selftests: mptcp: add fastclose env var

Use a new env var fastclose instead of passing fastclose to addr_nr_ns2.
It can be set with 'server' or 'client':

  addr_nr_ns2=fastclose_client \
          run_tests $ns1 $ns2 10.0.1.1

  ->

  fastclose=client \
          run_tests $ns1 $ns2 10.0.1.1.

With this change, the fullmesh flag setting code can be moved into
pm_nl_set_endpoint() from do_transfer().
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20230712-upstream-net-next-20230712-selftests-mptcp-use-local-env-v1-2-f1c8b62fbf95@tessares.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/mptcp/mptcp_join.sh

@@ -55,6 +55,7 @@ unset test_linkfail
 unset addr_nr_ns1
 unset addr_nr_ns2
 unset sflags
+unset fastclose
 
 # generated using "nfbpf_compile '(ip && (ip[54] & 0xf0) == 0x30) ||
 #				  (ip6 && (ip6[74] & 0xf0) == 0x30)'"
@@ -832,6 +833,12 @@ pm_nl_set_endpoint()
 	local addr_nr_ns2=${addr_nr_ns2:-0}
 	local sflags=${sflags:-""}
 
+	local flags="subflow"
+	if [[ "${addr_nr_ns2}" = "fullmesh_"* ]]; then
+		flags="${flags},fullmesh"
+		addr_nr_ns2=${addr_nr_ns2:9}
+	fi
+
 	# let the mptcp subflow be established in background before
 	# do endpoint manipulation
 	if [ $addr_nr_ns1 != "0" ] || [ $addr_nr_ns2 != "0" ]; then
@@ -984,6 +991,7 @@ do_transfer()
 	local port=$((10000 + TEST_COUNT - 1))
 	local cappid
 	local FAILING_LINKS=${FAILING_LINKS:-""}
+	local fastclose=${fastclose:-""}
 
 	:> "$cout"
 	:> "$sout"
@@ -1020,11 +1028,10 @@ do_transfer()
 		extra_args="-r ${speed:6}"
 	fi
 
-	local flags="subflow"
 	local extra_cl_args=""
 	local extra_srv_args=""
 	local trunc_size=""
-	if [[ "${addr_nr_ns2}" = "fastclose_"* ]]; then
+	if [ -n "${fastclose}" ]; then
 		if [ ${test_linkfail} -le 1 ]; then
 			echo "fastclose tests need test_linkfail argument"
 			fail_test
@@ -1033,7 +1040,7 @@ do_transfer()
 
 		# disconnect
 		trunc_size=${test_linkfail}
-		local side=${addr_nr_ns2:10}
+		local side=${fastclose}
 
 		if [ ${side} = "client" ]; then
 			extra_cl_args="-f ${test_linkfail}"
@@ -1046,10 +1053,6 @@ do_transfer()
 			fail_test
 			return 1
 		fi
-		addr_nr_ns2=0
-	elif [[ "${addr_nr_ns2}" = "fullmesh_"* ]]; then
-		flags="${flags},fullmesh"
-		addr_nr_ns2=${addr_nr_ns2:9}
 	fi
 
 	extra_srv_args="$extra_args $extra_srv_args"
@@ -3186,7 +3189,7 @@ fullmesh_tests()
 fastclose_tests()
 {
 	if reset_check_counter "fastclose test" "MPTcpExtMPFastcloseTx"; then
-		test_linkfail=1024 addr_nr_ns2=fastclose_client \
+		test_linkfail=1024 fastclose=client \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 0 0 0
 		chk_fclose_nr 1 1
@@ -3194,7 +3197,7 @@ fastclose_tests()
 	fi
 
 	if reset_check_counter "fastclose server test" "MPTcpExtMPFastcloseRx"; then
-		test_linkfail=1024 addr_nr_ns2=fastclose_server \
+		test_linkfail=1024 fastclose=server \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 0 0 0
 		chk_fclose_nr 1 1 invert