selftests: mptcp: reuse linkfail to make given size files

This patch reused the test_linkfail values above 2 to make test files with
the given sizes (KB) for both the client side and the server side. It's
useful for the test cases using different file sizes.
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -459,7 +459,7 @@ do_transfer()
 		local_addr="0.0.0.0"
 	fi
 
-	if [ "$test_link_fail" -eq 2 ];then
+	if [ "$test_link_fail" -gt 1 ];then
 		timeout ${timeout_test} \
 			ip netns exec ${listener_ns} \
 				./mptcp_connect -t ${timeout_poll} -l -p $port -s ${srv_proto} \
@@ -479,13 +479,19 @@ do_transfer()
 			ip netns exec ${connector_ns} \
 				./mptcp_connect -t ${timeout_poll} -p $port -s ${cl_proto} \
 					$extra_args $connect_addr < "$cin" > "$cout" &
-	else
+	elif [ "$test_link_fail" -eq 1 ] || [ "$test_link_fail" -eq 2 ];then
 		( cat "$cinfail" ; sleep 2; link_failure $listener_ns ; cat "$cinfail" ) | \
 			tee "$cinsent" | \
 			timeout ${timeout_test} \
 				ip netns exec ${connector_ns} \
 					./mptcp_connect -t ${timeout_poll} -p $port -s ${cl_proto} \
 						$extra_args $connect_addr > "$cout" &
+	else
+		cat "$cinfail" | tee "$cinsent" | \
+			timeout ${timeout_test} \
+				ip netns exec ${connector_ns} \
+					./mptcp_connect -t ${timeout_poll} -p $port -s ${cl_proto} \
+						$extra_args $connect_addr > "$cout" &
 	fi
 	cpid=$!
 
@@ -645,7 +651,7 @@ do_transfer()
 		return 1
 	fi
 
-	if [ "$test_link_fail" -eq 2 ];then
+	if [ "$test_link_fail" -gt 1 ];then
 		check_transfer $sinfail $cout "file received by client"
 	else
 		check_transfer $sin $cout "file received by client"
@@ -690,9 +696,18 @@ run_tests()
 	speed="${7:-fast}"
 	sflags="${8:-""}"
 
+	# The values above 2 are reused to make test files
+	# with the given sizes (KB)
+	if [ "$test_linkfail" -gt 2 ]; then
+		size=$test_linkfail
+
+		if [ -z "$cinfail" ]; then
+			cinfail=$(mktemp)
+		fi
+		make_file "$cinfail" "client" $size
 	# create the input file for the failure test when
 	# the first failure test run
-	if [ "$test_linkfail" -ne 0 -a -z "$cinfail" ]; then
+	elif [ "$test_linkfail" -ne 0 -a -z "$cinfail" ]; then
 		# the client file must be considerably larger
 		# of the maximum expected cwin value, or the
 		# link utilization will be not predicable
@@ -705,7 +720,14 @@ run_tests()
 		make_file "$cinfail" "client" $size
 	fi
 
-	if [ "$test_linkfail" -eq 2 -a -z "$sinfail" ]; then
+	if [ "$test_linkfail" -gt 2 ]; then
+		size=$test_linkfail
+
+		if [ -z "$sinfail" ]; then
+			sinfail=$(mktemp)
+		fi
+		make_file "$sinfail" "server" $size
+	elif [ "$test_linkfail" -eq 2 -a -z "$sinfail" ]; then
 		size=$((RANDOM%16))
 		size=$((size+1))
 		size=$((size*2048))