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fix: match routes on the priority properly
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Fixes siderolabs#7592

The problem was a mismatch between a "primary key" (ID) of the
`RouteSpec` and the way routes are looked up in the kernel - with two
idential routes but different priority Talos would end up in an infinite
loop fighting to remove and re-add back same route, as priority never
matches.

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>
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smira committed Aug 10, 2023
1 parent bff0d8f commit ee6d639
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Showing 2 changed files with 23 additions and 17 deletions.
35 changes: 21 additions & 14 deletions internal/app/machined/pkg/controllers/network/route_spec.go
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,6 @@ package network
import (
"context"
"fmt"
"net/netip"

"github.com/cosi-project/runtime/pkg/controller"
"github.com/cosi-project/runtime/pkg/resource"
Expand Down Expand Up @@ -120,31 +119,35 @@ func (ctrl *RouteSpecController) Run(ctx context.Context, r controller.Runtime,
}
}

func findRoutes(routes []rtnetlink.RouteMessage, family nethelpers.Family, destination netip.Prefix, gateway netip.Addr, table nethelpers.RoutingTable) []*rtnetlink.RouteMessage {
func findMatchingRoutes(existingRoutes []rtnetlink.RouteMessage, expected *network.RouteSpecSpec) []*rtnetlink.RouteMessage {
var result []*rtnetlink.RouteMessage //nolint:prealloc

for i, route := range routes {
if route.Family != uint8(family) {
for i, route := range existingRoutes {
if route.Family != uint8(expected.Family) {
continue
}

if int(route.DstLength) != destination.Bits() {
if int(route.DstLength) != expected.Destination.Bits() {
continue
}

if !route.Attributes.Dst.Equal(destination.Addr().AsSlice()) {
if !route.Attributes.Dst.Equal(expected.Destination.Addr().AsSlice()) {
continue
}

if !route.Attributes.Gateway.Equal(gateway.AsSlice()) {
if !route.Attributes.Gateway.Equal(expected.Gateway.AsSlice()) {
continue
}

if nethelpers.RoutingTable(route.Table) != table {
if nethelpers.RoutingTable(route.Table) != expected.Table {
continue
}

result = append(result, &routes[i])
if route.Attributes.Priority != expected.Priority {
continue
}

result = append(result, &existingRoutes[i])
}

return result
Expand Down Expand Up @@ -173,7 +176,7 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run

switch route.Metadata().Phase() {
case resource.PhaseTearingDown:
for _, existing := range findRoutes(routes, route.TypedSpec().Family, route.TypedSpec().Destination, route.TypedSpec().Gateway, route.TypedSpec().Table) {
for _, existing := range findMatchingRoutes(routes, route.TypedSpec()) {
// delete route
if err := conn.Route.Delete(existing); err != nil {
return fmt.Errorf("error removing route: %w", err)
Expand All @@ -184,6 +187,8 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run
zap.String("gateway", gatewayStr),
zap.Stringer("table", route.TypedSpec().Table),
zap.String("link", route.TypedSpec().OutLinkName),
zap.Uint32("priority", route.TypedSpec().Priority),
zap.Stringer("family", route.TypedSpec().Family),
)
}

Expand All @@ -199,7 +204,7 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run

matchFound := false

for _, existing := range findRoutes(routes, route.TypedSpec().Family, route.TypedSpec().Destination, route.TypedSpec().Gateway, route.TypedSpec().Table) {
for _, existing := range findMatchingRoutes(routes, route.TypedSpec()) {
var existingMTU uint32

if existing.Attributes.Metrics != nil {
Expand All @@ -209,7 +214,7 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run
// check if existing route matches the spec: if it does, skip update
if existing.Scope == uint8(route.TypedSpec().Scope) && nethelpers.RouteFlags(existing.Flags).Equal(route.TypedSpec().Flags) &&
existing.Protocol == uint8(route.TypedSpec().Protocol) &&
existing.Attributes.OutIface == linkIndex && existing.Attributes.Priority == route.TypedSpec().Priority &&
existing.Attributes.OutIface == linkIndex &&
(value.IsZero(route.TypedSpec().Source) ||
existing.Attributes.Src.Equal(route.TypedSpec().Source.AsSlice())) &&
existingMTU == route.TypedSpec().MTU {
Expand All @@ -228,6 +233,8 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run
zap.String("gateway", gatewayStr),
zap.Stringer("table", route.TypedSpec().Table),
zap.String("link", route.TypedSpec().OutLinkName),
zap.Uint32("priority", route.TypedSpec().Priority),
zap.Stringer("family", route.TypedSpec().Family),
zap.Stringer("old_scope", nethelpers.Scope(existing.Scope)),
zap.Stringer("new_scope", route.TypedSpec().Scope),
zap.Stringer("old_flags", nethelpers.RouteFlags(existing.Flags)),
Expand All @@ -236,8 +243,6 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run
zap.Stringer("new_protocol", route.TypedSpec().Protocol),
zap.Uint32("old_link_index", existing.Attributes.OutIface),
zap.Uint32("new_link_index", linkIndex),
zap.Uint32("old_priority", existing.Attributes.Priority),
zap.Uint32("new_priority", route.TypedSpec().Priority),
zap.Stringer("old_source", existing.Attributes.Src),
zap.String("new_source", sourceStr),
)
Expand Down Expand Up @@ -283,6 +288,8 @@ func (ctrl *RouteSpecController) syncRoute(ctx context.Context, r controller.Run
zap.String("gateway", gatewayStr),
zap.Stringer("table", route.TypedSpec().Table),
zap.String("link", route.TypedSpec().OutLinkName),
zap.Uint32("priority", route.TypedSpec().Priority),
zap.Stringer("family", route.TypedSpec().Family),
)
}

Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -240,7 +240,6 @@ func (suite *RouteSpecSuite) TestDefaultRoute() {

// update the route metric and mtu
ctest.UpdateWithConflicts(suite, def, func(defR *network.RouteSpec) error {
defR.TypedSpec().Priority = 1048577
defR.TypedSpec().MTU = 1700

return nil
Expand All @@ -253,8 +252,8 @@ func (suite *RouteSpecSuite) TestDefaultRoute() {
netip.Prefix{}, netip.MustParseAddr("127.0.11.2"), func(route rtnetlink.RouteMessage) error {
suite.Assert().Nil(route.Attributes.Dst)

if route.Attributes.Priority != 1048577 {
return fmt.Errorf("route metric wasn't updated: %d", route.Attributes.Priority)
if route.Attributes.Metrics == nil || route.Attributes.Metrics.MTU == 0 {
return fmt.Errorf("route metric wasn't updated: %v", route.Attributes.Metrics)
}

suite.Assert().EqualValues(1700, route.Attributes.Metrics.MTU)
Expand Down

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