From d7cc8252252f9e5b72975a3d498ba2ee08245740 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 9cc2c204baa3..3cb7dceca2d9 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; } -- 2.25.1