diff --git a/edns.go b/edns.go index 6f9d2ea3..55059eb1 100644 --- a/edns.go +++ b/edns.go @@ -102,12 +102,15 @@ func (rr *OPT) SetVersion(v uint8) { // ExtendedRcode returns the EDNS extended RCODE field (the upper 8 bits of the TTL). func (rr *OPT) ExtendedRcode() int { - return int((rr.Hdr.Ttl & 0xFF000000) >> 24) + return int((rr.Hdr.Ttl&0xFF000000)>>24) + 15 } // SetExtendedRcode sets the EDNS extended RCODE field. func (rr *OPT) SetExtendedRcode(v uint8) { - rr.Hdr.Ttl = rr.Hdr.Ttl&0x00FFFFFF | (uint32(v) << 24) + if v < RcodeBadVers { // Smaller than 16.. Use the 4 bits you have! + return + } + rr.Hdr.Ttl = rr.Hdr.Ttl&0x00FFFFFF | (uint32(v-15) << 24) } // UDPSize returns the UDP buffer size.