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95dbe9e7b3
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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.