986e43b19a
The current mac80211 mesh A-MSDU receive path fails to parse A-MSDU packets on mesh interfaces, because it assumes that the Mesh Control field is always directly after the 802.11 header. 802.11-2020 9.3.2.2.2 Figure 9-70 shows that the Mesh Control field is actually part of the A-MSDU subframe header. This makes more sense, since it allows packets for multiple different destinations to be included in the same A-MSDU, as long as RA and TID are still the same. Another issue is the fact that the A-MSDU subframe length field was apparently accidentally defined as little-endian in the standard. In order to fix this, the mesh forwarding path needs happen at a different point in the receive path. ieee80211_data_to_8023_exthdr is changed to ignore the mesh control field and leave it in after the ethernet header. This also affects the source/dest MAC address fields, which now in the case of mesh point to the mesh SA/DA. ieee80211_amsdu_to_8023s is changed to deal with the endian difference and to add the Mesh Control length to the subframe length, since it's not covered by the MSDU length field. With these changes, the mac80211 will get the same packet structure for converted regular data packets and unpacked A-MSDU subframes. The mesh forwarding checks are now only performed after the A-MSDU decap. For locally received packets, the Mesh Control header is stripped away. For forwarded packets, a new 802.11 header gets added. Signed-off-by: Felix Fietkau <nbd@nbd.name> Link: https://lore.kernel.org/r/20230213100855.34315-4-nbd@nbd.name [fix fortify build error] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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.