If dat is enabled it must be made sure that only the backbone gw which has claimed the remote destination for the ARP request answers the ARP request directly if the MAC address is known due to the local dat table. This prevents multiple ARP replies in a common backbone if more than one gateway already knows the remote mac searched for in the ARP request. Signed-off-by: Andreas Pape <apape(a)phoenixcontact.com> --- net/batman-adv/bridge_loop_avoidance.c | 49 ++++++++++++++++++++++++++++++++ net/batman-adv/bridge_loop_avoidance.h | 11 +++++++ net/batman-adv/distributed-arp-table.c | 15 ++++++++++ 3 files changed, 75 insertions(+), 0 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 748a9ea..2f46ce9 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -2045,3 +2045,52 @@ out: batadv_hardif_put(primary_if); return 0; } + +#ifdef CONFIG_BATMAN_ADV_DAT +/** + * batadv_bla_handle_local_claim - check if address is claimed + * + * @bat_priv: the bat priv with all the soft interface information + * @addr: mac address of which the claim status is checked + * @vid: the VLAN ID + * + * addr is checked if this address is claimed by the local device itself. + * + * Return: true if bla is disabled or the mac is claimed by the device, + * false if the device addr is already claimed by another gateway + */ +bool batadv_bla_handle_local_claim(struct batadv_priv *bat_priv, + u8 *addr, unsigned short vid) +{ + struct batadv_bla_claim search_claim; + struct batadv_bla_claim *claim = NULL; + struct batadv_hard_iface *primary_if = NULL; + bool ret = true; + + if (!atomic_read(&bat_priv->bridge_loop_avoidance)) + return ret; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + return ret; + + /* First look if the mac address is claimed */ + ether_addr_copy(search_claim.addr, addr); + search_claim.vid = vid; + + claim = batadv_claim_hash_find(bat_priv, &search_claim); + + /* If there is a claim and we are not owner of the claim, + * return false. + */ + if (claim) { + if (!batadv_compare_eth(claim->backbone_gw->orig, + primary_if->net_dev->dev_addr)) + ret = false; + batadv_claim_put(claim); + } + + batadv_hardif_put(primary_if); + return ret; +} +#endif diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h index 0f01dae..cc07be9 100644 --- a/net/batman-adv/bridge_loop_avoidance.h +++ b/net/batman-adv/bridge_loop_avoidance.h @@ -47,6 +47,10 @@ void batadv_bla_update_orig_address(struct batadv_priv *bat_priv, void batadv_bla_status_update(struct net_device *net_dev); int batadv_bla_init(struct batadv_priv *bat_priv); void batadv_bla_free(struct batadv_priv *bat_priv); +#ifdef CONFIG_BATMAN_ADV_DAT +bool batadv_bla_handle_local_claim(struct batadv_priv *bat_priv, u8 *addr, + unsigned short vid); +#endif #define BATADV_BLA_CRC_INIT 0 #else /* ifdef CONFIG_BATMAN_ADV_BLA */ @@ -112,6 +116,13 @@ static inline void batadv_bla_free(struct batadv_priv *bat_priv) { } +static inline +bool batadv_bla_handle_local_claim(struct batadv_priv *bat_priv, u8 *addr, + unsigned short vid) +{ + return true; +} + #endif /* ifdef CONFIG_BATMAN_ADV_BLA */ #endif /* ifndef _NET_BATMAN_ADV_BLA_H_ */ diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 278800a..c11f035 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -48,6 +48,7 @@ #include "originator.h" #include "send.h" #include "translation-table.h" +#include "bridge_loop_avoidance.h" static void batadv_dat_purge(struct work_struct *work); @@ -1003,6 +1004,20 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, goto out; } + /* If BLA is enabled, only send ARP replies if we have claimed + * the destination for the ARP request or if no one else of + * the backbone gws belonging to our backbone has claimed the + * destination. + */ + if (!batadv_bla_handle_local_claim(bat_priv, + dat_entry->mac_addr, vid)) { + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Device %pM claimed by another backbone gw. Don't send ARP reply!", + dat_entry->mac_addr); + ret = true; + goto out; + } + skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, bat_priv->soft_iface, ip_dst, hw_src, dat_entry->mac_addr, hw_src); -- 1.7.0.4 .................................................................. PHOENIX CONTACT ELECTRONICS GmbH Sitz der Gesellschaft / registered office of the company: 31812 Bad Pyrmont USt-Id-Nr.: DE811742156 Amtsgericht Hannover HRB 100528 / district court Hannover HRB 100528 Geschäftsführer / Executive Board: Roland Bent, Dr. Martin Heubeck ___________________________________________________________________ Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren, jegliche anderweitige Verwendung sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet. ---------------------------------------------------------------------------------------------------- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure, distribution or other use of the material or parts thereof is strictly forbidden. ___________________________________________________________________

