From: Jason Xing
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) our own independent reasons which aren't relying on other reasons at all
3) reuse MP_TCPRST option for MPTCP
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
---
include/net/rstreason.h | 106
1 file changed, 106 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 ..bc53b5a24505
--- /dev/null
+++ b/include/net/rstreason.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_RSTREASON_H
+#define _LINUX_RSTREASON_H
+#include
+#include
+
+#define DEFINE_RST_REASON(FN, FNe) \
+ FN(NOT_SPECIFIED) \
+ FN(NO_SOCKET) \
+ 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(ERROR) \
+ FNe(MAX)
+
+/**
+ * enum sk_rst_reason - the reasons of socket reset
+ *
+ * The reasons of sk reset, which are used in DCCP/TCP/MPTCP protocols.
+ *
+ * There are three parts in order:
+ * 1) skb drop reasons: relying on drop reasons for such as passive reset
+ * 2) independent reset reasons: such as active reset reasons
+ * 3) reset reasons in MPTCP: only for MPTCP use
+ */
+enum sk_rst_reason {
+ /* Refer to include/net/dropreason-core.h
+* Rely on skb drop reasons 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,
+
+ /* 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
