1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
// This file is part of Substrate.
// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//! [`Peerset`] implementation for `litep2p`.
//!
//! [`Peerset`] is a separate but related component running alongside the notification protocol,
//! responsible for maintaining connectivity to remote peers. [`Peerset`] has an imperfect view of
//! the network as the notification protocol is behind an asynchronous channel. Based on this
//! imperfect view, it tries to connect to remote peers and disconnect peers that should be
//! disconnected from.
//!
//! [`Peerset`] knows of two types of peers:
//! - normal peers
//! - reserved peers
//!
//! Reserved peers are those which the [`Peerset`] should be connected at all times and it will make
//! an effort to do so by constantly checking that there are no disconnected reserved peers (except
//! banned) and if there are, it will open substreams to them.
//!
//! [`Peerset`] may also contain "slots", both inbound and outbound, which mark how many incoming
//! and outgoing connections it should maintain at all times. Peers for the inbound slots are filled
//! by remote peers opening inbound substreams towards the local node and peers for the outbound
//! slots are filled by querying the `Peerstore` which contains all peers known to `sc-network`.
//! Peers for outbound slots are selected in a decreasing order of reputation.
use crate::{
peer_store::{PeerStoreProvider, ProtocolHandle},
service::traits::{self, ValidationResult},
ProtocolName, ReputationChange as Reputation,
};
use futures::{channel::oneshot, future::BoxFuture, stream::FuturesUnordered, Stream, StreamExt};
use futures_timer::Delay;
use litep2p::protocol::notification::NotificationError;
use sc_network_types::PeerId;
use sc_utils::mpsc::{tracing_unbounded, TracingUnboundedReceiver, TracingUnboundedSender};
use std::{
collections::{HashMap, HashSet},
future::Future,
pin::Pin,
sync::{
atomic::{AtomicUsize, Ordering},
Arc,
},
task::{Context, Poll},
time::Duration,
};
/// Logging target for the file.
const LOG_TARGET: &str = "sub-libp2p::peerset";
/// Default backoff for connection re-attempts.
const DEFAULT_BACKOFF: Duration = Duration::from_secs(5);
/// Open failure backoff.
const OPEN_FAILURE_BACKOFF: Duration = Duration::from_secs(5);
/// Slot allocation frequency.
///
/// How often should [`Peerset`] attempt to establish outbound connections.
const SLOT_ALLOCATION_FREQUENCY: Duration = Duration::from_secs(1);
/// Reputation adjustment when a peer gets disconnected.
///
/// Lessens the likelyhood of the peer getting selected for an outbound connection soon.
const DISCONNECT_ADJUSTMENT: Reputation = Reputation::new(-256, "Peer disconnected");
/// Reputation adjustment when a substream fails to open.
///
/// Lessens the likelyhood of the peer getting selected for an outbound connection soon.
const OPEN_FAILURE_ADJUSTMENT: Reputation = Reputation::new(-1024, "Open failure");
/// Is the peer reserved?
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum Reserved {
Yes,
No,
}
impl From<bool> for Reserved {
fn from(value: bool) -> Reserved {
match value {
true => Reserved::Yes,
false => Reserved::No,
}
}
}
impl From<Reserved> for bool {
fn from(value: Reserved) -> bool {
std::matches!(value, Reserved::Yes)
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum Direction {
/// Inbound substream.
Inbound(Reserved),
/// Outbound substream.
Outbound(Reserved),
}
impl From<Direction> for traits::Direction {
fn from(direction: Direction) -> traits::Direction {
match direction {
Direction::Inbound(_) => traits::Direction::Inbound,
Direction::Outbound(_) => traits::Direction::Outbound,
}
}
}
/// Open result for a fully-opened connection.
#[derive(PartialEq, Eq)]
pub enum OpenResult {
/// Accept the connection.
Accept {
/// Direction which [`Peerset`] considers to be correct.
direction: traits::Direction,
},
/// Reject the connection because it was canceled while it was opening.
Reject,
}
/// Commands emitted by other subsystems of the blockchain to [`Peerset`].
#[derive(Debug)]
pub enum PeersetCommand {
/// Set current reserved peer set.
///
/// This command removes all reserved peers that are not in `peers`.
SetReservedPeers {
/// New reserved peer set.
peers: HashSet<PeerId>,
},
/// Add one or more reserved peers.
///
/// This command doesn't remove any reserved peers but only add new peers.
AddReservedPeers {
/// Reserved peers to add.
peers: HashSet<PeerId>,
},
/// Remove reserved peers.
RemoveReservedPeers {
/// Reserved peers to remove.
peers: HashSet<PeerId>,
},
/// Set reserved-only mode to true/false.
SetReservedOnly {
/// Should the protocol only accept/establish connections to reserved peers.
reserved_only: bool,
},
/// Disconnect peer.
DisconnectPeer {
/// Peer ID.
peer: PeerId,
},
/// Get reserved peers.
GetReservedPeers {
/// `oneshot::Sender` for sending the current set of reserved peers.
tx: oneshot::Sender<Vec<PeerId>>,
},
}
/// Commands emitted by [`Peerset`] to the notification protocol.
#[derive(Debug)]
pub enum PeersetNotificationCommand {
/// Open substreams to one or more peers.
