One solution is to set up a dummy link using PPP/SLIP/PLIP,
but this seems (to me) too much overhead for too little gain.
This driver provides a small alternative. Thus you can do
-
+
[when not running slip]
ifconfig dummy slip.addr.ess.here up
[to go to slip]
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
+#include <linux/rtnetlink.h>
+#include <net/rtnetlink.h>
static int numdummies = 1;
static int dummy_xmit(struct sk_buff *skb, struct net_device *dev);
-static struct net_device_stats *dummy_get_stats(struct net_device *dev);
static int dummy_set_address(struct net_device *dev, void *p)
{
struct sockaddr *sa = p;
- if (!is_valid_ether_addr(sa->sa_data))
+ if (!is_valid_ether_addr(sa->sa_data))
return -EADDRNOTAVAIL;
-
+
memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
return 0;
}
{
}
-static void __init dummy_setup(struct net_device *dev)
+static const struct net_device_ops dummy_netdev_ops = {
+ .ndo_start_xmit = dummy_xmit,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_set_multicast_list = set_multicast_list,
+ .ndo_set_mac_address = dummy_set_address,
+};
+
+static void dummy_setup(struct net_device *dev)
{
+ ether_setup(dev);
+
/* Initialize the device structure. */
- dev->get_stats = dummy_get_stats;
- dev->hard_start_xmit = dummy_xmit;
- dev->set_multicast_list = set_multicast_list;
- dev->set_mac_address = dummy_set_address;
+ dev->netdev_ops = &dummy_netdev_ops;
+ dev->destructor = free_netdev;
/* Fill in device structure with ethernet-generic values. */
- ether_setup(dev);
dev->tx_queue_len = 0;
- dev->change_mtu = NULL;
dev->flags |= IFF_NOARP;
dev->flags &= ~IFF_MULTICAST;
- SET_MODULE_OWNER(dev);
random_ether_addr(dev->dev_addr);
}
static int dummy_xmit(struct sk_buff *skb, struct net_device *dev)
{
- struct net_device_stats *stats = netdev_priv(dev);
-
- stats->tx_packets++;
- stats->tx_bytes+=skb->len;
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
dev_kfree_skb(skb);
return 0;
}
-static struct net_device_stats *dummy_get_stats(struct net_device *dev)
+static int dummy_validate(struct nlattr *tb[], struct nlattr *data[])
{
- return netdev_priv(dev);
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+ return -EINVAL;
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+ return -EADDRNOTAVAIL;
+ }
+ return 0;
}
-static struct net_device **dummies;
+static struct rtnl_link_ops dummy_link_ops __read_mostly = {
+ .kind = "dummy",
+ .setup = dummy_setup,
+ .validate = dummy_validate,
+};
/* Number of dummy devices to be set up by this module. */
module_param(numdummies, int, 0);
MODULE_PARM_DESC(numdummies, "Number of dummy pseudo devices");
-static int __init dummy_init_one(int index)
+static int __init dummy_init_one(void)
{
struct net_device *dev_dummy;
int err;
- dev_dummy = alloc_netdev(sizeof(struct net_device_stats),
- "dummy%d", dummy_setup);
-
+ dev_dummy = alloc_netdev(0, "dummy%d", dummy_setup);
if (!dev_dummy)
return -ENOMEM;
- if ((err = register_netdev(dev_dummy))) {
- free_netdev(dev_dummy);
- dev_dummy = NULL;
- } else {
- dummies[index] = dev_dummy;
- }
+ err = dev_alloc_name(dev_dummy, dev_dummy->name);
+ if (err < 0)
+ goto err;
+ dev_dummy->rtnl_link_ops = &dummy_link_ops;
+ err = register_netdevice(dev_dummy);
+ if (err < 0)
+ goto err;
+ return 0;
+
+err:
+ free_netdev(dev_dummy);
return err;
}
-static void dummy_free_one(int index)
-{
- unregister_netdev(dummies[index]);
- free_netdev(dummies[index]);
-}
-
static int __init dummy_init_module(void)
-{
+{
int i, err = 0;
- dummies = kmalloc(numdummies * sizeof(void *), GFP_KERNEL);
- if (!dummies)
- return -ENOMEM;
+
+ rtnl_lock();
+ err = __rtnl_link_register(&dummy_link_ops);
+
for (i = 0; i < numdummies && !err; i++)
- err = dummy_init_one(i);
- if (err) {
- i--;
- while (--i >= 0)
- dummy_free_one(i);
- }
+ err = dummy_init_one();
+ if (err < 0)
+ __rtnl_link_unregister(&dummy_link_ops);
+ rtnl_unlock();
+
return err;
-}
+}
static void __exit dummy_cleanup_module(void)
{
- int i;
- for (i = 0; i < numdummies; i++)
- dummy_free_one(i);
- kfree(dummies);
+ rtnl_link_unregister(&dummy_link_ops);
}
module_init(dummy_init_module);
module_exit(dummy_cleanup_module);
MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("dummy");