B.A.T.M.A.N February 2017

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

12 participants
28 discussions

Re: [B.A.T.M.A.N.] Node freezes but still alive
by Derick Roman De Leon Leal 24 Feb '17

24 Feb '17

Thanks for the quick reply Linus, No transmission on IPv4, haven't tried on IPv6 but I assume is going to be the same. Luan Jinlu suggested that I should use a bssid that starts with 02. Is this a requirement for the mesh to work? Should I share a batman-adv log? which packet type should be more useful? Thanks a lot for your kind help!! Best Regards, Derick > ---------- Forwarded message ---------- > From: "Linus Lüssing" <linus.luessing(a)c0d3.blue> > To: The list for a Better Approach To Mobile Ad-hoc Networking <b.a.t.m.a.n(a)lists.open-mesh.org> > Cc: > Bcc: > Date: Fri, 24 Feb 2017 09:28:11 +0100 > Subject: Re: [B.A.T.M.A.N.] Node freezes but still alive > Hi Derick, > > On Thu, Feb 23, 2017 at 05:37:55PM -0600, Derick Roman De Leon Leal wrote: > > I have a little setup with two nodes and one gateway, from time to > > time one of the nodes just stops transmitting data. > > Very odd indeed. Can you check whether transmitting IPv4 or > IPv6 packets on adhoc0 directly still works when this happens? > > Cheers, Linus > > > _______________________________________________ > B.A.T.M.A.N mailing list > B.A.T.M.A.N(a)lists.open-mesh.org > https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n >

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[B.A.T.M.A.N.] Node freezes but still alive
by Derick Roman De Leon Leal 24 Feb '17

24 Feb '17

First of all, thanks in advance for this fantastic mesh protocol. I am kind of new at this so any advice is welcome. I have a little setup with two nodes and one gateway, from time to time one of the nodes just stops transmitting data. I see the node on the originators list but the TQ never changes unlike when its working OK that the TQ changes a bit during the day. The thing is that the node is there, since the last-seen time is updating every few seconds just like when is working normal. I have tried changing my batman configuration with no positive results. Also, I have changed the nodes and this is still happening. This happens and resolves itself in a couple of hours, but it does not happen in other setups I have with more nodes. I tried to search the internet for this issue with zero luck. The three devices are OM2P-HS v3 running Openwrt r49395 with batman-adv 2016.2 using BATMAN IV. Have you guys have encountered this problem before? Is my configuration wrong in any way? Do you have any recommendations for me? Below is the configuration I am using, hope this helps. Please let me know if there is any more information I can make available to you to help me solve this problem. Thanks a lot for taking the time to read all this. I appreciate any comments and feedback you can give. Kind Regards, Derick Nodes Configuration: ----------------------------------------------------- batman-adv +++++++++++++++++++++ config 'mesh' 'bat0' option 'interfaces' 'mesh' option 'aggregated_ogms' option 'ap_isolation' '1' option 'bonding' option 'fragmentation' '1' option 'gw_bandwidth' option 'gw_mode' 'client' option 'gw_sel_class' option 'log_level' option 'orig_interval' option 'vis_mode' option 'bridge_loop_avoidance' '1' option 'distributed_arp_table' option 'multicast_mode' option 'network_coding' option 'hop_penalty' option 'isolation_mark' wireless +++++++++++++++++++++++++++ config wifi-device radio0 option type mac80211 option channel 6 option hwmode 11g option path 'platform/ar934x_wmac' option htmode HT20 option country MX config wifi-iface wlan0 option ifname wlan0 option device radio0 option network lan option mode sta option encryption none option disabled 0 config wifi-iface mesh0 option device radio0 option ifname adhoc0 option network mesh option mode adhoc option ssid MY-SSID111 option bssid CA:FE:CA:FE:CA:FE 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 'fdaa:8902:bcc0::/48' config interface 'lan' option ifname 'eth0 bat0' option force_link '1' option type 'bridge' option proto 'dhcp' list dns 8.8.8.8 list dns 8.8.4.4 option peerdns 0 config interface 'wan' option ifname 'eth1' option proto 'dhcp' config interface 'wan6' option ifname 'eth1' option proto 'dhcpv6' config interface 'mesh' option proto 'batadv' option mtu '1528' option mesh 'bat0' Gateway configuration ------------------------------------------------------------- everything is the same as in the nodes configuration but batman-adv file. config 'mesh' 'bat0' option 'interfaces' 'mesh' option 'aggregated_ogms' option 'ap_isolation' '1' option 'bonding' option 'fragmentation' '1' option 'gw_bandwidth' option 'gw_mode' 'server' option 'gw_sel_class' option 'log_level' option 'orig_interval' option 'vis_mode' option 'bridge_loop_avoidance' '1' option 'distributed_arp_table' option 'multicast_mode' option 'network_coding' option 'hop_penalty' option 'isolation_mark'

