From 7e8f2186775157bc17a8c7b4d600545d3cb40ad5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 27 Nov 2018 22:24:52 -0800 Subject: [PATCH] nfp: avoid oversized TSO headers with metadata prepend In preparation for TSO over representors make sure the port id prepend will always fit in the frame. The current max header length is 255, which is ample, so assume worst case scenario of 8 byte prepend and save ourselves the conditionals. Signed-off-by: Jakub Kicinski Reviewed-by: Dirk van der Merwe Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index 9cc2c204baa3e..3cb7dceca2d90 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -3284,7 +3284,10 @@ nfp_net_features_check(struct sk_buff *skb, struct net_device *dev, hdrlen = skb_inner_transport_header(skb) - skb->data + inner_tcp_hdrlen(skb); - if (unlikely(hdrlen > NFP_NET_LSO_MAX_HDR_SZ)) + /* Assume worst case scenario of having longest possible + * metadata prepend - 8B + */ + if (unlikely(hdrlen > NFP_NET_LSO_MAX_HDR_SZ - 8)) features &= ~NETIF_F_GSO_MASK; } -- 2.39.5