src/lib.rs

   1 #![feature(cursor_remaining)]
   2 #![feature(hash_drain_filter)]
   3 #![feature(once_cell)]
   4 mod client;
   5 mod error;
   6 mod new;
   7 mod recv;
   8 mod send;
   9
  10 pub use prelude::*;
  11
  12 use async_trait::async_trait;
  13 use num_enum::TryFromPrimitive;
  14 use std::{
  15     cell::{Cell, OnceCell},
  16     collections::HashMap,
  17     io, ops,
  18     sync::Arc,
  19     time::Instant,
  20 };
  21 use tokio::{
  22     sync::{mpsc, watch, Mutex, RwLock},
  23     task::JoinSet,
  24 };
  25
  26 #[async_trait]
  27 pub trait UdpSender: Send + Sync + 'static {
  28     async fn send(&self, data: &[u8]) -> io::Result<()>;
  29 }
  30
  31 #[async_trait]
  32 pub trait UdpReceiver: Send + Sync + 'static {
  33     async fn recv(&self) -> io::Result<Vec<u8>>;
  34 }
  35
  36 #[derive(Debug, Copy, Clone, PartialEq)]
  37 #[repr(u16)]
  38 pub enum PeerID {
  39     Nil = 0,
  40     Srv,
  41     CltMin,
  42 }
  43
  44 #[derive(Debug, Copy, Clone, PartialEq, TryFromPrimitive)]
  45 #[repr(u8)]
  46 pub enum PktType {
  47     Ctl = 0,
  48     Orig,
  49     Split,
  50     Rel,
  51 }
  52
  53 #[derive(Debug, Copy, Clone, PartialEq, TryFromPrimitive)]
  54 #[repr(u8)]
  55 pub enum CtlType {
  56     Ack = 0,
  57     SetPeerID,
  58     Ping,
  59     Disco,
  60 }
  61
  62 #[derive(Debug)]
  63 pub struct Pkt<T> {
  64     pub unrel: bool,
  65     pub chan: u8,
  66     pub data: T,
  67 }
  68
  69 pub type InPkt = Result<Pkt<Vec<u8>>, error::Error>;
  70
  71 #[derive(Debug)]
  72 struct Ack {
  73     tx: watch::Sender<bool>,
  74     rx: watch::Receiver<bool>,
  75     data: Vec<u8>,
  76 }
  77
  78 #[derive(Debug)]
  79 struct Chan {
  80     acks: HashMap<u16, Ack>,
  81     seqnum: u16,
  82 }
  83
  84 #[derive(Debug)]
  85 struct RudpShare<S: UdpSender> {
  86     id: u16,
  87     remote_id: RwLock<u16>,
  88     chans: Vec<Mutex<Chan>>,
  89     udp_tx: S,
  90     close_tx: watch::Sender<bool>,
  91     tasks: Mutex<JoinSet<()>>,
  92 }
  93
  94 #[derive(Debug)]
  95 pub struct RudpReceiver<S: UdpSender> {
  96     share: Arc<RudpShare<S>>,
  97     pkt_rx: mpsc::UnboundedReceiver<InPkt>,
  98 }
  99
 100 #[derive(Debug)]
 101 pub struct RudpSender<S: UdpSender> {
 102     share: Arc<RudpShare<S>>,
 103 }
 104
 105 macro_rules! impl_share {
 106     ($T:ident) => {
 107         impl<S: UdpSender> $T<S> {
 108             pub async fn peer_id(&self) -> u16 {
 109                 self.share.id
 110             }
 111
 112             pub async fn is_server(&self) -> bool {
 113                 self.share.id == PeerID::Srv as u16
 114             }
 115
 116             pub async fn close(self) {
 117                 self.share.close_tx.send(true).ok();
 118
 119                 let mut tasks = self.share.tasks.lock().await;
 120                 while let Some(res) = tasks.join_next().await {
 121                     res.ok(); // TODO: handle error (?)
 122                 }
 123             }
 124         }
 125     };
 126 }
 127
 128 impl_share!(RudpReceiver);
 129 impl_share!(RudpSender);
 130
 131 impl<S: UdpSender> ops::Deref for RudpReceiver<S> {
 132     type Target = mpsc::UnboundedReceiver<InPkt>;
 133
 134     fn deref(&self) -> &Self::Target {
 135         &self.pkt_rx
 136     }
 137 }
 138
 139 impl<S: UdpSender> ops::DerefMut for RudpReceiver<S> {
 140     fn deref_mut(&mut self) -> &mut Self::Target {
 141         &mut self.pkt_rx
 142     }
 143 }
 144
 145 #[derive(Debug)]
 146 struct Split {
 147     timestamp: Option<Instant>,
 148     chunks: Vec<OnceCell<Vec<u8>>>,
 149     got: usize,
 150 }
 151
 152 struct RecvChan {
 153     packets: Vec<Cell<Option<Vec<u8>>>>, // char ** 😛
 154     splits: HashMap<u16, Split>,
 155     seqnum: u16,
 156     num: u8,
 157 }
 158
 159 struct RecvWorker<R: UdpReceiver, S: UdpSender> {
 160     share: Arc<RudpShare<S>>,
 161     close: watch::Receiver<bool>,
 162     chans: Arc<Vec<Mutex<RecvChan>>>,
 163     pkt_tx: mpsc::UnboundedSender<InPkt>,
 164     udp_rx: R,
 165 }
 166
 167 mod prelude {
 168     pub const PROTO_ID: u32 = 0x4f457403;
 169     pub const UDP_PKT_SIZE: usize = 512;
 170     pub const NUM_CHANS: usize = 3;
 171     pub const REL_BUFFER: usize = 0x8000;
 172     pub const INIT_SEQNUM: u16 = 65500;
 173     pub const TIMEOUT: u64 = 30;
 174     pub const PING_TIMEOUT: u64 = 5;
 175
 176     pub use super::{
 177         client::{connect, Sender as Client},
 178         error::Error,
 179         new::new,
 180         CtlType, InPkt, PeerID, Pkt, PktType, RudpReceiver, RudpSender, UdpReceiver, UdpSender,
 181     };
 182
 183     #[macro_export]
 184     macro_rules! ticker {
 185                 ($duration:expr, $close:expr, $body:block) => {
 186                         let mut interval = tokio::time::interval($duration);
 187
 188                         while tokio::select!{
 189                                 _ = interval.tick() => true,
 190                                 _ = $close.changed() => false,
 191                         } $body
 192                 };
 193         }
 194 }