README.md

ft_ping (@42Paris)

This project was code for Linux. Here is the subject.

About

ft_ping is a reimplementation in C of the ping utility based on the ping implementation from inetutils-2.0.

ft_ping uses a raw socket to send each second an ICMP Echo Request packet with a timestamp in its body. It will also display a line of information for each received ICMP packet.

It accepts a simple IPv4 address or hostname as a parameter, and supports both numerical IP addresses and hostnames.

The program should be run with appropriate permissions, as sending ICMP Echo Request packets may require administrative privileges.

When receiving an ICMP packet, ft_ping will check:

• If the packet was correctly addressed to this process by checking the PID stored in the ID field of ICMP Echo Request.
• If it's an error packet or not.

ft_ping will ping the targeted host until Ctrl+C is pressed. It will then display statistics about the received ICMP Echo Response packets.

ft_ping supports also the following options :

• -h: provides help information about the usage and command-line options of ft_ping.
• -q: enables quiet output, ft_ping will only display the end statistics.
• -v: enables verbose output and allows viewing the results in case of problems or errors related to the packets.

Example of error packet (packet filtered) with verbose output

Building and running the project

1. Download/Clone this repo

    git clone https://github.com/llefranc/42_ft_ping
   

2. cd into the root directory and run make

    cd 42_ft_ping
    make
   

3. Run ft_ping with appropriate permissions

    sudo ./ft_ping 192.168.0.1
    sudo ./ft_ping localhost
    sudo ./ft_ping google.com -v
   

Sources

• RFC of ICMP protocol
• RFC of IP protocol