net/mlx5e: Fix loopback self test when GRO is off

When GRO is off, the transport header pointer in sk_buff is
initialized to network's header.

To find the udp header, instead of using udp_hdr() which assumes
skb_network_header was set, manually calculate the udp header offset.

Fixes: 0952da791c97 ("net/mlx5e: Add support for loopback selftest")
Signed-off-by: Inbar Karmy <inbark@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c b/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
index 5a4608281f38..707976482c09 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
@@ -216,7 +216,8 @@ mlx5e_test_loopback_validate(struct sk_buff *skb,
         if (iph->protocol != IPPROTO_UDP)
                 goto out;
 
-        udph = udp_hdr(skb);
+        /* Don't assume skb_transport_header() was set */
+        udph = (struct udphdr *)((u8 *)iph + 4 * iph->ihl);
         if (udph->dest != htons(9))
                 goto out;