Pileus Git - ~andy/linux/blob - net/batman-adv/gateway_client.c

   1 /* Copyright (C) 2009-2014 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner
   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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "main.h"
  19 #include "sysfs.h"
  20 #include "gateway_client.h"
  21 #include "gateway_common.h"
  22 #include "hard-interface.h"
  23 #include "originator.h"
  24 #include "translation-table.h"
  25 #include "routing.h"
  26 #include <linux/ip.h>
  27 #include <linux/ipv6.h>
  28 #include <linux/udp.h>
  29 #include <linux/if_vlan.h>
  30
  31 /* These are the offsets of the "hw type" and "hw address length" in the dhcp
  32  * packet starting at the beginning of the dhcp header
  33  */
  34 #define BATADV_DHCP_HTYPE_OFFSET        1
  35 #define BATADV_DHCP_HLEN_OFFSET         2
  36 /* Value of htype representing Ethernet */
  37 #define BATADV_DHCP_HTYPE_ETHERNET      0x01
  38 /* This is the offset of the "chaddr" field in the dhcp packet starting at the
  39  * beginning of the dhcp header
  40  */
  41 #define BATADV_DHCP_CHADDR_OFFSET       28
  42
  43 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
  44 {
  45         if (atomic_dec_and_test(&gw_node->refcount))
  46                 kfree_rcu(gw_node, rcu);
  47 }
  48
  49 static struct batadv_gw_node *
  50 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
  51 {
  52         struct batadv_gw_node *gw_node;
  53
  54         rcu_read_lock();
  55         gw_node = rcu_dereference(bat_priv->gw.curr_gw);
  56         if (!gw_node)
  57                 goto out;
  58
  59         if (!atomic_inc_not_zero(&gw_node->refcount))
  60                 gw_node = NULL;
  61
  62 out:
  63         rcu_read_unlock();
  64         return gw_node;
  65 }
  66
  67 struct batadv_orig_node *
  68 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
  69 {
  70         struct batadv_gw_node *gw_node;
  71         struct batadv_orig_node *orig_node = NULL;
  72
  73         gw_node = batadv_gw_get_selected_gw_node(bat_priv);
  74         if (!gw_node)
  75                 goto out;
  76
  77         rcu_read_lock();
  78         orig_node = gw_node->orig_node;
  79         if (!orig_node)
  80                 goto unlock;
  81
  82         if (!atomic_inc_not_zero(&orig_node->refcount))
  83                 orig_node = NULL;
  84
  85 unlock:
  86         rcu_read_unlock();
  87 out:
  88         if (gw_node)
  89                 batadv_gw_node_free_ref(gw_node);
  90         return orig_node;
  91 }
  92
  93 static void batadv_gw_select(struct batadv_priv *bat_priv,
  94                              struct batadv_gw_node *new_gw_node)
  95 {
  96         struct batadv_gw_node *curr_gw_node;
  97
  98         spin_lock_bh(&bat_priv->gw.list_lock);
  99
 100         if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
 101                 new_gw_node = NULL;
 102
 103         curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
 104         rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
 105
 106         if (curr_gw_node)
 107                 batadv_gw_node_free_ref(curr_gw_node);
 108
 109         spin_unlock_bh(&bat_priv->gw.list_lock);
 110 }
 111
 112 /**
 113  * batadv_gw_reselect - force a gateway reselection
 114  * @bat_priv: the bat priv with all the soft interface information
 115  *
 116  * Set a flag to remind the GW component to perform a new gateway reselection.
 117  * However this function does not ensure that the current gateway is going to be
 118  * deselected. The reselection mechanism may elect the same gateway once again.
 119  *
 120  * This means that invoking batadv_gw_reselect() does not guarantee a gateway
 121  * change and therefore a uevent is not necessarily expected.
