Connections: Track, send, receive

Signed-off-by: Luca Fulchir <luca.fulchir@runesauth.com>

TODO

@@ -1 +1,6 @@
 * Wrapping for everything that wraps (sigh)
+* track user connection (add u64 from user)
+* API plit
+  * split API in ThreadLocal, ThreadSafe
+    * split send/recv API in Centralized, Connection
+  * all re wrappers on ThreadLocal-Centralized

flake.lock

@@ -5,11 +5,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1685518550,
-        "narHash": "sha256-o2d0KcvaXzTrPRIo0kOLV0/QXHhDQ5DTi+OxcjO8xqY=",
+        "lastModified": 1687171271,
+        "narHash": "sha256-BJlq+ozK2B1sJDQXS3tzJM5a+oVZmi1q0FlBK/Xqv7M=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "a1720a10a6cfe8234c0e93907ffe81be440f4cef",
+        "rev": "abfb11bd1aec8ced1c9bb9adfe68018230f4fb3c",
         "type": "github"
       },
       "original": {
@@ -38,11 +38,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1686921029,
-        "narHash": "sha256-J1bX9plPCFhTSh6E3TWn9XSxggBh/zDD4xigyaIQBy8=",
+        "lastModified": 1687555006,
+        "narHash": "sha256-GD2Kqb/DXQBRJcHqkM2qFZqbVenyO7Co/80JHRMg2U0=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "c7ff1b9b95620ce8728c0d7bd501c458e6da9e04",
+        "rev": "33223d479ffde3d05ac16c6dff04ae43cc27e577",
         "type": "github"
       },
       "original": {
@@ -54,11 +54,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1686960236,
-        "narHash": "sha256-AYCC9rXNLpUWzD9hm+askOfpliLEC9kwAo7ITJc4HIw=",
+        "lastModified": 1687502512,
+        "narHash": "sha256-dBL/01TayOSZYxtY4cMXuNCBk8UMLoqRZA+94xiFpJA=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "04af42f3b31dba0ef742d254456dc4c14eedac86",
+        "rev": "3ae20aa58a6c0d1ca95c9b11f59a2d12eebc511f",
         "type": "github"
       },
       "original": {
@@ -98,11 +98,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1687055571,
-        "narHash": "sha256-UvLoO6u5n9TzY80BpM4DaacxvyJl7u9mm9CA72d309g=",
+        "lastModified": 1687660699,
+        "narHash": "sha256-crI/CA/OJc778I5qJhwhhl8/PKKzc0D7vvVxOtjfvSo=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "2de557c780dcb127128ae987fca9d6c2b0d7dc0f",
+        "rev": "b3bd1d49f1ae609c1d68a66bba7a95a9a4256031",
         "type": "github"
       },
       "original": {

src/connection/handshake/tracker.rs

@@ -3,8 +3,9 @@
 use crate::{
     auth::{Domain, ServiceID},
     connection::{
+        self,
         handshake::{self, Error, Handshake},
-        Conn, IDRecv, IDSend,
+        Connection, IDRecv, IDSend,
     },
     enc::{
         self,
@@ -18,20 +19,27 @@ use crate::{
 use ::tokio::sync::oneshot;
 
 pub(crate) struct Server {
-    pub id: KeyID,
-    pub key: PrivKey,
-    pub domains: Vec<Domain>,
+    pub(crate) id: KeyID,
+    pub(crate) key: PrivKey,
+    pub(crate) domains: Vec<Domain>,
 }
 
-pub(crate) type ConnectAnswer = Result<(KeyID, IDSend), crate::Error>;
+pub(crate) type ConnectAnswer = Result<ConnectOk, crate::Error>;
+#[derive(Debug)]
+pub(crate) struct ConnectOk {
+    pub(crate) auth_key_id: KeyID,
+    pub(crate) auth_id_send: IDSend,
+    pub(crate) authsrv_conn: connection::AuthSrvConn,
+    pub(crate) service_conn: Option<connection::ServiceConn>,
+}
 
 pub(crate) struct Client {
-    pub service_id: ServiceID,
-    pub service_conn_id: IDRecv,
-    pub connection: Conn,
-    pub timeout: Option<::tokio::task::JoinHandle<()>>,
-    pub answer: oneshot::Sender<ConnectAnswer>,
-    pub srv_key_id: KeyID,
+    pub(crate) service_id: ServiceID,
+    pub(crate) service_conn_id: IDRecv,
+    pub(crate) connection: Connection,
+    pub(crate) timeout: Option<::tokio::time::Instant>,
+    pub(crate) answer: oneshot::Sender<ConnectAnswer>,
+    pub(crate) srv_key_id: KeyID,
 }
 
 /// Tracks the keys used by the client and the handshake
@@ -78,7 +86,7 @@ impl ClientList {
         pub_key: PubKey,
         service_id: ServiceID,
         service_conn_id: IDRecv,
-        connection: Conn,
+        connection: Connection,
         answer: oneshot::Sender<ConnectAnswer>,
         srv_key_id: KeyID,
     ) -> Result<(KeyID, &mut Client), oneshot::Sender<ConnectAnswer>> {
@@ -128,26 +136,28 @@ impl ClientList {
 #[derive(Debug, Clone)]
 pub(crate) struct AuthNeededInfo {
     /// Parsed handshake packet
-    pub handshake: Handshake,
+    pub(crate) handshake: Handshake,
     /// hkdf generated from the handshake
-    pub hkdf: Hkdf,
+    pub(crate) hkdf: Hkdf,
 }
 
 /// Client information needed to fully establish the conenction
 #[derive(Debug)]
 pub(crate) struct ClientConnectInfo {
     /// The service ID that we are connecting to
-    pub service_id: ServiceID,
+    pub(crate) service_id: ServiceID,
     /// The service ID that we are connecting to
-    pub service_connection_id: IDRecv,
+    pub(crate) service_connection_id: IDRecv,
     /// Parsed handshake packet
-    pub handshake: Handshake,
-    /// Conn
-    pub connection: Conn,
+    pub(crate) handshake: Handshake,
+    /// Old timeout for the handshake completion
+    pub(crate) old_timeout: ::tokio::time::Instant,
+    /// Connection
+    pub(crate) connection: Connection,
     /// where to wake up the waiting client
-    pub answer: oneshot::Sender<ConnectAnswer>,
-    /// server public key id that we used on the handshake
-    pub srv_key_id: KeyID,
+    pub(crate) answer: oneshot::Sender<ConnectAnswer>,
+    /// server pub(crate)lic key id that we used on the handshake
+    pub(crate) srv_key_id: KeyID,
 }
 /// Intermediate actions to be taken while parsing the handshake
 #[derive(Debug)]
@@ -231,7 +241,7 @@ impl Tracker {
         pub_key: PubKey,
         service_id: ServiceID,
         service_conn_id: IDRecv,
-        connection: Conn,
+        connection: Connection,
         answer: oneshot::Sender<ConnectAnswer>,
         srv_key_id: KeyID,
     ) -> Result<(KeyID, &mut Client), oneshot::Sender<ConnectAnswer>> {
@@ -366,13 +376,11 @@ impl Tracker {
                     }
                     let hshake =
                         self.hshake_cli.remove(resp.client_key_id).unwrap();
-                    if let Some(timeout) = hshake.timeout {
-                        timeout.abort();
-                    }
                     return Ok(Action::ClientConnect(ClientConnectInfo {
                         service_id: hshake.service_id,
                         service_connection_id: hshake.service_conn_id,
                         handshake,
+                        old_timeout: hshake.timeout.unwrap(),
                         connection: hshake.connection,
                         answer: hshake.answer,
                         srv_key_id: hshake.srv_key_id,

src/connection/mod.rs

@@ -5,21 +5,43 @@ pub mod packet;
 pub mod socket;
 pub mod stream;
 
-use ::std::{rc::Rc, vec::Vec};
+use ::core::num::Wrapping;
+use ::std::{
+    collections::{BTreeMap, HashMap, VecDeque},
+    vec::Vec,
+};
 
 pub use crate::connection::{handshake::Handshake, packet::Packet};
 
 use crate::{
+    connection::{socket::UdpClient, stream::StreamData},
     dnssec,
     enc::{
+        self,
         asym::PubKey,
         hkdf::Hkdf,
         sym::{self, CipherRecv, CipherSend},
         Random,
     },
-    inner::ThreadTracker,
+    inner::{worker, ThreadTracker},
 };
-use ::std::rc;
+
+/// Connection errors
+#[derive(::thiserror::Error, Debug, Copy, Clone)]
+pub enum Error {
+    /// Can't decrypt packet
+    #[error("Decrypt error: {0}")]
+    Decrypt(#[from] crate::enc::Error),
+    /// Error in parsing a packet realated to the connection
+    #[error("Chunk parsing: {0}")]
+    Parse(#[from] stream::Error),
+    /// No such Connection
+    #[error("No suck connection")]
+    NoSuchConnection,
+    /// No such Stream
+    #[error("No suck Stream")]
+    NoSuchStream,
+}
 
 /// Fenrir Connection ID
 ///
@@ -126,25 +148,72 @@ impl ProtocolVersion {
     }
 }
 
+/// Connection tracking id. Set by the user
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
+pub struct UserTracker(pub ::core::num::NonZeroU64);
+
+/// Unique tracker of connections
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
+pub struct LibTracker(Wrapping<u64>);
+impl LibTracker {
+    pub(crate) fn new(start: u16) -> Self {
+        Self(Wrapping(start as u64))
+    }
+    pub(crate) fn advance(&mut self, amount: u16) -> Self {
+        let old = self.0;
+        self.0 = self.0 + Wrapping(amount as u64);
+        LibTracker(old)
+    }
+}
+/// Collection of connection tracking, but user-given and library generated
+#[derive(Debug, Copy, Clone)]
+pub struct ConnTracker {
+    /// Optional tracker set by the user
+    pub user: Option<UserTracker>,
+    /// library generated tracker. Unique and non-repeating
+    pub(crate) lib: LibTracker,
+}
+
+impl PartialEq for ConnTracker {
+    fn eq(&self, other: &Self) -> bool {
+        self.lib == other.lib
+    }
+}
+impl Eq for ConnTracker {}
+
+/// Connection to an Authentication Server
+#[derive(Debug, Copy, Clone)]
+pub struct AuthSrvConn(pub ConnTracker);
+/// Connection to a service
+#[derive(Debug, Copy, Clone)]
+pub struct ServiceConn(pub ConnTracker);
+
+/*
+ * TODO: only on Thread{Local,Safe}::Connection oriented flows
 /// The connection, as seen from a user of libFenrir
 #[derive(Debug)]
-pub struct Connection(rc::Weak<Conn>);
-
-/// A single connection and its data
-#[derive(Debug)]
-pub(crate) struct Conn {
-    /// Receiving Conn ID
-    pub id_recv: IDRecv,
-    /// Sending Conn ID
-    pub id_send: IDSend,
-    /// The main hkdf used for all secrets in this connection
-    pub hkdf: Hkdf,
-    /// Cipher for decrypting data
-    pub cipher_recv: CipherRecv,
-    /// Cipher for encrypting data
-    pub cipher_send: CipherSend,
+pub struct Conn {
+    pub(crate) queue: ::async_channel::Sender<worker::Work>,
+    pub(crate) tracker: ConnTracker,
 }
 
