Implemented P2P network protocol. Refactored project structure.

Cargo.toml

@@ -23,6 +23,7 @@ chrono = "0.4.9"
 rand = "0.7.2"
 sqlite = "0.25.3"
 uuid = { version = "0.8.2", features = ["serde", "v4"] }
+mio = { version = "0.7", features = ["os-poll", "net"] }
 
 [build-dependencies]
 winres = "0.1"

alfis.cfg

@@ -1,5 +1,9 @@
 {
     "chain_name": "test",
     "version_flags": 0,
-    "key_file": "default.key"
+    "key_file": "default.key",
+    "listen": "127.0.0.1:4442",
+    "peers": [
+        "127.0.0.1:44421"
+    ]
 }

src/blockchain/block.rs

@@ -3,7 +3,6 @@ extern crate serde_json;
 extern crate num_bigint;
 extern crate num_traits;
 
-use super::*;
 use std::fmt::Debug;
 use chrono::Utc;
 use serde::{Serialize, Deserialize};
@@ -12,6 +11,7 @@ use num_traits::One;
 use crypto::sha2::Sha256;
 use crypto::digest::Digest;
 use crate::keys::Bytes;
+use crate::Transaction;
 
 #[derive(Clone, Serialize, Deserialize, PartialEq, Debug)]
 pub struct Block {

src/blockchain/blockchain.rs

@@ -1,6 +1,7 @@
-use crate::{Block, Transaction, Bytes, Keystore};
 use chrono::Utc;
-use sqlite::{Connection, State, Readable, Statement, Error};
+use sqlite::{Connection, Error, Readable, State, Statement};
+
+use crate::{Block, Bytes, Keystore, Transaction};
 
 const DB_NAME: &str = "blockchain.db";
 
@@ -112,6 +113,31 @@ impl Blockchain {
         statement.next().expect("Error adding transaction to DB");
     }
 
+    pub fn get_block(&self, index: u64) -> Option<Block> {
+        match self.db.prepare("SELECT * FROM blocks WHERE id=? LIMIT 1;") {
+            Ok(mut statement) => {
+                statement.bind(1, index as i64);
+                while statement.next().unwrap() == State::Row {
+                    return match Self::get_block_from_statement(&mut statement) {
+                        None => {
+                            println!("Something wrong with block in DB!");
+                            None
+                        }
+                        Some(block) => {
+                            println!("Loaded block: {:?}", &block);
+                            Some(block)
+                        }
+                    }
+                }
+                None
+            }
+            Err(_) => {
+                println!("Can't find block {}", index);
+                None
+            }
+        }
+    }
+
     pub fn is_domain_available(&self, domain: &str, keystore: &Keystore) -> bool {
         if domain.is_empty() {
             return false;
@@ -146,10 +172,19 @@ impl Blockchain {
         true
     }
 
-    pub fn get_last_block(&self) -> Option<Block> {
+    pub fn last_block(&self) -> Option<Block> {
         self.last_block.clone()
     }
 
+    pub fn height(&self) -> u64 {
+        match self.last_block {
+            None => { 0u64 }
+            Some(ref block) => {
+                block.index
+            }
+        }
+    }
+
     /*pub fn check(&self) -> bool {
         let mut prev_block = None;
         for block in self.blocks.iter() {
@@ -163,6 +198,7 @@ impl Blockchain {
     }*/
 
     fn check_block(&self, block: &Block, prev_block: &Option<Block>) -> bool {
+        // TODO check if it is already stored, or its height is more than we need
         if !Self::check_block_hash(block) {
             return false;
         }
@@ -194,4 +230,4 @@ impl Blockchain {
         let data = serde_json::to_string(&copy).unwrap();
         Block::hash(data.as_bytes()) == block.hash
     }
-}
+}

src/blockchain/mod.rs

@@ -0,0 +1,7 @@
+pub mod transaction;
+pub mod block;
+pub mod blockchain;
+
+pub use transaction::Transaction;
+pub use block::Block;
+pub use blockchain::Blockchain;

