lwn.git/net/batman-adv/network-coding.c, branch v5.7-rc6

batman-adv: fix batadv_nc_random_weight_tq

2020-04-21T08:08:04+00:00

and change to pseudorandom numbers, as this is a traffic dithering operation that doesn't need crypto-grade. The previous code operated in 4 steps: 1. Generate a random byte 0 <= rand_tq <= 255 2. Multiply it by BATADV_TQ_MAX_VALUE - tq 3. Divide by 255 (= BATADV_TQ_MAX_VALUE) 4. Return BATADV_TQ_MAX_VALUE - rand_tq This would apperar to scale (BATADV_TQ_MAX_VALUE - tq) by a random value between 0/255 and 255/255. But! The intermediate value between steps 3 and 4 is stored in a u8 variable. So it's truncated, and most of the time, is less than 255, after which the division produces 0. Specifically, if tq is odd, the product is always even, and can never be 255. If tq is even, there's exactly one random byte value that will produce a product byte of 255. Thus, the return value is 255 (511/512 of the time) or 254 (1/512 of the time). If we assume that the truncation is a bug, and the code is meant to scale the input, a simpler way of looking at it is that it's returning a random value between tq and BATADV_TQ_MAX_VALUE, inclusive. Well, we have an optimized function for doing just that. Fixes: 3c12de9a5c75 ("batman-adv: network coding - code and transmit packets if possible") Signed-off-by: George Spelvin Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: Update copyright years for 2020

2019-12-31T23:00:33+00:00

Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: no need to check return value of debugfs_create functions

2019-06-27T17:25:04+00:00

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Because we don't care if debugfs works or not, this trickles back a bit so we can clean things up by making some functions return void instead of an error value that is never going to fail. Cc: Marek Lindner Cc: Simon Wunderlich Cc: Antonio Quartulli Cc: "David S. Miller" Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: netdev@vger.kernel.org Signed-off-by: Greg Kroah-Hartman [sven@narfation.org: drop unused variables] Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: Drop license boilerplate

2019-03-25T08:31:35+00:00

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 Signed-off-by: Simon Wunderlich

batman-adv: Update copyright years for 2019

2019-01-04T10:04:24+00:00

Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: Prevent duplicated nc_node entry

2018-09-06T11:55:58+00:00

The function batadv_nc_get_nc_node is responsible for adding new nc_nodes to the in_coding_list and out_coding_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d56b1705e28c ("batman-adv: network coding - detect coding nodes and remove these after timeout") Signed-off-by: Sven Eckelmann Acked-by: Marek Lindner Signed-off-by: Simon Wunderlich

batman-adv: Update copyright years for 2018

2018-02-26T16:57:39+00:00

Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: Convert packet.h to uapi header

2017-12-21T20:35:53+00:00

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 Signed-off-by: David S. Miller

batman-adv: Use parentheses in function kernel-doc

2017-12-15T16:29:20+00:00

The documentation describing kernel-doc comments for functions ("How to format kernel-doc comments") uses parentheses at the end of the function name. Using this format allows to use a consistent style when adding documentation to a function and when referencing this function in a different kernel-doc section. Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich

batman-adv: Include net.h for net_ratelimited_function

2017-12-15T16:29:17+00:00

The linux/net.h provides the net_ratelimited_function. It should therefore be included directly before it is used. Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich