Add PeerManager::disconnect_all_peers to avoid complexity in BP

In the coming commits simply calling `timer_tick_occurred` will no
longer disconnect all peers, so its helpful to have a utility
method.

Author: TheBlueMatt

lightning-background-processor/src/lib.rs

@@ -14,8 +14,7 @@ use lightning::chain::chainmonitor::{ChainMonitor, Persist};
 use lightning::chain::keysinterface::{Sign, KeysInterface};
 use lightning::ln::channelmanager::ChannelManager;
 use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
-use lightning::ln::peer_handler::{PeerManager, SocketDescriptor};
-use lightning::ln::peer_handler::CustomMessageHandler;
+use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
 use lightning::routing::network_graph::NetGraphMsgHandler;
 use lightning::util::events::{Event, EventHandler, EventsProvider};
 use lightning::util::logger::Logger;
@@ -236,8 +235,7 @@ impl BackgroundProcessor {
 					// timer, we should have disconnected all sockets by now (and they're probably
 					// dead anyway), so disconnect them by calling `timer_tick_occurred()` twice.
 					log_trace!(logger, "Awoke after more than double our ping timer, disconnecting peers.");
-					peer_manager.timer_tick_occurred();
-					peer_manager.timer_tick_occurred();
+					peer_manager.disconnect_all_peers();
 					last_ping_call = Instant::now();
 				} else if last_ping_call.elapsed().as_secs() > PING_TIMER {
 					log_trace!(logger, "Calling PeerManager's timer_tick_occurred");

lightning/src/ln/peer_handler.rs

@@ -1431,6 +1431,23 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		}
 	}
 
+	/// Disconnects all currently-connected peers. This is useful on platforms where there may be
+	/// an indication that TCP sockets have stalled even if we weren't around to time them out
+	/// using regular ping/pongs.
+	pub fn disconnect_all_peers(&self) {
+		let mut peers_lock = self.peers.lock().unwrap();
+		let peers = &mut *peers_lock;
+		for (mut descriptor, peer) in peers.peers.drain() {
+			if let Some(node_id) = peer.their_node_id {
+				log_trace!(self.logger, "Disconnecting peer with id {} due to client request to disconnect all peers", node_id);
+				peers.node_id_to_descriptor.remove(&node_id);
+				self.message_handler.chan_handler.peer_disconnected(&node_id, false);
+			}
+			descriptor.disconnect_socket();
+		}
+		debug_assert!(peers.node_id_to_descriptor.is_empty());
+	}
+
 	/// Send pings to each peer and disconnect those which did not respond to the last round of
 	/// pings.
 	///