From 3d4b49b6933a539052dc72131ef497a8fe2d7d48 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Mon, 3 Dec 2018 19:21:23 -0600
Subject: [PATCH] reset the switch speed info for a peer whenever it changes
 coords, instead of only if they're a parent and change coords. Also, make
 sure packets in the sim preserve order when sending, to avoid races when
 testing

---
 src/yggdrasil/debug.go  | 54 ++++++++++++++++++++++++++---------------
 src/yggdrasil/switch.go | 28 ++++++++++-----------
 2 files changed, 48 insertions(+), 34 deletions(-)

diff --git a/src/yggdrasil/debug.go b/src/yggdrasil/debug.go
index 91f5770..7da8474 100644
--- a/src/yggdrasil/debug.go
+++ b/src/yggdrasil/debug.go
@@ -504,27 +504,43 @@ func (c *Core) DEBUG_addAllowedEncryptionPublicKey(boxStr string) {
 
 func DEBUG_simLinkPeers(p, q *peer) {
 	// Sets q.out() to point to p and starts p.linkLoop()
-	p.linkOut, q.linkOut = make(chan []byte, 1), make(chan []byte, 1)
-	go func() {
-		for bs := range p.linkOut {
-			q.handlePacket(bs)
+	goWorkers := func(source, dest *peer) {
+		source.linkOut = make(chan []byte, 1)
+		send := make(chan []byte, 1)
+		source.out = func(bs []byte) {
+			send <- bs
 		}
-	}()
-	go func() {
-		for bs := range q.linkOut {
-			p.handlePacket(bs)
-		}
-	}()
-	p.out = func(bs []byte) {
-		p.core.switchTable.idleIn <- p.port
-		go q.handlePacket(bs)
+		go source.linkLoop()
+		go func() {
+			var packets [][]byte
+			for {
+				select {
+				case packet := <-source.linkOut:
+					packets = append(packets, packet)
+					continue
+				case packet := <-send:
+					packets = append(packets, packet)
+					source.core.switchTable.idleIn <- source.port
+					continue
+				default:
+				}
+				if len(packets) > 0 {
+					dest.handlePacket(packets[0])
+					packets = packets[1:]
+					continue
+				}
+				select {
+				case packet := <-source.linkOut:
+					packets = append(packets, packet)
+				case packet := <-send:
+					packets = append(packets, packet)
+					source.core.switchTable.idleIn <- source.port
+				}
+			}
+		}()
 	}
-	q.out = func(bs []byte) {
-		q.core.switchTable.idleIn <- q.port
-		go p.handlePacket(bs)
-	}
-	go p.linkLoop()
-	go q.linkLoop()
+	goWorkers(p, q)
+	goWorkers(q, p)
 	p.core.switchTable.idleIn <- p.port
 	q.core.switchTable.idleIn <- q.port
 }
diff --git a/src/yggdrasil/switch.go b/src/yggdrasil/switch.go
index b04578c..9966103 100644
--- a/src/yggdrasil/switch.go
+++ b/src/yggdrasil/switch.go
@@ -377,6 +377,11 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 	doUpdate := false
 	oldSender := t.data.peers[fromPort]
 	if !equiv(&sender.locator, &oldSender.locator) {
+		// Reset faster info, we'll start refilling it right after this
+		sender.faster = nil
+		for _, peer := range t.data.peers {
+			delete(peer.faster, sender.port)
+		}
 		doUpdate = true
 	}
 	// Update the matrix of peer "faster" thresholds
@@ -387,25 +392,20 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 		for port, peer := range t.data.peers {
 			if port == fromPort {
 				continue
-			}
-			switch {
-			case msg.Root != peer.locator.root:
-				// Different roots, blindly guess that the relationships will stay the same?
-				sender.faster[port] = oldSender.faster[peer.port]
-			case sender.locator.tstamp <= peer.locator.tstamp:
-				// Slower than this node, penalize (more than the reward amount)
-				if oldSender.faster[port] > 1 {
-					sender.faster[port] = oldSender.faster[peer.port] - 2
-				} else {
-					sender.faster[port] = 0
-				}
-			default:
+			} else if sender.locator.root != peer.locator.root || sender.locator.tstamp > peer.locator.tstamp {
 				// We were faster than this node, so increment, as long as we don't overflow because of it
 				if oldSender.faster[peer.port] < switch_faster_threshold {
 					sender.faster[port] = oldSender.faster[peer.port] + 1
 				} else {
 					sender.faster[port] = switch_faster_threshold
 				}
+			} else {
+				// Slower than this node, penalize (more than the reward amount)
+				if oldSender.faster[port] > 1 {
+					sender.faster[port] = oldSender.faster[peer.port] - 2
+				} else {
+					sender.faster[port] = 0
+				}
 			}
 		}
 	}
@@ -457,12 +457,10 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 		// First, reset all faster-related info to 0.
 		// Then, de-parent the node and reprocess all messages to find a new parent.
 		t.parent = 0
-		sender.faster = nil
 		for _, peer := range t.data.peers {
 			if peer.port == sender.port {
 				continue
 			}
-			delete(peer.faster, sender.port)
 			t.unlockedHandleMsg(&peer.msg, peer.port, true)
 		}
 		// Process the sender last, to avoid keeping them as a parent if at all possible.