diff --git a/nameserver/server.go b/nameserver/server.go index 2aada3c3..d80846fb 100644 --- a/nameserver/server.go +++ b/nameserver/server.go @@ -215,70 +215,49 @@ func (s *DNSServer) Stop() error { } func (s *DNSServer) queryHandler(proto dnsProtocol) dns.HandlerFunc { - return func(w dns.ResponseWriter, r *dns.Msg) { - now := time.Now() - q := r.Question[0] - maxLen := getMaxReplyLen(r, proto) - lookups := []ZoneLookup{s.Zone, s.mdnsCli} - Debug.Printf("Query: %+v", q) - - reply, err := s.cache.Get(r, maxLen, time.Now()) - if err != nil { - if err == errNoLocalReplies { - Debug.Printf("[dns msgid %d] Cached 'no local replies' - skipping local lookup", r.MsgHdr.Id) - lookups = []ZoneLookup{s.Zone} - } else { - Debug.Printf("[dns msgid %d] Error from cache: %s", r.MsgHdr.Id, err) - w.WriteMsg(makeDNSFailResponse(r)) - return - } - } - if reply != nil { - Debug.Printf("[dns msgid %d] Returning reply from cache: %s/%d answers", - r.MsgHdr.Id, dns.RcodeToString[reply.MsgHdr.Rcode], len(reply.Answer)) - w.WriteMsg(reply) - return + zoneLookup := func(lookup ZoneLookup, q *dns.Question, r *dns.Msg) (*dns.Msg, []ZoneRecord, error) { + if ips, err := lookup.LookupName(q.Name); err != nil { + return nil, nil, err + } else { + return makeAddressReply(r, q, ips), ips, nil } + } - // catch unsupported queries - if q.Qtype != dns.TypeA { - Debug.Printf("[dns msgid %d] Unsuported query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype]) - m := makeDNSNotImplResponse(r) - s.cache.Put(r, m, negLocalTTL, 0, now) - w.WriteMsg(m) - return - } - - for _, lookup := range lookups { - if ips, err := lookup.LookupName(q.Name); err == nil { - m := makeAddressReply(r, &q, ips) - m.Authoritative = true - - Debug.Printf("[dns msgid %d] Caching response for %s-query for \"%s\": %s [code:%s]", - m.MsgHdr.Id, dns.TypeToString[q.Qtype], q.Name, ips, dns.RcodeToString[m.Rcode]) - s.cache.Put(r, m, nullTTL, 0, now) - w.WriteMsg(m) - return - } - now = time.Now() - } - - Info.Printf("[dns msgid %d] No results for type %s query %s [caching no-local]", - r.MsgHdr.Id, dns.TypeToString[q.Qtype], q.Name) - s.cache.Put(r, nil, negLocalTTL, CacheNoLocalReplies, now) + fallback := func(w dns.ResponseWriter, r *dns.Msg) { w.WriteMsg(makeDNSFailResponse(r)) } + + return s.commonQueryHandler(proto, "Query", dns.TypeA, zoneLookup, fallback) } func (s *DNSServer) rdnsHandler(proto dnsProtocol) dns.HandlerFunc { - fallback := s.notUsHandler(proto) + zoneLookup := func(lookup ZoneLookup, q *dns.Question, r *dns.Msg) (*dns.Msg, []ZoneRecord, error) { + if names, err := lookup.LookupInaddr(q.Name); err != nil { + return nil, nil, err + } else { + return makePTRReply(r, q, names), names, nil + } + } + + notUsHandler := s.notUsHandler(proto) + fallback := func(w dns.ResponseWriter, r *dns.Msg) { + Info.Printf("[dns msgid %d] -> sending to fallback server", r.MsgHdr.Id) + notUsHandler(w, r) + } + + return s.commonQueryHandler(proto, "Reverse query", dns.TypePTR, zoneLookup, fallback) +} + +func (s *DNSServer) commonQueryHandler(proto dnsProtocol, kind string, qtype uint16, + zoneLookup func(ZoneLookup, *dns.Question, *dns.Msg) (*dns.Msg, []ZoneRecord, error), fallback dns.HandlerFunc) dns.HandlerFunc { + return func(w dns.ResponseWriter, r *dns.Msg) { + q := r.Question[0] + Debug.Printf("[dns msgid %d] %s: %+v", r.MsgHdr.Id, kind, q) now := time.Now() - q := r.Question[0] + maxLen := getMaxReplyLen(r, proto) lookups := []ZoneLookup{s.Zone, s.mdnsCli} - maxLen := getMaxReplyLen(r, proto) - Debug.Printf("Reverse query: %+v", q) reply, err := s.cache.Get(r, maxLen, time.Now()) if err != nil { if err == errNoLocalReplies { @@ -298,9 +277,8 @@ func (s *DNSServer) rdnsHandler(proto dnsProtocol) dns.HandlerFunc { } // catch unsupported queries - if q.Qtype != dns.TypePTR { - Warning.Printf("[dns msgid %d] Unexpected reverse query type %s: %+v", - r.MsgHdr.Id, dns.TypeToString[q.Qtype], q) + if q.Qtype != qtype { + Debug.Printf("[dns msgid %d] Unsupported query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype]) m := makeDNSNotImplResponse(r) s.cache.Put(r, m, negLocalTTL, 0, now) w.WriteMsg(m) @@ -308,12 +286,10 @@ func (s *DNSServer) rdnsHandler(proto dnsProtocol) dns.HandlerFunc { } for _, lookup := range lookups { - if names, err := lookup.LookupInaddr(q.Name); err == nil { - m := makePTRReply(r, &q, names) + if m, answers, err := zoneLookup(lookup, &q, r); err == nil { m.Authoritative = true - - Debug.Printf("[dns msgid %d] Caching response for %s-query for \"%s\": %s [code:%s]", - m.MsgHdr.Id, dns.TypeToString[q.Qtype], q.Name, names, dns.RcodeToString[m.Rcode]) + Debug.Printf("[dns msgid %d] Caching response for type %s query for '%s': %s [code:%s]", + m.MsgHdr.Id, dns.TypeToString[q.Qtype], q.Name, answers, dns.RcodeToString[m.Rcode]) s.cache.Put(r, m, nullTTL, 0, now) w.WriteMsg(m) return @@ -321,9 +297,10 @@ func (s *DNSServer) rdnsHandler(proto dnsProtocol) dns.HandlerFunc { now = time.Now() } - Info.Printf("[dns msgid %d] No results for %s-query about '%s' [caching no-local] -> sending to fallback server", + Info.Printf("[dns msgid %d] No results for type %s query for '%s' [caching no-local]", r.MsgHdr.Id, dns.TypeToString[q.Qtype], q.Name) s.cache.Put(r, nil, negLocalTTL, CacheNoLocalReplies, now) + fallback(w, r) } }