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
batadv_gw_node_free_ref(struct batadv_gw_node * gw_node)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 batadv_orig_node_free_ref(gw_node->orig_node);
47 kfree_rcu(gw_node, rcu);
48 }
49 }
50
51 static struct batadv_gw_node *
batadv_gw_get_selected_gw_node(struct batadv_priv * bat_priv)52 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
53 {
54 struct batadv_gw_node *gw_node;
55
56 rcu_read_lock();
57 gw_node = rcu_dereference(bat_priv->gw.curr_gw);
58 if (!gw_node)
59 goto out;
60
61 if (!atomic_inc_not_zero(&gw_node->refcount))
62 gw_node = NULL;
63
64 out:
65 rcu_read_unlock();
66 return gw_node;
67 }
68
69 struct batadv_orig_node *
batadv_gw_get_selected_orig(struct batadv_priv * bat_priv)70 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
71 {
72 struct batadv_gw_node *gw_node;
73 struct batadv_orig_node *orig_node = NULL;
74
75 gw_node = batadv_gw_get_selected_gw_node(bat_priv);
76 if (!gw_node)
77 goto out;
78
79 rcu_read_lock();
80 orig_node = gw_node->orig_node;
81 if (!orig_node)
82 goto unlock;
83
84 if (!atomic_inc_not_zero(&orig_node->refcount))
85 orig_node = NULL;
86
87 unlock:
88 rcu_read_unlock();
89 out:
90 if (gw_node)
91 batadv_gw_node_free_ref(gw_node);
92 return orig_node;
93 }
94
batadv_gw_select(struct batadv_priv * bat_priv,struct batadv_gw_node * new_gw_node)95 static void batadv_gw_select(struct batadv_priv *bat_priv,
96 struct batadv_gw_node *new_gw_node)
97 {
98 struct batadv_gw_node *curr_gw_node;
99
100 spin_lock_bh(&bat_priv->gw.list_lock);
101
102 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
103 new_gw_node = NULL;
104
105 curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
106 rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
107
108 if (curr_gw_node)
109 batadv_gw_node_free_ref(curr_gw_node);
110
111 spin_unlock_bh(&bat_priv->gw.list_lock);
112 }
113
114 /**
115 * batadv_gw_reselect - force a gateway reselection
116 * @bat_priv: the bat priv with all the soft interface information
117 *
118 * Set a flag to remind the GW component to perform a new gateway reselection.
119 * However this function does not ensure that the current gateway is going to be
120 * deselected. The reselection mechanism may elect the same gateway once again.
121 *
122 * This means that invoking batadv_gw_reselect() does not guarantee a gateway
123 * change and therefore a uevent is not necessarily expected.
124 */
batadv_gw_reselect(struct batadv_priv * bat_priv)125 void batadv_gw_reselect(struct batadv_priv *bat_priv)
126 {
127 atomic_set(&bat_priv->gw.reselect, 1);
128 }
129
130 static struct batadv_gw_node *
batadv_gw_get_best_gw_node(struct batadv_priv * bat_priv)131 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
132 {
133 struct batadv_neigh_node *router;
134 struct batadv_neigh_ifinfo *router_ifinfo;
135 struct batadv_gw_node *gw_node, *curr_gw = NULL;
136 uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
137 uint32_t gw_divisor;
138 uint8_t max_tq = 0;
139 uint8_t tq_avg;
140 struct batadv_orig_node *orig_node;
141
142 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
143 gw_divisor *= 64;
144
145 rcu_read_lock();
146 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
147 if (gw_node->deleted)
148 continue;
149
150 orig_node = gw_node->orig_node;
151 router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
152 if (!router)
153 continue;
154
155 router_ifinfo = batadv_neigh_ifinfo_get(router,
156 BATADV_IF_DEFAULT);
157 if (!router_ifinfo)
158 goto next;
159
160 if (!atomic_inc_not_zero(&gw_node->refcount))
161 goto next;
162
163 tq_avg = router_ifinfo->bat_iv.tq_avg;
164
165 switch (atomic_read(&bat_priv->gw_sel_class)) {
166 case 1: /* fast connection */
167 tmp_gw_factor = tq_avg * tq_avg;
168 tmp_gw_factor *= gw_node->bandwidth_down;
169 tmp_gw_factor *= 100 * 100;
170 tmp_gw_factor /= gw_divisor;
171
172 if ((tmp_gw_factor > max_gw_factor) ||
