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// Copyright (C) 2015 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 server
import (
"fmt"
log "github.com/Sirupsen/logrus"
"github.com/osrg/gobgp/packet/bgp"
"github.com/osrg/gobgp/table"
"github.com/osrg/gobgp/zebra"
"net"
"strconv"
"strings"
"time"
)
func newIPRouteMessage(dst []*table.Path, version uint8, vrfId uint16) *zebra.Message {
paths := make([]*table.Path, 0, len(dst))
for _, path := range dst {
if path == nil || path.IsFromExternal() {
continue
}
paths = append(paths, path)
}
if len(paths) == 0 {
return nil
}
path := paths[0]
l := strings.SplitN(path.GetNlri().String(), "/", 2)
var command zebra.API_TYPE
var prefix net.IP
nexthops := make([]net.IP, 0, len(paths))
switch path.GetRouteFamily() {
case bgp.RF_IPv4_UC, bgp.RF_IPv4_VPN:
if path.IsWithdraw == true {
command = zebra.IPV4_ROUTE_DELETE
} else {
command = zebra.IPV4_ROUTE_ADD
}
if path.GetRouteFamily() == bgp.RF_IPv4_UC {
prefix = path.GetNlri().(*bgp.IPAddrPrefix).IPAddrPrefixDefault.Prefix.To4()
} else {
prefix = path.GetNlri().(*bgp.LabeledVPNIPAddrPrefix).IPAddrPrefixDefault.Prefix.To4()
}
for _, p := range paths {
nexthops = append(nexthops, p.GetNexthop().To4())
}
case bgp.RF_IPv6_UC, bgp.RF_IPv6_VPN:
if path.IsWithdraw == true {
command = zebra.IPV6_ROUTE_DELETE
} else {
command = zebra.IPV6_ROUTE_ADD
}
if path.GetRouteFamily() == bgp.RF_IPv6_UC {
prefix = path.GetNlri().(*bgp.IPv6AddrPrefix).IPAddrPrefixDefault.Prefix.To16()
} else {
prefix = path.GetNlri().(*bgp.LabeledVPNIPv6AddrPrefix).IPAddrPrefixDefault.Prefix.To16()
}
for _, p := range paths {
nexthops = append(nexthops, p.GetNexthop().To16())
}
default:
return nil
}
msgFlags := uint8(zebra.MESSAGE_NEXTHOP)
plen, _ := strconv.Atoi(l[1])
med, err := path.GetMed()
if err == nil {
msgFlags |= zebra.MESSAGE_METRIC
}
var flags zebra.FLAG
info := path.GetSource()
if info.AS == info.LocalAS {
flags = zebra.FLAG_IBGP | zebra.FLAG_INTERNAL
} else if info.MultihopTtl > 0 {
flags = zebra.FLAG_INTERNAL
}
return &zebra.Message{
Header: zebra.Header{
Len: zebra.HeaderSize(version),
Marker: zebra.HEADER_MARKER,
Version: version,
Command: command,
VrfId: vrfId,
},
Body: &zebra.IPRouteBody{
Type: zebra.ROUTE_BGP,
Flags: flags,
SAFI: zebra.SAFI_UNICAST,
Message: msgFlags,
Prefix: prefix,
PrefixLength: uint8(plen),
Nexthops: nexthops,
Metric: med,
},
}
}
func createPathFromIPRouteMessage(m *zebra.Message) *table.Path {
header := m.Header
body := m.Body.(*zebra.IPRouteBody)
family := bgp.RF_IPv6_UC
if header.Command == zebra.IPV4_ROUTE_ADD || header.Command == zebra.IPV4_ROUTE_DELETE {
family = bgp.RF_IPv4_UC
}
var nlri bgp.AddrPrefixInterface
pattr := make([]bgp.PathAttributeInterface, 0)
var mpnlri *bgp.PathAttributeMpReachNLRI
var isWithdraw bool = header.Command == zebra.IPV4_ROUTE_DELETE || header.Command == zebra.IPV6_ROUTE_DELETE
origin := bgp.NewPathAttributeOrigin(bgp.BGP_ORIGIN_ATTR_TYPE_IGP)
pattr = append(pattr, origin)
log.WithFields(log.Fields{
"Topic": "Zebra",
"RouteType": body.Type.String(),
"Flag": body.Flags.String(),
"Message": body.Message,
"Prefix": body.Prefix,
"PrefixLength": body.PrefixLength,
"Nexthop": body.Nexthops,
"IfIndex": body.Ifindexs,
"Metric": body.Metric,
"Distance": body.Distance,
"Mtu": body.Mtu,
"api": header.Command.String(),
}).Debugf("create path from ip route message.")
