Fix DNS exchange

dns/client.go

@@ -280,7 +280,7 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 		}
 	}
 	logExchangedResponse(c.logger, ctx, response, timeToLive)
-	return response, err
+	return response, nil
 }
 
 func (c *Client) Lookup(ctx context.Context, transport adapter.DNSTransport, domain string, options adapter.DNSQueryOptions, responseChecker func(responseAddrs []netip.Addr) bool) ([]netip.Addr, error) {

dns/rcode.go

@@ -5,6 +5,7 @@ import (
 )
 
 const (
+	RcodeSuccess     RcodeError = mDNS.RcodeSuccess
 	RcodeFormatError RcodeError = mDNS.RcodeFormatError
 	RcodeNameError   RcodeError = mDNS.RcodeNameError
 	RcodeRefused     RcodeError = mDNS.RcodeRefused

dns/transport/dhcp/dhcp_shared.go

@@ -43,7 +43,7 @@ func (t *Transport) exchangeParallel(ctx context.Context, servers []M.Socksaddr,
 			if response.Rcode != mDNS.RcodeSuccess {
 				err = dns.RcodeError(response.Rcode)
 			} else if len(dns.MessageToAddresses(response)) == 0 {
-				err = E.New(fqdn, ": empty result")
+				err = dns.RcodeSuccess
 			}
 		}
 		select {

dns/transport/local/local.go

@@ -95,7 +95,7 @@ func (t *Transport) exchangeParallel(ctx context.Context, systemConfig *dnsConfi
 			if response.Rcode != mDNS.RcodeSuccess {
 				err = dns.RcodeError(response.Rcode)
 			} else if len(dns.MessageToAddresses(response)) == 0 {
-				err = E.New(fqdn, ": empty result")
+				err = dns.RcodeSuccess
 			}
 		}
 		select {