Hi Pravin,
On 13/12/2020 20:32, Pravin Shelar wrote:
On Sat, Dec 12, 2020 at 11:56 PM Jonas Bonn <jo...@norrbonn.se> wrote:
Hi Pravin,
I've been thinking a bit about this and find it more and more
interesting. Could you post a bit of information about the ip-route
changes you'll make in order to support GTP LWT encapsulation? Could
you provide an example command line?
This is done as part of the magma core project
(https://www.magmacore.org/) that needs OVS GTP support.
I have started with OVS integration first, there are unit tests that
validate the GTP support. This is datapath related test, that has the
setup commands:
https://github.com/pshelar/ovs/blob/6ec6a2a86adc56c7c9dcab7b3a7b70bb6dad35c9/tests/system-layer3-tunnels.at#L158
That link just shows the classic setup using gtp-link and gtp-tunnel
from libgtpnl. It doesn't exercise LWT at all.
Once OVS patches are upstream I can post patches for ip-route command.
No, you should do it the other way around, please. Post the ip-route
changes along with this so we can see where this is going.
+#include <net/dst_metadata.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/ip.h>
@@ -73,6 +74,9 @@ struct gtp_dev {
unsigned int hash_size;
struct hlist_head *tid_hash;
struct hlist_head *addr_hash;
+ /* Used by flow based tunnel. */
+ bool collect_md;
+ struct socket *collect_md_sock;
I'm not convinced that you need to special-case LWT in this way. It
should be possible to just use the regular sk1u socket. I know that the
sk1u socket is created in userspace and might be set up to listen on the
wrong address, but that's a user error if they try to use that device
with LWT. You could easily make the sk1u socket an optional parameter
and create it (as you do in your patch) if it's not provided. Then
ip_tunnel_collect_metadata() would tell you whether to get the
encapsulaton details from the tunnel itself or whether to look up a PDP
context. That should suffice, right?
Sounds good. I have added it as part of v3.
Just to be clear, I still need collect_md_sock to keep reference to
the socket that is created as part of the newlink in kernel space.
Why? I don't see that there's anything special enough about that socket
that you can't just use it as sk1u. You might need to massage the types
a bit, but that doesn't seem like a big problem. What am I missing?
/Jonas
Thanks,
Pravin.
