B.A.T.M.A.N January 2019

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

11 participants
16 discussions

[B.A.T.M.A.N.] batman-adv and/or batmand porting effort to FreeBSD
by Mahdi Mokhtari 28 Dec '19

28 Dec '19

Hi, After some time of playing with the B.A.T.M.A.N protocol and net-interface on OpenWRT and Debian I was thinking to use it with the servers I use everyday (and maybe on routers/appliances I have nanoBSD on). So I started an effort... (As a background) I already ported some applications to FreeBSD [and I'm maintaining them] and also I did work already on the Linux emulation layer of FreeBSD (FreeBSD has a Linux syscall-emulation and Linux-KPI layers). So my approach (as naturally I didn't expect the build of batman-adv.ko to be successful as is), was based on the approach that we [at FreeBSD] did to port Linux's drm... <https://github.com/FreeBSDDesktop/kms-drm> I ended up in adding some header-files to FreeBSD Linux-KPI (like average.h, percpu.h, ...). Now I'm at a state that Netlink blocks me and I'm to determine next step :-) [Which I don't assume it being trivial with my current approach] So I'd like to ask: 1- Is it better approach to "rewrite" batman-adv.ko [at least Netlink-ish (let's call "Linuxism") parts] than what I'm doing now? 2- Any other efforts are being done out there? 3- is batmand deprecated [So I should mainly focus on batman-adv.ko]? 4- any other comments do you have? :D P.S. sorry if I'm not really good at starting conversation from scratch and out-of-nowhere :D but I hope by continuing the collaboration we can have better (more enriched) FreeBSD and better (as in more portable) B.A.T.M.A.N :-) -- Best regards, MMokhi.

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[B.A.T.M.A.N.] [PATCH v5 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available
by Marek Lindner 25 Nov '19

25 Nov '19

Under normal circumstances B.A.T.M.A.N. V retrieves the neighbor throughput values to populate its metric tables from the various drivers such as WiFi throughput tables and Ethernet throughput.. Whenever the interface drivers do not export link throughput information manual overrides become necessary. To further automate and thus better support these setups, ELP may call the batman-adv throughput meter to schedule a throughput estimation to be used to populate the metric table. v5: * fix tp_vars refcount on queue_work() failure * squash batadv_tp_start_work() into batadv_tp_start() v4: * read tp measurement result only once v3: * fix ELP tp meter result computation * use batadv_has_timed_out() instead of custom implementation * set ELP tp meter test duration to 1000ms in patch #6 * add comment explaining periodic scheduling v2: * added sysfs attribute to configure tp meter test duration * fixed null pointer dereference in TP meter packet sending routine * fixed storing the measured throughput in the correct variable * checkpatch/kerneldoc/sparse/smatch cleanup Antonio Quartulli (3): batman-adv: tp_meter - prevent concurrent tp_meter sessions by using workqueue batman-adv: tp_meter - don't check for existing session batman-adv: tp_meter - add option to perform one-hop test Marek Lindner (4): batman-adv: tp_meter - allow up to 10 queued sessions batman-adv: tp_meter - add caller distinction batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available batman-adv: ELP - add throughput meter test duration attribute .../ABI/testing/sysfs-class-net-batman-adv | 7 + include/uapi/linux/batadv_packet.h | 2 + net/batman-adv/bat_v.c | 1 + net/batman-adv/bat_v_elp.c | 69 ++- net/batman-adv/bat_v_elp.h | 21 + net/batman-adv/main.c | 10 +- net/batman-adv/main.h | 7 +- net/batman-adv/netlink.c | 3 +- net/batman-adv/routing.c | 6 +- net/batman-adv/sysfs.c | 3 + net/batman-adv/tp_meter.c | 484 +++++++++++------- net/batman-adv/tp_meter.h | 11 +- net/batman-adv/types.h | 36 ++ 13 files changed, 453 insertions(+), 207 deletions(-) -- 2.18.0

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[B.A.T.M.A.N.] [PATCH] batman-adv: handle race condition for claims also in batadv_bla_rx
by Simon Wunderlich 02 Jul '19

02 Jul '19

From: Andreas Pape <apape(a)phoenixcontact.com> Like in the case of the patch for batadv_bla_tx to handle a race condition when claiming a mac address for bla, a similar situation can occur when claiming is triggered via batadv_bla_rx. This patch solves this with a similar approach as for batadv_bla_tx. Signed-off-by: Andreas Pape <apape(a)phoenixcontact.com> --- net/batman-adv/bridge_loop_avoidance.c | 31 ++++++++++++++++++++----------- net/batman-adv/translation-table.c | 26 ++++++++++++++++++++++++++ net/batman-adv/translation-table.h | 3 +++ 3 files changed, 49 insertions(+), 11 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index d07e89e..cab8980 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1847,19 +1847,28 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, if (!claim) { /* possible optimization: race for a claim */ - /* No claim exists yet, claim it for us! + /* Make sure this packet is not looping back + * from our own backbone. */ - batadv_dbg(BATADV_DBG_BLA, bat_priv, - "bla_rx(): Unclaimed MAC %pM found. Claim it. Local: %s\n", - ethhdr->h_source, - batadv_is_my_client(bat_priv, - ethhdr->h_source, vid) ? - "yes" : "no"); - batadv_handle_claim(bat_priv, primary_if, - primary_if->net_dev->dev_addr, - ethhdr->h_source, vid); - goto allow; + if (batadv_tt_local_has_timed_out(bat_priv, ethhdr->h_source, + vid, 100)) { + /* No claim exists yet, claim it for us! + */ + batadv_dbg(BATADV_DBG_BLA, bat_priv, + "bla_rx(): Unclaimed MAC %pM found. Claim it. Local: %s\n", + ethhdr->h_source, + batadv_is_my_client(bat_priv, + ethhdr->h_source, vid) ? + "yes" : "no"); + + batadv_handle_claim(bat_priv, primary_if, + primary_if->net_dev->dev_addr, + ethhdr->h_source, vid); + goto allow; + } else { + goto handled; + } } /* if it is our own claim ... */ diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index e75b493..b908195 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -4380,3 +4380,29 @@ void batadv_tt_cache_destroy(void) kmem_cache_destroy(batadv_tt_req_cache); kmem_cache_destroy(batadv_tt_roam_cache); } + +bool batadv_tt_local_has_timed_out(struct batadv_priv *bat_priv, + const u8 *addr, unsigned short vid, + unsigned int timeout) +{ + struct batadv_tt_local_entry *tt_local_entry; + bool ret = true; + + tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid); + if (!tt_local_entry) + goto out; + /* Check if the client has been logically deleted (but is kept for + * consistency purpose) + */ + if ((tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING) || + (tt_local_entry->common.flags & BATADV_TT_CLIENT_ROAM)) + goto out; + /* Check that the tt_local_entry has a certain age */ + if (!batadv_has_timed_out(tt_local_entry->last_seen, timeout)) + ret = false; + +out: + if (tt_local_entry) + batadv_tt_local_entry_put(tt_local_entry); + return ret; +} diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h index 411d586..b05d0d8 100644 --- a/net/batman-adv/translation-table.h +++ b/net/batman-adv/translation-table.h @@ -65,5 +65,8 @@ bool batadv_tt_global_is_isolated(struct batadv_priv *bat_priv, int batadv_tt_cache_init(void); void batadv_tt_cache_destroy(void); +bool batadv_tt_local_has_timed_out(struct batadv_priv *bat_priv, + const u8 *addr, unsigned short vid, + unsigned int timeout); #endif /* _NET_BATMAN_ADV_TRANSLATION_TABLE_H_ */ -- 1.7.0.4

