Welcome to ft_ping, my school-sanctioned dive into the mysterious and emotionally detached world of ICMP packets. Inspired by the noble ping(8) utility and written entirely in C, this project seeks to answer a timeless question: "Is this host alive, or just ignoring me like everyone else?"

This isn’t just a clone — it’s a raw socket-powered, checksum-calculating, protocol-dissecting, TTL-respecting echo request renaissance.

“If you throw a stone into a well and no sound reaches you; then the time to live has exceeded.”
— probably Confucius.

tiboitel-ft_ping/
├── includes/         # Headers that hold the universe together
├── srcs/             # The source of all problems (and some solutions)
├── Makefile          # Because compiling by hand is for suckers
└── README.md         # This is fine piece of literature 👌

• 🛰 IPv4 & IPv6 support — ping like it's 1996 or 2096.

• 🧠 ICMP & ICMPv6 packet crafting and parsing.

• 🕵️ Verbose mode (-v) for the packet sniffer in you. Whatever it means.

• 👻 Numeric-only mode (-n) — because DNS is for the weak.

• ⏱ TTL tweaking (-t) to bring traceroute-esque enlightenment.

• 📉 RTT stats with min/avg/max/mdev — ping meets statistics class.

./ft_ping [options] <destination>

Flag

Description

-v

Verbose output (because info = power)

-n

No DNS reverse resolution, just IPs, baby

-t <ttl>

Set the TTL (Time To Live)

-6

Force IPv6, for when you're feeling futuristic

--version or -V

Print version info, like a proper Unix tool

Warning: actual understanding may result in increased respect for ICMP headers and decreased respect for humanity.

Your typical int main() but with baggage. Parses flags, sets up the environment, and launches the eternal ping_loop. Handles signals like a stoic samurai on SIGINT.

The engine room. Like Captain Kirk on caffeine, it loops through:

1. Preparing the packet

2. Sending it out into the abyss

3. Waiting for a reply

4. Parsing the reply and crying if it’s not ICMP_ECHOREPLY

5. Measuring time with surgical precision (or best effort)

Handles IPv4 and IPv6 with elegance (read: large if statements and duplicated logic but with fancy pointer to functions).

Forging raw ICMP/ICMPv6 packets with love, zeroes, and the power of bit-shifting. Parses responses and checks if the reply matches our sacred process ID.

Checksums: because life isn’t fair, and neither are corrupted packets.

Handles raw socket creation. Sets TTL, timeout, and other magic spells. Contains send_icmp_packet() and receive_icmp_reply(), which are as straightforward as they sound, until they segfault (they won’t. No heap, no troubles.).

All the stuff we didn’t know where to put, like:

• RTT calculations
• Printing epic stats
• ICMPv6 checksums that require a pseudo-header (because RFC says so, yeah, life is unfair)
• Updating stats like a ping historian

./ft_ping -v -n -t 42 google.com
PING google.com (142.250.180.206) 56(84) bytes of data.
64 bytes from 142.250.180.206: icmp_req=1 ttl=113 time=11.23 ms
64 bytes from 142.250.180.206: icmp_req=2 ttl=113 time=10.98 ms
...

Then you Ctrl+C, and it whispers:

--- google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 5004ms
rtt min/avg/max/mdev = 10.94/11.06/11.23/0.11 ms

We don't crash. We elegantly scream "Error" if:

• You send non-integer arguments
• Your TTL is something like 999
• You try to ping a cat instead of a host
• You forget arguments altogether
• You try to use ping as your LLM girlfriend

• Handles reverse DNS with getnameinfo, unless you're a cold-blooded -n user.
• Clean Makefile with rules even your mom could love: all, clean, fclean, re
• Setup your own TTL delay.

Because peer-reviewers are people too:

make
./ft_ping 8.8.8.8

Try Ctrl+C to unleash the final RTT stats. Feels powerful, doesn’t it?

Licensed under the School of Life. You can use, modify, and break this code however you want — just don’t blame me when it starts replying with existential dread.

Written by tiboitel, C wizard in training, certified ping philosopher, and probably the last human who builds Kernel in 3.9 on Debian 7 to make a project too old at 42.

If you enjoyed this, wait ‘til you see my traceroute clone in the future — it cries when packets die.

See you Space Cowboy 🤠 🚀