OpenSubstream {
/// Peer IDs.
peers: Vec<PeerId>,
},
/// Close substream to one or more peers.
CloseSubstream {
/// Peer IDs.
peers: Vec<PeerId>,
},
}
/// Peer state.
///
/// Peer can be in 6 different state:
/// - disconnected
/// - connected
/// - connection is opening
/// - connection is closing
/// - connection is backed-off
/// - connection is canceled
///
/// Opening and closing are separate states as litep2p guarantees to report when the substream is
/// either fully open or fully closed and the slot allocation for opening a substream is tied to a
/// state transition which moves the peer to [`PeerState::Opening`]. This is because it allows
/// reserving a slot for peer to prevent infinite outbound substreams. If the substream is opened
/// successfully, peer is moved to state [`PeerState::Connected`] but there is no modification to
/// the slot count as an outbound slot was already allocated for the peer. If the substream fails to
/// open, the event is reported by litep2p and [`Peerset::report_substream_open_failure()`] is
/// called which will decrease the outbound slot count. Similarly for inbound streams, the slot is
/// allocated in [`Peerset::report_inbound_substream()`] which will prevent `Peerset` from accepting
/// infinite inbound substreams. If the inbound substream fails to open and since [`Peerset`] was
/// notified of it, litep2p will report the open failure and the inbound slot count is once again
/// decreased in [`Peerset::report_substream_open_failure()`]. If the substream is opened
/// successfully, the slot count is not modified.
///
/// Since closing a substream is not instantaneous, there is a separate [`PeerState::Closing`]
/// state which indicates that the substream is being closed but hasn't been closed by litep2p yet.
/// This state is used to prevent invalid state transitions where, for example, [`Peerset`] would
/// close a substream and then try to reopen it immediately.
///
/// Irrespective of which side closed the substream (local/remote), the substream is chilled for a
/// small amount of time ([`DEFAULT_BACKOFF`]) and during this time no inbound or outbound
/// substreams are accepted/established. Any request to open an outbound substream while the peer
/// is backed-off is ignored. If the peer is a reserved peer, an outbound substream is not opened
/// for them immediately but after the back-off has expired, `Peerset` will attempt to open a
/// substream to the peer if it's still counted as a reserved peer.
///
/// Disconnections and open failures will contribute negatively to the peer score to prevent it from
/// being selected for another outbound substream request soon after the failure/disconnection. The
/// reputation decays towards zero over time and eventually the peer will be as likely to be
/// selected for an outbound substream as any other freshly added peer.
///
/// [`Peerset`] must also be able to handle the case where an outbound substream was opened to peer
/// and while it was opening, an inbound substream was received from that same peer. Since `litep2p`
/// is the source of truth of the actual state of the connection, [`Peerset`] must compensate for
/// this and if it happens that inbound substream is opened for a peer that was marked outbound, it
/// will attempt to allocate an inbound slot for the peer. If it fails to do so, the inbound
/// substream is rejected and the peer is marked as canceled.
///
/// Since substream is not opened immediately, a peer can be disconnected even if the substream was
/// not yet open. This can happen, for example, when a peer has connected over the syncing protocol
/// and it was added to, e.g., GRANDPA's reserved peers, an outbound substream was opened
/// ([`PeerState::Opening`]) and then the peer disconnected. This state transition is handled by the
/// [`Peerset`] with `PeerState::Canceled` which indicates that should the substream open
/// successfully, it should be closed immediately and if the connection is opened successfully while
/// the peer was marked as canceled, the substream will be closed without notifying the protocol
/// about the substream.
#[derive(Debug, PartialEq, Eq)]
pub enum PeerState {
/// No active connection to peer.
Disconnected,
/// Substream to peer was recently closed and the peer is currently backed off.
///
/// Backoff only applies to outbound substreams. Inbound substream will not experience any sort
/// of "banning" even if the peer is backed off and an inbound substream for the peer is
/// received.
Backoff,
/// Connection to peer is pending.
Opening {
/// Direction of the connection.
direction: Direction,
},
// Connected to peer.
Connected {
/// Is the peer inbound or outbound.
direction: Direction,
},
/// Substream was opened and while it was opening (no response had been heard from litep2p),
/// the substream was canceled by either calling `disconnect_peer()` or by removing peer
/// from the reserved set.
///
/// After the opened substream is acknowledged by litep2p (open success/failure), the peer is
/// moved to [`PeerState::Backoff`] from which it will then be moved to
/// [`PeerState::Disconnected`].
Canceled {
/// Is the peer inbound or outbound.
direction: Direction,
},
/// Connection to peer is closing.
///
/// State implies that the substream was asked to be closed by the local node and litep2p is
/// closing the substream. No command modifying the connection state is accepted until the
/// state has been set to [`PeerState::Disconnected`].
Closing {
/// Is the peer inbound or outbound.
direction: Direction,
},
}
/// `Peerset` implementation.
///
/// `Peerset` allows other subsystems of the blockchain to modify the connection state
/// of the notification protocol by adding and removing reserved peers.
///
/// `Peerset` is also responsible for maintaining the desired amount of peers the protocol is
/// connected to by establishing outbound connections and accepting/rejecting inbound connections.
