diff mbox

[net-next,rfc,V3,7/9] macvtap: allow TUNSETIFF to create multiqueue device

Message ID 1370414192-5830-8-git-send-email-jasowang@redhat.com
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

Jason Wang June 5, 2013, 6:36 a.m. UTC
Though the queue were in fact created by open(), we still need to add this check
to be compatible with tuntap which can let mgmt software use a single API to
manage queues. This patch only validates the device name and moves the TUNSETIFF
to a helper.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/macvtap.c |   51 ++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 40 insertions(+), 11 deletions(-)

Comments

Michael S. Tsirkin June 5, 2013, 10:43 a.m. UTC | #1
On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
> Though the queue were in fact created by open(), we still need to add this check
> to be compatible with tuntap which can let mgmt software use a single API to
> manage queues. This patch only validates the device name and moves the TUNSETIFF
> to a helper.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

The patch is OK, the description is confusing.
What you mean is simply:

	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
	tun behaviour.

And if you put it like this, I would say make this
the last patch in the series, so userspace
can use IFF_MULTI_QUEUE to detect new versus old
behaviour.

> ---
>  drivers/net/macvtap.c |   51 ++++++++++++++++++++++++++++++++++++++----------
>  1 files changed, 40 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> index 5ccba99..14764cc 100644
> --- a/drivers/net/macvtap.c
> +++ b/drivers/net/macvtap.c
> @@ -869,6 +869,7 @@ out:
>  	return ret;
>  }
>  
> +
>  static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
>  {
>  	struct macvlan_dev *vlan;

Please don't.

> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
>  	dev_put(vlan->dev);
>  }
>  
> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
> +{
> +	struct macvtap_queue *q = file->private_data;
> +	struct net *net = current->nsproxy->net_ns;
> +	struct inode *inode = file_inode(file);
> +	struct net_device *dev, *dev2;
> +	struct ifreq ifr;
> +
> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
> +		return -EFAULT;
> +
> +	/* To keep the same behavior of tuntap, validate ifr_name */

So I'm not sure - why is it important to validate ifr_name here?
We ignore the name for all other flags - why is IFF_MULTI_QUEUE
special?

> +	if (ifr.ifr_flags & IFF_MULTI_QUEUE) {
> +		dev = __dev_get_by_name(net, ifr.ifr_name);
> +		if (!dev)
> +			return -EINVAL;
> +
> +		dev2 = dev_get_by_macvtap_minor(iminor(inode));
> +		if (!dev2)
> +			return -EINVAL;
> +
> +		if (dev != dev2) {
> +			dev_put(dev2);
> +			return -EINVAL;
> +		}
> +
> +		dev_put(dev2);
> +	}
> +
> +	if ((ifr.ifr_flags & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
> +	    (IFF_NO_PI | IFF_TAP))
> +		return -EINVAL;
> +	else
> +		q->flags = ifr.ifr_flags;
> +
> +	return 0;
> +}
> +
>  /*
>   * provide compatibility with generic tun/tap interface
>   */
> @@ -905,17 +944,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
>  
>  	switch (cmd) {
>  	case TUNSETIFF:
> -		/* ignore the name, just look at flags */

This is actually a useful comment that you've removed.

> -		if (get_user(u, &ifr->ifr_flags))
> -			return -EFAULT;
> -
> -		ret = 0;
> -		if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
> -			ret = -EINVAL;
> -		else
> -			q->flags = u;
> -
> -		return ret;
> +		return macvtap_set_iff(file, ifr);
>  
>  	case TUNGETIFF:
>  		vlan = macvtap_get_vlan(q);
> -- 
> 1.7.1
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Jason Wang June 6, 2013, 3:13 a.m. UTC | #2
On 06/05/2013 06:43 PM, Michael S. Tsirkin wrote:
> On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
>> Though the queue were in fact created by open(), we still need to add this check
>> to be compatible with tuntap which can let mgmt software use a single API to
>> manage queues. This patch only validates the device name and moves the TUNSETIFF
>> to a helper.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> The patch is OK, the description is confusing.
> What you mean is simply:
>
> 	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
> 	tun behaviour.
>
> And if you put it like this, I would say make this
> the last patch in the series, so userspace
> can use IFF_MULTI_QUEUE to detect new versus old
> behaviour.

