maps: switch maglev to cilium/ebpf package

Signed-off-by: Gilberto Bertin <gilberto@isovalent.com>

cilium/cmd/bpf_lb_maglev_get.go

@@ -18,13 +18,12 @@ import (
 	"errors"
 	"strconv"
 
-	"github.com/cilium/cilium/pkg/bpf"
 	"github.com/cilium/cilium/pkg/command"
 	"github.com/cilium/cilium/pkg/common"
+	"github.com/cilium/cilium/pkg/ebpf"
 	"github.com/cilium/cilium/pkg/maps/lbmap"
 
 	"github.com/spf13/cobra"
-	"golang.org/x/sys/unix"
 )
 
 var bpfMaglevGetCmd = &cobra.Command{
@@ -47,24 +46,22 @@ var bpfMaglevGetCmd = &cobra.Command{
 		lookupTables := map[string][]string{}
 		found := false
 
-		for _, name := range []string{lbmap.MaglevOuter4MapName, lbmap.MaglevOuter6MapName} {
-			// See bpf_lb_maglev_list.go comment for why we use low-level routines
-			// to open and access the maps
-			if m, err := bpf.OpenMap(name); err != nil {
-				continue
-			} else {
-				err := bpf.LookupElement(m.GetFd(), key.GetKeyPtr(), val.GetValuePtr())
-				if err != nil {
-					if errors.Is(err, unix.ENOENT) {
-						continue
-					}
-					Fatalf("Unable to retrieve entry from %s with key %s: %s",
-						name, key, err)
-				} else {
-					found = true
-					parseMaglevEntry(key, val, lookupTables)
+		tableSize, err := lbmap.OpenMaglevMaps()
+		if err != nil {
+			Fatalf("Cannot initialize maglev maps: %s", err)
+		}
+
+		for name, m := range lbmap.GetOpenMaglevMaps() {
+			if err := m.Lookup(key, val); err != nil {
+				if errors.Is(err, ebpf.ErrKeyNotExist) {
+					continue
 				}
+				Fatalf("Unable to retrieve entry from %s with key %v: %s",
+					name, key, err)
 			}
+
+			found = true
+			parseMaglevEntry(key, val, tableSize, lookupTables)
 		}
 
 		if !found {

cilium/cmd/bpf_lb_maglev_list.go

@@ -16,11 +16,9 @@ package cmd
 
 import (
 	"fmt"
-	"unsafe"
 
 	"github.com/spf13/cobra"
 
-	"github.com/cilium/cilium/pkg/bpf"
 	"github.com/cilium/cilium/pkg/command"
 	"github.com/cilium/cilium/pkg/common"
 	"github.com/cilium/cilium/pkg/maps/lbmap"
@@ -48,57 +46,36 @@ var bpfMaglevListCmd = &cobra.Command{
 	},
 }
 
-var lookupTableSize = 0
-
-func parseMaglevEntry(key bpf.MapKey, value bpf.MapValue, tables map[string][]string) {
-	k := key.(*lbmap.MaglevOuterKey)
-	v := value.(*lbmap.MaglevOuterVal)
-
-	// Determine lookup table size by inspecting the first inner map
-	if lookupTableSize == 0 {
-		fd, err := bpf.MapFdFromID(int(v.FD))
-		if err != nil {
-			Fatalf("Unable to get map fd by id %d: %s", v.FD, err)
-		}
-		m, err := bpf.GetMapInfoByFd(uint32(fd))
-		if err != nil {
-			Fatalf("Unable to get map info by fd %d: %s", fd, err)
-		}
-		lookupTableSize = int(m.ValueSize) / 2
+func parseMaglevEntry(key *lbmap.MaglevOuterKey, value *lbmap.MaglevOuterVal, tableSize uint32, tables map[string][]string) {
+	innerMap, err := lbmap.MaglevInnerMapFromID(int(value.FD), tableSize)
+	if err != nil {
+		Fatalf("Unable to get map fd by id %d: %s", value.FD, err)
 	}
 
