From: Jason Xing <kernelx...@tencent.com>
Add a new standalone file for the easy future extension to support
both active reset and passive reset in the TCP/DCCP/MPTCP protocols.
This patch only does the preparations for reset reason mechanism,
nothing else changes.
The reset reasons are divided into three parts:
1) reuse drop reasons for passive reset in TCP
2) reuse MP_TCPRST option for MPTCP
3) our own reasons
I will implement the basic codes of active/passive reset reason in
those three protocols, which is not complete for this moment. But
it provides a new chance to let other people add more reasons into
it:)
Signed-off-by: Jason Xing <kernelx...@tencent.com>
---
include/net/rstreason.h | 93 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
create mode 100644 include/net/rstreason.h
diff --git a/include/net/rstreason.h b/include/net/rstreason.h
new file mode 100644
index 000000000000..24d098a78a60
--- /dev/null
+++ b/include/net/rstreason.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_RSTREASON_H
+#define _LINUX_RSTREASON_H
+#include <net/dropreason-core.h>
+
+#define DEFINE_RST_REASON(FN, FNe) \
+ FN(MPTCP_RST_EUNSPEC) \
+ FN(MPTCP_RST_EMPTCP) \
+ FN(MPTCP_RST_ERESOURCE) \
+ FN(MPTCP_RST_EPROHIBIT) \
+ FN(MPTCP_RST_EWQ2BIG) \
+ FN(MPTCP_RST_EBADPERF) \
+ FN(MPTCP_RST_EMIDDLEBOX) \
+ FN(NOT_SPECIFIED) \
+ FNe(MAX)
+
+#define RST_REASON_START (SKB_DROP_REASON_MAX + 1)
+
+/* There are three parts in order:
+ * 1) 0 - SKB_DROP_REASON_MAX: rely on drop reasons for passive reset in TCP
+ * 2) SKB_DROP_REASON_MAX + 1 - MPTCP_RST_EMIDDLEBOX: for MPTCP use
+ * 3) MPTCP_RST_EMIDDLEBOX - SK_RST_REASON_MAX: independent reset reason
+ */
+enum sk_rst_reason {
+ /* Leave this 'blank' part (0-SKB_DROP_REASON_MAX) for the reuse
+ * of skb drop reason because rst reason relies on what drop reason
+ * indicates exactly why it could happen.
+ */
+
+ /* Copy from include/uapi/linux/mptcp.h.
+ * These reset fields will not be changed since they adhere to
+ * RFC 8684. So do not touch them. I'm going to list each definition
+ * of them respectively.
+ */
+ /* Unspecified error.
+ * This is the default error; it implies that the subflow is no
+ * longer available. The presence of this option shows that the
+ * RST was generated by an MPTCP-aware device.
+ */
+ SK_RST_REASON_MPTCP_RST_EUNSPEC = RST_REASON_START,
+ /* MPTCP-specific error.
+ * An error has been detected in the processing of MPTCP options.
+ * This is the usual reason code to return in the cases where a RST
+ * is being sent to close a subflow because of an invalid response.
+ */
+ SK_RST_REASON_MPTCP_RST_EMPTCP,
+ /* Lack of resources.
+ * This code indicates that the sending host does not have enough
+ * resources to support the terminated subflow.
+ */
+ SK_RST_REASON_MPTCP_RST_ERESOURCE,
+ /* Administratively prohibited.
+ * This code indicates that the requested subflow is prohibited by
+ * the policies of the sending host.
+ */
+ SK_RST_REASON_MPTCP_RST_EPROHIBIT,
+ /* Too much outstanding data.
+ * This code indicates that there is an excessive amount of data
+ * that needs to be transmitted over the terminated subflow while
+ * having already been acknowledged over one or more other subflows.
+ * This may occur if a path has been unavailable for a short period
+ * and it is more efficient to reset and start again than it is to
+ * retransmit the queued data.
+ */
+ SK_RST_REASON_MPTCP_RST_EWQ2BIG,
+ /* Unacceptable performance.
+ * This code indicates that the performance of this subflow was
+ * too low compared to the other subflows of this Multipath TCP
+ * connection.
+ */
+ SK_RST_REASON_MPTCP_RST_EBADPERF,
+ /* Middlebox interference.
+ * Middlebox interference has been detected over this subflow,
+ * making MPTCP signaling invalid. For example, this may be sent
+ * if the checksum does not validate.
+ */
+ SK_RST_REASON_MPTCP_RST_EMIDDLEBOX,
+
+ /* For the real standalone socket reset reason, we start from here */
+ SK_RST_REASON_NOT_SPECIFIED,
+
+ /* Maximum of socket reset reasons.
+ * It shouldn't be used as a real 'reason'.
+ */
+ SK_RST_REASON_MAX,
+};
+
+static inline int convert_mptcp_reason(int reason)
+{
+ return reason += RST_REASON_START;
+}
+#endif
--
2.37.3
