simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

[Monthadar Al Jaberi]

On Thu, Feb 3, 2011 at 12:18 PM, Bjoern A. Zeeb
<bzeeb-lists at lists.zabbadoz.net> wrote:
> On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:
>
>> On Thu, Feb 3, 2011 at 11:59 AM, Bjoern A. Zeeb
>> <bzeeb-lists at lists.zabbadoz.net> wrote:
>>>
>>> On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:
>>>
>>>>>>> I don't understand why you saw a CRED_TO_VNET of 0
>>>>>>> I was under the impression that every process/thread in the system
>>>>>>> would
>>>>>>> be
>>>>>>> on vnet0
>>>>>>> in a vimage kernel.
>>>>>>
>>>>>> This is how my printf looks like:
>>>>>> struct thread *td = curthread;
>>>>>> struct vnet *v = TD_TO_VNET(td);
>>>>>> struct ucred *cred = CRED_TO_VNET(td->ucred);
>>>>>> struct vnet *td_vnet = td->td_vnet;
>>>>>
>>>>> here's your problem:
>>>>>
>>>>> strcut vnet *vnet = cred->cr_prison->pr_vnet;
>>>>
>>>> When I add CURVNET_SET(CRED_TO_VNET(curthread->td_ucred)); I get a panic
>>>> too...
>>>> But your suggestion works if I do like this:
>>>> curthread->td_vnet = curthread->td_ucred->cr_prison->pr_vnet;
>>>>
>>>> CRED_TO_VNET(curthread->td_ucred) returns NULL
>>>
>>> I wonder how you are building your module and if VIMAGE is properly
>>> defined.  If it's not that would explain a lot of things.
>>
>> I have put options VIMAGE, rebuild both world and kernel.
>>
>> I can create jails with vnet options...
>>
>> I build my module with the standard Makefile for modules:
>> ...
>> KMOD    =  wtap
>> ...
>> SRCS    =  if_wtap_module.c if_wtap.c if_medium.c hal.c
>>
>> .include <bsd.kmod.mk>
>
> Right but are you building your module along with the kernel or
> outside the tree?  In the latter case you may want to add soemthing
> like
>
> SRCS+=          opt_global.h
>
> .if defined(KERNBUILDDIR)
> MKDEP=          -include ${KERNBUILDDIR}/opt_global.h
> .else
> CFLAGS+=        -include opt_global.h
> MKDEP=          -include opt_global.h
>
> opt_global.h:
>        echo "#define VIMAGE 1" > ${.TARGET}
> .endif
>
> and/or point KERNBUILDDIR to where you built your kernels.

Thanks it works now..

>
>
>>>
>>>
>>>>>> printf("td=%p, td->td_vnet=%p, td->td_ucred=%p, TD_TO_VNET=%p,
>>>>>> CRED_TO_VNET=%p\n", td, td_vnet, td->td_ucred, v, cred);
>>>>>>
>>>>>> I made a fast search in /usr/src for "td_vnet" and found it was
>>>>>> assigned only in
>>>>>> int fork1(td, flags, pages, procp):
>>>>>> #ifdef VIMAGE
>>>>>>        td2->td_vnet = NULL;
>>>>>>        td2->td_vnet_lpush = NULL;
>>>>>> #endif
>>>>>
>>>>> Nice try.  Want another search?  Hint: there is this in vnet.h:
>>>>>
>>>>> #define curvnet curthread->td_vnet
>>>>>
>>>>> And then you'll, again, find the CURVNET_SET_* macros.
>>>>
>>>> Thank you
>>>
>>> Something you may find useful as well btw is:
>>>
>>> http://people.freebsd.org/~bz/20100530-02.vnet.9.html
>>
>> weired compiler complains about that there is no <sys/vnet.h>, I
>> include <net/vnet.h> maybe old documentation?
>
> it's net/vnet.h.  Documentation bug from a local transisiton time to
> the general framework.  Thanks for catching;)  net/vnet.h will
> obviously stay.
>
> --
> Bjoern A. Zeeb                                 You have to have visions!
>        <ks> Going to jail sucks -- <bz> All my daemons like it!
>  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html



-- 
//Monthadar Al Jaberi