[linux.git] / drivers / net / nlmon.c

#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)
{
	int len = skb->len;
	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);

	u64_stats_update_begin(&stats->syncp);
	stats->bytes += len;
	stats->packets++;
	u64_stats_update_end(&stats->syncp);

	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)
{
	int i;
	u64 bytes = 0, packets = 0;

	for_each_possible_cpu(i) {
		const struct pcpu_lstats *nl_stats;
		u64 tbytes, tpackets;
		unsigned int start;

		nl_stats = per_cpu_ptr(dev->lstats, i);

		do {
			start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
			tbytes = nl_stats->bytes;
			tpackets = nl_stats->packets;
		} while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));

		packets += tpackets;
		bytes += tbytes;
	}

	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 <[email protected]>");
MODULE_AUTHOR("Mathieu Geli <[email protected]>");
MODULE_DESCRIPTION("Netlink monitoring device");
MODULE_ALIAS_RTNL_LINK("nlmon");
Commit	Line	Data
e4fc408e DB	1	#include <linux/module.h>
	2	#include <linux/kernel.h>
	3	#include <linux/netdevice.h>
	4	#include <linux/netlink.h>
	5	#include <net/net_namespace.h>
	6	#include <linux/if_arp.h>
7e6d4da8	7	#include <net/rtnetlink.h>
e4fc408e	8
e4fc408e DB	9	static netdev_tx_t nlmon_xmit(struct sk_buff skb, struct net_device dev)
	10	{
	11	int len = skb->len;
	12	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
	13
	14	u64_stats_update_begin(&stats->syncp);
	15	stats->bytes += len;
	16	stats->packets++;
	17	u64_stats_update_end(&stats->syncp);
	18
	19	dev_kfree_skb(skb);
	20
	21	return NETDEV_TX_OK;
	22	}
	23
e4fc408e DB	24	static int nlmon_dev_init(struct net_device *dev)
e4fc408e DB	25	{
1c213bd2	26	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
e4fc408e DB	27	return dev->lstats == NULL ? -ENOMEM : 0;
	28	}
	29
	30	static void nlmon_dev_uninit(struct net_device *dev)
	31	{
	32	free_percpu(dev->lstats);
	33	}
	34
7e6d4da8 JP	35	struct nlmon {
	36	struct netlink_tap nt;
	37	};
e4fc408e DB	38
	39	static int nlmon_open(struct net_device *dev)
	40	{
7e6d4da8 JP	41	struct nlmon *nlmon = netdev_priv(dev);
	42
	43	nlmon->nt.dev = dev;
	44	nlmon->nt.module = THIS_MODULE;
	45	return netlink_add_tap(&nlmon->nt);
e4fc408e DB	46	}
	47
	48	static int nlmon_close(struct net_device *dev)
	49	{
7e6d4da8 JP	50	struct nlmon *nlmon = netdev_priv(dev);
	51
	52	return netlink_remove_tap(&nlmon->nt);
e4fc408e DB	53	}
e4fc408e DB	54
bc1f4470	55	static void
e4fc408e DB	56	nlmon_get_stats64(struct net_device dev, struct rtnl_link_stats64 stats)
	57	{
	58	int i;
	59	u64 bytes = 0, packets = 0;
	60
	61	for_each_possible_cpu(i) {
	62	const struct pcpu_lstats *nl_stats;
	63	u64 tbytes, tpackets;
	64	unsigned int start;
	65
	66	nl_stats = per_cpu_ptr(dev->lstats, i);
	67
	68	do {
57a7744e	69	start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
e4fc408e DB	70	tbytes = nl_stats->bytes;
e4fc408e DB	71	tpackets = nl_stats->packets;
57a7744e	72	} while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
e4fc408e DB	73
	74	packets += tpackets;
	75	bytes += tbytes;
	76	}
	77
	78	stats->rx_packets = packets;
	79	stats->tx_packets = 0;
	80
	81	stats->rx_bytes = bytes;
	82	stats->tx_bytes = 0;
e4fc408e DB	83	}
	84
	85	static u32 always_on(struct net_device *dev)
	86	{
	87	return 1;
	88	}
	89
	90	static const struct ethtool_ops nlmon_ethtool_ops = {
	91	.get_link = always_on,
	92	};
	93
	94	static const struct net_device_ops nlmon_ops = {
	95	.ndo_init = nlmon_dev_init,
	96	.ndo_uninit = nlmon_dev_uninit,
	97	.ndo_open = nlmon_open,
	98	.ndo_stop = nlmon_close,
	99	.ndo_start_xmit = nlmon_xmit,
	100	.ndo_get_stats64 = nlmon_get_stats64,
e4fc408e DB	101	};
e4fc408e DB	102
e4fc408e DB	103	static void nlmon_setup(struct net_device *dev)
	104	{
	105	dev->type = ARPHRD_NETLINK;
85773a61	106	dev->priv_flags \|= IFF_NO_QUEUE;
e4fc408e DB	107
	108	dev->netdev_ops = &nlmon_ops;
	109	dev->ethtool_ops = &nlmon_ethtool_ops;
cf124db5	110	dev->needs_free_netdev = true;
e4fc408e	111
b7d47ca2 DB	112	dev->features = NETIF_F_SG \| NETIF_F_FRAGLIST \|
b7d47ca2 DB	113	NETIF_F_HIGHDMA \| NETIF_F_LLTX;
e4fc408e DB	114	dev->flags = IFF_NOARP;
	115
	116	/* That's rather a softlimit here, which, of course,
	117	* can be altered. Not a real MTU, but what is to be
	118	* expected in most cases.
	119	*/
	120	dev->mtu = NLMSG_GOODSIZE;
e82621e3	121	dev->min_mtu = sizeof(struct nlmsghdr);
e4fc408e DB	122	}
e4fc408e DB	123
a8b8a889 MS	124	static int nlmon_validate(struct nlattr tb[], struct nlattr data[],
a8b8a889 MS	125	struct netlink_ext_ack *extack)
e4fc408e	126	{
7e6d4da8 JP	127	if (tb[IFLA_ADDRESS])
	128	return -EINVAL;
	129	return 0;
	130	}
e4fc408e	131
7e6d4da8 JP	132	static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	133	.kind = "nlmon",
	134	.priv_size = sizeof(struct nlmon),
	135	.setup = nlmon_setup,
	136	.validate = nlmon_validate,
	137	};
e4fc408e	138
7e6d4da8 JP	139	static __init int nlmon_register(void)
	140	{
	141	return rtnl_link_register(&nlmon_link_ops);
e4fc408e DB	142	}
	143
	144	static __exit void nlmon_unregister(void)
	145	{
7e6d4da8	146	rtnl_link_unregister(&nlmon_link_ops);
e4fc408e DB	147	}
	148
	149	module_init(nlmon_register);
	150	module_exit(nlmon_unregister);
	151
	152	MODULE_LICENSE("GPL v2");
	153	MODULE_AUTHOR("Daniel Borkmann <[email protected]>");
	154	MODULE_AUTHOR("Mathieu Geli <[email protected]>");
	155	MODULE_DESCRIPTION("Netlink monitoring device");
7e6d4da8	156	MODULE_ALIAS_RTNL_LINK("nlmon");