From e9adf327b019482beb98eb2a86809a67999e8fa0 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Wed, 7 Feb 2018 17:48:30 -0600
Subject: [PATCH] possibly fix deadlock from race in peer linkloop goroutine,
 add some related debug code to the admin

---
 src/yggdrasil/admin.go  | 27 +++++++++++++++++++++++++--
 src/yggdrasil/router.go | 37 ++++++++++++++-----------------------
 src/yggdrasil/tcp.go    | 11 ++++-------
 src/yggdrasil/udp.go    | 11 ++++-------
 4 files changed, 47 insertions(+), 39 deletions(-)

diff --git a/src/yggdrasil/admin.go b/src/yggdrasil/admin.go
index 419d7f1e..63b6d60d 100644
--- a/src/yggdrasil/admin.go
+++ b/src/yggdrasil/admin.go
@@ -41,11 +41,14 @@ func (a *admin) init(c *Core, listenaddr string) {
 		*out = a.getResponse_dot()
 	})
 	a.addHandler("getSelf", nil, func(out *[]byte, _ ...string) {
-		*out = []byte(a.printInfos(a.getData_getPeers()))
+		*out = []byte(a.printInfos([]admin_nodeInfo{*a.getData_getSelf()}))
 	})
 	a.addHandler("getPeers", nil, func(out *[]byte, _ ...string) {
 		*out = []byte(a.printInfos(a.getData_getPeers()))
 	})
+	a.addHandler("getSwitchPeers", nil, func(out *[]byte, _ ...string) {
+		*out = []byte(a.printInfos(a.getData_getSwitchPeers()))
+	})
 	a.addHandler("getDHT", nil, func(out *[]byte, _ ...string) {
 		*out = []byte(a.printInfos(a.getData_getDHT()))
 	})
@@ -152,6 +155,26 @@ func (a *admin) getData_getSelf() *admin_nodeInfo {
 }
 
 func (a *admin) getData_getPeers() []admin_nodeInfo {
+	ports := a.core.peers.ports.Load().(map[switchPort]*peer)
+	var peerInfos []admin_nodeInfo
+	var ps []switchPort
+	for port := range ports {
+		ps = append(ps, port)
+	}
+	sort.Slice(ps, func(i, j int) bool { return ps[i] < ps[j] })
+	for _, port := range ps {
+		p := ports[port]
+		addr := *address_addrForNodeID(getNodeID(&p.box))
+		info := admin_nodeInfo{
+			{"IP", net.IP(addr[:]).String()},
+			{"port", fmt.Sprint(port)},
+		}
+		peerInfos = append(peerInfos, info)
+	}
+	return peerInfos
+}
+
+func (a *admin) getData_getSwitchPeers() []admin_nodeInfo {
 	var peerInfos []admin_nodeInfo
 	table := a.core.switchTable.table.Load().(lookupTable)
 	peers := a.core.peers.ports.Load().(map[switchPort]*peer)
@@ -211,7 +234,7 @@ func (a *admin) getData_getSessions() []admin_nodeInfo {
 func (a *admin) getResponse_dot() []byte {
 	self := a.getData_getSelf().asMap()
 	myAddr := self["IP"]
-	peers := a.getData_getPeers()
+	peers := a.getData_getSwitchPeers()
 	dht := a.getData_getDHT()
 	sessions := a.getData_getSessions()
 	// Map of coords onto IP
diff --git a/src/yggdrasil/router.go b/src/yggdrasil/router.go
index 5c02943c..15e2ff3c 100644
--- a/src/yggdrasil/router.go
+++ b/src/yggdrasil/router.go
@@ -41,17 +41,15 @@ type router struct {
 func (r *router) init(core *Core) {
 	r.core = core
 	r.addr = *address_addrForNodeID(&r.core.dht.nodeID)
-	in := make(chan []byte, 32)                             // TODO something better than this...
+	in := make(chan []byte, 32)                               // TODO something better than this...
 	p := r.core.peers.newPeer(&r.core.boxPub, &r.core.sigPub) //, out, in)
 	p.out = func(packet []byte) {
 		// This is to make very sure it never blocks
-		for {
-			select {
-			case in <- packet:
-				return
-			default:
-				util_putBytes(<-in)
-			}
+		select {
+		case in <- packet:
+			return
+		default:
+			util_putBytes(packet)
 		}
 	}
 	r.in = in
@@ -147,13 +145,10 @@ func (r *router) sendPacket(bs []byte) {
 		fallthrough
 	//default: go func() { sinfo.send<-bs }()
 	default:
-		for {
-			select {
-			case sinfo.send <- bs:
-				return
-			default:
-				util_putBytes(<-sinfo.send)
-			}
+		select {
+		case sinfo.send <- bs:
+		default:
+			util_putBytes(bs)
 		}
 	}
 }
@@ -191,7 +186,6 @@ func (r *router) handleIn(packet []byte) {
 	case wire_ProtocolTraffic:
 		r.handleProto(packet)
 	default: /*panic("Should not happen in testing") ;*/
-		return
 	}
 }
 
@@ -206,13 +200,10 @@ func (r *router) handleTraffic(packet []byte) {
 		return
 	}
 	//go func () { sinfo.recv<-&p }()
-	for {
-		select {
-		case sinfo.recv <- &p:
-			return
-		default:
-			util_putBytes((<-sinfo.recv).payload)
-		}
+	select {
+	case sinfo.recv <- &p:
+	default:
+		util_putBytes(p.payload)
 	}
 }
 
diff --git a/src/yggdrasil/tcp.go b/src/yggdrasil/tcp.go
index ad9139a6..a190679f 100644
--- a/src/yggdrasil/tcp.go
+++ b/src/yggdrasil/tcp.go
@@ -176,13 +176,10 @@ func (iface *tcpInterface) handler(sock *net.TCPConn) {
 	}()
 	p.out = func(msg []byte) {
 		defer func() { recover() }()
-		for {
-			select {
-			case out <- msg:
-				return
-			default:
-				util_putBytes(<-out)
-			}
+		select {
+		case out <- msg:
+		default:
+			util_putBytes(msg)
 		}
 	}
 	sock.SetNoDelay(true)
diff --git a/src/yggdrasil/udp.go b/src/yggdrasil/udp.go
index 8d88df1d..81ff142e 100644
--- a/src/yggdrasil/udp.go
+++ b/src/yggdrasil/udp.go
@@ -224,13 +224,10 @@ func (iface *udpInterface) handleKeys(msg []byte, addr connAddr) {
 		}
 		conn.peer.out = func(msg []byte) {
 			defer func() { recover() }()
-			for {
-				select {
-				case conn.out <- msg:
-					return
-				default:
-					util_putBytes(<-conn.out)
-				}
+			select {
+			case conn.out <- msg:
+			default:
+				util_putBytes(msg)
 			}
 		}
 		go func() {