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 | |
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 | |
24 | static void vsockmon_dev_uninit(struct net_device *dev) |
25 | { |
26 | free_percpu(pdata: dev->lstats); |
27 | } |
28 | |
29 | struct vsockmon { |
30 | struct vsock_tap vt; |
31 | }; |
32 | |
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(vt: &vsockmon->vt); |
40 | } |
41 | |
42 | static int vsockmon_close(struct net_device *dev) |
43 | { |
44 | struct vsockmon *vsockmon = netdev_priv(dev); |
45 | |
46 | return vsock_remove_tap(vt: &vsockmon->vt); |
47 | } |
48 | |
49 | static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev) |
50 | { |
51 | dev_lstats_add(dev, len: skb->len); |
52 | |
53 | dev_kfree_skb(skb); |
54 | |
55 | return NETDEV_TX_OK; |
56 | } |
57 | |
58 | static void |
59 | vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) |
60 | { |
61 | dev_lstats_read(dev, packets: &stats->rx_packets, bytes: &stats->rx_bytes); |
62 | |
63 | stats->tx_packets = 0; |
64 | stats->tx_bytes = 0; |
65 | } |
66 | |
67 | static int vsockmon_is_valid_mtu(int new_mtu) |
68 | { |
69 | return new_mtu >= (int)sizeof(struct af_vsockmon_hdr); |
70 | } |
71 | |
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 | |
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 | |
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 | |
123 | static __init int vsockmon_register(void) |
124 | { |
125 | return rtnl_link_register(ops: &vsockmon_link_ops); |
126 | } |
127 | |
128 | static __exit void vsockmon_unregister(void) |
129 | { |
130 | rtnl_link_unregister(ops: &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 | |