431 lines
12 KiB
Go
431 lines
12 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 router
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"log"
|
|
"net"
|
|
"time"
|
|
|
|
"gitea.drjosh.dev/josh/jrouter/aurp"
|
|
"github.com/sfiera/multitalk/pkg/ddp"
|
|
)
|
|
|
|
const (
|
|
// TODO: check these parameters
|
|
lastHeardFromTimer = 90 * time.Second
|
|
tickleRetryLimit = 10
|
|
sendRetryTimer = 10 * time.Second
|
|
sendRetryLimit = 5
|
|
)
|
|
|
|
type receiverState int
|
|
|
|
const (
|
|
rsUnconnected receiverState = iota
|
|
rsConnected
|
|
rsWaitForOpenRsp
|
|
rsWaitForRIRsp
|
|
rsWaitForTickleAck
|
|
)
|
|
|
|
func (rs receiverState) String() string {
|
|
return map[receiverState]string{
|
|
rsUnconnected: "unconnected",
|
|
rsConnected: "connected",
|
|
rsWaitForOpenRsp: "waiting for Open-Rsp",
|
|
rsWaitForRIRsp: "waiting for RI-Rsp",
|
|
rsWaitForTickleAck: "waiting for Tickle-Ack",
|
|
}[rs]
|
|
}
|
|
|
|
type senderState int
|
|
|
|
const (
|
|
ssUnconnected senderState = iota
|
|
ssConnected
|
|
ssWaitForRIAck1
|
|
ssWaitForRIAck2
|
|
ssWaitForRIAck3
|
|
)
|
|
|
|
func (ss senderState) String() string {
|
|
return map[senderState]string{
|
|
ssUnconnected: "unconnected",
|
|
ssConnected: "connected",
|
|
ssWaitForRIAck1: "waiting for RI-Ack (1)",
|
|
ssWaitForRIAck2: "waiting for RI-Ack (2)",
|
|
ssWaitForRIAck3: "waiting for RI-Ack (3)",
|
|
}[ss]
|
|
}
|
|
|
|
type Peer struct {
|
|
Config *Config
|
|
Transport *aurp.Transport
|
|
UDPConn *net.UDPConn
|
|
RemoteAddr *net.UDPAddr
|
|
RecieveCh chan aurp.Packet
|
|
RoutingTable *RoutingTable
|
|
ZoneTable *ZoneTable
|
|
}
|
|
|
|
// Send encodes and sends pkt to the remote host.
|
|
func (p *Peer) Send(pkt aurp.Packet) (int, error) {
|
|
var b bytes.Buffer
|
|
if _, err := pkt.WriteTo(&b); err != nil {
|
|
return 0, err
|
|
}
|
|
log.Printf("AURP Peer: Sending %T (len %d) to %v", pkt, b.Len(), p.RemoteAddr)
|
|
return p.UDPConn.WriteToUDP(b.Bytes(), p.RemoteAddr)
|
|
}
|
|
|
|
func (p *Peer) Handle(ctx context.Context) error {
|
|
ticker := time.NewTicker(1 * time.Second)
|
|
defer ticker.Stop()
|
|
|
|
lastHeardFrom := time.Now()
|
|
lastSend := time.Now()
|
|
sendRetries := 0
|
|
|
|
rstate := rsUnconnected
|
|
sstate := ssUnconnected
|
|
|
|
// Write an Open-Req packet
|
|
if _, err := p.Send(p.Transport.NewOpenReqPacket(nil)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Open-Req packet: %v", err)
|
|
return err
|
|
}
|
|
|
|
rstate = rsWaitForOpenRsp
|
|
|
|
for {
|
|
select {
|
|
case <-ctx.Done():
|
|
if sstate == ssUnconnected {
|
|
// Return immediately
|
|
return ctx.Err()
|
|
}
|
|
// Send a best-effort Router Down before returning
|
|
if _, err := p.Send(p.Transport.NewRDPacket(aurp.ErrCodeNormalClose)); err != nil {
|
|
log.Printf("Couldn't send RD packet: %v", err)
|
|
}
|
|
return ctx.Err()
|
|
|
|
case <-ticker.C:
|
|
switch rstate {
|
|
case rsWaitForOpenRsp:
|
|
if time.Since(lastSend) <= sendRetryTimer {
|
|
break
|
|
}
|
|
if sendRetries >= sendRetryLimit {
|
|
log.Printf("AURP Peer: Send retry limit reached while waiting for Open-Rsp, closing connection")
|
|
rstate = rsUnconnected
|
|
break
|
|
}
|
|
|
|
// Send another Open-Req
|
|
sendRetries++
|
|
lastSend = time.Now()
|
|
if _, err := p.Send(p.Transport.NewOpenReqPacket(nil)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Open-Req packet: %v", err)
|
|
return err
|
|
}
|
|
|
|
case rsConnected:
|
|
// Check LHFT, send tickle?