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[B.A.T.M.A.N.] [RFC maint v2] batman-adv: fix adding VLANs with partial state
by Marek Lindner 09 Jun '19

09 Jun '19

Whenever a new VLAN is created on top of batman virtual interfaces the batman-adv kernel module creates internal structures to track the status of said VLAN. Amongst other things, the MAC address of the VLAN interface itself has to be stored. Without this change a VLAN and its infrastructure could be created while the interface MAC address is not stored without triggering any error, thus creating issues in other parts of the code. Prevent the VLAN from being created if the MAC address can not be stored. Fixes: 952cebb57518 ("batman-adv: add per VLAN interface attribute framework") Signed-off-by: Marek Lindner <mareklindner(a)neomailbox.ch> --- net/batman-adv/hard-interface.c | 2 +- net/batman-adv/soft-interface.c | 105 ++++++++++++++++++++++++-------- net/batman-adv/soft-interface.h | 3 +- 3 files changed, 83 insertions(+), 27 deletions(-) diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index c405d15b..0b22cc4d 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -1000,7 +1000,7 @@ static int batadv_hard_if_event(struct notifier_block *this, if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) { batadv_sysfs_add_meshif(net_dev); bat_priv = netdev_priv(net_dev); - batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS); + batadv_softif_create_vlan_late(bat_priv, BATADV_NO_FLAGS); return NOTIFY_DONE; } diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index edeffcb9..728d9d40 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -563,16 +563,36 @@ struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv, } /** - * batadv_softif_create_vlan() - allocate the needed resources for a new vlan + * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object + * @bat_priv: the bat priv with all the soft interface information + * @vlan: the object to remove + */ +static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv, + struct batadv_softif_vlan *vlan) +{ + /* explicitly remove the associated TT local entry because it is marked + * with the NOPURGE flag + */ + batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr, + vlan->vid, "vlan interface destroyed", false); + + batadv_sysfs_del_vlan(bat_priv, vlan); + batadv_softif_vlan_put(vlan); +} + +/** + * batadv_softif_create_vlan_early() - allocate the needed resources for a new + * vlan, defer sysfs creation till later * @bat_priv: the bat priv with all the soft interface information * @vid: the VLAN identifier * * Return: 0 on success, a negative error otherwise. */ -int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) +static int batadv_softif_create_vlan_early(struct batadv_priv *bat_priv, + unsigned short vid) { struct batadv_softif_vlan *vlan; - int err; + bool client_added; vlan = batadv_softif_vlan_get(bat_priv, vid); if (vlan) { @@ -590,12 +610,6 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) atomic_set(&vlan->ap_isolation, 0); - err = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan); - if (err) { - kfree(vlan); - return err; - } - spin_lock_bh(&bat_priv->softif_vlan_list_lock); kref_get(&vlan->refcount); hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list); @@ -604,32 +618,63 @@ int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid) /* add a new TT local entry. This one will be marked with the NOPURGE * flag */ - batadv_tt_local_add(bat_priv->soft_iface, - bat_priv->soft_iface->dev_addr, vid, - BATADV_NULL_IFINDEX, BATADV_NO_MARK); + client_added = batadv_tt_local_add(bat_priv->soft_iface, + bat_priv->soft_iface->dev_addr, vid, + BATADV_NULL_IFINDEX, BATADV_NO_MARK); /* don't return reference to new softif_vlan */ batadv_softif_vlan_put(vlan); + if (!client_added) { + batadv_softif_destroy_vlan(bat_priv, vlan); + return -ENOENT; + } + return 0; } /** - * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object + * batadv_softif_create_vlan_late() - complete softif vlan creation with the + * sysfs entries * @bat_priv: the bat priv with all the soft interface information - * @vlan: the object to remove + * @vid: the VLAN identifier + * + * Return: 0 on success, a negative error otherwise. */ -static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv, - struct batadv_softif_vlan *vlan) +int batadv_softif_create_vlan_late(struct batadv_priv *bat_priv, + unsigned short vid) { - /* explicitly remove the associated TT local entry because it is marked - * with the NOPURGE flag - */ - batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr, - vlan->vid, "vlan interface destroyed", false); + struct batadv_softif_vlan *vlan; + int ret; + + vlan = batadv_softif_vlan_get(bat_priv, vid); + if (!vlan) + return -ENOENT; + + ret = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan); - batadv_sysfs_del_vlan(bat_priv, vlan); batadv_softif_vlan_put(vlan); + return ret; +} + +/** + * batadv_softif_create_vlan() - allocate the needed resources for a new vlan + * @bat_priv: the bat priv with all the soft interface information + * @vid: the VLAN identifier + * + * Return: 0 on success, a negative error otherwise. + */ +static int batadv_softif_create_vlan(struct batadv_priv *bat_priv, + unsigned short vid) +{ + int err; + + err = batadv_softif_create_vlan_early(bat_priv, vid); + if (err) + return err; + + err = batadv_softif_create_vlan_late(bat_priv, vid); + return err; } /** @@ -648,6 +693,7 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto, { struct batadv_priv *bat_priv = netdev_priv(dev); struct batadv_softif_vlan *vlan; + bool client_added; int ret; /* only 802.1Q vlans are supported. @@ -683,9 +729,14 @@ static int batadv_interface_add_vid(struct net_device *dev, __be16 proto, * flag. This must be added again, even if the vlan object already * exists, because the entry was deleted by kill_vid() */ - batadv_tt_local_add(bat_priv->soft_iface, - bat_priv->soft_iface->dev_addr, vid, - BATADV_NULL_IFINDEX, BATADV_NO_MARK); + client_added = batadv_tt_local_add(bat_priv->soft_iface, + bat_priv->soft_iface->dev_addr, vid, + BATADV_NULL_IFINDEX, BATADV_NO_MARK); + + if (!client_added) { + batadv_softif_destroy_vlan(bat_priv, vlan); + return -ENOENT; + } return 0; } @@ -850,6 +901,10 @@ static int batadv_softif_init_late(struct net_device *dev) if (ret < 0) goto unreg_debugfs; + ret = batadv_softif_create_vlan_early(bat_priv, BATADV_NO_FLAGS); + if (ret < 0) + goto unreg_debugfs; + return 0; unreg_debugfs: diff --git a/net/batman-adv/soft-interface.h b/net/batman-adv/soft-interface.h index daf87f07..b8a9a3c8 100644 --- a/net/batman-adv/soft-interface.h +++ b/net/batman-adv/soft-interface.h @@ -36,7 +36,8 @@ struct net_device *batadv_softif_create(struct net *net, const char *name); void batadv_softif_destroy_sysfs(struct net_device *soft_iface); bool batadv_softif_is_valid(const struct net_device *net_dev); extern struct rtnl_link_ops batadv_link_ops; -int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid); +int batadv_softif_create_vlan_late(struct batadv_priv *bat_priv, + unsigned short vid); void batadv_softif_vlan_put(struct batadv_softif_vlan *softif_vlan); struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv, unsigned short vid); -- 2.17.0

