1 files changed, 133 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..b588f2d
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,133 @@
+use std::io;
+use std::path::Path;
+use std::process::exit;
+
+use clap::Parser;
+use tokio::net::TcpListener;
+use tracing::{debug, error, info};
+
+use crate::arguments::Mode;
+use crate::server::SharedConfig;
+
+mod arguments;
+mod client;
+mod config;
+mod server;
+
+fn load_config<P: AsRef<Path>>(file_path: P) -> config::Root {
+    let content = match std::fs::read_to_string(file_path) {
+        Ok(s) => s,
+        Err(why) => {
+            error!("Failed to read config file: {}", why);
+            exit(1);
+        }
+    };
+    let cfg: config::Root = match toml::from_str(content.as_str()) {
+        Ok(c) => c,
+        Err(why) => {
+            error!("Failed to parse config file: {}", why);
+            exit(1);
+        }
+    };
+    cfg
+}
+
+fn validate_config(cfg: &config::Root) {
+    for s in &cfg.service {
+        if s.name.contains("\r\n") {
+            error!("Service name contains CRLF: `{}`", &s.name);
+            exit(1);
+        }
+    }
+}
+
+#[tokio::main]
+async fn main() -> io::Result<()> {
+    tracing_subscriber::fmt::init();
+
+    let args = arguments::Args::parse();
+    info!("args: {:?}", args);
+    let cfg = load_config(&args.config);
+
+    validate_config(&cfg);
+
+    match args.mode {
+        Mode::SERVER => {
+            if cfg.server == None {
+                error!("Config `server` is required in current mode");
+                exit(1);
+            }
+            if cfg.service.is_empty() {
+                error!("No service is defined");
+                exit(1);
+            }
+            server_main(cfg).await
+        }
+        Mode::CLIENT => {
+            if cfg.client == None {
+                error!("Config `client` is required in current mode");
+                exit(1);
+            }
+            client_main(cfg).await
+        }
+    }
+}
+
+async fn server_main(cfg: config::Root) -> io::Result<()> {
+    let listener = TcpListener::bind(cfg.server.unwrap().listen).await?;
+    info!("Server listening on {:?}", listener);
+    let max_srv_name_length = cfg
+        .service
+        .iter()
+        .map(|s| s.name.len())
+        .max()
+        .expect("No service was defined in config");
+    debug!("Max service name length: {}", max_srv_name_length);
+    // this immutable object lives throughout the entire process lifetime,
+    // so we use 'static here for simplicity
+    let shared_config: &'static SharedConfig = Box::leak(Box::new(SharedConfig {
+        max_srv_name_length,
+        services: cfg.service,
+        allow_help: cfg.allow_help,
+    }));
+    loop {
+        let (sock, addr) = listener.accept().await?;
+        tokio::spawn(server::handle_client(shared_config, sock, addr));
+    }
+}
+
+async fn client_server_main(
+    upstream_addr: &'static String,
+    listener: TcpListener,
+    service_name: &'static String,
+) -> io::Result<()> {
+    loop {
+        let (sock, addr) = listener.accept().await?;
+        info!("Client connected: {}", addr);
+        tokio::spawn(client::handle_client(sock, upstream_addr, service_name));
+    }
+}
+
+async fn client_main(cfg: config::Root) -> io::Result<()> {
+    let mut fut_servers = Vec::new();
+
+    let upstream_addr = Box::leak(Box::new(cfg.client.unwrap().addr));
+
+    for s in cfg.service {
+        let listener = TcpListener::bind(&s.addr).await?;
+        info!("Server listening on {:?} (service {})", listener, &s.name);
+        let service_name = Box::leak(Box::new(s.name));
+        fut_servers.push(tokio::spawn(client_server_main(
+            upstream_addr,
+            listener,
+            service_name,
+        )));
+    }
+
+    for fut in fut_servers {
+        if let Err(why) = fut.await {
+            error!("Failed to join server future: {}", why);
+        }
+    }
+    Ok(())
+}