B.A.T.M.A.N October 2023

b.a.t.m.a.n@lists.open-mesh.org

8 participants
7 discussions

[PATCH v7 0/3] Implementation of a Stateless Multicast Packet Type
by Linus Lüssing 15 Nov '23

15 Nov '23

In-Reply-To: Hi, The following patchset implements a stateless, TVLV capable batman-adv multicast packet type. The new batman-adv multicast packet type allows to contain several originator destination MAC 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. The purpose of this new packet type is to allow to forward an IP multicast packet with less transmissions / overhead than the multicast-via-multiple-unicasts approach. Or to reach a lot more destinations (currently up to 196, depending on the payload size, see Wiki documentation for details) than with the default multicast fanout for the via-unicasts approach. This will allow using applications like mDNS again in several Freifunk communities. And with less transmissions will also make more bulky multicast applications, like media streaming (to an assessable amount of receivers) a lot more feasible. This approach is way simpler than the original multicast (tracker) packet approach we envisioned years ago. As it involves no maintenance of an extra, state based multicast routing table. However the TVLV capability should allow to extend things later, to split control and data plane a bit more for instance, to further increase the number of destinations, to further reduce overhead. A compact overview can be found in the Wiki here, including limitations: https://www.open-mesh.org/projects/batman-adv/wiki/Multicast-Packet-Type Regards, Linus --- Changelog v7: * PATCH 1/3: * rebased to current main/master branch (resolved net/multicast/routing.h) * renamed batadv_mcast_forw_orig_to_neigh() to batadv_orig_to_router() and moved it to originator.c, for reuse in fragmentation.c * added a SKB_LINEAR_ASSERT() to batadv_mcast_forw_packet() * adjusted batadv_mcast_forw_scrub_dests(): added a new macro that updates two dest pointers to avoid confusion due to two different updating methods, removed goto's and a little reordering * PATCH 2/3: * added SKB_LINEAR_ASSERT() to batadv_mcast_forw_scrape() * PATCH 3/3: * simplified batadv_mcast_forw_shrink_pack_dests(): moved parts to new sub function batadv_mcast_forw_shrink_fill(), removed keeping track of filler over the whole function (might be slower, as we might check+skip the same zero MAC entry multiple times, for each slot, but a lot easier to read - and we don't prioritize performance with this patchset yet) Changelog v6: * PATCH 2/3: * add missing include of linux/compiler.h for the newly added likely() in v5 * added kerneldoc for @num_dests_pushed to the in v5 newly added batadv_mcast_forw_push_adjust_padding() * updated kerneldoc of batadv_mcast_forw_push_adjust_padding(), original text was wrongly copy & pasted from batadv_mcast_forw_push_est_padding() without adjustments * PATCH 3/3: * added missing "static" attribute to the newly added batadv_mcast_forw_shrink_align_offset() in v5 Changelog v5: * removed patches 1/5 + 2/5, as they were already applied * rebased to current main branch * changed padding behaviour: * now 2 bytes padding on the end of the multicast tracker TVLV, if number of destination nodes is even * as number of destination nodes might change between initial check until after pushing them, functions to post-adjust padding after pushing were added * added/fixed TTL handling * removed skb_pull() bailing from sub-functions of batadv_mcast_forw_push(), to only have a single skb_pull() to keep track of in batadv_mcast_forw_push() to revert the changes to the skb; instead a "unsigned short *tvlv_len" is passsed along in batadv_mcast_.*push.*() functions to keep track of how many bytes were pushed * moved + verified skb->ip_summed invalidation * batadv_mcast_forw_shrink_tracker() xmas tree ordering * reword batadv_mcast_forw_push_dest() "Return:" kerneldoc * fixed spelling: outter -> outer Changelog v4: * PATCH 4/5: * add missing include for linux/types.h in multicast.h * add missing kerneldoc for @bat_priv in batadv_mcast_forw_push_dest() and batadv_mcast_forw_push_tvlvs() * use sizeof_field(type, field) instead of sizeof(((type *)0)->field) in batadv_mcast_forw_push_dest() * PATCH 5/5: * rename num_dests_remove to num_dests_reduce in batadv_mcast_forw_shrink_align_offse() to fix kerneldocs and for consistency * fix typo in kerneldoc in batadv_mcast_forw_shrink_update_headers() -> @num_dest_reduce -> @num_dests_reduce * use sizeof_field(type, field) instead of sizeof(((type *)0)->field) in batadv_mcast_forw_shrink_align_offset() Changelog v3: * PATCH 1/5: * remove now obsolete includes * PATCH 2/5: * fix batadv_tvlv_handler_register() in network-coding.c * add missing include for linux/skbuff.h * move variable declarations out of the switch case in batadv_tvlv_call_handler() * PATCH 3/5: * remove unnecessary include of multicast.h in routing.c * add a few missing includes to multicast_forw.c (linux/byteorder/generic.h, linux/errno.h, linux/gfp.h, linux/stddef.h uapi/linux/batadv_packet.h, multicast.h) * PATCH 4/5: * add missing rcu_read_unlock() in error case before returning in batadv_mcast_forw_push_dests_list() * remove unnecessary include of soft-interface.h in multicast_forw.c * add a few missing includes to multicast_forw.c (linux/bug.h, linux/build_bug.h, linux/limits.h, linux/rculist.h, linux/rcupdate.h, linux/string.h) * make batadv_mcast_forw_mode_by_count() static * fix return types in the declaration of batadv_mcast_forw_packet_hdrlen() and batadv_mcast_forw_push() in multicast.h * fix typo in commit message: "that the are capable of" -> "that the*y* are capable of" * PATCH 5/5: * make batadv_mcast_forw_shrink_pack_dests() adhere to 80 characters per line for consistency * add a "continue" statement after the jump label in batadv_mcast_forw_shrink_pack_dests() to silence the sparse error "error: label at end of compound statement" Changelog v2: * Add "[PATCH v2 0/5]" prefix to title of cover letter, so that Patchwork can hopefully find it - no other changes

