First commit

10 files changed, 1757 insertions, 0 deletions

diff --git a/src/conn.rs b/src/conn.rs
new file mode 100644
index 0000000..9b60d2a
--- /dev/null
+++ b/src/conn.rs
@@ -0,0 +1,280 @@
+use std::collections::HashMap;
+use std::net::SocketAddr;
+use std::sync::atomic::{self, AtomicU16};
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use bytes::Bytes;
+use log::{debug, trace};
+
+use sodiumoxide::crypto::sign::ed25519;
+use tokio::io::split;
+use tokio::net::TcpStream;
+use tokio::sync::{mpsc, oneshot, watch};
+
+use kuska_handshake::async_std::{
+	handshake_client, handshake_server, BoxStream, TokioCompatExt, TokioCompatExtRead,
+	TokioCompatExtWrite,
+};
+
+use crate::error::*;
+use crate::message::*;
+use crate::netapp::*;
+use crate::proto::*;
+use crate::util::*;
+
+pub struct ServerConn {
+	netapp: Arc<NetApp>,
+	pub remote_addr: SocketAddr,
+	pub peer_pk: ed25519::PublicKey,
+	resp_send: mpsc::UnboundedSender<(RequestID, RequestPriority, Vec<u8>)>,
+	close_send: watch::Sender<bool>,
+}
+
+impl ServerConn {
+	pub(crate) async fn run(netapp: Arc<NetApp>, socket: TcpStream) -> Result<(), Error> {
+		let mut asyncstd_socket = TokioCompatExt::wrap(socket);
+		let handshake = handshake_server(
+			&mut asyncstd_socket,
+			netapp.netid.clone(),
+			netapp.pubkey.clone(),
+			netapp.privkey.clone(),
+		)
+		.await?;
+		let peer_pk = handshake.peer_pk.clone();
+
+		let tokio_socket = asyncstd_socket.into_inner();
+		let remote_addr = tokio_socket.peer_addr().unwrap();
+
+		debug!(
+			"Handshake complete (server) with {}@{}",
+			hex::encode(&peer_pk),
+			remote_addr
+		);
+
+		let (read, write) = split(tokio_socket);
+
+		let read = TokioCompatExtRead::wrap(read);
+		let write = TokioCompatExtWrite::wrap(write);
+
+		let (box_stream_read, box_stream_write) =
+			BoxStream::from_handshake(read, write, handshake, 0x8000).split_read_write();
+
+		let (resp_send, resp_recv) = mpsc::unbounded_channel();
+
+		let (close_send, close_recv) = watch::channel(false);
+
+		let conn = Arc::new(ServerConn {
+			netapp: netapp.clone(),
+			remote_addr,
+			peer_pk: peer_pk.clone(),
+			resp_send,
+			close_send,
+		});
+
+		netapp.connected_as_server(peer_pk.clone(), conn.clone());
+
+		let conn2 = conn.clone();
+		let conn3 = conn.clone();
+		tokio::try_join!(
+			conn2.recv_loop(box_stream_read, close_recv.clone()),
+			conn3.send_loop(resp_recv, box_stream_write, close_recv.clone()),
+		)
+		.map(|_| ())
+		.log_err("ServerConn recv_loop/send_loop");
+
+		netapp.disconnected_as_server(&peer_pk, conn);
+
+		Ok(())
+	}
+
+	pub fn close(&self) {
+		self.close_send.broadcast(true).unwrap();
+	}
+}
+
+impl SendLoop for ServerConn {}
+
+#[async_trait]
+impl RecvLoop for ServerConn {
+	async fn recv_handler(self: Arc<Self>, id: u16, bytes: Vec<u8>) {
+		let bytes: Bytes = bytes.into();
+
+		let prio = bytes[0];
+
+		let mut kind_bytes = [0u8; 4];
+		kind_bytes.copy_from_slice(&bytes[1..5]);
+		let kind = u32::from_be_bytes(kind_bytes);
+
+		if let Some(handler) = self.netapp.msg_handlers.load().get(&kind) {
+			let resp = handler(self.peer_pk.clone(), bytes.slice(5..)).await;
+			self.resp_send
+				.send((id, prio, resp))
+				.log_err("ServerConn recv_handler send resp");
+		}
+	}
+}
+pub struct ClientConn {
+	pub netapp: Arc<NetApp>,
+	pub remote_addr: SocketAddr,
+	pub peer_pk: ed25519::PublicKey,
+	query_send: mpsc::UnboundedSender<(RequestID, RequestPriority, Vec<u8>)>,
+	next_query_number: AtomicU16,
+	resp_send: mpsc::UnboundedSender<(RequestID, Vec<u8>)>,
+	resp_notify_send: mpsc::UnboundedSender<(RequestID, oneshot::Sender<Vec<u8>>)>,
+	close_send: watch::Sender<bool>,
+}
+
+impl ClientConn {
+	pub(crate) async fn init(
+		netapp: Arc<NetApp>,
+		socket: TcpStream,
+		remote_pk: ed25519::PublicKey,
+	) -> Result<(), Error> {
+		let mut asyncstd_socket = TokioCompatExt::wrap(socket);
+
+		let handshake = handshake_client(
+			&mut asyncstd_socket,
+			netapp.netid.clone(),
+			netapp.pubkey.clone(),
+			netapp.privkey.clone(),
+			remote_pk.clone(),
+		)
+		.await?;
+
+		let tokio_socket = asyncstd_socket.into_inner();
+		let remote_addr = tokio_socket.peer_addr().unwrap();
+
+		debug!(
+			"Handshake complete (client) with {}@{}",
+			hex::encode(&remote_pk),
+			remote_addr
+		);
+
+		let (read, write) = split(tokio_socket);
+
+		let read = TokioCompatExtRead::wrap(read);
+		let write = TokioCompatExtWrite::wrap(write);
+
+		let (box_stream_read, box_stream_write) =
+			BoxStream::from_handshake(read, write, handshake, 0x8000).split_read_write();
+
+		let (query_send, query_recv) = mpsc::unbounded_channel();
+		let (resp_send, resp_recv) = mpsc::unbounded_channel();
+		let (resp_notify_send, resp_notify_recv) = mpsc::unbounded_channel();
+
+		let (close_send, close_recv) = watch::channel(false);
+
+		let conn = Arc::new(ClientConn {
+			netapp: netapp.clone(),
+			remote_addr,
+			peer_pk: remote_pk.clone(),
+			next_query_number: AtomicU16::from(0u16),
+			query_send,
+			resp_send,
+			resp_notify_send,
+			close_send,
+		});
+
+		netapp.connected_as_client(remote_pk.clone(), conn.clone());
+
+		tokio::spawn(async move {
+			let conn2 = conn.clone();
+			let conn3 = conn.clone();
+			let conn4 = conn.clone();
+			tokio::try_join!(
+				conn2.send_loop(query_recv, box_stream_write, close_recv.clone()),
+				conn3.recv_loop(box_stream_read, close_recv.clone()),
+				conn4.dispatch_resp(resp_recv, resp_notify_recv, close_recv.clone()),
+			)
+			.map(|_| ())
+			.log_err("ClientConn send_loop/recv_loop/dispatch_loop");
+
+			netapp.disconnected_as_client(&remote_pk, conn);
+		});
+
+		Ok(())
+	}
+
+	pub fn close(&self) {
+		self.close_send.broadcast(true).unwrap();
+	}
+
+	async fn dispatch_resp(
+		self: Arc<Self>,
+		mut resp_recv: mpsc::UnboundedReceiver<(RequestID, Vec<u8>)>,
+		mut resp_notify_recv: mpsc::UnboundedReceiver<(RequestID, oneshot::Sender<Vec<u8>>)>,
+		mut must_exit: watch::Receiver<bool>,
+	) -> Result<(), Error> {
