Make QuicFrame a standard-layout struct.
C++ provides certain guarantees about the way union fields interact, which are only valid for standard-layout types. Standard-layout types are not allowed to have data members in both base and derived types; this fixes that by moving QuicInlinedFrame::type into individual frames.
Also, before C++17, using offsetof() on non-standard-layout types is undefined behavor.
Thanks to Stephan Hartmann <stha09@googlemail.com> for pointing this problem out in <https://quiche-review.googlesource.com/c/quiche/+/10600>.
PiperOrigin-RevId: 320195673
Change-Id: I179634af3e3a199b7b7320a031b42898a5644824
diff --git a/quic/core/frames/quic_frame.h b/quic/core/frames/quic_frame.h
index a8aabfc..b5785b8 100644
--- a/quic/core/frames/quic_frame.h
+++ b/quic/core/frames/quic_frame.h
@@ -6,6 +6,7 @@
#define QUICHE_QUIC_CORE_FRAMES_QUIC_FRAME_H_
#include <ostream>
+#include <type_traits>
#include <vector>
#include "net/third_party/quiche/src/quic/core/frames/quic_ack_frame.h"
@@ -111,6 +112,8 @@
};
};
+static_assert(std::is_standard_layout<QuicFrame>::value,
+ "QuicFrame must have a standard layout");
static_assert(sizeof(QuicFrame) <= 24,
"Frames larger than 24 bytes should be referenced by pointer.");
static_assert(offsetof(QuicStreamFrame, type) == offsetof(QuicFrame, type),
diff --git a/quic/core/frames/quic_handshake_done_frame.h b/quic/core/frames/quic_handshake_done_frame.h
index c16c169..1dd3fa0 100644
--- a/quic/core/frames/quic_handshake_done_frame.h
+++ b/quic/core/frames/quic_handshake_done_frame.h
@@ -23,6 +23,8 @@
std::ostream& os,
const QuicHandshakeDoneFrame& handshake_done_frame);
+ QuicFrameType type;
+
// A unique identifier of this control frame. 0 when this frame is received,
// and non-zero when sent.
QuicControlFrameId control_frame_id = kInvalidControlFrameId;
diff --git a/quic/core/frames/quic_inlined_frame.h b/quic/core/frames/quic_inlined_frame.h
index 08c4869..cfa32dc 100644
--- a/quic/core/frames/quic_inlined_frame.h
+++ b/quic/core/frames/quic_inlined_frame.h
@@ -5,6 +5,8 @@
#ifndef QUICHE_QUIC_CORE_FRAMES_QUIC_INLINED_FRAME_H_
#define QUICHE_QUIC_CORE_FRAMES_QUIC_INLINED_FRAME_H_
+#include <type_traits>
+
#include "net/third_party/quiche/src/quic/core/quic_types.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_export.h"
@@ -16,13 +18,15 @@
// inline and out-of-line frame types.
template <typename DerivedT>
struct QUIC_EXPORT_PRIVATE QuicInlinedFrame {
- QuicInlinedFrame(QuicFrameType type) : type(type) {
+ QuicInlinedFrame(QuicFrameType type) {
+ static_cast<DerivedT*>(this)->type = type;
+ static_assert(std::is_standard_layout<DerivedT>::value,
+ "Inlined frame must have a standard layout");
static_assert(offsetof(DerivedT, type) == 0,
"type must be the first field.");
static_assert(sizeof(DerivedT) <= 24,
"Frames larger than 24 bytes should not be inlined.");
}
- QuicFrameType type;
};
} // namespace quic
diff --git a/quic/core/frames/quic_max_streams_frame.h b/quic/core/frames/quic_max_streams_frame.h
index e1595c0..902dbc2 100644
--- a/quic/core/frames/quic_max_streams_frame.h
+++ b/quic/core/frames/quic_max_streams_frame.h
@@ -28,6 +28,8 @@
std::ostream& os,
const QuicMaxStreamsFrame& frame);
+ QuicFrameType type;
+
// A unique identifier of this control frame. 0 when this frame is received,
// and non-zero when sent.
