Files
Modrinth-plus/packages/async-minecraft-ping/src/server.rs

429 lines
13 KiB
Rust

//! This module defines a wrapper around Minecraft's
//! [ServerListPing](https://wiki.vg/Server_List_Ping)
use std::time::Duration;
use serde::Deserialize;
use thiserror::Error;
use tokio::net::TcpStream;
use crate::protocol::{self, AsyncReadRawPacket, AsyncWriteRawPacket};
#[derive(Error, Debug)]
pub enum ServerError {
#[error("error reading or writing data")]
ProtocolError,
#[error("failed to connect to server")]
FailedToConnect,
#[error("connection timed out")]
ConnectionTimedOut,
#[error("invalid JSON response: \"{0}\"")]
InvalidJson(String),
#[error("mismatched pong payload (expected \"{expected}\", got \"{actual}\")")]
MismatchedPayload { expected: u64, actual: u64 },
}
impl From<protocol::ProtocolError> for ServerError {
fn from(_err: protocol::ProtocolError) -> Self {
ServerError::ProtocolError
}
}
/// Contains information about the server version.
#[derive(Debug, Deserialize)]
pub struct ServerVersion {
/// The server's Minecraft version, i.e. "1.15.2".
pub name: String,
/// The server's ServerListPing protocol version.
pub protocol: i32,
}
/// Contains information about a player.
#[derive(Debug, Deserialize)]
pub struct ServerPlayer {
/// The player's in-game name.
pub name: String,
/// The player's UUID.
pub id: String,
}
/// Contains information about the currently online
/// players.
#[derive(Debug, Deserialize)]
pub struct ServerPlayers {
/// The configured maximum number of players for the
/// server.
pub max: i32,
/// The number of players currently online.
pub online: i32,
/// An optional list of player information for
/// currently online players.
pub sample: Option<Vec<ServerPlayer>>,
}
/// Contains the server's MOTD.
#[derive(Debug, Deserialize)]
#[serde(untagged)]
pub enum ServerDescription {
Plain(String),
Object { text: String },
}
/// The decoded JSON response from a status query over
/// ServerListPing.
#[derive(Debug, Deserialize)]
pub struct StatusResponse {
/// Information about the server's version.
pub version: ServerVersion,
/// Information about currently online players.
pub players: ServerPlayers,
/// Single-field struct containing the server's MOTD.
pub description: ServerDescription,
/// Optional field containing a path to the server's
/// favicon.
pub favicon: Option<String>,
}
const LATEST_PROTOCOL_VERSION: usize = 578;
const DEFAULT_PORT: u16 = 25565;
const DEFAULT_TIMEOUT: Duration = Duration::from_secs(2);
/// Builder for a Minecraft
/// ServerListPing connection.
pub struct ConnectionConfig {
protocol_version: usize,
address: String,
port: u16,
timeout: Duration,
#[cfg(feature = "srv")]
srv_lookup: bool,
}
impl ConnectionConfig {
/// Initiates the Minecraft server
/// connection build process.
pub fn build<T: Into<String>>(address: T) -> Self {
ConnectionConfig {
protocol_version: LATEST_PROTOCOL_VERSION,
address: address.into(),
port: DEFAULT_PORT,
timeout: DEFAULT_TIMEOUT,
#[cfg(feature = "srv")]
srv_lookup: false,
}
}
/// Sets a specific
/// protocol version for the connection to
/// use. If not specified, the latest version
/// will be used.
pub fn with_protocol_version(mut self, protocol_version: usize) -> Self {
self.protocol_version = protocol_version;
self
}
/// Sets a specific port for the
/// connection to use. If not specified, the
/// default port of 25565 will be used.
pub fn with_port(mut self, port: u16) -> Self {
self.port = port;
self
}
/// Sets a specific timeout for the
/// connection to use. If not specified, the
/// timeout defaults to two seconds.
pub fn with_timeout(mut self, timeout: Duration) -> Self {
self.timeout = timeout;
self
}
/// Enables SRV record lookup for the connection.
