WIP: routers on ethertalk

main.go

@@ -224,18 +224,18 @@ func main() {
 
 	// -------------------------------- Peers ---------------------------------
 	var peersMu sync.Mutex
-	peers := make(map[udpAddr]*router.Peer)
+	peers := make(map[udpAddr]*router.AURPPeer)
 	status.AddItem(ctx, "AURP Peers", peerTableTemplate, func(context.Context) (any, error) {
-		var peerInfo []*router.Peer
+		var peerInfo []*router.AURPPeer
 		func() {
 			peersMu.Lock()
 			defer peersMu.Unlock()
-			peerInfo = make([]*router.Peer, 0, len(peers))
+			peerInfo = make([]*router.AURPPeer, 0, len(peers))
 			for _, p := range peers {
 				peerInfo = append(peerInfo, p)
 			}
 		}()
-		slices.SortFunc(peerInfo, func(pa, pb *router.Peer) int {
+		slices.SortFunc(peerInfo, func(pa, pb *router.AURPPeer) int {
 			return cmp.Or(
 				-cmp.Compare(
 					bool2Int(pa.ReceiverState() == router.ReceiverConnected),
@@ -257,7 +257,7 @@ func main() {
 	}
 
 	var wg sync.WaitGroup
-	goPeerHandler := func(p *router.Peer) {
+	goPeerHandler := func(p *router.AURPPeer) {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
@@ -308,7 +308,7 @@ func main() {
 			continue
 		}
 
-		peer := &router.Peer{
+		peer := &router.AURPPeer{
 			Config: cfg,
 			Transport: &aurp.Transport{
 				LocalDI:     localDI,
@@ -434,18 +434,29 @@ func main() {
 				// TODO: more generic routing
 				if ddpkt.DstNet != 0 && !(ddpkt.DstNet >= cfg.EtherTalk.NetStart && ddpkt.DstNet <= cfg.EtherTalk.NetEnd) {
 					// Is it for a network in the routing table?
-					rt := routes.LookupRoute(ddpkt.DstNet)
+					route := routes.LookupRoute(ddpkt.DstNet)
-					if rt == nil {
+					if route == nil {
 						log.Printf("DDP: no route for network %d", ddpkt.DstNet)
 						continue
 					}
 
+					switch {
+					case route.AURPPeer != nil:
 						// Encap ethPacket.Payload into an AURP packet
-					log.Printf("DDP: forwarding to AURP peer %v", rt.Peer.RemoteAddr)
+						log.Printf("DDP: forwarding to AURP peer %v", route.AURPPeer.RemoteAddr)
-					if _, err := rt.Peer.Send(rt.Peer.Transport.NewAppleTalkPacket(ethFrame.Payload)); err != nil {
+						if _, err := route.AURPPeer.Send(route.AURPPeer.Transport.NewAppleTalkPacket(ethFrame.Payload)); err != nil {
 							log.Printf("DDP: Couldn't forward packet to AURP peer: %v", err)
 						}
 
+					case route.EtherTalkPeer != nil:
+						// Route payload to another router over EtherTalk
+						// TODO: this is unlikely because we currenly only support 1 EtherTalk port
+						log.Printf("DDP: forwarding to EtherTalk peer %v", route.EtherTalkPeer.PeerAddr)
+						// Note: resolving AARP can block
+						if err := route.EtherTalkPeer.Forward(ctx, ddpkt); err != nil {
+							log.Printf("DDP: Couldn't forward packet to EtherTalk peer: %v", err)
+						}
+					}
 					continue
 				}
 
@@ -534,7 +545,7 @@ func main() {
 					continue
 				}
 				// New peer!
-				pr = &router.Peer{
+				pr = &router.AURPPeer{
 					Config: cfg,
 					Transport: &aurp.Transport{
 						LocalDI:     localDI,
@@ -584,14 +595,7 @@ func main() {
 					ddpkt.DstNet, ddpkt.DstNode, ddpkt.DstSocket,
 					ddpkt.Proto, len(ddpkt.Data))
 
-				// "Route" the packet
+				// Route the packet
-				// Since for now there's only one local network, the routing
-				// decision is pretty easy
-				// TODO: Fix this to support other AppleTalk routers
-				if ddpkt.DstNet < cfg.EtherTalk.NetStart || ddpkt.DstNet > cfg.EtherTalk.NetEnd {
-					log.Print("DDP/AURP: dropping packet not addressed to our EtherTalk range")
-					continue
-				}
 
