net: dsa: reduce number of protocol hooks
DSA is currently registering one packet_type function per EtherType it
needs to intercept in the receive path of a DSA-enabled Ethernet device.
Right now we have three of them: trailer, DSA and eDSA, and there might
be more in the future, this will not scale to the addition of new
protocols.
This patch proceeds with adding a new layer of abstraction and two new
functions:
dsa_switch_rcv() which will dispatch into the tag-protocol specific
receive function implemented by net/dsa/tag_*.c
dsa_slave_xmit() which will dispatch into the tag-protocol specific
transmit function implemented by net/dsa/tag_*.c
When we do create the per-port slave network devices, we iterate over
the switch protocol to assign the DSA-specific receive and transmit
operations.
A new fake ethertype value is used: ETH_P_XDSA to illustrate the fact
that this is no longer going to look like ETH_P_DSA or ETH_P_TRAILER
like it used to be.
This allows us to greatly simplify the check in eth_type_trans() and
always override the skb->protocol with ETH_P_XDSA for Ethernet switches
tagged protocol, while also reducing the number repetitive slave
netdevice_ops assignments.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h
index 0f8210b..aa63ed0 100644
--- a/include/uapi/linux/if_ether.h
+++ b/include/uapi/linux/if_ether.h
@@ -128,6 +128,7 @@
#define ETH_P_PHONET 0x00F5 /* Nokia Phonet frames */
#define ETH_P_IEEE802154 0x00F6 /* IEEE802.15.4 frame */
#define ETH_P_CAIF 0x00F7 /* ST-Ericsson CAIF protocol */
+#define ETH_P_XDSA 0x00F8 /* Multiplexed DSA protocol */
/*
* This is an Ethernet frame header.