If none of the backbone gateways in a bla setup has already knowledge of the mac address searched for in an incoming ARP request from the backbone an address resolution via the DHT of DAT is started. The gateway can send several ARP requests to different DHT nodes and therefore can get several replies. This patch assures that not all of the possible ARP replies are returned to the backbone by checking the local DAT cache of the gateway. If there is an entry in the local cache the gateway has already learned the requested address and there is no need to forward the additional reply to the backbone. Furthermore it is checked if this gateway has claimed the source of the ARP reply and only forwards it to the backbone if it has claimed the source or if there is no claim at all. Signed-off-by: Andreas Pape <apape(a)phoenixcontact.com> --- net/batman-adv/distributed-arp-table.c | 32 ++++++++++++++++++++++++++++++++ 1 files changed, 32 insertions(+), 0 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 58cb488..f025c69 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -1239,6 +1239,7 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, __be32 ip_src, ip_dst; u8 *hw_src, *hw_dst; bool dropped = false; + struct batadv_dat_entry *dat_entry = NULL; unsigned short vid; if (!atomic_read(&bat_priv->distributed_arp_table)) @@ -1258,12 +1259,41 @@ bool batadv_dat_snoop_incoming_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); + /* If ip_dst is already in cache and has the right mac address, + * drop this frame if this ARP reply is destined for us because it's + * most probably an ARP reply generated by another node of the DHT. + * We have most probably received already a reply earlier. Delivering + * this frame would lead to doubled receive of an ARP reply. + */ + dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid); + if ((dat_entry) && (batadv_compare_eth(hw_src, dat_entry->mac_addr))) { + batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n", + hw_src, &ip_src, hw_dst, &ip_dst, + dat_entry->mac_addr, &dat_entry->ip); + dropped = true; + goto out; + } + /* 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); + /* 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 + * already claimed that client. This prevents that different gateways + * to the same backbone all forward the ARP reply leading to multiple + * replies in the backbone. + */ + if (!batadv_bla_handle_local_claim(bat_priv, hw_src, vid)) { + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Device %pM claimed by another backbone gw. Drop ARP reply.\n", + hw_src); + dropped = true; + goto out; + } + /* if this REPLY is directed to a client of mine, let's deliver the * packet to the interface */ @@ -1276,6 +1306,8 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, out: if (dropped) kfree_skb(skb); + if (dat_entry) + batadv_dat_entry_put(dat_entry); /* if dropped == false -> deliver to the interface */ return dropped; } -- 1.7.0.4 .................................................................. PHOENIX CONTACT ELECTRONICS GmbH Sitz der Gesellschaft / registered office of the company: 31812 Bad Pyrmont USt-Id-Nr.: DE811742156 Amtsgericht Hannover HRB 100528 / district court Hannover HRB 100528 Geschäftsführer / Executive Board: Roland Bent, Dr. Martin Heubeck ___________________________________________________________________ Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren, jegliche anderweitige Verwendung sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet. ---------------------------------------------------------------------------------------------------- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure, distribution or other use of the material or parts thereof is strictly forbidden. ___________________________________________________________________

Some of the bla debug messages are extended and additional messages are added for easier bla debugging. Some debug messages introduced with the dat changes in prior patches of this patch series have been changed to be more compliant to other existing debug messages. Acked-by: Simon Wunderlich <sw(a)simonwunderlich.de> Signed-off-by: Andreas Pape <apape(a)phoenixcontact.com> --- net/batman-adv/bridge_loop_avoidance.c | 18 ++++++++++++++---- net/batman-adv/routing.c | 2 +- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 2f46ce9..c426327 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -715,8 +715,8 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, goto claim_free_ref; batadv_dbg(BATADV_DBG_BLA, bat_priv, - "bla_add_claim(): changing ownership for %pM, vid %d\n", - mac, BATADV_PRINT_VID(vid)); + "bla_add_claim(): changing ownership for %pM, vid %d to gw %pM\n", + mac, BATADV_PRINT_VID(vid), backbone_gw->orig); spin_lock_bh(&claim->backbone_gw->crc_lock); claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); @@ -1240,10 +1240,13 @@ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv, continue; batadv_dbg(BATADV_DBG_BLA, bat_priv, - "bla_purge_claims(): %pM, vid %d, time out\n", + "bla_purge_claims(): timed out.\n"); + +purge_now: + batadv_dbg(BATADV_DBG_BLA, bat_priv, + "bla_purge_claims(): %pM, vid %d\n", claim->addr, claim->vid); -purge_now: batadv_handle_unclaim(bat_priv, primary_if, claim->backbone_gw->orig, claim->addr, claim->vid); @@ -1787,6 +1790,13 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, /* possible optimization: race for a claim */ /* 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); diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 1ef0735..99186da 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -916,7 +916,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, if (orig_node && batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) { batadv_dbg(BATADV_DBG_BLA, bat_priv, - "Dropped unicast pkt received from another backbone gw %pM.\n", + "recv_unicast_packet(): Dropped unicast pkt received from another backbone gw %pM.\n", orig_addr); batadv_orig_node_put(orig_node); return NET_RX_DROP; -- 1.7.0.4 .................................................................. PHOENIX CONTACT ELECTRONICS GmbH Sitz der Gesellschaft / registered office of the company: 31812 Bad Pyrmont USt-Id-Nr.: DE811742156 Amtsgericht Hannover HRB 100528 / district court Hannover HRB 100528 Geschäftsführer / Executive Board: Roland Bent, Dr. Martin Heubeck ___________________________________________________________________ Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren, jegliche anderweitige Verwendung sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet. ---------------------------------------------------------------------------------------------------- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure, distribution or other use of the material or parts thereof is strictly forbidden. ___________________________________________________________________

On Friday 06 May 2016 10:58:23 Andreas Pape wrote: Haven't really looked at your patchset but was just interested in this new function. But I didn't came to look at it because I saw this weird include. Doesn't seem to make sense here at all when you look at the rest of the changes in this file: Kind regards, Sven