Moved layers to a separate package, preparing to add application layer

shadowy-pycoder · shadowy-pycoder · commit 2e02505c440d · 2024-08-27T10:07:31.000+03:00
diff --git a/cmd/mshark/cli.go b/cmd/mshark/cli.go
@@ -188,7 +188,6 @@ func root(args []string) error {
 		}
 		pw = append(pw, w)
 	}
-
 	if err := ms.OpenLive(&conf, pw...); err != nil {
 		return err
 	}
diff --git a/go.mod b/go.mod
@@ -6,11 +6,11 @@ require (
 	github.com/mdlayher/packet v1.1.2
 	github.com/packetcap/go-pcap v0.0.0-20240528124601-8c87ecf5dbc5
 	golang.org/x/net v0.28.0
-	golang.org/x/sys v0.24.0
 )
 
 require (
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sys v0.24.0 // indirect
 )
diff --git a/layers/arp.go b/layers/arp.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/dns.go b/layers/dns.go
@@ -0,0 +1,5 @@
+package layers
+
+// https://en.wikipedia.org/wiki/Domain_Name_System
+// port 53
+type DNSMessage struct{}
diff --git a/layers/ethernet.go b/layers/ethernet.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/ftp.go b/layers/ftp.go
@@ -0,0 +1,5 @@
+package layers
+
+// https://mavlink.io/zh/services/ftp.html
+// port 21 port 20
+type FTPMessage struct{}
diff --git a/layers/http.go b/layers/http.go
@@ -0,0 +1,5 @@
+package layers
+
+// https://developer.mozilla.org/en-US/docs/Web/HTTP/Messages
+// port 80
+type HTTPMessage struct{}
diff --git a/layers/icmp.go b/layers/icmp.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/icmpv6.go b/layers/icmpv6.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/ipv4.go b/layers/ipv4.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/ipv6.go b/layers/ipv6.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/snmp.go b/layers/snmp.go
@@ -0,0 +1,5 @@
+package layers
+
+// https://www.ranecommercial.com/legacy/pdf/ranenotes/SNMP_Simple_Network_Management_Protocol.pdf
+// port 161, 162
+type SNMPMessage struct{}
diff --git a/layers/ssh.go b/layers/ssh.go
@@ -0,0 +1,5 @@
+package layers
+
+// https://www.omnisecu.com/tcpip/ssh-packet-format.php
+// port 22
+type SSHMessage struct{}
diff --git a/layers/tcp.go b/layers/tcp.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/layers/tls.go b/layers/tls.go
@@ -0,0 +1,4 @@
+package layers
+
+// port 443
+type TLSMessage struct{}
diff --git a/layers/udp.go b/layers/udp.go
@@ -1,4 +1,4 @@
-package mshark
+package layers
 
 import (
 	"encoding/binary"
diff --git a/mshark.go b/mshark.go
@@ -10,25 +10,33 @@ import (
 
 	"github.com/mdlayher/packet"
 	"github.com/packetcap/go-pcap/filter"
+	"github.com/shadowy-pycoder/mshark/layers"
 	"golang.org/x/net/bpf"
-	"golang.org/x/sys/unix"
 )
 
+const unixEthPAll int = 0x03
+
 var _ PacketWriter = &Writer{}
 
 type PacketWriter interface {
 	WritePacket(timestamp time.Time, data []byte) error
 }
 
-type layers struct {
-	ether EthernetFrame
-	ip    IPv4Packet
-	ip6   IPv6Packet
-	arp   ARPPacket
-	tcp   TCPSegment
-	udp   UDPSegment
-	icmp  ICMPSegment
-	icmp6 ICMPv6Segment
+type layer struct {
+	ether layers.EthernetFrame
+	ip    layers.IPv4Packet
+	ip6   layers.IPv6Packet
+	arp   layers.ARPPacket
+	tcp   layers.TCPSegment
+	udp   layers.UDPSegment
+	icmp  layers.ICMPSegment
+	icmp6 layers.ICMPv6Segment
+	dns   layers.DNSMessage
+	ftp   layers.FTPMessage
+	http  layers.HTTPMessage
+	snmp  layers.SNMPMessage
+	ssh   layers.SSHMessage
+	tls   layers.TLSMessage
 }
 
 type Config struct {
@@ -42,7 +50,7 @@ type Config struct {
 
 type Writer struct {
 	w       io.Writer
-	layers  layers
+	layer   layer
 	packets uint64
 }
 
