[PATH] Allow mtu bigger than 1500 for ieee80211

[PATH] Allow mtu bigger than 1500 for ieee80211

[matthieu castet]

[-- Attachment #1: Type: text/plain, Size: 182 bytes --]

Hi

this patch allow to set the mtu between 1500 and 2304 (max octets in an 
MSDU) for devices using ieee80211 linux stack.

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>

[-- Attachment #2: ieee80211mtu --]
[-- Type: text/plain, Size: 773 bytes --]

Index: linux/net/ieee80211/ieee80211_module.c
===================================================================
--- linux.orig/net/ieee80211/ieee80211_module.c	2006-09-26 19:27:26.000000000 +0200
+++ linux/net/ieee80211/ieee80211_module.c	2006-09-28 19:50:53.000000000 +0200
@@ -118,6 +118,14 @@
 			      &ieee->network_free_list);
 }
 
+static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
+{
+	if ((new_mtu < 68) || (new_mtu > IEEE80211_DATA_LEN))
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+
 struct net_device *alloc_ieee80211(int sizeof_priv)
 {
 	struct ieee80211_device *ieee;
@@ -133,6 +141,7 @@
 	}
 	ieee = netdev_priv(dev);
 	dev->hard_start_xmit = ieee80211_xmit;
+	dev->change_mtu = ieee80211_change_mtu;
 
 	ieee->dev = dev;
 

Re: [PATH] Allow mtu bigger than 1500 for ieee80211

[Johannes Berg]

On Thu, 2006-09-28 at 19:57 +0200, matthieu castet wrote:

> +	if ((new_mtu < 68) || (new_mtu > IEEE80211_DATA_LEN))
> +		return -EINVAL;

What's with that lower limit, why 68?

johannes

Re: [PATH] Allow mtu bigger than 1500 for ieee80211

[Joerg Roedel]

On Fri, Sep 29, 2006 at 09:38:21AM +0200, Johannes Berg wrote:
> On Thu, 2006-09-28 at 19:57 +0200, matthieu castet wrote:
> 
> > +	if ((new_mtu < 68) || (new_mtu > IEEE80211_DATA_LEN))
> > +		return -EINVAL;
> 
> What's with that lower limit, why 68?

Isn't 68 the minimum MTU required by IPv4?

Re: [PATH] Allow mtu bigger than 1500 for ieee80211

[Johannes Berg]

On Fri, 2006-09-29 at 11:30 +0200, Joerg Roedel wrote:
> On Fri, Sep 29, 2006 at 09:38:21AM +0200, Johannes Berg wrote:
> > On Thu, 2006-09-28 at 19:57 +0200, matthieu castet wrote:
> > 
> > > +	if ((new_mtu < 68) || (new_mtu > IEEE80211_DATA_LEN))
> > > +		return -EINVAL;
> > 
> > What's with that lower limit, why 68?
> 
> Isn't 68 the minimum MTU required by IPv4?

No idea, but shouldn't there be a named constant somewhere for that
then?

johannes

Re: [PATH] Allow mtu bigger than 1500 for ieee80211

[Joerg Roedel]

On Fri, Sep 29, 2006 at 01:56:10PM +0200, Johannes Berg wrote:
> On Fri, 2006-09-29 at 11:30 +0200, Joerg Roedel wrote:

> > Isn't 68 the minimum MTU required by IPv4?
> 
> No idea, but shouldn't there be a named constant somewhere for that
> then?

Maybe. Other network drivers also implement this number as a hard value
in their change_mtu callback. For example, the default ethernet function
is implemented this way.

Joerg