Sync stuff.

syncwhole/src/datastore.rs

@@ -37,7 +37,7 @@ pub enum StoreResult {
     Rejected
 }
 
-/// API to be implemented by the data store we want to replicate.
+/// API to be implemented by the data set we want to replicate.
 ///
 /// The API specified here supports temporally subjective data sets. These are data sets
 /// where the existence or non-existence of a record may depend on the (real world) time.
@@ -45,11 +45,11 @@ pub enum StoreResult {
 /// what time I think it is" value to be considered locally so that data can be replicated
 /// as of any given time.
 ///
-/// The KEY_IS_COMPUTED constant must be set to indicate whether keys are a pure function of
+/// The KEY_IS_COMPUTED constant must be set to indicate whether keys are a function of
 /// values. If this is true, get_key() must be implemented.
 ///
 /// The implementation must be thread safe.
-pub trait Database: Sync + Send {
+pub trait DataStore: Sync + Send {
     /// Type to be enclosed in the Ok() enum value in LoadResult.
     type LoadResultValueType: AsRef<[u8]> + Send;
 
@@ -70,10 +70,13 @@ pub trait Database: Sync + Send {
     /// If KEY_IS_COMPUTED is true this must be implemented. The default implementation
     /// panics to indicate this. If KEY_IS_COMPUTED is false this is never called.
     #[allow(unused_variables)]
-    fn get_key(value: &[u8], key: &mut [u8]) {
+    fn get_key(&self, value: &[u8], key: &mut [u8]) {
         panic!("get_key() must be implemented if KEY_IS_COMPUTED is true");
     }
 
+    /// Get the domain of this data store, which is just an arbitrary unique identifier.
+    fn domain(&self) -> &str;
+
     /// Get an item if it exists as of a given reference time.
     ///
     /// The supplied key must be of length KEY_SIZE or this may panic.
@@ -115,24 +118,28 @@ pub trait Database: Sync + Send {
 /// A simple in-memory data store backed by a BTreeMap.
 pub struct MemoryDatabase<const KEY_SIZE: usize> {
     max_age: i64,
+    domain: String,
     db: Mutex<BTreeMap<[u8; KEY_SIZE], (i64, Arc<[u8]>)>>
 }
 
 impl<const KEY_SIZE: usize> MemoryDatabase<KEY_SIZE> {
-    pub fn new(max_age: i64) -> Self {
+    pub fn new(max_age: i64, domain: String) -> Self {
         Self {
             max_age: if max_age > 0 { max_age } else { i64::MAX },
+            domain,
             db: Mutex::new(BTreeMap::new())
         }
     }
 }
 
-impl<const KEY_SIZE: usize> Database for MemoryDatabase<KEY_SIZE> {
+impl<const KEY_SIZE: usize> DataStore for MemoryDatabase<KEY_SIZE> {
     type LoadResultValueType = Arc<[u8]>;
     const KEY_SIZE: usize = KEY_SIZE;
     const MAX_VALUE_SIZE: usize = 65536;
     const KEY_IS_COMPUTED: bool = false;
 
+    fn domain(&self) -> &str { self.domain.as_str() }
+
     fn load(&self, reference_time: i64, key: &[u8]) -> LoadResult<Self::LoadResultValueType> {
         let db = self.db.lock().unwrap();
         let e = db.get(key);

syncwhole/src/host.rs

@@ -10,6 +10,8 @@ use std::collections::HashSet;
 use std::error::Error;
 use std::net::SocketAddr;
 
+use crate::node::RemoteNodeInfo;
+
 /// A trait that users of syncwhole implement to provide configuration information and listen for events.
 pub trait Host: Sync + Send {
     /// Compute SHA512.
@@ -27,11 +29,16 @@ pub trait Host: Sync + Send {
     /// of the set is less than the minimum active link count the host wishes to maintain.
     fn get_more_endpoints(&self, current_endpoints: &HashSet<SocketAddr>) -> Vec<SocketAddr>;
 
