selftests: forwarding: Add a test for NH group stats

Add to lib.sh support for fetching NH stats, and a new library,
router_mpath_nh_lib.sh, with the common code for testing NH stats.
Use the latter from router_mpath_nh.sh and router_mpath_nh_res.sh.

The test works by sending traffic through a NH group, and checking that the
reported values correspond to what the link that ultimately receives the
traffic reports having seen.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/2a424c54062a5f1efd13b9ec5b2b0e29c6af2574.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
index d1bf39eaf2b3..e579c2e0c462 100644
--- a/tools/testing/selftests/net/forwarding/lib.sh
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -900,6 +900,33 @@ hw_stats_get()
 		jq ".[0].stats64.$dir.$stat"
 }
 
+__nh_stats_get()
+{
+	local key=$1; shift
+	local group_id=$1; shift
+	local member_id=$1; shift
+
+	ip -j -s -s nexthop show id $group_id |
+	    jq --argjson member_id "$member_id" --arg key "$key" \
+	       '.[].group_stats[] | select(.id == $member_id) | .[$key]'
+}
+
+nh_stats_get()
+{
+	local group_id=$1; shift
+	local member_id=$1; shift
+
+	__nh_stats_get packets "$group_id" "$member_id"
+}
+
+nh_stats_get_hw()
+{
+	local group_id=$1; shift
+	local member_id=$1; shift
+
+	__nh_stats_get packets_hw "$group_id" "$member_id"
+}
+
 humanize()
 {
 	local speed=$1; shift
@@ -2010,3 +2037,10 @@ bail_on_lldpad()
 		fi
 	fi
 }
+
+absval()
+{
+	local v=$1; shift
+
+	echo $((v > 0 ? v : -v))
+}