#include <linux/module.h> #include <linux/kernel.h> #include <linux/if_arp.h> #include <net/rtnetlink.h> #include <net/sock.h> #include <net/af_vsock.h> #include <uapi/linux/vsockmon.h> #include <linux/virtio_vsock.h> /* Virtio transport max packet size plus header */ #define DEFAULT_MTU (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + \ sizeof(struct af_vsockmon_hdr)) struct pcpu_lstats { u64 rx_packets; u64 rx_bytes; struct u64_stats_sync syncp; }; static int vsockmon_dev_init(struct net_device *dev) { dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); if (!dev->lstats) return -ENOMEM; return 0; } static void vsockmon_dev_uninit(struct net_device *dev) { free_percpu(dev->lstats); } struct vsockmon { struct vsock_tap vt; }; static int vsockmon_open(struct net_device *dev) { struct vsockmon *vsockmon = netdev_priv(dev); vsockmon->vt.dev = dev; vsockmon->vt.module = THIS_MODULE; return vsock_add_tap(&vsockmon->vt); } static int vsockmon_close(struct net_device *dev) { struct vsockmon *vsockmon = netdev_priv(dev); return vsock_remove_tap(&vsockmon->vt); } static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev) { int len = skb->len; struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats); u64_stats_update_begin(&stats->syncp); stats->rx_bytes += len; stats->rx_packets++; u64_stats_update_end(&stats->syncp); dev_kfree_skb(skb); return NETDEV_TX_OK; } static void vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) { int i; u64 bytes = 0, packets = 0; for_each_possible_cpu(i) { const struct pcpu_lstats *vstats; u64 tbytes, tpackets; unsigned int start; vstats = per_cpu_ptr(dev->lstats, i); do { start = u64_stats_fetch_begin_irq(&vstats->syncp); tbytes = vstats->rx_bytes; tpackets = vstats->rx_packets; } while (u64_stats_fetch_retry_irq(&vstats->syncp, start)); packets += tpackets; bytes += tbytes; } stats->rx_packets = packets; stats->tx_packets = 0; stats->rx_bytes = bytes; stats->tx_bytes = 0; } static int vsockmon_is_valid_mtu(int new_mtu) { return new_mtu >= (int)sizeof(struct af_vsockmon_hdr); } static int vsockmon_change_mtu(struct net_device *dev, int new_mtu) { if (!vsockmon_is_valid_mtu(new_mtu)) return -EINVAL; dev->mtu = new_mtu; return 0; } static const struct net_device_ops vsockmon_ops = { .ndo_init = vsockmon_dev_init, .ndo_uninit = vsockmon_dev_uninit, .ndo_open = vsockmon_open, .ndo_stop = vsockmon_close, .ndo_start_xmit = vsockmon_xmit, .ndo_get_stats64 = vsockmon_get_stats64, .ndo_change_mtu = vsockmon_change_mtu, }; static u32 always_on(struct net_device *dev) { return 1; } static const struct ethtool_ops vsockmon_ethtool_ops = { .get_link = always_on, }; static void vsockmon_setup(struct net_device *dev) { dev->type = ARPHRD_VSOCKMON; dev->priv_flags |= IFF_NO_QUEUE; dev->netdev_ops = &vsockmon_ops; dev->ethtool_ops = &vsockmon_ethtool_ops; dev->needs_free_netdev = true; dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | NETIF_F_LLTX; dev->flags = IFF_NOARP; dev->mtu = DEFAULT_MTU; } static struct rtnl_link_ops vsockmon_link_ops __read_mostly = { .kind = "vsockmon", .priv_size = sizeof(struct vsockmon), .setup = vsockmon_setup, }; static __init int vsockmon_register(void) { return rtnl_link_register(&vsockmon_link_ops); } static __exit void vsockmon_unregister(void) { rtnl_link_unregister(&vsockmon_link_ops); } module_init(vsockmon_register); module_exit(vsockmon_unregister); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>"); MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device."); MODULE_ALIAS_RTNL_LINK("vsockmon");