Initial commit: aquatic, udp bittorrent tracker

bittorrent_udp/src/converters/common.rs

@@ -0,0 +1,21 @@
+use crate::types;
+
+
+pub fn event_from_i32(i: i32) -> types::AnnounceEvent {
+    match i {
+        1 => types::AnnounceEvent::Completed,
+        2 => types::AnnounceEvent::Started,
+        3 => types::AnnounceEvent::Stopped,
+        _ => types::AnnounceEvent::None
+    }
+}
+
+
+pub fn event_to_i32(event: types::AnnounceEvent) -> i32 {
+    match event {
+        types::AnnounceEvent::None => 0,
+        types::AnnounceEvent::Completed => 1,
+        types::AnnounceEvent::Started => 2,
+        types::AnnounceEvent::Stopped => 3
+    }
+}

bittorrent_udp/src/converters/mod.rs

@@ -0,0 +1,6 @@
+pub mod common;
+pub mod requests;
+pub mod responses;
+
+pub use self::requests::*;
+pub use self::responses::*;

bittorrent_udp/src/converters/requests.rs

@@ -0,0 +1,187 @@
+use byteorder::{ReadBytesExt, WriteBytesExt, NetworkEndian};
+
+use std::io;
+use std::io::Read;
+use std::net::Ipv4Addr;
+
+use crate::types;
+
+use super::common::*;
+
+
+const MAGIC_NUMBER: i64 = 4_497_486_125_440;
+
+
+pub fn request_to_bytes(request: &types::Request) -> Vec<u8> {
+    let mut bytes = Vec::new();
+
+    match request {
+        types::Request::Connect(r) => {
+            bytes.write_i64::<NetworkEndian>(MAGIC_NUMBER).unwrap();
+            bytes.write_i32::<NetworkEndian>(0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+        },
+
+        types::Request::Announce(r) => {
+            bytes.write_i64::<NetworkEndian>(r.connection_id.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(1).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+
+            bytes.extend(r.info_hash.0.iter());
+            bytes.extend(r.peer_id.0.iter());
+
+            bytes.write_i64::<NetworkEndian>(r.bytes_downloaded.0).unwrap();
+            bytes.write_i64::<NetworkEndian>(r.bytes_left.0).unwrap();
+            bytes.write_i64::<NetworkEndian>(r.bytes_uploaded.0).unwrap();
+
+            bytes.write_i32::<NetworkEndian>(event_to_i32(r.event)).unwrap();
+
+            bytes.extend(&r.ip_address.map_or([0; 4], |ip| ip.octets()));
+
+            bytes.write_u32::<NetworkEndian>(0).unwrap(); // IP
+            bytes.write_u32::<NetworkEndian>(r.key.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.peers_wanted.0).unwrap();
+            bytes.write_u16::<NetworkEndian>(r.port.0).unwrap();
+        },
+
+        types::Request::Scrape(r) => {
+            bytes.write_i64::<NetworkEndian>(r.connection_id.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(2).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+
+            for info_hash in &r.info_hashes {
+                bytes.extend(info_hash.0.iter());
+            }
+        }
+
+        _ => () // Invalid requests should never happen
+    }
+
+    bytes
+}
+
+
+pub fn request_from_bytes(
+    bytes: &[u8],
+    max_scrape_torrents: u8,
+) -> types::Request {
+
+    match try_request_from_bytes(bytes, max_scrape_torrents){
+        Ok(request) => request,
+        Err(_) => types::Request::Error
+    }
+}
+
+
+fn try_request_from_bytes(
+    bytes: &[u8],
+    max_scrape_torrents: u8,
+) -> Result<types::Request,io::Error> {
+
+    let mut bytes = io::Cursor::new(bytes);
+
+    let connection_id =  bytes.read_i64::<NetworkEndian>()?;
+    let action =         bytes.read_i32::<NetworkEndian>()?;
+    let transaction_id = bytes.read_i32::<NetworkEndian>()?;
+
+    match action {
+        // Connect
+        0 => {
+            if connection_id == MAGIC_NUMBER {
+                Ok(types::Request::Connect(types::ConnectRequest {
