Merge pull request 'We have a server at least' (#3) from devel into master

Reviewed-on: #3

Cargo.toml

@@ -1,16 +1,27 @@
 [package]
-name = "template"
+name = "netpong"
 version = "0.1.0"
 edition = "2021"
-publish = false
+publish = true
 authors = ["Christoph J. Scherr <software@cscherr.de>"]
 license = "MIT"
-description = "No description yet"
+description = "let your servers play ping pong"
 readme = "README.md"
-homepage = "https://git.cscherr.de/PlexSheep/rs-base"
-repository = "https://git.cscherr.de/PlexSheep/rs-base"
-keywords = ["template"]
+homepage = "https://git.cscherr.de/PlexSheep/netpong"
+repository = "https://git.cscherr.de/PlexSheep/netpong"
+keywords = ["networking"]
 
 
 [dependencies]
+anyhow = "1.0.79"
+clap = "4.4.18"
+clap-num = "1.0.2"
+clap-verbosity-flag = "2.1.2"
+libpt = { version = "0.3.10", features = ["net"] }
+thiserror = "1.0.56"
+threadpool = { version = "1.8.1", optional = true }
+tokio = { version = "1.35.1", features = ["net", "rt", "macros"] }
 
+[features]
+default = ["server"]
+server = ["dep:threadpool"]

scripts/client.py

@@ -0,0 +1,21 @@
+import socket
+
+HOST = "127.0.0.1"
+PORT = 9999
+
+payload = b"ping\0"
+
+with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+    s.connect((HOST, PORT))
+    while True:
+        try:
+            s.sendall(payload)
+            print("> ping")
+        except Exception as e:
+            break
+        reply = s.recv(1024).decode()
+        if reply == "":
+            break
+        print(f"< {reply}")
+    print("connection shut down")
+

src/client/mod.rs

@@ -0,0 +1 @@
+

src/common/args.rs

@@ -0,0 +1,82 @@
+use libpt::log::{Level, Logger};
+
+use clap::Parser;
+use clap_verbosity_flag::{InfoLevel, Verbosity};
+
+use crate::common::conf::Mode;
+
+/// short about section displayed in help
+const ABOUT_ROOT: &'static str = r##"
+Let your hosts play ping pong over the network
+"##;
+/// longer about section displayed in help, is combined with [the short help](ABOUT_ROOT)
+static LONG_ABOUT_ROOT: &'static str = r##"
+
+    Connect to a ping pong server and periodically send a ping. The server will reply with a pong.
+    That's it really. You can also host your own netpong server (server feature).
+"##;
+
+#[derive(Debug, Clone, Parser)]
+#[command(
+    author,
+    version,
+    about = ABOUT_ROOT,
+    long_about = format!("{}{}", ABOUT_ROOT ,LONG_ABOUT_ROOT),
+    help_template =
+r#"{about-section}
+{usage-heading} {usage}
+{all-args}{tab}
+
+libpt: {version}
+Author: {author-with-newline}
+"#
+    )]
+pub(crate) struct Cli {
+    // clap_verbosity_flag seems to make this a global option implicitly
+    /// set a verbosity, multiple allowed (f.e. -vvv)
+    #[command(flatten)]
+    pub(crate) verbose: Verbosity<InfoLevel>,
+
+    /// show additional logging meta data
+    #[arg(long)]
+    pub(crate) meta: bool,
+
+    // host a server instead of connecting to one
+    #[cfg(feature = "server")]
+    #[arg(short, long, default_value_t = false)]
+    pub(crate) server: bool,
+
+    // how much threads the server should use
+    #[cfg(feature = "server")]
+    #[arg(short, long, default_value_t = 4)]
+    pub(crate) threads: usize,
+
+    #[arg(short, long, default_value_t = Mode::Tcp, ignore_case = true)]
+    pub(crate) mode: Mode,
+
+    /// Address of the server
+    pub(crate) addr: std::net::SocketAddr,
+}
+
+impl Cli {
+    pub fn cli_parse() -> Self {
+        let cli = Self::parse();
+        let ll: Level = match cli.verbose.log_level().unwrap().as_str() {
+            "TRACE" => Level::TRACE,
+            "DEBUG" => Level::DEBUG,
+            "INFO" => Level::INFO,
+            "WARN" => Level::WARN,
+            "ERROR" => Level::ERROR,
+            _ => {
+                unreachable!();
+            }
+        };
+        if cli.meta {
+            Logger::init(None, Some(ll)).expect("could not initialize Logger");
+        } else {
+            // less verbose version
+            Logger::init_mini(Some(ll)).expect("could not initialize Logger");
+        }
+        return cli;
+    }
+}

