net/batman-adv/soft-interface.c

   1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "soft-interface.h"
  22 #include "hard-interface.h"
  23 #include "distributed-arp-table.h"
  24 #include "routing.h"
  25 #include "send.h"
  26 #include "debugfs.h"
  27 #include "translation-table.h"
  28 #include "hash.h"
  29 #include "gateway_common.h"
  30 #include "gateway_client.h"
  31 #include "sysfs.h"
  32 #include "originator.h"
  33 #include <linux/slab.h>
  34 #include <linux/ethtool.h>
  35 #include <linux/etherdevice.h>
  36 #include <linux/if_vlan.h>
  37 #include "unicast.h"
  38 #include "bridge_loop_avoidance.h"
  39
  40
  41 static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd);
  42 static void batadv_get_drvinfo(struct net_device *dev,
  43                                struct ethtool_drvinfo *info);
  44 static u32 batadv_get_msglevel(struct net_device *dev);
  45 static void batadv_set_msglevel(struct net_device *dev, u32 value);
  46 static u32 batadv_get_link(struct net_device *dev);
  47 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data);
  48 static void batadv_get_ethtool_stats(struct net_device *dev,
  49                                      struct ethtool_stats *stats, u64 *data);
  50 static int batadv_get_sset_count(struct net_device *dev, int stringset);
  51
  52 static const struct ethtool_ops batadv_ethtool_ops = {
  53         .get_settings = batadv_get_settings,
  54         .get_drvinfo = batadv_get_drvinfo,
  55         .get_msglevel = batadv_get_msglevel,
  56         .set_msglevel = batadv_set_msglevel,
  57         .get_link = batadv_get_link,
  58         .get_strings = batadv_get_strings,
  59         .get_ethtool_stats = batadv_get_ethtool_stats,
  60         .get_sset_count = batadv_get_sset_count,
  61 };
  62
  63 int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
  64 {
  65         int result;
  66
  67         /* TODO: We must check if we can release all references to non-payload
  68          * data using skb_header_release in our skbs to allow skb_cow_header to
  69          * work optimally. This means that those skbs are not allowed to read
  70          * or write any data which is before the current position of skb->data
  71          * after that call and thus allow other skbs with the same data buffer
  72          * to write freely in that area.
  73          */
  74         result = skb_cow_head(skb, len);
  75         if (result < 0)
  76                 return result;
  77
  78         skb_push(skb, len);
  79         return 0;
  80 }
  81
  82 static int batadv_interface_open(struct net_device *dev)
  83 {
  84         netif_start_queue(dev);
  85         return 0;
  86 }
  87
  88 static int batadv_interface_release(struct net_device *dev)
  89 {
  90         netif_stop_queue(dev);
  91         return 0;
  92 }
  93
  94 static struct net_device_stats *batadv_interface_stats(struct net_device *dev)
  95 {
  96         struct batadv_priv *bat_priv = netdev_priv(dev);
  97         struct net_device_stats *stats = &bat_priv->stats;
  98
  99         stats->tx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_TX);
 100         stats->tx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_TX_BYTES);
 101         stats->tx_dropped = batadv_sum_counter(bat_priv, BATADV_CNT_TX_DROPPED);
 102         stats->rx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_RX);
 103         stats->rx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_RX_BYTES);
 104         return stats;
 105 }
 106
 107 static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
 108 {
 109         struct batadv_priv *bat_priv = netdev_priv(dev);
 110         struct sockaddr *addr = p;
 111         uint8_t old_addr[ETH_ALEN];
 112
 113         if (!is_valid_ether_addr(addr->sa_data))
 114                 return -EADDRNOTAVAIL;
 115
 116         memcpy(old_addr, dev->dev_addr, ETH_ALEN);
 117         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 118
 119         /* only modify transtable if it has been initialized before */
 120         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE) {
 121                 batadv_tt_local_remove(bat_priv, old_addr,
 122                                        "mac address changed", false);
 123                 batadv_tt_local_add(dev, addr->sa_data, BATADV_NULL_IFINDEX);
 124         }
 125
 126         dev->addr_assign_type &= ~NET_ADDR_RANDOM;
 127         return 0;
 128 }
 129
 130 static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
 131 {
 132         /* check ranges */
 133         if ((new_mtu < 68) || (new_mtu > batadv_hardif_min_mtu(dev)))
 134                 return -EINVAL;
 135
 136         dev->mtu = new_mtu;
 137
 138         return 0;
 139 }
 140
 141 static int batadv_interface_tx(struct sk_buff *skb,
 142                                struct net_device *soft_iface)
 143 {
 144         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 145         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 146         struct batadv_hard_iface *primary_if = NULL;
