137 lines
2.9 KiB
C
137 lines
2.9 KiB
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");
|