matejnesuta / isa-vut-fit

ISA project 2023/2024

DHCP monitoring tool for network prefix utilization

Author: Matej Nesuta

Login: xnesut00

Date: 20. 11. 2023

Points scored: 18/20

Description

Simple program in C, which provides statistics about the utilizations of a DHCP pool. The program works as a console application when analyzing a network interface. When utilization of a prefix surpasses 50% the program should send a syslog message. The program also has an option to parse a .pcap file, instead of choosing a network interface. In this case, the results are printed on the standard output after the parsing is finished.

Limitations

IPv4 addresses only: The tool is designed to work exclusively with IPv4 addresses. Support for IPv6 or other address types is not included.

No tunneling or VLAN support: Tunneling functionality is not supported in this tool. It operates solely within the constraints of IPv4 networking. Vlan tags are also not supported.

Usage

For usage there is helpAndExit() function which prints help message.

Example of usage with filename:

./dhcp-stats -r dhcp.pcapng 192.168.1.0/24 192.168.0.0/22

Output:

IP-Prefix Max-hosts Allocated addresses Utilization
192.168.1.0/24 254 0 0.00%
192.168.0.0/22 1022 1 0.10%

List of files

• main.c - main file
• parser.c - file for parsing the DHCP message
• parser.h - header file for parser.c
• utils.c - file for miscellaneous functions
• utils.h - header file for utils.c
• Makefile - makefile for compilation
• README - readme file
• manual.pdf - manual for this project
• dhcp-stats.1 - man page for this project