1
2#include <linux/module.h>
3#include <linux/kernel.h>
4#include <linux/if_arp.h>
5#include <net/rtnetlink.h>
6#include <net/sock.h>
7#include <net/af_vsock.h>
8#include <uapi/linux/vsockmon.h>
9#include <linux/virtio_vsock.h>
10
11
12#define DEFAULT_MTU (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + \
13 sizeof(struct af_vsockmon_hdr))
14
15static int vsockmon_dev_init(struct net_device *dev)
16{
17 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
18 if (!dev->lstats)
19 return -ENOMEM;
20 return 0;
21}
22
23static void vsockmon_dev_uninit(struct net_device *dev)
24{
25 free_percpu(dev->lstats);
26}
27
28struct vsockmon {
29 struct vsock_tap vt;
30};
31
32static int vsockmon_open(struct net_device *dev)
33{
34 struct vsockmon *vsockmon = netdev_priv(dev);
35
36 vsockmon->vt.dev = dev;
37 vsockmon->vt.module = THIS_MODULE;
38 return vsock_add_tap(&vsockmon->vt);
39}
40
41static int vsockmon_close(struct net_device *dev)
42{
43 struct vsockmon *vsockmon = netdev_priv(dev);
44
45 return vsock_remove_tap(&vsockmon->vt);
46}
47
48static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev)
49{
50 int len = skb->len;
51 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
52
53 u64_stats_update_begin(&stats->syncp);
54 stats->bytes += len;
55 stats->packets++;
56 u64_stats_update_end(&stats->syncp);
57
58 dev_kfree_skb(skb);
59
60 return NETDEV_TX_OK;
61}
62
63static void
64vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
65{
66 int i;
67 u64 bytes = 0, packets = 0;
68
69 for_each_possible_cpu(i) {
70 const struct pcpu_lstats *vstats;
71 u64 tbytes, tpackets;
72 unsigned int start;
73
74 vstats = per_cpu_ptr(dev->lstats, i);
75
76 do {
77 start = u64_stats_fetch_begin_irq(&vstats->syncp);
78 tbytes = vstats->bytes;
79 tpackets = vstats->packets;
80 } while (u64_stats_fetch_retry_irq(&vstats->syncp, start));
81
82 packets += tpackets;
83 bytes += tbytes;
84 }
85
86 stats->rx_packets = packets;
87 stats->tx_packets = 0;
88
89 stats->rx_bytes = bytes;
90 stats->tx_bytes = 0;
91}
92
93static int vsockmon_is_valid_mtu(int new_mtu)
94{
95 return new_mtu >= (int)sizeof(struct af_vsockmon_hdr);
96}
97
98static int vsockmon_change_mtu(struct net_device *dev, int new_mtu)
99{
100 if (!vsockmon_is_valid_mtu(new_mtu))
101 return -EINVAL;
102
103 dev->mtu = new_mtu;
104 return 0;
105}
106
107static const struct net_device_ops vsockmon_ops = {
108 .ndo_init = vsockmon_dev_init,
109 .ndo_uninit = vsockmon_dev_uninit,
110 .ndo_open = vsockmon_open,
111 .ndo_stop = vsockmon_close,
112 .ndo_start_xmit = vsockmon_xmit,
113 .ndo_get_stats64 = vsockmon_get_stats64,
114 .ndo_change_mtu = vsockmon_change_mtu,
115};
116
117static u32 always_on(struct net_device *dev)
118{
119 return 1;
120}
121
122static const struct ethtool_ops vsockmon_ethtool_ops = {
123 .get_link = always_on,
124};
125
126static void vsockmon_setup(struct net_device *dev)
127{
128 dev->type = ARPHRD_VSOCKMON;
129 dev->priv_flags |= IFF_NO_QUEUE;
130
131 dev->netdev_ops = &vsockmon_ops;
132 dev->ethtool_ops = &vsockmon_ethtool_ops;
133 dev->needs_free_netdev = true;
134
135 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
136 NETIF_F_HIGHDMA | NETIF_F_LLTX;
137
138 dev->flags = IFF_NOARP;
139
140 dev->mtu = DEFAULT_MTU;
141}
142
143static struct rtnl_link_ops vsockmon_link_ops __read_mostly = {
144 .kind = "vsockmon",
145 .priv_size = sizeof(struct vsockmon),
146 .setup = vsockmon_setup,
147};
148
149static __init int vsockmon_register(void)
150{
151 return rtnl_link_register(&vsockmon_link_ops);
152}
153
154static __exit void vsockmon_unregister(void)
155{
156 rtnl_link_unregister(&vsockmon_link_ops);
157}
158
159module_init(vsockmon_register);
160module_exit(vsockmon_unregister);
161
162MODULE_LICENSE("GPL v2");
163MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>");
164MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device.");
165MODULE_ALIAS_RTNL_LINK("vsockmon");
166