|
|
if time.Since(lastHeardFrom) <= lastHeardFromTimer {
|
|
break
|
|
}
|
|
if _, err := p.Send(p.Transport.NewTicklePacket()); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Tickle: %v", err)
|
|
return err
|
|
}
|
|
rstate = rsWaitForTickleAck
|
|
sendRetries = 0
|
|
lastSend = time.Now()
|
|
|
|
case rsWaitForTickleAck:
|
|
if time.Since(lastSend) <= sendRetryTimer {
|
|
break
|
|
}
|
|
if sendRetries >= tickleRetryLimit {
|
|
log.Printf("AURP Peer: Send retry limit reached while waiting for Tickle-Ack, closing connection")
|
|
rstate = rsUnconnected
|
|
p.RoutingTable.DeletePeer(p)
|
|
break
|
|
}
|
|
|
|
sendRetries++
|
|
lastSend = time.Now()
|
|
if _, err := p.Send(p.Transport.NewTicklePacket()); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Tickle: %v", err)
|
|
return err
|
|
}
|
|
// still in Wait For Tickle-Ack
|
|
|
|
case rsWaitForRIRsp:
|
|
if time.Since(lastSend) <= sendRetryTimer {
|
|
break
|
|
}
|
|
if sendRetries >= sendRetryLimit {
|
|
log.Printf("AURP Peer: Send retry limit reached while waiting for RI-Rsp, closing connection")
|
|
rstate = rsUnconnected
|
|
p.RoutingTable.DeletePeer(p)
|
|
break
|
|
}
|
|
|
|
// RI-Req is stateless, so we don't need to cache the one we
|
|
// sent earlier just to send it again
|
|
sendRetries++
|
|
if _, err := p.Send(p.Transport.NewRIReqPacket()); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send RI-Req packet: %v", err)
|
|
return err
|
|
}
|
|
// still in Wait For RI-Rsp
|
|
|
|
case rsUnconnected:
|
|
// TODO: periodically try to reconnect,
|
|
// if this peer is in the config file
|
|
}
|
|
|
|
case pkt := <-p.RecieveCh:
|
|
lastHeardFrom = time.Now()
|
|
|
|
switch pkt := pkt.(type) {
|
|
case *aurp.OpenReqPacket:
|
|
if sstate != ssUnconnected {
|
|
log.Printf("AURP Peer: Open-Req received but sender state is not unconnected (was %v)", sstate)
|
|
}
|
|
|
|
// The peer tells us their connection ID in Open-Req.
|
|
p.Transport.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.Transport.NewOpenRspPacket(0, int16(aurp.ErrCodeInvalidVersion), nil)
|
|
|
|
case len(pkt.Options) > 0:
|
|
// Options? OPTIONS? We don't accept no stinkin' _options_
|
|
orsp = p.Transport.NewOpenRspPacket(0, int16(aurp.ErrCodeOptionNegotiation), nil)
|
|
|
|
default:
|
|
// Accept it I guess.