+		let mut resps: HashMap<RequestID, Vec<u8>> = HashMap::new();
+		let mut resp_notify: HashMap<RequestID, oneshot::Sender<Vec<u8>>> = HashMap::new();
+		while !*must_exit.borrow() {
+			tokio::select! {
+				resp = resp_recv.recv() => {
+					if let Some((id, resp)) = resp {
+						trace!("dispatch_resp: got resp to {}, {} bytes", id, resp.len());
+						if let Some(ch) = resp_notify.remove(&id) {
+							ch.send(resp).map_err(|_| Error::Message("Could not dispatch reply".to_string()))?;
+						} else {
+							resps.insert(id, resp);
+						}
+					}
+				}
+				resp_ch = resp_notify_recv.recv() => {
+					if let Some((id, resp_ch)) = resp_ch {
+						trace!("dispatch_resp: got resp_ch {}", id);
+						if let Some(rs) = resps.remove(&id) {
+							resp_ch.send(rs).map_err(|_| Error::Message("Could not dispatch reply".to_string()))?;
+						} else {
+							resp_notify.insert(id, resp_ch);
+						}
+					}
+				}
+				exit = must_exit.recv() => {
+					if exit == Some(true) {
+						break;
+					}
+				}
+			}
+		}
+		Ok(())
+	}
+
+	pub async fn request<T>(
+		self: Arc<Self>,
+		rq: T,
+		prio: RequestPriority,
+	) -> Result<<T as Message>::Response, Error>
+	where
+		T: Message,
+	{
+		let id = self
+			.next_query_number
+			.fetch_add(1u16, atomic::Ordering::Relaxed);
+		let mut bytes = vec![prio];
+		bytes.extend_from_slice(&u32::to_be_bytes(T::KIND)[..]);
+		bytes.extend_from_slice(&rmp_to_vec_all_named(&rq)?[..]);
+
+		let (resp_send, resp_recv) = oneshot::channel();
+		self.resp_notify_send.send((id, resp_send))?;
+
+		trace!("request: query_send {}, {} bytes", id, bytes.len());
+		self.query_send.send((id, prio, bytes))?;
+
+		let resp = resp_recv.await?;
+
+		rmp_serde::decode::from_read_ref::<_, Result<<T as Message>::Response, String>>(&resp[..])?
+			.map_err(Error::Remote)
+	}
+}
+
+impl SendLoop for ClientConn {}
+
+#[async_trait]
+impl RecvLoop for ClientConn {
+	async fn recv_handler(self: Arc<Self>, id: RequestID, msg: Vec<u8>) {
+		self.resp_send
+			.send((id, msg))
+			.log_err("ClientConn::recv_handler");
+	}
+}
diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..b54423a
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,57 @@
+use err_derive::Error;
+use std::io;
+
+use log::error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+	#[error(display = "IO error: {}", _0)]
+	Io(#[error(source)] io::Error),
+
+	#[error(display = "Messagepack encode error: {}", _0)]
+	RMPEncode(#[error(source)] rmp_serde::encode::Error),
+	#[error(display = "Messagepack decode error: {}", _0)]
+	RMPDecode(#[error(source)] rmp_serde::decode::Error),
+
+	#[error(display = "Tokio join error: {}", _0)]
+	TokioJoin(#[error(source)] tokio::task::JoinError),
+
+	#[error(display = "oneshot receive error: {}", _0)]
+	OneshotRecv(#[error(source)] tokio::sync::oneshot::error::RecvError),
+
+	#[error(display = "Handshake error: {}", _0)]
+	Handshake(#[error(source)] kuska_handshake::async_std::Error),
+
+	#[error(display = "{}", _0)]
+	Message(String),
+
+	#[error(display = "Remote error: {}", _0)]
+	Remote(String),
+}
+
+impl<T> From<tokio::sync::watch::error::SendError<T>> for Error {
+	fn from(_e: tokio::sync::watch::error::SendError<T>) -> Error {
+		Error::Message(format!("Watch send error"))
+	}
+}
+
+impl<T> From<tokio::sync::mpsc::error::SendError<T>> for Error {
+	fn from(_e: tokio::sync::mpsc::error::SendError<T>) -> Error {
+		Error::Message(format!("MPSC send error"))
+	}
+}
+
+pub trait LogError {
+	fn log_err(self, msg: &'static str);
+}
+
+impl<E> LogError for Result<(), E>
+where
+	E: Into<Error>,
+{
+	fn log_err(self, msg: &'static str) {
+		if let Err(e) = self {
+			error!("Error: {}: {}", msg, Into::<Error>::into(e));
+		};
+	}
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..2db8a22
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,9 @@
+#![feature(map_first_last)]
+
+pub mod conn;
+pub mod error;
+pub mod message;
+pub mod netapp;
+pub mod peering;
+pub mod proto;
+pub mod util;
diff --git a/src/message.rs b/src/message.rs
new file mode 100644
index 0000000..bcc5aac
--- /dev/null
+++ b/src/message.rs
@@ -0,0 +1,18 @@
+use serde::{Deserialize, Serialize};
+
+pub type MessageKind = u32;
+
+pub trait Message: Serialize + for<'de> Deserialize<'de> + Send + Sync {
+	const KIND: MessageKind;
+	type Response: Serialize + for<'de> Deserialize<'de> + Send + Sync;
+}
+
+#[derive(Serialize, Deserialize)]
+pub(crate) struct HelloMessage {
+	pub server_port: u16,
+}
+
+impl Message for HelloMessage {
+	const KIND: MessageKind = 0x42000001;
+	type Response = ();
+}
diff --git a/src/netapp.rs b/src/netapp.rs
new file mode 100644
index 0000000..6f174b4
--- /dev/null
+++ b/src/netapp.rs
@@ -0,0 +1,214 @@
+use std::collections::HashMap;
+use std::net::SocketAddr;
+use std::pin::Pin;
+use std::sync::{Arc, RwLock};
+
+use std::future::Future;
+
+use log::{debug, info};
+
+use arc_swap::{ArcSwap, ArcSwapOption};
+use bytes::Bytes;
+
+use sodiumoxide::crypto::auth;
+use sodiumoxide::crypto::sign::ed25519;
+use tokio::net::{TcpListener, TcpStream};
+
+use crate::conn::*;
+use crate::error::*;
+use crate::message::*;
+use crate::proto::*;
+use crate::util::*;
+
+pub struct NetApp {
+	pub listen_addr: SocketAddr,
+	pub netid: auth::Key,
+	pub pubkey: ed25519::PublicKey,
+	pub privkey: ed25519::SecretKey,
+	pub server_conns: RwLock<HashMap<ed25519::PublicKey, Arc<ServerConn>>>,
+	pub client_conns: RwLock<HashMap<ed25519::PublicKey, Arc<ClientConn>>>,
+	pub(crate) msg_handlers: ArcSwap<
+		HashMap<
+			MessageKind,
+			Arc<
+				dyn Fn(
+						ed25519::PublicKey,
+						Bytes,
+					) -> Pin<Box<dyn Future<Output = Vec<u8>> + Sync + Send>>
+					+ Sync
+					+ Send,
+			>,
+		>,
+	>,
+	pub(crate) on_connected:
+		ArcSwapOption<Box<dyn Fn(ed25519::PublicKey, SocketAddr, bool) + Send + Sync>>,
+	pub(crate) on_disconnected: ArcSwapOption<Box<dyn Fn(ed25519::PublicKey, bool) + Send + Sync>>,
+}
+