+                    transaction_id:types::TransactionId(transaction_id)
+                }))
+            }
+            else {
+                Ok(types::Request::Invalid(types::InvalidRequest {
+                    transaction_id:types::TransactionId(transaction_id),
+                    message:
+                        "Please send protocol identifier in connect request"
+                        .to_string()
+                }))
+            }
+        },
+
+        // Announce
+        1 => {
+            let mut info_hash = [0; 20];
+            let mut peer_id = [0; 20];
+            let mut ip = [0; 4];
+
+            bytes.read_exact(&mut info_hash)?;
+            bytes.read_exact(&mut peer_id)?;
+
+            let bytes_downloaded = bytes.read_i64::<NetworkEndian>()?;
+            let bytes_left       = bytes.read_i64::<NetworkEndian>()?;
+            let bytes_uploaded   = bytes.read_i64::<NetworkEndian>()?;
+            let event            = bytes.read_i32::<NetworkEndian>()?;
+
+            bytes.read_exact(&mut ip)?;
+
+            let key              = bytes.read_u32::<NetworkEndian>()?;
+            let peers_wanted     = bytes.read_i32::<NetworkEndian>()?;
+            let port             = bytes.read_u16::<NetworkEndian>()?;
+
+            let opt_ip = if ip == [0; 4] {
+                None
+            }
+            else {
+                Some(Ipv4Addr::new(ip[0], ip[1], ip[2], ip[3]))
+            };
+
+            Ok(types::Request::Announce(types::AnnounceRequest {
+                connection_id:    types::ConnectionId(connection_id),
+                transaction_id:   types::TransactionId(transaction_id),
+                info_hash:        types::InfoHash(info_hash),
+                peer_id:          types::PeerId(peer_id),
+                bytes_downloaded: types::NumberOfBytes(bytes_downloaded),
+                bytes_uploaded:   types::NumberOfBytes(bytes_uploaded),
+                bytes_left:       types::NumberOfBytes(bytes_left),
+                event:            event_from_i32(event),
+                ip_address:       opt_ip,
+                key:              types::PeerKey(key),
+                peers_wanted:     types::NumberOfPeers(peers_wanted),
+                port:             types::Port(port)
+            }))
+        },
+
+        // Scrape
+        2 => {
+            let mut info_hashes = Vec::new();
+            let mut info_hash = [0; 20];
+
+            let mut i = 0;
+
+            loop {
+                if i > max_scrape_torrents {
+                    return Ok(types::Request::Invalid(types::InvalidRequest {
+                        transaction_id:   types::TransactionId(transaction_id),
+                        message: format!(
+                            "Too many torrents. Maximum is {}",
+                            max_scrape_torrents
+                        )
+                    }));
+                }
+
+                if bytes.read_exact(&mut info_hash).is_err(){
+                    break
+                }
+
+                info_hashes.push(types::InfoHash(info_hash));
+
+                i += 1;
+            }
+
+            Ok(types::Request::Scrape(types::ScrapeRequest {
+                connection_id:  types::ConnectionId(connection_id),
+                transaction_id: types::TransactionId(transaction_id),
+                info_hashes
+            }))
+        }
+
+        _ => Ok(types::Request::Invalid(types::InvalidRequest {
+            transaction_id: types::TransactionId(transaction_id),
+            message: "Invalid action".to_string()
+        }))
+    }
+}

