From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerhard Stenzel Subject: [PATCH v2 net] vxlan: fix incorrect initializer in union vxlan_addr Date: Fri, 22 Aug 2014 21:34:16 +0200 Message-ID: <53F79B38.8070806@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org, davem@davemloft.net Return-path: Received: from e06smtp14.uk.ibm.com ([195.75.94.110]:57366 "EHLO e06smtp14.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751679AbaHVTeV (ORCPT ); Fri, 22 Aug 2014 15:34:21 -0400 Received: from /spool/local by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 22 Aug 2014 20:34:19 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 7A941219002D for ; Fri, 22 Aug 2014 20:33:59 +0100 (BST) Received: from d06av12.portsmouth.uk.ibm.com (d06av12.portsmouth.uk.ibm.com [9.149.37.247]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s7MJYHIB32178206 for ; Fri, 22 Aug 2014 19:34:17 GMT Received: from d06av12.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av12.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s7MJYGJZ014717 for ; Fri, 22 Aug 2014 13:34:17 -0600 Sender: netdev-owner@vger.kernel.org List-ID: The first initializer in the following union vxlan_addr ipa = { .sin.sin_addr.s_addr = tip, .sa.sa_family = AF_INET, }; is optimised away by the compiler, due to the second initializer, therefore initialising .sin.sin_addr.s_addr always to 0. This results in netlink messages indicating a L3 miss never contain the missed IP address. This was observed with GCC 4.8 and 4.9. I do not know about previous versions. The problem affects user space programs relying on an IP address being sent as part of a netlink message indicating a L3 miss. Changing .sa.sa_family = AF_INET, to .sin.sin_family = AF_INET, fixes the problem. Signed-off-by: Gerhard Stenzel --- diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 1fb7b37..beb377b 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1327,7 +1327,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb) } else if (vxlan->flags & VXLAN_F_L3MISS) { union vxlan_addr ipa = { .sin.sin_addr.s_addr = tip, - .sa.sa_family = AF_INET, + .sin.sin_family = AF_INET, }; vxlan_ip_miss(dev, &ipa); @@ -1488,7 +1488,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb) } else if (vxlan->flags & VXLAN_F_L3MISS) { union vxlan_addr ipa = { .sin6.sin6_addr = msg->target, - .sa.sa_family = AF_INET6, + .sin6.sin6_family = AF_INET6, }; vxlan_ip_miss(dev, &ipa); @@ -1521,7 +1521,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) if (!n && (vxlan->flags & VXLAN_F_L3MISS)) { union vxlan_addr ipa = { .sin.sin_addr.s_addr = pip->daddr, - .sa.sa_family = AF_INET, + .sin.sin_family = AF_INET, }; vxlan_ip_miss(dev, &ipa); @@ -1542,7 +1542,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) if (!n && (vxlan->flags & VXLAN_F_L3MISS)) { union vxlan_addr ipa = { .sin6.sin6_addr = pip6->daddr, - .sa.sa_family = AF_INET6, + .sin6.sin6_family = AF_INET6, }; vxlan_ip_miss(dev, &ipa);