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