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[B.A.T.M.A.N.] [PATCH] batman-adv: Increase purge timeout on DAT DHT candidates
by Linus Lüssing 07 Apr '19

07 Apr '19

Currently, the DHT_GET messages of the DAT will likely be left unanswered due to the following issues: When a node has a matching DAT Cache entry for a local ARP Request then this node will answer it directly with the information provided by the cache. This however, will likely lead to missing ARP Replies from the original host. Which in turn leads to the DAT cache not being updated. Then the local DAT cache entry will time out, triggering a unicasted DHT_GET. However, as the 5min. timeout has passed, the DAT DHT candidates will likely have purged their entry, too. So basically this results in an ARP Request broadcast fallback every five minutes. A second issue is that it is quite common that a host which has long gone offline will be tried to be contacted by another one at some remote period larger than the current 5min. timeout. This too leads to flooded ARP Requests. With this patch the purge timeout for local DAT cache entries and entries submitted via a DHT_PUT message is differentiated: While the former stays at 5min. the latter is increased to 30min. Which decreases the rate of broadcasted ARP Requests. Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Some old investigations and analysis seemed to indicate a potential reduction of 91.71% of unanswered ARP Requests (45min: 97.95%, 60min: 98.95%): https://www.open-mesh.org/projects/batman-adv/wiki/DAT_DHCP_Snooping This patch is rebased on top of: "batman-adv: DHCP snooping for DAT" And it is a follow-up of: "batman-adv: Increase DHCP snooped DAT entry purge timeout in DHT" - https://patchwork.open-mesh.org/patch/17364/ --- net/batman-adv/distributed-arp-table.c | 39 ++++++++++++++++++++++------------ net/batman-adv/distributed-arp-table.h | 3 ++- net/batman-adv/main.h | 2 ++ net/batman-adv/routing.c | 8 ++++--- net/batman-adv/types.h | 5 +++++ 5 files changed, 39 insertions(+), 18 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 899ab051..34898abf 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -152,7 +152,9 @@ static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) { return batadv_has_timed_out(dat_entry->last_update, - BATADV_DAT_ENTRY_TIMEOUT); + BATADV_DAT_ENTRY_TIMEOUT) && + batadv_has_timed_out(dat_entry->last_dht_update, + BATADV_DAT_DHT_TIMEOUT); } /** @@ -369,9 +371,11 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, * @ip: ipv4 to add/edit * @mac_addr: mac address to assign to the given ipv4 * @vid: VLAN identifier + * @extended_timeout: whether this should be cached with an extended timeout */ -static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, - u8 *mac_addr, unsigned short vid) +static void +batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, u8 *mac_addr, + unsigned short vid, bool extended_timeout) { struct batadv_dat_entry *dat_entry; int hash_added; @@ -382,6 +386,10 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) ether_addr_copy(dat_entry->mac_addr, mac_addr); dat_entry->last_update = jiffies; + + if (extended_timeout) + dat_entry->last_dht_update = jiffies; + batadv_dbg(BATADV_DBG_DAT, bat_priv, "Entry updated: %pI4 %pM (vid: %d)\n", &dat_entry->ip, dat_entry->mac_addr, @@ -397,6 +405,7 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, dat_entry->vid = vid; ether_addr_copy(dat_entry->mac_addr, mac_addr); dat_entry->last_update = jiffies; + dat_entry->last_dht_update = extended_timeout ? jiffies : 0; kref_init(&dat_entry->refcount); kref_get(&dat_entry->refcount); @@ -1229,7 +1238,7 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, hw_src = batadv_arp_hw_src(skb, hdr_size); ip_dst = batadv_arp_ip_dst(skb, hdr_size); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); if (dat_entry) { @@ -1322,7 +1331,7 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST"); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); if (!dat_entry) @@ -1386,8 +1395,8 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, hw_dst = batadv_arp_hw_dst(skb, hdr_size); ip_dst = batadv_arp_ip_dst(skb, hdr_size); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, false); /* Send the ARP reply to the candidates for both the IP addresses that * the node obtained from the ARP reply @@ -1402,12 +1411,14 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, * @bat_priv: the bat priv with all the soft interface information * @skb: packet to check * @hdr_size: size of the encapsulation header + * @is_dht_put: whether this is a BATADV_P_DAT_DHT_PUT message * * Return: true if the packet was snooped and consumed by DAT. False if the * packet has to be delivered to the interface */ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, - struct sk_buff *skb, int hdr_size) + struct sk_buff *skb, int hdr_size, + bool is_dht_put) { struct batadv_dat_entry *dat_entry = NULL; u16 type; @@ -1450,8 +1461,8 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, /* Update our internal cache with both the IP addresses the node got * within the ARP reply */ - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, is_dht_put); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, is_dht_put); /* If BLA is enabled, only forward ARP replies if we have claimed the * source of the ARP reply or if no one else of the same backbone has @@ -1705,8 +1716,8 @@ static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr, skb_set_network_header(skb, ETH_HLEN); - batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid, false); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, false); batadv_dat_send_data(bat_priv, skb, yiaddr, vid, BATADV_P_DAT_DHT_PUT); batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); @@ -1827,8 +1838,8 @@ void batadv_dat_snoop_incoming_dhcp_ack(struct batadv_priv *bat_priv, hw_src = ethhdr->h_source; vid = batadv_dat_get_vid(skb, &hdr_size); - batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid, false); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); batadv_dbg(BATADV_DBG_DAT, bat_priv, "Snooped from incoming DHCPACK (server address): %pI4, %pM (vid: %i)\n", diff --git a/net/batman-adv/distributed-arp-table.h b/net/batman-adv/distributed-arp-table.h index 68c0ff32..21dbf285 100644 --- a/net/batman-adv/distributed-arp-table.h +++ b/net/batman-adv/distributed-arp-table.h @@ -45,7 +45,8 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, struct sk_buff *skb); bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, - struct sk_buff *skb, int hdr_size); + struct sk_buff *skb, int hdr_size, + bool is_dht_put); void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, struct sk_buff *skb, __be16 proto, diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 05cb9080..6c1488f8 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -51,6 +51,8 @@ #define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */ #define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */ #define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */ +#define BATADV_DAT_DHT_TIMEOUT (30 * 60000) /* 30 mins in milliseconds */ + /* sliding packet range of received originator messages in sequence numbers * (should be a multiple of our word size) */ diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index cae0e5dd..2b5d50ab 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -974,7 +974,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; int ret = NET_RX_DROP; - bool is4addr, is_gw; + bool is4addr, is_gw, is_dht_put = false; unicast_packet = (struct batadv_unicast_packet *)skb->data; is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; @@ -1033,6 +1033,8 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, orig_addr = unicast_4addr_packet->src; orig_node = batadv_orig_hash_find(bat_priv, orig_addr); + } else if (subtype == BATADV_P_DAT_DHT_PUT) { + is_dht_put = true; } } @@ -1040,7 +1042,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, hdr_size)) goto rx_success; if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, - hdr_size)) + hdr_size, is_dht_put)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); @@ -1277,7 +1279,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb, if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) goto rx_success; - if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) + if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size, false)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a21b34ed..74801d79 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -2280,6 +2280,11 @@ struct batadv_dat_entry { */ unsigned long last_update; + /** + * @last_dht_update: time in jiffies when a DHT_PUT was last received + */ + unsigned long last_dht_update; + /** @hash_entry: hlist node for &batadv_priv_dat.hash */ struct hlist_node hash_entry; -- 2.11.0