3 6

[PATCH v2] batman-adv: Switch to linux/sprintf.h
by Sven Eckelmann 30 Oct '23

30 Oct '23

The commit 39ced19b9e60 ("lib/vsprintf: split out sprintf() and friends") introduced a new header for the sprintf related functions which were previously exposed via linux/kernel.h. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- Changes in v2: - version for out-of-tree kernel with compat header - Link to v1: https://lore.kernel.org/r/20231030-sprintf_header-v1-1-2730d63953de@narfati… --- compat-include/linux/sprintf.h | 20 ++++++++++++++++++++ net/batman-adv/bridge_loop_avoidance.c | 2 +- net/batman-adv/gateway_client.c | 2 +- net/batman-adv/main.c | 1 + net/batman-adv/multicast.c | 2 +- 5 files changed, 24 insertions(+), 3 deletions(-) diff --git a/compat-include/linux/sprintf.h b/compat-include/linux/sprintf.h new file mode 100644 index 00000000..d3823277 --- /dev/null +++ b/compat-include/linux/sprintf.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors: + * + * Marek Lindner, Simon Wunderlich + * + * This file contains macros for maintaining compatibility with older versions + * of the Linux kernel. + */ + +#ifndef _NET_BATMAN_ADV_COMPAT_LINUX_SPRINTF_H_ +#define _NET_BATMAN_ADV_COMPAT_LINUX_SPRINTF_H_ + +#include <linux/version.h> +#if LINUX_VERSION_IS_GEQ(6, 6, 0) +#include_next <linux/sprintf.h> +#else +#include <linux/kernel.h> +#endif + +#endif /* _NET_BATMAN_ADV_COMPAT_LINUX_SPRINTF_H_ */ diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 37ce6cfb..5f46ca3d 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -20,7 +20,6 @@ #include <linux/if_vlan.h> #include <linux/jhash.h> #include <linux/jiffies.h> -#include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> @@ -31,6 +30,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/workqueue.h> diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index d26124bc..0ddd8b4b 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -18,7 +18,6 @@ #include <linux/in.h> #include <linux/ip.h> #include <linux/ipv6.h> -#include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> @@ -29,6 +28,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/udp.h> #include <net/sock.h> diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index e8a44991..928c78a5 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -33,6 +33,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/workqueue.h> diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 27511a06..7686caef 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -25,7 +25,6 @@ #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/jiffies.h> -#include <linux/kernel.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/netdevice.h> @@ -36,6 +35,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/types.h> --- base-commit: 5fecd4a389cea1b9719e9ec480d7257887e0dfdf change-id: 20231030-sprintf_header-47d656369468 Best regards, -- Sven Eckelmann <sven(a)narfation.org>

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[PATCH] batman-adv: Switch to linux/sprintf.h
by Sven Eckelmann 30 Oct '23

