func decodeLLDP(b []byte) (nom.Node, nom.Port, error) {
h := lldp.NewLinkDiscoveryProtocolWithBuf(b)
size := h.Size()
tlvb := b[size:]
chTLV := lldp.NewChassisMacTLVWithBuf(tlvb)
if chTLV.Size() == 0 {
return nom.Node{}, nom.Port{}, errors.New("decodeLLDP: no chassis id")
}
n := nom.Node{
MACAddr: chTLV.MacAddr(),
}
size += chTLV.Size()
tlvb = b[size:]
pTLV := lldp.NewLinkDiscoveryTLVWithBuf(tlvb)
if pTLV.Size() == 0 || pTLV.Type() != uint8(lldp.TLV_PORT_ID) {
return nom.Node{}, nom.Port{}, errors.New("decodeLLDP: no port id")
}
v := pTLV.Value()
if v[0] != uint8(lldp.PORT_TLV_IFACE_NAME) {
return nom.Node{}, nom.Port{}, errors.New("decodeLLDP: no port iface name")
}
portUID := nom.UID(v[1:])
nID, pID := nom.ParsePortUID(portUID)
n.ID = nID
return n, nom.Port{ID: pID, Node: n.UID()}, nil
}
func sendLLDPPacket(n nom.Node, p nom.Port, ctx bh.RcvContext) {
pkt := nom.PacketOut{
Node: n.UID(),
Packet: nom.Packet(encodeLLDP(n, p)),
BufferID: 0xFFFFFFFF,
Actions: []nom.Action{
nom.ActionForward{
Ports: []nom.UID{p.UID()},
},
},
}
ctx.Emit(pkt)
}
func TestLLDPEncode(t *testing.T) {
node := nom.Node{
ID: "n1",
MACAddr: [6]byte{1, 2, 3, 4, 5, 6},
}
port := nom.Port{
ID: "1",
Name: "if1",
MACAddr: [6]byte{1, 2, 3, 4, 5, 7},
Node: node.UID(),
}
b := encodeLLDP(node, port)
//for i := 0; i < len(b); i += 12 {
//j := 0
//for ; j < 12 && i+j < len(b); j++ {
//fmt.Printf("%02X ", b[i+j])
//}
//for k := j; k < 12; k++ {
//fmt.Print(" ")
//}
//fmt.Printf("\t%s\n", strconv.QuoteToASCII(string(b[i:i+j])))
//}
decN, decP, err := decodeLLDP(b)
if err != nil {
t.Errorf("Cannot decode LLDP: %v", err)
}
if decN.ID != node.ID {
t.Errorf("Invalid node ID decoded: %v != %v", decN.ID, node.ID)
}
if decN.MACAddr != node.MACAddr {
t.Errorf("Invalid node MAC decoded: %v != %v", decN.MACAddr, node.MACAddr)
}
if decP.ID != port.ID {
t.Errorf("Invalid port ID decoded: %v != %v", decP.ID, port.ID)
}
}