-    /// Called whenever we have successfully connected to a remote endpoint to (possibly) remember it.
+    /// Get the maximum number of endpoints allowed.
-    fn on_connect_success(&self, endpoint: &SocketAddr);
+    ///
+    /// This is checked on incoming connect and incoming links are refused if the total is over this count.
+    fn max_endpoints(&self) -> usize;
 
-    /// Called whenever an outgoing connection fails.
+    /// Called whenever we have successfully connected to a remote node (after connection is initialized).
-    fn on_connect_failure(&self, endpoint: &SocketAddr, reason: Box<dyn Error>);
+    fn on_connect(&self, info: &RemoteNodeInfo);
+
+    /// Called when an open connection is closed.
+    fn on_connection_closed(&self, endpoint: &SocketAddr, reason: Option<Box<dyn Error>>);
 
     /// Fill a buffer with secure random bytes.
     fn get_secure_random(&self, buf: &mut [u8]);

syncwhole/src/iblt.rs

@@ -6,9 +6,9 @@
  * https://www.zerotier.com/
  */
 
-use std::io::{Read, Write};
 use std::mem::{size_of, zeroed};
 use std::ptr::write_bytes;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
 use crate::varint;
 
@@ -103,13 +103,13 @@ impl<const B: usize> IBLT<B> {
         unsafe { write_bytes((&mut self.map as *mut IBLTEntry).cast::<u8>(), 0, size_of::<[IBLTEntry; B]>()) };
     }
 
-    pub fn read<R: Read>(&mut self, r: &mut R) -> std::io::Result<()> {
+    pub async fn read<R: AsyncReadExt + Unpin>(&mut self, r: &mut R) -> std::io::Result<()> {
-        r.read_exact(unsafe { &mut *(&mut self.salt as *mut u64).cast::<[u8; 8]>() })?;
+        r.read_exact(unsafe { &mut *(&mut self.salt as *mut u64).cast::<[u8; 8]>() }).await?;
         let mut prev_c = 0_i64;
         for b in self.map.iter_mut() {
-            r.read_exact(unsafe { &mut *(&mut b.key_sum as *mut u64).cast::<[u8; 8]>() })?;
+            let _ = r.read_exact(unsafe { &mut *(&mut b.key_sum as *mut u64).cast::<[u8; 8]>() }).await?;
-            r.read_exact(unsafe { &mut *(&mut b.check_hash_sum as *mut u64).cast::<[u8; 8]>() })?;
+            let _ = r.read_exact(unsafe { &mut *(&mut b.check_hash_sum as *mut u64).cast::<[u8; 8]>() }).await?;
-            let mut c = varint::read(r)? as i64;
+            let mut c = varint::read_async(r).await? as i64;
             if (c & 1) == 0 {
                 c = c.wrapping_shr(1);
             } else {
@@ -121,18 +121,18 @@ impl<const B: usize> IBLT<B> {
         Ok(())
     }
 
-    pub fn write<W: Write>(&self, w: &mut W) -> std::io::Result<()> {
+    pub async fn write<W: AsyncWriteExt + Unpin>(&self, w: &mut W) -> std::io::Result<()> {
-        w.write_all(unsafe { &*(&self.salt as *const u64).cast::<[u8; 8]>() })?;
+        let _ = w.write_all(unsafe { &*(&self.salt as *const u64).cast::<[u8; 8]>() }).await?;
         let mut prev_c = 0_i64;
         for b in self.map.iter() {
-            w.write_all(unsafe { &*(&b.key_sum as *const u64).cast::<[u8; 8]>() })?;
+            let _ = w.write_all(unsafe { &*(&b.key_sum as *const u64).cast::<[u8; 8]>() }).await?;
-            w.write_all(unsafe { &*(&b.check_hash_sum as *const u64).cast::<[u8; 8]>() })?;
+            let _ = w.write_all(unsafe { &*(&b.check_hash_sum as *const u64).cast::<[u8; 8]>() }).await?;
             let mut c = (b.count - prev_c).wrapping_shl(1);
             prev_c = b.count;
             if c < 0 {
                 c = -c | 1;
             }
-            varint::write(w, c as u64)?;
+            let _ = varint::write_async(w, c as u64).await?;
         }
         Ok(())
     }

