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 MP_TCPRST option for MPTCP
2) reuse drop reasons for passive reset in TCP
3) our own reasons which are not relying on other reasons at all
The benefits of a standalone reset reason are listed here:
1) it can cover more than one case, such as reset reasons in MPTCP,
active reset reasons.
2) people can easily/fastly understand and maintain this mechanism.
3) we get unified format of output with prefix stripped.
4) more new reset reasons are on the way
...
I will implement the basic codes of active/passive reset reason in
those three protocols, which are not complete for this moment. For
passive reset part in TCP, I only introduce the NO_SOCKET common case
which could be set as an example.
After this series applied, it will have the ability to open a new
gate to let other people contribute more reasons into it :)
Signed-off-by: Jason Xing <kernelx...@tencent.com>
---
include/net/rstreason.h | 144 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 144 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..c57bc5413c17
--- /dev/null
+++ b/include/net/rstreason.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_RSTREASON_H
+#define _LINUX_RSTREASON_H
+#include <net/dropreason-core.h>
+#include <uapi/linux/mptcp.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) \
+ FN(NO_SOCKET) \
+ FNe(MAX)
+
+/**
+ * There are three parts in order:
+ * 1) reset reason in MPTCP: only for MPTCP use
+ * 2) skb drop reason: relying on drop reasons for such as passive reset
+ * 3) independent reset reason: such as active reset reasons
+ */
+enum sk_rst_reason {
+ /**
+ * 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.
+ */
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EUNSPEC: 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,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EMPTCP: 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,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_ERESOURCE: 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,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EPROHIBIT: Administratively prohibited.
+ * This code indicates that the requested subflow is prohibited by
+ * the policies of the sending host.
+ */
+ SK_RST_REASON_MPTCP_RST_EPROHIBIT,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EWQ2BIG: 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,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EBADPERF: 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,
+ /**
+ * @SK_RST_REASON_MPTCP_RST_EMIDDLEBOX: 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,
+
+ /**
+ * Refer to include/net/dropreason-core.h
+ * Rely on skb drop reason because it indicates exactly why RST
+ * could happen.
+ */
+ /** @SK_RST_REASON_NOT_SPECIFIED: reset reason is not specified */
+ SK_RST_REASON_NOT_SPECIFIED,
+ /** @SK_RST_REASON_NO_SOCKET: no valid socket that can be used */
+ SK_RST_REASON_NO_SOCKET,
+
+ /** @SK_RST_REASON_ERROR: unexpected error happens */
+ SK_RST_REASON_ERROR,
+
+ /**
+ * @SK_RST_REASON_MAX: Maximum of socket reset reasons.
+ * It shouldn't be used as a real 'reason'.
+ */
+ SK_RST_REASON_MAX,
+};
+
+/* Convert reset reasons in MPTCP to our own enum type */
+static inline enum sk_rst_reason convert_mptcpreason(u32 reason)
+{
+ switch (reason) {
+ case MPTCP_RST_EUNSPEC:
+ return SK_RST_REASON_MPTCP_RST_EUNSPEC;
+ case MPTCP_RST_EMPTCP:
+ return SK_RST_REASON_MPTCP_RST_EMPTCP;
+ case MPTCP_RST_ERESOURCE:
+ return SK_RST_REASON_MPTCP_RST_ERESOURCE;
+ case MPTCP_RST_EPROHIBIT:
+ return SK_RST_REASON_MPTCP_RST_EPROHIBIT;
+ case MPTCP_RST_EWQ2BIG:
+ return SK_RST_REASON_MPTCP_RST_EWQ2BIG;
+ case MPTCP_RST_EBADPERF:
+ return SK_RST_REASON_MPTCP_RST_EBADPERF;
+ case MPTCP_RST_EMIDDLEBOX:
+ return SK_RST_REASON_MPTCP_RST_EMIDDLEBOX;
+ default:
+ /**
+ * It should not happen, or else errors may occur
+ * in MPTCP layer
+ */
+ return SK_RST_REASON_ERROR;
+ }
+}
+
+/* Convert reset reasons in MPTCP to our own enum type */
+static inline enum sk_rst_reason convert_dropreason(enum skb_drop_reason
reason)
+{
+ switch (reason) {
+ case SKB_DROP_REASON_NOT_SPECIFIED:
+ return SK_RST_REASON_NOT_SPECIFIED;
+ case SKB_DROP_REASON_NO_SOCKET:
+ return SK_RST_REASON_NO_SOCKET;
+ default:
+ /* If we don't have our own corresponding reason */
+ return SK_RST_REASON_NOT_SPECIFIED;
+ }
+}
+#endif
--
2.37.3