 122  */
 123 void batadv_gw_reselect(struct batadv_priv *bat_priv)
 124 {
 125         atomic_set(&bat_priv->gw.reselect, 1);
 126 }
 127
 128 static struct batadv_gw_node *
 129 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 130 {
 131         struct batadv_neigh_node *router;
 132         struct batadv_neigh_ifinfo *router_ifinfo;
 133         struct batadv_gw_node *gw_node, *curr_gw = NULL;
 134         uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
 135         uint32_t gw_divisor;
 136         uint8_t max_tq = 0;
 137         uint8_t tq_avg;
 138         struct batadv_orig_node *orig_node;
 139
 140         gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
 141         gw_divisor *= 64;
 142
 143         rcu_read_lock();
 144         hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
 145                 if (gw_node->deleted)
 146                         continue;
 147
 148                 orig_node = gw_node->orig_node;
 149                 router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
 150                 if (!router)
 151                         continue;
 152
 153                 router_ifinfo = batadv_neigh_ifinfo_get(router,
 154                                                         BATADV_IF_DEFAULT);
 155                 if (!router_ifinfo)
 156                         goto next;
 157
 158                 if (!atomic_inc_not_zero(&gw_node->refcount))
 159                         goto next;
 160
 161                 tq_avg = router_ifinfo->bat_iv.tq_avg;
 162
 163                 switch (atomic_read(&bat_priv->gw_sel_class)) {
 164                 case 1: /* fast connection */
 165                         tmp_gw_factor = tq_avg * tq_avg;
 166                         tmp_gw_factor *= gw_node->bandwidth_down;
 167                         tmp_gw_factor *= 100 * 100;
 168                         tmp_gw_factor /= gw_divisor;
 169
 170                         if ((tmp_gw_factor > max_gw_factor) ||
 171                             ((tmp_gw_factor == max_gw_factor) &&
 172                              (tq_avg > max_tq))) {
 173                                 if (curr_gw)
 174                                         batadv_gw_node_free_ref(curr_gw);
 175                                 curr_gw = gw_node;
 176                                 atomic_inc(&curr_gw->refcount);
 177                         }
 178                         break;
 179
 180                 default: /* 2:  stable connection (use best statistic)
 181                           * 3:  fast-switch (use best statistic but change as
 182                           *     soon as a better gateway appears)
 183                           * XX: late-switch (use best statistic but change as
 184                           *     soon as a better gateway appears which has
 185                           *     $routing_class more tq points)
 186                           */
 187                         if (tq_avg > max_tq) {
 188                                 if (curr_gw)
 189                                         batadv_gw_node_free_ref(curr_gw);
 190                                 curr_gw = gw_node;
 191                                 atomic_inc(&curr_gw->refcount);
 192                         }
 193                         break;
 194                 }
 195
 196                 if (tq_avg > max_tq)
 197                         max_tq = tq_avg;
 198
 199                 if (tmp_gw_factor > max_gw_factor)
 200                         max_gw_factor = tmp_gw_factor;
 201
 202                 batadv_gw_node_free_ref(gw_node);
 203
 204 next:
 205                 batadv_neigh_node_free_ref(router);
 206                 if (router_ifinfo)
 207                         batadv_neigh_ifinfo_free_ref(router_ifinfo);
 208         }
 209         rcu_read_unlock();
 210
 211         return curr_gw;
 212 }
 213
 214 /**
 215  * batadv_gw_check_client_stop - check if client mode has been switched off
 216  * @bat_priv: the bat priv with all the soft interface information
 217  *
 218  * This function assumes the caller has checked that the gw state *is actually
 219  * changing*. This function is not supposed to be called when there is no state
 220  * change.
