feat(p2p): added helpers to count relays found in peerstore, check if…

… they're connected and reconnect to them

core/network/p2p/relay_conn.go

@@ -0,0 +1,56 @@
+package p2p
+
+import (
+	"context"
+
+	host "github.com/libp2p/go-libp2p-host"
+	inet "github.com/libp2p/go-libp2p-net"
+	peer "github.com/libp2p/go-libp2p-peer"
+)
+
+func getRelaysFromPeerstore(host host.Host) peer.IDSlice {
+	var relays peer.IDSlice
+	peers := host.Peerstore().Peers()
+
+	for _, peer := range peers {
+		tags := host.ConnManager().GetTagInfo(peer)
+		if tags != nil {
+			val, exist := tags.Tags["relay-hop"]
+			if exist && val == 2 {
+				relays = append(relays, peer)
+			}
+		}
+	}
+
+	return relays
+}
+
+func CountConnectedRelays(host host.Host) int {
+	relays := getRelaysFromPeerstore(host)
+	connectedRelays := 0
+
+	for _, relay := range relays {
+		if host.Network().Connectedness(relay) == inet.Connected {
+			connectedRelays++
+		}
+	}
+
+	return connectedRelays
+}
+
+func ReconnectToRelays(host host.Host, limit int) int {
+	connectedRelays := 0
+	relays := getRelaysFromPeerstore(host)
+
+	for _, relay := range relays {
+		relayInfo := host.Peerstore().PeerInfo(relay)
+		if host.Connect(context.Background(), relayInfo) == nil {
+			connectedRelays++
+			if connectedRelays == limit {
+				break
+			}
+		}
+	}
+
+	return connectedRelays
+}