+impl Conn {
+    /// Queue some data to be sent in this connection
+    // TODO: send_and_wait, that wait for recipient ACK
+    pub async fn send(&mut self, stream: stream::ID, data: Vec<u8>) {
+        use crate::inner::worker::Work;
+        let _ = self
+            .queue
+            .send(Work::UserSend((self.tracker.lib, stream, data)))
+            .await;
+    }
+    /// Get the library tracking id
+    pub fn tracker(&self) -> ConnTracker {
+        self.tracker
+    }
+}
+*/
+
 /// Role: track the connection direction
 ///
 /// The Role is used to select the correct secrets, and track the direction
@@ -160,7 +229,48 @@ pub enum Role {
     Client,
 }
 
-impl Conn {
+#[derive(Debug)]
+enum TimerKind {
+    None,
+    SendData(::tokio::time::Instant),
+    Keepalive(::tokio::time::Instant),
+}
+
+pub(crate) enum Enqueue {
+    TimerWait,
+    Immediate(::tokio::time::Instant),
+}
+
+/// A single connection and its data
+#[derive(Debug)]
+pub(crate) struct Connection {
+    /// Receiving Conn ID
+    pub(crate) id_recv: IDRecv,
+    /// Sending Conn ID
+    pub(crate) id_send: IDSend,
+    /// User-managed id to track this connection
+    /// the user can set this to better track this connection
+    pub(crate) user_tracker: Option<UserTracker>,
+    pub(crate) lib_tracker: LibTracker,
+    /// Sending address
+    pub(crate) send_addr: UdpClient,
+    /// The main hkdf used for all secrets in this connection
+    hkdf: Hkdf,
+    /// Cipher for decrypting data
+    pub(crate) cipher_recv: CipherRecv,
+    /// Cipher for encrypting data
+    pub(crate) cipher_send: CipherSend,
+    mtu: usize,
+    next_timer: TimerKind,
+    /// send queue for each Stream
+    send_queue: BTreeMap<stream::ID, stream::SendTracker>,
+    last_stream_sent: stream::ID,
+    /// receive queue for each Stream
+    recv_queue: BTreeMap<stream::ID, stream::Stream>,
+    streams_ready: VecDeque<stream::ID>,
+}
+
+impl Connection {
     pub(crate) fn new(
         hkdf: Hkdf,
         cipher: sym::Kind,
@@ -178,19 +288,194 @@ impl Conn {
         let cipher_recv = CipherRecv::new(cipher, secret_recv);
         let cipher_send = CipherSend::new(cipher, secret_send, rand);
 
+        use ::std::net::{IpAddr, Ipv4Addr, SocketAddr};
         Self {
             id_recv: IDRecv(ID::Handshake),
             id_send: IDSend(ID::Handshake),
+            user_tracker: None,
+            lib_tracker: LibTracker::new(0),
+            // will be overwritten
+            send_addr: UdpClient(SocketAddr::new(
+                IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+                31337,
+            )),
             hkdf,
             cipher_recv,
             cipher_send,
+            mtu: 1200,
+            next_timer: TimerKind::None,
+            send_queue: BTreeMap::new(),
+            last_stream_sent: stream::ID(0),
+            recv_queue: BTreeMap::new(),
+            streams_ready: VecDeque::with_capacity(4),
+        }
+    }
+    pub(crate) fn get_data(&mut self) -> Option<Vec<(stream::ID, Vec<u8>)>> {
+        if self.streams_ready.is_empty() {
+            return None;
+        }
+        let ret_len = self.streams_ready.len();
+        let mut ret = Vec::with_capacity(ret_len);
+        while let Some(stream_id) = self.streams_ready.pop_front() {
+            let stream = match self.recv_queue.get_mut(&stream_id) {
+                Some(stream) => stream,
+                None => continue,
+            };
+            ret.push((stream_id, stream.get()));
+        }
+        Some(ret)
+    }
+    pub(crate) fn recv(
+        &mut self,
+        mut udp: crate::RawUdp,
+    ) -> Result<StreamData, Error> {
+        let mut data = &mut udp.data[ID::len()..];
+        let aad = enc::sym::AAD(&[]);
+        self.cipher_recv.decrypt(aad, &mut data)?;
+        let mut bytes_parsed = 0;
+        let mut chunks = Vec::with_capacity(2);
+        loop {
+            let chunk = match stream::Chunk::deserialize(&data[bytes_parsed..])
+            {
+                Ok(chunk) => chunk,
+                Err(e) => {
+                    return Err(e.into());
+                }
+            };
+            bytes_parsed = bytes_parsed + chunk.len();
+            chunks.push(chunk);
+            if bytes_parsed == data.len() {
+                break;
+            }
+        }
+        let mut data_ready = StreamData::NotReady;
+        for chunk in chunks.into_iter() {
+            let stream_id = chunk.id;
+            let stream = match self.recv_queue.get_mut(&stream_id) {
+                Some(stream) => stream,
+                None => {
+                    ::tracing::debug!("Ignoring chunk for unknown stream::ID");
+                    continue;
+                }
+            };
+            match stream.recv(chunk) {
+                Ok(status) => {
+                    if !self.streams_ready.contains(&stream_id) {
+                        self.streams_ready.push_back(stream_id);
+                    }
+                    data_ready = data_ready | status;
+                }
+                Err(e) => ::tracing::debug!("stream: {:?}: {:?}", stream_id, e),
+            }
+        }
+        Ok(data_ready)
+    }
+    pub(crate) fn enqueue(
+        &mut self,
+        stream: stream::ID,
+        data: Vec<u8>,
+    ) -> Result<Enqueue, Error> {
+        let stream = match self.send_queue.get_mut(&stream) {
+            None => return Err(Error::NoSuchStream),
+            Some(stream) => stream,
+        };
+        stream.enqueue(data);
+        let instant;
+        let ret;
+        self.next_timer = match self.next_timer {
+            TimerKind::None | TimerKind::Keepalive(_) => {
+                instant = ::tokio::time::Instant::now();
+                ret = Enqueue::Immediate(instant);
+                TimerKind::SendData(instant)
+            }
+            TimerKind::SendData(old_timer) => {
+                // There already is some data to be sent
+                // wait for this timer,
+                // or risk going over max transmission rate
+                ret = Enqueue::TimerWait;
+                TimerKind::SendData(old_timer)
+            }
+        };
+        Ok(ret)
+    }
+    pub(crate) fn write_pkt<'a>(
+        &mut self,
+        raw: &'a mut [u8],
+    ) -> Result<&'a [u8], enc::Error> {
+        assert!(raw.len() >= self.mtu, "I should have at least 1200 MTU");
+        if self.send_queue.len() == 0 {
+            return Err(enc::Error::NotEnoughData(0));
+        }
+        raw[..ID::len()]
+            .copy_from_slice(&self.id_send.0.as_u64().to_le_bytes());
+        let data_from = ID::len() + self.cipher_send.nonce_len().0;
+        let data_max_to = raw.len() - self.cipher_send.tag_len().0;
+        let mut chunk_from = data_from;
+        let mut available_len = data_max_to - data_from;
+
+        use std::ops::Bound::{Excluded, Included};
+        let last_stream = self.last_stream_sent;
+
+        // Loop over our streams, write them to the packet.
+        // Notes:
+        //  * to avoid starvation, just round-robin them all for now
+        //  * we can enqueue multiple times the same stream
+        //    This is useful especially for Datagram streams
+        'queueloop: {
+            for (id, stream) in self
+                .send_queue
+                .range_mut((Included(last_stream), Included(stream::ID::max())))
+            {
+                if available_len < stream::Chunk::headers_len() + 1 {
+                    break 'queueloop;
+                }
+                let bytes =
+                    stream.serialize(*id, &mut raw[chunk_from..data_max_to]);
+                if bytes == 0 {
+                    break 'queueloop;
+                }
+                available_len = available_len - bytes;
+                chunk_from = chunk_from + bytes;
+                self.last_stream_sent = *id;
+            }
+            if available_len > 0 {
+                for (id, stream) in self.send_queue.range_mut((
+                    Included(stream::ID::min()),
+                    Excluded(last_stream),
+                )) {
+                    if available_len < stream::Chunk::headers_len() + 1 {
+                        break 'queueloop;
+                    }
+                    let bytes = stream
+                        .serialize(*id, &mut raw[chunk_from..data_max_to]);
+                    if bytes == 0 {
+                        break 'queueloop;
+                    }
+                    available_len = available_len - bytes;
+                    chunk_from = chunk_from + bytes;
+                    self.last_stream_sent = *id;
+                }
+            }
+        }
+        if chunk_from == data_from {
+            return Err(enc::Error::NotEnoughData(0));
+        }
+        let data_to = chunk_from + self.cipher_send.tag_len().0;
+
+        // encrypt
+        let aad = sym::AAD(&[]);
+        match self.cipher_send.encrypt(aad, &mut raw[data_from..data_to]) {
+            Ok(_) => Ok(&raw[..data_to]),
+            Err(e) => Err(e),
         }
     }
 }
 
