migration to new dns library

2 files changed, 99 insertions, 30 deletions

diff --git a/internal/cache/cache.go b/internal/cache/cache.go
index 8b13dd1..bb35b8e 100644
--- a/internal/cache/cache.go
+++ b/internal/cache/cache.go
@@ -7,7 +7,7 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/miekg/dns"
+	"codeberg.org/miekg/dns"
 	_ "modernc.org/sqlite"
 )
 
@@ -119,7 +119,7 @@ func (c *Cache) Get(key Key) (*dns.Msg, bool) {
 	c.mu.RUnlock()
 
 	atomic.AddInt64(&c.hits, 1)
-	msg := e.msg.Copy()
+	msg := deepCopyMsg(e.msg)
 	remaining := e.remaining()
 	adjustTTL(msg, e.ttl, remaining)
 	return msg, true
@@ -134,7 +134,7 @@ func (c *Cache) Set(key Key, msg *dns.Msg, ttl time.Duration) {
 	}
 
 	e := &entry{
-		msg: msg.Copy(),
+		msg: deepCopyMsg(msg),
 		storedAt: time.Now(),
 		ttl: ttl,
 	}
@@ -228,10 +228,11 @@ func (c *Cache) writeToDB(key Key, e *entry) {
 	if c.db == nil {
 		return
 	}
-	data, err := e.msg.Pack()
+	err := e.msg.Pack()
 	if err != nil {
 		return
 	}
+	data := e.msg.Data
 	_, err = c.db.Exec(
 		`INSERT OR REPLACE INTO cache (name, qtype, class, data, stored_at, ttl_ns)
 		VALUES (?, ?, ?, ?, ?, ?)`,
@@ -269,7 +270,8 @@ func (c *Cache) loadFromDB() {
 		}
 
 		msg := new(dns.Msg)
-		if err := msg.Unpack(data); err != nil {
+		msg.Data = data
+		if err := msg.Unpack(); err != nil {
 			continue
 		}
 
@@ -300,23 +302,23 @@ func computeTTL(msg *dns.Msg) time.Duration {
 	var min uint32
 	first := true
 	for _, rr := range msg.Answer {
-		if first || rr.Header().Ttl < min {
-			min = rr.Header().Ttl
+		if first || rr.Header().TTL < min {
+			min = rr.Header().TTL
 			first = false
 		}
 	}
 	for _, rr := range msg.Ns {
-		if first || rr.Header().Ttl < min {
-			min = rr.Header().Ttl
+		if first || rr.Header().TTL < min {
+			min = rr.Header().TTL
 			first = false
 		}
 	}
 	for _, rr := range msg.Extra {
-		if rr.Header().Rrtype == dns.TypeOPT {
+		if dns.RRToType(rr) == dns.TypeOPT {
 			continue
 		}
-		if first || rr.Header().Ttl < min {
-			min = rr.Header().Ttl
+		if first || rr.Header().TTL < min {
+			min = rr.Header().TTL
 			first = false
 		}
 	}
@@ -334,22 +336,88 @@ func computeTTL(msg *dns.Msg) time.Duration {
 func adjustTTL(msg *dns.Msg, originalTTL, remaining time.Duration) {
 	ratio := float64(remaining) / float64(originalTTL)
 	for _, rr := range msg.Answer {
-		rr.Header().Ttl = applyRatio(rr.Header().Ttl, ratio)
+		rr.Header().TTL = applyRatio(rr.Header().TTL, ratio)
 	}
 	for _, rr := range msg.Ns {
-		if rr.Header().Rrtype == dns.TypeOPT {
+		if dns.RRToType(rr) == dns.TypeOPT {
 			continue
 		}
-		rr.Header().Ttl = applyRatio(rr.Header().Ttl, ratio)
+		rr.Header().TTL = applyRatio(rr.Header().TTL, ratio)
 	}
 	for _, rr := range msg.Extra {
-		if rr.Header().Rrtype == dns.TypeOPT {
+		if dns.RRToType(rr) == dns.TypeOPT {
 			continue
 		}
-		rr.Header().Ttl = applyRatio(rr.Header().Ttl, ratio)
+		rr.Header().TTL = applyRatio(rr.Header().TTL, ratio)
 	}
 }
 
