josh/jrouter
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implement BrRq-LkUp translation

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This commit is contained in:
Josh Deprez 2024-04-14 14:08:51 +10:00
parent 2870bc512e
commit b30d6fdef1
Signed by: josh
SSH key fingerprint: SHA256:zZji7w1Ilh2RuUpbQcqkLPrqmRwpiCSycbF2EfKm6Kw
1 changed files with 58 additions and 18 deletions
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76
main.go
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@ -278,24 +278,8 @@ func main() {
rtmpCh <- ddpkt
case 2: // The NIS (name information socket / NBP socket)
if ddpkt.Proto != ddp.ProtoNBP {
log.Printf("NBP: invalid DDP type %d on socket 2", ddpkt.Proto)
continue
}
nbpkt, err := nbp.Unmarshal(ddpkt.Data)
if err != nil {
log.Printf("NBP: invalid packet: %v", err)
continue
}
log.Printf("NBP: Got %v id %d with tuples %v", nbpkt.Function, nbpkt.NBPID, nbpkt.Tuples)
// Is it a BrRq?
if nbpkt.Function == nbp.FunctionBrRq {
// TODO: Translate it into a FwdReq and route it to the
// routers with the appropriate zone(s).
log.Print("NBP: TODO: BrRq-FwdReq translation")
if err := handleNBP(pcapHandle, myHWAddr, cfg, ddpkt); err != nil {
log.Printf("NBP: Couldn't handle: %v", err)
}
case 4: // The AEP socket
@ -450,6 +434,61 @@ func main() {
}
}
func handleNBP(pcapHandle *pcap.Handle, myHWAddr ethernet.Addr, cfg *config, ddpkt *ddp.ExtPacket) error {
if ddpkt.Proto != ddp.ProtoNBP {
return fmt.Errorf("invalid DDP type %d on socket 2", ddpkt.Proto)
}
nbpkt, err := nbp.Unmarshal(ddpkt.Data)
if err != nil {
return fmt.Errorf("invalid packet: %w", err)
}
log.Printf("NBP: Got %v id %d with tuples %v", nbpkt.Function, nbpkt.NBPID, nbpkt.Tuples)
// Is it a BrRq?
if nbpkt.Function != nbp.FunctionBrRq {
return nil
}
// There must be 1!
tuple := nbpkt.Tuples[0]
if tuple.Zone != cfg.EtherTalk.ZoneName {
// TODO: Translate it into a FwdReq and route it to the
// routers with the appropriate zone(s).
return errors.New("TODO: BrRq-FwdReq translation")
}
// If it's for the local zone, translate it to a LkUp and broadcast it back
// out the EtherTalk port.
// "Note: On an internet, nodes on extended networks performing lookups in
// their own zone must replace a zone name of asterisk (*) with their actual
// zone name before sending the packet to A-ROUTER. All nodes performing
// lookups in their own zone will receive LkUp packets from themselves
// (actually sent by a router). The node's NBP process should expect to
// receive these packets and must reply to them."
// TODO: use zone-specific multicast
nbpkt.Function = nbp.FunctionLkUp
nbpRaw, err := nbpkt.Marshal()
if err != nil {
return fmt.Errorf("couldn't marshal LkUp: %v", err)
}
ddpkt.DstNode = 0xFF // Broadcast node address within the dest network
ddpkt.Data = nbpRaw
outFrame, err := ethertalk.AppleTalk(myHWAddr, *ddpkt)
if err != nil {
return err
}
outFrameRaw, err := ethertalk.Marshal(*outFrame)
if err != nil {
return err
}
return pcapHandle.WritePacketData(outFrameRaw)
}
func handleZIP(pcapHandle *pcap.Handle, srcHWAddr, myHWAddr ethernet.Addr, myAddr aarp.AddrPair, cfg *config, ddpkt *ddp.ExtPacket) error {
switch ddpkt.Proto {
case 3: // ATP
@ -535,6 +574,7 @@ func handleNBPInAURP(pcapHandle *pcap.Handle, myHWAddr ethernet.Addr, ddpkt *ddp
log.Printf("NBP/DDP/AURP: Converting FwdReq to LkUp (%v)", nbpkt.Tuples[0])
// Convert it to a LkUp and broadcast on EtherTalk
// TODO: use zone-specific multicast
nbpkt.Function = nbp.FunctionLkUp
nbpRaw, err := nbpkt.Marshal()
if err != nil {