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 struct pcpu_lstats { 15 u64 rx_packets; 16 u64 rx_bytes; 17 struct u64_stats_sync syncp; 18 }; 19 20 static int vsockmon_dev_init(struct net_device *dev) 21 { 22 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); 23 if (!dev->lstats) 24 return -ENOMEM; 25 return 0; 26 } 27 28 static void vsockmon_dev_uninit(struct net_device *dev) 29 { 30 free_percpu(dev->lstats); 31 } 32 33 struct vsockmon { 34 struct vsock_tap vt; 35 }; 36 37 static int vsockmon_open(struct net_device *dev) 38 { 39 struct vsockmon *vsockmon = netdev_priv(dev); 40 41 vsockmon->vt.dev = dev; 42 vsockmon->vt.module = THIS_MODULE; 43 return vsock_add_tap(&vsockmon->vt); 44 } 45 46 static int vsockmon_close(struct net_device *dev) 47 { 48 struct vsockmon *vsockmon = netdev_priv(dev); 49 50 return vsock_remove_tap(&vsockmon->vt); 51 } 52 53 static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev) 54 { 55 int len = skb->len; 56 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats); 57 58 u64_stats_update_begin(&stats->syncp); 59 stats->rx_bytes += len; 60 stats->rx_packets++; 61 u64_stats_update_end(&stats->syncp); 62 63 dev_kfree_skb(skb); 64 65 return NETDEV_TX_OK; 66 } 67 68 static void 69 vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) 70 { 71 int i; 72 u64 bytes = 0, packets = 0; 73 74 for_each_possible_cpu(i) { 75 const struct pcpu_lstats *vstats; 76 u64 tbytes, tpackets; 77 unsigned int start; 78 79 vstats = per_cpu_ptr(dev->lstats, i); 80 81 do { 82 start = u64_stats_fetch_begin_irq(&vstats->syncp); 83 tbytes = vstats->rx_bytes; 84 tpackets = vstats->rx_packets; 85 } while (u64_stats_fetch_retry_irq(&vstats->syncp, start)); 86 87 packets += tpackets; 88 bytes += tbytes; 89 } 90 91 stats->rx_packets = packets; 92 stats->tx_packets = 0; 93 94 stats->rx_bytes = bytes; 95 stats->tx_bytes = 0; 96 } 97 98 static int vsockmon_is_valid_mtu(int new_mtu) 99 { 100 return new_mtu >= (int)sizeof(struct af_vsockmon_hdr); 101 } 102 103 static int vsockmon_change_mtu(struct net_device *dev, int new_mtu) 104 { 105 if (!vsockmon_is_valid_mtu(new_mtu)) 106 return -EINVAL; 107 108 dev->mtu = new_mtu; 109 return 0; 110 } 111 112 static const struct net_device_ops vsockmon_ops = { 113 .ndo_init = vsockmon_dev_init, 114 .ndo_uninit = vsockmon_dev_uninit, 115 .ndo_open = vsockmon_open, 116 .ndo_stop = vsockmon_close, 117 .ndo_start_xmit = vsockmon_xmit, 118 .ndo_get_stats64 = vsockmon_get_stats64, 119 .ndo_change_mtu = vsockmon_change_mtu, 120 }; 121 122 static u32 always_on(struct net_device *dev) 123 { 124 return 1; 125 } 126 127 static const struct ethtool_ops vsockmon_ethtool_ops = { 128 .get_link = always_on, 129 }; 130 131 static void vsockmon_setup(struct net_device *dev) 132 { 133 dev->type = ARPHRD_VSOCKMON; 134 dev->priv_flags |= IFF_NO_QUEUE; 135 136 dev->netdev_ops = &vsockmon_ops; 137 dev->ethtool_ops = &vsockmon_ethtool_ops; 138 dev->destructor = free_netdev; 139 140 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | 141 NETIF_F_HIGHDMA | NETIF_F_LLTX; 142 143 dev->flags = IFF_NOARP; 144 145 dev->mtu = DEFAULT_MTU; 146 } 147 148 static struct rtnl_link_ops vsockmon_link_ops __read_mostly = { 149 .kind = "vsockmon", 150 .priv_size = sizeof(struct vsockmon), 151 .setup = vsockmon_setup, 152 }; 153 154 static __init int vsockmon_register(void) 155 { 156 return rtnl_link_register(&vsockmon_link_ops); 157 } 158 159 static __exit void vsockmon_unregister(void) 160 { 161 rtnl_link_unregister(&vsockmon_link_ops); 162 } 163 164 module_init(vsockmon_register); 165 module_exit(vsockmon_unregister); 166 167 MODULE_LICENSE("GPL v2"); 168 MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>"); 169 MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device."); 170 MODULE_ALIAS_RTNL_LINK("vsockmon"); 171