[systemd-devel] [RFC][PATCH] net: set default DEVTYPE for all ethernet based devices

[Tom Gundersen]

On Sun, Jan 5, 2014 at 3:14 AM, Marcel Holtmann <marcel at holtmann.org> wrote:
> Hi Tom,
>
>> In systemd's networkd and udevd, we would like to give the administrator a
>> simple way to filter ethernet devices by their DEVTYPE. In order to avoid
>> having a special treatment of the case where DEVTYPE=(null), initialize it to
>> a default value, "ethernet", in the kernel.
>>
>> Signed-off-by: Tom Gundersen <teg at jklm.no>
>> Cc: Marcel Holtmann <marcel at holtmann.org>
>> Cc: Greg KH <gregkh at linuxfoundation.org>
>> ---
>>
>> Hi Greg and Marcel,
>>
>> This patch seems to do the right thing for me. Any comments before I send it
>> off to LKML?
>>
>> I suppose it may make sense to hide this behind a kernel option in case we are
>> worried about breaking existing users (but if ConnMan is adapted, I don't know
>> of any other issues, NetworkManager is not affected at least).
>>
>> Cheers,
>>
>> Tom
>>
>> net/core/dev.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index ba3b7ea..62881e0 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -6215,6 +6215,10 @@ void netdev_freemem(struct net_device *dev)
>>               kfree(addr);
>> }
>>
>> +static const struct device_type ethernet_type = {
>> +     .name = "ethernet",
>> +};
>> +
>> /**
>>  *    alloc_netdev_mqs - allocate network device
>>  *    @sizeof_priv:   size of private data to allocate space for
>> @@ -6305,6 +6309,8 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
>>               goto free_all;
>> #endif
>>
>> +     SET_NETDEV_DEVTYPE(dev, &ethernet_type);
>> +
>>       strcpy(dev->name, name);
>>       dev->group = INIT_NETDEV_GROUP;
>>       if (!dev->ethtool_ops)
>
> this means that every single netdev is defaulting to Ethernet. This includes also the fake ones like IrDA or raw IP ones like PPP or TUN devices. I do not think that is something we really want here.

Hm, so then the assumption I first worked under (DEVTYPE==(null) means
ethernet) is not really correct. Doesn't this give you problems in
ConnMan at the moment?

What do you think would be the correct behavior? To use this patch,
but also patch up IrDA, PPP, TUN and whatever else to set real
DEVTYPE's; or to leave them as essentially 'unknown', and go through
the ethernet drivers and set them to DEVTYPE='ethernet' one-by-one?

Cheers,

Tom