interprocess communication with netlinks

interprocess communication with netlinks

[Daniel Lezcano]

Hi netdev gurus !

I am trying to make several processes to communicate via the netlink 
protocol.

I saw a discussion around the AF_IPN (inter process communication) 
protocol and it seems the same can be done with the AF_NETLINK protocol 
with minor modifications in the kernel. Were these modifications done ?

I am trying to use multicast between several processes, for notification.

What protocol should I use to create the socket ?

    fd = socket(PF_NETLINK, SOCK_RAW,  ???);

I was not able to find any suitable pointer to explain how to do that, 
so I blindly tried several combinations but I am afraid to interact with 
the other netlink protocols when using a multicast group, especially 
when there are other applications like avahi-daemon or "ip monitor all".

Does anyone have a pointer to a documentation (not the redhat one, pls), 
or some clues ?

Thanks in advance.
  -- Daniel

Re: interprocess communication with netlinks

[Daniel Lezcano]

Tianjin Zhang wrote:
> i think the following  material can help you.
>
> 1. http://lwn.net/Articles/262385/  introduce the IPN,
>
> 2. http://www.linuxjournal.com/article/7356   introduce how to use netlink
> socket and why
>   
Thank you but I already saw these documents. I am used to play with the 
netlink for kernel <-> user communication, I am wondering if it is 
possible to have the applications to communicate, I mean user <-> user.

I saw a comment in the mailing list archive 
http://kerneltrap.org/mailarchive/linux-kernel/2007/12/7/493793/thread

"... with minor adjustments we have the facilities to
meet your needs.  There is no need for yet-another-protocol to do what
you're trying to do, we already have too much duplicated
functionality."


Were these "minor adjustements" done ?

Thanks
  -- Daniel

> On Fri, May 8, 2009 at 12:00 AM, Daniel Lezcano <daniel.lezcano@free.fr>wrote:
>
>   
>> Hi netdev gurus !
>>
>> I am trying to make several processes to communicate via the netlink
>> protocol.
>>
>> I saw a discussion around the AF_IPN (inter process communication) protocol
>> and it seems the same can be done with the AF_NETLINK protocol with minor
>> modifications in the kernel. Were these modifications done ?
>>
>> I am trying to use multicast between several processes, for notification.
>>
>> What protocol should I use to create the socket ?
>>
>>   fd = socket(PF_NETLINK, SOCK_RAW,  ???);
>>
>> I was not able to find any suitable pointer to explain how to do that, so I
>> blindly tried several combinations but I am afraid to interact with the
>> other netlink protocols when using a multicast group, especially when there
>> are other applications like avahi-daemon or "ip monitor all".
>>
>> Does anyone have a pointer to a documentation (not the redhat one, pls), or
>> some clues ?
>>
>> Thanks in advance.
>>  -- Daniel
>> --
>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>     
>
>   

Re: interprocess communication with netlinks

[Randy Dunlap]

Daniel Lezcano wrote:
> Tianjin Zhang wrote:
>> i think the following  material can help you.
>>
>> 1. http://lwn.net/Articles/262385/  introduce the IPN,
>>
>> 2. http://www.linuxjournal.com/article/7356   introduce how to use
>> netlink
>> socket and why
>>   
> Thank you but I already saw these documents. I am used to play with the
> netlink for kernel <-> user communication, I am wondering if it is
> possible to have the applications to communicate, I mean user <-> user.
> 
> I saw a comment in the mailing list archive
> http://kerneltrap.org/mailarchive/linux-kernel/2007/12/7/493793/thread
> 
> "... with minor adjustments we have the facilities to
> meet your needs.  There is no need for yet-another-protocol to do what
> you're trying to do, we already have too much duplicated
> functionality."
> 
> 
> Were these "minor adjustements" done ?
> 
> Thanks
>  -- Daniel
> 
>> On Fri, May 8, 2009 at 12:00 AM, Daniel Lezcano
>> <daniel.lezcano@free.fr>wrote:
>>
>>  
>>> Hi netdev gurus !
>>>
>>> I am trying to make several processes to communicate via the netlink
>>> protocol.
>>>
>>> I saw a discussion around the AF_IPN (inter process communication)
>>> protocol
>>> and it seems the same can be done with the AF_NETLINK protocol with
>>> minor
>>> modifications in the kernel. Were these modifications done ?
>>>
>>> I am trying to use multicast between several processes, for
>>> notification.
>>>
>>> What protocol should I use to create the socket ?
>>>
>>>   fd = socket(PF_NETLINK, SOCK_RAW,  ???);
>>>
>>> I was not able to find any suitable pointer to explain how to do
>>> that, so I
>>> blindly tried several combinations but I am afraid to interact with the
>>> other netlink protocols when using a multicast group, especially when
>>> there
>>> are other applications like avahi-daemon or "ip monitor all".
>>>
>>> Does anyone have a pointer to a documentation (not the redhat one,
>>> pls), or
>>> some clues ?