173 ((tmp_gw_factor == max_gw_factor) &&
174 (tq_avg > max_tq))) {
175 if (curr_gw)
176 batadv_gw_node_free_ref(curr_gw);
177 curr_gw = gw_node;
178 atomic_inc(&curr_gw->refcount);
179 }
180 break;
181
182 default: /* 2: stable connection (use best statistic)
183 * 3: fast-switch (use best statistic but change as
184 * soon as a better gateway appears)
185 * XX: late-switch (use best statistic but change as
186 * soon as a better gateway appears which has
187 * $routing_class more tq points)
188 */
189 if (tq_avg > max_tq) {
190 if (curr_gw)
191 batadv_gw_node_free_ref(curr_gw);
192 curr_gw = gw_node;
193 atomic_inc(&curr_gw->refcount);
194 }
195 break;
196 }
197
198 if (tq_avg > max_tq)
199 max_tq = tq_avg;
200
201 if (tmp_gw_factor > max_gw_factor)
202 max_gw_factor = tmp_gw_factor;
203
204 batadv_gw_node_free_ref(gw_node);
205
206 next:
207 batadv_neigh_node_free_ref(router);
208 if (router_ifinfo)
209 batadv_neigh_ifinfo_free_ref(router_ifinfo);
210 }
211 rcu_read_unlock();
212
213 return curr_gw;
214 }
215
216 /**
217 * batadv_gw_check_client_stop - check if client mode has been switched off
218 * @bat_priv: the bat priv with all the soft interface information
219 *
220 * This function assumes the caller has checked that the gw state *is actually
221 * changing*. This function is not supposed to be called when there is no state
222 * change.
223 */
batadv_gw_check_client_stop(struct batadv_priv * bat_priv)224 void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
225 {
226 struct batadv_gw_node *curr_gw;
227
228 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
229 return;
230
231 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
232 if (!curr_gw)
233 return;
234
235 /* deselect the current gateway so that next time that client mode is
236 * enabled a proper GW_ADD event can be sent
237 */
238 batadv_gw_select(bat_priv, NULL);
239
240 /* if batman-adv is switching the gw client mode off and a gateway was
241 * already selected, send a DEL uevent
242 */
243 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
244
245 batadv_gw_node_free_ref(curr_gw);
246 }
247
batadv_gw_election(struct batadv_priv * bat_priv)248 void batadv_gw_election(struct batadv_priv *bat_priv)
249 {
250 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
251 struct batadv_neigh_node *router = NULL;
252 struct batadv_neigh_ifinfo *router_ifinfo = NULL;
253 char gw_addr[18] = { '\0' };
254
255 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
256 goto out;
257
258 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
259
260 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
261 goto out;
262
263 next_gw = batadv_gw_get_best_gw_node(bat_priv);
264
265 if (curr_gw == next_gw)
266 goto out;
267
268 if (next_gw) {
269 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
270
271 router = batadv_orig_router_get(next_gw->orig_node,
272 BATADV_IF_DEFAULT);
273 if (!router) {
274 batadv_gw_reselect(bat_priv);
275 goto out;
276 }
277
278 router_ifinfo = batadv_neigh_ifinfo_get(router,
279 BATADV_IF_DEFAULT);
280 if (!router_ifinfo) {
281 batadv_gw_reselect(bat_priv);
282 goto out;
283 }
284 }
285
286 if ((curr_gw) && (!next_gw)) {
287 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
288 "Removing selected gateway - no gateway in range\n");
289 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
290 NULL);
291 } else if ((!curr_gw) && (next_gw)) {
292 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
293 "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
294 next_gw->orig_node->orig,
295 next_gw->bandwidth_down / 10,
296 next_gw->bandwidth_down % 10,
297 next_gw->bandwidth_up / 10,
298 next_gw->bandwidth_up % 10,
299 router_ifinfo->bat_iv.tq_avg);
300 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
301 gw_addr);
302 } else {
303 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
304 "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
305 next_gw->orig_node->orig,
