josh/jrouter
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Tickle handling

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This commit is contained in:
Josh Deprez 2024-03-30 14:13:34 +11:00
parent b9ae3cc426
commit 520046d86a
Signed by: josh
SSH key fingerprint: SHA256:zZji7w1Ilh2RuUpbQcqkLPrqmRwpiCSycbF2EfKm6Kw
4 changed files with 146 additions and 86 deletions
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28
aurp/errors.go
View file

@ -1,14 +1,26 @@
package aurp
type ErrorCode = int16
type ErrorCode int16
// Various error codes.
const (
ErrCodeNormalClose = -1
ErrCodeRoutingLoop = -2
ErrCodeOutOfSync = -3
ErrCodeOptionNegotiation = -4
ErrCodeInvalidVersion = -5
ErrCodeInsufficientResources = -6
ErrCodeAuthentication = -7
ErrCodeNormalClose ErrorCode = -1
ErrCodeRoutingLoop ErrorCode = -2
ErrCodeOutOfSync ErrorCode = -3
ErrCodeOptionNegotiation ErrorCode = -4
ErrCodeInvalidVersion ErrorCode = -5
ErrCodeInsufficientResources ErrorCode = -6
ErrCodeAuthentication ErrorCode = -7
)
func (e ErrorCode) String() string {
return map[ErrorCode]string{
ErrCodeNormalClose: "normal connection close",
ErrCodeRoutingLoop: "routing loop detected",
ErrCodeOutOfSync: "connection out of sync",
ErrCodeOptionNegotiation: "option-negotiation error",
ErrCodeInvalidVersion: "invalid version number",
ErrCodeInsufficientResources: "insufficient resources for connection",
ErrCodeAuthentication: "authentication error",
}[e]
}

20
aurp/transport.go
View file

@ -110,3 +110,23 @@ func (tr *Transport) NewOpenRspPacket(envFlags RoutingFlag, rateOrErr int16, opt
Options: opts,
}
}
func (tr *Transport) NewTicklePacket() *TicklePacket {
return &TicklePacket{
Header: Header{
TrHeader: tr.transaction(tr.LocalConnID),
CommandCode: CmdCodeTickle,
Flags: 0,
},
}
}
func (tr *Transport) NewTickleAckPacket() *TickleAckPacket {
return &TickleAckPacket{
Header: Header{
TrHeader: tr.transaction(tr.RemoteConnID),
CommandCode: CmdCodeTickleAck,
Flags: 0,
},
}
}

7
main.go
View file

@ -1,6 +1,7 @@
package main
import (
"context"
"flag"
"log"
"net"
@ -17,6 +18,8 @@ func main() {
flag.Parse()
log.Println("jrouter")
ctx := context.Background()
cfg, err := loadConfig(*configFilePath)
if err != nil {
log.Fatalf("Couldn't load configuration file: %v", err)
@ -83,7 +86,7 @@ func main() {
raddr: raddr,
recv: make(chan aurp.Packet, 1024),
}
go peer.handle()
go peer.handle(ctx)
peers[udpAddrFromNet(raddr)] = peer
}
@ -127,7 +130,7 @@ func main() {
recv: make(chan aurp.Packet, 1024),
}
peers[ra] = pr
go pr.handle()
go pr.handle(ctx)
}
// Pass the packet to the goroutine in charge of this peer.

