cleanup fakedns package

component/fakedns/server.go

@@ -0,0 +1,111 @@
+package fakedns
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+
+	trie "github.com/xjasonlyu/tun2socks/common/domain-trie"
+	"github.com/xjasonlyu/tun2socks/common/fakeip"
+
+	D "github.com/miekg/dns"
+)
+
+const (
+	dnsCacheSize int = 1000
+
+	dnsFakeTTL    uint32 = 1
+	dnsDefaultTTL uint32 = 600
+)
+
+var (
+	ServeAddr = "127.0.0.1:5353"
+)
+
+type Server struct {
+	*D.Server
+	p *fakeip.Pool
+	h handler
+}
+
+func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) {
+	if len(r.Question) == 0 {
+		D.HandleFailed(w, r)
+		return
+	}
+	s.h(w, r)
+}
+
+func (s *Server) Start() error {
+	_, port, err := net.SplitHostPort(ServeAddr)
+	if port == "0" || port == "" || err != nil {
+		return errors.New("address format error")
+	}
+
+	udpAddr, err := net.ResolveUDPAddr("udp", ServeAddr)
+	if err != nil {
+		return err
+	}
+
+	pc, err := net.ListenUDP("udp", udpAddr)
+	if err != nil {
+		return err
+	}
+
+	s.Server = &D.Server{Addr: ServeAddr, PacketConn: pc, Handler: s}
+	go func() {
+		s.ActivateAndServe()
+	}()
+
+	return nil
+}
+
+func (s *Server) Stop() error {
+	return s.Shutdown()
+}
+
+func (s *Server) IPToHost(ip net.IP) (string, bool) {
+	return s.p.LookBack(ip)
+}
+
+func NewServer(fakeIPRange, hosts string) (*Server, error) {
+	_, ipnet, err := net.ParseCIDR(fakeIPRange)
+	if err != nil {
+		return nil, err
+	}
+
+	pool, err := fakeip.New(ipnet, dnsCacheSize)
+	if err != nil {
+		return nil, err
+	}
+
+	hostsTree := func(str string) *trie.Trie {
+		// trim `'` `"` ` ` char
+		str = strings.Trim(str, "' \"")
+		if str == "" {
+			return nil
+		}
+		tree := trie.New()
+		s := strings.Split(str, ",")
+		for _, host := range s {
+			m := strings.Split(host, "=")
+			if len(m) != 2 {
+				continue
+			}
+			domain := strings.TrimSpace(m[0])
+			target := strings.TrimSpace(m[1])
+			if err := tree.Insert(domain, net.ParseIP(target)); err != nil {
+				panic(fmt.Sprintf("add hosts error: %v", err))
+			}
+		}
+		return tree
+	}(hosts)
+
+	handler := newHandler(hostsTree, pool)
+
+	return &Server{
+		p: pool,
+		h: handler,
+	}, nil
+}