Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / net / nlmon.c

diff --git a/kernel/drivers/net/nlmon.c b/kernel/drivers/net/nlmon.c
new file mode 100644 (file)
index 0000000..34924df
--- /dev/null
+++ b/kernel/drivers/net/nlmon.c
@@ -0,0 +1,181 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <net/net_namespace.h>
+#include <linux/if_arp.h>
+#include <net/rtnetlink.h>
+
+struct pcpu_lstats {
+       u64 packets;
+       u64 bytes;
+       struct u64_stats_sync syncp;
+};
+
+static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       int len = skb->len;
+       struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
+
+       u64_stats_update_begin(&stats->syncp);
+       stats->bytes += len;
+       stats->packets++;
+       u64_stats_update_end(&stats->syncp);
+
+       dev_kfree_skb(skb);
+
+       return NETDEV_TX_OK;
+}
+
+static int nlmon_is_valid_mtu(int new_mtu)
+{
+       /* Note that in netlink we do not really have an upper limit. On
+        * default, we use NLMSG_GOODSIZE. Here at least we should make
+        * sure that it's at least the header size.
+        */
+       return new_mtu >= (int) sizeof(struct nlmsghdr);
+}
+
+static int nlmon_change_mtu(struct net_device *dev, int new_mtu)
+{
+       if (!nlmon_is_valid_mtu(new_mtu))
+               return -EINVAL;
+
+       dev->mtu = new_mtu;
+       return 0;
+}
+
+static int nlmon_dev_init(struct net_device *dev)
+{
+       dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
+       return dev->lstats == NULL ? -ENOMEM : 0;
+}
+
+static void nlmon_dev_uninit(struct net_device *dev)
+{
+       free_percpu(dev->lstats);
+}
+
+struct nlmon {
+       struct netlink_tap nt;
+};
+
+static int nlmon_open(struct net_device *dev)
+{
+       struct nlmon *nlmon = netdev_priv(dev);
+
+       nlmon->nt.dev = dev;
+       nlmon->nt.module = THIS_MODULE;
+       return netlink_add_tap(&nlmon->nt);
+}
+
+static int nlmon_close(struct net_device *dev)
+{
+       struct nlmon *nlmon = netdev_priv(dev);
+
+       return netlink_remove_tap(&nlmon->nt);
+}
+
+static struct rtnl_link_stats64 *
+nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
+{
+       int i;
+       u64 bytes = 0, packets = 0;
+
+       for_each_possible_cpu(i) {
+               const struct pcpu_lstats *nl_stats;
+               u64 tbytes, tpackets;
+               unsigned int start;
+
+               nl_stats = per_cpu_ptr(dev->lstats, i);
+
+               do {
+                       start = u64_stats_fetch_begin_irq(&nl_stats->syncp);
+                       tbytes = nl_stats->bytes;
+                       tpackets = nl_stats->packets;
+               } while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start));
+
+               packets += tpackets;
+               bytes += tbytes;
+       }
+
+       stats->rx_packets = packets;
+       stats->tx_packets = 0;
+
+       stats->rx_bytes = bytes;
+       stats->tx_bytes = 0;
+
+       return stats;
+}
+
+static u32 always_on(struct net_device *dev)
+{
+       return 1;
+}
+
+static const struct ethtool_ops nlmon_ethtool_ops = {
+       .get_link = always_on,
+};
+
+static const struct net_device_ops nlmon_ops = {
+       .ndo_init = nlmon_dev_init,
+       .ndo_uninit = nlmon_dev_uninit,
+       .ndo_open = nlmon_open,
+       .ndo_stop = nlmon_close,
+       .ndo_start_xmit = nlmon_xmit,
+       .ndo_get_stats64 = nlmon_get_stats64,
+       .ndo_change_mtu = nlmon_change_mtu,
+};
+
+static void nlmon_setup(struct net_device *dev)
+{
+       dev->type = ARPHRD_NETLINK;
+       dev->tx_queue_len = 0;
+
+       dev->netdev_ops = &nlmon_ops;
+       dev->ethtool_ops = &nlmon_ethtool_ops;
+       dev->destructor = free_netdev;
+
+       dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
+                       NETIF_F_HIGHDMA | NETIF_F_LLTX;
+       dev->flags = IFF_NOARP;
+
+       /* That's rather a softlimit here, which, of course,
+        * can be altered. Not a real MTU, but what is to be
+        * expected in most cases.
+        */
+       dev->mtu = NLMSG_GOODSIZE;
+}
+
+static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+       if (tb[IFLA_ADDRESS])
+               return -EINVAL;
+       return 0;
+}
+
+static struct rtnl_link_ops nlmon_link_ops __read_mostly = {
+       .kind                   = "nlmon",
+       .priv_size              = sizeof(struct nlmon),
+       .setup                  = nlmon_setup,
+       .validate               = nlmon_validate,
+};
+
+static __init int nlmon_register(void)
+{
+       return rtnl_link_register(&nlmon_link_ops);
+}
+
+static __exit void nlmon_unregister(void)
+{
+       rtnl_link_unregister(&nlmon_link_ops);
+}
+
+module_init(nlmon_register);
+module_exit(nlmon_unregister);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
+MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>");
+MODULE_DESCRIPTION("Netlink monitoring device");
+MODULE_ALIAS_RTNL_LINK("nlmon");