[mirror_ubuntu-artful-kernel.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_is_valid_mtu(int new_mtu)
{
	/* Note that in netlink we do not really have an upper limit. On
	 * default, we use NLMSG_GOODSIZE. Here at least we should make
	 * sure that it's at least the header size.
	 */
	return new_mtu >= (int) sizeof(struct nlmsghdr);
}

static int nlmon_change_mtu(struct net_device *dev, int new_mtu)
{
	if (!nlmon_is_valid_mtu(new_mtu))
		return -EINVAL;

	dev->mtu = new_mtu;
	return 0;
}

static int nlmon_dev_init(struct net_device *dev)
{
	int i;

	dev->lstats = alloc_percpu(struct pcpu_lstats);

	for_each_possible_cpu(i) {
		struct pcpu_lstats *nlmstats;
		nlmstats = per_cpu_ptr(dev->lstats, i);
		u64_stats_init(&nlmstats->syncp);
	}

	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 struct rtnl_link_stats64 *
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_bh(&nl_stats->syncp);
			tbytes = nl_stats->bytes;
			tpackets = nl_stats->packets;
		} while (u64_stats_fetch_retry_bh(&nl_stats->syncp, start));

		packets += tpackets;
		bytes += tbytes;
	}

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

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

	return stats;
}

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,
	.ndo_change_mtu = nlmon_change_mtu,
};

static void nlmon_setup(struct net_device *dev)
{
	dev->type = ARPHRD_NETLINK;
	dev->tx_queue_len = 0;

	dev->netdev_ops	= &nlmon_ops;
	dev->ethtool_ops = &nlmon_ethtool_ops;
	dev->destructor	= free_netdev;

	dev->features = NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
	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;
}

