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-rw-r--r--packet/bgp.go116
-rw-r--r--packet/bgp_test.go8
2 files changed, 93 insertions, 31 deletions
diff --git a/packet/bgp.go b/packet/bgp.go
index 0c345ed2..fabcc44e 100644
--- a/packet/bgp.go
+++ b/packet/bgp.go
@@ -862,25 +862,38 @@ func getRouteDistinguisher(data []byte) RouteDistinguisherInterface {
return rd
}
-func labelDecode(data []byte) uint32 {
- return uint32(data[0])<<16 | uint32(data[1])<<8 | uint32(data[2])
-}
-
-func labelSerialize(label uint32, buf []byte) {
- buf[0] = byte((label >> 16) & 0xff)
- buf[1] = byte((label >> 8) & 0xff)
- buf[2] = byte(label & 0xff)
-}
+//
+// RFC3107 Carrying Label Information in BGP-4
+//
+// 4. Carrying Label Mapping Information
+//
+// b) Label:
+//
+// The Label field carries one or more labels (that corresponds to
+// the stack of labels [MPLS-ENCAPS(RFC3032)]). Each label is encoded as
+// 4 octets, where the high-order 20 bits contain the label value, and
+// the low order bit contains "Bottom of Stack"
+//
+// RFC3032 MPLS Label Stack Encoding
+//
+// 2.1. Encoding the Label Stack
+//
+// 0 1 2 3
+// 0 ... 9 0 ... 9 0 1 2 3 4 ... 9 0 1
+// +-----+-+-+---+-+-+-+-+-+-----+-+-+-+
+// | Label | Exp |S| TTL |
+// +-----+-+-+---+-+-+-+-+-+-----+-+-+-+
+//
-type Label struct {
+type MPLSLabelStack struct {
Labels []uint32
}
-func (l *Label) DecodeFromBytes(data []byte) error {
+func (l *MPLSLabelStack) DecodeFromBytes(data []byte) error {
labels := []uint32{}
foundBottom := false
- for len(data) >= 4 {
- label := uint32(data[0]<<16 | data[1]<<8 | data[2])
+ for len(data) >= 3 {
+ label := uint32(data[0])<<16 | uint32(data[1])<<8 | uint32(data[2])
data = data[3:]
labels = append(labels, label>>4)
if label&1 == 1 {
@@ -896,7 +909,7 @@ func (l *Label) DecodeFromBytes(data []byte) error {
return nil
}
-func (l *Label) Serialize() ([]byte, error) {
+func (l *MPLSLabelStack) Serialize() ([]byte, error) {
buf := make([]byte, len(l.Labels)*3)
for i, label := range l.Labels {
label = label << 4
@@ -908,15 +921,39 @@ func (l *Label) Serialize() ([]byte, error) {
return buf, nil
}
-func (l *Label) Len() int { return 3 * len(l.Labels) }
+func (l *MPLSLabelStack) Len() int { return 3 * len(l.Labels) }
-func NewLabel(labels ...uint32) *Label {
- return &Label{labels}
+func NewMPLSLabelStack(labels ...uint32) *MPLSLabelStack {
+ return &MPLSLabelStack{labels}
}
+//
+// RFC3107 Carrying Label Information in BGP-4
+//
+// 3. Carrying Label Mapping Information
+//
+// +----------------------+
+// | Length (1 octet) |
+// +----------------------+
+// | Label (3 octets) |
+// +----------------------+
+// .......................
+// +----------------------+
+// | Prefix (variable) |
+// +----------------------+
+//
+// RFC4364 BGP/MPLS IP VPNs
+//
+// 4.3.4. How VPN-IPv4 NLRI Is Carried in BGP
+//
+// The labeled VPN-IPv4 NLRI itself is encoded as specified in
+// [MPLS-BGP(RFC3107)], where the prefix consists of an 8-byte RD
+// followed by an IPv4 prefix.
+//
+
type LabelledVPNIPAddrPrefix struct {
IPAddrPrefixDefault
- Labels Label
+ Labels MPLSLabelStack
RD RouteDistinguisherInterface
addrlen uint8
}
@@ -973,7 +1010,7 @@ func (l *LabelledVPNIPAddrPrefix) ToApiStruct() *api.Nlri {
}
}
-func NewLabelledVPNIPAddrPrefix(length uint8, prefix string, label Label, rd RouteDistinguisherInterface) *LabelledVPNIPAddrPrefix {
+func NewLabelledVPNIPAddrPrefix(length uint8, prefix string, label MPLSLabelStack, rd RouteDistinguisherInterface) *LabelledVPNIPAddrPrefix {
rdlen := 0
if rd != nil {
rdlen = rd.Len()
@@ -994,7 +1031,7 @@ func (l *LabelledVPNIPv6AddrPrefix) AFI() uint16 {
return AFI_IP6
}
-func NewLabelledVPNIPv6AddrPrefix(length uint8, prefix string, label Label, rd RouteDistinguisherInterface) *LabelledVPNIPv6AddrPrefix {
+func NewLabelledVPNIPv6AddrPrefix(length uint8, prefix string, label MPLSLabelStack, rd RouteDistinguisherInterface) *LabelledVPNIPv6AddrPrefix {
rdlen := 0
if rd != nil {
rdlen = rd.Len()
@@ -1011,7 +1048,7 @@ func NewLabelledVPNIPv6AddrPrefix(length uint8, prefix string, label Label, rd R
type LabelledIPAddrPrefix struct {
IPAddrPrefixDefault
- Labels Label
+ Labels MPLSLabelStack
addrlen uint8
}
@@ -1079,7 +1116,7 @@ func (l *LabelledIPAddrPrefix) Serialize() ([]byte, error) {
return buf, nil
}
-func NewLabelledIPAddrPrefix(length uint8, prefix string, label Label) *LabelledIPAddrPrefix {
+func NewLabelledIPAddrPrefix(length uint8, prefix string, label MPLSLabelStack) *LabelledIPAddrPrefix {
return &LabelledIPAddrPrefix{
IPAddrPrefixDefault{length + uint8(label.Len()*8), net.ParseIP(prefix)},
label,
@@ -1091,7 +1128,7 @@ type LabelledIPv6AddrPrefix struct {
LabelledIPAddrPrefix
}
-func NewLabelledIPv6AddrPrefix(length uint8, prefix string, label Label) *LabelledIPv6AddrPrefix {
+func NewLabelledIPv6AddrPrefix(length uint8, prefix string, label MPLSLabelStack) *LabelledIPv6AddrPrefix {
return &LabelledIPv6AddrPrefix{
LabelledIPAddrPrefix{
IPAddrPrefixDefault{length + uint8(label.Len()*8), net.ParseIP(prefix)},
@@ -1250,6 +1287,31 @@ func (esi *EthernetSegmentIdentifier) String() string {
return s.String()
}
+//
+// I-D bess-evpn-overlay-01
+//
+// 5.1.3 Constructing EVPN BGP Routes
+//
+// For the balance of this memo, the MPLS label field will be
+// referred to as the VNI/VSID field. The VNI/VSID field is used for
+// both local and global VNIs/VSIDs, and for either case the entire 24-
+// bit field is used to encode the VNI/VSID value.
