diff options
Diffstat (limited to 'src/sync.rs')
| -rw-r--r-- | src/sync.rs | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/sync.rs b/src/sync.rs new file mode 100644 index 0000000..f89f2bb --- /dev/null +++ b/src/sync.rs @@ -0,0 +1,189 @@ + +use std::io::Read; +use std::net::TcpStream; +use integer_encoding::{VarIntReader, VarIntWriter, VarInt}; +use std::time::Duration; +use crypto::digest::Digest; +use crypto::blake2b::Blake2b; +use rand::{Rng, OsRng}; +use protobuf::Message; +use protobuf::core::parse_from_reader; +use protobuf::core::parse_from_bytes; + +use errors::*; +use network_proto::*; + +// TCP stream +// two varints + +pub enum DatNetMessage { + Register(Feed), + Handshake(Handshake), + Status(Info), + Have(Have), + Unhave(Unhave), + Want(Want), + Unwant(Unwant), + Request(Request), + Cancel(Cancel), + Data(Data), +} + +fn msg_code(msg: &DatNetMessage) -> u8 { + match msg { + &DatNetMessage::Register(_) => 0, + &DatNetMessage::Handshake(_) => 1, + &DatNetMessage::Status(_) => 2, + &DatNetMessage::Have(_) => 3, + &DatNetMessage::Unhave(_) => 4, + &DatNetMessage::Want(_) => 5, + &DatNetMessage::Unwant(_) => 6, + &DatNetMessage::Request(_) => 7, + &DatNetMessage::Cancel(_) => 8, + &DatNetMessage::Data(_) => 9, + } +} + +fn msg_sugar(msg: &DatNetMessage) -> &Message { + match msg { + &DatNetMessage::Register(ref m) => m, + &DatNetMessage::Handshake(ref m) => m, + &DatNetMessage::Status(ref m) => m, + &DatNetMessage::Have(ref m) => m, + &DatNetMessage::Unhave(ref m) => m, + &DatNetMessage::Want(ref m) => m, + &DatNetMessage::Unwant(ref m) => m, + &DatNetMessage::Request(ref m) => m, + &DatNetMessage::Cancel(ref m) => m, + &DatNetMessage::Data(ref m) => m, + } +} + +/// Represents a bi-directional connection to a network peer +/// +/// Spec says nonce is 32 bytes, by dat implementation (hypercore-protocol) is 24 bytes. +pub struct DatConnection { + nonce: [u8; 24], + remote_nonce: [u8; 24], + id: [u8; 32], + stream: TcpStream, +} + +impl DatConnection { + + pub fn connect(host_port: &str, key: &[u8]) -> Result<DatConnection> { + + let timeout = Duration::new(7, 0); + let mut rng = OsRng::new()?; + let mut nonce = [0; 24]; + rng.fill_bytes(&mut nonce); + let mut local_id = [0; 32]; + rng.fill_bytes(&mut local_id); + + // Connect to server + println!("Connecting to {}", host_port); + // TODO: timeout on connect (socketaddr dance) + let stream = TcpStream::connect(host_port)?; + stream.set_read_timeout(Some(timeout))?; + stream.set_write_timeout(Some(timeout))?; + + let mut dc = DatConnection { + nonce: nonce, + remote_nonce: [0; 24], + id: local_id, + stream, + }; + + // Exchange register/feed + dc.stream.set_nodelay(true)?; // Faster handshake + // calculate discovery key + let mut discovery_key = [0; 32]; + let mut hash = Blake2b::new_keyed(32, key); + hash.input(&"hypercore".as_bytes()); + hash.result(&mut discovery_key); + // send register + let mut register_msg = Feed::new(); + register_msg.set_discoveryKey(discovery_key.to_vec()); + register_msg.set_nonce(nonce.to_vec()); + dc.send_msg(false, &DatNetMessage::Register(register_msg))?; + + // read register + let (was_content, msg) = dc.recv_msg()?; + if was_content { + bail!("Expected metadata msg, not content"); + } + if let DatNetMessage::Register(registration) = msg { + if registration.get_discoveryKey()[0..32] != discovery_key[..] { + bail!("Remote peer not sharing same discovery key"); + } + // TODO: more satisfying way to do this transfer + let rn = registration.get_nonce(); + for i in 0..24 { + dc.remote_nonce[i] = rn[i]; + } + } else { + bail!("Expected Registration message, got something else"); + } + + // send handshake + // read handshake + + dc.stream.set_nodelay(false)?; // Back to normal + + Ok(dc) + } + + fn send_msg(&mut self, is_content: bool, dnm: &DatNetMessage) -> Result<()> { + + let header_int: u8 = (is_content as u8) << 4 | (msg_code(dnm) & 0x0F); + let msg: &Message = msg_sugar(dnm); + let total_message_size = (msg.compute_size() as usize) + header_int.required_space(); + + println!("SEND total_len={} header={} is_content={}", total_message_size, header_int, is_content); + + // send both header varints, and data + self.stream.write_varint(total_message_size)?; + self.stream.write_varint(header_int)?; + msg.write_to_writer(&mut self.stream)?; + + Ok(()) + } + + fn recv_msg(&mut self) -> Result<(bool, DatNetMessage)> { + let total_len: u64 = self.stream.read_varint()?; + let header: u8 = self.stream.read_varint()?; + + let is_content = (header & (1 << 4)) != 0; + + println!("RECV total_len={} header={} is_content={}", total_len, header, is_content); + + // XXX: replace with coded, buffered streams + let mut buf = [0; 1024]; + let msg_len = (total_len - 1) as usize; + let len = self.stream.read(&mut buf[0..msg_len])?; + println!("raw read: {} first={}", len, buf[0]); + + let dnm = match header & 0x0F { + 0 => DatNetMessage::Register(parse_from_bytes::<Feed>(&mut buf[0..msg_len])?), + 1 => DatNetMessage::Handshake(parse_from_reader::<Handshake>(&mut self.stream)?), + 2 => DatNetMessage::Status(parse_from_reader::<Info>(&mut self.stream)?), + 3 => DatNetMessage::Have(parse_from_reader::<Have>(&mut self.stream)?), + 4 => DatNetMessage::Unhave(parse_from_reader::<Unhave>(&mut self.stream)?), + 5 => DatNetMessage::Want(parse_from_reader::<Want>(&mut self.stream)?), + 6 => DatNetMessage::Unwant(parse_from_reader::<Unwant>(&mut self.stream)?), + 7 => DatNetMessage::Request(parse_from_reader::<Request>(&mut self.stream)?), + 8 => DatNetMessage::Cancel(parse_from_reader::<Cancel>(&mut self.stream)?), + 9 => DatNetMessage::Data(parse_from_reader::<Data>(&mut self.stream)?), + _ => bail!("Unimplemented message type received"), + }; + Ok((is_content, dnm)) + } + + fn receive_all(&self) -> Result<()> { + + // Status: downloading, not uploading + // Have: nothing + // Want: everything + unimplemented!(); + } +} |