From 62162d8c958b6f1cc36078d6e4da73304178947f Mon Sep 17 00:00:00 2001
From: Josh Deprez <josh.deprez@gmail.com>
Date: Fri, 5 Apr 2024 14:07:16 +1100
Subject: [PATCH] WIP AppleTalk

---
 go.mod  |  3 ++-
 go.sum  |  4 ++++
 main.go | 27 +++++++++++++++++++++++----
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/go.mod b/go.mod
index 8c85068..eb8b94f 100644
--- a/go.mod
+++ b/go.mod
@@ -9,5 +9,6 @@ require (
 
 require (
 	github.com/google/gopacket v1.1.19 // indirect
-	golang.org/x/sys v0.0.0-20190412213103-97732733099d // indirect
+	github.com/sfiera/multitalk v0.2.0 // indirect
+	golang.org/x/sys v0.5.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 982cfb6..d100d52 100644
--- a/go.sum
+++ b/go.sum
@@ -2,6 +2,8 @@ github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
 github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
+github.com/sfiera/multitalk v0.2.0 h1:FLLw7L6yNUTOdjMk2EgKnOwMKeu++t5zinv5qpTC2JM=
+github.com/sfiera/multitalk v0.2.0/go.mod h1:jGkgjgiyfuRMNKwfSjo/xR6b9nd10XF4smQAtApXFHc=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
@@ -12,6 +14,8 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
diff --git a/main.go b/main.go
index 8b3bb28..ab2632a 100644
--- a/main.go
+++ b/main.go
@@ -17,6 +17,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"flag"
@@ -31,6 +32,7 @@ import (
 
 	"gitea.drjosh.dev/josh/jrouter/atalk"
 	"gitea.drjosh.dev/josh/jrouter/aurp"
+	"github.com/sfiera/multitalk/pkg/ethertalk"
 )
 
 var hasPortRE = regexp.MustCompile(`:\d+$`)
@@ -136,6 +138,12 @@ func main() {
 
 	// AppleTalk packet loop
 	go func() {
+		iface, err := net.InterfaceByName(cfg.EtherTalk.Device)
+		if err != nil {
+			log.Fatalf("Couldn't find interface named %q: %v", cfg.EtherTalk.Device, err)
+		}
+		localMAC := iface.HardwareAddr
+
 		handle, err := atalk.StartPcap(cfg.EtherTalk.Device)
 		if err != nil {
 			log.Fatalf("Couldn't open network device for AppleTalk: %v", err)
@@ -143,11 +151,22 @@ func main() {
 		defer handle.Close()
 
 		for {
-			packet, _, err := handle.ReadPacketData()
+			rawPkt, _, err := handle.ReadPacketData()
 			if err != nil {
-				log.Fatalf("Couldn't read packet data: %v", err)
+				log.Fatalf("Couldn't read AppleTalk / AARP packet data: %v", err)
 			}
-			log.Printf("%x", packet)
+
+			var pkt ethertalk.Packet
+			if err := ethertalk.Unmarshal(rawPkt, &pkt); err != nil {
+				log.Printf("Couldn't unmarshal EtherTalk frame: %v", err)
+				continue
+			}
+
+			if bytes.Equal(pkt.Src[:], localMAC) {
+				continue
+			}
+
+			log.Printf("Read packet %s -> %s payload %x", pkt.Src, pkt.Dst, pkt.Payload)
 		}
 	}()
 
@@ -157,7 +176,7 @@ func main() {
 			return
 		}
 		ln.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
-		pktbuf := make([]byte, 65536)
+		pktbuf := make([]byte, 4096)
 		pktlen, raddr, readErr := ln.ReadFromUDP(pktbuf)
 
 		var operr *net.OpError