+async fn handler_aux<M, F, R>(handler: Arc<F>, remote: ed25519::PublicKey, bytes: Bytes) -> Vec<u8>
+where
+	M: Message + 'static,
+	F: Fn(ed25519::PublicKey, M) -> R + Send + Sync + 'static,
+	R: Future<Output = Result<<M as Message>::Response, Error>> + Send + Sync,
+{
+	debug!(
+		"Handling message of kind {:08x} from {}",
+		M::KIND,
+		hex::encode(remote)
+	);
+	let res = match rmp_serde::decode::from_read_ref::<_, M>(&bytes[..]) {
+		Ok(msg) => handler(remote.clone(), msg).await,
+		Err(e) => Err(e.into()),
+	};
+	let res = res.map_err(|e| format!("{}", e));
+	rmp_to_vec_all_named(&res).unwrap_or(vec![])
+}
+
+impl NetApp {
+	pub fn new(
+		listen_addr: SocketAddr,
+		netid: auth::Key,
+		privkey: ed25519::SecretKey,
+	) -> Arc<Self> {
+		let pubkey = privkey.public_key();
+		let netapp = Arc::new(Self {
+			listen_addr,
+			netid,
+			pubkey,
+			privkey,
+			server_conns: RwLock::new(HashMap::new()),
+			client_conns: RwLock::new(HashMap::new()),
+			msg_handlers: ArcSwap::new(Arc::new(HashMap::new())),
+			on_connected: ArcSwapOption::new(None),
+			on_disconnected: ArcSwapOption::new(None),
+		});
+
+		let netapp2 = netapp.clone();
+		netapp.add_msg_handler::<HelloMessage, _, _>(
+			move |from: ed25519::PublicKey, msg: HelloMessage| {
+				netapp2.handle_hello_message(from, msg);
+				async { Ok(()) }
+			},
+		);
+
+		netapp
+	}
+
+	pub fn add_msg_handler<M, F, R>(&self, handler: F)
+	where
+		M: Message + 'static,
+		F: Fn(ed25519::PublicKey, M) -> R + Send + Sync + 'static,
+		R: Future<Output = Result<<M as Message>::Response, Error>> + Send + Sync + 'static,
+	{
+		let handler = Arc::new(handler);
+		let fun = Arc::new(move |remote: ed25519::PublicKey, bytes: Bytes| {
+			let fun: Pin<Box<dyn Future<Output = Vec<u8>> + Sync + Send>> =
+				Box::pin(handler_aux(handler.clone(), remote, bytes));
+			fun
+		});
+		let mut handlers = self.msg_handlers.load().as_ref().clone();
+		handlers.insert(M::KIND, fun);
+		self.msg_handlers.store(Arc::new(handlers));
+	}
+
+	pub async fn listen(self: Arc<Self>) {
+		let mut listener = TcpListener::bind(self.listen_addr).await.unwrap();
+		info!("Listening on {}", self.listen_addr);
+
+		loop {
+			// The second item contains the IP and port of the new connection.
+			let (socket, _) = listener.accept().await.unwrap();
+			info!(
+				"Incoming connection from {}, negotiating handshake...",
+				socket.peer_addr().unwrap()
+			);
+			let self2 = self.clone();
+			tokio::spawn(async move {
+				ServerConn::run(self2, socket)
+					.await
+					.log_err("ServerConn::run");
+			});
+		}
+	}
+
+	pub async fn try_connect(
+		self: Arc<Self>,
+		ip: SocketAddr,
+		pk: ed25519::PublicKey,
+	) -> Result<(), Error> {
+		if self.client_conns.read().unwrap().contains_key(&pk) {
+			return Ok(());
+		}
+		let socket = TcpStream::connect(ip).await?;
+		info!("Connected to {}, negotiating handshake...", ip);
+		ClientConn::init(self, socket, pk.clone()).await?;
+		Ok(())
+	}
+
+	pub fn disconnect(self: Arc<Self>, id: &ed25519::PublicKey) {
+		let conn = self.client_conns.read().unwrap().get(id).cloned();
+		if let Some(c) = conn {
+			c.close();
+		}
+	}
+
+	pub(crate) fn connected_as_server(&self, id: ed25519::PublicKey, conn: Arc<ServerConn>) {
+		let mut conn_list = self.server_conns.write().unwrap();
+		conn_list.insert(id.clone(), conn);
+	}
+
+	fn handle_hello_message(&self, id: ed25519::PublicKey, msg: HelloMessage) {
+		if let Some(h) = self.on_connected.load().as_ref() {
+			if let Some(c) = self.server_conns.read().unwrap().get(&id) {
+				let remote_addr = SocketAddr::new(c.remote_addr.ip(), msg.server_port);
+				h(id, remote_addr, true);
+			}
+		}
+	}
+
+	pub(crate) fn disconnected_as_server(&self, id: &ed25519::PublicKey, conn: Arc<ServerConn>) {
+		let mut conn_list = self.server_conns.write().unwrap();
+		if let Some(c) = conn_list.get(id) {
+			if Arc::ptr_eq(c, &conn) {
+				conn_list.remove(id);
+			}
+
+			if let Some(h) = self.on_disconnected.load().as_ref() {
+				h(conn.peer_pk, true);
+			}
+		}
+	}
+
+	pub(crate) fn connected_as_client(&self, id: ed25519::PublicKey, conn: Arc<ClientConn>) {
+		{
+			let mut conn_list = self.client_conns.write().unwrap();
+			if let Some(old_c) = conn_list.insert(id.clone(), conn.clone()) {
+				tokio::spawn(async move { old_c.close() });
+			}
+		}
+
+		if let Some(h) = self.on_connected.load().as_ref() {
+			h(conn.peer_pk, conn.remote_addr, false);
+		}
+
+		tokio::spawn(async move {
+			let server_port = conn.netapp.listen_addr.port();
+			conn.request(HelloMessage { server_port }, prio::NORMAL)
+				.await
+				.log_err("Sending hello message");
+		});
+	}
+
+	pub(crate) fn disconnected_as_client(&self, id: &ed25519::PublicKey, conn: Arc<ClientConn>) {
+		let mut conn_list = self.client_conns.write().unwrap();
+		if let Some(c) = conn_list.get(id) {
+			if Arc::ptr_eq(c, &conn) {
+				conn_list.remove(id);
+			}
+
+			if let Some(h) = self.on_disconnected.load().as_ref() {
+				h(conn.peer_pk, false);
+			}
+		}
+	}
+}
diff --git a/src/peering/basalt.rs b/src/peering/basalt.rs
new file mode 100644
index 0000000..be807a8
--- /dev/null
+++ b/src/peering/basalt.rs
@@ -0,0 +1,475 @@
+use std::collections::HashSet;
+use std::net::SocketAddr;
+use std::sync::{Arc, RwLock};
+use std::time::Duration;
+
+use log::{debug, warn};
+use lru::LruCache;
+use rand::{thread_rng, Rng};
+use serde::{Deserialize, Serialize};
+
+use sodiumoxide::crypto::hash;
+use sodiumoxide::crypto::sign::ed25519;
+
+use crate::conn::*;
+use crate::message::*;
+use crate::netapp::*;
+use crate::proto::*;
+
+// -- Protocol messages --
+
+#[derive(Serialize, Deserialize)]
+struct PullMessage {}
+
+impl Message for PullMessage {
+	const KIND: MessageKind = 0x42001100;
+	type Response = PushMessage;
+}
+
+#[derive(Serialize, Deserialize)]
+struct PushMessage {
+	peers: Vec<Peer>,
+}
+
+impl Message for PushMessage {
+	const KIND: MessageKind = 0x42001101;
+	type Response = ();
+}
+
+// -- Algorithm data structures --
+
+type Seed = [u8; 32];