+//
+// We can't use type MPLSLabelStack for EVPN NLRI, because EVPN NLRI's MPLS
+// field can be filled with VXLAN VNI. In that case, we must avoid modifying
+// bottom of stack bit.
+//
+
+func labelDecode(data []byte) uint32 {
+ return uint32(data[0])<<16 | uint32(data[1])<<8 | uint32(data[2])
+}
+
+func labelSerialize(label uint32, buf []byte) {
+ buf[0] = byte((label >> 16) & 0xff)
+ buf[1] = byte((label >> 8) & 0xff)
+ buf[2] = byte(label & 0xff)
+}
+
type EVPNEthernetAutoDiscoveryRoute struct {
RD RouteDistinguisherInterface
ESI EthernetSegmentIdentifier
@@ -1708,13 +1770,13 @@ func NewPrefixFromRouteFamily(afi uint16, safi uint8) (prefix AddrPrefixInterfac
case RF_IPv6_UC, RF_IPv6_MC:
prefix = NewIPv6AddrPrefix(0, "")
case RF_IPv4_VPN:
- prefix = NewLabelledVPNIPAddrPrefix(0, "", *NewLabel(), nil)
+ prefix = NewLabelledVPNIPAddrPrefix(0, "", *NewMPLSLabelStack(), nil)
case RF_IPv6_VPN:
- prefix = NewLabelledVPNIPv6AddrPrefix(0, "", *NewLabel(), nil)
+ prefix = NewLabelledVPNIPv6AddrPrefix(0, "", *NewMPLSLabelStack(), nil)
case RF_IPv4_MPLS:
- prefix = NewLabelledIPAddrPrefix(0, "", *NewLabel())
+ prefix = NewLabelledIPAddrPrefix(0, "", *NewMPLSLabelStack())
case RF_IPv6_MPLS:
- prefix = NewLabelledIPv6AddrPrefix(0, "", *NewLabel())
+ prefix = NewLabelledIPv6AddrPrefix(0, "", *NewMPLSLabelStack())
case RF_EVPN:
prefix = NewEVPNNLRI(0, 0, nil)
case RF_RTC_UC:
diff --git a/packet/bgp_test.go b/packet/bgp_test.go
index 90ad7d20..16055819 100644
--- a/packet/bgp_test.go
+++ b/packet/bgp_test.go
@@ -69,9 +69,9 @@ func update() *BGPMessage {
}
mp_nlri := []AddrPrefixInterface{
- NewLabelledVPNIPAddrPrefix(20, "192.0.9.0", *NewLabel(1, 2, 3),
+ NewLabelledVPNIPAddrPrefix(20, "192.0.9.0", *NewMPLSLabelStack(1, 2, 3),
NewRouteDistinguisherTwoOctetAS(256, 10000)),
- NewLabelledVPNIPAddrPrefix(26, "192.10.8.192", *NewLabel(5, 6, 7, 8),
+ NewLabelledVPNIPAddrPrefix(26, "192.10.8.192", *NewMPLSLabelStack(5, 6, 7, 8),
NewRouteDistinguisherIPAddressAS("10.0.1.1", 10001)),
}
@@ -79,11 +79,11 @@ func update() *BGPMessage {
"fe80:1234:1234:5667:8967:af12:8912:1023")}
mp_nlri3 := []AddrPrefixInterface{NewLabelledVPNIPv6AddrPrefix(100,
- "fe80:1234:1234:5667:8967:af12:1203:33a1", *NewLabel(5, 6),
+ "fe80:1234:1234:5667:8967:af12:1203:33a1", *NewMPLSLabelStack(5, 6),
NewRouteDistinguisherFourOctetAS(5, 6))}
mp_nlri4 := []AddrPrefixInterface{NewLabelledIPAddrPrefix(25, "192.168.0.0",
- *NewLabel(5, 6, 7))}
+ *NewMPLSLabelStack(5, 6, 7))}
mac, _ := net.ParseMAC("01:23:45:67:89:ab")
mp_nlri5 := []AddrPrefixInterface{
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 19:17:02 +0000