func UpdatePathAggregator2ByteAs(msg *bgp.BGPUpdate) {
as := uint32(0)
var addr string
for i, attr := range msg.PathAttributes {
switch attr.(type) {
case *bgp.PathAttributeAggregator:
agg := attr.(*bgp.PathAttributeAggregator)
addr = agg.Value.Address.String()
if agg.Value.AS > (1<<16)-1 {
as = agg.Value.AS
msg.PathAttributes[i] = bgp.NewPathAttributeAggregator(uint16(bgp.AS_TRANS), addr)
} else {
msg.PathAttributes[i] = bgp.NewPathAttributeAggregator(uint16(agg.Value.AS), addr)
}
}
}
if as != 0 {
msg.PathAttributes = append(msg.PathAttributes, bgp.NewPathAttributeAs4Aggregator(as, addr))
}
}
func extractAggregator(args []string) ([]string, bgp.PathAttributeInterface, error) {
for idx, arg := range args {
if arg == "aggregator" {
if len(args) < (idx + 1) {
return nil, nil, fmt.Errorf("invalid aggregator format")
}
v := strings.SplitN(args[idx+1], ":", 2)
if len(v) != 2 {
return nil, nil, fmt.Errorf("invalid aggregator format")
}
as, err := strconv.ParseUint(v[0], 10, 32)
if err != nil {
return nil, nil, fmt.Errorf("invalid aggregator format")
}
attr := bgp.NewPathAttributeAggregator(uint32(as), net.ParseIP(v[1]).String())
return append(args[:idx], args[idx+2:]...), attr, nil
}
}
return args, nil, nil
}
func TestAggregator4BytesASes(t *testing.T) {
getAggr := func(msg *bgp.BGPUpdate) *bgp.PathAttributeAggregator {
for _, attr := range msg.PathAttributes {
switch attr.(type) {
case *bgp.PathAttributeAggregator:
return attr.(*bgp.PathAttributeAggregator)
}
}
return nil
}
getAggr4 := func(msg *bgp.BGPUpdate) *bgp.PathAttributeAs4Aggregator {
for _, attr := range msg.PathAttributes {
switch attr.(type) {
case *bgp.PathAttributeAs4Aggregator:
return attr.(*bgp.PathAttributeAs4Aggregator)
}
}
return nil
}
addr := "192.168.0.1"
as4 := uint32(100000)
as := uint32(1000)
msg := bgp.NewBGPUpdateMessage(nil, []bgp.PathAttributeInterface{bgp.NewPathAttributeAggregator(as4, addr)}, nil).Body.(*bgp.BGPUpdate)
// 4byte capable to 4byte capable for 4 bytes AS
assert.Equal(t, UpdatePathAggregator4ByteAs(msg), nil)
assert.Equal(t, getAggr(msg).Value.AS, as4)
assert.Equal(t, getAggr(msg).Value.Address.String(), addr)
// 4byte capable to 2byte capable for 4 bytes AS
UpdatePathAggregator2ByteAs(msg)
assert.Equal(t, getAggr(msg).Value.AS, uint32(bgp.AS_TRANS))
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
assert.Equal(t, getAggr4(msg).Value.AS, as4)
assert.Equal(t, getAggr4(msg).Value.Address.String(), addr)
msg = bgp.NewBGPUpdateMessage(nil, []bgp.PathAttributeInterface{bgp.NewPathAttributeAggregator(uint16(bgp.AS_TRANS), addr), bgp.NewPathAttributeAs4Aggregator(as4, addr)}, nil).Body.(*bgp.BGPUpdate)
assert.Equal(t, getAggr(msg).Value.AS, uint32(bgp.AS_TRANS))
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
// non 4byte capable to 4byte capable for 4 bytes AS
assert.Equal(t, UpdatePathAggregator4ByteAs(msg), nil)
assert.Equal(t, getAggr(msg).Value.AS, as4)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint32)
assert.Equal(t, getAggr(msg).Value.Address.String(), addr)
assert.Equal(t, getAggr4(msg), (*bgp.PathAttributeAs4Aggregator)(nil))
// non 4byte capable to non 4byte capable for 4 bytes AS
UpdatePathAggregator2ByteAs(msg)
assert.Equal(t, getAggr(msg).Value.AS, uint32(bgp.AS_TRANS))
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
assert.Equal(t, getAggr4(msg).Value.AS, as4)
assert.Equal(t, getAggr4(msg).Value.Address.String(), addr)
msg = bgp.NewBGPUpdateMessage(nil, []bgp.PathAttributeInterface{bgp.NewPathAttributeAggregator(uint32(as), addr)}, nil).Body.(*bgp.BGPUpdate)
// 4byte capable to 4byte capable for 2 bytes AS
assert.Equal(t, getAggr(msg).Value.AS, as)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint32)
assert.Equal(t, UpdatePathAggregator4ByteAs(msg), nil)
assert.Equal(t, getAggr(msg).Value.AS, as)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint32)
// 4byte capable to non 4byte capable for 2 bytes AS
UpdatePathAggregator2ByteAs(msg)
assert.Equal(t, getAggr4(msg), (*bgp.PathAttributeAs4Aggregator)(nil))
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
assert.Equal(t, getAggr(msg).Value.AS, as)
msg = bgp.NewBGPUpdateMessage(nil, []bgp.PathAttributeInterface{bgp.NewPathAttributeAggregator(uint16(as), addr)}, nil).Body.(*bgp.BGPUpdate)
// non 4byte capable to 4byte capable for 2 bytes AS
assert.Equal(t, getAggr(msg).Value.AS, as)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
assert.Equal(t, UpdatePathAggregator4ByteAs(msg), nil)
assert.Equal(t, getAggr(msg).Value.AS, as)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint32)
// non 4byte capable to non 4byte capable for 2 bytes AS
UpdatePathAggregator2ByteAs(msg)
assert.Equal(t, getAggr(msg).Value.AS, as)
assert.Equal(t, getAggr(msg).Value.Askind, reflect.Uint16)
assert.Equal(t, getAggr4(msg), (*bgp.PathAttributeAs4Aggregator)(nil))
}