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// Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package table
import (
"bytes"
"github.com/osrg/gobgp/packet"
)
func UpdatePathAttrs2ByteAs(msg *bgp.BGPUpdate) error {
var asAttr *bgp.PathAttributeAsPath
idx := 0
for i, attr := range msg.PathAttributes {
switch attr.(type) {
case *bgp.PathAttributeAsPath:
asAttr = attr.(*bgp.PathAttributeAsPath)
idx = i
}
}
if asAttr == nil {
return nil
}
msg.PathAttributes = cloneAttrSlice(msg.PathAttributes)
asAttr = msg.PathAttributes[idx].(*bgp.PathAttributeAsPath)
as4pathParam := make([]*bgp.As4PathParam, 0)
newASparams := make([]bgp.AsPathParamInterface, len(asAttr.Value))
for i, param := range asAttr.Value {
asParam := param.(*bgp.As4PathParam)
newAs := make([]uint32, 0)
oldAs := make([]uint16, len(asParam.AS))
for j := 0; j < len(asParam.AS); j++ {
if asParam.AS[j] > (1<<16)-1 {
oldAs[j] = bgp.AS_TRANS
newAs = append(newAs, asParam.AS[j])
} else {
oldAs[j] = uint16(asParam.AS[j])
}
}
newASparams[i] = bgp.NewAsPathParam(asParam.Type, oldAs)
if len(newAs) > 0 {
as4pathParam = append(as4pathParam, bgp.NewAs4PathParam(asParam.Type, newAs))
}
}
msg.PathAttributes[idx] = bgp.NewPathAttributeAsPath(newASparams)
if len(as4pathParam) > 0 {
msg.PathAttributes = append(msg.PathAttributes, bgp.NewPathAttributeAs4Path(as4pathParam))
}
return nil
}
func UpdatePathAttrs4ByteAs(msg *bgp.BGPUpdate) error {
newPathAttrs := make([]bgp.PathAttributeInterface, 0)
var asAttr *bgp.PathAttributeAsPath
var as4Attr *bgp.PathAttributeAs4Path
for _, attr := range msg.PathAttributes {
switch attr.(type) {
case *bgp.PathAttributeAsPath:
asAttr = attr.(*bgp.PathAttributeAsPath)
newPathAttrs = append(newPathAttrs, attr)
case *bgp.PathAttributeAs4Path:
as4Attr = attr.(*bgp.PathAttributeAs4Path)
default:
newPathAttrs = append(newPathAttrs, attr)
}
}
if asAttr == nil {
return nil
}
AS := make([]uint32, 0)
if as4Attr != nil {
for _, p := range as4Attr.Value {
AS = append(AS, p.AS...)
}
msg.PathAttributes = newPathAttrs
}
transIdx := 0
for i, param := range asAttr.Value {
asParam, y := param.(*bgp.AsPathParam)
if !y {
continue
}
newAS := make([]uint32, len(asParam.AS))
for j := 0; j < len(asParam.AS); j++ {
if asParam.AS[j] == bgp.AS_TRANS {
if transIdx == len(AS) {
//return error
}
newAS[j] = AS[transIdx]
transIdx++
} else {
newAS[j] = uint32(asParam.AS[j])
}
}
asAttr.Value[i] = bgp.NewAs4PathParam(asParam.Type, newAS)
}
if len(AS) != transIdx {
//return error
}
return nil
}
func cloneAttrSlice(attrs []bgp.PathAttributeInterface) []bgp.PathAttributeInterface {
clonedAttrs := make([]bgp.PathAttributeInterface, 0)
clonedAttrs = append(clonedAttrs, attrs...)
