From 3dab94be9f4cc500652fb0f9f97914da7be21794 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Thu, 7 Jun 2018 10:58:24 -0500
Subject: [PATCH] keep dht peers alive

---
 src/yggdrasil/dht.go    |  2 +-
 src/yggdrasil/peer.go   | 33 +++++++++++++++++----------------
 src/yggdrasil/router.go |  1 +
 src/yggdrasil/switch.go |  3 ++-
 4 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/src/yggdrasil/dht.go b/src/yggdrasil/dht.go
index e59017a..3c9f61c 100644
--- a/src/yggdrasil/dht.go
+++ b/src/yggdrasil/dht.go
@@ -81,7 +81,7 @@ type dht struct {
 func (t *dht) init(c *Core) {
 	t.core = c
 	t.nodeID = *t.core.GetNodeID()
-	t.peers = make(chan *dhtInfo, 1)
+	t.peers = make(chan *dhtInfo, 1024)
 	t.reqs = make(map[boxPubKey]map[NodeID]time.Time)
 }
 
diff --git a/src/yggdrasil/peer.go b/src/yggdrasil/peer.go
index ce5cd0c..00f8a9c 100644
--- a/src/yggdrasil/peer.go
+++ b/src/yggdrasil/peer.go
@@ -107,8 +107,8 @@ type peer struct {
 	lastAnc time.Time // TODO? rename and use this
 	// used for protocol traffic (to bypass queues)
 	linkOut (chan []byte)
-	lastMsg []byte          // last switchMsg accepted
 	doSend  (chan struct{}) // tell the linkLoop to send a switchMsg
+	dinfo   *dhtInfo        // used to keep the DHT working
 }
 
 const peer_Throttle = 1
@@ -186,21 +186,22 @@ func (ps *peers) sendSwitchMsgs() {
 	}
 }
 
-func (ps *peers) fixSwitchAfterPeerDisconnect() {
-	// TODO something better, this is very wasteful
-	ports := ps.getPorts()
-	for _, p := range ports {
-		if p.lastMsg == nil {
-			continue
-		}
-		p.handleSwitchMsg(p.lastMsg)
-	}
-}
-
 func (p *peer) linkLoop() {
 	go func() { p.doSend <- struct{}{} }()
-	for range p.doSend {
-		p.sendSwitchMsg()
+	tick := time.NewTicker(time.Second)
+	defer tick.Stop()
+	for {
+		select {
+		case _, ok := <-p.doSend:
+			if !ok {
+				return
+			}
+			p.sendSwitchMsg()
+		case _ = <-tick.C:
+			if p.dinfo != nil {
+				p.core.dht.peers <- p.dinfo
+			}
+		}
 	}
 }
 
@@ -224,7 +225,7 @@ func (p *peer) handlePacket(packet []byte) {
 }
 
 func (p *peer) handleTraffic(packet []byte, pTypeLen int) {
-	if p.port != 0 && p.lastMsg == nil {
+	if p.port != 0 && p.dinfo == nil {
 		// Drop traffic until the peer manages to send us at least one good switchMsg
 		return
 	}
@@ -356,7 +357,7 @@ func (p *peer) handleSwitchMsg(packet []byte) {
 		coords: l.getCoords(),
 	}
 	p.core.dht.peers <- &dinfo
-	p.lastMsg = packet
+	p.dinfo = &dinfo
 }
 
 func getBytesForSig(next *sigPubKey, loc *switchLocator) []byte {
diff --git a/src/yggdrasil/router.go b/src/yggdrasil/router.go
index 872a473..3246f63 100644
--- a/src/yggdrasil/router.go
+++ b/src/yggdrasil/router.go
@@ -93,6 +93,7 @@ func (r *router) mainLoop() {
 				// Any periodic maintenance stuff goes here
 				r.core.switchTable.doMaintenance()
 				r.core.dht.doMaintenance()
+				//r.core.peers.fixSwitchAfterPeerDisconnect() // FIXME makes sure dht peers get added quickly
 				util_getBytes() // To slowly drain things
 			}
 		case f := <-r.admin:
diff --git a/src/yggdrasil/switch.go b/src/yggdrasil/switch.go
index a9a0fcd..fec47af 100644
--- a/src/yggdrasil/switch.go
+++ b/src/yggdrasil/switch.go
@@ -230,7 +230,7 @@ func (t *switchTable) cleanRoot() {
 func (t *switchTable) removePeer(port switchPort) {
 	delete(t.data.peers, port)
 	t.updater.Store(&sync.Once{})
-	t.core.peers.fixSwitchAfterPeerDisconnect()
+	// TODO if parent, find a new peer to use as parent instead
 }
 
 func (t *switchTable) cleanDropped() {
@@ -287,6 +287,7 @@ func (t *switchTable) handleMessage(msg *switchMessage, fromPort switchPort, sig
 	doUpdate := false
 	if !equiv(&msg.locator, &oldSender.locator) {
 		doUpdate = true
+		//sender.firstSeen = now // TODO? uncomment to prevent flapping?
 	}
 	t.data.peers[fromPort] = sender
 	updateRoot := false