drivers/net/dummy.c

Source file repositories/reference/linux-study-clean/drivers/net/dummy.c

File Facts

System
Linux kernel
Corpus path
drivers/net/dummy.c
Extension
.c
Size
5027 bytes
Lines
201
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct net_device_ops dummy_netdev_ops = {
	.ndo_init		= dummy_dev_init,
	.ndo_start_xmit		= dummy_xmit,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_rx_mode_async	= set_multicast_list,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_get_stats64	= dummy_get_stats64,
	.ndo_change_carrier	= dummy_change_carrier,
};

static const struct ethtool_ops dummy_ethtool_ops = {
	.get_ts_info		= ethtool_op_get_ts_info,
};

static void dummy_setup(struct net_device *dev)
{
	ether_setup(dev);

	/* Initialize the device structure. */
	dev->netdev_ops = &dummy_netdev_ops;
	dev->ethtool_ops = &dummy_ethtool_ops;
	dev->needs_free_netdev = true;
	dev->request_ops_lock = true;

	/* Fill in device structure with ethernet-generic values. */
	dev->flags |= IFF_NOARP;
	dev->flags &= ~IFF_MULTICAST;
	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
	dev->lltx = true;
	dev->features	|= NETIF_F_SG | NETIF_F_FRAGLIST;
	dev->features	|= NETIF_F_GSO_SOFTWARE;
	dev->features	|= NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;
	dev->features	|= NETIF_F_GSO_ENCAP_ALL;
	dev->hw_features |= dev->features;
	dev->hw_enc_features |= dev->features;
	eth_hw_addr_random(dev);

	dev->min_mtu = 0;
	dev->max_mtu = 0;
}

static int dummy_validate(struct nlattr *tb[], struct nlattr *data[],
			  struct netlink_ext_ack *extack)
{
	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 rtnl_link_ops dummy_link_ops __read_mostly = {
	.kind		= DRV_NAME,
	.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(void)
{
	struct net_device *dev_dummy;
	int err;

	dev_dummy = alloc_netdev(0, "dummy%d", NET_NAME_ENUM, dummy_setup);
	if (!dev_dummy)
		return -ENOMEM;

	dev_dummy->rtnl_link_ops = &dummy_link_ops;
	err = register_netdev(dev_dummy);
	if (err < 0)
		goto err;
	return 0;

err:
	free_netdev(dev_dummy);
	return err;
}

static int __init dummy_init_module(void)
{
	int i, err = 0;

	err = rtnl_link_register(&dummy_link_ops);
	if (err < 0)
		return err;

Annotation

Implementation Notes