Sniffer

Program for monitoring network packets

sniffer is listening by default with filter:

• Interface: lo
• Protocol: UDP
• Port: 1234

And search for messages of two types:

Type 1

Type	Enrollment	Name Lenght	Name
1 Byte	8 Bytes	2 Bytes	According to Name Lenght

Type 2

Type	Enrollment
1 Byte	8 Bytes

Download libpcap

sudo apt-get install libpcap-dev

Compiling

# Compiling sniffer
gcc sniffer.c -lpcap -o sniffer

# Compiling sender
gcc sender.c -o sender

Running

For the sniffer add the interface in which you will be listening as a parameter

And for the sender add: out interface, destination mac, destination ip, port, enrollment, and the student's name (message type and name size will be inferred)

# In Terminal 1 
sudo ./sniffer lo

# In Terminal 2
sudo ./sender lo 00:00:00:00:00:00 127.0.0.1 1234 98764532 user_name # Pattern with menssage type 1
sudo ./sender lo 00:00:00:00:00:00 127.0.0.1 1234 98764532 # Or Pattern with menssage type 2