simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

[Monthadar Al Jaberi]

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>

>
>
>>>> 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?

>
> --
> 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