-	table := make([]uint16, lookupTableSize)
-	zero := uint32(0)
-	fd, err := bpf.MapFdFromID(int(v.FD))
-	if err != nil {
-		Fatalf("Unable to get map fd by id %d: %s", v.FD, err)
+	innerKey := lbmap.MaglevInnerKey{
+		Zero: 0,
 	}
-	if err := bpf.LookupElement(int(fd), unsafe.Pointer(&zero), unsafe.Pointer(&table[0])); err != nil {
-		Fatalf("Unable to lookup element in map by fd %d: %s", fd, err)
+	innerValue, err := innerMap.Lookup(&innerKey)
+	if err != nil {
+		Fatalf("Unable to lookup element in map by fd %d: %s", value.FD, err)
 	}
-	tables[k.ToNetwork().String()] = []string{fmt.Sprintf("%v", table)}
+
+	tables[fmt.Sprintf("%d", key.ToNetwork().RevNatID)] = []string{fmt.Sprintf("%v", innerValue.BackendIDs)}
 }
 
 func dumpMaglevTables(tables map[string][]string) {
-	parse := func(key bpf.MapKey, value bpf.MapValue) {
-		parseMaglevEntry(key, value, tables)
+	tableSize, err := lbmap.OpenMaglevMaps()
+	if err != nil {
+		Fatalf("Cannot initialize maglev maps: %s", err)
 	}
 
-	for _, name := range []string{lbmap.MaglevOuter4MapName, lbmap.MaglevOuter6MapName} {
-		// We cannot directly access the maps via lbmap.MaglevOuter{4,6}Map, as
-		// both are not initialized, and they cannot be initialized due to
-		// option.Config.MaglevTableSize not set in the cilium cli. Thus, we need
-		// to open map with the lower-level helper and set the fields required
-		// for the maps traversal.
-		if m, err := bpf.OpenMap(name); err != nil {
-			continue
-		} else {
-			m.MapKey = &lbmap.MaglevOuterKey{}
-			m.MapValue = &lbmap.MaglevOuterVal{}
-			m.DumpParser = bpf.ConvertKeyValue
-			if err := m.DumpWithCallbackIfExists(parse); err != nil {
-				Fatalf("Unable to dump %s: %s", name, err)
-			}
+	parse := func(key *lbmap.MaglevOuterKey, value *lbmap.MaglevOuterVal) {
+		parseMaglevEntry(key, value, tableSize, tables)
+	}
+
+	for name, m := range lbmap.GetOpenMaglevMaps() {
+		if err := m.IterateWithCallback(parse); err != nil {
+			Fatalf("Unable to dump %s: %v", name, err)
 		}
 	}
 }

daemon/cmd/datapath.go

@@ -457,7 +457,7 @@ func (d *Daemon) initMaps() error {
 	}
 
 	if option.Config.NodePortAlg == option.NodePortAlgMaglev {
-		if err := lbmap.InitMaglevMaps(option.Config.EnableIPv4, option.Config.EnableIPv6); err != nil {
+		if err := lbmap.InitMaglevMaps(option.Config.EnableIPv4, option.Config.EnableIPv6, uint32(option.Config.MaglevTableSize)); err != nil {
 			return err
 		}
 	}

pkg/ebpf/map.go

@@ -31,10 +31,17 @@ type MapSpec = ciliumebpf.MapSpec
 
 const (
 	PerCPUHash = ciliumebpf.PerCPUHash
+	Array      = ciliumebpf.Array
+	HashOfMaps = ciliumebpf.HashOfMaps
 
 	PinByName = ciliumebpf.PinByName
 )
 
+var (
+	ErrKeyNotExist = ciliumebpf.ErrKeyNotExist
+	LoadPinnedMap  = ciliumebpf.LoadPinnedMap
+)
+
 // IterateCallback represents the signature of the callback function expected by
 // the IterateWithCallback method, which in turn is used to iterate all the
 // keys/values of a map.
@@ -56,6 +63,37 @@ func NewMap(spec *MapSpec) *Map {
 	}
 }
 
+// OpenMap opens the given bpf map and generates the Map object based on the
+// information stored in the bpf map.
+func OpenMap(mapName string) (*Map, error) {
+	path := bpf.MapPath(mapName)
+
+	newMap, err := LoadPinnedMap(path, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	m := &Map{
+		Map:  newMap,
+		path: path,
+	}
+
+	registerMap(m)
+
+	return m, nil
+}
+
+func MapFromID(id int) (*Map, error) {
+	newMap, err := ciliumebpf.NewMapFromID(ciliumebpf.MapID(id))
+	if err != nil {
+		return nil, err
+	}
+
+	return &Map{
+		Map: newMap,
+	}, nil
+}
+
 // OpenOrCreate tries to open or create the eBPF map identified by the spec in
 // the Map object.
 func (m *Map) OpenOrCreate() error {
@@ -66,6 +104,10 @@ func (m *Map) OpenOrCreate() error {
 		return nil
 	}
 
+	if m.spec == nil {
+		return fmt.Errorf("cannot create map: nil map spec")
+	}
+
 	opts := ciliumebpf.MapOptions{
 		PinPath: bpf.MapPrefixPath(),
 	}