Enable rdma-sniffer for libpcap

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 2006557

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Hello Amir and thanks for this bug report. Dann identified a fix and forwarded it to Debian [1]. It is best if the change lands in Debian so Debian and other downstream distros will also benefit for the change, and Ubuntu developers won't have to maintain a delta.

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1030898

Apparently the libpcap Debian maintainer rejected adding the new libibverbs dependency:

> So far I've resisted adding extra binary dependencies to
> libpcap and this seems like a very specialized use case.

We could in principle add the dependency via an Ubuntu delta (the library is in main), but given that the package is currently a sync I believe that we need a use case that is compelling enough to justify the increased maintenance that comes with carrying a delta.

@Amir: can you please elaborate a bit more on the use case for which you need rdma sniffing? Is the feature going to be generally useful?

Once we get a better picture on why the feature is useful, I suggest trying once again to get it enabled in Debian by providing additional information to the Debian maintainer (the linked Debian bug doesn't explain much).

I am setting this one to incomplete until Amir provides the information requested by Paride. After doing so, please, set this bug status back to new.

This is functionality is going to be important for our customers. RDMA / RoCE are used extensively in our clusters, and we're going to run into more cases where people need to be able to trace the RDMA traffic. There are other tools in Ubuntu to manage OFED devices and RDMA, so RDMA support is there in general, but this one piece is missing. In short, tcpdump is intended to capture a variety of traffic protocols, and RDMA is one of those protocols which is seeing increased use.

Apparently Fedora has already created an RDMA enabled libpcap. A container based on fedora:latest is able to capture RDMA traffic with tcpdump. Is there maybe something there that could be leveraged?

This bug was fixed in the package libpcap - 1.10.4-4ubuntu3

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libpcap (1.10.4-4ubuntu3) noble; urgency=medium

  * Don't require ibverbs on i386

 -- Jeremy Bícha <email address hidden> Fri, 02 Feb 2024 16:41:24 -0500