Commit 9d680392 authored Apr 06, 2021 by Kurt Kanzenbach Committed by David S. Miller Apr 07, 2021

net: hsr: Reset MAC header for Tx path



Reset MAC header in HSR Tx path. This is needed, because direct packet
transmission, e.g. by specifying PACKET_QDISC_BYPASS does not reset the MAC
header.

This has been observed using the following setup:

|$ ip link add name hsr0 type hsr slave1 lan0 slave2 lan1 supervision 45 version 1
|$ ifconfig hsr0 up
|$ ./test hsr0

The test binary is using mmap'ed sockets and is specifying the
PACKET_QDISC_BYPASS socket option.

This patch resolves the following warning on a non-patched kernel:

|[  112.725394] ------------[ cut here ]------------
|[  112.731418] WARNING: CPU: 1 PID: 257 at net/hsr/hsr_forward.c:560 hsr_forward_skb+0x484/0x568
|[  112.739962] net/hsr/hsr_forward.c:560: Malformed frame (port_src hsr0)

The warning can be safely removed, because the other call sites of
hsr_forward_skb() make sure that the skb is prepared correctly.

Fixes: d346a3fa ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent cd904373

net/hsr/hsr_device.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -217,6 +217,7 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff skb, struct net_device dev)
		master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
		if (master) {
		skb->dev = master->dev;
		skb_reset_mac_header(skb);
		hsr_forward_skb(skb, master);
		} else {
		atomic_long_inc(&dev->tx_dropped);

net/hsr/hsr_forward.c

+0 −6

Original line number	Diff line number	Diff line
		@@ -555,12 +555,6 @@ void hsr_forward_skb(struct sk_buff skb, struct hsr_port port)
		{
		struct hsr_frame_info frame;

		if (skb_mac_header(skb) != skb->data) {
		WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
		__FILE__, __LINE__, port->dev->name);
		goto out_drop;
		}

		if (fill_frame_info(&frame, skb, port) < 0)
		goto out_drop;