 				// Check and adjust the Hop Count
 				// Note the ddp package doesn't make this simple
@@ -604,8 +608,44 @@ func main() {
 				ddpkt.Size &^= 0x3C00
 				ddpkt.Size |= hopCount << 10
 
+				if ddpkt.DstNet < cfg.EtherTalk.NetStart || ddpkt.DstNet > cfg.EtherTalk.NetEnd {
+					// Is it a network in the routing table?
+					route := routes.LookupRoute(ddpkt.DstNet)
+					if route == nil {
+						log.Printf("DDP/AURP: no route for packet (dstnet %d); dropping packet", ddpkt.DstNet)
+						break
+					}
+
+					switch {
+					case route.AURPPeer != nil:
+						// Routing between AURP peers... bit weird but OK
+						log.Printf("DDP/AURP: forwarding to AURP peer %v", route.AURPPeer.RemoteAddr)
+						outPkt, err := ddp.ExtMarshal(*ddpkt)
+						if err != nil {
+							log.Printf("DDP/AURP: Couldn't re-marshal packet: %v", err)
+							break
+						}
+						if _, err := route.AURPPeer.Send(route.AURPPeer.Transport.NewAppleTalkPacket(outPkt)); err != nil {
+							log.Printf("DDP/AURP: Couldn't forward packet to AURP peer: %v", err)
+						}
+
+					case route.EtherTalkPeer != nil:
+						// AURP peer -> EtherTalk peer
+						// Note: resolving AARP can block
+						log.Printf("DDP/AURP: forwarding to EtherTalk peer %v", route.EtherTalkPeer.PeerAddr)
+						if err := route.EtherTalkPeer.Forward(ctx, ddpkt); err != nil {
+							log.Printf("DDP/AURP: Couldn't forward packet to EtherTalk peer: %v", err)
+						}
+
+					default:
+						log.Print("DDP/AURP: no forwarding mechanism for route; dropping packet")
+
+					}
+					continue
+				}
+
 				// Is it addressed to me? Is it NBP?
-				if ddpkt.DstNode == 0 { // Node 0 = the router for the network
+				if ddpkt.DstNode == 0 { // Node 0 = any router for the network = me
 					if ddpkt.DstSocket != 2 {
 						// Something else?? TODO
 						log.Printf("DDP/AURP: I don't have anything 'listening' on socket %d", ddpkt.DstSocket)

router/nbp.go

@@ -110,7 +110,7 @@ func (rtr *Router) HandleNBP(srcHWAddr ethernet.Addr, ddpkt *ddp.ExtPacket) erro
 			if route == nil {
 				return fmt.Errorf("no route for network %d", z.Network)
 			}
-			peer := route.Peer
+			peer := route.AURPPeer
 			if peer == nil {
 				return fmt.Errorf("nil peer for route for network %d", z.Network)
 			}

router/nbp_aurp.go

@@ -24,7 +24,7 @@ import (
 	"github.com/sfiera/multitalk/pkg/ddp"
 )
 
-func (rtr *Router) HandleNBPInAURP(peer *Peer, ddpkt *ddp.ExtPacket) error {
+func (rtr *Router) HandleNBPInAURP(peer *AURPPeer, ddpkt *ddp.ExtPacket) error {
 	if ddpkt.Proto != ddp.ProtoNBP {
 		return fmt.Errorf("invalid DDP type %d on socket 2", ddpkt.Proto)
 	}

router/peer_aurp.go

@@ -92,8 +92,8 @@ func (ss SenderState) String() string {
 	}
 }
 
-// Peer handles the peering with a peer AURP router.
+// AURPPeer handles the peering with a peer AURP router.
-type Peer struct {
+type AURPPeer struct {
 	// Whole router config.
 	Config *Config
 
@@ -125,31 +125,31 @@ type Peer struct {
 	sstate SenderState
 }
 
-func (p *Peer) ReceiverState() ReceiverState {
+func (p *AURPPeer) ReceiverState() ReceiverState {
 	p.mu.RLock()
 	defer p.mu.RUnlock()
 	return p.rstate
 }
 
-func (p *Peer) SenderState() SenderState {
+func (p *AURPPeer) SenderState() SenderState {
 	p.mu.RLock()
 	defer p.mu.RUnlock()
 	return p.sstate
 }
 