 pub(crate) struct ConnList {
     thread_id: ThreadTracker,
-    connections: Vec<Option<Rc<Conn>>>,
+    connections: Vec<Option<Connection>>,
+    user_tracker: BTreeMap<LibTracker, usize>,
+    last_tracked: LibTracker,
     /// Bitmap to track which connection ids are used or free
     ids_used: Vec<::bitmaps::Bitmap<1024>>,
 }
@@ -206,11 +491,43 @@ impl ConnList {
         let mut ret = Self {
             thread_id,
             connections: Vec::with_capacity(INITIAL_CAP),
+            user_tracker: BTreeMap::new(),
+            last_tracked: LibTracker(Wrapping(0)),
             ids_used: vec![bitmap_id],
         };
         ret.connections.resize_with(INITIAL_CAP, || None);
         ret
     }
+    pub fn get_id_mut(&mut self, id: ID) -> Result<&mut Connection, Error> {
+        let conn_id = match id {
+            ID::ID(conn_id) => conn_id,
+            ID::Handshake => {
+                return Err(Error::NoSuchConnection);
+            }
+        };
+        let id_in_thread: usize =
+            (conn_id.get() / (self.thread_id.total as u64)) as usize;
+        if let Some(conn) = &mut self.connections[id_in_thread] {
+            Ok(conn)
+        } else {
+            return Err(Error::NoSuchConnection);
+        }
+    }
+    pub fn get_mut(
+        &mut self,
+        tracker: LibTracker,
+    ) -> Result<&mut Connection, Error> {
+        let idx = if let Some(idx) = self.user_tracker.get(&tracker) {
+            *idx
+        } else {
+            return Err(Error::NoSuchConnection);
+        };
+        if let Some(conn) = &mut self.connections[idx] {
+            Ok(conn)
+        } else {
+            return Err(Error::NoSuchConnection);
+        }
+    }
     pub fn len(&self) -> usize {
         let mut total: usize = 0;
         for bitmap in self.ids_used.iter() {
@@ -220,7 +537,23 @@ impl ConnList {
     }
     /// Only *Reserve* a connection,
     /// without actually tracking it in self.connections
+    pub(crate) fn reserve_and_track<'a>(
+        &'a mut self,
+        mut conn: Connection,
+    ) -> (LibTracker, &'a mut Connection) {
+        let (id_conn, id_in_thread) = self.reserve_first_with_idx();
+        conn.id_recv = id_conn;
+        let tracker = self.get_new_tracker(id_in_thread);
+        conn.lib_tracker = tracker;
+        self.connections[id_in_thread] = Some(conn);
+        (tracker, self.connections[id_in_thread].as_mut().unwrap())
+    }
+    /// Only *Reserve* a connection,
+    /// without actually tracking it in self.connections
     pub(crate) fn reserve_first(&mut self) -> IDRecv {
+        self.reserve_first_with_idx().0
+    }
+    fn reserve_first_with_idx(&mut self) -> (IDRecv, usize) {
         // uhm... bad things are going on here:
         // * id must be initialized, but only because:
         // * rust does not understand that after the `!found` id is always
@@ -258,10 +591,13 @@ impl ConnList {
         let actual_id = ((id_in_thread as u64) * (self.thread_id.total as u64))
             + (self.thread_id.id as u64);
         let new_id = IDRecv(ID::new_u64(actual_id));
-        new_id
+        (new_id, id_in_thread)
     }
     /// NOTE: does NOT check if the connection has been previously reserved!
-    pub(crate) fn track(&mut self, conn: Rc<Conn>) -> Result<(), ()> {
+    pub(crate) fn track(
+        &mut self,
+        mut conn: Connection,
+    ) -> Result<LibTracker, ()> {
         let conn_id = match conn.id_recv {
             IDRecv(ID::Handshake) => {
                 return Err(());
@@ -270,8 +606,22 @@ impl ConnList {
         };
         let id_in_thread: usize =
             (conn_id.get() / (self.thread_id.total as u64)) as usize;
+        let tracker = self.get_new_tracker(id_in_thread);
+        conn.lib_tracker = tracker;
         self.connections[id_in_thread] = Some(conn);
-        Ok(())
+        Ok(tracker)
+    }
+    fn get_new_tracker(&mut self, id_in_thread: usize) -> LibTracker {
+        let mut tracker;
+        loop {
+            tracker = self.last_tracked.advance(self.thread_id.total);
+            if self.user_tracker.get(&tracker).is_none() {
+                // like, never gonna happen, it's 64 bit
+                let _ = self.user_tracker.insert(tracker, id_in_thread);
+                break;
+            }
+        }
+        tracker
     }
     pub(crate) fn remove(&mut self, id: IDRecv) {
         if let IDRecv(ID::ID(raw_id)) = id {
@@ -303,7 +653,6 @@ enum MapEntry {
     Present(IDSend),
     Reserved,
 }
-use ::std::collections::HashMap;
 
 /// Link the public key of the authentication server to a connection id
 /// so that we can reuse that connection to ask for more authentications

src/connection/stream/errors.rs

@@ -1,10 +1,12 @@
 //! Errors while parsing streams
 
-
 /// Crypto errors
 #[derive(::thiserror::Error, Debug, Copy, Clone)]
 pub enum Error {
     /// Error while parsing key material
     #[error("Not enough data for stream chunk: {0}")]
     NotEnoughData(usize),
+    /// Sequence outside of the window
+    #[error("Sequence out of the sliding window")]
+    OutOfWindow,
 }

src/connection/stream/mod.rs

@@ -19,7 +19,7 @@ pub enum Kind {
 }
 
 /// Id of the stream
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ID(pub u16);
 
 impl ID {
@@ -27,6 +27,14 @@ impl ID {
     pub const fn len() -> usize {
         2
     }
+    /// Minimum possible Stream ID (u16::MIN)
+    pub const fn min() -> Self {
+        Self(u16::MIN)
+    }
+    /// Maximum possible Stream ID (u16::MAX)
+    pub const fn max() -> Self {
+        Self(u16::MAX)
+    }
 }
 
 /// length of the chunk
@@ -40,6 +48,30 @@ impl ChunkLen {
     }
 }
 
+//TODO: make pub?
+#[derive(Debug, Copy, Clone)]
+pub(crate) struct SequenceStart(pub(crate) Sequence);
+impl SequenceStart {
+    pub(crate) fn plus_u32(&self, other: u32) -> Sequence {
+        self.0.plus_u32(other)
+    }
+    pub(crate) fn offset(&self, seq: Sequence) -> usize {
+        if self.0 .0 <= seq.0 {
+            (seq.0 - self.0 .0).0 as usize
+        } else {
+            (seq.0 + (Sequence::max().0 - self.0 .0)).0 as usize
+        }
+    }
+}
+// SequenceEnd is INCLUSIVE
+#[derive(Debug, Copy, Clone)]
+pub(crate) struct SequenceEnd(pub(crate) Sequence);
+impl SequenceEnd {
+    pub(crate) fn plus_u32(&self, other: u32) -> Sequence {
+        self.0.plus_u32(other)
+    }
+}
+
 /// Sequence number to rebuild the stream correctly
 #[derive(Debug, Copy, Clone)]
 pub struct Sequence(pub ::core::num::Wrapping<u32>);
@@ -48,14 +80,52 @@ impl Sequence {
     const SEQ_NOFLAG: u32 = 0x3FFFFFFF;
     /// return a new sequence number, starting at random
     pub fn new(rand: &Random) -> Self {
-        let seq: u32 = 0;
-        rand.fill(&mut seq.to_le_bytes());
+        let mut raw_seq: [u8; 4] = [0; 4];
+        rand.fill(&mut raw_seq);
+        let seq = u32::from_le_bytes(raw_seq);
         Self(::core::num::Wrapping(seq & Self::SEQ_NOFLAG))
     }
     /// Length of the serialized field
     pub const fn len() -> usize {
         4
     }
+    /// Maximum possible sequence
+    pub const fn max() -> Self {
+        Self(::core::num::Wrapping(Self::SEQ_NOFLAG))
+    }
+    pub(crate) fn is_between(
+        &self,
+        start: SequenceStart,
+        end: SequenceEnd,
+    ) -> bool {
+        if start.0 .0 < end.0 .0 {
+            start.0 .0 <= self.0 && self.0 <= end.0 .0
+        } else {
+            start.0 .0 <= self.0 || self.0 <= end.0 .0
+        }
+    }
+    pub(crate) fn remaining_window(&self, end: SequenceEnd) -> u32 {
+        if self.0 <= end.0 .0 {
+            (end.0 .0 .0 - self.0 .0) + 1
+        } else {
+            end.0 .0 .0 + 1 + (Self::max().0 - self.0).0
+        }
+    }
+    pub(crate) fn plus_u32(self, other: u32) -> Self {
+        Self(::core::num::Wrapping(
+            (self.0 .0 + other) & Self::SEQ_NOFLAG,
+        ))
+    }
+}
+
+impl ::core::ops::Add for Sequence {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self {
+        Self(::core::num::Wrapping(
+            (self.0 + other.0).0 & Self::SEQ_NOFLAG,
+        ))
+    }
 }
 
 /// Chunk of data representing a stream
@@ -79,6 +149,10 @@ impl<'a> Chunk<'a> {
     const FLAGS_EXCLUDED_BITMASK: u8 = 0x3F;
     const FLAG_START_BITMASK: u8 = 0x80;
     const FLAG_END_BITMASK: u8 = 0x40;
+    /// Return the length of the header of a Chunk
+    pub const fn headers_len() -> usize {
+        ID::len() + ChunkLen::len() + Sequence::len()
+    }
     /// Returns the total length of the chunk, including headers
     pub fn len(&self) -> usize {
         ID::len() + ChunkLen::len() + Sequence::len() + self.data.len()
@@ -164,6 +238,26 @@ impl Tracker {
     }
 }
 
