[libvirt] [PATCH 2/4] interface_backend_udev: Implement link speed & state

[Daniel P. Berrange]

On Tue, Jun 03, 2014 at 02:22:10PM +0200, Michal Privoznik wrote:
> In previous commit the interface XML is prepared for exporting
> information on NIC link speed and state. This commit implement
> actual logic for getting such info and writing it into XML.
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
> 
> Notes:
>     For the kernel issue I've posted patch here:
>     
>     http://patchwork.ozlabs.org/patch/354928/
>     
>     But it wasn't accepted as developers are afraid of breaking backward
>     compatibility. Which is weird as in 2.6.X the kernel was reporting -1
>     instead of unsigned -1.
> 
>  src/interface/interface_backend_udev.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/src/interface/interface_backend_udev.c b/src/interface/interface_backend_udev.c
> index c5353ea..80ba93e 100644
> --- a/src/interface/interface_backend_udev.c
> +++ b/src/interface/interface_backend_udev.c
> @@ -1036,6 +1036,8 @@ udevGetIfaceDef(struct udev *udev, const char *name)
>      const char *mtu_str;
>      char *vlan_parent_dev = NULL;
>      const char *devtype;
> +    const char *operstate;
> +    const char *link_speed;
>  
>      /* Allocate our interface definition structure */
>      if (VIR_ALLOC(ifacedef) < 0)
> @@ -1059,6 +1061,31 @@ udevGetIfaceDef(struct udev *udev, const char *name)
>                     udev_device_get_sysattr_value(dev, "address")) < 0)
>          goto error;
>  
> +    operstate = udev_device_get_sysattr_value(dev, "operstate");
> +    if ((ifacedef->lnk.state = virInterfaceStateTypeFromString(operstate)) <= 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Unable to parse operstate: %s"),
> +                       operstate);
> +        goto error;
> +    }
> +
> +    link_speed = udev_device_get_sysattr_value(dev, "speed");
> +    if (link_speed) {
> +        if (virStrToLong_ul(link_speed, NULL, 10, &ifacedef->lnk.speed) < 0) {
> +            virReportError(VIR_ERR_INTERNAL_ERROR,
> +                           _("Unable to parse speed: %s"),
> +                           link_speed);
> +            goto error;
> +        }
> +
> +        /* Workaround broken kernel API. If the link is unplugged then
> +         * depending on the NIC driver, link speed can be reported as -1.
> +         * However, the value is printed out as unsigned integer instead of
> +         * signed one. Terrifying but true. */
> +        if ((int) ifacedef->lnk.speed == -1)
> +            ifacedef->lnk.speed = 0;
> +    }

This block of code is duplicated in two other places in your series.
I think it'd be worth having a function in virnetdev

  virNetDevGetLinkInfo(const char *ifname, int *speed, int *state)


Regards,
Daniel
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