]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
virtio_net: fix XDP code path in receive_small()
authorJesper Dangaard Brouer <brouer@redhat.com>
Tue, 20 Feb 2018 13:32:10 +0000 (14:32 +0100)
committerDavid S. Miller <davem@davemloft.net>
Wed, 21 Feb 2018 20:09:29 +0000 (15:09 -0500)
commit95dbe9e7b3720efa5cf83d21f44f6d953f7cf4a2
tree5141cfbc195758eeae8785691b99dc004bfd6dc6
parent7324f5399b06cdbbd1520b8fde8024035953179d
virtio_net: fix XDP code path in receive_small()

When configuring virtio_net to use the code path 'receive_small()',
in-order to get correct XDP_REDIRECT support, I discovered TCP packets
would get silently dropped when loading an XDP program action XDP_PASS.

The bug seems to be that receive_small() when XDP is loaded check that
hdr->hdr.flags is zero, which seems wrong as hdr.flags contains the
flags VIRTIO_NET_HDR_F_* :
 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */
 #define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */

TCP got dropped as it had the VIRTIO_NET_HDR_F_DATA_VALID flag set.

The flags that are relevant here are the VIRTIO_NET_HDR_GSO_* flags
stored in hdr->hdr.gso_type. Thus, the fix is just check that none of
the gso_type flags have been set.

Fixes: bb91accf2733 ("virtio-net: XDP support for small buffers")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/virtio_net.c