1e4fc408eSDaniel Borkmann #include <linux/module.h> 2e4fc408eSDaniel Borkmann #include <linux/kernel.h> 3e4fc408eSDaniel Borkmann #include <linux/netdevice.h> 4e4fc408eSDaniel Borkmann #include <linux/netlink.h> 5e4fc408eSDaniel Borkmann #include <net/net_namespace.h> 6e4fc408eSDaniel Borkmann #include <linux/if_arp.h> 77e6d4da8SJiri Pirko #include <net/rtnetlink.h> 8e4fc408eSDaniel Borkmann 9e4fc408eSDaniel Borkmann struct pcpu_lstats { 10e4fc408eSDaniel Borkmann u64 packets; 11e4fc408eSDaniel Borkmann u64 bytes; 12e4fc408eSDaniel Borkmann struct u64_stats_sync syncp; 13e4fc408eSDaniel Borkmann }; 14e4fc408eSDaniel Borkmann 15e4fc408eSDaniel Borkmann static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev) 16e4fc408eSDaniel Borkmann { 17e4fc408eSDaniel Borkmann int len = skb->len; 18e4fc408eSDaniel Borkmann struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats); 19e4fc408eSDaniel Borkmann 20e4fc408eSDaniel Borkmann u64_stats_update_begin(&stats->syncp); 21e4fc408eSDaniel Borkmann stats->bytes += len; 22e4fc408eSDaniel Borkmann stats->packets++; 23e4fc408eSDaniel Borkmann u64_stats_update_end(&stats->syncp); 24e4fc408eSDaniel Borkmann 25e4fc408eSDaniel Borkmann dev_kfree_skb(skb); 26e4fc408eSDaniel Borkmann 27e4fc408eSDaniel Borkmann return NETDEV_TX_OK; 28e4fc408eSDaniel Borkmann } 29e4fc408eSDaniel Borkmann 30e4fc408eSDaniel Borkmann static int nlmon_is_valid_mtu(int new_mtu) 31e4fc408eSDaniel Borkmann { 323b233fe0SDaniel Borkmann /* Note that in netlink we do not really have an upper limit. On 333b233fe0SDaniel Borkmann * default, we use NLMSG_GOODSIZE. Here at least we should make 343b233fe0SDaniel Borkmann * sure that it's at least the header size. 353b233fe0SDaniel Borkmann */ 363b233fe0SDaniel Borkmann return new_mtu >= (int) sizeof(struct nlmsghdr); 37e4fc408eSDaniel Borkmann } 38e4fc408eSDaniel Borkmann 39e4fc408eSDaniel Borkmann static int nlmon_change_mtu(struct net_device *dev, int new_mtu) 40e4fc408eSDaniel Borkmann { 41e4fc408eSDaniel Borkmann if (!nlmon_is_valid_mtu(new_mtu)) 42e4fc408eSDaniel Borkmann return -EINVAL; 43e4fc408eSDaniel Borkmann 44e4fc408eSDaniel Borkmann dev->mtu = new_mtu; 45e4fc408eSDaniel Borkmann return 0; 46e4fc408eSDaniel Borkmann } 47e4fc408eSDaniel Borkmann 48e4fc408eSDaniel Borkmann static int nlmon_dev_init(struct net_device *dev) 49e4fc408eSDaniel Borkmann { 50e4fc408eSDaniel Borkmann dev->lstats = alloc_percpu(struct pcpu_lstats); 51e4fc408eSDaniel Borkmann 52e4fc408eSDaniel Borkmann return dev->lstats == NULL ? -ENOMEM : 0; 53e4fc408eSDaniel Borkmann } 54e4fc408eSDaniel Borkmann 55e4fc408eSDaniel Borkmann static void nlmon_dev_uninit(struct net_device *dev) 56e4fc408eSDaniel Borkmann { 57e4fc408eSDaniel Borkmann free_percpu(dev->lstats); 58e4fc408eSDaniel Borkmann } 59e4fc408eSDaniel Borkmann 607e6d4da8SJiri Pirko struct nlmon { 617e6d4da8SJiri Pirko struct