///
/// When enabled, the library will query DNS for an SRV record
/// at `_minecraft._tcp.<address>`. If found, the target host
/// and port from the SRV record will be used instead of the
/// configured address and port.
///
/// This feature requires the `srv` feature to be enabled.
#[cfg(feature = "srv")]
pub fn with_srv_lookup(mut self) -> Self {
self.srv_lookup = true;
self
}
/// Connects to the server and consumes the builder.
pub async fn connect(self) -> Result<StatusConnection, ServerError> {
let (address, port) = self.resolve_address().await;
let stream = tokio::time::timeout(
self.timeout,
TcpStream::connect(format!("{}:{}", address, port)),
)
.await
.map_err(|_| ServerError::ConnectionTimedOut)?
.map_err(|_| ServerError::FailedToConnect)?;
Ok(StatusConnection {
stream,
protocol_version: self.protocol_version,
address,
port,
timeout: self.timeout,
})
}
#[cfg(feature = "srv")]
async fn resolve_address(&self) -> (String, u16) {
if !self.srv_lookup {
return (self.address.clone(), self.port);
}
// Try to resolve SRV record, fall back to original address on any failure
match self.lookup_srv().await {
Some((host, port)) => (host, port),
None => (self.address.clone(), self.port),
}
}
#[cfg(not(feature = "srv"))]
async fn resolve_address(&self) -> (String, u16) {
(self.address.clone(), self.port)
}
#[cfg(feature = "srv")]
async fn lookup_srv(&self) -> Option<(String, u16)> {
use hickory_resolver::TokioAsyncResolver;
let resolver = TokioAsyncResolver::tokio_from_system_conf().ok()?;
let srv_name = format!("_minecraft._tcp.{}", self.address);
let lookup = tokio::time::timeout(self.timeout, resolver.srv_lookup(&srv_name))
.await
.ok()?
.ok()?;
let record = lookup.iter().next()?;
let target = record.target().to_string();
// Remove trailing dot from DNS name
let host = target.trim_end_matches('.').to_string();
let port = record.port();
Some((host, port))
}
}
/// Convenience wrapper for easily connecting
/// to a server on the default port with
/// the latest protocol version.
pub async fn connect(address: String) -> Result<StatusConnection, ServerError> {
ConnectionConfig::build(address).connect().await
}
/// Wraps a built connection
pub struct StatusConnection {
stream: TcpStream,
protocol_version: usize,
address: String,
port: u16,
timeout: Duration,
}
impl StatusConnection {
/// Sends and reads the packets for the
/// ServerListPing status call.
///
/// Consumes the connection and returns a type
/// that can only issue pings. The resulting
/// status body is accessible via the `status`
/// property on `PingConnection`.
pub async fn status(mut self) -> Result<PingConnection, ServerError> {
let handshake = protocol::HandshakePacket::new(
self.protocol_version,
self.address.to_string(),
self.port,
);
self.stream
.write_packet_with_timeout(handshake, self.timeout)
.await?;
self.stream
.write_packet_with_timeout(protocol::RequestPacket::new(), self.timeout)
.await?;
let response: protocol::ResponsePacket =
self.stream.read_packet_with_timeout(self.timeout).await?;
let status: StatusResponse = serde_json::from_str(&response.body)
.map_err(|_| ServerError::InvalidJson(response.body))?;
Ok(PingConnection {
stream: self.stream,
protocol_version: self.protocol_version,
address: self.address,
port: self.port,
status,
timeout: self.timeout,
})
}
}
/// Wraps a built connection
///
/// Constructed by calling `status()` on
/// a `StatusConnection` struct.
#[allow(dead_code)]
pub struct PingConnection {
stream: TcpStream,
protocol_version: usize,
address: String,
port: u16,
timeout: Duration,
pub status: StatusResponse,
}
impl PingConnection {
/// Sends a ping to the Minecraft server with the
/// provided payload and asserts that the returned
/// payload is the same.
