cmds/exp/tcpdump: add tests

Signed-off-by: Fabian Wienand <[email protected]>

cmds/exp/tcpdump/domain_test.go

@@ -0,0 +1,85 @@
+// Copyright 2024 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"testing"
+
+	"github.com/gopacket/gopacket/layers"
+)
+
+func TestDnsData(t *testing.T) {
+	tests := []struct {
+		name     string
+		layer    *layers.DNS
+		expected string
+	}{
+		{
+			name: "No error response code, no answers",
+			layer: &layers.DNS{
+				ID:           1234,
+				ResponseCode: layers.DNSResponseCodeNoErr,
+				Questions: []layers.DNSQuestion{
+					{Type: layers.DNSTypeA, Name: []byte("example.com")},
+				},
+			},
+			expected: "1234 A? example.com (0)",
+		},
+		{
+			name: "Error response code",
+			layer: &layers.DNS{
+				ID:           5678,
+				ResponseCode: layers.DNSResponseCodeNXDomain,
+			},
+			expected: "5678 Non-Existent Domain (0)",
+		},
+		{
+			name: "answer",
+			layer: &layers.DNS{
+				ID:           9101,
+				ResponseCode: layers.DNSResponseCodeNoErr,
+				AA:           true,
+				Answers: []layers.DNSResourceRecord{
+					{Name: []byte("example.com"), Type: layers.DNSTypeA, Class: layers.DNSClassAny, IP: []byte{192, 0, 2, 1}},
+				},
+			},
+			expected: "9101*<Any, A> (0)",
+		},
+		{
+			name: " 2 answers",
+			layer: &layers.DNS{
+				ID:           9101,
+				ResponseCode: layers.DNSResponseCodeNoErr,
+				AA:           true,
+				Answers: []layers.DNSResourceRecord{
+					{Name: []byte("example.com"), Type: layers.DNSTypeA, Class: layers.DNSClassAny, IP: []byte{192, 0, 2, 1}},
+					{Name: []byte("example.io"), Type: layers.DNSTypeA, Class: layers.DNSClassAny, IP: []byte{192, 0, 2, 2}},
+				},
+			},
+			expected: "9101* 2/0/0 <Any, A>, <Any, A> (0)",
+		},
+		{
+			name: "Recursive desired",
+			layer: &layers.DNS{
+				ID:           1213,
+				ResponseCode: layers.DNSResponseCodeNoErr,
+				RD:           true,
+				Answers: []layers.DNSResourceRecord{
+					{Name: []byte("example.com"), Type: layers.DNSTypeA, Class: layers.DNSClassAny, IP: []byte{192, 0, 2, 1}},
+				},
+			},
+			expected: "1213+<Any, A> (0)",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := dnsData(tt.layer)
+			if result != tt.expected {
+				t.Errorf("dnsData() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}

cmds/exp/tcpdump/ethernet.go

@@ -10,8 +10,8 @@ import (
 )
 
 func (cmd cmd) ethernetInfo(ethernetLayer gopacket.LinkLayer, networkLayer gopacket.NetworkLayer) string {
-	if !cmd.Opts.ether {
-		return fmt.Sprintf("%s %s", networkLayer.NetworkFlow().EndpointType(), cmd.Opts.device)
+	if !cmd.Opts.Ether {
+		return fmt.Sprintf("%s %s", networkLayer.NetworkFlow().EndpointType(), cmd.Opts.Device)
 	}
 
 	src, dst := ethernetLayer.LinkFlow().Endpoints()
@@ -20,6 +20,7 @@ func (cmd cmd) ethernetInfo(ethernetLayer gopacket.LinkLayer, networkLayer gopac
 	if dstHost == "ff:ff:ff:ff:ff:ff" {
 		dstHost = "Broadcast"
 	}
+
 	length := len(ethernetLayer.LayerContents()) + len(ethernetLayer.LayerPayload())
 
 	return fmt.Sprintf("%s > %s, ethertype %s, length %d:", src, dstHost, networkLayer.NetworkFlow().EndpointType(), length)