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[B.A.T.M.A.N.] WARNING in batadv_mcast_mla_tt_retract
by syzbot 24 Mar '19

24 Mar '19

Hello, syzbot found the following crash on: HEAD commit: eed9688f8513 Merge branch 'ras-core-for-linus' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=103bffaf400000 kernel config: https://syzkaller.appspot.com/x/.config?x=fa5c63e12fd85b25 dashboard link: https://syzkaller.appspot.com/bug?extid=83f2d54ec6b7e417e13f compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+83f2d54ec6b7e417e13f(a)syzkaller.appspotmail.com bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves WARNING: CPU: 1 PID: 7 at net/batman-adv/multicast.c:337 batadv_mcast_mla_tt_retract+0x476/0x590 net/batman-adv/multicast.c:337 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 4.20.0+ #169 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_mcast_mla_update Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113 panic+0x2ad/0x55c kernel/panic.c:188 __warn.cold.8+0x20/0x45 kernel/panic.c:540 report_bug+0x254/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:batadv_mcast_mla_tt_retract+0x476/0x590 net/batman-adv/multicast.c:337 Code: 00 00 ad de 4c 89 ff 49 89 47 08 e8 b4 0f 03 fa e9 b6 fe ff ff 49 8d 47 10 48 89 85 60 ff ff ff e9 05 ff ff ff e8 4a 30 c0 f9 <0f> 0b e9 3f fc ff ff e8 6e 3b 03 fa e9 44 fe ff ff 4c 89 f7 e8 81 RSP: 0018:ffff8880a9e1f260 EFLAGS: 00010293 RAX: ffff8880a9e041c0 RBX: 0000000000000001 RCX: ffffffff87bedca3 RDX: 0000000000000000 RSI: ffffffff87bee066 RDI: 0000000000000007 RBP: ffff8880a9e1f328 R08: ffff8880a9e041c0 R09: ffffed1015ce5b8f R10: 0000000000000003 R11: ffff8880ae72dc7b R12: ffff8880a9e1f490 R13: 0000000000000000 R14: ffff888055b95fc0 R15: ffff8880a9e1f710 __batadv_mcast_mla_update net/batman-adv/multicast.c:635 [inline] batadv_mcast_mla_update+0x819/0x2da0 net/batman-adv/multicast.c:661 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug 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 bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.

