NDIS development

[Andrei Homescu]

Hello!

I've been studying the sources for ndis.sys for a while and I started
writing some functions, until now simple ones (wrappers for kernel
calls). I would like to implement NdisAllocatePacketPoolEx and
NdisPacketPoolUsage, but I don't think I can without modifying
NDIS_PACKET_POOL in w32api/include/ddk/ndis.h. Is that data structure
internal to ndis.sys or is publicly documented (and thus I can't touch
it)? I would like to add a couple of new members to count the overflow
packets and the used packets.
I've also been reading "Undocumented Windows NT" and I have a few
questions regarding some legal issues. Are the function declarations
for documented functions copied&pasted from the DDK? The undocumented
function declarations are obtained by disassembly of Windows sources?
Doesn't snooping around kernel code violate any copyright law?

Best regards,
Andrei Homescu

[Casper Hornstrup]

>   -----Original Message-----
>  From: ros-dev-bounces(a)reactos.com [mailto:[e-mail]] On Behalf Of
> Andrei Homescu
>  Sent: 24. juni 2005 13:50
>  To: ros-dev(a)reactos.com
>  Subject: [ros-dev] NDIS development
>  
>  Hello!
>  
>  I've been studying the sources for ndis.sys for a while and I started
>  writing some functions, until now simple ones (wrappers for kernel
>  calls). I would like to implement NdisAllocatePacketPoolEx and
>  NdisPacketPoolUsage, but I don't think I can without modifying
>  NDIS_PACKET_POOL in w32api/include/ddk/ndis.h. Is that data structure
>  internal to ndis.sys or is publicly documented (and thus I can't touch
>  it)? I would like to add a couple of new members to count the overflow
>  packets and the used packets. 
You can usually overlay the public structure with an internal NDIS
structure to access internal fields from within NDIS.

>   I've also been reading "Undocumented Windows
> NT" and I have a few
>  questions regarding some legal issues. Are the function declarations
>  for documented functions copied&pasted from the DDK? 
Most likely they are from MSDN or the Microsoft DDK documentation. If
they are not documented, then they are either different from the
structures used in Windows or from the DDK headers (needed if
compatibility is required). No matter where they came from, they
should have another format and the headers should have different
layouts. If not, then you should rearrange or reformat them to
avoid violating any copyright. Having identical structure layouts
is not violating any copyright. It may violate some crazy patent
though ;-(

>   The undocumented
>  function declarations are obtained by disassembly of Windows sources?
>  Doesn't snooping around kernel code violate any copyright law? 
It depends on which country you are in. In Denmark where I live, it
is legal to reverse engineer software for which you own a license
to. See http://reactos.com/wiki/index.php/Intellectual_Property_Policy
for more information.

>   
>  Best regards,
>  Andrei Homescu

[Andrei Homescu]

On 6/24/05, Casper Hornstrup <ch(a)csh-consult.dk> wrote:
>   
>  
> >   -----Original Message-----
> >  From: ros-dev-bounces(a)reactos.com [mailto:[e-mail]] On Behalf Of
> > Andrei Homescu
> >  Sent: 24. juni 2005 13:50
> >  To: ros-dev(a)reactos.com
> >  Subject: [ros-dev] NDIS development
> >
> >  Hello!
> >
> >  I've been studying the sources for ndis.sys for a while and I started
> >  writing some functions, until now simple ones (wrappers for kernel
> >  calls). I would like to implement NdisAllocatePacketPoolEx and
> >  NdisPacketPoolUsage, but I don't think I can without modifying
> >  NDIS_PACKET_POOL in w32api/include/ddk/ndis.h. Is that data structure
> >  internal to ndis.sys or is publicly documented (and thus I can't touch
> >  it)? I would like to add a couple of new members to count the overflow
> >  packets and the used packets. 
>  
>  You can usually overlay the public structure with an internal NDIS
>  structure to access internal fields from within NDIS. 
Yeah, but what I'm asking is if it's safe to add new members to it
without breaking existing drivers. It's not used in the Windows DDK
anywhere, nor in the ReactOS sources. I think it would be safe, but
maybe someone could prove me wrong.
The structure itself is internal to NDIS. Maybe I could move it from
the DDK header to the NDIS internal headers. As far as I have seen in
the source code, any such variable is only referenced by a pointer.

>   
> >   I've also been reading "Undocumented
> > Windows NT" and I have a few
> >  questions regarding some legal issues. Are the function declarations
> >  for documented functions copied&pasted from the DDK? 
>  
>  Most likely they are from MSDN or the Microsoft DDK documentation. If
>  they are not documented, then they are either different from the
>  structures used in Windows or from the DDK headers (needed if
>  compatibility is required). No matter where they came from, they
>  should have another format and the headers should have different
>  layouts. If not, then you should rearrange or reformat them to
>  avoid violating any copyright. Having identical structure layouts
>  is not violating any copyright. It may violate some crazy patent
>  though ;-(
>  
> >   The undocumented
> >  function declarations are obtained by disassembly of Windows sources?
> >  Doesn't snooping around kernel code violate any copyright law? 
>  
>  It depends on which country you are in. In Denmark where I live, it
>  is legal to reverse engineer software for which you own a license
>  to. See http://reactos.com/wiki/index.php/Intellectual_Property_Policy
>  for more information. 
Thank you, I hadn't read that document. It did clear up some pretty
big issues for me.
I live in Romania and AFAIK, the software laws here aren't very
mature, so reverse-engineering of software isn't even covered (I'll
have to check on that, though).

Thanks,
Andrei Homescu