#[derive(Debug)]
pub struct Peerset {
/// Protocol name.
protocol: ProtocolName,
/// RX channel for receiving commands.
cmd_rx: TracingUnboundedReceiver<PeersetCommand>,
/// Maximum number of outbound peers.
max_out: usize,
/// Current number of outbound peers.
num_out: usize,
/// Maximum number of inbound peers.
max_in: usize,
/// Current number of inbound peers.
num_in: usize,
/// Only connect to/accept connections from reserved peers.
reserved_only: bool,
/// Current reserved peer set.
reserved_peers: HashSet<PeerId>,
/// Handle to `Peerstore`.
peerstore_handle: Arc<dyn PeerStoreProvider>,
/// Peers.
peers: HashMap<PeerId, PeerState>,
/// Counter connected peers.
connected_peers: Arc<AtomicUsize>,
/// Pending backoffs for peers who recently disconnected.
pending_backoffs: FuturesUnordered<BoxFuture<'static, (PeerId, Reputation)>>,
/// Next time when [`Peerset`] should perform slot allocation.
next_slot_allocation: Delay,
}
macro_rules! decrement_or_warn {
($slot:expr, $protocol:expr, $peer:expr, $direction:expr) => {{
match $slot.checked_sub(1) {
Some(value) => {
$slot = value;
}
None => {
log::warn!(
target: LOG_TARGET,
"{}: state mismatch, {:?} is not counted as part of {:?} slots",
$protocol, $peer, $direction
);
debug_assert!(false);
}
}
}};
}
/// Handle to [`Peerset`], given to `Peerstore`.
#[derive(Debug)]
struct PeersetHandle {
/// TX channel for sending commands to [`Peerset`].
tx: TracingUnboundedSender<PeersetCommand>,
}
impl ProtocolHandle for PeersetHandle {
/// Disconnect peer, as a result of a ban.
fn disconnect_peer(&self, peer: PeerId) {
let _ = self.tx.unbounded_send(PeersetCommand::DisconnectPeer { peer });
}
}
impl Peerset {
/// Create new [`Peerset`].
pub fn new(
protocol: ProtocolName,
max_out: usize,
max_in: usize,
reserved_only: bool,
reserved_peers: HashSet<PeerId>,
connected_peers: Arc<AtomicUsize>,
peerstore_handle: Arc<dyn PeerStoreProvider>,
) -> (Self, TracingUnboundedSender<PeersetCommand>) {
let (cmd_tx, cmd_rx) = tracing_unbounded("mpsc-peerset-protocol", 100_000);
let peers = reserved_peers
.iter()
.map(|peer| (*peer, PeerState::Disconnected))
.collect::<HashMap<_, _>>();
// register protocol's command channel to `Peerstore` so it can issue disconnect commands
// if some connected peer gets banned.
peerstore_handle.register_protocol(Arc::new(PeersetHandle { tx: cmd_tx.clone() }));
(
Self {
protocol,
max_out,
num_out: 0usize,
max_in,
num_in: 0usize,
reserved_peers,
cmd_rx,
peerstore_handle,
reserved_only,
peers,
connected_peers,
pending_backoffs: FuturesUnordered::new(),
next_slot_allocation: Delay::new(SLOT_ALLOCATION_FREQUENCY),
},
cmd_tx,
)
}
/// Report to [`Peerset`] that a substream was opened.
///
/// Slot for the stream was "preallocated" when it was initiated (outbound) or accepted
/// (inbound) by the local node which is why this function doesn't allocate a slot for the peer.
///
/// Returns `true` if the substream should be kept open and `false` if the substream had been
/// canceled while it was opening and litep2p should close the substream.
pub fn report_substream_opened(
&mut self,
peer: PeerId,
direction: traits::Direction,
) -> OpenResult {
log::trace!(
target: LOG_TARGET,
"{}: substream opened to {peer:?}, direction {direction:?}, reserved peer {}",
self.protocol,
self.reserved_peers.contains(&peer),
);
let Some(state) = self.peers.get_mut(&peer) else {
log::warn!(target: LOG_TARGET, "{}: substream opened for unknown peer {peer:?}", self.protocol);
debug_assert!(false);
return OpenResult::Reject
};
match state {
PeerState::Opening { direction: substream_direction } => {
let real_direction: traits::Direction = (*substream_direction).into();
*state = PeerState::Connected { direction: *substream_direction };
self.connected_peers.fetch_add(1usize, Ordering::Relaxed);
return OpenResult::Accept { direction: real_direction }
},
// litep2p doesn't support the ability to cancel an opening substream so if the
// substream was closed while it was opening, it was marked as canceled and if the
// substream opens succesfully, it will be closed
PeerState::Canceled { direction: substream_direction } => {
log::trace!(
target: LOG_TARGET,
"{}: substream to {peer:?} is canceled, issue disconnection request",
self.protocol,
);
self.connected_peers.fetch_add(1usize, Ordering::Relaxed);
*state = PeerState::Closing { direction: *substream_direction };
return OpenResult::Reject
},
state => {
panic!("{}: invalid state for open substream {peer:?} {state:?}", self.protocol);
},
}
}
/// Report to [`Peerset`] that a substream was closed.
///
/// If the peer was not a reserved peer, the inbound/outbound slot count is adjusted to account
/// for the disconnected peer. After the connection is closed, the peer is chilled for a
/// duration of [`DEFAULT_BACKOFF`] which prevens [`Peerset`] from establishing/accepting new
/// connections for that time period.
pub fn report_substream_closed(&mut self, peer: PeerId) {
log::trace!(target: LOG_TARGET, "{}: substream closed to {peer:?}", self.protocol);
let Some(state) = self.peers.get_mut(&peer) else {
log::warn!(target: LOG_TARGET, "{}: substream closed for unknown peer {peer:?}", self.protocol);
debug_assert!(false);
return
};
match &state {
// close was initiated either by remote ([`PeerState::Connected`]) or local node
// ([`PeerState::Closing`]) and it was a non-reserved peer
PeerState::Connected { direction: Direction::Inbound(Reserved::No) } |
PeerState::Closing { direction: Direction::Inbound(Reserved::No) } => {
log::trace!(
target: LOG_TARGET,
"{}: inbound substream closed to non-reserved peer {peer:?}: {state:?}",
self.protocol,
);
decrement_or_warn!(
self.num_in,
peer,
self.protocol,
Direction::Inbound(Reserved::No)
);
},
// close was initiated either by remote ([`PeerState::Connected`]) or local node
// ([`PeerState::Closing`]) and it was a non-reserved peer
PeerState::Connected { direction: Direction::Outbound(Reserved::No) } |
PeerState::Closing { direction: Direction::Outbound(Reserved::No) } => {
log::trace!(
target: LOG_TARGET,
"{}: outbound substream closed to non-reserved peer {peer:?} {state:?}",
self.protocol,
);
decrement_or_warn!(
self.num_out,
peer,
self.protocol,
Direction::Outbound(Reserved::No)
);
},
// reserved peers don't require adjustments to slot counts
PeerState::Closing { .. } | PeerState::Connected { .. } => {
log::debug!(target: LOG_TARGET, "{}: reserved peer {peer:?} disconnected", self.protocol);
},
state => {
log::warn!(target: LOG_TARGET, "{}: invalid state for disconnected peer {peer:?}: {state:?}", self.protocol);
debug_assert!(false);
},
}
*state = PeerState::Backoff;
self.connected_peers.fetch_sub(1usize, Ordering::Relaxed);
self.pending_backoffs.push(Box::pin(async move {
Delay::new(DEFAULT_BACKOFF).await;
(peer, DISCONNECT_ADJUSTMENT)
}));
}
/// Report to [`Peerset`] that an inbound substream was opened and that it should validate it.
pub fn report_inbound_substream(&mut self, peer: PeerId) -> ValidationResult {
log::trace!(target: LOG_TARGET, "{}: inbound substream from {peer:?}", self.protocol);
if self.peerstore_handle.is_banned(&peer) {
log::debug!(
target: LOG_TARGET,
"{}: rejecting banned peer {peer:?}",
self.protocol,
);
return ValidationResult::Reject;
}
let state = self.peers.entry(peer).or_insert(PeerState::Disconnected);
let is_reserved_peer = self.reserved_peers.contains(&peer);
match state {
// disconnected peers proceed directly to inbound slot allocation
PeerState::Disconnected => {},
// peer is backed off but if it can be accepted (either a reserved peer or inbound slot
// available), accept the peer and then just ignore the back-off timer when it expires
PeerState::Backoff =>
if !is_reserved_peer && self.num_in == self.max_in {
log::trace!(
target: LOG_TARGET,
"{}: ({peer:?}) is backed-off and cannot accept, reject inbound substream",
self.protocol,
);
return ValidationResult::Reject
},
// `Peerset` had initiated an outbound substream but litep2p had received an inbound
// substream before the command to open the substream was received, meaning local and
// remote desired to open a connection at the same time. Since outbound substreams
// cannot be canceled with litep2p and the command has already been registered, accept
// the inbound peer since the local node had wished a connection to be opened either way
// but keep the direction of the substream as it was (outbound).
//
// litep2p doesn't care what `Peerset` considers the substream direction to be and since
// it's used for bookkeeping for substream counts, keeping the substream direction
// unmodified simplies the implementation a lot. The direction would otherwise be
// irrelevant for protocols but because `SyncingEngine` has a hack to reject excess
// inbound substreams, that system has to be kept working for the time being. Once that
// issue is fixed, this approach can be re-evaluated if need be.
PeerState::Opening { direction: Direction::Outbound(reserved) } => {
log::trace!(
target: LOG_TARGET,
"{}: inbound substream received for {peer:?} ({reserved:?}) that was marked outbound",
self.protocol,
);
return ValidationResult::Accept;
},
PeerState::Canceled { direction } => {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} is canceled, rejecting substream",
self.protocol,
);
*state = PeerState::Canceled { direction: *direction };
return ValidationResult::Reject
},
state => {
log::warn!(
target: LOG_TARGET,
"{}: invalid state ({state:?}) for inbound substream, peer {peer:?}",
self.protocol
);
debug_assert!(false);
return ValidationResult::Reject
},
}
if is_reserved_peer {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} accepting peer as reserved peer",
self.protocol,
);
*state = PeerState::Opening { direction: Direction::Inbound(is_reserved_peer.into()) };
return ValidationResult::Accept
}
if self.num_in < self.max_in {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} accepting peer as regular peer",
self.protocol,
);
self.num_in += 1;
*state = PeerState::Opening { direction: Direction::Inbound(is_reserved_peer.into()) };
return ValidationResult::Accept
}
log::trace!(
target: LOG_TARGET,
"{}: reject {peer:?}, not a reserved peer and no free inbound slots",
self.protocol,
);
*state = PeerState::Disconnected;
return ValidationResult::Reject
}
/// Report to [`Peerset`] that there was an error opening a substream.
