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KMSAN: uninit-value in batadv_hard_if_event (2)
by syzbot 13 Aug '20

13 Aug '20

Hello, syzbot found the following issue on: HEAD commit: ce8056d1 wip: changed copy_from_user where instrumented git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=106e4c3c900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe005fb99591f dashboard link: https://syzkaller.appspot.com/bug?extid=abbc768b560c84d92fd3 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+abbc768b560c84d92fd3(a)syzkaller.appspotmail.com usb 1-1: config 0 descriptor?? ===================================================== BUG: KMSAN: uninit-value in batadv_check_known_mac_addr net/batman-adv/hard-interface.c:512 [inline] BUG: KMSAN: uninit-value in batadv_hardif_add_interface net/batman-adv/hard-interface.c:944 [inline] BUG: KMSAN: uninit-value in batadv_hard_if_event+0x28d7/0x3bd0 net/batman-adv/hard-interface.c:1034 CPU: 0 PID: 8697 Comm: kworker/0:3 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 batadv_check_known_mac_addr net/batman-adv/hard-interface.c:512 [inline] batadv_hardif_add_interface net/batman-adv/hard-interface.c:944 [inline] batadv_hard_if_event+0x28d7/0x3bd0 net/batman-adv/hard-interface.c:1034 notifier_call_chain kernel/notifier.c:83 [inline] __raw_notifier_call_chain kernel/notifier.c:361 [inline] raw_notifier_call_chain+0x123/0x290 kernel/notifier.c:368 call_netdevice_notifiers_info net/core/dev.c:2027 [inline] call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] register_netdevice+0x3120/0x37d0 net/core/dev.c:9545 register_netdev+0xbe/0x100 net/core/dev.c:9645 rtl8150_probe+0x12d9/0x15b0 drivers/net/usb/rtl8150.c:916 usb_probe_interface+0xece/0x1550 drivers/usb/core/driver.c:374 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_set_configuration+0x380f/0x3f10 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:241 usb_probe_device+0x311/0x490 drivers/usb/core/driver.c:272 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554 hub_port_connect drivers/usb/core/hub.c:5208 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x5e7b/0x8a70 drivers/usb/core/hub.c:5576 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 set_ethernet_addr drivers/net/usb/rtl8150.c:282 [inline] rtl8150_probe+0x1236/0x15b0 drivers/net/usb/rtl8150.c:912 usb_probe_interface+0xece/0x1550 drivers/usb/core/driver.c:374 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_set_configuration+0x380f/0x3f10 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:241 usb_probe_device+0x311/0x490 drivers/usb/core/driver.c:272 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554 hub_port_connect drivers/usb/core/hub.c:5208 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x5e7b/0x8a70 drivers/usb/core/hub.c:5576 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Local variable ----node_id.i@rtl8150_probe created at: get_registers drivers/net/usb/rtl8150.c:911 [inline] set_ethernet_addr drivers/net/usb/rtl8150.c:281 [inline] rtl8150_probe+0xea7/0x15b0 drivers/net/usb/rtl8150.c:912 get_registers drivers/net/usb/rtl8150.c:911 [inline] set_ethernet_addr drivers/net/usb/rtl8150.c:281 [inline] rtl8150_probe+0xea7/0x15b0 drivers/net/usb/rtl8150.c:912 ===================================================== --- 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. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

1 1

Scientific research
by Venceslas Ngounou 05 Aug '20

05 Aug '20

Hi everyone, I went through online documentation on open-mesh.org and I have found many useful information. But there are some information I need. And I will be very glad if you could help me to have it. Please, I will mention few of them: - An up to date documentation on Echo Location Protocol (ELP). On open-mesh.org, the dedicated page has the mention OUTDATED. - An up to date documentation on the different packet types - Scientific papers (if any) related to the design or the modeling of the actuel version of BATMAN-adv. Thanks and Best regards, Venceslas.

1 0

Re: general protection fault in hci_phy_link_complete_evt
by syzbot 05 Aug '20

05 Aug '20

syzbot has bisected this issue to: commit b59abfbed638037f3b51eeb73266892cd2df177f Author: Johannes Berg <johannes.berg(a)intel.com> Date: Thu Sep 15 13:30:03 2016 +0000 mac80211_hwsim: statically initialize hwsim_radios list bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15dd5f98900000 start commit: c0842fbc random32: move the pseudo-random 32-bit definitio.. git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=17dd5f98900000 console output: https://syzkaller.appspot.com/x/log.txt?x=13dd5f98900000 kernel config: https://syzkaller.appspot.com/x/.config?x=cf567e8c7428377e dashboard link: https://syzkaller.appspot.com/bug?extid=18e38290a2a263b31aa0 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17e4e094900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1143e7ca900000 Reported-by: syzbot+18e38290a2a263b31aa0(a)syzkaller.appspotmail.com Fixes: b59abfbed638 ("mac80211_hwsim: statically initialize hwsim_radios list") For information about bisection process see: https://goo.gl/tpsmEJ#bisection

