_ Git - dnsseed-rust/blob - src/peer.rs

   1 use std::cmp;
   2 use std::net::{SocketAddr, IpAddr};
   3 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
   4
   5 use bitcoin::consensus::encode;
   6 use bitcoin::consensus::encode::{Decodable, Encodable};
   7 use bitcoin::network::address::Address;
   8 use bitcoin::network::constants::{Network, ServiceFlags};
   9 use bitcoin::network::message::{RawNetworkMessage, NetworkMessage};
  10 use bitcoin::network::message_network::VersionMessage;
  11
  12 use tokio::prelude::*;
  13 use tokio::codec;
  14 use tokio::codec::Framed;
  15 use tokio::net::TcpStream;
  16 use tokio::io::read_exact;
  17 use tokio::timer::Delay;
  18
  19 use futures::sync::mpsc;
  20
  21 use crate::printer::Printer;
  22
  23 struct BytesCoder<'a>(&'a mut bytes::BytesMut);
  24 impl<'a> std::io::Write for BytesCoder<'a> {
  25         fn write(&mut self, b: &[u8]) -> Result<usize, std::io::Error> {
  26                 self.0.extend_from_slice(&b);
  27                 Ok(b.len())
  28         }
  29         fn flush(&mut self) -> Result<(), std::io::Error> {
  30                 Ok(())
  31         }
  32 }
  33 struct BytesDecoder<'a> {
  34         buf: &'a mut bytes::BytesMut,
  35         pos: usize,
  36 }
  37 impl<'a> std::io::Read for BytesDecoder<'a> {
  38         fn read(&mut self, b: &mut [u8]) -> Result<usize, std::io::Error> {
  39                 let copy_len = cmp::min(b.len(), self.buf.len() - self.pos);
  40                 b[..copy_len].copy_from_slice(&self.buf[self.pos..self.pos + copy_len]);
  41                 self.pos += copy_len;
  42                 Ok(copy_len)
  43         }
  44 }
  45
  46 struct MsgCoder<'a>(&'a Printer);
  47 impl<'a> codec::Decoder for MsgCoder<'a> {
  48         type Item = Option<NetworkMessage>;
  49         type Error = encode::Error;
  50
  51         fn decode(&mut self, bytes: &mut bytes::BytesMut) -> Result<Option<Option<NetworkMessage>>, encode::Error> {
  52                 let mut decoder = BytesDecoder {
  53                         buf: bytes,
  54                         pos: 0
  55                 };
  56                 match RawNetworkMessage::consensus_decode(&mut decoder) {
  57                         Ok(res) => {
  58                                 decoder.buf.advance(decoder.pos);
  59                                 if res.magic == Network::Bitcoin.magic() {
  60                                         Ok(Some(Some(res.payload)))
  61                                 } else {
  62                                         Err(encode::Error::UnexpectedNetworkMagic {
  63                                                 expected: Network::Bitcoin.magic(),
  64                                                 actual: res.magic
  65                                         })
  66                                 }
  67                         },
  68                         Err(e) => match e {
  69                                 encode::Error::Io(_) => Ok(None),
  70                                 _ => {
  71                                         self.0.add_line(format!("Error decoding message: {:?}", e), true);
  72                                         Err(e)
  73                                 },
  74                         }
  75                 }
  76         }
  77 }
  78 impl<'a> codec::Encoder for MsgCoder<'a> {
  79         type Item = NetworkMessage;
  80         type Error = std::io::Error;
  81
  82         fn encode(&mut self, msg: NetworkMessage, res: &mut bytes::BytesMut) -> Result<(), std::io::Error> {
  83                 if let Err(_) = (RawNetworkMessage {
  84                         magic: Network::Bitcoin.magic(),
  85                         payload: msg,
  86                 }.consensus_encode(&mut BytesCoder(res))) {
  87                         //XXX
  88                 }
  89                 Ok(())
  90         }
  91 }
  92
  93 // base32 encoder and tests stolen (transliterated) from Bitcoin Core
  94 // Copyright (c) 2012-2019 The Bitcoin Core developers
  95 // Distributed under the MIT software license, see
  96 // http://www.opensource.org/licenses/mit-license.php.
  97 fn encode_base32(inp: &[u8]) -> String {
  98         let mut ret = String::with_capacity(((inp.len() + 4) / 5) * 8);
  99
 100         let alphabet = "abcdefghijklmnopqrstuvwxyz234567";
 101         let mut acc: u16 = 0;
 102         let mut bits: u8 = 0;
 103         for i in inp {
 104                 acc = ((acc << 8) | *i as u16) & ((1 << (8 + 5 - 1)) - 1);
 105                 bits += 8;
 106                 while bits >= 5 {
 107                         bits -= 5;
 108                         let idx = ((acc >> bits) & ((1 << 5) - 1)) as usize;
 109                         ret += &alphabet[idx..idx + 1];
 110                 }
 111         }
 112         if bits != 0 {
 113                 let idx = ((acc << (5 - bits)) & ((1 << 5) - 1)) as usize;
 114                 ret += &alphabet[idx..idx + 1];
 115         }
 116         while ret.len() % 8 != 0 { ret += "=" };
 117         return ret;
 118 }
 119
 120 #[test]
 121 fn test_encode_base32() {
 122         let tests_in = ["","f","fo","foo","foob","fooba","foobar"];
 123         let tests_out = ["","my======","mzxq====","mzxw6===","mzxw6yq=","mzxw6ytb","mzxw6ytboi======"];
 124         for (inp, out) in tests_in.iter().zip(tests_out.iter()) {
 125                 assert_eq!(&encode_base32(inp.as_bytes()), out);
 126         }
 127         // My seednode's onion addr:
 128         assert_eq!(&encode_base32(&[0x6a, 0x8b, 0xd2, 0x78, 0x3f, 0x7a, 0xf8, 0x92, 0x8f, 0x80]), "nkf5e6b7pl4jfd4a");
 129 }
 130
 131 /// Note that this should only be used for really small chunks, ie small enough to *definitely* fit
 132 /// in the outbound TCP buffer, and shouldn't (practically) block.
