From 68277a2c9d32fd9090247a5c08aaf1353049c0b1 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Wed, 9 Aug 2017 14:41:16 +0200 Subject: [PATCH 1/4] net-next: dsa: move struct dsa_device_ops to the global header file We need to access this struct from within the flow_dissector to fix dissection for packets coming in on DSA devices. Signed-off-by: Muciri Gatimu Signed-off-by: Shashidhar Lakkavalli Signed-off-by: John Crispin Signed-off-by: David S. Miller --- include/net/dsa.h | 7 +++++++ net/dsa/dsa_priv.h | 7 ------- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/net/dsa.h b/include/net/dsa.h index a4f66dbb4b7c..65d7804c6f69 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -101,6 +101,13 @@ struct dsa_platform_data { struct packet_type; +struct dsa_device_ops { + struct sk_buff *(*xmit)(struct sk_buff *skb, struct net_device *dev); + struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, + struct net_device *orig_dev); +}; + struct dsa_switch_tree { struct list_head list; diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 1debf9c42fc4..9c3eeb72462d 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -65,13 +65,6 @@ struct dsa_notifier_vlan_info { int port; }; -struct dsa_device_ops { - struct sk_buff *(*xmit)(struct sk_buff *skb, struct net_device *dev); - struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev, - struct packet_type *pt, - struct net_device *orig_dev); -}; - struct dsa_slave_priv { /* Copy of dp->ds->dst->tag_ops->xmit for faster access in hot path */ struct sk_buff * (*xmit)(struct sk_buff *skb, From 598a968011ffc4d624934995fe46d06bd450cdf4 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Wed, 9 Aug 2017 14:41:17 +0200 Subject: [PATCH 2/4] net-next: dsa: add flow_dissect callback to struct dsa_device_ops When the flow dissector first sees packets coming in on a DSA devices the 802.3 header wont be located where the code expects it to be as the tag is still present. Adding this new callback allows a DSA device to provide a new function that the flow_dissector can use to get the correct protocol and offset of the network header. Signed-off-by: Muciri Gatimu Signed-off-by: Shashidhar Lakkavalli Signed-off-by: John Crispin Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- include/net/dsa.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/net/dsa.h b/include/net/dsa.h index 65d7804c6f69..7f46b521313e 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -106,6 +106,8 @@ struct dsa_device_ops { struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); + int (*flow_dissect)(const struct sk_buff *skb, __be16 *proto, + int *offset); }; struct dsa_switch_tree { From 2dd592b274861021018446102fb443e24f72fe72 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Wed, 9 Aug 2017 14:41:18 +0200 Subject: [PATCH 3/4] net-next: tag_mtk: add flow_dissect callback to the ops struct The MT7530 inserts the 4 magic header in between the 802.3 address and protocol field. The patch implements the callback that can be called by the flow dissector to figure out the real protocol and offset of the network header. With this patch applied we can properly parse the packet and thus make hashing function properly. Signed-off-by: Muciri Gatimu Signed-off-by: Shashidhar Lakkavalli Signed-off-by: John Crispin Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- net/dsa/tag_mtk.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c index 2f32b7ea3365..02163c045a96 100644 --- a/net/dsa/tag_mtk.c +++ b/net/dsa/tag_mtk.c @@ -87,7 +87,17 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev, return skb; } +static int mtk_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto, + int *offset) +{ + *offset = 4; + *proto = ((__be16 *)skb->data)[1]; + + return 0; +} + const struct dsa_device_ops mtk_netdev_ops = { - .xmit = mtk_tag_xmit, - .rcv = mtk_tag_rcv, + .xmit = mtk_tag_xmit, + .rcv = mtk_tag_rcv, + .flow_dissect = mtk_tag_flow_dissect, }; From 43e665287f931a167cd2eea3387efda901bff0ce Mon Sep 17 00:00:00 2001 From: John Crispin Date: Wed, 9 Aug 2017 14:41:19 +0200 Subject: [PATCH 4/4] 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 Signed-off-by: Shashidhar Lakkavalli Signed-off-by: John Crispin Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- 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 0cc672aba1f0..5b5be9577257 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; + 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