_ Git - dnsseed-rust/blob - src/datastore.rs

   1 use std::{cmp, mem};
   2 use std::collections::{HashSet, HashMap, hash_map};
   3 use std::sync::{Arc, RwLock};
   4 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
   5 use std::time::{Duration, Instant};
   6 use std::io::{BufRead, BufReader};
   7
   8 use bitcoin::network::address::Address;
   9
  10 use rand::thread_rng;
  11 use rand::seq::{SliceRandom, IteratorRandom};
  12
  13 use tokio::prelude::*;
  14 use tokio::fs::File;
  15 use tokio::io::write_all;
  16
  17 use regex::Regex;
  18
  19 use crate::bgp_client::BGPClient;
  20
  21 pub const SECS_PER_SCAN_RESULTS: u64 = 15;
  22
  23 #[derive(Clone, Copy, Hash, PartialEq, Eq)]
  24 pub enum AddressState {
  25         Untested,
  26         LowBlockCount,
  27         HighBlockCount,
  28         LowVersion,
  29         BadVersion,
  30         NotFullNode,
  31         ProtocolViolation,
  32         Timeout,
  33         TimeoutDuringRequest,
  34         TimeoutAwaitingPong,
  35         TimeoutAwaitingAddr,
  36         TimeoutAwaitingBlock,
  37         Good,
  38         WasGood,
  39         EvilNode,
  40 }
  41
  42 impl AddressState {
  43         pub fn from_num(num: u8) -> Option<AddressState> {
  44                 match num {
  45                         0x0 => Some(AddressState::Untested),
  46                         0x1 => Some(AddressState::LowBlockCount),
  47                         0x2 => Some(AddressState::HighBlockCount),
  48                         0x3 => Some(AddressState::LowVersion),
  49                         0x4 => Some(AddressState::BadVersion),
  50                         0x5 => Some(AddressState::NotFullNode),
  51                         0x6 => Some(AddressState::ProtocolViolation),
  52                         0x7 => Some(AddressState::Timeout),
  53                         0x8 => Some(AddressState::TimeoutDuringRequest),
  54                         0x9 => Some(AddressState::TimeoutAwaitingPong),
  55                         0xa => Some(AddressState::TimeoutAwaitingAddr),
  56                         0xb => Some(AddressState::TimeoutAwaitingBlock),
  57                         0xc => Some(AddressState::Good),
  58                         0xd => Some(AddressState::WasGood),
  59                         0xe => Some(AddressState::EvilNode),
  60                         _   => None,
  61                 }
  62         }
  63
  64         pub fn to_num(&self) -> u8 {
  65                 match *self {
  66                         AddressState::Untested => 0,
  67                         AddressState::LowBlockCount => 1,
  68                         AddressState::HighBlockCount => 2,
  69                         AddressState::LowVersion => 3,
  70                         AddressState::BadVersion => 4,
  71                         AddressState::NotFullNode => 5,
  72                         AddressState::ProtocolViolation => 6,
  73                         AddressState::Timeout => 7,
  74                         AddressState::TimeoutDuringRequest => 8,
  75                         AddressState::TimeoutAwaitingPong => 9,
  76                         AddressState::TimeoutAwaitingAddr => 10,
  77                         AddressState::TimeoutAwaitingBlock => 11,
  78                         AddressState::Good => 12,
  79                         AddressState::WasGood => 13,
  80                         AddressState::EvilNode => 14,
  81                 }
  82         }
  83
  84         pub fn to_str(&self) -> &'static str {
  85                 match *self {
  86                         AddressState::Untested => "Untested",
  87                         AddressState::LowBlockCount => "Low Block Count",
  88                         AddressState::HighBlockCount => "High Block Count",
  89                         AddressState::LowVersion => "Low Version",
  90                         AddressState::BadVersion => "Bad Version",
  91                         AddressState::NotFullNode => "Not Full Node",
  92                         AddressState::ProtocolViolation => "Protocol Violation",
  93                         AddressState::Timeout => "Timeout",
  94                         AddressState::TimeoutDuringRequest => "Timeout During Request",
  95                         AddressState::TimeoutAwaitingPong => "Timeout Awaiting Pong",
  96                         AddressState::TimeoutAwaitingAddr => "Timeout Awaiting Addr",
  97                         AddressState::TimeoutAwaitingBlock => "Timeout Awaiting Block",
  98                         AddressState::Good => "Good",
  99                         AddressState::WasGood => "Was Good",
 100                         AddressState::EvilNode => "Evil Node",
 101                 }
 102         }
 103
 104         pub const fn get_count() -> u8 {
 105                 15
 106         }
 107 }
 108
 109 #[derive(Hash, PartialEq, Eq)]
 110 pub enum U64Setting {
 111         RunTimeout,
 112         WasGoodTimeout,
