283 lines
8.3 KiB
Rust
283 lines
8.3 KiB
Rust
use mio::*;
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use hash::*;
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use rlp::*;
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use network::connection::{EncryptedConnection, Packet};
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use network::handshake::Handshake;
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use error::*;
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use network::error::{NetworkError, DisconnectReason};
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use network::host::*;
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use network::node::NodeId;
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/// Peer session over encrypted connection.
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/// When created waits for Hello packet exchange and signals ready state.
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/// Sends and receives protocol packets and handles basic packes such as ping/pong and disconnect.
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pub struct Session {
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/// Shared session information
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pub info: SessionInfo,
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/// Underlying connection
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connection: EncryptedConnection,
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/// Session ready flag. Set after successfull Hello packet exchange
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had_hello: bool,
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}
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/// Structure used to report various session events.
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pub enum SessionData {
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None,
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/// Session is ready to send/receive packets.
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Ready,
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/// A packet has been received
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Packet {
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/// Packet data
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data: Vec<u8>,
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/// Packet protocol ID
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protocol: &'static str,
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/// Zero based packet ID
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packet_id: u8,
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},
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}
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/// Shared session information
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pub struct SessionInfo {
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/// Peer public key
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pub id: NodeId,
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/// Peer client ID
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pub client_version: String,
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/// Peer RLPx protocol version
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pub protocol_version: u32,
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/// Peer protocol capabilities
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capabilities: Vec<SessionCapabilityInfo>,
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}
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#[derive(Debug, PartialEq, Eq)]
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pub struct PeerCapabilityInfo {
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pub protocol: String,
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pub version: u8,
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}
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impl Decodable for PeerCapabilityInfo {
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fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
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let c = try!(decoder.as_list());
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let v: u32 = try!(Decodable::decode(&c[1]));
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Ok(PeerCapabilityInfo {
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protocol: try!(Decodable::decode(&c[0])),
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version: v as u8,
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})
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}
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}
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#[derive(Debug, PartialEq, Eq)]
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struct SessionCapabilityInfo {
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pub protocol: &'static str,
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pub version: u8,
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pub packet_count: u8,
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pub id_offset: u8,
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}
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const PACKET_HELLO: u8 = 0x80;
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const PACKET_DISCONNECT: u8 = 0x01;
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const PACKET_PING: u8 = 0x02;
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const PACKET_PONG: u8 = 0x03;
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const PACKET_GET_PEERS: u8 = 0x04;
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const PACKET_PEERS: u8 = 0x05;
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const PACKET_USER: u8 = 0x10;
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const PACKET_LAST: u8 = 0x7f;
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impl Session {
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/// Create a new session out of comepleted handshake. Consumes handshake object.
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pub fn new<Host:Handler<Timeout=Token>>(h: Handshake, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<Session, UtilError> {
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let id = h.id.clone();
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let connection = try!(EncryptedConnection::new(h));
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let mut session = Session {
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connection: connection,
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had_hello: false,
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info: SessionInfo {
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id: id,
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client_version: String::new(),
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protocol_version: 0,
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capabilities: Vec::new(),
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},
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};
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try!(session.write_hello(host));
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try!(session.write_ping());
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try!(session.connection.register(event_loop));
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Ok(session)
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}
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/// Check if session is ready to send/receive data
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pub fn is_ready(&self) -> bool {
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self.had_hello
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}
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/// Readable IO handler. Returns packet data if available.
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pub fn readable<Host:Handler>(&mut self, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<SessionData, UtilError> {
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match try!(self.connection.readable(event_loop)) {
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Some(data) => Ok(try!(self.read_packet(data, host))),
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None => Ok(SessionData::None)
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}
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}
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/// Writable IO handler. Sends pending packets.
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pub fn writable<Host:Handler>(&mut self, event_loop: &mut EventLoop<Host>, _host: &HostInfo) -> Result<(), UtilError> {
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self.connection.writable(event_loop)
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}
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/// Checks if peer supports given capability
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pub fn have_capability(&self, protocol: &str) -> bool {
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self.info.capabilities.iter().any(|c| c.protocol == protocol)
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}
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/// Update registration with the event loop. Should be called at the end of the IO handler.
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pub fn reregister<Host:Handler>(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
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self.connection.reregister(event_loop)
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}
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/// Send a protocol packet to peer.
