selftests: pmtu: detect correct binary to ping ipv6 addresses

Some systems don't have the ping6 binary anymore, and use ping for
everything. Detect the absence of ping6 and try to use ping instead.

Fixes: d1f1b9cbf34c ("selftests: net: Introduce first PMTU test")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 0ecf260..32a194e 100755 (executable)
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -46,6 +46,9 @@
 # Kselftest framework requirement - SKIP code is 4.
 ksft_skip=4
 
+# Some systems don't have a ping6 binary anymore
+which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
+
 tests="
        pmtu_vti6_exception             vti6: PMTU exceptions
        pmtu_vti4_exception             vti4: PMTU exceptions
@@ -274,7 +277,7 @@ test_pmtu_vti6_exception() {
        mtu "${ns_b}" veth_b 4000
        mtu "${ns_a}" vti6_a 5000
        mtu "${ns_b}" vti6_b 5000
-       ${ns_a} ping6 -q -i 0.1 -w 2 -s 60000 ${vti6_b_addr} > /dev/null
+       ${ns_a} ${ping6} -q -i 0.1 -w 2 -s 60000 ${vti6_b_addr} > /dev/null
 
        # Check that exception was created
        if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" = "" ]; then