src/context.rs

@@ -50,7 +50,9 @@ impl Context {
 pub struct Settings {
     pub chain_name: String,
     pub version_flags: u32,
-    pub key_file: String
+    pub key_file: String,
+    pub listen: String,
+    pub peers: Vec<String>
 }
 
 impl Settings {

src/lib.rs

@@ -1,19 +1,20 @@
-mod block;
-pub use crate::block::Block;
-mod blockchain;
+pub use blockchain::block::Block;
+pub use blockchain::transaction::Transaction;
+
 pub use crate::blockchain::Blockchain;
-pub mod transaction;
-pub use crate::transaction::Transaction;
-pub mod utils;
-pub use crate::utils::*;
-pub mod simplebus;
-pub use crate::simplebus::*;
-pub mod keys;
-pub use crate::keys::Keystore;
+pub use crate::context::Context;
+pub use crate::context::Settings;
 pub use crate::keys::Bytes;
+pub use crate::keys::Keystore;
+pub use crate::simplebus::*;
+pub use crate::utils::*;
+
+mod blockchain;
+pub mod utils;
+pub mod simplebus;
+pub mod keys;
 pub mod miner;
 pub mod context;
 pub mod event;
+pub mod p2p;
 
-pub use crate::context::Context;
-pub use crate::context::Settings;

src/main.rs

@@ -13,6 +13,7 @@ use web_view::*;
 use alfis::{Block, Blockchain, Bytes, Context, Keystore, Settings, Transaction};
 use alfis::event::Event;
 use alfis::miner::Miner;
+use alfis::p2p::Network;
 
 extern crate serde;
 extern crate serde_json;
@@ -37,6 +38,9 @@ fn main() {
     miner_obj.start_mining_thread();
     let miner: Arc<Mutex<Miner>> = Arc::new(Mutex::new(miner_obj));
 
+    let mut network = Network::new(context.clone());
+    network.start();
+
     create_genesis_if_needed(&context, &miner);
     run_interface(context.clone(), miner.clone());
 }
@@ -44,17 +48,17 @@ fn main() {
 fn create_genesis_if_needed(context: &Arc<Mutex<Context>>, miner: &Arc<Mutex<Miner>>) {
     // TODO check settings and if there is no mention of bootstrap nodes, generate genesis block
     let context_guard = context.lock().unwrap();
-    if context_guard.get_blockchain().get_last_block().is_none() {
+    if context_guard.get_blockchain().last_block().is_none() {
         // If blockchain is empty, we are going to mine a Genesis block
         create_genesis(miner.clone(), GENESIS_ZONE, &context_guard.get_keystore(), GENESIS_ZONE_DIFFICULTY);
     }
 }
 
 fn run_interface(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>) {
-    let file_content = include_str!("index.html");
-    let mut styles= inline_style(include_str!("bulma.css"));
-    styles.push_str(&inline_style(include_str!("loader.css")));
-    let scripts = inline_script(include_str!("scripts.js"));
+    let file_content = include_str!("webview/index.html");
+    let mut styles= inline_style(include_str!("webview/bulma.css"));
+    styles.push_str(&inline_style(include_str!("webview/loader.css")));
+    let scripts = inline_script(include_str!("webview/scripts.js"));
 
     let html = Content::Html(file_content.to_owned().replace("{styles}", &styles).replace("{scripts}", &scripts));
     web_view::builder()

src/miner.rs

@@ -110,7 +110,7 @@ impl Miner {
             }
 
             // Get last block for mining
-            let last_block = { context.lock().unwrap().blockchain.get_last_block() };
+            let last_block = { context.lock().unwrap().blockchain.last_block() };
             match last_block {
                 None => {
                     println!("Mining genesis block");

