// before:
// as-path : 65000, 4000, 23456, 23456, 40001
// as4-path : {10, 20, 30} 400000, 300000, 40001
// expected result:
// as-path : 65000, {10, 20, 30}, 400000, 300000, 40001
func TestAsPathAs4Trans5(t *testing.T) {
as := []uint16{65000, 4000, bgp.AS_TRANS, bgp.AS_TRANS, 40001}
params := []bgp.AsPathParamInterface{bgp.NewAsPathParam(bgp.BGP_ASPATH_ATTR_TYPE_SEQ, as)}
aspath := bgp.NewPathAttributeAsPath(params)
as4 := []uint32{400000, 300000, 40001}
as4param1 := bgp.NewAs4PathParam(bgp.BGP_ASPATH_ATTR_TYPE_SEQ, as4)
as5 := []uint32{10, 20, 30}
as4param2 := bgp.NewAs4PathParam(bgp.BGP_ASPATH_ATTR_TYPE_SET, as5)
param4s := []*bgp.As4PathParam{as4param2, as4param1}
as4path := bgp.NewPathAttributeAs4Path(param4s)
msg := bgp.NewBGPUpdateMessage(nil, []bgp.PathAttributeInterface{aspath, as4path}, nil).Body.(*bgp.BGPUpdate)
UpdatePathAttrs4ByteAs(msg)
assert.Equal(t, len(msg.PathAttributes), 1)
assert.Equal(t, len(msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value), 3)
assert.Equal(t, len(msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[0].(*bgp.As4PathParam).AS), 1)
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[0].(*bgp.As4PathParam).AS[0], uint32(65000))
assert.Equal(t, len(msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[1].(*bgp.As4PathParam).AS), 3)
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[1].(*bgp.As4PathParam).AS[0], uint32(10))
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[1].(*bgp.As4PathParam).AS[1], uint32(20))
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[1].(*bgp.As4PathParam).AS[2], uint32(30))
assert.Equal(t, len(msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[2].(*bgp.As4PathParam).AS), 3)
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[2].(*bgp.As4PathParam).AS[0], uint32(400000))
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[2].(*bgp.As4PathParam).AS[1], uint32(300000))
assert.Equal(t, msg.PathAttributes[0].(*bgp.PathAttributeAsPath).Value[2].(*bgp.As4PathParam).AS[2], uint32(40001))
}
func UpdatePathAttrs2ByteAs(msg *bgp.BGPUpdate) error {
ps := msg.PathAttributes
msg.PathAttributes = make([]bgp.PathAttributeInterface, len(ps))
copy(msg.PathAttributes, ps)
var asAttr *bgp.PathAttributeAsPath
idx := 0
for i, attr := range msg.PathAttributes {
if a, ok := attr.(*bgp.PathAttributeAsPath); ok {
asAttr = a
idx = i
break
}
}
if asAttr == nil {
return nil
}
as4Params := make([]*bgp.As4PathParam, 0, len(asAttr.Value))
as2Params := make([]bgp.AsPathParamInterface, 0, len(asAttr.Value))
mkAs4 := false
for _, param := range asAttr.Value {
as4Param := param.(*bgp.As4PathParam)
as2Path := make([]uint16, 0, len(as4Param.AS))
for _, as := range as4Param.AS {
if as > (1<<16)-1 {
mkAs4 = true
as2Path = append(as2Path, bgp.AS_TRANS)
} else {
as2Path = append(as2Path, uint16(as))
}
}
as2Params = append(as2Params, bgp.NewAsPathParam(as4Param.Type, as2Path))
// RFC 6793 4.2.2 Generating Updates
//
// Whenever the AS path information contains the AS_CONFED_SEQUENCE or
// AS_CONFED_SET path segment, the NEW BGP speaker MUST exclude such
// path segments from the AS4_PATH attribute being constructed.
if as4Param.Type != bgp.BGP_ASPATH_ATTR_TYPE_CONFED_SEQ && as4Param.Type != bgp.BGP_ASPATH_ATTR_TYPE_CONFED_SET {
as4Params = append(as4Params, as4Param)
}
}
msg.PathAttributes[idx] = bgp.NewPathAttributeAsPath(as2Params)
if mkAs4 {
msg.PathAttributes = append(msg.PathAttributes, bgp.NewPathAttributeAs4Path(as4Params))
}
return nil
}