blob: 6929b03ec638b04e561d168347cf2ba5bef241d6 [file] [log] [blame]
Daniel Borkmanne4fc4082013-06-21 19:38:08 +02001#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>
Jiri Pirko7e6d4da2013-07-02 10:55:31 +02007#include <net/rtnetlink.h>
Daniel Borkmanne4fc4082013-06-21 19:38:08 +02008
9struct pcpu_lstats {
10 u64 packets;
11 u64 bytes;
12 struct u64_stats_sync syncp;
13};
14
15static 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
30static int nlmon_is_valid_mtu(int new_mtu)
31{
Daniel Borkmann3b233fe2013-06-27 13:44:26 +020032 /* 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);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020037}
38
39static 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
48static int nlmon_dev_init(struct net_device *dev)
49{
WANG Cong1c213bd2014-02-13 11:46:28 -080050 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020051 return dev->lstats == NULL ? -ENOMEM : 0;
52}
53
54static void nlmon_dev_uninit(struct net_device *dev)
55{
56 free_percpu(dev->lstats);
57}
58
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020059struct nlmon {
60 struct netlink_tap nt;
61};
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020062
63static int nlmon_open(struct net_device *dev)
64{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020065 struct nlmon *nlmon = netdev_priv(dev);
66
67 nlmon->nt.dev = dev;
68 nlmon->nt.module = THIS_MODULE;
69 return netlink_add_tap(&nlmon->nt);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020070}
71
72static int nlmon_close(struct net_device *dev)
73{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020074 struct nlmon *nlmon = netdev_priv(dev);
75
76 return netlink_remove_tap(&nlmon->nt);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020077}
78
79static struct rtnl_link_stats64 *
80nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
81{
82 int i;
83 u64 bytes = 0, packets = 0;
84
85 for_each_possible_cpu(i) {
86 const struct pcpu_lstats *nl_stats;
87 u64 tbytes, tpackets;
88 unsigned int start;
89
90 nl_stats = per_cpu_ptr(dev->lstats, i);
91
92 do {
Eric W. Biederman57a77442014-03-13 21:26:42 -070093 start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020094 tbytes = nl_stats->bytes;
95 tpackets = nl_stats->packets;
Eric W. Biederman57a77442014-03-13 21:26:42 -070096 } while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020097
98 packets += tpackets;
99 bytes += tbytes;
100 }
101
102 stats->rx_packets = packets;
103 stats->tx_packets = 0;
104
105 stats->rx_bytes = bytes;
106 stats->tx_bytes = 0;
107
108 return stats;
109}
110
111static u32 always_on(struct net_device *dev)
112{
113 return 1;
114}
115
116static const struct ethtool_ops nlmon_ethtool_ops = {
117 .get_link = always_on,
118};
119
120static const struct net_device_ops nlmon_ops = {
121 .ndo_init = nlmon_dev_init,
122 .ndo_uninit = nlmon_dev_uninit,
123 .ndo_open = nlmon_open,
124 .ndo_stop = nlmon_close,
125 .ndo_start_xmit = nlmon_xmit,
126 .ndo_get_stats64 = nlmon_get_stats64,
127 .ndo_change_mtu = nlmon_change_mtu,
128};
129
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200130static void nlmon_setup(struct net_device *dev)
131{
132 dev->type = ARPHRD_NETLINK;
133 dev->tx_queue_len = 0;
134
135 dev->netdev_ops = &nlmon_ops;
136 dev->ethtool_ops = &nlmon_ethtool_ops;
137 dev->destructor = free_netdev;
138
139 dev->features = NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
140 dev->flags = IFF_NOARP;
141
142 /* That's rather a softlimit here, which, of course,
143 * can be altered. Not a real MTU, but what is to be
144 * expected in most cases.
145 */
146 dev->mtu = NLMSG_GOODSIZE;
147}
148
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200149static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[])
150{
151 if (tb[IFLA_ADDRESS])
152 return -EINVAL;
153 return 0;
154}
155
156static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
157 .kind = "nlmon",
158 .priv_size = sizeof(struct nlmon),
159 .setup = nlmon_setup,
160 .validate = nlmon_validate,
161};
162
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200163static __init int nlmon_register(void)
164{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200165 return rtnl_link_register(&nlmon_link_ops);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200166}
167
168static __exit void nlmon_unregister(void)
169{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200170 rtnl_link_unregister(&nlmon_link_ops);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200171}
172
173module_init(nlmon_register);
174module_exit(nlmon_unregister);
175
176MODULE_LICENSE("GPL v2");
177MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
178MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
179MODULE_DESCRIPTION("Netlink monitoring device");
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200180MODULE_ALIAS_RTNL_LINK("nlmon");