Merge pull request #78 from bio-routing/feature/unknown_attr_pass_extended_length

added support for extended legth on unknown attributes

.gitignore

@@ -16,6 +16,7 @@
 # IDE specific files
 .idea/
 *.iml
+.vscode
 
 # 'go build' binary
 bio-rd

protocols/bgp/packet/path_attributes.go

@@ -373,28 +373,28 @@ func dumpNBytes(buf *bytes.Buffer, n uint16) error {
 }
 
 // Serialize serializes a path attribute
-func (pa *PathAttribute) Serialize(buf *bytes.Buffer, opt *types.Options) uint8 {
-	pathAttrLen := uint8(0)
+func (pa *PathAttribute) Serialize(buf *bytes.Buffer, opt *types.Options) uint16 {
+	pathAttrLen := uint16(0)
 
 	switch pa.TypeCode {
 	case OriginAttr:
-		pathAttrLen = pa.serializeOrigin(buf)
+		pathAttrLen = uint16(pa.serializeOrigin(buf))
 	case ASPathAttr:
-		pathAttrLen = pa.serializeASPath(buf, opt)
+		pathAttrLen = uint16(pa.serializeASPath(buf, opt))
 	case NextHopAttr:
-		pathAttrLen = pa.serializeNextHop(buf)
+		pathAttrLen = uint16(pa.serializeNextHop(buf))
 	case MEDAttr:
-		pathAttrLen = pa.serializeMED(buf)
+		pathAttrLen = uint16(pa.serializeMED(buf))
 	case LocalPrefAttr:
-		pathAttrLen = pa.serializeLocalpref(buf)
+		pathAttrLen = uint16(pa.serializeLocalpref(buf))
 	case AtomicAggrAttr:
-		pathAttrLen = pa.serializeAtomicAggregate(buf)
+		pathAttrLen = uint16(pa.serializeAtomicAggregate(buf))
 	case AggregatorAttr:
-		pathAttrLen = pa.serializeAggregator(buf)
+		pathAttrLen = uint16(pa.serializeAggregator(buf))
 	case CommunitiesAttr:
-		pathAttrLen = pa.serializeCommunities(buf)
+		pathAttrLen = uint16(pa.serializeCommunities(buf))
 	case LargeCommunitiesAttr:
-		pathAttrLen = pa.serializeLargeCommunities(buf)
+		pathAttrLen = uint16(pa.serializeLargeCommunities(buf))
 	default:
 		pathAttrLen = pa.serializeUnknownAttribute(buf)
 	}
@@ -552,21 +552,30 @@ func (pa *PathAttribute) serializeLargeCommunities(buf *bytes.Buffer) uint8 {
 	return length
 }
 
-func (pa *PathAttribute) serializeUnknownAttribute(buf *bytes.Buffer) uint8 {
+func (pa *PathAttribute) serializeUnknownAttribute(buf *bytes.Buffer) uint16 {
 	attrFlags := uint8(0)
 	if pa.Optional {
 		attrFlags = setOptional(attrFlags)
 	}
+	if pa.ExtendedLength {
+		attrFlags = setExtendedLength(attrFlags)
+	}
 	attrFlags = setTransitive(attrFlags)
 
 	buf.WriteByte(attrFlags)
 	buf.WriteByte(pa.TypeCode)
 
 	b := pa.Value.([]byte)
-	buf.WriteByte(uint8(len(b)))
+	if pa.ExtendedLength {
+		l := len(b)
+		buf.WriteByte(uint8(l >> 8))
+		buf.WriteByte(uint8(l & 0x0000FFFF))
+	} else {
+		buf.WriteByte(uint8(len(b)))
+	}
 	buf.Write(b)
 
-	return uint8(len(b) + 2)
+	return uint16(len(b) + 2)
 }
 
 func fourBytesToUint32(address [4]byte) uint32 {

protocols/bgp/packet/path_attributes_test.go

@@ -1348,7 +1348,7 @@ func TestSerializeUnknownAttribute(t *testing.T) {
 		name        string
 		input       *PathAttribute
 		expected    []byte
-		expectedLen uint8
+		expectedLen uint16
 	}{
 		{
 			name: "Arbritary attribute",
@@ -1365,6 +1365,36 @@ func TestSerializeUnknownAttribute(t *testing.T) {
 			},
 			expectedLen: 6,
 		},
+		{
+			name: "Extended length",
+			input: &PathAttribute{
+				TypeCode:       200,
+				Value:          make([]byte, 256),
+				Transitive:     true,
+				ExtendedLength: true,
+			},
+			expected: []byte{
+				80,   // Attribute flags
+				200,  // Type
+				1, 0, // Length
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Payload
+			},
+			expectedLen: 258,
+		},
 	}
 
 	for _, test := range tests {

route/bgp_path.go

@@ -255,8 +255,8 @@ func (b *BGPPath) insertNewASSequence() {
 	pa := make(types.ASPath, len(b.ASPath)+1)
 	copy(pa[1:], b.ASPath)
 	pa[0] = types.ASPathSegment{
-		ASNs:  make([]uint32, 0),
-		Type:  packet.ASSequence,
+		ASNs: make([]uint32, 0),
+		Type: types.ASSequence,
 	}
 
 	b.ASPath = pa