netlink_tap nt; 627e6d4da8SJiri Pirko }; 63e4fc408eSDaniel Borkmann 64e4fc408eSDaniel Borkmann static int nlmon_open(struct net_device *dev) 65e4fc408eSDaniel Borkmann { 667e6d4da8SJiri Pirko struct nlmon *nlmon = netdev_priv(dev); 677e6d4da8SJiri Pirko 687e6d4da8SJiri Pirko nlmon->nt.dev = dev; 697e6d4da8SJiri Pirko nlmon->nt.module = THIS_MODULE; 707e6d4da8SJiri Pirko return netlink_add_tap(&nlmon->nt); 71e4fc408eSDaniel Borkmann } 72e4fc408eSDaniel Borkmann 73e4fc408eSDaniel Borkmann static int nlmon_close(struct net_device *dev) 74e4fc408eSDaniel Borkmann { 757e6d4da8SJiri Pirko struct nlmon *nlmon = netdev_priv(dev); 767e6d4da8SJiri Pirko 777e6d4da8SJiri Pirko return netlink_remove_tap(&nlmon->nt); 78e4fc408eSDaniel Borkmann } 79e4fc408eSDaniel Borkmann 80e4fc408eSDaniel Borkmann static struct rtnl_link_stats64 * 81e4fc408eSDaniel Borkmann nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) 82e4fc408eSDaniel Borkmann { 83e4fc408eSDaniel Borkmann int i; 84e4fc408eSDaniel Borkmann u64 bytes = 0, packets = 0; 85e4fc408eSDaniel Borkmann 86e4fc408eSDaniel Borkmann for_each_possible_cpu(i) { 87e4fc408eSDaniel Borkmann const struct pcpu_lstats *nl_stats; 88e4fc408eSDaniel Borkmann u64 tbytes, tpackets; 89e4fc408eSDaniel Borkmann unsigned int start; 90e4fc408eSDaniel Borkmann 91e4fc408eSDaniel Borkmann nl_stats = per_cpu_ptr(dev->lstats, i); 92e4fc408eSDaniel Borkmann 93e4fc408eSDaniel Borkmann do { 94e4fc408eSDaniel Borkmann start = u64_stats_fetch_begin_bh(&nl_stats->syncp); 95e4fc408eSDaniel Borkmann tbytes = nl_stats->bytes; 96e4fc408eSDaniel Borkmann tpackets = nl_stats->packets; 97e4fc408eSDaniel Borkmann } while (u64_stats_fetch_retry_bh(&nl_stats->syncp, start)); 98e4fc408eSDaniel Borkmann 99e4fc408eSDaniel Borkmann packets += tpackets; 100e4fc408eSDaniel Borkmann bytes += tbytes; 101e4fc408eSDaniel Borkmann } 102e4fc408eSDaniel Borkmann 103e4fc408eSDaniel Borkmann stats->rx_packets = packets; 104e4fc408eSDaniel Borkmann stats->tx_packets = 0; 105e4fc408eSDaniel Borkmann 106e4fc408eSDaniel Borkmann stats->rx_bytes = bytes; 107e4fc408eSDaniel Borkmann stats->tx_bytes = 0; 108e4fc408eSDaniel Borkmann 109e4fc408eSDaniel Borkmann return stats; 110e4fc408eSDaniel Borkmann } 111e4fc408eSDaniel Borkmann 112e4fc408eSDaniel Borkmann static u32 always_on(struct net_device *dev) 113e4fc408eSDaniel Borkmann { 114e4fc408eSDaniel Borkmann return 1; 115e4fc408eSDaniel Borkmann } 116e4fc408eSDaniel Borkmann 117e4fc408eSDaniel Borkmann static const struct ethtool_ops nlmon_ethtool_ops = { 118e4fc408eSDaniel Borkmann .get_link = always_on, 119e4fc408eSDaniel Borkmann }; 120e4fc408eSDaniel Borkmann 121e4fc408eSDaniel Borkmann static const struct net_device_ops nlmon_ops = { 122e4fc408eSDaniel Borkmann .ndo_init = nlmon_dev_init, 123e4fc408eSDaniel Borkmann .ndo_uninit = nlmon_dev_uninit, 124e4fc408eSDaniel Borkmann .ndo_open = nlmon_open, 125e4fc408eSDaniel Borkmann .ndo_stop = nlmon_close, 126e4fc408eSDaniel Borkmann .ndo_start_xmit = nlmon_xmit, 127e4fc408eSDaniel Borkmann .ndo_get_stats64 = nlmon_get_stats64, 128e4fc408eSDaniel Borkmann .ndo_change_mtu = nlmon_change_mtu, 129e4fc408eSDaniel Borkmann }; 130e4fc408eSDaniel Borkmann 131e4fc408eSDaniel Borkmann static void nlmon_setup(struct net_device *dev) 132e4fc408eSDaniel Borkmann { 133e4fc408eSDaniel Borkmann dev->type = ARPHRD_NETLINK; 134e4fc408eSDaniel Borkmann dev->tx_queue_len = 0; 135e4fc408eSDaniel Borkmann 136e4fc408eSDaniel Borkmann dev->netdev_ops = &nlmon_ops; 137e4fc408eSDaniel Borkmann dev->ethtool_ops = &nlmon_ethtool_ops; 138e4fc408eSDaniel Borkmann dev->destructor = free_netdev; 139e4fc408eSDaniel Borkmann 140e4fc408eSDaniel Borkmann dev->features = NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 141e4fc408eSDaniel Borkmann dev->flags = IFF_NOARP; 142e4fc408eSDaniel Borkmann 143e4fc408eSDaniel Borkmann /* That's rather a softlimit here, which, of course, 144e4fc408eSDaniel Borkmann * can be altered. Not a real MTU, but what is to be 145e4fc408eSDaniel Borkmann * expected in most cases. 146e4fc408eSDaniel Borkmann */ 147e4fc408eSDaniel Borkmann dev->mtu = NLMSG_GOODSIZE; 148e4fc408eSDaniel Borkmann } 149e4fc408eSDaniel Borkmann 1507e6d4da8SJiri Pirko static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[]) 1517e6d4da8SJiri Pirko { 1527e6d4da8SJiri Pirko if (tb[IFLA_ADDRESS]) 1537e6d4da8SJiri Pirko return -EINVAL; 1547e6d4da8SJiri Pirko return 0; 1557e6d4da8SJiri Pirko } 1567e6d4da8SJiri Pirko 1577e6d4da8SJiri Pirko static struct rtnl_link_ops nlmon_link_ops __read_mostly = { 1587e6d4da8SJiri Pirko .kind = "nlmon", 1597e6d4da8SJiri Pirko .priv_size = sizeof(struct nlmon), 1607e6d4da8SJiri Pirko .setup = nlmon_setup, 1617e6d4da8SJiri Pirko .validate = nlmon_validate, 1627e6d4da8SJiri Pirko }; 1637e6d4da8SJiri Pirko 164e4fc408eSDaniel Borkmann static __init int nlmon_register(void) 165e4fc408eSDaniel Borkmann { 1667e6d4da8SJiri Pirko return rtnl_link_register(&nlmon_link_ops); 167e4fc408eSDaniel Borkmann } 168e4fc408eSDaniel Borkmann 169e4fc408eSDaniel Borkmann static __exit void nlmon_unregister(void) 170e4fc408eSDaniel Borkmann { 1717e6d4da8SJiri Pirko rtnl_link_unregister(&nlmon_link_ops); 172e4fc408eSDaniel Borkmann } 173e4fc408eSDaniel Borkmann 174e4fc408eSDaniel Borkmann module_init(nlmon_register); 175e4fc408eSDaniel Borkmann module_exit(nlmon_unregister); 176e4fc408eSDaniel Borkmann 177e4fc408eSDaniel Borkmann MODULE_LICENSE("GPL v2"); 178e4fc408eSDaniel Borkmann MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>"); 179e4fc408eSDaniel Borkmann MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>"); 180e4fc408eSDaniel Borkmann MODULE_DESCRIPTION("Netlink monitoring device"); 1817e6d4da8SJiri Pirko MODULE_ALIAS_RTNL_LINK("nlmon"); 182