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?
I understand the advantages here of coupling to BPF and OVS. How does
storing the encapsulation parameters via ip-route compare to storing
them as PDP contexts from the point of view of resource consumption?
Are there are other advantages/disadvantages?
On 12/12/2020 05:40, Pravin B Shelar wrote:
Following patch add support for flow based tunneling API
to send and recv GTP tunnel packet over tunnel metadata API.
This would allow this device integration with OVS or eBPF using
flow based tunneling APIs.
Signed-off-by: Pravin B Shelar <pbshe...@fb.com>
---
Fixed according to comments from Jonas Bonn
---
drivers/net/gtp.c | 514 ++++++++++++++++++++---------
include/uapi/linux/gtp.h | 12 +
include/uapi/linux/if_link.h | 1 +
include/uapi/linux/if_tunnel.h | 1 +
tools/include/uapi/linux/if_link.h | 1 +
5 files changed, 382 insertions(+), 147 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 4c04e271f184..0e212a70fe4b 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -21,6 +21,7 @@
#include <linux/file.h>
#include <linux/gtp.h>
+#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?
/Jonas