 221  */
 222 void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
 223 {
 224         struct batadv_gw_node *curr_gw;
 225
 226         if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
 227                 return;
 228
 229         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 230         if (!curr_gw)
 231                 return;
 232
 233         /* deselect the current gateway so that next time that client mode is
 234          * enabled a proper GW_ADD event can be sent
 235          */
 236         batadv_gw_select(bat_priv, NULL);
 237
 238         /* if batman-adv is switching the gw client mode off and a gateway was
 239          * already selected, send a DEL uevent
 240          */
 241         batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
 242
 243         batadv_gw_node_free_ref(curr_gw);
 244 }
 245
 246 void batadv_gw_election(struct batadv_priv *bat_priv)
 247 {
 248         struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
 249         struct batadv_neigh_node *router = NULL;
 250         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 251         char gw_addr[18] = { '\0' };
 252
 253         if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
 254                 goto out;
 255
 256         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 257
 258         if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
 259                 goto out;
 260
 261         next_gw = batadv_gw_get_best_gw_node(bat_priv);
 262
 263         if (curr_gw == next_gw)
 264                 goto out;
 265
 266         if (next_gw) {
 267                 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
 268
 269                 router = batadv_orig_router_get(next_gw->orig_node,
 270                                                 BATADV_IF_DEFAULT);
 271                 if (!router) {
 272                         batadv_gw_reselect(bat_priv);
 273                         goto out;
 274                 }
 275
 276                 router_ifinfo = batadv_neigh_ifinfo_get(router,
 277                                                         BATADV_IF_DEFAULT);
 278                 if (!router_ifinfo) {
 279                         batadv_gw_reselect(bat_priv);
 280                         goto out;
 281                 }
 282         }
 283
 284         if ((curr_gw) && (!next_gw)) {
 285                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 286                            "Removing selected gateway - no gateway in range\n");
 287                 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
 288                                     NULL);
 289         } else if ((!curr_gw) && (next_gw)) {
 290                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 291                            "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
 292                            next_gw->orig_node->orig,
 293                            next_gw->bandwidth_down / 10,
 294                            next_gw->bandwidth_down % 10,
 295                            next_gw->bandwidth_up / 10,
 296                            next_gw->bandwidth_up % 10,
 297                            router_ifinfo->bat_iv.tq_avg);
 298                 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
 299                                     gw_addr);
 300         } else {
 301                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 302                            "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
 303                            next_gw->orig_node->orig,
 304                            next_gw->bandwidth_down / 10,
 305                            next_gw->bandwidth_down % 10,
 306                            next_gw->bandwidth_up / 10,
 307                            next_gw->bandwidth_up % 10,
 308                            router_ifinfo->bat_iv.tq_avg);
 309                 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
 310                                     gw_addr);
 311         }
 312
 313         batadv_gw_select(bat_priv, next_gw);
 314
 315 out:
 316         if (curr_gw)
 317                 batadv_gw_node_free_ref(curr_gw);
 318         if (next_gw)
 319                 batadv_gw_node_free_ref(next_gw);
 320         if (router)
 321                 batadv_neigh_node_free_ref(router);
 322         if (router_ifinfo)
 323                 batadv_neigh_ifinfo_free_ref(router_ifinfo);
 324 }
 325
 326 void batadv_gw_check_election(struct batadv_priv *bat_priv,
 327                               struct batadv_orig_node *orig_node)
 328 {
 329         struct batadv_neigh_ifinfo *router_orig_tq = NULL;
 330         struct batadv_neigh_ifinfo *router_gw_tq = NULL;
 331         struct batadv_orig_node *curr_gw_orig;
 332         struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
 333         uint8_t gw_tq_avg, orig_tq_avg;
 334
 335         curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
 336         if (!curr_gw_orig)
 337                 goto reselect;
 338
 339         router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
 340         if (!router_gw)
 341                 goto reselect;
 342
 343         router_gw_tq = batadv_neigh_ifinfo_get(router_gw,
 344                                                BATADV_IF_DEFAULT);
 345         if (!router_gw_tq)
 346                 goto reselect;
 347
 348         /* this node already is the gateway */
 349         if (curr_gw_orig == orig_node)
 350                 goto out;
 351
 352         router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
 353         if (!router_orig)
 354                 goto out;
 355
 356         router_orig_tq = batadv_neigh_ifinfo_get(router_orig,
 357                                                  BATADV_IF_DEFAULT);
 358         if (!router_orig_tq)
 359                 goto out;
 360
 361         gw_tq_avg = router_gw_tq->bat_iv.tq_avg;
 362         orig_tq_avg = router_orig_tq->bat_iv.tq_avg;
 363
 364         /* the TQ value has to be better */
