jrouter/main.go

517 lines
14 KiB
Go

/*
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 main
import (
"bufio"
"cmp"
"context"
"errors"
"flag"
"fmt"
"log"
"math/rand/v2"
"net"
"net/http"
"os"
"os/signal"
"regexp"
"runtime/debug"
"slices"
"strings"
"sync"
"time"
"gitea.drjosh.dev/josh/jrouter/aurp"
"gitea.drjosh.dev/josh/jrouter/router"
"gitea.drjosh.dev/josh/jrouter/status"
"github.com/google/gopacket/pcap"
"github.com/sfiera/multitalk/pkg/ddp"
"github.com/sfiera/multitalk/pkg/ethernet"
)
const routingTableTemplate = `
<table>
<thead><tr>
<th>Network range</th>
<th>Extended?</th>
<th>Zone names</th>
<th>Distance</th>
<th>Last seen</th>
<th>Port</th>
</tr></thead>
<tbody>
{{range $route := . }}
<tr>
<td>{{$route.NetStart}}{{if not (eq $route.NetStart $route.NetEnd)}} - {{$route.NetEnd}}{{end}}</td>
<td>{{if $route.Extended}}{{else}}-{{end}}</td>
<td>{{range $route.ZoneNames.ToSlice}}{{.}}<br>{{end}}</td>
<td>{{$route.Distance}}</td>
<td>{{$route.LastSeenAgo}}</td>
<td>
{{- with $route.AURPPeer -}}
{{.RemoteAddr}}
{{- end -}}
{{- with $route.EtherTalkPeer -}}
{{.Port.Device}} {{.PeerAddr.Network}}.{{.PeerAddr.Node}}
{{- end -}}
{{- with $route.EtherTalkDirect -}}
{{.Device}} {{.NetStart}}-{{.NetEnd}}
{{- end -}}
</td>
</tr>
{{end}}
</tbody>
</table>
`
const peerTableTemplate = `
<table>
<thead><tr>
<th>Configured addr</th>
<th>Remote addr</th>
<th>Receiver state</th>
<th>Sender state</th>
<th>Last heard from</th>
<th>Last reconnect</th>
<th>Last update</th>
<th>Last send</th>
<th>Send retries</th>
</tr></thead>
<tbody>
{{range $peer := . }}
<tr>
<td>{{$peer.ConfiguredAddr}}</td>
<td>{{$peer.RemoteAddr}}</td>
<td>{{$peer.ReceiverState}}</td>
<td>{{$peer.SenderState}}</td>
<td>{{$peer.LastHeardFromAgo}}</td>
<td>{{$peer.LastReconnectAgo}}</td>
<td>{{$peer.LastUpdateAgo}}</td>
<td>{{$peer.LastSendAgo}}</td>
<td>{{$peer.SendRetries}}</td>
</tr>
{{end}}
</tbody>
</table>
`
var hasPortRE = regexp.MustCompile(`:\d+$`)
var configFilePath = flag.String("config", "jrouter.yaml", "Path to configuration file to use")
func main() {
// For some reason it occasionally panics and the panics have no traceback?
