stop being authoritative for stuff not in internal dns

1 files changed, 25 insertions, 28 deletions

diff --git a/dns/server.go b/dns/server.go
index f5365e8..9b3e5e9 100644
--- a/dns/server.go
+++ b/dns/server.go
@@ -11,17 +11,13 @@ import (
 
 const MAX_RECURSION = 10
 
-func resolveRecursive(dbConn *sql.DB, dnsResolvers []string, domain string, qtype uint16, maxDepth int) ([]dns.RR, error) {
-	if maxDepth == 0 {
-		return nil, fmt.Errorf("too much recursion")
-	}
-
+func resolveInternalCNAMEs(dbConn *sql.DB, domain string, qtype uint16, maxDepth int) ([]dns.RR, error) {
 	internalCnames, err := database.FindDNSRecords(dbConn, domain, "CNAME")
 	if err != nil {
 		return nil, err
 	}
 
-	answers := []dns.RR{}
+	var answers []dns.RR
 	for _, record := range internalCnames {
 		cname, err := dns.NewRR(fmt.Sprintf("%s %d IN CNAME %s", record.Name, record.TTL, record.Content))
 		if err != nil {
@@ -29,7 +25,10 @@ func resolveRecursive(dbConn *sql.DB, dnsResolvers []string, domain string, qtyp
 		}
 		answers = append(answers, cname)
 
-		cnameRecursive, _ := resolveRecursive(dbConn, dnsResolvers, record.Content, qtype, maxDepth-1)
+		cnameRecursive, err := resolveDNS(dbConn, record.Content, qtype, maxDepth-1)
+		if err != nil {
+			return nil, err
+		}
 		answers = append(answers, cnameRecursive...)
 	}
 
@@ -43,37 +42,31 @@ func resolveRecursive(dbConn *sql.DB, dnsResolvers []string, domain string, qtyp
 		return nil, err
 	}
 	for _, record := range typeDnsRecords {
-		answer, err := dns.NewRR(fmt.Sprintf("%s %d IN %s %s", record.Name, record.TTL, record.Type, record.Content))
+		answer, err := dns.NewRR(fmt.Sprintf("%s %d IN %s %s", record.Name, record.TTL, qtypeName, record.Content))
 		if err != nil {
 			return nil, err
 		}
 		answers = append(answers, answer)
 	}
 
-	if len(answers) > 0 {
-		// base case; we found the answer
-		return answers, nil
-	}
+	return answers, nil
+}
 
-	message := new(dns.Msg)
-	message.SetQuestion(dns.Fqdn(domain), qtype)
-	message.RecursionDesired = true
+func resolveDNS(dbConn *sql.DB, domain string, qtype uint16, maxDepth int) ([]dns.RR, error) {
+	if maxDepth == 0 {
+		return nil, fmt.Errorf("too much recursion")
+	}
 
-	client := new(dns.Client)
+	answers, err := resolveInternalCNAMEs(dbConn, domain, qtype, maxDepth)
+	if err != nil {
+		return nil, err
+	}
 
-	i := 0
-	in, _, err := client.Exchange(message, dnsResolvers[i])
-	for err != nil {
-		i += 1
-		if i == len(dnsResolvers) {
-			log.Println(err)
-			return nil, err
-		}
-		in, _, err = client.Exchange(message, dnsResolvers[i])
+	if len(answers) > 0 {
+		return answers, nil
 	}
 
-	answers = append(answers, in.Answer...)
-	return answers, nil
+	return nil, fmt.Errorf("no records found for %s", domain)
 }
 
 type DnsHandler struct {
@@ -87,7 +80,7 @@ func (h *DnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	msg.Authoritative = true
 
 	for _, question := range r.Question {
-		answers, err := resolveRecursive(h.DbConn, h.DnsResolvers, question.Name, question.Qtype, MAX_RECURSION)
+		answers, err := resolveDNS(h.DbConn, question.Name, question.Qtype, MAX_RECURSION)
 		if err != nil {
 			fmt.Println(err)
 			continue
@@ -95,6 +88,10 @@ func (h *DnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		msg.Answer = append(msg.Answer, answers...)
 	}
 
+	if len(msg.Answer) == 0 {
+		msg.SetRcode(r, dns.RcodeNameError)
+	}
+
 	log.Println(msg.Answer)
 	w.WriteMsg(msg)
 }