 113         RescanInterval(AddressState),
 114         MinProtocolVersion,
 115 }
 116
 117 #[derive(Hash, PartialEq, Eq)]
 118 pub enum RegexSetting {
 119         SubverRegex,
 120 }
 121
 122 struct Node {
 123         last_update: Instant,
 124         last_good: Instant, // Ignored unless state is Good or WasGood
 125         last_services: u64,
 126         state: AddressState,
 127 }
 128
 129 struct Nodes {
 130         good_node_services: Vec<HashSet<SocketAddr>>,
 131         nodes_to_state: HashMap<SocketAddr, Node>,
 132         state_next_scan: Vec<Vec<(Instant, SocketAddr)>>,
 133 }
 134 struct NodesMutRef<'a> {
 135         good_node_services: &'a mut Vec<HashSet<SocketAddr>>,
 136         nodes_to_state: &'a mut HashMap<SocketAddr, Node>,
 137         state_next_scan: &'a mut Vec<Vec<(Instant, SocketAddr)>>,
 138
 139 }
 140 impl Nodes {
 141         fn borrow_mut<'a>(&'a mut self) -> NodesMutRef<'a> {
 142                 NodesMutRef {
 143                         good_node_services: &mut self.good_node_services,
 144                         nodes_to_state: &mut self.nodes_to_state,
 145                         state_next_scan: &mut self.state_next_scan,
 146                 }
 147         }
 148 }
 149
 150 pub struct Store {
 151         u64_settings: RwLock<HashMap<U64Setting, u64>>,
 152         subver_regex: RwLock<Arc<Regex>>,
 153         nodes: RwLock<Nodes>,
 154         store: String,
 155 }
 156
 157 impl Store {
 158         pub fn new(store: String) -> impl Future<Item=Store, Error=()> {
 159                 let settings_future = File::open(store.clone() + "/settings").and_then(|f| {
 160                         let mut l = BufReader::new(f).lines();
 161                         macro_rules! try_read {
 162                                 ($lines: expr, $ty: ty) => { {
 163                                         match $lines.next() {
 164                                                 Some(line) => match line {
 165                                                         Ok(line) => match line.parse::<$ty>() {
 166                                                                 Ok(res) => res,
 167                                                                 Err(e) => return future::err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
 168                                                         },
 169                                                         Err(e) => return future::err(e),
 170                                                 },
 171                                                 None => return future::err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "")),
 172                                         }
 173                                 } }
 174                         }
 175                         let mut u64s = HashMap::with_capacity(AddressState::get_count() as usize + 4);
 176                         u64s.insert(U64Setting::RunTimeout, try_read!(l, u64));
 177                         u64s.insert(U64Setting::WasGoodTimeout, try_read!(l, u64));
 178                         u64s.insert(U64Setting::MinProtocolVersion, try_read!(l, u64));
 179                         u64s.insert(U64Setting::RescanInterval(AddressState::Untested), try_read!(l, u64));
 180                         u64s.insert(U64Setting::RescanInterval(AddressState::LowBlockCount), try_read!(l, u64));
 181                         u64s.insert(U64Setting::RescanInterval(AddressState::HighBlockCount), try_read!(l, u64));
 182                         u64s.insert(U64Setting::RescanInterval(AddressState::LowVersion), try_read!(l, u64));
 183                         u64s.insert(U64Setting::RescanInterval(AddressState::BadVersion), try_read!(l, u64));
 184                         u64s.insert(U64Setting::RescanInterval(AddressState::NotFullNode), try_read!(l, u64));
 185                         u64s.insert(U64Setting::RescanInterval(AddressState::ProtocolViolation), try_read!(l, u64));
 186                         u64s.insert(U64Setting::RescanInterval(AddressState::Timeout), try_read!(l, u64));
 187                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest), try_read!(l, u64));
 188                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingPong), try_read!(l, u64));
 189                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingAddr), try_read!(l, u64));
 190                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingBlock), try_read!(l, u64));
 191                         u64s.insert(U64Setting::RescanInterval(AddressState::Good), try_read!(l, u64));
 192                         u64s.insert(U64Setting::RescanInterval(AddressState::WasGood), try_read!(l, u64));
 193                         u64s.insert(U64Setting::RescanInterval(AddressState::EvilNode), try_read!(l, u64));
 194                         future::ok((u64s, try_read!(l, Regex)))
 195                 }).or_else(|_| -> future::FutureResult<(HashMap<U64Setting, u64>, Regex), ()> {