debug.SetTraceback("all")
flag.Parse()
log.Println("jrouter")
cfg, err := router.LoadConfig(*configFilePath)
if err != nil {
log.Fatalf("Couldn't load configuration file: %v", err)
}
localIP := net.ParseIP(cfg.LocalIP).To4()
if localIP == nil {
iaddrs, err := net.InterfaceAddrs()
if err != nil {
log.Fatalf("Couldn't read network interface addresses: %v", err)
}
for _, iaddr := range iaddrs {
inet, ok := iaddr.(*net.IPNet)
if !ok {
continue
}
if !inet.IP.IsGlobalUnicast() {
continue
}
localIP = inet.IP.To4()
if localIP != nil {
break
}
}
if localIP == nil {
log.Fatalf("No global unicast IPv4 addresses on any network interfaces, and no valid local_ip address in configuration")
}
}
localDI := aurp.IPDomainIdentifier(localIP)
log.Printf("Using %v as local domain identifier", localIP)
log.Printf("EtherTalk configuration: %+v", cfg.EtherTalk)
ln, err := net.ListenUDP("udp4", &net.UDPAddr{Port: int(cfg.ListenPort)})
if err != nil {
log.Fatalf("AURP: Couldn't listen on udp4:387: %v", err)
}
defer ln.Close()
log.Printf("AURP: Listening on %v", ln.LocalAddr())
log.Println("Press ^C or send SIGINT to stop the router gracefully")
cctx, cancel := context.WithCancel(context.Background())
defer cancel()
ctx, _ := signal.NotifyContext(cctx, os.Interrupt)
// --------------------------------- HTTP ---------------------------------
http.HandleFunc("/status", status.Handle)
go func() {
log.Print(http.ListenAndServe(":9459", nil))
}()
// --------------------------------- Pcap ---------------------------------
// First check the interface
iface, err := net.InterfaceByName(cfg.EtherTalk.Device)
if err != nil {
log.Fatalf("Couldn't find interface named %q: %v", cfg.EtherTalk.Device, err)
}
myHWAddr := ethernet.Addr(iface.HardwareAddr)
if cfg.EtherTalk.EthAddr != "" {
// Override myHWAddr with the configured address
netHWAddr, err := net.ParseMAC(cfg.EtherTalk.EthAddr)
if err != nil {
log.Fatalf("Couldn't parse ethertalk.ethernet_addr value %q: %v", cfg.EtherTalk.EthAddr, err)
}
myHWAddr = ethernet.Addr(netHWAddr)
}
pcapHandle, err := pcap.OpenLive(cfg.EtherTalk.Device, 4096, true, 100*time.Millisecond)
if err != nil {
log.Fatalf("Couldn't open %q for packet capture: %v", cfg.EtherTalk.Device, err)
}
bpfFilter := fmt.Sprintf("(atalk or aarp) and (ether multicast or ether dst %s)", myHWAddr)
if err := pcapHandle.SetBPFFilter(bpfFilter); err != nil {
pcapHandle.Close()
log.Fatalf("Couldn't set BPF filter on packet capture: %v", err)
}
defer pcapHandle.Close()
// -------------------------------- Tables --------------------------------
routes := router.NewRouteTable()
status.AddItem(ctx, "Routing table", routingTableTemplate, func(context.Context) (any, error) {
rs := routes.Dump()
slices.SortFunc(rs, func(ra, rb router.Route) int {
return cmp.Compare(ra.NetStart, rb.NetStart)
})
return rs, nil
})
// -------------------------------- Peers ---------------------------------
var peersMu sync.Mutex
peers := make(map[udpAddr]*router.AURPPeer)
status.AddItem(ctx, "AURP Peers", peerTableTemplate, func(context.Context) (any, error) {
var peerInfo []*router.AURPPeer
func() {
peersMu.Lock()
defer peersMu.Unlock()
peerInfo = make([]*router.AURPPeer, 0, len(peers))
for _, p := range peers {
peerInfo = append(peerInfo, p)
}
}()
slices.SortFunc(peerInfo, func(pa, pb *router.AURPPeer) int {
return cmp.Or(
-cmp.Compare(
bool2Int(pa.ReceiverState() == router.ReceiverConnected),
bool2Int(pb.ReceiverState() == router.ReceiverConnected),
),
-cmp.Compare(
bool2Int(pa.SenderState() == router.SenderConnected),
bool2Int(pb.SenderState() == router.SenderConnected),
),
cmp.Compare(pa.ConfiguredAddr, pb.ConfiguredAddr),
)
})
return peerInfo, nil
})
var nextConnID uint16