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[B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: Fix double free during fragment merge error
by Sven Eckelmann 21 Feb '17

21 Feb '17

The function batadv_frag_skb_buffer was supposed not to consume the skbuff on errors. This was followed in the helper function batadv_frag_insert_packet when the skb would potentially be inserted in the fragment queue. But it could happen that the next helper function batadv_frag_merge_packets would try to merge the fragments and fail. This results in a kfree_skb of all the enqueued fragments (including the just inserted one). batadv_recv_frag_packet would detect the error in batadv_frag_skb_buffer and try to free the skb again. The behavior of batadv_frag_skb_buffer (and its helper batadv_frag_insert_packet) must therefore be changed to always consume the skbuff to have a common behavior and avoid the double kfree_skb. Fixes: 9b3eab61754d ("batman-adv: Receive fragmented packets and merge") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- Cc: Martin Hundebøll <martin(a)hundeboll.net> net/batman-adv/fragmentation.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index ead18ca8..7b523e6c 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -239,8 +239,10 @@ err_unlock: spin_unlock_bh(&chain->lock); err: - if (!ret) + if (!ret) { kfree(frag_entry_new); + kfree_skb(skb); + } return ret; } @@ -313,7 +315,7 @@ free: * * There are three possible outcomes: 1) Packet is merged: Return true and * set *skb to merged packet; 2) Packet is buffered: Return true and set *skb - * to NULL; 3) Error: Return false and leave skb as is. + * to NULL; 3) Error: Return false and free skb. * * Return: true when packet is merged or buffered, false when skb is not not * used. @@ -338,9 +340,9 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb, goto out_err; out: - *skb = skb_out; ret = true; out_err: + *skb = skb_out; return ret; } -- 2.11.0

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[B.A.T.M.A.N.] [PATCH maint] batman-adv: Fix transmission of final, 16th fragment
by Linus Lüssing 21 Feb '17

21 Feb '17

Trying to split and transmit a unicast packet in 16 parts will fail for the final fragment: After having sent the 15th one with a frag_packet.no index of 14, we will increase the the index to 15 - and return with an error code immediately, even though one more fragment is due for transmission and allowed. Fixing this issue by moving the check before incrementing the index. While at it, adding an unlikely(), because the check is actually more of an assertion. Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Compile time tested only --- net/batman-adv/fragmentation.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 0854ebd..f181868 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -499,6 +499,12 @@ int batadv_frag_send_packet(struct sk_buff *skb, /* Eat and send fragments from the tail of skb */ while (skb->len > max_fragment_size) { + /* The initial check in this function should cover this case */ + if (unlikely(frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1)) { + ret = -EINVAL; + goto put_primary_if; + } + skb_fragment = batadv_frag_create(skb, &frag_header, mtu); if (!skb_fragment) { ret = -ENOMEM; @@ -515,12 +521,6 @@ int batadv_frag_send_packet(struct sk_buff *skb, } frag_header.no++; - - /* The initial check in this function should cover this case */ - if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) { - ret = -EINVAL; - goto put_primary_if; - } } /* Make room for the fragment header. */ -- 2.1.4

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[B.A.T.M.A.N.] [PATCH] batman-adv: set git diff driver for C source code files
by Sven Eckelmann 21 Feb '17

21 Feb '17

From: Jean Delvare <jdelvare(a)suse.de> Git can be told to apply language-specific rules when generating diffs. Enable this for C source code files (*.c and *.h) so that function names are printed right. Specifically, doing so prevents "git diff" from mistakenly considering unindented goto labels as function names. Signed-off-by: Jean Delvare <jdelvare(a)suse.de> [sven(a)narfation.org: Ported patch from linux.git] Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- .gitattributes | 2 ++ 1 file changed, 2 insertions(+) diff --git a/.gitattributes b/.gitattributes index eeef3e0..1d2a7e9 100644 --- a/.gitattributes +++ b/.gitattributes @@ -1,2 +1,4 @@ /.gitignore export-ignore /.gitattributes export-ignore +*.c diff=cpp +*.h diff=cpp -- 2.11.0