1 0

Re: general protection fault in hci_event_packet
by syzbot 04 Aug '20

04 Aug '20

syzbot has bisected this issue to: commit 941992d2944789641470626e9336d663236b1d28 Author: Javier Martinez Canillas <javier(a)osg.samsung.com> Date: Mon Sep 12 14:03:34 2016 +0000 ethernet: amd: use IS_ENABLED() instead of checking for built-in or module bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=155180c2900000 start commit: bcf87687 Linux 5.8 git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=175180c2900000 console output: https://syzkaller.appspot.com/x/log.txt?x=135180c2900000 kernel config: https://syzkaller.appspot.com/x/.config?x=4b489d75d0c8859d dashboard link: https://syzkaller.appspot.com/bug?extid=0bef568258653cff272f syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1043af04900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12ca1dea900000 Reported-by: syzbot+0bef568258653cff272f(a)syzkaller.appspotmail.com Fixes: 941992d29447 ("ethernet: amd: use IS_ENABLED() instead of checking for built-in or module") For information about bisection process see: https://goo.gl/tpsmEJ#bisection

1 0

Re: KASAN: use-after-free Read in hci_send_acl
by syzbot 04 Aug '20

04 Aug '20

syzbot has bisected this issue to: commit 4ffcd582301bd020b1f9d00c55473af305ec19b5 Author: Michael Chan <michael.chan(a)broadcom.com> Date: Mon Sep 19 07:58:07 2016 +0000 bnxt_en: Pad TX packets below 52 bytes. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=167b0f04900000 start commit: ac3a0c84 Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=157b0f04900000 console output: https://syzkaller.appspot.com/x/log.txt?x=117b0f04900000 kernel config: https://syzkaller.appspot.com/x/.config?x=c0cfcf935bcc94d2 dashboard link: https://syzkaller.appspot.com/bug?extid=98228e7407314d2d4ba2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=152f1904900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1482dfca900000 Reported-by: syzbot+98228e7407314d2d4ba2(a)syzkaller.appspotmail.com Fixes: 4ffcd582301b ("bnxt_en: Pad TX packets below 52 bytes.") For information about bisection process see: https://goo.gl/tpsmEJ#bisection

1 0

[PATCH] batman-adv: Drop repeated words in comments
by Sven Eckelmann 31 Jul '20

31 Jul '20

checkpatch found various instances of "Possible repeated word" in various comments. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/bridge_loop_avoidance.c | 2 +- net/batman-adv/fragmentation.c | 2 +- net/batman-adv/hard-interface.c | 2 +- net/batman-adv/multicast.c | 2 +- net/batman-adv/network-coding.c | 2 +- net/batman-adv/send.c | 2 +- net/batman-adv/soft-interface.c | 4 ++-- 7 files changed, 8 insertions(+), 8 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 91a04ca3..5c41cc52 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1795,7 +1795,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, ret = queue_work(batadv_event_workqueue, &backbone_gw->report_work); - /* backbone_gw is unreferenced in the report work function function + /* backbone_gw is unreferenced in the report work function * if queue_work() call was successful */ if (!ret) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 9fdbe306..9a47ef8b 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -306,7 +306,7 @@ batadv_frag_merge_packets(struct hlist_head *chain) * set *skb to merged packet; 2) Packet is buffered: Return true and set *skb * to NULL; 3) Error: Return false and free skb. * - * Return: true when the packet is merged or buffered, false when skb is not not + * Return: true when the packet is merged or buffered, false when skb is not * used. */ bool batadv_frag_skb_buffer(struct sk_buff **skb, diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index fa06b51c..715f169c 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -599,7 +599,7 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) /* report to the other components the maximum amount of bytes that * batman-adv can send over the wire (without considering the payload * overhead). For example, this value is used by TT to compute the - * maximum local table table size + * maximum local table size */ atomic_set(&bat_priv->packet_size_max, min_mtu); diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index bdc4a1fb..1622c3f5 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -207,7 +207,7 @@ static u8 batadv_mcast_mla_rtr_flags_bridge_get(struct batadv_priv *bat_priv, return BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6; /* TODO: ask the bridge if a multicast router is present (the bridge - * is capable of performing proper RFC4286 multicast multicast router + * is capable of performing proper RFC4286 multicast router * discovery) instead of searching for a ff02::2 listener here */ ret = br_multicast_list_adjacent(dev, &bridge_mcast_list); diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 48d70785..64619b7a 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -250,7 +250,7 @@ static void batadv_nc_path_put(struct batadv_nc_path *nc_path) /** * batadv_nc_packet_free() - frees nc packet * @nc_packet: the nc packet to free - * @dropped: whether the packet is freed because is is dropped + * @dropped: whether the packet is freed because is dropped */ static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet, bool dropped) diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index d267b948..87017332 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -461,7 +461,7 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, /** * batadv_forw_packet_free() - free a forwarding packet * @forw_packet: The packet to free - * @dropped: whether the packet is freed because is is dropped + * @dropped: whether the packet is freed because is dropped * * This frees a forwarding packet and releases any resources it might * have claimed. diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 23833a0b..9d3974ba 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -649,7 +649,7 @@ static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv, /** * batadv_interface_add_vid() - ndo_add_vid API implementation * @dev: the netdev of the mesh interface - * @proto: protocol of the the vlan id + * @proto: protocol of the vlan id * @vid: identifier of the new vlan * * Set up all the internal structures for handling the new vlan on top of the @@ -707,7 +707,7 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto, /** * batadv_interface_kill_vid() - ndo_kill_vid API implementation * @dev: the netdev of the mesh interface - * @proto: protocol of the the vlan id + * @proto: protocol of the vlan id * @vid: identifier of the deleted vlan * * Destroy all the internal structures used to handle the vlan identified by vid -- 2.20.1