for nextConnID == 0 {
nextConnID = uint16(rand.IntN(0x10000))
}
var wg sync.WaitGroup
goPeerHandler := func(p *router.AURPPeer) {
wg.Add(1)
go func() {
defer wg.Done()
p.Handle(ctx)
}()
}
// ------------------------- Configured peer setup ------------------------
if cfg.PeerListURL != "" {
log.Printf("Fetching peer list from %s...", cfg.PeerListURL)
existing := len(cfg.Peers)
func() {
resp, err := http.Get(cfg.PeerListURL)
if err != nil {
log.Fatalf("Couldn't fetch peer list: %v", err)
}
defer resp.Body.Close()
sc := bufio.NewScanner(resp.Body)
for sc.Scan() {
p := strings.TrimSpace(sc.Text())
if p == "" {
continue
}
cfg.Peers = append(cfg.Peers, p)
}
if err := sc.Err(); err != nil {
log.Fatalf("Couldn't scan peer list response: %v", err)
}
}()
log.Printf("Fetched list containing %d peers", len(cfg.Peers)-existing)
}
for _, peerStr := range cfg.Peers {
if !hasPortRE.MatchString(peerStr) {
peerStr += ":387"
}
raddr, err := net.ResolveUDPAddr("udp4", peerStr)
if err != nil {
log.Printf("couldn't resolve UDP address, skipping: %v", err)
continue
}
log.Printf("resolved %q to %v", peerStr, raddr)
if raddr.IP.Equal(localIP) {
log.Printf("%v == %v == me, skipping", peerStr, raddr)
continue
}
peer := &router.AURPPeer{
Transport: &aurp.Transport{
LocalDI: localDI,
RemoteDI: aurp.IPDomainIdentifier(raddr.IP),
LocalConnID: nextConnID,
},
UDPConn: ln,
ConfiguredAddr: peerStr,
RemoteAddr: raddr,
ReceiveCh: make(chan aurp.Packet, 1024),
RouteTable: routes,
}
aurp.Inc(&nextConnID)
peersMu.Lock()
peers[udpAddrFromNet(raddr)] = peer
peersMu.Unlock()
goPeerHandler(peer)
}
// --------------------------------- AARP ---------------------------------
aarpMachine := router.NewAARPMachine(cfg, pcapHandle, myHWAddr)
go aarpMachine.Run(ctx)
// -------------------------------- Router --------------------------------
rooter := &router.Router{
Config: cfg,
RouteTable: routes,
// ZoneTable: zones,
}
etherTalkPort := &router.EtherTalkPort{
Device: cfg.EtherTalk.Device,
EthernetAddr: myHWAddr,
NetStart: cfg.EtherTalk.NetStart,
NetEnd: cfg.EtherTalk.NetEnd,
DefaultZoneName: cfg.EtherTalk.ZoneName,
AvailableZones: router.SetFromSlice([]string{cfg.EtherTalk.ZoneName}),
PcapHandle: pcapHandle,
AARPMachine: aarpMachine,
Router: rooter,
}
rooter.Ports = append(rooter.Ports, etherTalkPort)
routes.InsertEtherTalkDirect(etherTalkPort)
// --------------------------------- RTMP ---------------------------------
go etherTalkPort.RunRTMP(ctx)
// ---------------------- Raw AppleTalk/AARP inbound ----------------------
wg.Add(1)
go func() {
defer wg.Done()
ctx, setStatus, _ := status.AddSimpleItem(ctx, "EtherTalk inbound")
defer setStatus("EtherTalk Serve goroutine exited!")
setStatus(fmt.Sprintf("Listening on %s", cfg.EtherTalk.Device))
etherTalkPort.Serve(ctx)
}()
// ----------------------------- AURP inbound -----------------------------
wg.Add(1)
go func() {
defer wg.Done()
ctx, setStatus, done := status.AddSimpleItem(ctx, "AURP inbound")
defer done()
setStatus(fmt.Sprintf("Listening on UDP port %d", cfg.ListenPort))
for {
if ctx.Err() != nil {
return
}
ln.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
pktbuf := make([]byte, 4096)
pktlen, raddr, readErr := ln.ReadFromUDP(pktbuf)
var operr *net.OpError
if errors.As(readErr, &operr) && operr.Timeout() {
continue
}
// log.Printf("AURP: Received packet of length %d from %v", pktlen, raddr)
dh, pkt, parseErr := aurp.ParsePacket(pktbuf[:pktlen])
if parseErr != nil {
log.Printf("AURP: Failed to parse packet: %v", parseErr)
continue
}
if readErr != nil {
log.Printf("AURP: Failed to read packet: %v", readErr)
return
}
log.Printf("AURP: Got %T from %v (%v)", pkt, raddr, dh.SourceDI)
// Existing peer?