src/common/conf.rs

@@ -0,0 +1,65 @@
+use crate::common::args::Cli;
+use clap::ValueEnum;
+use std::{fmt::Display, time::Duration};
+
+const DEFAULT_TIMEOUT_LEN: u64 = 5000; // ms
+const DEFAULT_DELAY_LEN: u64 = 500; // ms
+const DEFAULT_WIN_AFTER: usize = 20;
+
+#[derive(Debug, Clone, Copy)]
+pub enum Mode {
+    Tcp,
+}
+
+impl ValueEnum for Mode {
+    fn to_possible_value(&self) -> Option<clap::builder::PossibleValue> {
+        Some(match self {
+            Self::Tcp => clap::builder::PossibleValue::new("tcp"),
+        })
+    }
+    fn value_variants<'a>() -> &'a [Self] {
+        &[Self::Tcp]
+    }
+    fn from_str(input: &str, ignore_case: bool) -> Result<Self, String> {
+        let comp: String = if ignore_case {
+            input.to_lowercase()
+        } else {
+            input.to_string()
+        };
+        match comp.as_str() {
+            "tcp" => return Ok(Self::Tcp),
+            _ => return Err(format!("\"{input}\" is not a valid mode")),
+        }
+    }
+}
+
+impl Display for Mode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let repr: String = match self {
+            Self::Tcp => format!("tcp"),
+        };
+        write!(f, "{}", repr)
+    }
+}
+
+pub struct Config {
+    pub addr: std::net::SocketAddr,
+    pub mode: Mode,
+    pub threads: usize,
+    pub timeout: Duration,
+    pub delay: Duration,
+    pub win_after: usize,
+}
+
+impl Config {
+    pub fn new(cli: &Cli) -> Self {
+        Config {
+            addr: cli.addr.clone(),
+            mode: cli.mode.clone(),
+            threads: cli.threads,
+            timeout: Duration::from_millis(DEFAULT_TIMEOUT_LEN),
+            delay: Duration::from_millis(DEFAULT_DELAY_LEN),
+            win_after: DEFAULT_WIN_AFTER,
+        }
+    }
+}

src/common/mod.rs

@@ -0,0 +1,2 @@
+pub mod args;
+pub mod conf;

src/main.rs

@@ -1,3 +1,33 @@
-fn main() {
-    println!("Hello, world!");
+//! # netpong
+//! This is pretty silly and only let's your client send "ping"
+//! over a connection, while letting a server reply pong to
+//! every connection. But I had to make it for some reason.
+
+use anyhow::Result;
+use libpt::log::*;
+use tokio;
+
+mod client;
+mod common;
+mod server;
+
+use common::{args::Cli, conf::*};
+
+use crate::server::Server;
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let cli = Cli::cli_parse();
+    debug!("dumping cli args:\n{:#?}", cli);
+
+    let cfg = Config::new(&cli);
+
+    #[cfg(feature = "server")]
+    if cli.server {
+        info!("starting server");
+        return Server::build(cfg).await?.run().await;
+    }
+    // implicit else, so we can work without the server feature
+    info!("starting client");
+    Ok(())
 }

src/server/errors.rs

@@ -0,0 +1,45 @@
+use std::{fmt::Display, string::FromUtf8Error};
+
+use anyhow;
+use thiserror::Error;
+use tokio::time::error::Elapsed;
+
+pub type Result<T> = std::result::Result<T, ServerError>;
+
+#[derive(Debug, Error)]
+pub enum ServerError {
+    Timeout(Elapsed),
+    Anyhow(anyhow::Error),
+    IO(std::io::Error),
+    Format(FromUtf8Error),
+}
+
+impl From<anyhow::Error> for ServerError {
+    fn from(value: anyhow::Error) -> Self {
+        Self::Anyhow(value)
+    }
+}
+
+impl From<std::io::Error> for ServerError {
+    fn from(value: std::io::Error) -> Self {
+        Self::IO(value)
+    }
+}
+
+impl From<FromUtf8Error> for ServerError {
+    fn from(value: FromUtf8Error) -> Self {
+        Self::Format(value)
+    }
+}
+
+impl From<Elapsed> for ServerError {
+    fn from(value: Elapsed) -> Self {
+        Self::Timeout(value)
+    }
+}
+
+impl Display for ServerError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}

