fix: watch bufer overrun for RouteStatus

smira · smira · commit 9b819ee1e1a3 · 2024-02-02T14:38:35.000+04:00
Fixes #8157 This PR contains two fixes, both related to the same problem. Several routes for different links but same IPv6 destination might exist at the same time, so route resource ID should handle that. The problem was that these routes were mis-reported causing internally updates for the same resources multiple times (equal to the number of the links). Don't trigger controllers more often than 10 times/seconds (with burst of 5) for kernel notifications. This ensures Talos doesn't try to reflect current state of the network subsystem too often as resources, which causes excessive CPU usage and might potentially lead to the buffer overrun under high rate of changes. Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com> (cherry picked from commit 474eccd)
diff --git a/internal/app/machined/pkg/controllers/kubespan/manager.go b/internal/app/machined/pkg/controllers/kubespan/manager.go
@@ -455,7 +455,7 @@ func (ctrl *ManagerController) Run(ctx context.Context, r controller.Runtime, lo
 			if err = r.Modify(ctx,
 				network.NewRouteSpec(
 					network.ConfigNamespaceName,
-					network.LayeredID(network.ConfigOperator, network.RouteID(spec.Table, spec.Family, spec.Destination, spec.Gateway, spec.Priority)),
+					network.LayeredID(network.ConfigOperator, network.RouteID(spec.Table, spec.Family, spec.Destination, spec.Gateway, spec.Priority, spec.OutLinkName)),
 				),
 				func(r resource.Resource) error {
 					*r.(*network.RouteSpec).TypedSpec() = spec
diff --git a/internal/app/machined/pkg/controllers/kubespan/manager_test.go b/internal/app/machined/pkg/controllers/kubespan/manager_test.go
@@ -233,6 +233,7 @@ func (suite *ManagerSuite) TestReconcile() {
 							netip.Prefix{},
 							netip.Addr{},
 							1,
+							"kubespan",
 						),
 					),
 					network.LayeredID(
@@ -243,6 +244,7 @@ func (suite *ManagerSuite) TestReconcile() {
 							netip.Prefix{},
 							netip.Addr{},
 							1,
+							"kubespan",
 						),
 					),
 				},
diff --git a/internal/app/machined/pkg/controllers/network/address_spec.go b/internal/app/machined/pkg/controllers/network/address_spec.go
@@ -54,7 +54,7 @@ func (ctrl *AddressSpecController) Outputs() []controller.Output {
 //nolint:gocyclo
 func (ctrl *AddressSpecController) Run(ctx context.Context, r controller.Runtime, logger *zap.Logger) error {
 	// watch link changes as some address might need to be re-applied if the link appears
-	watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK)
+	watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK)
 	if err != nil {
 		return err
 	}
diff --git a/internal/app/machined/pkg/controllers/network/address_status.go b/internal/app/machined/pkg/controllers/network/address_status.go
@@ -47,7 +47,7 @@ func (ctrl *AddressStatusController) Outputs() []controller.Output {
 //
 //nolint:gocyclo
 func (ctrl *AddressStatusController) Run(ctx context.Context, r controller.Runtime, logger *zap.Logger) error {
-	watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK|unix.RTMGRP_IPV4_IFADDR|unix.RTMGRP_IPV6_IFADDR)
+	watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK|unix.RTMGRP_IPV4_IFADDR|unix.RTMGRP_IPV6_IFADDR)
 	if err != nil {
 		return err
 	}
diff --git a/internal/app/machined/pkg/controllers/network/link_spec.go b/internal/app/machined/pkg/controllers/network/link_spec.go
@@ -67,7 +67,7 @@ func (ctrl *LinkSpecController) Run(ctx context.Context, r controller.Runtime, l
 	}
 
 	// watch link changes as some routes might need to be re-applied if the link appears
-	watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK)
+	watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK)
 	if err != nil {
 		return err
 	}
diff --git a/internal/app/machined/pkg/controllers/network/link_status.go b/internal/app/machined/pkg/controllers/network/link_status.go
@@ -72,14 +72,14 @@ func (ctrl *LinkStatusController) Run(ctx context.Context, r controller.Runtime,
 	// create watch connections to rtnetlink and ethtool via genetlink
 	// these connections are used only to join multicast groups and receive notifications on changes
 	// other connections are used to send requests and receive responses, as we can't mix the notifications and request/responses
-	rtnetlinkWatcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK)
+	rtnetlinkWatcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK)
 	if err != nil {
 		return err
 	}
 
 	defer rtnetlinkWatcher.Done()
 
