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(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(&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(&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, 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, &stats->rx_packets, &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(&vsockmon_link_ops); 126 } 127 128 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