net: don't reforward packets already forwarded by offload device
Just before queuing skb for xmit on port, check if skb has been marked by
switchdev port driver as already fordwarded by device. If so, drop skb. A
non-zero skb->offload_fwd_mark field is set by the switchdev port
driver/device on ingress to indicate the skb has already been forwarded by
the device to egress ports with matching dev->skb_mark. The switchdev port
driver would assign a non-zero dev->offload_skb_mark for each device port
netdev during registration, for example.
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 45cfd79..8364f29 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1456,6 +1456,8 @@
*
* @xps_maps: XXX: need comments on this one
*
+ * @offload_fwd_mark: Offload device fwding mark
+ *
* @trans_start: Time (in jiffies) of last Tx
* @watchdog_timeo: Represents the timeout that is used by
* the watchdog ( see dev_watchdog() )
@@ -1697,6 +1699,10 @@
struct xps_dev_maps __rcu *xps_maps;
#endif
+#ifdef CONFIG_NET_SWITCHDEV
+ u32 offload_fwd_mark;
+#endif
+
/* These may be needed for future network-power-down code. */
/*
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d6cdd6e..af7a096 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -506,6 +506,7 @@
* @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
* @napi_id: id of the NAPI struct this skb came from
* @secmark: security marking
+ * @offload_fwd_mark: fwding offload mark
* @mark: Generic packet mark
* @vlan_proto: vlan encapsulation protocol
* @vlan_tci: vlan tag control information
@@ -650,9 +651,15 @@
unsigned int sender_cpu;
};
#endif
+ union {
#ifdef CONFIG_NETWORK_SECMARK
- __u32 secmark;
+ __u32 secmark;
#endif
+#ifdef CONFIG_NET_SWITCHDEV
+ __u32 offload_fwd_mark;
+#endif
+ };
+
union {
__u32 mark;
__u32 reserved_tailroom;
diff --git a/net/core/dev.c b/net/core/dev.c
index 8810b6b..2ee15af 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3061,6 +3061,16 @@
else
skb_dst_force(skb);
+#ifdef CONFIG_NET_SWITCHDEV
+ /* Don't forward if offload device already forwarded */
+ if (skb->offload_fwd_mark &&
+ skb->offload_fwd_mark == dev->offload_fwd_mark) {
+ consume_skb(skb);
+ rc = NET_XMIT_SUCCESS;
+ goto out;
+ }
+#endif
+
txq = netdev_pick_tx(dev, skb, accel_priv);
q = rcu_dereference_bh(txq->qdisc);