diff mbox series

[net,7/7] selftests: mptcp: be more conservative with cookie MPJ limits

Message ID 20220218213544.70285-8-mathew.j.martineau@linux.intel.com (mailing list archive)
State Accepted
Commit e35f885b357d47e04380a2056d1b2cc3e6f4f24b
Delegated to: Netdev Maintainers
Headers show
Series mptcp: Fix address advertisement races and stabilize tests | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: geliangtang@xiaomi.com; 3 maintainers not CCed: linux-kselftest@vger.kernel.org geliangtang@xiaomi.com shuah@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: line length of 111 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mat Martineau Feb. 18, 2022, 9:35 p.m. UTC
From: Paolo Abeni <pabeni@redhat.com>

Since commit 2843ff6f36db ("mptcp: remote addresses fullmesh"), an
MPTCP client can attempt creating multiple MPJ subflow simultaneusly.

In such scenario the server, when syncookies are enabled, could end-up
accepting incoming MPJ syn even above the configured subflow limit, as
the such limit can be enforced in a reliable way only after the subflow
creation. In case of syncookie, only after the 3rd ack reception.

As a consequence the related self-tests case sporadically fails, as it
verify that the server always accept the expected number of MPJ syn.

Address the issues relaxing the MPJ syn number constrain. Note that the
check on the accepted number of MPJ 3rd ack still remains intact.

Fixes: 2843ff6f36db ("mptcp: remote addresses fullmesh")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 0d6a71e7bb59..0c8a2a20b96c 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -660,6 +660,7 @@  chk_join_nr()
 	local ack_nr=$4
 	local count
 	local dump_stats
+	local with_cookie
 
 	printf "%02u %-36s %s" "$TEST_COUNT" "$msg" "syn"
 	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}'`
@@ -673,12 +674,20 @@  chk_join_nr()
 	fi
 
 	echo -n " - synack"
+	with_cookie=`ip netns exec $ns2 sysctl -n net.ipv4.tcp_syncookies`
 	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}'`
 	[ -z "$count" ] && count=0
 	if [ "$count" != "$syn_ack_nr" ]; then
-		echo "[fail] got $count JOIN[s] synack expected $syn_ack_nr"
-		ret=1
-		dump_stats=1
+		# simult connections exceeding the limit with cookie enabled could go up to
+		# synack validation as the conn limit can be enforced reliably only after
+		# the subflow creation
+		if [ "$with_cookie" = 2 ] && [ "$count" -gt "$syn_ack_nr" ] && [ "$count" -le "$syn_nr" ]; then
+			echo -n "[ ok ]"
+		else
+			echo "[fail] got $count JOIN[s] synack expected $syn_ack_nr"
+			ret=1
+			dump_stats=1
+		fi
 	else
 		echo -n "[ ok ]"
 	fi