1 files changed, 172 insertions, 0 deletions
diff --git a/dnsd/server_test.go b/dnsd/server_test.go
new file mode 100644
index 0000000..a9cb726
--- /dev/null
+++ b/dnsd/server_test.go
@@ -0,0 +1,172 @@
+package dnsd
+
+import (
+	"database/sql"
+	"net"
+	"path/filepath"
+	"testing"
+
+	"github.com/miekg/dns"
+
+	"penguins.lan/database"
+	"penguins.lan/utils"
+)
+
+const (
+	testUser    = "tux"
+	testMac     = "aa:bb:cc:dd:ee:ff"
+	testMacLbl  = "aabbccddeeff"
+	testIP      = "192.168.8.50"
+	testZone    = "penguins.lan."
+	testApexIP  = "10.0.0.1"
+	testDevName = testMacLbl + "." + testUser + "." + testZone
+)
+
+// capWriter captures the reply a Handler writes instead of sending it.
+type capWriter struct{ msg *dns.Msg }
+
+func (c *capWriter) WriteMsg(m *dns.Msg) error { c.msg = m; return nil }
+func (c *capWriter) Write([]byte) (int, error) { return 0, nil }
+func (c *capWriter) Close() error              { return nil }
+func (c *capWriter) TsigStatus() error         { return nil }
+func (c *capWriter) TsigTimersOnly(bool)       {}
+func (c *capWriter) Hijack()                   {}
+func (c *capWriter) LocalAddr() net.Addr       { return &net.UDPAddr{} }
+func (c *capWriter) RemoteAddr() net.Addr      { return &net.UDPAddr{} }
+
+func testDB(t *testing.T) *sql.DB {
+	t.Helper()
+	db, err := sql.Open("sqlite3", filepath.Join(t.TempDir(), "d.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { db.Close() })
+	if _, err := database.Migrate(db); err != nil {
+		t.Fatal(err)
+	}
+	return db
+}
+
+func testHandler(db *sql.DB) *Handler {
+	return &Handler{DB: db, Zone: testZone, ServerIP: testApexIP}
+}
+
+// query runs one question through the handler and returns the reply.
+func query(t *testing.T, h *Handler, name string, qtype uint16) *dns.Msg {
+	t.Helper()
+	m := &dns.Msg{}
+	m.SetQuestion(dns.Fqdn(name), qtype)
+	w := &capWriter{}
+	h.ServeDNS(w, m)
+	if w.msg == nil {
+		t.Fatal("handler wrote no reply")
+	}
+	return w.msg
+}
+
+// seedDevice creates the user, binds the MAC, and marks it live at testIP.
+func seedDevice(t *testing.T, db *sql.DB) {
+	t.Helper()
+	user, err := database.CreateUser(db, "u1", testUser)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := database.AssociateMAC(db, testMac, user.ID); err != nil {
+		t.Fatal(err)
+	}
+	if err := database.RefreshConnections(db, map[string]string{testIP: testMac}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestDeviceRecordSynthesized(t *testing.T) {
+	db := testDB(t)
+	seedDevice(t, db)
+
+	reply := query(t, testHandler(db), testDevName, dns.TypeA)
+	if len(reply.Answer) != 1 {
+		t.Fatalf("answers = %d, want 1: %v", len(reply.Answer), reply.Answer)
+	}
+	a, ok := reply.Answer[0].(*dns.A)
+	if !ok || a.A.String() != testIP {
+		t.Fatalf("device A = %v, want %s", reply.Answer[0], testIP)
+	}
+}
+
+func TestPrimaryCNAMEFollowsToDeviceA(t *testing.T) {
+	db := testDB(t)
+	seedDevice(t, db)
+
+	// the wizard stores this: <user>.zone CNAME -> <mac>.<user>.zone
+	if _, err := database.SaveDNSRecord(db, &database.DNSRecord{
+		ID: "r1", UserID: "u1", Name: testUser + "." + testZone,
+		Type: "CNAME", Content: testDevName, TTL: 300,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := query(t, testHandler(db), testUser+"."+testZone, dns.TypeA)
+	var sawCNAME, sawA bool
+	for _, rr := range reply.Answer {
+		switch v := rr.(type) {
+		case *dns.CNAME:
+			sawCNAME = v.Target == testDevName
+		case *dns.A:
+			sawA = v.A.String() == testIP
+		}
+	}
+	if !sawCNAME || !sawA {
+		t.Fatalf("want CNAME->device + A=%s, got %v", testIP, reply.Answer)
+	}
+}
+
+func TestApexAnswersServerIP(t *testing.T) {
+	db := testDB(t)
+	reply := query(t, testHandler(db), testZone, dns.TypeA)
+	if len(reply.Answer) != 1 {
+		t.Fatalf("apex answers = %v", reply.Answer)
+	}
+	if a, ok := reply.Answer[0].(*dns.A); !ok || a.A.String() != testApexIP {
+		t.Fatalf("apex A = %v, want %s", reply.Answer[0], testApexIP)
+	}
+}
+
+func TestCustomTXTRecord(t *testing.T) {
+	db := testDB(t)
+	seedDevice(t, db)
+	name := "hello." + testUser + "." + testZone
+	if _, err := database.SaveDNSRecord(db, &database.DNSRecord{
+		ID: "r2", UserID: "u1", Name: name, Type: "TXT", Content: "\"waddle\"", TTL: 60,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := query(t, testHandler(db), name, dns.TypeTXT)
+	if len(reply.Answer) != 1 {
+		t.Fatalf("txt answers = %v", reply.Answer)
+	}
+	txt, ok := reply.Answer[0].(*dns.TXT)
+	if !ok || len(txt.Txt) != 1 || txt.Txt[0] != "waddle" {
+		t.Fatalf("txt = %v, want [waddle]", reply.Answer[0])
+	}
+}
+
+func TestUnknownNameIsNXDOMAIN(t *testing.T) {
+	db := testDB(t)
+	seedDevice(t, db)
+	reply := query(t, testHandler(db), "nope."+testZone, dns.TypeA)
+	if reply.Rcode != dns.RcodeNameError {
+		t.Fatalf("rcode = %d, want NXDOMAIN(%d)", reply.Rcode, dns.RcodeNameError)
+	}
+}
+
+// guard: a foreign MAC label under someone else's username must not resolve.
+func TestDeviceRecordRejectsForeignMAC(t *testing.T) {
+	db := testDB(t)
+	seedDevice(t, db)
+	other, _ := utils.ParseMac("11:22:33:44:55:66")
+	reply := query(t, testHandler(db), other.Compact()+"."+testUser+"."+testZone, dns.TypeA)
+	if reply.Rcode != dns.RcodeNameError {
+		t.Fatalf("foreign mac rcode = %d, want NXDOMAIN", reply.Rcode)
+	}
+}