diff options
| -rw-r--r-- | pkg/buffer/view.go | 14 | ||||
| -rw-r--r-- | pkg/tcpip/stack/packet_buffer.go | 14 | ||||
| -rw-r--r-- | pkg/tcpip/stack/packet_buffer_test.go | 26 |
3 files changed, 46 insertions, 8 deletions
diff --git a/pkg/buffer/view.go b/pkg/buffer/view.go index 7bcfcd543..a4610f977 100644 --- a/pkg/buffer/view.go +++ b/pkg/buffer/view.go @@ -378,6 +378,20 @@ func (v *View) Copy() (other View) { return } +// Clone makes a more shallow copy compared to Copy. The underlying payload +// slice (buffer.data) is shared but the buffers themselves are copied. +func (v *View) Clone() *View { + other := &View{ + size: v.size, + } + for buf := v.data.Front(); buf != nil; buf = buf.Next() { + newBuf := other.pool.getNoInit() + *newBuf = *buf + other.data.PushBack(newBuf) + } + return other +} + // Apply applies the given function across all valid data. func (v *View) Apply(fn func([]byte)) { for buf := v.data.Front(); buf != nil; buf = buf.Next() { diff --git a/pkg/tcpip/stack/packet_buffer.go b/pkg/tcpip/stack/packet_buffer.go index 9192d8433..29c22bfd4 100644 --- a/pkg/tcpip/stack/packet_buffer.go +++ b/pkg/tcpip/stack/packet_buffer.go @@ -282,14 +282,12 @@ func (pk *PacketBuffer) headerView(typ headerType) tcpipbuffer.View { return v } -// Clone makes a shallow copy of pk. -// -// Clone should be called in such cases so that no modifications is done to -// underlying packet payload. +// Clone makes a semi-deep copy of pk. The underlying packet payload is +// shared. Hence, no modifications is done to underlying packet payload. func (pk *PacketBuffer) Clone() *PacketBuffer { return &PacketBuffer{ PacketBufferEntry: pk.PacketBufferEntry, - buf: pk.buf, + buf: pk.buf.Clone(), reserved: pk.reserved, pushed: pk.pushed, consumed: pk.consumed, @@ -321,14 +319,14 @@ func (pk *PacketBuffer) Network() header.Network { } } -// CloneToInbound makes a shallow copy of the packet buffer to be used as an -// inbound packet. +// CloneToInbound makes a semi-deep copy of the packet buffer (similar to +// Clone) to be used as an inbound packet. // // See PacketBuffer.Data for details about how a packet buffer holds an inbound // packet. func (pk *PacketBuffer) CloneToInbound() *PacketBuffer { newPk := &PacketBuffer{ - buf: pk.buf, + buf: pk.buf.Clone(), // Treat unfilled header portion as reserved. reserved: pk.AvailableHeaderBytes(), } diff --git a/pkg/tcpip/stack/packet_buffer_test.go b/pkg/tcpip/stack/packet_buffer_test.go index a8da34992..87b023445 100644 --- a/pkg/tcpip/stack/packet_buffer_test.go +++ b/pkg/tcpip/stack/packet_buffer_test.go @@ -123,6 +123,32 @@ func TestPacketHeaderPush(t *testing.T) { } } +func TestPacketBufferClone(t *testing.T) { + data := concatViews(makeView(20), makeView(30), makeView(40)) + pk := NewPacketBuffer(PacketBufferOptions{ + // Make a copy of data to make sure our truth data won't be taint by + // PacketBuffer. + Data: buffer.NewViewFromBytes(data).ToVectorisedView(), + }) + + bytesToDelete := 30 + originalSize := data.Size() + + clonedPks := []*PacketBuffer{ + pk.Clone(), + pk.CloneToInbound(), + } + pk.Data().DeleteFront(bytesToDelete) + if got, want := pk.Data().Size(), originalSize-bytesToDelete; got != want { + t.Errorf("original packet was not changed: size expected = %d, got = %d", want, got) + } + for _, clonedPk := range clonedPks { + if got := clonedPk.Data().Size(); got != originalSize { + t.Errorf("cloned packet should not be modified: expected size = %d, got = %d", originalSize, got) + } + } +} + func TestPacketHeaderConsume(t *testing.T) { for _, test := range []struct { name string |