martillo-maldito/src/main.rs

pub mod iptables_save;
pub mod login_attempt;

use linemux::MuxedLines;
use login_attempt::LoginAttempt;
use std::collections::HashMap;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    let iptables = iptables::new(false).unwrap();
    let mut lines = MuxedLines::new()?;
    lines.add_file("/host_ssh/auth.log").await?;
    let mut login_attempts: HashMap<String, usize> = HashMap::new();

    println!("listening to changes over /host_ssh/auth.log");
    while let Ok(Some(line)) = lines.next_line().await {
        if let Some(login_attempt) = LoginAttempt::capture(line.line()) {
            println!(
                "failed login attempt from {}@{}:{}",
                login_attempt.user, login_attempt.ip, login_attempt.port
            );
            match login_attempts.get_mut(&login_attempt.ip) {
                Some(count) => {
                    *count += 1;

                    if *count == 3 {
                        match iptables.append_unique(
                            "filter",
                            "INPUT",
                            &format!("--source {} -j DROP", login_attempt.ip),
                        ) {
                            Ok(_) => {
                                println!("{} banned", login_attempt.ip);
                            }
                            Err(_) => {
                                println!("{} already banned", login_attempt.ip);
                            }
                        }
                        login_attempts.remove(&login_attempt.ip);
                    }
                }
                None => {
                    login_attempts.insert(login_attempt.ip.clone(), 1);
                }
            }
        }
    }
    Ok(())
}