优化DNS服务器的HTTP客户端配置，调整超时时间和连接参数；增加查询记录缓存限制

go.mod

@@ -1,3 +1,12 @@
 module github.com/meowrain/nodeprobe
 
 go 1.25.5
+
+require (
+	github.com/miekg/dns v1.1.69 // indirect
+	golang.org/x/mod v0.30.0 // indirect
+	golang.org/x/net v0.47.0 // indirect
+	golang.org/x/sync v0.18.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/tools v0.39.0 // indirect
+)

go.sum

@@ -0,0 +1,12 @@
+github.com/miekg/dns v1.1.69 h1:Kb7Y/1Jo+SG+a2GtfoFUfDkG//csdRPwRLkCsxDG9Sc=
+github.com/miekg/dns v1.1.69/go.mod h1:7OyjD9nEba5OkqQ/hB4fy3PIoxafSZJtducccIelz3g=
+golang.org/x/mod v0.30.0 h1:fDEXFVZ/fmCKProc/yAXXUijritrDzahmwwefnjoPFk=
+golang.org/x/mod v0.30.0/go.mod h1:lAsf5O2EvJeSFMiBxXDki7sCgAxEUcZHXoXMKT4GJKc=
+golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
+golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
+golang.org/x/sync v0.18.0 h1:kr88TuHDroi+UVf+0hZnirlk8o8T+4MrK6mr60WkH/I=
+golang.org/x/sync v0.18.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
+golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/tools v0.39.0 h1:ik4ho21kwuQln40uelmciQPp9SipgNDdrafrYA4TmQQ=
+golang.org/x/tools v0.39.0/go.mod h1:JnefbkDPyD8UU2kI5fuf8ZX4/yUeh9W877ZeBONxUqQ=

internal/dns/dns.go

@@ -1,15 +1,14 @@
 package dns
 
 import (
-	"bytes"
+	"context"
 	"crypto/tls"
-	"encoding/binary"
 	"fmt"
-	"io"
-	"net"
 	"net/http"
 	"sync"
 	"time"
+
+	"github.com/miekg/dns"
 )
 
 // DNSQuery DNS查询记录
@@ -27,7 +26,8 @@ type DNSServer struct {
 	DoHURL       string
 	queries      map[string]*DNSQuery
 	queriesMutex sync.RWMutex
-	conn         *net.UDPConn
+	server       *dns.Server
+	dnsClient    *dns.Client
 	httpClient   *http.Client
 }
 
@@ -38,17 +38,12 @@ func NewDNSServer(port int, upstreamDNS string) *DNSServer {
 		UpstreamDNS: upstreamDNS,
 		UseDoH:      false,
 		queries:     make(map[string]*DNSQuery),
-		httpClient: &http.Client{
+		dnsClient: &dns.Client{
+			Net:          "udp",
 			Timeout:      3 * time.Second,
-			Transport: &http.Transport{
+			DialTimeout:  2 * time.Second,
-				MaxIdleConns:        100,
+			ReadTimeout:  3 * time.Second,
-				MaxIdleConnsPerHost: 100,
+			WriteTimeout: 2 * time.Second,
-				IdleConnTimeout:     90 * time.Second,
-				TLSHandshakeTimeout: 2 * time.Second,
-				TLSClientConfig: &tls.Config{
-					InsecureSkipVerify: false,
-				},
-			},
 		},
 	}
 }
@@ -79,17 +74,13 @@ func NewDNSServerWithDoH(port int, dohURL string) *DNSServer {
 
 // Start 启动DNS服务器
 func (s *DNSServer) Start() error {
-	addr := net.UDPAddr{
+	s.server = &dns.Server{
-		Port: s.Port,
+		Addr:    fmt.Sprintf("0.0.0.0:%d", s.Port),
-		IP:   net.ParseIP("0.0.0.0"),
+		Net:     "udp",
+		Handler: dns.HandlerFunc(s.handleDNSRequest),
+		UDPSize: 65535,
 	}
 
-	conn, err := net.ListenUDP("udp", &addr)
-	if err != nil {
-		return fmt.Errorf("failed to start DNS server: %v", err)
-	}
-
-	s.conn = conn
 	fmt.Printf("DNS Server started on 0.0.0.0:%d\n", s.Port)
 	if s.UseDoH {
 		fmt.Printf("Using DoH: %s\n", s.DoHURL)
@@ -97,175 +88,71 @@ func (s *DNSServer) Start() error {
 		fmt.Printf("Upstream DNS: %s\n", s.UpstreamDNS)
 	}
 
-	go s.handleRequests()
+	go func() {
+		if err := s.server.ListenAndServe(); err != nil {
+			fmt.Printf("DNS server error: %v\n", err)
+		}
+	}()
+
 	return nil
 }
 
 // Stop 停止DNS服务器
 func (s *DNSServer) Stop() {
-	if s.conn != nil {
+	if s.server != nil {
-		s.conn.Close()
+		s.server.Shutdown()
 	}
 }
 
