aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/vsockmon.c
blob: c28bdce14fd5e32b287419227d7d33bf7835c409 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/if_arp.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <net/af_vsock.h>
#include <uapi/linux/vsockmon.h>
#include <linux/virtio_vsock.h>

/* Virtio transport max packet size plus header */
#define DEFAULT_MTU (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + \
		     sizeof(struct af_vsockmon_hdr))

struct pcpu_lstats {
	u64 rx_packets;
	u64 rx_bytes;
	struct u64_stats_sync syncp;
};

static int vsockmon_dev_init(struct net_device *dev)
{
	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
	if (!dev->lstats)
		return -ENOMEM;
	return 0;
}

static void vsockmon_dev_uninit(struct net_device *dev)
{
	free_percpu(dev->lstats);
}

struct vsockmon {
	struct vsock_tap vt;
};

static int vsockmon_open(struct net_device *dev)
{
	struct vsockmon *vsockmon = netdev_priv(dev);

	vsockmon->vt.dev = dev;
	vsockmon->vt.module = THIS_MODULE;
	return vsock_add_tap(&vsockmon->vt);
}

static int vsockmon_close(struct net_device *dev)
{
	struct vsockmon *vsockmon = netdev_priv(dev);

	return vsock_remove_tap(&vsockmon->vt);
}

static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev)
{
	int len = skb->len;
	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);

	u64_stats_update_begin(&stats->syncp);
	stats->rx_bytes += len;
	stats->rx_packets++;
	u64_stats_update_end(&stats->syncp);

	dev_kfree_skb(skb);

	return NETDEV_TX_OK;
}

static void
vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{
	int i;
	u64 bytes = 0, packets = 0;

	for_each_possible_cpu(i) {
		const struct pcpu_lstats *vstats;
		u64 tbytes, tpackets;
		unsigned int start;

		vstats = per_cpu_ptr(dev->lstats, i);

		do {
			start = u64_stats_fetch_begin_irq(&vstats->syncp);
			tbytes = vstats->rx_bytes;
			tpackets = vstats->rx_packets;
		} while (u64_stats_fetch_retry_irq(&vstats->syncp, start));

		packets += tpackets;
		bytes += tbytes;
	}

	stats->rx_packets = packets;
	stats->tx_packets = 0;

	stats->rx_bytes = bytes;
	stats->tx_bytes = 0;
}

static int vsockmon_is_valid_mtu(int new_mtu)
{
	return new_mtu >= (int)sizeof(struct af_vsockmon_hdr);
}

static int vsockmon_change_mtu(struct net_device *dev, int new_mtu)
{
	if (!vsockmon_is_valid_mtu(new_mtu))
		return -EINVAL;

	dev->mtu = new_mtu;
	return 0;
}

static const struct net_device_ops vsockmon_ops = {
	.ndo_init = vsockmon_dev_init,
	.ndo_uninit = vsockmon_dev_uninit,
	.ndo_open = vsockmon_open,
	.ndo_stop = vsockmon_close,
	.ndo_start_xmit = vsockmon_xmit,
	.ndo_get_stats64 = vsockmon_get_stats64,
	.ndo_change_mtu = vsockmon_change_mtu,
};

static u32 always_on(struct net_device *dev)
{
	return 1;
}

static const struct ethtool_ops vsockmon_ethtool_ops = {
	.get_link = always_on,
};

static void vsockmon_setup(struct net_device *dev)
{
	dev->type = ARPHRD_VSOCKMON;
	dev->priv_flags |= IFF_NO_QUEUE;

	dev->netdev_ops	= &vsockmon_ops;
	dev->ethtool_ops = &vsockmon_ethtool_ops;
	dev->needs_free_netdev = true;

	dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
			NETIF_F_HIGHDMA | NETIF_F_LLTX;

	dev->flags = IFF_NOARP;

	dev->mtu = DEFAULT_MTU;
}

static struct rtnl_link_ops vsockmon_link_ops __read_mostly = {
	.kind			= "vsockmon",
	.priv_size		= sizeof(struct vsockmon),
	.setup			= vsockmon_setup,
};

static __init int vsockmon_register(void)
{
	return rtnl_link_register(&vsockmon_link_ops);
}

static __exit void vsockmon_unregister(void)
{
	rtnl_link_unregister(&vsockmon_link_ops);
}

module_init(vsockmon_register);
module_exit(vsockmon_unregister);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>");
MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device.");
MODULE_ALIAS_RTNL_LINK("vsockmon");