///
/// Server closes the connection after a ping call,
/// so this method consumes the connection.
pub async fn ping(mut self, payload: u64) -> Result<(), ServerError> {
let ping = protocol::PingPacket::new(payload);
self.stream
.write_packet_with_timeout(ping, self.timeout)
.await?;
let pong: protocol::PongPacket = self.stream.read_packet_with_timeout(self.timeout).await?;
if pong.payload != payload {
return Err(ServerError::MismatchedPayload {
expected: payload,
actual: pong.payload,
});
}
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_server_description_plain() {
let json = r#""A Minecraft Server""#;
let desc: ServerDescription = serde_json::from_str(json).unwrap();
assert!(matches!(desc, ServerDescription::Plain(s) if s == "A Minecraft Server"));
}
#[test]
fn test_server_description_object() {
let json = r#"{"text":"A Minecraft Server"}"#;
let desc: ServerDescription = serde_json::from_str(json).unwrap();
assert!(matches!(desc, ServerDescription::Object { text } if text == "A Minecraft Server"));
}
#[test]
fn test_status_response_minimal() {
let json = r#"{
"version": {"name": "1.20.4", "protocol": 765},
"players": {"max": 20, "online": 5},
"description": "Welcome to the server"
}"#;
let response: StatusResponse = serde_json::from_str(json).unwrap();
assert_eq!(response.version.name, "1.20.4");
assert_eq!(response.version.protocol, 765);
assert_eq!(response.players.max, 20);
assert_eq!(response.players.online, 5);
assert!(response.players.sample.is_none());
assert!(response.favicon.is_none());
}
#[test]
fn test_status_response_with_players() {
let json = r#"{
"version": {"name": "1.20.4", "protocol": 765},
"players": {
"max": 20,
"online": 2,
"sample": [
{"name": "Player1", "id": "uuid-1"},
{"name": "Player2", "id": "uuid-2"}
]
},
"description": {"text": "Welcome"}
}"#;
let response: StatusResponse = serde_json::from_str(json).unwrap();
let sample = response.players.sample.unwrap();
assert_eq!(sample.len(), 2);
assert_eq!(sample[0].name, "Player1");
assert_eq!(sample[1].name, "Player2");
}
#[test]
fn test_status_response_with_favicon() {
let json = r#"{
"version": {"name": "1.20.4", "protocol": 765},
"players": {"max": 20, "online": 0},
"description": "Test",
"favicon": "data:image/png;base64,iVBORw0KGgo="
}"#;
let response: StatusResponse = serde_json::from_str(json).unwrap();
assert!(response.favicon.is_some());
assert!(response.favicon.unwrap().starts_with("data:image/png"));
}
#[test]
fn test_connection_config_defaults() {
let config = ConnectionConfig::build("localhost");
assert_eq!(config.address, "localhost");
assert_eq!(config.port, DEFAULT_PORT);
assert_eq!(config.timeout, DEFAULT_TIMEOUT);
assert_eq!(config.protocol_version, LATEST_PROTOCOL_VERSION);
}
#[test]
fn test_connection_config_with_port() {
let config = ConnectionConfig::build("localhost").with_port(12345);
assert_eq!(config.port, 12345);
}
#[test]
fn test_connection_config_with_timeout() {
let config = ConnectionConfig::build("localhost").with_timeout(Duration::from_secs(10));
assert_eq!(config.timeout, Duration::from_secs(10));
}
#[test]
fn test_connection_config_with_protocol_version() {
let config = ConnectionConfig::build("localhost").with_protocol_version(47);
assert_eq!(config.protocol_version, 47);
}
#[cfg(feature = "srv")]
#[test]
fn test_connection_config_with_srv_lookup() {
let config = ConnectionConfig::build("localhost").with_srv_lookup();
assert!(config.srv_lookup);
}
}