blob: c4b3362da4a2e33184b02dff0df3082b4d7e45e4 [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
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020030static int nlmon_dev_init(struct net_device *dev)
31{
WANG Cong1c213bd2014-02-13 11:46:28 -080032 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020033 return dev->lstats == NULL ? -ENOMEM : 0;
34}
35
36static void nlmon_dev_uninit(struct net_device *dev)
37{
38 free_percpu(dev->lstats);
39}
40
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020041struct nlmon {
42 struct netlink_tap nt;
43};
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020044
45static int nlmon_open(struct net_device *dev)
46{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020047 struct nlmon *nlmon = netdev_priv(dev);
48
49 nlmon->nt.dev = dev;
50 nlmon->nt.module = THIS_MODULE;
51 return netlink_add_tap(&nlmon->nt);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020052}
53
54static int nlmon_close(struct net_device *dev)
55{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +020056 struct nlmon *nlmon = netdev_priv(dev);
57
58 return netlink_remove_tap(&nlmon->nt);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020059}
60
stephen hemmingerbc1f4472017-01-06 19:12:52 -080061static void
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020062nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
63{
64 int i;
65 u64 bytes = 0, packets = 0;
66
67 for_each_possible_cpu(i) {
68 const struct pcpu_lstats *nl_stats;
69 u64 tbytes, tpackets;
70 unsigned int start;
71
72 nl_stats = per_cpu_ptr(dev->lstats, i);
73
74 do {
Eric W. Biederman57a77442014-03-13 21:26:42 -070075 start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020076 tbytes = nl_stats->bytes;
77 tpackets = nl_stats->packets;
Eric W. Biederman57a77442014-03-13 21:26:42 -070078 } while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020079
80 packets += tpackets;
81 bytes += tbytes;
82 }
83
84 stats->rx_packets = packets;
85 stats->tx_packets = 0;
86
87 stats->rx_bytes = bytes;
88 stats->tx_bytes = 0;
Daniel Borkmanne4fc4082013-06-21 19:38:08 +020089}
90
91static u32 always_on(struct net_device *dev)
92{
93 return 1;
94}
95
96static const struct ethtool_ops nlmon_ethtool_ops = {
97 .get_link = always_on,
98};
99
100static const struct net_device_ops nlmon_ops = {
101 .ndo_init = nlmon_dev_init,
102 .ndo_uninit = nlmon_dev_uninit,
103 .ndo_open = nlmon_open,
104 .ndo_stop = nlmon_close,
105 .ndo_start_xmit = nlmon_xmit,
106 .ndo_get_stats64 = nlmon_get_stats64,
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200107};
108
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200109static void nlmon_setup(struct net_device *dev)
110{
111 dev->type = ARPHRD_NETLINK;
Phil Sutter85773a62015-08-18 10:30:33 +0200112 dev->priv_flags |= IFF_NO_QUEUE;
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200113
114 dev->netdev_ops = &nlmon_ops;
115 dev->ethtool_ops = &nlmon_ethtool_ops;
David S. Millercf124db2017-05-08 12:52:56 -0400116 dev->needs_free_netdev = true;
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200117
Daniel Borkmannb7d47ca2014-03-27 16:34:59 +0100118 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
119 NETIF_F_HIGHDMA | NETIF_F_LLTX;
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200120 dev->flags = IFF_NOARP;
121
122 /* That's rather a softlimit here, which, of course,
123 * can be altered. Not a real MTU, but what is to be
124 * expected in most cases.
125 */
126 dev->mtu = NLMSG_GOODSIZE;
Zhang Shengjue82621e2016-12-07 17:26:05 +0800127 dev->min_mtu = sizeof(struct nlmsghdr);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200128}
129
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200130static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[])
131{
132 if (tb[IFLA_ADDRESS])
133 return -EINVAL;
134 return 0;
135}
136
137static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
138 .kind = "nlmon",
139 .priv_size = sizeof(struct nlmon),
140 .setup = nlmon_setup,
141 .validate = nlmon_validate,
142};
143
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200144static __init int nlmon_register(void)
145{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200146 return rtnl_link_register(&nlmon_link_ops);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200147}
148
149static __exit void nlmon_unregister(void)
150{
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200151 rtnl_link_unregister(&nlmon_link_ops);
Daniel Borkmanne4fc4082013-06-21 19:38:08 +0200152}
153
154module_init(nlmon_register);
155module_exit(nlmon_unregister);
156
157MODULE_LICENSE("GPL v2");
158MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
159MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
160MODULE_DESCRIPTION("Netlink monitoring device");
Jiri Pirko7e6d4da2013-07-02 10:55:31 +0200161MODULE_ALIAS_RTNL_LINK("nlmon");