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main.go
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main.go
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// Copyright (C) 2016 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 main
import (
"encoding/json"
"fmt"
"log"
"net"
"net/http"
"os"
"strconv"
"strings"
"time"
"github.com/Sirupsen/logrus"
etcd "github.com/coreos/etcd/client"
"github.com/coreos/etcd/pkg/transport"
bgpapi "github.com/osrg/gobgp/api"
bgpconfig "github.com/osrg/gobgp/config"
bgp "github.com/osrg/gobgp/packet/bgp"
bgpserver "github.com/osrg/gobgp/server"
bgptable "github.com/osrg/gobgp/table"
"github.com/vishvananda/netlink"
"golang.org/x/net/context"
)
const (
HOSTNAME = "HOSTNAME"
ETCD_SCHEME = "ETCD_SCHEME"
ETCD_AUTHORITY = "ETCD_AUTHORITY"
ETCD_KEY_FILE = "ETCD_KEY_FILE"
ETCD_CERT_FILE = "ETCD_CERT_FILE"
ETCD_CA_CERT_FILE = "ETCD_CA_CERT_FILE"
IP = "IP"
IP6 = "IP6"
CALICO_PREFIX = "/calico"
CALICO_BGP = CALICO_PREFIX + "/bgp/v1"
CALICO_AGGR = CALICO_PREFIX + "/ipam/v2/host"
defaultDialTimeout = 30 * time.Second
)
func underscore(ip string) string {
return strings.Map(func(r rune) rune {
switch r {
case '.', ':':
return '_'
}
return r
}, ip)
}
func errorButKeyNotFound(err error) error {
if e, ok := err.(etcd.Error); ok && e.Code == etcd.ErrorCodeKeyNotFound {
return nil
}
return err
}
func getTransport() (*http.Transport, error) {
cafile := os.Getenv(ETCD_CA_CERT_FILE)
certfile := os.Getenv(ETCD_CERT_FILE)
keyfile := os.Getenv(ETCD_KEY_FILE)
tls := transport.TLSInfo{
CAFile: cafile,
CertFile: certfile,
KeyFile: keyfile,
}
return transport.NewTransport(tls, defaultDialTimeout)
}
func getGlobalASN(api etcd.KeysAPI) (uint32, error) {
res, err := api.Get(context.Background(), fmt.Sprintf("%s/global/as_num", CALICO_BGP), nil)
if err != nil {
return 0, err
}
asn, err := strconv.ParseUint(res.Node.Value, 10, 32)
if err != nil {
return 0, err
}
return uint32(asn), nil
}
func getPeerASN(api etcd.KeysAPI, host string) (uint32, error) {
res, err := api.Get(context.Background(), fmt.Sprintf("%s/host/%s/as_num", CALICO_BGP, host), nil)
if errorButKeyNotFound(err) != nil {
return 0, err
}
if res != nil && res.Node != nil {
v, err := strconv.ParseUint(res.Node.Value, 10, 32)
if err != nil {
return 0, err
}
return uint32(v), nil
}
return getGlobalASN(api)
}
func getGlobalConfig(api etcd.KeysAPI) (*bgpconfig.Global, error) {
asn, err := getGlobalASN(api)
if err != nil {
return nil, err
}
return &bgpconfig.Global{
Config: bgpconfig.GlobalConfig{
As: asn,
RouterId: os.Getenv(IP),
},
}, nil
}
func isMeshMode(api etcd.KeysAPI) (bool, error) {
res, err := api.Get(context.Background(), fmt.Sprintf("%s/global/node_mesh", CALICO_BGP), nil)
if err != nil {
return false, err
}
m := &struct {
Enabled bool `json:"enabled"`
}{}
if err := json.Unmarshal([]byte(res.Node.Value), m); err != nil {
return false, err
}
return m.Enabled, nil
}
func getMeshNeighborConfigs(api etcd.KeysAPI) ([]*bgpconfig.Neighbor, error) {
globalASN, err := getGlobalASN(api)
if err != nil {
return nil, err
}
res, err := api.Get(context.Background(), fmt.Sprintf("%s/host", CALICO_BGP), &etcd.GetOptions{Recursive: true})
if err != nil {
return nil, err
}
ns := make([]*bgpconfig.Neighbor, 0, len(res.Node.Nodes))
for _, node := range res.Node.Nodes {
var v4, v6 string
peerASN := globalASN
for _, v := range node.Nodes {