 147         struct batadv_bcast_packet *bcast_packet;
 148         struct vlan_ethhdr *vhdr;
 149         __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
 150         static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
 151                                                    0x00, 0x00};
 152         static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
 153                                                     0x00, 0x00};
 154         unsigned int header_len = 0;
 155         int data_len = skb->len, ret;
 156         short vid __maybe_unused = -1;
 157         bool do_bcast = false;
 158         uint32_t seqno;
 159         unsigned long brd_delay = 1;
 160
 161         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 162                 goto dropped;
 163
 164         soft_iface->trans_start = jiffies;
 165
 166         switch (ntohs(ethhdr->h_proto)) {
 167         case ETH_P_8021Q:
 168                 vhdr = (struct vlan_ethhdr *)skb->data;
 169                 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
 170
 171                 if (vhdr->h_vlan_encapsulated_proto != ethertype)
 172                         break;
 173
 174                 /* fall through */
 175         case BATADV_ETH_P_BATMAN:
 176                 goto dropped;
 177         }
 178
 179         if (batadv_bla_tx(bat_priv, skb, vid))
 180                 goto dropped;
 181
 182         /* Register the client MAC in the transtable */
 183         batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);
 184
 185         /* don't accept stp packets. STP does not help in meshes.
 186          * better use the bridge loop avoidance ...
 187          *
 188          * The same goes for ECTP sent at least by some Cisco Switches,
 189          * it might confuse the mesh when used with bridge loop avoidance.
 190          */
 191         if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
 192                 goto dropped;
 193
 194         if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
 195                 goto dropped;
 196
 197         if (is_multicast_ether_addr(ethhdr->h_dest)) {
 198                 do_bcast = true;
 199
 200                 switch (atomic_read(&bat_priv->gw_mode)) {
 201                 case BATADV_GW_MODE_SERVER:
 202                         /* gateway servers should not send dhcp
 203                          * requests into the mesh
 204                          */
 205                         ret = batadv_gw_is_dhcp_target(skb, &header_len);
 206                         if (ret)
 207                                 goto dropped;
 208                         break;
 209                 case BATADV_GW_MODE_CLIENT:
 210                         /* gateway clients should send dhcp requests
 211                          * via unicast to their gateway
 212                          */
 213                         ret = batadv_gw_is_dhcp_target(skb, &header_len);
 214                         if (ret)
 215                                 do_bcast = false;
 216                         break;
 217                 case BATADV_GW_MODE_OFF:
 218                 default:
 219                         break;
 220                 }
 221         }
 222
 223         /* ethernet packet should be broadcasted */
 224         if (do_bcast) {
 225                 primary_if = batadv_primary_if_get_selected(bat_priv);
 226                 if (!primary_if)
 227                         goto dropped;
 228
 229                 /* in case of ARP request, we do not immediately broadcasti the
 230                  * packet, instead we first wait for DAT to try to retrieve the
 231                  * correct ARP entry
 232                  */
 233                 if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
 234                         brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
 235
 236                 if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
 237                         goto dropped;
 238
 239                 bcast_packet = (struct batadv_bcast_packet *)skb->data;
 240                 bcast_packet->header.version = BATADV_COMPAT_VERSION;
 241                 bcast_packet->header.ttl = BATADV_TTL;
 242
 243                 /* batman packet type: broadcast */
 244                 bcast_packet->header.packet_type = BATADV_BCAST;
 245                 bcast_packet->reserved = 0;
 246
 247                 /* hw address of first interface is the orig mac because only
 248                  * this mac is known throughout the mesh
 249                  */
 250                 memcpy(bcast_packet->orig,
 251                        primary_if->net_dev->dev_addr, ETH_ALEN);
 252
 253                 /* set broadcast sequence number */
 254                 seqno = atomic_inc_return(&bat_priv->bcast_seqno);
 255                 bcast_packet->seqno = htonl(seqno);
 256
 257                 batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay);
 258
 259                 /* a copy is stored in the bcast list, therefore removing
 260                  * the original skb.