pub fn report_substream_open_failure(&mut self, peer: PeerId, error: NotificationError) {
log::trace!(
target: LOG_TARGET,
"{}: failed to open substream to {peer:?}: {error:?}",
self.protocol,
);
match self.peers.get(&peer) {
Some(PeerState::Opening { direction: Direction::Outbound(Reserved::No) }) => {
decrement_or_warn!(
self.num_out,
self.protocol,
peer,
Direction::Outbound(Reserved::No)
);
},
Some(PeerState::Opening { direction: Direction::Inbound(Reserved::No) }) => {
decrement_or_warn!(
self.num_in,
self.protocol,
peer,
Direction::Inbound(Reserved::No)
);
},
Some(PeerState::Canceled { direction }) => match direction {
Direction::Inbound(Reserved::No) => {
decrement_or_warn!(
self.num_in,
self.protocol,
peer,
Direction::Inbound(Reserved::No)
);
},
Direction::Outbound(Reserved::No) => {
decrement_or_warn!(
self.num_out,
self.protocol,
peer,
Direction::Outbound(Reserved::No)
);
},
_ => {},
},
// reserved peers do not require change in the slot counts
Some(PeerState::Opening { direction: Direction::Inbound(Reserved::Yes) }) |
Some(PeerState::Opening { direction: Direction::Outbound(Reserved::Yes) }) => {
log::debug!(
target: LOG_TARGET,
"{}: substream open failure for reserved peer {peer:?}",
self.protocol,
);
},
state => {
log::debug!(
target: LOG_TARGET,
"{}: substream open failure for a unknown state: {state:?}",
self.protocol,
);
return;
},
}
self.peers.insert(peer, PeerState::Backoff);
self.pending_backoffs.push(Box::pin(async move {
Delay::new(OPEN_FAILURE_BACKOFF).await;
(peer, OPEN_FAILURE_ADJUSTMENT)
}));
}
/// [`Peerset`] had accepted a peer but it was then rejected by the protocol.
pub fn report_substream_rejected(&mut self, peer: PeerId) {
log::trace!(target: LOG_TARGET, "{}: {peer:?} rejected by the protocol", self.protocol);
match self.peers.remove(&peer) {
Some(PeerState::Opening { direction }) => match direction {
Direction::Inbound(Reserved::Yes) | Direction::Outbound(Reserved::Yes) => {
log::warn!(
target: LOG_TARGET,
"{}: reserved peer {peer:?} rejected by the protocol",
self.protocol,
);
self.peers.insert(peer, PeerState::Disconnected);
},
Direction::Inbound(Reserved::No) => {
decrement_or_warn!(
self.num_in,
peer,
self.protocol,
Direction::Inbound(Reserved::No)
);
self.peers.insert(peer, PeerState::Disconnected);
},
Direction::Outbound(Reserved::No) => {
decrement_or_warn!(
self.num_out,
peer,
self.protocol,
Direction::Outbound(Reserved::No)
);
self.peers.insert(peer, PeerState::Disconnected);
},
},
Some(state @ PeerState::Canceled { .. }) => {
log::debug!(
target: LOG_TARGET,
"{}: substream to {peer:?} rejected by protocol but already canceled",
self.protocol,
);
self.peers.insert(peer, state);
},
Some(state) => {
log::debug!(
target: LOG_TARGET,
"{}: {peer:?} rejected by the protocol but not opening anymore: {state:?}",
self.protocol,
);
self.peers.insert(peer, state);
},
None => {},
}
}
/// Calculate how many of the connected peers were counted as normal inbound/outbound peers
/// which is needed to adjust slot counts when new reserved peers are added
fn calculate_slot_adjustment<'a>(
&'a mut self,
peers: impl Iterator<Item = &'a PeerId>,
) -> (usize, usize) {
peers.fold((0, 0), |(mut inbound, mut outbound), peer| {
match self.peers.get_mut(peer) {
Some(PeerState::Disconnected | PeerState::Backoff) => {},
Some(
PeerState::Opening { ref mut direction } |
PeerState::Connected { ref mut direction } |
PeerState::Canceled { ref mut direction } |
PeerState::Closing { ref mut direction },
) => {
*direction = match direction {
Direction::Inbound(Reserved::No) => {
inbound += 1;
Direction::Inbound(Reserved::Yes)
},
Direction::Outbound(Reserved::No) => {
outbound += 1;
Direction::Outbound(Reserved::Yes)
},
ref direction => **direction,
};
},
None => {
self.peers.insert(*peer, PeerState::Disconnected);
},
}
(inbound, outbound)
})
}
/// Get the number of inbound peers.
#[cfg(test)]
pub fn num_in(&self) -> usize {
self.num_in
}
/// Get the number of outbound peers.
#[cfg(test)]
pub fn num_out(&self) -> usize {
self.num_out
}
/// Get reference to known peers.
