[linux-2.6-block.git] / drivers / net / nlmon.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/ethtool.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <net/net_namespace.h>
#include <linux/if_arp.h>
#include <net/rtnetlink.h>

static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev)
{
	dev_lstats_add(dev, skb->len);

	dev_kfree_skb(skb);

	return NETDEV_TX_OK;
}

static int nlmon_dev_init(struct net_device *dev)
{
	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
	return dev->lstats == NULL ? -ENOMEM : 0;
}

static void nlmon_dev_uninit(struct net_device *dev)
{
	free_percpu(dev->lstats);
}

struct nlmon {
	struct netlink_tap nt;
};

static int nlmon_open(struct net_device *dev)
{
	struct nlmon *nlmon = netdev_priv(dev);

	nlmon->nt.dev = dev;
	nlmon->nt.module = THIS_MODULE;
	return netlink_add_tap(&nlmon->nt);
}

static int nlmon_close(struct net_device *dev)
{
	struct nlmon *nlmon = netdev_priv(dev);

	return netlink_remove_tap(&nlmon->nt);
}

static void
nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{
	u64 packets, bytes;

	dev_lstats_read(dev, &packets, &bytes);

	stats->rx_packets = packets;
	stats->tx_packets = 0;

	stats->rx_bytes = bytes;
	stats->tx_bytes = 0;
}

static u32 always_on(struct net_device *dev)
{
	return 1;
}

static const struct ethtool_ops nlmon_ethtool_ops = {
	.get_link = always_on,
};

static const struct net_device_ops nlmon_ops = {
	.ndo_init = nlmon_dev_init,
	.ndo_uninit = nlmon_dev_uninit,
	.ndo_open = nlmon_open,
	.ndo_stop = nlmon_close,
	.ndo_start_xmit = nlmon_xmit,
	.ndo_get_stats64 = nlmon_get_stats64,
};

static void nlmon_setup(struct net_device *dev)
{
	dev->type = ARPHRD_NETLINK;
	dev->priv_flags |= IFF_NO_QUEUE;

	dev->netdev_ops	= &nlmon_ops;
	dev->ethtool_ops = &nlmon_ethtool_ops;
	dev->needs_free_netdev = true;

	dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
			NETIF_F_HIGHDMA | NETIF_F_LLTX;
	dev->flags = IFF_NOARP;

	/* That's rather a softlimit here, which, of course,
	 * can be altered. Not a real MTU, but what is to be
	 * expected in most cases.
	 */
	dev->mtu = NLMSG_GOODSIZE;
	dev->min_mtu = sizeof(struct nlmsghdr);
}

static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[],
			  struct netlink_ext_ack *extack)
{
	if (tb[IFLA_ADDRESS])
		return -EINVAL;
	return 0;
}

static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	.kind			= "nlmon",
	.priv_size		= sizeof(struct nlmon),
	.setup			= nlmon_setup,
	.validate		= nlmon_validate,
};

static __init int nlmon_register(void)
{
	return rtnl_link_register(&nlmon_link_ops);
}

static __exit void nlmon_unregister(void)
{
	rtnl_link_unregister(&nlmon_link_ops);
}