 func applyRatio(ttl uint32, ratio float64) uint32 {
 	return uint32(float64(ttl) * ratio)
 }
+
+func deepCopyMsg(msg *dns.Msg) *dns.Msg {
+	cp := new(dns.Msg)
+	cp.Response = msg.Response
+	cp.ID = msg.ID
+	cp.Opcode = msg.Opcode
+	cp.Authoritative = msg.Authoritative
+	cp.Truncated = msg.Truncated
+	cp.RecursionDesired = msg.RecursionDesired
+	cp.RecursionAvailable = msg.RecursionAvailable
+	cp.Rcode = msg.Rcode
+	cp.UDPSize = msg.UDPSize
+	cp.Question = copyRRSlice(msg.Question)
+	cp.Answer = copyRRSlice(msg.Answer)
+	cp.Ns = copyRRSlice(msg.Ns)
+	cp.Extra = copyRRSlice(msg.Extra)
+	return cp
+}
+
+func copyRRSlice(src []dns.RR) []dns.RR {
+	if src == nil {
+		return nil
+	}
+	dst := make([]dns.RR, len(src))
+	for i, rr := range src {
+		dst[i] = copyRR(rr)
+	}
+	return dst
+}
+
+func copyRR(rr dns.RR) dns.RR {
+	if rr == nil {
+		return nil
+	}
+	switch v := rr.(type) {
+	case *dns.A:
+		cp := *v
+		return &cp
+	case *dns.AAAA:
+		cp := *v
+		return &cp
+	case *dns.NS:
+		cp := *v
+		return &cp
+	case *dns.CNAME:
+		cp := *v
+		return &cp
+	case *dns.SOA:
+		cp := *v
+		return &cp
+	case *dns.MX:
+		cp := *v
+		return &cp
+	case *dns.TXT:
+		cp := *v
+		return &cp
+	case *dns.SRV:
+		cp := *v
+		return &cp
+	case *dns.PTR:
+		cp := *v
+		return &cp
+	default:
+		return rr
+	}
+}
diff --git a/internal/cache/cache_test.go b/internal/cache/cache_test.go
index 6556dcb..33e1d30 100644
--- a/internal/cache/cache_test.go
+++ b/internal/cache/cache_test.go
@@ -2,11 +2,12 @@ package cache
 
 import (
 	"fmt"
-	"net"
+	"net/netip"
 	"testing"
 	"time"
 
-	"github.com/miekg/dns"
+	"codeberg.org/miekg/dns"
+	"codeberg.org/miekg/dns/rdata"
 )
 
 func TestSetGet(t *testing.T) {
@@ -18,8 +19,8 @@ func TestSetGet(t *testing.T) {
 
 	msg := new(dns.Msg)
 	msg.Answer = append(msg.Answer, &dns.A{
-		Hdr: dns.RR_Header{Name: "example.com.", Rrtype: dns.TypeA, Ttl:300},
-		A: net.IPv4(1,2,3,4),
+		Hdr: dns.Header{Name: "example.com.", Class: dns.ClassINET, TTL: 300},
+		A:   rdata.A{Addr: netip.AddrFrom4([4]byte{1, 2, 3, 4})},
 	})
 
 	key := Key{Name: "example.com.", Qtype: dns.TypeA, Class: dns.ClassINET}
@@ -33,8 +34,8 @@ func TestSetGet(t *testing.T) {
 		t.Fatalf("expected 1 answer, got %d", len(got.Answer))
 	}
 	a, _ := got.Answer[0].(*dns.A)
-	if !a.A.Equal(net.IPv4(1,2,3,4)) {
-		t.Errorf("IP = %s, want 1.2.3.4", a.A)
+	if a.A.Addr != netip.AddrFrom4([4]byte{1, 2, 3, 4}) {
+		t.Errorf("IP = %s, want 1.2.3.4", a.A.Addr)
 	}
 }
 
@@ -67,7 +68,7 @@ func TestEviction(t *testing.T) {
 func TestComputeTTL(t *testing.T) {
 	msg := new(dns.Msg)
 	msg.Answer = append(msg.Answer, &dns.A{
-		Hdr: dns.RR_Header{Name: "x.", Rrtype: dns.TypeA, Ttl: 120},
+		Hdr: dns.Header{Name: "x.", Class: dns.ClassINET, TTL: 120},
 	})
 	if d := computeTTL(msg); d != 120*time.Second {
 		t.Errorf("TTL = %v, want 120s", d)
@@ -78,8 +79,8 @@ func TestNegativeTTL(t *testing.T) {
 	msg := new(dns.Msg)
 	msg.Rcode = dns.RcodeNameError
 	msg.Ns = append(msg.Ns, &dns.SOA{
-		Hdr:   dns.RR_Header{Name: "com.", Rrtype: dns.TypeSOA, Ttl: 900},
-		Minttl: 300,
+		Hdr: dns.Header{Name: "com.", Class: dns.ClassINET, TTL: 900},
+		SOA: rdata.SOA{Minttl: 300},
 	})
 	if d := computeTTL(msg); d != 300*time.Second {
 		t.Errorf("negative TTL = %v, want 300s", d)
@@ -116,8 +117,8 @@ func TestSQLitePersistence(t *testing.T) {
 
 	msg := new(dns.Msg)
 	msg.Answer = append(msg.Answer, &dns.A{
-		Hdr: dns.RR_Header{Name: "x.com.", Rrtype: dns.TypeA, Ttl: 300},
-		A:   net.IPv4(1, 2, 3, 4),
+		Hdr: dns.Header{Name: "x.com.", Class: dns.ClassINET, TTL: 300},
+		A:   rdata.A{Addr: netip.AddrFrom4([4]byte{1, 2, 3, 4})},
 	})
 	key := Key{Name: "x.com.", Qtype: dns.TypeA, Class: dns.ClassINET}
 	c.Set(key, msg, 300*time.Second)
@@ -134,7 +135,7 @@ func TestSQLitePersistence(t *testing.T) {
 		t.Fatal("expected cache hit from SQLite load")
 	}
 	a, _ := got.Answer[0].(*dns.A)
-	if !a.A.Equal(net.IPv4(1, 2, 3, 4)) {
-		t.Errorf("IP = %s, want 1.2.3.4", a.A)
+	if a.A.Addr != netip.AddrFrom4([4]byte{1, 2, 3, 4}) {
+		t.Errorf("IP = %s, want 1.2.3.4", a.A.Addr)
 	}
 }