return clonedAttrs
}
func createUpdateMsgFromPath(path Path, msg *bgp.BGPMessage) *bgp.BGPMessage {
rf := path.GetRouteFamily()
if rf == bgp.RF_IPv4_UC {
if path.IsWithdraw() {
draw := path.getNlri().(*bgp.WithdrawnRoute)
if msg != nil {
u := msg.Body.(*bgp.BGPUpdate)
u.WithdrawnRoutes = append(u.WithdrawnRoutes, *draw)
return nil
} else {
return bgp.NewBGPUpdateMessage([]bgp.WithdrawnRoute{*draw}, []bgp.PathAttributeInterface{}, []bgp.NLRInfo{})
}
} else {
nlri := path.getNlri().(*bgp.NLRInfo)
if msg != nil {
u := msg.Body.(*bgp.BGPUpdate)
u.NLRI = append(u.NLRI, *nlri)
} else {
pathAttrs := path.getPathAttrs()
return bgp.NewBGPUpdateMessage([]bgp.WithdrawnRoute{}, pathAttrs, []bgp.NLRInfo{*nlri})
}
}
} else if rf == bgp.RF_IPv6_UC {
if path.IsWithdraw() {
if msg != nil {
idx, _ := path.getPathAttr(bgp.BGP_ATTR_TYPE_MP_REACH_NLRI)
u := msg.Body.(*bgp.BGPUpdate)
unreach := u.PathAttributes[idx].(*bgp.PathAttributeMpUnreachNLRI)
unreach.Value = append(unreach.Value, path.getNlri())
} else {
clonedAttrs := cloneAttrSlice(path.getPathAttrs())
idx, attr := path.getPathAttr(bgp.BGP_ATTR_TYPE_MP_REACH_NLRI)
reach := attr.(*bgp.PathAttributeMpReachNLRI)
clonedAttrs[idx] = bgp.NewPathAttributeMpUnreachNLRI(reach.Value)
return bgp.NewBGPUpdateMessage([]bgp.WithdrawnRoute{}, clonedAttrs, []bgp.NLRInfo{})
}
} else {
if msg != nil {
idx, _ := path.getPathAttr(bgp.BGP_ATTR_TYPE_MP_REACH_NLRI)
u := msg.Body.(*bgp.BGPUpdate)
reachAttr := u.PathAttributes[idx].(*bgp.PathAttributeMpReachNLRI)
u.PathAttributes[idx] = bgp.NewPathAttributeMpReachNLRI(reachAttr.Nexthop.String(),
append(reachAttr.Value, path.getNlri()))
} else {
// we don't need to clone here but we
// might merge path to this message in
// the future so let's clone anyway.
clonedAttrs := cloneAttrSlice(path.getPathAttrs())
return bgp.NewBGPUpdateMessage([]bgp.WithdrawnRoute{}, clonedAttrs, []bgp.NLRInfo{})
}
}
}
return nil
}
func isSamePathAttrs(pList1 []bgp.PathAttributeInterface, pList2 []bgp.PathAttributeInterface) bool {
if len(pList1) != len(pList2) {
return false
}
for i, p1 := range pList1 {
_, y := p1.(*bgp.PathAttributeMpReachNLRI)
if y {
continue
}
b1, _ := p1.Serialize()
b2, _ := pList2[i].Serialize()
if bytes.Compare(b1, b2) != 0 {
return false
}
}
return true
}
func isMergeable(p1 Path, p2 Path) bool {
if p1 == nil {
return false
}
if p1.GetRouteFamily() != bgp.RF_IPv4_UC {
return false
}
if p1.getSource() == p2.getSource() && isSamePathAttrs(p1.getPathAttrs(), p2.getPathAttrs()) {
return true
}
return false
}
func CreateUpdateMsgFromPaths(pathList []Path) []*bgp.BGPMessage {
var pre Path
var msgs []*bgp.BGPMessage
for _, path := range pathList {
y := isMergeable(pre, path)
if y {
msg := msgs[len(msgs)-1]
createUpdateMsgFromPath(path, msg)
} else {
msg := createUpdateMsgFromPath(path, nil)
pre = path
msgs = append(msgs, msg)
}
}
return msgs
}
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