Loopback Bind Checker (src/bind.rs)

Utility to determine if a bind address is loopback, used in config validation.

// Source: https://github.com/moltis-org/moltis | License: MIT | Copyright 2025 Fabien Penso
// Provided via justclaw.it.com; keep this notice with the code.
//! Bind-address classification shared by config validation and the gateway.

use std::net::IpAddr;

/// Whether `bind` only accepts connections from this machine.
///
/// Accepts `localhost`, any `*.localhost` name (RFC 6761), and loopback IPs
/// with or without IPv6 brackets.
#[must_use]
pub fn is_loopback_bind(bind: &str) -> bool {
    let host = bind.trim().trim_end_matches('.');
    if host.eq_ignore_ascii_case("localhost") || host.to_ascii_lowercase().ends_with(".localhost") {
        return true;
    }
    host.trim_start_matches('[')
        .trim_end_matches(']')
        .parse::<IpAddr>()
        .is_ok_and(|ip| ip.is_loopb

... (truncated -- full source via MCP)