path := strings.Split(v.Key, "/")
key := path[len(path)-1]
switch key {
case "ip_addr_v4":
v4 = v.Value
if v4 == os.Getenv(IP) {
v4 = ""
}
case "ip_addr_v6":
v6 = v.Value
if v6 == os.Getenv(IP6) {
v6 = ""
}
case "as_num":
asn, err := strconv.ParseUint(v.Value, 10, 32)
if err != nil {
return nil, err
}
peerASN = uint32(asn)
default:
log.Printf("unhandled key: %s", v.Key)
}
}
if v4 != "" {
id := strings.Replace(v4, ".", "_", -1)
ns = append(ns, &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: v4,
PeerAs: peerASN,
Description: fmt.Sprintf("Mesh_%s", id),
},
})
}
if v6 != "" {
id := strings.Replace(v4, ":", "_", -1)
ns = append(ns, &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: v6,
PeerAs: peerASN,
Description: fmt.Sprintf("Mesh_%s", id),
},
})
}
}
return ns, nil
}
func getNeighborConfigFromPeer(node *etcd.Node, neighborType string) (*bgpconfig.Neighbor, error) {
m := &struct {
IP string `json:"ip"`
ASN string `json:"as_num"`
}{}
if err := json.Unmarshal([]byte(node.Value), m); err != nil {
return nil, err
}
asn, err := strconv.ParseUint(m.ASN, 10, 32)
if err != nil {
return nil, err
}
return &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: m.IP,
PeerAs: uint32(asn),
Description: fmt.Sprintf("%s_%s", strings.Title(neighborType), underscore(m.IP)),
},
}, nil
}
func getNonMeshNeighborConfigs(api etcd.KeysAPI, neighborType, version string) ([]*bgpconfig.Neighbor, error) {
var key string
switch neighborType {
case "global":
key = fmt.Sprintf("%s/global/peer_%s", CALICO_BGP, version)
case "node":
key = fmt.Sprintf("%s/host/%s/peer_%s", CALICO_BGP, os.Getenv(HOSTNAME), version)
default:
return nil, fmt.Errorf("invalid neighbor type: %s", neighborType)
}
res, err := api.Get(context.Background(), key, &etcd.GetOptions{Recursive: true})
if errorButKeyNotFound(err) != nil {
return nil, err
}
if res == nil {
return nil, nil
}
ns := make([]*bgpconfig.Neighbor, 0, len(res.Node.Nodes))
for _, node := range res.Node.Nodes {
var n *bgpconfig.Neighbor
if n, err = getNeighborConfigFromPeer(node, neighborType); err != nil {
return nil, err
}
ns = append(ns, n)
}
return ns, nil
}
func getGlobalNeighborConfigs(api etcd.KeysAPI) ([]*bgpconfig.Neighbor, error) {
v4s, err := getNonMeshNeighborConfigs(api, "global", "v4")
if err != nil {
return nil, err
}
v6s, err := getNonMeshNeighborConfigs(api, "global", "v6")
if err != nil {
return nil, err
}
return append(v4s, v6s...), nil
}
func getNodeSpecificNeighborConfigs(api etcd.KeysAPI) ([]*bgpconfig.Neighbor, error) {
v4s, err := getNonMeshNeighborConfigs(api, "node", "v4")
if err != nil {
return nil, err
}
v6s, err := getNonMeshNeighborConfigs(api, "node", "v6")
if err != nil {
return nil, err
}
return append(v4s, v6s...), nil
}
func getNeighborConfigs(api etcd.KeysAPI) ([]*bgpconfig.Neighbor, error) {
var neighbors []*bgpconfig.Neighbor
// --- Node-to-node mesh ---
if mesh, err := isMeshMode(api); err == nil && mesh {
ns, err := getMeshNeighborConfigs(api)
if err != nil {
return nil, err
}
neighbors = append(neighbors, ns...)
} else if err != nil {
return nil, err
}
// --- Global peers ---
if ns, err := getGlobalNeighborConfigs(api); err != nil {
return nil, err
} else {
neighbors = append(neighbors, ns...)
}
// --- Node-specific peers ---
if ns, err := getNodeSpecificNeighborConfigs(api); err != nil {
return nil, err
} else {
neighbors = append(neighbors, ns...)