-	ethtoolWatcher, err := watch.NewEthtool(r)
+	ethtoolWatcher, err := watch.NewEthtool(watch.NewDefaultRateLimitedTrigger(ctx, r))
 	if err != nil {
 		logger.Warn("ethtool watcher failed to start", zap.Error(err))
 	} else {
diff --git a/internal/app/machined/pkg/controllers/network/operator_spec.go b/internal/app/machined/pkg/controllers/network/operator_spec.go
@@ -302,7 +302,10 @@ func (ctrl *OperatorSpecController) reconcileOperatorOutputs(ctx context.Context
 			if err := apply(
 				network.NewRouteSpec(
 					network.ConfigNamespaceName,
-					fmt.Sprintf("%s/%s", op.Operator.Prefix(), network.RouteID(routeSpec.Table, routeSpec.Family, routeSpec.Destination, routeSpec.Gateway, routeSpec.Priority)),
+					fmt.Sprintf("%s/%s",
+						op.Operator.Prefix(),
+						network.RouteID(routeSpec.Table, routeSpec.Family, routeSpec.Destination, routeSpec.Gateway, routeSpec.Priority, routeSpec.OutLinkName),
+					),
 				),
 				func(r resource.Resource) {
 					*r.(*network.RouteSpec).TypedSpec() = routeSpec
diff --git a/internal/app/machined/pkg/controllers/network/platform_config.go b/internal/app/machined/pkg/controllers/network/platform_config.go
@@ -281,7 +281,10 @@ func (ctrl *PlatformConfigController) apply(ctx context.Context, r controller.Ru
 			idBuilder: func(spec interface{}) (resource.ID, error) {
 				routeSpec := spec.(network.RouteSpecSpec) //nolint:errcheck,forcetypeassert
 
-				return network.LayeredID(network.ConfigPlatform, network.RouteID(routeSpec.Table, routeSpec.Family, routeSpec.Destination, routeSpec.Gateway, routeSpec.Priority)), nil
+				return network.LayeredID(
+					network.ConfigPlatform,
+					network.RouteID(routeSpec.Table, routeSpec.Family, routeSpec.Destination, routeSpec.Gateway, routeSpec.Priority, routeSpec.OutLinkName),
+				), nil
 			},
 			resourceBuilder: func(id string) resource.Resource {
 				return network.NewRouteSpec(network.ConfigNamespaceName, id)
diff --git a/internal/app/machined/pkg/controllers/network/route_config.go b/internal/app/machined/pkg/controllers/network/route_config.go
@@ -155,7 +155,7 @@ func (ctrl *RouteConfigController) apply(ctx context.Context, r controller.Runti
 
 	for _, route := range routes {
 		route := route
-		id := network.LayeredID(route.ConfigLayer, network.RouteID(route.Table, route.Family, route.Destination, route.Gateway, route.Priority))
+		id := network.LayeredID(route.ConfigLayer, network.RouteID(route.Table, route.Family, route.Destination, route.Gateway, route.Priority, route.OutLinkName))
 
 		if err := r.Modify(
 			ctx,
diff --git a/internal/app/machined/pkg/controllers/network/route_config_test.go b/internal/app/machined/pkg/controllers/network/route_config_test.go
@@ -231,7 +231,7 @@ func (suite *RouteConfigSuite) TestMachineConfiguration() {
 
 	suite.assertRoutes(
 		[]string{
-			"configuration/inet6/2001:470:6d:30e:8ed2:b60c:9d2f:803b//1024",
+			"configuration/eth2/inet6/2001:470:6d:30e:8ed2:b60c:9d2f:803b//1024",
 			"configuration/inet4/10.0.3.1/10.0.3.0/24/1024",
 			"configuration/inet4/192.168.0.25/192.168.0.0/18/25",
 			"configuration/inet4/192.244.0.1/192.244.0.0/24/1024",
diff --git a/internal/app/machined/pkg/controllers/network/route_merge.go b/internal/app/machined/pkg/controllers/network/route_merge.go
@@ -73,7 +73,7 @@ func (ctrl *RouteMergeController) Run(ctx context.Context, r controller.Runtime,
 
 		for _, res := range list.Items {
 			route := res.(*network.RouteSpec) //nolint:errcheck,forcetypeassert
-			id := network.RouteID(route.TypedSpec().Table, route.TypedSpec().Family, route.TypedSpec().Destination, route.TypedSpec().Gateway, route.TypedSpec().Priority)
+			id := network.RouteID(route.TypedSpec().Table, route.TypedSpec().Family, route.TypedSpec().Destination, route.TypedSpec().Gateway, route.TypedSpec().Priority, route.TypedSpec().OutLinkName)
 
