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1// SPDX-License-Identifier: GPL-2.0-only2#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 16struct vsockmon {17 struct vsock_tap vt;18};19 20static 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 29static 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 36static 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 45static void46vsockmon_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 51static int vsockmon_is_valid_mtu(int new_mtu)52{53 return new_mtu >= (int)sizeof(struct af_vsockmon_hdr);54}55 56static 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 65static 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 73static u32 always_on(struct net_device *dev)74{75 return 1;76}77 78static const struct ethtool_ops vsockmon_ethtool_ops = {79 .get_link = always_on,80};81 82static void vsockmon_setup(struct net_device *dev)83{84 dev->type = ARPHRD_VSOCKMON;85 dev->priv_flags |= IFF_NO_QUEUE;86 dev->lltx = true;87 88 dev->netdev_ops = &vsockmon_ops;89 dev->ethtool_ops = &vsockmon_ethtool_ops;90 dev->needs_free_netdev = true;91 92 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;93 94 dev->flags = IFF_NOARP;95 96 dev->mtu = DEFAULT_MTU;97 dev->pcpu_stat_type = NETDEV_PCPU_STAT_LSTATS;98}99 100static struct rtnl_link_ops vsockmon_link_ops __read_mostly = {101 .kind = "vsockmon",102 .priv_size = sizeof(struct vsockmon),103 .setup = vsockmon_setup,104};105 106static __init int vsockmon_register(void)107{108 return rtnl_link_register(&vsockmon_link_ops);109}110 111static __exit void vsockmon_unregister(void)112{113 rtnl_link_unregister(&vsockmon_link_ops);114}115 116module_init(vsockmon_register);117module_exit(vsockmon_unregister);118 119MODULE_LICENSE("GPL v2");120MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>");121MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device.");122MODULE_ALIAS_RTNL_LINK("vsockmon");123