 133 macro_rules! try_write_small {
 134         ($sock: expr, $obj: expr) => { {
 135                 match $sock.write_all($obj) {
 136                         Ok(()) => {},
 137                         Err(e) => return future::Either::A(future::err(e)),
 138                 }
 139         } }
 140 }
 141
 142 pub struct Peer {}
 143 impl Peer {
 144         pub fn new(addr: SocketAddr, tor_proxy: &SocketAddr, timeout: Duration, printer: &'static Printer) -> impl Future<Error=(), Item=(mpsc::Sender<NetworkMessage>, impl Stream<Item=Option<NetworkMessage>, Error=encode::Error>)> {
 145                 let connect_timeout = Delay::new(Instant::now() + timeout.clone()).then(|_| {
 146                         future::err(std::io::Error::new(std::io::ErrorKind::TimedOut, "timeout reached"))
 147                 });
 148                 match addr.ip() {
 149                         IpAddr::V6(v6addr) if v6addr.octets()[..6] == [0xFD,0x87,0xD8,0x7E,0xEB,0x43][..] => {
 150                                 future::Either::A(connect_timeout.select(TcpStream::connect(&tor_proxy)
 151                                         .and_then(move |mut stream: TcpStream| {
 152                                                 try_write_small!(stream, &[5u8, 1u8, 0u8]); // SOCKS5 with 1 method and no auth
 153                                                 future::Either::B(read_exact(stream, [0u8; 2]).and_then(move |(mut stream, response)| {
 154                                                         if response != [5, 0] { // SOCKS5 with no auth successful
 155                                                                 future::Either::B(future::Either::A(future::err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Failed to authenticate"))))
 156                                                         } else {
 157                                                                 let hostname = encode_base32(&v6addr.octets()[6..]) + ".onion";
 158                                                                 let mut connect_msg = Vec::with_capacity(7 + hostname.len());
 159                                                                 // SOCKS5 command CONNECT (+ reserved byte) to hostname with given len
 160                                                                 connect_msg.extend_from_slice(&[5u8, 1u8, 0u8, 3u8, hostname.len() as u8]);
 161                                                                 connect_msg.extend_from_slice(hostname.as_bytes());
 162                                                                 connect_msg.push((addr.port() >> 8) as u8);
 163                                                                 connect_msg.push((addr.port() >> 0) as u8);
 164                                                                 try_write_small!(stream, &connect_msg);
 165                                                                 future::Either::B(future::Either::B(read_exact(stream, [0u8; 4]).and_then(move |(stream, response)| {
 166                                                                         if response[..3] != [5, 0, 0] {
 167                                                                                 future::Either::B(future::err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Failed to authenticate")))
 168                                                                         } else {
 169                                                                                 if response[3] == 1 {
 170                                                                                         future::Either::A(future::Either::A(read_exact(stream, [0; 6]).and_then(|(stream, _)| future::ok(stream))))
 171                                                                                 } else if response[3] == 4 {
 172                                                                                         future::Either::A(future::Either::B(read_exact(stream, [0; 18]).and_then(|(stream, _)| future::ok(stream))))
 173                                                                                 } else {
 174                                                                                         future::Either::B(future::err(std::io::Error::new(std::io::ErrorKind::InvalidData, "Bogus proxy address value")))
 175                                                                                 }
 176                                                                         }
 177                                                                 })))
 178                                                         }
 179                                                 }))
 180                                         })
 181                                 ).and_then(|(stream, _)| future::ok(stream)).or_else(|(e, _)| future::err(e)))
 182                         },
 183                         _ => future::Either::B(connect_timeout.select(TcpStream::connect(&addr))
 184                                 .and_then(|(stream, _)| future::ok(stream)).or_else(|(e, _)| future::err(e))),
 185                 }.and_then(move |stream| {
 186                                 let (write, read) = Framed::new(stream, MsgCoder(printer)).split();
 187                                 let (mut sender, receiver) = mpsc::channel(10); // We never really should send more than 10 messages unless they're dumb
 188                                 tokio::spawn(write.sink_map_err(|_| { () }).send_all(receiver)
 189                                         .then(|_| {
 190                                                 future::err(())
 191                                         }));
 192                                 let _ = sender.try_send(NetworkMessage::Version(VersionMessage {
 193                                         version: 70015,
 194                                         services: ServiceFlags::WITNESS,
 195                                         timestamp: SystemTime::now().duration_since(UNIX_EPOCH).expect("time > 1970").as_secs() as i64,
 196                                         receiver: Address::new(&addr, ServiceFlags::NONE),
 197                                         sender: Address::new(&"0.0.0.0:0".parse().unwrap(), ServiceFlags::WITNESS),
 198                                         nonce: 0xdeadbeef,
 199                                         user_agent: "/rust-bitcoin:0.18/bluematt-tokio-client:0.1/".to_string(),
 200                                         start_height: 0,
 201                                         relay: false,
 202                                 }));
 203                                 future::ok((sender, read))
 204                         })
 205                 .or_else(move |_| {
 206                         Delay::new(Instant::now() + timeout / 10).then(|_| future::err(()))
 207                 })
 208         }
 209 }