Keep track of basic aliveness for peers regardless if direct or indirect connectivity and use this for multicast propagation. Also consolidate adding of active bridges via the same functor as regular multicast next hops.

node/Peer.cpp

@@ -35,6 +35,7 @@ namespace ZeroTier {
 
 Peer::Peer() :
 	_lastUsed(0),
+	_lastReceive(0),
 	_lastUnicastFrame(0),
 	_lastMulticastFrame(0),
 	_lastAnnouncedTo(0),
@@ -47,6 +48,7 @@ Peer::Peer(const Identity &myIdentity,const Identity &peerIdentity)
 	throw(std::runtime_error) :
 	_id(peerIdentity),
 	_lastUsed(0),
+	_lastReceive(0),
 	_lastUnicastFrame(0),
 	_lastMulticastFrame(0),
 	_lastAnnouncedTo(0),
@@ -73,6 +75,9 @@ void Peer::receive(
 	// Update system-wide last packet receive time
 	*((const_cast<uint64_t *>(&(_r->timeOfLastPacketReceived)))) = now;
 
+	// Global last receive time regardless of path
+	_lastReceive = now;
+
 	// Learn paths from direct packets (hops == 0)
 	if (!hops) {
 		{