openethereum/util/src/network/session.rs
2016-03-20 16:21:49 +01:00

410 lines
12 KiB
Rust

// Copyright 2015, 2016 Ethcore (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::net::SocketAddr;
use std::io;
use mio::*;
use hash::*;
use rlp::*;
use network::connection::{EncryptedConnection, Packet};
use network::handshake::Handshake;
use error::*;
use io::{IoContext, StreamToken};
use network::error::{NetworkError, DisconnectReason};
use network::host::*;
use network::node_table::NodeId;
use time;
const PING_TIMEOUT_SEC: u64 = 30;
const PING_INTERVAL_SEC: u64 = 30;
/// Peer session over encrypted connection.
/// When created waits for Hello packet exchange and signals ready state.
/// Sends and receives protocol packets and handles basic packes such as ping/pong and disconnect.
pub struct Session {
/// Shared session information
pub info: SessionInfo,
/// Underlying connection
connection: EncryptedConnection,
/// Session ready flag. Set after successfull Hello packet exchange
had_hello: bool,
/// Session is no longer active flag.
expired: bool,
ping_time_ns: u64,
pong_time_ns: Option<u64>,
}
/// Structure used to report various session events.
pub enum SessionData {
None,
/// Session is ready to send/receive packets.
Ready,
/// A packet has been received
Packet {
/// Packet data
data: Vec<u8>,
/// Packet protocol ID
protocol: &'static str,
/// Zero based packet ID
packet_id: u8,
},
}
/// Shared session information
pub struct SessionInfo {
/// Peer public key
pub id: NodeId,
/// Peer client ID
pub client_version: String,
/// Peer RLPx protocol version
pub protocol_version: u32,
/// Peer protocol capabilities
capabilities: Vec<SessionCapabilityInfo>,
/// Peer ping delay in milliseconds
pub ping_ms: Option<u64>,
}
#[derive(Debug, PartialEq, Eq)]
pub struct PeerCapabilityInfo {
pub protocol: String,
pub version: u8,
}
impl Decodable for PeerCapabilityInfo {
fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
let c = decoder.as_rlp();
Ok(PeerCapabilityInfo {
protocol: try!(c.val_at(0)),
version: try!(c.val_at(1))
})
}
}
#[derive(Debug)]
struct SessionCapabilityInfo {
pub protocol: &'static str,
pub version: u8,
pub packet_count: u8,
pub id_offset: u8,
}
const PACKET_HELLO: u8 = 0x80;
const PACKET_DISCONNECT: u8 = 0x01;
const PACKET_PING: u8 = 0x02;
const PACKET_PONG: u8 = 0x03;
const PACKET_GET_PEERS: u8 = 0x04;
const PACKET_PEERS: u8 = 0x05;
const PACKET_USER: u8 = 0x10;
const PACKET_LAST: u8 = 0x7f;
impl Session {
/// Create a new session out of comepleted handshake. This clones the handshake connection object
/// and leaves the handhsake in limbo to be deregistered from the event loop.
pub fn new(h: &mut Handshake, host: &HostInfo) -> Result<Session, UtilError> {
let id = h.id.clone();
let connection = try!(EncryptedConnection::new(h));
let mut session = Session {
connection: connection,
had_hello: false,
info: SessionInfo {
id: id,
client_version: String::new(),
protocol_version: 0,
capabilities: Vec::new(),
ping_ms: None,
},
ping_time_ns: 0,
pong_time_ns: None,
expired: false,
};
try!(session.write_hello(host));
try!(session.send_ping());
Ok(session)
}
/// Get id of the remote peer
pub fn id(&self) -> &NodeId {
&self.info.id
}
/// Check if session is ready to send/receive data
pub fn is_ready(&self) -> bool {
self.had_hello
}
/// Mark this session as inactive to be deleted lated.
pub fn set_expired(&mut self) {
self.expired = true;
}
/// Check if this session is expired.
pub fn expired(&self) -> bool {
self.expired
}
/// Replace socket token
pub fn set_token(&mut self, token: StreamToken) {
self.connection.set_token(token);
}
/// Get remote peer address
pub fn remote_addr(&self) -> io::Result<SocketAddr> {
self.connection.remote_addr()
}
/// Readable IO handler. Returns packet data if available.
