On 06/13/2014 10:50 AM, Martin Kletzander wrote:
> On Fri, Jun 13, 2014 at 10:31:53AM +0300, Laine Stump wrote:
>> On 06/13/2014 10:10 AM, Martin Kletzander wrote:
>>> On Fri, Jun 13, 2014 at 08:46:59AM +0200, Michal Privoznik wrote:
>>>> The kernel's more broken than one would think. Various drivers report
>>>> various (usually spurious) values if the interface is down. While on
>>>> some we experience -EINVAL when read()-ing the speed sysfs file, with
>>>> other drivers we might get anything from 0 to UINT_MAX. If that's the
>>>> case it's better to not report link speed. Well, the interface is down
>>>> anyway.
>>>>
>>>> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
>>>> ---
>>>> src/util/virnetdev.c | 13 ++++++++++++-
>>>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
>>>> index 6f3a202..80ef572 100644
>>>> --- a/src/util/virnetdev.c
>>>> +++ b/src/util/virnetdev.c
>>>> @@ -1843,7 +1843,7 @@ virNetDevGetLinkInfo(const char *ifname,
>>>> char *buf = NULL;
>>>> char *tmp;
>>>> int tmp_state;
>>>> - unsigned int tmp_speed;
>>>> + unsigned int tmp_speed; /* virInterfaceState */
>>>>
>>>
>>> You probably wanted to put this comment next to the line with
>>> tmp_state and not tmp_speed.
>>>
>>>> if (virNetDevSysfsFile(&path, ifname, "operstate") < 0)
>>>> goto cleanup;
>>>> @@ -1875,6 +1875,16 @@ virNetDevGetLinkInfo(const char *ifname,
>>>>
>>>> lnk->state = tmp_state;
>>>>
>>>> + /* Shortcut to avoid some kernel issues. If link is down (and
>>>> possibly in
>>>> + * other states too) several drivers report several values.
>>>> While igb
>>>> + * reports 65535, realtek goes with 10. To avoid muddying XML
>>>> with insane
>>>> + * values, don't report link speed */
>>>> + if (lnk->state == VIR_INTERFACE_STATE_DOWN) {
>>
>> Also for VIR_INTERFACE_LOWER_LAYER_DOWN (verified by looking at the
>> speed reported by a macvtap device when its physdev is down). And I'm
>> not sure how to get an interface into "NOT_PRESENT" or "DORMANT" state,
>> but I would imagine that the speed should be 0 in those cases too.
>>
>
> I've seen many other states I have no idea how to achieve. Wouldn't
> it make more sense to report the speed only if the state is UP?
That makes enough sense to me that I changed my netcf patch to do just
that - it sets speed to 0 unless operstate is "up". Still open for
debate though :-) I just sent the patch to
netcf-devel@xxxxxxxxxxxxxxxxxxxxxx
Note that netcf will now report link state for interfaces that are a
subordinate of another interface (e.g. the ethernets attached to a
bridge or a bond, or a bond attached to a bridge). libvirt tosses those
out, so I should probably do a patch to remedy that.
>
>> ACK with LOWER_LAYER_DOWN added (I won't insist on the others
>> until/unless I see experimental evidence that they need it).
>>
>> BTW, thinking more about bridge devices - maybe they should be given
>> state "up" if the device has been ifup'ed.
I've decided against this in netcf, and instead simply omit the <link>
element entirely if the interface type is bridge.
>> In other words, in their case
>> you could call the functional equivalent of if_is_active() in netcf
>> (which does an SIOCGIFFLAGS ioctl and checks for the IFF_UP flag). (in
>> any case, bridges should probably just always report a speed of 0).
>>
--
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