Initial Commit

src/types.rs

@@ -0,0 +1,55 @@
+use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
+use std::sync::Arc;
+use tokio::net::UdpSocket;
+
+pub struct Sockets {
+    pub primary: Arc<UdpSocket>,
+    pub secondary: Arc<UdpSocket>,
+    pub alt: Arc<UdpSocket>,
+    pub p33334: Arc<UdpSocket>,
+    pub p33335: Arc<UdpSocket>,
+}
+
+pub struct Message {
+    pub r#type: u32,
+    pub external_port: u32,
+    pub external_address: Ipv4Addr,
+    pub local_address: u32,
+}
+
+impl Message {
+    pub fn from_bytes(bytes: &[u8]) -> Result<Self, String> {
+        if bytes.len() < 16 {
+            return Err(format!("Buffer too short, expected 16 bytes but found {} bytes", bytes.len()))
+        };
+
+        let r#type = u32::from_be_bytes(bytes[0..4].try_into().unwrap());
+        let external_port = u32::from_be_bytes(bytes[4..8].try_into().unwrap());
+        let external_address = Ipv4Addr::from(u32::from_be_bytes(bytes[8..12].try_into().unwrap()));
+        let local_address = u32::from_be_bytes(bytes[12..16].try_into().unwrap());
+
+        Ok(Message{
+            r#type,
+            external_port,
+            external_address,
+            local_address,
+        })
+    }
+
+    pub fn to_response_bytes(&self, socket: Arc<UdpSocket>, remote_addr: SocketAddrV4) -> Result<[u8; 16], String> {
+        let mut bytes = [0u8; 16];
+
+        bytes[0..4].copy_from_slice(&self.r#type.to_be_bytes());
+        bytes[4..8].copy_from_slice(&remote_addr.port().to_be_bytes());
+        bytes[8..12].copy_from_slice(&u32::from(*remote_addr.ip()).to_be_bytes());
+        let local_ip = match socket.local_addr().unwrap() {
+            SocketAddr::V4(addr) => *addr.ip(),
+            SocketAddr::V6(_) => {
+                return Err("Ipv6 not supported".into());
+            },
+        };
+        bytes[12..16].copy_from_slice(&u32::from(local_ip).to_be_bytes());
+
+        Ok(bytes)
+    }
+}