 365         if (orig_tq_avg < gw_tq_avg)
 366                 goto out;
 367
 368         /* if the routing class is greater than 3 the value tells us how much
 369          * greater the TQ value of the new gateway must be
 370          */
 371         if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
 372             (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
 373                 goto out;
 374
 375         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 376                    "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
 377                    gw_tq_avg, orig_tq_avg);
 378
 379 reselect:
 380         batadv_gw_reselect(bat_priv);
 381 out:
 382         if (curr_gw_orig)
 383                 batadv_orig_node_free_ref(curr_gw_orig);
 384         if (router_gw)
 385                 batadv_neigh_node_free_ref(router_gw);
 386         if (router_orig)
 387                 batadv_neigh_node_free_ref(router_orig);
 388         if (router_gw_tq)
 389                 batadv_neigh_ifinfo_free_ref(router_gw_tq);
 390         if (router_orig_tq)
 391                 batadv_neigh_ifinfo_free_ref(router_orig_tq);
 392
 393         return;
 394 }
 395
 396 /**
 397  * batadv_gw_node_add - add gateway node to list of available gateways
 398  * @bat_priv: the bat priv with all the soft interface information
 399  * @orig_node: originator announcing gateway capabilities
 400  * @gateway: announced bandwidth information
 401  */
 402 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
 403                                struct batadv_orig_node *orig_node,
 404                                struct batadv_tvlv_gateway_data *gateway)
 405 {
 406         struct batadv_gw_node *gw_node;
 407
 408         if (gateway->bandwidth_down == 0)
 409                 return;
 410
 411         gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
 412         if (!gw_node)
 413                 return;
 414
 415         INIT_HLIST_NODE(&gw_node->list);
 416         gw_node->orig_node = orig_node;
 417         atomic_set(&gw_node->refcount, 1);
 418
 419         spin_lock_bh(&bat_priv->gw.list_lock);
 420         hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
 421         spin_unlock_bh(&bat_priv->gw.list_lock);
 422
 423         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 424                    "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
 425                    orig_node->orig,
 426                    ntohl(gateway->bandwidth_down) / 10,
 427                    ntohl(gateway->bandwidth_down) % 10,
 428                    ntohl(gateway->bandwidth_up) / 10,
 429                    ntohl(gateway->bandwidth_up) % 10);
 430 }
 431
 432 /**
 433  * batadv_gw_node_get - retrieve gateway node from list of available gateways
 434  * @bat_priv: the bat priv with all the soft interface information
 435  * @orig_node: originator announcing gateway capabilities
 436  *
 437  * Returns gateway node if found or NULL otherwise.
 438  */
 439 static struct batadv_gw_node *
 440 batadv_gw_node_get(struct batadv_priv *bat_priv,
 441                    struct batadv_orig_node *orig_node)
 442 {
 443         struct batadv_gw_node *gw_node_tmp, *gw_node = NULL;
 444
 445         rcu_read_lock();
 446         hlist_for_each_entry_rcu(gw_node_tmp, &bat_priv->gw.list, list) {
 447                 if (gw_node_tmp->orig_node != orig_node)
 448                         continue;
 449
 450                 if (gw_node_tmp->deleted)
 451                         continue;
 452
 453                 if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
 454                         continue;
 455
 456                 gw_node = gw_node_tmp;
 457                 break;
 458         }
 459         rcu_read_unlock();
 460
 461         return gw_node;
 462 }
 463
 464 /**
 465  * batadv_gw_node_update - update list of available gateways with changed
 466  *  bandwidth information
 467  * @bat_priv: the bat priv with all the soft interface information
 468  * @orig_node: originator announcing gateway capabilities
 469  * @gateway: announced bandwidth information
 470  */
 471 void batadv_gw_node_update(struct batadv_priv *bat_priv,
 472                            struct batadv_orig_node *orig_node,
 473                            struct batadv_tvlv_gateway_data *gateway)
 474 {
 475         struct batadv_gw_node *gw_node, *curr_gw = NULL;
 476
 477         gw_node = batadv_gw_node_get(bat_priv, orig_node);
 478         if (!gw_node) {
 479                 batadv_gw_node_add(bat_priv, orig_node, gateway);
 480                 goto out;
 481         }
 482
 483         if ((gw_node->bandwidth_down == ntohl(gateway->bandwidth_down)) &&
 484             (gw_node->bandwidth_up == ntohl(gateway->bandwidth_up)))
 485                 goto out;
 486
 487         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 488                    "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
 489                    orig_node->orig,
 490                    gw_node->bandwidth_down / 10,
 491                    gw_node->bandwidth_down % 10,
 492                    gw_node->bandwidth_up / 10,
 493                    gw_node->bandwidth_up % 10,
 494                    ntohl(gateway->bandwidth_down) / 10,
 495                    ntohl(gateway->bandwidth_down) % 10,
 496                    ntohl(gateway->bandwidth_up) / 10,
 497                    ntohl(gateway->bandwidth_up) % 10);
 498
 499         gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
 500         gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
 501
 502         gw_node->deleted = 0;
 503         if (ntohl(gateway->bandwidth_down) == 0) {
 504                 gw_node->deleted = jiffies;
 505                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 506                            "Gateway %pM removed from gateway list\n",
 507                            orig_node->orig);
 508
 509                 /* Note: We don't need a NULL check here, since curr_gw never
 510                  * gets dereferenced.
