67 lines
2 KiB
Go
67 lines
2 KiB
Go
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/*
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Copyright 2024 Josh Deprez
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package main
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import (
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"fmt"
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"gitea.drjosh.dev/josh/jrouter/atalk/aep"
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"github.com/google/gopacket/pcap"
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"github.com/sfiera/multitalk/pkg/ddp"
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"github.com/sfiera/multitalk/pkg/ethernet"
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"github.com/sfiera/multitalk/pkg/ethertalk"
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)
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func handleAEP(pcapHandle *pcap.Handle, src, dst ethernet.Addr, ddpkt *ddp.ExtPacket) error {
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if ddpkt.Proto != ddp.ProtoAEP {
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return fmt.Errorf("invalid DDP type %d on socket 4", ddpkt.Proto)
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}
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ep, err := aep.Unmarshal(ddpkt.Data)
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if err != nil {
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return err
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}
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switch ep.Function {
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case aep.EchoReply:
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// we didn't send a request? I don't think?
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// we shouldn't be sending them from this socket
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return fmt.Errorf("echo reply received at socket 4 why?")
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case aep.EchoRequest:
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// Uno Reverso the packet
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// "The client can send the Echo Request datagram through any socket
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// the client has open, and the Echo Reply will come back to this socket."
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ddpkt.DstNet, ddpkt.SrcNet = ddpkt.SrcNet, ddpkt.DstNet
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ddpkt.DstNode, ddpkt.SrcNode = ddpkt.SrcNode, ddpkt.DstNode
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ddpkt.DstSocket, ddpkt.SrcSocket = ddpkt.SrcSocket, ddpkt.DstSocket
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ddpkt.Data[0] = byte(aep.EchoReply)
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ethFrame, err := ethertalk.AppleTalk(src, *ddpkt)
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if err != nil {
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return err
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}
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ethFrame.Dst = dst
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ethFrameRaw, err := ethertalk.Marshal(*ethFrame)
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if err != nil {
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return err
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}
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return pcapHandle.WritePacketData(ethFrameRaw)
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default:
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return fmt.Errorf("invalid AEP function %d", ep.Function)
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}
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}
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