Commit 43e66528 authored Aug 09, 2017 by John Crispin Committed by David S. Miller Aug 09, 2017

net-next: dsa: fix flow dissection



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.

Signed-off-by: Muciri Gatimu <muciri@openmesh.com>
Signed-off-by: Shashidhar Lakkavalli <shashidhar.lakkavalli@openmesh.com>
Signed-off-by: John Crispin <john@phrozen.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2dd592b2

net/core/flow_dissector.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@
		#include <linux/ip.h>
		#include <linux/ipv6.h>
		#include <linux/if_vlan.h>
		#include <net/dsa.h>
		#include <net/ip.h>
		#include <net/ipv6.h>
		#include <net/gre.h>
		@@ -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;
		int offset;

		ops = skb->dev->dsa_ptr->tag_ops;
		if (ops->flow_dissect &&
		!ops->flow_dissect(skb, &proto, &offset)) {
		hlen -= offset;
		nhoff += offset;
		}
		}
		}

		/* It is ensured by skb_flow_dissector_init() that control key will

Admin message