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[B.A.T.M.A.N.] [RFC v4 00/19] batman-adv: netlink restructuring, part 2
by Sven Eckelmann 07 Feb '19

07 Feb '19

Hi, Jiri Pirko called the batman-adv configuration interface a while back "a huge mistake" [1] and suggested genl as alternative. The first reimplementation [2] (based on the team/devlink design) was rejected. This second implementation is now using a nl80211-like design. The objects which can now be modified/queried are: * mesh/soft-interface (BATADV_CMD_GET_MESH/BATADV_CMD_SET_MESH) * slave/hard-interface (BATADV_CMD_GET_HARDIF/BATADV_CMD_SET_HARDIF) * vlan (BATADV_CMD_GET_VLAN/BATADV_CMD_SET_VLAN) Such a set messages automatically triggers a *_SET_* "reply" via the config multicast group. The same behavior was also added to the sysfs interface. I would like to ask the other developers to check whether their configuration values are represented correctly. And please also check whether the current implementation might collide with some other features which you might have in your pipeline. Unfortunately, Linus Luessing is the only batman-adv developer who provided feedback. There were also two topics which were not yet really discussed and thus these requests (from Linus) were not yet implemented: * convert BATADV_ATTR_MULTICAST_MODE_ENABLED to an u32 and let don't handle it like a boolean. Instead use it to select how multicast traffic has to be handled: - 0: ignore multicast optimization and just flood it like broadcast traffic - 1: enabled multicast optimization - 2: undefined but also some kind of multicast optimization - 3: undefined but also some kind of multicast of optimization - ... * convert BATADV_ATTR_AGGREGATION_OGM_ENABLED to u32 and use it to mark which type of traffic should be aggregated: - bit 0: enable aggregation of OGM(2)s - bit 1: yet undefined packet type which allows some kind of aggregation - bit 2: yet undefined packet type which allows some kind of aggregation - ... v4: === Incorporate various feedback from * Linus Luessing: - Fix typos/spelling/grammar problems: + "already allow" -> "already allows" + "mesh mesh" -> "mesh" + "safed" -> "saved" - Let batadv_get_softif_from_info actually return net_device instead of net_device private data (batadv_priv) - store genl_info_net(info) in temporary variable to avoid line breaks in function parameters - document that batadv_get_*_from_info functions increase the reference counter of the returned object - directly drop reference counter to hard_dev net_device in batadv_get_hardif_from_info instead of doing that in batadv_post_doit - fix NULL pointer deref of primary_if when batadv device doesn't have any slave device - rewrite user_ptr[1] flags precheck in batadv_pre_doit to count the number of set bits (to only allow one of the flags which use user_ptr[1]) * Jiri Pirko: - Add _ENABLED Postfix for boolean attributes: + BATADV_ATTR_AGGREGATED_OGMS_ENABLED + BATADV_ATTR_AP_ISOLATION_ENABLED + BATADV_ATTR_BONDING_ENABLED + BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED + BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED + BATADV_ATTR_FRAGMENTATION_ENABLED + BATADV_ATTR_MULTICAST_MODE_ENABLED + BATADV_ATTR_NETWORK_CODING_ENABLED v3: === * correctly assign kernel-doc for BATADV_GW_MODE_CLIENT * fix validation check for gw.sel_class * fix setting of BATADV_ATTR_ORIG_INTERVAL * Cc the (most likely) responsible developers for each setting to more directly ask them for feedback v2: === * rewrite everything in a more nl80211-like message/attribute format. Kind regards, Sven [1] https://www.open-mesh.org/issues/300 [2] https://patchwork.open-mesh.org/cover/17610/ Sven Eckelmann (19): batman-adv: Move common genl doit code pre/post hooks batman-adv: Prepare framework for mesh genl config batman-adv: Prepare framework for hardif genl config batman-adv: Prepare framework for vlan genl config batman-adv: Add aggregated_ogms mesh genl configuration batman-adv: Add ap_isolation mesh/vlan genl configuration batman-adv: Add bonding mesh genl configuration batman-adv: Add bridge_loop_avoidance mesh genl configuration batman-adv: Add distributed_arp_table mesh genl configuration batman-adv: Add fragmentation mesh genl configuration batman-adv: Add gateway mesh genl configuration batman-adv: Add hop_penalty mesh genl configuration batman-adv: Add log_level mesh genl configuration batman-adv: Add multicast_mode mesh genl configuration batman-adv: Add network_coding mesh genl configuration batman-adv: Add orig_interval mesh genl configuration batman-adv: Add elp_interval hardif genl configuration batman-adv: Add throughput_override hardif genl configuration batman-adv: Trigger genl notification on sysfs config change include/uapi/linux/batman_adv.h | 189 +++++- net/batman-adv/gateway_client.c | 1 - net/batman-adv/gateway_common.c | 1 + net/batman-adv/gateway_common.h | 6 - net/batman-adv/netlink.c | 1080 +++++++++++++++++++++++++++---- net/batman-adv/netlink.h | 6 + net/batman-adv/soft-interface.c | 2 +- net/batman-adv/sysfs.c | 64 +- 8 files changed, 1202 insertions(+), 147 deletions(-) -- 2.20.1

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Re: [B.A.T.M.A.N.] [patch 2/2] scripts/spdxcheck.py: Handle special quotation mark comments
by Sven Eckelmann 06 Feb '19

06 Feb '19

On Wednesday, 16 January 2019 11.26.53 CET Thomas Gleixner wrote: > The SuperH boot code files use a magic format for the SPDX identifier > comment: > > LIST "SPDX-License-Identifier: .... " > > The trailing quotation mark is not stripped before the token parser is > invoked and causes the scan to fail. Handle it gracefully. [...] This patch introduces a false positive when checking files with an ANSI-C style /* SPDX-License-Identifier: .... */ comment line. $ ./scripts/checkpatch.pl -q -f include/linux/bug.h WARNING: 'SPDX-License-Identifier: GPL-2.0 */' is not supported in LICENSES/... #1: FILE: include/linux/bug.h:1: +/* SPDX-License-Identifier: GPL-2.0 */ total: 0 errors, 1 warnings, 79 lines checked checkpatch.pl is already stripping the "/* " prefix and only sends the remaining "SPDX-License-Identifier: GPL-2.0 */" via stdin to scripts/spdxcheck.py. Thus the newly introduced check > + # Remove trailing comment closure > + if line.startswith('/*'): > + expr = expr.rstrip('*/').strip() doesn't match and thus the code doesn't remove the " */" at the end of the line. Kind regards, Sven

2 2

[B.A.T.M.A.N.] [PATCH] batman-adv: Add multicast-to-unicast support for multiple targets
by Linus Lüssing 29 Jan '19

