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 | struct vsockmon { |
17 | struct vsock_tap vt; |
18 | }; |
19 | |
20 | static int vsockmon_open(struct net_device *dev) |
21 | { |
22 | struct vsockmon *vsockmon = netdev_priv(dev); |
23 | |
24 | vsockmon->vt.dev = dev; |
25 | vsockmon->vt.module = THIS_MODULE; |
26 | return vsock_add_tap(vt: &vsockmon->vt); |
27 | } |
28 | |
29 | static int vsockmon_close(struct net_device *dev) |
30 | { |
31 | struct vsockmon *vsockmon = netdev_priv(dev); |
32 | |
33 | return vsock_remove_tap(vt: &vsockmon->vt); |
34 | } |
35 | |
36 | static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev) |
37 | { |
38 | dev_lstats_add(dev, len: skb->len); |
39 | |
40 | dev_kfree_skb(skb); |
41 | |
42 | return NETDEV_TX_OK; |
43 | } |
44 | |
45 | static void |
46 | vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) |
47 | { |
48 | dev_lstats_read(dev, packets: &stats->rx_packets, bytes: &stats->rx_bytes); |
49 | } |
50 | |
51 | static int vsockmon_is_valid_mtu(int new_mtu) |
52 | { |
53 | return new_mtu >= (int)sizeof(struct af_vsockmon_hdr); |
54 | } |
55 | |
56 | static int vsockmon_change_mtu(struct net_device *dev, int new_mtu) |
57 | { |
58 | if (!vsockmon_is_valid_mtu(new_mtu)) |
59 | return -EINVAL; |
60 | |
61 | dev->mtu = new_mtu; |
62 | return 0; |
63 | } |
64 | |
65 | static const struct net_device_ops vsockmon_ops = { |
66 | .ndo_open = vsockmon_open, |
67 | .ndo_stop = vsockmon_close, |
68 | .ndo_start_xmit = vsockmon_xmit, |
69 | .ndo_get_stats64 = vsockmon_get_stats64, |
70 | .ndo_change_mtu = vsockmon_change_mtu, |
71 | }; |
72 | |
73 | static u32 always_on(struct net_device *dev) |
74 | { |
75 | return 1; |
76 | } |
77 | |
78 | static const struct ethtool_ops vsockmon_ethtool_ops = { |
79 | .get_link = always_on, |
80 | }; |
81 | |
82 | static void vsockmon_setup(struct net_device *dev) |
83 | { |
84 | dev->type = ARPHRD_VSOCKMON; |
85 | dev->priv_flags |= IFF_NO_QUEUE; |
86 | |
87 | dev->netdev_ops = &vsockmon_ops; |
88 | dev->ethtool_ops = &vsockmon_ethtool_ops; |
89 | dev->needs_free_netdev = true; |
90 | |
91 | dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | |
92 | NETIF_F_HIGHDMA | NETIF_F_LLTX; |
93 | |
94 | dev->flags = IFF_NOARP; |
95 | |
96 | dev->mtu = DEFAULT_MTU; |
97 | dev->pcpu_stat_type = NETDEV_PCPU_STAT_LSTATS; |
98 | } |
99 | |
100 | static struct rtnl_link_ops vsockmon_link_ops __read_mostly = { |
101 | .kind = "vsockmon" , |
102 | .priv_size = sizeof(struct vsockmon), |
103 | .setup = vsockmon_setup, |
104 | }; |
105 | |
106 | static __init int vsockmon_register(void) |
107 | { |
108 | return rtnl_link_register(ops: &vsockmon_link_ops); |
109 | } |
110 | |
111 | static __exit void vsockmon_unregister(void) |
112 | { |
113 | rtnl_link_unregister(ops: &vsockmon_link_ops); |
114 | } |
115 | |
116 | module_init(vsockmon_register); |
117 | module_exit(vsockmon_unregister); |
118 | |
119 | MODULE_LICENSE("GPL v2" ); |
120 | MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>" ); |
121 | MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device." ); |
122 | MODULE_ALIAS_RTNL_LINK("vsockmon" ); |
123 | |