306 next_gw->bandwidth_down / 10,
307 next_gw->bandwidth_down % 10,
308 next_gw->bandwidth_up / 10,
309 next_gw->bandwidth_up % 10,
310 router_ifinfo->bat_iv.tq_avg);
311 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
312 gw_addr);
313 }
314
315 batadv_gw_select(bat_priv, next_gw);
316
317 out:
318 if (curr_gw)
319 batadv_gw_node_free_ref(curr_gw);
320 if (next_gw)
321 batadv_gw_node_free_ref(next_gw);
322 if (router)
323 batadv_neigh_node_free_ref(router);
324 if (router_ifinfo)
325 batadv_neigh_ifinfo_free_ref(router_ifinfo);
326 }
327
batadv_gw_check_election(struct batadv_priv * bat_priv,struct batadv_orig_node * orig_node)328 void batadv_gw_check_election(struct batadv_priv *bat_priv,
329 struct batadv_orig_node *orig_node)
330 {
331 struct batadv_neigh_ifinfo *router_orig_tq = NULL;
332 struct batadv_neigh_ifinfo *router_gw_tq = NULL;
333 struct batadv_orig_node *curr_gw_orig;
334 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
335 uint8_t gw_tq_avg, orig_tq_avg;
336
337 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
338 if (!curr_gw_orig)
339 goto reselect;
340
341 router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
342 if (!router_gw)
343 goto reselect;
344
345 router_gw_tq = batadv_neigh_ifinfo_get(router_gw,
346 BATADV_IF_DEFAULT);
347 if (!router_gw_tq)
348 goto reselect;
349
350 /* this node already is the gateway */
351 if (curr_gw_orig == orig_node)
352 goto out;
353
354 router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
355 if (!router_orig)
356 goto out;
357
358 router_orig_tq = batadv_neigh_ifinfo_get(router_orig,
359 BATADV_IF_DEFAULT);
360 if (!router_orig_tq)
361 goto out;
362
363 gw_tq_avg = router_gw_tq->bat_iv.tq_avg;
364 orig_tq_avg = router_orig_tq->bat_iv.tq_avg;
365
366 /* the TQ value has to be better */
367 if (orig_tq_avg < gw_tq_avg)
368 goto out;
369
370 /* if the routing class is greater than 3 the value tells us how much
371 * greater the TQ value of the new gateway must be
372 */
373 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
374 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
375 goto out;
376
377 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
378 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
379 gw_tq_avg, orig_tq_avg);
380
381 reselect:
382 batadv_gw_reselect(bat_priv);
383 out:
384 if (curr_gw_orig)
385 batadv_orig_node_free_ref(curr_gw_orig);
386 if (router_gw)
387 batadv_neigh_node_free_ref(router_gw);
388 if (router_orig)
389 batadv_neigh_node_free_ref(router_orig);
390 if (router_gw_tq)
391 batadv_neigh_ifinfo_free_ref(router_gw_tq);
392 if (router_orig_tq)
393 batadv_neigh_ifinfo_free_ref(router_orig_tq);
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 */
batadv_gw_node_add(struct batadv_priv * bat_priv,struct batadv_orig_node * orig_node,struct batadv_tvlv_gateway_data * gateway)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 if (!atomic_inc_not_zero(&orig_node->refcount))
412 return;
413
414 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
415 if (!gw_node) {
416 batadv_orig_node_free_ref(orig_node);
417 return;
418 }
419
420 INIT_HLIST_NODE(&gw_node->list);
421 gw_node->orig_node = orig_node;
422 atomic_set(&gw_node->refcount, 1);
423
424 spin_lock_bh(&bat_priv->gw.list_lock);
425 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
426 spin_unlock_bh(&bat_priv->gw.list_lock);
427
428 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
429 "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
430 orig_node->orig,
431 ntohl(gateway->bandwidth_down) / 10,
432 ntohl(gateway->bandwidth_down) % 10,
433 ntohl(gateway->bandwidth_up) / 10,
434 ntohl(gateway->bandwidth_up) % 10);
435 }
436
437 /**
438 * batadv_gw_node_get - retrieve gateway node from list of available gateways
439 * @bat_priv: the bat priv with all the soft interface information
440 * @orig_node: originator announcing gateway capabilities
441 *
442 * Returns gateway node if found or NULL otherwise.