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[B.A.T.M.A.N.] Interface limit 127 in bat0?!
by jens 21 Feb '17

21 Feb '17

i observe a limit of 127 interfaces which can be hooked into bat0 where do i find this limit, or does somebody can tell me more about this? Or, if it is a good idea to circumwent this at all? Or, if its even possible in actual protocoll structure. background: Freifunk with tunneldigger and l2tp tunnel interfaces put a whole lot of l2tp-eth interfaces in a bridge and hook the bridge into batman, which make trouble and also doesnt feel like good practice. (i think to circumvent this limit) Freifunk with wireguard and gretap also have a lot of gretap tunnel interfaces - but without bridging is limited to 127 interfaces (we also experiment with vxlan which is limited to v4 in bridge forwarding and by this not really an option - idea was to hook vxlan0 in bat0 , which may be similar to bridging l2tp-eth) you can find the test here (in german) https://forum.freifunk.net/t/500-gretap-tunnel-interfaces-in-batman-einhaen… or the wireguard in freifunk structures (batman network) here https://forum.freifunk.net/t/wireguard-0-0-20161230-mit-linux-3-18-kernel-u… the error if you exceed the interface limit in dmesg : |Error - can't write to file '/sys/class/net/gre127/batman_adv/mesh_iface': Cannot allocate memory| -- make the world nicer, please use PGP encryption

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Re: [B.A.T.M.A.N.] Interface limit 127 in bat0?!
by Andrew Lunn 21 Feb '17

21 Feb '17

Hi Jens The script i just used is: # add one if per 3 second and give output, also monitor dmesg dmesg -w & for i in `seq 1 255`; do # one interface ip link add gre$i type gretap local 192.168.99.1 remote 192.168.3.$i ttl 255 dev lan1 ip link set up dev gre$i batctl if add gre$i # another inf ip link add grex$i type gretap local 192.168.99.1 remote 192.168.4.$i ttl 255 dev lan1 ip link set up dev grex$i batctl if add grex$i echo -n $(uptime|cut -d"," -f4-) $(ifconfig lan1|grep TX\ p) $i sleep 3 done So this adds two interfaces per 3 seconds to bat0. root@wrt1900ac:~# batctl if grex122: active gre123: active grex123: active gre124: active grex124: active gre125: active grex125: active gre126: active ... grex119: active gre120: active grex120: active gre121: active grex121: active gre122: active root@wrt1900ac:~# batctl if | wc 344 688 5116 So i have 344 interfaces in the mesh. No memory problems reported. Andrew

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[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Remove preprocessor checks in multicast.c
by Sven Eckelmann 20 Feb '17

20 Feb '17

It is not necessary to disable these code sections in case other kernel features are disabled. Instead the IS_ENABLED tests can be added directly in the code and the compiler can remove the unnecessary code parts during its optimization run. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/multicast.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 952ba81..0e9112c 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -182,10 +182,8 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src) { if (src->proto == htons(ETH_P_IP)) ip_eth_mc_map(src->u.ip4, dst); -#if IS_ENABLED(CONFIG_IPV6) - else if (src->proto == htons(ETH_P_IPV6)) + else if (IS_ENABLED(CONFIG_IPV6) && src->proto == htons(ETH_P_IPV6)) ipv6_eth_mc_map(&src->u.ip6, dst); -#endif else eth_zero_addr(dst); } @@ -494,9 +492,8 @@ static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv) if (!bridged) goto update; -#if !IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) - pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n"); -#endif + if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING)) + pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n"); querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP); querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP); @@ -671,7 +668,6 @@ static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv, return 0; } -#if IS_ENABLED(CONFIG_IPV6) /** * batadv_mcast_is_report_ipv6 - check for MLD reports * @skb: the ethernet frame destined for the mesh @@ -736,7 +732,6 @@ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv, return 0; } -#endif /** * batadv_mcast_forw_mode_check - check for optimized forwarding potential @@ -765,11 +760,12 @@ static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv, case ETH_P_IP: return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb, is_unsnoopable); -#if IS_ENABLED(CONFIG_IPV6) case ETH_P_IPV6: + if (!IS_ENABLED(CONFIG_IPV6)) + return -EINVAL; + return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb, is_unsnoopable); -#endif default: return -EINVAL; } -- 2.11.0