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pub fn send_packet(&mut self, protocol: &str, packet_id: u8, data: &[u8]) -> Result<(), UtilError> {
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let mut i = 0usize;
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while protocol != self.info.capabilities[i].protocol {
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i += 1;
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if i == self.info.capabilities.len() {
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debug!(target: "net", "Unkown protocol: {:?}", protocol);
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return Ok(())
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}
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}
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let pid = self.info.capabilities[i].id_offset + packet_id;
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let mut rlp = RlpStream::new();
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rlp.append(&(pid as u32));
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rlp.append_raw(data, 1);
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self.connection.send_packet(&rlp.out())
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}
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fn read_packet(&mut self, packet: Packet, host: &HostInfo) -> Result<SessionData, UtilError> {
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if packet.data.len() < 2 {
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return Err(From::from(NetworkError::BadProtocol));
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}
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let packet_id = packet.data[0];
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if packet_id != PACKET_HELLO && packet_id != PACKET_DISCONNECT && !self.had_hello {
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return Err(From::from(NetworkError::BadProtocol));
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}
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match packet_id {
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PACKET_HELLO => {
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let rlp = UntrustedRlp::new(&packet.data[1..]); //TODO: validate rlp expected size
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try!(self.read_hello(&rlp, host));
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Ok(SessionData::Ready)
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},
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PACKET_DISCONNECT => Err(From::from(NetworkError::Disconnect(DisconnectReason::DisconnectRequested))),
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PACKET_PING => {
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try!(self.write_pong());
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Ok(SessionData::None)
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},
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PACKET_GET_PEERS => Ok(SessionData::None), //TODO;
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PACKET_PEERS => Ok(SessionData::None),
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PACKET_USER ... PACKET_LAST => {
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let mut i = 0usize;
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while packet_id < self.info.capabilities[i].id_offset {
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i += 1;
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if i == self.info.capabilities.len() {
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debug!(target: "net", "Unkown packet: {:?}", packet_id);
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return Ok(SessionData::None)
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}
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}
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// map to protocol
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let protocol = self.info.capabilities[i].protocol;
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let pid = packet_id - self.info.capabilities[i].id_offset;
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Ok(SessionData::Packet { data: packet.data, protocol: protocol, packet_id: pid } )
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},
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_ => {
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debug!(target: "net", "Unkown packet: {:?}", packet_id);
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Ok(SessionData::None)
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}
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}
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}
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fn write_hello(&mut self, host: &HostInfo) -> Result<(), UtilError> {
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let mut rlp = RlpStream::new();
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rlp.append_raw(&[PACKET_HELLO as u8], 0);
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rlp.append_list(5)
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.append(&host.protocol_version)
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.append(&host.client_version)
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.append(&host.capabilities)
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.append(&host.listen_port)
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.append(host.id());
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self.connection.send_packet(&rlp.out())
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}
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fn read_hello(&mut self, rlp: &UntrustedRlp, host: &HostInfo) -> Result<(), UtilError> {
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let protocol = try!(rlp.val_at::<u32>(0));
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let client_version = try!(rlp.val_at::<String>(1));
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let peer_caps = try!(rlp.val_at::<Vec<PeerCapabilityInfo>>(2));
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let id = try!(rlp.val_at::<NodeId>(4));
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// Intersect with host capabilities
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// Leave only highset mutually supported capability version
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let mut caps: Vec<SessionCapabilityInfo> = Vec::new();
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for hc in &host.capabilities {
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if peer_caps.iter().any(|c| c.protocol == hc.protocol && c.version == hc.version) {
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caps.push(SessionCapabilityInfo {
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protocol: hc.protocol,
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version: hc.version,
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id_offset: 0,
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packet_count: hc.packet_count,
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});
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}
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}
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caps.retain(|c| host.capabilities.iter().any(|hc| hc.protocol == c.protocol && hc.version == c.version));
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let mut i = 0;
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while i < caps.len() {
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if caps.iter().any(|c| c.protocol == caps[i].protocol && c.version > caps[i].version) {
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caps.remove(i);
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}
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else {
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i += 1;
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}
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}
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i = 0;
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let mut offset: u8 = PACKET_USER;
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while i < caps.len() {
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caps[i].id_offset = offset;
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offset += caps[i].packet_count;
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i += 1;
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}
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trace!(target: "net", "Hello: {} v{} {} {:?}", client_version, protocol, id, caps);
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self.info.client_version = client_version;
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self.info.capabilities = caps;
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if protocol != host.protocol_version {
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return Err(From::from(self.disconnect(DisconnectReason::UselessPeer)));
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}
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self.had_hello = true;
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Ok(())
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}
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fn write_ping(&mut self) -> Result<(), UtilError> {
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self.send(try!(Session::prepare(PACKET_PING)))
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}
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fn write_pong(&mut self) -> Result<(), UtilError> {
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self.send(try!(Session::prepare(PACKET_PONG)))
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}
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fn disconnect(&mut self, reason: DisconnectReason) -> NetworkError {
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let mut rlp = RlpStream::new();
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rlp.append(&(PACKET_DISCONNECT as u32));
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rlp.append_list(1);
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rlp.append(&(reason.clone() as u32));
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self.connection.send_packet(&rlp.out()).ok();
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NetworkError::Disconnect(reason)
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}
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fn prepare(packet_id: u8) -> Result<RlpStream, UtilError> {
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let mut rlp = RlpStream::new();
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rlp.append(&(packet_id as u32));
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rlp.append_list(0);
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Ok(rlp)
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}
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fn send(&mut self, rlp: RlpStream) -> Result<(), UtilError> {
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self.connection.send_packet(&rlp.out())
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}
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}
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