fail2ban-rs 1.0.0

A pure-Rust fail2ban replacement. Single static binary, fast two-phase matching, nftables/iptables firewall backends.
Documentation 
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//! Ban time calculation with optional escalation.
//!
//! Extracted from the tracker module to keep it under the 500-line limit.

use std::collections::HashMap;

use crate::config::JailConfig;

/// Per-jail parameters relevant to ban calculations.
pub(crate) struct JailParams {
    pub(crate) max_retry: u32,
    pub(crate) find_time: i64,
    pub(crate) ban_time: i64,
    pub(crate) webhook: Option<String>,
    pub(crate) bantime_increment: bool,
    pub(crate) bantime_factor: f64,
    pub(crate) bantime_multipliers: Vec<u32>,
    pub(crate) bantime_maxtime: i64,
}

/// Calculate effective ban time with optional escalation.
pub(crate) fn calc_ban_time(base: i64, count: u32, params: &JailParams) -> i64 {
    if !params.bantime_increment || base < 0 {
        return base;
    }
    let multiplier = if !params.bantime_multipliers.is_empty() {
        let idx = (count as usize).min(params.bantime_multipliers.len() - 1);
        params.bantime_multipliers[idx] as f64
    } else {
        let exp = count.min(20);
        2_f64.powi(exp as i32)
    };
    let effective = (base as f64 * multiplier * params.bantime_factor) as i64;
    if params.bantime_maxtime > 0 {
        effective.min(params.bantime_maxtime)
    } else {
        effective
    }
}

/// Build per-jail parameter maps from configuration.
pub(crate) fn build_jail_params(
    configs: &HashMap<String, JailConfig>,
) -> HashMap<String, JailParams> {
    configs
        .iter()
        .map(|(name, cfg)| {
            (
                name.clone(),
                JailParams {
                    max_retry: cfg.max_retry,
                    find_time: cfg.find_time,
                    ban_time: cfg.ban_time,
                    webhook: cfg.webhook.clone(),
                    bantime_increment: cfg.bantime_increment,
                    bantime_factor: cfg.bantime_factor,
                    bantime_multipliers: cfg.bantime_multipliers.clone(),
                    bantime_maxtime: cfg.bantime_maxtime,
                },
            )
        })
        .collect()
}