diff --git a/edns.go b/edns.go index 8df0ec90..844cf92b 100644 --- a/edns.go +++ b/edns.go @@ -151,6 +151,16 @@ func (rr *OPT) SetDo(do ...bool) { } } +// Z returns the Z part of the OPT RR as a uint16 with only the 15 least significant bits used. +func (rr *OPT) Z() uint16 { + return uint16(rr.Hdr.Ttl & 0x7FFF) +} + +// SetZ sets the Z part of the OPT RR, note only the 15 least significant bits of z are used. +func (rr *OPT) SetZ(z uint16) { + rr.Hdr.Ttl = rr.Hdr.Ttl&^0x7FFF | uint32(z&0x7FFF) +} + // EDNS0 defines an EDNS0 Option. An OPT RR can have multiple options appended to it. type EDNS0 interface { // Option returns the option code for the option. diff --git a/edns_test.go b/edns_test.go index d18961ed..ab2a3b1f 100644 --- a/edns_test.go +++ b/edns_test.go @@ -133,3 +133,28 @@ func TestEDNS0_UL(t *testing.T) { } } } + +func TestZ(t *testing.T) { + e := &OPT{} + e.Hdr.Name = "." + e.Hdr.Rrtype = TypeOPT + e.SetVersion(8) + e.SetDo() + if e.Z() != 0 { + t.Errorf("expected Z of 0, got %d", e.Z()) + } + e.SetZ(5) + if e.Z() != 5 { + t.Errorf("expected Z of 5, got %d", e.Z()) + } + e.SetZ(0xFFFF) + if e.Z() != 0x7FFF { + t.Errorf("expected Z of 0x7FFFF, got %d", e.Z()) + } + if e.Version() != 8 { + t.Errorf("expected version to still be 8, got %d", e.Version()) + } + if !e.Do() { + t.Error("expected DO to be set") + } +}