443 */
444 static struct batadv_gw_node *
batadv_gw_node_get(struct batadv_priv * bat_priv,struct batadv_orig_node * orig_node)445 batadv_gw_node_get(struct batadv_priv *bat_priv,
446 struct batadv_orig_node *orig_node)
447 {
448 struct batadv_gw_node *gw_node_tmp, *gw_node = NULL;
449
450 rcu_read_lock();
451 hlist_for_each_entry_rcu(gw_node_tmp, &bat_priv->gw.list, list) {
452 if (gw_node_tmp->orig_node != orig_node)
453 continue;
454
455 if (gw_node_tmp->deleted)
456 continue;
457
458 if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
459 continue;
460
461 gw_node = gw_node_tmp;
462 break;
463 }
464 rcu_read_unlock();
465
466 return gw_node;
467 }
468
469 /**
470 * batadv_gw_node_update - update list of available gateways with changed
471 * bandwidth information
472 * @bat_priv: the bat priv with all the soft interface information
473 * @orig_node: originator announcing gateway capabilities
474 * @gateway: announced bandwidth information
475 */
batadv_gw_node_update(struct batadv_priv * bat_priv,struct batadv_orig_node * orig_node,struct batadv_tvlv_gateway_data * gateway)476 void batadv_gw_node_update(struct batadv_priv *bat_priv,
477 struct batadv_orig_node *orig_node,
478 struct batadv_tvlv_gateway_data *gateway)
479 {
480 struct batadv_gw_node *gw_node, *curr_gw = NULL;
481
482 gw_node = batadv_gw_node_get(bat_priv, orig_node);
483 if (!gw_node) {
484 batadv_gw_node_add(bat_priv, orig_node, gateway);
485 goto out;
486 }
487
488 if ((gw_node->bandwidth_down == ntohl(gateway->bandwidth_down)) &&
489 (gw_node->bandwidth_up == ntohl(gateway->bandwidth_up)))
490 goto out;
491
492 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
493 "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
494 orig_node->orig,
495 gw_node->bandwidth_down / 10,
496 gw_node->bandwidth_down % 10,
497 gw_node->bandwidth_up / 10,
498 gw_node->bandwidth_up % 10,
499 ntohl(gateway->bandwidth_down) / 10,
500 ntohl(gateway->bandwidth_down) % 10,
501 ntohl(gateway->bandwidth_up) / 10,
502 ntohl(gateway->bandwidth_up) % 10);
503
504 gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
505 gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
506
507 gw_node->deleted = 0;
508 if (ntohl(gateway->bandwidth_down) == 0) {
509 gw_node->deleted = jiffies;
510 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
511 "Gateway %pM removed from gateway list\n",
512 orig_node->orig);
513
514 /* Note: We don't need a NULL check here, since curr_gw never
515 * gets dereferenced.