}
return neighbors, nil
}
func makePath(key string, isWithdrawal bool) (*bgptable.Path, error) {
path := strings.Split(key, "/")
elems := strings.Split(path[len(path)-1], "-")
if len(elems) != 2 {
return nil, fmt.Errorf("invalid prefix format: %s", path[len(path)-1])
}
prefix := elems[0]
masklen, err := strconv.ParseUint(elems[1], 10, 8)
if err != nil {
return nil, err
}
p := net.ParseIP(prefix)
v4 := true
if p == nil {
return nil, fmt.Errorf("invalid prefix format: %s", key)
} else if p.To4() == nil {
v4 = false
}
var nlri bgp.AddrPrefixInterface
if v4 {
nlri = bgp.NewIPAddrPrefix(uint8(masklen), prefix)
} else {
nlri = bgp.NewIPv6AddrPrefix(uint8(masklen), prefix)
}
attrs := []bgp.PathAttributeInterface{
bgp.NewPathAttributeOrigin(0),
}
if v4 {
attrs = append(attrs, bgp.NewPathAttributeNextHop(os.Getenv(IP)))
} else {
attrs = append(attrs, bgp.NewPathAttributeMpReachNLRI(os.Getenv(IP6), []bgp.AddrPrefixInterface{nlri}))
}
return bgptable.NewPath(nil, nlri, isWithdrawal, attrs, time.Now(), false), nil
}
func getAssignedPrefixes(api etcd.KeysAPI) ([]*bgptable.Path, error) {
var ps []*bgptable.Path
f := func(version string) error {
res, err := api.Get(context.Background(), fmt.Sprintf("%s/%s/%s/block", CALICO_AGGR, os.Getenv(HOSTNAME), version), &etcd.GetOptions{Recursive: true})
if err != nil {
return err
}
for _, v := range res.Node.Nodes {
path, err := makePath(v.Key, false)
if err != nil {
return err
}
ps = append(ps, path)
}
return nil
}
if os.Getenv(IP) != "" {
if err := f("ipv4"); err != nil {
return nil, err
}
}
if os.Getenv(IP6) != "" {
if err := f("ipv6"); err != nil {
return nil, err
}
}
return ps, nil
}
func watchPrefix(api etcd.KeysAPI, bgpServer *bgpserver.BgpServer) error {
watcher := api.Watcher(fmt.Sprintf("%s/%s", CALICO_AGGR, os.Getenv(HOSTNAME)), &etcd.WatcherOptions{Recursive: true})
for {
var err error
res, err := watcher.Next(context.Background())
if err != nil {
return err
}
var path *bgptable.Path
if res.Action == "delete" {
path, err = makePath(res.Node.Key, true)
} else {
path, err = makePath(res.Node.Key, false)
}
if err != nil {
return err
}
if _, err := bgpServer.AddPath("", []*bgptable.Path{path}); err != nil {
return err
}
log.Printf("add path: %s", path)
}
}
func watchBGPConfig(api etcd.KeysAPI, bgpServer *bgpserver.BgpServer) error {
watcher := api.Watcher(fmt.Sprintf("%s", CALICO_BGP), &etcd.WatcherOptions{
Recursive: true,
})
for {
res, err := watcher.Next(context.Background())
if err != nil {
return err
}
log.Printf("watch: %v", res)
handleNonMeshNeighbor := func(neighborType string) error {
switch res.Action {
case "delete":
n, err := getNeighborConfigFromPeer(res.PrevNode, neighborType)
if err != nil {
return err
}
return bgpServer.DeleteNeighbor(n)
case "set":
n, err := getNeighborConfigFromPeer(res.Node, neighborType)
if err != nil {
return err
}
return bgpServer.AddNeighbor(n)
}
log.Printf("unhandled action: %s", res.Action)
return nil
}
key := res.Node.Key
switch {
case strings.HasPrefix(key, fmt.Sprintf("%s/global/peer_", CALICO_BGP)):
err = handleNonMeshNeighbor("global")
case strings.HasPrefix(key, fmt.Sprintf("%s/host/%s/peer_", CALICO_BGP, os.Getenv(HOSTNAME))):
err = handleNonMeshNeighbor("node")
case strings.HasPrefix(key, fmt.Sprintf("%s/host/%s", CALICO_BGP, os.Getenv(HOSTNAME))):
log.Println("Local host config update. Restart")
os.Exit(1)
case strings.HasPrefix(key, fmt.Sprintf("%s/host", CALICO_BGP)):
elems := strings.Split(key, "/")
if len(elems) < 4 {
log.Printf("unhandled key: %s", key)
continue
}
deleteNeighbor := func(node *etcd.Node) error {
n := &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: node.Value,
},
}
return bgpServer.DeleteNeighbor(n)
}
host := elems[len(elems)-2]
switch elems[len(elems)-1] {
case "ip_addr_v4", "ip_addr_v6":
switch res.Action {
case "delete":
if err = deleteNeighbor(res.PrevNode); err != nil {
return err
}
case "set":
if res.PrevNode != nil {
if err = deleteNeighbor(res.PrevNode); err != nil {
return err
}
}
asn, err := getPeerASN(api, host)