syncwhole/src/lib.rs

@@ -1,7 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * (c)2022 ZeroTier, Inc.
+ * https://www.zerotier.com/
+ */
+
 pub(crate) mod varint;
 pub(crate) mod protocol;
 pub(crate) mod iblt;
-pub mod database;
+
+pub mod datastore;
 pub mod node;
 pub mod host;
 

syncwhole/src/node.rs

@@ -7,19 +7,19 @@
  */
 
 use std::collections::HashMap;
-use std::net::SocketAddr;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
 use std::sync::{Arc, Weak};
 use std::sync::atomic::{AtomicI64, Ordering};
-use std::time::Duration;
+use std::time::{Duration, SystemTime};
-use serde::{Deserialize, Serialize};
 
-use tokio::io::{AsyncReadExt, AsyncWriteExt, BufReader};
+use serde::{Deserialize, Serialize};
+use tokio::io::{AsyncReadExt, AsyncWriteExt, BufReader, BufWriter};
 use tokio::net::{TcpListener, TcpSocket, TcpStream};
 use tokio::net::tcp::{OwnedReadHalf, OwnedWriteHalf};
 use tokio::sync::Mutex;
 use tokio::task::JoinHandle;
 
-use crate::database::Database;
+use crate::datastore::DataStore;
 use crate::host::Host;
 use crate::ms_monotonic;
 use crate::protocol::*;
@@ -27,92 +27,130 @@ use crate::varint;
 
 const CONNECTION_TIMEOUT: i64 = 60000;
 const CONNECTION_KEEPALIVE_AFTER: i64 = 20000;
+const IO_BUFFER_SIZE: usize = 65536;
 
-struct Connection {
+#[derive(Clone, PartialEq, Eq)]
-    writer: Mutex<OwnedWriteHalf>,
+pub struct RemoteNodeInfo {
-    last_send_time: AtomicI64,
+    pub node_name: Option<String>,
-    last_receive_time: AtomicI64,
+    pub node_contact: Option<String>,
-    io_task: std::sync::Mutex<Option<JoinHandle<std::io::Result<()>>>>,
+    pub endpoint: SocketAddr,
-    incoming: bool
+    pub preferred_endpoints: Vec<SocketAddr>,
+    pub connect_time: SystemTime,
+    pub inbound: bool,
+    pub initialized: bool,
 }
 
-impl Connection {
+pub struct Node<D: DataStore + 'static, H: Host + 'static> {
-    async fn send(&self, data: &[u8], now: i64) -> std::io::Result<()> {
+    internal: Arc<NodeInternal<D, H>>,
-        self.writer.lock().await.write_all(data).await.map(|_| {
+    housekeeping_task: JoinHandle<()>,
-            self.last_send_time.store(now, Ordering::Relaxed);
+    listener_task: JoinHandle<()>
+}
+
+impl<D: DataStore + 'static, H: Host + 'static> Node<D, H> {
+    pub async fn new(db: Arc<D>, host: Arc<H>, bind_address: SocketAddr) -> std::io::Result<Self> {
+        let listener = if bind_address.is_ipv4() { TcpSocket::new_v4() } else { TcpSocket::new_v6() }?;
+        if listener.set_reuseport(true).is_err() {
+            listener.set_reuseaddr(true)?;
+        }
+        listener.bind(bind_address.clone())?;
+        let listener = listener.listen(1024)?;
+
+        let internal = Arc::new(NodeInternal::<D, H> {
+            anti_loopback_secret: {
+                let mut tmp = [0_u8; 16];
+                host.get_secure_random(&mut tmp);
+                tmp
+            },
+            db: db.clone(),
+            host: host.clone(),
+            bind_address,
+            connections: Mutex::new(HashMap::with_capacity(64)),
+        });
+
+        Ok(Self {
+            internal: internal.clone(),
+            housekeeping_task: tokio::spawn(internal.clone().housekeeping_task_main()),
+            listener_task: tokio::spawn(internal.listener_task_main(listener)),
         })
     }
 