1 0

[PATCH] batman-adv: Fix own OGM check in aggregated OGMs
by Linus Lüssing 30 Jul '20

30 Jul '20

The own OGM check is currently misplaced and can lead to the following issues: For one thing we might receive an aggregated OGM from a neighbor node which has our own OGM in the first place. We would then not only skip our own OGM but erroneously also any other, following OGM in the aggregate. For another, we might receive an OGM aggregate which has our own OGM in a place other then the first one. Then we would wrongly not skip this OGM, leading to populating the orginator and gateway table with ourself. The latter seems to not only be a cosmetic issue, but there were reports that this causes issues with various subsystems of batman-adv, too. For instance there were reports about issues with DAT and either disabling DAT or aggregation seemed to solve it. Fixing these issues by applying the own OGM check not on the first OGM in an aggregate but for each OGM in an aggregate instead. Fixes: 667996ebeab ("batman-adv: OGMv2 - implement originators logic") Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- net/batman-adv/bat_v_ogm.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 0f8495b9..717fe657 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -881,6 +881,12 @@ static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, ogm_packet->version, ntohs(ogm_packet->tvlv_len)); + if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: originator packet from ourself\n"); + return; + } + /* If the throughput metric is 0, immediately drop the packet. No need * to create orig_node / neigh_node for an unusable route. */ @@ -1008,11 +1014,6 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) goto free_skb; - ogm_packet = (struct batadv_ogm2_packet *)skb->data; - - if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) - goto free_skb; - batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, skb->len + ETH_HLEN); -- 2.28.0.rc1

1 0

batadv gw_mode client 0?
by Rob Cowart 28 Jul '20

28 Jul '20

Hi, We've been using batman with alfred and MQTT on raspbian for about 3 years. We found it to be useful up to about 15 nodes, and then we'd saturate the wifi. Then we downgraded the driver and we can get slightly over 30. but something we found was all of our nodes were using gw_mode client 0, and we realized this isn't listed in the spec. Do you know what it does in that case, does it use the default of 20? Thanks, Rov