ra := udpAddrFromNet(raddr)
peersMu.Lock()
pr := peers[ra]
if pr == nil {
if !cfg.OpenPeering {
log.Printf("AURP: Got packet from %v but it's not in my config and open peering is disabled; dropping the packet", raddr)
peersMu.Unlock()
continue
}
// New peer!
pr = &router.AURPPeer{
Transport: &aurp.Transport{
LocalDI: localDI,
RemoteDI: dh.SourceDI, // platinum rule
LocalConnID: nextConnID,
},
UDPConn: ln,
RemoteAddr: raddr,
ReceiveCh: make(chan aurp.Packet, 1024),
RouteTable: routes,
}
aurp.Inc(&nextConnID)
peers[ra] = pr
goPeerHandler(pr)
}
peersMu.Unlock()
switch dh.PacketType {
case aurp.PacketTypeRouting:
// It's AURP routing data.
// Pass the packet to the goroutine in charge of this peer.
select {
case pr.ReceiveCh <- pkt:
// That's it for us.
case <-ctx.Done():
return
}
continue
case aurp.PacketTypeAppleTalk:
apkt, ok := pkt.(*aurp.AppleTalkPacket)
if !ok {
log.Printf("AURP: Got %T but domain header packet type was %v ?", pkt, dh.PacketType)
continue
}
// Route or otherwise handle the encapsulated AppleTalk traffic
ddpkt := new(ddp.ExtPacket)
if err := ddp.ExtUnmarshal(apkt.Data, ddpkt); err != nil {
log.Printf("AURP: Couldn't unmarshal encapsulated DDP packet: %v", err)
continue
}
// log.Printf("DDP/AURP: Got %d.%d.%d -> %d.%d.%d proto %d data len %d",
// ddpkt.SrcNet, ddpkt.SrcNode, ddpkt.SrcSocket,
// ddpkt.DstNet, ddpkt.DstNode, ddpkt.DstSocket,
// ddpkt.Proto, len(ddpkt.Data))
// Is it addressed to me?
var localPort *router.EtherTalkPort
for _, port := range rooter.Ports {
if ddpkt.DstNet >= port.NetStart && ddpkt.DstNet <= port.NetEnd {
localPort = port
break
}
}
if ddpkt.DstNode == 0 && localPort != nil { // Node 0 = any router for the network = me
// Is it NBP? FwdReq needs translating.
if ddpkt.DstSocket != 2 {
// Something else?? TODO
log.Printf("DDP/AURP: I don't have anything 'listening' on socket %d", ddpkt.DstSocket)
continue
}
// It's NBP, specifically it should be a FwdReq
if err := rooter.HandleNBPFromAURP(ctx, ddpkt); err != nil {
log.Printf("NBP/DDP/AURP: %v", err)
}
continue
}
// Route the packet!
if err := rooter.Forward(ctx, ddpkt); err != nil {
log.Printf("DDP/AURP: Couldn't route packet: %v", err)
}
default:
log.Printf("AURP: Got unknown packet type %v", dh.PacketType)
}
}
}()
// -------------------------------- Close ---------------------------------
wg.Wait()
}
// Hashable net.UDPAddr
type udpAddr struct {
ipv4 [4]byte
port uint16
}
func udpAddrFromNet(a *net.UDPAddr) udpAddr {
return udpAddr{
ipv4: [4]byte(a.IP.To4()),
port: uint16(a.Port),
}
}
func (u udpAddr) toNet() *net.UDPAddr {
return &net.UDPAddr{
IP: u.ipv4[:],
Port: int(u.port),
}
}
func bool2Int(b bool) int {
if b {
return 1
}
return 0
}