src/p2p/message.rs

@@ -0,0 +1,47 @@
+extern crate serde;
+extern crate serde_json;
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum Message {
+    Error,
+    Hand { chain: String, version: u32 },
+    Shake { ok: bool, height: u64 },
+    Ping { height: u64 },
+    Pong { height: u64 },
+    GetPeers,
+    Peers,
+    GetBlock { index: u64 },
+    Block { index: u64, block: String },
+}
+
+impl Message {
+    pub fn from_bytes(bytes: Vec<u8>) -> Result<Self, ()> {
+        let text = String::from_utf8(bytes).unwrap_or(String::from("Error{}"));
+        match serde_json::from_str(&text) {
+            Ok(cmd) => Ok(cmd),
+            Err(_) => Err(())
+        }
+    }
+
+    pub fn hand(chain: &str, version: u32) -> Self {
+        Message::Hand { chain: chain.to_owned(), version }
+    }
+
+    pub fn shake(ok: bool, height: u64) -> Self {
+        Message::Shake { ok, height }
+    }
+
+    pub fn ping(height: u64) -> Self {
+        Message::Ping { height }
+    }
+
+    pub fn pong(height: u64) -> Self {
+        Message::Pong { height }
+    }
+
+    pub fn block(height: u64, str: String) -> Self {
+        Message::Block { index: height, block: str }
+    }
+}

src/p2p/mod.rs

@@ -0,0 +1,9 @@
+pub mod network;
+pub mod message;
+pub mod state;
+pub mod peer;
+
+pub use network::Network;
+pub use message::Message;
+pub use state::State;
+

