实现异步处理+缓存。

cacher.go

@@ -0,0 +1,128 @@
+package godns
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/panjf2000/ants/v2"
+	"github.com/tochusc/godns/dns"
+)
+
+type Cacher struct {
+	CacheLocation string
+	CacherLogger  *log.Logger
+	CacherPool    *ants.Pool
+}
+
+type CacherConfig struct {
+	CacheLocation string
+	LogWriter     io.Writer
+}
+
+func NewCacher(conf CacherConfig, pool *ants.Pool) *Cacher {
+	cacherLogger := log.New(conf.LogWriter, "Cacher: ", log.LstdFlags)
+
+	return &Cacher{
+		CacheLocation: conf.CacheLocation,
+		CacherLogger:  cacherLogger,
+		CacherPool:    pool,
+	}
+}
+
+func (c *Cacher) CacheResponse(data []byte) error {
+	ident, err := IdentifyMessage(data)
+	if err != nil {
+		c.CacherLogger.Printf("Error identifying response: %v", err)
+		return err
+	}
+
+	path := filepath.Join(c.CacheLocation, ident)
+
+	// 将响应缓存到磁盘
+
+	// 如果缓存目录不存在，创建目录
+	if _, err := os.Stat(c.CacheLocation); os.IsNotExist(err) {
+		err := os.MkdirAll(c.CacheLocation, 0755)
+		if err != nil {
+			c.CacherLogger.Printf("Error creating cache directory %s: %v", c.CacheLocation, err)
+			return err
+		}
+	}
+
+	// 创建缓存文件
+	file, err := os.Create(path)
+	if err != nil {
+		c.CacherLogger.Printf("Error creating cache file %s: %v", ident, err)
+		return err
+	}
+
+	_, err = file.Write(data)
+	if err != nil {
+		c.CacherLogger.Printf("Error writing cache file %s: %v", ident, err)
+		return err
+	}
+
+	file.Close()
+	c.CacherLogger.Printf("Cache saved %s\n", ident)
+
+	return nil
+}
+
+func (c *Cacher) FetchCache(connInfo ConnectionInfo) ([]byte, error) {
+
+	ident, err := IdentifyMessage(connInfo.Packet)
+	if err != nil {
+		c.CacherLogger.Printf("Error identifying response: %v", err)
+		return []byte{}, err
+	}
+
+	path := filepath.Join(c.CacheLocation, ident)
+
+	file, err := os.Open(path)
+	if err != nil {
+		c.CacherLogger.Printf("Cache miss %s\n", ident)
+		return []byte{}, err
+	}
+	defer file.Close()
+
+	cache := make([]byte, 65535)
+	rd, err := file.Read(cache)
+	if err != nil {
+		c.CacherLogger.Printf("Error reading cache file %s: %v", ident, err)
+		return []byte{}, err
+	}
+
+	c.CacherLogger.Printf("Cache hit %s\n", ident)
+
+	// 修改Cache内容
+	cache[0] = connInfo.Packet[0]
+	cache[1] = connInfo.Packet[1]
+	for i := 0; ; i++ {
+		cache[12+i] = connInfo.Packet[12+i]
+
+		if cache[12+i] > dns.NamePointerFlag {
+			cache[13+i] = connInfo.Packet[13+i]
+			break
+		}
+		if cache[12+i] == 0x00 {
+			break
+		}
+	}
+
+	return cache[:rd], nil
+}
+
+func IdentifyMessage(data []byte) (string, error) {
+	// 解析 DNS 请求
+	qName, offset, err := dns.DecodeDomainNameFromBuffer(data, 12)
+	if err != nil {
+		return "", err
+	}
+	qType := dns.DNSType(binary.BigEndian.Uint16(data[offset : offset+2]))
+	qClass := dns.DNSClass(binary.BigEndian.Uint16(data[offset+2 : offset+4]))
+	return fmt.Sprintf("%s-%s-%s", qName, qType.String(), qClass.String()), nil
+}

dns/xperi/dnssec.go

@@ -423,7 +423,7 @@ func GenerateRandomRRRRSIG(rrSet []dns.DNSResourceRecord, algo dns.DNSSECAlgorit
 	return rr
 }
 
-func GenerateRandomRDATADS(oName string, kRDATA dns.DNSRDATADNSKEY, dType dns.DNSSECDigestType) dns.DNSRDATADS {
+func GenerateRandomRDATADS(oName string, keytag int, algo dns.DNSSECAlgorithm, dType dns.DNSSECDigestType) dns.DNSRDATADS {
 	rText := []byte(GenerateRandomString(96))
 	var digest []byte
 	switch dType {
@@ -442,15 +442,15 @@ func GenerateRandomRDATADS(oName string, kRDATA dns.DNSRDATADNSKEY, dType dns.DN
 
 	// 4. 构建 DS RDATA
 	return dns.DNSRDATADS{
-		KeyTag:     CalculateKeyTag(kRDATA),
-		Algorithm:  kRDATA.Algorithm,
+		KeyTag:     uint16(keytag),
+		Algorithm:  algo,
 		DigestType: dType,
 		Digest:     digest[:],
 	}
 }
 
-func GenerateRandomRRDS(oName string, kRDATA dns.DNSRDATADNSKEY, dType dns.DNSSECDigestType) dns.DNSResourceRecord {
-	rdata := GenerateRandomRDATADS(oName, kRDATA, dType)
+func GenerateRandomRRDS(oName string, keytag int, algo dns.DNSSECAlgorithm, dType dns.DNSSECDigestType) dns.DNSResourceRecord {
+	rdata := GenerateRandomRDATADS(oName, keytag, algo, dType)
 	rr := dns.DNSResourceRecord{
 		Name:  oName,
 		Type:  dns.DNSRRTypeDS,