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libnetwork: some minor refactoring / cleanup
- don't pass the query's quetion.name separately, as we're already passing the query itself. - remove a "fallthrough" in favor of combining the cases in the switch Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This commit is contained in:
Sebastiaan van Stijn
parent
d86a331fa4
commit
79d6e935ad
1 changed files with 36 additions and 31 deletions
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@ -228,7 +228,8 @@ func createRespMsg(query *dns.Msg) *dns.Msg {
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return resp
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}
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func (r *resolver) handleMXQuery(name string, query *dns.Msg) (*dns.Msg, error) {
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func (r *resolver) handleMXQuery(query *dns.Msg) (*dns.Msg, error) {
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name := query.Question[0].Name
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addrv4, _ := r.backend.ResolveName(name, types.IPv4)
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addrv6, _ := r.backend.ResolveName(name, types.IPv6)
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@ -244,9 +245,12 @@ func (r *resolver) handleMXQuery(name string, query *dns.Msg) (*dns.Msg, error)
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return resp, nil
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}
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func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.Msg, error) {
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var addr []net.IP
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var ipv6Miss bool
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func (r *resolver) handleIPQuery(query *dns.Msg, ipType int) (*dns.Msg, error) {
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var (
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addr []net.IP
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ipv6Miss bool
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name = query.Question[0].Name
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)
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addr, ipv6Miss = r.backend.ResolveName(name, ipType)
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if addr == nil && ipv6Miss {
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@ -283,8 +287,11 @@ func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.
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return resp, nil
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}
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func (r *resolver) handlePTRQuery(ptr string, query *dns.Msg) (*dns.Msg, error) {
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var parts []string
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func (r *resolver) handlePTRQuery(query *dns.Msg) (*dns.Msg, error) {
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var (
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parts []string
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ptr = query.Question[0].Name
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)
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if strings.HasSuffix(ptr, ptrIPv4domain) {
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parts = strings.Split(ptr, ptrIPv4domain)
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@ -314,8 +321,8 @@ func (r *resolver) handlePTRQuery(ptr string, query *dns.Msg) (*dns.Msg, error)
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return resp, nil
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}
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func (r *resolver) handleSRVQuery(svc string, query *dns.Msg) (*dns.Msg, error) {
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func (r *resolver) handleSRVQuery(query *dns.Msg) (*dns.Msg, error) {
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svc := query.Question[0].Name
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srv, ip := r.backend.ResolveService(svc)
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if len(srv) == 0 {
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@ -371,25 +378,26 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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return
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}
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name := query.Question[0].Name
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switch query.Question[0].Qtype {
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queryName := query.Question[0].Name
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queryType := query.Question[0].Qtype
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switch queryType {
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case dns.TypeA:
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resp, err = r.handleIPQuery(name, query, types.IPv4)
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resp, err = r.handleIPQuery(query, types.IPv4)
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case dns.TypeAAAA:
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resp, err = r.handleIPQuery(name, query, types.IPv6)
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resp, err = r.handleIPQuery(query, types.IPv6)
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case dns.TypeMX:
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resp, err = r.handleMXQuery(name, query)
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resp, err = r.handleMXQuery(query)
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case dns.TypePTR:
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resp, err = r.handlePTRQuery(name, query)
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resp, err = r.handlePTRQuery(query)
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case dns.TypeSRV:
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resp, err = r.handleSRVQuery(name, query)
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resp, err = r.handleSRVQuery(query)
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default:
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queryType := dns.TypeToString[query.Question[0].Qtype]
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logrus.Debugf("[resolver] query type %s is not supported by the embedded DNS and will be forwarded to external DNS", queryType)
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logrus.Debugf("[resolver] query type %s is not supported by the embedded DNS and will be forwarded to external DNS", dns.TypeToString[queryType])
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}
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if err != nil {
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logrus.WithError(err).Errorf("[resolver] failed to handle query: %s (%s) from %s", name, dns.TypeToString[query.Question[0].Qtype], extConn.LocalAddr().String())
