migration to new dns library

1 files changed, 85 insertions, 17 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
+	}
+}