init torrent.get_peers() with async_std::UdpSocket

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 
 
 [dependencies]
+async-std = { version = "1.6.1", features = ["attributes"] }
 serde_bencode = "^0.2.1"
 serde = "^1.0.0"
 serde_derive = "^1.0.0"

README.md

@@ -0,0 +1,2 @@
+# torrent-rs
+BitTorrent client

src/lib.rs

@@ -1,6 +1,9 @@
+use async_std::net::{SocketAddr, ToSocketAddrs, UdpSocket};
+use std::error::Error;
+
 use byteorder::{BigEndian, ByteOrder};
 use rand::Rng;
-use sha1::{Digest, Sha1};
+use sha1::{Sha1, Digest};
 
 extern crate serde;
 extern crate serde_bencode;
@@ -87,10 +90,67 @@ impl Torrent {
         let result = hasher.finalize();
         result.to_vec()
     }
-}
+    pub fn protocol(&self) -> Option<&str> {
+        match &self.announce {
+            Some(s) => {
+                let aux: Vec<&str> = s.split(":").collect();
+                Some(aux[0])
+            }
+            _ => None,
+        }
+    }
+    // pub fn peer(&self) -> Option<&str> {
+    //     match &self.announce {
+    //         Some(s) => {
+    //             let aux: Vec<&str> = s.split(":").collect();
+    //             Some(aux[1])
+    //         }
+    //         _ => None,
+    //     }
+    // }
+    pub async fn get_peers(&self) -> Result<(), Box<dyn Error>> {
+        if self.protocol().unwrap() != "udp" {
+            panic!("not udp: {:?}", self.protocol().unwrap());
+        }
 
-const CONNECT_MSG: u32 = 0;
-const ANNOUNCE_MSG: u32 = 1;
+        let peer = self.announce.clone().unwrap().replace("udp://", "");
+        println!("peer {:?}", peer);
+        let socket = UdpSocket::bind("0.0.0.0:6681").await?;
+
+        let conn_req = conn_req_msg().to_vec();
+        println!("SENDING conn_req {:?}", conn_req);
+        socket.send_to(&conn_req, &peer).await?;
+
+        // let mut res: Vec<u8>;
+        let mut buf = vec![0; 1024];
+
+        let peers = loop {
+            let (n, src) = socket.recv_from(&mut buf).await?;
+
+            let typ = resp_type(&buf);
+            println!("res {:?}", &buf[0..n]);
+            println!("t {:?}", typ);
+            // match typ {
+            if typ == CONNECT_MSG {
+                println!("TYPE: CONNECT: {:?}", CONNECT_MSG);
+                let conn_resp = parse_connect_resp(&buf);
+                println!("conn_resp {:?}", conn_resp);
+                let announce_req = ann_req_msg(conn_resp.connection_id, self, 6681);
+                println!("announce_req {:?}", announce_req);
+                socket.send_to(&announce_req[..], &src).await?;
+            } else if typ==ANNOUNCE_MSG {
+                println!("TYPE: ANNOUNCE: {:?}", ANNOUNCE_MSG);
+                let ann_resp = parse_announce_resp(&buf);
+                println!("PEERS1 {:?}", ann_resp.peers);
+                break ann_resp.peers;
+            }
+            println!("End");
+        };
+        println!("PEERS2 {:?}", peers);
+
+        Ok(())
+    }
+}
 
 fn conn_req_msg() -> [u8; 16] {
     let mut b: [u8; 16] = [0; 16];
@@ -113,11 +173,9 @@ fn ann_req_msg(connection_id: u64, torrent: &Torrent, port: u16) -> Vec {
     // TODO [56..64] downloaded
     println!("torrent.size(): {:?}", torrent.size());
     BigEndian::write_u64(&mut b[64..72], torrent.size()); // [64..72] left
-
     // TODO [72..80] uploaded
     // TODO [80..84] event (0:none, 1:completed, 2:started, 3:stopped)
     // TODO [84..88] ip address
-
     let random_bytes = rand::thread_rng().gen::<[u8; 4]>();
     b[88..92].clone_from_slice(&random_bytes[..]); // [88..92] key (random)
     BigEndian::write_i32(&mut b[92..96], -1); // [92..96] num_want (default: -1)
@@ -125,6 +183,8 @@ fn ann_req_msg(connection_id: u64, torrent: &Torrent, port: u16) -> Vec {
     b.to_vec()
 }
 
+const CONNECT_MSG: u32 = 0;
+const ANNOUNCE_MSG: u32 = 1;
 fn resp_type(b: &Vec<u8>) -> u32 {
     let action = BigEndian::read_u32(&b[0..4]);
     if action == 0 {
@@ -151,7 +211,7 @@ fn parse_connect_resp(b: &Vec) -> ConnResp {
 #[derive(Debug)]
 struct Peer {
     ip: u32,
-    port: u32,
+    port: u32
 }
 
 #[derive(Debug)]
@@ -165,11 +225,11 @@ struct AnnResp {
 }
 fn parse_announce_resp(b: &Vec<u8>) -> AnnResp {
     let mut peers: Vec<Peer> = Vec::new();
-    let n_peers = (b.len() - 20) / 6;
+    let n_peers = (b.len()-20)/6;
     for i in 0..n_peers {
         let peer: Peer = Peer {
-            ip: BigEndian::read_u32(&b[20 + (6 * i)..24 + (6 * i)]),
-            port: BigEndian::read_u32(&b[24 + (6 * i)..26 + (6 * i)]),
+            ip: BigEndian::read_u32(&b[20+(6*i)..24+(6*i)]),
+            port: BigEndian::read_u32(&b[24+(6*i)..26+(6*i)]),
         };
         peers.push(peer);
     }
@@ -180,7 +240,7 @@ fn parse_announce_resp(b: &Vec) -> AnnResp {
         interval: BigEndian::read_u32(&b[8..12]),
         leechers: BigEndian::read_u32(&b[12..16]),
         seeders: BigEndian::read_u32(&b[16..20]),
-        peers: peers,
+        peers: peers
     };
 
     ann_resp
@@ -190,12 +250,18 @@ fn parse_announce_resp(b: &Vec) -> AnnResp {
 mod tests {
     use super::*;
 
-    #[test]
-    fn test_read() {
+    // #[test]
+    #[async_std::test]
+    async fn test_read() {
         let t = Torrent::open("test.torrent");
+        // println!("{:?}", t);
         println!("torrent: {:?}", t.info.name);
         println!("announce: {:?}", t.announce.clone().unwrap());
+        println!("protocol: {:?}", t.protocol().unwrap());
 
         println!("conn_req_msg: {:?}", conn_req_msg());
+
+        let r = t.get_peers().await;
+        println!("get_peers r: {:?}", r);
     }
 }