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use humphrey::app::{App, ErrorHandler, WebsocketHandler};
use humphrey::route::RouteHandler;
use crate::config::{Config, LoadBalancerMode};
use crate::logger::Logger;
use crate::proxy::pipe;
use crate::server::rand::{Choose, Lcg};
use std::net::TcpStream;
use std::sync::{Arc, Mutex};
use std::thread::spawn;
#[derive(Default)]
struct AppState {
load_balancer: Mutex<LoadBalancer>,
blacklist: Vec<String>,
logger: Logger,
}
impl From<&Config> for AppState {
fn from(config: &Config) -> Self {
Self {
load_balancer: Mutex::new(LoadBalancer::from(config)),
blacklist: config.blacklist.clone(),
logger: Logger::from(config),
}
}
}
pub fn main(config: Config) {
let app: App<AppState> = App::new_with_config(config.threads, AppState::from(&config))
.with_custom_connection_handler(handler);
let addr = format!("{}:{}", config.address, config.port);
let logger = &app.get_state().logger;
logger.info("Parsed configuration, starting load balancer");
logger.info(&format!("Running at {}", addr));
logger.info(&format!(
"Using load balancer mode {:?}",
&config.load_balancer_mode.as_ref().unwrap()
));
logger.debug(&format!("Configuration: {:?}", &config));
app.run(addr).unwrap();
}
#[derive(Default)]
struct LoadBalancer {
targets: Vec<String>,
mode: LoadBalancerMode,
index: usize,
lcg: Lcg,
}
impl LoadBalancer {
pub fn select_target(&mut self) -> String {
match self.mode {
LoadBalancerMode::RoundRobin => {
let target_index = self.index;
self.index += 1;
if self.index == self.targets.len() {
self.index = 0;
}
self.targets[target_index].clone()
}
LoadBalancerMode::Random => self.targets.choose(&mut self.lcg).unwrap().clone(),
}
}
}
impl From<&Config> for LoadBalancer {
fn from(config: &Config) -> Self {
Self {
targets: config.load_balancer_targets.clone().unwrap(),
mode: config.load_balancer_mode.clone().unwrap(),
index: 0,
lcg: Lcg::new(),
}
}
}
fn handler(
mut source: TcpStream,
_: Arc<Vec<RouteHandler<AppState>>>,
_: Arc<ErrorHandler>,
_: Arc<WebsocketHandler<AppState>>,
state: Arc<AppState>,
) {
let address = source.peer_addr();
if address.is_err() {
state.logger.warn("Corrupted stream attempted to connect");
return;
}
let address = address.unwrap().ip().to_string();
if state.blacklist.contains(&address) {
state
.logger
.warn(&format!("{}: Blacklisted IP tried to connect", &address));
return;
}
let mut load_balancer_lock = state.load_balancer.lock().unwrap();
let target = load_balancer_lock.select_target();
drop(load_balancer_lock);
if let Ok(mut destination) = TcpStream::connect(&target) {
state
.logger
.info(&format!("{} -> {}: Connection started", &address, &target));
let mut source_clone = source.try_clone().unwrap();
let mut destination_clone = destination.try_clone().unwrap();
let forward = spawn(move || pipe(&mut source, &mut destination));
let backward = spawn(move || pipe(&mut destination_clone, &mut source_clone));
if let Err(_) = forward.join().unwrap() {
state.logger.error(&format!(
"{}: Error proxying data from client to target, connection closed",
&address
));
}
if let Err(_) = backward.join().unwrap() {
state.logger.error(&format!(
"{}: Error proxying data from target to client, connection closed",
&address
));
}
state.logger.info(&format!(
"{} -> {}: Session complete, connection closed",
&address, &target
));
} else {
state.logger.error(&format!(
"Could not connect to load balancer target {}",
target
))
}
}