Merge branch 'mptcp-fixes-for-v6-6'

Mat Martineau says:

====================
mptcp: Fixes for v6.6

Patch 1 corrects the logic for MP_JOIN tests where 0 RSTs are expected.

Patch 2 ensures MPTCP packets are not incorrectly coalesced in the TCP
backlog queue.

Patch 3 avoids a zero-window probe and associated WARN_ON_ONCE() in an
expected MPTCP reinjection scenario.

Patches 4 & 5 allow an initial MPTCP subflow to be closed cleanly
instead of always sending RST. Associated selftest is updated.
====================

Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-0-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 19 insertions, 2 deletions

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index ee1f89a872b3..dc895b7b94e1 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -1432,7 +1432,9 @@ chk_rst_nr()
 	count=$(get_counter ${ns_tx} "MPTcpExtMPRstTx")
 	if [ -z "$count" ]; then
 		print_skip
-	elif [ $count -lt $rst_tx ]; then
+	# accept more rst than expected except if we don't expect any
+	elif { [ $rst_tx -ne 0 ] && [ $count -lt $rst_tx ]; } ||
+	     { [ $rst_tx -eq 0 ] && [ $count -ne 0 ]; }; then
 		fail_test "got $count MP_RST[s] TX expected $rst_tx"
 	else
 		print_ok
@@ -1442,7 +1444,9 @@ chk_rst_nr()
 	count=$(get_counter ${ns_rx} "MPTcpExtMPRstRx")
 	if [ -z "$count" ]; then
 		print_skip
-	elif [ "$count" -lt "$rst_rx" ]; then
+	# accept more rst than expected except if we don't expect any
+	elif { [ $rst_rx -ne 0 ] && [ $count -lt $rst_rx ]; } ||
+	     { [ $rst_rx -eq 0 ] && [ $count -ne 0 ]; }; then
 		fail_test "got $count MP_RST[s] RX expected $rst_rx"
 	else
 		print_ok
@@ -2305,6 +2309,7 @@ remove_tests()
 		chk_join_nr 1 1 1
 		chk_rm_tx_nr 1
 		chk_rm_nr 1 1
+		chk_rst_nr 0 0
 	fi
 
 	# multiple subflows, remove
@@ -2317,6 +2322,7 @@ remove_tests()
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 2 2 2
 		chk_rm_nr 2 2
+		chk_rst_nr 0 0
 	fi
 
 	# single address, remove
@@ -2329,6 +2335,7 @@ remove_tests()
 		chk_join_nr 1 1 1
 		chk_add_nr 1 1
 		chk_rm_nr 1 1 invert
+		chk_rst_nr 0 0
 	fi
 
 	# subflow and signal, remove
@@ -2342,6 +2349,7 @@ remove_tests()
 		chk_join_nr 2 2 2
 		chk_add_nr 1 1
 		chk_rm_nr 1 1
+		chk_rst_nr 0 0
 	fi
 
 	# subflows and signal, remove
@@ -2356,6 +2364,7 @@ remove_tests()
 		chk_join_nr 3 3 3
 		chk_add_nr 1 1
 		chk_rm_nr 2 2
+		chk_rst_nr 0 0
 	fi
 
 	# addresses remove
@@ -2370,6 +2379,7 @@ remove_tests()
 		chk_join_nr 3 3 3
 		chk_add_nr 3 3
 		chk_rm_nr 3 3 invert
+		chk_rst_nr 0 0
 	fi
 
 	# invalid addresses remove
@@ -2384,6 +2394,7 @@ remove_tests()
 		chk_join_nr 1 1 1
 		chk_add_nr 3 3
 		chk_rm_nr 3 1 invert
+		chk_rst_nr 0 0
 	fi
 
 	# subflows and signal, flush
@@ -2398,6 +2409,7 @@ remove_tests()
 		chk_join_nr 3 3 3
 		chk_add_nr 1 1
 		chk_rm_nr 1 3 invert simult
+		chk_rst_nr 0 0
 	fi
 
 	# subflows flush
@@ -2417,6 +2429,7 @@ remove_tests()
 		else
 			chk_rm_nr 3 3
 		fi
+		chk_rst_nr 0 0
 	fi
 
 	# addresses flush
@@ -2431,6 +2444,7 @@ remove_tests()
 		chk_join_nr 3 3 3
 		chk_add_nr 3 3
 		chk_rm_nr 3 3 invert simult
+		chk_rst_nr 0 0
 	fi
 
 	# invalid addresses flush
@@ -2445,6 +2459,7 @@ remove_tests()
 		chk_join_nr 1 1 1
 		chk_add_nr 3 3
 		chk_rm_nr 3 1 invert
+		chk_rst_nr 0 0
 	fi
 
 	# remove id 0 subflow
@@ -2456,6 +2471,7 @@ remove_tests()
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 1 1 1
 		chk_rm_nr 1 1
+		chk_rst_nr 0 0
 	fi
 
 	# remove id 0 address
@@ -2468,6 +2484,7 @@ remove_tests()
 		chk_join_nr 1 1 1
 		chk_add_nr 1 1
 		chk_rm_nr 1 1 invert
+		chk_rst_nr 0 0 invert
 	fi
 }