if err != nil {
return err
}
n := &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: res.Node.Value,
PeerAs: asn,
Description: fmt.Sprintf("Mesh_%s", underscore(res.Node.Value)),
},
}
if err = bgpServer.AddNeighbor(n); err != nil {
return err
}
}
case "as_num":
var asn uint32
if res.Action == "set" {
v, err := strconv.ParseUint(res.Node.Value, 10, 32)
if err != nil {
return err
}
asn = uint32(v)
} else {
asn, err = getGlobalASN(api)
if err != nil {
return err
}
}
for _, version := range []string{"v4", "v6"} {
res, err := api.Get(context.Background(), fmt.Sprintf("%s/host/%s/ip_addr_%s", CALICO_BGP, host, version), nil)
if errorButKeyNotFound(err) != nil {
return err
}
if res == nil {
continue
}
if err = deleteNeighbor(res.Node); err != nil {
return err
}
ip := res.Node.Value
n := &bgpconfig.Neighbor{
Config: bgpconfig.NeighborConfig{
NeighborAddress: ip,
PeerAs: asn,
Description: fmt.Sprintf("Mesh_%s", underscore(ip)),
},
}
if err = bgpServer.AddNeighbor(n); err != nil {
return err
}
}
default:
log.Printf("unhandled key: %s", key)
}
case strings.HasPrefix(key, fmt.Sprintf("%s/global/as_num", CALICO_BGP)):
log.Println("Global AS number update. Restart")
os.Exit(1)
case strings.HasPrefix(key, fmt.Sprintf("%s/global/node_mesh", CALICO_BGP)):
mesh, err := isMeshMode(api)
if err != nil {
return err
}
ns, err := getMeshNeighborConfigs(api)
if err != nil {
return err
}
for _, n := range ns {
if mesh {
err = bgpServer.AddNeighbor(n)
} else {
err = bgpServer.DeleteNeighbor(n)
}
if err != nil {
return err
}
}
}
if err != nil {
return err
}
}
}
func injectRoute(path *bgptable.Path) error {
nexthop := path.GetNexthop()
nlri := path.GetNlri()
var family int
var d string
switch f := path.GetRouteFamily(); f {
case bgp.RF_IPv4_UC:
family = netlink.FAMILY_V4
d = "0.0.0.0/0"
case bgp.RF_IPv6_UC:
family = netlink.FAMILY_V6
d = "::/0"
default:
log.Printf("only supports injecting ipv4/ipv6 unicast route: %s", f)
return nil
}
dst, _ := netlink.ParseIPNet(nlri.String())
route := &netlink.Route{
Dst: dst,
Gw: nexthop,
}
routes, _ := netlink.RouteList(nil, family)
for _, route := range routes {
if route.Dst != nil {
d = route.Dst.String()
}
if d == dst.String() {
err := netlink.RouteDel(&route)
if err != nil {
return err
}
}
}
if path.IsWithdraw {
log.Printf("removed route %s from kernel", nlri)
return nil
}
log.Printf("added route %s to kernel", nlri)
return netlink.RouteAdd(route)
}
func monitorPath(watcher *bgpserver.Watcher) error {
for {
ev := <-watcher.Event()
msg, ok := ev.(*bgpserver.WatchEventBestPath)
if !ok {
continue
}
for _, path := range msg.PathList {
if path.IsLocal() {
continue
}
if err := injectRoute(path); err != nil {
return err
}
}
}
}
func main() {
logrus.SetLevel(logrus.DebugLevel)
etcdAuthority := os.Getenv(ETCD_AUTHORITY)
etcdScheme := os.Getenv(ETCD_SCHEME)
if etcdScheme == "" {
etcdScheme = "http"
}
transport, err := getTransport()
if err != nil {
log.Fatal(err)
}
config := etcd.Config{
Endpoints: []string{fmt.Sprintf("%s://%s", etcdScheme, etcdAuthority)},
Transport: transport,
}
cli, err := etcd.New(config)
if err != nil {
log.Fatal(err)
}
bgpServer := bgpserver.NewBgpServer()
go bgpServer.Serve()
bgpAPIServer := bgpapi.NewGrpcServer(bgpServer, ":50051")
go bgpAPIServer.Serve()
api := etcd.NewKeysAPI(cli)
globalConfig, err := getGlobalConfig(api)
if err != nil {
log.Fatal(err)
}
if err := bgpServer.Start(globalConfig); err != nil {
log.Fatal(err)
}
watcher := bgpServer.Watch(bgpserver.WatchBestPath())
go func() {
log.Fatal(monitorPath(watcher))
}()
paths, err := getAssignedPrefixes(api)
if err != nil {
log.Fatal(err)
}
if _, err := bgpServer.AddPath("", paths); err != nil {
log.Fatal(err)
}
go func() {
log.Fatal(watchPrefix(api, bgpServer))
}()
neighborConfigs, err := getNeighborConfigs(api)
if err != nil {
log.Fatal(err)
}
for _, n := range neighborConfigs {
if err = bgpServer.AddNeighbor(n); err != nil {
log.Fatal(err)
}
}
go func() {
log.Fatal(watchBGPConfig(api, bgpServer))
}()
ch := make(chan struct{})
<-ch
}