From patchwork Tue May 27 22:45:49 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jon Maxwell X-Patchwork-Id: 353194 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 83C6F140098 for ; Wed, 28 May 2014 08:46:27 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752772AbaE0WqK (ORCPT ); Tue, 27 May 2014 18:46:10 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:47456 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbaE0WqI (ORCPT ); Tue, 27 May 2014 18:46:08 -0400 Received: by mail-pa0-f41.google.com with SMTP id kx10so49522pab.14 for ; Tue, 27 May 2014 15:46:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=Y0ZcmZtzDJYXIxa5wuP+zJgiw+MARnPcC3V3OMM2pVw=; b=TpaAA3xbA2NxgOQ/vnRBhQNTOaJfmlhTJ44RLEu/Z6/MrfqUEzmbvqKKsZYgqfPTOa vmgdtnvPt5CW8wARHXV8DsgkEoMBIaUilGl2VtDbvHMBgjfflnQLM9KxHaplFeYzuDTx I3Zd6MP7uOqC09/QP+7BR7GbyxYJzMzUibF5LaW+q7373VhKoJj8LEUh/Wa3x2pfXcz5 XMOQfnKjJthCHHleRwWI0VvnKy0ErWVOZ0ju81KvJJy0/zshsOKOX+Oe8JX/b8fZ6CPs 5NSxci6EJnMjcsqHF2RrPTUaElfs310st/qllPYSI3CSikz3pHXpi0q/LiYMgHAk+vxN vUPg== X-Received: by 10.66.150.228 with SMTP id ul4mr41407083pab.16.1401230767891; Tue, 27 May 2014 15:46:07 -0700 (PDT) Received: from dhcp-1-107.bne.redhat.com (110-175-8-199.static.tpgi.com.au. [110.175.8.199]) by mx.google.com with ESMTPSA id ga1sm25019713pbb.82.2014.05.27.15.46.04 for (version=TLSv1.2 cipher=AES128-GCM-SHA256 bits=128/128); Tue, 27 May 2014 15:46:07 -0700 (PDT) From: Jon Maxwell To: stephen@networkplumber.org Cc: davem@davemloft.net, makita.toshiaki@lab.ntt.co.jp, vyasevic@redhat.com, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jpirko@redhat.com, jmaxwell37@gmail.com, jmaxwell@redhat.com Subject: [PATCH net] bridge: notify user space after fdb update Date: Wed, 28 May 2014 08:45:49 +1000 Message-Id: <1401230749-19507-1-git-send-email-jmaxwell37@gmail.com> X-Mailer: git-send-email 1.8.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org There has been a number incidents recently where customers running KVM have reported that VM hosts on different Hypervisors are unreachable. Based on pcap traces we found that the bridge was broadcasting the ARP request out onto the network. However some NICs have an inbuilt switch which on occasions were broadcasting the VMs ARP request back through the physical NIC on the Hypervisor. This resulted in the bridge changing ports and incorrectly learning that the VMs mac address was external. As a result the ARP reply was directed back onto the external network and VM never updated it's ARP cache. This patch will notify the bridge command, after a fdb has been updated to identify such port toggling. Signed-off-by: Jon Maxwell --- net/bridge/br_fdb.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index 9203d5a..f3ee2da 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -487,6 +487,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, { struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *fdb; + bool fdb_modified = 0; /* some users want to always flood. */ if (hold_time(br) == 0) @@ -507,10 +508,15 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, source->dev->name); } else { /* fastpath: update of existing entry */ - fdb->dst = source; + if (unlikely(source != fdb->dst)) { + fdb->dst = source; + fdb_modified = 1; + } fdb->updated = jiffies; if (unlikely(added_by_user)) fdb->added_by_user = 1; + if (unlikely(fdb_modified)) + fdb_notify(br, fdb, RTM_NEWNEIGH); } } else { spin_lock(&br->hash_lock);