 196                         let mut u64s = HashMap::with_capacity(15);
 197                         u64s.insert(U64Setting::RunTimeout, 120);
 198                         u64s.insert(U64Setting::WasGoodTimeout, 21600);
 199                         u64s.insert(U64Setting::RescanInterval(AddressState::Untested), 1);
 200                         u64s.insert(U64Setting::RescanInterval(AddressState::LowBlockCount), 3600);
 201                         u64s.insert(U64Setting::RescanInterval(AddressState::HighBlockCount), 7200);
 202                         u64s.insert(U64Setting::RescanInterval(AddressState::LowVersion), 21600);
 203                         u64s.insert(U64Setting::RescanInterval(AddressState::BadVersion), 21600);
 204                         u64s.insert(U64Setting::RescanInterval(AddressState::NotFullNode), 86400);
 205                         u64s.insert(U64Setting::RescanInterval(AddressState::ProtocolViolation), 86400);
 206                         u64s.insert(U64Setting::RescanInterval(AddressState::Timeout), 86400);
 207                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest), 21600);
 208                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingPong), 3600);
 209                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingAddr), 1800);
 210                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutAwaitingBlock), 3600);
 211                         u64s.insert(U64Setting::RescanInterval(AddressState::Good), 1800);
 212                         u64s.insert(U64Setting::RescanInterval(AddressState::WasGood), 1800);
 213                         u64s.insert(U64Setting::RescanInterval(AddressState::EvilNode), 315360000);
 214                         u64s.insert(U64Setting::MinProtocolVersion, 70002);
 215                         future::ok((u64s, Regex::new(".*").unwrap()))
 216                 });
 217
 218                 macro_rules! nodes_uninitd {
 219                         () => { {
 220                                 let mut state_vecs = Vec::with_capacity(AddressState::get_count() as usize);
 221                                 for _ in 0..AddressState::get_count() {
 222                                         state_vecs.push(Vec::new());
 223                                 }
 224                                 let mut good_node_services = Vec::with_capacity(64);
 225                                 for _ in 0..64 {
 226                                         good_node_services.push(HashSet::new());
 227                                 }
 228                                 Nodes {
 229                                         good_node_services,
 230                                         nodes_to_state: HashMap::new(),
 231                                         state_next_scan: state_vecs,
 232                                 }
 233                         } }
 234                 }
 235
 236                 let nodes_future = File::open(store.clone() + "/nodes").and_then(|f| {
 237                         let mut res = nodes_uninitd!();
 238                         let l = BufReader::new(f).lines();
 239                         for line_res in l {
 240                                 let line = match line_res {
 241                                         Ok(l) => l,
 242                                         Err(_) => return future::ok(res),
 243                                 };
 244                                 let mut line_iter = line.split(',');
 245                                 macro_rules! try_read {
 246                                         ($lines: expr, $ty: ty) => { {
 247                                                 match $lines.next() {
 248                                                         Some(line) => match line.parse::<$ty>() {
 249                                                                 Ok(res) => res,
 250                                                                 Err(_) => return future::ok(res),
 251                                                         },
 252                                                         None => return future::ok(res),
 253                                                 }
 254                                         } }
 255                                 }
 256                                 let sockaddr = try_read!(line_iter, SocketAddr);
 257                                 let state = try_read!(line_iter, u8);
 258                                 let last_services = try_read!(line_iter, u64);
 259                                 let node = Node {
 260                                         state: match AddressState::from_num(state) {
 261                                                 Some(v) => v,
 262                                                 None => return future::ok(res),
 263                                         },
 264                                         last_services,