src/p2p/network.rs

@@ -0,0 +1,329 @@
+extern crate serde;
+extern crate serde_json;
+
+use std::{io, thread};
+use std::collections::HashMap;
+use std::io::{Read, Write};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
+use mio::{Events, Interest, Poll, Registry, Token};
+use mio::event::Event;
+use mio::net::{TcpListener, TcpStream};
+use serde::{Deserialize, Serialize};
+
+use crate::{Context, Block};
+use crate::p2p::Message;
+use crate::p2p::State;
+use crate::p2p::peer::Peer;
+
+const SERVER: Token = Token(0);
+const POLL_TIMEOUT: Option<Duration> = Some(Duration::from_millis(1000));
+
+pub struct Network {
+    context: Arc<Mutex<Context>>
+}
+
+impl Network {
+    pub fn new(context: Arc<Mutex<Context>>) -> Self {
+        Network { context }
+    }
+
+    pub fn start(&mut self) -> Result<(), String> {
+        let (listen_addr, peers) = {
+            let c = self.context.lock().unwrap();
+            (c.settings.listen.clone(), c.settings.peers.clone())
+        };
+
+        // Starting server socket
+        let addr = listen_addr.parse().expect("Error parsing listen address");
+        let mut server = TcpListener::bind(addr).expect("Can't bind to address");
+        println!("Started node listener on {}", server.local_addr().unwrap());
+
+        let mut events = Events::with_capacity(64);
+        let mut poll = Poll::new().expect("Unable to create poll");
+        poll.registry().register(&mut server, SERVER, Interest::READABLE).expect("Error registering poll");
+        let context = self.context.clone();
+        thread::spawn(move || {
+            // Unique token for each incoming connection.
+            let mut unique_token = Token(SERVER.0 + 1);
+            // Map of `Token` -> `TcpStream`.
+            let mut connections = HashMap::new();
+            // States of peer connections, and some data to send when sockets become writable
+            let mut peer_state: HashMap<Token, Peer> = HashMap::new();
+            // Starting peer connections to bootstrap nodes
+            for peer in peers.iter() {
+                match TcpStream::connect(peer.parse().expect("Error parsing peer address")) {
+                    Ok(mut stream) => {
+                        println!("Created connection to peer {}", &peer);
+                        let token = next(&mut unique_token);
+                        poll.registry().register(&mut stream, token, Interest::WRITABLE).unwrap();
+                        peer_state.insert(token, Peer::new(peer.clone(), State::Connecting));
+                        connections.insert(token, stream);
+                    }
+                    Err(e) => {
+                        println!("Error connecting to peer {}: {}", &peer, e);
+                    }
+                }
+            }
+
+            loop {
+                // Poll Mio for events, blocking until we get an event.
+                poll.poll(&mut events, POLL_TIMEOUT).expect("Error polling sockets");
+                //println!("Polling finished, got events: {}", !events.is_empty());
+
+                // Process each event.
+                for event in events.iter() {
+                    println!("Event for {} is {:?}", event.token().0, &event);
+                    // We can use the token we previously provided to `register` to determine for which socket the event is.
+                    match event.token() {
+                        SERVER => {
+                            // If this is an event for the server, it means a connection is ready to be accepted.
+                            let connection = server.accept();
+                            match connection {
+                                Ok((mut connection, address)) => {
+                                    println!("Accepted connection from: {}", address);
+                                    let token = next(&mut unique_token);
+                                    poll.registry().register(&mut connection, token, Interest::READABLE).expect("Error registering poll");
+                                    peer_state.insert(token, Peer::new(address.to_string(), State::Connected));
+                                    connections.insert(token, connection);
+                                }
+                                Err(_) => {}
+                            }
+                        }
+                        token => {
+                            match connections.get_mut(&token) {
+                                Some(connection) => {
+                                    match handle_connection_event(context.clone(), &mut peer_state, &poll.registry(), connection, &event) {
+                                        Ok(result) => {
+                                            if !result {
+                                                connections.remove(&token);
+                                                peer_state.remove(&token);
+                                            }
+                                        }
+                                        Err(err) => {}
+                                    }
+                                }
+                                None => { println!("Odd event from poll"); }
+                            }
+                        }
+                    }
+                }
+                // Send pings to idle peers
+                for (token, peer) in peer_state.iter_mut() {
+                    match peer.get_state() {
+                        State::Idle { from } => {
+                            if from.elapsed().as_secs() >= 30 {
+                                let c = context.lock().unwrap();
+                                peer.set_state(State::message(Message::ping(c.blockchain.height())));
+                                let mut connection = connections.get_mut(&token).unwrap();
+                                poll.registry().reregister(connection, token.clone(), Interest::WRITABLE).unwrap();
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+        });
+        Ok(())
+    }
+}
+
+fn handle_connection_event(context: Arc<Mutex<Context>>, peer_state: &mut HashMap<Token, Peer>, registry: &Registry, connection: &mut TcpStream, event: &Event) -> io::Result<bool> {
+    if event.is_error() {
+        return Ok(false);
+    }
+
+    if event.is_readable() {
+        let data_size = match connection.read_u32::<BigEndian>() {
+            Ok(size) => { size as usize }
+            Err(e) => {
+                println!("Error reading from socket! {}", e);
+                0
+            }
+        };
+        println!("Payload size is {}", data_size);
+
+        // TODO check for very big buffer, make it no more 10Mb
+        let mut buf = vec![0u8; data_size];
+        let mut bytes_read = 0;
+        loop {
+            match connection.read(&mut buf[bytes_read..]) {
+                Ok(bytes) => {
+                    bytes_read += bytes;
+                }
+                // Would block "errors" are the OS's way of saying that the connection is not actually ready to perform this I/O operation.
+                Err(ref err) if would_block(err) => break,
+                Err(ref err) if interrupted(err) => continue,
