VE489 Project

Final project for VE489 SU2020

Requirements

Ubuntu Linux system, Mininet (see project description for details)

Part 2 - TCP File Transfer Server

For convenience, in the following parts, I actually share the finalproject folder between my windows host and guest Linux OS in VirtualBox.

Compile and run

The examples given in the following steps assume the server runs at 10.0.0.1:8001 (h1:8001), and client runs at 10.0.0.2:8002 (h2:8002).

1. Compile using Makefile, so that ftrans is generated

2. Launch the Mininet network topology p1_topo.py

   sudo python p1_topo.py

3. Open two terminals for server and client, respectively

   For example,

   xterm h1 h2

4. Run the server in the current directory

   ./ftrans -s -p <port>

   For example,

   ./ftrans -s -p 8001

5. Create a new directory for client and copy ftrans into it

   For example,

   mkdir client

6. (Optional; For writing the report)

   Capture the packets sent and received on client with tcpdump and dumping the output into a .pcap file

   tcpdump tcp port 8002 -s 65535 -w <filename>.pcap

   Then open the generated .pcap file in Wireshark

7. Run the client in the client/ directory

   ./ftrans -c -h <server's IP/hostname> -sp <server port> -f <filename> -cp <client port>

   For example,

   ./ftrans -c -h 10.0.0.1 -sp 8001 -f 10MB.txt -cp 8002
   ./ftrans -c -h 10.0.0.1 -sp 8001 -f file3.jpg -cp 8002

8. Check the difference between delivered and original files. They are expected to be the same.

   For example,

   diff 10MB.txt client/10MB.txt

Test files

In this project, test files with different sizes are needed. For instance, the following command could generate a test txt file whose size is about 1000KB.

cat /dev/urandom | sed 's/[^a-zA-Z0-9]//g'| strings -n 5 | head -n 160000 > 1000KB.txt

To know the exact file size, windows users may just check the file properties, or use

wc -c <filename>

in Linux to see how many bytes the filename contains.

Part 3 - Reliable Transmission

The 3 subparts in this part share the same format for running. Examples here assume the sender runs at 10.0.0.1:8001 (h1:8001), receiver runs at 10.0.0.2:8002 (h2:8002), and a man-in-the-middle proxy runs at 10.0.0.3:8003 (h3:8003). More details could be found in the project description.

1. Compile using Makefile, so that sr and mitm are generated

2. Launch the Mininet network topology normal_topo.py

   sudo python normal_topo.py

3. Open three terminals for server, client and the man-in-the-middle proxy, respectively

   xterm h1 h2 h3

4. Run the man-in-middle proxy

   ./mitm <shuffle> <loss> <error> <receiver's ip> <receiver's port> <sender's ip> <sender's port>

   For example, to simulate the case of reordering, 5% loss, 5% error

   ./mitm 1 5 5 10.0.0.2 8002 10.0.0.1 8001

5. Create a new directory for receiver and copy sr into it

   For example,

   mkdir recv

   Change directory to recv/, and create a new directory for the output delivered files

   For example,

   mkdir recv_dir

6. Run the receiver in the recv/ directory

   ./sr -r <port> <window size> <recv dir> <log file>

   For example,

   ./sr -r 8002 10 recv_dir/ recv.log

7. Run the sender in the original directory

   ./sr -s <receiver's IP> <receiver's port> <sender's port> <window size> <file to send> <log file>

   For example,

   ./sr -s 10.0.0.3 8003 8001 10 10MB.txt send.log

   In this case, sender actually transmit files to mitm, and mitm relay packets between sender and receiver.

   In addition, to measure the time on the sender side, use

   time ./sr -s 10.0.0.2 8002 8001 10 file3.jpg send.log

   and find the real time printed on the terminal.

8. Check the difference between delivered and original files. They are expected to be the same.

   For example,

   diff 10MB.txt recv/recv_dir/file_0.txt
   diff file3.jpg recv/recv_dir/file_1.txt

   Additionally, view the send.log and recv.log file to see the header information for checking the correctness.

Directory structure

.
├── README.md
├── part2
│   ├── 100B.txt
│   ├── 100KB.txt
│   ├── 10MB.txt               // test files 
│   ├── Makefile
│   ├── dump.pcap              // output file for tcpdump 
│   ├── file3.jpg              // test file 
│   ├── ftrans.cc              // implemention of the TCP file transfer server
│   └── p1_topo.py             // Mininet network topology used in this part 
├── part3
│   ├── part3-1
│   │   ├── 1000KB.txt
│   │   ├── 100KB.txt
│   │   ├── 10MB.txt           // test files  
│   │   ├── Makefile
│   │   ├── SRHeader.h         // definition of SRHeader used in sr.c   
│   │   ├── crc32.h            // crc32 function used in sr.c    
│   │   ├── file3.jpg          // test file
│   │   ├── lossy_topo.py
│   │   ├── mitm.c             // man-in-the-middle (MITM) written by TA 
│   │   ├── normal_topo.py     // Mininet network topology used in this part
│   │   └── sr.c               // implementation of the simple SR
│   ├── part3-2
│   │   ├── 1000KB.txt
│   │   ├── 100KB.txt
│   │   ├── 10MB.txt
│   │   ├── Makefile
│   │   ├── SRHeader.h
│   │   ├── crc32.h
│   │   ├── file3.jpg
│   │   ├── lossy_topo.py
│   │   ├── mitm.c
│   │   ├── normal_topo.py
│   │   └── sr.c
│   └── part3-3
│       ├── 1000KB.txt
│       ├── 100KB.txt
│       ├── 10MB.txt
│       ├── Makefile
│       ├── SRHeader.h
│       ├── crc32.h
│       ├── file3.jpg
│       ├── lossy_topo.py
│       ├── mitm.c
│       ├── normal_topo.py
│       └── sr.c
├── report.pdf                 // report
└── ve489_project.pdf          // project description