 261                  */
 262                 kfree_skb(skb);
 263
 264         /* unicast packet */
 265         } else {
 266                 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) {
 267                         ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr);
 268                         if (ret)
 269                                 goto dropped;
 270                 }
 271
 272                 if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
 273                         goto dropped;
 274
 275                 batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
 276
 277                 ret = batadv_unicast_send_skb(bat_priv, skb);
 278                 if (ret != 0)
 279                         goto dropped_freed;
 280         }
 281
 282         batadv_inc_counter(bat_priv, BATADV_CNT_TX);
 283         batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
 284         goto end;
 285
 286 dropped:
 287         kfree_skb(skb);
 288 dropped_freed:
 289         batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
 290 end:
 291         if (primary_if)
 292                 batadv_hardif_free_ref(primary_if);
 293         return NETDEV_TX_OK;
 294 }
 295
 296 void batadv_interface_rx(struct net_device *soft_iface,
 297                          struct sk_buff *skb, struct batadv_hard_iface *recv_if,
 298                          int hdr_size, struct batadv_orig_node *orig_node)
 299 {
 300         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 301         struct ethhdr *ethhdr;
 302         struct vlan_ethhdr *vhdr;
 303         struct batadv_header *batadv_header = (struct batadv_header *)skb->data;
 304         short vid __maybe_unused = -1;
 305         __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
 306         bool is_bcast;
 307
 308         is_bcast = (batadv_header->packet_type == BATADV_BCAST);
 309
 310         /* check if enough space is available for pulling, and pull */
 311         if (!pskb_may_pull(skb, hdr_size))
 312                 goto dropped;
 313
 314         skb_pull_rcsum(skb, hdr_size);
 315         skb_reset_mac_header(skb);
 316
 317         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 318
 319         switch (ntohs(ethhdr->h_proto)) {
 320         case ETH_P_8021Q:
 321                 vhdr = (struct vlan_ethhdr *)skb->data;
 322                 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
 323
 324                 if (vhdr->h_vlan_encapsulated_proto != ethertype)
 325                         break;
 326
 327                 /* fall through */
 328         case BATADV_ETH_P_BATMAN:
 329                 goto dropped;
 330         }
 331
 332         /* skb->dev & skb->pkt_type are set here */
 333         if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 334                 goto dropped;
 335         skb->protocol = eth_type_trans(skb, soft_iface);
 336
 337         /* should not be necessary anymore as we use skb_pull_rcsum()
 338          * TODO: please verify this and remove this TODO
 339          * -- Dec 21st 2009, Simon Wunderlich
 340          */
 341
 342         /* skb->ip_summed = CHECKSUM_UNNECESSARY; */
 343
 344         batadv_inc_counter(bat_priv, BATADV_CNT_RX);
 345         batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
 346                            skb->len + ETH_HLEN);
 347
 348         soft_iface->last_rx = jiffies;
 349
 350         if (orig_node)
 351                 batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
 352                                                      ethhdr->h_source);
 353
 354         if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source, ethhdr->h_dest))
 355                 goto dropped;
 356
 357         /* Let the bridge loop avoidance check the packet. If will
 358          * not handle it, we can safely push it up.
 359          */
 360         if (batadv_bla_rx(bat_priv, skb, vid, is_bcast))
 361                 goto out;
 362
 363         netif_rx(skb);
 364         goto out;
 365
 366 dropped:
 367         kfree_skb(skb);
 368 out:
 369         return;
 370 }
 371
 372 /* batman-adv network devices have devices nesting below it and are a special
 373  * "super class" of normal network devices; split their locks off into a
 374  * separate class since they always nest.
