net/mlx5e: XDP, Drop fragmented packets larger than MTU size

[ Upstream commit bcaf109f794744c14da0e9123b31d1f4571b0a35 ]

XDP transmits fragmented packets that are larger than MTU size instead of
dropping those packets. The drop check that checks whether a packet is larger
than MTU is comparing MTU size against the linear part length only.

Adjust the drop check to compare MTU size against both linear and non-linear
part lengths to avoid transmitting fragmented packets larger than MTU size.

Fixes: 39a1665d16a2 ("net/mlx5e: Implement sending multi buffer XDP frames")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 8bed17d..b723ff5 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -493,6 +493,7 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
        dma_addr_t dma_addr = xdptxd->dma_addr;
        u32 dma_len = xdptxd->len;
        u16 ds_cnt, inline_hdr_sz;
+       unsigned int frags_size;
        u8 num_wqebbs = 1;
        int num_frags = 0;
        bool inline_ok;
@@ -503,8 +504,9 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
 
        inline_ok = sq->min_inline_mode == MLX5_INLINE_MODE_NONE ||
                dma_len >= MLX5E_XDP_MIN_INLINE;
+       frags_size = xdptxd->has_frags ? xdptxdf->sinfo->xdp_frags_size : 0;
 
-       if (unlikely(!inline_ok || sq->hw_mtu < dma_len)) {
+       if (unlikely(!inline_ok || sq->hw_mtu < dma_len + frags_size)) {
                stats->err++;
                return false;
        }