bittorrent_udp/src/converters/responses.rs

@@ -0,0 +1,231 @@
+use byteorder::{ReadBytesExt, WriteBytesExt, NetworkEndian};
+
+use std::io;
+use std::io::Read;
+use std::net::{IpAddr, Ipv6Addr, Ipv4Addr};
+
+use crate::types;
+
+
+pub fn response_to_bytes(
+    response: &types::Response,
+    ip_version: types::IpVersion
+) -> Vec<u8> {
+    let mut bytes = Vec::new();
+
+    match response {
+        types::Response::Connect(r) => {
+            bytes.write_i32::<NetworkEndian>(0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+            bytes.write_i64::<NetworkEndian>(r.connection_id.0).unwrap();
+        },
+
+        types::Response::Announce(r) => {
+            bytes.write_i32::<NetworkEndian>(1).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.announce_interval.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.leechers.0).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.seeders.0).unwrap();
+
+            // Write peer IPs and ports. Silently ignore peers with wrong
+            // IP version
+            for peer in r.peers.iter(){
+                let mut correct = false;
+
+                match peer.ip_address {
+                    IpAddr::V4(ip) => {
+                        if let types::IpVersion::IPv4 = ip_version {
+                            bytes.extend(&ip.octets());
+                            correct = true;
+                        }
+                    },
+                    IpAddr::V6(ip) => {
+                        if let types::IpVersion::IPv6 = ip_version {
+                            bytes.extend(&ip.octets());
+                            correct = true;
+                        }
+                    }
+                }
+
+                if correct {
+                    bytes.write_u16::<NetworkEndian>(peer.port.0).unwrap();
+                }
+            }
+        },
+
+        types::Response::Scrape(r) => {
+            bytes.write_i32::<NetworkEndian>(2).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+
+            for torrent_stat in r.torrent_stats.iter(){
+                bytes.write_i32::<NetworkEndian>(torrent_stat.seeders.0)
+                    .unwrap();
+                bytes.write_i32::<NetworkEndian>(torrent_stat.completed.0)
+                    .unwrap();
+                bytes.write_i32::<NetworkEndian>(torrent_stat.leechers.0)
+                    .unwrap();
+            }
+        },
+
+        types::Response::Error(r) => {
+            bytes.write_i32::<NetworkEndian>(3).unwrap();
+            bytes.write_i32::<NetworkEndian>(r.transaction_id.0).unwrap();
+
+            bytes.extend(r.message.as_bytes().iter());
+        },
+    }
+
+    bytes
+}
+
+
+pub fn response_from_bytes(
+    bytes: &[u8],
+    ip_version: types::IpVersion,
+) -> Result<types::Response, io::Error> {
+
+    let mut bytes = io::Cursor::new(bytes);
+
+    let action         = bytes.read_i32::<NetworkEndian>()?;
+    let transaction_id = bytes.read_i32::<NetworkEndian>()?;
+
+    match action {
+
+        // Connect
+        0 => {
+            let connection_id =  bytes.read_i64::<NetworkEndian>()?;
+
+            Ok(types::Response::Connect(types::ConnectResponse {
+                connection_id:  types::ConnectionId(connection_id),
+                transaction_id: types::TransactionId(transaction_id)
+            }))
+        },
+
+        // Announce
+        1 => {
+            let announce_interval =  bytes.read_i32::<NetworkEndian>()?;
+            let leechers =  bytes.read_i32::<NetworkEndian>()?;
+            let seeders =  bytes.read_i32::<NetworkEndian>()?;
+
+            let mut peers = Vec::new();
+
+            loop {
+                let mut opt_ip_address = None;
+
+                match ip_version {
+                    types::IpVersion::IPv4 => {
+                        let mut ip_bytes = [0; 4];
+
+                        if bytes.read_exact(&mut ip_bytes).is_ok() {
+                            opt_ip_address = Some(IpAddr::V4(Ipv4Addr::new(
+                                ip_bytes[0],
+                                ip_bytes[1],
+                                ip_bytes[2],
+                                ip_bytes[3],
+                            )));
+                        }
+                    },
+                    types::IpVersion::IPv6 => {
+                        let mut ip_bytes = [0; 16];
+
+                        if bytes.read_exact(&mut ip_bytes).is_ok() {
+                            let mut ip_bytes_ref = &ip_bytes[..];
+
+                            opt_ip_address = Some(IpAddr::V6(Ipv6Addr::new(
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                                ip_bytes_ref.read_u16::<NetworkEndian>()?,
+                            )));
+                        }
+                    },
+                }
+                if let Some(ip_address) = opt_ip_address {
+                    if let Ok(port) = bytes.read_u16::<NetworkEndian>() {
+                        peers.push(types::ResponsePeer {
+                            ip_address,
+                            port: types::Port(port),
+                        });
+                    }
+                    else {
+                        break;
+                    }
+                }
+                else {
+                    break;
+                }
+            }
+
+            Ok(types::Response::Announce(types::AnnounceResponse {
+                transaction_id:    types::TransactionId(transaction_id),
+                announce_interval: types::AnnounceInterval(announce_interval),
+                leechers:          types::NumberOfPeers(leechers),
+                seeders:           types::NumberOfPeers(seeders),
+                peers
+            }))
+
+        },
+
+        // Scrape
+        2 => {
+            let mut stats = Vec::new();
+
+            // TODO: transition to while let && when available
+            loop {
+                if let Ok(seeders) = bytes.read_i32::<NetworkEndian>() {
+                    if let Ok(downloaded) = bytes.read_i32::<NetworkEndian>() {
+                        if let Ok(leechers) = bytes.read_i32::<NetworkEndian>() {
+                            stats.push(types::TorrentScrapeStatistics {
+                                seeders:   types::NumberOfPeers(seeders),
+                                completed: types::NumberOfDownloads(downloaded),
+                                leechers:  types::NumberOfPeers(leechers)
+                            });
+                        }
+                        else {
+                            break;
+                        }
+                    }
+                    else {
+                        break;
+                    }
+                }
+                else {
+                    break;
+                }
+            }
+
+            Ok(types::Response::Scrape(types::ScrapeResponse {
+                transaction_id: types::TransactionId(transaction_id),
+                torrent_stats:  stats
+            }))
+        },
+
+        // Error
+        3 => {
+            let mut message_bytes = Vec::new();
+
+            bytes.read_to_end(&mut message_bytes)?;
+
+            let message = match String::from_utf8(message_bytes) {
+                Ok(message) => message,
+                Err(_)      => "".to_string()
+            };
+
+            Ok(types::Response::Error(types::ErrorResponse {
+                transaction_id: types::TransactionId(transaction_id),
+                message
+            }))
+        },
+
+        _ => {
+            Ok(types::Response::Error(types::ErrorResponse {
+                transaction_id: types::TransactionId(transaction_id),
+                message: "Invalid action".to_string()
+            }))
+        }
+    }
+}

