Merge 533a9343c8 into aa8348f790

Refactored obj.go to a more generic approach
Added object support for already implemented expressions
Added test for limit object
Fixes https://github.com/google/nftables/issues/253

obj.go

@@ -69,9 +69,6 @@ type Obj interface {
 	objType() ObjType
 }
 
-// ObjAttr represents nftables stateful object attributes
-// Corresponds to netfilter nft_object_attributes as per
-// https://git.netfilter.org/libnftnl/tree/include/linux/netfilter/nf_tables.h?id=116e95aa7b6358c917de8c69f6f173874030b46b#n1626
 type ObjAttr struct {
 	Table *Table
 	Name  string
@@ -157,32 +154,17 @@ func (cc *Conn) DeleteObject(o Obj) {
 
 // GetObj is a legacy method that return all Obj that belongs
 // to the same table as the given one
-// This function will determine whether returned object will be
-// one of legacy types QuotaObj/CounterObj or the new ObjAttr
-// type struct based passed o parameter type
-// If o is of type ObjAttr, the implementation will work with
-// the new ObjAttr type, otherwise falls back to legacy QuotaObj/CounterObj
 func (cc *Conn) GetObj(o Obj) ([]Obj, error) {
 	return cc.getObjWithLegacyType(nil, o.table(), unix.NFT_MSG_GETOBJ, cc.useLegacyObjType(o))
 }
 
 // GetObjReset is a legacy method that reset all Obj that belongs
 // the same table as the given one
-// This function will determine whether returned object will be
-// one of legacy types QuotaObj/CounterObj or the new ObjAttr
-// type struct based passed o parameter type
-// If o is of type ObjAttr, the implementation will work with
-// the new ObjAttr type, otherwise falls back to legacy QuotaObj/CounterObj
 func (cc *Conn) GetObjReset(o Obj) ([]Obj, error) {
 	return cc.getObjWithLegacyType(nil, o.table(), unix.NFT_MSG_GETOBJ_RESET, cc.useLegacyObjType(o))
 }
 
 // GetObject gets the specified Object
-// This function will determine whether returned object will be
-// one of legacy types QuotaObj/CounterObj or the new ObjAttr
-// type struct based passed o parameter type
-// If o is of type ObjAttr, the implementation will work with
-// the new ObjAttr type, otherwise falls back to legacy QuotaObj/CounterObj
 func (cc *Conn) GetObject(o Obj) (Obj, error) {
 	objs, err := cc.getObj(o, o.table(), unix.NFT_MSG_GETOBJ)
 
@@ -194,18 +176,11 @@ func (cc *Conn) GetObject(o Obj) (Obj, error) {
 }
 
 // GetObjects get all the Obj that belongs to the given table
-// This function will always return legacy QuotaObj/CounterObj
-// types for backwards compatibility
 func (cc *Conn) GetObjects(t *Table) ([]Obj, error) {
 	return cc.getObj(nil, t, unix.NFT_MSG_GETOBJ)
 }
 
 // ResetObject reset the given Obj
-// This function will determine whether returned object will be
-// one of legacy types QuotaObj/CounterObj or the new ObjAttr
-// type struct based passed o parameter type
-// If o is of type ObjAttr, the implementation will work with
-// the new ObjAttr type, otherwise falls back to legacy QuotaObj/CounterObj
 func (cc *Conn) ResetObject(o Obj) (Obj, error) {
 	objs, err := cc.getObj(o, o.table(), unix.NFT_MSG_GETOBJ_RESET)
 
