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set: fix byte order metadata for host-endian types and map data #355

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138 changes: 138 additions & 0 deletions nftables_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3742,6 +3742,144 @@ func TestCreateAutoMergeSet(t *testing.T) {
}
}

func TestSetByteOrderRoundTrip(t *testing.T) {
tests := []struct {
name string
set nftables.Set
elems []nftables.SetElement
wantKeyOrder binaryutil.ByteOrder
wantDataOrder binaryutil.ByteOrder
}{
{
name: "constant set defaults key byteorder to big-endian",
set: nftables.Set{
Constant: true,
KeyType: nftables.TypeInetService,
},
elems: []nftables.SetElement{
{Key: binaryutil.BigEndian.PutUint16(80)},
},
wantKeyOrder: binaryutil.BigEndian,
},
{
name: "explicit host-endian key byteorder",
set: nftables.Set{
KeyType: nftables.TypeMark,
KeyByteOrder: binaryutil.NativeEndian,
},
elems: []nftables.SetElement{
{Key: binaryutil.NativeEndian.PutUint32(1)},
},
wantKeyOrder: binaryutil.NativeEndian,
},
{
name: "interval set defaults key byteorder to big-endian",
set: nftables.Set{
Interval: true,
KeyType: nftables.TypeInetService,
},
wantKeyOrder: binaryutil.BigEndian,
},
{
name: "interval set with explicit host-endian key byteorder",
set: nftables.Set{
Interval: true,
KeyType: nftables.TypeMark,
KeyByteOrder: binaryutil.NativeEndian,
},
elems: []nftables.SetElement{
{Key: binaryutil.NativeEndian.PutUint32(7)},
},
wantKeyOrder: binaryutil.NativeEndian,
},
{
name: "map with explicit host-endian key and data byteorder",
set: nftables.Set{
KeyType: nftables.TypeMark,
DataType: nftables.TypeMark,
KeyByteOrder: binaryutil.NativeEndian,
DataByteOrder: binaryutil.NativeEndian,
IsMap: true,
},
elems: []nftables.SetElement{
{
Key: binaryutil.NativeEndian.PutUint32(1),
Val: binaryutil.NativeEndian.PutUint32(2),
},
},
wantKeyOrder: binaryutil.NativeEndian,
wantDataOrder: binaryutil.NativeEndian,
},
{
name: "map with explicit data byteorder only",
set: nftables.Set{
KeyType: nftables.TypeInetService,
DataType: nftables.TypeMark,
DataByteOrder: binaryutil.NativeEndian,
IsMap: true,
},
elems: []nftables.SetElement{
{
Key: binaryutil.BigEndian.PutUint16(22),
Val: binaryutil.NativeEndian.PutUint32(1),
},
},
wantDataOrder: binaryutil.NativeEndian,
},
}

for i, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
conn, newNS := nftest.OpenSystemConn(t, *enableSysTests)
defer nftest.CleanupSystemConn(t, newNS)
defer conn.FlushRuleset()

table := conn.AddTable(&nftables.Table{
Name: fmt.Sprintf("byteorder-table-%d", i),
Family: nftables.TableFamilyIPv4,
})

set := tt.set
set.Table = table
set.Name = fmt.Sprintf("byteorder-set-%d", i)

if err := conn.AddSet(&set, tt.elems); err != nil {
t.Fatalf("failed to add set: %v", err)
}
if err := conn.Flush(); err != nil {
t.Fatalf("failed to flush: %v", err)
}

gotSet, err := conn.GetSetByName(table, set.Name)
if err != nil {
t.Fatalf("failed to find set %q: %v", set.Name, err)
}
if gotSet.KeyByteOrder != tt.wantKeyOrder {
t.Fatalf("set.KeyByteOrder = %v, want %v", gotSet.KeyByteOrder, tt.wantKeyOrder)
}
if gotSet.DataByteOrder != tt.wantDataOrder {
t.Fatalf("set.DataByteOrder = %v, want %v", gotSet.DataByteOrder, tt.wantDataOrder)
}

gotElems, err := conn.GetSetElements(gotSet)
if err != nil {
t.Fatalf("failed to get set elements: %v", err)
}
if got, want := len(gotElems), len(tt.elems); got != want {
t.Fatalf("got %d elements, want %d", got, want)
}
for i := range tt.elems {
if !bytes.Equal(gotElems[i].Key, tt.elems[i].Key) {
t.Fatalf("element[%d].Key = %x, want %x", i, gotElems[i].Key, tt.elems[i].Key)
}
if !bytes.Equal(gotElems[i].Val, tt.elems[i].Val) {
t.Fatalf("element[%d].Val = %x, want %x", i, gotElems[i].Val, tt.elems[i].Val)
}
}
})
}
}

