Re: [PATCH v2] examples/rpcapd: demo version of packet capture daemon

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon, 21 Sep 2026 17:43:31 +0100
Marat Khalili <qm2k21@gmail.com> wrote:

> On 21/09/2026 16:58, Stephen Hemminger wrote:
> > On Mon, 21 Sep 2026 10:51:39 +0100
> > Marat Khalili <qm2k21@gmail.com> wrote:
> >  
> >>>    examples/rpcapd/meson.build            |   19 +
> >>>    examples/rpcapd/rpcap-protocol.h       |  127 +++  
> >> Could we just use one from libpcap?  
> > Could but since most distro's don't enable rpcapd the header
> > file is not exported. We could "vendor it".  
> Is it possible to use your new app without having a full version of 
> libpcap in the system (that would have this rpcap-protocol.h anyway)? In 
> "Client Setup" you mention that libpcap must be rebuilt with remote 
> support enabled, and at this moment our own abridged copy of 
> rpcap-protocol.h becomes redundant. Our copy allows building the 
> application in systems where rpcapd is missing or built without the 
> remote support, but then the build result cannot be used. Am I 
> misunderstanding something?

Read the docs, there are two issues:
 1. You need to rebuild libpcap since rpcap is a security problem,
    it is not enabled by default. Tcpdump et al will not support
    rpcap without rebuild.

 2. The rpcap-protocol.h file is not exported by libpcap and
    considered internal. The original is too damn messy to use
    in DPDK as a copy.