#[cfg(test)]
pub fn peers(&self) -> &HashMap<PeerId, PeerState> {
&self.peers
}
/// Get reference to reserved peers.
#[cfg(test)]
pub fn reserved_peers(&self) -> &HashSet<PeerId> {
&self.reserved_peers
}
}
impl Stream for Peerset {
type Item = PeersetNotificationCommand;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
while let Poll::Ready(Some((peer, reputation))) = self.pending_backoffs.poll_next_unpin(cx)
{
log::trace!(target: LOG_TARGET, "{}: backoff expired for {peer:?}", self.protocol);
if std::matches!(self.peers.get(&peer), None | Some(PeerState::Backoff)) {
self.peers.insert(peer, PeerState::Disconnected);
}
self.peerstore_handle.report_peer(peer, reputation);
}
if let Poll::Ready(Some(action)) = Pin::new(&mut self.cmd_rx).poll_next(cx) {
match action {
PeersetCommand::DisconnectPeer { peer } if !self.reserved_peers.contains(&peer) =>
match self.peers.remove(&peer) {
Some(PeerState::Connected { direction }) => {
log::trace!(
target: LOG_TARGET,
"{}: close connection to {peer:?}, direction {direction:?}",
self.protocol,
);
self.peers.insert(peer, PeerState::Closing { direction });
return Poll::Ready(Some(PeersetNotificationCommand::CloseSubstream {
peers: vec![peer],
}))
},
Some(PeerState::Backoff) => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect {peer:?}, already backed-off",
self.protocol,
);
self.peers.insert(peer, PeerState::Backoff);
},
// substream might have been opening but not yet fully open when the
// protocol or `Peerstore` request the connection to be closed
//
// if the substream opens successfully, close it immediately and mark the
// peer as `Disconnected`
Some(PeerState::Opening { direction }) => {
log::trace!(
target: LOG_TARGET,
"{}: canceling substream to disconnect peer {peer:?}",
self.protocol,
);
self.peers.insert(peer, PeerState::Canceled { direction });
},
// protocol had issued two disconnection requests in rapid succession and
// the substream hadn't closed before the second disconnection request was
// received, this is harmless and can be ignored.
Some(state @ PeerState::Closing { .. }) => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect {peer:?}, already closing ({state:?})",
self.protocol,
);
self.peers.insert(peer, state);
},
// if peer is banned, e.g. due to genesis mismatch, `Peerstore` will issue a
// global disconnection request to all protocols, irrespective of the
// connectivity state. Peer isn't necessarily connected to all protocols at
// all times so this is a harmless state to be in if a disconnection request
// is received.
Some(state @ PeerState::Disconnected) => {
self.peers.insert(peer, state);
},
// peer had an opening substream earlier which was canceled and then,
// e.g., the peer was banned which caused it to be disconnected again
Some(state @ PeerState::Canceled { .. }) => {
log::debug!(
target: LOG_TARGET,
"{}: cannot disconnect {peer:?}, already canceled ({state:?})",
self.protocol,
);
self.peers.insert(peer, state);
},
// peer doesn't exist
//
// this can happen, for example, when peer connects over
// `/block-announces/1` and it has wrong genesis hash which initiates a ban
// for that peer. Since the ban is reported to all protocols but the peer
// mightn't have been registered to GRANDPA or transactions yet, the peer
// doesn't exist in their `Peerset`s and the error can just be ignored.
None => {
log::debug!(target: LOG_TARGET, "{}: {peer:?} doesn't exist", self.protocol);
},
},
PeersetCommand::DisconnectPeer { peer } => {
log::debug!(
target: LOG_TARGET,
"{}: ignoring disconnection request for reserved peer {peer}",
self.protocol,
);
},
// set new reserved peers for the protocol
//
// current reserved peers not in the new set are disconnected and the new reserved
// peers are scheduled for outbound substreams
PeersetCommand::SetReservedPeers { peers } => {
log::debug!(target: LOG_TARGET, "{}: set reserved peers {peers:?}", self.protocol);
// reserved peers don't consume any slots so if there are any regular connected
// peers, inbound/outbound slot count must be adjusted to not account for these
// peers anymore
//
// calculate how many of the previously connected peers were counted as regular
// peers and substract these counts from `num_out`/`num_in`
let (in_peers, out_peers) = self.calculate_slot_adjustment(peers.iter());
self.num_out -= out_peers;
self.num_in -= in_peers;
// add all unknown peers to `self.peers`
peers.iter().for_each(|peer| {
if !self.peers.contains_key(peer) {
self.peers.insert(*peer, PeerState::Disconnected);
}
});
// collect all peers who are not in the new reserved set
let peers_to_remove = self
.peers
.iter()
.filter_map(|(peer, _)| (!peers.contains(peer)).then_some(*peer))
.collect::<HashSet<_>>();
self.reserved_peers = peers;
let peers = peers_to_remove
.into_iter()
.filter(|peer| {
match self.peers.remove(&peer) {
Some(PeerState::Connected { direction }) => {
log::trace!(
target: LOG_TARGET,
"{}: close connection to {peer:?}, direction {direction:?}",
self.protocol,
);
self.peers.insert(*peer, PeerState::Closing { direction });
true
},
// substream might have been opening but not yet fully open when
