From: Petr Machata <petrm@mellanox.com>
Date: Thu, 20 Sep 2018 06:21:35 +0000 (+0300)
Subject: selftests: forwarding: lib: Add mtu_set(), mtu_restore()
X-Git-Tag: v4.20-rc1~27^2~308^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a381ed12ea33888a08f0e3e5ba22a255fa5f7257;p=thirdparty%2Flinux.git

selftests: forwarding: lib: Add mtu_set(), mtu_restore()

Some selftests need to tweak MTU of an interface, and naturally should
at teardown restore the MTU back to the original value. Add two
functions to facilitate this MTU handling: mtu_set() to change MTU
value, and mtu_reset() to change it back to what it was before.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
index 4c2351996a7f3..0e73698b20489 100644
--- a/tools/testing/selftests/net/forwarding/lib.sh
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -549,6 +549,23 @@ forwarding_restore()
 	sysctl_restore net.ipv4.conf.all.forwarding
 }
 
+declare -A MTU_ORIG
+mtu_set()
+{
+	local dev=$1; shift
+	local mtu=$1; shift
+
+	MTU_ORIG["$dev"]=$(ip -j link show dev $dev | jq -e '.[].mtu')
+	ip link set dev $dev mtu $mtu
+}
+
+mtu_restore()
+{
+	local dev=$1; shift
+
+	ip link set dev $dev mtu ${MTU_ORIG["$dev"]}
+}
+
 tc_offload_check()
 {
 	local num_netifs=${1:-$NUM_NETIFS}