net: dsa: sja1105: Don't store frame type in skb->cb (e8d67fa5) · Commits · 戴 / test

Due to a confusion I thought that eth_type_trans() was called by the network stack whereas it can actually be called by network drivers to figure out the skb protocol and next packet_type handlers. In light of the above, it is not safe to store the frame type from the DSA tagger's .filter callback (first entry point on RX path), since GRO is yet to be invoked on the received traffic. Hence it is very likely that the skb->cb will actually get overwritten between eth_type_trans() and the actual DSA packet_type handler. Of course, what this patch fixes is the actual overwriting of the SJA1105_SKB_CB(skb)->type field from the GRO layer, which made all frames be seen as SJA1105_FRAME_TYPE_NORMAL (0). Fixes: ("net: dsa: sja1105: Add support for traffic through standalone ports") Signed-off-by:

Vladimir Oltean <olteanv@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/dsa/sja1105.h

+0 −12

Original line number	Diff line number	Diff line
		@@ -20,18 +20,6 @@
		#define SJA1105_LINKLOCAL_FILTER_B 0x011B19000000ull
		#define SJA1105_LINKLOCAL_FILTER_B_MASK 0xFFFFFF000000ull

		enum sja1105_frame_type {
		SJA1105_FRAME_TYPE_NORMAL = 0,
		SJA1105_FRAME_TYPE_LINK_LOCAL,
		};

		struct sja1105_skb_cb {
		enum sja1105_frame_type type;
		};

		#define SJA1105_SKB_CB(skb) \
		((struct sja1105_skb_cb *)DSA_SKB_CB_PRIV(skb))

		struct sja1105_port {
		struct dsa_port *dp;
		int mgmt_slot;

net/dsa/tag_sja1105.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -28,14 +28,10 @@ static inline bool sja1105_is_link_local(const struct sk_buff *skb)
		*/
		static bool sja1105_filter(const struct sk_buff skb, struct net_device dev)
		{
		if (sja1105_is_link_local(skb)) {
		SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_LINK_LOCAL;
		if (sja1105_is_link_local(skb))
		return true;
		}
		if (!dsa_port_is_vlan_filtering(dev->dsa_ptr)) {
		SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_NORMAL;
		if (!dsa_port_is_vlan_filtering(dev->dsa_ptr))
		return true;
		}
		return false;
		}

		@@ -84,7 +80,7 @@ static struct sk_buff sja1105_rcv(struct sk_buff skb,

		skb->offload_fwd_mark = 1;

		if (SJA1105_SKB_CB(skb)->type == SJA1105_FRAME_TYPE_LINK_LOCAL) {
		if (sja1105_is_link_local(skb)) {
		/* Management traffic path. Switch embeds the switch ID and
		* port ID into bytes of the destination MAC, courtesy of
		* the incl_srcpt options.

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