 375  */
 376 static struct lock_class_key batadv_netdev_xmit_lock_key;
 377 static struct lock_class_key batadv_netdev_addr_lock_key;
 378
 379 /**
 380  * batadv_set_lockdep_class_one - Set lockdep class for a single tx queue
 381  * @dev: device which owns the tx queue
 382  * @txq: tx queue to modify
 383  * @_unused: always NULL
 384  */
 385 static void batadv_set_lockdep_class_one(struct net_device *dev,
 386                                          struct netdev_queue *txq,
 387                                          void *_unused)
 388 {
 389         lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
 390 }
 391
 392 /**
 393  * batadv_set_lockdep_class - Set txq and addr_list lockdep class
 394  * @dev: network device to modify
 395  */
 396 static void batadv_set_lockdep_class(struct net_device *dev)
 397 {
 398         lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
 399         netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
 400 }
 401
 402 /**
 403  * batadv_softif_init - Late stage initialization of soft interface
 404  * @dev: registered network device to modify
 405  *
 406  * Returns error code on failures
 407  */
 408 static int batadv_softif_init(struct net_device *dev)
 409 {
 410         batadv_set_lockdep_class(dev);
 411
 412         return 0;
 413 }
 414
 415 static const struct net_device_ops batadv_netdev_ops = {
 416         .ndo_init = batadv_softif_init,
 417         .ndo_open = batadv_interface_open,
 418         .ndo_stop = batadv_interface_release,
 419         .ndo_get_stats = batadv_interface_stats,
 420         .ndo_set_mac_address = batadv_interface_set_mac_addr,
 421         .ndo_change_mtu = batadv_interface_change_mtu,
 422         .ndo_start_xmit = batadv_interface_tx,
 423         .ndo_validate_addr = eth_validate_addr
 424 };
 425
 426 static void batadv_interface_setup(struct net_device *dev)
 427 {
 428         struct batadv_priv *priv = netdev_priv(dev);
 429
 430         ether_setup(dev);
 431
 432         dev->netdev_ops = &batadv_netdev_ops;
 433         dev->destructor = free_netdev;
 434         dev->tx_queue_len = 0;
 435
 436         /* can't call min_mtu, because the needed variables
 437          * have not been initialized yet
 438          */
 439         dev->mtu = ETH_DATA_LEN;
 440         /* reserve more space in the skbuff for our header */
 441         dev->hard_header_len = BATADV_HEADER_LEN;
 442
 443         /* generate random address */
 444         eth_hw_addr_random(dev);
 445
 446         SET_ETHTOOL_OPS(dev, &batadv_ethtool_ops);
 447
 448         memset(priv, 0, sizeof(*priv));
 449 }
 450
 451 struct net_device *batadv_softif_create(const char *name)
 452 {
 453         struct net_device *soft_iface;
 454         struct batadv_priv *bat_priv;
 455         int ret;
 456         size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM;
 457
 458         soft_iface = alloc_netdev(sizeof(*bat_priv), name,
 459                                   batadv_interface_setup);
 460
 461         if (!soft_iface)
 462                 goto out;
 463
 464         bat_priv = netdev_priv(soft_iface);
 465
 466         /* batadv_interface_stats() needs to be available as soon as
 467          * register_netdevice() has been called
 468          */
 469         bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(uint64_t));
 470         if (!bat_priv->bat_counters)
 471                 goto free_soft_iface;
 472
 473         ret = register_netdevice(soft_iface);
 474         if (ret < 0) {
 475                 pr_err("Unable to register the batman interface '%s': %i\n",
 476                        name, ret);
 477                 goto free_bat_counters;
 478         }
 479
 480         atomic_set(&bat_priv->aggregated_ogms, 1);
 481         atomic_set(&bat_priv->bonding, 0);
 482         atomic_set(&bat_priv->bridge_loop_avoidance, 0);
 483 #ifdef CONFIG_BATMAN_ADV_DAT
 484         atomic_set(&bat_priv->distributed_arp_table, 1);
 485 #endif
 486         atomic_set(&bat_priv->ap_isolation, 0);
 487         atomic_set(&bat_priv->vis_mode, BATADV_VIS_TYPE_CLIENT_UPDATE);
 488         atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
 489         atomic_set(&bat_priv->gw_sel_class, 20);
 490         atomic_set(&bat_priv->gw_bandwidth, 41);
 491         atomic_set(&bat_priv->orig_interval, 1000);
 492         atomic_set(&bat_priv->hop_penalty, 30);
 493         atomic_set(&bat_priv->log_level, 0);
 494         atomic_set(&bat_priv->fragmentation, 1);
 495         atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
 496         atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
 497
 498         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 499         atomic_set(&bat_priv->bcast_seqno, 1);
 500         atomic_set(&bat_priv->tt.vn, 0);
 501         atomic_set(&bat_priv->tt.local_changes, 0);