+
+#[derive(Hash, Clone, Copy, Debug, PartialOrd, PartialEq, Eq, Serialize, Deserialize)]
+struct Peer {
+	id: ed25519::PublicKey,
+	addr: SocketAddr,
+}
+
+type Cost = [u8; 40];
+const MAX_COST: Cost = [0xffu8; 40];
+
+impl Peer {
+	fn cost(&self, seed: &Seed) -> Cost {
+		let mut hasher = hash::State::new();
+		hasher.update(&seed[..]);
+
+		let mut cost = [0u8; 40];
+		match self.addr {
+			SocketAddr::V4(v4addr) => {
+				let v4ip = v4addr.ip().octets();
+
+				for i in 0..4 {
+					let mut h = hasher.clone();
+					h.update(&v4ip[..i + 1]);
+					cost[i * 8..(i + 1) * 8].copy_from_slice(&h.finalize()[..8]);
+				}
+			}
+			SocketAddr::V6(v6addr) => {
+				let v6ip = v6addr.ip().octets();
+
+				for i in 0..4 {
+					let mut h = hasher.clone();
+					h.update(&v6ip[..i + 2]);
+					cost[i * 8..(i + 1) * 8].copy_from_slice(&h.finalize()[..8]);
+				}
+			}
+		}
+
+		{
+			let mut h5 = hasher.clone();
+			h5.update(&format!("{}", self.addr).into_bytes()[..]);
+			cost[32..40].copy_from_slice(&h5.finalize()[..8]);
+		}
+
+		cost
+	}
+}
+
+struct BasaltSlot {
+	seed: Seed,
+	peer: Option<Peer>,
+}
+
+impl BasaltSlot {
+	fn cost(&self) -> Cost {
+		self.peer.map(|p| p.cost(&self.seed)).unwrap_or(MAX_COST)
+	}
+}
+
+struct BasaltView {
+	i_reset: usize,
+	slots: Vec<BasaltSlot>,
+}
+
+impl BasaltView {
+	fn new(size: usize) -> Self {
+		let slots = (0..size)
+			.map(|_| BasaltSlot {
+				seed: rand_seed(),
+				peer: None,
+			})
+			.collect::<Vec<_>>();
+		Self { i_reset: 0, slots }
+	}
+
+	fn current_peers(&self) -> HashSet<Peer> {
+		self.slots
+			.iter()
+			.filter(|s| s.peer.is_some())
+			.map(|s| s.peer.unwrap().clone())
+			.collect::<HashSet<_>>()
+	}
+	fn current_peers_vec(&self) -> Vec<Peer> {
+		self.current_peers().drain().collect::<Vec<_>>()
+	}
+
+	fn sample(&self, count: usize) -> Vec<Peer> {
+		let possibles = self
+			.slots
+			.iter()
+			.enumerate()
+			.filter(|(_i, s)| s.peer.is_some())
+			.map(|(i, _s)| i)
+			.collect::<Vec<_>>();
+		if possibles.len() == 0 {
+			vec![]
+		} else {
+			let mut ret = vec![];
+			let mut rng = thread_rng();
+			for _i in 0..count {
+				let idx = rng.gen_range(0, possibles.len());
+				ret.push(self.slots[possibles[idx]].peer.unwrap());
+			}
+			ret
+		}
+	}
+
+	fn update_slot(&mut self, i: usize, peers: &[Peer]) {
+		let mut slot_cost = self.slots[i].cost();
+
+		for peer in peers.iter() {
+			let peer_cost = peer.cost(&self.slots[i].seed);
+			if self.slots[i].peer.is_none() || peer_cost < slot_cost {
+				self.slots[i].peer = Some(*peer);
+				slot_cost = peer_cost;
+			}
+		}
+	}
+	fn update_all_slots(&mut self, peers: &[Peer]) {
+		for i in 0..self.slots.len() {
+			self.update_slot(i, peers);
+		}
+	}
+
+	fn disconnected(&mut self, id: ed25519::PublicKey) {
+		let mut cleared_slots = vec![];
+		for i in 0..self.slots.len() {
+			if let Some(p) = self.slots[i].peer {
+				if p.id == id {
+					self.slots[i].peer = None;
+					cleared_slots.push(i);
+				}
+			}
+		}
+
+		let remaining_peers = self.current_peers_vec();
+
+		for i in cleared_slots {
+			self.update_slot(i, &remaining_peers[..]);
+		}
+	}
+
+	fn should_try_list(&self, peers: &[Peer]) -> Vec<Peer> {
+		// Select peers that have lower cost than any of our slots
+		let mut ret = HashSet::new();
+
+		for i in 0..self.slots.len() {
+			if self.slots[i].peer.is_none() {
+				return peers.to_vec();
+			}
+			let mut min_cost = self.slots[i].cost();
+			let mut min_peer = None;
+			for peer in peers.iter() {
+				if ret.contains(peer) {
+					continue;
+				}
+				let peer_cost = peer.cost(&self.slots[i].seed);
+				if peer_cost < min_cost {
+					min_cost = peer_cost;
+					min_peer = Some(*peer);
+				}
+			}
+			if let Some(p) = min_peer {
+				ret.insert(p);
+				if ret.len() == peers.len() {
+					break;
+				}
+			}
+		}
+
+		ret.drain().collect::<Vec<_>>()
+	}
+
+	fn reset_some_slots(&mut self, count: usize) {
+		for _i in 0..count {
+			self.slots[self.i_reset].seed = rand_seed();
+			self.i_reset = (self.i_reset + 1) % self.slots.len();
+		}
+	}
+}
+
+pub struct BasaltParams {
+	pub view_size: usize,
+	pub cache_size: usize,
+	pub exchange_interval: Duration,
+	pub reset_interval: Duration,
+	pub reset_count: usize,
+}
+
+pub struct Basalt {
+	netapp: Arc<NetApp>,
+
+	param: BasaltParams,
+	bootstrap_peers: Vec<Peer>,
+
+	view: RwLock<BasaltView>,
+	current_attempts: RwLock<HashSet<Peer>>,
+	backlog: RwLock<LruCache<Peer, ()>>,
+}
+
+impl Basalt {
+	pub fn new(
+		netapp: Arc<NetApp>,
+		bootstrap_list: Vec<(ed25519::PublicKey, SocketAddr)>,
+		param: BasaltParams,
+	) -> Arc<Self> {
+		let bootstrap_peers = bootstrap_list
+			.iter()
+			.map(|(id, addr)| Peer {
+				id: *id,
+				addr: *addr,
+			})
+			.collect::<Vec<_>>();
+
+		let view = BasaltView::new(param.view_size);
+		let backlog = LruCache::new(param.cache_size);
+
+		let basalt = Arc::new(Self {
+			netapp: netapp.clone(),
+			param,
+			bootstrap_peers,
+			view: RwLock::new(view),
+			current_attempts: RwLock::new(HashSet::new()),
+			backlog: RwLock::new(backlog),
+		});
+
+		let basalt2 = basalt.clone();
+		netapp.on_connected.store(Some(Arc::new(Box::new(
+			move |pk: ed25519::PublicKey, addr: SocketAddr, is_incoming: bool| {
+				basalt2.on_connected(pk, addr, is_incoming);
+			},
+		))));
+
+		let basalt2 = basalt.clone();
+		netapp.on_disconnected.store(Some(Arc::new(Box::new(
+			move |pk: ed25519::PublicKey, is_incoming: bool| {
+				basalt2.on_disconnected(pk, is_incoming);
+			},
+		))));
+
+		let basalt2 = basalt.clone();
+		netapp.add_msg_handler::<PullMessage, _, _>(
+			move |_from: ed25519::PublicKey, _pullmsg: PullMessage| {
+				let push_msg = basalt2.make_push_message();
+				async move { Ok(push_msg) }
+			},
+		);
+
+		let basalt2 = basalt.clone();
+		netapp.add_msg_handler::<PushMessage, _, _>(
+			move |_from: ed25519::PublicKey, push_msg: PushMessage| {
+				basalt2.handle_peer_list(&push_msg.peers[..]);
