From patchwork Thu Sep 18 00:10:21 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David L Stevens X-Patchwork-Id: 390567 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 43344140180 for ; Thu, 18 Sep 2014 10:10:30 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753741AbaIRAK0 (ORCPT ); Wed, 17 Sep 2014 20:10:26 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:47141 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752994AbaIRAKZ (ORCPT ); Wed, 17 Sep 2014 20:10:25 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s8I0ANBc031106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 18 Sep 2014 00:10:24 GMT Received: from aserz7021.oracle.com (aserz7021.oracle.com [141.146.126.230]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s8I0AMV3027899 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 18 Sep 2014 00:10:23 GMT Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserz7021.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s8I0AM7S028639; Thu, 18 Sep 2014 00:10:22 GMT Received: from [10.154.186.239] (/10.154.186.239) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 17 Sep 2014 17:10:21 -0700 Message-ID: <541A22ED.9030707@oracle.com> Date: Wed, 17 Sep 2014 20:10:21 -0400 From: David L Stevens Organization: Oracle Corporation User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: David Miller CC: netdev@vger.kernel.org Subject: [PATCHv6 net-next 3/3] sunvnet: generate ICMP PTMUD messages for smaller port MTUs X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch sends ICMP and ICMPv6 messages for Path MTU Discovery when a remote port MTU is smaller than the device MTU. This allows mixing newer VIO protocol devices that support MTU negotiation with older devices that do not on the same vswitch. It also allows Linux-Linux LDOMs to use 64K-1 data packets even though Solaris vswitch is limited to <16K MTU. Signed-off-by: David L Stevens --- drivers/net/ethernet/sun/sunvnet.c | 37 +++++++++++++++++++++++++++++++++++- 1 files changed, 36 insertions(+), 1 deletions(-) diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index 5e64e60..3c4ee18 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -17,6 +17,13 @@ #include #include +#if IS_ENABLED(CONFIG_IPV6) +#include +#endif + +#include +#include + #include #include @@ -791,8 +798,36 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) if (unlikely(!port)) goto out_dropped; - if (skb->len > port->rmtu) + if (skb->len > port->rmtu) { + unsigned long localmtu = port->rmtu - ETH_HLEN; + + if (vio_version_after_eq(&port->vio, 1, 3)) + localmtu -= VLAN_HLEN; + + if (skb->protocol == htons(ETH_P_IP)) { + struct flowi4 fl4; + struct rtable *rt = NULL; + + memset(&fl4, 0, sizeof(fl4)); + fl4.flowi4_oif = dev->ifindex; + fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); + fl4.daddr = ip_hdr(skb)->daddr; + fl4.saddr = ip_hdr(skb)->saddr; + + rt = ip_route_output_key(dev_net(dev), &fl4); + if (!IS_ERR(rt)) { + skb_dst_set(skb, &rt->dst); + icmp_send(skb, ICMP_DEST_UNREACH, + ICMP_FRAG_NEEDED, + htonl(localmtu)); + } + } +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, localmtu); +#endif goto out_dropped; + } spin_lock_irqsave(&port->vio.lock, flags);