Re: The patch of gnumach to enable the user to set the network device into the promiscuous mode

[zhengda]

Samuel Thibault wrote:
> > On Fri, Aug 8, 2008 at 9:33 PM, Samuel Thibault <samuel.thibault@ens-lyon.org>
> > wrote:
> >     zhengda, le Fri 08 Aug 2008 06:44:16 +0200, a écrit :
> >     > +    dev->flags = (flags &
> >     > +            (IFF_BROADCAST | IFF_DEBUG | IFF_LOOPBACK |
> >     > +             IFF_POINTOPOINT | IFF_NOTRAILERS | IFF_RUNNING |
> >     > +             IFF_NOARP | IFF_PROMISC | IFF_ALLMULTI | IFF_SLAVE
> >     > +             | IFF_MASTER | IFF_MULTICAST))
> >     > +        | (dev->flags & (IFF_SOFTHEADERS|IFF_UP));
> >     
>
> I had a look in if_hdr.h, there's a IFF_CANTCHANGE macro, which includes
> BROADCAST, POINTOPOINT and RUNNING, shouldn't at least these be excluded
> from set_flags then?  When I look at the corresponding nowaday's linux
> code:
>
>         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
>                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
>                                IFF_AUTOMEDIA)) |
>                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
>                                     IFF_ALLMULTI));
>         ...
>         (plus IFF_UP, IFF_PROMISC and IFF_ALLMULTI which are handled
>         separately)
>
> it looks so.
I don't know.
look at the code in gnumach/linux/dev/net/core/dev.c (in line 1130):
               dev->flags = (ifr.ifr_flags & (
                   IFF_BROADCAST | IFF_DEBUG | IFF_LOOPBACK |
                   IFF_POINTOPOINT | IFF_NOTRAILERS | IFF_RUNNING |
                   IFF_NOARP | IFF_PROMISC | IFF_ALLMULTI | IFF_SLAVE | 
IFF_MASTER
                   | IFF_MULTICAST)) | (dev->flags & 
(IFF_SOFTHEADERS|IFF_UP));
I think the person who wrote the patch copied the code from here.
but maybe you're right.

Zheng Da