+				async move { Ok(()) }
+			},
+		);
+
+		basalt
+	}
+
+	pub fn sample(&self, count: usize) -> Vec<ed25519::PublicKey> {
+		self.view
+			.read()
+			.unwrap()
+			.sample(count)
+			.iter()
+			.map(|p| p.id)
+			.collect::<Vec<_>>()
+	}
+
+	pub async fn run(self: Arc<Self>) {
+		for peer in self.bootstrap_peers.iter() {
+			tokio::spawn(self.clone().try_connect(*peer));
+		}
+
+		let pushpull_loop = self.clone().run_pushpull_loop();
+		let reset_loop = self.run_reset_loop();
+		tokio::join!(pushpull_loop, reset_loop);
+	}
+
+	async fn run_pushpull_loop(self: Arc<Self>) {
+		loop {
+			tokio::time::delay_for(self.param.exchange_interval).await;
+
+			let peers = self.view.read().unwrap().sample(2);
+			if peers.len() == 2 {
+				let (c1, c2) = {
+					let client_conns = self.netapp.client_conns.read().unwrap();
+					(
+						client_conns.get(&peers[0].id).cloned(),
+						client_conns.get(&peers[1].id).cloned(),
+					)
+				};
+				if let Some(c) = c1 {
+					tokio::spawn(self.clone().do_pull(c));
+				}
+				if let Some(c) = c2 {
+					tokio::spawn(self.clone().do_push(c));
+				}
+			}
+		}
+	}
+
+	async fn do_pull(self: Arc<Self>, peer: Arc<ClientConn>) {
+		match peer.request(PullMessage {}, prio::NORMAL).await {
+			Ok(resp) => {
+				self.handle_peer_list(&resp.peers[..]);
+			}
+			Err(e) => {
+				warn!("Error during pull exchange: {}", e);
+			}
+		};
+	}
+
+	async fn do_push(self: Arc<Self>, peer: Arc<ClientConn>) {
+		let push_msg = self.make_push_message();
+		if let Err(e) = peer.request(push_msg, prio::NORMAL).await {
+			warn!("Error during push exchange: {}", e);
+		}
+	}
+
+	fn make_push_message(&self) -> PushMessage {
+		let current_peers = self.view.read().unwrap().current_peers_vec();
+		PushMessage {
+			peers: current_peers,
+		}
+	}
+
+	async fn run_reset_loop(self: Arc<Self>) {
+		loop {
+			tokio::time::delay_for(self.param.reset_interval).await;
+
+			{
+				let mut view = self.view.write().unwrap();
+				let prev_peers = view.current_peers();
+				let prev_peers_vec = prev_peers.iter().cloned().collect::<Vec<_>>();
+
+				view.reset_some_slots(self.param.reset_count);
+				view.update_all_slots(&prev_peers_vec[..]);
+
+				let new_peers = view.current_peers();
+				drop(view);
+
+				self.close_all_diff(&prev_peers, &new_peers);
+			}
+
+			let mut to_retry_maybe = self.bootstrap_peers.clone();
+			for (peer, _) in self.backlog.read().unwrap().iter() {
+				if !self.bootstrap_peers.contains(peer) {
+					to_retry_maybe.push(*peer);
+				}
+			}
+			self.handle_peer_list(&to_retry_maybe[..]);
+		}
+	}
+
+	fn handle_peer_list(self: &Arc<Self>, peers: &[Peer]) {
+		let to_connect = self.view.read().unwrap().should_try_list(peers);
+
+		for peer in to_connect.iter() {
+			tokio::spawn(self.clone().try_connect(*peer));
+		}
+	}
+
+	async fn try_connect(self: Arc<Self>, peer: Peer) {
+		{
+			let view = self.view.read().unwrap();
+			let mut attempts = self.current_attempts.write().unwrap();
+
+			if view.slots.iter().any(|x| x.peer == Some(peer)) {
+				return;
+			}
+			if attempts.contains(&peer) {
+				return;
+			}
+
+			attempts.insert(peer);
+		}
+		let res = self.netapp.clone().try_connect(peer.addr, peer.id).await;
+		debug!("Connection attempt to {}: {:?}", peer.addr, res);
+
+		self.current_attempts.write().unwrap().remove(&peer);
+
+		if res.is_err() {
+			self.backlog.write().unwrap().pop(&peer);
+		}
+	}
+
+	fn on_connected(self: &Arc<Self>, pk: ed25519::PublicKey, addr: SocketAddr, is_incoming: bool) {
+		if is_incoming {
+			self.handle_peer_list(&[Peer{id: pk, addr}][..]);
+		} else {
+			let peer = Peer { id: pk, addr };
+
+			let mut backlog = self.backlog.write().unwrap();
+			if backlog.get(&peer).is_none() {
+				backlog.put(peer, ());
+			}
+			drop(backlog);
+
+			let mut view = self.view.write().unwrap();
+			let prev_peers = view.current_peers();
+
+			view.update_all_slots(&[peer][..]);
+
+			let new_peers = view.current_peers();
+			drop(view);
+
+			self.close_all_diff(&prev_peers, &new_peers);
+		}
+	}
+
+	fn on_disconnected(&self, pk: ed25519::PublicKey, is_incoming: bool) {
+		if !is_incoming {
+			self.view.write().unwrap().disconnected(pk);
+		}
+	}
+
+	fn close_all_diff(&self, prev_peers: &HashSet<Peer>, new_peers: &HashSet<Peer>) {
+		let client_conns = self.netapp.client_conns.read().unwrap();
+		for peer in prev_peers.iter() {
+			if !new_peers.contains(peer) {
+				if let Some(c) = client_conns.get(&peer.id) {
+					debug!("Closing connection to {} ({})", hex::encode(peer.id), peer.addr);
+					c.close();
+				}
+			}
+		}
+	}
+}
+
+fn rand_seed() -> Seed {
+	let mut seed = [0u8; 32];
+	sodiumoxide::randombytes::randombytes_into(&mut seed[..]);
+	seed
+}
diff --git a/src/peering/fullmesh.rs b/src/peering/fullmesh.rs
new file mode 100644
index 0000000..e04beb6
--- /dev/null
+++ b/src/peering/fullmesh.rs
@@ -0,0 +1,437 @@
+use std::collections::{HashMap, VecDeque};
+use std::net::SocketAddr;
+use std::sync::atomic::{self, AtomicU64};
+use std::sync::{Arc, RwLock};
+use std::time::{Duration, Instant};
+
+use log::{debug, info, trace, warn};
+use serde::{Deserialize, Serialize};
+
+use sodiumoxide::crypto::hash;
+use sodiumoxide::crypto::sign::ed25519;
+
+use crate::conn::*;
+use crate::message::*;
+use crate::netapp::*;
+use crate::proto::*;
+
+const CONN_RETRY_INTERVAL: Duration = Duration::from_secs(30);
+const CONN_MAX_RETRIES: usize = 10;
+const PING_INTERVAL: Duration = Duration::from_secs(10);
+const LOOP_DELAY: Duration = Duration::from_secs(1);
+
+// -- Protocol messages --
+
+#[derive(Serialize, Deserialize)]
+struct PingMessage {
+	pub id: u64,
+	pub peer_list_hash: hash::Digest,
+}
+
+impl Message for PingMessage {
+	const KIND: MessageKind = 0x42001000;
+	type Response = PingMessage;
+}
+
+#[derive(Serialize, Deserialize)]
+struct PeerListMessage {
+	pub list: Vec<(ed25519::PublicKey, SocketAddr)>,
+}
+
+impl Message for PeerListMessage {
+	const KIND: MessageKind = 0x42001001;