177
peer.go
View file

@ -2,8 +2,10 @@ package main
import (
"bytes"
"context"
"log"
"net"
"time"
"gitea.drjosh.dev/josh/jrouter/aurp"
)
@ -13,6 +15,8 @@ type peer struct {
conn *net.UDPConn
raddr *net.UDPAddr
recv chan aurp.Packet
lastHeardFrom time.Time
}
// send encodes and sends pkt to the remote host.
@ -24,94 +28,115 @@ func (p *peer) send(pkt aurp.Packet) (int, error) {
return p.conn.WriteToUDP(b.Bytes(), p.raddr)
}
func (p *peer) handle() {
func (p *peer) handle(ctx context.Context) error {
ticker := time.NewTicker(1 * time.Second)
defer ticker.Stop()
// Write an Open-Req packet
n, err := p.send(p.tr.NewOpenReqPacket(nil))
if err != nil {
log.Printf("Couldn't send Open-Req packet: %v", err)
return
return err
}
log.Printf("Sent Open-Req (len %d) to peer %v", n, p.raddr)
for pkt := range p.recv {
switch pkt := pkt.(type) {
case *aurp.AppleTalkPacket:
// Probably something like:
//
// * parse the DDP header
// * check that this is headed for our local network
// * write the packet out in an EtherTalk frame
//
// or maybe if we were implementing a "central hub"
//
// * parse the DDP header
// * see if we know the network
// * forward to the peer with that network and lowest metric
for {
select {
case <-ctx.Done():
return ctx.Err()
case *aurp.OpenReqPacket:
// The peer tells us their connection ID in Open-Req.
p.tr.RemoteConnID = pkt.ConnectionID
// Formulate a response.
var orsp *aurp.OpenRspPacket
switch {
case pkt.Version != 1:
// Respond with Open-Rsp with unknown version error.
orsp = p.tr.NewOpenRspPacket(0, aurp.ErrCodeInvalidVersion, nil)
case len(pkt.Options) > 0:
// Options? OPTIONS? We don't accept no stinkin' _options_
orsp = p.tr.NewOpenRspPacket(0, aurp.ErrCodeOptionNegotiation, nil)
default:
// Accept it I guess.
orsp = p.tr.NewOpenRspPacket(0, 1, nil)
case <-ticker.C:
// TODO: time-based state changes
// Check LHFT, send tickle?
if time.Since(p.lastHeardFrom) > 10*time.Second {
if _, err := p.send(p.tr.NewTicklePacket()); err != nil {
log.Printf("Couldn't send Tickle: %v", err)
}
}
log.Printf("Responding with %T", orsp)
case pkt := <-p.recv:
switch pkt := pkt.(type) {
case *aurp.AppleTalkPacket:
// Probably something like:
//
// * parse the DDP header
// * check that this is headed for our local network
// * write the packet out in an EtherTalk frame
//
// or maybe if we were implementing a "central hub"
//
// * parse the DDP header
// * see if we know the network
// * forward to the peer with that network and lowest metric
if _, err := p.send(orsp); err != nil {
log.Printf("Couldn't send Open-Rsp: %v", err)
case *aurp.OpenReqPacket:
// The peer tells us their connection ID in Open-Req.
p.tr.RemoteConnID = pkt.ConnectionID
// Formulate a response.
var orsp *aurp.OpenRspPacket
switch {
case pkt.Version != 1:
// Respond with Open-Rsp with unknown version error.
orsp = p.tr.NewOpenRspPacket(0, int16(aurp.ErrCodeInvalidVersion), nil)
case len(pkt.Options) > 0:
// Options? OPTIONS? We don't accept no stinkin' _options_
orsp = p.tr.NewOpenRspPacket(0, int16(aurp.ErrCodeOptionNegotiation), nil)
default:
// Accept it I guess.
orsp = p.tr.NewOpenRspPacket(0, 1, nil)
}
log.Printf("Responding with %T", orsp)
if _, err := p.send(orsp); err != nil {
log.Printf("Couldn't send Open-Rsp: %v", err)
}
case *aurp.OpenRspPacket:
if pkt.RateOrErrCode < 0 {
// It's an error code.
log.Printf("Open-Rsp error code from peer %v: %d", p.raddr.IP, pkt.RateOrErrCode)
// Close the connection
}
// TODO: Make other requests
case *aurp.RIReqPacket:
// TODO: Respond with RI-Rsp
case *aurp.RIRspPacket:
// TODO: Repsond with RI-Ack
// TODO: Integrate info into route table
case *aurp.RIAckPacket:
// TODO: Continue sending next RI-Rsp (streamed)
// TODO: If SZI flag is set, send ZI-Rsp (transaction)
case *aurp.RIUpdPacket:
// TODO: Integrate info into route table
case *aurp.RDPacket:
// TODO: Remove router from tables
// TODO: Close connection
log.Printf("Router Down: error code %d %s", pkt.ErrorCode, pkt.ErrorCode)
case *aurp.ZIReqPacket:
// TODO: Respond with ZI-Rsp
case *aurp.ZIRspPacket:
// TODO: Integrate info into zone table
case *aurp.TicklePacket:
if _, err := p.send(p.tr.NewTickleAckPacket()); err != nil {
log.Printf("Couldn't send Tickle-Ack: %v", err)
}
case *aurp.TickleAckPacket:
p.lastHeardFrom = time.Now()
}
case *aurp.OpenRspPacket:
if pkt.RateOrErrCode < 0 {
// It's an error code.
log.Printf("Open-Rsp error code from peer %v: %d", p.raddr.IP, pkt.RateOrErrCode)
// Close the connection
}
// TODO: Make other requests
case *aurp.RIReqPacket:
// TODO: Respond with RI-Rsp
case *aurp.RIRspPacket:
// TODO: Repsond with RI-Ack
// TODO: Integrate info into route table
case *aurp.RIAckPacket:
// TODO: Continue sending next RI-Rsp (streamed)
// TODO: If SZI flag is set, send ZI-Rsp (transaction)
case *aurp.RIUpdPacket:
// TODO: Integrate info into route table
case *aurp.RDPacket:
// TODO: Remove router from tables
// TODO: Close connection
case *aurp.ZIReqPacket:
// TODO: Respond with ZI-Rsp
case *aurp.ZIRspPacket:
// TODO: Integrate info into zone table
case *aurp.TicklePacket:
// TODO: Respond with TickleAck
case *aurp.TickleAckPacket:
// TODO: Reset LHFT
}
}
}