net: hsr: fix incorrect lsdu size in the tag of HSR frames for small …

…frames

For small Ethernet frames with size less than minimum size 66 for HSR
vs 60 for regular Ethernet frames, hsr driver currently doesn't pad the
frame to make it minimum size. This results in incorrect LSDU size being
populated in the HSR tag for these frames. Fix this by padding the frame
to the minimum size applicable for HSR.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr/hsr_forward.c

@@ -127,6 +127,9 @@ static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame,
 	int lane_id;
 	int lsdu_size;
 
+	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
+	skb_put_padto(skb, ETH_ZLEN + HSR_HLEN);
+
 	if (port->type == HSR_PT_SLAVE_A)
 		lane_id = 0;
 	else