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