-    async fn send_obj<O: Serialize>(&self, message_type: u8, obj: &O, now: i64) -> std::io::Result<()> {
+    #[inline(always)]
-        let data = rmp_serde::encode::to_vec_named(&obj);
+    pub async fn connect(&self, endpoint: &SocketAddr) -> std::io::Result<bool> {
-        if data.is_ok() {
+        self.internal.connect(endpoint).await
-            let data = data.unwrap();
-            let mut tmp = [0_u8; 16];
-            tmp[0] = message_type;
-            let len = 1 + varint::encode(&mut tmp[1..], data.len() as u64);
-            let mut writer = self.writer.lock().await;
-            writer.write_all(&tmp[0..len]).await?;
-            writer.write_all(data.as_slice()).await?;
-            self.last_send_time.store(now, Ordering::Relaxed);
-            Ok(())
-        } else {
-            Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "serialize failure"))
-        }
     }
 
-    fn kill(&self) {
+    pub fn list_connections(&self) -> Vec<RemoteNodeInfo> {
-        let _ = self.io_task.lock().unwrap().take().map(|h| h.abort());
+        let mut connections = self.internal.connections.blocking_lock();
-    }
+        let mut cl: Vec<RemoteNodeInfo> = Vec::with_capacity(connections.len());
-
+        connections.retain(|_, c| {
-    async fn read_msg<'a>(&self, reader: &mut BufReader<OwnedReadHalf>, buf: &'a mut Vec<u8>, message_size: usize, now: i64) -> std::io::Result<&'a [u8]> {
+            c.0.upgrade().map_or(false, |c| {
-        if message_size > buf.len() {
+                cl.push(c.info.lock().unwrap().clone());
-            buf.resize(((message_size / 4096) + 1) * 4096, 0);
+                true
-        }
+            })
-        let b = &mut buf.as_mut_slice()[0..message_size];
+        });
-        reader.read_exact(b).await?;
+        cl
-        self.last_receive_time.store(now, Ordering::Relaxed);
-        Ok(b)
-    }
-
-    async fn read_obj<'a, O: Deserialize<'a>>(&self, reader: &mut BufReader<OwnedReadHalf>, buf: &'a mut Vec<u8>, message_size: usize, now: i64) -> std::io::Result<O> {
-        rmp_serde::from_slice(self.read_msg(reader, buf, message_size, now).await?).map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e.to_string()))
     }
 }
 
-pub struct NodeInternal<D: Database + 'static, H: Host + 'static> {
+impl<D: DataStore + 'static, H: Host + 'static> Drop for Node<D, H> {
-    anti_loopback_secret: [u8; 64],
+    fn drop(&mut self) {
+        self.housekeeping_task.abort();
+        self.listener_task.abort();
+    }
+}
+
+pub struct NodeInternal<D: DataStore + 'static, H: Host + 'static> {
+    anti_loopback_secret: [u8; 16],
     db: Arc<D>,
     host: Arc<H>,
     bind_address: SocketAddr,
-    connections: Mutex<HashMap<SocketAddr, Weak<Connection>>>,
+    connections: Mutex<HashMap<SocketAddr, (Weak<Connection>, Option<JoinHandle<std::io::Result<()>>>)>>,
 }
 
-impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
+impl<D: DataStore + 'static, H: Host + 'static> NodeInternal<D, H> {
     async fn housekeeping_task_main(self: Arc<Self>) {
         loop {
-            tokio::time::sleep(Duration::from_millis(CONNECTION_KEEPALIVE_AFTER as u64)).await;
+            tokio::time::sleep(Duration::from_millis((CONNECTION_KEEPALIVE_AFTER / 2) as u64)).await;
 