-func (p *Peer) setRState(rstate ReceiverState) {
+func (p *AURPPeer) setRState(rstate ReceiverState) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	p.rstate = rstate
 }
 
-func (p *Peer) setSState(sstate SenderState) {
+func (p *AURPPeer) setSState(sstate SenderState) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	p.sstate = sstate
 }
 
-func (p *Peer) disconnect() {
+func (p *AURPPeer) disconnect() {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	p.rstate = ReceiverUnconnected
@@ -157,7 +157,7 @@ func (p *Peer) disconnect() {
 }
 
 // Send encodes and sends pkt to the remote host.
-func (p *Peer) Send(pkt aurp.Packet) (int, error) {
+func (p *AURPPeer) Send(pkt aurp.Packet) (int, error) {
 	var b bytes.Buffer
 	if _, err := pkt.WriteTo(&b); err != nil {
 		return 0, err
@@ -166,7 +166,7 @@ func (p *Peer) Send(pkt aurp.Packet) (int, error) {
 	return p.UDPConn.WriteToUDP(b.Bytes(), p.RemoteAddr)
 }
 
-func (p *Peer) Handle(ctx context.Context) error {
+func (p *AURPPeer) Handle(ctx context.Context) error {
 	rticker := time.NewTicker(1 * time.Second)
 	defer rticker.Stop()
 	sticker := time.NewTicker(1 * time.Second)
@@ -244,7 +244,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 				if sendRetries >= tickleRetryLimit {
 					log.Printf("AURP Peer: Send retry limit reached while waiting for Tickle-Ack, closing connection")
 					p.setRState(ReceiverUnconnected)
-					p.RoutingTable.DeletePeer(p)
+					p.RoutingTable.DeleteAURPPeer(p)
 					break
 				}
 
@@ -263,7 +263,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 				if sendRetries >= sendRetryLimit {
 					log.Printf("AURP Peer: Send retry limit reached while waiting for RI-Rsp, closing connection")
 					p.setRState(ReceiverUnconnected)
-					p.RoutingTable.DeletePeer(p)
+					p.RoutingTable.DeleteAURPPeer(p)
 					break
 				}
 
@@ -458,7 +458,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 				log.Printf("AURP Peer: Learned about these networks: %v", pkt.Networks)
 
 				for _, nt := range pkt.Networks {
-					p.RoutingTable.InsertRoute(
+					p.RoutingTable.InsertAURPRoute(
 						p,
 						nt.Extended,
 						ddp.Network(nt.RangeStart),
@@ -534,7 +534,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 						// Do nothing except respond with RI-Ack
 
 					case aurp.EventCodeNA:
-						if err := p.RoutingTable.InsertRoute(
+						if err := p.RoutingTable.InsertAURPRoute(
 							p,
 							et.Extended,
 							et.RangeStart,
@@ -546,10 +546,10 @@ func (p *Peer) Handle(ctx context.Context) error {
 						ackFlag = aurp.RoutingFlagSendZoneInfo
 
 					case aurp.EventCodeND:
-						p.RoutingTable.DeletePeerNetwork(p, et.RangeStart)
+						p.RoutingTable.DeleteAURPPeerNetwork(p, et.RangeStart)
 
 					case aurp.EventCodeNDC:
-						p.RoutingTable.UpdateRouteDistance(p, et.RangeStart, et.Distance+1)
+						p.RoutingTable.UpdateAURPRouteDistance(p, et.RangeStart, et.Distance+1)
 
 					case aurp.EventCodeNRC:
 						// "An exterior router sends a Network Route Change
@@ -557,7 +557,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 						// through its local internet changes to a path through
 						// a tunneling port, causing split-horizoned processing
 						// to eliminate that network’s routing information."
-						p.RoutingTable.DeletePeerNetwork(p, et.RangeStart)
+						p.RoutingTable.DeleteAURPPeerNetwork(p, et.RangeStart)
 
 					case aurp.EventCodeZC:
 						// "This event is reserved for future use."
@@ -575,7 +575,7 @@ func (p *Peer) Handle(ctx context.Context) error {
 				}
 
 				log.Printf("AURP Peer: Router Down: error code %d %s", pkt.ErrorCode, pkt.ErrorCode)
-				p.RoutingTable.DeletePeer(p)
+				p.RoutingTable.DeleteAURPPeer(p)
 