There's also a paper/doc here:
  http://people.redhat.com/nhorman/papers/netlink.pdf

-- 
~Randy
LPC 2009, Sept. 23-25, Portland, Oregon
http://linuxplumbersconf.org/2009/

Re: interprocess communication with netlinks

[Neil Horman]

On Mon, May 11, 2009 at 12:36:43PM -0700, Randy Dunlap wrote:
> Daniel Lezcano wrote:
> > Tianjin Zhang wrote:
> >> i think the following  material can help you.
> >>
> >> 1. http://lwn.net/Articles/262385/  introduce the IPN,
> >>
> >> 2. http://www.linuxjournal.com/article/7356   introduce how to use
> >> netlink
> >> socket and why
> >>   
> > Thank you but I already saw these documents. I am used to play with the
> > netlink for kernel <-> user communication, I am wondering if it is
> > possible to have the applications to communicate, I mean user <-> user.
> > 
> > I saw a comment in the mailing list archive
> > http://kerneltrap.org/mailarchive/linux-kernel/2007/12/7/493793/thread
> > 
> > "... with minor adjustments we have the facilities to
> > meet your needs.  There is no need for yet-another-protocol to do what
> > you're trying to do, we already have too much duplicated
> > functionality."
> > 
> > 
> > Were these "minor adjustements" done ?
> > 
> > Thanks
> >  -- Daniel
> > 
> >> On Fri, May 8, 2009 at 12:00 AM, Daniel Lezcano
> >> <daniel.lezcano@free.fr>wrote:
> >>
> >>  
> >>> Hi netdev gurus !
> >>>
> >>> I am trying to make several processes to communicate via the netlink
> >>> protocol.
> >>>
> >>> I saw a discussion around the AF_IPN (inter process communication)
> >>> protocol
> >>> and it seems the same can be done with the AF_NETLINK protocol with
> >>> minor
> >>> modifications in the kernel. Were these modifications done ?
> >>>
> >>> I am trying to use multicast between several processes, for
> >>> notification.
> >>>
> >>> What protocol should I use to create the socket ?
> >>>
> >>>   fd = socket(PF_NETLINK, SOCK_RAW,  ???);
> >>>
> >>> I was not able to find any suitable pointer to explain how to do
> >>> that, so I
> >>> blindly tried several combinations but I am afraid to interact with the
> >>> other netlink protocols when using a multicast group, especially when
> >>> there
> >>> are other applications like avahi-daemon or "ip monitor all".
> >>>
> >>> Does anyone have a pointer to a documentation (not the redhat one,
> >>> pls), or
> >>> some clues ?
> 
> There's also a paper/doc here:
>   http://people.redhat.com/nhorman/papers/netlink.pdf
> 
Apologies that its still not finished.  I've been trying to get that done
forever.

Neil

> -- 
> ~Randy
> LPC 2009, Sept. 23-25, Portland, Oregon
> http://linuxplumbersconf.org/2009/
> --
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