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
|
use super::*;
use byteorder::{BigEndian, WriteBytesExt};
use std::{
borrow::Cow,
collections::HashMap,
io::{self, Write},
sync::Arc,
};
use tokio::sync::{watch, Mutex, RwLock};
pub type Ack = Option<watch::Receiver<bool>>;
#[derive(Debug)]
pub(crate) struct AckWait {
pub(crate) tx: watch::Sender<bool>,
pub(crate) rx: watch::Receiver<bool>,
pub(crate) data: Vec<u8>,
}
#[derive(Debug)]
pub(crate) struct Chan {
pub(crate) acks: HashMap<u16, AckWait>,
pub(crate) seqnum: u16,
pub(crate) splits_seqnum: u16,
}
#[derive(Debug)]
pub struct Sender<S: UdpSender> {
pub(crate) id: u16,
pub(crate) remote_id: RwLock<u16>,
pub(crate) chans: [Mutex<Chan>; NUM_CHANS],
udp: S,
close: watch::Sender<bool>,
}
impl<S: UdpSender> Sender<S> {
pub fn new(udp: S, close: watch::Sender<bool>, id: u16, remote_id: u16) -> Arc<Self> {
Arc::new(Self {
id,
remote_id: RwLock::new(remote_id),
udp,
close,
chans: std::array::from_fn(|_| {
Mutex::new(Chan {
acks: HashMap::new(),
seqnum: INIT_SEQNUM,
splits_seqnum: INIT_SEQNUM,
})
}),
})
}
pub async fn send_rudp(&self, pkt: Pkt<'_>) -> io::Result<Ack> {
if pkt.size() > UDP_PKT_SIZE {
let chunks = pkt
.data
.chunks(UDP_PKT_SIZE - (pkt.header_size() + 1 + 2 + 2 + 2));
let num_chunks: u16 = chunks
.len()
.try_into()
.map_err(|_| io::Error::new(io::ErrorKind::Other, "too many chunks"))?;
let seqnum = {
let mut chan = self.chans[pkt.chan as usize].lock().await;
let sn = chan.splits_seqnum;
chan.splits_seqnum = chan.splits_seqnum.overflowing_add(1).0;
sn
};
for (i, ch) in chunks.enumerate() {
self.send_rudp_type(
PktType::Orig,
Some((seqnum, num_chunks, i as u16)),
Pkt {
unrel: pkt.unrel,
chan: pkt.chan,
data: Cow::Borrowed(ch),
},
)
.await?;
}
Ok(None) // TODO: ack
} else {
self.send_rudp_type(PktType::Orig, None, pkt).await
}
}
pub async fn send_rudp_type(
&self,
tp: PktType,
chunk: Option<(u16, u16, u16)>,
pkt: Pkt<'_>,
) -> io::Result<Ack> {
let mut buf =
Vec::with_capacity(pkt.size() + if chunk.is_some() { 1 + 2 + 2 + 2 } else { 0 });
buf.write_u32::<BigEndian>(PROTO_ID)?;
buf.write_u16::<BigEndian>(*self.remote_id.read().await)?;
buf.write_u8(pkt.chan)?;
let mut chan = self.chans[pkt.chan as usize].lock().await;
let seqnum = chan.seqnum;
if !pkt.unrel {
buf.write_u8(PktType::Rel as u8)?;
buf.write_u16::<BigEndian>(seqnum)?;
}
if let Some((seqnum, count, index)) = chunk {
buf.write_u8(PktType::Split as u8)?;
buf.write_u16::<BigEndian>(seqnum)?;
buf.write_u16::<BigEndian>(count)?;
buf.write_u16::<BigEndian>(index)?;
} else {
buf.write_u8(tp as u8)?;
}
buf.write_all(pkt.data.as_ref())?;
self.send_udp(&buf).await?;
if pkt.unrel {
Ok(None)
} else {
// TODO: reliable window
let (tx, rx) = watch::channel(false);
chan.acks.insert(
seqnum,
AckWait {
tx,
rx: rx.clone(),
data: buf,
},
);
chan.seqnum = chan.seqnum.overflowing_add(1).0;
Ok(Some(rx))
}
}
pub async fn send_udp(&self, data: &[u8]) -> io::Result<()> {
if data.len() > UDP_PKT_SIZE {
panic!(
"attempted to send a packet with len {} > {UDP_PKT_SIZE}",
data.len()
);
}
self.udp.send(data).await
}
pub async fn peer_id(&self) -> u16 {
self.id
}
pub async fn is_server(&self) -> bool {
self.id == PeerID::Srv as u16
}
pub fn close(&self) {
self.close.send(true).ok();
}
}
|