 265                                         last_update: Instant::now(),
 266                                         last_good: Instant::now(),
 267                                 };
 268                                 if node.state == AddressState::Good {
 269                                         for i in 0..64 {
 270                                                 if node.last_services & (1 << i) != 0 {
 271                                                         res.good_node_services[i].insert(sockaddr);
 272                                                 }
 273                                         }
 274                                 }
 275                                 res.state_next_scan[node.state.to_num() as usize].push((Instant::now(), sockaddr));
 276                                 res.nodes_to_state.insert(sockaddr, node);
 277                         }
 278                         future::ok(res)
 279                 }).or_else(|_| -> future::FutureResult<Nodes, ()> {
 280                         future::ok(nodes_uninitd!())
 281                 });
 282                 settings_future.join(nodes_future).and_then(move |((u64_settings, regex), nodes)| {
 283                         future::ok(Store {
 284                                 u64_settings: RwLock::new(u64_settings),
 285                                 subver_regex: RwLock::new(Arc::new(regex)),
 286                                 nodes: RwLock::new(nodes),
 287                                 store,
 288                         })
 289                 })
 290         }
 291
 292         pub fn get_u64(&self, setting: U64Setting) -> u64 {
 293                 *self.u64_settings.read().unwrap().get(&setting).unwrap()
 294         }
 295
 296         pub fn set_u64(&self, setting: U64Setting, value: u64) {
 297                 *self.u64_settings.write().unwrap().get_mut(&setting).unwrap() = value;
 298         }
 299
 300         pub fn get_node_count(&self, state: AddressState) -> usize {
 301                 self.nodes.read().unwrap().state_next_scan[state.to_num() as usize].len()
 302         }
 303
 304         pub fn get_regex(&self, _setting: RegexSetting) -> Arc<Regex> {
 305                 Arc::clone(&*self.subver_regex.read().unwrap())
 306         }
 307
 308         pub fn set_regex(&self, _setting: RegexSetting, value: Regex) {
 309                 *self.subver_regex.write().unwrap() = Arc::new(value);
 310         }
 311
 312         pub fn add_fresh_addrs<I: Iterator<Item=SocketAddr>>(&self, addresses: I) -> u64 {
 313                 let mut res = 0;
 314                 let mut nodes = self.nodes.write().unwrap();
 315                 let cur_time = Instant::now();
 316                 for addr in addresses {
 317                         match nodes.nodes_to_state.entry(addr.clone()) {
 318                                 hash_map::Entry::Vacant(e) => {
 319                                         e.insert(Node {
 320                                                 state: AddressState::Untested,
 321                                                 last_services: 0,
 322                                                 last_update: cur_time,
 323                                                 last_good: cur_time,
 324                                         });
 325                                         nodes.state_next_scan[AddressState::Untested.to_num() as usize].push((cur_time, addr));
 326                                         res += 1;
 327                                 },
 328                                 hash_map::Entry::Occupied(_) => {},
 329                         }
 330                 }
 331                 res
 332         }
 333
 334         pub fn add_fresh_nodes(&self, addresses: &Vec<(u32, Address)>) {
 335                 self.add_fresh_addrs(addresses.iter().filter_map(|(_, addr)| {
 336                         match addr.socket_addr() {
 337                                 Ok(socketaddr) => Some(socketaddr),
 338                                 Err(_) => None, // TODO: Handle onions
 339                         }
 340                 }));
 341         }
 342
 343         pub fn set_node_state(&self, addr: SocketAddr, state: AddressState, services: u64) -> AddressState {
 344                 let mut nodes_lock = self.nodes.write().unwrap();
 345                 let nodes = nodes_lock.borrow_mut();
 346                 let now = Instant::now();
 347
 348                 let state_ref = nodes.nodes_to_state.entry(addr).or_insert(Node {
 349                         state: AddressState::Untested,
 350                         last_services: 0,
 351                         last_update: now,
 352                         last_good: now,
 353                 });
 354                 let ret = state_ref.state;
 355                 if (state_ref.state == AddressState::Good || state_ref.state == AddressState::WasGood)
 356                                 && state != AddressState::Good