+#[derive(Debug, Eq, PartialEq)]
+pub(crate) enum StreamData {
+    /// not enough data to return somthing to the user
+    NotReady = 0,
+    /// we can return something to the user
+    Ready,
+}
+impl ::core::ops::BitOr for StreamData {
+    type Output = Self;
+
+    // Required method
+    fn bitor(self, other: Self) -> Self::Output {
+        if self == StreamData::Ready || other == StreamData::Ready {
+            StreamData::Ready
+        } else {
+            StreamData::NotReady
+        }
+    }
+}
+
 /// Actual stream-tracking structure
 #[derive(Debug, Clone)]
 pub(crate) struct Stream {
@@ -180,4 +274,79 @@ impl Stream {
             data: Tracker::new(kind, rand),
         }
     }
+    pub(crate) fn recv(&mut self, chunk: Chunk) -> Result<StreamData, Error> {
+        match &mut self.data {
+            Tracker::ROB(tracker) => tracker.recv(chunk),
+        }
+    }
+    pub(crate) fn get(&mut self) -> Vec<u8> {
+        match &mut self.data {
+            Tracker::ROB(tracker) => tracker.get(),
+        }
+    }
+}
+
+/// Track what has been sent and what has been ACK'd from a stream
+#[derive(Debug)]
+pub(crate) struct SendTracker {
+    queue: Vec<Vec<u8>>,
+    sent: Vec<usize>,
+    ackd: Vec<usize>,
+    chunk_started: bool,
+    is_datagram: bool,
+    next_sequence: Sequence,
+}
+impl SendTracker {
+    pub(crate) fn new(rand: &Random) -> Self {
+        Self {
+            queue: Vec::with_capacity(4),
+            sent: Vec::with_capacity(4),
+            ackd: Vec::with_capacity(4),
+            chunk_started: false,
+            is_datagram: false,
+            next_sequence: Sequence::new(rand),
+        }
+    }
+    /// Enqueue user data to be sent
+    pub(crate) fn enqueue(&mut self, data: Vec<u8>) {
+        self.queue.push(data);
+        self.sent.push(0);
+        self.ackd.push(0);
+    }
+    /// Write the user data to the buffer and mark it as sent
+    pub(crate) fn get(&mut self, out: &mut [u8]) -> usize {
+        let data = match self.queue.get(0) {
+            Some(data) => data,
+            None => return 0,
+        };
+        let len = ::std::cmp::min(out.len(), data.len());
+        out[..len].copy_from_slice(&data[self.sent[0]..len]);
+        self.sent[0] = self.sent[0] + len;
+        len
+    }
+    /// Mark the sent data as successfully received from the receiver
+    pub(crate) fn ack(&mut self, size: usize) {
+        todo!()
+    }
+    pub(crate) fn serialize(&mut self, id: ID, raw: &mut [u8]) -> usize {
+        let max_data_len = raw.len() - Chunk::headers_len();
+        let data_len = ::std::cmp::min(max_data_len, self.queue[0].len());
+        let flag_start = !self.chunk_started;
+        let flag_end = self.is_datagram && data_len == self.queue[0].len();
+        let chunk = Chunk {
+            id,
+            flag_start,
+            flag_end,
+            sequence: self.next_sequence,
+            data: &self.queue[0][..data_len],
+        };
+        self.next_sequence = Sequence(
+            self.next_sequence.0 + ::core::num::Wrapping(data_len as u32),
+        );
+        if chunk.flag_end {
+            self.chunk_started = false;
+        }
+        chunk.serialize(raw);
+        data_len
+    }
 }

src/connection/stream/rob.rs

@@ -1,29 +0,0 @@
-//! Implementation of the Reliable, Ordered, Bytestream transmission model
-//! AKA: TCP-like
-
-use crate::{
-    connection::stream::{Chunk, Error, Sequence},
-    enc::Random,
-};
-
-/// Reliable, Ordered, Bytestream stream tracker
-/// AKA: TCP-like
-#[derive(Debug, Clone)]
-pub(crate) struct ReliableOrderedBytestream {
-    window_start: Sequence,
-    window_len: usize,
-    data: Vec<u8>,
-}
-
-impl ReliableOrderedBytestream {
-    pub(crate) fn new(rand: &Random) -> Self {
-        Self {
-            window_start: Sequence::new(rand),
-            window_len: 1048576, // 1MB. should be enough for anybody. (lol)
-            data: Vec::new(),
-        }
-    }
-    pub(crate) fn recv(&mut self, chunk: Chunk) -> Result<(), Error> {
-        todo!()
-    }
-}

src/connection/stream/rob/mod.rs

@@ -0,0 +1,210 @@
+//! Implementation of the Reliable, Ordered, Bytestream transmission model
+//! AKA: TCP-like
+
+use crate::{
+    connection::stream::{
+        Chunk, Error, Sequence, SequenceEnd, SequenceStart, StreamData,
+    },
+    enc::Random,
+};
+
+#[cfg(test)]
+mod tests;
+
+/// Reliable, Ordered, Bytestream stream tracker
+/// AKA: TCP-like
+#[derive(Debug, Clone)]
+pub(crate) struct ReliableOrderedBytestream {
+    pub(crate) window_start: SequenceStart,
+    window_end: SequenceEnd,
+    pivot: u32,
+    data: Vec<u8>,
+    missing: Vec<(Sequence, Sequence)>,
+}
+
+impl ReliableOrderedBytestream {
+    pub(crate) fn new(rand: &Random) -> Self {
+        let window_len = 1048576; // 1MB. should be enough for anybody. (lol)
+        let window_start = SequenceStart(Sequence::new(rand));
+        let window_end = SequenceEnd(window_start.0.plus_u32(window_len - 1));
+        let mut data = Vec::with_capacity(window_len as usize);
+        data.resize(data.capacity(), 0);
+
+        Self {
+            window_start,
+            window_end,
+            pivot: window_len,
+            data,
+            missing: [(window_start.0, window_end.0)].to_vec(),
+        }
+    }
+    pub(crate) fn with_window_size(rand: &Random, size: u32) -> Self {
+        assert!(
+            size < Sequence::max().0 .0,
+            "Max window size is {}",
+            Sequence::max().0 .0
+        );
+        let window_len = size; // 1MB. should be enough for anybody. (lol)
+        let window_start = SequenceStart(Sequence::new(rand));
+        let window_end = SequenceEnd(window_start.0.plus_u32(window_len - 1));
+        let mut data = Vec::with_capacity(window_len as usize);
+        data.resize(data.capacity(), 0);
+
+        Self {
+            window_start,
+            window_end,
+            pivot: window_len,
+            data,
+            missing: [(window_start.0, window_end.0)].to_vec(),
+        }
+    }
+    pub(crate) fn window_size(&self) -> u32 {
+        self.data.len() as u32
+    }
+    pub(crate) fn get(&mut self) -> Vec<u8> {
+        if self.missing.len() == 0 {
+            let (first, second) = self.data.split_at(self.pivot as usize);
+            let mut ret = Vec::with_capacity(self.data.len());
+            ret.extend_from_slice(first);
+            ret.extend_from_slice(second);
+            self.window_start =
+                SequenceStart(self.window_start.plus_u32(ret.len() as u32));
+            self.window_end =
+                SequenceEnd(self.window_end.plus_u32(ret.len() as u32));
+            self.data.clear();
+            return ret;
+        }
+        let data_len = self.window_start.offset(self.missing[0].0);
+        let last_missing_idx = self.missing.len() - 1;
+        let mut last_missing = &mut self.missing[last_missing_idx];
+        last_missing.1 = last_missing.1.plus_u32(data_len as u32);
+        self.window_start =
+            SequenceStart(self.window_start.plus_u32(data_len as u32));
+        self.window_end =
+            SequenceEnd(self.window_end.plus_u32(data_len as u32));
+
+        let mut ret = Vec::with_capacity(data_len);
+        let (first, second) = self.data[..].split_at(self.pivot as usize);
+        let first_len = ::core::cmp::min(data_len, first.len());
+        let second_len = data_len - first_len;
+
+        ret.extend_from_slice(&first[..first_len]);
+        ret.extend_from_slice(&second[..second_len]);
+
+        self.pivot =
+            ((self.pivot as usize + data_len) % self.data.len()) as u32;
+        ret
+    }
+    pub(crate) fn recv(&mut self, chunk: Chunk) -> Result<StreamData, Error> {
+        if !chunk
+            .sequence
+            .is_between(self.window_start, self.window_end)
+        {
+            return Err(Error::OutOfWindow);
+        }
+        // make sure we consider only the bytes inside the sliding window
+        let maxlen = ::std::cmp::min(
+            chunk.sequence.remaining_window(self.window_end) as usize,
+            chunk.data.len(),
+        );
+        if maxlen == 0 {
+            // empty window or empty chunk, but we don't care
+            return Err(Error::OutOfWindow);
+        }
+        // translate Sequences to offsets in self.data
+        let data = &chunk.data[..maxlen];
+        let offset = self.window_start.offset(chunk.sequence);
+        let offset_end = offset + chunk.data.len() - 1;
+
+        // Find the chunks we are missing that we can copy,
+        // and fix the missing tracker
+        let mut copy_ranges = Vec::new();
+        let mut to_delete = Vec::new();
+        let mut to_add = Vec::new();
+        // note: the ranges are (INCLUSIVE, INCLUSIVE)
+        for (idx, el) in self.missing.iter_mut().enumerate() {
+            let missing_from = self.window_start.offset(el.0);
+            if missing_from > offset_end {
+                break;
+            }
+            let missing_to = self.window_start.offset(el.1);
+            if missing_to < offset {
+                continue;
+            }
+            if missing_from >= offset && missing_from <= offset_end {
+                if missing_to <= offset_end {
+                    //  [.....chunk.....]
+                    //    [..missing..]
+                    to_delete.push(idx);
+                    copy_ranges.push((missing_from, missing_to));
+                } else {
+                    //   [....chunk....]
+                    //        [...missing...]
+                    copy_ranges.push((missing_from, offset_end));
+                    el.0 =
+                        el.0.plus_u32(((offset_end - missing_from) + 1) as u32);
+                }
+            } else if missing_from < offset {
+                if missing_to > offset_end {
+                    //     [..chunk..]
+                    //  [....missing....]
+                    to_add.push((
+                        el.0.plus_u32(((offset_end - missing_from) + 1) as u32),
+                        el.1,
+                    ));
+                    el.1 = el.0.plus_u32(((offset - missing_from) - 1) as u32);
+                    copy_ranges.push((offset, offset_end));
+                } else if offset <= missing_to {
+                    //       [....chunk....]
+                    //   [...missing...]
+                    copy_ranges.push((offset, (missing_to - 0)));
+                    el.1 =
+                        el.0.plus_u32(((offset_end - missing_from) - 1) as u32);
+                }
+            }
+        }
+        {
+            let mut deleted = 0;
+            for idx in to_delete.into_iter() {
+                self.missing.remove(idx + deleted);
+                deleted = deleted + 1;
+            }
+        }
+        self.missing.append(&mut to_add);
+        self.missing
+            .sort_by(|(from_a, _), (from_b, _)| from_a.0 .0.cmp(&from_b.0 .0));
+
+        // copy only the missing data
+        let (first, second) = self.data[..].split_at_mut(self.pivot as usize);
+        for (from, to) in copy_ranges.into_iter() {
+            let to = to + 1;
+            if from <= first.len() {
+                let first_from = from;
+                let first_to = ::core::cmp::min(first.len(), to);
+                let data_first_from = from - offset;
+                let data_first_to = first_to - offset;
+                first[first_from..first_to]
+                    .copy_from_slice(&data[data_first_from..data_first_to]);
+
+                let second_to = to - first_to;
+                let data_second_to = data_first_to + second_to;
+                second[..second_to]
+                    .copy_from_slice(&data[data_first_to..data_second_to]);
+            } else {
+                let second_from = from - first.len();
+                let second_to = to - first.len();
+                let data_from = from - offset;
+                let data_to = to - offset;
+                second[second_from..second_to]
+                    .copy_from_slice(&data[data_from..data_to]);
+            }
+        }
+        if self.missing.len() == 0
+            || self.window_start.offset(self.missing[0].0) == 0
+        {
+            Ok(StreamData::Ready)
+        } else {
+            Ok(StreamData::NotReady)
+        }
+    }
+}