switch family {
case bgp.RF_IPv4_UC:
nlri = bgp.NewIPAddrPrefix(body.PrefixLength, body.Prefix.String())
nexthop := bgp.NewPathAttributeNextHop(body.Nexthops[0].String())
pattr = append(pattr, nexthop)
case bgp.RF_IPv6_UC:
nlri = bgp.NewIPv6AddrPrefix(body.PrefixLength, body.Prefix.String())
mpnlri = bgp.NewPathAttributeMpReachNLRI(body.Nexthops[0].String(), []bgp.AddrPrefixInterface{nlri})
pattr = append(pattr, mpnlri)
default:
log.WithFields(log.Fields{
"Topic": "Zebra",
}).Errorf("unsupport address family: %s", family)
return nil
}
med := bgp.NewPathAttributeMultiExitDisc(body.Metric)
pattr = append(pattr, med)
path := table.NewPath(nil, nlri, isWithdraw, pattr, time.Now(), false)
path.SetIsFromExternal(true)
return path
}
type zebraClient struct {
client *zebra.Client
server *BgpServer
dead chan struct{}
}
func (z *zebraClient) stop() {
close(z.dead)
}
func (z *zebraClient) loop() {
w := z.server.Watch(WatchBestPath())
defer func() { w.Stop() }()
for {
select {
case <-z.dead:
return
case msg := <-z.client.Receive():
switch msg.Body.(type) {
case *zebra.IPRouteBody:
if p := createPathFromIPRouteMessage(msg); p != nil {
if _, err := z.server.AddPath("", []*table.Path{p}); err != nil {
log.Errorf("failed to add path from zebra: %s", p)
}
}
}
case ev := <-w.Event():
msg := ev.(*WatchEventBestPath)
if table.UseMultiplePaths.Enabled {
for _, dst := range msg.MultiPathList {
if m := newIPRouteMessage(dst, z.client.Version, 0); m != nil {
z.client.Send(m)
}
}
} else {
for _, path := range msg.PathList {
if len(path.VrfIds) == 0 {
path.VrfIds = []uint16{0}
}
for _, i := range path.VrfIds {
if m := newIPRouteMessage([]*table.Path{path}, z.client.Version, i); m != nil {
z.client.Send(m)
}
}
}
}
}
}
}
func newZebraClient(s *BgpServer, url string, protos []string, version uint8) (*zebraClient, error) {
l := strings.SplitN(url, ":", 2)
if len(l) != 2 {
return nil, fmt.Errorf("unsupported url: %s", url)
}
cli, err := zebra.NewClient(l[0], l[1], zebra.ROUTE_BGP, version)
if err != nil {
return nil, err
}
cli.SendHello()
cli.SendRouterIDAdd()
cli.SendInterfaceAdd()
for _, typ := range protos {
t, err := zebra.RouteTypeFromString(typ)
if err != nil {
return nil, err
}
cli.SendRedistribute(t, zebra.VRF_DEFAULT)
}
w := &zebraClient{
dead: make(chan struct{}),
client: cli,
server: s,
}
go w.loop()
return w, nil
}
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