 357                                 && state_ref.last_good >= now - Duration::from_secs(self.get_u64(U64Setting::WasGoodTimeout)) {
 358                         state_ref.state = AddressState::WasGood;
 359                         for i in 0..64 {
 360                                 if state_ref.last_services & (1 << i) != 0 {
 361                                         nodes.good_node_services[i].remove(&addr);
 362                                 }
 363                         }
 364                         state_ref.last_services = 0;
 365                         nodes.state_next_scan[AddressState::WasGood.to_num() as usize].push((now, addr));
 366                 } else {
 367                         state_ref.state = state;
 368                         if state == AddressState::Good {
 369                                 for i in 0..64 {
 370                                         if services & (1 << i) != 0 && state_ref.last_services & (1 << i) == 0 {
 371                                                 nodes.good_node_services[i].insert(addr);
 372                                         } else if services & (1 << i) == 0 && state_ref.last_services & (1 << i) != 0 {
 373                                                 nodes.good_node_services[i].remove(&addr);
 374                                         }
 375                                 }
 376                                 state_ref.last_services = services;
 377                                 state_ref.last_good = now;
 378                         }
 379                         nodes.state_next_scan[state.to_num() as usize].push((now, addr));
 380                 }
 381                 state_ref.last_update = now;
 382                 ret
 383         }
 384
 385         pub fn save_data(&'static self) -> impl Future<Item=(), Error=()> {
 386                 let settings_file = self.store.clone() + "/settings";
 387                 let settings_future = File::create(settings_file.clone() + ".tmp").and_then(move |f| {
 388                         let settings_string = format!("{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}",
 389                                 self.get_u64(U64Setting::RunTimeout),
 390                                 self.get_u64(U64Setting::WasGoodTimeout),
 391                                 self.get_u64(U64Setting::MinProtocolVersion),
 392                                 self.get_u64(U64Setting::RescanInterval(AddressState::Untested)),
 393                                 self.get_u64(U64Setting::RescanInterval(AddressState::LowBlockCount)),
 394                                 self.get_u64(U64Setting::RescanInterval(AddressState::HighBlockCount)),
 395                                 self.get_u64(U64Setting::RescanInterval(AddressState::LowVersion)),
 396                                 self.get_u64(U64Setting::RescanInterval(AddressState::BadVersion)),
 397                                 self.get_u64(U64Setting::RescanInterval(AddressState::NotFullNode)),
 398                                 self.get_u64(U64Setting::RescanInterval(AddressState::ProtocolViolation)),
 399                                 self.get_u64(U64Setting::RescanInterval(AddressState::Timeout)),
 400                                 self.get_u64(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest)),
 401                                 self.get_u64(U64Setting::RescanInterval(AddressState::TimeoutAwaitingPong)),
 402                                 self.get_u64(U64Setting::RescanInterval(AddressState::TimeoutAwaitingAddr)),
 403                                 self.get_u64(U64Setting::RescanInterval(AddressState::TimeoutAwaitingBlock)),
 404                                 self.get_u64(U64Setting::RescanInterval(AddressState::Good)),
 405                                 self.get_u64(U64Setting::RescanInterval(AddressState::WasGood)),
 406                                 self.get_u64(U64Setting::RescanInterval(AddressState::EvilNode)),
 407                                 self.get_regex(RegexSetting::SubverRegex).as_str());
 408                         write_all(f, settings_string).and_then(|(mut f, _)| {
 409                                 f.poll_sync_all()
 410                         }).and_then(|_| {
 411                                 tokio::fs::rename(settings_file.clone() + ".tmp", settings_file)
 412                         })
 413                 });
 414
 415                 let nodes_file = self.store.clone() + "/nodes";
 416                 let nodes_future = File::create(nodes_file.clone() + ".tmp").and_then(move |f| {
 417                         let mut nodes_buff = String::new();
 418                         {
 419                                 let nodes = self.nodes.read().unwrap();
 420                                 nodes_buff.reserve(nodes.nodes_to_state.len() * 20);
 421                                 for (ref sockaddr, ref node) in nodes.nodes_to_state.iter() {