 				// Respond with RI-Ack
 				if _, err := p.Send(p.Transport.NewRIAckPacket(pkt.ConnectionID, pkt.Sequence, 0)); err != nil {

router/peer_eth.go

@@ -0,0 +1,54 @@
+/*
+   Copyright 2024 Josh Deprez
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package router
+
+import (
+	"context"
+
+	"github.com/google/gopacket/pcap"
+	"github.com/sfiera/multitalk/pkg/ddp"
+	"github.com/sfiera/multitalk/pkg/ethernet"
+	"github.com/sfiera/multitalk/pkg/ethertalk"
+)
+
+// EtherTalkPeer holds data needed to exchange routes and zones with another
+// router on the EtherTalk network.
+type EtherTalkPeer struct {
+	PcapHandle *pcap.Handle
+	MyHWAddr   ethernet.Addr
+	AARP       *AARPMachine
+	PeerAddr   ddp.Addr
+}
+
+// Forward forwards a DDP packet to the next router.
+func (p *EtherTalkPeer) Forward(ctx context.Context, pkt *ddp.ExtPacket) error {
+	// TODO: AARP resolution can block
+	de, err := p.AARP.Resolve(ctx, p.PeerAddr)
+	if err != nil {
+		return err
+	}
+	outFrame, err := ethertalk.AppleTalk(p.MyHWAddr, *pkt)
+	if err != nil {
+		return err
+	}
+	outFrame.Dst = de
+	outFrameRaw, err := ethertalk.Marshal(*outFrame)
+	if err != nil {
+		return err
+	}
+	return p.PcapHandle.WritePacketData(outFrameRaw)
+}

router/route.go

@@ -24,15 +24,18 @@ import (
 	"github.com/sfiera/multitalk/pkg/ddp"
 )
 
-// const maxRouteAge = 10 * time.Minute // TODO: confirm
+const maxRouteAge = 10 * time.Minute // TODO: confirm
 
 type Route struct {
 	Extended bool
 	NetStart ddp.Network
 	NetEnd   ddp.Network
-	Peer     *Peer
 	Distance uint8
 	LastSeen time.Time
+
+	// Exactly one of the following should be set
+	AURPPeer      *AURPPeer
+	EtherTalkPeer *EtherTalkPeer
 }
 
 func (r Route) LastSeenAgo() string {
@@ -70,15 +73,13 @@ func (rt *RoutingTable) LookupRoute(network ddp.Network) *Route {
 
 	var bestRoute *Route
 	for r := range rt.routes {
-		if r.Peer == nil {
-			continue
-		}
 		if network < r.NetStart || network > r.NetEnd {
 			continue
 		}
-		// if time.Since(r.LastSeen) > maxRouteAge {
+		// Exclude EtherTalk routes that are too old
-		// 	continue
+		if r.EtherTalkPeer != nil && time.Since(r.LastSeen) > maxRouteAge {
-		// }
+			continue
+		}
 		if bestRoute == nil {
 			bestRoute = r
 			continue
@@ -90,41 +91,41 @@ func (rt *RoutingTable) LookupRoute(network ddp.Network) *Route {
 	return bestRoute
 }
 
-func (rt *RoutingTable) DeletePeer(peer *Peer) {
+func (rt *RoutingTable) DeleteAURPPeer(peer *AURPPeer) {
 	rt.mu.Lock()
 	defer rt.mu.Unlock()
 
 	for route := range rt.routes {
-		if route.Peer == peer {
+		if route.AURPPeer == peer {
 			delete(rt.routes, route)
 		}
 	}
 }
 
-func (rt *RoutingTable) DeletePeerNetwork(peer *Peer, network ddp.Network) {
+func (rt *RoutingTable) DeleteAURPPeerNetwork(peer *AURPPeer, network ddp.Network) {
 	rt.mu.Lock()
 	defer rt.mu.Unlock()
 
 	for route := range rt.routes {
-		if route.Peer == peer && route.NetStart == network {
+		if route.AURPPeer == peer && route.NetStart == network {
 			delete(rt.routes, route)
 		}
 	}
 }
 