module_init(nlmon_register);
module_exit(nlmon_unregister);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
MODULE_DESCRIPTION("Netlink monitoring device");
MODULE_ALIAS_RTNL_LINK("nlmon");
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
cc69837f	2	#include <linux/ethtool.h>
e4fc408e DB	3	#include <linux/module.h>
	4	#include <linux/kernel.h>
	5	#include <linux/netdevice.h>
	6	#include <linux/netlink.h>
	7	#include <net/net_namespace.h>
	8	#include <linux/if_arp.h>
7e6d4da8	9	#include <net/rtnetlink.h>
e4fc408e	10
e4fc408e DB	11	static netdev_tx_t nlmon_xmit(struct sk_buff skb, struct net_device dev)
e4fc408e DB	12	{
3ed91226	13	dev_lstats_add(dev, skb->len);
e4fc408e DB	14
	15	dev_kfree_skb(skb);
	16
	17	return NETDEV_TX_OK;
	18	}
	19
e4fc408e DB	20	static int nlmon_dev_init(struct net_device *dev)
e4fc408e DB	21	{
1c213bd2	22	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
e4fc408e DB	23	return dev->lstats == NULL ? -ENOMEM : 0;
	24	}
	25
	26	static void nlmon_dev_uninit(struct net_device *dev)
	27	{
	28	free_percpu(dev->lstats);
	29	}
	30
7e6d4da8 JP	31	struct nlmon {
	32	struct netlink_tap nt;
	33	};
e4fc408e DB	34
	35	static int nlmon_open(struct net_device *dev)
	36	{
7e6d4da8 JP	37	struct nlmon *nlmon = netdev_priv(dev);
	38
	39	nlmon->nt.dev = dev;
	40	nlmon->nt.module = THIS_MODULE;
	41	return netlink_add_tap(&nlmon->nt);
e4fc408e DB	42	}
	43
	44	static int nlmon_close(struct net_device *dev)
	45	{
7e6d4da8 JP	46	struct nlmon *nlmon = netdev_priv(dev);
	47
	48	return netlink_remove_tap(&nlmon->nt);
e4fc408e DB	49	}
e4fc408e DB	50
bc1f4470	51	static void
e4fc408e DB	52	nlmon_get_stats64(struct net_device dev, struct rtnl_link_stats64 stats)
e4fc408e DB	53	{
3ed91226	54	u64 packets, bytes;
e4fc408e	55
3ed91226	56	dev_lstats_read(dev, &packets, &bytes);
e4fc408e DB	57
	58	stats->rx_packets = packets;
	59	stats->tx_packets = 0;
	60
	61	stats->rx_bytes = bytes;
	62	stats->tx_bytes = 0;
e4fc408e DB	63	}
	64
	65	static u32 always_on(struct net_device *dev)
	66	{
	67	return 1;
	68	}
	69
	70	static const struct ethtool_ops nlmon_ethtool_ops = {
	71	.get_link = always_on,
	72	};
	73
	74	static const struct net_device_ops nlmon_ops = {
	75	.ndo_init = nlmon_dev_init,
	76	.ndo_uninit = nlmon_dev_uninit,
	77	.ndo_open = nlmon_open,
	78	.ndo_stop = nlmon_close,
	79	.ndo_start_xmit = nlmon_xmit,
	80	.ndo_get_stats64 = nlmon_get_stats64,
e4fc408e DB	81	};
e4fc408e DB	82
e4fc408e DB	83	static void nlmon_setup(struct net_device *dev)
	84	{
	85	dev->type = ARPHRD_NETLINK;
85773a61	86	dev->priv_flags \|= IFF_NO_QUEUE;
e4fc408e DB	87
	88	dev->netdev_ops = &nlmon_ops;
	89	dev->ethtool_ops = &nlmon_ethtool_ops;
cf124db5	90	dev->needs_free_netdev = true;
e4fc408e	91
b7d47ca2 DB	92	dev->features = NETIF_F_SG \| NETIF_F_FRAGLIST \|
b7d47ca2 DB	93	NETIF_F_HIGHDMA \| NETIF_F_LLTX;
e4fc408e DB	94	dev->flags = IFF_NOARP;
	95
	96	/* That's rather a softlimit here, which, of course,
	97	* can be altered. Not a real MTU, but what is to be
	98	* expected in most cases.
	99	*/
	100	dev->mtu = NLMSG_GOODSIZE;
e82621e3	101	dev->min_mtu = sizeof(struct nlmsghdr);
e4fc408e DB	102	}
e4fc408e DB	103
a8b8a889 MS	104	static int nlmon_validate(struct nlattr tb[], struct nlattr data[],
a8b8a889 MS	105	struct netlink_ext_ack *extack)
e4fc408e	106	{
7e6d4da8 JP	107	if (tb[IFLA_ADDRESS])
	108	return -EINVAL;
	109	return 0;
	110	}
e4fc408e	111
7e6d4da8 JP	112	static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	113	.kind = "nlmon",
	114	.priv_size = sizeof(struct nlmon),
	115	.setup = nlmon_setup,
	116	.validate = nlmon_validate,
	117	};
e4fc408e	118
7e6d4da8 JP	119	static __init int nlmon_register(void)
	120	{
	121	return rtnl_link_register(&nlmon_link_ops);
e4fc408e DB	122	}
	123
	124	static __exit void nlmon_unregister(void)
	125	{
7e6d4da8	126	rtnl_link_unregister(&nlmon_link_ops);
e4fc408e DB	127	}
	128
	129	module_init(nlmon_register);
	130	module_exit(nlmon_unregister);
	131
	132	MODULE_LICENSE("GPL v2");
	133	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	134	MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
	135	MODULE_DESCRIPTION("Netlink monitoring device");
7e6d4da8	136	MODULE_ALIAS_RTNL_LINK("nlmon");