mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git
synced 2026-04-03 23:38:12 -04:00
a2fb4bc4e2
The virtio specification are introducing support for GSO over UDP tunnel. This patch brings in the needed defines and the additional virtio hdr parsing/building helpers. The UDP tunnel support uses additional fields in the virtio hdr, and such fields location can change depending on other negotiated features - specifically VIRTIO_NET_F_HASH_REPORT. Try to be as conservative as possible with the new field validation. Existing implementation for plain GSO offloads allow for invalid/ self-contradictory values of such fields. With GSO over UDP tunnel we can be more strict, with no need to deal with legacy implementation. Since the checksum-related field validation is asymmetric in the driver and in the device, introduce a separate helper to implement the new checks (to be used only on the driver side). Note that while the feature space exceeds the 64-bit boundaries, the guest offload space is fixed by the specification of the VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET command to a 64-bit size. Prior to the UDP tunnel GSO support, each guest offload bit corresponded to the feature bit with the same value and vice versa. Due to the limited 'guest offload' space, relevant features in the high 64 bits are 'mapped' to free bits in the lower range. That is simpler than defining a new command (and associated features) to exchange an extended guest offloads set. As a consequence, the uAPIs also specify the mapped guest offload value corresponding to the UDP tunnel GSO features. Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> -- v4 -> v5: - avoid lines above 80 chars v3 -> v4: - fixed offset for UDP GSO tunnel, update accordingly the helpers - tried to clarified vlan_hlen semantic - virtio_net_chk_data_valid() -> virtio_net_handle_csum_offload() v2 -> v3: - add definitions for possible vnet hdr layouts with tunnel support v1 -> v2: - 'relay' -> 'rely' typo - less unclear comment WRT enforced inner GSO checks - inner header fields are allowed only with 'modern' virtio, thus are always le - clarified in the commit message the need for 'mapped features' defines - assume little_endian is true when UDP GSO is enabled. - fix inner proto type value
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
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.