Make sense, thanks.
>
>> ---
>>  drivers/net/macvtap.c |   51 ++++++++++++++++++++++++++++++++++++++----------
>>  1 files changed, 40 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
>> index 5ccba99..14764cc 100644
>> --- a/drivers/net/macvtap.c
>> +++ b/drivers/net/macvtap.c
>> @@ -869,6 +869,7 @@ out:
>>  	return ret;
>>  }
>>  
>> +
>>  static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
>>  {
>>  	struct macvlan_dev *vlan;
> Please don't.

Ok.
>
>> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
>>  	dev_put(vlan->dev);
>>  }
>>  
>> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
>> +{
>> +	struct macvtap_queue *q = file->private_data;
>> +	struct net *net = current->nsproxy->net_ns;
>> +	struct inode *inode = file_inode(file);
>> +	struct net_device *dev, *dev2;
>> +	struct ifreq ifr;
>> +
>> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
>> +		return -EFAULT;
>> +
>> +	/* To keep the same behavior of tuntap, validate ifr_name */
> So I'm not sure - why is it important to validate ifr_name here?
> We ignore the name for all other flags - why is IFF_MULTI_QUEUE
> special?

It raises another question, why not validate ifname like tuntap? We
should warn userspace about their error, otherwise they may create
queues on the wrong device. In fact I want validate for both, but keep
the behaviour w/o IFF_MULTI_QUEUE for backward compatibility.
>
>> +	if (ifr.ifr_flags & IFF_MULTI_QUEUE) {
>> +		dev = __dev_get_by_name(net, ifr.ifr_name);
>> +		if (!dev)
>> +			return -EINVAL;
>> +
>> +		dev2 = dev_get_by_macvtap_minor(iminor(inode));
>> +		if (!dev2)
>> +			return -EINVAL;
>> +
>> +		if (dev != dev2) {
>> +			dev_put(dev2);
>> +			return -EINVAL;
>> +		}
>> +
>> +		dev_put(dev2);
>> +	}
>> +
>> +	if ((ifr.ifr_flags & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
>> +	    (IFF_NO_PI | IFF_TAP))
>> +		return -EINVAL;
>> +	else
>> +		q->flags = ifr.ifr_flags;
>> +
>> +	return 0;
>> +}
>> +
>>  /*
>>   * provide compatibility with generic tun/tap interface
>>   */
>> @@ -905,17 +944,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
>>  
>>  	switch (cmd) {
>>  	case TUNSETIFF:
>> -		/* ignore the name, just look at flags */
> This is actually a useful comment that you've removed.

Will get it back.
>
>> -		if (get_user(u, &ifr->ifr_flags))
>> -			return -EFAULT;
>> -
>> -		ret = 0;
>> -		if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
>> -			ret = -EINVAL;
>> -		else
>> -			q->flags = u;
>> -
>> -		return ret;
>> +		return macvtap_set_iff(file, ifr);
>>  
>>  	case TUNGETIFF:
>>  		vlan = macvtap_get_vlan(q);
>> -- 
>> 1.7.1

