From a778e91ca195754dccca3c64dee63db317c2ba1b Mon Sep 17 00:00:00 2001
From: Viktor Liu <viktor@netbird.io>
Date: Fri, 20 Dec 2024 13:38:50 +0100
Subject: [PATCH] Add udp hook test

---
 client/firewall/uspfilter/uspfilter_test.go | 75 +++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/client/firewall/uspfilter/uspfilter_test.go b/client/firewall/uspfilter/uspfilter_test.go
index 5ad8ab4a270..4677c07c4d4 100644
--- a/client/firewall/uspfilter/uspfilter_test.go
+++ b/client/firewall/uspfilter/uspfilter_test.go
@@ -3,6 +3,7 @@ package uspfilter
 import (
 	"fmt"
 	"net"
+	"sync"
 	"testing"
 	"time"
 
@@ -384,6 +385,80 @@ func TestRemovePacketHook(t *testing.T) {
 	}
 }
 
+func TestProcessOutgoingHooks(t *testing.T) {
+	manager := &Manager{
+		outgoingRules: map[string]RuleSet{},
+		wgNetwork: &net.IPNet{
+			IP:   net.ParseIP("100.10.0.0"),
+			Mask: net.CIDRMask(16, 32),
+		},
+		decoders: sync.Pool{
+			New: func() any {
+				d := &decoder{
+					decoded: []gopacket.LayerType{},
+				}
+				d.parser = gopacket.NewDecodingLayerParser(
+					layers.LayerTypeIPv4,
+					&d.eth, &d.ip4, &d.ip6, &d.icmp4, &d.icmp6, &d.tcp, &d.udp,
+				)
+				d.parser.IgnoreUnsupported = true
+				return d
+			},
+		},
+	}
+
+	hookCalled := false
+	hookID := manager.AddUDPPacketHook(
+		false,
+		net.ParseIP("100.10.0.100"),
+		53,
+		func([]byte) bool {
+			hookCalled = true
+			return true
+		},
+	)
+	require.NotEmpty(t, hookID)
+
+	// Create test UDP packet
+	ipv4 := &layers.IPv4{
+		TTL:      64,
+		Version:  4,
+		SrcIP:    net.ParseIP("100.10.0.1"),
+		DstIP:    net.ParseIP("100.10.0.100"),
+		Protocol: layers.IPProtocolUDP,
+	}
+	udp := &layers.UDP{
+		SrcPort: 51334,
+		DstPort: 53,
+	}
+
+	err := udp.SetNetworkLayerForChecksum(ipv4)
+	require.NoError(t, err)
+	payload := gopacket.Payload([]byte("test"))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{
+		ComputeChecksums: true,
+		FixLengths:       true,
+	}
+	err = gopacket.SerializeLayers(buf, opts, ipv4, udp, payload)
+	require.NoError(t, err)
+
+	// Test hook gets called
+	result := manager.processOutgoingHooks(buf.Bytes())
+	require.True(t, result)
+	require.True(t, hookCalled)
+
+	// Test non-UDP packet is ignored
+	ipv4.Protocol = layers.IPProtocolTCP
+	buf = gopacket.NewSerializeBuffer()
+	err = gopacket.SerializeLayers(buf, opts, ipv4)
+	require.NoError(t, err)
+
+	result = manager.processOutgoingHooks(buf.Bytes())
+	require.False(t, result)
+}
+
 func TestUSPFilterCreatePerformance(t *testing.T) {
 	for _, testMax := range []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000} {
 		t.Run(fmt.Sprintf("Testing %d rules", testMax), func(t *testing.T) {