 502         atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
 503 #ifdef CONFIG_BATMAN_ADV_BLA
 504         atomic_set(&bat_priv->bla.num_requests, 0);
 505 #endif
 506         bat_priv->tt.last_changeset = NULL;
 507         bat_priv->tt.last_changeset_len = 0;
 508         bat_priv->tt.poss_change = false;
 509
 510         bat_priv->primary_if = NULL;
 511         bat_priv->num_ifaces = 0;
 512
 513         ret = batadv_algo_select(bat_priv, batadv_routing_algo);
 514         if (ret < 0)
 515                 goto unreg_soft_iface;
 516
 517         ret = batadv_sysfs_add_meshif(soft_iface);
 518         if (ret < 0)
 519                 goto unreg_soft_iface;
 520
 521         ret = batadv_debugfs_add_meshif(soft_iface);
 522         if (ret < 0)
 523                 goto unreg_sysfs;
 524
 525         ret = batadv_mesh_init(soft_iface);
 526         if (ret < 0)
 527                 goto unreg_debugfs;
 528
 529         return soft_iface;
 530
 531 unreg_debugfs:
 532         batadv_debugfs_del_meshif(soft_iface);
 533 unreg_sysfs:
 534         batadv_sysfs_del_meshif(soft_iface);
 535 unreg_soft_iface:
 536         free_percpu(bat_priv->bat_counters);
 537         unregister_netdevice(soft_iface);
 538         return NULL;
 539
 540 free_bat_counters:
 541         free_percpu(bat_priv->bat_counters);
 542 free_soft_iface:
 543         free_netdev(soft_iface);
 544 out:
 545         return NULL;
 546 }
 547
 548 void batadv_softif_destroy(struct net_device *soft_iface)
 549 {
 550         batadv_debugfs_del_meshif(soft_iface);
 551         batadv_sysfs_del_meshif(soft_iface);
 552         batadv_mesh_free(soft_iface);
 553         unregister_netdevice(soft_iface);
 554 }
 555
 556 int batadv_softif_is_valid(const struct net_device *net_dev)
 557 {
 558         if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
 559                 return 1;
 560
 561         return 0;
 562 }
 563
 564 /* ethtool */
 565 static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 566 {
 567         cmd->supported = 0;
 568         cmd->advertising = 0;
 569         ethtool_cmd_speed_set(cmd, SPEED_10);
 570         cmd->duplex = DUPLEX_FULL;
 571         cmd->port = PORT_TP;
 572         cmd->phy_address = 0;
 573         cmd->transceiver = XCVR_INTERNAL;
 574         cmd->autoneg = AUTONEG_DISABLE;
 575         cmd->maxtxpkt = 0;
 576         cmd->maxrxpkt = 0;
 577
 578         return 0;
 579 }
 580
 581 static void batadv_get_drvinfo(struct net_device *dev,
 582                                struct ethtool_drvinfo *info)
 583 {
 584         strcpy(info->driver, "B.A.T.M.A.N. advanced");
 585         strcpy(info->version, BATADV_SOURCE_VERSION);
 586         strcpy(info->fw_version, "N/A");
 587         strcpy(info->bus_info, "batman");
 588 }
 589
 590 static u32 batadv_get_msglevel(struct net_device *dev)
 591 {
 592         return -EOPNOTSUPP;
 593 }
 594
 595 static void batadv_set_msglevel(struct net_device *dev, u32 value)
 596 {
 597 }
 598
 599 static u32 batadv_get_link(struct net_device *dev)
 600 {
 601         return 1;
 602 }
 603
 604 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
 605  * Declare each description string in struct.name[] to get fixed sized buffer
 606  * and compile time checking for strings longer than ETH_GSTRING_LEN.
 607  */
 608 static const struct {
 609         const char name[ETH_GSTRING_LEN];
 610 } batadv_counters_strings[] = {
 611         { "tx" },
 612         { "tx_bytes" },
 613         { "tx_dropped" },
 614         { "rx" },
 615         { "rx_bytes" },
 616         { "forward" },
 617         { "forward_bytes" },
 618         { "mgmt_tx" },
 619         { "mgmt_tx_bytes" },
 620         { "mgmt_rx" },
 621         { "mgmt_rx_bytes" },
 622         { "tt_request_tx" },
 623         { "tt_request_rx" },
 624         { "tt_response_tx" },
 625         { "tt_response_rx" },
 626         { "tt_roam_adv_tx" },
 627         { "tt_roam_adv_rx" },
 628 };
 629
 630 static void batadv_get_strings(struct net_device *dev, uint32_t stringset,
 631                                uint8_t *data)
 632 {
 633         if (stringset == ETH_SS_STATS)
 634                 memcpy(data, batadv_counters_strings,
 635                        sizeof(batadv_counters_strings));
 636 }
 637
 638 static void batadv_get_ethtool_stats(struct net_device *dev,
 639                                      struct ethtool_stats *stats,
 640                                      uint64_t *data)
 641 {
 642         struct batadv_priv *bat_priv = netdev_priv(dev);
 643         int i;
 644
 645         for (i = 0; i < BATADV_CNT_NUM; i++)
 646                 data[i] = batadv_sum_counter(bat_priv, i);
 647 }
 648
 649 static int batadv_get_sset_count(struct net_device *dev, int stringset)
 650 {
 651         if (stringset == ETH_SS_STATS)
 652                 return BATADV_CNT_NUM;
 653
 654         return -EOPNOTSUPP;
 655 }