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Michael S. Tsirkin June 6, 2013, 6:59 a.m. UTC | #3
On Thu, Jun 06, 2013 at 11:13:29AM +0800, Jason Wang wrote:
> On 06/05/2013 06:43 PM, Michael S. Tsirkin wrote:
> > On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
> >> Though the queue were in fact created by open(), we still need to add this check
> >> to be compatible with tuntap which can let mgmt software use a single API to
> >> manage queues. This patch only validates the device name and moves the TUNSETIFF
> >> to a helper.
> >>
> >> Signed-off-by: Jason Wang <jasowang@redhat.com>
> > The patch is OK, the description is confusing.
> > What you mean is simply:
> >
> > 	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
> > 	tun behaviour.
> >
> > And if you put it like this, I would say make this
> > the last patch in the series, so userspace
> > can use IFF_MULTI_QUEUE to detect new versus old
> > behaviour.
> 
> Make sense, thanks.
> >
> >> ---
> >>  drivers/net/macvtap.c |   51 ++++++++++++++++++++++++++++++++++++++----------
> >>  1 files changed, 40 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> >> index 5ccba99..14764cc 100644
> >> --- a/drivers/net/macvtap.c
> >> +++ b/drivers/net/macvtap.c
> >> @@ -869,6 +869,7 @@ out:
> >>  	return ret;
> >>  }
> >>  
> >> +
> >>  static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
> >>  {
> >>  	struct macvlan_dev *vlan;
> > Please don't.
> 
> Ok.
> >
> >> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
> >>  	dev_put(vlan->dev);
> >>  }
> >>  
> >> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
> >> +{
> >> +	struct macvtap_queue *q = file->private_data;
> >> +	struct net *net = current->nsproxy->net_ns;
> >> +	struct inode *inode = file_inode(file);
> >> +	struct net_device *dev, *dev2;
> >> +	struct ifreq ifr;
> >> +
> >> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
> >> +		return -EFAULT;
> >> +
> >> +	/* To keep the same behavior of tuntap, validate ifr_name */
> > So I'm not sure - why is it important to validate ifr_name here?
> > We ignore the name for all other flags - why is IFF_MULTI_QUEUE
> > special?
> 
> It raises another question, why not validate ifname like tuntap? We
> should warn userspace about their error, otherwise they may create
> queues on the wrong device. In fact I want validate for both, but keep
> the behaviour w/o IFF_MULTI_QUEUE for backward compatibility.

Basically macvtap ignores ifr_name because it doesn't need it.
Making it ignore it without IFF_MULTI_QUEUE but
not with IFF_MULTI_QUEUE seems ugly.

Do you think we'll need ifr_name at some point?
Why not validate then, when we actually do?


> >
> >> +	if (ifr.ifr_flags & IFF_MULTI_QUEUE) {
> >> +		dev = __dev_get_by_name(net, ifr.ifr_name);
> >> +		if (!dev)
> >> +			return -EINVAL;
> >> +
> >> +		dev2 = dev_get_by_macvtap_minor(iminor(inode));
> >> +		if (!dev2)
> >> +			return -EINVAL;
> >> +
> >> +		if (dev != dev2) {
> >> +			dev_put(dev2);
> >> +			return -EINVAL;
> >> +		}
> >> +
> >> +		dev_put(dev2);
> >> +	}
> >> +
> >> +	if ((ifr.ifr_flags & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
> >> +	    (IFF_NO_PI | IFF_TAP))
> >> +		return -EINVAL;
> >> +	else
> >> +		q->flags = ifr.ifr_flags;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >>  /*
> >>   * provide compatibility with generic tun/tap interface
> >>   */
> >> @@ -905,17 +944,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
> >>  
> >>  	switch (cmd) {
> >>  	case TUNSETIFF:
> >> -		/* ignore the name, just look at flags */
> > This is actually a useful comment that you've removed.
> 
> Will get it back.
> >
> >> -		if (get_user(u, &ifr->ifr_flags))
> >> -			return -EFAULT;
> >> -
> >> -		ret = 0;
> >> -		if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
> >> -			ret = -EINVAL;
> >> -		else
> >> -			q->flags = u;
> >> -
> >> -		return ret;
> >> +		return macvtap_set_iff(file, ifr);
> >>  
> >>  	case TUNGETIFF:
> >>  		vlan = macvtap_get_vlan(q);
> >> -- 
> >> 1.7.1
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Jason Wang June 6, 2013, 7:12 a.m. UTC | #4
On 06/06/2013 02:59 PM, Michael S. Tsirkin wrote:
> On Thu, Jun 06, 2013 at 11:13:29AM +0800, Jason Wang wrote:
>> On 06/05/2013 06:43 PM, Michael S. Tsirkin wrote:
>>> On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
>>>> Though the queue were in fact created by open(), we still need to add this check
>>>> to be compatible with tuntap which can let mgmt software use a single API to
>>>> manage queues. This patch only validates the device name and moves the TUNSETIFF
>>>> to a helper.
>>>>
>>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>> The patch is OK, the description is confusing.
>>> What you mean is simply:
>>>
>>> 	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
>>> 	tun behaviour.
>>>
>>> And if you put it like this, I would say make this
>>> the last patch in the series, so userspace
>>> can use IFF_MULTI_QUEUE to detect new versus old
>>> behaviour.

