Reset MAC header in case of using packet_direct_xmit(), e.g. by specifying
PACKET_QDISC_BYPASS. This is needed, because other code such as the HSR layer
expects the MAC header to be correctly set.
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 MAC header is also reset unconditionally in case of PACKET_QDISC_BYPASS is
not used.
Signed-off-by: Kurt Kanzenbach <k...@linutronix.de>
---
net/packet/af_packet.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 118d585337d7..6325c9b7df38 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -241,6 +241,7 @@ static void __fanout_link(struct sock *sk, struct
packet_sock *po);
static int packet_direct_xmit(struct sk_buff *skb)
{
+ skb_reset_mac_header(skb);
return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
}
--
2.20.1