 422                                         nodes_buff += &sockaddr.to_string();
 423                                         nodes_buff += ",";
 424                                         nodes_buff += &node.state.to_num().to_string();
 425                                         nodes_buff += ",";
 426                                         nodes_buff += &node.last_services.to_string();
 427                                         nodes_buff += "\n";
 428                                 }
 429                         }
 430                         write_all(f, nodes_buff)
 431                 }).and_then(|(mut f, _)| {
 432                         f.poll_sync_all()
 433                 }).and_then(|_| {
 434                         tokio::fs::rename(nodes_file.clone() + ".tmp", nodes_file)
 435                 });
 436
 437                 settings_future.join(nodes_future).then(|_| { future::ok(()) })
 438         }
 439
 440         pub fn write_dns(&'static self, bgp_client: Arc<BGPClient>) -> impl Future<Item=(), Error=()> {
 441                 let dns_file = self.store.clone() + "/nodes.dump";
 442                 File::create(dns_file.clone() + ".tmp").and_then(move |f| {
 443                         let mut dns_buff = String::new();
 444                         {
 445                                 let mut rng = thread_rng();
 446                                 for i in &[1u64, 4, 5, 8, 9, 12, 13, 1024, 1025, 1028, 1029, 1032, 1033, 1036, 1037] {
 447                                         let mut tor_set: Vec<Ipv6Addr> = Vec::new();
 448                                         let mut v6_set: Vec<Ipv6Addr> = Vec::new();
 449                                         let mut v4_set: Vec<Ipv4Addr> = Vec::new();
 450                                         macro_rules! add_addr { ($addr: expr) => {
 451                                                 match $addr.ip() {
 452                                                         IpAddr::V4(v4addr) => v4_set.push(v4addr),
 453                                                         IpAddr::V6(v6addr) if v6addr.octets()[..6] == [0xFD,0x87,0xD8,0x7E,0xEB,0x43][..] => tor_set.push(v6addr),
 454                                                         IpAddr::V6(v6addr) => v6_set.push(v6addr),
 455                                                 }
 456                                         } }
 457                                         {
 458                                                 let nodes = self.nodes.read().unwrap();
 459                                                 if i.count_ones() == 1 {
 460                                                         for j in 0..64 {
 461                                                                 if i & (1 << j) != 0 {
 462                                                                         let set_ref = &nodes.good_node_services[j];
 463                                                                         for a in set_ref.iter().filter(|e| e.port() == 8333) {
 464                                                                                 add_addr!(a);
 465                                                                         }
 466                                                                         break;
 467                                                                 }
 468                                                         }
 469                                                 } else if i.count_ones() == 2 {
 470                                                         let mut first_set = None;
 471                                                         let mut second_set = None;
 472                                                         for j in 0..64 {
 473                                                                 if i & (1 << j) != 0 {
 474                                                                         if first_set == None {
 475                                                                                 first_set = Some(&nodes.good_node_services[j]);
 476                                                                         } else {
 477                                                                                 second_set = Some(&nodes.good_node_services[j]);
 478                                                                                 break;
 479                                                                         }
 480                                                                 }
 481                                                         }
 482                                                         for a in first_set.unwrap().intersection(&second_set.unwrap()).filter(|e| e.port() == 8333) {
 483                                                                 add_addr!(a);
 484                                                         }
 485                                                 } else {
