add dns server test

main.go

@@ -1,62 +1,3 @@
 package main
 
-import (
-	"log"
-	"net"
-)
-
-func main() {
-	qname := "google.com"
-	qtype := A
-
-	packet := NewDnsPacket()
-	packet.header.id = 1234
-	packet.header.questions = 1
-	packet.header.recursionDesired = true
-	packet.questions = append(packet.questions, DnsQuestion{name: qname, qtype: qtype})
-
-	requestBuf := NewBytePacketBuffer()
-	err := packet.write(requestBuf)
-	if err != nil {
-		log.Fatalf("error writing packet: %v", err)
-	}
-
-	udpAddr, err := net.ResolveUDPAddr("udp", "8.8.8.8:53")
-	if err != nil {
-		log.Fatalf("error resolving address: %v", err)
-	}
-	conn, err := net.DialUDP("udp", nil, udpAddr)
-	if err != nil {
-		log.Fatalf("error dialing: %v", err)
-	}
-	defer conn.Close()
-	_, err = conn.Write(requestBuf.buf[0:requestBuf.pos])
-	if err != nil {
-		log.Fatalf("error writing request: %v", err)
-	}
-
-	responseBuf := NewBytePacketBuffer()
-	_, _, err = conn.ReadFromUDP(responseBuf.buf)
-	if err != nil {
-		log.Fatalf("error reading response: %v", err)
-	}
-
-	resPacket := NewDnsPacket()
-	err = resPacket.fromBuffer(responseBuf)
-	if err != nil {
-		log.Fatalf("error reading response: %v", err)
-	}
-
-	for _, q := range resPacket.questions {
-		log.Printf("question: %+v", q)
-	}
-	for _, a := range resPacket.answers {
-		log.Printf("answer: %+v", a)
-	}
-	for _, a := range resPacket.authorities {
-		log.Printf("authority: %+v", a)
-	}
-	for _, a := range resPacket.resources {
-		log.Printf("resource: %+v", a)
-	}
-}
+func main() {}

main_test.go

@@ -1,8 +1,11 @@
 package main
 
 import (
+	"log"
+	"net"
 	"os"
 	"testing"
+	"time"
 )
 
 func TestQueryPacket(t *testing.T) {
@@ -114,3 +117,47 @@ func TestResponsePacket(t *testing.T) {
 		t.Errorf("expected record %+v, got %+v", expectedDnsRecords[0], packet.answers[0])
 	}
 }
+
+func TestDNSServer(t *testing.T) {
+	packet := NewDnsPacket()
+	packet.header.id = 1234
+	packet.header.questions = 1
+	packet.header.recursionDesired = true
+	packet.questions = append(packet.questions, DnsQuestion{name: "google.com", qtype: A})
+
+	requestBuf := NewBytePacketBuffer()
+	err := packet.write(requestBuf)
+	if err != nil {
+		log.Fatalf("error writing packet: %v", err)
+	}
+
+	udpAddr, err := net.ResolveUDPAddr("udp", "8.8.8.8:53")
+	if err != nil {
+		log.Fatalf("error resolving address: %v", err)
+	}
+	conn, err := net.DialUDP("udp", nil, udpAddr)
+	if err != nil {
+		log.Fatalf("error dialing: %v", err)
+	}
+	defer conn.Close()
+	_, err = conn.Write(requestBuf.buf[0:requestBuf.pos])
+	if err != nil {
+		log.Fatalf("error writing request: %v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+
+	responseBuf := NewBytePacketBuffer()
+	_, _, err = conn.ReadFromUDP(responseBuf.buf)
+	if err != nil {
+		log.Fatalf("error reading response: %v", err)
+	}
+
+	resPacket := NewDnsPacket()
+	err = resPacket.fromBuffer(responseBuf)
+	if err != nil {
+		log.Fatalf("error reading response: %v", err)
+	}
+
+	log.Printf("response packet header: %+v", resPacket)
+}