[...]
>>>> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
>>>>  	dev_put(vlan->dev);
>>>>  }
>>>>  
>>>> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
>>>> +{
>>>> +	struct macvtap_queue *q = file->private_data;
>>>> +	struct net *net = current->nsproxy->net_ns;
>>>> +	struct inode *inode = file_inode(file);
>>>> +	struct net_device *dev, *dev2;
>>>> +	struct ifreq ifr;
>>>> +
>>>> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
>>>> +		return -EFAULT;
>>>> +
>>>> +	/* To keep the same behavior of tuntap, validate ifr_name */
>>> So I'm not sure - why is it important to validate ifr_name here?
>>> We ignore the name for all other flags - why is IFF_MULTI_QUEUE
>>> special?
>> It raises another question, why not validate ifname like tuntap? We
>> should warn userspace about their error, otherwise they may create
>> queues on the wrong device. In fact I want validate for both, but keep
>> the behaviour w/o IFF_MULTI_QUEUE for backward compatibility.
> Basically macvtap ignores ifr_name because it doesn't need it.
> Making it ignore it without IFF_MULTI_QUEUE but
> not with IFF_MULTI_QUEUE seems ugly.
>
> Do you think we'll need ifr_name at some point?
> Why not validate then, when we actually do?
>
>
>

If we want to be more compatible with tuntap to simplify userspace codes.

E.g: There's a userspace who want to create both taps and macvtaps using
the same codes. For tuntap, we can let kernel name the device, so
creating a mq device looks like:

open()
tunsetiff()
if_name = tungetiff()
tunsetiff(if_name)
...
tunsetiff(if_name)

For tuntap, if we specifies a wrong ifr_name, kernel will complains.
We'd better do the same for macvtap.