30 Oct '23

The commit 39ced19b9e60 ("lib/vsprintf: split out sprintf() and friends") introduced a new header for the sprintf related functions which were previously exposed via linux/kernel.h. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/bridge_loop_avoidance.c | 2 +- net/batman-adv/gateway_client.c | 2 +- net/batman-adv/main.c | 1 + net/batman-adv/multicast.c | 2 +- 4 files changed, 4 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 37ce6cfb..5f46ca3d 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -20,7 +20,6 @@ #include <linux/if_vlan.h> #include <linux/jhash.h> #include <linux/jiffies.h> -#include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> @@ -31,6 +30,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/workqueue.h> diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index d26124bc..0ddd8b4b 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -18,7 +18,6 @@ #include <linux/in.h> #include <linux/ip.h> #include <linux/ipv6.h> -#include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> @@ -29,6 +28,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/udp.h> #include <net/sock.h> diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index e8a44991..928c78a5 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -33,6 +33,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/workqueue.h> diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 27511a06..7686caef 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -25,7 +25,6 @@ #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/jiffies.h> -#include <linux/kernel.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/netdevice.h> @@ -36,6 +35,7 @@ #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/types.h> --- base-commit: 5fecd4a389cea1b9719e9ec480d7257887e0dfdf change-id: 20231030-sprintf_header-47d656369468 Best regards, -- Sven Eckelmann <sven(a)narfation.org>

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[PATCH RFC 0/2] Better throughput estimation on half duplex interfaces
by Remi Pommarel 18 Oct '23

18 Oct '23

Currently BATMAN_V path throughput computation algorithm takes into account store & forward WiFi characteristics. When an originator forwards an OGM on the same interface it received it, the path throughput is divided by two. Let's consider the topology below +-------+ +-------+ +-------+ | Orig0 | <------ | Orig1 | <------ | Orig2 | +-------+ T01 +-------+ T12 +-------+ Where Orig0's OGM is received on same WiFi (non full duplex) interface as the one used to forward it to Orig2. And where T01 is the estimated throughput for link between Orig0 and Orig1 and T12 is the one between Orig1 and Orig2. Let's note PT02 the B.A.T.M.A.N-Adv estimated throughput for the end-to-end path between Orig2 and Orig0. In this case Orig0 broadcasts its own OGM initialized with BATADV_THROUGHPUT_MAX_VALUE. Orig1 receives it and compares it with the estimated link throughput T01. Thus Orig1 considers the path to reach Orig0 has an end-to-end throughput of T01, so far so good. Then Orig1 first adapts the Orig0 OGM throughput to T01/2 then forwards it on same interface it received it. Orig2 receives it and first thing Orig2 does is checking if T12 is lower than the received OGM throughput (i.e. T01/2), and if that is the case T12 is considered to be the new end-to-end path throughput. The first issue I see here is that Orig2 does not know the path to reach Orig0 has to get half duplex penalty because it is forwarded on same WiFi interface on Orig1, only Orig1 knows that. Thus if T12 is lower that T01/2, T12 will be chosen as the Orig2 to Orig0 path throughput (i.e PT02) and the half duplex penalty is lost. The first patch of this series aims to fix that by adding a flag in OGM packets to inform Orig2 the path to reach Orig0 shares the same half duplex interface and that it has to apply the dividing by two penalty on its link throughput. The other thing I think can be improved, is this dividing by 2 penalty. This penalty seems a bit off the expected estimation most of the time. The way I approach this half duplex penalty is by trying to compute the maximum number of bytes that can go from Orig0 to Orig2 passing through Orig1 in one second. And because of half duplex characteristic of WiFi you can't transfer bytes from Orig0 to Orig1 and Orig1 to Orig2 simultaneously. So at the end it comes down to finding the maximum number of bytes (x) that can go from Orig0 to Orig1 and then from Orig1 to reach Orig2 within one second as below: x / T01 + x / T12 = TotalTripTime With x/T01 and x/T12 being the time x bytes takes to go from Orig0 to Orig1 and Orig1 to Orig2 respectfully. So by solving the above for x with TotalTripTime being 1second: x = T01 * T12 / (T01 + T12) Thus if T01 == T12 Orig1 takes the same time to receive bytes from Orig2 than to forward them to Orig1 then dividing by two makes sense. But if let says Orig1 forwards data to Orig0 twice as fast as it receives it from Orig2 (e.g. T12 = 3MB/s and T01 = 6MB/s), throughput can reach up to two third of T12 throughput (e.g. Orig2 sends 2 MB to Orig1 taking 2/3 of a second which is then forward to Orig0 taking the remaining 1/3 of a second reaching an overall throughput of 2MB/s). Reasoning by recurrence the following formula can be applied to find estimated path throughput for any half duplex chain between OrigX to OrigY through OrigZ: PTzx = PTyx * Tzy / (PTyx + Tzy) Where PTzx and PTyx are estimated throughput for end-to-end path between OrigZ and OrigX, and OrigY and OrigX respectively. And where Tzy is the estimated throughput for link between OrigZ and OrigY. The second patch from this series moves from the divided by two forward penalty to the one above. Remi Pommarel (2): batman-adv: Keep half duplex penalty on OGM receiving side also batman-adv: Better half duplex penalty estimation include/uapi/linux/batadv_packet.h | 8 ++++++ net/batman-adv/bat_v_ogm.c | 44 ++++++++++++++++++++++++++---- net/batman-adv/types.h | 3 ++ 3 files changed, 49 insertions(+), 6 deletions(-) -- 2.40.0

