Re: [PATCH v4 net-next 0/3] add support for sending RFC8335 PROBE

[Andreas Roeseler]

On Thu, 2020-11-19 at 21:01 -0700, David Ahern wrote:
> On 11/19/20 8:51 PM, David Ahern wrote:
> > On 11/17/20 5:46 PM, Andreas Roeseler wrote:
> > > The popular utility ping has several severe limitations such as
> > > the
> > > inability to query specific  interfaces on a node and requiring
> > > bidirectional connectivity between the probing and the probed
> > > interfaces. RFC8335 attempts to solve these limitations by
> > > creating the
> > > new utility PROBE which is a specialized ICMP message that makes
> > > use of
> > > the ICMP Extension Structure outlined in RFC4884.
> > > 
> > > This patchset adds definitions for the ICMP Extended Echo Request
> > > and
> > > Reply (PROBE) types for both IPv4 and IPv6. It also expands the
> > > list of
> > > supported ICMP messages to accommodate PROBEs.
> > > 
> > 
> > You are updating the send, but what about the response side?
> > 
> 
> you also are not setting 'ICMP Extension Structure'. From:
> https://tools.ietf.org/html/rfc8335
> 
>    o  ICMP Extension Structure: The ICMP Extension Structure
> identifies
>       the probed interface.
> 
>    Section 7 of [RFC4884] defines the ICMP Extension Structure.  As
> per
>    RFC 4884, the Extension Structure contains exactly one Extension
>    Header followed by one or more objects.  When applied to the ICMP
>    Extended Echo Request message, the ICMP Extension Structure MUST
>    contain exactly one instance of the Interface Identification
> Object
>    (see Section 2.1).

I am currently finishing testing and polishing the response side and
hope to be sendding out v1 of the patch in the upcoming few weeks.

As for the 'ICMP Extension Structure', I have been working with the
iputils package to add a command to send PROBE messages, and the
changes included in this patchset are all that are necessary to be able
to send PROBEs using the existing ping framework.