From patchwork Fri Feb 26 13:18:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andreas Pape X-Patchwork-Id: 15848 X-Patchwork-Delegate: mareklindner@neomailbox.ch Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from open-mesh.org (localhost [127.0.0.1]) by open-mesh.org (Postfix) with ESMTP id 3441F8190D; Fri, 26 Feb 2016 14:18:45 +0100 (CET) Received-SPF: None (no SPF record) identity=mailfrom; client-ip=62.157.123.121; helo=mail2.phoenixcontact.com; envelope-from=apape@phoenixcontact.com; receiver=b.a.t.m.a.n@lists.open-mesh.org Authentication-Results: open-mesh.org; dmarc=none header.from=phoenixcontact.com Received: from mail2.phoenixcontact.com (mail2.phoenixcontact.com [62.157.123.121]) by open-mesh.org (Postfix) with ESMTPS id 3AD7A8190A for ; Fri, 26 Feb 2016 14:18:43 +0100 (CET) Received: from localhost.localdomain ([149.208.237.66]) by de-nice01.de.phoenixcontact.com with ESMTP id 2016022614184157-38956 ; Fri, 26 Feb 2016 14:18:41 +0100 From: Andreas Pape To: b.a.t.m.a.n@lists.open-mesh.org X-Mailer: git-send-email 1.7.0.4 X-MIMETrack: Itemize by SMTP Server on DE-NICE01/Hub/SRV/DE/Phoenix Contact at 26.02.2016 14:18:41, Serialize by ntm_grab.EXE on nemex02/spoke/SRV/DE/Phoenix Contact at 26.02.2016 14:18:34, Serialize complete at 26.02.2016 14:18:34, Itemize by ntm_grab.EXE on nemex02/spoke/SRV/DE/Phoenix Contact at 26.02.2016 14:18:34, Serialize by Router on nemex02/spoke/SRV/DE/Phoenix Contact at 26.02.2016 14:18:35, Serialize complete at 26.02.2016 14:18:35 X-TNEFEvaluated: 1 Message-ID: <1456492719-29748-1-git-send-email-apape@phoenixcontact.com> Date: Fri, 26 Feb 2016 14:18:39 +0100 content-transfer-encoding: quoted-printable content-type: text/plain; charset="utf-8" Subject: [B.A.T.M.A.N.] [PATCHv2 3/7] batman-adv: prevent duplication of ARP replies when DAT is used X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" 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 it must be prevented that multiple ARP replies are generated and returned to the backbone by the dat address resolution mechanism of other dat enabled nodes of the mesh. Signed-off-by: Andreas Pape --- net/batman-adv/distributed-arp-table.c | 65 +++++++++++++++++++++++++++++++- 1 files changed, 64 insertions(+), 1 deletions(-) -- 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 diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 0f899b9..f60fccb 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -1081,6 +1081,8 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, u8 *hw_src; struct sk_buff *skb_new; struct batadv_dat_entry *dat_entry = NULL; + struct batadv_unicast_4addr_packet *unicast_4addr_packet; + struct batadv_orig_node *orig_node = NULL; bool ret = false; unsigned short vid; int err; @@ -1104,8 +1106,38 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); - if (!dat_entry) + if (!dat_entry) { + /* Check if this is a 4addr unicast DAT_DHT_GET frame from + * another backbone gw of the same backbone. If yes, drop + * it as this leads to multiplication of arp requests in bla + * setups as long as there is no dat_entry fo this answer. + * In this case better drop the DHT_GET. Normal bla code + * doesn't take care of these packets as they are tunneled + * via unicast. + */ + unicast_4addr_packet = + (struct batadv_unicast_4addr_packet *)skb->data; + orig_node = + batadv_orig_hash_find(bat_priv, + unicast_4addr_packet->src); + if (orig_node) { + if ((unicast_4addr_packet->u.packet_type == + BATADV_UNICAST_4ADDR) && + (unicast_4addr_packet->subtype == + BATADV_P_DAT_DHT_GET) && + (batadv_bla_is_backbone_gw(skb, orig_node, + hdr_size))) { + batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP request removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; originator: %pM\n", + hw_src, &ip_src, + batadv_arp_hw_dst(skb, hdr_size), + &ip_dst, unicast_4addr_packet->src); + ret = true; + } + batadv_orig_node_put(orig_node); + } + goto out; + } skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, bat_priv->soft_iface, ip_dst, hw_src, @@ -1204,6 +1236,7 @@ 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)) @@ -1223,12 +1256,40 @@ 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. We have + * most probably received already a reply from someone else. 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 */ @@ -1241,6 +1302,8 @@ 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; }