Re: Userspace - Kernel Space "Connector" test

From: Midhun A
Date: Fri Apr 04 2008 - 03:01:43 EST


Hey,

Thanks a lot. I have changed the idx value to 7 and it worked. :)

Thanks,
Midhun

On Thu, Mar 27, 2008 at 8:08 PM, Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:
> Hi.
>
>
> On Wed, Mar 26, 2008 at 03:41:16PM +0530, Midhun A (midhunagni@xxxxxxxxx) wrote:
> > I want to use the Connector module (CONFIG_CONNECTOR) for Kernel
> > space to User space communication. My kernel version is 2.6.22.
> > Before using it, I am trying out the example programs in the
> > Documentation folder. I have cn_test.c built into the kernel (not
> > loaded as a module) and I have compiled ucon.c.
>
> You have to use smaller index than 32 or increase CN_NETLINK_USERS
> parameter in include/linux/connector.h
>
> Currently all kernel users fit that limitation, which is ok.
>
> Also, parameter used in bind() is a bitmap of requested groups, to
> listen on 0x123 idx you have to add it via setsockopt(), which is
> commented in ucon.c.
>
> So, either switch to smaller group number (connector index) or increase
> above limit. If you will select the former case (it is simpler from
> userspace point of view), you have to change bind() group, note that it
> is a bitmap, os group N equals to (1<<N) bind() value. If you will
> select the latter case and recompile connector module, then you have to
> uncomment setsockopt() code in ucon.c
>
> Both methods work, and you will get something like this:
> $ sudo ./ucon
> Thu Mar 27 17:29:19 2008 : [123.457] [00000002.00000000].
> Thu Mar 27 17:29:20 2008 : [123.457] [00000003.00000000].
> Thu Mar 27 17:29:21 2008 : [123.457] [00000004.00000000].
> Thu Mar 27 17:29:22 2008 : [123.457] [00000005.00000000].
> Thu Mar 27 17:29:23 2008 : [123.457] [00000006.00000000].
>
> --
> Evgeniy Polyakov
>
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