             let mut to_ping: Vec<Arc<Connection>> = Vec::new();
+            let mut dead: Vec<(SocketAddr, Option<JoinHandle<std::io::Result<()>>>)> = Vec::new();
+
             let mut connections = self.connections.lock().await;
             let now = ms_monotonic();
-            connections.retain(|_, c| {
+            connections.retain(|sa, c| {
-                c.upgrade().map_or(false, |c| {
+                let cc = c.0.upgrade();
-                    if (now - c.last_receive_time.load(Ordering::Relaxed)) < CONNECTION_TIMEOUT {
+                if cc.is_some() {
-                        if (now - c.last_send_time.load(Ordering::Relaxed)) > CONNECTION_KEEPALIVE_AFTER {
+                    let cc = cc.unwrap();
-                            to_ping.push(c);
+                    if (now - cc.last_receive_time.load(Ordering::Relaxed)) < CONNECTION_TIMEOUT {
+                        if (now - cc.last_send_time.load(Ordering::Relaxed)) >= CONNECTION_KEEPALIVE_AFTER {
+                            to_ping.push(cc);
                         }
+                        true
                     } else {
-                        c.kill();
+                        c.1.take().map(|j| j.abort());
-                        return false;
+                        false
                     }
-                    return true;
+                } else {
-                })
+                    let _ = c.1.take().map(|j| dead.push((sa.clone(), Some(j))));
+                    false
+                }
             });
             drop(connections); // release lock
+
+            for d in dead.iter_mut() {
+                d.1.take().unwrap().await.map_or_else(|e| {
+                    self.host.on_connection_closed(&d.0, Some(Box::new(std::io::Error::new(std::io::ErrorKind::Other, "timed out"))));
+                }, |r| {
+                    if r.is_ok() {
+                        self.host.on_connection_closed(&d.0, None);
+                    } else {
+                        self.host.on_connection_closed(&d.0, Some(Box::new(r.unwrap_err())));
+                    }
+                });
+            }
+
             for c in to_ping.iter() {
-                if c.send(&[MESSAGE_TYPE_NOP, 0], now).await.is_err() {
+                let _ = c.send(&[MESSAGE_TYPE_NOP, 0], now).await;
-                    c.kill();
-                }
             }
         }
     }
@@ -120,7 +158,7 @@ impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
     async fn listener_task_main(self: Arc<Self>, listener: TcpListener) {
         loop {
             let socket = listener.accept().await;
-            if socket.is_ok() {
+            if self.connections.lock().await.len() < self.host.max_endpoints() && socket.is_ok() {
                 let (stream, endpoint) = socket.unwrap();
                 Self::connection_start(&self, endpoint, stream, true).await;
             }
@@ -141,8 +179,9 @@ impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
             preferred_ipv6: None
         }, ms_monotonic()).await?;
 
+        let mut init_received = false;
         let mut initialized = false;
-        let mut reader = BufReader::with_capacity(65536, reader);
+        let mut reader = BufReader::with_capacity(IO_BUFFER_SIZE, reader);
         let mut buf: Vec<u8> = Vec::new();
         buf.resize(4096, 0);
         loop {
@@ -156,20 +195,56 @@ impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
 
             match message_type {
                 MESSAGE_TYPE_INIT => {
-                    if initialized {
+                    if init_received {
                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "duplicate init"));
                     }
+
                     let msg: msg::Init = connection.read_obj(&mut reader, &mut buf, message_size as usize, now).await?;
 
+                    if !msg.domain.as_str().eq(self.db.domain()) {
+                        return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "data set domain mismatch"));
+                    }
+                    if msg.key_size != D::KEY_SIZE as u16 || msg.max_value_size > D::MAX_VALUE_SIZE as u64 {
+                        return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "data set key/value sizing mismatch"));
+                    }
+
                     let mut antiloop = msg.anti_loopback_challenge.to_vec();
                     let _ = std::io::Write::write_all(&mut antiloop, &self.anti_loopback_secret);
                     let antiloop = H::sha512(antiloop.as_slice());
-
                     connection.send_obj(MESSAGE_TYPE_INIT_RESPONSE, &msg::InitResponse {
                         anti_loopback_response: &antiloop[0..16]
                     }, now).await?;
 
