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	Do not set rtnl_link_stats64 fields to zero, since they are zeroed before ops->ndo_get_stats64 is called in core dev_get_stats() function. Also, simplify the data collection by removing the temporary variable. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			116 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			116 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/ethtool.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/netlink.h>
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#include <net/net_namespace.h>
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#include <linux/if_arp.h>
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#include <net/rtnetlink.h>
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static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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	dev_lstats_add(dev, skb->len);
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	dev_kfree_skb(skb);
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	return NETDEV_TX_OK;
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}
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struct nlmon {
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	struct netlink_tap nt;
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};
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static int nlmon_open(struct net_device *dev)
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{
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	struct nlmon *nlmon = netdev_priv(dev);
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	nlmon->nt.dev = dev;
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	nlmon->nt.module = THIS_MODULE;
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	return netlink_add_tap(&nlmon->nt);
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}
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static int nlmon_close(struct net_device *dev)
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{
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	struct nlmon *nlmon = netdev_priv(dev);
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	return netlink_remove_tap(&nlmon->nt);
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}
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static void
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nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
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{
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	dev_lstats_read(dev, &stats->rx_packets, &stats->rx_bytes);
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}
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static u32 always_on(struct net_device *dev)
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{
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	return 1;
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}
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static const struct ethtool_ops nlmon_ethtool_ops = {
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	.get_link = always_on,
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};
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static const struct net_device_ops nlmon_ops = {
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	.ndo_open = nlmon_open,
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	.ndo_stop = nlmon_close,
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	.ndo_start_xmit = nlmon_xmit,
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	.ndo_get_stats64 = nlmon_get_stats64,
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};
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static void nlmon_setup(struct net_device *dev)
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{
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	dev->type = ARPHRD_NETLINK;
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	dev->priv_flags |= IFF_NO_QUEUE;
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	dev->netdev_ops	= &nlmon_ops;
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	dev->ethtool_ops = &nlmon_ethtool_ops;
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	dev->needs_free_netdev = true;
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	dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
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			NETIF_F_HIGHDMA | NETIF_F_LLTX;
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	dev->flags = IFF_NOARP;
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	dev->pcpu_stat_type = NETDEV_PCPU_STAT_LSTATS;
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	/* That's rather a softlimit here, which, of course,
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	 * can be altered. Not a real MTU, but what is to be
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	 * expected in most cases.
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	 */
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	dev->mtu = NLMSG_GOODSIZE;
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	dev->min_mtu = sizeof(struct nlmsghdr);
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}
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static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[],
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			  struct netlink_ext_ack *extack)
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{
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	if (tb[IFLA_ADDRESS])
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		return -EINVAL;
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	return 0;
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}
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static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
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	.kind			= "nlmon",
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	.priv_size		= sizeof(struct nlmon),
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	.setup			= nlmon_setup,
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	.validate		= nlmon_validate,
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};
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static __init int nlmon_register(void)
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{
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	return rtnl_link_register(&nlmon_link_ops);
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}
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static __exit void nlmon_unregister(void)
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{
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	rtnl_link_unregister(&nlmon_link_ops);
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}
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module_init(nlmon_register);
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module_exit(nlmon_unregister);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
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MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
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MODULE_DESCRIPTION("Netlink monitoring device");
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MODULE_ALIAS_RTNL_LINK("nlmon");
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