|
|
orsp = p.Transport.NewOpenRspPacket(0, 1, nil)
|
|
}
|
|
|
|
if _, err := p.Send(orsp); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Open-Rsp: %v", err)
|
|
return err
|
|
}
|
|
if orsp.RateOrErrCode >= 0 {
|
|
sstate = ssConnected
|
|
}
|
|
|
|
// If receiver is unconnected, commence connecting
|
|
if rstate == rsUnconnected {
|
|
lastSend = time.Now()
|
|
sendRetries = 0
|
|
if _, err := p.Send(p.Transport.NewOpenReqPacket(nil)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Open-Req packet: %v", err)
|
|
return err
|
|
}
|
|
rstate = rsWaitForOpenRsp
|
|
}
|
|
|
|
case *aurp.OpenRspPacket:
|
|
if rstate != rsWaitForOpenRsp {
|
|
log.Printf("AURP Peer: Received Open-Rsp but was not waiting for one (receiver state was %v)", rstate)
|
|
}
|
|
if pkt.RateOrErrCode < 0 {
|
|
// It's an error code.
|
|
log.Printf("AURP Peer: Open-Rsp error code from peer %v: %d", p.RemoteAddr.IP, pkt.RateOrErrCode)
|
|
rstate = rsUnconnected
|
|
break
|
|
}
|
|
//log.Printf("AURP Peer: Data receiver is connected!")
|
|
rstate = rsConnected
|
|
|
|
// Send an RI-Req
|
|
sendRetries = 0
|
|
if _, err := p.Send(p.Transport.NewRIReqPacket()); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send RI-Req packet: %v", err)
|
|
return err
|
|
}
|
|
rstate = rsWaitForRIRsp
|
|
|
|
case *aurp.RIReqPacket:
|
|
if sstate != ssConnected {
|
|
log.Printf("AURP Peer: Received RI-Req but was not expecting one (sender state was %v)", sstate)
|
|
}
|
|
|
|
nets := aurp.NetworkTuples{
|
|
{
|
|
Extended: true,
|
|
RangeStart: uint16(p.Config.EtherTalk.NetStart),
|
|
RangeEnd: uint16(p.Config.EtherTalk.NetEnd),
|
|
Distance: 0,
|
|
},
|
|
}
|
|
p.Transport.LocalSeq = 1
|
|
if _, err := p.Send(p.Transport.NewRIRspPacket(aurp.RoutingFlagLast, nets)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send RI-Rsp packet: %v", err)
|
|
return err
|
|
}
|
|
sstate = ssWaitForRIAck1
|
|
|
|
case *aurp.RIRspPacket:
|
|
if rstate != rsWaitForRIRsp {
|
|
log.Printf("Received RI-Rsp but was not waiting for one (receiver state was %v)", rstate)
|
|
}
|
|
|
|
log.Printf("AURP Peer: Learned about these networks: %v", pkt.Networks)
|
|
|
|
for _, nt := range pkt.Networks {
|
|
p.RoutingTable.UpsertRoute(
|
|
nt.Extended,
|
|
ddp.Network(nt.RangeStart),
|
|
ddp.Network(nt.RangeEnd),
|
|
p,
|
|
nt.Distance,
|
|
)
|
|
}
|
|
|
|
// TODO: track which networks we don't have zone info for, and
|
|
// only set SZI for those ?
|
|
if _, err := p.Send(p.Transport.NewRIAckPacket(pkt.ConnectionID, pkt.Sequence, aurp.RoutingFlagSendZoneInfo)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send RI-Ack packet: %v", err)
|
|
return err
|
|
}
|
|
if pkt.Flags&aurp.RoutingFlagLast != 0 {
|
|
// No longer waiting for an RI-Rsp
|
|
rstate = rsConnected
|
|
}
|
|
|
|
case *aurp.RIAckPacket:
|
|
switch sstate {
|
|
case ssWaitForRIAck1:
|
|
// We sent an RI-Rsp, this is the RI-Ack we expected.
|
|
|
|
case ssWaitForRIAck2:
|
|
// We sent an RI-Upd, this is the RI-Ack we expected.
|
|
|
|
case ssWaitForRIAck3:
|
|
// We sent an RD... Why are we here?