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[B.A.T.M.A.N.] [PATCH] batman-adv: Fix unbalanced braces around else statement
by Sven Eckelmann 20 Feb '17

20 Feb '17

Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/translation-table.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 6077a87d46f0..a75f0a640bcd 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -2253,12 +2253,13 @@ batadv_tt_global_del_roaming(struct batadv_priv *bat_priv, /* its the last one, mark for roaming. */ tt_global_entry->common.flags |= BATADV_TT_CLIENT_ROAM; tt_global_entry->roam_at = jiffies; - } else + } else { /* there is another entry, we can simply delete this * one and can still use the other one. */ batadv_tt_global_del_orig_node(bat_priv, tt_global_entry, orig_node, message); + } } /** @@ -2314,10 +2315,11 @@ static void batadv_tt_global_del(struct batadv_priv *bat_priv, /* local entry exists, case 2: client roamed to us. */ batadv_tt_global_del_orig_list(tt_global_entry); batadv_tt_global_free(bat_priv, tt_global_entry, message); - } else + } else { /* no local entry exists, case 1: check for roaming */ batadv_tt_global_del_roaming(bat_priv, tt_global_entry, orig_node, message); + } out: if (tt_global_entry)

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[B.A.T.M.A.N.] [PATCH] RFC: batman-adv: BATMAN V: Make route switching more opportunistic
by Linus Lüssing 17 Feb '17

17 Feb '17

Increase route switching likelikood with every seqno we missed from our currently selected router. This is safe to do without causing any loops at any time because the sequence number is strictly larger than the one we last got from our selected router. --- Another idea to improve route convergence time. Simpler than the "Rest-In-Peace" protocol idea, but they should be combinable. Idea is a little inspired from once again potentially having missed a bus: Should I stick to the plan of taking the bus and wait a few more minutes (maybe it is just late?) or should I walk instead? (Here in Lübeck buses usually arrive about every 30min. - or not all between 00:30 and 04:30 - so it often makes sense to just use the slower alternative of walking if you have missed it :-) ) Also inspired by the asymmetric link penalty. Potential cons: * might potentially increase route flappiness if the route has a certain amount of packet loss / length -> Maybe additional to broadcasting OGMs to neighbors, distribute it to a few, good/promising ones via unicast, too? PS: Please disregard the patch style, it's just an RFC for the concept/idea for now :-) --- net/batman-adv/bat_v_ogm.c | 51 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 03a35c9..08a79a9 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -492,6 +492,53 @@ out: } /** + * batadv_v_ogm_seq_tx - penalize router throughput + * @router_throughput: the router throughput to penalize + * @seq_diff: seqno diff between OGM and current router + */ +static u32 batadv_v_ogm_seq_tx(u32 router_throughput, u32 seq_diff) +{ + const u32 m = BATADV_OGM_MAX_ORIGDIFF; + const u32 r = router_throughput; + const u32 d = seq_diff; + u64 ret; + + if (s <= 1) + return r; + else if (s >= d) + return 0; + + /* f(x) = [ - 1/(m-1)^2 * (d-1)^2 + 1 ] * r */ + ret = r * (m-1) * (m-1) - r * (d-1) * (d-1) + return (u32)(ret / ( (m-1) * (m-1) )); + + /** + * For BATADV_OGM_MAX_ORIGDIFF == 5 equivalent to: + */ + switch(seq_diff) { + case 0: + /* fallthrough */ + case 1: + /* no penalty for seq-diff == 1 either, + * maybe the best route has just a little more + * latency + */ + return router_throughput; + case 2: + /* 15/16 */ + return 0.9375 * router_throughput; + case 3: + /* 3/4 */ + return 0.75 * router_throughput; + case 4: + /* 7/16 */ + return 0.4375 * router_throughput; + default: + return 0; + } +} + +/** * batadv_v_ogm_route_update - update routes based on OGM * @bat_priv: the bat priv with all the soft interface information * @ethhdr: the Ethernet header of the OGM2 @@ -570,8 +617,8 @@ static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv, router_throughput = router_ifinfo->bat_v.throughput; neigh_throughput = neigh_ifinfo->bat_v.throughput; - if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) && - (router_throughput >= neigh_throughput)) + if (batadv_v_ogm_seq_tx(router_throughput, neigh_seq_diff) + >= neigh_throughput) goto out; } -- 2.1.4

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B.A.T.M.A.N February 2017