From 4e85862a855d6a9f13ccbcccfbf512ba6db0364d Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Thu, 18 Feb 2021 12:07:04 +0100 Subject: =?UTF-8?q?Publish=20B=E1=B4=80s=E1=B4=80=CA=9F=E1=B4=9B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- src/peering/basalt.rs | 476 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/peering/mod.rs | 1 + 2 files changed, 477 insertions(+) create mode 100644 src/peering/basalt.rs (limited to 'src') diff --git a/src/peering/basalt.rs b/src/peering/basalt.rs new file mode 100644 index 0000000..3c1fc9e --- /dev/null +++ b/src/peering/basalt.rs @@ -0,0 +1,476 @@ +use std::collections::HashSet; +use std::net::SocketAddr; +use std::sync::{Arc, RwLock}; +use std::time::Duration; + +use log::{debug, info, trace, warn}; +use lru::LruCache; +use rand::{thread_rng, Rng}; +use serde::{Deserialize, Serialize}; + +use sodiumoxide::crypto::hash; + +use crate::message::*; +use crate::netapp::*; +use crate::proto::*; +use crate::NodeID; + +// -- 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, +} + +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: NodeID, + 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, hex::encode(self.id)).into_bytes()[..]); + cost[32..40].copy_from_slice(&h5.finalize()[..8]); + } + + cost + } +} + +struct BasaltSlot { + seed: Seed, + peer: Option, +} + +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, +} + +impl BasaltView { + fn new(size: usize) -> Self { + let slots = (0..size) + .map(|_| BasaltSlot { + seed: rand_seed(), + peer: None, + }) + .collect::>(); + Self { i_reset: 0, slots } + } + + fn current_peers(&self) -> HashSet { + self.slots + .iter() + .filter(|s| s.peer.is_some()) + .map(|s| s.peer.unwrap().clone()) + .collect::>() + } + fn current_peers_vec(&self) -> Vec { + self.current_peers().drain().collect::>() + } + + fn sample(&self, count: usize) -> Vec { + let possibles = self + .slots + .iter() + .enumerate() + .filter(|(_i, s)| s.peer.is_some()) + .map(|(i, _s)| i) + .collect::>(); + 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 { + trace!( + "Best match for slot {}: {}@{} (cost {})", + i, + hex::encode(peer.id), + peer.addr, + hex::encode(peer_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: NodeID) { + 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 { + // 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::>() + } + + fn reset_some_slots(&mut self, count: usize) { + for _i in 0..count { + trace!("Reset slot {}", self.i_reset); + 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, + + param: BasaltParams, + bootstrap_peers: Vec, + + view: RwLock, + current_attempts: RwLock>, + backlog: RwLock>, +} + +impl Basalt { + pub fn new( + netapp: Arc, + bootstrap_list: Vec<(NodeID, SocketAddr)>, + param: BasaltParams, + ) -> Arc { + let bootstrap_peers = bootstrap_list + .iter() + .map(|(id, addr)| Peer { + id: *id, + addr: *addr, + }) + .collect::>(); + + 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(move |id: NodeID, addr: SocketAddr, is_incoming: bool| { + basalt2.on_connected(id, addr, is_incoming); + }); + + let basalt2 = basalt.clone(); + netapp.on_disconnected(move |id: NodeID, is_incoming: bool| { + basalt2.on_disconnected(id, is_incoming); + }); + + let basalt2 = basalt.clone(); + netapp.add_msg_handler::(move |_from: NodeID, _pullmsg: PullMessage| { + let push_msg = basalt2.make_push_message(); + async move { push_msg } + }); + + let basalt2 = basalt.clone(); + netapp.add_msg_handler::(move |_from: NodeID, push_msg: PushMessage| { + basalt2.handle_peer_list(&push_msg.peers[..]); + async move { () } + }); + + basalt + } + + pub fn sample(&self, count: usize) -> Vec { + self.view + .read() + .unwrap() + .sample(count) + .iter() + .map(|p| { + debug!("KYEV S {}", hex::encode(p.id)); + p.id + }) + .collect::>() + } + + pub async fn run(self: Arc) { + 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) { + loop { + tokio::time::delay_for(self.param.exchange_interval).await; + + let peers = self.view.read().unwrap().sample(2); + if peers.len() == 2 { + tokio::spawn(self.clone().do_pull(peers[0].id)); + tokio::spawn(self.clone().do_push(peers[1].id)); + } + } + } + + async fn do_pull(self: Arc, peer: NodeID) { + match self + .netapp + .request(&peer, PullMessage {}, PRIO_NORMAL) + .await + { + Ok(resp) => { + self.handle_peer_list(&resp.peers[..]); + trace!("KYEV PEXi {}", hex::encode(peer)); + } + Err(e) => { + warn!("Error during pull exchange: {}", e); + } + }; + } + + async fn do_push(self: Arc, peer: NodeID) { + let push_msg = self.make_push_message(); + match self.netapp.request(&peer, push_msg, PRIO_NORMAL).await { + Ok(_) => { + trace!("KYEV PEXo {}", hex::encode(peer)); + } + Err(e) => { + 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) { + loop { + tokio::time::delay_for(self.param.reset_interval).await; + + { + debug!("KYEV R {}", self.param.reset_count); + + let mut view = self.view.write().unwrap(); + let prev_peers = view.current_peers(); + let prev_peers_vec = prev_peers.iter().cloned().collect::>(); + + 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, 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, 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; + trace!("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, id: NodeID, addr: SocketAddr, is_incoming: bool) { + if is_incoming { + self.handle_peer_list(&[Peer { id, addr }][..]); + } else { + info!("KYEV C {} {}", hex::encode(id), addr); + let peer = Peer { id, 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, id: NodeID, is_incoming: bool) { + if !is_incoming { + info!("KYEV D {}", hex::encode(id)); + self.view.write().unwrap().disconnected(id); + } + } + + fn close_all_diff(&self, prev_peers: &HashSet, new_peers: &HashSet) { + for peer in prev_peers.iter() { + if !new_peers.contains(peer) { + self.netapp.disconnect(&peer.id); + } + } + } +} + +fn rand_seed() -> Seed { + let mut seed = [0u8; 32]; + sodiumoxide::randombytes::randombytes_into(&mut seed[..]); + seed +} diff --git a/src/peering/mod.rs b/src/peering/mod.rs index 044b1df..15b870a 100644 --- a/src/peering/mod.rs +++ b/src/peering/mod.rs @@ -1 +1,2 @@ pub mod fullmesh; +pub mod basalt; -- cgit v1.2.3