[PATCH 4.4 21/76] hsr: reset network header when supervision frame is created

Greg Kroah-Hartman
2020-01-22T09:31:03Z

From: Taehee Yoo <ap420073@gmail.com>

commit 3ed0a1d563903bdb4b4c36c58c4d9c1bcb23a6e6 upstream.

The supervision frame is L2 frame.
When supervision frame is created, hsr module doesn't set network header.
If tap routine is enabled, dev_queue_xmit_nit() is called and it checks
network_header. If network_header pointer wasn't set(or invalid),
it resets network_header and warns.
In order to avoid unnecessary warning message, resetting network_header
is needed.

Test commands:
ip netns add nst
ip link add veth0 type veth peer name veth1
ip link add veth2 type veth peer name veth3
ip link set veth1 netns nst
ip link set veth3 netns nst
ip link set veth0 up
ip link set veth2 up
ip link add hsr0 type hsr slave1 veth0 slave2 veth2
ip a a 192.168.100.1/24 dev hsr0
ip link set hsr0 up
ip netns exec nst ip link set veth1 up
ip netns exec nst ip link set veth3 up
ip netns exec nst ip link add hsr1 type hsr slave1 veth1 slave2 veth3
ip netns exec nst ip a a 192.168.100.2/24 dev hsr1
ip netns exec nst ip link set hsr1 up
tcpdump -nei veth0

Splat looks like:
[ 175.852292][ C3] protocol 88fb is buggy, dev veth0

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/hsr/hsr_device.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -289,6 +289,8 @@ static void send_hsr_supervision_frame(s
skb->dev->dev_addr, skb->len) <= 0)
goto out;
skb_reset_mac_header(skb);
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);

hsr_stag = (typeof(hsr_stag)) skb_put(skb, sizeof(*hsr_stag));