cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

nlmon.c (2993B)

      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/netdevice.h>
      6#include <linux/netlink.h>
      7#include <net/net_namespace.h>
      8#include <linux/if_arp.h>
      9#include <net/rtnetlink.h>
     10
     11static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev)
     12{
     13	dev_lstats_add(dev, skb->len);
     14
     15	dev_kfree_skb(skb);
     16
     17	return NETDEV_TX_OK;
     18}
     19
     20static int nlmon_dev_init(struct net_device *dev)
     21{
     22	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
     23	return dev->lstats == NULL ? -ENOMEM : 0;
     24}
     25
     26static void nlmon_dev_uninit(struct net_device *dev)
     27{
     28	free_percpu(dev->lstats);
     29}
     30
     31struct nlmon {
     32	struct netlink_tap nt;
     33};
     34
     35static int nlmon_open(struct net_device *dev)
     36{
     37	struct nlmon *nlmon = netdev_priv(dev);
     38
     39	nlmon->nt.dev = dev;
     40	nlmon->nt.module = THIS_MODULE;
     41	return netlink_add_tap(&nlmon->nt);
     42}
     43
     44static int nlmon_close(struct net_device *dev)
     45{
     46	struct nlmon *nlmon = netdev_priv(dev);
     47
     48	return netlink_remove_tap(&nlmon->nt);
     49}
     50
     51static void
     52nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
     53{
     54	u64 packets, bytes;
     55
     56	dev_lstats_read(dev, &packets, &bytes);
     57
     58	stats->rx_packets = packets;
     59	stats->tx_packets = 0;
     60
     61	stats->rx_bytes = bytes;
     62	stats->tx_bytes = 0;
     63}
     64
     65static u32 always_on(struct net_device *dev)
     66{
     67	return 1;
     68}
     69
     70static const struct ethtool_ops nlmon_ethtool_ops = {
     71	.get_link = always_on,
     72};
     73
     74static const struct net_device_ops nlmon_ops = {
     75	.ndo_init = nlmon_dev_init,
     76	.ndo_uninit = nlmon_dev_uninit,
     77	.ndo_open = nlmon_open,
     78	.ndo_stop = nlmon_close,
     79	.ndo_start_xmit = nlmon_xmit,
     80	.ndo_get_stats64 = nlmon_get_stats64,
     81};
     82
     83static void nlmon_setup(struct net_device *dev)
     84{
     85	dev->type = ARPHRD_NETLINK;
     86	dev->priv_flags |= IFF_NO_QUEUE;
     87
     88	dev->netdev_ops	= &nlmon_ops;
     89	dev->ethtool_ops = &nlmon_ethtool_ops;
     90	dev->needs_free_netdev = true;
     91
     92	dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
     93			NETIF_F_HIGHDMA | NETIF_F_LLTX;
     94	dev->flags = IFF_NOARP;
     95
     96	/* That's rather a softlimit here, which, of course,
     97	 * can be altered. Not a real MTU, but what is to be
     98	 * expected in most cases.
     99	 */
    100	dev->mtu = NLMSG_GOODSIZE;
    101	dev->min_mtu = sizeof(struct nlmsghdr);
    102}
    103
    104static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[],
    105			  struct netlink_ext_ack *extack)
    106{
    107	if (tb[IFLA_ADDRESS])
    108		return -EINVAL;
    109	return 0;
    110}
    111
    112static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
    113	.kind			= "nlmon",
    114	.priv_size		= sizeof(struct nlmon),
    115	.setup			= nlmon_setup,
    116	.validate		= nlmon_validate,
    117};
    118
    119static __init int nlmon_register(void)
    120{
    121	return rtnl_link_register(&nlmon_link_ops);
    122}
    123
    124static __exit void nlmon_unregister(void)
    125{
    126	rtnl_link_unregister(&nlmon_link_ops);
    127}
    128
    129module_init(nlmon_register);
    130module_exit(nlmon_unregister);
    131
    132MODULE_LICENSE("GPL v2");
    133MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
    134MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
    135MODULE_DESCRIPTION("Netlink monitoring device");
    136MODULE_ALIAS_RTNL_LINK("nlmon");