chore: initial commit for phase06

apps/daemon/src/game/rcon.rs

@@ -0,0 +1,87 @@
+use anyhow::{Result, Context};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpStream;
+use tracing::debug;
+
+/// RCON packet types
+const PACKET_LOGIN: i32 = 3;
+const PACKET_COMMAND: i32 = 2;
+const PACKET_RESPONSE: i32 = 0;
+
+/// A minimal Source RCON client.
+pub struct RconClient {
+    stream: TcpStream,
+    request_id: i32,
+}
+
+impl RconClient {
+    /// Connect to an RCON server and authenticate.
+    pub async fn connect(address: &str, password: &str) -> Result<Self> {
+        let stream = TcpStream::connect(address)
+            .await
+            .context("Failed to connect to RCON")?;
+
+        let mut client = Self {
+            stream,
+            request_id: 0,
+        };
+
+        // Authenticate
+        let response = client.send_packet(PACKET_LOGIN, password).await?;
+        if response.id == -1 {
+            anyhow::bail!("RCON authentication failed");
+        }
+
+        debug!(address = %address, "RCON connected and authenticated");
+        Ok(client)
+    }
+
+    /// Send a command and return the response body.
+    pub async fn command(&mut self, cmd: &str) -> Result<String> {
+        let response = self.send_packet(PACKET_COMMAND, cmd).await?;
+        Ok(response.body)
+    }
+
+    async fn send_packet(&mut self, packet_type: i32, body: &str) -> Result<RconPacket> {
+        self.request_id += 1;
+        let id = self.request_id;
+
+        let body_bytes = body.as_bytes();
+        let length = 4 + 4 + body_bytes.len() + 2; // id + type + body + 2 null bytes
+
+        // Write packet
+        self.stream.write_i32_le(length as i32).await?;
+        self.stream.write_i32_le(id).await?;
+        self.stream.write_i32_le(packet_type).await?;
+        self.stream.write_all(body_bytes).await?;
+        self.stream.write_all(&[0, 0]).await?; // two null terminators
+        self.stream.flush().await?;
+
+        // Read response
+        let resp_length = self.stream.read_i32_le().await?;
+        let resp_id = self.stream.read_i32_le().await?;
+        let resp_type = self.stream.read_i32_le().await?;
+
+        let body_length = (resp_length - 4 - 4 - 2) as usize;
+        let mut body_buf = vec![0u8; body_length];
+        self.stream.read_exact(&mut body_buf).await?;
+
+        // Read two null terminators
+        let mut null_buf = [0u8; 2];
+        self.stream.read_exact(&mut null_buf).await?;
+
+        let response_body = String::from_utf8_lossy(&body_buf).to_string();
+
+        Ok(RconPacket {
+            id: resp_id,
+            packet_type: resp_type,
+            body: response_body,
+        })
+    }
+}
+
+struct RconPacket {
+    id: i32,
+    packet_type: i32,
+    body: String,
+}