[...]
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Michael S. Tsirkin June 6, 2013, 7:26 a.m. UTC | #5
On Thu, Jun 06, 2013 at 03:12:52PM +0800, Jason Wang wrote:
> On 06/06/2013 02:59 PM, Michael S. Tsirkin wrote:
> > On Thu, Jun 06, 2013 at 11:13:29AM +0800, Jason Wang wrote:
> >> On 06/05/2013 06:43 PM, Michael S. Tsirkin wrote:
> >>> On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
> >>>> Though the queue were in fact created by open(), we still need to add this check
> >>>> to be compatible with tuntap which can let mgmt software use a single API to
> >>>> manage queues. This patch only validates the device name and moves the TUNSETIFF
> >>>> to a helper.
> >>>>
> >>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> >>> The patch is OK, the description is confusing.
> >>> What you mean is simply:
> >>>
> >>> 	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
> >>> 	tun behaviour.
> >>>
> >>> And if you put it like this, I would say make this
> >>> the last patch in the series, so userspace
> >>> can use IFF_MULTI_QUEUE to detect new versus old
> >>> behaviour.
> 
> [...]
> >>>> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
> >>>>  	dev_put(vlan->dev);
> >>>>  }
> >>>>  
> >>>> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
> >>>> +{
> >>>> +	struct macvtap_queue *q = file->private_data;
> >>>> +	struct net *net = current->nsproxy->net_ns;
> >>>> +	struct inode *inode = file_inode(file);
> >>>> +	struct net_device *dev, *dev2;
> >>>> +	struct ifreq ifr;
> >>>> +
> >>>> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
> >>>> +		return -EFAULT;
> >>>> +
> >>>> +	/* To keep the same behavior of tuntap, validate ifr_name */
> >>> So I'm not sure - why is it important to validate ifr_name here?
> >>> We ignore the name for all other flags - why is IFF_MULTI_QUEUE
> >>> special?
> >> It raises another question, why not validate ifname like tuntap? We
> >> should warn userspace about their error, otherwise they may create
> >> queues on the wrong device. In fact I want validate for both, but keep
> >> the behaviour w/o IFF_MULTI_QUEUE for backward compatibility.
> > Basically macvtap ignores ifr_name because it doesn't need it.
> > Making it ignore it without IFF_MULTI_QUEUE but
> > not with IFF_MULTI_QUEUE seems ugly.
> >
> > Do you think we'll need ifr_name at some point?
> > Why not validate then, when we actually do?
> >
> >
> >
> 
> If we want to be more compatible with tuntap to simplify userspace codes.
> 
> E.g: There's a userspace who want to create both taps and macvtaps using
> the same codes. For tuntap, we can let kernel name the device, so
> creating a mq device looks like:
> 
> open()
> tunsetiff()
> if_name = tungetiff()
> tunsetiff(if_name)
> ...
> tunsetiff(if_name)
> 
> For tuntap, if we specifies a wrong ifr_name, kernel will complains.
> We'd better do the same for macvtap.
> 
> [...]

I don't think we need to worry about returning same error to buggy
applications. Maybe it would make sense if we did it like this
the first time around, or maybe it won't, but adding
inconsistency between macvtap interfaces is even worse.
Jason Wang June 6, 2013, 7:31 a.m. UTC | #6
On 06/06/2013 03:26 PM, Michael S. Tsirkin wrote:
> On Thu, Jun 06, 2013 at 03:12:52PM +0800, Jason Wang wrote:
>> On 06/06/2013 02:59 PM, Michael S. Tsirkin wrote:
>>> On Thu, Jun 06, 2013 at 11:13:29AM +0800, Jason Wang wrote:
>>>> On 06/05/2013 06:43 PM, Michael S. Tsirkin wrote:
>>>>> On Wed, Jun 05, 2013 at 02:36:30PM +0800, Jason Wang wrote:
>>>>>> Though the queue were in fact created by open(), we still need to add this check
>>>>>> to be compatible with tuntap which can let mgmt software use a single API to
>>>>>> manage queues. This patch only validates the device name and moves the TUNSETIFF
>>>>>> to a helper.
>>>>>>
>>>>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>>>> The patch is OK, the description is confusing.
>>>>> What you mean is simply:
>>>>>
>>>>> 	Allow IFF_MULTI_QUEUE in TUNSETIFF for macvtap, to match
>>>>> 	tun behaviour.
>>>>>
>>>>> And if you put it like this, I would say make this
>>>>> the last patch in the series, so userspace
>>>>> can use IFF_MULTI_QUEUE to detect new versus old
>>>>> behaviour.
>> [...]
>>>>>> @@ -887,6 +888,44 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
>>>>>>  	dev_put(vlan->dev);
>>>>>>  }
>>>>>>  
>>>>>> +static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
>>>>>> +{
>>>>>> +	struct macvtap_queue *q = file->private_data;
>>>>>> +	struct net *net = current->nsproxy->net_ns;
>>>>>> +	struct inode *inode = file_inode(file);
>>>>>> +	struct net_device *dev, *dev2;
>>>>>> +	struct ifreq ifr;
>>>>>> +
>>>>>> +	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
>>>>>> +		return -EFAULT;
>>>>>> +
>>>>>> +	/* To keep the same behavior of tuntap, validate ifr_name */
>>>>> So I'm not sure - why is it important to validate ifr_name here?
>>>>> We ignore the name for all other flags - why is IFF_MULTI_QUEUE
>>>>> special?
>>>> It raises another question, why not validate ifname like tuntap? We
>>>> should warn userspace about their error, otherwise they may create
>>>> queues on the wrong device. In fact I want validate for both, but keep
>>>> the behaviour w/o IFF_MULTI_QUEUE for backward compatibility.
>>> Basically macvtap ignores ifr_name because it doesn't need it.
>>> Making it ignore it without IFF_MULTI_QUEUE but
>>> not with IFF_MULTI_QUEUE seems ugly.
>>>
>>> Do you think we'll need ifr_name at some point?
>>> Why not validate then, when we actually do?
>>>
>>>
>>>
>> If we want to be more compatible with tuntap to simplify userspace codes.
>>
>> E.g: There's a userspace who want to create both taps and macvtaps using
>> the same codes. For tuntap, we can let kernel name the device, so
>> creating a mq device looks like:
>>
>> open()
>> tunsetiff()
>> if_name = tungetiff()
>> tunsetiff(if_name)
>> ...
>> tunsetiff(if_name)
>>
>> For tuntap, if we specifies a wrong ifr_name, kernel will complains.
>> We'd better do the same for macvtap.
>>
>> [...]
> I don't think we need to worry about returning same error to buggy
> applications. Maybe it would make sense if we did it like this
> the first time around, or maybe it won't, but adding
> inconsistency between macvtap interfaces is even worse.
>