src/connection/stream/rob/tests.rs

@@ -0,0 +1,249 @@
+use crate::{
+    connection::stream::{self, rob::*, Chunk},
+    enc::Random,
+};
+
+#[::tracing_test::traced_test]
+#[test]
+fn test_stream_rob_sequential() {
+    let rand = Random::new();
+    let mut rob = ReliableOrderedBytestream::with_window_size(&rand, 1048576);
+
+    let mut data = Vec::with_capacity(1024);
+    data.resize(data.capacity(), 0);
+    rand.fill(&mut data[..]);
+
+    let start = rob.window_start.0;
+
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start,
+        data: &data[..512],
+    };
+    let got = rob.get();
+    assert!(&got[..] == &[], "rob: got data?");
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[..512] == &got[..],
+        "ROB1: DIFF: {:?} {:?}",
+        &data[..512].len(),
+        &got[..].len()
+    );
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: true,
+        sequence: start.plus_u32(512),
+        data: &data[512..],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[512..] == &got[..],
+        "ROB2: DIFF: {:?} {:?}",
+        &data[512..].len(),
+        &got[..].len()
+    );
+}
+
+#[::tracing_test::traced_test]
+#[test]
+fn test_stream_rob_retransmit() {
+    let rand = Random::new();
+    let max_window: usize = 100;
+    let mut rob =
+        ReliableOrderedBytestream::with_window_size(&rand, max_window as u32);
+
+    let mut data = Vec::with_capacity(120);
+    data.resize(data.capacity(), 0);
+    for i in 0..data.len() {
+        data[i] = i as u8;
+    }
+
+    let start = rob.window_start.0;
+
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start,
+        data: &data[..40],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: false,
+        sequence: start.plus_u32(50),
+        data: &data[50..60],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: false,
+        sequence: start.plus_u32(40),
+        data: &data[40..60],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: false,
+        sequence: start.plus_u32(80),
+        data: &data[80..],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: false,
+        sequence: start.plus_u32(50),
+        data: &data[50..90],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: false,
+        sequence: start.plus_u32(max_window as u32),
+        data: &data[max_window..],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: false,
+        flag_end: true,
+        sequence: start.plus_u32(90),
+        data: &data[90..max_window],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[..max_window] == &got[..],
+        "DIFF:\n {:?}\n {:?}",
+        &data[..max_window],
+        &got[..],
+    );
+}
+#[::tracing_test::traced_test]
+#[test]
+fn test_stream_rob_rolling() {
+    let rand = Random::new();
+    let max_window: usize = 100;
+    let mut rob =
+        ReliableOrderedBytestream::with_window_size(&rand, max_window as u32);
+
+    let mut data = Vec::with_capacity(120);
+    data.resize(data.capacity(), 0);
+    for i in 0..data.len() {
+        data[i] = i as u8;
+    }
+
+    let start = rob.window_start.0;
+
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start,
+        data: &data[..40],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start.plus_u32(50),
+        data: &data[50..100],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[..40] == &got[..],
+        "DIFF:\n {:?}\n {:?}",
+        &data[..40],
+        &got[..],
+    );
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start.plus_u32(40),
+        data: &data[40..],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[40..] == &got[..],
+        "DIFF:\n {:?}\n {:?}",
+        &data[40..],
+        &got[..],
+    );
+}
+#[::tracing_test::traced_test]
+#[test]
+fn test_stream_rob_rolling_second_case() {
+    let rand = Random::new();
+    let max_window: usize = 100;
+    let mut rob =
+        ReliableOrderedBytestream::with_window_size(&rand, max_window as u32);
+
+    let mut data = Vec::with_capacity(120);
+    data.resize(data.capacity(), 0);
+    for i in 0..data.len() {
+        data[i] = i as u8;
+    }
+
+    let start = rob.window_start.0;
+
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start,
+        data: &data[..40],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start.plus_u32(50),
+        data: &data[50..100],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[..40] == &got[..],
+        "DIFF:\n {:?}\n {:?}",
+        &data[..40],
+        &got[..],
+    );
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start.plus_u32(40),
+        data: &data[40..100],
+    };
+    let _ = rob.recv(chunk);
+    let chunk = Chunk {
+        id: stream::ID(42),
+        flag_start: true,
+        flag_end: false,
+        sequence: start.plus_u32(100),
+        data: &data[100..],
+    };
+    let _ = rob.recv(chunk);
+    let got = rob.get();
+    assert!(
+        &data[40..] == &got[..],
+        "DIFF:\n {:?}\n {:?}",
+        &data[40..],
+        &got[..],
+    );
+}

src/enc/sym.rs

@@ -241,6 +241,14 @@ impl CipherSend {
     pub fn kind(&self) -> Kind {
         self.cipher.kind()
     }
+    /// Get the length of the nonce  for this cipher
+    pub fn nonce_len(&self) -> NonceLen {
+        self.cipher.nonce_len()
+    }
+    /// Get the length of the nonce  for this cipher
+    pub fn tag_len(&self) -> TagLen {
+        self.cipher.tag_len()
+    }
 }
 
 /// XChaCha20Poly1305 cipher

src/inner/mod.rs

@@ -4,6 +4,10 @@
 
 pub(crate) mod worker;
 
+use crate::inner::worker::Work;
+use ::std::{collections::BTreeMap, vec::Vec};
+use ::tokio::time::Instant;
+
 /// Track the total number of threads and our index
 /// 65K cpus should be enough for anybody
 #[derive(Debug, Clone, Copy)]
@@ -12,3 +16,109 @@ pub(crate) struct ThreadTracker {
     /// Note: starts from 1
     pub id: u16,
 }
+
+pub(crate) static mut SLEEP_RESOLUTION: ::std::time::Duration =
+    if cfg!(linux) || cfg!(macos) {
+        ::std::time::Duration::from_millis(1)
+    } else {
+        // windows
+        ::std::time::Duration::from_millis(16)
+    };
+
+pub(crate) async fn set_minimum_sleep_resolution() {
+    let nanosleep = ::std::time::Duration::from_nanos(1);
+    let mut tests: usize = 3;
+
+    while tests > 0 {
+        let pre_sleep = ::std::time::Instant::now();
+        ::tokio::time::sleep(nanosleep).await;
+        let post_sleep = ::std::time::Instant::now();
+        let slept_for = post_sleep - pre_sleep;
+        #[allow(unsafe_code)]
+        unsafe {
+            if slept_for < SLEEP_RESOLUTION {
+                SLEEP_RESOLUTION = slept_for;
+            }
+        }
+        tests = tests - 1;
+    }
+}
+
+/// Sleeping has a higher resolution that we would like for packet pacing.
+/// So we sleep for however log we need, then chunk up all the work here
+/// we will end up chunking the work in SLEEP_RESOLUTION, then we will busy wait
+/// for more precise timing
+pub(crate) struct Timers {
+    times: BTreeMap<Instant, Work>,
+}
+
+impl Timers {
+    pub(crate) fn new() -> Self {
+        Self {
+            times: BTreeMap::new(),
+        }
+    }
+    pub(crate) fn get_next(&self) -> ::tokio::time::Sleep {
+        match self.times.keys().next() {
+            Some(entry) => ::tokio::time::sleep_until((*entry).into()),
+            None => {
+                ::tokio::time::sleep(::std::time::Duration::from_secs(3600))
+            }
+        }
+    }
+    pub(crate) fn add(
+        &mut self,
+        duration: ::tokio::time::Duration,
+        work: Work,
+    ) -> ::tokio::time::Instant {
+        // the returned time is the key in the map.
+        // Make sure it is unique.
+        //
+        // We can be pretty sure we won't do a lot of stuff
+        // in a single nanosecond, so if we hit a time that is already present
+        // just add a nanosecond and retry
+        let mut time = ::tokio::time::Instant::now() + duration;
+        let mut work = work;
+        loop {
+            if let Some(old_val) = self.times.insert(time, work) {
+                work = self.times.insert(time, old_val).unwrap();
+                time = time + ::std::time::Duration::from_nanos(1);
+            } else {
+                break;
+            }
+        }
+        time
+    }
+    pub(crate) fn remove(&mut self, time: ::tokio::time::Instant) {
+        let _ = self.times.remove(&time);
+    }
+    /// Get all the work from now up until now + SLEEP_RESOLUTION
+    pub(crate) fn get_work(&mut self) -> Vec<Work> {
+        let now: ::tokio::time::Instant = ::std::time::Instant::now().into();
+        let mut ret = Vec::with_capacity(4);
+        let mut count_rm = 0;
+        #[allow(unsafe_code)]
+        let next_instant = unsafe { now + SLEEP_RESOLUTION };
+        let mut iter = self.times.iter_mut().peekable();
+        loop {
+            match iter.peek() {
+                None => break,
+                Some(next) => {
+                    if *next.0 > next_instant {
+                        break;
+                    }
+                }
+            }
+            let mut work = Work::DropHandshake(crate::enc::asym::KeyID(0));
+            let mut entry = iter.next().unwrap();
+            ::core::mem::swap(&mut work, &mut entry.1);
+            ret.push(work);
+            count_rm = count_rm + 1;
+        }
+        while count_rm > 0 {
+            self.times.pop_first();
+            count_rm = count_rm - 1;
+        }
+        ret
+    }
+}

src/inner/worker.rs

@@ -11,17 +11,19 @@ use crate::{
         },
         packet::{self, Packet},
         socket::{UdpClient, UdpServer},
-        Conn, ConnList, IDSend,
+        stream, AuthSrvConn, ConnList, ConnTracker, Connection, IDSend,
+        LibTracker, ServiceConn,
     },
     dnssec,
     enc::{
+        self,
         asym::{self, KeyID, PrivKey, PubKey},
         hkdf::{self, Hkdf},
         sym, Random, Secret,
     },
     inner::ThreadTracker,
 };
-use ::std::{sync::Arc, vec::Vec};
+use ::std::{collections::VecDeque, sync::Arc, vec::Vec};
 /// This worker must be cpu-pinned
 use ::tokio::{
     net::UdpSocket,
@@ -44,6 +46,25 @@ pub(crate) struct ConnectInfo {
     // TODO: UserID, Token information
 }
 
