Don't announce own ASN in ASPath if iBGP

protocols/bgp/server/update_sender.go

@@ -15,18 +15,20 @@ import (
 // UpdateSender converts table changes into BGP update messages
 type UpdateSender struct {
 	routingtable.ClientManager
-	fsm *FSM
+	fsm  *FSM
+	iBGP bool
 }
 
 func newUpdateSender(fsm *FSM) *UpdateSender {
 	return &UpdateSender{
-		fsm: fsm,
+		fsm:  fsm,
+		iBGP: fsm.localASN == fsm.remoteASN,
 	}
 }
 
 // AddPath serializes a new path and sends out a BGP update message
 func (u *UpdateSender) AddPath(pfx net.Prefix, p *route.Path) error {
-	asPathPA, err := packet.ParseASPathStr(strings.TrimRight(fmt.Sprintf("%d %s", u.fsm.localASN, p.BGPPath.ASPath), " "))
+	asPathPA, err := packet.ParseASPathStr(asPathString(u.iBGP, u.fsm.localASN, p.BGPPath.ASPath))
 	if err != nil {
 		return fmt.Errorf("Unable to parse AS path: %v", err)
 	}
@@ -74,3 +76,12 @@ func (u *UpdateSender) UpdateNewClient(client routingtable.RouteTableClient) err
 	log.Warningf("BGP Update Sender: UpdateNewClient() not supported")
 	return nil
 }
+
+func asPathString(iBGP bool, localASN uint16, asPath string) string {
+	ret := ""
+	if iBGP {
+		ret = ret + fmt.Sprintf("%d ", localASN)
+	}
+	ret = ret + asPath
+	return strings.TrimRight(ret, " ")
+}

protocols/bgp/server/update_sender_add_path.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"fmt"
-	"strings"
 
 	log "github.com/sirupsen/logrus"
 
@@ -15,18 +14,20 @@ import (
 // UpdateSenderAddPath converts table changes into BGP update messages with add path
 type UpdateSenderAddPath struct {
 	routingtable.ClientManager
-	fsm *FSM
+	fsm  *FSM
+	iBGP bool
 }
 
 func newUpdateSenderAddPath(fsm *FSM) *UpdateSenderAddPath {
 	return &UpdateSenderAddPath{
-		fsm: fsm,
+		fsm:  fsm,
+		iBGP: fsm.localASN == fsm.remoteASN,
 	}
 }
 
 // AddPath serializes a new path and sends out a BGP update message
 func (u *UpdateSenderAddPath) AddPath(pfx net.Prefix, p *route.Path) error {
-	asPathPA, err := packet.ParseASPathStr(strings.TrimRight(fmt.Sprintf("%d %s", u.fsm.localASN, p.BGPPath.ASPath), " "))
+	asPathPA, err := packet.ParseASPathStr(asPathString(u.iBGP, u.fsm.localASN, p.BGPPath.ASPath))
 	if err != nil {
 		return fmt.Errorf("Unable to parse AS path: %v", err)
 	}