Golang Path.Clone方法代码示例

// 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
}