[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>

struct pcpu_lstats {
	u64 packets;
	u64 bytes;
	struct u64_stats_sync syncp;
};

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 DB	8
	9	struct pcpu_lstats {
	10	u64 packets;
	11	u64 bytes;
	12	struct u64_stats_sync syncp;
	13	};
	14
	15	static netdev_tx_t nlmon_xmit(struct sk_buff skb, struct net_device dev)
	16	{
	17	int len = skb->len;
	18	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
	19
	20	u64_stats_update_begin(&stats->syncp);
	21	stats->bytes += len;
	22	stats->packets++;
	23	u64_stats_update_end(&stats->syncp);
	24
	25	dev_kfree_skb(skb);
	26
	27	return NETDEV_TX_OK;
	28	}
	29
e4fc408e DB	30	static int nlmon_dev_init(struct net_device *dev)
e4fc408e DB	31	{
1c213bd2	32	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
e4fc408e DB	33	return dev->lstats == NULL ? -ENOMEM : 0;
	34	}
	35
	36	static void nlmon_dev_uninit(struct net_device *dev)
	37	{
	38	free_percpu(dev->lstats);
	39	}
	40
7e6d4da8 JP	41	struct nlmon {
	42	struct netlink_tap nt;
	43	};
e4fc408e DB	44
	45	static int nlmon_open(struct net_device *dev)
	46	{
7e6d4da8 JP	47	struct nlmon *nlmon = netdev_priv(dev);
	48
	49	nlmon->nt.dev = dev;
	50	nlmon->nt.module = THIS_MODULE;
	51	return netlink_add_tap(&nlmon->nt);
e4fc408e DB	52	}
	53
	54	static int nlmon_close(struct net_device *dev)
	55	{
7e6d4da8 JP	56	struct nlmon *nlmon = netdev_priv(dev);
	57
	58	return netlink_remove_tap(&nlmon->nt);
e4fc408e DB	59	}
e4fc408e DB	60
bc1f4470	61	static void
e4fc408e DB	62	nlmon_get_stats64(struct net_device dev, struct rtnl_link_stats64 stats)
	63	{
	64	int i;
	65	u64 bytes = 0, packets = 0;
	66
	67	for_each_possible_cpu(i) {
	68	const struct pcpu_lstats *nl_stats;
	69	u64 tbytes, tpackets;
	70	unsigned int start;
	71
	72	nl_stats = per_cpu_ptr(dev->lstats, i);
	73
	74	do {
57a7744e	75	start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
e4fc408e DB	76	tbytes = nl_stats->bytes;
e4fc408e DB	77	tpackets = nl_stats->packets;
57a7744e	78	} while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
e4fc408e DB	79
	80	packets += tpackets;
	81	bytes += tbytes;
	82	}
	83
	84	stats->rx_packets = packets;
	85	stats->tx_packets = 0;
	86
	87	stats->rx_bytes = bytes;
	88	stats->tx_bytes = 0;
e4fc408e DB	89	}
	90
	91	static u32 always_on(struct net_device *dev)
	92	{
	93	return 1;
	94	}
	95
	96	static const struct ethtool_ops nlmon_ethtool_ops = {
	97	.get_link = always_on,
	98	};
	99
	100	static const struct net_device_ops nlmon_ops = {
	101	.ndo_init = nlmon_dev_init,
	102	.ndo_uninit = nlmon_dev_uninit,
	103	.ndo_open = nlmon_open,
	104	.ndo_stop = nlmon_close,
	105	.ndo_start_xmit = nlmon_xmit,
	106	.ndo_get_stats64 = nlmon_get_stats64,
e4fc408e DB	107	};
e4fc408e DB	108
e4fc408e DB	109	static void nlmon_setup(struct net_device *dev)
	110	{
	111	dev->type = ARPHRD_NETLINK;
85773a61	112	dev->priv_flags \|= IFF_NO_QUEUE;
e4fc408e DB	113
	114	dev->netdev_ops = &nlmon_ops;
	115	dev->ethtool_ops = &nlmon_ethtool_ops;
cf124db5	116	dev->needs_free_netdev = true;
e4fc408e	117
b7d47ca2 DB	118	dev->features = NETIF_F_SG \| NETIF_F_FRAGLIST \|
b7d47ca2 DB	119	NETIF_F_HIGHDMA \| NETIF_F_LLTX;
e4fc408e DB	120	dev->flags = IFF_NOARP;
	121
	122	/* That's rather a softlimit here, which, of course,
	123	* can be altered. Not a real MTU, but what is to be
	124	* expected in most cases.
	125	*/
	126	dev->mtu = NLMSG_GOODSIZE;
e82621e3	127	dev->min_mtu = sizeof(struct nlmsghdr);
e4fc408e DB	128	}
e4fc408e DB	129
a8b8a889 MS	130	static int nlmon_validate(struct nlattr tb[], struct nlattr data[],
a8b8a889 MS	131	struct netlink_ext_ack *extack)
e4fc408e	132	{
7e6d4da8 JP	133	if (tb[IFLA_ADDRESS])
	134	return -EINVAL;
	135	return 0;
	136	}
e4fc408e	137
7e6d4da8 JP	138	static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	139	.kind = "nlmon",
	140	.priv_size = sizeof(struct nlmon),
	141	.setup = nlmon_setup,
	142	.validate = nlmon_validate,
	143	};
e4fc408e	144
7e6d4da8 JP	145	static __init int nlmon_register(void)
	146	{
	147	return rtnl_link_register(&nlmon_link_ops);
e4fc408e DB	148	}
	149
	150	static __exit void nlmon_unregister(void)
	151	{
7e6d4da8	152	rtnl_link_unregister(&nlmon_link_ops);
e4fc408e DB	153	}
	154
	155	module_init(nlmon_register);
	156	module_exit(nlmon_unregister);
	157
	158	MODULE_LICENSE("GPL v2");
	159	MODULE_AUTHOR("Daniel Borkmann <[email protected]>");
	160	MODULE_AUTHOR("Mathieu Geli <[email protected]>");
	161	MODULE_DESCRIPTION("Netlink monitoring device");
7e6d4da8	162	MODULE_ALIAS_RTNL_LINK("nlmon");