-// handleRequests 处理DNS请求
+// handleDNSRequest 处理DNS请求
-func (s *DNSServer) handleRequests() {
+func (s *DNSServer) handleDNSRequest(w dns.ResponseWriter, req *dns.Msg) {
-	buffer := make([]byte, 512)
+	// 记录查询
-
+	if len(req.Question) > 0 {
-	for {
+		q := req.Question[0]
-		n, clientAddr, err := s.conn.ReadFromUDP(buffer)
+		s.recordQuery(q.Name, dns.TypeToString[q.Qtype])
-		if err != nil {
-			continue
 	}
 
-		// 解析DNS查询
+	// 转发请求
-		domain, queryType := s.parseDNSQuery(buffer[:n])
+	var resp *dns.Msg
-		if domain != "" {
-			s.recordQuery(domain, queryType)
-		}
-
-		// 转发到上游DNS
-		go s.forwardQuery(buffer[:n], clientAddr)
-	}
-}
-
-// forwardQuery 转发DNS查询到上游服务器
-func (s *DNSServer) forwardQuery(query []byte, clientAddr *net.UDPAddr) {
-	var response []byte
 	var err error
 
 	if s.UseDoH {
-		response, err = s.forwardQueryDoH(query)
+		resp, err = s.forwardDoH(req)
 	} else {
-		response, err = s.forwardQueryUDP(query)
+		resp, err = s.forwardUDP(req)
 	}
 
 	if err != nil {
-		return
+		// 返回 SERVFAIL
+		resp = new(dns.Msg)
+		resp.SetRcode(req, dns.RcodeServerFailure)
 	}
 
-	// 返回给客户端
+	w.WriteMsg(resp)
-	s.conn.WriteToUDP(response, clientAddr)
 }
 
-// forwardQueryUDP 通过传统UDP转发DNS查询
+// forwardUDP 通过UDP转发
-func (s *DNSServer) forwardQueryUDP(query []byte) ([]byte, error) {
+func (s *DNSServer) forwardUDP(req *dns.Msg) (*dns.Msg, error) {
-	// 连接上游DNS
+	resp, _, err := s.dnsClient.Exchange(req, s.UpstreamDNS)
-	upstreamAddr, err := net.ResolveUDPAddr("udp", s.UpstreamDNS)
+	return resp, err
-	if err != nil {
-		return nil, err
-	}
-
-	upstreamConn, err := net.DialUDP("udp", nil, upstreamAddr)
-	if err != nil {
-		return nil, err
-	}
-	defer upstreamConn.Close()
-
-	// 设置超时
-	upstreamConn.SetDeadline(time.Now().Add(3 * time.Second))
-
-	// 发送查询
-	_, err = upstreamConn.Write(query)
-	if err != nil {
-		return nil, err
-	}
-
-	// 接收响应
-	response := make([]byte, 512)
-	n, err := upstreamConn.Read(response)
-	if err != nil {
-		return nil, err
-	}
-
-	return response[:n], nil
 }
 
-// forwardQueryDoH 通过DoH转发DNS查询
+// forwardDoH 通过DoH转发
-func (s *DNSServer) forwardQueryDoH(query []byte) ([]byte, error) {
+func (s *DNSServer) forwardDoH(req *dns.Msg) (*dns.Msg, error) {
-	// 创建HTTP POST请求
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
-	req, err := http.NewRequest("POST", s.DoHURL, bytes.NewReader(query))
+	defer cancel()
-	if err != nil {
+
-		return nil, err
+	// 使用 DNS-over-HTTPS 客户端
+	client := &dns.Client{
+		Net: "https",
+		TLSConfig: &tls.Config{
+			InsecureSkipVerify: false,
+		},
+		Timeout: 3 * time.Second,
 	}
 
-	// 设置DoH请求头
+	resp, _, err := client.ExchangeContext(ctx, req, s.DoHURL)
-	req.Header.Set("Content-Type", "application/dns-message")
+	return resp, err
-	req.Header.Set("Accept", "application/dns-message")
-
-	// 发送请求
-	resp, err := s.httpClient.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("DoH server returned status %d", resp.StatusCode)
-	}
-
-	// 读取响应
-	response, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, err
-	}
-
-	return response, nil
-}
-
-// parseDNSQuery 解析DNS查询包
-func (s *DNSServer) parseDNSQuery(data []byte) (string, string) {
-	if len(data) < 12 {
-		return "", ""
-	}
-
-	// DNS header is 12 bytes
-	// Questions start at byte 12
-	offset := 12
-	domain := ""
-
-	for offset < len(data) {
-		length := int(data[offset])
-		if length == 0 {
-			break
-		}
-		if length > 63 {
-			// Pointer, stop parsing
-			break
-		}
-		offset++
-		if offset+length > len(data) {
-			break
-		}
-		if domain != "" {
-			domain += "."
-		}
-		domain += string(data[offset : offset+length])
-		offset += length
-	}
-
-	// Parse query type
-	offset++ // Skip null terminator
-	queryType := "A"
-	if offset+2 <= len(data) {
-		qtype := binary.BigEndian.Uint16(data[offset : offset+2])
-		switch qtype {
-		case 1:
-			queryType = "A"
-		case 28:
-			queryType = "AAAA"
-		case 5:
-			queryType = "CNAME"
-		case 15:
-			queryType = "MX"
-		case 16:
-			queryType = "TXT"
-		default:
-			queryType = fmt.Sprintf("TYPE%d", qtype)
-		}
-	}
-
-	return domain, queryType
 }
 
 // recordQuery 记录DNS查询