516 */
517 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
518 if (gw_node == curr_gw)
519 batadv_gw_reselect(bat_priv);
520 }
521
522 out:
523 if (curr_gw)
524 batadv_gw_node_free_ref(curr_gw);
525 if (gw_node)
526 batadv_gw_node_free_ref(gw_node);
527 }
528
batadv_gw_node_delete(struct batadv_priv * bat_priv,struct batadv_orig_node * orig_node)529 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
530 struct batadv_orig_node *orig_node)
531 {
532 struct batadv_tvlv_gateway_data gateway;
533
534 gateway.bandwidth_down = 0;
535 gateway.bandwidth_up = 0;
536
537 batadv_gw_node_update(bat_priv, orig_node, &gateway);
538 }
539
batadv_gw_node_purge(struct batadv_priv * bat_priv)540 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
541 {
542 struct batadv_gw_node *gw_node, *curr_gw;
543 struct hlist_node *node_tmp;
544 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
545 int do_reselect = 0;
546
547 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
548
549 spin_lock_bh(&bat_priv->gw.list_lock);
550
551 hlist_for_each_entry_safe(gw_node, node_tmp,
552 &bat_priv->gw.list, list) {
553 if (((!gw_node->deleted) ||
554 (time_before(jiffies, gw_node->deleted + timeout))) &&
555 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
556 continue;
557
558 if (curr_gw == gw_node)
559 do_reselect = 1;
560
561 hlist_del_rcu(&gw_node->list);
562 batadv_gw_node_free_ref(gw_node);
563 }
564
565 spin_unlock_bh(&bat_priv->gw.list_lock);
566
567 /* gw_reselect() needs to acquire the gw_list_lock */
568 if (do_reselect)
569 batadv_gw_reselect(bat_priv);
570
571 if (curr_gw)
572 batadv_gw_node_free_ref(curr_gw);
573 }
574
575 /* fails if orig_node has no router */
batadv_write_buffer_text(struct batadv_priv * bat_priv,struct seq_file * seq,const struct batadv_gw_node * gw_node)576 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
577 struct seq_file *seq,
578 const struct batadv_gw_node *gw_node)
579 {
580 struct batadv_gw_node *curr_gw;
581 struct batadv_neigh_node *router;
582 struct batadv_neigh_ifinfo *router_ifinfo = NULL;
583 int ret = -1;
584
585 router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
586 if (!router)
587 goto out;
588
589 router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
590 if (!router_ifinfo)
591 goto out;
592
593 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
594
595 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
596 (curr_gw == gw_node ? "=>" : " "),
597 gw_node->orig_node->orig,
598 router_ifinfo->bat_iv.tq_avg, router->addr,
599 router->if_incoming->net_dev->name,
600 gw_node->bandwidth_down / 10,
601 gw_node->bandwidth_down % 10,
602 gw_node->bandwidth_up / 10,
603 gw_node->bandwidth_up % 10);
604
605 if (curr_gw)
606 batadv_gw_node_free_ref(curr_gw);
607 out:
608 if (router_ifinfo)
609 batadv_neigh_ifinfo_free_ref(router_ifinfo);
610 if (router)
611 batadv_neigh_node_free_ref(router);
612 return ret;
613 }
614
batadv_gw_client_seq_print_text(struct seq_file * seq,void * offset)615 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
616 {
617 struct net_device *net_dev = (struct net_device *)seq->private;
618 struct batadv_priv *bat_priv = netdev_priv(net_dev);
619 struct batadv_hard_iface *primary_if;
620 struct batadv_gw_node *gw_node;
621 int gw_count = 0;
622
623 primary_if = batadv_seq_print_text_primary_if_get(seq);
624 if (!primary_if)
625 goto out;
626
627 seq_printf(seq,
628 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
629 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
630 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
631 primary_if->net_dev->dev_addr, net_dev->name);
632
633 rcu_read_lock();
634 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
635 if (gw_node->deleted)
636 continue;
637
638 /* fails if orig_node has no router */
639 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
640 continue;
641
642 gw_count++;
643 }
644 rcu_read_unlock();
645
646 if (gw_count == 0)
647 seq_puts(seq, "No gateways in range ...\n");
648
649 out:
650 if (primary_if)
651 batadv_hardif_free_ref(primary_if);
652 return 0;
653 }
654
655 /**
656 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
657 * @skb: the packet to check
658 * @header_len: a pointer to the batman-adv header size
659 * @chaddr: buffer where the client address will be stored. Valid
660 * only if the function returns BATADV_DHCP_TO_CLIENT
661 *
662 * Returns:
663 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
664 * while parsing it
665 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
666 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
667 *
668 * This function may re-allocate the data buffer of the skb passed as argument.