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Re: Inquiry about Communication Issue between Nodes in "ONLY two nodes mesh network" with batman-adv
by Simon Wunderlich 16 Oct '23

16 Oct '23

On Monday, October 16, 2023 4:12:41 PM CEST XU Yang wrote: > Dear maintainer, > > I am a developer currently using the batman-adv library in research and have > encountered some issues that I hope you might be able to assist with. > In setting up a mesh network using batman-adv, I've noticed that when only > two nodes are present in the network, they are unable to communicate with > each other. However, once a third node is introduced, all nodes can > communicate normally. Further testing has revealed that even with two > nodes, despite good ad-hoc wifi connection quality, the nodes remain > invisible to each other. > Here are the system and configuration details: > > Hardware: Jetson Orin NX with rtl8822ce > Operating System: L4T r35.3.1 Ubuntu20.04 > batman-adv version: 2023.2-9-g5fecd4a3 > > The configuration code we use is in the attachment. > > > I appreciate your time in reading this email and look forward to your > response. I hope you might be able to help me understand the cause of this > issue and suggest possible methods to resolve it. Hi Young Xu, this sounds like a underlying Wi-Fi driver issue. You may want to set up IP addresses on the base Wi-Fi interfaces (e.g. wlan0) and try to ping between the nodes directly, without batman-adv. You may also check further with "iw wlan0 station dump" (or similar) who receives packets by whom, or check with tcpdump if you see the OGM broadcasts. I haven't seen many Realtek Wi-Fi devices to use batman-adv, and at least in the past my experience with those devices not very positive, so also for that reason I'd look into driver related issues first. Cheers, Simon

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Re: [syzbot] [batman?] INFO: rcu detected stall in rtnl_newlink (3)
by syzbot 14 Oct '23

14 Oct '23

syzbot suspects this issue was fixed by commit: commit e739718444f7bf2fa3d70d101761ad83056ca628 Author: Kuniyuki Iwashima <kuniyu(a)amazon.com> Date: Sat Jul 29 00:07:05 2023 +0000 net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15b26a4d680000 start commit: d528014517f2 Revert ".gitignore: ignore *.cover and *.mbx" git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=d576750da57ebbb5 dashboard link: https://syzkaller.appspot.com/bug?extid=afb3084a933aa2bdacc6 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15849d08a80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13184990a80000 If the result looks correct, please mark the issue as fixed by replying with: #syz fix: net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX. For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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[syzbot] Monthly batman report (Oct 2023)
by syzbot 09 Oct '23

09 Oct '23

Hello batman maintainers/developers, This is a 31-day syzbot report for the batman subsystem. All related reports/information can be found at: https://syzkaller.appspot.com/upstream/s/batman During the period, 0 new issues were detected and 0 were fixed. In total, 7 issues are still open and 22 have been fixed so far. Some of the still happening issues: Ref Crashes Repro Title <1> 167 Yes INFO: rcu detected stall in batadv_nc_worker (3) https://syzkaller.appspot.com/bug?extid=69904c3b4a09e8fa2e1b <2> 150 No KMSAN: uninit-value in bpf_prog_run_generic_xdp https://syzkaller.appspot.com/bug?extid=0e6ddb1ef80986bdfe64 <3> 2 Yes memory leak in skb_clone (2) https://syzkaller.appspot.com/bug?extid=92f9b5fba2df252a3569 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller(a)googlegroups.com. To disable reminders for individual bugs, reply with the following command: #syz set <Ref> no-reminders To change bug's subsystems, reply with: #syz set <Ref> subsystems: new-subsystem You may send multiple commands in a single email message.

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B.A.T.M.A.N October 2023