+                // Other errors we'll consider fatal.
+                Err(err) => return Err(err),
+            }
+        }
+
+        if bytes_read == data_size {
+            match Message::from_bytes(buf) {
+                Ok(message) => {
+                    println!("Got message from socket {}: {:?}", &event.token().0, &message);
+                    let new_state = handle_message(context.clone(), message);
+                    match new_state {
+                        State::Message { data } => {
+                            if event.is_writable() {
+                                // TODO handle all errors and buffer data to send
+                                send_message(connection, &data);
+                            } else {
+                                registry.reregister(connection, event.token(), Interest::WRITABLE).unwrap();
+                                let mut peer = peer_state.get_mut(&event.token()).unwrap();
+                                peer.set_state(State::Message { data });
+                            }
+                        }
+                        State::Connecting => {}
+                        State::Connected => {}
+                        State::Idle { .. } => {
+                            let mut peer = peer_state.get_mut(&event.token()).unwrap();
+                            peer.set_state(State::idle());
+                        }
+                        State::Error => {}
+                        State::Banned => {}
+                        State::Offline { .. } => {
+                            let mut peer = peer_state.get_mut(&event.token()).unwrap();
+                            peer.set_state(State::offline(1));
+                        }
+                    }
+                }
+                Err(_) => {}
+            }
+        } else {
+            // Consider connection as unreliable
+            return Ok(false);
+        }
+    }
+
+    if event.is_writable() {
+        println!("Socket {} is writable", event.token().0);
+        match peer_state.get(&event.token()) {
+            None => {}
+            Some(peer) => {
+                match peer.get_state() {
+                    State::Connecting => {
+                        println!("Hello needed for socket {}", event.token().0);
+                        let data: String = {
+                            let mut c = context.lock().unwrap();
+                            let message = Message::Hand { chain: c.settings.chain_name.clone(), version: c.settings.version_flags };
+                            serde_json::to_string(&message).unwrap()
+                        };
+                        send_message(connection, &data.into_bytes());
+                        println!("Sent hello through socket {}", event.token().0);
+                    }
+                    State::Message { data } => {
+                        println!("Sending data to socket {}: {}", event.token().0, &String::from_utf8(data.clone()).unwrap());
+                        send_message(connection, data);
+                    }
+                    State::Connected => {}
+                    State::Idle { from } => {
+                        if from.elapsed().as_secs() >= 30 {
+                            let data: String = {
+                                let mut c = context.lock().unwrap();
+                                let message = Message::ping(c.blockchain.height());
+                                serde_json::to_string(&message).unwrap()
+                            };
+                            send_message(connection, &data.into_bytes());
+                        }
+                    }
+                    State::Error => {}
+                    State::Banned => {}
+                    State::Offline { .. } => {}
+                }
+            }
+        }
+        registry.reregister(connection, event.token(), Interest::READABLE).unwrap();
+    }
+
+    Ok(true)
+}
+
+fn send_message(connection: &mut TcpStream, data: &Vec<u8>) {
+    // TODO handle errors
+    connection.write_u32::<BigEndian>(data.len() as u32);
+    connection.write_all(&data).expect("Error writing to socket");
+    connection.flush();
+}
+
+fn handle_message(context: Arc<Mutex<Context>>, message: Message) -> State {
+    match message {
+        Message::Hand { chain, version } => {
+            let context = context.lock().unwrap();
+            if chain == context.settings.chain_name && version == context.settings.version_flags {
+                State::message(Message::shake(true, context.blockchain.height()))
+            } else {
+                State::Error
+            }
+        }
+        Message::Shake { ok, height } => {
+            if ok {
+                let context = context.lock().unwrap();
+                if height > context.blockchain.height() {
+                    State::message(Message::GetBlock { index: context.blockchain.height() + 1u64 })
+                } else {
+                    State::idle()
+                }
+            } else {
+                State::Error
+            }
+        }
+        Message::Error => { State::Error }
+        Message::Ping { height } => {
+            let context = context.lock().unwrap();
+            if height > context.blockchain.height() {
+                State::message(Message::GetBlock { index: context.blockchain.height() + 1u64 })
+            } else {
+                State::message(Message::pong(context.blockchain.height()))
+            }
+        }
+        Message::Pong { height } => {
+            let context = context.lock().unwrap();
+            if height > context.blockchain.height() {
+                State::message(Message::GetBlock { index: context.blockchain.height() + 1u64 })
+            } else {
+                State::idle()
+            }
+        }
+        Message::GetPeers => { State::Error }
+        Message::Peers => { State::Error }
+        Message::GetBlock { index } => {
+            let context = context.lock().unwrap();
+            match context.blockchain.get_block(index) {
+                Some(block) => State::message(Message::block(block.index, serde_json::to_string(&block).unwrap())),
+                None => State::Error
+            }
+        }
+        Message::Block { index, block } => {
+            let block: Block = match serde_json::from_str(&block) {
+                Ok(block) => block,
+                Err(_) => return State::Error
+            };
+            // TODO check if the block is good
+            let context = context.clone();
+            thread::spawn(move || {
+                let mut context = context.lock().unwrap();
+                context.blockchain.add_block(block);
+                context.bus.post(crate::event::Event::BlockchainChanged)
+            });
+            State::idle()
+        }
+    }
+}
+
+fn next(current: &mut Token) -> Token {
+    let next = current.0;
+    current.0 += 1;
+    Token(next)
+}
+
+fn would_block(err: &io::Error) -> bool {
+    err.kind() == io::ErrorKind::WouldBlock
+}
+
+fn interrupted(err: &io::Error) -> bool {
+    err.kind() == io::ErrorKind::Interrupted
+}

