1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/ethtool.h>
3 #include <linux/module.h>
4 #include <linux/kernel.h>
5 #include <linux/netdevice.h>
6 #include <linux/netlink.h>
7 #include <net/net_namespace.h>
8 #include <linux/if_arp.h>
9 #include <net/rtnetlink.h>
11 static netdev_tx_t
nlmon_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
13 dev_lstats_add(dev
, skb
->len
);
21 struct netlink_tap nt
;
24 static int nlmon_open(struct net_device
*dev
)
26 struct nlmon
*nlmon
= netdev_priv(dev
);
29 nlmon
->nt
.module
= THIS_MODULE
;
30 return netlink_add_tap(&nlmon
->nt
);
33 static int nlmon_close(struct net_device
*dev
)
35 struct nlmon
*nlmon
= netdev_priv(dev
);
37 return netlink_remove_tap(&nlmon
->nt
);
41 nlmon_get_stats64(struct net_device
*dev
, struct rtnl_link_stats64
*stats
)
43 dev_lstats_read(dev
, &stats
->rx_packets
, &stats
->rx_bytes
);
46 static u32
always_on(struct net_device
*dev
)
51 static const struct ethtool_ops nlmon_ethtool_ops
= {
52 .get_link
= always_on
,
55 static const struct net_device_ops nlmon_ops
= {
56 .ndo_open
= nlmon_open
,
57 .ndo_stop
= nlmon_close
,
58 .ndo_start_xmit
= nlmon_xmit
,
59 .ndo_get_stats64
= nlmon_get_stats64
,
62 static void nlmon_setup(struct net_device
*dev
)
64 dev
->type
= ARPHRD_NETLINK
;
65 dev
->priv_flags
|= IFF_NO_QUEUE
;
67 dev
->netdev_ops
= &nlmon_ops
;
68 dev
->ethtool_ops
= &nlmon_ethtool_ops
;
69 dev
->needs_free_netdev
= true;
71 dev
->features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
72 NETIF_F_HIGHDMA
| NETIF_F_LLTX
;
73 dev
->flags
= IFF_NOARP
;
74 dev
->pcpu_stat_type
= NETDEV_PCPU_STAT_LSTATS
;
76 /* That's rather a softlimit here, which, of course,
77 * can be altered. Not a real MTU, but what is to be
78 * expected in most cases.
80 dev
->mtu
= NLMSG_GOODSIZE
;
81 dev
->min_mtu
= sizeof(struct nlmsghdr
);
84 static int nlmon_validate(struct nlattr
*tb
[], struct nlattr
*data
[],
85 struct netlink_ext_ack
*extack
)
92 static struct rtnl_link_ops nlmon_link_ops __read_mostly
= {
94 .priv_size
= sizeof(struct nlmon
),
96 .validate
= nlmon_validate
,
99 static __init
int nlmon_register(void)
101 return rtnl_link_register(&nlmon_link_ops
);
104 static __exit
void nlmon_unregister(void)
106 rtnl_link_unregister(&nlmon_link_ops
);
109 module_init(nlmon_register
);
110 module_exit(nlmon_unregister
);
112 MODULE_LICENSE("GPL v2");
113 MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
114 MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
115 MODULE_DESCRIPTION("Netlink monitoring device");
116 MODULE_ALIAS_RTNL_LINK("nlmon");