[systemd-devel] [RFC][PATCH v2] net: set default DEVTYPE for all ethernet based devices

[Tom Gundersen]

In systemd's networkd and udevd, we would like to give the administrator a
simple way to filter net devices by their DEVTYPE [0][1]. Other software
such as ConnMan and NetworkManager uses a similar filtering already.

Currently, plain ethernet devices have DEVTYPE=(null). This patch sets the
devtype to "ethernet" instead. This avoids the need for special-casing the
DEVTYPE=(null) case in userspace, and also avoids false positives, as there
are several other types of netdevs that also have DEVTYPE=(null).

Notice that this is done, as suggested by Marcel, in alloc_etherdev_mqs(),
and as best I can tell it will not give any false positives. I considered
doing it in ether_setup() instead as that seemed more intuitive, but that
would give a lot of false positives indeed.

[0]: <http://www.freedesktop.org/software/systemd/man/systemd-networkd.service.html#Type>
[1]: <http://www.freedesktop.org/software/systemd/man/udev.html#Type>

Signed-off-by: Tom Gundersen <teg at jklm.no>
Cc: Marcel Holtmann <marcel at holtmann.org>
Cc: Greg KH <gregkh at linuxfoundation.org>
---
 net/ethernet/eth.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 8f032ba..b76dc17 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -369,6 +369,10 @@ void ether_setup(struct net_device *dev)
 }
 EXPORT_SYMBOL(ether_setup);
 
+static const struct device_type eth_type = {
+	.name = "ethernet",
+};
+
 /**
  * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
  * @sizeof_priv: Size of additional driver-private structure to be allocated
@@ -387,7 +391,13 @@ EXPORT_SYMBOL(ether_setup);
 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
 				      unsigned int rxqs)
 {
-	return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);
+	struct net_device* dev;
+
+	dev = alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);
+	if (dev)
+		dev->dev.type = &eth_type;
+
+	return dev;
 }
 EXPORT_SYMBOL(alloc_etherdev_mqs);
 
-- 
1.8.5.2