[PATCH net 3/5] selftests: mptcp: join: cover ADD_ADDR tx drop and list progress

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

From: Li Xiasong <lixiasong1@huawei.com>

Extend add_addr_ports_tests with IPv6 signaling cases that exercise
ADD_ADDR tx-space shortage when tcp_timestamps are enabled.

Add one case to verify PM still progresses to later signal endpoints
after the first one is dropped.

This covers both failure accounting and the non-blocking behavior of
the announce list after a tx-space drop on pure ACK.

Signed-off-by: Li Xiasong <lixiasong1@huawei.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
To: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 31 +++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index beec41f6662a..5acd12021e6e 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -1828,6 +1828,22 @@ chk_add_tx_nr()
 	fi
 }
 
+chk_add_drop_tx_nr()
+{
+	local drop_tx_nr=$1
+	local count
+
+	print_check "add addr tx drop"
+	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtAddAddrTxDrop")
+	if [ -z "$count" ]; then
+		print_skip
+	elif [ "$count" != "$drop_tx_nr" ]; then
+		fail_test "got $count ADD_ADDR drop[s] TX, expected $drop_tx_nr"
+	else
+		print_ok
+	fi
+}
+
 chk_rm_nr()
 {
 	local rm_addr_nr=$1
@@ -3278,6 +3294,21 @@ add_addr_ports_tests()
 
 		chk_mpc_endp_attempt ${retl} 1
 	fi
+
+	# first signal address drops, second one still progresses
+	if reset "signal addr list progresses after tx drop"; then
+		pm_nl_set_limits $ns1 0 2
+		pm_nl_set_limits $ns2 1 0
+		ip netns exec $ns1 sysctl -q net.ipv4.tcp_timestamps=1
+		ip netns exec $ns2 sysctl -q net.ipv4.tcp_timestamps=1
+
+		pm_nl_add_endpoint $ns1 dead:beef:2::1 flags signal port 10100
+		pm_nl_add_endpoint $ns1 dead:beef:3::1 flags signal
+		run_tests $ns1 $ns2 dead:beef:1::1
+		chk_add_drop_tx_nr 1
+		chk_add_tx_nr 1 1
+		chk_add_nr 1 1 0
+	fi
 }
 
 bind_tests()

-- 
2.53.0