@@ -217,8 +192,6 @@ func (cc *Conn) ResetObject(o Obj) (Obj, error) {
 }
 
 // ResetObjects reset all the Obj that belongs to the given table
-// This function will always return legacy QuotaObj/CounterObj
-// types for backwards compatibility
 func (cc *Conn) ResetObjects(t *Table) ([]Obj, error) {
 	return cc.getObj(nil, t, unix.NFT_MSG_GETOBJ_RESET)
 }
@@ -246,30 +219,61 @@ func objFromMsg(msg netlink.Message, returnLegacyType bool) (Obj, error) {
 		case unix.NFTA_OBJ_TYPE:
 			objectType = ad.Uint32()
 		case unix.NFTA_OBJ_DATA:
-			if returnLegacyType {
+			if !returnLegacyType {
-				return objDataFromMsgLegacy(ad, table, name, objectType)
+				o := ObjAttr{
+					Table: table,
+					Name:  name,
+					Type:  ObjType(objectType),
+				}
+
+				objs, err := parseexprfunc.ParseExprBytesFunc(byte(o.family()), ad, objByObjTypeMagic[o.Type])
+				if err != nil {
+					return nil, err
+				}
+				exprs := make([]expr.Any, len(objs))
+				for i := range exprs {
+					exprs[i] = objs[i].(expr.Any)
+				}
+				if len(exprs) == 0 {
+					return nil, fmt.Errorf("objFromMsg: exprs is empty for obj %v", o)
+				}
+
+				o.Obj = exprs[0]
+				return &o, ad.Err()
 			}
 
-			o := ObjAttr{
+			switch objectType {
-				Table: table,
+			case unix.NFT_OBJECT_COUNTER:
-				Name:  name,
+				o := CounterObj{
-				Type:  ObjType(objectType),
+					Table: table,
-			}
+					Name:  name,
+				}
 
-			objs, err := parseexprfunc.ParseExprBytesFunc(byte(o.family()), ad, objByObjTypeMagic[o.Type])
+				ad.Do(func(b []byte) error {
-			if err != nil {
+					ad, err := netlink.NewAttributeDecoder(b)
-				return nil, err
+					if err != nil {
-			}
+						return err
-			exprs := make([]expr.Any, len(objs))
+					}
-			for i := range exprs {
+					ad.ByteOrder = binary.BigEndian
-				exprs[i] = objs[i].(expr.Any)
+					return o.unmarshal(ad)
-			}
+				})
-			if len(exprs) == 0 {
+				return &o, ad.Err()
-				return nil, fmt.Errorf("objFromMsg: exprs is empty for obj %v", o)
+			case unix.NFT_OBJECT_QUOTA:
-			}
+				o := QuotaObj{
+					Table: table,
+					Name:  name,
+				}
 
-			o.Obj = exprs[0]
+				ad.Do(func(b []byte) error {
-			return &o, ad.Err()
+					ad, err := netlink.NewAttributeDecoder(b)
+					if err != nil {
+						return err
+					}
+					ad.ByteOrder = binary.BigEndian
+					return o.unmarshal(ad)
+				})
+				return &o, ad.Err()
+			}
 		}
 	}
 	if err := ad.Err(); err != nil {
@@ -278,45 +282,6 @@ func objFromMsg(msg netlink.Message, returnLegacyType bool) (Obj, error) {
 	return nil, fmt.Errorf("malformed stateful object")
 }
 
-func objDataFromMsgLegacy(ad *netlink.AttributeDecoder, table *Table, name string, objectType uint32) (Obj, error) {
-	switch objectType {
-	case unix.NFT_OBJECT_COUNTER:
-		o := CounterObj{
-			Table: table,
-			Name:  name,
-		}
-
-		ad.Do(func(b []byte) error {
-			ad, err := netlink.NewAttributeDecoder(b)
-			if err != nil {
-				return err
-			}
-			ad.ByteOrder = binary.BigEndian
-			return o.unmarshal(ad)
-		})
-		return &o, ad.Err()
-	case unix.NFT_OBJECT_QUOTA:
-		o := QuotaObj{
-			Table: table,
-			Name:  name,
-		}
-
-		ad.Do(func(b []byte) error {
-			ad, err := netlink.NewAttributeDecoder(b)
-			if err != nil {
-				return err
-			}
-			ad.ByteOrder = binary.BigEndian
-			return o.unmarshal(ad)
-		})
-		return &o, ad.Err()
-	}
-	if err := ad.Err(); err != nil {
-		return nil, err
-	}
-	return nil, fmt.Errorf("malformed stateful object")
-}
-
 func (cc *Conn) getObj(o Obj, t *Table, msgType uint16) ([]Obj, error) {
 	return cc.getObjWithLegacyType(o, t, msgType, cc.useLegacyObjType(o))
 }