Merge branch 'mptcp-next'

Mat Martineau says:

====================
mptcp: Optimize output options and add MP_FAIL

This patch set contains two groups of changes that we've been testing in
the MPTCP tree.

The first optimizes the code path and data structure for populating
MPTCP option headers when transmitting.

Patch 1 reorganizes code to reduce the number of conditionals that need
to be evaluated in common cases.

Patch 2 rearranges struct mptcp_out_options to save 80 bytes (on x86_64).

The next five patches add partial support for the MP_FAIL option as
defined in RFC 8684. MP_FAIL is an option header used to cleanly handle
MPTCP checksum failures. When the MPTCP checksum detects an error in the
MPTCP DSS header or the data mapped by that header, the receiver uses a
TCP RST with MP_FAIL to close the subflow that experienced the error and
provide associated MPTCP sequence number information to the peer. RFC
8684 also describes how a single-subflow connection can discard corrupt
data and remain connected under certain conditions using MP_FAIL, but
that feature is not implemented here.

Patches 3-5 implement MP_FAIL transmit and receive, and integrates with
checksum validation.

Patches 6 & 7 add MP_FAIL selftests and the MIBs required for those
tests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 9 deletions

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 8b5af683a818..6026bbefbffd 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -58,10 +58,6 @@ struct mptcp_addr_info {
 struct mptcp_out_options {
 #if IS_ENABLED(CONFIG_MPTCP)
 	u16 suboptions;
-	u64 sndr_key;
-	u64 rcvr_key;
-	u64 ahmac;
-	struct mptcp_addr_info addr;
 	struct mptcp_rm_list rm_list;
 	u8 join_id;
 	u8 backup;
@@ -69,11 +65,26 @@ struct mptcp_out_options {
 	   reset_transient:1,
 	   csum_reqd:1,
 	   allow_join_id0:1;
-	u32 nonce;
-	u64 thmac;
-	u32 token;
-	u8 hmac[20];
-	struct mptcp_ext ext_copy;
+	union {
+		struct {
+			u64 sndr_key;
+			u64 rcvr_key;
+		};
+		struct {
+			struct mptcp_addr_info addr;
+			u64 ahmac;
+		};
+		struct {
+			struct mptcp_ext ext_copy;
+			u64 fail_seq;
+		};
+		struct {
+			u32 nonce;
+			u32 token;
+			u64 thmac;
+			u8 hmac[20];
+		};
+	};
 #endif
 };