Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			163 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			163 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #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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| 
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| struct pcpu_lstats {
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| 	u64 packets;
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| 	u64 bytes;
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| 	struct u64_stats_sync syncp;
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| };
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| 
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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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| 	int len = skb->len;
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| 	struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
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| 
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| 	u64_stats_update_begin(&stats->syncp);
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| 	stats->bytes += len;
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| 	stats->packets++;
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| 	u64_stats_update_end(&stats->syncp);
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| 
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| 	dev_kfree_skb(skb);
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| 
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| 	return NETDEV_TX_OK;
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| }
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| 
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| static int nlmon_dev_init(struct net_device *dev)
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| {
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| 	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
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| 	return dev->lstats == NULL ? -ENOMEM : 0;
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| }
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| 
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| static void nlmon_dev_uninit(struct net_device *dev)
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| {
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| 	free_percpu(dev->lstats);
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| }
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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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| 
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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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| 
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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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| 
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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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| 
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| 	return netlink_remove_tap(&nlmon->nt);
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| }
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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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| 	int i;
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| 	u64 bytes = 0, packets = 0;
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| 
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| 	for_each_possible_cpu(i) {
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| 		const struct pcpu_lstats *nl_stats;
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| 		u64 tbytes, tpackets;
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| 		unsigned int start;
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| 
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| 		nl_stats = per_cpu_ptr(dev->lstats, i);
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| 
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| 		do {
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| 			start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
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| 			tbytes = nl_stats->bytes;
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| 			tpackets = nl_stats->packets;
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| 		} while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
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| 
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| 		packets += tpackets;
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| 		bytes += tbytes;
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| 	}
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| 
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| 	stats->rx_packets = packets;
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| 	stats->tx_packets = 0;
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| 
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| 	stats->rx_bytes = bytes;
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| 	stats->tx_bytes = 0;
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| }
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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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| 
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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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| 
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| static const struct net_device_ops nlmon_ops = {
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| 	.ndo_init = nlmon_dev_init,
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| 	.ndo_uninit = nlmon_dev_uninit,
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| module_init(nlmon_register);
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| module_exit(nlmon_unregister);
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| 
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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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