src/p2p/peer.rs

@@ -0,0 +1,20 @@
+use crate::p2p::State;
+
+pub struct Peer {
+    addr: String,
+    state: State,
+}
+
+impl Peer {
+    pub fn new(addr: String, state: State) -> Self {
+        Peer { addr, state }
+    }
+
+    pub fn get_state(&self) -> &State {
+        &self.state
+    }
+
+    pub fn set_state(&mut self, state: State) {
+        self.state = state;
+    }
+}

src/p2p/state.rs

@@ -0,0 +1,38 @@
+use std::time::Instant;
+use crate::p2p::Message;
+
+pub enum State {
+    Connecting,
+    Connected,
+    Idle { from: Instant },
+    Message { data: Vec<u8> },
+    Error,
+    Banned,
+    Offline { from: Instant, attempts: usize },
+}
+
+impl State {
+    pub fn idle() -> Self {
+        Self::Idle { from: Instant::now() }
+    }
+
+    pub fn offline(attempts: usize) -> Self {
+        Self::Offline { attempts, from: Instant::now() }
+    }
+
+    pub fn still_offline(state: Self) -> Self {
+        match state {
+            State::Offline { attempts, from } => {
+                Self::Offline { attempts: attempts + 1, from }
+            }
+            _ => {
+                Self::Offline { attempts: 1, from: Instant::now() }
+            }
+        }
+    }
+
+    pub fn message(message: Message) -> Self {
+        let response = serde_json::to_string(&message).unwrap();
+        State::Message {data: Vec::from(response.as_bytes()) }
+    }
+}

src/styles.css

@@ -1,75 +0,0 @@
-html {
-    background: #202020;
-    background-attachment: fixed;
-}
-html, body {
-    width: 100%;
-    height: 100%;
-    margin: 0;
-    padding: 0;
-    background: linear-gradient(0deg, #404040, #090909);
-    background-attachment: fixed;
-    overflow: hidden;
-}
-h1, h2, h3 { color: #dddddd; }
-p { color: #dddddd; }
-a { color: #dddddd; }
- /* Style the tab */
-.tab {
-  overflow: hidden;
-  border: 0px;
-  background: linear-gradient(180deg, #404040, #202020);
-}
-
-/* Style the buttons that are used to open the tab content */
-.tab button {
-  background: inherit;
-  color: #dddddd;
-  float: left;
-  border: none;
-  outline: none;
-  cursor: pointer;
-  padding: 8px 16px;
-  transition: 0.3s;
-}
-
-/* Change background color of buttons on hover */
-.tab button:hover {
-  background: linear-gradient(180deg, #808080, #202020);
-}
-
-/* Create an active/current tablink class */
-.tab button.active {
-  background: linear-gradient(180deg, #606060, #202020);
-}
-
-/* Style the tab content */
-.tabcontent {
-  display: none;
-  padding: 12px 12px;
-  border: 0px;
-  border-top: none;
-  height: 100%;
-}
-
-button {
-  border: none;
-  outline: none;
-  color: #dddddd;
-  padding: 8px 8px;
-  background: linear-gradient(180deg, #404040, #202020);
-}
-
-.tabcontent button {
-  min-width: 200px;
-}
-
-.footer {
-  position: fixed;
-  left: 0;
-  bottom: 0;
-  width: 100%;
-  background-color: #404040;
-  color: #dddddd;
-  padding: 6px 12px;
-}