pub fn readable<Message>(&mut self, io: &IoContext<Message>, host: &HostInfo) -> Result<SessionData, UtilError> where Message: Send + Sync + Clone {
if self.expired() {
return Ok(SessionData::None)
}
match try!(self.connection.readable(io)) {
Some(data) => Ok(try!(self.read_packet(data, host))),
None => Ok(SessionData::None)
}
}
/// Writable IO handler. Sends pending packets.
pub fn writable<Message>(&mut self, io: &IoContext<Message>, _host: &HostInfo) -> Result<(), UtilError> where Message: Send + Sync + Clone {
if self.expired() {
return Ok(())
}
self.connection.writable(io)
}
/// Checks if peer supports given capability
pub fn have_capability(&self, protocol: &str) -> bool {
self.info.capabilities.iter().any(|c| c.protocol == protocol)
}
/// Register the session socket with the event loop
pub fn register_socket<Host:Handler<Timeout = Token>>(&self, reg: Token, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
if self.expired() {
return Ok(());
}
try!(self.connection.register_socket(reg, event_loop));
Ok(())
}
/// Update registration with the event loop. Should be called at the end of the IO handler.
pub fn update_socket<Host:Handler>(&self, reg:Token, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
if self.expired() {
return Ok(());
}
self.connection.update_socket(reg, event_loop)
}
/// Delete registration
pub fn deregister_socket<Host:Handler>(&self, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
self.connection.deregister_socket(event_loop)
}
/// Send a protocol packet to peer.
pub fn send_packet(&mut self, protocol: &str, packet_id: u8, data: &[u8]) -> Result<(), UtilError> {
if self.info.capabilities.is_empty() || !self.had_hello {
debug!(target: "network", "Sending to unconfirmed session {}, protocol: {}, packet: {}", self.token(), protocol, packet_id);
return Err(From::from(NetworkError::BadProtocol));
}
if self.expired() {
return Err(From::from(NetworkError::Expired));
}
let mut i = 0usize;
while protocol != self.info.capabilities[i].protocol {
i += 1;
if i == self.info.capabilities.len() {
debug!(target: "net", "Unknown protocol: {:?}", protocol);
return Ok(())
}
}
let pid = self.info.capabilities[i].id_offset + packet_id;
let mut rlp = RlpStream::new();
rlp.append(&(pid as u32));
rlp.append_raw(data, 1);
self.connection.send_packet(&rlp.out())
}
/// Keep this session alive. Returns false if ping timeout happened
pub fn keep_alive<Message>(&mut self, io: &IoContext<Message>) -> bool where Message: Send + Sync + Clone {
let timed_out = if let Some(pong) = self.pong_time_ns {
pong - self.ping_time_ns > PING_TIMEOUT_SEC * 1000_000_000
} else {
time::precise_time_ns() - self.ping_time_ns > PING_TIMEOUT_SEC * 1000_000_000
};
if !timed_out && time::precise_time_ns() - self.ping_time_ns > PING_INTERVAL_SEC * 1000_000_000 {
if let Err(e) = self.send_ping() {
debug!("Error sending ping message: {:?}", e);
}
io.update_registration(self.token()).unwrap_or_else(|e| debug!(target: "net", "Session registration error: {:?}", e));
}
!timed_out
}
pub fn token(&self) -> StreamToken {
self.connection.token()
}
fn read_packet(&mut self, packet: Packet, host: &HostInfo) -> Result<SessionData, UtilError> {
if packet.data.len() < 2 {
return Err(From::from(NetworkError::BadProtocol));
}
let packet_id = packet.data[0];
if packet_id != PACKET_HELLO && packet_id != PACKET_DISCONNECT && !self.had_hello {
return Err(From::from(NetworkError::BadProtocol));
}
match packet_id {
PACKET_HELLO => {
let rlp = UntrustedRlp::new(&packet.data[1..]); //TODO: validate rlp expected size
try!(self.read_hello(&rlp, host));
Ok(SessionData::Ready)
},
PACKET_DISCONNECT => {
let rlp = UntrustedRlp::new(&packet.data[1..]);
let reason: u8 = try!(rlp.val_at(0));
Err(From::from(NetworkError::Disconnect(DisconnectReason::from_u8(reason))))