+                    init_received = true;
+
+                    let mut info = connection.info.lock().unwrap();
+                    info.node_name = msg.node_name.clone();
+                    info.node_contact = msg.node_contact.clone();
+                    let _ = msg.preferred_ipv4.map(|pv4| {
+                        info.preferred_endpoints.push(SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(pv4.ip[0], pv4.ip[1], pv4.ip[2], pv4.ip[3]), pv4.port)));
+                    });
+                    let _ = msg.preferred_ipv6.map(|pv6| {
+                        info.preferred_endpoints.push(SocketAddr::V6(SocketAddrV6::new(Ipv6Addr::from(pv6.ip), pv6.port, 0, 0)));
+                    });
+                },
+                MESSAGE_TYPE_INIT_RESPONSE => {
+                    if initialized {
+                        return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "duplicate init response"));
+                    }
+
+                    let msg: msg::InitResponse = connection.read_obj(&mut reader, &mut buf, message_size as usize, now).await?;
+                    let mut antiloop = challenge.to_vec();
+                    let _ = std::io::Write::write_all(&mut antiloop, &self.anti_loopback_secret);
+                    let antiloop = H::sha512(antiloop.as_slice());
+                    if msg.anti_loopback_response.eq(&antiloop[0..16]) {
+                        return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "rejected connection to self"));
+                    }
+
                     initialized = true;
+                    let mut info = connection.info.lock().unwrap();
+                    info.initialized = true;
+                    let info = info.clone();
+                    self.host.on_connect(&info);
                 },
                 _ => {
                     // Skip messages that aren't recognized or don't need to be parsed like NOP.
@@ -185,21 +260,29 @@ impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
         }
     }
 
-    async fn connection_start(self: &Arc<Self>, endpoint: SocketAddr, stream: TcpStream, incoming: bool) -> bool {
+    async fn connection_start(self: &Arc<Self>, endpoint: SocketAddr, stream: TcpStream, inbound: bool) -> bool {
+        let _ = stream.set_nodelay(true);
         let (reader, writer) = stream.into_split();
+
         let mut ok = false;
         let _ = self.connections.lock().await.entry(endpoint.clone()).or_insert_with(|| {
             ok = true;
             let now = ms_monotonic();
             let connection = Arc::new(Connection {
-                writer: Mutex::new(writer),
+                writer: Mutex::new(BufWriter::with_capacity(IO_BUFFER_SIZE, writer)),
                 last_send_time: AtomicI64::new(now),
                 last_receive_time: AtomicI64::new(now),
-                io_task: std::sync::Mutex::new(None),
+                info: std::sync::Mutex::new(RemoteNodeInfo {
-                incoming
+                    node_name: None,
+                    node_contact: None,
+                    endpoint: endpoint.clone(),
+                    preferred_endpoints: Vec::new(),
+                    connect_time: SystemTime::now(),
+                    inbound,
+                    initialized: false
+                }),
             });
-            let _ = connection.io_task.lock().unwrap().insert(tokio::spawn(Self::connection_io_task_main(self.clone(), connection.clone(), reader)));
+            (Arc::downgrade(&connection), Some(tokio::spawn(self.clone().connection_io_task_main(connection.clone(), reader))))
-            Arc::downgrade(&connection)
         });
         ok
     }
@@ -219,70 +302,59 @@ impl<D: Database + 'static, H: Host + 'static> NodeInternal<D, H> {
     }
 }
 
-impl<D: Database + 'static, H: Host + 'static> Drop for NodeInternal<D, H> {
+impl<D: DataStore + 'static, H: Host + 'static> Drop for NodeInternal<D, H> {
     fn drop(&mut self) {
         for (_, c) in self.connections.blocking_lock().drain() {
-            let _ = c.upgrade().map(|c| c.kill());
+            c.1.map(|c| c.abort());
         }
     }
 }
 
-pub struct Node<D: Database + 'static, H: Host + 'static> {
+struct Connection {
-    internal: Arc<NodeInternal<D, H>>,
+    writer: Mutex<BufWriter<OwnedWriteHalf>>,
-    housekeeping_task: JoinHandle<()>,
+    last_send_time: AtomicI64,
-    listener_task: JoinHandle<()>
+    last_receive_time: AtomicI64,
+    info: std::sync::Mutex<RemoteNodeInfo>,
 }
 