// the protocol request the reserved set to be changed
Some(PeerState::Opening { direction }) => {
log::trace!(
target: LOG_TARGET,
"{}: cancel substream to {peer:?}, direction {direction:?}",
self.protocol,
);
self.peers.insert(*peer, PeerState::Canceled { direction });
false
},
Some(state) => {
self.peers.insert(*peer, state);
false
},
None => {
log::debug!(target: LOG_TARGET, "{}: {peer:?} doesn't exist", self.protocol);
debug_assert!(false);
false
},
}
})
.collect();
log::trace!(
target: LOG_TARGET,
"{}: close substreams to {peers:?}",
self.protocol,
);
return Poll::Ready(Some(PeersetNotificationCommand::CloseSubstream { peers }))
},
PeersetCommand::AddReservedPeers { peers } => {
log::debug!(target: LOG_TARGET, "{}: add reserved peers {peers:?}", self.protocol);
// reserved peers don't consume any slots so if there are any regular connected
// peers, inbound/outbound slot count must be adjusted to not account for these
// peers anymore
//
// calculate how many of the previously connected peers were counted as regular
// peers and substract these counts from `num_out`/`num_in`
let (in_peers, out_peers) = self.calculate_slot_adjustment(peers.iter());
self.num_out -= out_peers;
self.num_in -= in_peers;
let peers = peers
.iter()
.filter_map(|peer| {
if !self.reserved_peers.insert(*peer) {
log::warn!(
target: LOG_TARGET,
"{}: {peer:?} is already a reserved peer",
self.protocol,
);
return None
}
std::matches!(
self.peers.get_mut(peer),
None | Some(PeerState::Disconnected)
)
.then(|| {
self.peers.insert(
*peer,
PeerState::Opening {
direction: Direction::Outbound(Reserved::Yes),
},
);
*peer
})
})
.collect();
log::debug!(target: LOG_TARGET, "{}: start connecting to {peers:?}", self.protocol);
return Poll::Ready(Some(PeersetNotificationCommand::OpenSubstream { peers }))
},
PeersetCommand::RemoveReservedPeers { peers } => {
log::debug!(target: LOG_TARGET, "{}: remove reserved peers {peers:?}", self.protocol);
let peers_to_remove = peers
.iter()
.filter_map(|peer| {
if !self.reserved_peers.remove(peer) {
log::debug!(
target: LOG_TARGET,
"{}: {peer} is not a reserved peer",
self.protocol,
);
return None
}
match self.peers.remove(peer)? {
// peer might have already disconnected by the time request to
// disconnect them was received and the peer was backed off but
// it had no expired by the time the request to disconnect the
// peer was received
PeerState::Backoff => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect removed reserved peer {peer:?}, already backed-off",
self.protocol,
);
self.peers.insert(*peer, PeerState::Backoff);
None
},
// if there is a rapid change in substream state, the peer may
// be canceled when the substream is asked to be closed.
//
// this can happen if substream is first opened and the very
// soon after canceled. The substream may not have had time to
// open yet and second open is ignored. If the substream is now
// closed again before it has had time to open, it will be in
// canceled state since `Peerset` is still waiting to hear
// either success/failure on the original substream it tried to
// cancel.
PeerState::Canceled { direction } => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect removed reserved peer {peer:?}, already canceled",
self.protocol,
);
self.peers.insert(*peer, PeerState::Canceled { direction });
None
},
// substream to the peer might have failed to open which caused
// the peer to be backed off
//
// the back-off might've expired by the time the peer was
// disconnected at which point the peer is already disconnected
// when the protocol asked the peer to be disconnected
PeerState::Disconnected => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect removed reserved peer {peer:?}, already disconnected",
self.protocol,
);
self.peers.insert(*peer, PeerState::Disconnected);
None
},
// if a node disconnects, it's put into `PeerState::Closing`
// which indicates that `Peerset` wants the substream closed and
// has asked litep2p to close it but it hasn't yet received a
// confirmation. If the peer is added as a reserved peer while
// the substream is closing, the peer will remain in the closing
// state as `Peerset` can't do anything with the peer until it
// has heard from litep2p. It's possible that the peer is then
// removed from the reserved set before substream close event
// has been reported to `Peerset` (which the code below is
// handling) and it will once again be ignored until the close
// event is heard from litep2p.
PeerState::Closing { direction } => {
log::trace!(
target: LOG_TARGET,
"{}: cannot disconnect removed reserved peer {peer:?}, already closing",
self.protocol,
);
self.peers.insert(*peer, PeerState::Closing { direction });
None
},
// peer is currently connected as a reserved peer
//
// check if the peer can be accepted as a regular peer based on its
// substream direction and available slots
//
// if there are enough slots, the peer is just converted to
// a regular peer and the used slot count is increased and if the
// peer cannot be accepted, litep2p is asked to close the substream.
