1 files changed, 59 insertions, 0 deletions
diff --git a/dhcpv6/options/dnsrecursivenameserver.go b/dhcpv6/options/dnsrecursivenameserver.go
new file mode 100644
index 0000000..a28fd1d
--- /dev/null
+++ b/dhcpv6/options/dnsrecursivenameserver.go
@@ -0,0 +1,59 @@
+package options
+
+// This module defines the OptDNSRecursiveNameServer structure.
+// https://www.ietf.org/rfc/rfc3646.txt
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net"
+)
+
+type OptDNSRecursiveNameServer struct {
+	nameServers []net.IP
+}
+
+func (op *OptDNSRecursiveNameServer) Code() OptionCode {
+	return DNS_RECURSIVE_NAME_SERVER
+}
+
+func (op *OptDNSRecursiveNameServer) ToBytes() []byte {
+	buf := make([]byte, 4)
+	binary.BigEndian.PutUint16(buf[0:2], uint16(DNS_RECURSIVE_NAME_SERVER))
+	binary.BigEndian.PutUint16(buf[2:4], uint16(op.Length()))
+	for _, ns := range op.nameServers {
+		buf = append(buf, ns...)
+	}
+	return buf
+}
+
+func (op *OptDNSRecursiveNameServer) NameServers() []net.IP {
+	return op.nameServers
+}
+
+func (op *OptDNSRecursiveNameServer) SetNameServers(ns []net.IP) {
+	op.nameServers = ns
+}
+
+func (op *OptDNSRecursiveNameServer) Length() int {
+	return len(op.nameServers) * net.IPv6len
+}
+
+func (op *OptDNSRecursiveNameServer) String() string {
+	return fmt.Sprintf("OptDNSRecursiveNameServer{nameservers=%v}", op.nameServers)
+}
+
+// build an OptDNSRecursiveNameServer structure from a sequence of bytes.
+// The input data does not include option code and length bytes.
+func ParseOptDNSRecursiveNameServer(data []byte) (*OptDNSRecursiveNameServer, error) {
+	if len(data)%2 != 0 {
+		return nil, fmt.Errorf("Invalid OptDNSRecursiveNameServer data: length is not a multiple of 2")
+	}
+	opt := OptDNSRecursiveNameServer{}
+	var nameServers []net.IP
+	for i := 0; i < len(data); i += net.IPv6len {
+		nameServers = append(nameServers, data[i:i+net.IPv6len])
+	}
+	opt.nameServers = nameServers
+	return &opt, nil
+}