--- /dev/null
+From 7a1b3490f47e88ec4cbde65f1a77a0f4bc972282 Mon Sep 17 00:00:00 2001
+From: Davide Caratti <dcaratti@redhat.com>
+Date: Fri, 29 Mar 2024 13:08:52 +0100
+Subject: mptcp: don't account accept() of non-MPC client as fallback to TCP
+
+From: Davide Caratti <dcaratti@redhat.com>
+
+commit 7a1b3490f47e88ec4cbde65f1a77a0f4bc972282 upstream.
+
+Current MPTCP servers increment MPTcpExtMPCapableFallbackACK when they
+accept non-MPC connections. As reported by Christoph, this is "surprising"
+because the counter might become greater than MPTcpExtMPCapableSYNRX.
+
+MPTcpExtMPCapableFallbackACK counter's name suggests it should only be
+incremented when a connection was seen using MPTCP options, then a
+fallback to TCP has been done. Let's do that by incrementing it when
+the subflow context of an inbound MPC connection attempt is dropped.
+Also, update mptcp_connect.sh kselftest, to ensure that the
+above MIB does not increment in case a pure TCP client connects to a
+MPTCP server.
+
+Fixes: fc518953bc9c ("mptcp: add and use MIB counter infrastructure")
+Cc: stable@vger.kernel.org
+Reported-by: Christoph Paasch <cpaasch@apple.com>
+Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/449
+Signed-off-by: Davide Caratti <dcaratti@redhat.com>
+Reviewed-by: Mat Martineau <martineau@kernel.org>
+Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Link: https://lore.kernel.org/r/20240329-upstream-net-20240329-fallback-mib-v1-1-324a8981da48@kernel.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/mptcp/protocol.c | 3 ---
+ net/mptcp/subflow.c | 2 ++
+ tools/testing/selftests/net/mptcp/mptcp_connect.sh | 7 +++++++
+ 3 files changed, 9 insertions(+), 3 deletions(-)
+
+--- a/net/mptcp/protocol.c
++++ b/net/mptcp/protocol.c
+@@ -3349,9 +3349,6 @@ static struct sock *mptcp_accept(struct
+
+ newsk = new_mptcp_sock;
+ MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
+- } else {
+- MPTCP_INC_STATS(sock_net(sk),
+- MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
+ }
+
+ out:
+--- a/net/mptcp/subflow.c
++++ b/net/mptcp/subflow.c
+@@ -816,6 +816,8 @@ dispose_child:
+ return child;
+
+ fallback:
++ if (fallback)
++ SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
+ mptcp_subflow_drop_ctx(child);
+ return child;
+ }
+--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
++++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+@@ -439,6 +439,7 @@ do_transfer()
+ local stat_cookierx_last=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv")
+ local stat_csum_err_s=$(get_mib_counter "${listener_ns}" "MPTcpExtDataCsumErr")
+ local stat_csum_err_c=$(get_mib_counter "${connector_ns}" "MPTcpExtDataCsumErr")
++ local stat_tcpfb_last_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK")
+
+ timeout ${timeout_test} \
+ ip netns exec ${listener_ns} \
+@@ -504,6 +505,7 @@ do_transfer()
+ local stat_cookietx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesSent")
+ local stat_cookierx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv")
+ local stat_ooo_now=$(get_mib_counter "${listener_ns}" "TcpExtTCPOFOQueue")
++ local stat_tcpfb_now_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK")
+
+ expect_synrx=$((stat_synrx_last_l))
+ expect_ackrx=$((stat_ackrx_last_l))
+@@ -548,6 +550,11 @@ do_transfer()
+ fi
+ fi
+
++ if [ ${stat_ooo_now} -eq 0 ] && [ ${stat_tcpfb_last_l} -ne ${stat_tcpfb_now_l} ]; then
++ printf "[ FAIL ]\nunexpected fallback to TCP"
++ rets=1
++ fi
++
+ if [ $retc -eq 0 ] && [ $rets -eq 0 ]; then
+ printf "[ OK ]"
+ fi
--- /dev/null
+From 629b35a225b0d49fbcff3b5c22e3b983c7c7b36f Mon Sep 17 00:00:00 2001
+From: Geliang Tang <geliang.tang@suse.com>
+Date: Wed, 25 Oct 2023 16:37:11 -0700
+Subject: selftests: mptcp: display simult in extra_msg
+
+From: Geliang Tang <geliang.tang@suse.com>
+
+commit 629b35a225b0d49fbcff3b5c22e3b983c7c7b36f upstream.
+
+Just like displaying "invert" after "Info: ", "simult" should be
+displayed too when rm_subflow_nr doesn't match the expect value in
+chk_rm_nr():
+
+ syn [ ok ]
+ synack [ ok ]
+ ack [ ok ]
+ add [ ok ]
+ echo [ ok ]
+ rm [ ok ]
+ rmsf [ ok ] 3 in [2:4]
+ Info: invert simult
+
+ syn [ ok ]
+ synack [ ok ]
+ ack [ ok ]
+ add [ ok ]
+ echo [ ok ]
+ rm [ ok ]
+ rmsf [ ok ]
+ Info: invert
+
+Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
+Signed-off-by: Geliang Tang <geliang.tang@suse.com>
+Signed-off-by: Mat Martineau <martineau@kernel.org>
+Link: https://lore.kernel.org/r/20231025-send-net-next-20231025-v1-10-db8f25f798eb@kernel.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ tools/testing/selftests/net/mptcp/mptcp_join.sh | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
++++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
+@@ -1771,7 +1771,10 @@ chk_rm_nr()
+ # in case of simult flush, the subflow removal count on each side is
+ # unreliable
+ count=$((count + cnt))
+- [ "$count" != "$rm_subflow_nr" ] && suffix="$count in [$rm_subflow_nr:$((rm_subflow_nr*2))]"
++ if [ "$count" != "$rm_subflow_nr" ]; then
++ suffix="$count in [$rm_subflow_nr:$((rm_subflow_nr*2))]"
++ extra_msg="$extra_msg simult"
++ fi
+ if [ $count -ge "$rm_subflow_nr" ] && \
+ [ "$count" -le "$((rm_subflow_nr *2 ))" ]; then
+ echo -n "[ ok ] $suffix"
projects / thirdparty / kernel / stable-queue.git / commitdiff