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logrus.WithError(err).Errorf("[resolver] failed to handle query: %s (%s) from %s", queryName, dns.TypeToString[queryType], extConn.LocalAddr().String())
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return
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}
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@ -409,11 +417,9 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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// in the root domain don't forward it out. We will return
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// failure and let the client retry with the search domain
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// attached
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switch query.Question[0].Qtype {
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case dns.TypeA:
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fallthrough
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case dns.TypeAAAA:
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if r.backend.NdotsSet() && !strings.Contains(strings.TrimSuffix(name, "."), ".") {
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switch queryType {
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case dns.TypeA, dns.TypeAAAA:
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if r.backend.NdotsSet() && !strings.Contains(strings.TrimSuffix(queryName, "."), ".") {
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resp = createRespMsg(query)
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}
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}
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@ -461,8 +467,7 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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logrus.WithField("retries", i).Warnf("[resolver] connect failed: %s", err)
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continue
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}
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queryType := dns.TypeToString[query.Question[0].Qtype]
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logrus.Debugf("[resolver] query %s (%s) from %s, forwarding to %s:%s", name, queryType,
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logrus.Debugf("[resolver] query %s (%s) from %s, forwarding to %s:%s", queryName, dns.TypeToString[queryType],
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extConn.LocalAddr().String(), proto, extDNS.IPStr)
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// Timeout has to be set for every IO operation.
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@ -503,18 +508,18 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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r.forwardQueryEnd()
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if resp == nil {
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logrus.Debugf("[resolver] external DNS %s:%s returned empty response for %q", proto, extDNS.IPStr, name)
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logrus.Debugf("[resolver] external DNS %s:%s returned empty response for %q", proto, extDNS.IPStr, queryName)
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break
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}
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switch resp.Rcode {
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case dns.RcodeServerFailure, dns.RcodeRefused:
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// Server returned FAILURE: continue with the next external DNS server
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// Server returned REFUSED: this can be a transitional status, so continue with the next external DNS server
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s for %q", proto, extDNS.IPStr, statusString(resp.Rcode), name)
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s for %q", proto, extDNS.IPStr, statusString(resp.Rcode), queryName)
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continue
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case dns.RcodeNameError:
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// Server returned NXDOMAIN. Stop resolution if it's an authoritative answer (see RFC 8020: https://tools.ietf.org/html/rfc8020#section-2)
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s for %q", proto, extDNS.IPStr, statusString(resp.Rcode), name)
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s for %q", proto, extDNS.IPStr, statusString(resp.Rcode), queryName)
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if resp.Authoritative {
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break
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}
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@ -523,7 +528,7 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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// All is well
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default:
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// Server gave some error. Log the error, and continue with the next external DNS server
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s (code %d) for %q", proto, extDNS.IPStr, statusString(resp.Rcode), resp.Rcode, name)
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logrus.Debugf("[resolver] external DNS %s:%s responded with %s (code %d) for %q", proto, extDNS.IPStr, statusString(resp.Rcode), resp.Rcode, queryName)
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continue
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}
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answers := 0
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@ -543,7 +548,7 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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}
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}
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if resp.Answer == nil || answers == 0 {
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logrus.Debugf("[resolver] external DNS %s:%s did not return any %s records for %q", proto, extDNS.IPStr, queryType, name)
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logrus.Debugf("[resolver] external DNS %s:%s did not return any %s records for %q", proto, extDNS.IPStr, dns.TypeToString[queryType], queryName)
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}
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resp.Compress = true
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break
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@ -554,7 +559,7 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
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}
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if err = w.WriteMsg(resp); err != nil {
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logrus.WithError(err).Errorf("[resolver] failed to write resolver response")
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logrus.WithError(err).Errorf("[resolver] failed to write response")
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}
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}
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