src/server/mod.rs

@@ -0,0 +1,125 @@
+#![cfg(feature = "server")]
+use std::time::Duration;
+
+use libpt::log::{debug, info, trace, warn};
+use tokio::{
+    io::{AsyncBufReadExt, AsyncWriteExt, BufReader},
+    net::{TcpListener, TcpStream},
+    time::timeout,
+};
+
+use crate::common::conf::Config;
+
+pub mod errors;
+use errors::*;
+
+pub struct Server {
+    cfg: Config,
+    pub timeout: Option<Duration>,
+    server: TcpListener,
+}
+
+impl Server {
+    pub async fn build(cfg: Config) -> anyhow::Result<Self> {
+        let server = TcpListener::bind(cfg.addr).await?;
+        let timeout = Some(Duration::from_secs(5));
+        Ok(Server {
+            cfg,
+            timeout,
+            server,
+        })
+    }
+    pub async fn run(self) -> anyhow::Result<()> {
+        loop {
+            let (stream, addr) = match self.server.accept().await {
+                Ok(s) => s,
+                Err(err) => {
+                    warn!("could not accept stream: {err:?}");
+                    continue;
+                }
+            };
+            match self.handle_stream(stream).await {
+                Ok(_) => (),
+                Err(err) => {
+                    match err {
+                        ServerError::Timeout(_) => {
+                            info!("stream {:?} timed out", addr)
+                        }
+                        _ => {
+                            warn!("error while handling stream: {:?}", err)
+                        }
+                    }
+                    continue;
+                }
+            };
+        }
+    }
+
+    async fn handle_stream(&self, stream: TcpStream) -> Result<()> {
+        let mut pings: usize = 0;
+        let addr = match stream.peer_addr() {
+            Ok(a) => a,
+            Err(err) => {
+                debug!("could not get peer address: {:?}", err);
+                return Err(err.into());
+            }
+        };
+        info!("new peer: {:?}", addr);
+        let mut buf = Vec::new();
+        let mut reader = BufReader::new(stream);
+        let mut len;
+        loop {
+            len = match self.read(&mut reader, &mut buf).await {
+                Ok(len) => len,
+                Err(err) => {
+                    match err {
+                        ServerError::Timeout(_) => {
+                            info!("peer {:?} timed out", addr)
+                        }
+                        _ => return Err(err),
+                    }
+                    break;
+                }
+            };
+            trace!("received message: {:X?}", buf);
+            if len == 0 {
+                trace!("len is apperently 0: {len:?}");
+                break;
+            } else {
+                let msg = self.decode(&buf)?;
+                info!("< {:?} : {}", addr, msg);
+                if msg.contains("ping") {
+                    pings += 1;
+                }
+                if pings < self.cfg.win_after {
+                    reader.write_all(b"pong\0").await?;
+                    info!("> {:?} : pong", addr,);
+                } else {
+                    reader.write_all(b"you win!\0").await?;
+                    info!("> {:?} : you win!", addr,);
+                    reader.shutdown().await?;
+                    break;
+                }
+                buf.clear();
+
+                // we should wait, so that we don't spam the client
+                std::thread::sleep(self.cfg.delay);
+            }
+        }
+        info!("disconnected peer: {:?}", addr);
+        Ok(())
+    }
+
+    #[inline]
+    fn decode(&self, buf: &Vec<u8>) -> Result<String> {
+        Ok(String::from_utf8(buf.clone())?.replace('\n', "\\n"))
+    }
+
+    #[inline]
+    async fn read(&self, reader: &mut BufReader<TcpStream>, buf: &mut Vec<u8>) -> Result<usize> {
+        match timeout(self.cfg.timeout, reader.read_until(0x00, buf)).await? {
+            Ok(len) => Ok(len),
+            Err(err) => Err(err.into()),
+        }
+    }
+}