669 */
670 enum batadv_dhcp_recipient
batadv_gw_dhcp_recipient_get(struct sk_buff * skb,unsigned int * header_len,uint8_t * chaddr)671 batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
672 uint8_t *chaddr)
673 {
674 enum batadv_dhcp_recipient ret = BATADV_DHCP_NO;
675 struct ethhdr *ethhdr;
676 struct iphdr *iphdr;
677 struct ipv6hdr *ipv6hdr;
678 struct udphdr *udphdr;
679 struct vlan_ethhdr *vhdr;
680 int chaddr_offset;
681 __be16 proto;
682 uint8_t *p;
683
684 /* check for ethernet header */
685 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
686 return BATADV_DHCP_NO;
687
688 ethhdr = eth_hdr(skb);
689 proto = ethhdr->h_proto;
690 *header_len += ETH_HLEN;
691
692 /* check for initial vlan header */
693 if (proto == htons(ETH_P_8021Q)) {
694 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
695 return BATADV_DHCP_NO;
696
697 vhdr = vlan_eth_hdr(skb);
698 proto = vhdr->h_vlan_encapsulated_proto;
699 *header_len += VLAN_HLEN;
700 }
701
702 /* check for ip header */
703 switch (proto) {
704 case htons(ETH_P_IP):
705 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
706 return BATADV_DHCP_NO;
707
708 iphdr = (struct iphdr *)(skb->data + *header_len);
709 *header_len += iphdr->ihl * 4;
710
711 /* check for udp header */
712 if (iphdr->protocol != IPPROTO_UDP)
713 return BATADV_DHCP_NO;
714
715 break;
716 case htons(ETH_P_IPV6):
717 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
718 return BATADV_DHCP_NO;
719
720 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
721 *header_len += sizeof(*ipv6hdr);
722
723 /* check for udp header */
724 if (ipv6hdr->nexthdr != IPPROTO_UDP)
725 return BATADV_DHCP_NO;
726
727 break;
728 default:
729 return BATADV_DHCP_NO;
730 }
731
732 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
733 return BATADV_DHCP_NO;
734
735 /* skb->data might have been reallocated by pskb_may_pull() */
736 ethhdr = eth_hdr(skb);
737 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
738 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
739
740 udphdr = (struct udphdr *)(skb->data + *header_len);
741 *header_len += sizeof(*udphdr);
742
743 /* check for bootp port */
744 switch (proto) {
745 case htons(ETH_P_IP):
746 if (udphdr->dest == htons(67))
747 ret = BATADV_DHCP_TO_SERVER;
748 else if (udphdr->source == htons(67))
749 ret = BATADV_DHCP_TO_CLIENT;
750 break;
751 case htons(ETH_P_IPV6):
752 if (udphdr->dest == htons(547))
753 ret = BATADV_DHCP_TO_SERVER;
754 else if (udphdr->source == htons(547))
755 ret = BATADV_DHCP_TO_CLIENT;
756 break;
757 }
758
759 chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET;
760 /* store the client address if the message is going to a client */
761 if (ret == BATADV_DHCP_TO_CLIENT &&
762 pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) {
763 /* check if the DHCP packet carries an Ethernet DHCP */
764 p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET;
765 if (*p != BATADV_DHCP_HTYPE_ETHERNET)
766 return BATADV_DHCP_NO;
767
768 /* check if the DHCP packet carries a valid Ethernet address */
769 p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET;
770 if (*p != ETH_ALEN)
771 return BATADV_DHCP_NO;
772
773 ether_addr_copy(chaddr, skb->data + chaddr_offset);
774 }
775
776 return ret;
777 }
778 /**
779 * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
780 * @bat_priv: the bat priv with all the soft interface information
781 * @skb: the outgoing packet
782 *
783 * Check if the skb is a DHCP request and if it is sent to the current best GW
784 * server. Due to topology changes it may be the case that the GW server
785 * previously selected is not the best one anymore.
