v6: add DNS getter (and rename DNSRecursiveNameServer to DNS)

Signed-off-by: Chris Koch <chrisko@google.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/dhcpv6/dhcpv6message.go b/dhcpv6/dhcpv6message.go
index 28853f1..400c46a 100644
--- a/dhcpv6/dhcpv6message.go
+++ b/dhcpv6/dhcpv6message.go
@@ -92,6 +92,18 @@ func (mo MessageOptions) RequestedOptions() OptionCodes {
 	return oro.OptionCodes
 }
 
+// DNS returns the DNS Recursive Name Server option as defined by RFC 3646.
+func (mo MessageOptions) DNS() []net.IP {
+	opt := mo.Options.GetOne(OptionDNSRecursiveNameServer)
+	if opt == nil {
+		return nil
+	}
+	if dns, ok := opt.(*optDNS); ok {
+		return dns.NameServers
+	}
+	return nil
+}
+
 // Message represents a DHCPv6 Message as defined by RFC 3315 Section 6.
 type Message struct {
 	MessageType   MessageType