1 files changed, 133 insertions, 0 deletions
diff --git a/p2p/src/message.rs b/p2p/src/message.rs
new file mode 100644
index 0000000..833f6f4
--- /dev/null
+++ b/p2p/src/message.rs
@@ -0,0 +1,133 @@
+use std::collections::HashMap;
+
+use bincode::{Decode, Encode};
+
+use karyons_net::{Addr, Port};
+
+use crate::{protocol::ProtocolID, routing_table::Entry, utils::VersionInt, PeerID};
+
+/// The size of the message header, in bytes.
+pub const MSG_HEADER_SIZE: usize = 6;
+
+/// The maximum allowed size for a message in bytes.
+pub const MAX_ALLOWED_MSG_SIZE: u32 = 1000000;
+
+/// Defines the main message in the Karyon P2P network.
+///
+/// This message structure consists of a header and payload, where the header
+/// typically contains essential information about the message, and the payload
+/// contains the actual data being transmitted.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct NetMsg {
+    pub header: NetMsgHeader,
+    pub payload: Vec<u8>,
+}
+
+/// Represents the header of a message.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct NetMsgHeader {
+    pub command: NetMsgCmd,
+    pub payload_size: u32,
+}
+
+/// Defines message commands.
+#[derive(Decode, Encode, Debug, Clone)]
+#[repr(u8)]
+pub enum NetMsgCmd {
+    Version,
+    Verack,
+    Protocol,
+    Shutdown,
+
+    // NOTE: The following commands are used during the lookup process.
+    Ping,
+    Pong,
+    FindPeer,
+    Peer,
+    Peers,
+}
+
+/// Defines a message related to a specific protocol.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct ProtocolMsg {
+    pub protocol_id: ProtocolID,
+    pub payload: Vec<u8>,
+}
+
+/// Version message, providing information about a peer's capabilities.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct VerMsg {
+    pub peer_id: PeerID,
+    pub version: VersionInt,
+    pub protocols: HashMap<ProtocolID, VersionInt>,
+}
+
+/// VerAck message acknowledging the receipt of a Version message.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct VerAckMsg(pub PeerID);
+
+/// Shutdown message.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct ShutdownMsg(pub u8);
+
+/// Ping message with a nonce and version information.
+#[derive(Decode, Encode, Debug, Clone)]
+pub struct PingMsg {
+    pub nonce: [u8; 32],
+    pub version: VersionInt,
+}
+
+/// Ping message with a nonce.
+#[derive(Decode, Encode, Debug)]
+pub struct PongMsg(pub [u8; 32]);
+
+/// FindPeer message used to find a specific peer.
+#[derive(Decode, Encode, Debug)]
+pub struct FindPeerMsg(pub PeerID);
+
+/// PeerMsg containing information about a peer.
+#[derive(Decode, Encode, Debug, Clone, PartialEq, Eq)]
+pub struct PeerMsg {
+    pub peer_id: PeerID,
+    pub addr: Addr,
+    pub port: Port,
+    pub discovery_port: Port,
+}
+
+/// PeersMsg a list of `PeerMsg`.
+#[derive(Decode, Encode, Debug)]
+pub struct PeersMsg(pub Vec<PeerMsg>);
+
+macro_rules! get_msg_payload {
+    ($a:ident, $b:expr) => {
+        if let NetMsgCmd::$a = $b.header.command {
+            $b.payload
+        } else {
+            return Err(Error::InvalidMsg(format!("Unexpected msg{:?}", $b)));
+        }
+    };
+}
+
+pub(super) use get_msg_payload;
+
+impl From<Entry> for PeerMsg {
+    fn from(entry: Entry) -> PeerMsg {
+        PeerMsg {
+            peer_id: PeerID(entry.key),
+            addr: entry.addr,
+            port: entry.port,
+            discovery_port: entry.discovery_port,
+        }
+    }
+}
+
+impl From<PeerMsg> for Entry {
+    fn from(peer: PeerMsg) -> Entry {
+        Entry {
+            key: peer.peer_id.0,
+            addr: peer.addr,
+            port: peer.port,
+            discovery_port: peer.discovery_port,
+        }
+    }
+}