+	type Response = PeerListMessage;
+}
+
+// -- Algorithm data structures --
+
+#[derive(Debug)]
+struct PeerInfo {
+	addr: SocketAddr,
+	state: PeerConnState,
+	last_seen: Option<Instant>,
+	ping: VecDeque<Duration>,
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct PeerInfoPub {
+	pub id: ed25519::PublicKey,
+	pub addr: SocketAddr,
+	pub state: PeerConnState,
+	pub last_seen: Option<Instant>,
+	pub avg_ping: Option<Duration>,
+	pub max_ping: Option<Duration>,
+	pub med_ping: Option<Duration>,
+}
+
+// PeerConnState: possible states for our tentative connections to given peer
+// This module is only interested in recording connection info for outgoing
+// TCP connections
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum PeerConnState {
+	// This entry represents ourself
+	Ourself,
+
+	// We currently have a connection to this peer
+	Connected,
+
+	// Our next connection tentative (the nth, where n is the first value)
+	// will be at given Instant
+	Waiting(usize, Instant),
+
+	// A connection tentative is in progress
+	Trying(usize),
+
+	// We abandonned trying to connect to this peer (too many failed attempts)
+	Abandonned,
+}
+
+struct KnownHosts {
+	list: HashMap<ed25519::PublicKey, PeerInfo>,
+	hash: hash::Digest,
+}
+
+impl KnownHosts {
+	fn new() -> Self {
+		let list = HashMap::new();
+		let hash = Self::calculate_hash(&list);
+		Self { list, hash }
+	}
+	fn update_hash(&mut self) {
+		self.hash = Self::calculate_hash(&self.list);
+	}
+	fn map_into_vec(
+		input: &HashMap<ed25519::PublicKey, PeerInfo>,
+	) -> Vec<(ed25519::PublicKey, SocketAddr)> {
+		let mut list = Vec::with_capacity(input.len());
+		for (id, peer) in input.iter() {
+			if peer.state == PeerConnState::Connected || peer.state == PeerConnState::Ourself {
+				list.push((id.clone(), peer.addr));
+			}
+		}
+		list
+	}
+	fn calculate_hash(input: &HashMap<ed25519::PublicKey, PeerInfo>) -> hash::Digest {
+		let mut list = Self::map_into_vec(input);
+		list.sort();
+		let mut hash_state = hash::State::new();
+		for (id, addr) in list {
+			hash_state.update(&id[..]);
+			hash_state.update(&format!("{}", addr).into_bytes()[..]);
+		}
+		hash_state.finalize()
+	}
+}
+
+pub struct FullMeshPeeringStrategy {
+	netapp: Arc<NetApp>,
+	known_hosts: RwLock<KnownHosts>,
+	next_ping_id: AtomicU64,
+}
+
+impl FullMeshPeeringStrategy {
+	pub fn new(
+		netapp: Arc<NetApp>,
+		bootstrap_list: Vec<(ed25519::PublicKey, SocketAddr)>,
+	) -> Arc<Self> {
+		let mut known_hosts = KnownHosts::new();
+		for (pk, addr) in bootstrap_list {
+			if pk != netapp.pubkey {
+				known_hosts.list.insert(
+					pk,
+					PeerInfo {
+						addr: addr,
+						state: PeerConnState::Waiting(0, Instant::now()),
+						last_seen: None,
+						ping: VecDeque::new(),
+					},
+				);
+			}
+		}
+
+		let strat = Arc::new(Self {
+			netapp: netapp.clone(),
+			known_hosts: RwLock::new(known_hosts),
+			next_ping_id: AtomicU64::new(42),
+		});
+
+		let strat2 = strat.clone();
+		netapp.add_msg_handler::<PingMessage, _, _>(
+			move |from: ed25519::PublicKey, ping: PingMessage| {
+				let ping_resp = PingMessage {
+					id: ping.id,
+					peer_list_hash: strat2.known_hosts.read().unwrap().hash,
+				};
+				async move {
+					debug!("Ping from {}", hex::encode(&from));
+					Ok(ping_resp)
+				}
+			},
+		);
+
+		let strat2 = strat.clone();
+		netapp.add_msg_handler::<PeerListMessage, _, _>(
+			move |_from: ed25519::PublicKey, peer_list: PeerListMessage| {
+				strat2.handle_peer_list(&peer_list.list[..]);
+				let peer_list = KnownHosts::map_into_vec(&strat2.known_hosts.read().unwrap().list);
+				let resp = PeerListMessage { list: peer_list };
+				async move { Ok(resp) }
+			},
+		);
+
+		let strat2 = strat.clone();
+		netapp.on_connected.store(Some(Arc::new(Box::new(
+			move |pk: ed25519::PublicKey, addr: SocketAddr, is_incoming: bool| {
+				let strat2 = strat2.clone();
+				tokio::spawn(strat2.on_connected(pk, addr, is_incoming));
+			},
+		))));
+
+		let strat2 = strat.clone();
+		netapp.on_disconnected.store(Some(Arc::new(Box::new(
+			move |pk: ed25519::PublicKey, is_incoming: bool| {
+				let strat2 = strat2.clone();
+				tokio::spawn(strat2.on_disconnected(pk, is_incoming));
+			},
+		))));
+
+		strat
+	}
+
+	pub async fn run(self: Arc<Self>) {
+		loop {
+			// 1. Read current state: get list of connected peers (ping them)
+			let known_hosts = self.known_hosts.read().unwrap();
+			debug!("known_hosts: {} peers", known_hosts.list.len());
+
+			let mut to_ping = vec![];
+			let mut to_retry = vec![];
+			for (id, info) in known_hosts.list.iter() {
+				debug!("{}, {:?}", hex::encode(id), info);
+				match info.state {
+					PeerConnState::Connected => {
+						let must_ping = match info.last_seen {
+							None => true,
+							Some(t) => Instant::now() - t > PING_INTERVAL,
+						};
+						if must_ping {
+							to_ping.push(id.clone());
+						}
+					}
+					PeerConnState::Waiting(_, t) => {
+						if Instant::now() >= t {
+							to_retry.push(id.clone());
+						}
+					}
+					_ => (),
+				}
+			}
+			drop(known_hosts);
+
+			// 2. Dispatch ping to hosts
+			trace!("to_ping: {} peers", to_retry.len());
+			for id in to_ping {
+				tokio::spawn(self.clone().ping(id));
+			}
+
+			// 3. Try reconnects
+			trace!("to_retry: {} peers", to_retry.len());
+			if !to_retry.is_empty() {
+				let mut known_hosts = self.known_hosts.write().unwrap();
+				for id in to_retry {
+					if let Some(h) = known_hosts.list.get_mut(&id) {
+						if let PeerConnState::Waiting(i, _) = h.state {
+							info!(
+								"Retrying connection to {} at {} ({})",
+								hex::encode(&id),
+								h.addr,
+								i + 1
+							);
+							h.state = PeerConnState::Trying(i);
+							tokio::spawn(self.clone().try_connect(id, h.addr.clone()));
+						}
+					}
+				}
+			}
+
+			// 4. Sleep before next loop iteration
+			tokio::time::delay_for(LOOP_DELAY).await;
+		}
+	}
+
+	async fn ping(self: Arc<Self>, id: ed25519::PublicKey) {