}
PACKET_PING => {
try!(self.send_pong());
Ok(SessionData::None)
},
PACKET_PONG => {
self.pong_time_ns = Some(time::precise_time_ns());
self.info.ping_ms = Some((self.pong_time_ns.unwrap() - self.ping_time_ns) / 1000_000);
Ok(SessionData::None)
},
PACKET_GET_PEERS => Ok(SessionData::None), //TODO;
PACKET_PEERS => Ok(SessionData::None),
PACKET_USER ... PACKET_LAST => {
let mut i = 0usize;
while packet_id < self.info.capabilities[i].id_offset {
i += 1;
if i == self.info.capabilities.len() {
debug!(target: "net", "Unknown packet: {:?}", packet_id);
return Ok(SessionData::None)
}
}
// map to protocol
let protocol = self.info.capabilities[i].protocol;
let pid = packet_id - self.info.capabilities[i].id_offset;
Ok(SessionData::Packet { data: packet.data, protocol: protocol, packet_id: pid } )
},
_ => {
debug!(target: "net", "Unknown packet: {:?}", packet_id);
Ok(SessionData::None)
}
}
}
fn write_hello(&mut self, host: &HostInfo) -> Result<(), UtilError> {
let mut rlp = RlpStream::new();
rlp.append_raw(&[PACKET_HELLO as u8], 0);
rlp.begin_list(5)
.append(&host.protocol_version)
.append(&host.client_version)
.append(&host.capabilities)
.append(&host.local_endpoint.address.port())
.append(host.id());
self.connection.send_packet(&rlp.out())
}
fn read_hello(&mut self, rlp: &UntrustedRlp, host: &HostInfo) -> Result<(), UtilError> {
let protocol = try!(rlp.val_at::<u32>(0));
let client_version = try!(rlp.val_at::<String>(1));
let peer_caps = try!(rlp.val_at::<Vec<PeerCapabilityInfo>>(2));
let id = try!(rlp.val_at::<NodeId>(4));
// Intersect with host capabilities
// Leave only highset mutually supported capability version
let mut caps: Vec<SessionCapabilityInfo> = Vec::new();
for hc in &host.capabilities {
if peer_caps.iter().any(|c| c.protocol == hc.protocol && c.version == hc.version) {
caps.push(SessionCapabilityInfo {
protocol: hc.protocol,
version: hc.version,
id_offset: 0,
packet_count: hc.packet_count,
});
}
}
caps.retain(|c| host.capabilities.iter().any(|hc| hc.protocol == c.protocol && hc.version == c.version));
let mut i = 0;
while i < caps.len() {
if caps.iter().any(|c| c.protocol == caps[i].protocol && c.version > caps[i].version) {
caps.remove(i);
}
else {
i += 1;
}
}
i = 0;
let mut offset: u8 = PACKET_USER;
while i < caps.len() {
caps[i].id_offset = offset;
offset += caps[i].packet_count;
i += 1;
}
trace!(target: "network", "Hello: {} v{} {} {:?}", client_version, protocol, id, caps);
self.info.client_version = client_version;
self.info.capabilities = caps;
if self.info.capabilities.is_empty() {
trace!(target: "network", "No common capabilities with peer.");
return Err(From::from(self.disconnect(DisconnectReason::UselessPeer)));
}
if protocol != host.protocol_version {
trace!(target: "network", "Peer protocol version mismatch: {}", protocol);
return Err(From::from(self.disconnect(DisconnectReason::UselessPeer)));
}
self.had_hello = true;
Ok(())
}
/// Senf ping packet
pub fn send_ping(&mut self) -> Result<(), UtilError> {
try!(self.send(try!(Session::prepare(PACKET_PING))));
self.ping_time_ns = time::precise_time_ns();
self.pong_time_ns = None;
Ok(())
}
fn send_pong(&mut self) -> Result<(), UtilError> {
self.send(try!(Session::prepare(PACKET_PONG)))
}
/// Disconnect this session
pub fn disconnect(&mut self, reason: DisconnectReason) -> NetworkError {
let mut rlp = RlpStream::new();
rlp.append(&(PACKET_DISCONNECT as u32));
rlp.begin_list(1);
rlp.append(&(reason as u32));
self.connection.send_packet(&rlp.out()).ok();
NetworkError::Disconnect(reason)
}
fn prepare(packet_id: u8) -> Result<RlpStream, UtilError> {
let mut rlp = RlpStream::new();
rlp.append(&(packet_id as u32));
rlp.begin_list(0);
Ok(rlp)
}
fn send(&mut self, rlp: RlpStream) -> Result<(), UtilError> {
self.connection.send_packet(&rlp.out())
}
}