func TestIP6SetAddElements(t *testing.T) {
// Create a new network namespace to test these operations,
// and tear down the namespace at test completion.
Expand Down
45 changes: 39 additions & 6 deletions set.go
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Original file line number Diff line number Diff line change
Expand Up @@ -267,8 +267,9 @@ type Set struct {
DataType SetDatatype
// Either host (binaryutil.NativeEndian) or big (binaryutil.BigEndian) endian as per
// https://git.netfilter.org/nftables/tree/include/datatype.h?id=d486c9e626405e829221b82d7355558005b26d8a#n109
KeyByteOrder binaryutil.ByteOrder
Comment string
KeyByteOrder binaryutil.ByteOrder
DataByteOrder binaryutil.ByteOrder
Comment string
// Indicates that the set has "size" specifier
Size uint32
}
Expand Down Expand Up @@ -716,12 +717,27 @@ func (cc *Conn) AddSet(s *Set, vals []SetElement) error {
// https://git.netfilter.org/libnftnl/tree/include/udata.h#n17
var userData []byte

if s.Anonymous || s.Constant || s.Interval || s.KeyByteOrder == binaryutil.BigEndian {
// Semantically useless - kept for binary compatability with nft
userData = userdata.AppendUint32(userData, userdata.NFTNL_UDATA_SET_KEYBYTEORDER, 2)
} else if s.KeyByteOrder == binaryutil.NativeEndian {
// Emit KEYBYTEORDER metadata matching nft C tool behavior (mnl.c:mnl_nft_set_add).
// Anonymous, constant, and interval sets always need byte order metadata.
// When KeyByteOrder is explicitly set, use it; otherwise default to big-endian
// for backward compatibility with prior library behavior.
if s.KeyByteOrder == binaryutil.NativeEndian {
// Per https://git.netfilter.org/nftables/tree/src/mnl.c?id=187c6d01d35722618c2711bbc49262c286472c8f#n1165
userData = userdata.AppendUint32(userData, userdata.NFTNL_UDATA_SET_KEYBYTEORDER, 1)
} else if s.Anonymous || s.Constant || s.Interval || s.KeyByteOrder == binaryutil.BigEndian {
userData = userdata.AppendUint32(userData, userdata.NFTNL_UDATA_SET_KEYBYTEORDER, 2)
}

// Emit DATABYTEORDER for maps, matching nft C tool behavior (mnl.c:mnl_nft_set_add).
// Without this, nft list ruleset cannot determine the data byte order and displays
// host-endian values (like marks) as byte-swapped on LE systems.
if s.IsMap {
switch s.DataByteOrder {
case binaryutil.NativeEndian:
userData = userdata.AppendUint32(userData, userdata.NFTNL_UDATA_SET_DATABYTEORDER, 1)
case binaryutil.BigEndian:
userData = userdata.AppendUint32(userData, userdata.NFTNL_UDATA_SET_DATABYTEORDER, 2)
}
}

if s.Interval && s.AutoMerge {
Expand Down Expand Up @@ -862,6 +878,12 @@ func setsFromMsg(msg netlink.Message) (*Set, error) {
set.DataType.Bytes = binary.BigEndian.Uint32(ad.Bytes())
case unix.NFTA_SET_USERDATA:
data := ad.Bytes()
if val, ok := userdata.GetUint32(data, userdata.NFTNL_UDATA_SET_KEYBYTEORDER); ok {
set.KeyByteOrder = parseSetByteOrder(val)
}
if val, ok := userdata.GetUint32(data, userdata.NFTNL_UDATA_SET_DATABYTEORDER); ok {
set.DataByteOrder = parseSetByteOrder(val)
}
if val, ok := userdata.GetString(data, userdata.NFTNL_UDATA_SET_COMMENT); ok {
set.Comment = val
}
Expand Down Expand Up @@ -891,6 +913,17 @@ func setsFromMsg(msg netlink.Message) (*Set, error) {
return &set, nil
}

func parseSetByteOrder(v uint32) binaryutil.ByteOrder {
switch v {
case 1:
return binaryutil.NativeEndian
case 2:
return binaryutil.BigEndian
default:
return nil
}
}

func parseSetDatatype(magic uint32) (SetDatatype, error) {
types := make([]SetDatatype, 0, 32/SetConcatTypeBits)
for magic != 0 {
Expand Down