92 lines
1.7 KiB
Go
92 lines
1.7 KiB
Go
package dns
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import (
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"errors"
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"net"
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"github.com/Dreamacro/clash/common/sockopt"
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"github.com/Dreamacro/clash/context"
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"github.com/Dreamacro/clash/log"
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D "github.com/miekg/dns"
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)
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var (
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address string
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server = &Server{}
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dnsDefaultTTL uint32 = 600
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)
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type Server struct {
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*D.Server
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handler handler
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}
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// ServeDNS implement D.Handler ServeDNS
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func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) {
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msg, err := handlerWithContext(s.handler, r)
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if err != nil {
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D.HandleFailed(w, r)
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return
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}
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msg.Compress = true
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w.WriteMsg(msg)
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}
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func handlerWithContext(handler handler, msg *D.Msg) (*D.Msg, error) {
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if len(msg.Question) == 0 {
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return nil, errors.New("at least one question is required")
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}
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ctx := context.NewDNSContext(msg)
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return handler(ctx, msg)
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}
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func (s *Server) SetHandler(handler handler) {
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s.handler = handler
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}
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func ReCreateServer(addr string, resolver *Resolver, mapper *ResolverEnhancer) error {
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if addr == address && resolver != nil {
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handler := NewHandler(resolver, mapper)
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server.SetHandler(handler)
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return nil
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}
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if server.Server != nil {
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server.Shutdown()
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server = &Server{}
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address = ""
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}
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_, port, err := net.SplitHostPort(addr)
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if port == "0" || port == "" || err != nil {
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return nil
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}
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udpAddr, err := net.ResolveUDPAddr("udp", addr)
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if err != nil {
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return err
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}
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p, err := net.ListenUDP("udp", udpAddr)
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if err != nil {
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return err
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}
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err = sockopt.UDPReuseaddr(p)
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if err != nil {
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log.Warnln("Failed to Reuse UDP Address: %s", err)
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}
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address = addr
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handler := NewHandler(resolver, mapper)
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server = &Server{handler: handler}
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server.Server = &D.Server{Addr: addr, PacketConn: p, Handler: server}
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go func() {
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server.ActivateAndServe()
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}()
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return nil
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}
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