47ef50eb04
[ Upstream commit 33c563ebf8d3deed7d8addd20d77398ac737ef9a ]
Userspace assumes vlan header is present at a given offset, but vlan
offload allows to store this in metadata fields of the skbuff. Hence
mangling vlan results in a garbled packet. Handle this transparently by
adding a parser to the kernel.
If vlan metadata is present and payload offset is over 12 bytes (source
and destination mac address fields), then subtract vlan header present
in vlan metadata, otherwise mangle vlan metadata based on offset and
length, extracting data from the source register.
This is similar to:
8cfd23e67401 ("netfilter: nft_payload: work around vlan header stripping")
to deal with vlan payload mangling.
Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 Restructured Text 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.