Merge pull request #48 from bio-routing/fix/aspath

Fixing AS path change on propagation

main.go

@@ -13,8 +13,15 @@ import (
 	"github.com/bio-routing/bio-rd/routingtable"
 	"github.com/bio-routing/bio-rd/routingtable/filter"
 	"github.com/bio-routing/bio-rd/routingtable/locRIB"
+
+	bnet "github.com/bio-routing/bio-rd/net"
 )
 
+func strAddr(s string) uint32 {
+	ret, _ := bnet.StrToAddr(s)
+	return ret
+}
+
 func main() {
 	logrus.Printf("This is a BGP speaker\n")
 

protocols/bgp/server/fsm_established.go

@@ -58,8 +58,10 @@ func (s *establishedState) init() {
 	s.fsm.adjRIBIn.Register(s.fsm.peer.importFilter)
 
 	n := &routingtable.Neighbor{
-		Type:    route.BGPPathType,
-		Address: tnet.IPv4ToUint32(s.fsm.peer.addr),
+		Type:     route.BGPPathType,
+		Address:  tnet.IPv4ToUint32(s.fsm.peer.addr),
+		IBGP:     s.fsm.peer.localASN == s.fsm.peer.peerASN,
+		LocalASN: s.fsm.peer.localASN,
 	}
 
 	clientOptions := routingtable.ClientOptions{}

protocols/bgp/server/update_helper.go

@@ -10,8 +10,8 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-func pathAttribues(p *route.Path, fsm *FSM) (*packet.PathAttribute, error) {
-	asPathPA, err := packet.ParseASPathStr(strings.TrimRight(fmt.Sprintf("%d %s", fsm.peer.localASN, p.BGPPath.ASPath), " "))
+func pathAttribues(p *route.Path) (*packet.PathAttribute, error) {
+	asPathPA, err := packet.ParseASPathStr(strings.TrimRight(p.BGPPath.ASPath, " "))
 	if err != nil {
 		return nil, fmt.Errorf("Unable to parse AS path: %v", err)
 	}

protocols/bgp/server/update_sender.go

@@ -28,7 +28,7 @@ func newUpdateSender(fsm *FSM) *UpdateSender {
 
 // AddPath serializes a new path and sends out a BGP update message
 func (u *UpdateSender) AddPath(pfx net.Prefix, p *route.Path) error {
-	pathAttrs, err := pathAttribues(p, u.fsm)
+	pathAttrs, err := pathAttribues(p)
 	if err != nil {
 		log.Errorf("Unable to create BGP Update: %v", err)
 		return nil

protocols/bgp/server/update_sender_add_path.go

@@ -25,7 +25,7 @@ func newUpdateSenderAddPath(fsm *FSM) *UpdateSenderAddPath {
 
 // AddPath serializes a new path and sends out a BGP update message
 func (u *UpdateSenderAddPath) AddPath(pfx net.Prefix, p *route.Path) error {
-	pathAttrs, err := pathAttribues(p, u.fsm)
+	pathAttrs, err := pathAttribues(p)
 
 	if err != nil {
 		log.Errorf("Unable to create BGP Update: %v", err)

routingtable/adjRIBOut/adj_rib_out.go

@@ -39,6 +39,11 @@ func (a *AdjRIBOut) AddPath(pfx net.Prefix, p *route.Path) error {
 		return nil
 	}
 
+	p = p.Copy()
+	if !a.neighbor.IBGP {
+		p.BGPPath.ASPath = fmt.Sprintf("%d %s", a.neighbor.LocalASN, p.BGPPath.ASPath)
+	}
+
 	a.mu.Lock()
 	defer a.mu.Unlock()
 

routingtable/adjRIBOutAddPath/adj_rib_out_add_path.go

@@ -41,6 +41,11 @@ func (a *AdjRIBOutAddPath) AddPath(pfx net.Prefix, p *route.Path) error {
 		return nil
 	}
 
+	p = p.Copy()
+	if !a.neighbor.IBGP {
+		p.BGPPath.ASPath = fmt.Sprintf("%d %s", a.neighbor.LocalASN, p.BGPPath.ASPath)
+	}
+
 	a.mu.Lock()
 	defer a.mu.Unlock()
 

routingtable/neighbor.go

@@ -10,4 +10,7 @@ type Neighbor struct {
 
 	// IBGP returns if local ASN is equal to remote ASN
 	IBGP bool
+
+	// Local ASN of session
+	LocalASN uint32
 }