weiranfu / simple-ftp

A simple FTP protocol implemented with UDP and Go-back-N

simple-ftp

Transfer file from one host to another.

Simple FTP uses UDP to send packets, and Go-back-N automatic repeat request (ARQ) schema to support a reliable data transfer service.

Architecture

Simple FTP client will buffer data into Go-back-N segments, and send these segments in UDP segments to Simple FTP server.

Go-back-N Segment

Go-back-N segment has a header and Maximum Segment Size (MSS) bytes data.

The header of the segment contains three fields:

• a 32-bit sequence number
• a 16-bit checksum of the data & header part
• a 16-bit segment type field

Segment type field:
0101010101010101 means data packet, 1010101010101010 means ACK packet.

Build from source

Prerequisites

Install Java & Maven:

• JDK 8+
• Maven version 3.x

Other dependencies

picocli are required.

Download the source

$ git clone https://github.com/weiranfu/simple-ftp.git

$ cd simple-ftp/

Build the source

$ mvn clean install

How to run

At simple-ftp/ folder

echo "alias ftp-server='java -cp $PWD/target/simple-ftp-1.0-SNAPSHOT-jar-with-dependencies.jar SimpleFTPServer'" >> ~/.bashrc

echo "alias ftp-client='java -cp $PWD/target/simple-ftp-1.0-SNAPSHOT-jar-with-dependencies.jar SimpleFTPClient'" >> ~/.bashrc

source ~/.bashrc

Run the FTP Server

$ ftp-server -p <port number> -f <file path> -P <loss posibility>

Run the FTP Client

$ ftp-client -h <hostname> -p <port number> -f <file path> -w <window size> -m <MSS>

See ftp-server --help and ftp-client --help for more information.

License

MIT