|
|
continue
|
|
|
|
default:
|
|
log.Printf("AURP Peer: Received RI-Ack but was not waiting for one (sender state was %v)", sstate)
|
|
}
|
|
|
|
sstate = ssConnected
|
|
|
|
// If SZI flag is set, send ZI-Rsp (transaction)
|
|
// TODO: only respond with zones for networks that were in the
|
|
// RI-Rsp that corresponded to this RI-Ack
|
|
if pkt.Flags&aurp.RoutingFlagSendZoneInfo != 0 {
|
|
zones := aurp.ZoneTuples{
|
|
{
|
|
Network: uint16(p.Config.EtherTalk.NetStart),
|
|
Name: p.Config.EtherTalk.ZoneName,
|
|
},
|
|
}
|
|
if _, err := p.Send(p.Transport.NewZIRspPacket(zones)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send ZI-Rsp packet: %v", err)
|
|
}
|
|
}
|
|
|
|
// TODO: Continue sending next RI-Rsp (streamed)?
|
|
|
|
case *aurp.RIUpdPacket:
|
|
// TODO: Integrate info into route table
|
|
|
|
case *aurp.RDPacket:
|
|
if rstate == rsUnconnected || rstate == rsWaitForOpenRsp {
|
|
log.Printf("AURP Peer: Received RD but was not expecting one (receiver state was %v)", rstate)
|
|
}
|
|
|
|
log.Printf("AURP Peer: Router Down: error code %d %s", pkt.ErrorCode, pkt.ErrorCode)
|
|
p.RoutingTable.DeletePeer(p)
|
|
|
|
// Respond with RI-Ack
|
|
if _, err := p.Send(p.Transport.NewRIAckPacket(pkt.ConnectionID, pkt.Sequence, 0)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send RI-Ack: %v", err)
|
|
return err
|
|
}
|
|
// Connection closed
|
|
rstate = rsUnconnected
|
|
|
|
case *aurp.ZIReqPacket:
|
|
// TODO: only respond with zones for networks specified by the
|
|
// ZI-Req
|
|
zones := aurp.ZoneTuples{
|
|
{
|
|
Network: uint16(p.Config.EtherTalk.NetStart),
|
|
Name: p.Config.EtherTalk.ZoneName,
|
|
},
|
|
}
|
|
if _, err := p.Send(p.Transport.NewZIRspPacket(zones)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send ZI-Rsp packet: %v", err)
|
|
return err
|
|
}
|
|
|
|
case *aurp.ZIRspPacket:
|
|
log.Printf("AURP Peer: Learned about these zones: %v", pkt.Zones)
|
|
for _, zt := range pkt.Zones {
|
|
p.ZoneTable.Upsert(ddp.Network(zt.Network), zt.Name, false)
|
|
}
|
|
|
|
case *aurp.GDZLReqPacket:
|
|
if _, err := p.Send(p.Transport.NewGDZLRspPacket(-1, nil)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send GDZL-Rsp packet: %v", err)
|
|
return err
|
|
}
|
|
|
|
case *aurp.GDZLRspPacket:
|
|
log.Printf("AURP Peer: Received a GDZL-Rsp, but I wouldn't have sent a GDZL-Req - that's weird")
|
|
|
|
case *aurp.GZNReqPacket:
|
|
if _, err := p.Send(p.Transport.NewGZNRspPacket(pkt.ZoneName, false, nil)); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send GZN-Rsp packet: %v", err)
|
|
return err
|
|
}
|
|
|
|
case *aurp.GZNRspPacket:
|
|
log.Printf("AURP Peer: Received a GZN-Rsp, but I wouldn't have sent a GZN-Req - that's weird")
|
|
|
|
case *aurp.TicklePacket:
|
|
// Immediately respond with Tickle-Ack
|
|
if _, err := p.Send(p.Transport.NewTickleAckPacket()); err != nil {
|
|
log.Printf("AURP Peer: Couldn't send Tickle-Ack: %v", err)
|
|
return err
|
|
}
|
|
|
|
case *aurp.TickleAckPacket:
|
|
if rstate != rsWaitForTickleAck {
|
|
log.Printf("AURP Peer: Received Tickle-Ack but was not waiting for one (receiver state was %v)", rstate)
|
|
}
|
|
rstate = rsConnected
|
|
}
|
|
}
|
|
}
|
|
}
|