async-traceroute

This is an implementation of the Traceroute program written in Rust.

Usage: traceroute [OPTIONS] <HOST>

Arguments:
  <HOST>  

Options:
  -m, --max-hops <MAX_HOPS>          Set the max number of hops (max TTL to be reached) [default: 30]
  -q, --queries <QUERIES>            Set the number of probes per each hop [default: 3]
  -w, --wait <WAIT>                  Wait for a probe no more than <WAIT> [default: 3s]
  -N, --sim-queries <SIM_QUERIES>    Set the number of probes to be tried simultaneously [default: 16]
  -P, --probe-method <PROBE_METHOD>  [default: udp] [possible values: udp, tcp, icmp]
  -n                                 Do not resolve IP addresses to their domain names
  -h, --help                         Print help
  -V, --version                      Print version

You can integrate async-traceroute into your project by using it as a library. Here is a code example showing how to perform a traceroute to google.com:

use futures::pin_mut;
use futures_util::StreamExt;

use async_traceroute::TracerouteBuilder;
use async_traceroute::utils::dns::dns_lookup_first_ipv4_addr;

#[tokio::main]
async fn main() -> Result<(), String> {
    let ip_addr = match dns_lookup_first_ipv4_addr("google.com").await {
        None => return Err(String::from("Hostname not resolvable")),
        Some(ip_addr) => ip_addr,
    };
    
    let traceroute = TracerouteBuilder::udp()
        .target_ip_address(ip_addr)
        .max_ttl(15)
        .queries_per_hop(3)
        .max_wait_probe(Duration::from_secs(3))
        .simultaneous_queries(16)
        .active_dns_lookup(true)
        .initial_destination_port(33434)
        .build();
    
    let traceroute_stream = match traceroute {
        Ok(traceroute) => traceroute.trace(),
        Err(error) => return Err(error),
    };

    pin_mut!(traceroute_stream);
    
    while let Some(probe_result) = traceroute_stream.next().await {
        println!("{:?}", probe_result);
    }

    Ok(())
}

What is Traceroute

Traceroute allows you to see the path an IP packet takes from one host to another. It uses the TTL (Time To Live) field in the IP packet to elicit an ICMP Time to Live Exceeded message from each router along the path. Each router that handles the packet decreases the TTL field, which effectively acts as a Hop Counter. When a router receives an IP datagram with the TTL field set to 0, it responds with an ICMP Time to Live Exceeded that reveals its IP address.

Several traceroute probe methods exist. This diagram shows how the UDP-based traceroute method works.

Main Libraries

• tokio (async runtime)
• socket2 (includes raw sockets)
• libpnet (API for low level networking)
• clap (command-line argument parser)