Running    :
		The server accepts a single optional commandline parameter which 	is the port number to which the server will listen for client connection	. If the parameter is not specified the server listens on a 
	DEFAULT PORT 21000.
	e.g. 
		./server 12345  #server will listen on port 12345
		./server 	#server will listen on port 21000

		The myftp client command prompt looks like "myftp>"
		The client accepts two optional commandline parameters which are
	the server ip/name and the port number. both the parameters are optional
	. If only the server ip/name is specified the client will try to connect
	to a ftp server on that ip/name on port 21000. If no commandline 
	parameters are given the client goes to a myftp prompt from where a 
	connection could be made to a server using the "open" command.

		Typing "help" on the myftp prompt gives a simple help output.

Description:
	The protocol implemented in myftp is based on RFC 959.
	The following diagram shows the structure of ftp as implemented in
 myftp. 
                                            -------------
                                            |/---------\|
                                            ||   User  ||    --------
                                            ||Interface|<--->| User |
                                            |\----^----/|    --------
                  ----------                |     |     |
                  |/------\|  FTP Commands  |/----V----\|
                  ||Server|<---------------->|   User  ||
                  ||  PI  ||   FTP Replies  ||    PI   ||
                  |\--^---/|                |\----^----/|
                  |   |    |                |     |     |
      --------    |/--V---\|      Data      |/----V----\|    --------
      | File |<--->|Server|<---------------->|  User   |<--->| File |
      |System|    || DTP  ||   Connection   ||   DTP   ||    |System|
      --------    |\------/|                |\---------/|    --------
                  ----------                -------------

                  Server-FTP                   USER-FTP

				FTP Structure
				=============

	The explanation that follows is with respect to this diagram.
	The files contained in this package and their descriptions and
 functionality are as follows:

	The package is in tar.gz format in file myftp.tar.gz.

 README : This file.

 CLIENT CODE
 -----------
 ui.c   : This file implements the User Interface for the client.
		It shows the prompt to the user and validates the user input.
	It then calls the functions from the file pi.c which is explained later.
	This file defines an array 'avail_comm' of structures 'command_tag'
	which holds all the commands supported by myftp client. this file also
	contains functions required for parsing and manipulating the responses
	and return codes of the server.

 ui.h   : The include file for ui.c
		defines values for constants used for commands.

 pi.c   : This file implements the Protocol Interface for the client.
		This file contains functions which implement the CLIENT side of
	the FTP protocol.  This functions are called from ui.c. each command is 
	normally mapped to a function which takes care of sending the command 
	and receiving and decoding/parsing the server response. The funtions 
	return a value to the ui.c funtions stating success or failure. 
	A global variable 'status' is defined which maintains the current state 
	of the ftp client with respect to the server.

 pi.h   : The include file for pi.c
		defines the various status of the client.

 SERVER CODE
 -----------

 server.c : This file implements the Protocol Interface for the server.
		This file contains functions which implement the SERVER side of 
	the FTP protocol. The function run_ftp() creates a listening socket 
	which waits for client connections. after accepting a connection it 
	forks and the control is passed to the command_loop() function which
	reads the clients requests and sends responses and data as required.
	A global variable 'status' maintains the status of the server.
		User validation is done by the server by comparing the username
	and password sent by the client with the data in the "passwd" file. The
	passwd file must be in the same directory as the server. The fields in
	the passwd file are similar to the fields in the /etc/passwd file except
	that the password field is not encrypted.

 server.h : The include file for server.c
		defines the server states and commands.

 COMMON CODE
 -----------

 comm.c   : This file contains the common SOCKET code used by both server and 
	client of myftp.
		This file mainly contains the calls to socket api.

	Function accept_connection() accepts connection.

	Function create_listen_socket() creates a socket bind it to a specific
	port and interface if specified and sets the SO_REUSEADDR option for the
	socket and then calls listen on the socket.

	Function get_data() calls read_write_data() to get data from the 
	connection.

	Function put_data() calls read_write_data() to send data thru the
	connection.

	Function get_data_connection_info() converts data received with PORT 
	command to ip address and port number.

	Function get_port_info() returns the port info in a string format to
	be sent with the PORT command.

	Function get_reply() reads a response from the connection.

	Function open_sock_connection() calls connect for given server and port
	and populates a connection structure with the information.

	Function read_write_data() called by get_data() and put_data() reads 
	data from one file descriptor and write it to another one till EOF is 
	encountered on the first.

	Function send_request()  sends a request string over a connection.

 makefile : make rules for the myftp server and client.

 passwd   : file to hold passwords. Just the first two fields are important. But
	they should be ":" seperated.