1 #include <linux/module.h> 2 #include <linux/kernel.h> 3 #include <linux/if_arp.h> 4 #include <net/rtnetlink.h> 5 #include <net/sock.h> 6 #include <net/af_vsock.h> 7 #include <uapi/linux/vsockmon.h> 8 #include <linux/virtio_vsock.h> 9 10 /* Virtio transport max packet size plus header */ 11 #define DEFAULT_MTU (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + \ 12 sizeof(struct af_vsockmon_hdr)) 13 14 static int vsockmon_dev_init(struct net_device *dev) 15 { 16 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); 17 if (!dev->lstats) 18 return -ENOMEM; 19 return 0; 20 } 21 22 static void vsockmon_dev_uninit(struct net_device *dev) 23 { 24 free_percpu(dev->lstats); 25 } 26 27 struct vsockmon { 28 struct vsock_tap vt; 29 }; 30 31 static int vsockmon_open(struct net_device *dev) 32 { 33 struct vsockmon *vsockmon = netdev_priv(dev); 34 35 vsockmon->vt.dev = dev; 36 vsockmon->vt.module = THIS_MODULE; 37 return vsock_add_tap(&vsockmon->vt); 38 } 39 40 static int vsockmon_close(struct net_device *dev) 41 { 42 struct vsockmon *vsockmon = netdev_priv(dev); 43 44 return vsock_remove_tap(&vsockmon->vt); 45 } 46 47 static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev) 48 { 49 int len = skb->len; 50 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats); 51 52 u64_stats_update_begin(&stats->syncp); 53 stats->bytes += len; 54 stats->packets++; 55 u64_stats_update_end(&stats->syncp); 56 57 dev_kfree_skb(skb); 58 59 return NETDEV_TX_OK; 60 } 61 62 static void 63 vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) 64 { 65 int i; 66 u64 bytes = 0, packets = 0; 67 68 for_each_possible_cpu(i) { 69 const struct pcpu_lstats *vstats; 70 u64 tbytes, tpackets; 71 unsigned int start; 72 73 vstats = per_cpu_ptr(dev->lstats, i); 74 75 do { 76 start = u64_stats_fetch_begin_irq(&vstats->syncp); 77 tbytes = vstats->bytes; 78 tpackets = vstats->packets; 79 } while (u64_stats_fetch_retry_irq(&vstats->syncp, start)); 80 81 packets += tpackets; 82 bytes += tbytes; 83 } 84 85 stats->rx_packets = packets; 86 stats->tx_packets = 0; 87 88 stats->rx_bytes = bytes; 89 stats->tx_bytes = 0; 90 } 91 92 static int vsockmon_is_valid_mtu(int new_mtu) 93 { 94 return new_mtu >= (int)sizeof(struct af_vsockmon_hdr); 95 } 96 97 static int vsockmon_change_mtu(struct net_device *dev, int new_mtu) 98 { 99 if (!vsockmon_is_valid_mtu(new_mtu)) 100 return -EINVAL; 101 102 dev->mtu = new_mtu; 103 return 0; 104 } 105 106 static const struct net_device_ops vsockmon_ops = { 107 .ndo_init = vsockmon_dev_init, 108 .ndo_uninit = vsockmon_dev_uninit, 109 .ndo_open = vsockmon_open, 110 .ndo_stop = vsockmon_close, 111 .ndo_start_xmit = vsockmon_xmit, 112 .ndo_get_stats64 = vsockmon_get_stats64, 113 .ndo_change_mtu = vsockmon_change_mtu, 114 }; 115 116 static u32 always_on(struct net_device *dev) 117 { 118 return 1; 119 } 120 121 static const struct ethtool_ops vsockmon_ethtool_ops = { 122 .get_link = always_on, 123 }; 124 125 static void vsockmon_setup(struct net_device *dev) 126 { 127 dev->type = ARPHRD_VSOCKMON; 128 dev->priv_flags |= IFF_NO_QUEUE; 129 130 dev->netdev_ops = &vsockmon_ops; 131 dev->ethtool_ops = &vsockmon_ethtool_ops; 132 dev->needs_free_netdev = true; 133 134 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | 135 NETIF_F_HIGHDMA | NETIF_F_LLTX; 136 137 dev->flags = IFF_NOARP; 138 139 dev->mtu = DEFAULT_MTU; 140 } 141 142 static struct rtnl_link_ops vsockmon_link_ops __read_mostly = { 143 .kind = "vsockmon", 144 .priv_size = sizeof(struct vsockmon), 145 .setup = vsockmon_setup, 146 }; 147 148 static __init int vsockmon_register(void) 149 { 150 return rtnl_link_register(&vsockmon_link_ops); 151 } 152 153 static __exit void vsockmon_unregister(void) 154 { 155 rtnl_link_unregister(&vsockmon_link_ops); 156 } 157 158 module_init(vsockmon_register); 159 module_exit(vsockmon_unregister); 160 161 MODULE_LICENSE("GPL v2"); 162 MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>"); 163 MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device."); 164 MODULE_ALIAS_RTNL_LINK("vsockmon"); 165