From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754010AbdGUI7P (ORCPT ); Fri, 21 Jul 2017 04:59:15 -0400 Received: from nbd.name ([46.4.11.11]:51387 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753829AbdGUI7C (ORCPT ); Fri, 21 Jul 2017 04:59:02 -0400 From: John Crispin To: Andrew Lunn , Vivien Didelot , Florian Fainelli , "David S . Miller" Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, John Crispin Subject: [PATCH V2 3/4] net-next: dsa: fix flow dissection Date: Fri, 21 Jul 2017 10:58:12 +0200 Message-Id: <20170721085813.30789-3-john@phrozen.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170721085813.30789-1-john@phrozen.org> References: <20170721085813.30789-1-john@phrozen.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RPS and probably other kernel features are currently broken on some if not all DSA devices. The root cause of this is that skb_hash will call the flow_dissector. At this point the skb still contains the magic switch header and the skb->protocol field is not set up to the correct 802.3 value yet. By the time the tag specific code is called, removing the header and properly setting the protocol an invalid hash is already set. In the case of the mt7530 this will result in all flows always having the same hash. This patch makes the flow dissector honour the nh and protocol offset defined by the dsa tag driver thus fixing dissection, hashing and RPS. Signed-off-by: John Crispin --- net/core/flow_dissector.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index fc5fc4594c90..1268ae75c3b3 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -440,6 +441,17 @@ bool __skb_flow_dissect(const struct sk_buff *skb, skb->vlan_proto : skb->protocol; nhoff = skb_network_offset(skb); hlen = skb_headlen(skb); + + if (unlikely(netdev_uses_dsa(skb->dev))) { + const struct dsa_device_ops *ops; + u8 *p = (u8 *)data; + + ops = skb->dev->dsa_ptr->tag_ops; + if (ops->hash_proto_off) + proto = (u16)p[ops->hash_proto_off]; + hlen -= ops->hash_nh_off; + nhoff += ops->hash_nh_off; + } } /* It is ensured by skb_flow_dissector_init() that control key will -- 2.11.0