QuicControlFrameId control_frame_id = kInvalidControlFrameId;
diff --git a/quic/core/frames/quic_mtu_discovery_frame.h b/quic/core/frames/quic_mtu_discovery_frame.h
index 330df21..52e980d 100644
--- a/quic/core/frames/quic_mtu_discovery_frame.h
+++ b/quic/core/frames/quic_mtu_discovery_frame.h
@@ -16,6 +16,8 @@
struct QUIC_EXPORT_PRIVATE QuicMtuDiscoveryFrame
: public QuicInlinedFrame<QuicMtuDiscoveryFrame> {
QuicMtuDiscoveryFrame() : QuicInlinedFrame(MTU_DISCOVERY_FRAME) {}
+
+ QuicFrameType type;
};
} // namespace quic
diff --git a/quic/core/frames/quic_padding_frame.h b/quic/core/frames/quic_padding_frame.h
index 0918f0f..09ddb89 100644
--- a/quic/core/frames/quic_padding_frame.h
+++ b/quic/core/frames/quic_padding_frame.h
@@ -25,6 +25,8 @@
std::ostream& os,
const QuicPaddingFrame& padding_frame);
+ QuicFrameType type;
+
// -1: full padding to the end of a max-sized packet
// otherwise: only pad up to num_padding_bytes bytes
int num_padding_bytes = -1;
diff --git a/quic/core/frames/quic_ping_frame.h b/quic/core/frames/quic_ping_frame.h
index 5cefdf9..04f5afb 100644
--- a/quic/core/frames/quic_ping_frame.h
+++ b/quic/core/frames/quic_ping_frame.h
@@ -23,6 +23,8 @@
std::ostream& os,
const QuicPingFrame& ping_frame);
+ QuicFrameType type;
+
// A unique identifier of this control frame. 0 when this frame is received,
// and non-zero when sent.
QuicControlFrameId control_frame_id = kInvalidControlFrameId;
diff --git a/quic/core/frames/quic_stop_waiting_frame.h b/quic/core/frames/quic_stop_waiting_frame.h
index 84bfc2a..b05d2e1 100644
--- a/quic/core/frames/quic_stop_waiting_frame.h
+++ b/quic/core/frames/quic_stop_waiting_frame.h
@@ -21,6 +21,8 @@
std::ostream& os,
const QuicStopWaitingFrame& s);
+ QuicFrameType type;
+
// The lowest packet we've sent which is unacked, and we expect an ack for.
QuicPacketNumber least_unacked;
};
diff --git a/quic/core/frames/quic_stream_frame.h b/quic/core/frames/quic_stream_frame.h
index f807ee1..10ad7db 100644
--- a/quic/core/frames/quic_stream_frame.h
+++ b/quic/core/frames/quic_stream_frame.h
@@ -35,6 +35,7 @@
bool operator!=(const QuicStreamFrame& rhs) const;
+ QuicFrameType type;
bool fin = false;
QuicPacketLength data_length = 0;
// TODO(wub): Change to a QuicUtils::GetInvalidStreamId when it is not version
diff --git a/quic/core/frames/quic_streams_blocked_frame.h b/quic/core/frames/quic_streams_blocked_frame.h
index 91c7ac9..2df9636 100644
--- a/quic/core/frames/quic_streams_blocked_frame.h
+++ b/quic/core/frames/quic_streams_blocked_frame.h
@@ -28,6 +28,8 @@
std::ostream& os,
const QuicStreamsBlockedFrame& frame);
+ QuicFrameType type;
+
// A unique identifier of this control frame. 0 when this frame is received,
// and non-zero when sent.
QuicControlFrameId control_frame_id = kInvalidControlFrameId;