static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[])
{
	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
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
	30	static int nlmon_is_valid_mtu(int new_mtu)
	31	{
3b233fe0 DB	32	/* Note that in netlink we do not really have an upper limit. On
	33	* default, we use NLMSG_GOODSIZE. Here at least we should make
	34	* sure that it's at least the header size.
	35	*/
	36	return new_mtu >= (int) sizeof(struct nlmsghdr);
e4fc408e DB	37	}
	38
	39	static int nlmon_change_mtu(struct net_device *dev, int new_mtu)
	40	{
	41	if (!nlmon_is_valid_mtu(new_mtu))
	42	return -EINVAL;
	43
	44	dev->mtu = new_mtu;
	45	return 0;
	46	}
	47
	48	static int nlmon_dev_init(struct net_device *dev)
	49	{
827da44c JS	50	int i;
827da44c JS	51
e4fc408e DB	52	dev->lstats = alloc_percpu(struct pcpu_lstats);
e4fc408e DB	53
827da44c JS	54	for_each_possible_cpu(i) {
	55	struct pcpu_lstats *nlmstats;
	56	nlmstats = per_cpu_ptr(dev->lstats, i);
	57	u64_stats_init(&nlmstats->syncp);
	58	}
	59
e4fc408e DB	60	return dev->lstats == NULL ? -ENOMEM : 0;
	61	}
	62
	63	static void nlmon_dev_uninit(struct net_device *dev)
	64	{
	65	free_percpu(dev->lstats);
	66	}
	67
7e6d4da8 JP	68	struct nlmon {
	69	struct netlink_tap nt;
	70	};
e4fc408e DB	71
	72	static int nlmon_open(struct net_device *dev)
	73	{
7e6d4da8 JP	74	struct nlmon *nlmon = netdev_priv(dev);
	75
	76	nlmon->nt.dev = dev;
	77	nlmon->nt.module = THIS_MODULE;
	78	return netlink_add_tap(&nlmon->nt);
e4fc408e DB	79	}
	80
	81	static int nlmon_close(struct net_device *dev)
	82	{
7e6d4da8 JP	83	struct nlmon *nlmon = netdev_priv(dev);
	84
	85	return netlink_remove_tap(&nlmon->nt);
e4fc408e DB	86	}
	87
	88	static struct rtnl_link_stats64 *
	89	nlmon_get_stats64(struct net_device dev, struct rtnl_link_stats64 stats)
	90	{
	91	int i;
	92	u64 bytes = 0, packets = 0;
	93
	94	for_each_possible_cpu(i) {
	95	const struct pcpu_lstats *nl_stats;
	96	u64 tbytes, tpackets;
	97	unsigned int start;
	98
	99	nl_stats = per_cpu_ptr(dev->lstats, i);
	100
	101	do {
	102	start = u64_stats_fetch_begin_bh(&nl_stats->syncp);
	103	tbytes = nl_stats->bytes;
	104	tpackets = nl_stats->packets;
	105	} while (u64_stats_fetch_retry_bh(&nl_stats->syncp, start));
	106
	107	packets += tpackets;
	108	bytes += tbytes;
	109	}
	110
	111	stats->rx_packets = packets;
	112	stats->tx_packets = 0;
	113
	114	stats->rx_bytes = bytes;
	115	stats->tx_bytes = 0;
	116
	117	return stats;
	118	}
	119
	120	static u32 always_on(struct net_device *dev)
	121	{
	122	return 1;
	123	}
	124
	125	static const struct ethtool_ops nlmon_ethtool_ops = {
	126	.get_link = always_on,
	127	};
	128
	129	static const struct net_device_ops nlmon_ops = {
	130	.ndo_init = nlmon_dev_init,
	131	.ndo_uninit = nlmon_dev_uninit,
	132	.ndo_open = nlmon_open,
	133	.ndo_stop = nlmon_close,
	134	.ndo_start_xmit = nlmon_xmit,
	135	.ndo_get_stats64 = nlmon_get_stats64,
	136	.ndo_change_mtu = nlmon_change_mtu,
	137	};
	138
e4fc408e DB	139	static void nlmon_setup(struct net_device *dev)
	140	{
	141	dev->type = ARPHRD_NETLINK;
	142	dev->tx_queue_len = 0;
	143
	144	dev->netdev_ops = &nlmon_ops;
	145	dev->ethtool_ops = &nlmon_ethtool_ops;
	146	dev->destructor = free_netdev;
	147
	148	dev->features = NETIF_F_FRAGLIST \| NETIF_F_HIGHDMA;
	149	dev->flags = IFF_NOARP;
	150
	151	/* That's rather a softlimit here, which, of course,
	152	* can be altered. Not a real MTU, but what is to be
	153	* expected in most cases.
	154	*/
	155	dev->mtu = NLMSG_GOODSIZE;
	156	}
	157
7e6d4da8	158	static int nlmon_validate(struct nlattr tb[], struct nlattr data[])
e4fc408e	159	{
7e6d4da8 JP	160	if (tb[IFLA_ADDRESS])
	161	return -EINVAL;
	162	return 0;
	163	}
e4fc408e	164
7e6d4da8 JP	165	static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	166	.kind = "nlmon",
	167	.priv_size = sizeof(struct nlmon),
	168	.setup = nlmon_setup,
	169	.validate = nlmon_validate,
	170	};
e4fc408e	171
7e6d4da8 JP	172	static __init int nlmon_register(void)
	173	{
	174	return rtnl_link_register(&nlmon_link_ops);
e4fc408e DB	175	}
	176
	177	static __exit void nlmon_unregister(void)
	178	{
7e6d4da8	179	rtnl_link_unregister(&nlmon_link_ops);
e4fc408e DB	180	}
	181
	182	module_init(nlmon_register);
	183	module_exit(nlmon_unregister);
	184
	185	MODULE_LICENSE("GPL v2");
	186	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	187	MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
	188	MODULE_DESCRIPTION("Netlink monitoring device");
7e6d4da8	189	MODULE_ALIAS_RTNL_LINK("nlmon");