cmds/exp/tcpdump/ethernet_test.go

@@ -0,0 +1,100 @@
+// Copyright 2024 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"testing"
+
+	"github.com/gopacket/gopacket"
+	"github.com/gopacket/gopacket/layers"
+)
+
+func TestEthernetInfo(t *testing.T) {
+	tests := []struct {
+		name           string
+		cmd            cmd
+		ethernetLayer  gopacket.LinkLayer
+		networkLayer   gopacket.NetworkLayer
+		expectedOutput string
+	}{
+		{
+			name: "Ether option disabled",
+			cmd: cmd{
+				Opts: flags{
+					Ether:  false,
+					Device: "eth0",
+				},
+			},
+			ethernetLayer: &layers.Ethernet{
+				SrcMAC:       []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55},
+				DstMAC:       []byte{0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB},
+				EthernetType: layers.EthernetTypeIPv4,
+			},
+			networkLayer: &layers.IPv4{
+				SrcIP:    []byte{192, 168, 0, 1},
+				DstIP:    []byte{192, 168, 0, 2},
+				Protocol: layers.IPProtocolTCP,
+			},
+			expectedOutput: "IPv4 eth0",
+		},
+		{
+			name: "Ether option enabled with broadcast",
+			cmd: cmd{
+				Opts: flags{
+					Ether:  true,
+					Device: "eth0",
+				},
+			},
+			ethernetLayer: &layers.Ethernet{
+				SrcMAC:       []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55},
+				DstMAC:       []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+				EthernetType: layers.EthernetTypeIPv4,
+				Length:       14,
+				BaseLayer: layers.BaseLayer{
+					Contents: []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0x08, 0x00},
+				},
+			},
+			networkLayer: &layers.IPv4{
+				SrcIP:    []byte{192, 168, 0, 1},
+				DstIP:    []byte{192, 168, 0, 2},
+				Protocol: layers.IPProtocolTCP,
+			},
+			expectedOutput: "00:11:22:33:44:55 > Broadcast, ethertype IPv4, length 14:",
+		},
+		{
+			name: "Ether option enabled with unicast",
+			cmd: cmd{
+				Opts: flags{
+					Ether:  true,
+					Device: "eth0",
+				},
+			},
+			ethernetLayer: &layers.Ethernet{
+				SrcMAC:       []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55},
+				DstMAC:       []byte{0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB},
+				EthernetType: layers.EthernetTypeIPv4,
+				Length:       14,
+				BaseLayer: layers.BaseLayer{
+					Contents: []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0x08, 0x00},
+				},
+			},
+			networkLayer: &layers.IPv4{
+				SrcIP:    []byte{192, 168, 0, 1},
+				DstIP:    []byte{192, 168, 0, 2},
+				Protocol: layers.IPProtocolTCP,
+			},
+			expectedOutput: "00:11:22:33:44:55 > 66:77:88:99:aa:bb, ethertype IPv4, length 14:",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := tt.cmd.ethernetInfo(tt.ethernetLayer, tt.networkLayer)
+			if result != tt.expectedOutput {
+				t.Errorf("ethernetInfo() = %v, want %v", result, tt.expectedOutput)
+			}
+		})
+	}
+}

cmds/exp/tcpdump/filter.txt

@@ -0,0 +1 @@
+tcp

cmds/exp/tcpdump/icmp_test.go

@@ -0,0 +1,64 @@
+// Copyright 2024 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"testing"
+
+	"github.com/gopacket/gopacket"
+	"github.com/gopacket/gopacket/layers"
+)
+
+func TestParseICMP(t *testing.T) {
+	tests := []struct {
+		name           string
+		packet         gopacket.Packet
+		expectedOutput string
+	}{
+		{
+			name: "ICMPv4 Echo Request",
+			packet: gopacket.NewPacket(
+				[]byte{
+					0x08, 0x00, 0x4d, 0x3d, 0x00, 0x46, 0x00, 0x01, 0x61, 0x62, 0x63, 0x64,
+				},
+				layers.LayerTypeICMPv4,
+				gopacket.Default,
+			),
+			expectedOutput: "ICMP EchoRequest, id 70, seq 1, length 12",
+		},
+		{
+			name: "ICMPv6 Echo Request",
+			packet: gopacket.NewPacket(
+				[]byte{
+					0x80, 0x00, 0x4d, 0x3d, 0x1c, 0x46, 0x00, 0x01, 0x61, 0x62, 0x63, 0x64,
+				},
+				layers.LayerTypeICMPv6,
+				gopacket.Default,
+			),
+			expectedOutput: "ICMP6 EchoRequest, length 12",
+		},
+		{
+			name: "Non-ICMP Packet",
+			packet: gopacket.NewPacket(
+				[]byte{
+					0x45, 0x00, 0x00, 0x3c, 0x1c, 0x46, 0x40, 0x00, 0x40, 0x06, 0xb1, 0xe6, 0xc0, 0xa8, 0x00, 0x68,
+					0xc0, 0xa8, 0x00, 0x01,
+				},
+				layers.LayerTypeIPv4,
+				gopacket.Default,
+			),
+			expectedOutput: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := parseICMP(tt.packet)
+			if result != tt.expectedOutput {
+				t.Errorf("parseICMP() = %v, want %v", result, tt.expectedOutput)
+			}
+		})
+	}
+}