[RFC PATCH v2 41/45] selftests: mptcp: make tc delays random

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

From: Florian Westphal <fw@strlen.de>

test with less predictable setups:
tc qdisc delay is now random, same for reordering and loss.
Main motivation is to cover more scenarious without a large
increase in test-time.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 .../selftests/net/mptcp/mptcp_connect.sh      | 28 +++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index d029bdc5946d..fb9bf9f4fc8b 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -277,8 +277,32 @@ for sender in 1 2 3 4;do
 	do_ping ns4 ns$sender 10.0.3.1
 done
 
-tc -net ns2 qdisc add dev ns2eth3 root netem loss random 1
-tc -net ns3 qdisc add dev ns3eth4 root netem delay 10ms reorder 25% 50% gap 5
+loss=$((RANDOM%101))
+if [ $loss -eq 100 ] ;then
+	loss=1%
+	tc -net ns2 qdisc add dev ns2eth3 root netem loss random $loss
+elif [ $loss -ge 10 ]; then
+	loss=0.$loss%
+	tc -net ns2 qdisc add dev ns2eth3 root netem loss random $loss
+elif [ $loss -ge 1 ]; then
+	loss=0.0$loss%
+	tc -net ns2 qdisc add dev ns2eth3 root netem loss random $loss
+fi
+
+delay=$((RANDOM%1200))
+reorder1=$((RANDOM%25))
+reorder2=$((RANDOM%50))
+gap=$((RANDOM%100))
+if [ $gap -gt 0 ]; then
+	gap="gap $gap"
+else
+	gap=""
+fi
+
+if [ $reorder1 -gt 0 ] && [ $reorder2 -gt 0 ]; then
+  tc -net ns3 qdisc add dev ns3eth4 root netem delay ${delay}ms reorder ${reorder1}% ${reorder2}% $gap
+fi
+echo "INFO: Using loss of $loss, delay $delay ms, reorder: $reorder1, $reorder2 $gap on ns3eth4"
 
 for sender in 1 2 3 4;do
 	run_tests ns1 ns$sender 10.0.1.1
-- 
2.23.0