 511                  */
 512                 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 513                 if (gw_node == curr_gw)
 514                         batadv_gw_reselect(bat_priv);
 515         }
 516
 517 out:
 518         if (curr_gw)
 519                 batadv_gw_node_free_ref(curr_gw);
 520         if (gw_node)
 521                 batadv_gw_node_free_ref(gw_node);
 522 }
 523
 524 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
 525                            struct batadv_orig_node *orig_node)
 526 {
 527         struct batadv_tvlv_gateway_data gateway;
 528
 529         gateway.bandwidth_down = 0;
 530         gateway.bandwidth_up = 0;
 531
 532         batadv_gw_node_update(bat_priv, orig_node, &gateway);
 533 }
 534
 535 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
 536 {
 537         struct batadv_gw_node *gw_node, *curr_gw;
 538         struct hlist_node *node_tmp;
 539         unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
 540         int do_reselect = 0;
 541
 542         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 543
 544         spin_lock_bh(&bat_priv->gw.list_lock);
 545
 546         hlist_for_each_entry_safe(gw_node, node_tmp,
 547                                   &bat_priv->gw.list, list) {
 548                 if (((!gw_node->deleted) ||
 549                      (time_before(jiffies, gw_node->deleted + timeout))) &&
 550                     atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
 551                         continue;
 552
 553                 if (curr_gw == gw_node)
 554                         do_reselect = 1;
 555
 556                 hlist_del_rcu(&gw_node->list);
 557                 batadv_gw_node_free_ref(gw_node);
 558         }
 559
 560         spin_unlock_bh(&bat_priv->gw.list_lock);
 561
 562         /* gw_reselect() needs to acquire the gw_list_lock */
 563         if (do_reselect)
 564                 batadv_gw_reselect(bat_priv);
 565
 566         if (curr_gw)
 567                 batadv_gw_node_free_ref(curr_gw);
 568 }
 569
 570 /* fails if orig_node has no router */
 571 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
 572                                     struct seq_file *seq,
 573                                     const struct batadv_gw_node *gw_node)
 574 {
 575         struct batadv_gw_node *curr_gw;
 576         struct batadv_neigh_node *router;
 577         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 578         int ret = -1;
 579
 580         router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
 581         if (!router)
 582                 goto out;
 583
 584         router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
 585         if (!router_ifinfo)
 586                 goto out;
 587
 588         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 589
 590         ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
 591                          (curr_gw == gw_node ? "=>" : "  "),
 592                          gw_node->orig_node->orig,
 593                          router_ifinfo->bat_iv.tq_avg, router->addr,
 594                          router->if_incoming->net_dev->name,
 595                          gw_node->bandwidth_down / 10,
 596                          gw_node->bandwidth_down % 10,
 597                          gw_node->bandwidth_up / 10,
 598                          gw_node->bandwidth_up % 10);
 599
 600         if (curr_gw)
 601                 batadv_gw_node_free_ref(curr_gw);
 602 out:
 603         if (router_ifinfo)
 604                 batadv_neigh_ifinfo_free_ref(router_ifinfo);
 605         if (router)
 606                 batadv_neigh_node_free_ref(router);
 607         return ret;
 608 }
 609
 610 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
 611 {
 612         struct net_device *net_dev = (struct net_device *)seq->private;
 613         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 614         struct batadv_hard_iface *primary_if;
 615         struct batadv_gw_node *gw_node;
 616         int gw_count = 0;
 617
 618         primary_if = batadv_seq_print_text_primary_if_get(seq);
 619         if (!primary_if)
 620                 goto out;
 621
 622         seq_printf(seq,
 623                    "      %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
 624                    "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
 625                    BATADV_SOURCE_VERSION, primary_if->net_dev->name,
 626                    primary_if->net_dev->dev_addr, net_dev->name);
 627
 628         rcu_read_lock();
 629         hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
 630                 if (gw_node->deleted)
 631                         continue;
 632
 633                 /* fails if orig_node has no router */
 634                 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
 635                         continue;
 636
 637                 gw_count++;
 638         }
 639         rcu_read_unlock();
 640
 641         if (gw_count == 0)
 642                 seq_puts(seq, "No gateways in range ...\n");
 643
 644 out:
 645         if (primary_if)
 646                 batadv_hardif_free_ref(primary_if);
 647         return 0;
 648 }
 649
 650 /**
 651  * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
 652  * @skb: the packet to check
 653  * @header_len: a pointer to the batman-adv header size
 654  * @chaddr: buffer where the client address will be stored. Valid
 655  *  only if the function returns BATADV_DHCP_TO_CLIENT
 656  *
 657  * Returns:
 658  * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
 659  *   while parsing it
 660  * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
 661  * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
 662  *
 663  * This function may re-allocate the data buffer of the skb passed as argument.