+		let peer = {
+			match self.netapp.client_conns.read().unwrap().get(&id) {
+				None => {
+					warn!("Should ping {}, but no connection", hex::encode(id));
+					return;
+				}
+				Some(peer) => peer.clone(),
+			}
+		};
+
+		let peer_list_hash = self.known_hosts.read().unwrap().hash;
+		let ping_id = self.next_ping_id.fetch_add(1u64, atomic::Ordering::Relaxed);
+		let ping_time = Instant::now();
+		let ping_msg = PingMessage {
+			id: ping_id,
+			peer_list_hash,
+		};
+
+		debug!(
+			"Sending ping {} to {} at {:?}",
+			ping_id,
+			hex::encode(id),
+			ping_time
+		);
+		match peer.clone().request(ping_msg, prio::HIGH).await {
+			Err(e) => warn!("Error pinging {}: {}", hex::encode(id), e),
+			Ok(ping_resp) => {
+				let resp_time = Instant::now();
+				debug!(
+					"Got ping response from {} at {:?}",
+					hex::encode(id),
+					resp_time
+				);
+				{
+					let mut known_hosts = self.known_hosts.write().unwrap();
+					if let Some(host) = known_hosts.list.get_mut(&id) {
+						host.last_seen = Some(resp_time);
+						host.ping.push_back(resp_time - ping_time);
+						while host.ping.len() > 10 {
+							host.ping.pop_front();
+						}
+					}
+				}
+				if ping_resp.peer_list_hash != peer_list_hash {
+					self.exchange_peers(peer).await;
+				}
+			}
+		}
+	}
+
+	async fn exchange_peers(self: Arc<Self>, peer: Arc<ClientConn>) {
+		let peer_list = KnownHosts::map_into_vec(&self.known_hosts.read().unwrap().list);
+		let pex_message = PeerListMessage { list: peer_list };
+		match peer.request(pex_message, prio::BACKGROUND).await {
+			Err(e) => warn!("Error doing peer exchange: {}", e),
+			Ok(resp) => {
+				self.handle_peer_list(&resp.list[..]);
+			}
+		}
+	}
+
+	fn handle_peer_list(&self, list: &[(ed25519::PublicKey, SocketAddr)]) {
+		let mut known_hosts = self.known_hosts.write().unwrap();
+		for (id, addr) in list.iter() {
+			if !known_hosts.list.contains_key(id) {
+				known_hosts.list.insert(*id, self.new_peer(id, *addr));
+			}
+		}
+	}
+
+	async fn try_connect(self: Arc<Self>, id: ed25519::PublicKey, addr: SocketAddr) {
+		let conn_result = self.netapp.clone().try_connect(addr, id.clone()).await;
+		if let Err(e) = conn_result {
+			warn!("Error connecting to {}: {}", hex::encode(id), e);
+			let mut known_hosts = self.known_hosts.write().unwrap();
+			if let Some(host) = known_hosts.list.get_mut(&id) {
+				host.state = match host.state {
+					PeerConnState::Trying(i) => {
+						if i >= CONN_MAX_RETRIES {
+							PeerConnState::Abandonned
+						} else {
+							PeerConnState::Waiting(i + 1, Instant::now() + CONN_RETRY_INTERVAL)
+						}
+					}
+					_ => PeerConnState::Waiting(0, Instant::now() + CONN_RETRY_INTERVAL),
+				};
+			}
+		}
+	}
+
+	async fn on_connected(
+		self: Arc<Self>,
+		pk: ed25519::PublicKey,
+		addr: SocketAddr,
+		is_incoming: bool,
+	) {
+		if is_incoming {
+			if !self.known_hosts.read().unwrap().list.contains_key(&pk) {
+				self.known_hosts
+					.write()
+					.unwrap()
+					.list
+					.insert(pk, self.new_peer(&pk, addr));
+			}
+		} else {
+			info!("Successfully connected to {} at {}", hex::encode(&pk), addr);
+			let mut known_hosts = self.known_hosts.write().unwrap();
+			if let Some(host) = known_hosts.list.get_mut(&pk) {
+				host.state = PeerConnState::Connected;
+				known_hosts.update_hash();
+			}
+		}
+	}
+
+	async fn on_disconnected(self: Arc<Self>, pk: ed25519::PublicKey, is_incoming: bool) {
+		if !is_incoming {
+			info!("Connection to {} was closed", hex::encode(pk));
+			let mut known_hosts = self.known_hosts.write().unwrap();
+			if let Some(host) = known_hosts.list.get_mut(&pk) {
+				host.state = PeerConnState::Waiting(0, Instant::now());
+				known_hosts.update_hash();
+			}
+		}
+	}
+
+	pub fn get_peer_list(&self) -> Vec<PeerInfoPub> {
+		let known_hosts = self.known_hosts.read().unwrap();
+		let mut ret = Vec::with_capacity(known_hosts.list.len());
+		for (id, info) in known_hosts.list.iter() {
+			let mut pings = info.ping.iter().cloned().collect::<Vec<_>>();
+			pings.sort();
+			if pings.len() > 0 {
+				ret.push(PeerInfoPub {
+					id: id.clone(),
+					addr: info.addr,
+					state: info.state,
+					last_seen: info.last_seen,
+					avg_ping: Some(
+						pings
+							.iter()
+							.fold(Duration::from_secs(0), |x, y| x + *y)
+							.div_f64(pings.len() as f64),
+					),
+					max_ping: pings.last().cloned(),
+					med_ping: Some(pings[pings.len() / 2]),
+				});
+			} else {
+				ret.push(PeerInfoPub {
+					id: id.clone(),
+					addr: info.addr,
+					state: info.state,
+					last_seen: info.last_seen,
+					avg_ping: None,
+					max_ping: None,
+					med_ping: None,
+				});
+			}
+		}
+		ret
+	}
+
+	fn new_peer(&self, id: &ed25519::PublicKey, addr: SocketAddr) -> PeerInfo {
+		let state = if *id == self.netapp.pubkey {
+			PeerConnState::Ourself
+		} else {
+			PeerConnState::Waiting(0, Instant::now())
+		};
+		PeerInfo {
+			addr,
+			state,
+			last_seen: None,
+			ping: VecDeque::new(),
+		}
+	}
+}
diff --git a/src/peering/mod.rs b/src/peering/mod.rs
new file mode 100644
index 0000000..beb2e18
--- /dev/null
+++ b/src/peering/mod.rs
@@ -0,0 +1,2 @@
+pub mod basalt;
+pub mod fullmesh;
diff --git a/src/proto.rs b/src/proto.rs
new file mode 100644
index 0000000..58c914e
--- /dev/null
+++ b/src/proto.rs
@@ -0,0 +1,251 @@
+use std::collections::{BTreeMap, HashMap, VecDeque};
+use std::sync::Arc;
+
+use log::trace;
+
+use async_trait::async_trait;
+
+use async_std::io::prelude::WriteExt;
+use async_std::io::ReadExt;
+
+use tokio::io::{ReadHalf, WriteHalf};
+use tokio::net::TcpStream;
+use tokio::sync::{mpsc, watch};
+
+use crate::error::*;
+
+use kuska_handshake::async_std::{BoxStreamRead, BoxStreamWrite, TokioCompat};
+
+const MAX_CHUNK_SIZE: usize = 0x4000;
+
+pub mod prio {
+	pub const HIGH: u8 = 0x20;
+	pub const NORMAL: u8 = 0x40;
+	pub const BACKGROUND: u8 = 0x80;
+
+	pub const PRIMARY: u8 = 0x00;
+	pub const SECONDARY: u8 = 0x01;
+}
+
