cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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vsockmon.c (3120B)

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