 664  */
 665 enum batadv_dhcp_recipient
 666 batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
 667                              uint8_t *chaddr)
 668 {
 669         enum batadv_dhcp_recipient ret = BATADV_DHCP_NO;
 670         struct ethhdr *ethhdr;
 671         struct iphdr *iphdr;
 672         struct ipv6hdr *ipv6hdr;
 673         struct udphdr *udphdr;
 674         struct vlan_ethhdr *vhdr;
 675         int chaddr_offset;
 676         __be16 proto;
 677         uint8_t *p;
 678
 679         /* check for ethernet header */
 680         if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
 681                 return BATADV_DHCP_NO;
 682
 683         ethhdr = (struct ethhdr *)skb->data;
 684         proto = ethhdr->h_proto;
 685         *header_len += ETH_HLEN;
 686
 687         /* check for initial vlan header */
 688         if (proto == htons(ETH_P_8021Q)) {
 689                 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
 690                         return BATADV_DHCP_NO;
 691
 692                 vhdr = (struct vlan_ethhdr *)skb->data;
 693                 proto = vhdr->h_vlan_encapsulated_proto;
 694                 *header_len += VLAN_HLEN;
 695         }
 696
 697         /* check for ip header */
 698         switch (proto) {
 699         case htons(ETH_P_IP):
 700                 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
 701                         return BATADV_DHCP_NO;
 702
 703                 iphdr = (struct iphdr *)(skb->data + *header_len);
 704                 *header_len += iphdr->ihl * 4;
 705
 706                 /* check for udp header */
 707                 if (iphdr->protocol != IPPROTO_UDP)
 708                         return BATADV_DHCP_NO;
 709
 710                 break;
 711         case htons(ETH_P_IPV6):
 712                 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
 713                         return BATADV_DHCP_NO;
 714
 715                 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
 716                 *header_len += sizeof(*ipv6hdr);
 717
 718                 /* check for udp header */
 719                 if (ipv6hdr->nexthdr != IPPROTO_UDP)
 720                         return BATADV_DHCP_NO;
 721
 722                 break;
 723         default:
 724                 return BATADV_DHCP_NO;
 725         }
 726
 727         if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
 728                 return BATADV_DHCP_NO;
 729
 730         /* skb->data might have been reallocated by pskb_may_pull() */
 731         ethhdr = (struct ethhdr *)skb->data;
 732         if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
 733                 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
 734
 735         udphdr = (struct udphdr *)(skb->data + *header_len);
 736         *header_len += sizeof(*udphdr);
 737
 738         /* check for bootp port */
 739         switch (proto) {
 740         case htons(ETH_P_IP):
 741                 if (udphdr->dest == htons(67))
 742                         ret = BATADV_DHCP_TO_SERVER;
 743                 else if (udphdr->source == htons(67))
 744                         ret = BATADV_DHCP_TO_CLIENT;
 745                 break;
 746         case htons(ETH_P_IPV6):
 747                 if (udphdr->dest == htons(547))
 748                         ret = BATADV_DHCP_TO_SERVER;
 749                 else if (udphdr->source == htons(547))
 750                         ret = BATADV_DHCP_TO_CLIENT;
 751                 break;
 752         }
 753
 754         chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET;
 755         /* store the client address if the message is going to a client */
 756         if (ret == BATADV_DHCP_TO_CLIENT &&
 757             pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) {
 758                 /* check if the DHCP packet carries an Ethernet DHCP */
 759                 p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET;
 760                 if (*p != BATADV_DHCP_HTYPE_ETHERNET)
 761                         return BATADV_DHCP_NO;
 762
 763                 /* check if the DHCP packet carries a valid Ethernet address */
 764                 p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET;
 765                 if (*p != ETH_ALEN)
 766                         return BATADV_DHCP_NO;
 767
 768                 memcpy(chaddr, skb->data + chaddr_offset, ETH_ALEN);
 769         }
 770
 771         return ret;
 772 }
 773 /**
 774  * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
 775  * @bat_priv: the bat priv with all the soft interface information
 776  * @skb: the outgoing packet
 777  *
 778  * Check if the skb is a DHCP request and if it is sent to the current best GW
 779  * server. Due to topology changes it may be the case that the GW server
 780  * previously selected is not the best one anymore.
