[PATCH][netifd] system-linux: initialize ifreq struct before using it

[Alin Năstac]

Hi Hans,

I have the confirmation, this change fixed my problem.

Given the fact that my commit fixes an obvious programming error, I
don't think I need to put a detailed explanation in the commit
description.

BR,
Alin

On Thu, Oct 8, 2020 at 2:35 PM Alin Năstac <alin.nastac at gmail.com> wrote:
>
> Hi Hans,
>
> The issue I have involved adding an external device to the lan bridge
> through add_device ubus call. Sometimes this operation fails to add
> the new bridge port with the following device debug traces:
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]:
> device_create_default(525): Create simple device 'wds1_1_2'
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]:
> device_init_virtual(478): Initialize device 'wds1_1_2'
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]:
> device_set_present(634): Network device 'wds1_1_2' is now present
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]:
> __device_add_user(710): Add user for device 'wds1_1_2', refcount=1
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]: device_claim(413):
> Claim Network device wds1_1_2, new active count: 1
> Wed Oct  7 04:22:57 2020 daemon.err netifd[2843]: device_claim(432):
> claim Network device wds1_1_2 failed: -1
>
> I'm not sure it fixes the problem I experience (the jury is still out
> on that), but it is definitely caused by system_if_resolve() failure
> to retrieve the interface index. Looking at the handling of
> SIOCGIFINDEX in the kernel, it shouldn't matter if the rest of the
> fields are uninitialized, but a variable should always be initialized
> before its first use.
>
> BR,
> Alin
>
> On Thu, Oct 8, 2020 at 2:15 PM Hans Dedecker <dedeckeh at gmail.com> wrote:
> >
> > Hi Alin,
> >
> > On Thu, Oct 8, 2020 at 1:31 PM Alin Nastac <alin.nastac at gmail.com> wrote:
> > Could you add which issue this fixes ?
> >
> > Thx
> > Hans
> > >
> > > Signed-off-by: Alin Nastac <alin.nastac at gmail.com>
> > > ---
> > >  system-linux.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/system-linux.c b/system-linux.c
> > > index 6778b1d..9188899 100644
> > > --- a/system-linux.c
> > > +++ b/system-linux.c
> > > @@ -904,6 +904,8 @@ failure:
> > >  int system_if_resolve(struct device *dev)
> > >  {
> > >         struct ifreq ifr;
> > > +
> > > +       memset(&ifr, 0, sizeof(ifr));
> > >         strncpy(ifr.ifr_name, dev->ifname, sizeof(ifr.ifr_name) - 1);
> > >         if (!ioctl(sock_ioctl, SIOCGIFINDEX, &ifr))
> > >                 return ifr.ifr_ifindex;
> > > --
> > > 2.7.4
> > >