@@ -58,60 +66,60 @@ func (mw *Writer) WritePacket(timestamp time.Time, data []byte) error {
 	mw.packets++
 	fmt.Fprintf(mw.w, "- Packet: %d Timestamp: %s\n", mw.packets, timestamp.Format("2006-01-02T15:04:05-0700"))
 	fmt.Fprintln(mw.w, "==================================================================")
-	if err := mw.layers.ether.Parse(data); err != nil {
+	if err := mw.layer.ether.Parse(data); err != nil {
 		return err
 	}
-	fmt.Fprintln(mw.w, mw.layers.ether.String())
-	switch mw.layers.ether.NextLayer() {
+	fmt.Fprintln(mw.w, mw.layer.ether.String())
+	switch mw.layer.ether.NextLayer() {
 	case "IPv4":
-		if err := mw.layers.ip.Parse(mw.layers.ether.Payload); err != nil {
+		if err := mw.layer.ip.Parse(mw.layer.ether.Payload); err != nil {
 			return err
 		}
-		fmt.Fprintln(mw.w, mw.layers.ip.String())
-		switch mw.layers.ip.NextLayer() {
+		fmt.Fprintln(mw.w, mw.layer.ip.String())
+		switch mw.layer.ip.NextLayer() {
 		case "TCP":
-			if err := mw.layers.tcp.Parse(mw.layers.ip.Payload); err != nil {
+			if err := mw.layer.tcp.Parse(mw.layer.ip.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.tcp.String())
+			fmt.Fprintln(mw.w, mw.layer.tcp.String())
 		case "UDP":
-			if err := mw.layers.udp.Parse(mw.layers.ip.Payload); err != nil {
+			if err := mw.layer.udp.Parse(mw.layer.ip.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.udp.String())
+			fmt.Fprintln(mw.w, mw.layer.udp.String())
 		case "ICMP":
-			if err := mw.layers.icmp.Parse(mw.layers.ip.Payload); err != nil {
+			if err := mw.layer.icmp.Parse(mw.layer.ip.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.icmp.String())
+			fmt.Fprintln(mw.w, mw.layer.icmp.String())
 		}
 	case "IPv6":
-		if err := mw.layers.ip6.Parse(mw.layers.ether.Payload); err != nil {
+		if err := mw.layer.ip6.Parse(mw.layer.ether.Payload); err != nil {
 			return err
 		}
-		fmt.Fprintln(mw.w, mw.layers.ip6.String())
-		switch mw.layers.ip6.NextLayer() {
+		fmt.Fprintln(mw.w, mw.layer.ip6.String())
+		switch mw.layer.ip6.NextLayer() {
 		case "TCP":
-			if err := mw.layers.tcp.Parse(mw.layers.ip6.Payload); err != nil {
+			if err := mw.layer.tcp.Parse(mw.layer.ip6.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.tcp.String())
+			fmt.Fprintln(mw.w, mw.layer.tcp.String())
 		case "UDP":
-			if err := mw.layers.udp.Parse(mw.layers.ip6.Payload); err != nil {
+			if err := mw.layer.udp.Parse(mw.layer.ip6.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.udp.String())
+			fmt.Fprintln(mw.w, mw.layer.udp.String())
 		case "ICMPv6":
-			if err := mw.layers.icmp6.Parse(mw.layers.ip6.Payload); err != nil {
+			if err := mw.layer.icmp6.Parse(mw.layer.ip6.Payload); err != nil {
 				return err
 			}
-			fmt.Fprintln(mw.w, mw.layers.icmp6.String())
+			fmt.Fprintln(mw.w, mw.layer.icmp6.String())
 		}
 	case "ARP":
-		if err := mw.layers.arp.Parse(mw.layers.ether.Payload); err != nil {
+		if err := mw.layer.arp.Parse(mw.layer.ether.Payload); err != nil {
 			return err
 		}
-		fmt.Fprintln(mw.w, mw.layers.arp.String())
+		fmt.Fprintln(mw.w, mw.layer.arp.String())
 	}
 	return nil
 }
@@ -195,7 +203,7 @@ func OpenLive(conf *Config, pw ...PacketWriter) error {
 	}
 
 	// opening connection
-	c, err := packet.Listen(conf.Device, packet.Raw, unix.ETH_P_ALL, &packetcfg)
+	c, err := packet.Listen(conf.Device, packet.Raw, unixEthPAll, &packetcfg)
 	if err != nil {
 		if errors.Is(err, os.ErrPermission) {
 			return fmt.Errorf("permission denied (try setting CAP_NET_RAW capability): %v", err)

Original file line number	Diff line number	Diff line change
`@@ -188,7 +188,6 @@ func root(args []string) error {`
`188`	`188`	`}`
`189`	`189`	`pw = append(pw, w)`
`190`	`190`	`}`
`191`		`-`
`192`	`191`	`if err := ms.OpenLive(&conf, pw...); err != nil {`
`193`	`192`	`return err`
`194`	`193`	`}`
Original file line number	Diff line number	Diff line change
`@@ -6,11 +6,11 @@ require (`
`6`	`6`	`github.com/mdlayher/packet v1.1.2`
`7`	`7`	`github.com/packetcap/go-pcap v0.0.0-20240528124601-8c87ecf5dbc5`
`8`	`8`	`golang.org/x/net v0.28.0`
`9`		`- golang.org/x/sys v0.24.0`
`10`	`9`	`)`
`11`	`10`
`12`	`11`	`require (`
`13`	`12`	`github.com/josharian/native v1.1.0 // indirect`
`14`	`13`	`github.com/mdlayher/socket v0.4.1 // indirect`
`15`	`14`	`golang.org/x/sync v0.1.0 // indirect`
	`15`	`+ golang.org/x/sys v0.24.0 // indirect`
`16`	`16`	`)`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package mshark`
	`1`	`+package layers`
`2`	`2`
`3`	`3`	`import (`
`4`	`4`	`"encoding/binary"`