29 Jan '19

With this patch multicast packets with a limited number of destinations (current default: 16) will be split and transmitted by the originator as individual unicast transmissions. Wifi broadcasts with their low bitrate are still a costly undertaking. In a mesh network this cost multiplies with the overall size of the mesh network. Therefore using multiple unicast transmissions instead of broadcast flooding is almost always less burdensome for the mesh network. The maximum amount of unicast packets can be configured via the newly introduced multicast_fanout parameter. If this limit is exceeded distribution will fall back to classic broadcast flooding. The multicast-to-unicast conversion is performed on the initial multicast sender node and counts on a final destination node, mesh-wide basis (and not next hop, neighbor node basis). Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- This patch introduces a new sysfs parameter even though upstream has signalized that we should switch to / add netlink support for configuration. If upstream were to complain about yet another sysfs-only parameter, I'd argue that netlink config support is advancing but needs a bit more discussion and maturing. And it has no advantage to halt progress in other directions for that. Furthermore, there is a bit of urgency for this patch with the increasing size of batman-adv mesh networks and the multicast burden this creates. Finally, this patch was tested (and as far as I know is still applied) in some Freifunk communities. Maybe someone can add a "Tested-by" for this patch from there. For my and other people's tests see descriptions here: https://github.com/freifunk-gluon/gluon/pull/1357 --- Documentation/ABI/testing/sysfs-class-net-mesh | 9 + net/batman-adv/multicast.c | 268 ++++++++++++++++++++++++- net/batman-adv/multicast.h | 17 ++ net/batman-adv/soft-interface.c | 8 +- net/batman-adv/sysfs.c | 3 + net/batman-adv/translation-table.c | 6 +- net/batman-adv/translation-table.h | 4 + net/batman-adv/types.h | 6 + 8 files changed, 315 insertions(+), 6 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-net-mesh b/Documentation/ABI/testing/sysfs-class-net-mesh index c2b956d4..18734a36 100644 --- a/Documentation/ABI/testing/sysfs-class-net-mesh +++ b/Documentation/ABI/testing/sysfs-class-net-mesh @@ -76,6 +76,15 @@ Description: is used to classify clients as "isolated" by the Extended Isolation feature. +What: /sys/class/net/<mesh_iface>/mesh/multicast_fanout +Date: Feb 2018 +Contact: Linus Lüssing <linus.luessing(a)c0d3.blue> +Description: + Defines the maximum number of packet copies that may + be generated for a multicast-to-unicast conversion. + Once this limit is exceeded distribution will fall + back to broadcast. + What: /sys/class/net/<mesh_iface>/mesh/multicast_mode Date: Feb 2014 Contact: Linus Lüssing <linus.luessing(a)web.de> diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 5de6a375..d85c2226 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -66,6 +66,7 @@ #include "hash.h" #include "log.h" #include "netlink.h" +#include "send.h" #include "soft-interface.h" #include "translation-table.h" #include "tvlv.h" @@ -992,6 +993,7 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, int ret, tt_count, ip_count, unsnoop_count, total_count; bool is_unsnoopable = false; struct ethhdr *ethhdr; + unsigned int mcast_fanout; ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable); if (ret == -ENOMEM) @@ -1025,8 +1027,272 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, case 0: return BATADV_FORW_NONE; default: - return BATADV_FORW_ALL; + mcast_fanout = atomic_read(&bat_priv->multicast_fanout); + + if (!unsnoop_count && total_count <= mcast_fanout) + return BATADV_FORW_SOME; } + + return BATADV_FORW_ALL; +} + +/** + * batadv_mcast_forw_tt_send() - send a packet to multicast listeners + * @bat_priv: the bat priv with all the soft interface information + * @skb: the multicast packet to transmit + * @vid: the vlan identifier + * @limit: number of remaining, maximum transmissions + * + * Sends copies of a frame with multicast destination to any multicast + * listener registered in the translation table. A transmission is performed + * via a batman-adv unicast packet for each such destination node. + * + * Return: NET_XMIT_DROP if limit was reached or on memory allocation failure, + * NET_XMIT_SUCCESS otherwise. + */ +static int +batadv_mcast_forw_tt_send(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid, unsigned int *limit) +{ + unsigned int limit_tmp = *limit; + int ret = NET_XMIT_SUCCESS; + struct sk_buff *newskb; + + struct batadv_tt_orig_list_entry *orig_entry; + + struct batadv_tt_global_entry *tt_global; + const u8 *addr = eth_hdr(skb)->h_dest; + + tt_global = batadv_tt_global_hash_find(bat_priv, addr, vid); + if (!tt_global) + return NET_XMIT_DROP; + + rcu_read_lock(); + hlist_for_each_entry_rcu(orig_entry, &tt_global->orig_list, list) { + if (!limit_tmp) { + ret = NET_XMIT_DROP; + break; + } + + newskb = skb_copy(skb, GFP_ATOMIC); + if (!newskb) { + ret = NET_XMIT_DROP; + break; + } + + ret = batadv_send_skb_unicast(bat_priv, newskb, + BATADV_UNICAST, 0, + orig_entry->orig_node, vid); + + if (ret != NET_XMIT_SUCCESS) { + /* use kfree_skb() to signalize losses here, but keep + * trying other destinations + */ + kfree_skb(newskb); + ret = NET_XMIT_SUCCESS; + } + + limit_tmp--; + } + rcu_read_unlock(); + + batadv_tt_global_entry_put(tt_global); + *limit = limit_tmp; + + return ret; +} + +/** + * batadv_mcast_forw_want_all_ipv4_send() - send to nodes with want-all-ipv4 + * @bat_priv: the bat priv with all the soft interface information + * @skb: the multicast packet to transmit + * @vid: the vlan identifier + * @limit: number of remaining, maximum transmissions + * + * Sends copies of a frame with multicast destination to any node with a + * BATADV_MCAST_WANT_ALL_IPV4 flag set. A transmission is performed via a + * batman-adv unicast packet for each such destination node. + * + * Return: NET_XMIT_DROP if limit was reached or on memory allocation failure, + * NET_XMIT_SUCCESS otherwise. + */ +static int +batadv_mcast_forw_want_all_ipv4_send(struct batadv_priv *bat_priv, + struct sk_buff *skb, unsigned short vid, + unsigned int *limit) +{ + struct batadv_orig_node *orig_node; + unsigned int limit_tmp = *limit; + int ret = NET_XMIT_SUCCESS; + struct sk_buff *newskb; + + rcu_read_lock(); + hlist_for_each_entry_rcu(orig_node, + &bat_priv->mcast.want_all_ipv4_list, + mcast_want_all_ipv4_node) { + if (!limit_tmp) { + ret = NET_XMIT_DROP; + break; + } + + newskb = skb_copy(skb, GFP_ATOMIC); + if (!newskb) { + ret = NET_XMIT_DROP; + break; + } + + ret = batadv_send_skb_unicast(bat_priv, newskb, + BATADV_UNICAST, 0, + orig_node, vid); + + if (ret != NET_XMIT_SUCCESS) { + /* use kfree_skb() to signalize losses here, but keep + * trying other destinations + */ + kfree_skb(newskb); + ret = NET_XMIT_SUCCESS; + } + + limit_tmp--; + } + rcu_read_unlock(); + + *limit = limit_tmp; + return ret; +} + +/** + * batadv_mcast_forw_want_all_ipv6_send() - send to nodes with want-all-ipv6 + * @bat_priv: the bat priv with all the soft interface information + * @skb: The multicast packet to transmit + * @vid: the vlan identifier + * @limit: number of remaining, maximum transmissions + * + * Sends copies of a frame with multicast destination to any node with a + * BATADV_MCAST_WANT_ALL_IPV6 flag set. A transmission is performed via a + * batman-adv unicast packet for each such destination node. + * + * Return: NET_XMIT_DROP if limit was reached or on memory allocation failure, + * NET_XMIT_SUCCESS otherwise. + */ +static int +batadv_mcast_forw_want_all_ipv6_send(struct batadv_priv *bat_priv, + struct sk_buff *skb, unsigned short vid, + unsigned int *limit) +{ + struct batadv_orig_node *orig_node; + unsigned int limit_tmp = *limit; + int ret = NET_XMIT_SUCCESS; + struct sk_buff *newskb; + + rcu_read_lock(); + hlist_for_each_entry_rcu(orig_node, + &bat_priv->mcast.want_all_ipv6_list, + mcast_want_all_ipv6_node) { + if (!limit_tmp) { + ret = NET_XMIT_DROP; + break; + } + + newskb = skb_copy(skb, GFP_ATOMIC); + if (!newskb) { + ret = NET_XMIT_DROP; + break; + } + + ret = batadv_send_skb_unicast(bat_priv, newskb, + BATADV_UNICAST, 0, + orig_node, vid); + + if (ret != NET_XMIT_SUCCESS) { + /* use kfree_skb() to signalize losses here, but keep + * trying other destinations + */ + kfree_skb(newskb); + ret = NET_XMIT_SUCCESS; + } + + limit_tmp--; + } + rcu_read_unlock(); + + *limit = limit_tmp; + return ret; +} + +/** + * batadv_mcast_forw_want_all_send() - send packet to nodes in a want-all list + * @bat_priv: the bat priv with all the soft interface information + * @skb: the multicast packet to transmit + * @vid: the vlan identifier + * @limit: number of remaining, maximum transmissions + * + * Sends copies of a frame with multicast destination to any node with a + * BATADV_MCAST_WANT_ALL_IPV4 or BATADV_MCAST_WANT_ALL_IPV6 flag set. A + * transmission is performed via a batman-adv unicast packet for each such + * destination node. + * + * Return: NET_XMIT_DROP if limit was reached, on memory allocation failure + * or if the protocol family is neither IPv4 nor IPv6. NET_XMIT_SUCCESS + * otherwise. + */ +static int +batadv_mcast_forw_want_all_send(struct batadv_priv *bat_priv, + struct sk_buff *skb, unsigned short vid, + unsigned int *limit) +{ + switch (ntohs(eth_hdr(skb)->h_proto)) { + case ETH_P_IP: + return batadv_mcast_forw_want_all_ipv4_send(bat_priv, skb, vid, + limit); + case ETH_P_IPV6: + return batadv_mcast_forw_want_all_ipv6_send(bat_priv, skb, vid, + limit); + default: + /* we shouldn't be here... */ + return NET_XMIT_DROP; + } +} + +/** + * batadv_mcast_forw_send() - send packet to any detected multicast recpient + * @bat_priv: the bat priv with all the soft interface information + * @skb: the multicast packet to transmit + * @vid: the vlan identifier + * @limit: number of remaining, maximum transmissions + * + * Sends copies of a frame with multicast destination to any node that signaled + * interest in it, that is either via the translation table or the according + * want-all flags. A transmission is performed via a batman-adv unicast packet + * for each such destination node. + * + * If NET_XMIT_DROP is returned then caller needs to free the provided skb. + * Otherwise it is consumed. + * + * Return: NET_XMIT_DROP if limit was reached, on memory allocation failure + * or if the protocol family is neither IPv4 nor IPv6. NET_XMIT_SUCCESS + * otherwise. + */ +int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ + /* The previous forw mode check will try to limit to the configured + * fanout. Here, we allow a little bit of flexibility in case some + * new listeners might have joined between these function calls. + */ + unsigned int limit = 2 * atomic_read(&bat_priv->multicast_fanout); + int ret; + + ret = batadv_mcast_forw_tt_send(bat_priv, skb, vid, &limit); + if (ret != NET_XMIT_SUCCESS) + return ret; + + ret = batadv_mcast_forw_want_all_send(bat_priv, skb, vid, &limit); + if (ret != NET_XMIT_SUCCESS) + return ret; + + consume_skb(skb); + return ret; } /** diff --git a/net/batman-adv/multicast.h b/net/batman-adv/multicast.h index 466013fe..24424e51 100644 --- a/net/batman-adv/multicast.h +++ b/net/batman-adv/multicast.h @@ -36,6 +36,13 @@ enum batadv_forw_mode { BATADV_FORW_ALL, /** + * @BATADV_FORW_SOME: forward the packet to some nodes (currently via + * a multicast-to-unicast conversion and the BATMAN unicast routing + * protocol) + */ + BATADV_FORW_SOME, + + /** * @BATADV_FORW_SINGLE: forward the packet to a single node (currently * via the BATMAN unicast routing protocol) */ @@ -51,6 +58,9 @@ enum batadv_forw_mode batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_orig_node **mcast_single_orig); +int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid); + void batadv_mcast_init(struct batadv_priv *bat_priv); int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset); @@ -73,6 +83,13 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, return BATADV_FORW_ALL; } +static inline int +batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ + return NET_XMIT_DROP; +} + static inline int batadv_mcast_init(struct batadv_priv *bat_priv) { return 0; diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 5357dcae..9adb9ad1 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -209,7 +209,7 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, unsigned short vid; u32 seqno; int gw_mode; - enum batadv_forw_mode forw_mode; + enum batadv_forw_mode forw_mode = BATADV_FORW_SINGLE; struct batadv_orig_node *mcast_single_orig = NULL; int network_offset = ETH_HLEN; @@ -308,7 +308,8 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, if (forw_mode == BATADV_FORW_NONE) goto dropped; - if (forw_mode == BATADV_FORW_SINGLE) + if (forw_mode == BATADV_FORW_SINGLE || + forw_mode == BATADV_FORW_SOME) do_bcast = false; } } @@ -368,6 +369,8 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0, mcast_single_orig, vid); + } else if (forw_mode == BATADV_FORW_SOME) { + ret = batadv_mcast_forw_send(bat_priv, skb, vid); } else { if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb)) @@ -809,6 +812,7 @@ static int batadv_softif_init_late(struct net_device *dev) bat_priv->mcast.querier_ipv6.shadowing = false; bat_priv->mcast.flags = BATADV_NO_FLAGS; atomic_set(&bat_priv->multicast_mode, 1); + atomic_set(&bat_priv->multicast_fanout, 16); atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0); atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0); atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0); diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index e1b81626..15c06b4c 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -697,6 +697,8 @@ static BATADV_ATTR(gw_bandwidth, 0644, batadv_show_gw_bwidth, batadv_store_gw_bwidth); #ifdef CONFIG_BATMAN_ADV_MCAST BATADV_ATTR_SIF_BOOL(multicast_mode, 0644, NULL); +BATADV_ATTR_SIF_UINT(multicast_fanout, multicast_fanout, 0644, 1, INT_MAX, + NULL); #endif #ifdef CONFIG_BATMAN_ADV_DEBUG BATADV_ATTR_SIF_UINT(log_level, log_level, 0644, 0, BATADV_DBG_ALL, NULL); @@ -718,6 +720,7 @@ static struct batadv_attribute *batadv_mesh_attrs[] = { #endif #ifdef CONFIG_BATMAN_ADV_MCAST &batadv_attr_multicast_mode, + &batadv_attr_multicast_fanout, #endif &batadv_attr_fragmentation, &batadv_attr_routing_algo, diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index f73d7913..8f83554b 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -61,6 +61,7 @@ #include "log.h" #include "netlink.h" #include "originator.h" +#include "send.h" #include "soft-interface.h" #include "tvlv.h" @@ -205,7 +206,7 @@ batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const u8 *addr, * Return: a pointer to the corresponding tt_global_entry struct if the client * is found, NULL otherwise. */ -static struct batadv_tt_global_entry * +struct batadv_tt_global_entry * batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr, unsigned short vid) { @@ -300,8 +301,7 @@ static void batadv_tt_global_entry_release(struct kref *ref) * possibly release it * @tt_global_entry: tt_global_entry to be free'd */ -static void -batadv_tt_global_entry_put(struct batadv_tt_global_entry *tt_global_entry) +void batadv_tt_global_entry_put(struct batadv_tt_global_entry *tt_global_entry) { kref_put(&tt_global_entry->common.refcount, batadv_tt_global_entry_release); diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h index 61bca75e..5b41f217 100644 --- a/net/batman-adv/translation-table.h +++ b/net/batman-adv/translation-table.h @@ -41,6 +41,10 @@ int batadv_tt_global_dump(struct sk_buff *msg, struct netlink_callback *cb); void batadv_tt_global_del_orig(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, s32 match_vid, const char *message); +struct batadv_tt_global_entry * +batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr, + unsigned short vid); +void batadv_tt_global_entry_put(struct batadv_tt_global_entry *tt_global_entry); int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const u8 *addr, unsigned short vid); struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a21b34ed..d22cf01e 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1565,6 +1565,12 @@ struct batadv_priv { * node's sender/originating side */ atomic_t multicast_mode; + + /** + * @multicast_fanout: Maximum number of packet copies to generate for a + * multicast-to-unicast conversion + */ + atomic_t multicast_fanout; #endif /** @orig_interval: OGM broadcast interval in milliseconds */ -- 2.11.0

