Refuse dynamic updates properly (#124)

joohoi · Oct 31, 2018 · 3bb130d · 3bb130d
1 parent 1d85bf7
commit 3bb130d
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Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/README.md b/README.md
@@ -303,6 +303,7 @@ logformat = "text"
 - unreleased
  - New
  - Command line flag `-c` to specify location of config file.
+ - Proper refusal of dynamic update requests.
 - v0.5
  - New
  - Configurable certificate cache directory

diff --git a/dns.go b/dns.go
@@ -56,7 +56,6 @@ func answer(q dns.Question) ([]dns.RR, int, error) {
  if !ok {
  rcode = dns.RcodeNameError
  }
-
  }
  log.WithFields(log.Fields{"qtype": dns.TypeToString[rtype], "domain": domain, "rcode": dns.RcodeToString[rcode]}).Debug("Answering question for domain")
  return r, rcode, nil
@@ -68,6 +67,9 @@ func handleRequest(w dns.ResponseWriter, r *dns.Msg) {
 
  if r.Opcode == dns.OpcodeQuery {
  readQuery(m)
+ } else if r.Opcode == dns.OpcodeUpdate {
+ log.Debug("Refusing DNS Dynamic update request")
+ m.MsgHdr.Rcode = dns.RcodeRefused
  }
 
  w.WriteMsg(m)