67 lines
2 KiB
Go
67 lines
2 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 (
|
|
"context"
|
|
"fmt"
|
|
|
|
"github.com/sfiera/multitalk/pkg/ddp"
|
|
)
|
|
|
|
type Router struct {
|
|
Config *Config
|
|
RouteTable *RouteTable
|
|
ZoneTable *ZoneTable
|
|
}
|
|
|
|
// Forward routes a packet towards the right destination.
|
|
// It increments the hop count, then looks up the best route for the network,
|
|
// then transmits the packet according to the route.
|
|
func (rtr *Router) Forward(ctx context.Context, ddpkt *ddp.ExtPacket) error {
|
|
// Check and adjust the Hop Count
|
|
// Note the ddp package doesn't make this simple
|
|
hopCount := (ddpkt.Size & 0x3C00) >> 10
|
|
if hopCount >= 15 {
|
|
return fmt.Errorf("hop count exceeded (%d >= 15)", hopCount)
|
|
}
|
|
hopCount++
|
|
ddpkt.Size &^= 0x3C00
|
|
ddpkt.Size |= hopCount << 10
|
|
|
|
switch route := rtr.RouteTable.LookupRoute(ddpkt.DstNet); {
|
|
case route == nil:
|
|
return fmt.Errorf("no route for packet (dstnet %d); dropping packet", ddpkt.DstNet)
|
|
|
|
case route.AURPPeer != nil:
|
|
// log.Printf("Forwarding packet to AURP peer %v", route.AURPPeer.RemoteAddr)
|
|
return route.AURPPeer.Forward(ddpkt)
|
|
|
|
case route.EtherTalkPeer != nil:
|
|
// log.Printf("Forwarding to EtherTalk peer %v", route.EtherTalkPeer.PeerAddr)
|
|
// Note: resolving AARP can block
|
|
return route.EtherTalkPeer.Forward(ctx, ddpkt)
|
|
|
|
case route.EtherTalkDirect != nil:
|
|
// log.Printf("Outputting to EtherTalk directly")
|
|
// Note: resolving AARP can block
|
|
return route.EtherTalkDirect.Send(ctx, ddpkt)
|
|
|
|
default:
|
|
return fmt.Errorf("no forwarding mechanism for route! %+v", route)
|
|
}
|
|
}
|