+pub type RequestID = u16;
+pub type RequestPriority = u8;
+
+struct SendQueueItem {
+	id: RequestID,
+	prio: RequestPriority,
+	data: Vec<u8>,
+	cursor: usize,
+}
+
+struct SendQueue {
+	items: BTreeMap<u8, VecDeque<SendQueueItem>>,
+}
+
+impl SendQueue {
+	fn new() -> Self {
+		Self {
+			items: BTreeMap::new(),
+		}
+	}
+	fn push(&mut self, item: SendQueueItem) {
+		let prio = item.prio;
+		let mut items_at_prio = self
+			.items
+			.remove(&prio)
+			.unwrap_or(VecDeque::with_capacity(4));
+		items_at_prio.push_back(item);
+		self.items.insert(prio, items_at_prio);
+	}
+	fn pop(&mut self) -> Option<SendQueueItem> {
+		match self.items.pop_first() {
+			None => None,
+			Some((prio, mut items_at_prio)) => {
+				let ret = items_at_prio.pop_front();
+				if !items_at_prio.is_empty() {
+					self.items.insert(prio, items_at_prio);
+				}
+				ret
+			}
+		}
+	}
+}
+
+#[async_trait]
+pub(crate) trait SendLoop: Sync {
+	async fn send_loop(
+		self: Arc<Self>,
+		mut msg_recv: mpsc::UnboundedReceiver<(RequestID, RequestPriority, Vec<u8>)>,
+		mut write: BoxStreamWrite<TokioCompat<WriteHalf<TcpStream>>>,
+		mut must_exit: watch::Receiver<bool>,
+	) -> Result<(), Error> {
+		let mut sending = SendQueue::new();
+		while !*must_exit.borrow() {
+			if let Ok((id, prio, data)) = msg_recv.try_recv() {
+				trace!("send_loop: got {}, {} bytes", id, data.len());
+				sending.push(SendQueueItem {
+					id,
+					prio,
+					data,
+					cursor: 0,
+				});
+			} else if let Some(mut item) = sending.pop() {
+				trace!(
+					"send_loop: sending bytes for {} ({} bytes, {} already sent)",
+					item.id,
+					item.data.len(),
+					item.cursor
+				);
+				let header_id = u16::to_be_bytes(item.id);
+				if write_all_or_exit(&header_id[..], &mut write, &mut must_exit)
+					.await?
+					.is_none()
+				{
+					break;
+				}
+
+				if item.data.len() - item.cursor > MAX_CHUNK_SIZE {
+					let header_size = u16::to_be_bytes(MAX_CHUNK_SIZE as u16 | 0x8000);
+					if write_all_or_exit(&header_size[..], &mut write, &mut must_exit)
+						.await?
+						.is_none()
+					{
+						break;
+					}
+
+					let new_cursor = item.cursor + MAX_CHUNK_SIZE as usize;
+					if write_all_or_exit(
+						&item.data[item.cursor..new_cursor],
+						&mut write,
+						&mut must_exit,
+					)
+					.await?
+					.is_none()
+					{
+						break;
+					}
+					item.cursor = new_cursor;
+
+					sending.push(item);
+				} else {
+					let send_len = (item.data.len() - item.cursor) as u16;
+
+					let header_size = u16::to_be_bytes(send_len);
+					if write_all_or_exit(&header_size[..], &mut write, &mut must_exit)
+						.await?
+						.is_none()
+					{
+						break;
+					}
+
+					if write_all_or_exit(&item.data[item.cursor..], &mut write, &mut must_exit)
+						.await?
+						.is_none()
+					{
+						break;
+					}
+				}
+				write.flush().await.log_err("Could not flush in send_loop");
+			} else {
+				let (id, prio, data) = msg_recv
+					.recv()
+					.await
+					.ok_or(Error::Message("Connection closed.".into()))?;
+				trace!("send_loop: got {}, {} bytes", id, data.len());
+				sending.push(SendQueueItem {
+					id,
+					prio,
+					data,
+					cursor: 0,
+				});
+			}
+		}
+		Ok(())
+	}
+}
+
+#[async_trait]
+pub(crate) trait RecvLoop: Sync + 'static {
+	async fn recv_handler(self: Arc<Self>, id: RequestID, msg: Vec<u8>);
+
+	async fn recv_loop(
+		self: Arc<Self>,
+		mut read: BoxStreamRead<TokioCompat<ReadHalf<TcpStream>>>,
+		mut must_exit: watch::Receiver<bool>,
+	) -> Result<(), Error> {
+		let mut receiving = HashMap::new();
+		while !*must_exit.borrow() {
+			trace!("recv_loop: reading packet");
+			let mut header_id = [0u8; 2];
+			if read_exact_or_exit(&mut header_id[..], &mut read, &mut must_exit)
+				.await?
+				.is_none()
+			{
+				break;
+			}
+			let id = RequestID::from_be_bytes(header_id);
+			trace!("recv_loop: got header id: {:04x}", id);
+
+			let mut header_size = [0u8; 2];
+			if read_exact_or_exit(&mut header_size[..], &mut read, &mut must_exit)
+				.await?
+				.is_none()
+			{
+				break;
+			}
+			let size = RequestID::from_be_bytes(header_size);
+			trace!("recv_loop: got header size: {:04x}", id);
+
+			let has_cont = (size & 0x8000) != 0;
+			let size = size & !0x8000;
+
+			let mut next_slice = vec![0; size as usize];
+			if read_exact_or_exit(&mut next_slice[..], &mut read, &mut must_exit)
+				.await?
+				.is_none()
+			{
+				break;
+			}
+			trace!("recv_loop: read {} bytes", size);
+
+			let mut msg_bytes = receiving.remove(&id).unwrap_or(vec![]);
+			msg_bytes.extend_from_slice(&next_slice[..]);
+
+			if has_cont {
+				receiving.insert(id, msg_bytes);
+			} else {
+				tokio::spawn(self.clone().recv_handler(id, msg_bytes));
+			}
+		}
+		Ok(())
+	}
+}
+
+async fn read_exact_or_exit(
+	buf: &mut [u8],
+	read: &mut BoxStreamRead<TokioCompat<ReadHalf<TcpStream>>>,
+	must_exit: &mut watch::Receiver<bool>,
+) -> Result<Option<()>, Error> {
+	tokio::select!(
+		res = read.read_exact(buf) => Ok(Some(res?)),
+		_ = await_exit(must_exit) => Ok(None),
+	)
+}
+
+async fn write_all_or_exit(
+	buf: &[u8],
+	write: &mut BoxStreamWrite<TokioCompat<WriteHalf<TcpStream>>>,
+	must_exit: &mut watch::Receiver<bool>,
+) -> Result<Option<()>, Error> {
+	tokio::select!(
+		res = write.write_all(buf) => Ok(Some(res?)),
+		_ = await_exit(must_exit) => Ok(None),
+	)
+}
+
+async fn await_exit(must_exit: &mut watch::Receiver<bool>) {
+	loop {
+		if must_exit.recv().await == Some(true) {
+			return;
+		}
+	}
+}
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..e83822e
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,14 @@
+use serde::Serialize;
+
+// util
+pub fn rmp_to_vec_all_named<T>(val: &T) -> Result<Vec<u8>, rmp_serde::encode::Error>
+where
+	T: Serialize + ?Sized,
+{
+	let mut wr = Vec::with_capacity(128);
+	let mut se = rmp_serde::Serializer::new(&mut wr)
+		.with_struct_map()
+		.with_string_variants();
+	val.serialize(&mut se)?;
+	Ok(wr)
+}