PeerState::Connected { direction } => match direction {
Direction::Inbound(_) => match self.num_in < self.max_in {
true => {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} converted to regular inbound peer (inbound open)",
self.protocol,
);
self.num_in += 1;
self.peers.insert(
*peer,
PeerState::Connected {
direction: Direction::Inbound(Reserved::No),
},
);
None
},
false => {
self.peers.insert(
*peer,
PeerState::Closing {
direction: Direction::Inbound(Reserved::Yes),
},
);
Some(*peer)
},
},
Direction::Outbound(_) => match self.num_out < self.max_out {
true => {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} converted to regular outbound peer (outbound open)",
self.protocol,
);
self.num_out += 1;
self.peers.insert(
*peer,
PeerState::Connected {
direction: Direction::Outbound(Reserved::No),
},
);
None
},
false => {
self.peers.insert(
*peer,
PeerState::Closing {
direction: Direction::Outbound(Reserved::Yes),
},
);
Some(*peer)
},
},
},
PeerState::Opening { direction } => match direction {
Direction::Inbound(_) => match self.num_in < self.max_in {
true => {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} converted to regular inbound peer (inbound opening)",
self.protocol,
);
self.num_in += 1;
self.peers.insert(
*peer,
PeerState::Opening {
direction: Direction::Inbound(Reserved::No),
},
);
None
},
false => {
self.peers.insert(
*peer,
PeerState::Canceled {
direction: Direction::Inbound(Reserved::Yes),
},
);
None
},
},
Direction::Outbound(_) => match self.num_out < self.max_out {
true => {
log::trace!(
target: LOG_TARGET,
"{}: {peer:?} converted to regular outbound peer (outbound opening)",
self.protocol,
);
self.num_out += 1;
self.peers.insert(
*peer,
PeerState::Opening {
direction: Direction::Outbound(Reserved::No),
},
);
None
},
false => {
self.peers.insert(
*peer,
PeerState::Canceled {
direction: Direction::Outbound(Reserved::Yes),
},
);
None
},
},
},
}
})
.collect();
log::debug!(
target: LOG_TARGET,
"{}: close substreams to {peers_to_remove:?}",
self.protocol,
);
return Poll::Ready(Some(PeersetNotificationCommand::CloseSubstream {
peers: peers_to_remove,
}))
},
PeersetCommand::SetReservedOnly { reserved_only } => {
log::debug!(target: LOG_TARGET, "{}: set reserved only mode to {reserved_only}", self.protocol);
// update mode and if it's set to true, disconnect all non-reserved peers
self.reserved_only = reserved_only;
if reserved_only {
let peers_to_remove = self
.peers
.iter()
.filter_map(|(peer, state)| {
(!self.reserved_peers.contains(peer) &&
std::matches!(state, PeerState::Connected { .. }))
.then_some(*peer)
})
.collect::<Vec<_>>();
// set peers to correct states
// peers who are connected are move to [`PeerState::Closing`]
// and peers who are already opening are moved to [`PeerState::Canceled`]
// and if the substream for them opens, it will be closed right after.
self.peers.iter_mut().for_each(|(_, state)| match state {
PeerState::Connected { direction } => {
*state = PeerState::Closing { direction: *direction };
},
// peer for whom a substream was opening are canceled and if the
// substream opens successfully, it will be closed immediately
PeerState::Opening { direction } => {
*state = PeerState::Canceled { direction: *direction };
},
_ => {},
});
return Poll::Ready(Some(PeersetNotificationCommand::CloseSubstream {
peers: peers_to_remove,
}))
}
},
PeersetCommand::GetReservedPeers { tx } => {
let _ = tx.send(self.reserved_peers.iter().cloned().collect());
},
}
}
// periodically check if `Peerset` is currently not connected to some reserved peers
// it should be connected to
//
// also check if there are free outbound slots and if so, fetch peers with highest
// reputations from `Peerstore` and start opening substreams to these peers
if let Poll::Ready(()) = Pin::new(&mut self.next_slot_allocation).poll(cx) {
let mut connect_to = self
.peers
.iter()
.filter_map(|(peer, state)| {
(self.reserved_peers.contains(peer) &&
std::matches!(state, PeerState::Disconnected) &&
!self.peerstore_handle.is_banned(peer))
.then_some(*peer)
})
.collect::<Vec<_>>();
connect_to.iter().for_each(|peer| {
self.peers.insert(
*peer,
PeerState::Opening { direction: Direction::Outbound(Reserved::Yes) },
);
});
// if the number of outbound peers is lower than the desired amount of outbound peers,
// query `PeerStore` and try to get a new outbound candidated.
if self.num_out < self.max_out && !self.reserved_only {
let ignore: HashSet<PeerId> = self
.peers
.iter()
.filter_map(|(peer, state)| {
(!std::matches!(state, PeerState::Disconnected)).then_some(*peer)
})
.collect();
let peers: Vec<_> =
self.peerstore_handle.outgoing_candidates(self.max_out - self.num_out, ignore);
if peers.len() > 0 {
peers.iter().for_each(|peer| {
self.peers.insert(
*peer,
PeerState::Opening { direction: Direction::Outbound(Reserved::No) },
);
});
self.num_out += peers.len();
connect_to.extend(peers);
}
}
// start timer for the next allocation and if there were peers which the `Peerset`
// wasn't connected but should be, send command to litep2p to start opening substreams.
self.next_slot_allocation = Delay::new(SLOT_ALLOCATION_FREQUENCY);
if !connect_to.is_empty() {
log::trace!(
target: LOG_TARGET,
"{}: start connecting to peers {connect_to:?}",
self.protocol,
);
return Poll::Ready(Some(PeersetNotificationCommand::OpenSubstream {
peers: connect_to,
}))
}
}
Poll::Pending
}
}