3 8

Batman_V Originator Loop Issue
by lavincent15＠gmail.com 27 Jul '20

27 Jul '20

Running batctl 2020.1-openwrt-1 [batman-adv: 2020.1-openwrt-2] When running a two node network with one node connected to my lan and the other operating as an access point, my network works great. I can connect clients to my batman nodes and access my LAN. When booting up a third node. My network works for 1 minute, then breaks down. My LAN cannot ping any of the batman nodes anymore. I keep receiving messages like this: "[ 2900.755655] br-lan: received packet on bat0 with own address as source address (addr:8c:ae:4c:db:14:5c, vlan:0)" which signifies a bridge loop I think. My originator messages look wrong as I can see my host originator messages along with all the neigbor nodes: root@OpenWrt:/etc/config# batctl o -n [B.A.T.M.A.N. adv 2020.1-openwrt-2, MainIF/MAC: mesh0/00:30:1a:4e:b8:26 (bat0/f2:07:f1:5f:e0:78 BATMAN_V)] Originator last-seen ( throughput) Nexthop [outgoingIF] * 00:30:1a:4e:b8:18 0.570s ( 86.7) 00:30:1a:4e:b8:2e [ mesh0] 00:30:1a:4e:b8:18 0.570s ( 21.6) 00:30:1a:4e:b8:18 [ mesh0] * 00:30:1a:4e:b8:2e 1.510s ( 212.6) 00:30:1a:4e:b8:2e [ mesh0] 00:30:1a:4e:b8:2e 1.510s ( 38.9) 00:30:1a:4e:b8:18 [ mesh0] 00:30:1a:4e:b8:26 1.510s ( 38.9) 00:30:1a:4e:b8:18 [ mesh0] * 00:30:1a:4e:b8:26 1.510s ( 108.9) 00:30:1a:4e:b8:2e [ mesh0] root@OpenWrt:/etc/config# batctl n -n [B.A.T.M.A.N. adv 2020.1-openwrt-2, MainIF/MAC: mesh0/00:30:1a:4e:b8:26 (bat0/f2:07:f1:5f:e0:78 BATMAN_V)] IF Neighbor last-seen 00:30:1a:4e:b8:2e 0.490s ( 179.0) [ mesh0] 00:30:1a:4e:b8:18 0.380s ( 79.2) [ mesh0] Here is my /etc/config/network: config interface 'loopback' option ifname 'lo' option proto 'static' option ipaddr '127.0.0.1' option netmask '255.0.0.0' config globals 'globals' option ula_prefix 'fdc4:e092:8929::/48' config interface 'lan' option type 'bridge' option proto 'static' option ipaddr '192.168.0.32' option netmask '255.255.255.0' option ip6assign '60' option gateway '192.168.0.1' list dns '8.8.8.8' option ifname 'bat0 eth0' config interface 'nwi_mesh0' option mtu '2304' option proto 'batadv_hardif' option master 'bat0' config interface 'bat0' option proto 'batadv' option routing_algo 'BATMAN_V' option aggregated_ogms '1' option ap_isolation '0' option bonding '0' option fragmentation '1' option gw_mode 'server' option log_level '0' option orig_interval '1000' option bridge_loop_avoidance '1' option distributed_arp_table '1' option multicast_mode '1' option network_coding '0' option hop_penalty '30' option isolation_mark '0x00000000/0x00000000' And here is my /etc/config/wireless root@OpenWrt:/etc/config# cat wireless config wifi-device 'radio0' option type 'mac80211' option channel '36' option hwmode '11a' option path 'soc0/soc/1ffc000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0' option htmode 'VHT80' config wifi-iface 'mesh0' option device 'radio0' option ifname 'mesh0' option network 'nwi_mesh0' option mode 'mesh' option mesh_fwding '0' option mesh_id 'batman_mesh' option encryption 'none' config wifi-iface 'wifinet0' option device 'radio0' option mode 'ap' option ssid 'N2-Lander' option encryption 'psk2' option key 'finnjamin' option ifname 'wlan0' option network 'lan' Any and all help is greatly appreciated

3 9

Delay starting TCP connections across the mesh
by John Sager 27 Jul '20

27 Jul '20

I'm experimenting with a mesh network in the house. It has 4 nodes running batman_adv (BATMAN_IV) on stock OpenWrt 19.07.3 (i.e batman-adv-2019.2) on TP-Link WR902AC devices. The nodes mesh on 'mesh point' links on 2.4GHz and one node connects to the home wired network. In the scenario, I have a laptop connected to the AP on one of the mesh nodes (not the gateway). I make a ssh connection from this to a host on the wired network. There is a consistent delay of about 8 seconds before the 'password' prompt comes back from the remote host. I rebuilt OpenWrt 19.07.3 for that device, and ticked all the debug options for batman-adv. Running tcpdump on both soft and hard interfaces, and trace-cmd to capture the debug info, I find the following: The DNS request and response for the remote host name, and the consequent ARP request and response go through within milliseconds. However the TCP SYN is received by the bat0 interface but is not forwarded on the mesh0 interface. SYN re-sends after 1 sec, then 2 sec are not forwarded either. Only the 3rd re-send (after another 4 sec) gets forwarded and then the ssh session proceeds normally. Looking at the code, and after adding extra batadv_dbg() calls, I discover that the 'orig_node' returned by 'batadv_transtable_search()' on the dest address is NULL so the SYN gets thrown away by 'batadv_send_skb_unicast()'. It is only after receiving an OGM message with a TT update for the remote host MAC from the gateway node that the local translation table gets populated with the remote host's MAC. I should say that I've set the 'orig_interval' to 3000 to reduce batman traffic, so that probably has an effect on the delay. I do wonder why the ARP response is not used to populate the translation table immediately, as an ARP response is always going to be followed immediately by returning IP packets. The ARPs are snooped for the distributed ARP table anyway so why not use that information for the translation table too? regards, John Sager

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