1 files changed, 107 insertions, 0 deletions
diff --git a/pkg/packet/bgp/prefix_sid_sstlv.go b/pkg/packet/bgp/prefix_sid_sstlv.go
new file mode 100644
index 00000000..14ff621a
--- /dev/null
+++ b/pkg/packet/bgp/prefix_sid_sstlv.go
@@ -0,0 +1,107 @@
+package bgp
+
+import "encoding/binary"
+
+const (
+	subSubTLVHdrLen = 3
+)
+
+type SubSubTLVType uint8
+
+type SubSubTLV struct {
+	Type   SubSubTLVType
+	Length uint16
+}
+
+func (s *SubSubTLV) Len() int {
+	return int(s.Length) + subSubTLVHdrLen
+}
+
+func (s *SubSubTLV) Serialize(value []byte) ([]byte, error) {
+	if len(value) != int(s.Length) {
+		return nil, malformedAttrListErr("serialization failed: Prefix SID TLV malformed")
+	}
+	// Extra byte is reserved
+	buf := make([]byte, subSubTLVHdrLen+len(value))
+	p := 0
+	buf[p] = byte(s.Type)
+	p++
+	binary.BigEndian.PutUint16(buf[p:p+2], uint16(s.Length))
+	p += 2
+	copy(buf[p:], value)
+
+	return buf, nil
+}
+
+func (s *SubSubTLV) DecodeFromBytes(data []byte) ([]byte, error) {
+	if len(data) < prefixSIDtlvHdrLen {
+		return nil, malformedAttrListErr("decoding failed: Prefix SID Sub Sub TLV malformed")
+	}
+	s.Type = SubSubTLVType(data[0])
+	s.Length = binary.BigEndian.Uint16(data[1:3])
+
+	if len(data) < s.Len() {
+		return nil, malformedAttrListErr("decoding failed: Prefix SID Sub Sub TLV malformed")
+	}
+
+	return data[prefixSIDtlvHdrLen:s.Len()], nil
+}
+
+// SRv6SIDStructureSubSubTLV defines a structure of SRv6 SID Structure Sub Sub TLV (type 1) object
+// https://tools.ietf.org/html/draft-dawra-bess-srv6-services-02#section-2.1.2.1
+type SRv6SIDStructureSubSubTLV struct {
+	SubSubTLV
+	LocalBlockLength    uint8 `json:"local_block_length,omitempty"`
+	LocatorNodeLength   uint8 `json:"locator_node_length,omitempty"`
+	FunctionLength      uint8 `json:"function_length,omitempty"`
+	ArgumentLength      uint8 `json:"argument_length,omitempty"`
+	TranspositionLength uint8 `json:"transposition_length,omitempty"`
+	TranspositionOffset uint8 `json:"transposition_offset,omitempty"`
+}
+
+func (s *SRv6SIDStructureSubSubTLV) Len() int {
+	return int(s.Length) + subSubTLVHdrLen
+}
+
+func (s *SRv6SIDStructureSubSubTLV) Serialize() ([]byte, error) {
+	buf := make([]byte, s.Length)
+	p := 0
+	buf[p] = s.LocalBlockLength
+	p++
+	buf[p] = s.LocatorNodeLength
+	p++
+	buf[p] = s.FunctionLength
+	p++
+	buf[p] = s.ArgumentLength
+	p++
+	buf[p] = s.TranspositionLength
+	p++
+	buf[p] = s.TranspositionOffset
+
+	return s.SubSubTLV.Serialize(buf)
+}
+
+func (s *SRv6SIDStructureSubSubTLV) DecodeFromBytes(data []byte) error {
+	if len(data) < subSubTLVHdrLen {
+		return malformedAttrListErr("decoding failed: Prefix SID Sub Sub TLV malformed")
+	}
+	s.Type = SubSubTLVType(data[0])
+	s.Length = binary.BigEndian.Uint16(data[1:3])
+
+	s.LocalBlockLength = data[3]
+	s.LocatorNodeLength = data[4]
+	s.FunctionLength = data[5]
+	s.ArgumentLength = data[6]
+	s.TranspositionLength = data[7]
+	s.TranspositionOffset = data[8]
+
+	return nil
+}
+
+func (s *SRv6SIDStructureSubSubTLV) MarshalJSON() ([]byte, error) {
+	return nil, nil
+}
+
+func (s *SRv6SIDStructureSubSubTLV) String() string {
+	return ""
+}