786 *
787 * Returns true if the packet destination is unicast and it is not the best gw,
788 * false otherwise.
789 *
790 * This call might reallocate skb data.
791 * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
792 */
batadv_gw_out_of_range(struct batadv_priv * bat_priv,struct sk_buff * skb)793 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
794 struct sk_buff *skb)
795 {
796 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
797 struct batadv_orig_node *orig_dst_node = NULL;
798 struct batadv_gw_node *gw_node = NULL, *curr_gw = NULL;
799 struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo;
800 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
801 bool out_of_range = false;
802 uint8_t curr_tq_avg;
803 unsigned short vid;
804
805 vid = batadv_get_vid(skb, 0);
806
807 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
808 ethhdr->h_dest, vid);
809 if (!orig_dst_node)
810 goto out;
811
812 gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
813 if (!gw_node)
814 goto out;
815
816 switch (atomic_read(&bat_priv->gw_mode)) {
817 case BATADV_GW_MODE_SERVER:
818 /* If we are a GW then we are our best GW. We can artificially
819 * set the tq towards ourself as the maximum value
820 */
821 curr_tq_avg = BATADV_TQ_MAX_VALUE;
822 break;
823 case BATADV_GW_MODE_CLIENT:
824 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
825 if (!curr_gw)
826 goto out;
827
828 /* packet is going to our gateway */
829 if (curr_gw->orig_node == orig_dst_node)
830 goto out;
831
832 /* If the dhcp packet has been sent to a different gw,
833 * we have to evaluate whether the old gw is still
834 * reliable enough
835 */
836 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
837 NULL);
838 if (!neigh_curr)
839 goto out;
840
841 curr_ifinfo = batadv_neigh_ifinfo_get(neigh_curr,
842 BATADV_IF_DEFAULT);
843 if (!curr_ifinfo)
844 goto out;
845
846 curr_tq_avg = curr_ifinfo->bat_iv.tq_avg;
847 batadv_neigh_ifinfo_free_ref(curr_ifinfo);
848
849 break;
850 case BATADV_GW_MODE_OFF:
851 default:
852 goto out;
853 }
854
855 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
856 if (!neigh_old)
857 goto out;
858
859 old_ifinfo = batadv_neigh_ifinfo_get(neigh_old, BATADV_IF_DEFAULT);
860 if (!old_ifinfo)
861 goto out;
862
863 if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD)
864 out_of_range = true;
865 batadv_neigh_ifinfo_free_ref(old_ifinfo);
866
867 out:
868 if (orig_dst_node)
869 batadv_orig_node_free_ref(orig_dst_node);
870 if (curr_gw)
871 batadv_gw_node_free_ref(curr_gw);
872 if (gw_node)
873 batadv_gw_node_free_ref(gw_node);
874 if (neigh_old)
875 batadv_neigh_node_free_ref(neigh_old);
876 if (neigh_curr)
877 batadv_neigh_node_free_ref(neigh_curr);
878 return out_of_range;
879 }
880