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path: root/include/uapi/linux/batadv_packet.h
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2024-10-05batman-adv: Add flex array to struct batadv_tvlv_tt_dataErick Archer
The "struct batadv_tvlv_tt_data" uses a dynamically sized set of trailing elements. Specifically, it uses an array of structures of type "batadv_tvlv_tt_vlan_data". So, use the preferred way in the kernel declaring a flexible array [1]. At the same time, prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). In this case, it is important to note that the attribute used is specifically __counted_by_be since variable "num_vlan" is of type __be16. The following change to the "batadv_tt_tvlv_ogm_handler_v1" function: - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); - tt_change = (struct batadv_tvlv_tt_change *)(tt_vlan + num_vlan); + tt_change = (struct batadv_tvlv_tt_change *)((void *)tt_data + + flex_size); is intended to prevent the compiler from generating an "out-of-bounds" notification due to the __counted_by attribute. The compiler can do a pointer calculation using the vlan_data flexible array memory, or in other words, this may be calculated as an array offset, since it is the same as: &tt_data->vlan_data[num_vlan] Therefore, we go past the end of the array. In other "multiple trailing flexible array" situations, this has been solved by addressing from the base pointer, since the compiler either knows the full allocation size or it knows nothing about it (this case, since it came from a "void *" function argument). The order in which the structure batadv_tvlv_tt_data and the structure batadv_tvlv_tt_vlan_data are defined must be swap to avoid an incomplete type error. Also, avoid the open-coded arithmetic in memory allocator functions [2] using the "struct_size" macro and use the "flex_array_size" helper to clarify some calculations, when possible. Moreover, the new structure member also allow us to avoid the open-coded arithmetic on pointers in some situations. Take advantage of this. This code was detected with the help of Coccinelle, and audited and modified manually. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays [1] Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2] Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Erick Archer <erick.archer@outlook.com> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2023-11-14batman-adv: mcast: implement multicast packet reception and forwardingLinus Lüssing
Implement functionality to receive and forward a new TVLV capable multicast packet type. The new batman-adv multicast packet type allows to contain several originator destination addresses within a TVLV. Routers on the way will potentially split the batman-adv multicast packet and adjust its tracker TVLV contents. Routing decisions are still based on the selected BATMAN IV or BATMAN V routing algorithm. So this new batman-adv multicast packet type retains the same loop-free properties. Also a new OGM multicast TVLV flag is introduced to signal to other nodes that we are capable of handling a batman-adv multicast packet and multicast tracker TVLV. And that all of our hard interfaces have an MTU of at least 1280 bytes (IPv6 minimum MTU), as a simple solution for now to avoid MTU issues while forwarding. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2023-01-21batman-adv: tvlv: prepare for tvlv enabled multicast packet typeLinus Lüssing
Prepare TVLV infrastructure for more packet types, in particular the upcoming batman-adv multicast packet type. For that swap the OGM vs. unicast-tvlv packet boolean indicator to an explicit unsigned integer packet type variable. And provide the skb to a call to batadv_tvlv_containers_process(), as later the multicast packet's TVLV handler will need to have access not only to the TVLV but the full skb for forwarding. Forwarding will be invoked from the multicast packet's TVLVs' contents later. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2021-02-06batman-adv: Drop publication years from copyright infoSven Eckelmann
The batman-adv source code was using the year of publication (to net-next) as "last" year for the copyright statement. The whole source code mentioned in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity regarding the publishing year. This avoided having outdated (in sense of year information - not copyright holder) publishing information inside several files. But since the simple "update copyright year" commit (without other changes) in the file was not well received in the upstream kernel, the option to not have a copyright year (for initial and last publication) in the files are chosen instead. More detailed information about the years can still be retrieved from the SCM system. Signed-off-by: Sven Eckelmann <sven@narfation.org> Acked-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2020-06-26batman-adv: Fix typos and grammar in documentationSven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2020-01-01batman-adv: Update copyright years for 2020Sven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-06-27batman-adv: mcast: detect, distribute and maintain multicast router presenceLinus Lüssing
To be able to apply our group aware multicast optimizations to packets with a scope greater than link-local we need to not only keep track of multicast listeners but also multicast routers. With this patch a node detects the presence of multicast routers on its segment by checking if /proc/sys/net/ipv{4,6}/conf/<bat0|br0(bat)>/mc_forwarding is set for one thing. This option is enabled by multicast routing daemons and needed for the kernel's multicast routing tables to receive and route packets. For another thing if a bridge is configured on top of bat0 then the presence of an IPv6 multicast router behind this bridge is currently detected by checking for an IPv6 multicast "All Routers Address" (ff02::2). This should later be replaced by querying the bridge, which performs proper, RFC4286 compliant Multicast Router Discovery (our simplified approach includes more hosts than necessary, most notably not just multicast routers but also unicast ones and is not applicable for IPv4). If no multicast router is detected then this is signalized via the new BATADV_MCAST_WANT_NO_RTR4 and BATADV_MCAST_WANT_NO_RTR6 multicast tvlv flags. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-03-25batman-adv: Drop license boilerplateSven Eckelmann
All files got a SPDX-License-Identifier with commit 7db7d9f369a4 ("batman-adv: Add SPDX license identifier above copyright header"). All the required information about the license conditions can be found in LICENSES/. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-02-09batman-adv: Fix typo "reseved" -> "reserved"Sven Eckelmann
checkpatch.pl complains since commit 45e417022023 ("scripts/spelling.txt: add more spellings to spelling.txt") about an additional spelling mistake in batman-adv:` CHECK: 'reseved' may be misspelled - perhaps 'reserved'? #232: FILE: include/uapi/linux/batadv_packet.h:232: + * @flags: reseved for routing relevant flags - currently always 0 Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-01-04batman-adv: Update copyright years for 2019Sven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2018-02-27batman-adv: always assume 2-byte packet alignmentMatthias Schiffer
NIC drivers generally try to ensure that the "network header" is aligned to a 4-byte boundary. This is not always possible: When Ethernet frames are encapsulated in other packets with 4-byte aligned headers, the inner Ethernet header will have 4-byte alignment, and in consequence, the inner network header is aligned to 2, but not to 4 bytes. Most parts of batman-adv only care about 2-byte alignment; in particular, no unaligned accesses occur in performance-critical paths that handle actual payload data. This is not true for OGM handling: the seqno and crc fields are accessed as 32-bit values. To avoid these unaligned accesses, this patch reduces the expected packet alignment to 2 bytes for all of batadv's packet types. As no unaligned accesses existed on the performance-critical paths anyways, this chance does have any (positive or negative) effect on performance, but it still makes sense to avoid these accesses to prevent log noise when examining other unaligned accesses in the kernel while batman-adv is active. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2018-02-26batman-adv: Update copyright years for 2018Sven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2017-12-21batman-adv: Convert packet.h to uapi headerSven Eckelmann
The header file is used by different userspace programs to inject packets or to decode sniffed packets. It should therefore be available to them as userspace header. Also other components in the kernel (like the flow dissector) require access to the packet definitions to be able to decode ETH_P_BATMAN ethernet packets. Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com> Signed-off-by: David S. Miller <davem@davemloft.net>