-impl<D: Database + 'static, H: Host + 'static> Node<D, H> {
+impl Connection {
-    pub async fn new(db: Arc<D>, host: Arc<H>, bind_address: SocketAddr) -> std::io::Result<Self> {
+    async fn send(&self, data: &[u8], now: i64) -> std::io::Result<()> {
-        let listener = if bind_address.is_ipv4() { TcpSocket::new_v4() } else { TcpSocket::new_v6() }?;
+        let mut writer = self.writer.lock().await;
-        if listener.set_reuseport(true).is_err() {
+        writer.write_all(data).await?;
-            listener.set_reuseaddr(true)?;
+        writer.flush().await?;
+        self.last_send_time.store(now, Ordering::Relaxed);
+        Ok(())
+    }
+
+    async fn send_obj<O: Serialize>(&self, message_type: u8, obj: &O, now: i64) -> std::io::Result<()> {
+        let data = rmp_serde::encode::to_vec_named(&obj);
+        if data.is_ok() {
+            let data = data.unwrap();
+            let mut tmp = [0_u8; 16];
+            tmp[0] = message_type;
+            let len = 1 + varint::encode(&mut tmp[1..], data.len() as u64);
+            let mut writer = self.writer.lock().await;
+            writer.write_all(&tmp[0..len]).await?;
+            writer.write_all(data.as_slice()).await?;
+            writer.flush().await?;
+            self.last_send_time.store(now, Ordering::Relaxed);
+            Ok(())
+        } else {
+            Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "serialize failure"))
         }
-        listener.bind(bind_address.clone())?;
-        let listener = listener.listen(1024)?;
-
-        let internal = Arc::new(NodeInternal::<D, H> {
-            anti_loopback_secret: {
-                let mut tmp = [0_u8; 64];
-                host.get_secure_random(&mut tmp);
-                tmp
-            },
-            db: db.clone(),
-            host: host.clone(),
-            bind_address,
-            connections: Mutex::new(HashMap::with_capacity(64)),
-        });
-        Ok(Self {
-            internal: internal.clone(),
-            housekeeping_task: tokio::spawn(internal.clone().housekeeping_task_main()),
-            listener_task: tokio::spawn(internal.listener_task_main(listener)),
-        })
     }
 
-    #[inline(always)]
+    async fn read_msg<'a>(&self, reader: &mut BufReader<OwnedReadHalf>, buf: &'a mut Vec<u8>, message_size: usize, now: i64) -> std::io::Result<&'a [u8]> {
-    pub async fn connect(&self, endpoint: &SocketAddr) -> std::io::Result<bool> {
+        if message_size > buf.len() {
-        self.internal.connect(endpoint).await
+            buf.resize(((message_size / 4096) + 1) * 4096, 0);
+        }
+        let b = &mut buf.as_mut_slice()[0..message_size];
+        reader.read_exact(b).await?;
+        self.last_receive_time.store(now, Ordering::Relaxed);
+        Ok(b)
     }
 
-    pub fn list_connections(&self) -> Vec<SocketAddr> {
+    async fn read_obj<'a, O: Deserialize<'a>>(&self, reader: &mut BufReader<OwnedReadHalf>, buf: &'a mut Vec<u8>, message_size: usize, now: i64) -> std::io::Result<O> {
-        let mut connections = self.internal.connections.blocking_lock();
+        rmp_serde::from_slice(self.read_msg(reader, buf, message_size, now).await?).map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e.to_string()))
-        let mut cl: Vec<SocketAddr> = Vec::with_capacity(connections.len());
-        connections.retain(|sa, c| {
-            if c.strong_count() > 0 {
-                cl.push(sa.clone());
-                true
-            } else {
-                false
-            }
-        });
-        cl
-    }
-}
-
-impl<D: Database + 'static, H: Host + 'static> Drop for Node<D, H> {
-    fn drop(&mut self) {
-        self.housekeeping_task.abort();
-        self.listener_task.abort();
     }
 }