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(&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(&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, 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, &stats->rx_packets, &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 WRITE_ONCE(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(&vsockmon_link_ops); 109 } 110 111 static __exit void vsockmon_unregister(void) 112 { 113 rtnl_link_unregister(&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