 			existing, ok := routes[id]
 			if ok && existing.TypedSpec().ConfigLayer > route.TypedSpec().ConfigLayer {
diff --git a/internal/app/machined/pkg/controllers/network/route_spec.go b/internal/app/machined/pkg/controllers/network/route_spec.go
@@ -50,7 +50,7 @@ func (ctrl *RouteSpecController) Outputs() []controller.Output {
 //nolint:gocyclo
 func (ctrl *RouteSpecController) Run(ctx context.Context, r controller.Runtime, logger *zap.Logger) error {
 	// watch link changes as some routes might need to be re-applied if the link appears
-	watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK|unix.RTMGRP_IPV4_ROUTE)
+	watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK|unix.RTMGRP_IPV4_ROUTE)
 	if err != nil {
 		return err
 	}
diff --git a/internal/app/machined/pkg/controllers/network/route_status.go b/internal/app/machined/pkg/controllers/network/route_status.go
@@ -47,7 +47,7 @@ func (ctrl *RouteStatusController) Outputs() []controller.Output {
 //
 //nolint:gocyclo
 func (ctrl *RouteStatusController) Run(ctx context.Context, r controller.Runtime, logger *zap.Logger) error {
-	watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_IPV4_MROUTE|unix.RTMGRP_IPV4_ROUTE|unix.RTMGRP_IPV6_MROUTE|unix.RTMGRP_IPV6_ROUTE)
+	watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_IPV4_MROUTE|unix.RTMGRP_IPV4_ROUTE|unix.RTMGRP_IPV6_MROUTE|unix.RTMGRP_IPV6_ROUTE)
 	if err != nil {
 		return err
 	}
@@ -104,7 +104,9 @@ func (ctrl *RouteStatusController) Run(ctx context.Context, r controller.Runtime
 			dstPrefix := netip.PrefixFrom(dstAddr, int(route.DstLength))
 			srcAddr, _ := netip.AddrFromSlice(route.Attributes.Src)
 			gatewayAddr, _ := netip.AddrFromSlice(route.Attributes.Gateway)
-			id := network.RouteID(nethelpers.RoutingTable(route.Table), nethelpers.Family(route.Family), dstPrefix, gatewayAddr, route.Attributes.Priority)
+			outLinkName := linkLookup[route.Attributes.OutIface]
+
+			id := network.RouteID(nethelpers.RoutingTable(route.Table), nethelpers.Family(route.Family), dstPrefix, gatewayAddr, route.Attributes.Priority, outLinkName)
 
 			if err = r.Modify(ctx, network.NewRouteStatus(network.NamespaceName, id), func(r resource.Resource) error {
 				status := r.(*network.RouteStatus).TypedSpec()
@@ -114,7 +116,7 @@ func (ctrl *RouteStatusController) Run(ctx context.Context, r controller.Runtime
 				status.Source = srcAddr
 				status.Gateway = gatewayAddr
 				status.OutLinkIndex = route.Attributes.OutIface
-				status.OutLinkName = linkLookup[route.Attributes.OutIface]
+				status.OutLinkName = outLinkName
 				status.Priority = route.Attributes.Priority
 				status.Table = nethelpers.RoutingTable(route.Table)
 				status.Scope = nethelpers.Scope(route.Scope)
diff --git a/internal/app/machined/pkg/controllers/network/watch/trigger.go b/internal/app/machined/pkg/controllers/network/watch/trigger.go
@@ -0,0 +1,74 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package watch
+
+import (
+	"context"
+
+	"golang.org/x/time/rate"
+)
+
+// RateLimitedTrigger wraps a Trigger with rate limiting.
+type RateLimitedTrigger struct {
+	trigger Trigger
+	limiter *rate.Limiter
+	ch      chan struct{}
+}
+
+// Interface check.
+var _ Trigger = &RateLimitedTrigger{}
+
+// NewRateLimitedTrigger creates a new RateLimitedTrigger with specified params.
+//
+// Trigger's goroutine exists when the context is canceled.
+func NewRateLimitedTrigger(ctx context.Context, trigger Trigger, rateLimit rate.Limit, burst int) *RateLimitedTrigger {
+	t := &RateLimitedTrigger{
+		trigger: trigger,
+		limiter: rate.NewLimiter(rateLimit, burst),
+		ch:      make(chan struct{}),
+	}
+
+	go t.run(ctx)
+
+	return t
+}
+
+// NewDefaultRateLimitedTrigger creates a new RateLimitedTrigger with default params.
+func NewDefaultRateLimitedTrigger(ctx context.Context, trigger Trigger) *RateLimitedTrigger {
+	const (
+		defaultRate  = 10 // 10 events per second
+		defaultBurst = 5  // 5 events
+	)
+
+	return NewRateLimitedTrigger(ctx, trigger, defaultRate, defaultBurst)
+}
+
+// QueueReconcile implements Trigger interface.
+//
+// The event is queued if the goroutine is ready to accept it (otherwise it's already
+// busy processing a previous event).
+// This function returns immediately.
+func (t *RateLimitedTrigger) QueueReconcile() {
+	select {
+	case t.ch <- struct{}{}:
+	default:
+	}
+}
+
+func (t *RateLimitedTrigger) run(ctx context.Context) {
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.ch:
+		}
+
+		if err := t.limiter.Wait(ctx); err != nil {
+			return
+		}
+
+		t.trigger.QueueReconcile()
+	}
+}
diff --git a/internal/app/machined/pkg/controllers/network/watch/trigger_test.go b/internal/app/machined/pkg/controllers/network/watch/trigger_test.go
@@ -0,0 +1,45 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package watch_test
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/siderolabs/talos/internal/app/machined/pkg/controllers/network/watch"
+)
+
+type mockTrigger struct {
+	count atomic.Int64
+}
+
+func (t *mockTrigger) QueueReconcile() {
+	t.count.Add(1)
+}
+
+func (t *mockTrigger) Get() int64 {
+	return t.count.Load()
+}
+
+func TestRateLimitedTrigger(t *testing.T) {
+	mock := &mockTrigger{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	t.Cleanup(cancel)
+
+	trigger := watch.NewRateLimitedTrigger(ctx, mock, 10, 5)
+
+	start := time.Now()
+
+	for time.Since(start) < time.Second {
+		trigger.QueueReconcile()
+	}
+
+	assert.InDelta(t, int64(14), mock.Get(), 5)
+}
diff --git a/pkg/machinery/resources/network/network.go b/pkg/machinery/resources/network/network.go
@@ -33,17 +33,21 @@ func LinkID(linkName string) string {
 }
 
