rust-opensmtpd/opensmtpd/examples/counter.rs

use log;
use opensmtpd::{run_filter, Address, Filter, ReportEntry};
use opensmtpd_derive::register;
use simplelog::{Config, LevelFilter, WriteLogger};
use std::fs::File;

pub const DEFAULT_LOG_FILE: &str = "/tmp/counter.log";

#[derive(Default)]
struct MyCounter {
	nb_connected: u64,
	nb_total: u64,
}

impl Filter for MyCounter {
	#[register]
	fn on_report_link_connect(
		&mut self,
		_entry: &ReportEntry,
		_rdns: &str,
		_fcrdns: &str,
		_src: &Address,
		_dest: &Address,
	) {
		self.nb_connected += 1;
		self.nb_total += 1;
		log::info!(
			"New client (connected: {}, total: {})",
			self.nb_connected,
			self.nb_total
		);
	}

	#[register]
	fn on_report_link_disconnect(&mut self, _entry: &ReportEntry) {
		self.nb_connected -= 1;
		log::info!(
			"Client left (connected: {}, total: {})",
			self.nb_connected,
			self.nb_total
		);
	}
}

fn main() {
	let log_file = std::env::var("LOG_FILE").unwrap_or(String::from(DEFAULT_LOG_FILE));
	WriteLogger::init(
		LevelFilter::Info,
		Config::default(),
		File::create(&log_file).unwrap(),
	)
	.unwrap();
	let mut my_counter: MyCounter = Default::default();
	run_filter(&mut my_counter);
}