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[B.A.T.M.A.N.] "Kernel bug detected [...] nf_ct_del_from_dying_or_unconfirmed_list"
by Linus Lüssing 29 Jan '19

29 Jan '19

Hi, I was trying to implement a multicast-to-multi-unicast conversion in batman-adv with the following patch: https://patchwork.open-mesh.org/patch/17729/ However, on OpenWrt with a 4.9.146 kernel I get a "Kernel bug detected [...] nf_ct_del_from_dying_or_unconfirmed_list". This only happens upon sending a SIGTERM to the network manager "netifd" (so upon network shutdown). And only if the node is connected to mesh of reasonable size, so if there is a certain amount of multicast traffic for the multicast-to-multi-unicast patch to work on. Upon normal operation, no such crash seems to occur. The crash itself is triggered by the: BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode)); in here: https://elixir.bootlin.com/linux/v4.9.146/source/net/netfilter/nf_conntrack… What confuses me a bit is, that the multicast-to-multi-unicast conversion uses the same/similar, simple skb_copy() approach like the "classic broadcast flooding" approach in batman-adv so far. The latter too transmits three redundant frames via skb_copy() to increase reliability for Wifi broadcast packets. One difference is that the broadcast flooding adds a bit of delay between each transmission. Which the multicast-to-multi-unicast doesn't. Looking at "git log net/netfilter/nf_conntrack_core.c" I noticed "netfilter: nfnetlink_queue: resolve clash for unconfirmed conntracks" (368982cd7). Which says: "In nfqueue, two consecutive skbuffs may race to create the conntrack entry. Hence, the one that loses the race gets dropped due to clash in the insertion into the hashes from the nf_conntrack_confirm() path." This patch is only part of >= 4.18, so not part of the firmware we use yet. Could this issue somehow be related? Other than that I was wondering whether we might be missing to reset something after skb_copy()-ing. We do a "skb->protocol = htons(ETH_P_BATMAN)" right before the dev_queue_xmit(skb) call in batman-adv which sends the encapsulated frame into the mesh. And we do a nf_reset(skb) after decapsulating a frame received from the mesh. But maybe that is not enough? Ticket this issue was reported at: https://github.com/freifunk-gluon/gluon/issues/1468 Regards, Linus

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B.A.T.M.A.N January 2019