Add dns forwarding server library

2018-11-28 15:40:56 +03:00
parent 39eccc62b1
commit 5a548be16c
8 changed files with 1216 additions and 0 deletions
--- a/dnsforward/cache_test.go
+++ b/dnsforward/cache_test.go
@@ -0,0 +1,144 @@
+package dnsforward
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/go-test/deep"
+	"github.com/miekg/dns"
+)
+
+func RR(rr string) dns.RR {
+	r, err := dns.NewRR(rr)
+	if err != nil {
+		panic(err)
+	}
+	return r
+}
+
+// deepEqual is same as deep.Equal, except:
+//  * ignores Id when comparing
+//  * question names are not case sensetive
+func deepEqualMsg(left *dns.Msg, right *dns.Msg) []string {
+	temp := *left
+	temp.Id = right.Id
+	for i := range left.Question {
+		left.Question[i].Name = strings.ToLower(left.Question[i].Name)
+	}
+	for i := range right.Question {
+		right.Question[i].Name = strings.ToLower(right.Question[i].Name)
+	}
+	return deep.Equal(&temp, right)
+}
+
+func TestCacheSanity(t *testing.T) {
+	cache := cache{}
+	request := dns.Msg{}
+	request.SetQuestion("google.com.", dns.TypeA)
+	_, ok := cache.Get(&request)
+	if ok {
+		t.Fatal("empty cache replied with positive response")
+	}
+}
+
+type tests struct {
+	cache []testEntry
+	cases []testCase
+}
+
+type testEntry struct {
+	q string
+	t uint16
+	a []dns.RR
+}
+
+type testCase struct {
+	q  string
+	t  uint16
+	a  []dns.RR
+	ok bool
+}
+
+func TestCache(t *testing.T) {
+	tests := tests{
+		cache: []testEntry{
+			{q: "google.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}},
+		},
+		cases: []testCase{
+			{q: "google.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}, ok: true},
+			{q: "google.com.", t: dns.TypeMX, ok: false},
+		},
+	}
+	runTests(t, tests)
+}
+
+func TestCacheMixedCase(t *testing.T) {
+	tests := tests{
+		cache: []testEntry{
+			{q: "gOOgle.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}},
+		},
+		cases: []testCase{
+			{q: "gOOgle.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}, ok: true},
+			{q: "google.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}, ok: true},
+			{q: "GOOGLE.COM.", t: dns.TypeA, a: []dns.RR{RR("google.com. 3600 IN A 8.8.8.8")}, ok: true},
+			{q: "gOOgle.com.", t: dns.TypeMX, ok: false},
+			{q: "google.com.", t: dns.TypeMX, ok: false},
+			{q: "GOOGLE.COM.", t: dns.TypeMX, ok: false},
+		},
+	}
+	runTests(t, tests)
+}
+
+func TestZeroTTL(t *testing.T) {
+	tests := tests{
+		cache: []testEntry{
+			{q: "gOOgle.com.", t: dns.TypeA, a: []dns.RR{RR("google.com. 0 IN A 8.8.8.8")}},
+		},
+		cases: []testCase{
+			{q: "google.com.", t: dns.TypeA, ok: false},
+			{q: "google.com.", t: dns.TypeA, ok: false},
+			{q: "google.com.", t: dns.TypeA, ok: false},
+			{q: "google.com.", t: dns.TypeMX, ok: false},
+			{q: "google.com.", t: dns.TypeMX, ok: false},
+			{q: "google.com.", t: dns.TypeMX, ok: false},
+		},
+	}
+	runTests(t, tests)
+}
+
+func runTests(t *testing.T, tests tests) {
+	t.Helper()
+	cache := cache{}
+	for _, tc := range tests.cache {
+		reply := dns.Msg{}
+		reply.SetQuestion(tc.q, tc.t)
+		reply.Response = true
+		reply.Answer = tc.a
+		cache.Set(&reply)
+	}
+	for _, tc := range tests.cases {
+		request := dns.Msg{}
+		request.SetQuestion(tc.q, tc.t)
+		val, ok := cache.Get(&request)
+		if diff := deep.Equal(ok, tc.ok); diff != nil {
+			t.Error(diff)
+		}
+		if tc.a != nil {
+			if ok == false {
+				continue
+			}
+			reply := dns.Msg{}
+			reply.SetQuestion(tc.q, tc.t)
+			reply.Response = true
+			reply.Answer = tc.a
+			cache.Set(&reply)
+			if diff := deepEqualMsg(val, &reply); diff != nil {
+				t.Error(diff)
+			} else {
+				if diff := deep.Equal(val, reply); diff == nil {
+					t.Error("different message ID were not caught")
+				}
+			}
+		}
+	}
+}