dns: add mapping of response code to human readable names

This mapping can be used to print an error message based on error code
on response.

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/dns/dns.go b/lib/dns/dns.go
index 467659d0..450709a6 100644
--- a/lib/dns/dns.go
+++ b/lib/dns/dns.go
@@ -214,3 +214,16 @@ const (
 	// zone transfer) for particular data.
 	RCodeRefused
 )
+
+//
+// rcodeNames contains mapping of response code with their human readable
+// names.
+//
+var rcodeNames = map[ResponseCode]string{
+	RCodeOK:             "OK",
+	RCodeErrFormat:      "ERR_FORMAT",
+	RCodeErrServer:      "ERR_SERVER",
+	RCodeErrName:        "ERR_NAME",
+	RCodeNotImplemented: "ERR_NOT_IMPLEMENTED",
+	RCodeRefused:        "ERR_REFUSED",
+}