[Solved] COE768 Project-Network File Transfer Application

In this project, you will implement a file transfer application based on TCP_ The server is a concurrent server that can handle multiple file transfer sessions. The client can both upload files to and download files from the server. In addition, the client can request the change of directory and list the files in a given directory. Figure 1 shows the PDU format to be used in the implementation_

size of the Data field_ The data field contains the data, there are eight PDU types_

• ^.1ype This PDU is sent by the client to request a file download. The Data field

contains the file name and the length field indicates the length of the name_

• Type This PDU is sent by the client to request a file upload. The Data field containsthe file name and the length field indicate the length of the name.
• Type R. This PDU is sent by the server to indicate that it is ready
• Type F This PDU contains the file data. The length field indicates the size of the file.
• Type *E This PDU is used to report error. The Data field contains the error message and the length field indicates the size of the message_
• Type ^.P This PDU is sent by the client to request the change of directory_ The Data field contains the directory path name
• Type This PDU is sent by the client to request the list of files in a given directory.The Data field contains the directory path name
• Type This PDU is sent by the server_ The data field contains the list of file names_

Flow Diagrams

Figures 2, 3, 4, 5 and 6 show the PDLT exchange scenarios for the file download, file upload, error reporting, change directory and list directory, respectively.

PDU(0.1ength.filename)PDU(F.length.Data)

Fig 2: File Download

TCP Server

_ _

PD U(U,Iength,filename)

PDU(F,length,Data)

Fig 3: File Upload

TCP Server

PDU(UID.Iength,filename)

PDU(Elength,message)

Fig 4: Error Reporting

Client TCP

PDU(P,length,dir_path)

a.

–⁴

4-

PDU(R,0

Fig 5: Change directory

-____

POU(L,Iength,dir_path)

^–-III

_

PDU(1,1ength,list_of_files) .4-

Fig 6: List Directory