+/// return to the user the data received from a connection
+#[derive(Debug, Clone)]
+pub struct ConnData {
+    /// Connection tracking information
+    pub conn: ConnTracker,
+    /// received data, for each stream
+    pub data: Vec<(stream::ID, Vec<u8>)>,
+}
+
+/// Connection event. Mostly used to give the data to the user
+#[derive(Debug, Clone)]
+#[non_exhaustive]
+pub enum Event {
+    /// Work loop has exited. nothing more to do
+    End,
+    /// Data from a connection
+    Data(ConnData),
+}
+
 pub(crate) enum Work {
     /// ask the thread to report to the main thread the total number of
     /// connections present
@@ -51,6 +72,8 @@ pub(crate) enum Work {
     Connect(ConnectInfo),
     DropHandshake(KeyID),
     Recv(RawUdp),
+    UserSend((LibTracker, stream::ID, Vec<u8>)),
+    SendData((LibTracker, ::tokio::time::Instant)),
 }
 
 /// Actual worker implementation.
@@ -64,11 +87,15 @@ pub struct Worker {
     token_check: Option<Arc<Mutex<TokenChecker>>>,
     sockets: Vec<Arc<UdpSocket>>,
     queue: ::async_channel::Receiver<Work>,
+    queue_sender: ::async_channel::Sender<Work>,
     queue_timeouts_recv: mpsc::UnboundedReceiver<Work>,
     queue_timeouts_send: mpsc::UnboundedSender<Work>,
     thread_channels: Vec<::async_channel::Sender<Work>>,
     connections: ConnList,
+    // connectsion untracker by the user. (users still needs to get(..) them)
+    untracked_connections: VecDeque<LibTracker>,
     handshakes: handshake::Tracker,
+    work_timers: super::Timers,
 }
 
 #[allow(unsafe_code)]
@@ -82,6 +109,7 @@ impl Worker {
         token_check: Option<Arc<Mutex<TokenChecker>>>,
         sockets: Vec<Arc<UdpSocket>>,
         queue: ::async_channel::Receiver<Work>,
+        queue_sender: ::async_channel::Sender<Work>,
     ) -> ::std::io::Result<Self> {
         let (queue_timeouts_send, queue_timeouts_recv) =
             mpsc::unbounded_channel();
@@ -118,17 +146,93 @@ impl Worker {
             token_check,
             sockets,
             queue,
+            queue_sender,
             queue_timeouts_recv,
             queue_timeouts_send,
             thread_channels: Vec::new(),
             connections: ConnList::new(thread_id),
+            untracked_connections: VecDeque::with_capacity(8),
             handshakes,
+            work_timers: super::Timers::new(),
         })
     }
+    /// return a handle to the worker that you can use to send data
+    /// The handle will enqueue work in the main worker and is thread-local safe
+    ///
+    /// While this does not require `&mut` on the `Worker`, everything
+    /// will be put in the work queue,
+    /// So you might have less immediate results in a few cases
+    pub fn handle(&self) -> Handle {
+        Handle {
+            queue: self.queue_sender.clone(),
+        }
+    }
+    /// change the UserTracker in the connection
+    ///
+    /// This is `unsafe` because you will be responsible for manually updating
+    /// any copy of the `ConnTracker` you might have cloned around
+    #[allow(unsafe_code)]
+    pub unsafe fn set_connection_tracker(
+        &mut self,
+        tracker: ConnTracker,
+        new_id: connection::UserTracker,
+    ) -> Result<ConnTracker, crate::Error> {
+        let conn = self.connections.get_mut(tracker.lib)?;
+        conn.user_tracker = Some(new_id);
+        Ok(ConnTracker {
+            lib: tracker.lib,
+            user: Some(new_id),
+        })
+    }
+    /// Enqueue data to send
+    pub fn send(
+        &mut self,
+        tracker: LibTracker,
+        stream: stream::ID,
+        data: Vec<u8>,
+    ) -> Result<(), crate::Error> {
+        let conn = self.connections.get_mut(tracker)?;
+        conn.enqueue(stream, data)?;
+        Ok(())
+    }
+    /// Returns new connections, if any
+    ///
+    /// You can provide an optional tracker, different from the library tracker.
+    ///
+    /// Differently from the library tracker, you can change this later on,
+    /// but you will be responsible to change it on every `ConnTracker`
+    /// you might have cloned elsewhere
+    pub fn try_get_connection(
+        &mut self,
+        tracker: Option<connection::UserTracker>,
+    ) -> Option<ConnTracker> {
+        let ret_tracker = ConnTracker {
+            lib: self.untracked_connections.pop_front()?,
+            user: None,
+        };
+        match tracker {
+            Some(tracker) => {
+                #[allow(unsafe_code)]
+                match unsafe {
+                    self.set_connection_tracker(ret_tracker, tracker)
+                } {
+                    Ok(tracker) => Some(tracker),
+                    Err(_) => {
+                        // we had a connection, but it expired before the user
+                        // remembered to get it. Just remove it from the queue.
+                        None
+                    }
+                }
+            }
+            None => Some(ret_tracker),
+        }
+    }
 
     /// Continuously loop and process work as needed
-    pub async fn work_loop(&mut self) {
+    pub async fn work_loop(&mut self) -> Result<Event, crate::Error> {
         'mainloop: loop {
+            let next_timer = self.work_timers.get_next();
+            ::tokio::pin!(next_timer);
             let work = ::tokio::select! {
                 tell_stopped = self.stop_working.recv() => {
                     if let Ok(stop_ch) = tell_stopped {
@@ -137,6 +241,13 @@ impl Worker {
                     }
                     break;
                 }
+                () = &mut next_timer =>  {
+                    let work_list = self.work_timers.get_work();
+                    for w in work_list.into_iter() {
+                        let _ = self.queue_sender.send(w).await;
+                    }
+                    continue 'mainloop;
+                }
                 maybe_timeout = self.queue.recv() => {
                     match maybe_timeout {
                         Ok(work) => work,
@@ -293,12 +404,14 @@ impl Worker {
                         // are PubKey::Exchange
                         unreachable!()
                     }
-                    let mut conn = Conn::new(
+                    let mut conn = Connection::new(
                         hkdf,
                         cipher_selected,
                         connection::Role::Client,
                         &self.rand,
                     );
+                    let dest = UdpClient(addr.as_sockaddr().unwrap());
+                    conn.send_addr = dest;
 
                     let auth_recv_id = self.connections.reserve_first();
                     let service_conn_id = self.connections.reserve_first();
@@ -389,15 +502,13 @@ impl Worker {
                     // send always from the first socket
                     // FIXME: select based on routing table
                     let sender = self.sockets[0].local_addr().unwrap();
-                    let dest = UdpClient(addr.as_sockaddr().unwrap());
 
                     // start the timeout right before sending the packet
-                    hshake.timeout = Some(::tokio::task::spawn_local(
-                        Self::handshake_timeout(
-                            self.queue_timeouts_send.clone(),
-                            client_key_id,
-                        ),
-                    ));
+                    let time_drop = self.work_timers.add(
+                        ::tokio::time::Duration::from_secs(10),
+                        Work::DropHandshake(client_key_id),
+                    );
+                    hshake.timeout = Some(time_drop);
 