Ok, I will drop this patch in next version.
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diff mbox

Patch

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 5ccba99..14764cc 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -869,6 +869,7 @@  out:
 	return ret;
 }
 
+
 static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
 {
 	struct macvlan_dev *vlan;
@@ -887,6 +888,44 @@  static void macvtap_put_vlan(struct macvlan_dev *vlan)
 	dev_put(vlan->dev);
 }
 
+static int macvtap_set_iff(struct file *file, struct ifreq __user *ifr_u)
+{
+	struct macvtap_queue *q = file->private_data;
+	struct net *net = current->nsproxy->net_ns;
+	struct inode *inode = file_inode(file);
+	struct net_device *dev, *dev2;
+	struct ifreq ifr;
+
+	if (copy_from_user(&ifr, ifr_u, sizeof(struct ifreq)))
+		return -EFAULT;
+
+	/* To keep the same behavior of tuntap, validate ifr_name */
+	if (ifr.ifr_flags & IFF_MULTI_QUEUE) {
+		dev = __dev_get_by_name(net, ifr.ifr_name);
+		if (!dev)
+			return -EINVAL;
+
+		dev2 = dev_get_by_macvtap_minor(iminor(inode));
+		if (!dev2)
+			return -EINVAL;
+
+		if (dev != dev2) {
+			dev_put(dev2);
+			return -EINVAL;
+		}
+
+		dev_put(dev2);
+	}
+
+	if ((ifr.ifr_flags & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
+	    (IFF_NO_PI | IFF_TAP))
+		return -EINVAL;
+	else
+		q->flags = ifr.ifr_flags;
+
+	return 0;
+}
+
 /*
  * provide compatibility with generic tun/tap interface
  */
@@ -905,17 +944,7 @@  static long macvtap_ioctl(struct file *file, unsigned int cmd,
 
 	switch (cmd) {
 	case TUNSETIFF:
-		/* ignore the name, just look at flags */
-		if (get_user(u, &ifr->ifr_flags))
-			return -EFAULT;
-
-		ret = 0;
-		if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
-			ret = -EINVAL;
-		else
-			q->flags = u;
-
-		return ret;
+		return macvtap_set_iff(file, ifr);
 
 	case TUNGETIFF:
 		vlan = macvtap_get_vlan(q);