 // RouteID builds ID (primary key) for the route.
-func RouteID(table nethelpers.RoutingTable, family nethelpers.Family, destination netip.Prefix, gateway netip.Addr, priority uint32) string {
+func RouteID(table nethelpers.RoutingTable, family nethelpers.Family, destination netip.Prefix, gateway netip.Addr, priority uint32, outLinkName string) string {
 	dst, _ := destination.MarshalText() //nolint:errcheck
 	gw, _ := gateway.MarshalText()      //nolint:errcheck
 
-	tablePrefix := ""
+	prefix := ""
 
 	if table != nethelpers.TableMain {
-		tablePrefix = fmt.Sprintf("%s/", table)
+		prefix = fmt.Sprintf("%s/", table)
 	}
 
-	return fmt.Sprintf("%s%s/%s/%s/%d", tablePrefix, family, string(gw), string(dst), priority)
+	if family == nethelpers.FamilyInet6 {
+		prefix += fmt.Sprintf("%s/", outLinkName)
+	}
+
+	return fmt.Sprintf("%s%s/%s/%s/%d", prefix, family, string(gw), string(dst), priority)
 }
 
 // OperatorID builds ID (primary key) for the operators.

Original file line number	Diff line number	Diff line change
`@@ -54,7 +54,7 @@ func (ctrl *AddressSpecController) Outputs() []controller.Output {`
`54`	`54`	`//nolint:gocyclo`
`55`	`55`	`func (ctrl AddressSpecController) Run(ctx context.Context, r controller.Runtime, logger zap.Logger) error {`
`56`	`56`	`// watch link changes as some address might need to be re-applied if the link appears`
`57`		`- watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK)`
	`57`	`+ watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK)`
`58`	`58`	`if err != nil {`
`59`	`59`	`return err`
`60`	`60`	`}`
Original file line number	Diff line number	Diff line change
`@@ -47,7 +47,7 @@ func (ctrl *AddressStatusController) Outputs() []controller.Output {`
`47`	`47`	`//`
`48`	`48`	`//nolint:gocyclo`
`49`	`49`	`func (ctrl AddressStatusController) Run(ctx context.Context, r controller.Runtime, logger zap.Logger) error {`
`50`		`- watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK\|unix.RTMGRP_IPV4_IFADDR\|unix.RTMGRP_IPV6_IFADDR)`
	`50`	`+ watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK\|unix.RTMGRP_IPV4_IFADDR\|unix.RTMGRP_IPV6_IFADDR)`
`51`	`51`	`if err != nil {`
`52`	`52`	`return err`
`53`	`53`	`}`
Original file line number	Diff line number	Diff line change
`@@ -67,7 +67,7 @@ func (ctrl *LinkSpecController) Run(ctx context.Context, r controller.Runtime, l`
`67`	`67`	`}`
`68`	`68`
`69`	`69`	`// watch link changes as some routes might need to be re-applied if the link appears`
`70`		`- watcher, err := watch.NewRtNetlink(r, unix.RTMGRP_LINK)`
	`70`	`+ watcher, err := watch.NewRtNetlink(watch.NewDefaultRateLimitedTrigger(ctx, r), unix.RTMGRP_LINK)`
`71`	`71`	`if err != nil {`
`72`	`72`	`return err`
`73`	`73`	`}`