bittorrent_udp/src/lib.rs

@@ -0,0 +1,2 @@
+pub mod converters;
+pub mod types;

bittorrent_udp/src/types/common.rs

@@ -0,0 +1,50 @@
+use std::net;
+
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub enum IpVersion {
+    IPv4,
+    IPv6
+}
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct AnnounceInterval (pub i32);
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct InfoHash (pub [u8; 20]);
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct ConnectionId (pub i64);
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct TransactionId (pub i32);
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct NumberOfBytes (pub i64);
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct NumberOfPeers (pub i32);
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct NumberOfDownloads (pub i32);
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct Port (pub u16);
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug, PartialOrd, Ord)]
+pub struct PeerId (pub [u8; 20]);
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub struct PeerKey (pub u32);
+
+
+#[derive(Hash, PartialEq, Eq, Clone, Debug)]
+pub struct ResponsePeer {
+    pub ip_address:    net::IpAddr,
+    pub port:          Port,
+}

bittorrent_udp/src/types/mod.rs

@@ -0,0 +1,7 @@
+pub mod common;
+pub mod request;
+pub mod response;
+
+pub use self::common::*;
+pub use self::request::*;
+pub use self::response::*;

bittorrent_udp/src/types/request.rs

@@ -0,0 +1,59 @@
+use std::net::Ipv4Addr;
+
+use super::common::*;
+
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub enum AnnounceEvent {
+    Started,
+    Stopped,
+    Completed,
+    None
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ConnectRequest {
+    pub transaction_id:   TransactionId
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct AnnounceRequest {
+    pub connection_id:    ConnectionId,
+    pub transaction_id:   TransactionId,
+    pub info_hash:        InfoHash,
+    pub peer_id:          PeerId,
+    pub bytes_downloaded: NumberOfBytes,
+    pub bytes_uploaded:   NumberOfBytes,
+    pub bytes_left:       NumberOfBytes,
+    pub event:            AnnounceEvent,
+    pub ip_address:       Option<Ipv4Addr>, 
+    pub key:              PeerKey,
+    pub peers_wanted:     NumberOfPeers,
+    pub port:             Port
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ScrapeRequest {
+    pub connection_id:    ConnectionId,
+    pub transaction_id:   TransactionId,
+    pub info_hashes:      Vec<InfoHash>
+}
+
+/// This is used for returning specific errors from the parser
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct InvalidRequest { 
+    pub transaction_id:   TransactionId,
+    pub message:          String
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub enum Request {
+    Connect(ConnectRequest),
+    Announce(AnnounceRequest),
+    Scrape(ScrapeRequest),
+    Invalid(InvalidRequest),
+
+    /// Should ideally only be used when no transaction id can be parsed,
+    /// but is currently also used as a catch-all for non-specific errors
+    Error, 
+}

bittorrent_udp/src/types/response.rs

@@ -0,0 +1,45 @@
+use super::common::*;
+
+
+
+#[derive(PartialEq, Eq, Debug, Copy, Clone)]
+pub struct TorrentScrapeStatistics {
+    pub seeders:   NumberOfPeers,
+    pub completed: NumberOfDownloads,
+    pub leechers:  NumberOfPeers
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ConnectResponse {
+    pub connection_id:     ConnectionId,
+    pub transaction_id:    TransactionId
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct AnnounceResponse {
+    pub transaction_id:    TransactionId,
+    pub announce_interval: AnnounceInterval,
+    pub leechers:          NumberOfPeers,
+    pub seeders:           NumberOfPeers,
+    pub peers:             Vec<ResponsePeer>
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ScrapeResponse {
+    pub transaction_id:    TransactionId,
+    pub torrent_stats:     Vec<TorrentScrapeStatistics>
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ErrorResponse {
+    pub transaction_id:    TransactionId,
+    pub message:           String
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub enum Response {
+    Connect(ConnectResponse),
+    Announce(AnnounceResponse),
+    Scrape(ScrapeResponse),
+    Error(ErrorResponse),
+}