                     // send packet
                     self.send_packet(raw, dest, UdpServer(sender)).await;
@@ -413,21 +524,70 @@ impl Worker {
                         }
                     };
                 }
-                Work::Recv(pkt) => {
-                    self.recv(pkt).await;
+                Work::Recv(pkt) => match self.recv(pkt).await {
+                    Ok(event) => return Ok(event),
+                    Err(_) => continue 'mainloop,
+                },
+                Work::UserSend((tracker, stream, data)) => {
+                    let conn = match self.connections.get_mut(tracker) {
+                        Ok(conn) => conn,
+                        Err(_) => continue 'mainloop,
+                    };
+                    use connection::Enqueue;
+                    if let Ok(enqueued) = conn.enqueue(stream, data) {
+                        match enqueued {
+                            Enqueue::Immediate(instant) => {
+                                let _ = self
+                                    .queue_sender
+                                    .send(Work::SendData((tracker, instant)))
+                                    .await;
+                            }
+                            Enqueue::TimerWait => {}
+                        }
+                    }
+                }
+                Work::SendData((tracker, instant)) => {
+                    // make sure we don't process events before they are
+                    // actually needed.
+                    // This is basically busy waiting with extra steps,
+                    // but we don't want to spawn lots of timers and
+                    // we don't really have a fine-grained sleep that is
+                    // multiplatform
+                    let now = ::tokio::time::Instant::now();
+                    if instant <= now {
+                        let _ = self
+                            .queue_sender
+                            .send(Work::SendData((tracker, instant)))
+                            .await;
+                        continue;
+                    }
+
+                    let mut raw: Vec<u8> = Vec::with_capacity(1200);
+                    raw.resize(raw.capacity(), 0);
+                    let conn = match self.connections.get_mut(tracker) {
+                        Ok(conn) => conn,
+                        Err(_) => continue,
+                    };
+                    let pkt = match conn.write_pkt(&mut raw) {
+                        Ok(pkt) => pkt,
+                        Err(enc::Error::NotEnoughData(0)) => continue,
+                        Err(e) => {
+                            ::tracing::error!("Packet generation: {:?}", e);
+                            continue;
+                        }
+                    };
+                    let dest = conn.send_addr;
+                    let src = UdpServer(self.sockets[0].local_addr().unwrap());
+                    let len = pkt.len();
+                    raw.truncate(len);
+                    let _ = self.send_packet(raw, dest, src);
                 }
             }
         }
-    }
-    async fn handshake_timeout(
-        timeout_queue: mpsc::UnboundedSender<Work>,
-        key_id: KeyID,
-    ) {
-        ::tokio::time::sleep(::std::time::Duration::from_secs(10)).await;
-        let _ = timeout_queue.send(Work::DropHandshake(key_id));
+        Ok(Event::End)
     }
     /// Read and do stuff with the raw udp packet
-    async fn recv(&mut self, mut udp: RawUdp) {
+    async fn recv(&mut self, mut udp: RawUdp) -> Result<Event, ()> {
         if udp.packet.id.is_handshake() {
             let handshake = match Handshake::deserialize(
                 &udp.data[connection::ID::len()..],
@@ -435,7 +595,7 @@ impl Worker {
                 Ok(handshake) => handshake,
                 Err(e) => {
                     ::tracing::debug!("Handshake parsing: {}", e);
-                    return;
+                    return Err(());
                 }
             };
             let action = match self.handshakes.recv_handshake(
@@ -445,190 +605,255 @@ impl Worker {
                 Ok(action) => action,
                 Err(err) => {
                     ::tracing::debug!("Handshake recv error {}", err);
-                    return;
+                    return Err(());
                 }
             };
-            match action {
-                handshake::Action::AuthNeeded(authinfo) => {
-                    let req;
-                    if let handshake::Data::DirSync(DirSync::Req(r)) =
-                        authinfo.handshake.data
-                    {
-                        req = r;
-                    } else {
-                        ::tracing::error!("AuthInfo on non DS::Req");
-                        return;
-                    }
-                    let req_data = match req.data {
-                        dirsync::req::State::ClearText(req_data) => req_data,
-                        _ => {
-                            ::tracing::error!("AuthNeeded: expected ClearText");
-                            assert!(false, "AuthNeeded: unreachable");
-                            return;
-                        }
-                    };
-                    // FIXME: This part can take a while,
-                    // we should just spawn it probably
-                    let maybe_auth_check = {
-                        match &self.token_check {
-                            None => {
-                                if req_data.auth.user == auth::USERID_ANONYMOUS
-                                {
-                                    Ok(true)
-                                } else {
-                                    Ok(false)
-                                }
-                            }
-                            Some(token_check) => {
-                                let tk_check = token_check.lock().await;
-                                tk_check(
-                                    req_data.auth.user,
-                                    req_data.auth.token,
-                                    req_data.auth.service_id,
-                                    req_data.auth.domain,
-                                )
-                                .await
-                            }
-                        }
-                    };
-                    let is_authenticated = match maybe_auth_check {
-                        Ok(is_authenticated) => is_authenticated,
-                        Err(_) => {
-                            ::tracing::error!("error in token auth");
-                            // TODO: retry?
-                            return;
-                        }
-                    };
-                    if !is_authenticated {
-                        ::tracing::warn!(
-                            "Wrong authentication for user {:?}",
-                            req_data.auth.user
-                        );
-                        // TODO: error response
-                        return;
-                    }
-                    // Client has correctly authenticated
-                    // TODO: contact the service, get the key and
-                    // connection ID
-                    let srv_conn_id = connection::ID::new_rand(&self.rand);
-                    let srv_secret = Secret::new_rand(&self.rand);
-                    let head_len = req.cipher.nonce_len();
-                    let tag_len = req.cipher.tag_len();
-
-                    let mut auth_conn = Conn::new(
-                        authinfo.hkdf,
-                        req.cipher,
-                        connection::Role::Server,
-                        &self.rand,
-                    );
-                    auth_conn.id_send = IDSend(req_data.id);
-                    // track connection
-                    let auth_id_recv = self.connections.reserve_first();
-                    auth_conn.id_recv = auth_id_recv;
-
-                    let resp_data = dirsync::resp::Data {
-                        client_nonce: req_data.nonce,
-                        id: auth_conn.id_recv.0,
-                        service_connection_id: srv_conn_id,
-                        service_key: srv_secret,
-                    };
-                    use crate::enc::sym::AAD;
-                    // no aad for now
-                    let aad = AAD(&mut []);
-
-                    let resp = dirsync::resp::Resp {
-                        client_key_id: req_data.client_key_id,
-                        data: dirsync::resp::State::ClearText(resp_data),
-                    };
-                    let encrypt_from =
-                        connection::ID::len() + resp.encrypted_offset();
-                    let encrypt_until =
-                        encrypt_from + resp.encrypted_length(head_len, tag_len);
-                    let resp_handshake = Handshake::new(
-                        handshake::Data::DirSync(DirSync::Resp(resp)),
-                    );
-                    let packet = Packet {
-                        id: connection::ID::new_handshake(),
-                        data: packet::Data::Handshake(resp_handshake),
-                    };
-                    let tot_len = packet.len(head_len, tag_len);
-                    let mut raw_out = Vec::<u8>::with_capacity(tot_len);
-                    raw_out.resize(tot_len, 0);
-                    packet.serialize(head_len, tag_len, &mut raw_out);
-
-                    if let Err(e) = auth_conn
-                        .cipher_send
-                        .encrypt(aad, &mut raw_out[encrypt_from..encrypt_until])
-                    {
-                        ::tracing::error!("can't encrypt: {:?}", e);
-                        return;
-                    }
-                    self.send_packet(raw_out, udp.src, udp.dst).await;
+            self.recv_handshake(udp, action).await;
+            Err(())
+        } else {
+            self.recv_packet(udp)
+        }
+    }
+    /// Receive a non-handshake packet
+    fn recv_packet(&mut self, udp: RawUdp) -> Result<Event, ()> {
+        let conn = match self.connections.get_id_mut(udp.packet.id) {
+            Ok(conn) => conn,
+            Err(_) => return Err(()),
+        };
+        match conn.recv(udp) {
+            Ok(stream::StreamData::NotReady) => Err(()),
+            Ok(stream::StreamData::Ready) => Ok(Event::Data(ConnData {
+                conn: ConnTracker {
+                    user: conn.user_tracker,
+                    lib: conn.lib_tracker,
+                },
+                data: conn.get_data().unwrap(),
+            })),
+            Err(e) => {
+                ::tracing::trace!("Conn Recv: {:?}", e.to_string());
+                Err(())
+            }
+        }
+    }
+    /// Receive an handshake packet
+    async fn recv_handshake(&mut self, udp: RawUdp, action: handshake::Action) {
+        match action {
+            handshake::Action::AuthNeeded(authinfo) => {
+                let req;
+                if let handshake::Data::DirSync(DirSync::Req(r)) =
+                    authinfo.handshake.data
+                {
+                    req = r;
+                } else {
+                    ::tracing::error!("AuthInfo on non DS::Req");
+                    return;
                 }
-                handshake::Action::ClientConnect(cci) => {
-                    let ds_resp;
-                    if let handshake::Data::DirSync(DirSync::Resp(resp)) =
-                        cci.handshake.data
-                    {
-                        ds_resp = resp;
-                    } else {
-                        ::tracing::error!("ClientConnect on non DS::Resp");
+                let req_data = match req.data {
+                    dirsync::req::State::ClearText(req_data) => req_data,
+                    _ => {
+                        ::tracing::error!("AuthNeeded: expected ClearText");
+                        assert!(false, "AuthNeeded: unreachable");
                         return;
                     }
-                    // track connection
-                    let resp_data;
-                    if let dirsync::resp::State::ClearText(r_data) =
-                        ds_resp.data
-                    {
-                        resp_data = r_data;
-                    } else {
-                        ::tracing::error!(
-                            "ClientConnect on non DS::Resp::ClearText"
-                        );
-                        unreachable!();
+                };
+                // FIXME: This part can take a while,
+                // we should just spawn it probably
+                let maybe_auth_check = {
+                    match &self.token_check {
+                        None => {
+                            if req_data.auth.user == auth::USERID_ANONYMOUS {
+                                Ok(true)
+                            } else {
+                                Ok(false)
+                            }
+                        }
+                        Some(token_check) => {
+                            let tk_check = token_check.lock().await;
+                            tk_check(
+                                req_data.auth.user,
+                                req_data.auth.token,
+                                req_data.auth.service_id,
+                                req_data.auth.domain,
+                            )
+                            .await
+                        }
                     }
-                    let auth_srv_conn = IDSend(resp_data.id);
-                    let mut conn = cci.connection;
-                    conn.id_send = auth_srv_conn;
-                    let id_recv = conn.id_recv;
-                    let cipher = conn.cipher_recv.kind();
-                    // track the connection to the authentication server
-                    if self.connections.track(conn.into()).is_err() {
-                        ::tracing::error!("Could not track new connection");
+                };
+                let is_authenticated = match maybe_auth_check {
+                    Ok(is_authenticated) => is_authenticated,
+                    Err(_) => {
+                        ::tracing::error!("error in token auth");
+                        // TODO: retry?
+                        return;
+                    }
+                };
+                if !is_authenticated {
+                    ::tracing::warn!(
+                        "Wrong authentication for user {:?}",
+                        req_data.auth.user
+                    );
+                    // TODO: error response
+                    return;
+                }
+                // Client has correctly authenticated
+                // TODO: contact the service, get the key and
+                // connection ID
+                let srv_conn_id = connection::ID::new_rand(&self.rand);
+                let srv_secret = Secret::new_rand(&self.rand);
+                let head_len = req.cipher.nonce_len();
+                let tag_len = req.cipher.tag_len();
+
+                let mut auth_conn = Connection::new(
+                    authinfo.hkdf,
+                    req.cipher,
+                    connection::Role::Server,
+                    &self.rand,
+                );
+                auth_conn.id_send = IDSend(req_data.id);
+                auth_conn.send_addr = udp.src;
+                // track connection
+                let auth_id_recv = self.connections.reserve_first();
+                auth_conn.id_recv = auth_id_recv;
+                let (tracker, auth_conn) =
+                    self.connections.reserve_and_track(auth_conn);
+                self.untracked_connections.push_back(tracker);
+
+                let resp_data = dirsync::resp::Data {
+                    client_nonce: req_data.nonce,
+                    id: auth_conn.id_recv.0,
+                    service_connection_id: srv_conn_id,
+                    service_key: srv_secret,
+                };
+                use crate::enc::sym::AAD;
+                // no aad for now
+                let aad = AAD(&mut []);
+
+                let resp = dirsync::resp::Resp {
+                    client_key_id: req_data.client_key_id,
+                    data: dirsync::resp::State::ClearText(resp_data),
+                };
+                let encrypt_from =
+                    connection::ID::len() + resp.encrypted_offset();
+                let encrypt_until =
+                    encrypt_from + resp.encrypted_length(head_len, tag_len);
+                let resp_handshake = Handshake::new(handshake::Data::DirSync(
+                    DirSync::Resp(resp),
+                ));
+                let packet = Packet {
+                    id: connection::ID::new_handshake(),
+                    data: packet::Data::Handshake(resp_handshake),
+                };
+                let tot_len = packet.len(head_len, tag_len);
+                let mut raw_out = Vec::<u8>::with_capacity(tot_len);
+                raw_out.resize(tot_len, 0);
+                packet.serialize(head_len, tag_len, &mut raw_out);
+
+                if let Err(e) = auth_conn
+                    .cipher_send
+                    .encrypt(aad, &mut raw_out[encrypt_from..encrypt_until])
+                {
+                    ::tracing::error!("can't encrypt: {:?}", e);
+                    return;
+                }
+                self.send_packet(raw_out, udp.src, udp.dst).await;
+            }
+            handshake::Action::ClientConnect(cci) => {
+                self.work_timers.remove(cci.old_timeout);
+                let ds_resp;
+                if let handshake::Data::DirSync(DirSync::Resp(resp)) =
+                    cci.handshake.data
+                {
+                    ds_resp = resp;
+                } else {
+                    ::tracing::error!("ClientConnect on non DS::Resp");
+                    return;
+                }
+                // track connection
+                let resp_data;
+                if let dirsync::resp::State::ClearText(r_data) = ds_resp.data {
+                    resp_data = r_data;
+                } else {
+                    ::tracing::error!(
+                        "ClientConnect on non DS::Resp::ClearText"
+                    );
+                    unreachable!();
+                }
+                let auth_id_send = IDSend(resp_data.id);
+                let mut conn = cci.connection;
+                conn.id_send = auth_id_send;
+                let id_recv = conn.id_recv;
+                let cipher = conn.cipher_recv.kind();
+                // track the connection to the authentication server
+                let track_auth_conn = match self.connections.track(conn) {
+                    Ok(track_auth_conn) => track_auth_conn,
+                    Err(_) => {
+                        ::tracing::error!(
+                            "Could not track new auth srv connection"
+                        );
                         self.connections.remove(id_recv);
+                        // FIXME: proper connection closing
                         let _ = cci.answer.send(Err(
                             handshake::Error::InternalTracking.into(),
                         ));
                         return;
                     }
-                    if cci.service_id != auth::SERVICEID_AUTH {
-                        // create and track the connection to the service
-                        // SECURITY: xor with secrets
-                        //FIXME: the Secret should be XORed with the client
-                        // stored secret (if any)
-                        let hkdf = Hkdf::new(
-                            hkdf::Kind::Sha3,
-                            cci.service_id.as_bytes(),
-                            resp_data.service_key,
-                        );
-                        let mut service_connection = Conn::new(
-                            hkdf,
-                            cipher,
-                            connection::Role::Client,
-                            &self.rand,
-                        );
-                        service_connection.id_recv = cci.service_connection_id;
-                        service_connection.id_send =
-                            IDSend(resp_data.service_connection_id);
-                        let _ =
-                            self.connections.track(service_connection.into());
-                    }
-                    let _ =
-                        cci.answer.send(Ok((cci.srv_key_id, auth_srv_conn)));
+                };
+                let authsrv_conn = AuthSrvConn(ConnTracker {
+                    lib: track_auth_conn,
+                    user: None,
+                });
+                let mut service_conn = None;
+                if cci.service_id != auth::SERVICEID_AUTH {
+                    // create and track the connection to the service
+                    // SECURITY: xor with secrets
+                    //FIXME: the Secret should be XORed with the client
+                    // stored secret (if any)
+                    let hkdf = Hkdf::new(
+                        hkdf::Kind::Sha3,
+                        cci.service_id.as_bytes(),
+                        resp_data.service_key,
+                    );
+                    let mut service_connection = Connection::new(
+                        hkdf,
+                        cipher,
+                        connection::Role::Client,
+                        &self.rand,
+                    );
+                    service_connection.id_recv = cci.service_connection_id;
+                    service_connection.id_send =
+                        IDSend(resp_data.service_connection_id);
+                    let track_serv_conn =
+                        match self.connections.track(service_connection) {
+                            Ok(track_serv_conn) => track_serv_conn,
+                            Err(_) => {
+                                ::tracing::error!(
+                                    "Could not track new service connection"
+                                );
+                                self.connections
+                                    .remove(cci.service_connection_id);
+                                // FIXME: proper connection closing
+                                // FIXME: drop auth srv connection if we just
+                                // established it
+                                let _ = cci.answer.send(Err(
+                                    handshake::Error::InternalTracking.into(),
+                                ));
+                                return;
+                            }
+                        };
+                    service_conn = Some(ServiceConn(ConnTracker {
+                        lib: track_serv_conn,
+                        user: None,
+                    }));
                 }
-                handshake::Action::Nothing => {}
-            };
-        }
+                let _ = cci.answer.send(Ok(handshake::tracker::ConnectOk {
+                    auth_key_id: cci.srv_key_id,
+                    auth_id_send,
+                    authsrv_conn,
+                    service_conn,
+                }));
+            }
+            handshake::Action::Nothing => {}
+        };
     }
     async fn send_packet(
         &self,
@@ -653,3 +878,16 @@ impl Worker {
         let _res = src_sock.send_to(&data, client.0).await;
     }
 }
+
+/// Handle to send work asyncronously to the worker
+#[derive(Debug, Clone)]
+pub struct Handle {
+    queue: ::async_channel::Sender<Work>,
+}
+
+impl Handle {
+    // TODO
+    // pub fn send(..)
+    // pub fn set_connection_id(..)
+    // try_get_new_connections()
+}

