On 10/18/2018 10:28 PM, Yousong Zhou wrote:
On Fri, 19 Oct 2018 at 01:13, Gregory Rose <[email protected]> wrote:
On 10/17/2018 6:01 AM, Yousong Zhou wrote:
I tried to use ip-over-gre with openvswitch 2.8.4, but no "ip proto
47" traffic can be seen with tcpdump. Later I added a WARN_ON_ONCE(1)
line just before the "goto drop" statement in ovs_vport_send() and it
was triggered right away thus pinpointed the problem.
It looks to me openvswitch linux kernel datapath always create
ARPHRD_IPGRE device and never set dev->type to ARPHRD_NONE. Please
correct me if this is not the case. The ovs-vswitchd.conf.db doc says
setting packet_type=legacy_l3 should work. I am trying to figure
what's the missing piece.
Openvswitch 2.8.4 depends on the built-in gre kernel module and it is true that
module will always set the device type to ARPHRD_IPGRE upon initial creation
but if the tunnel is set to a metadata type tunnel then the device type should
be reset to ARPHRD_NONE.
From ../net/ipv4/ip_gre.c:L1037
if (data[IFLA_GRE_COLLECT_METADATA]) {
struct ip_tunnel *t = netdev_priv(dev);
t->collect_md = true;
if (dev->type == ARPHRD_IPGRE)
dev->type = ARPHRD_NONE;
}
https://elixir.bootlin.com/linux/v4.6/source/net/ipv4/ip_gre.c#L1037
Perhaps that code is not being hit?
No, nl_attr *data[] was zeroed out in gretap_fb_dev_create().
And you are sure there is no subsequent call to ipgre_netlink_parms()?
t->collect_md = true was also set there. There was a patch [1] to
workaround this but it seems that the function is compat code and
kernel would rather not adding feature to it.
By the way, does someone know what is the meaning of _fb_ in
gretap_fb_dev_create()?
[1] [net-next,v12,9/9] openvswitch: use ipgre tunnel rather than
gretap tunnel, https://patchwork.ozlabs.org/patch/682916/
yousong
The _fb_ stands for either "fall back" or "fully backed" device (I've
heard both). It's necessary for namespace support IIRC.
- Greg
_______________________________________________
discuss mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
