1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
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!();
}
}
|