src/lib.rs

@@ -34,12 +34,12 @@ use crate::{
         AuthServerConnections, Packet,
     },
     inner::{
-        worker::{ConnectInfo, RawUdp, Work, Worker},
+        worker::{ConnectInfo, Event, RawUdp, Work, Worker},
         ThreadTracker,
     },
 };
 pub use config::Config;
-pub use connection::Connection;
+pub use connection::{AuthSrvConn, ServiceConn};
 
 /// Main fenrir library errors
 #[derive(::thiserror::Error, Debug)]
@@ -59,15 +59,15 @@ pub enum Error {
     /// Handshake errors
     #[error("Handshake: {0:?}")]
     Handshake(#[from] handshake::Error),
-    /// Key error
-    #[error("key: {0:?}")]
-    Key(#[from] crate::enc::Error),
     /// Resolution problems. wrong or incomplete DNSSEC data
     #[error("DNSSEC resolution: {0}")]
     Resolution(String),
     /// Wrapper on encryption errors
-    #[error("Encrypt: {0}")]
-    Encrypt(enc::Error),
+    #[error("Crypto: {0}")]
+    Crypto(#[from] enc::Error),
+    /// Wrapper on connection errors
+    #[error("Connection: {0}")]
+    Connection(#[from] connection::Error),
 }
 
 pub(crate) enum StopWorking {
@@ -176,6 +176,7 @@ impl Fenrir {
         config: &Config,
         tokio_rt: Arc<::tokio::runtime::Runtime>,
     ) -> Result<Self, Error> {
+        inner::set_minimum_sleep_resolution().await;
         let (sender, _) = ::tokio::sync::broadcast::channel(1);
         let dnssec = dnssec::Dnssec::new(&config.resolvers)?;
         // bind sockets early so we can change "port 0" (aka: random)
@@ -214,6 +215,7 @@ impl Fenrir {
     pub async fn with_workers(
         config: &Config,
     ) -> Result<(Self, Vec<Worker>), Error> {
+        inner::set_minimum_sleep_resolution().await;
         let (stop_working, _) = ::tokio::sync::broadcast::channel(1);
         let dnssec = dnssec::Dnssec::new(&config.resolvers)?;
         // bind sockets early so we can change "port 0" (aka: random)
@@ -382,7 +384,7 @@ impl Fenrir {
         &self,
         domain: &Domain,
         service: ServiceID,
-    ) -> Result<(), Error> {
+    ) -> Result<(AuthSrvConn, Option<ServiceConn>), Error> {
         let resolved = self.resolv(domain).await?;
         self.connect_resolved(resolved, domain, service).await
     }
@@ -392,7 +394,7 @@ impl Fenrir {
         resolved: dnssec::Record,
         domain: &Domain,
         service: ServiceID,
-    ) -> Result<(), Error> {
+    ) -> Result<(AuthSrvConn, Option<ServiceConn>), Error> {
         loop {
             // check if we already have a connection to that auth. srv
             let is_reserved = {
@@ -460,29 +462,28 @@ impl Fenrir {
             .await;
 
         match recv.await {
-            Ok(res) => {
-                match res {
-                    Err(e) => {
-                        let mut conn_auth_lock =
-                            self.conn_auth_srv.lock().await;
-                        conn_auth_lock.remove_reserved(&resolved);
-                        Err(e)
-                    }
-                    Ok((key_id, id_send)) => {
-                        let key = resolved
-                            .public_keys
-                            .iter()
-                            .find(|k| k.0 == key_id)
-                            .unwrap();
-                        let mut conn_auth_lock =
-                            self.conn_auth_srv.lock().await;
-                        conn_auth_lock.add(&key.1, id_send, &resolved);
-
-                        //FIXME: user needs to somehow track the connection
-                        Ok(())
-                    }
+            Ok(res) => match res {
+                Err(e) => {
+                    let mut conn_auth_lock = self.conn_auth_srv.lock().await;
+                    conn_auth_lock.remove_reserved(&resolved);
+                    Err(e)
                 }
-            }
+                Ok(connections) => {
+                    let key = resolved
+                        .public_keys
+                        .iter()
+                        .find(|k| k.0 == connections.auth_key_id)
+                        .unwrap();
+                    let mut conn_auth_lock = self.conn_auth_srv.lock().await;
+                    conn_auth_lock.add(
+                        &key.1,
+                        connections.auth_id_send,
+                        &resolved,
+                    );
+
+                    Ok((connections.authsrv_conn, connections.service_conn))
+                }
+            },
             Err(e) => {
                 // Thread dropped the sender. no more thread?
                 let mut conn_auth_lock = self.conn_auth_srv.lock().await;
@@ -524,6 +525,7 @@ impl Fenrir {
             self.token_check.clone(),
             socks,
             work_recv,
+            work_send.clone(),
         )
         .await?;
         // don't keep around private keys too much
@@ -547,7 +549,6 @@ impl Fenrir {
         }
         Ok(worker)
     }
-
     // needs to be called before add_sockets
     /// Start one working thread for each physical cpu
     /// threads are pinned to each cpu core.
@@ -589,6 +590,7 @@ impl Fenrir {
             let th_tokio_rt = tokio_rt.clone();
             let th_config = self.cfg.clone();
             let (work_send, work_recv) = ::async_channel::unbounded::<Work>();
+            let th_work_send = work_send.clone();
             let th_stop_working = self.stop_working.subscribe();
             let th_token_check = self.token_check.clone();
             let th_sockets = sockets.clone();
@@ -629,13 +631,23 @@ impl Fenrir {
                         th_token_check,
                         th_sockets,
                         work_recv,
+                        th_work_send,
                     )
                     .await
                     {
                         Ok(worker) => worker,
                         Err(_) => return,
                     };
-                    worker.work_loop().await
+                    loop {
+                        match worker.work_loop().await {
+                            Ok(_) => continue,
+                            Ok(Event::End) => break,
+                            Err(e) => {
+                                ::tracing::error!("Worker: {:?}", e);
+                                break;
+                            }
+                        }
+                    }
                 });
             });
             loop {

src/tests.rs

@@ -88,7 +88,7 @@ async fn test_connection_dirsync() {
         .connect_resolved(dnssec_record, &test_domain, auth::SERVICEID_AUTH)
         .await
     {
-        Ok(()) => {}
+        Ok((_, _)) => {}
         Err(e) => {
             assert!(false, "Err on client connection: {:?}", e);
         }