 781  *
 782  * Returns true if the packet destination is unicast and it is not the best gw,
 783  * false otherwise.
 784  *
 785  * This call might reallocate skb data.
 786  * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
 787  */
 788 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
 789                             struct sk_buff *skb)
 790 {
 791         struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
 792         struct batadv_orig_node *orig_dst_node = NULL;
 793         struct batadv_gw_node *gw_node = NULL, *curr_gw = NULL;
 794         struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo;
 795         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 796         bool out_of_range = false;
 797         uint8_t curr_tq_avg;
 798         unsigned short vid;
 799
 800         vid = batadv_get_vid(skb, 0);
 801
 802         orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
 803                                                  ethhdr->h_dest, vid);
 804         if (!orig_dst_node)
 805                 goto out;
 806
 807         gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
 808         if (!gw_node->bandwidth_down == 0)
 809                 goto out;
 810
 811         switch (atomic_read(&bat_priv->gw_mode)) {
 812         case BATADV_GW_MODE_SERVER:
 813                 /* If we are a GW then we are our best GW. We can artificially
 814                  * set the tq towards ourself as the maximum value
 815                  */
 816                 curr_tq_avg = BATADV_TQ_MAX_VALUE;
 817                 break;
 818         case BATADV_GW_MODE_CLIENT:
 819                 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 820                 if (!curr_gw)
 821                         goto out;
 822
 823                 /* packet is going to our gateway */
 824                 if (curr_gw->orig_node == orig_dst_node)
 825                         goto out;
 826
 827                 /* If the dhcp packet has been sent to a different gw,
 828                  * we have to evaluate whether the old gw is still
 829                  * reliable enough
 830                  */
 831                 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
 832                                                 NULL);
 833                 if (!neigh_curr)
 834                         goto out;
 835
 836                 curr_ifinfo = batadv_neigh_ifinfo_get(neigh_curr,
 837                                                       BATADV_IF_DEFAULT);
 838                 if (!curr_ifinfo)
 839                         goto out;
 840
 841                 curr_tq_avg = curr_ifinfo->bat_iv.tq_avg;
 842                 batadv_neigh_ifinfo_free_ref(curr_ifinfo);
 843
 844                 break;
 845         case BATADV_GW_MODE_OFF:
 846         default:
 847                 goto out;
 848         }
 849
 850         neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
 851         if (!neigh_old)
 852                 goto out;
 853
 854         old_ifinfo = batadv_neigh_ifinfo_get(neigh_old, BATADV_IF_DEFAULT);
 855         if (!old_ifinfo)
 856                 goto out;
 857
 858         if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD)
 859                 out_of_range = true;
 860         batadv_neigh_ifinfo_free_ref(old_ifinfo);
 861
 862 out:
 863         if (orig_dst_node)
 864                 batadv_orig_node_free_ref(orig_dst_node);
 865         if (curr_gw)
 866                 batadv_gw_node_free_ref(curr_gw);
 867         if (gw_node)
 868                 batadv_gw_node_free_ref(gw_node);
 869         if (neigh_old)
 870                 batadv_neigh_node_free_ref(neigh_old);
 871         if (neigh_curr)
 872                 batadv_neigh_node_free_ref(neigh_curr);
 873         return out_of_range;
 874 }