 486                                                         //TODO: Could optimize this one a bit
 487                                                         let mut intersection;
 488                                                         let mut intersection_set_ref = None;
 489                                                         for j in 0..64 {
 490                                                                 if i & (1 << j) != 0 {
 491                                                                         if intersection_set_ref == None {
 492                                                                                 intersection_set_ref = Some(&nodes.good_node_services[j]);
 493                                                                         } else {
 494                                                                                 let new_intersection = intersection_set_ref.unwrap()
 495                                                                                         .intersection(&nodes.good_node_services[j]).map(|e| (*e).clone()).collect();
 496                                                                                 intersection = Some(new_intersection);
 497                                                                                 intersection_set_ref = Some(intersection.as_ref().unwrap());
 498                                                                         }
 499                                                                 }
 500                                                         }
 501                                                         for a in intersection_set_ref.unwrap().iter().filter(|e| e.port() == 8333) {
 502                                                                 add_addr!(a);
 503                                                         }
 504                                                 }
 505                                         }
 506                                         let mut asn_set = HashSet::with_capacity(cmp::max(v4_set.len(), v6_set.len()));
 507                                         asn_set.insert(0);
 508                                         for a in v4_set.iter().filter(|a| asn_set.insert(bgp_client.get_asn(IpAddr::V4(**a)))).choose_multiple(&mut rng, 21) {
 509                                                 dns_buff += &format!("x{:x}.dnsseed\tIN\tA\t{}\n", i, a);
 510                                         }
 511                                         asn_set.clear();
 512                                         asn_set.insert(0);
 513                                         for a in v6_set.iter().filter(|a| asn_set.insert(bgp_client.get_asn(IpAddr::V6(**a)))).choose_multiple(&mut rng, 10) {
 514                                                 dns_buff += &format!("x{:x}.dnsseed\tIN\tAAAA\t{}\n", i, a);
 515                                         }
 516                                         for a in tor_set.iter().choose_multiple(&mut rng, 2) {
 517                                                 dns_buff += &format!("x{:x}.dnsseed\tIN\tAAAA\t{}\n", i, a);
 518                                         }
 519                                 }
 520                         }
 521                         write_all(f, dns_buff)
 522                 }).and_then(|(mut f, _)| {
 523                         f.poll_sync_all()
 524                 }).and_then(|_| {
 525                         tokio::fs::rename(dns_file.clone() + ".tmp", dns_file)
 526                 }).then(|_| { future::ok(()) })
 527         }
 528
 529         pub fn get_next_scan_nodes(&self) -> Vec<SocketAddr> {
 530                 let mut res = Vec::with_capacity(128);
 531                 let cur_time = Instant::now();
 532
 533                 {
 534                         let mut nodes = self.nodes.write().unwrap();
 535                         for (idx, state_nodes) in nodes.state_next_scan.iter_mut().enumerate() {
 536                                 let rescan_interval = cmp::max(self.get_u64(U64Setting::RescanInterval(AddressState::from_num(idx as u8).unwrap())), 1);
 537                                 let cmp_time = cur_time - Duration::from_secs(rescan_interval);
 538                                 let split_point = cmp::min(SECS_PER_SCAN_RESULTS * state_nodes.len() as u64 / rescan_interval,
 539                                                 state_nodes.binary_search_by(|a| a.0.cmp(&cmp_time)).unwrap_or_else(|idx| idx) as u64);
 540                                 let mut new_nodes = state_nodes.split_off(split_point as usize);
 541                                 mem::swap(&mut new_nodes, state_nodes);
 542                                 for (_, node) in new_nodes.drain(..) {
 543                                         res.push(node);
 544                                 }
 545                         }
 546                 }
 547                 res.shuffle(&mut thread_rng());
 548                 res
 549         }
 550 }