-func (rt *RoutingTable) UpdateRouteDistance(peer *Peer, network ddp.Network, distance uint8) {
+func (rt *RoutingTable) UpdateAURPRouteDistance(peer *AURPPeer, network ddp.Network, distance uint8) {
 	rt.mu.Lock()
 	defer rt.mu.Unlock()
 
 	for route := range rt.routes {
-		if route.Peer == peer && route.NetStart == network {
+		if route.AURPPeer == peer && route.NetStart == network {
 			route.Distance = distance
 			route.LastSeen = time.Now()
 		}
 	}
 }
 
-func (rt *RoutingTable) InsertRoute(peer *Peer, extended bool, netStart, netEnd ddp.Network, metric uint8) error {
+func (rt *RoutingTable) UpsertEthRoute(peer *EtherTalkPeer, extended bool, netStart, netEnd ddp.Network, metric uint8) error {
 	if netStart > netEnd {
 		return fmt.Errorf("invalid network range [%d, %d]", netStart, netEnd)
 	}
@@ -136,9 +137,33 @@ func (rt *RoutingTable) InsertRoute(peer *Peer, extended bool, netStart, netEnd
 		Extended:      extended,
 		NetStart:      netStart,
 		NetEnd:        netEnd,
-		Peer:     peer,
 		Distance:      metric,
 		LastSeen:      time.Now(),
+		EtherTalkPeer: peer,
+	}
+
+	rt.mu.Lock()
+	defer rt.mu.Unlock()
+	// TODO: update if present rather than insert
+	rt.routes[r] = struct{}{}
+	return nil
+}
+
+func (rt *RoutingTable) InsertAURPRoute(peer *AURPPeer, extended bool, netStart, netEnd ddp.Network, metric uint8) error {
+	if netStart > netEnd {
+		return fmt.Errorf("invalid network range [%d, %d]", netStart, netEnd)
+	}
+	if netStart != netEnd && !extended {
+		return fmt.Errorf("invalid network range [%d, %d] for nonextended network", netStart, netEnd)
+	}
+
+	r := &Route{
+		Extended: extended,
+		NetStart: netStart,
+		NetEnd:   netEnd,
+		Distance: metric,
+		LastSeen: time.Now(),
+		AURPPeer: peer,
 	}
 
 	rt.mu.Lock()
@@ -152,12 +177,10 @@ func (rt *RoutingTable) ValidRoutes() []*Route {
 	defer rt.mu.Unlock()
 	valid := make([]*Route, 0, len(rt.routes))
 	for r := range rt.routes {
-		if r.Peer == nil {
+		// Exclude EtherTalk routes that are too old
+		if r.EtherTalkPeer != nil && time.Since(r.LastSeen) > maxRouteAge {
 			continue
 		}
-		// if time.Since(r.LastSeen) > maxRouteAge {
-		// 	continue
-		// }
 		valid = append(valid, r)
 	}
 	return valid

router/rtmp.go

@@ -159,14 +159,30 @@ func (m *RTMPMachine) Run(ctx context.Context, incomingCh <-chan *ddp.ExtPacket)
 					}
 
 				case rtmp.FunctionLoopProbe:
-					log.Printf("RTMP: TODO: handle Loop Probes")
+					log.Print("RTMP: TODO: handle Loop Probes")
 
 				}
 
 			case ddp.ProtoRTMPResp:
 				// It's a peer router on the AppleTalk network!
-				// TODO: integrate this information with the routing table?
 				log.Print("RTMP: Got Response or Data")
+				dataPkt, err := rtmp.UnmarshalDataPacket(pkt.Data)
+				if err != nil {
+					log.Printf("RTMP: Couldn't unmarshal RTMP Data packet: %v", err)
+					break
+				}
+				peer := &EtherTalkPeer{
+					PcapHandle: m.PcapHandle,
+					MyHWAddr:   m.AARP.myAddr.Hardware,
+					AARP:       m.AARP,
+					PeerAddr:   dataPkt.RouterAddr,
+				}
+
+				for _, rt := range dataPkt.NetworkTuples {
+					if err := m.RoutingTable.UpsertEthRoute(peer, rt.Extended, rt.RangeStart, rt.RangeEnd, rt.Distance+1); err != nil {
+						log.Printf("RTMP: Couldn't upsert EtherTalk route: %v", err)
+					}
+				}
 
 			default:
 				log.Printf("RTMP: invalid DDP type %d on socket 1", pkt.Proto)