// Compare path with a policy's condition in stored order in the policy.
// If a condition match, then this function stops evaluation and
// subsequent conditions are skipped.
func (p *Policy) Apply(path *table.Path) (bool, RouteType, *table.Path) {
for _, statement := range p.Statements {
result := statement.evaluate(path)
log.WithFields(log.Fields{
"Topic": "Policy",
"Path": path,
"PolicyName": p.Name,
}).Debug("statement.Conditions.evaluate : ", result)
var p *table.Path
if result {
//Routing action
p = statement.routingAction.apply(path)
if p != nil {
// apply all modification actions
cloned := path.Clone(p.IsWithdraw)
for _, action := range statement.modificationActions {
cloned = action.apply(cloned)
}
return true, ROUTE_TYPE_ACCEPT, cloned
} else {
return true, ROUTE_TYPE_REJECT, nil
}
}
}
return false, ROUTE_TYPE_NONE, nil
}
func (peer *Peer) filterpath(path *table.Path) *table.Path {
// special handling for RTC nlri
// see comments in (*Destination).Calculate()
if path != nil && path.GetRouteFamily() == bgp.RF_RTC_UC && !path.IsWithdraw {
// if we already sent the same nlri, ignore this
if peer.adjRibOut.Exists(path) {
return nil
}
dst := peer.localRib.GetDestination(path)
path = nil
// we send a path even if it is not a best path
for _, p := range dst.GetKnownPathList(peer.TableID()) {
// just take care not to send back it
if peer.ID() != p.GetSource().Address.String() {
path = p
break
}
}
}
if filterpath(peer, path) == nil {
return nil
}
if !peer.isRouteServerClient() {
path = path.Clone(path.IsWithdraw)
path.UpdatePathAttrs(peer.fsm.gConf, peer.fsm.pConf)
}
options := &table.PolicyOptions{
Info: peer.fsm.peerInfo,
}
path = peer.policy.ApplyPolicy(peer.TableID(), table.POLICY_DIRECTION_EXPORT, path, options)
// remove local-pref attribute
// we should do this after applying export policy since policy may
// set local-preference
if path != nil && peer.fsm.pConf.Config.PeerType == config.PEER_TYPE_EXTERNAL {
path.RemoveLocalPref()
}
return path
}
func (peer *Peer) filterpath(path, old *table.Path) *table.Path {
// special handling for RTC nlri
// see comments in (*Destination).Calculate()
if path != nil && path.GetRouteFamily() == bgp.RF_RTC_UC && !path.IsWithdraw {
// If we already sent the same nlri, send unnecessary
// update. Fix this after the API change between table
// and server packages.
dst := peer.localRib.GetDestination(path)
path = nil
// we send a path even if it is not a best path
for _, p := range dst.GetKnownPathList(peer.TableID()) {
// just take care not to send back it
if peer.ID() != p.GetSource().Address.String() {
path = p
break
}
}
}
// only allow vpnv4 and vpnv6 paths to be advertised to VRFed neighbors.
// also check we can import this path using table.CanImportToVrf()
// if we can, make it local path by calling (*Path).ToLocal()
if path != nil && peer.fsm.pConf.Config.Vrf != "" {
if f := path.GetRouteFamily(); f != bgp.RF_IPv4_VPN && f != bgp.RF_IPv6_VPN {
return nil
}
vrf := peer.localRib.Vrfs[peer.fsm.pConf.Config.Vrf]
if table.CanImportToVrf(vrf, path) {
path = path.ToLocal()
} else {
return nil
}
}
if path = filterpath(peer, path, old); path == nil {
return nil
}
path = path.Clone(path.IsWithdraw)
path.UpdatePathAttrs(peer.fsm.gConf, peer.fsm.pConf)
options := &table.PolicyOptions{
Info: peer.fsm.peerInfo,
}
path = peer.policy.ApplyPolicy(peer.TableID(), table.POLICY_DIRECTION_EXPORT, path, options)
// draft-uttaro-idr-bgp-persistence-02
// 4.3. Processing LLGR_STALE Routes
//
// The route SHOULD NOT be advertised to any neighbor from which the
// Long-lived Graceful Restart Capability has not been received. The
// exception is described in the Optional Partial Deployment
// Procedure section (Section 4.7). Note that this requirement
// implies that such routes should be withdrawn from any such neighbor.
if path != nil && !path.IsWithdraw && !peer.isLLGREnabledFamily(path.GetRouteFamily()) && path.IsLLGRStale() {
// we send unnecessary withdrawn even if we didn't
// sent the route.
path = path.Clone(true)
}
// remove local-pref attribute
// we should do this after applying export policy since policy may
// set local-preference
if path != nil && !peer.isIBGPPeer() && !peer.isRouteServerClient() {
path.RemoveLocalPref()
}
return path
}