Re: [PATCH net-next 08/14] gtp: Support encpasulating over IPv6

On Wed, Sep 20, 2017 at 5:04 PM, Harald Welte [off-list ref] wrote:

Hi Tom,

On Wed, Sep 20, 2017 at 01:40:54PM -0700, Tom Herbert wrote:

quoted

On Wed, Sep 20, 2017 at 12:45 PM, David Miller [off-list ref] wrote:

quoted

There is a socket associated with the tunnel to do the encapsulation
and it has an address family, right?

If fd's are set from userspace for the sockets then we could derive
the address family from them. I'll change that. Although, looking at
now I am wondering why were passing fds into GTP instead of just
having the kernel create the UDP port like is done for other encaps.

because the userspace process has to take care of those bits of GTP-U
that the kernel doesn't, such as responding to GTP ECHO requests with
GTP echo responses.  Only the "GTP Message type G-PDU" is handled in the
kernel, as only those frames contain user plane.  See table 1 of Section
7.1 of 3GPP TS 29.060.

Okay, thanks for the explanation.

Tom