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

// SPDX-License-Identifier: GPL-2.0-only
#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 <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
e4fc408e DB	2	#include <linux/module.h>
	3	#include <linux/kernel.h>
	4	#include <linux/netdevice.h>
	5	#include <linux/netlink.h>
	6	#include <net/net_namespace.h>
	7	#include <linux/if_arp.h>
7e6d4da8	8	#include <net/rtnetlink.h>
e4fc408e	9
e4fc408e DB	10	static netdev_tx_t nlmon_xmit(struct sk_buff skb, struct net_device dev)
	11	{
	12	int len = skb->len;
	13	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
	14
	15	u64_stats_update_begin(&stats->syncp);
	16	stats->bytes += len;
	17	stats->packets++;
	18	u64_stats_update_end(&stats->syncp);
	19
	20	dev_kfree_skb(skb);
	21
	22	return NETDEV_TX_OK;
	23	}
	24
e4fc408e DB	25	static int nlmon_dev_init(struct net_device *dev)
e4fc408e DB	26	{
1c213bd2	27	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
e4fc408e DB	28	return dev->lstats == NULL ? -ENOMEM : 0;
	29	}
	30
	31	static void nlmon_dev_uninit(struct net_device *dev)
	32	{
	33	free_percpu(dev->lstats);
	34	}
	35
7e6d4da8 JP	36	struct nlmon {
	37	struct netlink_tap nt;
	38	};
e4fc408e DB	39
	40	static int nlmon_open(struct net_device *dev)
	41	{
7e6d4da8 JP	42	struct nlmon *nlmon = netdev_priv(dev);
	43
	44	nlmon->nt.dev = dev;
	45	nlmon->nt.module = THIS_MODULE;
	46	return netlink_add_tap(&nlmon->nt);
e4fc408e DB	47	}
	48
	49	static int nlmon_close(struct net_device *dev)
	50	{
7e6d4da8 JP	51	struct nlmon *nlmon = netdev_priv(dev);
	52
	53	return netlink_remove_tap(&nlmon->nt);
e4fc408e DB	54	}
e4fc408e DB	55
bc1f4470	56	static void
e4fc408e DB	57	nlmon_get_stats64(struct net_device dev, struct rtnl_link_stats64 stats)
	58	{
	59	int i;
	60	u64 bytes = 0, packets = 0;
	61
	62	for_each_possible_cpu(i) {
	63	const struct pcpu_lstats *nl_stats;
	64	u64 tbytes, tpackets;
	65	unsigned int start;
	66
	67	nl_stats = per_cpu_ptr(dev->lstats, i);
	68
	69	do {
57a7744e	70	start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
e4fc408e DB	71	tbytes = nl_stats->bytes;
e4fc408e DB	72	tpackets = nl_stats->packets;
57a7744e	73	} while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
e4fc408e DB	74
	75	packets += tpackets;
	76	bytes += tbytes;
	77	}
	78
	79	stats->rx_packets = packets;
	80	stats->tx_packets = 0;
	81
	82	stats->rx_bytes = bytes;
	83	stats->tx_bytes = 0;
e4fc408e DB	84	}
	85
	86	static u32 always_on(struct net_device *dev)
	87	{
	88	return 1;
	89	}
	90
	91	static const struct ethtool_ops nlmon_ethtool_ops = {
	92	.get_link = always_on,
	93	};
	94
	95	static const struct net_device_ops nlmon_ops = {
	96	.ndo_init = nlmon_dev_init,
	97	.ndo_uninit = nlmon_dev_uninit,
	98	.ndo_open = nlmon_open,
	99	.ndo_stop = nlmon_close,
	100	.ndo_start_xmit = nlmon_xmit,
	101	.ndo_get_stats64 = nlmon_get_stats64,
e4fc408e DB	102	};
e4fc408e DB	103
e4fc408e DB	104	static void nlmon_setup(struct net_device *dev)
	105	{
	106	dev->type = ARPHRD_NETLINK;
85773a61	107	dev->priv_flags \|= IFF_NO_QUEUE;
e4fc408e DB	108
	109	dev->netdev_ops = &nlmon_ops;
	110	dev->ethtool_ops = &nlmon_ethtool_ops;
cf124db5	111	dev->needs_free_netdev = true;
e4fc408e	112
b7d47ca2 DB	113	dev->features = NETIF_F_SG \| NETIF_F_FRAGLIST \|
b7d47ca2 DB	114	NETIF_F_HIGHDMA \| NETIF_F_LLTX;
e4fc408e DB	115	dev->flags = IFF_NOARP;
	116
	117	/* That's rather a softlimit here, which, of course,
	118	* can be altered. Not a real MTU, but what is to be
	119	* expected in most cases.
	120	*/
	121	dev->mtu = NLMSG_GOODSIZE;
e82621e3	122	dev->min_mtu = sizeof(struct nlmsghdr);
e4fc408e DB	123	}
e4fc408e DB	124
a8b8a889 MS	125	static int nlmon_validate(struct nlattr tb[], struct nlattr data[],
a8b8a889 MS	126	struct netlink_ext_ack *extack)
e4fc408e	127	{
7e6d4da8 JP	128	if (tb[IFLA_ADDRESS])
	129	return -EINVAL;
	130	return 0;
	131	}
e4fc408e	132
7e6d4da8 JP	133	static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
	134	.kind = "nlmon",
	135	.priv_size = sizeof(struct nlmon),
	136	.setup = nlmon_setup,
	137	.validate = nlmon_validate,
	138	};
e4fc408e	139
7e6d4da8 JP	140	static __init int nlmon_register(void)
	141	{
	142	return rtnl_link_register(&nlmon_link_ops);
e4fc408e DB	143	}
	144
	145	static __exit void nlmon_unregister(void)
	146	{
7e6d4da8	147	rtnl_link_unregister(&nlmon_link_ops);
e4fc408e DB	148	}
	149
	150	module_init(nlmon_register);
	151	module_exit(nlmon_unregister);
	152
	153	MODULE_LICENSE("GPL v2");
	154	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	155	MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
	156	MODULE_DESCRIPTION("Netlink monitoring device");
7e6d4da8	157	MODULE_ALIAS_RTNL_LINK("nlmon");